/*
* Send a single message to the TCP at address specified by
* the given TCP/IP header. If m == 0, then we make a copy
* of the tcpiphdr at ti and send directly to the addressed host.
* This is used to force keep alive messages out using the TCP
* template for a connection tp->t_template. If flags are given
* then we send a message back to the TCP which originated the
* segment ti, and discard the mbuf containing it and any other
* attached mbufs.
*
* In any case the ack and sequence number of the transmitted
* segment are as specified by the parameters.
*/
void
tcp_respond(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m,
tcp_seq ack, tcp_seq seq, int flags, unsigned short af)
{
register int tlen;
int win = 0;
DEBUG_CALL("tcp_respond");
DEBUG_ARG("tp = %p", tp);
DEBUG_ARG("ti = %p", ti);
DEBUG_ARG("m = %p", m);
DEBUG_ARG("ack = %u", ack);
DEBUG_ARG("seq = %u", seq);
DEBUG_ARG("flags = %x", flags);
if (tp)
win = sbspace(&tp->t_socket->so_rcv);
if (m == NULL) {
if (!tp || (m = m_get(tp->t_socket->slirp)) == NULL)
return;
tlen = 0;
m->m_data += IF_MAXLINKHDR;
*mtod(m, struct tcpiphdr *) = *ti;
ti = mtod(m, struct tcpiphdr *);
memset(&ti->ti, 0, sizeof(ti->ti));
flags = TH_ACK;
} else {
int
sbappendcontrol(struct sockbuf *sb, struct mbuf *m0, struct mbuf *control)
{
struct mbuf *m, *mlast, *n;
int space = 0;
if (control == NULL)
panic("sbappendcontrol");
for (m = control; ; m = m->m_next) {
space += m->m_len;
if (m->m_next == NULL)
break;
}
n = m; /* save pointer to last control buffer */
for (m = m0; m; m = m->m_next)
space += m->m_len;
if (space > sbspace(sb))
return (0);
n->m_next = m0; /* concatenate data to control */
SBLASTRECORDCHK(sb, "sbappendcontrol 1");
for (m = control; m->m_next != NULL; m = m->m_next)
sballoc(sb, m);
sballoc(sb, m);
mlast = m;
SBLINKRECORD(sb, control);
sb->sb_mbtail = mlast;
SBLASTMBUFCHK(sb, "sbappendcontrol");
SBLASTRECORDCHK(sb, "sbappendcontrol 2");
return (1);
}
/*
* Send a single message to the TCP at address specified by
* the given TCP/IP header. If m == 0, then we make a copy
* of the tcpiphdr at ti and send directly to the addressed host.
* This is used to force keep alive messages out using the TCP
* template for a connection tp->t_template. If flags are given
* then we send a message back to the TCP which originated the
* segment ti, and discard the mbuf containing it and any other
* attached mbufs.
*
* In any case the ack and sequence number of the transmitted
* segment are as specified by the parameters.
*/
void tcp_respond(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m, tcp_seq ack, tcp_seq seq, int flags)
{
int tlen;
int win = 0;
DEBUG_CALL("tcp_respond");
DEBUG_ARG("tp = %lx", (long)tp);
DEBUG_ARG("ti = %lx", (long)ti);
DEBUG_ARG("m = %lx", (long)m);
DEBUG_ARG("ack = %u", ack);
DEBUG_ARG("seq = %u", seq);
DEBUG_ARG("flags = %x", flags);
if (tp)
win = sbspace(&tp->t_socket->so_rcv);
if (m == 0) {
if ((m = m_get()) == NULL)
return;
#ifdef TCP_COMPAT_42
tlen = 1;
#else
tlen = 0;
#endif
m->m_data += if_maxlinkhdr;
*mtod(m, struct tcpiphdr *) = *ti;
ti = mtod(m, struct tcpiphdr *);
flags = TH_ACK;
} else {
/*
* Send a single message to the TCP at address specified by
* the given TCP/IP header. If m == 0, then we make a copy
* of the tcpiphdr at ti and send directly to the addressed host.
* This is used to force keep alive messages out using the TCP
* template for a connection tp->t_template. If flags are given
* then we send a message back to the TCP which originated the
* segment ti, and discard the mbuf containing it and any other
* attached mbufs.
*
* In any case the ack and sequence number of the transmitted
* segment are as specified by the parameters.
*/
void
tcp_respond(PNATState pData, struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m, tcp_seq ack, tcp_seq seq, int flags)
{
register int tlen;
int win = 0;
LogFlowFunc(("ENTER: tp = %R[tcpcb793], ti = %lx, m = %lx, ack = %u, seq = %u, flags = %x\n",
tp, (long)ti, (long)m, ack, seq, flags));
if (tp)
win = sbspace(&tp->t_socket->so_rcv);
if (m == 0)
{
if ((m = m_gethdr(pData, M_DONTWAIT, MT_HEADER)) == NULL)
return;
#ifdef TCP_COMPAT_42
tlen = 1;
#else
tlen = 0;
#endif
m->m_data += if_maxlinkhdr;
m->m_pkthdr.header = mtod(m, void *);
*mtod(m, struct tcpiphdr *) = *ti;
ti = mtod(m, struct tcpiphdr *);
flags = TH_ACK;
}
else
{
static int
rfcomm_attach(struct socket *so, int proto)
{
int error;
KASSERT(so->so_pcb == NULL);
if (so->so_lock == NULL) {
mutex_obj_hold(bt_lock);
so->so_lock = bt_lock;
solock(so);
}
KASSERT(solocked(so));
/*
* Since we have nothing to add, we attach the DLC
* structure directly to our PCB pointer.
*/
error = soreserve(so, rfcomm_sendspace, rfcomm_recvspace);
if (error)
return error;
error = rfcomm_attach_pcb((struct rfcomm_dlc **)&so->so_pcb,
&rfcomm_proto, so);
if (error)
return error;
error = rfcomm_rcvd_pcb(so->so_pcb, sbspace(&so->so_rcv));
if (error) {
rfcomm_detach_pcb((struct rfcomm_dlc **)&so->so_pcb);
return error;
}
return 0;
}
int
sbappendcontrol_locked(struct sockbuf *sb, struct mbuf *m0,
struct mbuf *control)
{
struct mbuf *m, *n, *mlast;
int space;
SOCKBUF_LOCK_ASSERT(sb);
if (control == 0)
panic("sbappendcontrol_locked");
space = m_length(control, &n) + m_length(m0, NULL);
if (space > sbspace(sb))
return (0);
n->m_next = m0; /* concatenate data to control */
SBLASTRECORDCHK(sb);
for (m = control; m->m_next; m = m->m_next)
sballoc(sb, m);
sballoc(sb, m);
mlast = m;
SBLINKRECORD(sb, control);
sb->sb_mbtail = mlast;
SBLASTMBUFCHK(sb);
SBLASTRECORDCHK(sb);
return (1);
}
/* You'd certainly better have an iocount on the vnode! */
int
fifo_freespace(struct vnode *vp, long *count)
{
struct socket *rsock;
rsock = vp->v_fifoinfo->fi_readsock;
socket_lock(rsock, 1);
*count = sbspace(&rsock->so_rcv);
socket_unlock(rsock, 1);
return 0;
}
/*
* natmintr: interrupt
*
* Note: we expect a socket pointer in rcvif rather than an interface
* pointer. We can get the interface pointer from the so's PCB if we really
* need it.
*/
void
natmintr(struct mbuf *m)
{
struct socket *so;
struct natmpcb *npcb;
#ifdef DIAGNOSTIC
M_ASSERTPKTHDR(m);
#endif
NATM_LOCK();
npcb = (struct natmpcb *)m->m_pkthdr.rcvif; /* XXX: overloaded */
so = npcb->npcb_socket;
npcb->npcb_inq--;
if (npcb->npcb_flags & NPCB_DRAIN) {
if (npcb->npcb_inq == 0)
free(npcb, M_PCB); /* done! */
NATM_UNLOCK();
m_freem(m);
return;
}
if (npcb->npcb_flags & NPCB_FREE) {
NATM_UNLOCK();
m_freem(m); /* drop */
return;
}
#ifdef NEED_TO_RESTORE_IFP
m->m_pkthdr.rcvif = npcb->npcb_ifp;
#else
#ifdef DIAGNOSTIC
m->m_pkthdr.rcvif = NULL; /* null it out to be safe */
#endif
#endif
if (sbspace(&so->so_rcv) > m->m_pkthdr.len) {
#ifdef NATM_STAT
natm_sookcnt++;
natm_sookbytes += m->m_pkthdr.len;
#endif
sbappendrecord(&so->so_rcv, m);
sorwakeup(so);
NATM_UNLOCK();
} else {
#ifdef NATM_STAT
natm_sodropcnt++;
natm_sodropbytes += m->m_pkthdr.len;
#endif
NATM_UNLOCK();
m_freem(m);
}
}
static int
rfcomm_rcvd(struct socket *so, int flags, struct lwp *l)
{
struct rfcomm_dlc *pcb = so->so_pcb;
KASSERT(solocked(so));
if (pcb == NULL)
return EINVAL;
return rfcomm_rcvd_pcb(pcb, sbspace(&so->so_rcv));
}
int
filt_fifowrite(struct knote *kn, long hint)
{
struct socket *so = (struct socket *)kn->kn_hook;
kn->kn_data = sbspace(&so->so_snd);
if (so->so_state & SS_CANTSENDMORE) {
kn->kn_flags |= EV_EOF;
return (1);
}
kn->kn_flags &= ~EV_EOF;
return (kn->kn_data >= so->so_snd.sb_lowat);
}
/*
* Append address and data, and optionally, control (ancillary) data
* to the receive queue of a socket. If present,
* m0 must include a packet header with total length.
* Returns 0 if no space in sockbuf or insufficient mbufs.
*/
int
sbappendaddr(struct sockbuf *sb, struct sockaddr *asa, struct mbuf *m0,
struct mbuf *control)
{
struct mbuf *m, *n, *nlast;
int space = asa->sa_len;
if (m0 && (m0->m_flags & M_PKTHDR) == 0)
panic("sbappendaddr");
if (m0)
space += m0->m_pkthdr.len;
for (n = control; n; n = n->m_next) {
space += n->m_len;
if (n->m_next == NULL) /* keep pointer to last control buf */
break;
}
if (space > sbspace(sb))
return (0);
if (asa->sa_len > MLEN)
return (0);
MGET(m, M_DONTWAIT, MT_SONAME);
if (m == NULL)
return (0);
m->m_len = asa->sa_len;
memcpy(mtod(m, caddr_t), asa, asa->sa_len);
if (n)
n->m_next = m0; /* concatenate data to control */
else
control = m0;
m->m_next = control;
SBLASTRECORDCHK(sb, "sbappendaddr 1");
for (n = m; n->m_next != NULL; n = n->m_next)
sballoc(sb, n);
sballoc(sb, n);
nlast = n;
SBLINKRECORD(sb, m);
sb->sb_mbtail = nlast;
SBLASTMBUFCHK(sb, "sbappendaddr");
SBLASTRECORDCHK(sb, "sbappendaddr 2");
return (1);
}
/*
* Append address and data, and optionally, control (ancillary) data to the
* receive queue of a socket. If present, m0 must include a packet header
* with total length. Returns 0 if no space in sockbuf or insufficient
* mbufs.
*/
int
sbappendaddr_locked(struct sockbuf *sb, const struct sockaddr *asa,
struct mbuf *m0, struct mbuf *control)
{
struct mbuf *m, *n, *nlast;
int space = asa->sa_len;
SOCKBUF_LOCK_ASSERT(sb);
if (m0 && (m0->m_flags & M_PKTHDR) == 0)
panic("sbappendaddr_locked");
if (m0)
space += m0->m_pkthdr.len;
space += m_length(control, &n);
if (space > sbspace(sb))
return (0);
#if MSIZE <= 256
if (asa->sa_len > MLEN)
return (0);
#endif
MGET(m, M_DONTWAIT, MT_SONAME);
if (m == 0)
return (0);
m->m_len = asa->sa_len;
bcopy(asa, mtod(m, caddr_t), asa->sa_len);
if (n){
CHECK_ADD_LINKCNT(n, m0, NULL, "sbappendaddr_locked");
n->m_next = m0; /* concatenate data to control */
}else
control = m0;
CHECK_ADD_LINKCNT(m, control, NULL, "sbappendaddr_locked");
m->m_next = control;
for (n = m; n->m_next != NULL; n = n->m_next)
sballoc(sb, n);
sballoc(sb, n);
nlast = n;
SBLINKRECORD(sb, m);
sb->sb_mbtail = nlast;
SBLASTMBUFCHK(sb);
SBLASTRECORDCHK(sb);
return (1);
}
static void
sco_input(void *arg, struct mbuf *m)
{
struct socket *so = arg;
/*
* since this data is time sensitive, if the buffer
* is full we just dump data until the latest one
* will fit.
*/
while (m->m_pkthdr.len > sbspace(&so->so_rcv))
sbdroprecord(&so->so_rcv);
DPRINTFN(10, "received %d bytes\n", m->m_pkthdr.len);
sbappendrecord(&so->so_rcv, m);
sorwakeup(so);
}
key_receive(struct socket *so, struct mbuf **paddr, struct uio *uio,
struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
#endif
{
struct rawcb *rp = sotorawcb(so);
struct keycb *kp = (struct keycb *)rp;
int error;
#ifndef __FreeBSD__
error = (*kp->kp_receive)(so, paddr, uio, mp0, controlp, flagsp);
#else
error = soreceive(so, paddr, uio, mp0, controlp, flagsp);
#endif
if (kp->kp_queue &&
sbspace(&rp->rcb_socket->so_rcv) > kp->kp_queue->m_pkthdr.len)
sorwakeup(so);
return error;
}
/*
* Append address and data, and optionally, control (ancillary) data to the
* receive queue of a socket. If present, m0 must include a packet header
* with total length. Returns 0 if no space in sockbuf or insufficient
* mbufs.
*/
int
sbappendaddr_locked(struct sockbuf *sb, const struct sockaddr *asa,
struct mbuf *m0, struct mbuf *control)
{
struct mbuf *ctrl_last;
int space = asa->sa_len;
SOCKBUF_LOCK_ASSERT(sb);
if (m0 && (m0->m_flags & M_PKTHDR) == 0)
panic("sbappendaddr_locked");
if (m0)
space += m0->m_pkthdr.len;
space += m_length(control, &ctrl_last);
if (space > sbspace(sb))
return (0);
return (sbappendaddr_locked_internal(sb, asa, m0, control, ctrl_last));
}
static int
filt_fifowrite(struct knote *kn, long hint)
{
struct socket *so;
int rv;
so = (struct socket *)kn->kn_hook;
if (hint != NOTE_SUBMIT)
solock(so);
kn->kn_data = sbspace(&so->so_snd);
if (so->so_state & SS_CANTSENDMORE) {
kn->kn_flags |= EV_EOF;
rv = 1;
} else {
kn->kn_flags &= ~EV_EOF;
rv = (kn->kn_data >= so->so_snd.sb_lowat);
}
if (hint != NOTE_SUBMIT)
sounlock(so);
return rv;
}
/*
* Do a send by putting data in output queue and updating urgent
* marker if URG set. Possibly send more data. Unlike the other
* pru_*() routines, the mbuf chains are our responsibility. We
* must either enqueue them or free them. The other pru_* routines
* generally are caller-frees.
*/
static int
tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
struct sockaddr *nam, struct mbuf *control, struct thread *td)
{
int error = 0;
struct inpcb *inp;
struct tcpcb *tp = NULL;
int headlocked = 0;
#ifdef INET6
int isipv6;
#endif
TCPDEBUG0;
/*
* We require the pcbinfo lock in two cases:
*
* (1) An implied connect is taking place, which can result in
* binding IPs and ports and hence modification of the pcb hash
* chains.
*
* (2) PRUS_EOF is set, resulting in explicit close on the send.
*/
if ((nam != NULL) || (flags & PRUS_EOF)) {
INP_INFO_WLOCK(&V_tcbinfo);
headlocked = 1;
}
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp_usr_send: inp == NULL"));
INP_WLOCK(inp);
if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
if (control)
m_freem(control);
if (m)
m_freem(m);
error = ECONNRESET;
goto out;
}
#ifdef INET6
isipv6 = nam && nam->sa_family == AF_INET6;
#endif /* INET6 */
tp = intotcpcb(inp);
TCPDEBUG1();
if (control) {
/* TCP doesn't do control messages (rights, creds, etc) */
if (control->m_len) {
m_freem(control);
if (m)
m_freem(m);
error = EINVAL;
goto out;
}
m_freem(control); /* empty control, just free it */
}
if (!(flags & PRUS_OOB)) {
sbappendstream(&so->so_snd, m);
if (nam && tp->t_state < TCPS_SYN_SENT) {
/*
* Do implied connect if not yet connected,
* initialize window to default value, and
* initialize maxseg/maxopd using peer's cached
* MSS.
*/
INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
#ifdef INET6
if (isipv6)
error = tcp6_connect(tp, nam, td);
else
#endif /* INET6 */
error = tcp_connect(tp, nam, td);
if (error)
goto out;
tp->snd_wnd = TTCP_CLIENT_SND_WND;
tcp_mss(tp, -1);
}
if (flags & PRUS_EOF) {
/*
* Close the send side of the connection after
* the data is sent.
*/
INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
socantsendmore(so);
tcp_usrclosed(tp);
}
if (headlocked) {
INP_INFO_WUNLOCK(&V_tcbinfo);
headlocked = 0;
}
if (!(inp->inp_flags & INP_DROPPED)) {
if (flags & PRUS_MORETOCOME)
tp->t_flags |= TF_MORETOCOME;
error = tcp_output_send(tp);
if (flags & PRUS_MORETOCOME)
tp->t_flags &= ~TF_MORETOCOME;
}
} else {
/*
* XXXRW: PRUS_EOF not implemented with PRUS_OOB?
*/
SOCKBUF_LOCK(&so->so_snd);
if (sbspace(&so->so_snd) < -512) {
SOCKBUF_UNLOCK(&so->so_snd);
m_freem(m);
error = ENOBUFS;
goto out;
}
/*
* According to RFC961 (Assigned Protocols),
* the urgent pointer points to the last octet
* of urgent data. We continue, however,
* to consider it to indicate the first octet
* of data past the urgent section.
* Otherwise, snd_up should be one lower.
*/
sbappendstream_locked(&so->so_snd, m);
SOCKBUF_UNLOCK(&so->so_snd);
if (nam && tp->t_state < TCPS_SYN_SENT) {
/*
* Do implied connect if not yet connected,
* initialize window to default value, and
* initialize maxseg/maxopd using peer's cached
* MSS.
*/
INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
#ifdef INET6
if (isipv6)
error = tcp6_connect(tp, nam, td);
else
#endif /* INET6 */
error = tcp_connect(tp, nam, td);
if (error)
goto out;
tp->snd_wnd = TTCP_CLIENT_SND_WND;
tcp_mss(tp, -1);
INP_INFO_WUNLOCK(&V_tcbinfo);
headlocked = 0;
} else if (nam) {
INP_INFO_WUNLOCK(&V_tcbinfo);
headlocked = 0;
}
tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
tp->t_flags |= TF_FORCEDATA;
error = tcp_output_send(tp);
tp->t_flags &= ~TF_FORCEDATA;
}
out:
TCPDEBUG2((flags & PRUS_OOB) ? PRU_SENDOOB :
((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
INP_WUNLOCK(inp);
if (headlocked)
INP_INFO_WUNLOCK(&V_tcbinfo);
return (error);
}
/*
* TCP input routine, follows pages 65-76 of the
* protocol specification dated September, 1981 very closely.
*/
void
tcp_input(struct mbuf *m, int iphlen, struct socket *inso)
{
struct ip save_ip, *ip;
register struct tcpiphdr *ti;
caddr_t optp = NULL;
int optlen = 0;
int len, tlen, off;
register struct tcpcb *tp = NULL;
register int tiflags;
struct socket *so = NULL;
int todrop, acked, ourfinisacked, needoutput = 0;
int iss = 0;
u_long tiwin;
int ret;
struct ex_list *ex_ptr;
Slirp *slirp;
DEBUG_CALL("tcp_input");
DEBUG_ARGS((dfd, " m = %8lx iphlen = %2d inso = %lx\n",
(long )m, iphlen, (long )inso ));
/*
* If called with m == 0, then we're continuing the connect
*/
if (m == NULL) {
so = inso;
slirp = so->slirp;
/* Re-set a few variables */
tp = sototcpcb(so);
m = so->so_m;
so->so_m = NULL;
ti = so->so_ti;
tiwin = ti->ti_win;
tiflags = ti->ti_flags;
goto cont_conn;
}
slirp = m->slirp;
/*
* Get IP and TCP header together in first mbuf.
* Note: IP leaves IP header in first mbuf.
*/
ti = mtod(m, struct tcpiphdr *);
if (iphlen > sizeof(struct ip )) {
ip_stripoptions(m, (struct mbuf *)0);
iphlen=sizeof(struct ip );
}
/* XXX Check if too short */
/*
* Save a copy of the IP header in case we want restore it
* for sending an ICMP error message in response.
*/
ip=mtod(m, struct ip *);
save_ip = *ip;
save_ip.ip_len+= iphlen;
/*
* Checksum extended TCP header and data.
*/
tlen = ((struct ip *)ti)->ip_len;
tcpiphdr2qlink(ti)->next = tcpiphdr2qlink(ti)->prev = NULL;
memset(&ti->ti_i.ih_mbuf, 0 , sizeof(struct mbuf_ptr));
ti->ti_x1 = 0;
ti->ti_len = htons((uint16_t)tlen);
len = sizeof(struct ip ) + tlen;
if(cksum(m, len)) {
goto drop;
}
/*
* Check that TCP offset makes sense,
* pull out TCP options and adjust length. XXX
*/
off = ti->ti_off << 2;
if (off < sizeof (struct tcphdr) || off > tlen) {
goto drop;
}
tlen -= off;
ti->ti_len = tlen;
if (off > sizeof (struct tcphdr)) {
optlen = off - sizeof (struct tcphdr);
optp = mtod(m, caddr_t) + sizeof (struct tcpiphdr);
}
tiflags = ti->ti_flags;
/*
* Convert TCP protocol specific fields to host format.
*/
NTOHL(ti->ti_seq);
NTOHL(ti->ti_ack);
NTOHS(ti->ti_win);
NTOHS(ti->ti_urp);
/*
* Drop TCP, IP headers and TCP options.
*/
m->m_data += sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
m->m_len -= sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
/*
* Locate pcb for segment.
*/
findso:
so = slirp->tcp_last_so;
if (so->so_fport != ti->ti_dport ||
so->so_lport != ti->ti_sport ||
so->so_laddr.s_addr != ti->ti_src.s_addr ||
so->so_faddr.s_addr != ti->ti_dst.s_addr) {
so = solookup(&slirp->tcb, ti->ti_src, ti->ti_sport,
ti->ti_dst, ti->ti_dport);
if (so)
slirp->tcp_last_so = so;
}
/*
* If the state is CLOSED (i.e., TCB does not exist) then
* all data in the incoming segment is discarded.
* If the TCB exists but is in CLOSED state, it is embryonic,
* but should either do a listen or a connect soon.
*
* state == CLOSED means we've done socreate() but haven't
* attached it to a protocol yet...
*
* XXX If a TCB does not exist, and the TH_SYN flag is
* the only flag set, then create a session, mark it
* as if it was LISTENING, and continue...
*/
if (so == NULL) {
if (slirp->restricted) {
/* Any hostfwds will have an existing socket, so we only get here
* for non-hostfwd connections. These should be dropped, unless it
* happens to be a guestfwd.
*/
for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
if (ex_ptr->ex_fport == ti->ti_dport &&
ti->ti_dst.s_addr == ex_ptr->ex_addr.s_addr) {
break;
}
}
if (!ex_ptr) {
goto dropwithreset;
}
}
if ((tiflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK)) != TH_SYN)
goto dropwithreset;
if ((so = socreate(slirp)) == NULL)
goto dropwithreset;
if (tcp_attach(so) < 0) {
free(so); /* Not sofree (if it failed, it's not insqued) */
goto dropwithreset;
}
sbreserve(&so->so_snd, TCP_SNDSPACE);
sbreserve(&so->so_rcv, TCP_RCVSPACE);
so->so_laddr = ti->ti_src;
so->so_lport = ti->ti_sport;
so->so_faddr = ti->ti_dst;
so->so_fport = ti->ti_dport;
if ((so->so_iptos = tcp_tos(so)) == 0)
so->so_iptos = ((struct ip *)ti)->ip_tos;
tp = sototcpcb(so);
tp->t_state = TCPS_LISTEN;
}
/*
* If this is a still-connecting socket, this probably
* a retransmit of the SYN. Whether it's a retransmit SYN
* or something else, we nuke it.
*/
if (so->so_state & SS_ISFCONNECTING)
goto drop;
tp = sototcpcb(so);
/* XXX Should never fail */
if (tp == NULL)
goto dropwithreset;
if (tp->t_state == TCPS_CLOSED)
goto drop;
tiwin = ti->ti_win;
/*
* Segment received on connection.
* Reset idle time and keep-alive timer.
*/
tp->t_idle = 0;
if (SO_OPTIONS)
tp->t_timer[TCPT_KEEP] = TCPTV_KEEPINTVL;
else
tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_IDLE;
/*
* Process options if not in LISTEN state,
* else do it below (after getting remote address).
*/
if (optp && tp->t_state != TCPS_LISTEN)
tcp_dooptions(tp, (u_char *)optp, optlen, ti);
/*
* Header prediction: check for the two common cases
* of a uni-directional data xfer. If the packet has
* no control flags, is in-sequence, the window didn't
* change and we're not retransmitting, it's a
* candidate. If the length is zero and the ack moved
* forward, we're the sender side of the xfer. Just
* free the data acked & wake any higher level process
* that was blocked waiting for space. If the length
* is non-zero and the ack didn't move, we're the
* receiver side. If we're getting packets in-order
* (the reassembly queue is empty), add the data to
* the socket buffer and note that we need a delayed ack.
*
* XXX Some of these tests are not needed
* eg: the tiwin == tp->snd_wnd prevents many more
* predictions.. with no *real* advantage..
*/
if (tp->t_state == TCPS_ESTABLISHED &&
(tiflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK)) == TH_ACK &&
ti->ti_seq == tp->rcv_nxt &&
tiwin && tiwin == tp->snd_wnd &&
tp->snd_nxt == tp->snd_max) {
if (ti->ti_len == 0) {
if (SEQ_GT(ti->ti_ack, tp->snd_una) &&
SEQ_LEQ(ti->ti_ack, tp->snd_max) &&
tp->snd_cwnd >= tp->snd_wnd) {
/*
* this is a pure ack for outstanding data.
*/
if (tp->t_rtt &&
SEQ_GT(ti->ti_ack, tp->t_rtseq))
tcp_xmit_timer(tp, tp->t_rtt);
acked = ti->ti_ack - tp->snd_una;
sbdrop(&so->so_snd, acked);
tp->snd_una = ti->ti_ack;
m_free(m);
/*
* If all outstanding data are acked, stop
* retransmit timer, otherwise restart timer
* using current (possibly backed-off) value.
* If process is waiting for space,
* wakeup/selwakeup/signal. If data
* are ready to send, let tcp_output
* decide between more output or persist.
*/
if (tp->snd_una == tp->snd_max)
tp->t_timer[TCPT_REXMT] = 0;
else if (tp->t_timer[TCPT_PERSIST] == 0)
tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
/*
* This is called because sowwakeup might have
* put data into so_snd. Since we don't so sowwakeup,
* we don't need this.. XXX???
*/
if (so->so_snd.sb_cc)
(void) tcp_output(tp);
return;
}
} else if (ti->ti_ack == tp->snd_una &&
tcpfrag_list_empty(tp) &&
ti->ti_len <= sbspace(&so->so_rcv)) {
/*
* this is a pure, in-sequence data packet
* with nothing on the reassembly queue and
* we have enough buffer space to take it.
*/
tp->rcv_nxt += ti->ti_len;
/*
* Add data to socket buffer.
*/
if (so->so_emu) {
if (tcp_emu(so,m)) sbappend(so, m);
} else
sbappend(so, m);
/*
* If this is a short packet, then ACK now - with Nagel
* congestion avoidance sender won't send more until
* he gets an ACK.
*
* It is better to not delay acks at all to maximize
* TCP throughput. See RFC 2581.
*/
tp->t_flags |= TF_ACKNOW;
tcp_output(tp);
return;
}
} /* header prediction */
/*
* Calculate amount of space in receive window,
* and then do TCP input processing.
* Receive window is amount of space in rcv queue,
* but not less than advertised window.
*/
{ int win;
win = sbspace(&so->so_rcv);
if (win < 0)
win = 0;
tp->rcv_wnd = max(win, (int)(tp->rcv_adv - tp->rcv_nxt));
}
switch (tp->t_state) {
/*
* If the state is LISTEN then ignore segment if it contains an RST.
* If the segment contains an ACK then it is bad and send a RST.
* If it does not contain a SYN then it is not interesting; drop it.
* Don't bother responding if the destination was a broadcast.
* Otherwise initialize tp->rcv_nxt, and tp->irs, select an initial
* tp->iss, and send a segment:
* <SEQ=ISS><ACK=RCV_NXT><CTL=SYN,ACK>
* Also initialize tp->snd_nxt to tp->iss+1 and tp->snd_una to tp->iss.
* Fill in remote peer address fields if not previously specified.
* Enter SYN_RECEIVED state, and process any other fields of this
* segment in this state.
*/
case TCPS_LISTEN: {
if (tiflags & TH_RST)
goto drop;
if (tiflags & TH_ACK)
goto dropwithreset;
if ((tiflags & TH_SYN) == 0)
goto drop;
/*
* This has way too many gotos...
* But a bit of spaghetti code never hurt anybody :)
*/
/*
* If this is destined for the control address, then flag to
* tcp_ctl once connected, otherwise connect
*/
if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) ==
slirp->vnetwork_addr.s_addr) {
if (so->so_faddr.s_addr != slirp->vhost_addr.s_addr &&
so->so_faddr.s_addr != slirp->vnameserver_addr.s_addr) {
/* May be an add exec */
for (ex_ptr = slirp->exec_list; ex_ptr;
ex_ptr = ex_ptr->ex_next) {
if(ex_ptr->ex_fport == so->so_fport &&
so->so_faddr.s_addr == ex_ptr->ex_addr.s_addr) {
so->so_state |= SS_CTL;
break;
}
}
if (so->so_state & SS_CTL) {
goto cont_input;
}
}
/* CTL_ALIAS: Do nothing, tcp_fconnect will be called on it */
}
if (so->so_emu & EMU_NOCONNECT) {
so->so_emu &= ~EMU_NOCONNECT;
goto cont_input;
}
if ((tcp_fconnect(so) == -1) &&
#if defined(_WIN32)
socket_error() != WSAEWOULDBLOCK
#else
(errno != EINPROGRESS) && (errno != EWOULDBLOCK)
#endif
) {
u_char code=ICMP_UNREACH_NET;
DEBUG_MISC((dfd, " tcp fconnect errno = %d-%s\n",
errno,strerror(errno)));
if(errno == ECONNREFUSED) {
/* ACK the SYN, send RST to refuse the connection */
tcp_respond(tp, ti, m, ti->ti_seq+1, (tcp_seq)0,
TH_RST|TH_ACK);
} else {
if(errno == EHOSTUNREACH) code=ICMP_UNREACH_HOST;
HTONL(ti->ti_seq); /* restore tcp header */
HTONL(ti->ti_ack);
HTONS(ti->ti_win);
HTONS(ti->ti_urp);
m->m_data -= sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
m->m_len += sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
*ip=save_ip;
icmp_error(m, ICMP_UNREACH,code, 0,strerror(errno));
}
tcp_close(tp);
m_free(m);
} else {
/*
* Haven't connected yet, save the current mbuf
* and ti, and return
* XXX Some OS's don't tell us whether the connect()
* succeeded or not. So we must time it out.
*/
so->so_m = m;
so->so_ti = ti;
tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
tp->t_state = TCPS_SYN_RECEIVED;
tcp_template(tp);
}
return;
cont_conn:
/* m==NULL
* Check if the connect succeeded
*/
if (so->so_state & SS_NOFDREF) {
tp = tcp_close(tp);
goto dropwithreset;
}
cont_input:
tcp_template(tp);
if (optp)
tcp_dooptions(tp, (u_char *)optp, optlen, ti);
if (iss)
tp->iss = iss;
else
tp->iss = slirp->tcp_iss;
slirp->tcp_iss += TCP_ISSINCR/2;
tp->irs = ti->ti_seq;
tcp_sendseqinit(tp);
tcp_rcvseqinit(tp);
tp->t_flags |= TF_ACKNOW;
tp->t_state = TCPS_SYN_RECEIVED;
tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
goto trimthenstep6;
} /* case TCPS_LISTEN */
/*
* If the state is SYN_SENT:
* if seg contains an ACK, but not for our SYN, drop the input.
* if seg contains a RST, then drop the connection.
* if seg does not contain SYN, then drop it.
* Otherwise this is an acceptable SYN segment
* initialize tp->rcv_nxt and tp->irs
* if seg contains ack then advance tp->snd_una
* if SYN has been acked change to ESTABLISHED else SYN_RCVD state
* arrange for segment to be acked (eventually)
* continue processing rest of data/controls, beginning with URG
*/
case TCPS_SYN_SENT:
if ((tiflags & TH_ACK) &&
(SEQ_LEQ(ti->ti_ack, tp->iss) ||
SEQ_GT(ti->ti_ack, tp->snd_max)))
goto dropwithreset;
if (tiflags & TH_RST) {
if (tiflags & TH_ACK) {
tcp_drop(tp, 0); /* XXX Check t_softerror! */
}
goto drop;
}
if ((tiflags & TH_SYN) == 0)
goto drop;
if (tiflags & TH_ACK) {
tp->snd_una = ti->ti_ack;
if (SEQ_LT(tp->snd_nxt, tp->snd_una))
tp->snd_nxt = tp->snd_una;
}
tp->t_timer[TCPT_REXMT] = 0;
tp->irs = ti->ti_seq;
tcp_rcvseqinit(tp);
tp->t_flags |= TF_ACKNOW;
if (tiflags & TH_ACK && SEQ_GT(tp->snd_una, tp->iss)) {
soisfconnected(so);
tp->t_state = TCPS_ESTABLISHED;
(void) tcp_reass(tp, (struct tcpiphdr *)0,
(struct mbuf *)0);
/*
* if we didn't have to retransmit the SYN,
* use its rtt as our initial srtt & rtt var.
*/
if (tp->t_rtt)
tcp_xmit_timer(tp, tp->t_rtt);
} else
tp->t_state = TCPS_SYN_RECEIVED;
trimthenstep6:
/*
* Advance ti->ti_seq to correspond to first data byte.
* If data, trim to stay within window,
* dropping FIN if necessary.
*/
ti->ti_seq++;
if (ti->ti_len > tp->rcv_wnd) {
todrop = ti->ti_len - tp->rcv_wnd;
m_adj(m, -todrop);
ti->ti_len = tp->rcv_wnd;
tiflags &= ~TH_FIN;
}
tp->snd_wl1 = ti->ti_seq - 1;
tp->rcv_up = ti->ti_seq;
goto step6;
} /* switch tp->t_state */
/*
* States other than LISTEN or SYN_SENT.
* Check that at least some bytes of segment are within
* receive window. If segment begins before rcv_nxt,
* drop leading data (and SYN); if nothing left, just ack.
*/
todrop = tp->rcv_nxt - ti->ti_seq;
if (todrop > 0) {
if (tiflags & TH_SYN) {
tiflags &= ~TH_SYN;
ti->ti_seq++;
if (ti->ti_urp > 1)
ti->ti_urp--;
else
tiflags &= ~TH_URG;
todrop--;
}
/*
* Following if statement from Stevens, vol. 2, p. 960.
*/
if (todrop > ti->ti_len
|| (todrop == ti->ti_len && (tiflags & TH_FIN) == 0)) {
/*
* Any valid FIN must be to the left of the window.
* At this point the FIN must be a duplicate or out
* of sequence; drop it.
*/
tiflags &= ~TH_FIN;
/*
* Send an ACK to resynchronize and drop any data.
* But keep on processing for RST or ACK.
*/
tp->t_flags |= TF_ACKNOW;
todrop = ti->ti_len;
}
m_adj(m, todrop);
ti->ti_seq += todrop;
ti->ti_len -= todrop;
if (ti->ti_urp > todrop)
ti->ti_urp -= todrop;
else {
tiflags &= ~TH_URG;
ti->ti_urp = 0;
}
}
/*
* If new data are received on a connection after the
* user processes are gone, then RST the other end.
*/
if ((so->so_state & SS_NOFDREF) &&
tp->t_state > TCPS_CLOSE_WAIT && ti->ti_len) {
tp = tcp_close(tp);
goto dropwithreset;
}
/*
* If segment ends after window, drop trailing data
* (and PUSH and FIN); if nothing left, just ACK.
*/
todrop = (ti->ti_seq+ti->ti_len) - (tp->rcv_nxt+tp->rcv_wnd);
if (todrop > 0) {
if (todrop >= ti->ti_len) {
/*
* If a new connection request is received
* while in TIME_WAIT, drop the old connection
* and start over if the sequence numbers
* are above the previous ones.
*/
if (tiflags & TH_SYN &&
tp->t_state == TCPS_TIME_WAIT &&
SEQ_GT(ti->ti_seq, tp->rcv_nxt)) {
iss = tp->rcv_nxt + TCP_ISSINCR;
tp = tcp_close(tp);
goto findso;
}
/*
* If window is closed can only take segments at
* window edge, and have to drop data and PUSH from
* incoming segments. Continue processing, but
* remember to ack. Otherwise, drop segment
* and ack.
*/
if (tp->rcv_wnd == 0 && ti->ti_seq == tp->rcv_nxt) {
tp->t_flags |= TF_ACKNOW;
} else {
goto dropafterack;
}
}
m_adj(m, -todrop);
ti->ti_len -= todrop;
tiflags &= ~(TH_PUSH|TH_FIN);
}
/*
* If the RST bit is set examine the state:
* SYN_RECEIVED STATE:
* If passive open, return to LISTEN state.
* If active open, inform user that connection was refused.
* ESTABLISHED, FIN_WAIT_1, FIN_WAIT2, CLOSE_WAIT STATES:
* Inform user that connection was reset, and close tcb.
* CLOSING, LAST_ACK, TIME_WAIT STATES
* Close the tcb.
*/
if (tiflags&TH_RST) switch (tp->t_state) {
case TCPS_SYN_RECEIVED:
case TCPS_ESTABLISHED:
case TCPS_FIN_WAIT_1:
case TCPS_FIN_WAIT_2:
case TCPS_CLOSE_WAIT:
tp->t_state = TCPS_CLOSED;
tcp_close(tp);
goto drop;
case TCPS_CLOSING:
case TCPS_LAST_ACK:
case TCPS_TIME_WAIT:
tcp_close(tp);
goto drop;
}
/*
* If a SYN is in the window, then this is an
* error and we send an RST and drop the connection.
*/
if (tiflags & TH_SYN) {
tp = tcp_drop(tp,0);
goto dropwithreset;
}
/*
* If the ACK bit is off we drop the segment and return.
*/
if ((tiflags & TH_ACK) == 0) goto drop;
/*
* Ack processing.
*/
switch (tp->t_state) {
/*
* In SYN_RECEIVED state if the ack ACKs our SYN then enter
* ESTABLISHED state and continue processing, otherwise
* send an RST. una<=ack<=max
*/
case TCPS_SYN_RECEIVED:
if (SEQ_GT(tp->snd_una, ti->ti_ack) ||
SEQ_GT(ti->ti_ack, tp->snd_max))
goto dropwithreset;
tp->t_state = TCPS_ESTABLISHED;
/*
* The sent SYN is ack'ed with our sequence number +1
* The first data byte already in the buffer will get
* lost if no correction is made. This is only needed for
* SS_CTL since the buffer is empty otherwise.
* tp->snd_una++; or:
*/
tp->snd_una=ti->ti_ack;
if (so->so_state & SS_CTL) {
/* So tcp_ctl reports the right state */
ret = tcp_ctl(so);
if (ret == 1) {
soisfconnected(so);
so->so_state &= ~SS_CTL; /* success XXX */
} else if (ret == 2) {
so->so_state &= SS_PERSISTENT_MASK;
so->so_state |= SS_NOFDREF; /* CTL_CMD */
} else {
needoutput = 1;
tp->t_state = TCPS_FIN_WAIT_1;
}
} else {
soisfconnected(so);
}
(void) tcp_reass(tp, (struct tcpiphdr *)0, (struct mbuf *)0);
tp->snd_wl1 = ti->ti_seq - 1;
/* Avoid ack processing; snd_una==ti_ack => dup ack */
goto synrx_to_est;
/* fall into ... */
/*
* In ESTABLISHED state: drop duplicate ACKs; ACK out of range
* ACKs. If the ack is in the range
* tp->snd_una < ti->ti_ack <= tp->snd_max
* then advance tp->snd_una to ti->ti_ack and drop
* data from the retransmission queue. If this ACK reflects
* more up to date window information we update our window information.
*/
case TCPS_ESTABLISHED:
case TCPS_FIN_WAIT_1:
case TCPS_FIN_WAIT_2:
case TCPS_CLOSE_WAIT:
case TCPS_CLOSING:
case TCPS_LAST_ACK:
case TCPS_TIME_WAIT:
if (SEQ_LEQ(ti->ti_ack, tp->snd_una)) {
if (ti->ti_len == 0 && tiwin == tp->snd_wnd) {
DEBUG_MISC((dfd, " dup ack m = %lx so = %lx\n",
(long )m, (long )so));
/*
* If we have outstanding data (other than
* a window probe), this is a completely
* duplicate ack (ie, window info didn't
* change), the ack is the biggest we've
* seen and we've seen exactly our rexmt
* threshold of them, assume a packet
* has been dropped and retransmit it.
* Kludge snd_nxt & the congestion
* window so we send only this one
* packet.
*
* We know we're losing at the current
* window size so do congestion avoidance
* (set ssthresh to half the current window
* and pull our congestion window back to
* the new ssthresh).
*
* Dup acks mean that packets have left the
* network (they're now cached at the receiver)
* so bump cwnd by the amount in the receiver
* to keep a constant cwnd packets in the
* network.
*/
if (tp->t_timer[TCPT_REXMT] == 0 ||
ti->ti_ack != tp->snd_una)
tp->t_dupacks = 0;
else if (++tp->t_dupacks == TCPREXMTTHRESH) {
tcp_seq onxt = tp->snd_nxt;
u_int win =
min(tp->snd_wnd, tp->snd_cwnd) / 2 /
tp->t_maxseg;
if (win < 2)
win = 2;
tp->snd_ssthresh = win * tp->t_maxseg;
tp->t_timer[TCPT_REXMT] = 0;
tp->t_rtt = 0;
tp->snd_nxt = ti->ti_ack;
tp->snd_cwnd = tp->t_maxseg;
(void) tcp_output(tp);
tp->snd_cwnd = tp->snd_ssthresh +
tp->t_maxseg * tp->t_dupacks;
if (SEQ_GT(onxt, tp->snd_nxt))
tp->snd_nxt = onxt;
goto drop;
} else if (tp->t_dupacks > TCPREXMTTHRESH) {
tp->snd_cwnd += tp->t_maxseg;
(void) tcp_output(tp);
goto drop;
}
} else
tp->t_dupacks = 0;
break;
}
synrx_to_est:
/*
* If the congestion window was inflated to account
* for the other side's cached packets, retract it.
*/
if (tp->t_dupacks > TCPREXMTTHRESH &&
tp->snd_cwnd > tp->snd_ssthresh)
tp->snd_cwnd = tp->snd_ssthresh;
tp->t_dupacks = 0;
if (SEQ_GT(ti->ti_ack, tp->snd_max)) {
goto dropafterack;
}
acked = ti->ti_ack - tp->snd_una;
/*
* If transmit timer is running and timed sequence
* number was acked, update smoothed round trip time.
* Since we now have an rtt measurement, cancel the
* timer backoff (cf., Phil Karn's retransmit alg.).
* Recompute the initial retransmit timer.
*/
if (tp->t_rtt && SEQ_GT(ti->ti_ack, tp->t_rtseq))
tcp_xmit_timer(tp,tp->t_rtt);
/*
* If all outstanding data is acked, stop retransmit
* timer and remember to restart (more output or persist).
* If there is more data to be acked, restart retransmit
* timer, using current (possibly backed-off) value.
*/
if (ti->ti_ack == tp->snd_max) {
tp->t_timer[TCPT_REXMT] = 0;
needoutput = 1;
} else if (tp->t_timer[TCPT_PERSIST] == 0)
tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
/*
* When new data is acked, open the congestion window.
* If the window gives us less than ssthresh packets
* in flight, open exponentially (maxseg per packet).
* Otherwise open linearly: maxseg per window
* (maxseg^2 / cwnd per packet).
*/
{
register u_int cw = tp->snd_cwnd;
register u_int incr = tp->t_maxseg;
if (cw > tp->snd_ssthresh)
incr = incr * incr / cw;
tp->snd_cwnd = min(cw + incr, TCP_MAXWIN<<tp->snd_scale);
}
if (acked > so->so_snd.sb_cc) {
tp->snd_wnd -= so->so_snd.sb_cc;
sbdrop(&so->so_snd, (int )so->so_snd.sb_cc);
ourfinisacked = 1;
} else {
sbdrop(&so->so_snd, acked);
tp->snd_wnd -= acked;
ourfinisacked = 0;
}
tp->snd_una = ti->ti_ack;
if (SEQ_LT(tp->snd_nxt, tp->snd_una))
tp->snd_nxt = tp->snd_una;
switch (tp->t_state) {
/*
* In FIN_WAIT_1 STATE in addition to the processing
* for the ESTABLISHED state if our FIN is now acknowledged
* then enter FIN_WAIT_2.
*/
case TCPS_FIN_WAIT_1:
if (ourfinisacked) {
/*
* If we can't receive any more
* data, then closing user can proceed.
* Starting the timer is contrary to the
* specification, but if we don't get a FIN
* we'll hang forever.
*/
if (so->so_state & SS_FCANTRCVMORE) {
tp->t_timer[TCPT_2MSL] = TCP_MAXIDLE;
}
tp->t_state = TCPS_FIN_WAIT_2;
}
break;
/*
* In CLOSING STATE in addition to the processing for
* the ESTABLISHED state if the ACK acknowledges our FIN
* then enter the TIME-WAIT state, otherwise ignore
* the segment.
*/
case TCPS_CLOSING:
if (ourfinisacked) {
tp->t_state = TCPS_TIME_WAIT;
tcp_canceltimers(tp);
tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL;
}
break;
/*
* In LAST_ACK, we may still be waiting for data to drain
* and/or to be acked, as well as for the ack of our FIN.
* If our FIN is now acknowledged, delete the TCB,
* enter the closed state and return.
*/
case TCPS_LAST_ACK:
if (ourfinisacked) {
tcp_close(tp);
goto drop;
}
break;
/*
* In TIME_WAIT state the only thing that should arrive
* is a retransmission of the remote FIN. Acknowledge
* it and restart the finack timer.
*/
case TCPS_TIME_WAIT:
tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL;
goto dropafterack;
}
} /* switch(tp->t_state) */
step6:
/*
* Update window information.
* Don't look at window if no ACK: TAC's send garbage on first SYN.
*/
if ((tiflags & TH_ACK) &&
(SEQ_LT(tp->snd_wl1, ti->ti_seq) ||
(tp->snd_wl1 == ti->ti_seq && (SEQ_LT(tp->snd_wl2, ti->ti_ack) ||
(tp->snd_wl2 == ti->ti_ack && tiwin > tp->snd_wnd))))) {
tp->snd_wnd = tiwin;
tp->snd_wl1 = ti->ti_seq;
tp->snd_wl2 = ti->ti_ack;
if (tp->snd_wnd > tp->max_sndwnd)
tp->max_sndwnd = tp->snd_wnd;
needoutput = 1;
}
/*
* Process segments with URG.
*/
if ((tiflags & TH_URG) && ti->ti_urp &&
TCPS_HAVERCVDFIN(tp->t_state) == 0) {
/*
* This is a kludge, but if we receive and accept
* random urgent pointers, we'll crash in
* soreceive. It's hard to imagine someone
* actually wanting to send this much urgent data.
*/
if (ti->ti_urp + so->so_rcv.sb_cc > so->so_rcv.sb_datalen) {
ti->ti_urp = 0;
tiflags &= ~TH_URG;
goto dodata;
}
/*
* If this segment advances the known urgent pointer,
* then mark the data stream. This should not happen
* in CLOSE_WAIT, CLOSING, LAST_ACK or TIME_WAIT STATES since
* a FIN has been received from the remote side.
* In these states we ignore the URG.
*
* According to RFC961 (Assigned Protocols),
* the urgent pointer points to the last octet
* of urgent data. We continue, however,
* to consider it to indicate the first octet
* of data past the urgent section as the original
* spec states (in one of two places).
*/
if (SEQ_GT(ti->ti_seq+ti->ti_urp, tp->rcv_up)) {
tp->rcv_up = ti->ti_seq + ti->ti_urp;
so->so_urgc = so->so_rcv.sb_cc +
(tp->rcv_up - tp->rcv_nxt); /* -1; */
tp->rcv_up = ti->ti_seq + ti->ti_urp;
}
} else
/*
* If no out of band data is expected,
* pull receive urgent pointer along
* with the receive window.
*/
if (SEQ_GT(tp->rcv_nxt, tp->rcv_up))
tp->rcv_up = tp->rcv_nxt;
dodata:
/*
* If this is a small packet, then ACK now - with Nagel
* congestion avoidance sender won't send more until
* he gets an ACK.
*/
if (ti->ti_len && (unsigned)ti->ti_len <= 5 &&
((struct tcpiphdr_2 *)ti)->first_char == (char)27) {
tp->t_flags |= TF_ACKNOW;
}
/*
* Process the segment text, merging it into the TCP sequencing queue,
* and arranging for acknowledgment of receipt if necessary.
* This process logically involves adjusting tp->rcv_wnd as data
* is presented to the user (this happens in tcp_usrreq.c,
* case PRU_RCVD). If a FIN has already been received on this
* connection then we just ignore the text.
*/
if ((ti->ti_len || (tiflags&TH_FIN)) &&
TCPS_HAVERCVDFIN(tp->t_state) == 0) {
TCP_REASS(tp, ti, m, so, tiflags);
} else {
m_free(m);
tiflags &= ~TH_FIN;
}
/*
* If FIN is received ACK the FIN and let the user know
* that the connection is closing.
*/
if (tiflags & TH_FIN) {
if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
/*
* If we receive a FIN we can't send more data,
* set it SS_FDRAIN
* Shutdown the socket if there is no rx data in the
* buffer.
* soread() is called on completion of shutdown() and
* will got to TCPS_LAST_ACK, and use tcp_output()
* to send the FIN.
*/
sofwdrain(so);
tp->t_flags |= TF_ACKNOW;
tp->rcv_nxt++;
}
switch (tp->t_state) {
/*
* In SYN_RECEIVED and ESTABLISHED STATES
* enter the CLOSE_WAIT state.
*/
case TCPS_SYN_RECEIVED:
case TCPS_ESTABLISHED:
if(so->so_emu == EMU_CTL) /* no shutdown on socket */
tp->t_state = TCPS_LAST_ACK;
else
tp->t_state = TCPS_CLOSE_WAIT;
break;
/*
* If still in FIN_WAIT_1 STATE FIN has not been acked so
* enter the CLOSING state.
*/
case TCPS_FIN_WAIT_1:
tp->t_state = TCPS_CLOSING;
break;
/*
* In FIN_WAIT_2 state enter the TIME_WAIT state,
* starting the time-wait timer, turning off the other
* standard timers.
*/
case TCPS_FIN_WAIT_2:
tp->t_state = TCPS_TIME_WAIT;
tcp_canceltimers(tp);
tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL;
break;
/*
* In TIME_WAIT state restart the 2 MSL time_wait timer.
*/
case TCPS_TIME_WAIT:
tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL;
break;
}
}
/*
* Return any desired output.
*/
if (needoutput || (tp->t_flags & TF_ACKNOW)) {
(void) tcp_output(tp);
}
return;
dropafterack:
/*
* Generate an ACK dropping incoming segment if it occupies
* sequence space, where the ACK reflects our state.
*/
if (tiflags & TH_RST)
goto drop;
m_free(m);
tp->t_flags |= TF_ACKNOW;
(void) tcp_output(tp);
return;
dropwithreset:
/* reuses m if m!=NULL, m_free() unnecessary */
if (tiflags & TH_ACK)
tcp_respond(tp, ti, m, (tcp_seq)0, ti->ti_ack, TH_RST);
else {
if (tiflags & TH_SYN) ti->ti_len++;
tcp_respond(tp, ti, m, ti->ti_seq+ti->ti_len, (tcp_seq)0,
TH_RST|TH_ACK);
}
return;
drop:
/*
* Drop space held by incoming segment and return.
*/
m_free(m);
}
int
tcp_output(struct tcpcb * tp)
{
struct socket * so = tp->t_inpcb->inp_socket;
int len;
long win;
int off, flags, error;
struct mbuf * m;
struct tcpiphdr * ti;
unsigned optlen = 0;
int idle, sendalot;
struct mbuf * sendm; /* mbuf which contains data to send */
struct mbuf * tcp_mbuf; /* mbuf containing TCP header */
int bufoff; /* offset of data in sendm->m_data */
#ifdef TCP_SACK
int sack_resend;
int sack_hole = 0; /* next sack hole to fill */
if(tp->t_flags & TF_SACKREPLY)
{
/* we are resending based on a received SACK header */
sack_resend = TRUE;
tp->t_flags &= ~TF_SACKREPLY; /* clear flag */
}
else
sack_resend = FALSE;
#endif /* TCP_SACK */
/*
* Determine length of data that should be transmitted,
* and flags that will be used.
* If there is some data or critical controls (SYN, RST)
* to send, then transmit; otherwise, investigate further.
*/
idle = (tp->snd_max == tp->snd_una);
again:
sendalot = 0;
off = (int)(tp->snd_nxt - tp->snd_una);
win = (long)tp->snd_wnd; /* set basic send window */
if (win > (long)tp->snd_cwnd) /* see if we need congestion control */
{
win = (int)(tp->snd_cwnd & ~(ALIGN_TYPE-1)); /* keep data aligned */
}
/*
* If in persist timeout with window of 0, send 1 byte.
* Otherwise, if window is small but nonzero
* and timer expired, we will send what we can
* and go to transmit state.
*/
if (tp->t_force)
{
if (win == 0)
win = 1;
else
{
tp->t_timer[TCPT_PERSIST] = 0;
tp->t_rxtshift = 0;
}
}
#ifdef TCP_SACK
/* See if we need to adjust the offset for a sack resend */
if(sack_resend)
{
off = (int)(tp->sack_hole_start[sack_hole] - tp->snd_una);
/* if this hole's already been acked then punt and move to next hole */
if(off < 0)
{
/* clear out the acked hole */
tp->sack_hole_start[sack_hole] = tp->sack_hole_end[sack_hole] = 0;
/* see if we're done with SACK hole list (2 tests) */
if(++sack_hole >= SACK_BLOCKS)
return 0;
if(tp->sack_hole_start[sack_hole] == tp->sack_hole_end[sack_hole])
return 0;
goto again;
}
tp->snd_nxt = tp->sack_hole_start[sack_hole];
len = (int)(tp->sack_hole_end[sack_hole] - tp->sack_hole_start[sack_hole]);
len = (int)MIN(len, (int)win);
}
else
#endif /* TCP_SACK */
{
/* set length of packets which are not sack resends */
len = (int)MIN(so->so_snd.sb_cc, (unsigned)win) - off;
}
flags = tcp_outflags[tp->t_state];
/* See if we need to build TCP options field. This test should be fast. */
#if (defined(TCP_TIMESTAMP) | defined(TCP_SACK))
if((flags & TH_SYN) ||
/* !!!??? (so->so_options & SO_TIMESTAMP) || */
(tp->t_flags & TF_SACKNOW)
)
{
optlen = bld_options(tp, &tcp_optionbuf[optlen], flags, so);
}
#else
/* If other options not defined this build then don't bother to call bld_options() except
* on SYN packets
*/
if(flags & TH_SYN)
{
optlen = bld_options(tp, &tcp_optionbuf[optlen], flags, so);
}
#endif
if (len < 0)
{
/*
* If FIN has been sent but not acked,
* but we haven't been called to retransmit,
* len will be -1. Otherwise, window shrank
* after we sent into it. If window shrank to 0,
* cancel pending retransmit and pull snd_nxt
* back to (closed) window. We will enter persist
* state below. If the window didn't close completely,
* just wait for an ACK.
*/
len = 0;
if (win == 0)
{
tp->t_timer[TCPT_REXMT] = 0;
tp->snd_nxt = tp->snd_una;
}
}
if (len > (int)tp->t_maxseg)
{
len = tp->t_maxseg;
sendalot = 1;
}
#ifdef IP_V4
#ifdef IP_PMTU
{
int pmtu = tp->t_inpcb->inp_pmtu - 40;
if (len > pmtu)
{
len = pmtu - 40;
sendalot = 1;
}
}
#endif /* IP_PMTU */
/* We don't need a pmtu test for IPv6. V6 code limits t_maxseg to
* the Path MTU, so the test above the v4 ifdef above covers us.
*/
#endif /* IP_V4 */
if (SEQ_LT(tp->snd_nxt + len, tp->snd_una + so->so_snd.sb_cc))
flags &= ~TH_FIN;
win = (long)(sbspace(&so->so_rcv));
/*
* If our state indicates that FIN should be sent
* and we have not yet done so, or we're retransmitting the FIN,
* then we need to send.
*/
if ((flags & TH_FIN) &&
(so->so_snd.sb_cc == 0) &&
((tp->t_flags & TF_SENTFIN) == 0 || tp->snd_nxt == tp->snd_una))
{
goto send;
}
/*
* Send if we owe peer an ACK.
*/
if (tp->t_flags & TF_ACKNOW)
goto send;
if (flags & (TH_SYN|TH_RST))
goto send;
if (SEQ_GT(tp->snd_up, tp->snd_una))
goto send;
/*
* Sender silly window avoidance. If connection is idle
* and can send all data, a maximum segment,
* at least a maximum default-size segment do it,
* or are forced, do it; otherwise don't bother.
* If peer's buffer is tiny, then send
* when window is at least half open.
* If retransmitting (possibly after persist timer forced us
* to send into a small window), then must resend.
*/
if (len)
{
if (len == (int)tp->t_maxseg)
goto send;
if ((idle || tp->t_flags & TF_NODELAY) &&
len + off >= (int)so->so_snd.sb_cc)
{
goto send;
}
if (tp->t_force)
goto send;
if (len >= (int)(tp->max_sndwnd / 2))
goto send;
if (SEQ_LT(tp->snd_nxt, tp->snd_max))
goto send;
}
/*
* Compare available window to amount of window
* known to peer (as advertised window less
* next expected input). If the difference is at least two
* max size segments or at least 35% of the maximum possible
* window, then want to send a window update to peer.
*/
if (win > 0)
{
int adv = (int)win - (int)(tp->rcv_adv - tp->rcv_nxt);
if (so->so_rcv.sb_cc == 0 && adv >= (int)(tp->t_maxseg * 2))
goto send;
if (100 * (u_int)adv / so->so_rcv.sb_hiwat >= 35)
goto send;
}
/*
* TCP window updates are not reliable, rather a polling protocol
* using ``persist'' packets is used to insure receipt of window
* updates. The three ``states'' for the output side are:
* idle not doing retransmits or persists
* persisting to move a small or zero window
* (re)transmitting and thereby not persisting
*
* tp->t_timer[TCPT_PERSIST]
* is set when we are in persist state.
* tp->t_force
* is set when we are called to send a persist packet.
* tp->t_timer[TCPT_REXMT]
* is set when we are retransmitting
* The output side is idle when both timers are zero.
*
* If send window is too small, there is data to transmit, and no
* retransmit or persist is pending, then go to persist state.
* If nothing happens soon, send when timer expires:
* if window is nonzero, transmit what we can,
* otherwise force out a byte.
*/
if (so->so_snd.sb_cc && tp->t_timer[TCPT_REXMT] == 0 &&
tp->t_timer[TCPT_PERSIST] == 0)
{
tp->t_rxtshift = 0;
tcp_setpersist(tp);
}
/*
* No reason to send a segment, just return.
*/
return (0);
send:
ENTER_CRIT_SECTION(tp);
/* Limit send length to the current buffer so as to
* avoid doing the "mbuf shuffle" in m_copy().
*/
bufoff = off;
sendm = so->so_snd.sb_mb;
if (len)
{
/* find mbuf containing data to send (at "off") */
while (sendm) /* loop through socket send list */
{
bufoff -= sendm->m_len;
if (bufoff < 0) /* if off is in this buffer, break */
break;
sendm = sendm->m_next;
}
if (!sendm) { dtrap(); /* shouldn't happen */ }
bufoff += sendm->m_len; /* index to next data to send in msend */
/* if socket has multiple unsent mbufs, set flag for send to loop */
if ((sendm->m_next) && (len > (int)sendm->m_len))
{
flags &= ~TH_FIN; /* don't FIN on segment prior to last */
sendalot = 1; /* set to send more segments */
}
if((flags & TH_FIN) && (so->so_snd.sb_cc > (unsigned)len))
{
/* This can happen on slow links (PPP) which retry the last
* segment - the one with the FIN bit attached to data.
*/
flags &= ~TH_FIN; /* don't FIN on segment prior to last */
}
/* only send the rest of msend */
len = min(len, (int)sendm->m_len);
/* if we're not sending starting at sendm->m_data (in which
* case bufoff != 0), then we will copy the data; else we would
* write IP/TCP headers over sent but un-ack'ed data in sendm.
* Similarly, if sendm->m_data is not aligned with respect to
* sendm->m_base and ALIGN_TYPE, we will copy the data to
* ensure that it (and the then-prepended IP/TCP headers) will
* be aligned according to ALIGN_TYPE.
*/
if ((bufoff != 0) || /* data not front aligned in send mbuf? */
(((sendm->m_data - sendm->m_base) & (ALIGN_TYPE - 1)) != 0))
{
len = min(len, (int)(sendm->m_len - bufoff)); /* limit len again */
/* One more test - if this data is not aligned with the front
* of the m_data buffer then we can't use it in place, else we
* might write the IP/TCP header over data that has not yet
* been acked. In this case we must make sure our send
* fits into a little buffer and send what we can.
*/
if ((len > (int)(lilbufsiz - HDRSLEN)) && /* length is bigger the small buffer? */
(bigfreeq.q_len < 2)) /* and we are low on big buffers */
{
len = lilbufsiz - HDRSLEN;
}
}
}
/* if send data is sufficiently aligned in packet, prepend TCP/IP header
* in the space provided.
*/
if (len && (bufoff == 0) &&
(sendm->pkt->inuse == 1) &&
(((sendm->m_data - sendm->m_base) & (ALIGN_TYPE - 1)) == 0) &&
(optlen == 0))
{
/* get an empty mbuf to "clone" the data */
m = m_getnbuf(MT_TXDATA, 0);
if (!m)
{
EXIT_CRIT_SECTION(tp);
return (ENOBUFS);
}
m->pkt = sendm->pkt; /* copy packet location in new mbuf */
m->pkt->inuse++; /* bump packet's use count */
m->m_base = sendm->m_base; /* clone mbuf members */
m->m_memsz = sendm->m_memsz;
m->m_len = len + TCPIPHDRSZ; /* adjust clone for header */
m->m_data = sendm->m_data - TCPIPHDRSZ;
}
else /* either no data or data is not front aligned in mbuf */
{
/* Grab a header mbuf, attaching a copy of data to be
* transmitted, and initialize the header from
* the template for sends on this connection.
*/
m = m_getwithdata (MT_HEADER, IFNETHDR_SIZE + TCPIPHDRSZ);
if (m ==(struct mbuf *)NULL)
{
EXIT_CRIT_SECTION(tp);
return ENOBUFS;
}
m->m_len = TCPIPHDRSZ;
m->m_data += IFNETHDR_SIZE;/* Move this to sizeof tcpip hdr leave*/
/* 14 bytes for ethernet header */
if (len) /* attach any data to send */
{
m->m_next = m_copy(so->so_snd.sb_mb, off, (int) len);
if (m->m_next == 0)
{
m_freem(m);
EXIT_CRIT_SECTION(tp);
return ENOBUFS;
}
}
}
EXIT_CRIT_SECTION(tp);
if (len)
{
if (tp->t_force && len == 1)
tcpstat.tcps_sndprobe++;
else if (SEQ_LT(tp->snd_nxt, tp->snd_max))
{
tcpstat.tcps_sndrexmitpack++;
tcpstat.tcps_sndrexmitbyte += len;
#ifdef TCP_SACK
if(sack_resend)
tcpstat.tcps_sackresend++;
#endif
}
else
{
tcpstat.tcps_sndpack++;
tcpstat.tcps_sndbyte += len;
}
}
else if (tp->t_flags & TF_ACKNOW)
{
tcpstat.tcps_sndacks++;
}
else if (flags & (TH_SYN|TH_FIN|TH_RST))
tcpstat.tcps_sndctrl++;
else if (SEQ_GT(tp->snd_up, tp->snd_una))
tcpstat.tcps_sndurg++;
else
tcpstat.tcps_sndwinup++;
ti = (struct tcpiphdr *)(m->m_data+sizeof(struct ip)-sizeof(struct ipovly));
if ((char *)ti < m->pkt->nb_buff)
{
panic("tcp_out- packet ptr underflow\n");
}
tcp_mbuf = m; /* flag TCP header mbuf */
#ifdef IP_V6 /* Dual mode code */
if(so->so_domain == AF_INET6)
{
m = mbuf_prepend(m, sizeof(struct ipv6));
if(m == NULL)
{
/* this can happen when we run out of mbufs or pkt buffers
* That is, mfreeq is empty or (lilfreeq, bigfreeq) are empty.
* One solution is to find out which one is getting full and
* then increase them.
*/
dtrap(); /* This is really rare... */
m_freem(tcp_mbuf); /* Free TCP/data chain */
return ENOBUFS;
}
/* strip overlay from front of TCP header */
tcp_mbuf->m_data += sizeof(struct ipovly);
tcp_mbuf->m_len -= sizeof(struct ipovly);
}
#endif /* end IP_V6 */
if (tp->t_template == 0)
panic("tcp_output");
MEMCPY((char*)ti, (char*)tp->t_template, sizeof(struct tcpiphdr));
/*
* Fill in fields, remembering maximum advertised
* window for use in delaying messages about window sizes.
* If resending a FIN, be sure not to use a new sequence number.
*/
if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
tp->snd_nxt == tp->snd_max)
{
tp->snd_nxt--;
}
ti->ti_seq = htonl(tp->snd_nxt);
ti->ti_ack = htonl(tp->rcv_nxt);
/*
* If we're sending a SYN, check the IP address of the interface
* that we will (likely) use to send the IP datagram -- if it's
* changed from what is in the template (as it might if this is
* a retransmission, and the original SYN caused PPP to start
* bringing the interface up, and PPP has got a new IP address
* via IPCP), update the template and the inpcb with the new
* address.
*/
if (flags & TH_SYN)
{
struct inpcb * inp;
inp = (struct inpcb *)so->so_pcb;
switch(so->so_domain)
{
#ifdef IP_V4
case AF_INET:
{
ip_addr src;
#ifdef INCLUDE_PPP
if(((flags & TH_ACK) == 0) && /* SYN only, not SYN/ACK */
(inp->ifp) && /* Make sure we have iface */
(inp->ifp->mib.ifType == PPP)) /* only PPP type */
{
dtrap(); /* remove after confirmed to work in PPP */
src = ip_mymach(ti->ti_dst.s_addr);
if (src != ti->ti_src.s_addr)
{
ti->ti_src.s_addr = src;
tp->t_template->ti_src.s_addr = src;
tp->t_inpcb->inp_laddr.s_addr = src;
}
}
#endif /* INCLUDE_PPP */
/* If this is a SYN (not a SYN/ACK) then set the pmtu */
if((flags & TH_ACK) == 0)
{
#ifdef IP_PMTU
inp->inp_pmtu = pmtucache_get(inp->inp_faddr.s_addr);
#else /* not compiled for pathmtu, guess based on iface */
{
NET ifp;
/* find iface for route. Pass "src" as nexthop return */
ifp = iproute(ti->ti_dst.s_addr, &src);
if(ifp)
inp->inp_pmtu = ifp->n_mtu - (ifp->n_lnh + 40);
else
inp->inp_pmtu = 580; /* Ugh. */
}
#endif /* IP_PMTU */
}
break;
}
#endif /* IP_V4 */
#ifdef IP_V6
case AF_INET6:
{
struct ip6_inaddr * local;
local = ip6_myaddr(&tp->t_inpcb->ip6_faddr, inp->ifp);
/* If we got a local address & it's not the one in the pcb, then
* we assume it changed at the iface and fix it in the pcb. Unlike
* v4, we don't have an IP header yet, not do we have a template
* to worry about.
*/
if((local) &&
(!IP6EQ(&local->addr, &tp->t_inpcb->ip6_laddr)))
{
IP6CPY(&tp->t_inpcb->ip6_laddr, &local->addr);
}
/* If this is a SYN (not a SYN/ACK) then set the pmtu */
if((flags & TH_ACK) == 0)
{
inp->inp_pmtu = ip6_pmtulookup(&inp->ip6_laddr, inp->ifp);
}
break;
}
#endif /* IP_V6 */
default:
dtrap(); /* bad domain setting */
}
}
/* fill in options if any are set */
if (optlen)
{
struct mbuf * mopt;
mopt = m_getwithdata(MT_TXDATA, MAXOPTLEN);
if (mopt == NULL)
{
m_freem(m);
return (ENOBUFS);
}
/* insert options mbuf after after tmp_mbuf */
mopt->m_next = tcp_mbuf->m_next;
tcp_mbuf->m_next = mopt;
/* extend options to aligned address */
while(optlen & 0x03)
tcp_optionbuf[optlen++] = TCPOPT_EOL;
MEMCPY(mtod(mopt, char *), tcp_optionbuf, optlen);
mopt->m_len = optlen;
/* use portable macro to set tcp data offset bits */
SET_TH_OFF(ti->ti_t, ((sizeof (struct tcphdr) + optlen) >> 2));
}
ti->ti_flags = (u_char)flags;
/*
* Calculate receive window. Don't shrink window,
* but avoid silly window syndrome.
*/
if (win < (long)(so->so_rcv.sb_hiwat / 4) && win < (long)tp->t_maxseg)
win = 0;
if (win < (long)(tp->rcv_adv - tp->rcv_nxt))
win = (long)(tp->rcv_adv - tp->rcv_nxt);
/* do check for Iniche buffer limits -JB- */
if (bigfreeq.q_len == 0) /* If queue length is 0, set window to 0 */
{
win = 0;
}
else if(win > (((long)bigfreeq.q_len - 1) * (long)bigbufsiz))
{
win = ((long)bigfreeq.q_len - 1) * bigbufsiz;
}
#ifdef TCP_WIN_SCALE
if(tp->t_flags & TF_WINSCALE)
{
ti->ti_win = htons((u_short)(win >> tp->rcv_wind_scale)); /* apply scale */
}
void
natmintr()
{
int s;
struct mbuf *m;
struct socket *so;
struct natmpcb *npcb;
next:
s = splnet();
IF_DEQUEUE(&natmintrq, m);
splx(s);
if (m == NULL)
return;
#ifdef DIAGNOSTIC
if ((m->m_flags & M_PKTHDR) == 0)
panic("natmintr no HDR");
#endif
npcb = (struct natmpcb *) m->m_pkthdr.rcvif; /* XXX: overloaded */
so = npcb->npcb_socket;
s = splnet(); /* could have atm devs @ different levels */
npcb->npcb_inq--;
splx(s);
if (npcb->npcb_flags & NPCB_DRAIN) {
m_freem(m);
if (npcb->npcb_inq == 0)
free(npcb, M_PCB); /* done! */
goto next;
}
if (npcb->npcb_flags & NPCB_FREE) {
m_freem(m); /* drop */
goto next;
}
#ifdef NEED_TO_RESTORE_IFP
m->m_pkthdr.rcvif = npcb->npcb_ifp;
#else
#ifdef DIAGNOSTIC
m->m_pkthdr.rcvif = NULL; /* null it out to be safe */
#endif
#endif
if (sbspace(&so->so_rcv) > m->m_pkthdr.len ||
((npcb->npcb_flags & NPCB_RAW) != 0 && so->so_rcv.sb_cc < NPCB_RAWCC) ) {
#ifdef NATM_STAT
natm_sookcnt++;
natm_sookbytes += m->m_pkthdr.len;
#endif
sbappendrecord(&so->so_rcv, m);
sorwakeup(so);
} else {
#ifdef NATM_STAT
natm_sodropcnt++;
natm_sodropbytes += m->m_pkthdr.len;
#endif
m_freem(m);
}
goto next;
}
/*
* Append address and data, and optionally, control (ancillary) data
* to the receive queue of a socket. If present,
* m0 must include a packet header with total length.
* Returns 0 if no space in sockbuf or insufficient mbufs.
*/
int
sbappendaddr(struct sockbuf *sb, const struct sockaddr *asa, struct mbuf *m0,
struct mbuf *control)
{
struct mbuf *m, *n, *nlast;
int space, len;
KASSERT(solocked(sb->sb_so));
space = asa->sa_len;
if (m0 != NULL) {
if ((m0->m_flags & M_PKTHDR) == 0)
panic("sbappendaddr");
space += m0->m_pkthdr.len;
#ifdef MBUFTRACE
m_claimm(m0, sb->sb_mowner);
#endif
}
for (n = control; n; n = n->m_next) {
space += n->m_len;
MCLAIM(n, sb->sb_mowner);
if (n->m_next == 0) /* keep pointer to last control buf */
break;
}
if (space > sbspace(sb))
return (0);
MGET(m, M_DONTWAIT, MT_SONAME);
if (m == 0)
return (0);
MCLAIM(m, sb->sb_mowner);
/*
* XXX avoid 'comparison always true' warning which isn't easily
* avoided.
*/
len = asa->sa_len;
if (len > MLEN) {
MEXTMALLOC(m, asa->sa_len, M_NOWAIT);
if ((m->m_flags & M_EXT) == 0) {
m_free(m);
return (0);
}
}
m->m_len = asa->sa_len;
memcpy(mtod(m, void *), asa, asa->sa_len);
if (n)
n->m_next = m0; /* concatenate data to control */
else
control = m0;
m->m_next = control;
SBLASTRECORDCHK(sb, "sbappendaddr 1");
for (n = m; n->m_next != NULL; n = n->m_next)
sballoc(sb, n);
sballoc(sb, n);
nlast = n;
SBLINKRECORD(sb, m);
sb->sb_mbtail = nlast;
SBLASTMBUFCHK(sb, "sbappendaddr");
SBLASTRECORDCHK(sb, "sbappendaddr 2");
return (1);
}
int
sbappendaddrchain(struct sockbuf *sb, const struct sockaddr *asa,
struct mbuf *m0, int sbprio)
{
int space;
struct mbuf *m, *n, *n0, *nlast;
int error;
KASSERT(solocked(sb->sb_so));
/*
* XXX sbprio reserved for encoding priority of this* request:
* SB_PRIO_NONE --> honour normal sb limits
* SB_PRIO_ONESHOT_OVERFLOW --> if socket has any space,
* take whole chain. Intended for large requests
* that should be delivered atomically (all, or none).
* SB_PRIO_OVERDRAFT -- allow a small (2*MLEN) overflow
* over normal socket limits, for messages indicating
* buffer overflow in earlier normal/lower-priority messages
* SB_PRIO_BESTEFFORT --> ignore limits entirely.
* Intended for kernel-generated messages only.
* Up to generator to avoid total mbuf resource exhaustion.
*/
(void)sbprio;
if (m0 && (m0->m_flags & M_PKTHDR) == 0)
panic("sbappendaddrchain");
space = sbspace(sb);
#ifdef notyet
/*
* Enforce SB_PRIO_* limits as described above.
*/
#endif
n0 = NULL;
nlast = NULL;
for (m = m0; m; m = m->m_nextpkt) {
struct mbuf *np;
#ifdef MBUFTRACE
m_claimm(m, sb->sb_mowner);
#endif
/* Prepend sockaddr to this record (m) of input chain m0 */
n = m_prepend_sockaddr(sb, m, asa);
if (n == NULL) {
error = ENOBUFS;
goto bad;
}
/* Append record (asa+m) to end of new chain n0 */
if (n0 == NULL) {
n0 = n;
} else {
nlast->m_nextpkt = n;
}
/* Keep track of last record on new chain */
nlast = n;
for (np = n; np; np = np->m_next)
sballoc(sb, np);
}
SBLASTRECORDCHK(sb, "sbappendaddrchain 1");
/* Drop the entire chain of (asa+m) records onto the socket */
SBLINKRECORDCHAIN(sb, n0, nlast);
SBLASTRECORDCHK(sb, "sbappendaddrchain 2");
for (m = nlast; m->m_next; m = m->m_next)
;
sb->sb_mbtail = m;
SBLASTMBUFCHK(sb, "sbappendaddrchain");
return (1);
bad:
/*
* On error, free the prepended addreseses. For consistency
* with sbappendaddr(), leave it to our caller to free
* the input record chain passed to us as m0.
*/
while ((n = n0) != NULL) {
struct mbuf *np;
/* Undo the sballoc() of this record */
for (np = n; np; np = np->m_next)
sbfree(sb, np);
n0 = n->m_nextpkt; /* iterate at next prepended address */
MFREE(n, np); /* free prepended address (not data) */
}
return 0;
}
int
sosend(struct socket *so,
struct mbuf *nam, /* sockaddr, if UDP socket, NULL if TCP */
char *data, /* data to send */
int *data_length, /* IN/OUT length of (remaining) data */
int flags)
{
struct mbuf *head = (struct mbuf *)NULL;
struct mbuf *m;
int space;
int resid;
int len;
int error = 0;
int dontroute;
int first = 1;
resid = *data_length;
/*
* In theory resid should be unsigned.
* However, space must be signed, as it might be less than 0
* if we over-committed, and we must use a signed comparison
* of space and resid. On the other hand, a negative resid
* causes us to loop sending 0-length segments to the protocol.
*/
if (resid < 0)
return (EINVAL);
INET_TRACE (INETM_IO, ("INET:sosend: so %lx resid %d sb_hiwat %d so_state %x\n",
so, resid, so->so_snd.sb_hiwat, so->so_state));
if (sosendallatonce(so) && (resid > (int)so->so_snd.sb_hiwat))
return (EMSGSIZE);
dontroute = (flags & MSG_DONTROUTE) &&
((so->so_options & SO_DONTROUTE) == 0) &&
(so->so_proto->pr_flags & PR_ATOMIC);
#define snderr(errno) { error = errno; goto release; }
restart:
sblock(&so->so_snd);
do
{
if (so->so_error)
{
error = so->so_error;
so->so_error = 0; /* ??? */
goto release;
}
if (so->so_state & SS_CANTSENDMORE)
snderr(EPIPE);
if ((so->so_state & SS_ISCONNECTED) == 0)
{
if (so->so_proto->pr_flags & PR_CONNREQUIRED)
snderr(ENOTCONN);
if (nam == 0)
snderr(EDESTADDRREQ);
}
if (flags & MSG_OOB)
space = 1024;
else
{
space = (int)sbspace(&so->so_snd);
if ((sosendallatonce(so) && (space < resid)) ||
((resid >= CLBYTES) && (space < CLBYTES) &&
(so->so_snd.sb_cc >= CLBYTES) &&
((so->so_state & SS_NBIO) == 0) &&
((flags & MSG_DONTWAIT) == 0)))
{
if ((so->so_state & SS_NBIO) || (flags & MSG_DONTWAIT))
{
if (first)
error = EWOULDBLOCK;
goto release;
}
sbunlock(&so->so_snd);
sbwait(&so->so_snd);
goto restart;
}
}
if ( space <= 0 )
{
/* no space in socket send buffer - see if we can wait */
if ((so->so_state & SS_NBIO) || (flags & MSG_DONTWAIT))
{
if (first) /* report first error */
error = EWOULDBLOCK;
goto release;
}
/* If blocking socket, let someone else run */
sbunlock(&so->so_snd);
sbwait(&so->so_snd);
goto restart;
}
while (space > 0)
{
len = resid;
if ( so->so_type == SOCK_STREAM )
{
m = m_getwithdata(MT_TXDATA, len);
if (!m)
snderr(ENOBUFS);
MEMCPY(m->m_data, data, len);
so->so_snd.sb_flags |= SB_MBCOMP; /* allow compression */
}
else
{
m = m_get (M_WAIT, MT_TXDATA);
m->m_data = data;
}
INET_TRACE (INETM_IO,
("sosend:got %d bytes so %lx mlen %d, off %d mtod %x\n",
len, so, m->m_len, m->m_off, mtod (m, caddr_t)));
*data_length -= len;
resid -= len;
data += len;
m->m_len = len;
if (head == (struct mbuf *)NULL)
head = m;
if (error)
goto release;
if (*data_length <= 0)
break;
}
if (dontroute)
so->so_options |= SO_DONTROUTE;
so->so_req = (flags & MSG_OOB) ? PRU_SENDOOB : PRU_SEND;
error = (*so->so_proto->pr_usrreq)(so, head, nam);
if (dontroute)
so->so_options &= ~SO_DONTROUTE;
head = (struct mbuf *)NULL;
first = 0;
} while ((resid != 0) && (error == 0));
release:
sbunlock(&so->so_snd);
if (head)
m_freem(head);
return error;
}
/*
* User Request.
* up is socket
* m is either
* optional mbuf chain containing message
* ioctl command (PRU_CONTROL)
* nam is either
* optional mbuf chain containing an address
* ioctl data (PRU_CONTROL)
* optionally protocol number (PRU_ATTACH)
* message flags (PRU_RCVD)
* ctl is either
* optional mbuf chain containing socket options
* optional interface pointer (PRU_CONTROL, PRU_PURGEIF)
* l is pointer to process requesting action (if any)
*
* we are responsible for disposing of m and ctl if
* they are mbuf chains
*/
int
rfcomm_usrreq(struct socket *up, int req, struct mbuf *m,
struct mbuf *nam, struct mbuf *ctl, struct lwp *l)
{
struct rfcomm_dlc *pcb = up->so_pcb;
struct sockaddr_bt *sa;
struct mbuf *m0;
int err = 0;
DPRINTFN(2, "%s\n", prurequests[req]);
switch (req) {
case PRU_CONTROL:
return EPASSTHROUGH;
case PRU_PURGEIF:
return EOPNOTSUPP;
case PRU_ATTACH:
if (up->so_lock == NULL) {
mutex_obj_hold(bt_lock);
up->so_lock = bt_lock;
solock(up);
}
KASSERT(solocked(up));
if (pcb != NULL)
return EINVAL;
/*
* Since we have nothing to add, we attach the DLC
* structure directly to our PCB pointer.
*/
err = soreserve(up, rfcomm_sendspace, rfcomm_recvspace);
if (err)
return err;
err = rfcomm_attach((struct rfcomm_dlc **)&up->so_pcb,
&rfcomm_proto, up);
if (err)
return err;
err = rfcomm_rcvd(up->so_pcb, sbspace(&up->so_rcv));
if (err) {
rfcomm_detach((struct rfcomm_dlc **)&up->so_pcb);
return err;
}
return 0;
}
if (pcb == NULL) {
err = EINVAL;
goto release;
}
switch(req) {
case PRU_DISCONNECT:
soisdisconnecting(up);
return rfcomm_disconnect(pcb, up->so_linger);
case PRU_ABORT:
rfcomm_disconnect(pcb, 0);
soisdisconnected(up);
/* fall through to */
case PRU_DETACH:
return rfcomm_detach((struct rfcomm_dlc **)&up->so_pcb);
case PRU_BIND:
KASSERT(nam != NULL);
sa = mtod(nam, struct sockaddr_bt *);
if (sa->bt_len != sizeof(struct sockaddr_bt))
return EINVAL;
if (sa->bt_family != AF_BLUETOOTH)
return EAFNOSUPPORT;
return rfcomm_bind(pcb, sa);
case PRU_CONNECT:
KASSERT(nam != NULL);
sa = mtod(nam, struct sockaddr_bt *);
if (sa->bt_len != sizeof(struct sockaddr_bt))
return EINVAL;
if (sa->bt_family != AF_BLUETOOTH)
return EAFNOSUPPORT;
soisconnecting(up);
return rfcomm_connect(pcb, sa);
case PRU_PEERADDR:
KASSERT(nam != NULL);
sa = mtod(nam, struct sockaddr_bt *);
nam->m_len = sizeof(struct sockaddr_bt);
return rfcomm_peeraddr(pcb, sa);
case PRU_SOCKADDR:
KASSERT(nam != NULL);
sa = mtod(nam, struct sockaddr_bt *);
nam->m_len = sizeof(struct sockaddr_bt);
return rfcomm_sockaddr(pcb, sa);
case PRU_SHUTDOWN:
socantsendmore(up);
break;
case PRU_SEND:
KASSERT(m != NULL);
if (ctl) /* no use for that */
m_freem(ctl);
m0 = m_copypacket(m, M_DONTWAIT);
if (m0 == NULL)
return ENOMEM;
sbappendstream(&up->so_snd, m);
return rfcomm_send(pcb, m0);
case PRU_SENSE:
return 0; /* (no release) */
case PRU_RCVD:
return rfcomm_rcvd(pcb, sbspace(&up->so_rcv));
case PRU_RCVOOB:
return EOPNOTSUPP; /* (no release) */
case PRU_LISTEN:
return rfcomm_listen(pcb);
case PRU_ACCEPT:
KASSERT(nam != NULL);
sa = mtod(nam, struct sockaddr_bt *);
nam->m_len = sizeof(struct sockaddr_bt);
return rfcomm_peeraddr(pcb, sa);
case PRU_CONNECT2:
case PRU_SENDOOB:
case PRU_FASTTIMO:
case PRU_SLOWTIMO:
case PRU_PROTORCV:
case PRU_PROTOSEND:
err = EOPNOTSUPP;
break;
default:
UNKNOWN(req);
err = EOPNOTSUPP;
break;
}
release:
if (m) m_freem(m);
if (ctl) m_freem(ctl);
return err;
}
static int
soo_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *active_cred,
struct thread *td)
{
struct socket *so = fp->f_data;
int error = 0;
switch (cmd) {
case FIONBIO:
SOCK_LOCK(so);
if (*(int *)data)
so->so_state |= SS_NBIO;
else
so->so_state &= ~SS_NBIO;
SOCK_UNLOCK(so);
break;
case FIOASYNC:
/*
* XXXRW: This code separately acquires SOCK_LOCK(so) and
* SOCKBUF_LOCK(&so->so_rcv) even though they are the same
* mutex to avoid introducing the assumption that they are
* the same.
*/
if (*(int *)data) {
SOCK_LOCK(so);
so->so_state |= SS_ASYNC;
SOCK_UNLOCK(so);
SOCKBUF_LOCK(&so->so_rcv);
so->so_rcv.sb_flags |= SB_ASYNC;
SOCKBUF_UNLOCK(&so->so_rcv);
SOCKBUF_LOCK(&so->so_snd);
so->so_snd.sb_flags |= SB_ASYNC;
SOCKBUF_UNLOCK(&so->so_snd);
} else {
SOCK_LOCK(so);
so->so_state &= ~SS_ASYNC;
SOCK_UNLOCK(so);
SOCKBUF_LOCK(&so->so_rcv);
so->so_rcv.sb_flags &= ~SB_ASYNC;
SOCKBUF_UNLOCK(&so->so_rcv);
SOCKBUF_LOCK(&so->so_snd);
so->so_snd.sb_flags &= ~SB_ASYNC;
SOCKBUF_UNLOCK(&so->so_snd);
}
break;
case FIONREAD:
/* Unlocked read. */
*(int *)data = sbavail(&so->so_rcv);
break;
case FIONWRITE:
/* Unlocked read. */
*(int *)data = sbavail(&so->so_snd);
break;
case FIONSPACE:
/* Unlocked read. */
if ((so->so_snd.sb_hiwat < sbused(&so->so_snd)) ||
(so->so_snd.sb_mbmax < so->so_snd.sb_mbcnt))
*(int *)data = 0;
else
*(int *)data = sbspace(&so->so_snd);
break;
case FIOSETOWN:
error = fsetown(*(int *)data, &so->so_sigio);
break;
case FIOGETOWN:
*(int *)data = fgetown(&so->so_sigio);
break;
case SIOCSPGRP:
error = fsetown(-(*(int *)data), &so->so_sigio);
break;
case SIOCGPGRP:
*(int *)data = -fgetown(&so->so_sigio);
break;
case SIOCATMARK:
/* Unlocked read. */
*(int *)data = (so->so_rcv.sb_state & SBS_RCVATMARK) != 0;
break;
default:
/*
* Interface/routing/protocol specific ioctls: interface and
* routing ioctls should have a different entry since a
* socket is unnecessary.
*/
if (IOCGROUP(cmd) == 'i')
error = ifioctl(so, cmd, data, td);
else if (IOCGROUP(cmd) == 'r') {
CURVNET_SET(so->so_vnet);
error = rtioctl_fib(cmd, data, so->so_fibnum);
CURVNET_RESTORE();
} else {
CURVNET_SET(so->so_vnet);
error = ((*so->so_proto->pr_usrreqs->pru_control)
(so, cmd, data, 0, td));
CURVNET_RESTORE();
}
break;
}
return (error);
}
static int
handle_ddp_data(struct toepcb *toep, __be32 ddp_report, __be32 rcv_nxt, int len)
{
uint32_t report = be32toh(ddp_report);
unsigned int db_flag;
struct inpcb *inp = toep->inp;
struct tcpcb *tp;
struct socket *so;
struct sockbuf *sb;
struct mbuf *m;
db_flag = report & F_DDP_BUF_IDX ? DDP_BUF1_ACTIVE : DDP_BUF0_ACTIVE;
if (__predict_false(!(report & F_DDP_INV)))
CXGBE_UNIMPLEMENTED("DDP buffer still valid");
INP_WLOCK(inp);
so = inp_inpcbtosocket(inp);
sb = &so->so_rcv;
if (__predict_false(inp->inp_flags & (INP_DROPPED | INP_TIMEWAIT))) {
/*
* XXX: think a bit more.
* tcpcb probably gone, but socket should still be around
* because we always wait for DDP completion in soreceive no
* matter what. Just wake it up and let it clean up.
*/
CTR5(KTR_CXGBE, "%s: tid %u, seq 0x%x, len %d, inp_flags 0x%x",
__func__, toep->tid, be32toh(rcv_nxt), len, inp->inp_flags);
SOCKBUF_LOCK(sb);
goto wakeup;
}
tp = intotcpcb(inp);
len += be32toh(rcv_nxt) - tp->rcv_nxt;
tp->rcv_nxt += len;
tp->t_rcvtime = ticks;
#ifndef USE_DDP_RX_FLOW_CONTROL
KASSERT(tp->rcv_wnd >= len, ("%s: negative window size", __func__));
tp->rcv_wnd -= len;
#endif
m = get_ddp_mbuf(len);
SOCKBUF_LOCK(sb);
if (report & F_DDP_BUF_COMPLETE)
toep->ddp_score = DDP_HIGH_SCORE;
else
discourage_ddp(toep);
/* receive buffer autosize */
if (sb->sb_flags & SB_AUTOSIZE &&
V_tcp_do_autorcvbuf &&
sb->sb_hiwat < V_tcp_autorcvbuf_max &&
len > (sbspace(sb) / 8 * 7)) {
unsigned int hiwat = sb->sb_hiwat;
unsigned int newsize = min(hiwat + V_tcp_autorcvbuf_inc,
V_tcp_autorcvbuf_max);
if (!sbreserve_locked(sb, newsize, so, NULL))
sb->sb_flags &= ~SB_AUTOSIZE;
else
toep->rx_credits += newsize - hiwat;
}
KASSERT(toep->sb_cc >= sbused(sb),
("%s: sb %p has more data (%d) than last time (%d).",
__func__, sb, sbused(sb), toep->sb_cc));
toep->rx_credits += toep->sb_cc - sbused(sb);
#ifdef USE_DDP_RX_FLOW_CONTROL
toep->rx_credits -= len; /* adjust for F_RX_FC_DDP */
#endif
sbappendstream_locked(sb, m, 0);
toep->sb_cc = sbused(sb);
wakeup:
KASSERT(toep->ddp_flags & db_flag,
("%s: DDP buffer not active. toep %p, ddp_flags 0x%x, report 0x%x",
__func__, toep, toep->ddp_flags, report));
toep->ddp_flags &= ~db_flag;
sorwakeup_locked(so);
SOCKBUF_UNLOCK_ASSERT(sb);
INP_WUNLOCK(inp);
return (0);
}
void
tcp_respond(struct tcpcb *tp,
struct tcpiphdr *ti,
tcp_seq ack,
tcp_seq seq,
int flags,
struct mbuf *ti_mbuf)
{
int tlen; /* tcp data len - 0 or 1 */
int domain; /* AF_INET or AF_INET6 */
int win = 0; /* window to use in sent packet */
struct mbuf *m; /* mbuf to send */
struct tcpiphdr *tmp_thdr; /* scratch */
if (tp)
win = (int)sbspace(&tp->t_inpcb->inp_socket->so_rcv);
/* Figure out of we can recycle the passed buffer or if we need a
* new one. Construct the easy parts of the the TCP and IP headers.
*/
if (flags == 0) /* sending keepalive from timer */
{
/* no flags == need a new buffer */
m = m_getwithdata (MT_HEADER, HDRSLEN);
if (m == NULL)
return;
tlen = 1; /* Keepalives have one byte of data */
m->m_len = TCPIPHDRSZ + tlen;
/*
* Copy template contents into the mbuf and set ti to point
* to the header structure in the mbuf.
*/
tmp_thdr = (struct tcpiphdr *)((char *)m->m_data + sizeof(struct ip)
- sizeof(struct ipovly));
if ((char *)tmp_thdr < m->pkt->nb_buff)
{
panic("tcp_respond- packet ptr underflow\n");
}
MEMCPY(tmp_thdr, ti, sizeof(struct tcpiphdr));
ti = tmp_thdr;
flags = TH_ACK;
domain = tp->t_inpcb->inp_socket->so_domain;
}
else /* Flag was passed (e.g. reset); recycle passed mbuf */
{
m = ti_mbuf; /*dtom(ti);*/
if (m->pkt->type == IPTP) /* IPv4 packet */
domain = AF_INET;
else
domain = AF_INET6;
M_FREEM(m->m_next);
m->m_next = 0;
tlen = 0; /* NO data */
m->m_len = TCPIPHDRSZ;
xchg(ti->ti_dport, ti->ti_sport, u_short);
if (m->pkt->type == IPTP)
xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, u_long);
if (flags & TH_RST) /* count resets in MIB */
TCP_MIB_INC(tcpOutRsts); /* keep MIB stats */
}
/* finish constructing the TCP header */
ti->ti_seq = htonl(seq);
ti->ti_ack = htonl(ack);
ti->ti_t.th_doff = 0x50; /* NetPort: init data offset bits */
ti->ti_flags = (u_char)flags;
ti->ti_win = htons((u_short)win);
ti->ti_urp = 0;
ti->ti_t.th_sum = 0;
/* Finish constructing IP header and send, based on IP type in use */
switch(domain)
{
#ifdef IP_V4
case AF_INET:
{
struct ip *pip;
pip = (struct ip *)((char *)ti + sizeof(struct ipovly)
- sizeof(struct ip));
m->pkt->nb_tlen = m->pkt->nb_plen = pip->ip_len = (unshort)(TCPIPHDRSZ + tlen);
/* If our system's max. MAC header size is geater than the size
* of the MAC header in the received packet then we need to
* adjust the IP header offset to allow for this. Since the packets
* are only headers they should always fit.
*/
if (pip >= (struct ip *)(m->pkt->nb_buff + MaxLnh))
{
/* headers will fit, just set pointer */
m->m_data = m->pkt->nb_prot = (char *)pip;
}
else /* MAC may not fit, adjust pointer and move headers back */
{
m->m_data = m->pkt->nb_prot = m->pkt->nb_buff + MaxLnh; /* new ptr */
MEMMOVE(m->m_data, pip, TCPIPHDRSZ); /* move back tcp/ip headers */
}
#ifdef DOS_SYN
if (!tp)
{
/* In the case of a SYN DOS attack, many RST|ACK replies
* have no tp structure and need to be freed.
*/
M_FREEM(m);
}
else
#endif
{
struct ip_socopts *sopts;
int ret;
if (tp && tp->t_inpcb && tp->t_inpcb->inp_socket)
{
sopts = tp->t_inpcb->inp_socket->so_optsPack;
}
else
sopts = (struct ip_socopts *)NULL;
ret = ip_output(m, sopts);
}
break;
}
#endif /* IP_V4 */
#ifdef IP_V6
case AF_INET6:
{
struct ipv6 * pip6;
struct mbuf * ip_m; /* IP header's mbuf */
/* Get mbuf space for the IP header. mbuf m shold contain the
* TCP header somewhere, so set m_dsata to that and try to prepend
* an IPv6 header.
*/
m->m_data = (char *)&ti->ti_t; /* TCP header */
m->m_len = sizeof(struct tcphdr);
ip_m = mbuf_prepend(m, sizeof(struct ipv6));
if (!ip_m)
{
m_free(m);
return;
}
pip6 = (struct ipv6 *)ip_m->m_data;
/* we have to find the IPv6 addresses. If a packet was passed
* then get them form that, otherwise get them from the passed tp.
* we should always have one or the other.
*/
if (ti_mbuf)
{
ip6_addr tmp;
struct ipv6 *inpip = ti_mbuf->pkt->ip6_hdr;
/* pip6 and inpip may be the same, so swap the IP addresses
* through a tmp variable.
*/
IP6CPY(&tmp, &inpip->ip_src);
IP6CPY(&pip6->ip_src, &inpip->ip_dest);
IP6CPY(&pip6->ip_dest, &tmp);
}
else if (tp)
{
struct inpcb *inp = tp->t_inpcb;
IP6CPY(&pip6->ip_src, &inp->ip6_laddr);
IP6CPY(&pip6->ip_dest, &inp->ip6_faddr);
}
else
{
dtrap();
break;
}
/* best effort send */
/* send down to glue layer to IPv6 */
/* and don't forget the so_optsPack */
#ifdef DOS_SYN
if (!tp)
{
/* In the case of a SYN DOS attack, many RST|ACK replies
* have no tp structure and need to be freed.
*/
M_FREEM(m);
}
else
#endif /* DOS_SYN */
{
struct ip_socopts *sopts;
int ret;
if (tp && tp->t_inpcb && tp->t_inpcb->inp_socket)
sopts = tp->t_inpcb->inp_socket->so_optsPack;
else
sopts = (struct ip_socopts *)NULL;
ret = tcp6_send(tp, ip_m, &ti->ti_t,
sizeof(struct ipv6) + sizeof(struct tcphdr) + tlen,
sopts);
}
break;
}
#endif /* IP_V6 */
default:
dtrap();
break;
}
return;
}
/*
* Do a send by putting data in output queue and updating urgent
* marker if URG set. Possibly send more data. Unlike the other
* pru_*() routines, the mbuf chains are our responsibility. We
* must either enqueue them or free them. The other pru_* routines
* generally are caller-frees.
*/
static int
tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
struct sockaddr *nam, struct mbuf *control, struct proc *p)
{
int s = splnet();
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp;
#ifdef INET6
int isipv6;
#endif
TCPDEBUG0;
if (inp == NULL) {
/*
* OOPS! we lost a race, the TCP session got reset after
* we checked SS_CANTSENDMORE, eg: while doing uiomove or a
* network interrupt in the non-splnet() section of sosend().
*/
if (m)
m_freem(m);
if (control)
m_freem(control);
error = ECONNRESET; /* XXX EPIPE? */
tp = NULL;
TCPDEBUG1();
goto out;
}
#ifdef INET6
isipv6 = nam && nam->sa_family == AF_INET6;
#endif /* INET6 */
tp = intotcpcb(inp);
TCPDEBUG1();
if (control) {
/* TCP doesn't do control messages (rights, creds, etc) */
if (control->m_len) {
m_freem(control);
if (m)
m_freem(m);
error = EINVAL;
goto out;
}
m_freem(control); /* empty control, just free it */
}
if(!(flags & PRUS_OOB)) {
sbappend(&so->so_snd, m);
if (nam && tp->t_state < TCPS_SYN_SENT) {
/*
* Do implied connect if not yet connected,
* initialize window to default value, and
* initialize maxseg/maxopd using peer's cached
* MSS.
*/
#ifdef INET6
if (isipv6)
error = tcp6_connect(tp, nam, p);
else
#endif /* INET6 */
error = tcp_connect(tp, nam, p);
if (error)
goto out;
tp->snd_wnd = TTCP_CLIENT_SND_WND;
tcp_mss(tp, -1);
}
if (flags & PRUS_EOF) {
/*
* Close the send side of the connection after
* the data is sent.
*/
socantsendmore(so);
tp = tcp_usrclosed(tp);
}
if (tp != NULL) {
if (flags & PRUS_MORETOCOME)
tp->t_flags |= TF_MORETOCOME;
error = tcp_output(tp);
if (flags & PRUS_MORETOCOME)
tp->t_flags &= ~TF_MORETOCOME;
}
} else {
if (sbspace(&so->so_snd) < -512) {
m_freem(m);
error = ENOBUFS;
goto out;
}
/*
* According to RFC961 (Assigned Protocols),
* the urgent pointer points to the last octet
* of urgent data. We continue, however,
* to consider it to indicate the first octet
* of data past the urgent section.
* Otherwise, snd_up should be one lower.
*/
sbappend(&so->so_snd, m);
if (nam && tp->t_state < TCPS_SYN_SENT) {
/*
* Do implied connect if not yet connected,
* initialize window to default value, and
* initialize maxseg/maxopd using peer's cached
* MSS.
*/
#ifdef INET6
if (isipv6)
error = tcp6_connect(tp, nam, p);
else
#endif /* INET6 */
error = tcp_connect(tp, nam, p);
if (error)
goto out;
tp->snd_wnd = TTCP_CLIENT_SND_WND;
tcp_mss(tp, -1);
}
tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
tp->t_force = 1;
error = tcp_output(tp);
tp->t_force = 0;
}
COMMON_END((flags & PRUS_OOB) ? PRU_SENDOOB :
((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
}
/*
* TCP input routine, follows pages 65-76 of the
* protocol specification dated September, 1981 very closely.
*/
void
tcp_input(usn_mbuf_t *m, int iphlen)
{
struct tcpiphdr *ti;
struct inpcb *inp;
u_char *optp = NULL;
int optlen;
int len, tlen, off;
struct tcpcb *tp = 0;
int tiflags;
struct usn_socket *so = 0;
int todrop, acked, ourfinisacked;
int needoutput = 0;
short ostate;
struct usn_in_addr laddr;
int dropsocket = 0;
int iss = 0;
u_long tiwin, ts_val, ts_ecr;
int ts_present = 0;
(void)needoutput;
g_tcpstat.tcps_rcvtotal++;
// Get IP and TCP header together in first mbuf.
// Note: IP leaves IP header in first mbuf.
ti = mtod(m, struct tcpiphdr *);
if (iphlen > sizeof (usn_ip_t))
ip_stripoptions(m, (usn_mbuf_t *)0);
if (m->mlen < sizeof (struct tcpiphdr)) {
if ((m = m_pullup(m, sizeof (struct tcpiphdr))) == 0) {
g_tcpstat.tcps_rcvshort++;
return;
}
ti = mtod(m, struct tcpiphdr *);
}
#ifdef DUMP_PAYLOAD
dump_chain(m,"tcp");
#endif
/*
* Checksum extended TCP header and data.
*/
tlen = ntohs(((usn_ip_t *)ti)->ip_len);
len = sizeof (usn_ip_t) + tlen;
ti->ti_next = ti->ti_prev = 0;
ti->ti_x1 = 0;
ti->ti_len = (u_short)tlen;
HTONS(ti->ti_len);
ti->ti_sum = in_cksum(m, len);
if (ti->ti_sum) {
g_tcpstat.tcps_rcvbadsum++;
goto drop;
}
/*
* Check that TCP offset makes sense,
* pull out TCP options and adjust length. XXX
*/
off = ti->ti_off << 2;
if (off < sizeof (struct tcphdr) || off > tlen) {
g_tcpstat.tcps_rcvbadoff++;
goto drop;
}
tlen -= off;
ti->ti_len = tlen;
if (off > sizeof (struct tcphdr)) {
if (m->mlen < sizeof(usn_ip_t) + off) {
if ((m = m_pullup(m, sizeof (usn_ip_t) + off)) == 0) {
g_tcpstat.tcps_rcvshort++;
return;
}
ti = mtod(m, struct tcpiphdr *);
}
optlen = off - sizeof (struct tcphdr);
optp = mtod(m, u_char *) + sizeof (struct tcpiphdr);
// Do quick retrieval of timestamp options ("options
// prediction?"). If timestamp is the only option and it's
// formatted as recommended in RFC 1323 appendix A, we
// quickly get the values now and not bother calling
// tcp_dooptions(), etc.
if ((optlen == TCPOLEN_TSTAMP_APPA ||
(optlen > TCPOLEN_TSTAMP_APPA &&
optp[TCPOLEN_TSTAMP_APPA] == TCPOPT_EOL)) &&
*(u_int *)optp == htonl(TCPOPT_TSTAMP_HDR) &&
(ti->ti_flags & TH_SYN) == 0) {
ts_present = 1;
ts_val = ntohl(*(u_long *)(optp + 4));
ts_ecr = ntohl(*(u_long *)(optp + 8));
optp = NULL; // we've parsed the options
}
}
tiflags = ti->ti_flags;
// Convert TCP protocol specific fields to host format.
NTOHL(ti->ti_seq);
NTOHL(ti->ti_ack);
NTOHS(ti->ti_win);
NTOHS(ti->ti_urp);
// Locate pcb for segment.
findpcb:
inp = g_tcp_last_inpcb;
if (inp->inp_lport != ti->ti_dport ||
inp->inp_fport != ti->ti_sport ||
inp->inp_faddr.s_addr != ti->ti_src.s_addr ||
inp->inp_laddr.s_addr != ti->ti_dst.s_addr) {
inp = in_pcblookup(&g_tcb, ti->ti_src, ti->ti_sport,
ti->ti_dst, ti->ti_dport, INPLOOKUP_WILDCARD);
if (inp)
g_tcp_last_inpcb = inp;
++g_tcpstat.tcps_pcbcachemiss;
}
// If the state is CLOSED (i.e., TCB does not exist) then
// all data in the incoming segment is discarded.
// If the TCB exists but is in CLOSED state, it is embryonic,
// but should either do a listen or a connect soon.
if (inp == 0)
goto dropwithreset;
tp = intotcpcb(inp);
DEBUG("found inp cb, laddr=%x, lport=%d, faddr=%x,"
" fport=%d, tp_state=%d, tp_flags=%d",
inp->inp_laddr.s_addr,
inp->inp_lport,
inp->inp_faddr.s_addr,
inp->inp_fport, tp->t_state, tp->t_flags);
if (tp == 0)
goto dropwithreset;
if (tp->t_state == TCPS_CLOSED)
goto drop;
// Unscale the window into a 32-bit value.
if ((tiflags & TH_SYN) == 0)
tiwin = ti->ti_win << tp->snd_scale;
else
tiwin = ti->ti_win;
so = inp->inp_socket;
DEBUG("socket info, options=%x", so->so_options);
if (so->so_options & (SO_DEBUG|SO_ACCEPTCONN)) {
if (so->so_options & SO_DEBUG) {
ostate = tp->t_state;
g_tcp_saveti = *ti;
}
if (so->so_options & SO_ACCEPTCONN) {
if ((tiflags & (TH_RST|TH_ACK|TH_SYN)) != TH_SYN) {
// Note: dropwithreset makes sure we don't
// send a reset in response to a RST.
if (tiflags & TH_ACK) {
g_tcpstat.tcps_badsyn++;
goto dropwithreset;
}
DEBUG("SYN is expected, tiflags=%d", tiflags);
goto drop;
}
so = sonewconn(so, 0);
if (so == 0) {
DEBUG("failed to create new connection, tiflags=%d", tiflags);
goto drop;
}
// Mark socket as temporary until we're
// committed to keeping it. The code at
// ``drop'' and ``dropwithreset'' check the
// flag dropsocket to see if the temporary
// socket created here should be discarded.
// We mark the socket as discardable until
// we're committed to it below in TCPS_LISTEN.
dropsocket++;
inp = (struct inpcb *)so->so_pcb;
inp->inp_laddr = ti->ti_dst;
inp->inp_lport = ti->ti_dport;
// BSD >= 4.3
inp->inp_options = ip_srcroute();
tp = intotcpcb(inp);
tp->t_state = TCPS_LISTEN;
// Compute proper scaling value from buffer space
while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
TCP_MAXWIN << tp->request_r_scale < so->so_rcv->sb_hiwat)
tp->request_r_scale++;
}
}
// Segment received on connection.
// Reset idle time and keep-alive timer.
tp->t_idle = 0;
tp->t_timer[TCPT_KEEP] = g_tcp_keepidle;
// Process options if not in LISTEN state,
// else do it below (after getting remote address).
if (optp && tp->t_state != TCPS_LISTEN)
tcp_dooptions(tp, optp, optlen, ti,
&ts_present, &ts_val, &ts_ecr);
// Header prediction: check for the two common cases
// of a uni-directional data xfer. If the packet has
// no control flags, is in-sequence, the window didn't
// change and we're not retransmitting, it's a
// candidate. If the length is zero and the ack moved
// forward, we're the sender side of the xfer. Just
// free the data acked & wake any higher level process
// that was blocked waiting for space. If the length
// is non-zero and the ack didn't move, we're the
// receiver side. If we're getting packets in-order
// (the reassembly queue is empty), add the data to
// the socket buffer and note that we need a delayed ack.
if (tp->t_state == TCPS_ESTABLISHED &&
(tiflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK)) == TH_ACK &&
(!ts_present || TSTMP_GEQ(ts_val, tp->ts_recent)) &&
ti->ti_seq == tp->rcv_nxt &&
tiwin && tiwin == tp->snd_wnd &&
tp->snd_nxt == tp->snd_max) {
// If last ACK falls within this segment's sequence numbers,
// record the timestamp.
if ( ts_present && TSTMP_GEQ(ts_val, tp->ts_recent) &&
SEQ_LEQ(ti->ti_seq, tp->last_ack_sent) ){
tp->ts_recent_age = g_tcp_now;
tp->ts_recent = ts_val;
}
if (ti->ti_len == 0) {
if (SEQ_GT(ti->ti_ack, tp->snd_una) &&
SEQ_LEQ(ti->ti_ack, tp->snd_max) &&
tp->snd_cwnd >= tp->snd_wnd) {
// this is a pure ack for outstanding data.
++g_tcpstat.tcps_predack;
if (ts_present)
tcp_xmit_timer(tp, g_tcp_now-ts_ecr+1);
else if (tp->t_rtt &&
SEQ_GT(ti->ti_ack, tp->t_rtseq))
tcp_xmit_timer(tp, tp->t_rtt);
acked = ti->ti_ack - tp->snd_una;
g_tcpstat.tcps_rcvackpack++;
g_tcpstat.tcps_rcvackbyte += acked;
TRACE("drop so_snd buffer, drop_bytes=%d, len=%d",
acked, so->so_snd.sb_cc);
sbdrop(so->so_snd, acked);
tp->snd_una = ti->ti_ack;
usn_free_cmbuf(m);
// If all outstanding data are acked, stop
// retransmit timer, otherwise restart timer
// using current (possibly backed-off) value.
// If process is waiting for space,
// wakeup/selwakeup/signal. If data
// are ready to send, let tcp_output
// decide between more output or persist.
if (tp->snd_una == tp->snd_max)
tp->t_timer[TCPT_REXMT] = 0;
else if (tp->t_timer[TCPT_PERSIST] == 0)
tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
if (so->so_options & SO_DEBUG)
tcp_trace(TA_INPUT, ostate, tp, &g_tcp_saveti, 0);
//if (so->so_snd->sb_flags & SB_NOTIFY) {
// usnet_tcpin_wwakeup(so, USN_TCP_IN, usn_tcpev_sbnotify, 0);
// sowwakeup(so);
//}
// send buffer is available for app thread.
usnet_tcpin_wwakeup(so, USN_TCP_IN, USN_TCPEV_WRITE, 0);
if (so->so_snd->sb_cc)
tcp_output(tp);
return;
}
} else if (ti->ti_ack == tp->snd_una &&
tp->seg_next == (struct tcpiphdr *)tp &&
ti->ti_len <= sbspace(so->so_rcv)) {
// this is a pure, in-sequence data packet
// with nothing on the reassembly queue and
// we have enough buffer space to take it.
++g_tcpstat.tcps_preddat;
tp->rcv_nxt += ti->ti_len;
g_tcpstat.tcps_rcvpack++;
g_tcpstat.tcps_rcvbyte += ti->ti_len;
// Drop TCP, IP headers and TCP options then add data
// to socket buffer.
m->head += sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
m->mlen -= sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
TRACE("add data to rcv buf");
sbappend(so->so_rcv, m);
sorwakeup(so);
// new data is available for app threads.
usnet_tcpin_rwakeup(so, USN_TCP_IN, USN_TCPEV_READ, m);
if (so->so_options & SO_DEBUG) {
TRACE("tcp trace, so_options=%d", so->so_options);
tcp_trace(TA_INPUT, ostate, tp, &g_tcp_saveti, 0);
}
tp->t_flags |= TF_DELACK;
return;
}
}
// Drop TCP, IP headers and TCP options.
m->head += sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
m->mlen -= sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
// Calculate amount of space in receive window,
// and then do TCP input processing.
// Receive window is amount of space in rcv queue,
// but not less than advertised window.
{
int win;
win = sbspace(so->so_rcv);
if (win < 0)
win = 0;
tp->rcv_wnd = max(win, (int)(tp->rcv_adv - tp->rcv_nxt));
}
switch (tp->t_state) {
// If the state is LISTEN then ignore segment if it contains an RST.
// If the segment contains an ACK then it is bad and send a RST.
// If it does not contain a SYN then it is not interesting; drop it.
// Don't bother responding if the destination was a broadcast.
// Otherwise initialize tp->rcv_nxt, and tp->irs, select an initial
// tp->iss, and send a segment:
// <SEQ=ISS><ACK=RCV_NXT><CTL=SYN,ACK>
// Also initialize tp->snd_nxt to tp->iss+1 and tp->snd_una to tp->iss.
// Fill in remote peer address fields if not previously specified.
// Enter SYN_RECEIVED state, and process any other fields of this
// segment in this state.
case TCPS_LISTEN: {
usn_mbuf_t *am;
struct usn_sockaddr_in *sin;
if (tiflags & TH_RST)
goto drop;
if (tiflags & TH_ACK)
goto dropwithreset;
if ((tiflags & TH_SYN) == 0)
goto drop;
// RFC1122 4.2.3.10, p. 104: discard bcast/mcast SYN
// in_broadcast() should never return true on a received
// packet with M_BCAST not set.
//if (m->m_flags & (M_BCAST|M_MCAST) ||
// IN_MULTICAST(ntohl(ti->ti_dst.s_addr)))
// goto drop;
am = usn_get_mbuf(0, BUF_MSIZE, 0); // XXX: the size!
if (am == NULL)
goto drop;
am->mlen = sizeof (struct usn_sockaddr_in);
sin = mtod(am, struct usn_sockaddr_in *);
sin->sin_family = AF_INET;
sin->sin_len = sizeof(*sin);
sin->sin_addr = ti->ti_src;
sin->sin_port = ti->ti_sport;
bzero((caddr_t)sin->sin_zero, sizeof(sin->sin_zero));
laddr = inp->inp_laddr;
if (inp->inp_laddr.s_addr == USN_INADDR_ANY)
inp->inp_laddr = ti->ti_dst;
if (in_pcbconnect(inp, am)) {
inp->inp_laddr = laddr;
usn_free_mbuf(am);
goto drop;
}
usn_free_mbuf(am);
tp->t_template = tcp_template(tp);
if (tp->t_template == 0) {
tp = tcp_drop(tp, ENOBUFS);
dropsocket = 0; // socket is already gone
goto drop;
}
if (optp)
tcp_dooptions(tp, optp, optlen, ti,
&ts_present, &ts_val, &ts_ecr);
if (iss)
tp->iss = iss;
else
tp->iss = g_tcp_iss;
g_tcp_iss += TCP_ISSINCR/4;
tp->irs = ti->ti_seq;
tcp_sendseqinit(tp);
tcp_rcvseqinit(tp);
tp->t_flags |= TF_ACKNOW;
TRACE("change tcp state to TCPS_SYN_RECEIVED, state=%d, tp_flags=%d",
tp->t_state, tp->t_flags);
tp->t_state = TCPS_SYN_RECEIVED;
// tcp event
usnet_tcpin_ewakeup(so, USN_TCP_IN, USN_TCPST_SYN_RECEIVED, 0);
tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
dropsocket = 0; // committed to socket
g_tcpstat.tcps_accepts++;
goto trimthenstep6;
}
// If the state is SYN_SENT:
// if seg contains an ACK, but not for our SYN, drop the input.
// if seg contains a RST, then drop the connection.
// if seg does not contain SYN, then drop it.
// Otherwise this is an acceptable SYN segment
// initialize tp->rcv_nxt and tp->irs
// if seg contains ack then advance tp->snd_una
// if SYN has been acked change to ESTABLISHED else SYN_RCVD state
// arrange for segment to be acked (eventually)
// continue processing rest of data/controls, beginning with URG
case TCPS_SYN_SENT:
if ((tiflags & TH_ACK) &&
(SEQ_LEQ(ti->ti_ack, tp->iss) ||
SEQ_GT(ti->ti_ack, tp->snd_max)))
goto dropwithreset;
if (tiflags & TH_RST) {
if (tiflags & TH_ACK)
tp = tcp_drop(tp, ECONNREFUSED);
goto drop;
}
if ((tiflags & TH_SYN) == 0)
goto drop;
if (tiflags & TH_ACK) {
tp->snd_una = ti->ti_ack;
if (SEQ_LT(tp->snd_nxt, tp->snd_una))
tp->snd_nxt = tp->snd_una;
tp->t_timer[TCPT_REXMT] = 0;
}
tp->irs = ti->ti_seq;
tcp_rcvseqinit(tp);
tp->t_flags |= TF_ACKNOW;
TRACE("ack now, tp flags=%d", tp->t_flags);
// XXX: remove second test.
if (tiflags & TH_ACK /*&& SEQ_GT(tp->snd_una, tp->iss)*/) {
g_tcpstat.tcps_connects++;
soisconnected(so);
TRACE("change tcp state to TCPS_ESTABLISHED,"
" state=%d, tp_flags=%d", tp->t_state, tp->t_flags);
tp->t_state = TCPS_ESTABLISHED;
// Do window scaling on this connection?
if ((tp->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) ==
(TF_RCVD_SCALE|TF_REQ_SCALE)) {
tp->snd_scale = tp->requested_s_scale;
tp->rcv_scale = tp->request_r_scale;
}
tcp_reass(tp, (struct tcpiphdr *)0, (usn_mbuf_t *)0);
// if we didn't have to retransmit the SYN,
// use its rtt as our initial srtt & rtt var.
if (tp->t_rtt)
tcp_xmit_timer(tp, tp->t_rtt);
} else {
TRACE("change tcp state to TCPS_SYN_RECEIVED, state=%d, tp_flags=%d",
tp->t_state, tp->t_flags);
tp->t_state = TCPS_SYN_RECEIVED;
// tcp event
usnet_tcpin_ewakeup(so, USN_TCP_IN, USN_TCPST_SYN_RECEIVED, 0);
}
trimthenstep6:
// Advance ti->ti_seq to correspond to first data byte.
// If data, trim to stay within window,
// dropping FIN if necessary.
ti->ti_seq++;
if (ti->ti_len > tp->rcv_wnd) {
todrop = ti->ti_len - tp->rcv_wnd;
m_adj(m, -todrop);
ti->ti_len = tp->rcv_wnd;
tiflags &= ~TH_FIN;
g_tcpstat.tcps_rcvpackafterwin++;
g_tcpstat.tcps_rcvbyteafterwin += todrop;
}
tp->snd_wl1 = ti->ti_seq - 1;
tp->rcv_up = ti->ti_seq;
goto step6;
}
// States other than LISTEN or SYN_SENT.
// First check timestamp, if present.
// Then check that at least some bytes of segment are within
// receive window. If segment begins before rcv_nxt,
// drop leading data (and SYN); if nothing left, just ack.
//
// RFC 1323 PAWS: If we have a timestamp reply on this segment
// and it's less than ts_recent, drop it.
if (ts_present && (tiflags & TH_RST) == 0 && tp->ts_recent &&
TSTMP_LT(ts_val, tp->ts_recent)) {
// Check to see if ts_recent is over 24 days old.
if ((int)(g_tcp_now - tp->ts_recent_age) > TCP_PAWS_IDLE) {
// Invalidate ts_recent. If this segment updates
// ts_recent, the age will be reset later and ts_recent
// will get a valid value. If it does not, setting
// ts_recent to zero will at least satisfy the
// requirement that zero be placed in the timestamp
// echo reply when ts_recent isn't valid. The
// age isn't reset until we get a valid ts_recent
// because we don't want out-of-order segments to be
// dropped when ts_recent is old.
tp->ts_recent = 0;
} else {
g_tcpstat.tcps_rcvduppack++;
g_tcpstat.tcps_rcvdupbyte += ti->ti_len;
g_tcpstat.tcps_pawsdrop++;
goto dropafterack;
}
}
todrop = tp->rcv_nxt - ti->ti_seq;
if (todrop > 0) {
if (tiflags & TH_SYN) {
tiflags &= ~TH_SYN;
ti->ti_seq++;
if (ti->ti_urp > 1)
ti->ti_urp--;
else
tiflags &= ~TH_URG;
todrop--;
}
if ( todrop >= ti->ti_len ||
( todrop == ti->ti_len && (tiflags & TH_FIN ) == 0 ) ) {
// Any valid FIN must be to the left of the window.
// At this point the FIN must be a duplicate or
// out of sequence; drop it.
tiflags &= ~TH_FIN;
// Send an ACK to resynchronize and drop any data
// But keep on processing for RST or ACK.
tp->t_flags |= TF_ACKNOW;
TRACE("send ack now to resync, tp_flags=%d", tp->t_flags);
todrop = ti->ti_len;
g_tcpstat.tcps_rcvdupbyte += ti->ti_len;
g_tcpstat.tcps_rcvduppack++;
} else {
g_tcpstat.tcps_rcvpartduppack++;
g_tcpstat.tcps_rcvpartdupbyte += ti->ti_len;
}
m_adj(m, todrop);
ti->ti_seq += todrop;
ti->ti_len -= todrop;
if (ti->ti_urp > todrop)
ti->ti_urp -= todrop;
else {
tiflags &= ~TH_URG;
ti->ti_urp = 0;
}
}
// If new data are received on a connection after the
// user processes are gone, then RST the other end.
if ((so->so_state & USN_NOFDREF) &&
tp->t_state > TCPS_CLOSE_WAIT && ti->ti_len) {
tp = tcp_close(tp);
g_tcpstat.tcps_rcvafterclose++;
goto dropwithreset;
}
// If segment ends after window, drop trailing data
// (and PUSH and FIN); if nothing left, just ACK.
todrop = (ti->ti_seq+ti->ti_len) - (tp->rcv_nxt+tp->rcv_wnd);
if (todrop > 0) {
g_tcpstat.tcps_rcvpackafterwin++;
if (todrop >= ti->ti_len) {
g_tcpstat.tcps_rcvbyteafterwin += ti->ti_len;
// If a new connection request is received
// while in TIME_WAIT, drop the old connection
// and start over if the sequence numbers
// are above the previous ones.
if (tiflags & TH_SYN &&
tp->t_state == TCPS_TIME_WAIT &&
SEQ_GT(ti->ti_seq, tp->rcv_nxt)) {
iss = tp->snd_nxt + TCP_ISSINCR;
tp = tcp_close(tp);
goto findpcb;
}
// If window is closed can only take segments at
// window edge, and have to drop data and PUSH from
// incoming segments. Continue processing, but
// remember to ack. Otherwise, drop segment
// and ack.
if (tp->rcv_wnd == 0 && ti->ti_seq == tp->rcv_nxt) {
tp->t_flags |= TF_ACKNOW;
g_tcpstat.tcps_rcvwinprobe++;
} else
goto dropafterack;
} else
g_tcpstat.tcps_rcvbyteafterwin += todrop;
m_adj(m, -todrop);
ti->ti_len -= todrop;
tiflags &= ~(TH_PUSH|TH_FIN);
}
// check valid timestamp. Replace code above.
if (ts_present && TSTMP_GEQ(ts_val, tp->ts_recent) &&
SEQ_LEQ(ti->ti_seq, tp->last_ack_sent) ) {
tp->ts_recent_age = g_tcp_now;
tp->ts_recent = ts_val;
}
// If the RST bit is set examine the state:
// SYN_RECEIVED STATE:
// If passive open, return to LISTEN state.
// If active open, inform user that connection was refused.
// ESTABLISHED, FIN_WAIT_1, FIN_WAIT2, CLOSE_WAIT STATES:
// Inform user that connection was reset, and close tcb.
// CLOSING, LAST_ACK, TIME_WAIT STATES
// Close the tcb.
if (tiflags&TH_RST) switch (tp->t_state) {
case TCPS_SYN_RECEIVED:
so->so_error = ECONNREFUSED;
goto close;
case TCPS_ESTABLISHED:
case TCPS_FIN_WAIT_1:
case TCPS_FIN_WAIT_2:
case TCPS_CLOSE_WAIT:
so->so_error = ECONNRESET;
close:
DEBUG("change tcp state to TCPS_CLOSED, state=%d", tp->t_state);
tp->t_state = TCPS_CLOSED;
// tcp event
usnet_tcpin_ewakeup(so, USN_TCP_IN, USN_TCPST_CLOSED, 0);
g_tcpstat.tcps_drops++;
tp = tcp_close(tp);
goto drop;
case TCPS_CLOSING:
case TCPS_LAST_ACK:
case TCPS_TIME_WAIT:
tp = tcp_close(tp);
goto drop;
}
// If a SYN is in the window, then this is an
// error and we send an RST and drop the connection.
if (tiflags & TH_SYN) {
tp = tcp_drop(tp, ECONNRESET);
goto dropwithreset;
}
// If the ACK bit is off we drop the segment and return.
if ((tiflags & TH_ACK) == 0)
goto drop;
// Ack processing.
switch (tp->t_state) {
// In SYN_RECEIVED state if the ack ACKs our SYN then enter
// ESTABLISHED state and continue processing, otherwise
// send an RST.
case TCPS_SYN_RECEIVED:
if (SEQ_GT(tp->snd_una, ti->ti_ack) ||
SEQ_GT(ti->ti_ack, tp->snd_max))
goto dropwithreset;
g_tcpstat.tcps_connects++;
DEBUG("change tcp state to TCPS_ESTABLISHED, state=%d", tp->t_state);
tp->t_state = TCPS_ESTABLISHED;
soisconnected(so);
// Do window scaling?
if ((tp->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) ==
(TF_RCVD_SCALE|TF_REQ_SCALE)) {
tp->snd_scale = tp->requested_s_scale;
tp->rcv_scale = tp->request_r_scale;
}
tcp_reass(tp, (struct tcpiphdr *)0, (usn_mbuf_t *)0);
tp->snd_wl1 = ti->ti_seq - 1;
// fall into ...
// In ESTABLISHED state: drop duplicate ACKs; ACK out of range
// ACKs. If the ack is in the range
// tp->snd_una < ti->ti_ack <= tp->snd_max
// then advance tp->snd_una to ti->ti_ack and drop
// data from the retransmission queue. If this ACK reflects
// more up to date window information we update our window information.
case TCPS_ESTABLISHED:
case TCPS_FIN_WAIT_1:
case TCPS_FIN_WAIT_2:
case TCPS_CLOSE_WAIT:
case TCPS_CLOSING:
case TCPS_LAST_ACK:
case TCPS_TIME_WAIT:
if (SEQ_LEQ(ti->ti_ack, tp->snd_una)) {
if (ti->ti_len == 0 && tiwin == tp->snd_wnd) {
g_tcpstat.tcps_rcvdupack++;
// If we have outstanding data (other than
// a window probe), this is a completely
// duplicate ack (ie, window info didn't
// change), the ack is the biggest we've
// seen and we've seen exactly our rexmt
// threshhold of them, assume a packet
// has been dropped and retransmit it.
// Kludge snd_nxt & the congestion
// window so we send only this one
// packet.
//
// We know we're losing at the current
// window size so do congestion avoidance
// (set ssthresh to half the current window
// and pull our congestion window back to
// the new ssthresh).
//
// Dup acks mean that packets have left the
// network (they're now cached at the receiver)
// so bump cwnd by the amount in the receiver
// to keep a constant cwnd packets in the
// network.
if (tp->t_timer[TCPT_REXMT] == 0 ||
ti->ti_ack != tp->snd_una)
tp->t_dupacks = 0;
else if (++tp->t_dupacks == g_tcprexmtthresh) {
// congestion avoidance
tcp_seq onxt = tp->snd_nxt;
u_int win =
min(tp->snd_wnd, tp->snd_cwnd) / 2 / tp->t_maxseg;
if (win < 2)
win = 2;
tp->snd_ssthresh = win * tp->t_maxseg;
tp->t_timer[TCPT_REXMT] = 0;
tp->t_rtt = 0;
tp->snd_nxt = ti->ti_ack;
tp->snd_cwnd = tp->t_maxseg;
tcp_output(tp);
tp->snd_cwnd = tp->snd_ssthresh +
tp->t_maxseg * tp->t_dupacks;
if (SEQ_GT(onxt, tp->snd_nxt))
tp->snd_nxt = onxt;
goto drop;
} else if (tp->t_dupacks > g_tcprexmtthresh) {
tp->snd_cwnd += tp->t_maxseg;
tcp_output(tp);
goto drop;
}
} else
tp->t_dupacks = 0;
break;
}
// If the congestion window was inflated to account
// for the other side's cached packets, retract it.
if (tp->t_dupacks > g_tcprexmtthresh &&
tp->snd_cwnd > tp->snd_ssthresh)
tp->snd_cwnd = tp->snd_ssthresh;
tp->t_dupacks = 0;
if (SEQ_GT(ti->ti_ack, tp->snd_max)) {
g_tcpstat.tcps_rcvacktoomuch++;
goto dropafterack;
}
acked = ti->ti_ack - tp->snd_una;
g_tcpstat.tcps_rcvackpack++;
g_tcpstat.tcps_rcvackbyte += acked;
// If we have a timestamp reply, update smoothed
// round trip time. If no timestamp is present but
// transmit timer is running and timed sequence
// number was acked, update smoothed round trip time.
// Since we now have an rtt measurement, cancel the
// timer backoff (cf., Phil Karn's retransmit alg.).
// Recompute the initial retransmit timer.
if (ts_present)
tcp_xmit_timer(tp, g_tcp_now-ts_ecr+1);
else if (tp->t_rtt && SEQ_GT(ti->ti_ack, tp->t_rtseq))
tcp_xmit_timer(tp,tp->t_rtt);
// If all outstanding data is acked, stop retransmit
// timer and remember to restart (more output or persist).
// If there is more data to be acked, restart retransmit
// timer, using current (possibly backed-off) value.
if (ti->ti_ack == tp->snd_max) {
tp->t_timer[TCPT_REXMT] = 0;
DEBUG("change needoutput to 1");
needoutput = 1;
tp->t_flags |= TF_NEEDOUTPUT;
} else if (tp->t_timer[TCPT_PERSIST] == 0)
tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
// When new data is acked, open the congestion window.
// If the window gives us less than ssthresh packets
// in flight, open exponentially (maxseg per packet).
// Otherwise open linearly: maxseg per window
// (maxseg * (maxseg / cwnd) per packet).
{
u_int cw = tp->snd_cwnd;
u_int incr = tp->t_maxseg;
if (cw > tp->snd_ssthresh)
incr = incr * incr / cw;
tp->snd_cwnd = min(cw + incr, TCP_MAXWIN<<tp->snd_scale);
}
if (acked > so->so_snd->sb_cc) {
tp->snd_wnd -= so->so_snd->sb_cc;
DEBUG("drop all so_snd buffer, drop_bytes=%d, acked=%d",
so->so_snd->sb_cc, acked);
sbdrop(so->so_snd, (int)so->so_snd->sb_cc);
ourfinisacked = 1;
} else {
DEBUG("drop so_snd buffer, drop_bytes=%d, len=%d", acked, so->so_snd->sb_cc);
sbdrop(so->so_snd, acked);
tp->snd_wnd -= acked;
ourfinisacked = 0;
}
//if (so->so_snd->sb_flags & SB_NOTIFY) {
sowwakeup(so);
usnet_tcpin_wwakeup(so, USN_TCP_IN, USN_TCPEV_WRITE, 0);
//}
tp->snd_una = ti->ti_ack;
if (SEQ_LT(tp->snd_nxt, tp->snd_una))
tp->snd_nxt = tp->snd_una;
switch (tp->t_state) {
// In FIN_WAIT_1 STATE in addition to the processing
// for the ESTABLISHED state if our FIN is now acknowledged
// then enter FIN_WAIT_2.
case TCPS_FIN_WAIT_1:
if (ourfinisacked) {
// If we can't receive any more
// data, then closing user can proceed.
// Starting the timer is contrary to the
// specification, but if we don't get a FIN
// we'll hang forever.
if (so->so_state & USN_CANTRCVMORE) {
soisdisconnected(so);
tp->t_timer[TCPT_2MSL] = g_tcp_maxidle;
}
DEBUG("change tcp state to TCPS_FIN_WAIT_2, state=%d", tp->t_state);
tp->t_state = TCPS_FIN_WAIT_2;
usnet_tcpin_ewakeup(so, USN_TCP_IN, USN_TCPST_FIN_WAIT2, 0);
}
break;
// In CLOSING STATE in addition to the processing for
// the ESTABLISHED state if the ACK acknowledges our FIN
// then enter the TIME-WAIT state, otherwise ignore
// the segment.
case TCPS_CLOSING:
if (ourfinisacked) {
DEBUG("change tcp state to TCPS_TIME_WAIT, state=%d", tp->t_state);
tp->t_state = TCPS_TIME_WAIT;
usnet_tcpin_ewakeup(so, USN_TCP_IN, USN_TCPST_TIME_WAIT, 0);
tcp_canceltimers(tp);
tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL;
soisdisconnected(so);
}
break;
// In LAST_ACK, we may still be waiting for data to drain
// and/or to be acked, as well as for the ack of our FIN.
// If our FIN is now acknowledged, delete the TCB,
// enter the closed state and return.
case TCPS_LAST_ACK:
if (ourfinisacked) {
tp = tcp_close(tp);
goto drop;
}
break;
// In TIME_WAIT state the only thing that should arrive
// is a retransmission of the remote FIN. Acknowledge
// it and restart the finack timer.
case TCPS_TIME_WAIT:
tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL;
goto dropafterack;
}
}
step6:
// Update window information.
// Don't look at window if no ACK: TAC's send garbage on first SYN.
if ((tiflags & TH_ACK) &&
(SEQ_LT(tp->snd_wl1, ti->ti_seq) ||
(tp->snd_wl1 == ti->ti_seq && (SEQ_LT(tp->snd_wl2, ti->ti_ack) ||
(tp->snd_wl2 == ti->ti_ack && tiwin > tp->snd_wnd) )) )) {
// keep track of pure window updates
if (ti->ti_len == 0 &&
tp->snd_wl2 == ti->ti_ack && tiwin > tp->snd_wnd)
g_tcpstat.tcps_rcvwinupd++;
tp->snd_wnd = tiwin;
tp->snd_wl1 = ti->ti_seq;
tp->snd_wl2 = ti->ti_ack;
if (tp->snd_wnd > tp->max_sndwnd)
tp->max_sndwnd = tp->snd_wnd;
DEBUG("change needoutput to 1");
tp->t_flags |= TF_NEEDOUTPUT;
needoutput = 1;
}
// Process segments with URG.
if ((tiflags & TH_URG) && ti->ti_urp &&
TCPS_HAVERCVDFIN(tp->t_state) == 0) {
// This is a kludge, but if we receive and accept
// random urgent pointers, we'll crash in
// soreceive. It's hard to imagine someone
// actually wanting to send this much urgent data.
if (ti->ti_urp + so->so_rcv->sb_cc > g_sb_max) {
ti->ti_urp = 0; // XXX
tiflags &= ~TH_URG; // XXX
goto dodata; // XXX
}
// If this segment advances the known urgent pointer,
// then mark the data stream. This should not happen
// in CLOSE_WAIT, CLOSING, LAST_ACK or TIME_WAIT STATES since
// a FIN has been received from the remote side.
// In these states we ignore the URG.
//
// According to RFC961 (Assigned Protocols),
// the urgent pointer points to the last octet
// of urgent data. We continue, however,
// to consider it to indicate the first octet
// of data past the urgent section as the original
// spec states (in one of two places).
if (SEQ_GT(ti->ti_seq+ti->ti_urp, tp->rcv_up)) {
tp->rcv_up = ti->ti_seq + ti->ti_urp;
so->so_oobmark = so->so_rcv->sb_cc +
(tp->rcv_up - tp->rcv_nxt) - 1;
if (so->so_oobmark == 0)
so->so_state |= USN_RCVATMARK;
sohasoutofband(so);
// send async event to app threads.
usnet_tcpin_ewakeup(so, USN_TCP_IN, USN_TCPEV_OUTOFBOUND, 0);
tp->t_oobflags &= ~(TCPOOB_HAVEDATA | TCPOOB_HADDATA);
}
// Remove out of band data so doesn't get presented to user.
// This can happen independent of advancing the URG pointer,
// but if two URG's are pending at once, some out-of-band
// data may creep in... ick.
if (ti->ti_urp <= ti->ti_len
#ifdef SO_OOBINLINE
&& (so->so_options & SO_OOBINLINE) == 0
#endif
)
tcp_pulloutofband(so, ti, m);
} else
// If no out of band data is expected,
// pull receive urgent pointer along
// with the receive window.
if (SEQ_GT(tp->rcv_nxt, tp->rcv_up))
tp->rcv_up = tp->rcv_nxt;
dodata: // XXX
#ifdef DUMP_PAYLOAD
DEBUG("Handle data");
dump_chain(m,"tcp");
#endif
// Process the segment text, merging it into the TCP sequencing queue,
// and arranging for acknowledgment of receipt if necessary.
// This process logically involves adjusting tp->rcv_wnd as data
// is presented to the user (this happens in tcp_usrreq.c,
// case PRU_RCVD). If a FIN has already been received on this
// connection then we just ignore the text.
if ((ti->ti_len || (tiflags&TH_FIN)) &&
TCPS_HAVERCVDFIN(tp->t_state) == 0) {
TCP_REASS(tp, ti, m, so, tiflags);
// Note the amount of data that peer has sent into
// our window, in order to estimate the sender's
// buffer size.
len = so->so_rcv->sb_hiwat - (tp->rcv_adv - tp->rcv_nxt);
} else {
usn_free_cmbuf(m);
tiflags &= ~TH_FIN;
}
// If FIN is received ACK the FIN and let the user know
// that the connection is closing.
if (tiflags & TH_FIN) {
if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
socantrcvmore(so);
tp->t_flags |= TF_ACKNOW;
TRACE("ack FIN now, tp flags=%d", tp->t_flags);
tp->rcv_nxt++;
}
switch (tp->t_state) {
// In SYN_RECEIVED and ESTABLISHED STATES
// enter the CLOSE_WAIT state.
case TCPS_SYN_RECEIVED:
case TCPS_ESTABLISHED:
TRACE("change tcp state to TCPS_CLOSE_WAIT, state=%d", tp->t_state);
tp->t_state = TCPS_CLOSE_WAIT;
soewakeup(so, 0);
usnet_tcpin_ewakeup(so, USN_TCP_IN, USN_TCPST_CLOSE_WAIT, 0);
break;
// If still in FIN_WAIT_1 STATE FIN has not been acked so
// enter the CLOSING state.
case TCPS_FIN_WAIT_1:
TRACE("change tcp state to TCPS_CLOSING, state=%d", tp->t_state);
tp->t_state = TCPS_CLOSING;
usnet_tcpin_ewakeup(so, USN_TCP_IN, USN_TCPST_CLOSING, 0);
break;
// In FIN_WAIT_2 state enter the TIME_WAIT state,
// starting the time-wait timer, turning off the other
// standard timers.
case TCPS_FIN_WAIT_2:
TRACE("change tcp state to TCPS_TIME_WAIT, state=%d", tp->t_state);
tp->t_state = TCPS_TIME_WAIT;
tcp_canceltimers(tp);
tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL;
soisdisconnected(so);
usnet_tcpin_ewakeup(so, USN_TCP_IN, USN_TCPST_TIME_WAIT, 0);
break;
// In TIME_WAIT state restart the 2 MSL time_wait timer.
case TCPS_TIME_WAIT:
tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL;
break;
}
}
if (so->so_options & SO_DEBUG) {
TRACE("tcp trace, so_options=%d", so->so_options);
tcp_trace(TA_INPUT, ostate, tp, &g_tcp_saveti, 0);
}
// Return any desired output.
//if (needoutput || (tp->t_flags & TF_ACKNOW)){
if (tp->t_flags & TF_NEEDOUTPUT || (tp->t_flags & TF_ACKNOW)){
TRACE("ack now or need to ouput, tp->t_flags=%d", tp->t_flags);
tcp_output(tp);
}
return;
dropafterack:
TRACE("dropafterack");
// Generate an ACK dropping incoming segment if it occupies
// sequence space, where the ACK reflects our state.
if (tiflags & TH_RST)
goto drop;
usn_free_cmbuf(m);
tp->t_flags |= TF_ACKNOW;
TRACE("ack now, tp flags=%d", tp->t_flags);
tcp_output(tp);
return;
dropwithreset:
TRACE("dropwithreset");
// Generate a RST, dropping incoming segment.
// Make ACK acceptable to originator of segment.
// Don't bother to respond if destination was broadcast/multicast.
#define USN_MULTICAST(i) (((u_int)(i) & 0xf0000000) == 0xe0000000)
if ((tiflags & TH_RST) || m->flags & (BUF_BCAST|BUF_MCAST) ||
USN_MULTICAST(ntohl(ti->ti_dst.s_addr)))
goto drop;
if (tiflags & TH_ACK)
tcp_respond(tp, ti, m, (tcp_seq)0, ti->ti_ack, TH_RST);
else {
if (tiflags & TH_SYN)
ti->ti_len++;
tcp_respond(tp, ti, m, ti->ti_seq+ti->ti_len, (tcp_seq)0,
TH_RST|TH_ACK);
}
// destroy temporarily created socket
if (dropsocket)
soabort(so);
return;
drop:
TRACE("drop");
// Drop space held by incoming segment and return.
if (tp && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) {
TRACE("tcp trace: drop a socket");
tcp_trace(TA_DROP, ostate, tp, &g_tcp_saveti, 0);
}
usn_free_cmbuf(m);
// destroy temporarily created socket
if (dropsocket)
soabort(so);
return;
}
/*
* send message to the socket.
*/
static int
key_sendup0(struct rawcb *rp, struct mbuf *m, int promisc, int canwait)
{
struct keycb *kp = (struct keycb *)rp;
struct mbuf *n;
int error = 0;
if (canwait) {
if (kp->kp_queue) {
for (n = kp->kp_queue; n && n->m_nextpkt;
n = n->m_nextpkt)
;
n->m_nextpkt = m;
m = kp->kp_queue;
kp->kp_queue = NULL;
} else
m->m_nextpkt = NULL; /* just for safety */
} else
m->m_nextpkt = NULL;
for (; m && error == 0; m = n) {
n = m->m_nextpkt;
if (promisc) {
struct sadb_msg *pmsg;
M_PREPEND(m, sizeof(struct sadb_msg), M_NOWAIT);
if (m && m->m_len < sizeof(struct sadb_msg))
m = m_pullup(m, sizeof(struct sadb_msg));
if (!m) {
pfkeystat.in_nomem++;
error = ENOBUFS;
goto recovery;
}
m->m_pkthdr.len += sizeof(*pmsg);
pmsg = mtod(m, struct sadb_msg *);
bzero(pmsg, sizeof(*pmsg));
pmsg->sadb_msg_version = PF_KEY_V2;
pmsg->sadb_msg_type = SADB_X_PROMISC;
pmsg->sadb_msg_len = PFKEY_UNIT64(m->m_pkthdr.len);
/* pid and seq? */
pfkeystat.in_msgtype[pmsg->sadb_msg_type]++;
}
if (canwait &&
sbspace(&rp->rcb_socket->so_rcv) < m->m_pkthdr.len) {
error = EAGAIN;
goto recovery;
}
m->m_nextpkt = NULL;
if (!sbappendaddr(&rp->rcb_socket->so_rcv,
(struct sockaddr *)&key_src, m, NULL)) {
pfkeystat.in_nomem++;
error = ENOBUFS;
goto recovery;
} else {
sorwakeup(rp->rcb_socket);
error = 0;
}
}
return (error);
recovery:
if (kp->kp_queue) {
/*
* insert m to the head of queue, as normally mbuf on the queue
* is less important than others.
*/
if (m) {
m->m_nextpkt = kp->kp_queue;
kp->kp_queue = m;
}
} else {
/* recover the queue */
if (!m) {
/* first ENOBUFS case */
kp->kp_queue = n;
} else {
kp->kp_queue = m;
m->m_nextpkt = n;
}
}
return (error);
}
