int
tcp_rcv(PACKET pkt) /* NOTE: pkt has nb_prot pointing to IP header */
{
struct mbuf * m_in;
struct ip * bip; /* IP header, berkeley version */
struct tcphdr * tcpp;
unshort len; /* scratch length holder */
/* For TCP, the netport IP layer is modified to set nb_prot to the
* start of the IP header (not TCP). We need to do some further
* mods which the BSD code expects:
*/
bip = (struct ip *)pkt->nb_prot; /* get ip header */
len = ntohs(bip->ip_len); /* get length in local endian */
/* verify checksum of received packet */
tcpp = (struct tcphdr *)ip_data(bip);
if (tcp_cksum(bip) != tcpp->th_sum)
{
TCP_MIB_INC(tcpInErrs); /* keep MIB stats */
tcpstat.tcps_rcvbadsum++; /* keep BSD stats */
LOCK_NET_RESOURCE(FREEQ_RESID);
pk_free(pkt); /* punt packet */
UNLOCK_NET_RESOURCE(FREEQ_RESID);
return ENP_BAD_HEADER;
}
m_in = m_getnbuf(MT_RXDATA, 0);
if (!m_in){
LOCK_NET_RESOURCE(FREEQ_RESID);
pk_free(pkt);
UNLOCK_NET_RESOURCE(FREEQ_RESID);
return ENP_RESOURCE;
}
IN_PROFILER(PF_TCP, PF_ENTRY); /* measure time in TCP */
/* subtract IP header length from total IP packet length */
len -= ((unshort)(bip->ip_ver_ihl & 0x0f) << 2);
bip->ip_len = len; /* put TCP length in struct for TCP code to use */
/* set mbuf to point to start of IP header (not TCP) */
m_in->pkt = pkt;
m_in->m_data = pkt->nb_prot;
m_in->m_len = pkt->nb_plen;
m_in->m_base = pkt->nb_buff; /* ??? */
m_in->m_memsz = pkt->nb_blen; /* ??? */
tcp_input(m_in, pkt->net);
IN_PROFILER(PF_TCP, PF_EXIT); /* measure time in TCP */
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;
}
int
tcp_usrreq(struct socket * so,
struct mbuf * m,
struct mbuf * nam)
{
struct inpcb * inp;
struct tcpcb * tp;
int error = 0;
int req;
#ifdef DO_TCPTRACE
int ostate;
#endif
req = so->so_req; /* get request from socket struct */
inp = sotoinpcb(so);
/*
* When a TCP is attached to a socket, then there will be
* a (struct inpcb) pointed at by the socket, and this
* structure will point at a subsidary (struct tcpcb).
*/
if (inp == 0 && req != PRU_ATTACH)
{
return (EINVAL);
}
if (inp)
tp = intotcpcb(inp);
else /* inp and tp not set, make sure this is OK: */
{
if (req == PRU_ATTACH)
tp = NULL; /* stifle compiler warnings about using unassigned tp*/
else
{
dtrap(); /* programming error? */
return EINVAL;
}
}
switch (req)
{
/*
* TCP attaches to socket via PRU_ATTACH, reserving space,
* and an internet control block.
*/
case PRU_ATTACH:
if (inp)
{
error = EISCONN;
break;
}
error = tcp_attach(so);
if (error)
break;
if ((so->so_options & SO_LINGER) && so->so_linger == 0)
so->so_linger = TCP_LINGERTIME;
#ifdef DO_TCPTRACE
SETTP(tp, sototcpcb(so));
#endif
break;
/*
* PRU_DETACH detaches the TCP protocol from the socket.
* If the protocol state is non-embryonic, then can't
* do this directly: have to initiate a PRU_DISCONNECT,
* which may finish later; embryonic TCB's can just
* be discarded here.
*/
case PRU_DETACH:
if (tp->t_state > TCPS_LISTEN)
SETTP(tp, tcp_disconnect(tp));
else
SETTP(tp, tcp_close(tp));
break;
/*
* Give the socket an address.
*/
case PRU_BIND:
/* bind is quite different for IPv4 and v6, so we use two
* seperate pcbbind routines. so_domain was checked for
* validity way up in t_bind()
*/
#ifdef IP_V4
if(inp->inp_socket->so_domain == AF_INET)
{
error = in_pcbbind(inp, nam);
break;
}
#endif /* IP_V4 */
#ifdef IP_V6
if(inp->inp_socket->so_domain == AF_INET6)
{
error = ip6_pcbbind(inp, nam);
break;
}
#endif /* IP_V6 */
dtrap(); /* not v4 or v6? */
error = EINVAL;
break;
/*
* Prepare to accept connections.
*/
case PRU_LISTEN:
if (inp->inp_lport == 0)
error = in_pcbbind(inp, (struct mbuf *)0);
if (error == 0)
tp->t_state = TCPS_LISTEN;
break;
/*
* Initiate connection to peer.
* Create a template for use in transmissions on this connection.
* Enter SYN_SENT state, and mark socket as connecting.
* Start keep-alive timer, and seed output sequence space.
* Send initial segment on connection.
*/
case PRU_CONNECT:
if (inp->inp_lport == 0)
{
#ifdef IP_V4
#ifndef IP_V6 /* v4 only */
error = in_pcbbind(inp, (struct mbuf *)0);
#else /* dual mode */
if(so->so_domain == AF_INET)
error = in_pcbbind(inp, (struct mbuf *)0);
else
error = ip6_pcbbind(inp, (struct mbuf *)0);
#endif /* end dual mode code */
#else /* no v4, v6 only */
error = ip6_pcbbind(inp, (struct mbuf *)0);
#endif /* end v6 only */
if (error)
break;
}
#ifdef IP_V4
#ifndef IP_V6 /* v4 only */
error = in_pcbconnect(inp, nam);
#else /* dual mode */
if(so->so_domain == AF_INET)
error = in_pcbconnect(inp, nam);
else
error = ip6_pcbconnect(inp, nam);
#endif /* end dual mode code */
#else /* no v4, v6 only */
error = ip6_pcbconnect(inp, nam);
#endif /* end v6 only */
if (error)
break;
tp->t_template = tcp_template(tp);
if (tp->t_template == 0)
{
#ifdef IP_V4
#ifndef IP_V6 /* v4 only */
in_pcbdisconnect(inp);
#else /* dual mode */
if(so->so_domain == AF_INET)
in_pcbdisconnect(inp);
else
ip6_pcbdisconnect(inp);
#endif /* end dual mode code */
#else /* no v4, v6 only */
ip6_pcbdisconnect(inp);
#endif /* end v6 only */
error = ENOBUFS;
break;
}
soisconnecting(so);
tcpstat.tcps_connattempt++;
tp->t_state = TCPS_SYN_SENT;
tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
tp->iss = tcp_iss;
tcp_iss += (tcp_seq)(TCP_ISSINCR/2);
tcp_sendseqinit(tp);
error = tcp_output(tp);
if (!error)
TCP_MIB_INC(tcpActiveOpens); /* keep MIB stats */
break;
/*
* Create a TCP connection between two sockets.
*/
case PRU_CONNECT2:
error = EOPNOTSUPP;
break;
/*
* Initiate disconnect from peer.
* If connection never passed embryonic stage, just drop;
* else if don't need to let data drain, then can just drop anyways,
* else have to begin TCP shutdown process: mark socket disconnecting,
* drain unread data, state switch to reflect user close, and
* send segment (e.g. FIN) to peer. Socket will be really disconnected
* when peer sends FIN and acks ours.
*
* SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
*/
case PRU_DISCONNECT:
SETTP(tp, tcp_disconnect(tp));
break;
/*
* Accept a connection. Essentially all the work is
* done at higher levels; just return the address
* of the peer, storing through addr.
*/
case PRU_ACCEPT:
{
struct sockaddr_in * sin = mtod(nam, struct sockaddr_in *);
#ifdef IP_V6
struct sockaddr_in6 * sin6 = mtod(nam, struct sockaddr_in6 *);
#endif
#ifdef IP_V6
if (so->so_domain == AF_INET6)
{
nam->m_len = sizeof (struct sockaddr_in6);
sin6->sin6_port = inp->inp_fport;
sin6->sin6_family = AF_INET6;
IP6CPY(&sin6->sin6_addr, &inp->ip6_faddr);
}
#endif
#ifdef IP_V4
if (so->so_domain == AF_INET)
{
nam->m_len = sizeof (struct sockaddr_in);
sin->sin_family = AF_INET;
sin->sin_port = inp->inp_fport;
sin->sin_addr = inp->inp_faddr;
}
#endif
if ( !(so->so_domain == AF_INET) &&
!(so->so_domain == AF_INET6)
)
{
dprintf("*** PRU_ACCEPT bad domain = %d\n", so->so_domain);
dtrap();
}
TCP_MIB_INC(tcpPassiveOpens); /* keep MIB stats */
break;
}
/*
* Mark the connection as being incapable of further output.
*/
case PRU_SHUTDOWN:
socantsendmore(so);
tp = tcp_usrclosed(tp);
if (tp)
error = tcp_output(tp);
break;
/*
* After a receive, possibly send window update to peer.
*/
case PRU_RCVD:
(void) tcp_output(tp);
break;
/*
* Do a send by putting data in output queue and updating urgent
* marker if URG set. Possibly send more data.
*/
case PRU_SEND:
if (so->so_pcb == NULL)
{ /* Return EPIPE error if socket is not connected */
error = EPIPE;
break;
}
sbappend(&so->so_snd, m);
error = tcp_output(tp);
if (error == ENOBUFS)
sbdropend(&so->so_snd,m); /* Remove data from socket buffer */
break;
/*
* Abort the TCP.
*/
case PRU_ABORT:
SETTP(tp, tcp_drop(tp, ECONNABORTED));
break;
case PRU_SENSE:
/* ((struct stat *) m)->st_blksize = so->so_snd.sb_hiwat; */
dtrap(); /* does this ever happen? */
return (0);
case PRU_RCVOOB:
if ((so->so_oobmark == 0 &&
(so->so_state & SS_RCVATMARK) == 0) ||
#ifdef SO_OOBINLINE
so->so_options & SO_OOBINLINE ||
#endif
tp->t_oobflags & TCPOOB_HADDATA)
{
error = EINVAL;
break;
}
if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0)
{
error = EWOULDBLOCK;
break;
}
m->m_len = 1;
*mtod(m, char *) = tp->t_iobc;
if ((MBUF2LONG(nam) & MSG_PEEK) == 0)
tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
break;
case PRU_SENDOOB:
if (so->so_pcb == NULL)
{ /* Return EPIPE error if socket is not connected */
error = EPIPE;
break;
}
if (sbspace(&so->so_snd) == 0)
{
m_freem(m);
error = ENOBUFS;
break;
}
/*
* 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);
tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
tp->t_force = 1;
error = tcp_output(tp);
if (error == ENOBUFS)
sbdropend(&so->so_snd,m); /* Remove data from socket buffer */
tp->t_force = 0;
break;
case PRU_SOCKADDR:
/* sockaddr and peeraddr have to switch based on IP type */
#ifdef IP_V4
#ifndef IP_V6 /* v4 only */
in_setsockaddr(inp, nam);
#else /* dual mode */
if(so->so_domain == AF_INET6)
ip6_setsockaddr(inp, nam);
else
in_setsockaddr(inp, nam);
#endif /* dual mode */
#else /* IP_V6 */
ip6_setsockaddr(inp, nam);
#endif
break;
case PRU_PEERADDR:
#ifdef IP_V4
#ifndef IP_V6 /* v4 only */
in_setpeeraddr(inp, nam);
#else /* dual mode */
if(so->so_domain == AF_INET6)
ip6_setpeeraddr(inp, nam);
else
in_setpeeraddr(inp, nam);
#endif /* dual mode */
#else /* IP_V6 */
ip6_setpeeraddr(inp, nam);
#endif
break;
case PRU_SLOWTIMO:
SETTP(tp, tcp_timers(tp, (int)MBUF2LONG(nam)));
#ifdef DO_TCPTRACE
req |= (long)nam << 8; /* for debug's sake */
#endif
break;
default:
panic("tcp_usrreq");
}
#ifdef DO_TCPTRACE
if (tp && (so->so_options & SO_DEBUG))
tcp_trace("usrreq: state: %d, tcpcb: %x, req: %d",
ostate, tp, req);
#endif
return (error);
}
