void
ip_frag_timer (void)
{
T_NET_BUF *frag;
int_t ix;
syscall(wai_sem(SEM_IP4_FRAG_QUEUE));
for (ix = NUM_IP4_FRAG_QUEUE; ix -- > 0; ) {
frag = ip_frag_queue[ix];
if (frag != NULL && GET_QIP4_HDR(frag)->ttl > 0 &&
-- GET_QIP4_HDR(frag)->ttl == 0) {
NET_COUNT_IP4(net_count_ip4[NC_IP4_FRAG_IN_TMOUT], 1);
NET_COUNT_IP4(net_count_ip4[NC_IP4_FRAG_IN_DROP], 1);
ip_freef(ix);
}
}
syscall(sig_sem(SEM_IP4_FRAG_QUEUE));
}
/*
* IP timer processing;
* if a timer expires on a reassembly
* queue, discard it.
*/
void ip_slowtimo(void)
{
struct ipq *fp;
DEBUG_CALL("ip_slowtimo");
fp = (struct ipq *) ipq.next;
if (fp == 0)
return;
while (fp != &ipq) {
--fp->ipq_ttl;
fp = (struct ipq *) fp->next;
if (((struct ipq *)(fp->prev))->ipq_ttl == 0) {
ipstat.ips_fragtimeout++;
ip_freef((struct ipq *) fp->prev);
}
}
}
static T_NET_BUF *
ip_reass (T_IP4_HDR *ip4h, T_NET_BUF *input)
{
T_NET_BUF *frag, *prev;
T_IN4_ADDR dst, src;
int_t ix;
uint_t id, off, len;
NET_COUNT_IP4(net_count_ip4[NC_IP4_FRAG_IN_FRAGS], 1);
NET_COUNT_MIB(ip_stats.ipReasmReqds, 1);
src = ntohl(ip4h->src);
dst = ntohl(ip4h->dst);
NTOHS(ip4h->id);
NTOHS(ip4h->flg_off);
id = ip4h->id;
ix = id % NUM_IP4_FRAG_QUEUE;
syscall(wai_sem(SEM_IP4_FRAG_QUEUE));
/*
* ID、IPアドレス、上位プロトコルが異なるフラグメントがキューに有れば破棄する。
*/
frag = ip_frag_queue[ix];
if (frag != NULL &&
(id != GET_IP4_HDR(frag)->id ||
dst != frag_dst[ix] ||
src != ntohl(GET_IP4_HDR(frag)->src) ||
ip4h->proto != GET_IP4_HDR(frag)->proto)) {
NET_COUNT_IP4(net_count_ip4[NC_IP4_FRAG_IN_DROP], 1);
NET_COUNT_MIB(ip_stats.ipReasmFails, 1);
ip_freef(ix);
}
frag = ip_frag_queue[ix];
if (frag == NULL) {
NET_COUNT_IP4(net_count_ip4[NC_IP4_FRAG_IN], 1);
/* 新規の ID なら、宛先アドレスを保存して、キューにつなぐ。*/
frag_dst [ix] = dst;
ip_frag_queue[ix] = input;
((T_QIP4_HDR *)ip4h)->next = NULL;
input = NULL;
/* 再構成タイムアウトを設定する。*/
ip4h->ttl = IP4_FRAGTTL;
}
else {
/* 正しい位置に挿入する。*/
prev = NULL;
while (frag != NULL &&
IP4_FLGOFF_OFF(ip4h->flg_off) >
IP4_FLGOFF_OFF(GET_QIP4_HDR(frag)->flg_off)) {
prev = frag;
frag = GET_QIP4_HDR(frag)->next;
}
((T_QIP4_HDR *)ip4h)->next = frag;
if (prev == NULL) {
ip4h->ttl = GET_QIP4_HDR(frag)->ttl;
ip_frag_queue[ix] = input;
}
else
GET_QIP4_HDR(prev)->next = input;
input = NULL;
/* 全てのフラグメントが揃っているか調べる。*/
off = 0;
for (frag = ip_frag_queue[ix]; frag != NULL; frag = GET_QIP4_HDR(frag)->next) {
if ((IP4_FLGOFF_OFF(GET_QIP4_HDR(frag)->flg_off) << 3) != off) {
/* 途中が抜けていたら終了する。*/
syscall(sig_sem(SEM_IP4_FRAG_QUEUE));
return NULL;
}
off += ntohs(GET_QIP4_HDR(frag)->len) - (IP4_VHL_HL(GET_QIP4_HDR(frag)->vhl) << 2);
prev = frag;
}
/* 全てのフラグメントが揃ったら再構成する。*/
if ((GET_QIP4_HDR(prev)->flg_off & IP4_MF) == 0) {
/* ネットワークバッファを獲得する。*/
if (tget_net_buf(&input, IF_IP4_HDR_SIZE + off, TMO_IP4_FRAG_GET_NET_BUF) == E_OK) {
NET_COUNT_IP4(net_count_ip4[NC_IP4_FRAG_IN_OK], 1);
NET_COUNT_MIB(ip_stats.ipReasmOKs, 1);
/* IPv4 ヘッダを設定する。*/
frag = ip_frag_queue[ix];
ip4h = GET_IP4_HDR(input);
*ip4h = *GET_IP4_HDR(frag);
ip4h->dst = htonl(frag_dst[ix]);
ip4h->len = htons(IP4_HDR_SIZE + off);
ip4h->vhl = IP4_MAKE_VHL(IPV4_VERSION, IP4_HDR_SIZE >> 2);
ip4h->ttl = GET_QIP4_HDR(prev)->ttl;
ip4h->flg_off = ip4h->id = 0;
/* データグラムを再構成する。*/
off = IP4_HDR_SIZE;
while (frag != NULL) {
len = ntohs(GET_QIP4_HDR(frag)->len) - (IP4_VHL_HL(GET_QIP4_HDR(frag)->vhl) << 2);
memcpy((uint8_t *)ip4h + off, GET_QIP4_SDU(frag), len);
off += len;
frag = GET_QIP4_HDR(frag)->next;
}
}
else {
NET_COUNT_IP4(net_count_ip4[NC_IP4_FRAG_IN_NO_BUF], 1);
NET_COUNT_IP4(net_count_ip4[NC_IP4_FRAG_IN_DROP], 1);
NET_COUNT_MIB(ip_stats.ipReasmFails, 1);
}
/* キューを空にする。*/
ip_freef(ix);
}
/*
* Ip input routine. Checksum and byte swap header. If fragmented
* try to reassemble. Process options. Pass to next level.
*/
void
ip_input(struct mbuf *m)
{
Slirp *slirp = m->slirp;
struct ip *ip;
int hlen;
DEBUG_CALL("ip_input");
DEBUG_ARG("m = %lx", (long)m);
DEBUG_ARG("m_len = %d", m->m_len);
if (m->m_len < sizeof (struct ip)) {
return;
}
ip = mtod(m, struct ip *);
if (ip->ip_v != IPVERSION) {
goto bad;
}
hlen = ip->ip_hl << 2;
if (hlen<sizeof(struct ip ) || hlen>m->m_len) {/* min header length */
goto bad; /* or packet too short */
}
/* keep ip header intact for ICMP reply
* ip->ip_sum = cksum(m, hlen);
* if (ip->ip_sum) {
*/
if(cksum(m,hlen)) {
goto bad;
}
/*
* Convert fields to host representation.
*/
NTOHS(ip->ip_len);
if (ip->ip_len < hlen) {
goto bad;
}
NTOHS(ip->ip_id);
NTOHS(ip->ip_off);
/*
* Check that the amount of data in the buffers
* is as at least much as the IP header would have us expect.
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
if (m->m_len < ip->ip_len) {
goto bad;
}
if (slirp->restricted) {
if ((ip->ip_dst.s_addr & slirp->vnetwork_mask.s_addr) ==
slirp->vnetwork_addr.s_addr) {
if (ip->ip_dst.s_addr == 0xffffffff && ip->ip_p != IPPROTO_UDP)
goto bad;
} else {
uint32_t inv_mask = ~slirp->vnetwork_mask.s_addr;
struct ex_list *ex_ptr;
if ((ip->ip_dst.s_addr & inv_mask) == inv_mask) {
goto bad;
}
for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next)
if (ex_ptr->ex_addr.s_addr == ip->ip_dst.s_addr)
break;
if (!ex_ptr)
goto bad;
}
}
/* Should drop packet if mbuf too long? hmmm... */
if (m->m_len > ip->ip_len)
m_adj(m, ip->ip_len - m->m_len);
/* check ip_ttl for a correct ICMP reply */
if(ip->ip_ttl==0 || ip->ip_ttl==1) {
icmp_error(m, ICMP_TIMXCEED,ICMP_TIMXCEED_INTRANS, 0,"ttl");
goto bad;
}
/*
* If offset or IP_MF are set, must reassemble.
* Otherwise, nothing need be done.
* (We could look in the reassembly queue to see
* if the packet was previously fragmented,
* but it's not worth the time; just let them time out.)
*
* XXX This should fail, don't fragment yet
*/
if (ip->ip_off &~ IP_DF) {
struct ipq *fp;
struct qlink *l;
/*
* Look for queue of fragments
* of this datagram.
*/
for (l = slirp->ipq.ip_link.next; l != &slirp->ipq.ip_link;
l = l->next) {
fp = container_of(l, struct ipq, ip_link);
if (ip->ip_id == fp->ipq_id &&
ip->ip_src.s_addr == fp->ipq_src.s_addr &&
ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
ip->ip_p == fp->ipq_p)
goto found;
}
fp = NULL;
found:
/*
* Adjust ip_len to not reflect header,
* set ip_mff if more fragments are expected,
* convert offset of this to bytes.
*/
ip->ip_len -= hlen;
if (ip->ip_off & IP_MF)
ip->ip_tos |= 1;
else
ip->ip_tos &= ~1;
ip->ip_off <<= 3;
/*
* If datagram marked as having more fragments
* or if this is not the first fragment,
* attempt reassembly; if it succeeds, proceed.
*/
if (ip->ip_tos & 1 || ip->ip_off) {
ip = ip_reass(slirp, ip, fp);
if (ip == NULL)
return;
m = dtom(slirp, ip);
} else if (fp)
ip_freef(slirp, fp);
} else
/*
* Ip input routine. Checksum and byte swap header. If fragmented
* try to reassemble. Process options. Pass to next level.
*/
void
ipintr()
{
register struct ip *ip;
register struct mbuf *m;
register struct ipq *fp;
register struct in_ifaddr *ia;
int hlen, s;
next:
/*
* Get next datagram off input queue and get IP header
* in first mbuf.
*/
s = splimp();
IF_DEQUEUE(&ipintrq, m);
splx(s);
if (m == 0)
return;
#ifdef DIAGNOSTIC
if ((m->m_flags & M_PKTHDR) == 0)
panic("ipintr no HDR");
#endif
/*
* If no IP addresses have been set yet but the interfaces
* are receiving, can't do anything with incoming packets yet.
*/
if (in_ifaddr == NULL)
goto bad;
ipstat.ips_total++;
if (m->m_len < sizeof (struct ip) &&
(m = m_pullup(m, sizeof (struct ip))) == 0) {
ipstat.ips_toosmall++;
goto next;
}
ip = mtod(m, struct ip *);
if (ip->ip_v != IPVERSION) {
ipstat.ips_badvers++;
goto bad;
}
hlen = ip->ip_hl << 2;
if (hlen < sizeof(struct ip)) { /* minimum header length */
ipstat.ips_badhlen++;
goto bad;
}
if (hlen > m->m_len) {
if ((m = m_pullup(m, hlen)) == 0) {
ipstat.ips_badhlen++;
goto next;
}
ip = mtod(m, struct ip *);
}
ip->ip_sum = in_cksum(m, hlen);
if (ip->ip_sum) {
ipstat.ips_badsum++;
goto bad;
}
/*
* Convert fields to host representation.
*/
NTOHS(ip->ip_len);
if (ip->ip_len < hlen) {
ipstat.ips_badlen++;
goto bad;
}
NTOHS(ip->ip_id);
NTOHS(ip->ip_off);
/*
* Check that the amount of data in the buffers
* is as at least much as the IP header would have us expect.
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
if (m->m_pkthdr.len < ip->ip_len) {
ipstat.ips_tooshort++;
goto bad;
}
if (m->m_pkthdr.len > ip->ip_len) {
if (m->m_len == m->m_pkthdr.len) {
m->m_len = ip->ip_len;
m->m_pkthdr.len = ip->ip_len;
} else
m_adj(m, ip->ip_len - m->m_pkthdr.len);
}
/*
* Process options and, if not destined for us,
* ship it on. ip_dooptions returns 1 when an
* error was detected (causing an icmp message
* to be sent and the original packet to be freed).
*/
ip_nhops = 0; /* for source routed packets */
if (hlen > sizeof (struct ip) && ip_dooptions(m))
goto next;
/*
* Check our list of addresses, to see if the packet is for us.
*/
for (ia = in_ifaddr; ia; ia = ia->ia_next) {
#define satosin(sa) ((struct sockaddr_in *)(sa))
if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr)
goto ours;
if (
#ifdef DIRECTED_BROADCAST
ia->ia_ifp == m->m_pkthdr.rcvif &&
#endif
(ia->ia_ifp->if_flags & IFF_BROADCAST)) {
u_long t;
if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
ip->ip_dst.s_addr)
goto ours;
if (ip->ip_dst.s_addr == ia->ia_netbroadcast.s_addr)
goto ours;
/*
* Look for all-0's host part (old broadcast addr),
* either for subnet or net.
*/
t = ntohl(ip->ip_dst.s_addr);
if (t == ia->ia_subnet)
goto ours;
if (t == ia->ia_net)
goto ours;
}
}
if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
struct in_multi *inm;
#ifdef MROUTING
extern struct socket *ip_mrouter;
if (ip_mrouter) {
/*
* If we are acting as a multicast router, all
* incoming multicast packets are passed to the
* kernel-level multicast forwarding function.
* The packet is returned (relatively) intact; if
* ip_mforward() returns a non-zero value, the packet
* must be discarded, else it may be accepted below.
*
* (The IP ident field is put in the same byte order
* as expected when ip_mforward() is called from
* ip_output().)
*/
ip->ip_id = htons(ip->ip_id);
if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
ipstat.ips_cantforward++;
m_freem(m);
goto next;
}
ip->ip_id = ntohs(ip->ip_id);
/*
* The process-level routing demon needs to receive
* all multicast IGMP packets, whether or not this
* host belongs to their destination groups.
*/
if (ip->ip_p == IPPROTO_IGMP)
goto ours;
ipstat.ips_forward++;
}
#endif
/*
* See if we belong to the destination multicast group on the
* arrival interface.
*/
IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
if (inm == NULL) {
ipstat.ips_cantforward++;
m_freem(m);
goto next;
}
goto ours;
}
if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
goto ours;
if (ip->ip_dst.s_addr == INADDR_ANY)
goto ours;
/*
* Not for us; forward if possible and desirable.
*/
if (ipforwarding == 0) {
ipstat.ips_cantforward++;
m_freem(m);
} else
ip_forward(m, 0);
goto next;
ours:
/*
* If offset or IP_MF are set, must reassemble.
* Otherwise, nothing need be done.
* (We could look in the reassembly queue to see
* if the packet was previously fragmented,
* but it's not worth the time; just let them time out.)
*/
if (ip->ip_off &~ IP_DF) {
if (m->m_flags & M_EXT) { /* XXX */
if ((m = m_pullup(m, sizeof (struct ip))) == 0) {
ipstat.ips_toosmall++;
goto next;
}
ip = mtod(m, struct ip *);
}
/*
* Look for queue of fragments
* of this datagram.
*/
for (fp = ipq.next; fp != &ipq; fp = fp->next)
if (ip->ip_id == fp->ipq_id &&
ip->ip_src.s_addr == fp->ipq_src.s_addr &&
ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
ip->ip_p == fp->ipq_p)
goto found;
fp = 0;
found:
/*
* Adjust ip_len to not reflect header,
* set ip_mff if more fragments are expected,
* convert offset of this to bytes.
*/
ip->ip_len -= hlen;
((struct ipasfrag *)ip)->ipf_mff &= ~1;
if (ip->ip_off & IP_MF)
((struct ipasfrag *)ip)->ipf_mff |= 1;
ip->ip_off <<= 3;
/*
* If datagram marked as having more fragments
* or if this is not the first fragment,
* attempt reassembly; if it succeeds, proceed.
*/
if (((struct ipasfrag *)ip)->ipf_mff & 1 || ip->ip_off) {
ipstat.ips_fragments++;
ip = ip_reass((struct ipasfrag *)ip, fp);
if (ip == 0)
goto next;
ipstat.ips_reassembled++;
m = dtom(ip);
} else
if (fp)
ip_freef(fp);
} else
/*
* Ip input routine. Checksum and byte swap header. If fragmented
* try to reassemble. Process options. Pass to next level.
*/
void
ip_input(struct mbuf *m)
{
register struct ip *ip;
int hlen;
DEBUG_CALL("ip_input");
DEBUG_ARG("m = %lx", (long)m);
DEBUG_ARG("m_len = %d", m->m_len);
STAT(ipstat.ips_total++);
if (m->m_len < (int)sizeof (struct ip)) {
STAT(ipstat.ips_toosmall++);
return;
}
ip = mtod(m, struct ip *);
if (ip->ip_v != IPVERSION) {
STAT(ipstat.ips_badvers++);
goto bad;
}
hlen = ip->ip_hl << 2;
if (hlen < (int)sizeof(struct ip ) || hlen>m->m_len) {/* min header length */
STAT(ipstat.ips_badhlen++); /* or packet too short */
goto bad;
}
/* keep ip header intact for ICMP reply
* ip->ip_sum = cksum(m, hlen);
* if (ip->ip_sum) {
*/
if(cksum(m,hlen)) {
STAT(ipstat.ips_badsum++);
goto bad;
}
/*
* Convert fields to host representation.
*/
NTOHS(ip->ip_len);
if (ip->ip_len < hlen) {
STAT(ipstat.ips_badlen++);
goto bad;
}
NTOHS(ip->ip_id);
NTOHS(ip->ip_off);
/*
* Check that the amount of data in the buffers
* is as at least much as the IP header would have us expect.
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
if (m->m_len < ip->ip_len) {
STAT(ipstat.ips_tooshort++);
goto bad;
}
if (slirp_restrict) {
if (ip_geth(ip->ip_dst) != special_addr_ip) {
if (ip_getn(ip->ip_dst) == 0xffffffffu && ip->ip_p != IPPROTO_UDP)
goto bad;
} else {
int host = ip_geth(ip->ip_dst) & 0xff;
struct ex_list *ex_ptr;
if (host == 0xff)
goto bad;
for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next)
if (ex_ptr->ex_addr == host)
break;
if (!ex_ptr)
goto bad;
}
}
/* Should drop packet if mbuf too long? hmmm... */
if (m->m_len > ip->ip_len)
m_adj(m, ip->ip_len - m->m_len);
/* check ip_ttl for a correct ICMP reply */
if(ip->ip_ttl==0 || ip->ip_ttl==1) {
icmp_error(m, ICMP_TIMXCEED,ICMP_TIMXCEED_INTRANS, 0,"ttl");
goto bad;
}
/*
* Process options and, if not destined for us,
* ship it on. ip_dooptions returns 1 when an
* error was detected (causing an icmp message
* to be sent and the original packet to be freed).
*/
/* We do no IP options */
/* if (hlen > sizeof (struct ip) && ip_dooptions(m))
* goto next;
*/
/*
* If offset or IP_MF are set, must reassemble.
* Otherwise, nothing need be done.
* (We could look in the reassembly queue to see
* if the packet was previously fragmented,
* but it's not worth the time; just let them time out.)
*
* XXX This should fail, don't fragment yet
*/
if (ip->ip_off &~ IP_DF) {
register struct ipq *fp;
struct qlink *l;
/*
* Look for queue of fragments
* of this datagram.
*/
for (l = ipq.ip_link.next; l != &ipq.ip_link; l = l->next) {
fp = container_of(l, struct ipq, ip_link);
if (ip->ip_id == fp->ipq_id &&
ip_equal(ip->ip_src, fp->ipq_src) &&
ip_equal(ip->ip_dst, fp->ipq_dst) &&
ip->ip_p == fp->ipq_p)
goto found;
}
fp = NULL;
found:
/*
* Adjust ip_len to not reflect header,
* set ip_mff if more fragments are expected,
* convert offset of this to bytes.
*/
ip->ip_len -= hlen;
if (ip->ip_off & IP_MF)
ip->ip_tos |= 1;
else
ip->ip_tos &= ~1;
ip->ip_off <<= 3;
/*
* If datagram marked as having more fragments
* or if this is not the first fragment,
* attempt reassembly; if it succeeds, proceed.
*/
if (ip->ip_tos & 1 || ip->ip_off) {
STAT(ipstat.ips_fragments++);
ip = ip_reass(ip, fp);
if (ip == NULL)
return;
STAT(ipstat.ips_reassembled++);
m = dtom(ip);
} else if (fp)
ip_freef(fp);
} else
/*
* Ip input routine. Checksum and byte swap header. If fragmented
* try to reassemble. Process options. Pass to next level.
*/
void ip_input(struct mbuf *m)
{
struct ip *ip;
int hlen;
DEBUG_CALL("ip_input");
DEBUG_ARG("m = %lx", (long)m);
DEBUG_ARG("m_len = %d", m->m_len);
ipstat.ips_total++;
if (m->m_len < sizeof (struct ip)) {
ipstat.ips_toosmall++;
return;
}
ip = mtod(m, struct ip *);
if (ip->ip_v != IPVERSION) {
ipstat.ips_badvers++;
goto bad;
}
hlen = ip->ip_hl << 2;
if (hlen<sizeof(struct ip ) || hlen>m->m_len) {/* min header length */
ipstat.ips_badhlen++; /* or packet too short */
goto bad;
}
/* keep ip header intact for ICMP reply
* ip->ip_sum = cksum(m, hlen);
* if (ip->ip_sum) {
*/
if(cksum(m,hlen)) {
ipstat.ips_badsum++;
goto bad;
}
/*
* Convert fields to host representation.
*/
NTOHS(ip->ip_len);
if (ip->ip_len < hlen) {
ipstat.ips_badlen++;
goto bad;
}
NTOHS(ip->ip_id);
NTOHS(ip->ip_off);
/*
* Check that the amount of data in the buffers
* is as at least much as the IP header would have us expect.
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
if (m->m_len < ip->ip_len) {
ipstat.ips_tooshort++;
goto bad;
}
/* Should drop packet if mbuf too long? hmmm... */
if (m->m_len > ip->ip_len)
m_adj(m, ip->ip_len - m->m_len);
/* check ip_ttl for a correct ICMP reply */
if(ip->ip_ttl==0 || ip->ip_ttl==1) {
icmp_error(m, ICMP_TIMXCEED,ICMP_TIMXCEED_INTRANS, 0,"ttl");
goto bad;
}
/*
* Process options and, if not destined for us,
* ship it on. ip_dooptions returns 1 when an
* error was detected (causing an icmp message
* to be sent and the original packet to be freed).
*/
/* We do no IP options */
/* if (hlen > sizeof (struct ip) && ip_dooptions(m))
* goto next;
*/
/*
* If offset or IP_MF are set, must reassemble.
* Otherwise, nothing need be done.
* (We could look in the reassembly queue to see
* if the packet was previously fragmented,
* but it's not worth the time; just let them time out.)
*
* XXX This should fail, don't fragment yet
*/
if (ip->ip_off &~ IP_DF) {
register struct ipq *fp;
/*
* Look for queue of fragments
* of this datagram.
*/
for (fp = (struct ipq *) ipq.next; fp != &ipq;
fp = (struct ipq *) fp->next)
if (ip->ip_id == fp->ipq_id &&
ip->ip_src.s_addr == fp->ipq_src.s_addr &&
ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
ip->ip_p == fp->ipq_p)
goto found;
fp = 0;
found:
/*
* Adjust ip_len to not reflect header,
* set ip_mff if more fragments are expected,
* convert offset of this to bytes.
*/
ip->ip_len -= hlen;
if (ip->ip_off & IP_MF)
((struct ipasfrag *)ip)->ipf_mff |= 1;
else
((struct ipasfrag *)ip)->ipf_mff &= ~1;
ip->ip_off <<= 3;
/*
* If datagram marked as having more fragments
* or if this is not the first fragment,
* attempt reassembly; if it succeeds, proceed.
*/
if (((struct ipasfrag *)ip)->ipf_mff & 1 || ip->ip_off) {
ipstat.ips_fragments++;
ip = ip_reass((struct ipasfrag *)ip, fp);
if (ip == 0)
return;
ipstat.ips_reassembled++;
m = dtom(ip);
} else
if (fp)
ip_freef(fp);
} else
ip->ip_len -= hlen;
/*
* Switch out to protocol's input routine.
*/
ipstat.ips_delivered++;
switch (ip->ip_p) {
case IPPROTO_TCP:
tcp_input(m, hlen, (struct socket *)NULL);
break;
case IPPROTO_UDP:
udp_input(m, hlen);
break;
case IPPROTO_ICMP:
icmp_input(m, hlen);
break;
default:
ipstat.ips_noproto++;
m_free(m);
}
return;
bad:
m_freem(m);
return;
}
/*
* Ip input routine. Checksum and byte swap header. If fragmented
* try to reassamble. If complete and fragment queue exists, discard.
* Process options. Pass to next level.
*/
ipintr()
{
register struct ip *ip;
register struct mbuf *m;
struct mbuf *m0;
register int i;
register struct ipq *fp;
register struct in_ifaddr *ia;
struct ifnet *ifp;
int hlen, s;
/* IOdebug( "ipintr: called" ); */
next:
/*
* Get next datagram off input queue and get IP header
* in first mbuf.
*/
s = splimp();
IF_DEQUEUEIF(&ipintrq, m, ifp);
splx(s);
if (m == NULL)
{
/* IOdebug( "ipintr: no more mbufs" ); */
return;
}
/*
* If no IP addresses have been set yet but the interfaces
* are receiving, can't do anything with incoming packets yet.
*/
if (in_ifaddr == NULL)
goto bad;
ipstat.ips_total++;
if ((m->m_off > MMAXOFF || m->m_len < sizeof (struct ip)) &&
(m = m_pullup(m, sizeof (struct ip))) == 0) {
ipstat.ips_toosmall++;
goto next;
}
ip = mtod(m, struct ip *);
hlen = ip->ip_hl << 2;
if (hlen < sizeof(struct ip)) { /* minimum header length */
ipstat.ips_badhlen++;
goto bad;
}
if (hlen > m->m_len) {
if ((m = m_pullup(m, hlen)) == 0) {
ipstat.ips_badhlen++;
goto next;
}
ip = mtod(m, struct ip *);
}
if (ipcksum)
if (ip->ip_sum = in_cksum(m, hlen)) {
ipstat.ips_badsum++;
/* IOdebug( "ipintr: bad checksum" ); */
goto bad;
}
/*
* Convert fields to host representation.
*/
ip->ip_len = ntohs((u_short)ip->ip_len);
if (ip->ip_len < hlen) {
ipstat.ips_badlen++;
goto bad;
}
ip->ip_id = ntohs(ip->ip_id);
ip->ip_off = ntohs((u_short)ip->ip_off);
/*
* Check that the amount of data in the buffers
* is as at least much as the IP header would have us expect.
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
i = -(u_short)ip->ip_len;
m0 = m;
for (;;) {
i += m->m_len;
if (m->m_next == 0)
break;
m = m->m_next;
}
if (i != 0) {
if (i < 0) {
ipstat.ips_tooshort++;
m = m0;
goto bad;
}
if (i <= m->m_len)
m->m_len -= i;
else
m_adj(m0, -i);
}
m = m0;
/*
* Process options and, if not destined for us,
* ship it on. ip_dooptions returns 1 when an
* error was detected (causing an icmp message
* to be sent and the original packet to be freed).
*/
ip_nhops = 0; /* for source routed packets */
if (hlen > sizeof (struct ip) && ip_dooptions(ip, ifp))
goto next;
/*
* Check our list of addresses, to see if the packet is for us.
*/
/* IOdebug( "ipintr: checking address" ); */
for (ia = in_ifaddr; ia; ia = ia->ia_next) {
#define satosin(sa) ((struct sockaddr_in *)(sa))
if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr)
goto ours;
if (
#ifdef DIRECTED_BROADCAST
ia->ia_ifp == ifp &&
#endif
(ia->ia_ifp->if_flags & IFF_BROADCAST)) {
u_long t;
if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
ip->ip_dst.s_addr)
goto ours;
if (ip->ip_dst.s_addr == ia->ia_netbroadcast.s_addr)
goto ours;
/*
* Look for all-0's host part (old broadcast addr),
* either for subnet or net.
*/
t = ntohl(ip->ip_dst.s_addr);
if (t == ia->ia_subnet)
goto ours;
if (t == ia->ia_net)
goto ours;
}
}
if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
goto ours;
if (ip->ip_dst.s_addr == INADDR_ANY)
goto ours;
/*
* Not for us; forward if possible and desirable.
*/
ip_forward(ip, ifp);
/* IOdebug( "ipintr: not for us" ); */
goto next;
ours:
/* IOdebug( "ipintr: ours" ); */
/*
* If offset or IP_MF are set, must reassemble.
* Otherwise, nothing need be done.
* (We could look in the reassembly queue to see
* if the packet was previously fragmented,
* but it's not worth the time; just let them time out.)
*/
if (ip->ip_off &~ IP_DF) {
/*
* Look for queue of fragments
* of this datagram.
*/
for (fp = ipq.next; fp != &ipq; fp = fp->next)
if (ip->ip_id == fp->ipq_id &&
ip->ip_src.s_addr == fp->ipq_src.s_addr &&
ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
ip->ip_p == fp->ipq_p)
goto found;
fp = 0;
found:
/*
* Adjust ip_len to not reflect header,
* set ip_mff if more fragments are expected,
* convert offset of this to bytes.
*/
ip->ip_len -= hlen;
((struct ipasfrag *)ip)->ipf_mff = 0;
if (ip->ip_off & IP_MF)
((struct ipasfrag *)ip)->ipf_mff = 1;
ip->ip_off <<= 3;
/*
* If datagram marked as having more fragments
* or if this is not the first fragment,
* attempt reassembly; if it succeeds, proceed.
*/
if (((struct ipasfrag *)ip)->ipf_mff || ip->ip_off)
{
/* IOdebug( "ipintr: attempting reassembly" ); */
ipstat.ips_fragments++;
ip = ip_reass((struct ipasfrag *)ip, fp);
if (ip == NULL)
{
/* IOdebug( "ipintr: attempt failed" ); */
goto next;
}
m = dtom(ip);
}
else
if (fp)
ip_freef(fp);
} else
ip->ip_len -= hlen;
/*
* Switch out to protocol's input routine.
*/
/* IOdebug( "ipintr: handling packet of len %d", ip->ip_len ); */
(*inetsw[ip_protox[ip->ip_p]].pr_input)(m, ifp);
/* IOdebug( "ipintr: handled" ); */
goto next;
bad:
/* IOdebug( "ipintr: bad input" ); */
m_freem(m);
goto next;
}