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[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [libnetworking/] [netinet/] [ip_input.c] - Rev 310
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/* * Copyright (c) 1982, 1986, 1988, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 * $Id: ip_input.c,v 1.2 2001-09-27 12:01:55 chris Exp $ * $ANA: ip_input.c,v 1.5 1996/09/18 14:34:59 wollman Exp $ */ #define _IP_VHL #include "opt_ipfw.h" #include <stddef.h> #include <sys/param.h> #include <sys/systm.h> #include <sys/malloc.h> #include <sys/mbuf.h> #include <sys/domain.h> #include <sys/protosw.h> #include <sys/socket.h> #include <sys/errno.h> #include <sys/time.h> #include <sys/kernel.h> #include <sys/syslog.h> #include <sys/sysctl.h> #include <net/if.h> #include <net/if_dl.h> #include <net/route.h> #include <net/netisr.h> #include <netinet/in.h> #include <netinet/in_systm.h> #include <netinet/in_var.h> #include <netinet/ip.h> #include <netinet/in_pcb.h> #include <netinet/in_var.h> #include <netinet/ip_var.h> #include <netinet/ip_icmp.h> #include <machine/in_cksum.h> #include <sys/socketvar.h> #ifdef IPFIREWALL #include <netinet/ip_fw.h> #endif int rsvp_on = 0; static int ip_rsvp_on; struct socket *ip_rsvpd; static int ipforwarding = 0; SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW, &ipforwarding, 0, ""); static int ipsendredirects = 1; /* XXX */ SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW, &ipsendredirects, 0, ""); int ip_defttl = IPDEFTTL; SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW, &ip_defttl, 0, ""); static int ip_dosourceroute = 0; SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW, &ip_dosourceroute, 0, ""); static int ip_acceptsourceroute = 0; SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute, CTLFLAG_RW, &ip_acceptsourceroute, 0, ""); #ifdef DIAGNOSTIC static int ipprintfs = 0; #endif extern struct domain inetdomain; extern struct protosw inetsw[]; u_char ip_protox[IPPROTO_MAX]; static int ipqmaxlen = IFQ_MAXLEN; struct in_ifaddr *in_ifaddr; /* first inet address */ struct ifqueue ipintrq; SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RD, &ipintrq.ifq_maxlen, 0, ""); SYSCTL_INT(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLFLAG_RD, &ipintrq.ifq_drops, 0, ""); struct ipstat ipstat; /* Packet reassembly stuff */ #define IPREASS_NHASH_LOG2 6 #define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2) #define IPREASS_HMASK (IPREASS_NHASH - 1) #define IPREASS_HASH(x,y) \ (((((x) & 0xF) | ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK) static struct ipq ipq[IPREASS_NHASH]; static int nipq = 0; /* total # of reass queues */ static int maxnipq; #ifdef IPCTL_DEFMTU SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW, &ip_mtu, 0, ""); #endif #if !defined(COMPAT_IPFW) || COMPAT_IPFW == 1 #undef COMPAT_IPFW #define COMPAT_IPFW 1 #else #undef COMPAT_IPFW #endif #ifdef COMPAT_IPFW /* Firewall hooks */ ip_fw_chk_t *ip_fw_chk_ptr; ip_fw_ctl_t *ip_fw_ctl_ptr; /* IP Network Address Translation (NAT) hooks */ ip_nat_t *ip_nat_ptr; ip_nat_ctl_t *ip_nat_ctl_ptr; #endif /* * We need to save the IP options in case a protocol wants to respond * to an incoming packet over the same route if the packet got here * using IP source routing. This allows connection establishment and * maintenance when the remote end is on a network that is not known * to us. */ static int ip_nhops = 0; static struct ip_srcrt { struct in_addr dst; /* final destination */ char nop; /* one NOP to align */ char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */ struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)]; } ip_srcrt; #ifdef IPDIVERT /* * Shared variable between ip_input() and ip_reass() to communicate * about which packets, once assembled from fragments, get diverted, * and to which port. */ static u_short frag_divert_port; #endif static void save_rte __P((u_char *, struct in_addr)); static void ip_deq __P((struct ipasfrag *)); static int ip_dooptions __P((struct mbuf *)); static void ip_enq __P((struct ipasfrag *, struct ipasfrag *)); static void ip_forward __P((struct mbuf *, int)); static void ip_freef __P((struct ipq *)); static struct ip * ip_reass __P((struct ipasfrag *, struct ipq *, struct ipq *)); static struct in_ifaddr * ip_rtaddr __P((struct in_addr)); void ipintr __P((void)); /* * IP initialization: fill in IP protocol switch table. * All protocols not implemented in kernel go to raw IP protocol handler. */ void ip_init() { register struct protosw *pr; register int i; pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW); if (pr == 0) panic("ip_init"); for (i = 0; i < IPPROTO_MAX; i++) ip_protox[i] = pr - inetsw; for (pr = inetdomain.dom_protosw; pr < inetdomain.dom_protoswNPROTOSW; pr++) if (pr->pr_domain->dom_family == PF_INET && pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) ip_protox[pr->pr_protocol] = pr - inetsw; for (i = 0; i < IPREASS_NHASH; i++) ipq[i].next = ipq[i].prev = &ipq[i]; maxnipq = nmbclusters/4; ip_id = rtems_bsdnet_seconds_since_boot() & 0xffff; ipintrq.ifq_maxlen = ipqmaxlen; #ifdef IPFIREWALL ip_fw_init(); #endif #ifdef IPNAT ip_nat_init(); #endif } static struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET }; static struct route ipforward_rt; /* * 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; struct ipq *fp; struct in_ifaddr *ia; int i, hlen; u_short sum; #ifdef DIAGNOSTIC if ((m->m_flags & M_PKTHDR) == 0) panic("ip_input 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_pkthdr.len < sizeof(struct ip)) goto tooshort; #if defined(DIAGNOSTIC) && defined(ORIGINAL_FREEBSD_CODE) if (m->m_len < sizeof(struct ip)) panic("ipintr mbuf too short"); #endif if (m->m_len < sizeof (struct ip) && (m = m_pullup(m, sizeof (struct ip))) == 0) { ipstat.ips_toosmall++; return; } ip = mtod(m, struct ip *); if (IP_VHL_V(ip->ip_vhl) != IPVERSION) { ipstat.ips_badvers++; goto bad; } hlen = IP_VHL_HL(ip->ip_vhl) << 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++; return; } ip = mtod(m, struct ip *); } if (hlen == sizeof(struct ip)) { sum = in_cksum_hdr(ip); } else { sum = in_cksum(m, hlen); } if (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) { tooshort: 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); } /* * IpHack's section. * Right now when no processing on packet has done * and it is still fresh out of network we do our black * deals with it. * - Firewall: deny/allow/divert * - Xlate: translate packet's addr/port (NAT). * - Wrap: fake packet's addr/port <unimpl.> * - Encapsulate: put it in another IP and send out. <unimp.> */ #ifdef COMPAT_IPFW if (ip_fw_chk_ptr) { #ifdef IPDIVERT u_short port; port = (*ip_fw_chk_ptr)(&ip, hlen, NULL, ip_divert_ignore, &m); ip_divert_ignore = 0; if (port) { /* Divert packet */ frag_divert_port = port; goto ours; } #else /* If ipfw says divert, we have to just drop packet */ if ((*ip_fw_chk_ptr)(&ip, hlen, NULL, 0, &m)) { m_freem(m); m = NULL; } #endif if (!m) return; } if (ip_nat_ptr && !(*ip_nat_ptr)(&ip, &m, m->m_pkthdr.rcvif, IP_NAT_IN)) return; #endif /* * 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)) return; /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no * matter if it is destined to another node, or whether it is * a multicast one, RSVP wants it! and prevents it from being forwarded * anywhere else. Also checks if the rsvp daemon is running before * grabbing the packet. */ if (rsvp_on && ip->ip_p==IPPROTO_RSVP) goto ours; /* * 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; #ifdef BOOTP_COMPAT if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) goto ours; #endif if (ia->ia_ifp && ia->ia_ifp->if_flags & IFF_BROADCAST) { 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; } } if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) { struct in_multi *inm; 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(ip, m->m_pkthdr.rcvif, m, 0) != 0) { ipstat.ips_cantforward++; m_freem(m); return; } 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++; } /* * 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); return; } 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); return; 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 | IP_RF)) { if (m->m_flags & M_EXT) { /* XXX */ if ((m = m_pullup(m, sizeof (struct ip))) == 0) { ipstat.ips_toosmall++; #ifdef IPDIVERT frag_divert_port = 0; #endif return; } ip = mtod(m, struct ip *); } sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id); /* * Look for queue of fragments * of this datagram. */ for (fp = ipq[sum].next; fp != &ipq[sum]; 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; /* check if there's a place for the new queue */ if (nipq > maxnipq) { /* * drop something from the tail of the current queue * before proceeding further */ if (ipq[sum].prev == &ipq[sum]) { /* gak */ for (i = 0; i < IPREASS_NHASH; i++) { if (ipq[i].prev != &ipq[i]) { ip_freef(ipq[i].prev); break; } } } else ip_freef(ipq[sum].prev); } 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, &ipq[sum]); if (ip == 0) return; ipstat.ips_reassembled++; m = dtom(ip); #ifdef IPDIVERT if (frag_divert_port) { ip->ip_len += hlen; HTONS(ip->ip_len); HTONS(ip->ip_off); HTONS(ip->ip_id); ip->ip_sum = 0; ip->ip_sum = in_cksum_hdr(ip); NTOHS(ip->ip_id); NTOHS(ip->ip_off); NTOHS(ip->ip_len); ip->ip_len -= hlen; } #endif } else if (fp) ip_freef(fp); } else ip->ip_len -= hlen; #ifdef IPDIVERT /* * Divert reassembled packets to the divert protocol if required */ if (frag_divert_port) { ipstat.ips_delivered++; ip_divert_port = frag_divert_port; frag_divert_port = 0; (*inetsw[ip_protox[IPPROTO_DIVERT]].pr_input)(m, hlen); return; } /* Don't let packets divert themselves */ if (ip->ip_p == IPPROTO_DIVERT) { ipstat.ips_noproto++; goto bad; } #endif /* * Switch out to protocol's input routine. */ ipstat.ips_delivered++; (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen); return; bad: m_freem(m); } /* * IP software interrupt routine - to go away sometime soon */ void ipintr(void) { int s; struct mbuf *m; while(1) { s = splimp(); IF_DEQUEUE(&ipintrq, m); splx(s); if (m == 0) return; ip_input(m); } } NETISR_SET(NETISR_IP, ipintr); /* * Take incoming datagram fragment and try to * reassemble it into whole datagram. If a chain for * reassembly of this datagram already exists, then it * is given as fp; otherwise have to make a chain. */ static struct ip * ip_reass(ip, fp, where) register struct ipasfrag *ip; register struct ipq *fp; struct ipq *where; { register struct mbuf *m = dtom(ip); register struct ipasfrag *q; struct mbuf *t; int hlen = ip->ip_hl << 2; int i, next; /* * Presence of header sizes in mbufs * would confuse code below. */ m->m_data += hlen; m->m_len -= hlen; /* * If first fragment to arrive, create a reassembly queue. */ if (fp == 0) { if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL) goto dropfrag; fp = mtod(t, struct ipq *); insque(fp, where); nipq++; fp->ipq_ttl = IPFRAGTTL; fp->ipq_p = ip->ip_p; fp->ipq_id = ip->ip_id; fp->ipq_next = fp->ipq_prev = (struct ipasfrag *)fp; fp->ipq_src = ((struct ip *)ip)->ip_src; fp->ipq_dst = ((struct ip *)ip)->ip_dst; #ifdef IPDIVERT fp->ipq_divert = 0; #endif q = (struct ipasfrag *)fp; goto insert; } /* * Find a segment which begins after this one does. */ for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = q->ipf_next) if (q->ip_off > ip->ip_off) break; /* * If there is a preceding segment, it may provide some of * our data already. If so, drop the data from the incoming * segment. If it provides all of our data, drop us. */ if (q->ipf_prev != (struct ipasfrag *)fp) { i = q->ipf_prev->ip_off + q->ipf_prev->ip_len - ip->ip_off; if (i > 0) { if (i >= ip->ip_len) goto dropfrag; m_adj(dtom(ip), i); ip->ip_off += i; ip->ip_len -= i; } } /* * While we overlap succeeding segments trim them or, * if they are completely covered, dequeue them. */ while (q != (struct ipasfrag *)fp && ip->ip_off + ip->ip_len > q->ip_off) { struct mbuf *m0; i = (ip->ip_off + ip->ip_len) - q->ip_off; if (i < q->ip_len) { q->ip_len -= i; q->ip_off += i; m_adj(dtom(q), i); break; } m0 = dtom(q); q = q->ipf_next; ip_deq(q->ipf_prev); m_freem(m0); } insert: #ifdef IPDIVERT /* * Any fragment diverting causes the whole packet to divert */ if (frag_divert_port != 0) fp->ipq_divert = frag_divert_port; frag_divert_port = 0; #endif /* * Stick new segment in its place; * check for complete reassembly. */ ip_enq(ip, q->ipf_prev); next = 0; for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = q->ipf_next) { if (q->ip_off != next) return (0); next += q->ip_len; } if (q->ipf_prev->ipf_mff & 1) return (0); /* * Reassembly is complete. Make sure the packet is a sane size. */ if (next + (IP_VHL_HL(((struct ip *)fp->ipq_next)->ip_vhl) << 2) > IP_MAXPACKET) { ipstat.ips_toolong++; ip_freef(fp); return (0); } /* * Concatenate fragments. */ q = fp->ipq_next; m = dtom(q); t = m->m_next; m->m_next = 0; m_cat(m, t); q = q->ipf_next; while (q != (struct ipasfrag *)fp) { t = dtom(q); q = q->ipf_next; m_cat(m, t); } #ifdef IPDIVERT /* * Record divert port for packet, if any */ frag_divert_port = fp->ipq_divert; #endif /* * Create header for new ip packet by * modifying header of first packet; * dequeue and discard fragment reassembly header. * Make header visible. */ ip = fp->ipq_next; ip->ip_len = next; ip->ipf_mff &= ~1; ((struct ip *)ip)->ip_src = fp->ipq_src; ((struct ip *)ip)->ip_dst = fp->ipq_dst; remque(fp); nipq--; (void) m_free(dtom(fp)); m = dtom(ip); m->m_len += (ip->ip_hl << 2); m->m_data -= (ip->ip_hl << 2); /* some debugging cruft by sklower, below, will go away soon */ if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */ register int plen = 0; for (t = m; m; m = m->m_next) plen += m->m_len; t->m_pkthdr.len = plen; } return ((struct ip *)ip); dropfrag: ipstat.ips_fragdropped++; m_freem(m); return (0); } /* * Free a fragment reassembly header and all * associated datagrams. */ static void ip_freef(fp) struct ipq *fp; { register struct ipasfrag *q, *p; for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = p) { p = q->ipf_next; ip_deq(q); m_freem(dtom(q)); } remque(fp); (void) m_free(dtom(fp)); nipq--; } /* * Put an ip fragment on a reassembly chain. * Like insque, but pointers in middle of structure. */ static void ip_enq(p, prev) register struct ipasfrag *p, *prev; { p->ipf_prev = prev; p->ipf_next = prev->ipf_next; prev->ipf_next->ipf_prev = p; prev->ipf_next = p; } /* * To ip_enq as remque is to insque. */ static void ip_deq(p) register struct ipasfrag *p; { p->ipf_prev->ipf_next = p->ipf_next; p->ipf_next->ipf_prev = p->ipf_prev; } /* * IP timer processing; * if a timer expires on a reassembly * queue, discard it. */ void ip_slowtimo() { register struct ipq *fp; int s = splnet(); int i; for (i = 0; i < IPREASS_NHASH; i++) { fp = ipq[i].next; if (fp == 0) continue; while (fp != &ipq[i]) { --fp->ipq_ttl; fp = fp->next; if (fp->prev->ipq_ttl == 0) { ipstat.ips_fragtimeout++; ip_freef(fp->prev); } } } splx(s); } /* * Drain off all datagram fragments. */ void ip_drain() { int i; for (i = 0; i < IPREASS_NHASH; i++) { while (ipq[i].next != &ipq[i]) { ipstat.ips_fragdropped++; ip_freef(ipq[i].next); } } in_rtqdrain(); } /* * Do option processing on a datagram, * possibly discarding it if bad options are encountered, * or forwarding it if source-routed. * Returns 1 if packet has been forwarded/freed, * 0 if the packet should be processed further. */ static int ip_dooptions(m) struct mbuf *m; { register struct ip *ip = mtod(m, struct ip *); register u_char *cp; register struct ip_timestamp *ipt; register struct in_ifaddr *ia; int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0; struct in_addr *sin, dst; n_time ntime; dst = ip->ip_dst; cp = (u_char *)(ip + 1); cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip); for (; cnt > 0; cnt -= optlen, cp += optlen) { opt = cp[IPOPT_OPTVAL]; if (opt == IPOPT_EOL) break; if (opt == IPOPT_NOP) optlen = 1; else { optlen = cp[IPOPT_OLEN]; if (optlen <= 0 || optlen > cnt) { code = &cp[IPOPT_OLEN] - (u_char *)ip; goto bad; } } switch (opt) { default: break; /* * Source routing with record. * Find interface with current destination address. * If none on this machine then drop if strictly routed, * or do nothing if loosely routed. * Record interface address and bring up next address * component. If strictly routed make sure next * address is on directly accessible net. */ case IPOPT_LSRR: case IPOPT_SSRR: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { code = &cp[IPOPT_OFFSET] - (u_char *)ip; goto bad; } ipaddr.sin_addr = ip->ip_dst; ia = (struct in_ifaddr *) ifa_ifwithaddr((struct sockaddr *)&ipaddr); if (ia == 0) { if (opt == IPOPT_SSRR) { type = ICMP_UNREACH; code = ICMP_UNREACH_SRCFAIL; goto bad; } if (!ip_dosourceroute) goto nosourcerouting; /* * Loose routing, and not at next destination * yet; nothing to do except forward. */ break; } off--; /* 0 origin */ if (off > optlen - sizeof(struct in_addr)) { /* * End of source route. Should be for us. */ if (!ip_acceptsourceroute) goto nosourcerouting; save_rte(cp, ip->ip_src); break; } if (!ip_dosourceroute) { char buf[4*sizeof "123"]; nosourcerouting: strcpy(buf, inet_ntoa(ip->ip_dst)); log(LOG_WARNING, "attempted source route from %s to %s\n", inet_ntoa(ip->ip_src), buf); type = ICMP_UNREACH; code = ICMP_UNREACH_SRCFAIL; goto bad; } /* * locate outgoing interface */ (void)memcpy(&ipaddr.sin_addr, cp + off, sizeof(ipaddr.sin_addr)); if (opt == IPOPT_SSRR) { #define INA struct in_ifaddr * #define SA struct sockaddr * if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0) ia = (INA)ifa_ifwithnet((SA)&ipaddr); } else ia = ip_rtaddr(ipaddr.sin_addr); if (ia == 0) { type = ICMP_UNREACH; code = ICMP_UNREACH_SRCFAIL; goto bad; } ip->ip_dst = ipaddr.sin_addr; (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr), sizeof(struct in_addr)); cp[IPOPT_OFFSET] += sizeof(struct in_addr); /* * Let ip_intr's mcast routing check handle mcast pkts */ forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr)); break; case IPOPT_RR: if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) { code = &cp[IPOPT_OFFSET] - (u_char *)ip; goto bad; } /* * If no space remains, ignore. */ off--; /* 0 origin */ if (off > optlen - sizeof(struct in_addr)) break; (void)memcpy(&ipaddr.sin_addr, &ip->ip_dst, sizeof(ipaddr.sin_addr)); /* * locate outgoing interface; if we're the destination, * use the incoming interface (should be same). */ if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 && (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) { type = ICMP_UNREACH; code = ICMP_UNREACH_HOST; goto bad; } (void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr), sizeof(struct in_addr)); cp[IPOPT_OFFSET] += sizeof(struct in_addr); break; case IPOPT_TS: code = cp - (u_char *)ip; ipt = (struct ip_timestamp *)cp; if (ipt->ipt_len < 5) goto bad; if (ipt->ipt_ptr > ipt->ipt_len - sizeof (long)) { if (++ipt->ipt_oflw == 0) goto bad; break; } sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1); switch (ipt->ipt_flg) { case IPOPT_TS_TSONLY: break; case IPOPT_TS_TSANDADDR: if (ipt->ipt_ptr + sizeof(n_time) + sizeof(struct in_addr) > ipt->ipt_len) goto bad; ipaddr.sin_addr = dst; ia = (INA)ifaof_ifpforaddr((SA)&ipaddr, m->m_pkthdr.rcvif); if (ia == 0) continue; (void)memcpy(sin, &IA_SIN(ia)->sin_addr, sizeof(struct in_addr)); ipt->ipt_ptr += sizeof(struct in_addr); break; case IPOPT_TS_PRESPEC: if (ipt->ipt_ptr + sizeof(n_time) + sizeof(struct in_addr) > ipt->ipt_len) goto bad; (void)memcpy(&ipaddr.sin_addr, sin, sizeof(struct in_addr)); if (ifa_ifwithaddr((SA)&ipaddr) == 0) continue; ipt->ipt_ptr += sizeof(struct in_addr); break; default: goto bad; } ntime = iptime(); (void)memcpy(cp + ipt->ipt_ptr - 1, &ntime, sizeof(n_time)); ipt->ipt_ptr += sizeof(n_time); } } if (forward && ipforwarding) { ip_forward(m, 1); return (1); } return (0); bad: ip->ip_len -= IP_VHL_HL(ip->ip_vhl) << 2; /* XXX icmp_error adds in hdr length */ icmp_error(m, type, code, 0, 0); ipstat.ips_badoptions++; return (1); } /* * Given address of next destination (final or next hop), * return internet address info of interface to be used to get there. */ static struct in_ifaddr * ip_rtaddr(dst) struct in_addr dst; { register struct sockaddr_in *sin; sin = (struct sockaddr_in *) &ipforward_rt.ro_dst; if (ipforward_rt.ro_rt == 0 || dst.s_addr != sin->sin_addr.s_addr) { if (ipforward_rt.ro_rt) { RTFREE(ipforward_rt.ro_rt); ipforward_rt.ro_rt = 0; } sin->sin_family = AF_INET; sin->sin_len = sizeof(*sin); sin->sin_addr = dst; rtalloc_ign(&ipforward_rt, RTF_PRCLONING); } if (ipforward_rt.ro_rt == 0) return ((struct in_ifaddr *)0); return ((struct in_ifaddr *) ipforward_rt.ro_rt->rt_ifa); } /* * Save incoming source route for use in replies, * to be picked up later by ip_srcroute if the receiver is interested. */ void save_rte(option, dst) u_char *option; struct in_addr dst; { unsigned olen; olen = option[IPOPT_OLEN]; #ifdef DIAGNOSTIC if (ipprintfs) printf("save_rte: olen %d\n", olen); #endif if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst))) return; bcopy(option, ip_srcrt.srcopt, olen); ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr); ip_srcrt.dst = dst; } /* * Retrieve incoming source route for use in replies, * in the same form used by setsockopt. * The first hop is placed before the options, will be removed later. */ struct mbuf * ip_srcroute() { register struct in_addr *p, *q; register struct mbuf *m; if (ip_nhops == 0) return ((struct mbuf *)0); m = m_get(M_DONTWAIT, MT_SOOPTS); if (m == 0) return ((struct mbuf *)0); #define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt)) /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */ m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) + OPTSIZ; #ifdef DIAGNOSTIC if (ipprintfs) printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len); #endif /* * First save first hop for return route */ p = &ip_srcrt.route[ip_nhops - 1]; *(mtod(m, struct in_addr *)) = *p--; #ifdef DIAGNOSTIC if (ipprintfs) printf(" hops %lx", ntohl(mtod(m, struct in_addr *)->s_addr)); #endif /* * Copy option fields and padding (nop) to mbuf. */ ip_srcrt.nop = IPOPT_NOP; ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF; (void)memcpy(mtod(m, caddr_t) + sizeof(struct in_addr), &ip_srcrt.nop, OPTSIZ); q = (struct in_addr *)(mtod(m, caddr_t) + sizeof(struct in_addr) + OPTSIZ); #undef OPTSIZ /* * Record return path as an IP source route, * reversing the path (pointers are now aligned). */ while (p >= ip_srcrt.route) { #ifdef DIAGNOSTIC if (ipprintfs) printf(" %lx", ntohl(q->s_addr)); #endif *q++ = *p--; } /* * Last hop goes to final destination. */ *q = ip_srcrt.dst; #ifdef DIAGNOSTIC if (ipprintfs) printf(" %lx\n", ntohl(q->s_addr)); #endif return (m); } /* * Strip out IP options, at higher * level protocol in the kernel. * Second argument is buffer to which options * will be moved, and return value is their length. * XXX should be deleted; last arg currently ignored. */ void ip_stripoptions(m, mopt) register struct mbuf *m; struct mbuf *mopt; { register int i; struct ip *ip = mtod(m, struct ip *); register caddr_t opts; int olen; olen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip); opts = (caddr_t)(ip + 1); i = m->m_len - (sizeof (struct ip) + olen); bcopy(opts + olen, opts, (unsigned)i); m->m_len -= olen; if (m->m_flags & M_PKTHDR) m->m_pkthdr.len -= olen; ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2); } u_char inetctlerrmap[PRC_NCMDS] = { 0, 0, 0, 0, 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, EMSGSIZE, EHOSTUNREACH, 0, 0, 0, 0, 0, 0, ENOPROTOOPT }; /* * Forward a packet. If some error occurs return the sender * an icmp packet. Note we can't always generate a meaningful * icmp message because icmp doesn't have a large enough repertoire * of codes and types. * * If not forwarding, just drop the packet. This could be confusing * if ipforwarding was zero but some routing protocol was advancing * us as a gateway to somewhere. However, we must let the routing * protocol deal with that. * * The srcrt parameter indicates whether the packet is being forwarded * via a source route. */ static void ip_forward(m, srcrt) struct mbuf *m; int srcrt; { register struct ip *ip = mtod(m, struct ip *); register struct sockaddr_in *sin; register struct rtentry *rt; int error, type = 0, code = 0; struct mbuf *mcopy; n_long dest; struct ifnet *destifp; dest = 0; #ifdef DIAGNOSTIC if (ipprintfs) printf("forward: src %lx dst %lx ttl %x\n", ip->ip_src.s_addr, ip->ip_dst.s_addr, ip->ip_ttl); #endif if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) { ipstat.ips_cantforward++; m_freem(m); return; } HTONS(ip->ip_id); if (ip->ip_ttl <= IPTTLDEC) { icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0); return; } ip->ip_ttl -= IPTTLDEC; sin = (struct sockaddr_in *)&ipforward_rt.ro_dst; if ((rt = ipforward_rt.ro_rt) == 0 || ip->ip_dst.s_addr != sin->sin_addr.s_addr) { if (ipforward_rt.ro_rt) { RTFREE(ipforward_rt.ro_rt); ipforward_rt.ro_rt = 0; } sin->sin_family = AF_INET; sin->sin_len = sizeof(*sin); sin->sin_addr = ip->ip_dst; rtalloc_ign(&ipforward_rt, RTF_PRCLONING); if (ipforward_rt.ro_rt == 0) { icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0); return; } rt = ipforward_rt.ro_rt; } /* * Save at most 64 bytes of the packet in case * we need to generate an ICMP message to the src. */ mcopy = m_copy(m, 0, imin((int)ip->ip_len, 64)); /* * If forwarding packet using same interface that it came in on, * perhaps should send a redirect to sender to shortcut a hop. * Only send redirect if source is sending directly to us, * and if packet was not source routed (or has any options). * Also, don't send redirect if forwarding using a default route * or a route modified by a redirect. */ #define satosin(sa) ((struct sockaddr_in *)(sa)) if (rt->rt_ifp == m->m_pkthdr.rcvif && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 && satosin(rt_key(rt))->sin_addr.s_addr != 0 && ipsendredirects && !srcrt) { #define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa)) u_long src = ntohl(ip->ip_src.s_addr); if (RTA(rt) && (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) { if (rt->rt_flags & RTF_GATEWAY) dest = satosin(rt->rt_gateway)->sin_addr.s_addr; else dest = ip->ip_dst.s_addr; /* Router requirements says to only send host redirects */ type = ICMP_REDIRECT; code = ICMP_REDIRECT_HOST; #ifdef DIAGNOSTIC if (ipprintfs) printf("redirect (%d) to %lx\n", code, (u_long)dest); #endif } } error = ip_output(m, (struct mbuf *)0, &ipforward_rt, IP_FORWARDING, 0); if (error) ipstat.ips_cantforward++; else { ipstat.ips_forward++; if (type) ipstat.ips_redirectsent++; else { if (mcopy) m_freem(mcopy); return; } } if (mcopy == NULL) return; destifp = NULL; switch (error) { case 0: /* forwarded, but need redirect */ /* type, code set above */ break; case ENETUNREACH: /* shouldn't happen, checked above */ case EHOSTUNREACH: case ENETDOWN: case EHOSTDOWN: default: type = ICMP_UNREACH; code = ICMP_UNREACH_HOST; break; case EMSGSIZE: type = ICMP_UNREACH; code = ICMP_UNREACH_NEEDFRAG; if (ipforward_rt.ro_rt) destifp = ipforward_rt.ro_rt->rt_ifp; ipstat.ips_cantfrag++; break; case ENOBUFS: type = ICMP_SOURCEQUENCH; code = 0; break; } icmp_error(mcopy, type, code, dest, destifp); } void ip_savecontrol(inp, mp, ip, m) register struct inpcb *inp; register struct mbuf **mp; register struct ip *ip; register struct mbuf *m; { if (inp->inp_socket->so_options & SO_TIMESTAMP) { struct timeval tv; microtime(&tv); *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), SCM_TIMESTAMP, SOL_SOCKET); if (*mp) mp = &(*mp)->m_next; } if (inp->inp_flags & INP_RECVDSTADDR) { *mp = sbcreatecontrol((caddr_t) &ip->ip_dst, sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP); if (*mp) mp = &(*mp)->m_next; } #ifdef notyet /* XXX * Moving these out of udp_input() made them even more broken * than they already were. */ /* options were tossed already */ if (inp->inp_flags & INP_RECVOPTS) { *mp = sbcreatecontrol((caddr_t) opts_deleted_above, sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP); if (*mp) mp = &(*mp)->m_next; } /* ip_srcroute doesn't do what we want here, need to fix */ if (inp->inp_flags & INP_RECVRETOPTS) { *mp = sbcreatecontrol((caddr_t) ip_srcroute(), sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP); if (*mp) mp = &(*mp)->m_next; } #endif if (inp->inp_flags & INP_RECVIF) { struct sockaddr_dl sdl; sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]); sdl.sdl_family = AF_LINK; sdl.sdl_index = m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0; sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0; *mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len, IP_RECVIF, IPPROTO_IP); if (*mp) mp = &(*mp)->m_next; } } int ip_rsvp_init(struct socket *so) { if (so->so_type != SOCK_RAW || so->so_proto->pr_protocol != IPPROTO_RSVP) return EOPNOTSUPP; if (ip_rsvpd != NULL) return EADDRINUSE; ip_rsvpd = so; /* * This may seem silly, but we need to be sure we don't over-increment * the RSVP counter, in case something slips up. */ if (!ip_rsvp_on) { ip_rsvp_on = 1; rsvp_on++; } return 0; } int ip_rsvp_done(void) { ip_rsvpd = NULL; /* * This may seem silly, but we need to be sure we don't over-decrement * the RSVP counter, in case something slips up. */ if (ip_rsvp_on) { ip_rsvp_on = 0; rsvp_on--; } return 0; }
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