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/* $OpenBSD: packet.c,v 1.14 2015/05/05 01:26:37 jsg Exp $ */ |
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/* |
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* Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org> |
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* |
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* Permission to use, copy, modify, and distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <sys/types.h> |
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#include <sys/socket.h> |
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#include <sys/uio.h> |
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#include <netinet/in.h> |
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#include <netinet/ip.h> |
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#include <netinet/ip6.h> |
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#include <arpa/inet.h> |
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#include <net/if_dl.h> |
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#include <errno.h> |
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#include <event.h> |
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#include <limits.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include "ospf6d.h" |
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#include "ospf6.h" |
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#include "log.h" |
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#include "ospfe.h" |
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int ip_hdr_sanity_check(const struct ip6_hdr *, u_int16_t); |
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int ospf_hdr_sanity_check(struct ospf_hdr *, u_int16_t, |
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const struct iface *, struct in6_addr *); |
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struct iface *find_iface(struct ospfd_conf *, unsigned int, |
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struct in6_addr *); |
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int |
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gen_ospf_hdr(struct ibuf *buf, struct iface *iface, u_int8_t type) |
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{ |
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struct ospf_hdr ospf_hdr; |
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bzero(&ospf_hdr, sizeof(ospf_hdr)); |
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ospf_hdr.version = OSPF6_VERSION; |
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ospf_hdr.type = type; |
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ospf_hdr.rtr_id = ospfe_router_id(); |
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if (iface->type != IF_TYPE_VIRTUALLINK) |
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ospf_hdr.area_id = iface->area_id.s_addr; |
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ospf_hdr.instance = DEFAULT_INSTANCE_ID; |
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ospf_hdr.zero = 0; /* must be zero */ |
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return (ibuf_add(buf, &ospf_hdr, sizeof(ospf_hdr))); |
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} |
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int |
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upd_ospf_hdr(struct ibuf *buf, struct iface *iface) |
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{ |
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struct ospf_hdr *ospf_hdr; |
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if ((ospf_hdr = ibuf_seek(buf, 0, sizeof(*ospf_hdr))) == NULL) |
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fatalx("upd_ospf_hdr: buf_seek failed"); |
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/* update length */ |
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if (buf->wpos > USHRT_MAX) |
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fatalx("upd_ospf_hdr: resulting ospf packet too big"); |
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ospf_hdr->len = htons((u_int16_t)buf->wpos); |
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ospf_hdr->chksum = 0; /* calculated via IPV6_CHECKSUM */ |
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return (0); |
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} |
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/* send and receive packets */ |
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int |
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send_packet(struct iface *iface, void *pkt, size_t len, |
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struct in6_addr *dst) |
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{ |
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struct sockaddr_in6 sa6; |
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/* setup buffer */ |
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bzero(&sa6, sizeof(sa6)); |
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sa6.sin6_family = AF_INET6; |
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sa6.sin6_len = sizeof(sa6); |
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sa6.sin6_addr = *dst; |
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/* don't we all love link local scope and all the needed hacks for it */ |
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if (IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MC_LINKLOCAL(dst)) |
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sa6.sin6_scope_id = iface->ifindex; |
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/* set outgoing interface for multicast traffic */ |
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if (IN6_IS_ADDR_MULTICAST(dst)) |
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if (if_set_mcast(iface) == -1) { |
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log_warn("send_packet: error setting multicast " |
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"interface, %s", iface->name); |
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return (-1); |
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} |
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if (sendto(iface->fd, pkt, len, 0, (struct sockaddr *)&sa6, |
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sizeof(sa6)) == -1) { |
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log_warn("send_packet: error sending packet on interface %s", |
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iface->name); |
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return (-1); |
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} |
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return (0); |
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} |
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void |
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recv_packet(int fd, short event, void *bula) |
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{ |
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union { |
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struct cmsghdr hdr; |
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char buf[CMSG_SPACE(sizeof(struct in6_pktinfo))]; |
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} cmsgbuf; |
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struct msghdr msg; |
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struct iovec iov; |
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struct in6_addr addr, dest; |
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struct sockaddr_in6 src; |
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struct ospfd_conf *xconf = bula; |
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struct ospf_hdr *ospf_hdr; |
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struct iface *iface; |
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struct nbr *nbr = NULL; |
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char *buf; |
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struct cmsghdr *cmsg; |
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ssize_t r; |
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u_int16_t len; |
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int l; |
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unsigned int ifindex = 0; |
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if (event != EV_READ) |
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return; |
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/* setup buffer */ |
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bzero(&msg, sizeof(msg)); |
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iov.iov_base = buf = pkt_ptr; |
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iov.iov_len = READ_BUF_SIZE; |
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msg.msg_name = &src; |
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msg.msg_namelen = sizeof(src); |
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msg.msg_iov = &iov; |
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msg.msg_iovlen = 1; |
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msg.msg_control = &cmsgbuf.buf; |
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msg.msg_controllen = sizeof(cmsgbuf.buf); |
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if ((r = recvmsg(fd, &msg, 0)) == -1) { |
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if (errno != EAGAIN && errno != EINTR) |
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log_debug("recv_packet: read error: %s", |
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strerror(errno)); |
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return; |
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} |
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for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; |
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cmsg = CMSG_NXTHDR(&msg, cmsg)) { |
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if (cmsg->cmsg_level == IPPROTO_IPV6 && |
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cmsg->cmsg_type == IPV6_PKTINFO) { |
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ifindex = ((struct in6_pktinfo *) |
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CMSG_DATA(cmsg))->ipi6_ifindex; |
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dest = ((struct in6_pktinfo *) |
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CMSG_DATA(cmsg))->ipi6_addr; |
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break; |
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} |
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} |
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/* find a matching interface */ |
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if ((iface = find_iface(xconf, ifindex, &src.sin6_addr)) == NULL) { |
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/* XXX add a counter here */ |
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return; |
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} |
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/* |
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* Packet needs to be sent to AllSPFRouters or AllDRouters |
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* or to the address of the interface itself. |
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* AllDRouters is only valid for DR and BDR but this is checked later. |
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*/ |
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inet_pton(AF_INET6, AllSPFRouters, &addr); |
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if (!IN6_ARE_ADDR_EQUAL(&dest, &addr)) { |
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inet_pton(AF_INET6, AllDRouters, &addr); |
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if (!IN6_ARE_ADDR_EQUAL(&dest, &addr)) { |
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if (!IN6_ARE_ADDR_EQUAL(&dest, &iface->addr)) { |
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log_debug("recv_packet: packet sent to wrong " |
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"address %s, interface %s", |
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log_in6addr(&dest), iface->name); |
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return; |
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} |
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} |
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} |
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len = (u_int16_t)r; |
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/* OSPF header sanity checks */ |
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if (len < sizeof(*ospf_hdr)) { |
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log_debug("recv_packet: bad packet size"); |
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return; |
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} |
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ospf_hdr = (struct ospf_hdr *)buf; |
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if ((l = ospf_hdr_sanity_check(ospf_hdr, len, iface, &dest)) == -1) |
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return; |
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nbr = nbr_find_id(iface, ospf_hdr->rtr_id); |
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if (ospf_hdr->type != PACKET_TYPE_HELLO && nbr == NULL) { |
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log_debug("recv_packet: unknown neighbor ID"); |
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return; |
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} |
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buf += sizeof(*ospf_hdr); |
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len = l - sizeof(*ospf_hdr); |
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/* switch OSPF packet type */ |
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switch (ospf_hdr->type) { |
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case PACKET_TYPE_HELLO: |
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inet_pton(AF_INET6, AllDRouters, &addr); |
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if (IN6_ARE_ADDR_EQUAL(&dest, &addr)) { |
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log_debug("recv_packet: invalid destination IP " |
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"address"); |
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break; |
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} |
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recv_hello(iface, &src.sin6_addr, ospf_hdr->rtr_id, buf, len); |
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break; |
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case PACKET_TYPE_DD: |
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recv_db_description(nbr, buf, len); |
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break; |
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case PACKET_TYPE_LS_REQUEST: |
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recv_ls_req(nbr, buf, len); |
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break; |
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case PACKET_TYPE_LS_UPDATE: |
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recv_ls_update(nbr, buf, len); |
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break; |
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case PACKET_TYPE_LS_ACK: |
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recv_ls_ack(nbr, buf, len); |
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break; |
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default: |
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log_debug("recv_packet: unknown OSPF packet type, interface %s", |
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iface->name); |
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} |
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} |
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int |
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ospf_hdr_sanity_check(struct ospf_hdr *ospf_hdr, u_int16_t len, |
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const struct iface *iface, struct in6_addr *dst) |
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{ |
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struct in6_addr addr; |
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struct in_addr id; |
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if (ospf_hdr->version != OSPF6_VERSION) { |
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log_debug("recv_packet: invalid OSPF version %d", |
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ospf_hdr->version); |
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return (-1); |
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} |
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if (ntohs(ospf_hdr->len) > len || |
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len <= sizeof(struct ospf_hdr)) { |
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log_debug("recv_packet: invalid OSPF packet length %d", |
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ntohs(ospf_hdr->len)); |
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return (-1); |
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} |
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if (iface->type != IF_TYPE_VIRTUALLINK) { |
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if (ospf_hdr->area_id != iface->area_id.s_addr) { |
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id.s_addr = ospf_hdr->area_id; |
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log_debug("recv_packet: invalid area ID %s, " |
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"interface %s", inet_ntoa(id), iface->name); |
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return (-1); |
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} |
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} else { |
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if (ospf_hdr->area_id != 0) { |
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id.s_addr = ospf_hdr->area_id; |
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log_debug("recv_packet: invalid area ID %s, " |
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"interface %s", inet_ntoa(id), iface->name); |
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return (-1); |
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} |
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} |
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if (iface->type == IF_TYPE_BROADCAST || iface->type == IF_TYPE_NBMA) { |
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if (inet_pton(AF_INET6, AllDRouters, &addr) == 0) |
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fatalx("recv_packet: inet_pton"); |
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if (IN6_ARE_ADDR_EQUAL(dst, &addr) && |
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(iface->state & IF_STA_DRORBDR) == 0) { |
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log_debug("recv_packet: invalid destination IP in " |
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"state %s, interface %s", |
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if_state_name(iface->state), iface->name); |
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return (-1); |
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} |
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} |
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return (ntohs(ospf_hdr->len)); |
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} |
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struct iface * |
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find_iface(struct ospfd_conf *xconf, unsigned int ifindex, struct in6_addr *src) |
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{ |
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struct area *area; |
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struct iface *iface, *match = NULL; |
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/* |
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* Returned interface needs to be active. |
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* Virtual-Links have higher precedence so the full interface |
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* list needs to be scanned for possible matches. |
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*/ |
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LIST_FOREACH(area, &xconf->area_list, entry) { |
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LIST_FOREACH(iface, &area->iface_list, entry) { |
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switch (iface->type) { |
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case IF_TYPE_VIRTUALLINK: |
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if (IN6_ARE_ADDR_EQUAL(src, &iface->dst) && |
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!(iface->cflags & F_IFACE_PASSIVE)) |
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return (iface); |
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break; |
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default: |
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if (ifindex == iface->ifindex && |
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!(iface->cflags & F_IFACE_PASSIVE)) |
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match = iface; |
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break; |
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} |
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} |
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} |
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return (match); |
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} |