diff options
Diffstat (limited to 'usr.sbin/ospf6d/packet.c')
| -rw-r--r-- | usr.sbin/ospf6d/packet.c | 361 |
1 files changed, 361 insertions, 0 deletions
diff --git a/usr.sbin/ospf6d/packet.c b/usr.sbin/ospf6d/packet.c new file mode 100644 index 00000000000..2e833c48c27 --- /dev/null +++ b/usr.sbin/ospf6d/packet.c @@ -0,0 +1,361 @@ +/* $OpenBSD: packet.c,v 1.1 2007/10/08 10:44:50 norby Exp $ */ + +/* + * Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/uio.h> + +#include <netinet/in.h> +#include <netinet/in_systm.h> +#include <netinet/ip.h> +#include <netinet/ip6.h> +#include <arpa/inet.h> +#include <net/if_dl.h> + +#include <errno.h> +#include <event.h> +#include <stdlib.h> +#include <string.h> + +#include "ospf6d.h" +#include "ospf6.h" +#include "log.h" +#include "ospfe.h" + +int ip_hdr_sanity_check(const struct ip6_hdr *, u_int16_t); +int ospf_hdr_sanity_check(const struct ip6_hdr *, + struct ospf_hdr *, u_int16_t, const struct iface *); +struct iface *find_iface(struct ospfd_conf *, unsigned int, struct in6_addr); + +int +gen_ospf_hdr(struct buf *buf, struct iface *iface, u_int8_t type) +{ + struct ospf_hdr ospf_hdr; + + bzero(&ospf_hdr, sizeof(ospf_hdr)); + ospf_hdr.version = OSPF6_VERSION; + ospf_hdr.type = type; + ospf_hdr.rtr_id = ospfe_router_id(); + if (iface->type != IF_TYPE_VIRTUALLINK) + ospf_hdr.area_id = iface->area->id.s_addr; + ospf_hdr.instance = DEFAULT_INSTANCE_ID; + ospf_hdr.zero = 0; /* must be zero */ + + return (buf_add(buf, &ospf_hdr, sizeof(ospf_hdr))); +} + +int +upd_ospf_hdr(struct buf *buf, struct iface *iface) +{ + struct ospf_hdr *ospf_hdr; + + if ((ospf_hdr = buf_seek(buf, 0, sizeof(ospf_hdr))) == NULL) + fatalx("upd_ospf_hdr: buf_seek failed"); + + /* update length */ + if (buf->wpos > USHRT_MAX) + fatalx("upd_ospf_hdr: resulting ospf packet too big"); + ospf_hdr->len = htons((u_int16_t)buf->wpos); + + ospf_hdr->chksum = in_cksum(buf->buf, buf->wpos); /* XXX */ + + return (0); +} + +/* send and receive packets */ +int +send_packet(struct iface *iface, void *pkt, size_t len, + struct sockaddr_in6 *dst) +{ + struct msghdr msg; + struct iovec iov[1]; + /* setup buffer */ + bzero(&msg, sizeof(msg)); + iov[0].iov_base = pkt; + iov[0].iov_len = len; + msg.msg_name = dst; + msg.msg_namelen = sizeof(*dst); + msg.msg_iov = iov; + msg.msg_iovlen = 1; + + /* set outgoing interface for multicast traffic */ + if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr)) + if (if_set_mcast(iface) == -1) { + log_warn("send_packet: error setting multicast " + "interface, %s", iface->name); + return (-1); + } + + + log_debug("send_packet: iface %d addr %s", iface->ifindex, + log_in6addr(&iface->addr)); + log_debug("send_packet: dest %s", log_in6addr(&dst->sin6_addr)); + if (sendmsg(iface->fd, &msg, MSG_DONTROUTE) == -1) { + log_warn("send_packet: error sending packet on interface %s", + iface->name); + return (-1); + } + + return (0); +} + +void +recv_packet(int fd, short event, void *bula) +{ + char cbuf[CMSG_SPACE(sizeof(struct sockaddr_dl))]; + struct msghdr msg; + struct iovec iov; + struct ip6_hdr ip_hdr; + struct in6_addr addr; + struct ospfd_conf *xconf = bula; + struct ospf_hdr *ospf_hdr; + struct iface *iface; + struct nbr *nbr = NULL; + char *buf; + struct cmsghdr *cmsg; + ssize_t r; + u_int16_t len; + int l; + unsigned int ifindex = 0; + + if (event != EV_READ) + return; + + /* setup buffer */ + bzero(&msg, sizeof(msg)); + iov.iov_base = buf = pkt_ptr; + iov.iov_len = READ_BUF_SIZE; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + msg.msg_control = cbuf; + msg.msg_controllen = sizeof(cbuf); + + if ((r = recvmsg(fd, &msg, 0)) == -1) { + if (errno != EAGAIN && errno != EINTR) + log_debug("recv_packet: read error: %s", + strerror(errno)); + return; + } + for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; + cmsg = CMSG_NXTHDR(&msg, cmsg)) { + if (cmsg->cmsg_level == IPPROTO_IPV6 && + cmsg->cmsg_type == IP_RECVIF) { + ifindex = ((struct sockaddr_dl *) + CMSG_DATA(cmsg))->sdl_index; + break; + } + } + + len = (u_int16_t)r; + + /* IP header sanity checks */ + if (len < sizeof(ip_hdr)) { + log_warnx("recv_packet: bad packet size"); + return; + } + memcpy(&ip_hdr, buf, sizeof(ip_hdr)); + if ((l = ip_hdr_sanity_check(&ip_hdr, len)) == -1) + return; + buf += l; + len -= l; + + /* find a matching interface */ + if ((iface = find_iface(xconf, ifindex, ip_hdr.ip6_src)) == NULL) { + /* XXX add a counter here */ + return; + } +#if 1 + /* + * Packet needs to be sent to AllSPFRouters or AllDRouters + * or to the address of the interface itself. + * AllDRouters is only valid for DR and BDR but this is checked later. + */ + inet_pton(AF_INET6, AllSPFRouters, &addr); + + if (!IN6_ARE_ADDR_EQUAL(&ip_hdr.ip6_dst, &addr)) { + inet_pton(AF_INET6, AllDRouters, &addr); + if (!IN6_ARE_ADDR_EQUAL(&ip_hdr.ip6_dst, &addr)) { + if (!IN6_ARE_ADDR_EQUAL(&ip_hdr.ip6_dst, + &iface->addr)) { + log_debug("recv_packet: packet sent to wrong " + "address %s, interface %s", + log_in6addr(&ip_hdr.ip6_dst), iface->name); + return; + } + } + } +#endif + /* OSPF header sanity checks */ + if (len < sizeof(*ospf_hdr)) { + log_debug("recv_packet: bad packet size"); + return; + } + ospf_hdr = (struct ospf_hdr *)buf; + + if ((l = ospf_hdr_sanity_check(&ip_hdr, ospf_hdr, len, iface)) == -1) + return; + + nbr = nbr_find_id(iface, ospf_hdr->rtr_id); + if (ospf_hdr->type != PACKET_TYPE_HELLO && nbr == NULL) { + log_debug("recv_packet: unknown neighbor ID"); + return; + } + + if (in_cksum(buf, len)) { + log_warnx("recv_packet: invalid checksum, " + "interface %s", iface->name); + return; + } + + buf += sizeof(*ospf_hdr); + len = l - sizeof(*ospf_hdr); + + /* switch OSPF packet type */ + switch (ospf_hdr->type) { + case PACKET_TYPE_HELLO: + inet_pton(AF_INET6, AllDRouters, &addr); + if (IN6_ARE_ADDR_EQUAL(&ip_hdr.ip6_dst, &addr)) { + log_debug("recv_packet: invalid destination IP " + "address"); + break; + } + + recv_hello(iface, ip_hdr.ip6_src, ospf_hdr->rtr_id, buf, len); + break; + case PACKET_TYPE_DD: + recv_db_description(nbr, buf, len); + break; + case PACKET_TYPE_LS_REQUEST: + recv_ls_req(nbr, buf, len); + break; + case PACKET_TYPE_LS_UPDATE: + recv_ls_update(nbr, buf, len); + break; + case PACKET_TYPE_LS_ACK: + recv_ls_ack(nbr, buf, len); + break; + default: + log_debug("recv_packet: unknown OSPF packet type, interface %s", + iface->name); + } +} + +int +ip_hdr_sanity_check(const struct ip6_hdr *ip_hdr, u_int16_t len) +{ + if (ntohs(ip_hdr->ip6_plen) != len) { + log_debug("recv_packet: invalid IP packet length %u", + ntohs(ip_hdr->ip6_plen)); + return (-1); + } + + if (ip_hdr->ip6_nxt != IPPROTO_OSPF) + /* this is enforced by the socket itself */ + fatalx("recv_packet: invalid IP proto"); + +//XXX return (ip_hdr->ip_hl << 2); + return (sizeof(struct ip6_hdr)); +} + +int +ospf_hdr_sanity_check(const struct ip6_hdr *ip_hdr, struct ospf_hdr *ospf_hdr, + u_int16_t len, const struct iface *iface) +{ + struct in6_addr addr; + struct in_addr id; + + if (ospf_hdr->version != OSPF6_VERSION) { + log_debug("recv_packet: invalid OSPF version %d", + ospf_hdr->version); + return (-1); + } + + if (ntohs(ospf_hdr->len) > len || + len <= sizeof(struct ospf_hdr)) { + log_debug("recv_packet: invalid OSPF packet length %d", + ntohs(ospf_hdr->len)); + return (-1); + } + + if (iface->type != IF_TYPE_VIRTUALLINK) { + if (ospf_hdr->area_id != iface->area->id.s_addr) { + id.s_addr = ospf_hdr->area_id; + log_debug("recv_packet: invalid area ID %s, " + "interface %s", inet_ntoa(id), iface->name); + return (-1); + } + } else { + if (ospf_hdr->area_id != 0) { + id.s_addr = ospf_hdr->area_id; + log_debug("recv_packet: invalid area ID %s, " + "interface %s", inet_ntoa(id), iface->name); + return (-1); + } + } + + if (iface->type == IF_TYPE_BROADCAST || iface->type == IF_TYPE_NBMA) { + if (inet_pton(AF_INET6, AllDRouters, &addr) == 0) + fatalx("recv_packet: inet_pton"); + if (IN6_ARE_ADDR_EQUAL(&ip_hdr->ip6_dst, &addr) && + (iface->state & IF_STA_DRORBDR) == 0) { + log_debug("recv_packet: invalid destination IP in " + "state %s, interface %s", + if_state_name(iface->state), iface->name); + return (-1); + } + } + + return (ntohs(ospf_hdr->len)); +} + +struct iface * +find_iface(struct ospfd_conf *xconf, unsigned int ifindex, struct in6_addr src) +{ + struct area *area = NULL; + struct iface *iface = NULL; + + /* returned interface needs to be active */ + LIST_FOREACH(area, &xconf->area_list, entry) { + LIST_FOREACH(iface, &area->iface_list, entry) { + switch (iface->type) { + case IF_TYPE_VIRTUALLINK: + if (IN6_ARE_ADDR_EQUAL(&src, &iface->dst) && + !iface->passive) + return (iface); + break; + case IF_TYPE_POINTOPOINT: + if (ifindex == iface->ifindex && + IN6_ARE_ADDR_EQUAL(&iface->dst, &src) && + !iface->passive) + return (iface); + break; + default: +#if 0 + if (ifindex == iface->ifindex && + (iface->addr.s_addr & iface->mask.s_addr) == + (src.s_addr & iface->mask.s_addr) && + !iface->passive) + return (iface); +#endif + break; + } + } + } + + return (NULL); +} |