From 60943122f7b3a5896ce64c9000e119931484c12c Mon Sep 17 00:00:00 2001 From: Guus Sliepen Date: Mon, 6 Oct 2003 13:49:57 +0000 Subject: [PATCH] Copy structs from packets to the stack before using them, to prevent alignment issues. --- src/route.c | 309 +++++++++++++++++++++++++++++----------------------- 1 file changed, 175 insertions(+), 134 deletions(-) diff --git a/src/route.c b/src/route.c index e9e07f67..d38b08e4 100644 --- a/src/route.c +++ b/src/route.c @@ -17,7 +17,7 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: route.c,v 1.1.2.66 2003/10/01 09:14:01 guus Exp $ + $Id: route.c,v 1.1.2.67 2003/10/06 13:49:57 guus Exp $ */ #include "system.h" @@ -57,6 +57,17 @@ int macexpire = 600; bool overwrite_mac = false; mac_t mymac = {{0xFE, 0xFD, 0, 0, 0, 0}}; +/* Sizes of various headers */ + +static size_t ether_size = sizeof(struct ether_header); +static size_t arp_size = sizeof(struct ether_arp); +static size_t ip_size = sizeof(struct ip); +static size_t icmp_size = sizeof(struct icmp) - sizeof(struct ip); +static size_t ip6_size = sizeof(struct ip6_hdr); +static size_t icmp6_size = sizeof(struct icmp6_hdr); +static size_t ns_size = sizeof(struct nd_neighbor_solicit); +static size_t opt_size = sizeof(struct nd_opt_hdr); + /* RFC 1071 */ static uint16_t inet_checksum(void *data, int len, uint16_t prevsum) @@ -78,13 +89,18 @@ static uint16_t inet_checksum(void *data, int len, uint16_t prevsum) return ~checksum; } -static bool ratelimit(void) { +static bool ratelimit(int frequency) { static time_t lasttime = 0; + static int count = 0; - if(lasttime == now) - return true; + if(lasttime == now) { + if(++count > frequency) + return true; + } else { + lasttime = now; + count = 0; + } - lasttime = now; return false; } @@ -174,59 +190,68 @@ static node_t *route_mac(vpn_packet_t *packet) static void route_ipv4_unreachable(vpn_packet_t *packet, uint8_t code) { - struct ip *hdr; - struct icmp *icmp; + struct ip ip; + struct icmp icmp; struct in_addr ip_src; struct in_addr ip_dst; uint32_t oldlen; - if(ratelimit()) + if(ratelimit(3)) return; cp(); - hdr = (struct ip *)(packet->data + 14); - icmp = (struct icmp *)(packet->data + 14 + 20); + /* Copy headers from packet into properly aligned structs on the stack */ + + memcpy(&ip, packet->data + ether_size, ip_size); + memcpy(&icmp, packet->data + ether_size + ip_size, icmp_size); /* Remember original source and destination */ - memcpy(&ip_src, &hdr->ip_src, 4); - memcpy(&ip_dst, &hdr->ip_dst, 4); - oldlen = packet->len - 14; + memcpy(&ip_src, &ip.ip_src, sizeof(ip_src)); + memcpy(&ip_dst, &ip.ip_dst, sizeof(ip_dst)); + + oldlen = packet->len - ether_size; - if(oldlen >= IP_MSS - sizeof(*hdr) - sizeof(*icmp)) - oldlen = IP_MSS - sizeof(*hdr) - sizeof(*icmp); + if(oldlen >= IP_MSS - ip_size - icmp_size) + oldlen = IP_MSS - ip_size - icmp_size; /* Copy first part of original contents to ICMP message */ - memmove(&icmp->icmp_ip, hdr, oldlen); + memmove(packet->data + ether_size + ip_size + icmp_size, packet->data + ether_size, oldlen); /* Fill in IPv4 header */ - hdr->ip_v = 4; - hdr->ip_hl = sizeof(*hdr) / 4; - hdr->ip_tos = 0; - hdr->ip_len = htons(20 + 8 + oldlen); - hdr->ip_id = 0; - hdr->ip_off = 0; - hdr->ip_ttl = 255; - hdr->ip_p = IPPROTO_ICMP; - hdr->ip_sum = 0; - memcpy(&hdr->ip_src, &ip_dst, 4); - memcpy(&hdr->ip_dst, &ip_src, 4); - - hdr->ip_sum = inet_checksum(hdr, 20, ~0); + ip.ip_v = 4; + ip.ip_hl = ip_size / 4; + ip.ip_tos = 0; + ip.ip_len = htons(ip_size + icmp_size + oldlen); + ip.ip_id = 0; + ip.ip_off = 0; + ip.ip_ttl = 255; + ip.ip_p = IPPROTO_ICMP; + ip.ip_sum = 0; + memcpy(&ip.ip_src, &ip_dst, sizeof(ip_src)); + memcpy(&ip.ip_dst, &ip_src, sizeof(ip_dst)); + + ip.ip_sum = inet_checksum(&ip, ip_size, ~0); /* Fill in ICMP header */ - icmp->icmp_type = ICMP_DEST_UNREACH; - icmp->icmp_code = code; - icmp->icmp_cksum = 0; + icmp.icmp_type = ICMP_DEST_UNREACH; + icmp.icmp_code = code; + icmp.icmp_cksum = 0; - icmp->icmp_cksum = inet_checksum(icmp, 8 + oldlen, ~0); + icmp.icmp_cksum = inet_checksum(&icmp, icmp_size, ~0); + icmp.icmp_cksum = inet_checksum(packet->data + ether_size + ip_size + icmp_size, oldlen, icmp.icmp_cksum); + + /* Copy structs on stack back to packet */ + + memcpy(packet->data + ether_size, &ip, ip_size); + memcpy(packet->data + ether_size + ip_size, &icmp, icmp_size); - packet->len = 14 + 20 + 8 + oldlen; + packet->len = ether_size + ip_size + icmp_size + oldlen; write_packet(packet); } @@ -261,8 +286,8 @@ static node_t *route_ipv4(vpn_packet_t *packet) static void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code) { - struct ip6_hdr *hdr; - struct icmp6_hdr *icmp; + struct ip6_hdr ip6; + struct icmp6_hdr icmp6; uint16_t checksum; struct { @@ -272,55 +297,64 @@ static void route_ipv6_unreachable(vpn_packet_t *packet, uint8_t code) uint32_t next; } pseudo; - if(ratelimit()) + if(ratelimit(3)) return; cp(); - hdr = (struct ip6_hdr *)(packet->data + 14); - icmp = (struct icmp6_hdr *)(packet->data + 14 + sizeof(*hdr)); + /* Copy headers from packet to structs on the stack */ + + memcpy(&ip6, packet->data + ether_size, ip6_size); + memcpy(&icmp6, packet->data + ether_size + ip6_size, icmp6_size); /* Remember original source and destination */ - memcpy(&pseudo.ip6_src, &hdr->ip6_dst, 16); - memcpy(&pseudo.ip6_dst, &hdr->ip6_src, 16); - pseudo.length = ntohs(hdr->ip6_plen) + sizeof(*hdr); + memcpy(&pseudo.ip6_src, &ip6.ip6_dst, sizeof(ip6.ip6_src)); + memcpy(&pseudo.ip6_dst, &ip6.ip6_src, sizeof(ip6.ip6_dst)); + + pseudo.length = ntohs(ip6.ip6_plen) + ip6_size; - if(pseudo.length >= IP_MSS - sizeof(*hdr) - sizeof(*icmp)) - pseudo.length = IP_MSS - sizeof(*hdr) - sizeof(*icmp); + if(pseudo.length >= IP_MSS - ip6_size - icmp6_size) + pseudo.length = IP_MSS - ip6_size - icmp6_size; /* Copy first part of original contents to ICMP message */ - memmove(((char *)icmp) + sizeof(*icmp), hdr, pseudo.length); + memmove(packet->data + ether_size + ip6_size + icmp6_size, packet->data + ether_size, pseudo.length); /* Fill in IPv6 header */ - hdr->ip6_flow = htonl(0x60000000UL); - hdr->ip6_plen = htons(sizeof(*icmp) + pseudo.length); - hdr->ip6_nxt = IPPROTO_ICMPV6; - hdr->ip6_hlim = 255; - memcpy(&hdr->ip6_dst, &pseudo.ip6_dst, 16); - memcpy(&hdr->ip6_src, &pseudo.ip6_src, 16); + ip6.ip6_flow = htonl(0x60000000UL); + ip6.ip6_plen = htons(icmp6_size + pseudo.length); + ip6.ip6_nxt = IPPROTO_ICMPV6; + ip6.ip6_hlim = 255; + memcpy(&ip6.ip6_src, &pseudo.ip6_src, sizeof(ip6.ip6_src)); + memcpy(&ip6.ip6_dst, &pseudo.ip6_dst, sizeof(ip6.ip6_dst)); /* Fill in ICMP header */ - icmp->icmp6_type = ICMP6_DST_UNREACH; - icmp->icmp6_code = code; - icmp->icmp6_cksum = 0; + icmp6.icmp6_type = ICMP6_DST_UNREACH; + icmp6.icmp6_code = code; + icmp6.icmp6_cksum = 0; /* Create pseudo header */ - pseudo.length = htonl(sizeof(*icmp) + pseudo.length); + pseudo.length = htonl(icmp6_size + pseudo.length); pseudo.next = htonl(IPPROTO_ICMPV6); /* Generate checksum */ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); - checksum = inet_checksum(icmp, ntohl(pseudo.length), checksum); + checksum = inet_checksum(&icmp6, icmp6_size, checksum); + checksum = inet_checksum(packet->data + ether_size + ip6_size + icmp6_size, ntohl(pseudo.length) - icmp6_size, checksum); - icmp->icmp6_cksum = checksum; + icmp6.icmp6_cksum = checksum; + + /* Copy structs on stack back to packet */ + + memcpy(packet->data + ether_size, &ip6, ip6_size); + memcpy(packet->data + ether_size + ip6_size, &icmp6, icmp6_size); - packet->len = 14 + sizeof(*hdr) + ntohl(pseudo.length); + packet->len = ether_size + ip6_size + ntohl(pseudo.length); write_packet(packet); } @@ -358,9 +392,9 @@ static node_t *route_ipv6(vpn_packet_t *packet) static void route_neighborsol(vpn_packet_t *packet) { - struct ip6_hdr *hdr; - struct nd_neighbor_solicit *ns; - struct nd_opt_hdr *opt; + struct ip6_hdr ip6; + struct nd_neighbor_solicit ns; + struct nd_opt_hdr opt; subnet_t *subnet; uint16_t checksum; @@ -373,34 +407,37 @@ static void route_neighborsol(vpn_packet_t *packet) cp(); - hdr = (struct ip6_hdr *)(packet->data + 14); - ns = (struct nd_neighbor_solicit *)(packet->data + 14 + sizeof(*hdr)); - opt = (struct nd_opt_hdr *)(packet->data + 14 + sizeof(*hdr) + sizeof(*ns)); + /* Copy headers from packet to structs on the stack */ + + memcpy(&ip6, packet->data + ether_size, ip6_size); + memcpy(&ns, packet->data + ether_size + ip6_size, ns_size); + memcpy(&opt, packet->data + ether_size + ip6_size + ns_size, opt_size); /* First, snatch the source address from the neighbor solicitation packet */ if(overwrite_mac) - memcpy(mymac.x, packet->data + 6, 6); + memcpy(mymac.x, packet->data + ETH_ALEN, ETH_ALEN); /* Check if this is a valid neighbor solicitation request */ - if(ns->nd_ns_hdr.icmp6_type != ND_NEIGHBOR_SOLICIT || - opt->nd_opt_type != ND_OPT_SOURCE_LINKADDR) { + if(ns.nd_ns_hdr.icmp6_type != ND_NEIGHBOR_SOLICIT || + opt.nd_opt_type != ND_OPT_SOURCE_LINKADDR) { ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type neighbor solicitation request")); return; } /* Create pseudo header */ - memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16); - memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16); - pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6); + memcpy(&pseudo.ip6_src, &ip6.ip6_src, sizeof(ip6.ip6_src)); + memcpy(&pseudo.ip6_dst, &ip6.ip6_dst, sizeof(ip6.ip6_dst)); + pseudo.length = htonl(ns_size + opt_size + ETH_ALEN); pseudo.next = htonl(IPPROTO_ICMPV6); /* Generate checksum */ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); - checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum); + checksum = inet_checksum(&ns, ns_size, checksum); + checksum = inet_checksum(&opt, opt_size, checksum); if(checksum) { ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: checksum error for neighbor solicitation request")); @@ -409,18 +446,18 @@ static void route_neighborsol(vpn_packet_t *packet) /* Check if the IPv6 address exists on the VPN */ - subnet = lookup_subnet_ipv6((ipv6_t *) &ns->nd_ns_target); + subnet = lookup_subnet_ipv6((ipv6_t *) &ns.nd_ns_target); if(!subnet) { ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: neighbor solicitation request for unknown address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"), - ntohs(((uint16_t *) &ns->nd_ns_target)[0]), - ntohs(((uint16_t *) &ns->nd_ns_target)[1]), - ntohs(((uint16_t *) &ns->nd_ns_target)[2]), - ntohs(((uint16_t *) &ns->nd_ns_target)[3]), - ntohs(((uint16_t *) &ns->nd_ns_target)[4]), - ntohs(((uint16_t *) &ns->nd_ns_target)[5]), - ntohs(((uint16_t *) &ns->nd_ns_target)[6]), - ntohs(((uint16_t *) &ns->nd_ns_target)[7])); + ntohs(((uint16_t *) &ns.nd_ns_target)[0]), + ntohs(((uint16_t *) &ns.nd_ns_target)[1]), + ntohs(((uint16_t *) &ns.nd_ns_target)[2]), + ntohs(((uint16_t *) &ns.nd_ns_target)[3]), + ntohs(((uint16_t *) &ns.nd_ns_target)[4]), + ntohs(((uint16_t *) &ns.nd_ns_target)[5]), + ntohs(((uint16_t *) &ns.nd_ns_target)[6]), + ntohs(((uint16_t *) &ns.nd_ns_target)[7])); return; } @@ -432,35 +469,39 @@ static void route_neighborsol(vpn_packet_t *packet) /* Create neighbor advertation reply */ - memcpy(packet->data, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* copy destination address */ - packet->data[ETHER_ADDR_LEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */ + memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN); /* copy destination address */ + packet->data[ETH_ALEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */ - memcpy(&hdr->ip6_dst, &hdr->ip6_src, 16); /* swap destination and source protocol address */ - memcpy(&hdr->ip6_src, &ns->nd_ns_target, 16); /* ... */ + memcpy(&ip6.ip6_src, &ns.nd_ns_target, sizeof(ip6.ip6_src)); /* swap destination and source protocol address */ + memcpy(&ip6.ip6_dst, &ip6.ip6_src, sizeof(ip6.ip6_dst)); /* ... */ - memcpy((char *) opt + sizeof(*opt), packet->data + ETHER_ADDR_LEN, 6); /* add fake source hard addr */ + memcpy(&opt + opt_size, packet->data + ETH_ALEN, ETH_ALEN); /* add fake source hard addr */ - ns->nd_ns_hdr.icmp6_cksum = 0; - ns->nd_ns_hdr.icmp6_type = ND_NEIGHBOR_ADVERT; - ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[0] = 0x40; /* Set solicited flag */ - ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[1] = - ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[2] = - ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[3] = 0; - opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; + ns.nd_ns_cksum = 0; + ns.nd_ns_type = ND_NEIGHBOR_ADVERT; + ns.nd_ns_reserved = htonl(0x40000000UL); /* Set solicited flag */ + opt.nd_opt_type = ND_OPT_TARGET_LINKADDR; /* Create pseudo header */ - memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16); - memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16); - pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6); + memcpy(&pseudo.ip6_src, &ip6.ip6_src, sizeof(ip6.ip6_src)); + memcpy(&pseudo.ip6_dst, &ip6.ip6_dst, sizeof(ip6.ip6_dst)); + pseudo.length = htonl(ns_size + opt_size + ETH_ALEN); pseudo.next = htonl(IPPROTO_ICMPV6); /* Generate checksum */ checksum = inet_checksum(&pseudo, sizeof(pseudo), ~0); - checksum = inet_checksum(ns, sizeof(*ns) + 8, checksum); + checksum = inet_checksum(&ns, ns_size, checksum); + checksum = inet_checksum(&opt, opt_size, checksum); + + ns.nd_ns_hdr.icmp6_cksum = checksum; - ns->nd_ns_hdr.icmp6_cksum = checksum; + /* Copy structs on stack back to packet */ + + memcpy(packet->data + ether_size, &ip6, ip6_size); + memcpy(packet->data + ether_size + ip6_size, &ns, ns_size); + memcpy(packet->data + ether_size + ip6_size + ns_size, &opt, opt_size); write_packet(packet); } @@ -469,40 +510,37 @@ static void route_neighborsol(vpn_packet_t *packet) static void route_arp(vpn_packet_t *packet) { - struct ether_arp *arp; + struct ether_arp arp; subnet_t *subnet; - uint8_t ipbuf[4]; + struct in_addr addr; cp(); /* First, snatch the source address from the ARP packet */ if(overwrite_mac) - memcpy(mymac.x, packet->data + 6, 6); + memcpy(mymac.x, packet->data + ETH_ALEN, ETH_ALEN); - /* This routine generates replies to ARP requests. - You don't need to set NOARP flag on the interface anymore (which is broken on FreeBSD). - Most of the code here is taken from choparp.c by Takamichi Tateoka (tree@mma.club.uec.ac.jp) - */ + /* Copy headers from packet to structs on the stack */ - arp = (struct ether_arp *)(packet->data + 14); + memcpy(&arp, packet->data + ether_size, arp_size); /* Check if this is a valid ARP request */ - if(ntohs(arp->arp_hrd) != ARPHRD_ETHER || ntohs(arp->arp_pro) != ETHERTYPE_IP || - arp->arp_hln != ETHER_ADDR_LEN || arp->arp_pln != 4 || ntohs(arp->arp_op) != ARPOP_REQUEST) { + if(ntohs(arp.arp_hrd) != ARPHRD_ETHER || ntohs(arp.arp_pro) != ETH_P_IP || + arp.arp_hln != ETH_ALEN || arp.arp_pln != sizeof(addr) || ntohs(arp.arp_op) != ARPOP_REQUEST) { ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: received unknown type ARP request")); return; } /* Check if the IPv4 address exists on the VPN */ - subnet = lookup_subnet_ipv4((ipv4_t *) arp->arp_tpa); + subnet = lookup_subnet_ipv4((ipv4_t *) &arp.arp_tpa); if(!subnet) { ifdebug(TRAFFIC) logger(LOG_WARNING, _("Cannot route packet: ARP request for unknown address %d.%d.%d.%d"), - arp->arp_tpa[0], arp->arp_tpa[1], arp->arp_tpa[2], - arp->arp_tpa[3]); + arp.arp_tpa[0], arp.arp_tpa[1], arp.arp_tpa[2], + arp.arp_tpa[3]); return; } @@ -511,16 +549,20 @@ static void route_arp(vpn_packet_t *packet) if(subnet->owner == myself) return; /* silently ignore */ - memcpy(packet->data, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* copy destination address */ - packet->data[ETHER_ADDR_LEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */ + memcpy(packet->data, packet->data + ETH_ALEN, ETH_ALEN); /* copy destination address */ + packet->data[ETH_ALEN * 2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */ + + memcpy(&addr, arp.arp_tpa, sizeof(addr)); /* save protocol addr */ + memcpy(arp.arp_tpa, arp.arp_spa, sizeof(addr)); /* swap destination and source protocol address */ + memcpy(arp.arp_spa, &addr, sizeof(addr)); /* ... */ - memcpy(ipbuf, arp->arp_tpa, 4); /* save protocol addr */ - memcpy(arp->arp_tpa, arp->arp_spa, 4); /* swap destination and source protocol address */ - memcpy(arp->arp_spa, ipbuf, 4); /* ... */ + memcpy(arp.arp_tha, arp.arp_sha, ETH_ALEN); /* set target hard/proto addr */ + memcpy(arp.arp_sha, packet->data + ETH_ALEN, ETH_ALEN); /* add fake source hard addr */ + arp.arp_op = htons(ARPOP_REPLY); - memcpy(arp->arp_tha, arp->arp_sha, 10); /* set target hard/proto addr */ - memcpy(arp->arp_sha, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* add fake source hard addr */ - arp->arp_op = htons(ARPOP_REPLY); + /* Copy structs on stack back to packet */ + + memcpy(packet->data + ether_size, &arp, arp_size); write_packet(packet); } @@ -532,7 +574,7 @@ void route_outgoing(vpn_packet_t *packet) cp(); - if(packet->len < 14) { + if(packet->len < ether_size) { ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); return; } @@ -543,8 +585,8 @@ void route_outgoing(vpn_packet_t *packet) case RMODE_ROUTER: type = ntohs(*((uint16_t *)(&packet->data[12]))); switch (type) { - case 0x0800: - if(packet->len < 34) { + case ETH_P_IP: + if(packet->len < ether_size + ip_size) { ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); return; } @@ -552,21 +594,21 @@ void route_outgoing(vpn_packet_t *packet) n = route_ipv4(packet); break; - case 0x86DD: - if(packet->len < 54) { + case ETH_P_IPV6: + if(packet->len < ether_size + ip6_size) { ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); return; } - if(packet->data[20] == IPPROTO_ICMPV6 && packet->len >= 62 && packet->data[54] == ND_NEIGHBOR_SOLICIT) { + if(packet->data[20] == IPPROTO_ICMPV6 && packet->len >= ether_size + ip6_size + ns_size && packet->data[54] == ND_NEIGHBOR_SOLICIT) { route_neighborsol(packet); return; } n = route_ipv6(packet); break; - case 0x0806: - if(packet->len < 42) { + case ETH_P_ARP: + if(packet->len < ether_size + arp_size) { ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); return; } @@ -598,9 +640,8 @@ void route_outgoing(vpn_packet_t *packet) void route_incoming(node_t *source, vpn_packet_t *packet) { - if(packet->len < 14) { - ifdebug(TRAFFIC) logger(LOG_WARNING, _("Got too short packet from %s (%s)"), - source->name, source->hostname); + if(packet->len < ether_size) { + ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); return; } @@ -612,8 +653,8 @@ void route_incoming(node_t *source, vpn_packet_t *packet) type = ntohs(*((uint16_t *)(&packet->data[12]))); switch (type) { - case 0x0800: - if(packet->len < 34) { + case ETH_P_IP: + if(packet->len < ether_size + ip_size) { ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); return; } @@ -621,8 +662,8 @@ void route_incoming(node_t *source, vpn_packet_t *packet) n = route_ipv4(packet); break; - case 0x86DD: - if(packet->len < 54) { + case ETH_P_IPV6: + if(packet->len < ether_size + ip6_size) { ifdebug(TRAFFIC) logger(LOG_WARNING, _("Read too short packet")); return; } @@ -638,7 +679,7 @@ void route_incoming(node_t *source, vpn_packet_t *packet) if(n) { if(n == myself) { if(overwrite_mac) - memcpy(packet->data, mymac.x, 6); + memcpy(packet->data, mymac.x, ETH_ALEN); write_packet(packet); } else send_packet(n, packet); -- 2.39.5