From 994adadf2752fd7515ee30ed5fdb91178a615fe9 Mon Sep 17 00:00:00 2001 From: "Vittorio Gambaletta (VittGam)" Date: Fri, 25 Sep 2015 16:51:51 +0200 Subject: [PATCH] Remove forward declaration for do_decrement_ttl. Signed-off-by: Vittorio Gambaletta # Conflicts: # src/route.c --- src/route.c | 510 ++++++++++++++++++++++++++-------------------------- 1 file changed, 254 insertions(+), 256 deletions(-) diff --git a/src/route.c b/src/route.c index e5b68b7d..0c9f2aa1 100644 --- a/src/route.c +++ b/src/route.c @@ -55,8 +55,6 @@ static const size_t icmp6_size = sizeof(struct icmp6_hdr); static const size_t ns_size = sizeof(struct nd_neighbor_solicit); static const size_t opt_size = sizeof(struct nd_opt_hdr); -static bool do_decrement_ttl(node_t *source, vpn_packet_t *packet); - #ifndef MAX #define MAX(a, b) ((a) > (b) ? (a) : (b)) #endif @@ -107,6 +105,260 @@ static bool checklength(node_t *source, vpn_packet_t *packet, length_t length) { return true; } +static void swap_mac_addresses(vpn_packet_t *packet) { + mac_t tmp; + memcpy(&tmp, &DATA(packet)[0], sizeof tmp); + memcpy(&DATA(packet)[0], &DATA(packet)[6], sizeof tmp); + memcpy(&DATA(packet)[6], &tmp, sizeof tmp); +} + +/* RFC 792 */ + +static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) { + struct ip ip = {0}; + struct icmp icmp = {0}; + + struct in_addr ip_src; + struct in_addr ip_dst; + uint32_t oldlen; + + if(ratelimit(3)) + return; + + /* Swap Ethernet source and destination addresses */ + + swap_mac_addresses(packet); + + /* Copy headers from packet into properly aligned structs on the stack */ + + memcpy(&ip, DATA(packet) + ether_size, ip_size); + + /* Remember original source and destination */ + + ip_src = ip.ip_src; + ip_dst = ip.ip_dst; + + /* Try to reply with an IP address assigned to the local machine */ + + if (type == ICMP_TIME_EXCEEDED && code == ICMP_EXC_TTL) { + int sockfd = socket(AF_INET, SOCK_DGRAM, 0); + if (sockfd != -1) { + struct sockaddr_in addr; + memset(&addr, 0, sizeof(addr)); + addr.sin_family = AF_INET; + addr.sin_addr = ip.ip_src; + if (!connect(sockfd, (const struct sockaddr*) &addr, sizeof(addr))) { + memset(&addr, 0, sizeof(addr)); + addr.sin_family = AF_INET; + socklen_t addrlen = sizeof(addr); + if (!getsockname(sockfd, (struct sockaddr*) &addr, &addrlen) && addrlen <= sizeof(addr)) { + ip_dst = addr.sin_addr; + } + } + close(sockfd); + } + } + + oldlen = packet->len - ether_size; + + if(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) + icmp.icmp_nextmtu = htons(packet->len - ether_size); + + 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(DATA(packet) + ether_size + ip_size + icmp_size, DATA(packet) + ether_size, oldlen); + + /* Fill in IPv4 header */ + + 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; + ip.ip_src = ip_dst; + ip.ip_dst = ip_src; + + ip.ip_sum = inet_checksum(&ip, ip_size, ~0); + + /* Fill in ICMP header */ + + icmp.icmp_type = type; + icmp.icmp_code = code; + icmp.icmp_cksum = 0; + + icmp.icmp_cksum = inet_checksum(&icmp, icmp_size, ~0); + icmp.icmp_cksum = inet_checksum(DATA(packet) + ether_size + ip_size + icmp_size, oldlen, icmp.icmp_cksum); + + /* Copy structs on stack back to packet */ + + memcpy(DATA(packet) + ether_size, &ip, ip_size); + memcpy(DATA(packet) + ether_size + ip_size, &icmp, icmp_size); + + packet->len = ether_size + ip_size + icmp_size + oldlen; + + send_packet(source, packet); +} + +/* RFC 2463 */ + +static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) { + struct ip6_hdr ip6; + struct icmp6_hdr icmp6 = {0}; + uint16_t checksum; + + struct { + struct in6_addr ip6_src; /* source address */ + struct in6_addr ip6_dst; /* destination address */ + uint32_t length; + uint32_t next; + } pseudo; + + if(ratelimit(3)) + return; + + /* Swap Ethernet source and destination addresses */ + + swap_mac_addresses(packet); + + /* Copy headers from packet to structs on the stack */ + + memcpy(&ip6, DATA(packet) + ether_size, ip6_size); + + /* Remember original source and destination */ + + pseudo.ip6_src = ip6.ip6_dst; + pseudo.ip6_dst = ip6.ip6_src; + + /* Try to reply with an IP address assigned to the local machine */ + + if (type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT) { + int sockfd = socket(AF_INET6, SOCK_DGRAM, 0); + if (sockfd != -1) { + struct sockaddr_in6 addr; + memset(&addr, 0, sizeof(addr)); + addr.sin6_family = AF_INET6; + addr.sin6_addr = ip6.ip6_src; + if (!connect(sockfd, (const struct sockaddr*) &addr, sizeof(addr))) { + memset(&addr, 0, sizeof(addr)); + addr.sin6_family = AF_INET6; + socklen_t addrlen = sizeof(addr); + if (!getsockname(sockfd, (struct sockaddr*) &addr, &addrlen) && addrlen <= sizeof(addr)) { + pseudo.ip6_src = addr.sin6_addr; + } + } + close(sockfd); + } + } + + pseudo.length = packet->len - ether_size; + + if(type == ICMP6_PACKET_TOO_BIG) + icmp6.icmp6_mtu = htonl(pseudo.length); + + 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(DATA(packet) + ether_size + ip6_size + icmp6_size, DATA(packet) + ether_size, pseudo.length); + + /* Fill in IPv6 header */ + + ip6.ip6_flow = htonl(0x60000000UL); + ip6.ip6_plen = htons(icmp6_size + pseudo.length); + ip6.ip6_nxt = IPPROTO_ICMPV6; + ip6.ip6_hlim = 255; + ip6.ip6_src = pseudo.ip6_src; + ip6.ip6_dst = pseudo.ip6_dst; + + /* Fill in ICMP header */ + + icmp6.icmp6_type = type; + icmp6.icmp6_code = code; + icmp6.icmp6_cksum = 0; + + /* Create pseudo header */ + + pseudo.length = htonl(icmp6_size + pseudo.length); + pseudo.next = htonl(IPPROTO_ICMPV6); + + /* Generate checksum */ + + checksum = inet_checksum(&pseudo, sizeof pseudo, ~0); + checksum = inet_checksum(&icmp6, icmp6_size, checksum); + checksum = inet_checksum(DATA(packet) + ether_size + ip6_size + icmp6_size, ntohl(pseudo.length) - icmp6_size, checksum); + + icmp6.icmp6_cksum = checksum; + + /* Copy structs on stack back to packet */ + + memcpy(DATA(packet) + ether_size, &ip6, ip6_size); + memcpy(DATA(packet) + ether_size + ip6_size, &icmp6, icmp6_size); + + packet->len = ether_size + ip6_size + ntohl(pseudo.length); + + send_packet(source, packet); +} + +static bool do_decrement_ttl(node_t *source, vpn_packet_t *packet) { + uint16_t type = DATA(packet)[12] << 8 | DATA(packet)[13]; + length_t ethlen = ether_size; + + if(type == ETH_P_8021Q) { + type = DATA(packet)[16] << 8 | DATA(packet)[17]; + ethlen += 4; + } + + switch (type) { + case ETH_P_IP: + if(!checklength(source, packet, ethlen + ip_size)) + return false; + + if(DATA(packet)[ethlen + 8] <= 1) { + if(DATA(packet)[ethlen + 11] != IPPROTO_ICMP || DATA(packet)[ethlen + 32] != ICMP_TIME_EXCEEDED) + route_ipv4_unreachable(source, packet, ethlen, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL); + return false; + } + + uint16_t old = DATA(packet)[ethlen + 8] << 8 | DATA(packet)[ethlen + 9]; + DATA(packet)[ethlen + 8]--; + uint16_t new = DATA(packet)[ethlen + 8] << 8 | DATA(packet)[ethlen + 9]; + + uint32_t checksum = DATA(packet)[ethlen + 10] << 8 | DATA(packet)[ethlen + 11]; + checksum += old + (~new & 0xFFFF); + while(checksum >> 16) + checksum = (checksum & 0xFFFF) + (checksum >> 16); + DATA(packet)[ethlen + 10] = checksum >> 8; + DATA(packet)[ethlen + 11] = checksum & 0xff; + + return true; + + case ETH_P_IPV6: + if(!checklength(source, packet, ethlen + ip6_size)) + return false; + + if(DATA(packet)[ethlen + 7] <= 1) { + if(DATA(packet)[ethlen + 6] != IPPROTO_ICMPV6 || DATA(packet)[ethlen + 40] != ICMP6_TIME_EXCEEDED) + route_ipv6_unreachable(source, packet, ethlen, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_TRANSIT); + return false; + } + + DATA(packet)[ethlen + 7]--; + + return true; + + default: + return true; + } +} + static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *packet) { if(!source || !via || !(via->options & OPTION_CLAMP_MSS)) return; @@ -188,13 +440,6 @@ static void clamp_mss(const node_t *source, const node_t *via, vpn_packet_t *pac } } -static void swap_mac_addresses(vpn_packet_t *packet) { - mac_t tmp; - memcpy(&tmp, &DATA(packet)[0], sizeof tmp); - memcpy(&DATA(packet)[0], &DATA(packet)[6], sizeof tmp); - memcpy(&DATA(packet)[6], &tmp, sizeof tmp); -} - static void age_subnets(void *data) { bool left = false; @@ -260,100 +505,6 @@ static void route_broadcast(node_t *source, vpn_packet_t *packet) { broadcast_packet(source, packet); } -/* RFC 792 */ - -static void route_ipv4_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) { - struct ip ip = {0}; - struct icmp icmp = {0}; - - struct in_addr ip_src; - struct in_addr ip_dst; - uint32_t oldlen; - - if(ratelimit(3)) - return; - - /* Swap Ethernet source and destination addresses */ - - swap_mac_addresses(packet); - - /* Copy headers from packet into properly aligned structs on the stack */ - - memcpy(&ip, DATA(packet) + ether_size, ip_size); - - /* Remember original source and destination */ - - ip_src = ip.ip_src; - ip_dst = ip.ip_dst; - - /* Try to reply with an IP address assigned to the local machine */ - - if (type == ICMP_TIME_EXCEEDED && code == ICMP_EXC_TTL) { - int sockfd = socket(AF_INET, SOCK_DGRAM, 0); - if (sockfd != -1) { - struct sockaddr_in addr; - memset(&addr, 0, sizeof(addr)); - addr.sin_family = AF_INET; - addr.sin_addr = ip.ip_src; - if (!connect(sockfd, (const struct sockaddr*) &addr, sizeof(addr))) { - memset(&addr, 0, sizeof(addr)); - addr.sin_family = AF_INET; - socklen_t addrlen = sizeof(addr); - if (!getsockname(sockfd, (struct sockaddr*) &addr, &addrlen) && addrlen <= sizeof(addr)) { - ip_dst = addr.sin_addr; - } - } - close(sockfd); - } - } - - oldlen = packet->len - ether_size; - - if(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) - icmp.icmp_nextmtu = htons(packet->len - ether_size); - - 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(DATA(packet) + ether_size + ip_size + icmp_size, DATA(packet) + ether_size, oldlen); - - /* Fill in IPv4 header */ - - 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; - ip.ip_src = ip_dst; - ip.ip_dst = ip_src; - - ip.ip_sum = inet_checksum(&ip, ip_size, ~0); - - /* Fill in ICMP header */ - - icmp.icmp_type = type; - icmp.icmp_code = code; - icmp.icmp_cksum = 0; - - icmp.icmp_cksum = inet_checksum(&icmp, icmp_size, ~0); - icmp.icmp_cksum = inet_checksum(DATA(packet) + ether_size + ip_size + icmp_size, oldlen, icmp.icmp_cksum); - - /* Copy structs on stack back to packet */ - - memcpy(DATA(packet) + ether_size, &ip, ip_size); - memcpy(DATA(packet) + ether_size + ip_size, &icmp, icmp_size); - - packet->len = ether_size + ip_size + icmp_size + oldlen; - - send_packet(source, packet); -} - /* RFC 791 */ static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet, length_t ether_size) { @@ -478,107 +629,6 @@ static void route_ipv4(node_t *source, vpn_packet_t *packet) { send_packet(subnet->owner, packet); } -/* RFC 2463 */ - -static void route_ipv6_unreachable(node_t *source, vpn_packet_t *packet, length_t ether_size, uint8_t type, uint8_t code) { - struct ip6_hdr ip6; - struct icmp6_hdr icmp6 = {0}; - uint16_t checksum; - - struct { - struct in6_addr ip6_src; /* source address */ - struct in6_addr ip6_dst; /* destination address */ - uint32_t length; - uint32_t next; - } pseudo; - - if(ratelimit(3)) - return; - - /* Swap Ethernet source and destination addresses */ - - swap_mac_addresses(packet); - - /* Copy headers from packet to structs on the stack */ - - memcpy(&ip6, DATA(packet) + ether_size, ip6_size); - - /* Remember original source and destination */ - - pseudo.ip6_src = ip6.ip6_dst; - pseudo.ip6_dst = ip6.ip6_src; - - /* Try to reply with an IP address assigned to the local machine */ - - if (type == ICMP6_TIME_EXCEEDED && code == ICMP6_TIME_EXCEED_TRANSIT) { - int sockfd = socket(AF_INET6, SOCK_DGRAM, 0); - if (sockfd != -1) { - struct sockaddr_in6 addr; - memset(&addr, 0, sizeof(addr)); - addr.sin6_family = AF_INET6; - addr.sin6_addr = ip6.ip6_src; - if (!connect(sockfd, (const struct sockaddr*) &addr, sizeof(addr))) { - memset(&addr, 0, sizeof(addr)); - addr.sin6_family = AF_INET6; - socklen_t addrlen = sizeof(addr); - if (!getsockname(sockfd, (struct sockaddr*) &addr, &addrlen) && addrlen <= sizeof(addr)) { - pseudo.ip6_src = addr.sin6_addr; - } - } - close(sockfd); - } - } - - pseudo.length = packet->len - ether_size; - - if(type == ICMP6_PACKET_TOO_BIG) - icmp6.icmp6_mtu = htonl(pseudo.length); - - 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(DATA(packet) + ether_size + ip6_size + icmp6_size, DATA(packet) + ether_size, pseudo.length); - - /* Fill in IPv6 header */ - - ip6.ip6_flow = htonl(0x60000000UL); - ip6.ip6_plen = htons(icmp6_size + pseudo.length); - ip6.ip6_nxt = IPPROTO_ICMPV6; - ip6.ip6_hlim = 255; - ip6.ip6_src = pseudo.ip6_src; - ip6.ip6_dst = pseudo.ip6_dst; - - /* Fill in ICMP header */ - - icmp6.icmp6_type = type; - icmp6.icmp6_code = code; - icmp6.icmp6_cksum = 0; - - /* Create pseudo header */ - - pseudo.length = htonl(icmp6_size + pseudo.length); - pseudo.next = htonl(IPPROTO_ICMPV6); - - /* Generate checksum */ - - checksum = inet_checksum(&pseudo, sizeof pseudo, ~0); - checksum = inet_checksum(&icmp6, icmp6_size, checksum); - checksum = inet_checksum(DATA(packet) + ether_size + ip6_size + icmp6_size, ntohl(pseudo.length) - icmp6_size, checksum); - - icmp6.icmp6_cksum = checksum; - - /* Copy structs on stack back to packet */ - - memcpy(DATA(packet) + ether_size, &ip6, ip6_size); - memcpy(DATA(packet) + ether_size + ip6_size, &icmp6, icmp6_size); - - packet->len = ether_size + ip6_size + ntohl(pseudo.length); - - send_packet(source, packet); -} - static void route_neighborsol(node_t *source, vpn_packet_t *packet); static void route_ipv6(node_t *source, vpn_packet_t *packet) { @@ -960,58 +1010,6 @@ static void send_pcap(vpn_packet_t *packet) { } } -static bool do_decrement_ttl(node_t *source, vpn_packet_t *packet) { - uint16_t type = DATA(packet)[12] << 8 | DATA(packet)[13]; - length_t ethlen = ether_size; - - if(type == ETH_P_8021Q) { - type = DATA(packet)[16] << 8 | DATA(packet)[17]; - ethlen += 4; - } - - switch (type) { - case ETH_P_IP: - if(!checklength(source, packet, ethlen + ip_size)) - return false; - - if(DATA(packet)[ethlen + 8] <= 1) { - if(DATA(packet)[ethlen + 11] != IPPROTO_ICMP || DATA(packet)[ethlen + 32] != ICMP_TIME_EXCEEDED) - route_ipv4_unreachable(source, packet, ethlen, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL); - return false; - } - - uint16_t old = DATA(packet)[ethlen + 8] << 8 | DATA(packet)[ethlen + 9]; - DATA(packet)[ethlen + 8]--; - uint16_t new = DATA(packet)[ethlen + 8] << 8 | DATA(packet)[ethlen + 9]; - - uint32_t checksum = DATA(packet)[ethlen + 10] << 8 | DATA(packet)[ethlen + 11]; - checksum += old + (~new & 0xFFFF); - while(checksum >> 16) - checksum = (checksum & 0xFFFF) + (checksum >> 16); - DATA(packet)[ethlen + 10] = checksum >> 8; - DATA(packet)[ethlen + 11] = checksum & 0xff; - - return true; - - case ETH_P_IPV6: - if(!checklength(source, packet, ethlen + ip6_size)) - return false; - - if(DATA(packet)[ethlen + 7] <= 1) { - if(DATA(packet)[ethlen + 6] != IPPROTO_ICMPV6 || DATA(packet)[ethlen + 40] != ICMP6_TIME_EXCEEDED) - route_ipv6_unreachable(source, packet, ethlen, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_TRANSIT); - return false; - } - - DATA(packet)[ethlen + 7]--; - - return true; - - default: - return true; - } -} - void route(node_t *source, vpn_packet_t *packet) { if(pcap) send_pcap(packet); -- 2.20.1