rofl0r | 202db37 | 2013-04-05 19:26:51 +0200 | [diff] [blame] | 1 | #define _GNU_SOURCE |
rofl0r | 202db37 | 2013-04-05 19:26:51 +0200 | [diff] [blame] | 2 | #include <errno.h> |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 3 | #include <string.h> |
| 4 | #include <stdlib.h> |
rofl0r | 202db37 | 2013-04-05 19:26:51 +0200 | [diff] [blame] | 5 | #include <unistd.h> |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 6 | #include <ifaddrs.h> |
| 7 | #include <syscall.h> |
| 8 | #include <net/if.h> |
| 9 | #include <netinet/in.h> |
| 10 | #include "netlink.h" |
rofl0r | 202db37 | 2013-04-05 19:26:51 +0200 | [diff] [blame] | 11 | |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 12 | #define IFADDRS_HASH_SIZE 64 |
| 13 | |
| 14 | /* getifaddrs() reports hardware addresses with PF_PACKET that implies |
| 15 | * struct sockaddr_ll. But e.g. Infiniband socket address length is |
| 16 | * longer than sockaddr_ll.ssl_addr[8] can hold. Use this hack struct |
| 17 | * to extend ssl_addr - callers should be able to still use it. */ |
| 18 | struct sockaddr_ll_hack { |
| 19 | unsigned short sll_family, sll_protocol; |
| 20 | int sll_ifindex; |
| 21 | unsigned short sll_hatype; |
| 22 | unsigned char sll_pkttype, sll_halen; |
| 23 | unsigned char sll_addr[24]; |
| 24 | }; |
| 25 | |
| 26 | union sockany { |
| 27 | struct sockaddr sa; |
| 28 | struct sockaddr_ll_hack ll; |
rofl0r | c82f53f | 2013-04-05 22:06:35 +0200 | [diff] [blame] | 29 | struct sockaddr_in v4; |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 30 | struct sockaddr_in6 v6; |
| 31 | }; |
rofl0r | c82f53f | 2013-04-05 22:06:35 +0200 | [diff] [blame] | 32 | |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 33 | struct ifaddrs_storage { |
rofl0r | c82f53f | 2013-04-05 22:06:35 +0200 | [diff] [blame] | 34 | struct ifaddrs ifa; |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 35 | struct ifaddrs_storage *hash_next; |
| 36 | union sockany addr, netmask, ifu; |
| 37 | unsigned int index; |
rofl0r | c82f53f | 2013-04-05 22:06:35 +0200 | [diff] [blame] | 38 | char name[IFNAMSIZ+1]; |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 39 | }; |
rofl0r | c82f53f | 2013-04-05 22:06:35 +0200 | [diff] [blame] | 40 | |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 41 | struct ifaddrs_ctx { |
| 42 | struct ifaddrs_storage *first; |
| 43 | struct ifaddrs_storage *last; |
| 44 | struct ifaddrs_storage *hash[IFADDRS_HASH_SIZE]; |
| 45 | }; |
rofl0r | 202db37 | 2013-04-05 19:26:51 +0200 | [diff] [blame] | 46 | |
| 47 | void freeifaddrs(struct ifaddrs *ifp) |
| 48 | { |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 49 | struct ifaddrs *n; |
| 50 | while (ifp) { |
| 51 | n = ifp->ifa_next; |
| 52 | free(ifp); |
| 53 | ifp = n; |
rofl0r | 202db37 | 2013-04-05 19:26:51 +0200 | [diff] [blame] | 54 | } |
| 55 | } |
| 56 | |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 57 | static void copy_addr(struct sockaddr **r, int af, union sockany *sa, void *addr, size_t addrlen, int ifindex) |
rofl0r | 202db37 | 2013-04-05 19:26:51 +0200 | [diff] [blame] | 58 | { |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 59 | uint8_t *dst; |
| 60 | int len; |
| 61 | |
| 62 | switch (af) { |
| 63 | case AF_INET: |
| 64 | dst = (uint8_t*) &sa->v4.sin_addr; |
| 65 | len = 4; |
| 66 | break; |
| 67 | case AF_INET6: |
| 68 | dst = (uint8_t*) &sa->v6.sin6_addr; |
| 69 | len = 16; |
| 70 | if (IN6_IS_ADDR_LINKLOCAL(addr) || IN6_IS_ADDR_MC_LINKLOCAL(addr)) |
| 71 | sa->v6.sin6_scope_id = ifindex; |
| 72 | break; |
| 73 | default: |
| 74 | return; |
rofl0r | 9947ed5 | 2013-04-09 11:00:52 +0200 | [diff] [blame] | 75 | } |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 76 | if (addrlen < len) return; |
| 77 | sa->sa.sa_family = af; |
| 78 | memcpy(dst, addr, len); |
| 79 | *r = &sa->sa; |
rofl0r | 202db37 | 2013-04-05 19:26:51 +0200 | [diff] [blame] | 80 | } |
| 81 | |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 82 | static void gen_netmask(struct sockaddr **r, int af, union sockany *sa, int prefixlen) |
rofl0r | 202db37 | 2013-04-05 19:26:51 +0200 | [diff] [blame] | 83 | { |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 84 | uint8_t addr[16] = {0}; |
| 85 | int i; |
| 86 | |
| 87 | if (prefixlen > 8*sizeof(addr)) prefixlen = 8*sizeof(addr); |
| 88 | i = prefixlen / 8; |
| 89 | memset(addr, 0xff, i); |
| 90 | if (i < sizeof(addr)) addr[i++] = 0xff << (8 - (prefixlen % 8)); |
| 91 | copy_addr(r, af, sa, addr, sizeof(addr), 0); |
| 92 | } |
| 93 | |
| 94 | static void copy_lladdr(struct sockaddr **r, union sockany *sa, void *addr, size_t addrlen, int ifindex, unsigned short hatype) |
| 95 | { |
| 96 | if (addrlen > sizeof(sa->ll.sll_addr)) return; |
| 97 | sa->ll.sll_family = AF_PACKET; |
| 98 | sa->ll.sll_ifindex = ifindex; |
| 99 | sa->ll.sll_hatype = hatype; |
| 100 | sa->ll.sll_halen = addrlen; |
| 101 | memcpy(sa->ll.sll_addr, addr, addrlen); |
| 102 | *r = &sa->sa; |
| 103 | } |
| 104 | |
| 105 | static int netlink_msg_to_ifaddr(void *pctx, struct nlmsghdr *h) |
| 106 | { |
| 107 | struct ifaddrs_ctx *ctx = pctx; |
| 108 | struct ifaddrs_storage *ifs, *ifs0; |
| 109 | struct ifinfomsg *ifi = NLMSG_DATA(h); |
| 110 | struct ifaddrmsg *ifa = NLMSG_DATA(h); |
| 111 | struct rtattr *rta; |
| 112 | int stats_len = 0; |
| 113 | |
| 114 | if (h->nlmsg_type == RTM_NEWLINK) { |
| 115 | for (rta = NLMSG_RTA(h, sizeof(*ifi)); NLMSG_RTAOK(rta, h); rta = RTA_NEXT(rta)) { |
| 116 | if (rta->rta_type != IFLA_STATS) continue; |
| 117 | stats_len = RTA_DATALEN(rta); |
| 118 | break; |
rofl0r | 202db37 | 2013-04-05 19:26:51 +0200 | [diff] [blame] | 119 | } |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 120 | } else { |
| 121 | for (ifs0 = ctx->hash[ifa->ifa_index % IFADDRS_HASH_SIZE]; ifs0; ifs0 = ifs0->hash_next) |
| 122 | if (ifs0->index == ifa->ifa_index) |
| 123 | break; |
| 124 | if (!ifs0) return 0; |
rofl0r | 202db37 | 2013-04-05 19:26:51 +0200 | [diff] [blame] | 125 | } |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 126 | |
| 127 | ifs = calloc(1, sizeof(struct ifaddrs_storage) + stats_len); |
| 128 | if (ifs == 0) return -1; |
| 129 | |
| 130 | if (h->nlmsg_type == RTM_NEWLINK) { |
| 131 | ifs->index = ifi->ifi_index; |
| 132 | ifs->ifa.ifa_flags = ifi->ifi_flags; |
| 133 | |
| 134 | for (rta = NLMSG_RTA(h, sizeof(*ifi)); NLMSG_RTAOK(rta, h); rta = RTA_NEXT(rta)) { |
| 135 | switch (rta->rta_type) { |
| 136 | case IFLA_IFNAME: |
| 137 | if (RTA_DATALEN(rta) < sizeof(ifs->name)) { |
| 138 | memcpy(ifs->name, RTA_DATA(rta), RTA_DATALEN(rta)); |
| 139 | ifs->ifa.ifa_name = ifs->name; |
| 140 | } |
| 141 | break; |
| 142 | case IFLA_ADDRESS: |
| 143 | copy_lladdr(&ifs->ifa.ifa_addr, &ifs->addr, RTA_DATA(rta), RTA_DATALEN(rta), ifi->ifi_index, ifi->ifi_type); |
| 144 | break; |
| 145 | case IFLA_BROADCAST: |
| 146 | copy_lladdr(&ifs->ifa.ifa_broadaddr, &ifs->ifu, RTA_DATA(rta), RTA_DATALEN(rta), ifi->ifi_index, ifi->ifi_type); |
| 147 | break; |
| 148 | case IFLA_STATS: |
| 149 | ifs->ifa.ifa_data = (void*)(ifs+1); |
| 150 | memcpy(ifs->ifa.ifa_data, RTA_DATA(rta), RTA_DATALEN(rta)); |
| 151 | break; |
| 152 | } |
| 153 | } |
| 154 | if (ifs->ifa.ifa_name) { |
| 155 | unsigned int bucket = ifs->index % IFADDRS_HASH_SIZE; |
| 156 | ifs->hash_next = ctx->hash[bucket]; |
| 157 | ctx->hash[bucket] = ifs; |
| 158 | } |
| 159 | } else { |
| 160 | ifs->ifa.ifa_name = ifs0->ifa.ifa_name; |
| 161 | ifs->ifa.ifa_flags = ifs0->ifa.ifa_flags; |
| 162 | for (rta = NLMSG_RTA(h, sizeof(*ifa)); NLMSG_RTAOK(rta, h); rta = RTA_NEXT(rta)) { |
| 163 | switch (rta->rta_type) { |
| 164 | case IFA_ADDRESS: |
Jo-Philipp Wich | 7b71284 | 2015-11-19 21:43:10 +0100 | [diff] [blame] | 165 | /* If ifa_addr is already set we, received an IFA_LOCAL before |
| 166 | * so treat this as destination address */ |
| 167 | if (ifs->ifa.ifa_addr) |
| 168 | copy_addr(&ifs->ifa.ifa_dstaddr, ifa->ifa_family, &ifs->ifu, RTA_DATA(rta), RTA_DATALEN(rta), ifa->ifa_index); |
| 169 | else |
| 170 | copy_addr(&ifs->ifa.ifa_addr, ifa->ifa_family, &ifs->addr, RTA_DATA(rta), RTA_DATALEN(rta), ifa->ifa_index); |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 171 | break; |
| 172 | case IFA_BROADCAST: |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 173 | copy_addr(&ifs->ifa.ifa_broadaddr, ifa->ifa_family, &ifs->ifu, RTA_DATA(rta), RTA_DATALEN(rta), ifa->ifa_index); |
| 174 | break; |
Jo-Philipp Wich | 7b71284 | 2015-11-19 21:43:10 +0100 | [diff] [blame] | 175 | case IFA_LOCAL: |
| 176 | /* If ifa_addr is set and we get IFA_LOCAL, assume we have |
| 177 | * a point-to-point network. Move address to correct field. */ |
| 178 | if (ifs->ifa.ifa_addr) { |
| 179 | ifs->ifu = ifs->addr; |
| 180 | ifs->ifa.ifa_dstaddr = &ifs->ifu.sa; |
| 181 | memset(&ifs->addr, 0, sizeof(ifs->addr)); |
| 182 | } |
| 183 | copy_addr(&ifs->ifa.ifa_addr, ifa->ifa_family, &ifs->addr, RTA_DATA(rta), RTA_DATALEN(rta), ifa->ifa_index); |
| 184 | break; |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 185 | case IFA_LABEL: |
| 186 | if (RTA_DATALEN(rta) < sizeof(ifs->name)) { |
| 187 | memcpy(ifs->name, RTA_DATA(rta), RTA_DATALEN(rta)); |
| 188 | ifs->ifa.ifa_name = ifs->name; |
| 189 | } |
| 190 | break; |
| 191 | } |
| 192 | } |
| 193 | if (ifs->ifa.ifa_addr) |
| 194 | gen_netmask(&ifs->ifa.ifa_netmask, ifa->ifa_family, &ifs->netmask, ifa->ifa_prefixlen); |
| 195 | } |
| 196 | |
| 197 | if (ifs->ifa.ifa_name) { |
| 198 | if (!ctx->first) ctx->first = ifs; |
| 199 | if (ctx->last) ctx->last->ifa.ifa_next = &ifs->ifa; |
| 200 | ctx->last = ifs; |
| 201 | } else { |
| 202 | free(ifs); |
| 203 | } |
| 204 | return 0; |
rofl0r | 202db37 | 2013-04-05 19:26:51 +0200 | [diff] [blame] | 205 | } |
| 206 | |
| 207 | int getifaddrs(struct ifaddrs **ifap) |
| 208 | { |
Timo Teräs | 08e4052 | 2014-04-08 14:03:16 +0000 | [diff] [blame] | 209 | struct ifaddrs_ctx _ctx, *ctx = &_ctx; |
| 210 | int r; |
| 211 | memset(ctx, 0, sizeof *ctx); |
| 212 | r = __rtnetlink_enumerate(AF_UNSPEC, AF_UNSPEC, netlink_msg_to_ifaddr, ctx); |
| 213 | if (r == 0) *ifap = &ctx->first->ifa; |
| 214 | else freeifaddrs(&ctx->first->ifa); |
| 215 | return r; |
rofl0r | 202db37 | 2013-04-05 19:26:51 +0200 | [diff] [blame] | 216 | } |