10 #define IFADDRS_HASH_SIZE 64
13 unsigned int hash_next;
15 unsigned char namelen;
19 struct ifnameindexctx {
20 unsigned int num, allocated, str_bytes;
21 struct ifnamemap *list;
22 unsigned int hash[IFADDRS_HASH_SIZE];
25 static int netlink_msg_to_nameindex(void *pctx, struct nlmsghdr *h)
27 struct ifnameindexctx *ctx = pctx;
28 struct ifnamemap *map;
31 int index, type, namelen, bucket;
33 if (h->nlmsg_type == RTM_NEWLINK) {
34 struct ifinfomsg *ifi = NLMSG_DATA(h);
35 index = ifi->ifi_index;
37 rta = NLMSG_RTA(h, sizeof(*ifi));
39 struct ifaddrmsg *ifa = NLMSG_DATA(h);
40 index = ifa->ifa_index;
42 rta = NLMSG_RTA(h, sizeof(*ifa));
44 for (; NLMSG_RTAOK(rta, h); rta = RTA_NEXT(rta)) {
45 if (rta->rta_type != type) continue;
47 namelen = RTA_DATALEN(rta) - 1;
48 if (namelen > IFNAMSIZ) return 0;
50 /* suppress duplicates */
51 bucket = index % IFADDRS_HASH_SIZE;
52 i = ctx->hash[bucket];
54 map = &ctx->list[i-1];
55 if (map->index == index &&
56 map->namelen == namelen &&
57 memcmp(map->name, RTA_DATA(rta), namelen) == 0)
62 if (ctx->num >= ctx->allocated) {
63 size_t a = ctx->allocated ? ctx->allocated * 2 + 1 : 8;
64 if (a > SIZE_MAX/sizeof *map) return -1;
65 map = realloc(ctx->list, a * sizeof *map);
70 map = &ctx->list[ctx->num];
72 map->namelen = namelen;
73 memcpy(map->name, RTA_DATA(rta), namelen);
74 ctx->str_bytes += namelen + 1;
76 map->hash_next = ctx->hash[bucket];
77 ctx->hash[bucket] = ctx->num;
83 struct if_nameindex *if_nameindex()
85 struct ifnameindexctx _ctx, *ctx = &_ctx;
86 struct if_nameindex *ifs = 0, *d;
92 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
93 memset(ctx, 0, sizeof(*ctx));
94 if (__rtnetlink_enumerate(AF_UNSPEC, AF_INET, netlink_msg_to_nameindex, ctx) < 0) goto err;
96 ifs = malloc(sizeof(struct if_nameindex[ctx->num+1]) + ctx->str_bytes);
99 p = (char*)(ifs + ctx->num + 1);
100 for (i = ctx->num, d = ifs, s = ctx->list; i; i--, s++, d++) {
101 d->if_index = s->index;
103 memcpy(p, s->name, s->namelen);
110 pthread_setcancelstate(cs, 0);