diff options
Diffstat (limited to 'libc-top-half/musl/src/network/getifaddrs.c')
| -rw-r--r-- | libc-top-half/musl/src/network/getifaddrs.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/libc-top-half/musl/src/network/getifaddrs.c b/libc-top-half/musl/src/network/getifaddrs.c new file mode 100644 index 0000000..fed75bd --- /dev/null +++ b/libc-top-half/musl/src/network/getifaddrs.c @@ -0,0 +1,216 @@ +#define _GNU_SOURCE +#include <errno.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> +#include <ifaddrs.h> +#include <syscall.h> +#include <net/if.h> +#include <netinet/in.h> +#include "netlink.h" + +#define IFADDRS_HASH_SIZE 64 + +/* getifaddrs() reports hardware addresses with PF_PACKET that implies + * struct sockaddr_ll. But e.g. Infiniband socket address length is + * longer than sockaddr_ll.ssl_addr[8] can hold. Use this hack struct + * to extend ssl_addr - callers should be able to still use it. */ +struct sockaddr_ll_hack { + unsigned short sll_family, sll_protocol; + int sll_ifindex; + unsigned short sll_hatype; + unsigned char sll_pkttype, sll_halen; + unsigned char sll_addr[24]; +}; + +union sockany { + struct sockaddr sa; + struct sockaddr_ll_hack ll; + struct sockaddr_in v4; + struct sockaddr_in6 v6; +}; + +struct ifaddrs_storage { + struct ifaddrs ifa; + struct ifaddrs_storage *hash_next; + union sockany addr, netmask, ifu; + unsigned int index; + char name[IFNAMSIZ+1]; +}; + +struct ifaddrs_ctx { + struct ifaddrs_storage *first; + struct ifaddrs_storage *last; + struct ifaddrs_storage *hash[IFADDRS_HASH_SIZE]; +}; + +void freeifaddrs(struct ifaddrs *ifp) +{ + struct ifaddrs *n; + while (ifp) { + n = ifp->ifa_next; + free(ifp); + ifp = n; + } +} + +static void copy_addr(struct sockaddr **r, int af, union sockany *sa, void *addr, size_t addrlen, int ifindex) +{ + uint8_t *dst; + int len; + + switch (af) { + case AF_INET: + dst = (uint8_t*) &sa->v4.sin_addr; + len = 4; + break; + case AF_INET6: + dst = (uint8_t*) &sa->v6.sin6_addr; + len = 16; + if (IN6_IS_ADDR_LINKLOCAL(addr) || IN6_IS_ADDR_MC_LINKLOCAL(addr)) + sa->v6.sin6_scope_id = ifindex; + break; + default: + return; + } + if (addrlen < len) return; + sa->sa.sa_family = af; + memcpy(dst, addr, len); + *r = &sa->sa; +} + +static void gen_netmask(struct sockaddr **r, int af, union sockany *sa, int prefixlen) +{ + uint8_t addr[16] = {0}; + int i; + + if (prefixlen > 8*sizeof(addr)) prefixlen = 8*sizeof(addr); + i = prefixlen / 8; + memset(addr, 0xff, i); + if (i < sizeof(addr)) addr[i++] = 0xff << (8 - (prefixlen % 8)); + copy_addr(r, af, sa, addr, sizeof(addr), 0); +} + +static void copy_lladdr(struct sockaddr **r, union sockany *sa, void *addr, size_t addrlen, int ifindex, unsigned short hatype) +{ + if (addrlen > sizeof(sa->ll.sll_addr)) return; + sa->ll.sll_family = AF_PACKET; + sa->ll.sll_ifindex = ifindex; + sa->ll.sll_hatype = hatype; + sa->ll.sll_halen = addrlen; + memcpy(sa->ll.sll_addr, addr, addrlen); + *r = &sa->sa; +} + +static int netlink_msg_to_ifaddr(void *pctx, struct nlmsghdr *h) +{ + struct ifaddrs_ctx *ctx = pctx; + struct ifaddrs_storage *ifs, *ifs0; + struct ifinfomsg *ifi = NLMSG_DATA(h); + struct ifaddrmsg *ifa = NLMSG_DATA(h); + struct rtattr *rta; + int stats_len = 0; + + if (h->nlmsg_type == RTM_NEWLINK) { + for (rta = NLMSG_RTA(h, sizeof(*ifi)); NLMSG_RTAOK(rta, h); rta = RTA_NEXT(rta)) { + if (rta->rta_type != IFLA_STATS) continue; + stats_len = RTA_DATALEN(rta); + break; + } + } else { + for (ifs0 = ctx->hash[ifa->ifa_index % IFADDRS_HASH_SIZE]; ifs0; ifs0 = ifs0->hash_next) + if (ifs0->index == ifa->ifa_index) + break; + if (!ifs0) return 0; + } + + ifs = calloc(1, sizeof(struct ifaddrs_storage) + stats_len); + if (ifs == 0) return -1; + + if (h->nlmsg_type == RTM_NEWLINK) { + ifs->index = ifi->ifi_index; + ifs->ifa.ifa_flags = ifi->ifi_flags; + + for (rta = NLMSG_RTA(h, sizeof(*ifi)); NLMSG_RTAOK(rta, h); rta = RTA_NEXT(rta)) { + switch (rta->rta_type) { + case IFLA_IFNAME: + if (RTA_DATALEN(rta) < sizeof(ifs->name)) { + memcpy(ifs->name, RTA_DATA(rta), RTA_DATALEN(rta)); + ifs->ifa.ifa_name = ifs->name; + } + break; + case IFLA_ADDRESS: + copy_lladdr(&ifs->ifa.ifa_addr, &ifs->addr, RTA_DATA(rta), RTA_DATALEN(rta), ifi->ifi_index, ifi->ifi_type); + break; + case IFLA_BROADCAST: + copy_lladdr(&ifs->ifa.ifa_broadaddr, &ifs->ifu, RTA_DATA(rta), RTA_DATALEN(rta), ifi->ifi_index, ifi->ifi_type); + break; + case IFLA_STATS: + ifs->ifa.ifa_data = (void*)(ifs+1); + memcpy(ifs->ifa.ifa_data, RTA_DATA(rta), RTA_DATALEN(rta)); + break; + } + } + if (ifs->ifa.ifa_name) { + unsigned int bucket = ifs->index % IFADDRS_HASH_SIZE; + ifs->hash_next = ctx->hash[bucket]; + ctx->hash[bucket] = ifs; + } + } else { + ifs->ifa.ifa_name = ifs0->ifa.ifa_name; + ifs->ifa.ifa_flags = ifs0->ifa.ifa_flags; + for (rta = NLMSG_RTA(h, sizeof(*ifa)); NLMSG_RTAOK(rta, h); rta = RTA_NEXT(rta)) { + switch (rta->rta_type) { + case IFA_ADDRESS: + /* If ifa_addr is already set we, received an IFA_LOCAL before + * so treat this as destination address */ + if (ifs->ifa.ifa_addr) + copy_addr(&ifs->ifa.ifa_dstaddr, ifa->ifa_family, &ifs->ifu, RTA_DATA(rta), RTA_DATALEN(rta), ifa->ifa_index); + else + copy_addr(&ifs->ifa.ifa_addr, ifa->ifa_family, &ifs->addr, RTA_DATA(rta), RTA_DATALEN(rta), ifa->ifa_index); + break; + case IFA_BROADCAST: + copy_addr(&ifs->ifa.ifa_broadaddr, ifa->ifa_family, &ifs->ifu, RTA_DATA(rta), RTA_DATALEN(rta), ifa->ifa_index); + break; + case IFA_LOCAL: + /* If ifa_addr is set and we get IFA_LOCAL, assume we have + * a point-to-point network. Move address to correct field. */ + if (ifs->ifa.ifa_addr) { + ifs->ifu = ifs->addr; + ifs->ifa.ifa_dstaddr = &ifs->ifu.sa; + memset(&ifs->addr, 0, sizeof(ifs->addr)); + } + copy_addr(&ifs->ifa.ifa_addr, ifa->ifa_family, &ifs->addr, RTA_DATA(rta), RTA_DATALEN(rta), ifa->ifa_index); + break; + case IFA_LABEL: + if (RTA_DATALEN(rta) < sizeof(ifs->name)) { + memcpy(ifs->name, RTA_DATA(rta), RTA_DATALEN(rta)); + ifs->ifa.ifa_name = ifs->name; + } + break; + } + } + if (ifs->ifa.ifa_addr) + gen_netmask(&ifs->ifa.ifa_netmask, ifa->ifa_family, &ifs->netmask, ifa->ifa_prefixlen); + } + + if (ifs->ifa.ifa_name) { + if (!ctx->first) ctx->first = ifs; + if (ctx->last) ctx->last->ifa.ifa_next = &ifs->ifa; + ctx->last = ifs; + } else { + free(ifs); + } + return 0; +} + +int getifaddrs(struct ifaddrs **ifap) +{ + struct ifaddrs_ctx _ctx, *ctx = &_ctx; + int r; + memset(ctx, 0, sizeof *ctx); + r = __rtnetlink_enumerate(AF_UNSPEC, AF_UNSPEC, netlink_msg_to_ifaddr, ctx); + if (r == 0) *ifap = &ctx->first->ifa; + else freeifaddrs(&ctx->first->ifa); + return r; +} |