>From 137e4bc5ad24ba7e261483378cb8de549777fa44 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Timo=20Ter=C3=A4s?= Date: Tue, 8 Apr 2014 14:03:16 +0000 Subject: [PATCH] reimplement if_nameindex and getifaddrs using netlink --- src/network/getifaddrs.c | 314 ++++++++++++++++++++++++--------------------- src/network/if_nameindex.c | 132 +++++++++++++------ src/network/netlink.c | 52 ++++++++ src/network/netlink.h | 94 ++++++++++++++ 4 files changed, 407 insertions(+), 185 deletions(-) create mode 100644 src/network/netlink.c create mode 100644 src/network/netlink.h diff --git a/src/network/getifaddrs.c b/src/network/getifaddrs.c index 5a94cc7..89a8f72 100644 --- a/src/network/getifaddrs.c +++ b/src/network/getifaddrs.c @@ -1,181 +1,203 @@ -/* (C) 2013 John Spencer. released under musl's standard MIT license. */ -#undef _GNU_SOURCE #define _GNU_SOURCE -#include -#include -#include /* IFNAMSIZ, ifreq, ifconf */ -#include -#include -#include #include -#include /* inet_pton */ +#include +#include #include -#include -#include +#include +#include +#include +#include +#include "netlink.h" -typedef union { - struct sockaddr_in6 v6; +#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; -} soa; + struct sockaddr_in6 v6; +}; -typedef struct ifaddrs_storage { +struct ifaddrs_storage { struct ifaddrs ifa; - soa addr; - soa netmask; - soa dst; + struct ifaddrs_storage *hash_next; + union sockany addr, netmask, ifu; + unsigned int index; char name[IFNAMSIZ+1]; -} stor; -#define next ifa.ifa_next +}; -static stor* list_add(stor** list, stor** head, char* ifname) +struct ifaddrs_ctx { + struct ifaddrs_storage *first; + struct ifaddrs_storage *last; + struct ifaddrs_storage *hash[IFADDRS_HASH_SIZE]; +}; + +void freeifaddrs(struct ifaddrs *ifp) { - stor* curr = calloc(1, sizeof(stor)); - if(curr) { - strcpy(curr->name, ifname); - curr->ifa.ifa_name = curr->name; - if(*head) (*head)->next = (struct ifaddrs*) curr; - *head = curr; - if(!*list) *list = curr; + struct ifaddrs *n; + while (ifp) { + n = ifp->ifa_next; + free(ifp); + ifp = n; } - return curr; } -void freeifaddrs(struct ifaddrs *ifp) +static void copy_addr(struct sockaddr **r, int af, union sockany *sa, void *addr, size_t addrlen, int ifindex) { - stor *head = (stor *) ifp; - while(head) { - void *p = head; - head = (stor *) head->next; - free(p); + 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 ipv6netmask(unsigned prefix_length, struct sockaddr_in6 *sa) +static void gen_netmask(struct sockaddr **r, int af, union sockany *sa, int prefixlen) { - unsigned char* hb = sa->sin6_addr.s6_addr; - unsigned onebytes = prefix_length / 8; - unsigned bits = prefix_length % 8; - unsigned nullbytes = 16 - onebytes; - memset(hb, -1, onebytes); - memset(hb+onebytes, 0, nullbytes); - if(bits) { - unsigned char x = -1; - x <<= 8 - bits; - hb[onebytes] = x; - } + 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 dealwithipv6(stor **list, stor** head) +static void copy_lladdr(struct sockaddr **r, union sockany *sa, void *addr, size_t addrlen, int ifindex, unsigned short hatype) { - FILE* f = fopen("/proc/net/if_inet6", "rbe"); - /* 00000000000000000000000000000001 01 80 10 80 lo - A B C D E F - all numbers in hex - A = addr B=netlink device#, C=prefix length, - D = scope value (ipv6.h) E = interface flags (rnetlink.h, addrconf.c) - F = if name */ - char v6conv[32 + 7 + 1], *v6; - char *line, linebuf[512]; - if(!f) return; - while((line = fgets(linebuf, sizeof linebuf, f))) { - v6 = v6conv; - size_t i = 0; - for(; i < 8; i++) { - memcpy(v6, line, 4); - v6+=4; - *v6++=':'; - line+=4; - } - --v6; *v6 = 0; - line++; - unsigned b, c, d, e; - char name[IFNAMSIZ+1]; - if(5 == sscanf(line, "%x %x %x %x %s", &b, &c, &d, &e, name)) { - struct sockaddr_in6 sa = {0}; - if(1 == inet_pton(AF_INET6, v6conv, &sa.sin6_addr)) { - sa.sin6_family = AF_INET6; - stor* curr = list_add(list, head, name); - if(!curr) goto out; - curr->addr.v6 = sa; - curr->ifa.ifa_addr = (struct sockaddr*) &curr->addr; - ipv6netmask(c, &sa); - curr->netmask.v6 = sa; - curr->ifa.ifa_netmask = (struct sockaddr*) &curr->netmask; - /* find ipv4 struct with the same interface name to copy flags */ - stor* scan = *list; - for(;scan && strcmp(name, scan->name);scan=(stor*)scan->next); - if(scan) curr->ifa.ifa_flags = scan->ifa.ifa_flags; - else curr->ifa.ifa_flags = 0; - } else errno = 0; - } - } - out: - fclose(f); + 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; } -int getifaddrs(struct ifaddrs **ifap) +static int netlink_msg_to_ifaddr(void *pctx, struct nlmsghdr *h) { - stor *list = 0, *head = 0; - struct if_nameindex* ii = if_nameindex(); - if(!ii) return -1; - size_t i; - for(i = 0; ii[i].if_index || ii[i].if_name; i++) { - stor* curr = list_add(&list, &head, ii[i].if_name); - if(!curr) { - if_freenameindex(ii); - goto err2; + 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; } - if_freenameindex(ii); - - int sock = socket(PF_INET, SOCK_DGRAM|SOCK_CLOEXEC, IPPROTO_IP); - if(sock == -1) goto err2; - struct ifreq reqs[32]; /* arbitrary chosen boundary */ - struct ifconf conf = {.ifc_len = sizeof reqs, .ifc_req = reqs}; - if(-1 == ioctl(sock, SIOCGIFCONF, &conf)) goto err; - size_t reqitems = conf.ifc_len / sizeof(struct ifreq); - for(head = list; head; head = (stor*)head->next) { - for(i = 0; i < reqitems; i++) { - // get SIOCGIFADDR of active interfaces. - if(!strcmp(reqs[i].ifr_name, head->name)) { - head->addr.v4 = *(struct sockaddr_in*)&reqs[i].ifr_addr; - head->ifa.ifa_addr = (struct sockaddr*) &head->addr; + + 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; } } - struct ifreq req; - snprintf(req.ifr_name, sizeof req.ifr_name, "%s", head->name); - if(-1 == ioctl(sock, SIOCGIFFLAGS, &req)) goto err; - - head->ifa.ifa_flags = req.ifr_flags; - if(head->ifa.ifa_addr) { - /* or'ing flags with IFF_LOWER_UP on active interfaces to mimic glibc */ - head->ifa.ifa_flags |= IFF_LOWER_UP; - if(-1 == ioctl(sock, SIOCGIFNETMASK, &req)) goto err; - head->netmask.v4 = *(struct sockaddr_in*)&req.ifr_netmask; - head->ifa.ifa_netmask = (struct sockaddr*) &head->netmask; - - if(head->ifa.ifa_flags & IFF_POINTOPOINT) { - if(-1 == ioctl(sock, SIOCGIFDSTADDR, &req)) goto err; - head->dst.v4 = *(struct sockaddr_in*)&req.ifr_dstaddr; - } else { - if(-1 == ioctl(sock, SIOCGIFBRDADDR, &req)) goto err; - head->dst.v4 = *(struct sockaddr_in*)&req.ifr_broadaddr; + 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: + copy_addr(&ifs->ifa.ifa_addr, ifa->ifa_family, &ifs->addr, RTA_DATA(rta), RTA_DATALEN(rta), ifa->ifa_index); + break; + case IFA_BROADCAST: + /* For point-to-point links this is peer, but ifa_broadaddr + * and ifa_dstaddr are union, so this works for both. */ + copy_addr(&ifs->ifa.ifa_broadaddr, ifa->ifa_family, &ifs->ifu, 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; } - head->ifa.ifa_ifu.ifu_dstaddr = (struct sockaddr*) &head->dst; } + 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); } - close(sock); - void* last = 0; - for(head = list; head; head=(stor*)head->next) last=head; - head = last; - dealwithipv6(&list, &head); - *ifap = (struct ifaddrs*) list; return 0; - err: - close(sock); - err2: - freeifaddrs((struct ifaddrs*) list); - return -1; } +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; +} diff --git a/src/network/if_nameindex.c b/src/network/if_nameindex.c index 53b80b2..f8dda54 100644 --- a/src/network/if_nameindex.c +++ b/src/network/if_nameindex.c @@ -1,55 +1,109 @@ #define _GNU_SOURCE #include -#include -#include -#include #include -#include "syscall.h" +#include +#include +#include +#include "netlink.h" -static void *do_nameindex(int s, size_t n) -{ - size_t i, len, k; - struct ifconf conf; - struct if_nameindex *idx; +#define IFADDRS_HASH_SIZE 64 - idx = malloc(n * (sizeof(struct if_nameindex)+sizeof(struct ifreq))); - if (!idx) return 0; +struct ifnamemap { + unsigned int hash_next; + unsigned int index; + unsigned char namelen; + char name[IFNAMSIZ]; +}; - conf.ifc_buf = (void *)&idx[n]; - conf.ifc_len = len = n * sizeof(struct ifreq); - if (ioctl(s, SIOCGIFCONF, &conf) < 0) { - free(idx); - return 0; - } - if (conf.ifc_len == len) { - free(idx); - return (void *)-1; +struct ifnameindexctx { + unsigned int num, allocated, str_bytes; + struct ifnamemap *list; + unsigned int hash[IFADDRS_HASH_SIZE]; +}; + +static int netlink_msg_to_nameindex(void *pctx, struct nlmsghdr *h) +{ + struct ifnameindexctx *ctx = pctx; + struct ifnamemap *map; + struct rtattr *rta; + unsigned int i; + int index, type, namelen, bucket; + + if (h->nlmsg_type == RTM_NEWLINK) { + struct ifinfomsg *ifi = NLMSG_DATA(h); + index = ifi->ifi_index; + type = IFLA_IFNAME; + rta = NLMSG_RTA(h, sizeof(*ifi)); + } else { + struct ifaddrmsg *ifa = NLMSG_DATA(h); + index = ifa->ifa_index; + type = IFA_LABEL; + rta = NLMSG_RTA(h, sizeof(*ifa)); } + for (; NLMSG_RTAOK(rta, h); rta = RTA_NEXT(rta)) { + if (rta->rta_type != type) continue; - n = conf.ifc_len / sizeof(struct ifreq); - for (i=k=0; i IFNAMSIZ) return 0; + + /* suppress duplicates */ + bucket = index % IFADDRS_HASH_SIZE; + i = ctx->hash[bucket]; + while (i) { + map = &ctx->list[i-1]; + if (map->index == index && + map->namelen == namelen && + memcmp(map->name, RTA_DATA(rta), namelen) == 0) + return 0; + i = map->hash_next; } - idx[i-k].if_index = conf.ifc_req[i].ifr_ifindex; - idx[i-k].if_name = conf.ifc_req[i].ifr_name; - } - idx[i-k].if_name = 0; - idx[i-k].if_index = 0; - return idx; + if (ctx->num >= ctx->allocated) { + size_t a = ctx->allocated ? ctx->allocated * 2 + 1 : 8; + if (a > SIZE_MAX/sizeof *map) return -1; + map = realloc(ctx->list, a * sizeof *map); + if (!map) return -1; + ctx->list = map; + ctx->allocated = a; + } + map = &ctx->list[ctx->num]; + map->index = index; + map->namelen = namelen; + memcpy(map->name, RTA_DATA(rta), namelen); + ctx->str_bytes += namelen + 1; + ctx->num++; + map->hash_next = ctx->hash[bucket]; + ctx->hash[bucket] = ctx->num; + return 0; + } + return 0; } struct if_nameindex *if_nameindex() { - size_t n; - void *p = 0; - int s = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0); - if (s>=0) { - for (n=0; (p=do_nameindex(s, n)) == (void *)-1; n++); - __syscall(SYS_close, s); + struct ifnameindexctx _ctx, *ctx = &_ctx; + struct if_nameindex *ifs = 0, *d; + struct ifnamemap *s; + char *p; + int i; + + memset(ctx, 0, sizeof(*ctx)); + if (__rtnetlink_enumerate(AF_UNSPEC, AF_INET, netlink_msg_to_nameindex, ctx) < 0) goto err; + + ifs = malloc(sizeof(struct if_nameindex[ctx->num+1]) + ctx->str_bytes); + if (!ifs) goto err; + + p = (char*)(ifs + ctx->num + 1); + for (i = ctx->num, d = ifs, s = ctx->list; i; i--, s++, d++) { + d->if_index = s->index; + d->if_name = p; + memcpy(p, s->name, s->namelen); + p += s->namelen; + *p++ = 0; } - errno = ENOBUFS; - return p; + d->if_index = 0; + d->if_name = 0; +err: + free(ctx->list); + return ifs; } diff --git a/src/network/netlink.c b/src/network/netlink.c new file mode 100644 index 0000000..94dba7f --- /dev/null +++ b/src/network/netlink.c @@ -0,0 +1,52 @@ +#include +#include +#include +#include +#include "netlink.h" + +static int __netlink_enumerate(int fd, unsigned int seq, int type, int af, + int (*cb)(void *ctx, struct nlmsghdr *h), void *ctx) +{ + struct nlmsghdr *h; + union { + uint8_t buf[8192]; + struct { + struct nlmsghdr nlh; + struct rtgenmsg g; + } req; + struct nlmsghdr reply; + } u; + int r, ret; + + memset(&u.req, 0, sizeof(u.req)); + u.req.nlh.nlmsg_len = sizeof(u.req); + u.req.nlh.nlmsg_type = type; + u.req.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST; + u.req.nlh.nlmsg_seq = seq; + u.req.g.rtgen_family = af; + r = send(fd, &u.req, sizeof(u.req), 0); + if (r < 0) return r; + + while (1) { + r = recv(fd, u.buf, sizeof(u.buf), MSG_DONTWAIT); + if (r <= 0) return -1; + for (h = &u.reply; NLMSG_OK(h, (void*)&u.buf[r]); h = NLMSG_NEXT(h)) { + if (h->nlmsg_type == NLMSG_DONE) return 0; + if (h->nlmsg_type == NLMSG_ERROR) return -1; + ret = cb(ctx, h); + if (ret) return ret; + } + } +} + +int __rtnetlink_enumerate(int link_af, int addr_af, int (*cb)(void *ctx, struct nlmsghdr *h), void *ctx) +{ + int fd, r; + + fd = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC, NETLINK_ROUTE); + if (fd < 0) return -1; + r = __netlink_enumerate(fd, 1, RTM_GETLINK, link_af, cb, ctx); + if (!r) r = __netlink_enumerate(fd, 2, RTM_GETADDR, addr_af, cb, ctx); + __syscall(SYS_close,fd); + return r; +} diff --git a/src/network/netlink.h b/src/network/netlink.h new file mode 100644 index 0000000..20700ac --- /dev/null +++ b/src/network/netlink.h @@ -0,0 +1,94 @@ +#include + +/* linux/netlink.h */ + +#define NETLINK_ROUTE 0 + +struct nlmsghdr { + uint32_t nlmsg_len; + uint16_t nlmsg_type; + uint16_t nlmsg_flags; + uint32_t nlmsg_seq; + uint32_t nlmsg_pid; +}; + +#define NLM_F_REQUEST 1 +#define NLM_F_MULTI 2 +#define NLM_F_ACK 4 + +#define NLM_F_ROOT 0x100 +#define NLM_F_MATCH 0x200 +#define NLM_F_ATOMIC 0x400 +#define NLM_F_DUMP (NLM_F_ROOT|NLM_F_MATCH) + +#define NLMSG_NOOP 0x1 +#define NLMSG_ERROR 0x2 +#define NLMSG_DONE 0x3 +#define NLMSG_OVERRUN 0x4 + +/* linux/rtnetlink.h */ + +#define RTM_NEWLINK 16 +#define RTM_GETLINK 18 +#define RTM_NEWADDR 20 +#define RTM_GETADDR 22 + +struct rtattr { + unsigned short rta_len; + unsigned short rta_type; +}; + +struct rtgenmsg { + unsigned char rtgen_family; +}; + +struct ifinfomsg { + unsigned char ifi_family; + unsigned char __ifi_pad; + unsigned short ifi_type; + int ifi_index; + unsigned ifi_flags; + unsigned ifi_change; +}; + +/* linux/if_link.h */ + +#define IFLA_ADDRESS 1 +#define IFLA_BROADCAST 2 +#define IFLA_IFNAME 3 +#define IFLA_STATS 7 + +/* linux/if_addr.h */ + +struct ifaddrmsg { + uint8_t ifa_family; + uint8_t ifa_prefixlen; + uint8_t ifa_flags; + uint8_t ifa_scope; + uint32_t ifa_index; +}; + +#define IFA_ADDRESS 1 +#define IFA_LOCAL 2 +#define IFA_LABEL 3 +#define IFA_BROADCAST 4 + +/* musl */ + +#define NETLINK_ALIGN(len) (((len)+3) & ~3) +#define NLMSG_DATA(nlh) ((void*)((char*)(nlh)+sizeof(struct nlmsghdr))) +#define NLMSG_DATALEN(nlh) ((nlh)->nlmsg_len-sizeof(struct nlmsghdr)) +#define NLMSG_DATAEND(nlh) ((char*)(nlh)+(nlh)->nlmsg_len) +#define NLMSG_NEXT(nlh) (struct nlmsghdr*)((char*)(nlh)+NETLINK_ALIGN((nlh)->nlmsg_len)) +#define NLMSG_OK(nlh,end) ((char*)(end)-(char*)(nlh) >= sizeof(struct nlmsghdr)) + +#define RTA_DATA(rta) ((void*)((char*)(rta)+sizeof(struct rtattr))) +#define RTA_DATALEN(rta) ((rta)->rta_len-sizeof(struct rtattr)) +#define RTA_DATAEND(rta) ((char*)(rta)+(rta)->rta_len) +#define RTA_NEXT(rta) (struct rtattr*)((char*)(rta)+NETLINK_ALIGN((rta)->rta_len)) +#define RTA_OK(nlh,end) ((char*)(end)-(char*)(rta) >= sizeof(struct rtattr)) + +#define NLMSG_RTA(nlh,len) ((void*)((char*)(nlh)+sizeof(struct nlmsghdr)+NETLINK_ALIGN(len))) +#define NLMSG_RTAOK(rta,nlh) RTA_OK(rta,NLMSG_DATAEND(nlh)) + +int __rtnetlink_enumerate(int link_af, int addr_af, int (*cb)(void *ctx, struct nlmsghdr *h), void *ctx); -- 2.0.3