On Tue, Aug 7, 2018 at 5:49 AM, Charles Myers <charles.my...@spirent.com>
wrote:
> libc code is from musl library
Which version? It's not the version we have in musl/, right? So which
version?
> with minor change to prevent partial reads if faster than sender.
>
Is this fixing a bug in musl (in which case you should probably report it
to them), or in OSv?
>
> Signed-off-by: Charles Myers <charles.my...@spirent.com>
> ---
> Makefile | 1 +
> libc/network/getifaddrs.c | 392 ++++++++++++++++++++----------
> --------------
> libc/network/if_nameindex.c | 136 ++++++++++-----
> libc/network/netlink.c | 66 ++++++++
> libc/network/netlink.h | 94 +++++++++++
> 5 files changed, 435 insertions(+), 254 deletions(-)
> create mode 100644 libc/network/netlink.c
> create mode 100644 libc/network/netlink.h
>
> diff --git a/Makefile b/Makefile
> index 49e61b8..d5b6fda 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1387,6 +1387,7 @@ musl += network/getservbyname.o
> musl += network/getservbyport_r.o
> musl += network/getservbyport.o
> libc += network/getifaddrs.o
> +libc += network/netlink.o
> libc += network/if_nameindex.o
> musl += network/if_freenameindex.o
> libc += network/res_init.o
> diff --git a/libc/network/getifaddrs.c b/libc/network/getifaddrs.c
> index 4cdf4d6..3b92599 100644
> --- a/libc/network/getifaddrs.c
> +++ b/libc/network/getifaddrs.c
> @@ -1,252 +1,216 @@
> -/* (C) 2013 John Spencer. released under musl's standard MIT license. */
> -#undef _GNU_SOURCE
> -#define _GNU_SOURCE
> -#include <ifaddrs.h>
> -#include <stdlib.h>
> -#include <net/if.h> /* IFNAMSIZ, ifreq, ifconf */
> -#include <stdio.h>
> -#include <ctype.h>
> -#include <string.h>
> +//#define _GNU_SOURCE
> #include <errno.h>
> -#include <arpa/inet.h> /* inet_pton */
> +#include <string.h>
> +#include <stdlib.h>
> #include <unistd.h>
> -#include <sys/ioctl.h>
> -#include <netpacket/packet.h>
> -#include <net/if_arp.h>
> -
> -typedef union {
> - struct sockaddr_in6 v6;
> +#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_ll hw;
> -} 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)
> -{
> - 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;
> - }
> - return curr;
> -}
> +struct ifaddrs_ctx {
> + struct ifaddrs_storage *first;
> + struct ifaddrs_storage *last;
> + struct ifaddrs_storage *hash[IFADDRS_HASH_SIZE];
> +};
>
> void freeifaddrs(struct ifaddrs *ifp)
> {
> - stor *head = (stor *) ifp;
> - while(head) {
> - void *p = head;
> - head = (stor *) head->next;
> - free(p);
> + struct ifaddrs *n;
> + while (ifp) {
> + n = ifp->ifa_next;
> + free(ifp);
> + ifp = n;
> }
> }
>
> -static void ipv6netmask(unsigned prefix_length, struct sockaddr_in6 *sa)
> +static void copy_addr(struct sockaddr **r, int af, union sockany *sa,
> void *addr, size_t addrlen, int ifindex)
> {
> - 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 *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 dealwithipv6(stor **list, stor** head)
> +static void gen_netmask(struct sockaddr **r, int af, union sockany *sa,
> int prefixlen)
> {
> - FILE* f = fopen("/proc/net/if_inet6", "r");
> - /* 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);
> + 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);
> }
>
> -int allocate_and_add_ifaddrs(stor **list, stor **head, struct
> if_nameindex *ii)
> +static void copy_lladdr(struct sockaddr **r, union sockany *sa, void
> *addr, size_t addrlen, int ifindex, unsigned short hatype)
> {
> - 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) {
> - return 0;
> - }
> - }
> - return i;
> + 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 fill_mac_addrs(int sock, stor *list, struct if_nameindex *ii)
> +static int netlink_msg_to_ifaddr(void *pctx, struct nlmsghdr *h)
> {
> - stor *head;
> - size_t i;
> -
> - for(head = list, i = 0;
> - head; head = (stor*)(head->next)) {
> - struct sockaddr_ll *hw_addr = (struct sockaddr_ll *)
> &head->addr;
> - head->ifa.ifa_addr = (struct sockaddr*) &head->addr;
> - struct ifreq req;
> - int ret;
> -
> - if (!ii[i].if_name) {
> - continue;
> + struct ifaddrs_ctx *ctx = pctx;
> + struct ifaddrs_storage *ifs, *ifs0 = NULL;
> + 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;
> }
> -
> - /* zero the ifreq structure */
> - memset(&req, 0, sizeof(req));
> -
> - /* fill in the interface name */
> - strlcpy(req.ifr_name, ii[i].if_name, IFNAMSIZ);
> -
> - /* Get the hardware address */
> - ret = ioctl(sock, SIOCGIFHWADDR, &req);
> - if (ret == -1) {
> - return ret;
> - }
> -
> - /* Fill address, index, type, length, familly */
> - memcpy(hw_addr->sll_addr, req.ifr_hwaddr.sa_data,
> IFHWADDRLEN);
> - hw_addr->sll_ifindex = ii[i].if_index;
> - hw_addr->sll_hatype = ARPHRD_ETHER;
> - hw_addr->sll_halen = IFHWADDRLEN;
> - hw_addr->sll_family = AF_PACKET;
> -
> - /* Get and fill the address flags */
> - ret = ioctl(sock, SIOCGIFFLAGS, &req);
> - if (ret == - 1) {
> - return ret;
> - }
> - head->ifa.ifa_flags = req.ifr_flags;
> - i++;
> + } 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;
> }
>
> - return 0;
> -}
> + ifs = calloc(1, sizeof(struct ifaddrs_storage) + stats_len);
> + if (ifs == 0) return -1;
>
> -int getifaddrs(struct ifaddrs **ifap)
> -{
> - stor *list = 0, *head = 0;
> - struct if_nameindex* ii = if_nameindex();
> - if(!ii) return -1;
> - int addr_count;
> - size_t i;
> - // allocate and add to the list twice the number of
> - // interface of ifaddr storage in order to have enough
> - // for MAC HW addresses that require their own location.
> - for (i = 0; i < 2; i++) {
> - addr_count =
> - allocate_and_add_ifaddrs(&list, &head, ii);
> - if (!addr_count) {
> - if_freenameindex(ii);
> - goto err2;
> - }
> - }
> - 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);
> - int j;
> - // loop and fill the INET addrs
> - for(head = list, j = 0; head && j < addr_count; head =
> (stor*)head->next, j++) {
> - 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;
> + 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:
> + /* 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;
> }
> - 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 (-1 == fill_mac_addrs(sock, head, ii)) {
> - goto err;
> +
> + 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/libc/network/if_nameindex.c b/libc/network/if_nameindex.c
> index b0a4f5c..7c36c85 100644
> --- a/libc/network/if_nameindex.c
> +++ b/libc/network/if_nameindex.c
> @@ -1,58 +1,114 @@
> -#define _GNU_SOURCE
> +//#define _GNU_SOURCE
> #include <net/if.h>
> -#include <stdlib.h>
> -#include <sys/socket.h>
> -#include <sys/ioctl.h>
> #include <errno.h>
> #include <unistd.h>
> -#include <sys/syscall.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <pthread.h>
> +#include "netlink.h"
>
> -#include <stdio.h>
> +#define IFADDRS_HASH_SIZE 64
>
> -static void *do_nameindex(int s, size_t n)
> -{
> - size_t i, len, k;
> - struct ifconf conf;
> - struct if_nameindex *idx;
> +struct ifnamemap {
> + unsigned int hash_next;
> + unsigned int index;
> + unsigned char namelen;
> + char name[IFNAMSIZ];
> +};
>
> - idx = malloc(n * (sizeof(struct if_nameindex)+sizeof(struct
> ifreq)));
> - if (!idx) return 0;
> +struct ifnameindexctx {
> + unsigned int num, allocated, str_bytes;
> + struct ifnamemap *list;
> + unsigned int hash[IFADDRS_HASH_SIZE];
> +};
>
> - 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;
> +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;
> +
> + namelen = RTA_DATALEN(rta) - 1;
> + if (namelen > IFNAMSIZ) return 0;
>
> - n = conf.ifc_len / sizeof(struct ifreq);
> - for (i=k=0; i<n; i++) {
> - if (ioctl(s, SIOCGIFINDEX, &conf.ifc_req[i]) < 0) {
> - k++;
> - continue;
> + /* 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_INET, 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;
> + int cs;
> +
> + pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
> + 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;
> }
> + d->if_index = 0;
> + d->if_name = 0;
> +err:
> + pthread_setcancelstate(cs, 0);
> + free(ctx->list);
> errno = ENOBUFS;
> - return p;
> + return ifs;
> }
> diff --git a/libc/network/netlink.c b/libc/network/netlink.c
> new file mode 100644
> index 0000000..ab0437a
> --- /dev/null
> +++ b/libc/network/netlink.c
> @@ -0,0 +1,66 @@
> +#include <errno.h>
> +#include <string.h>
> +#include <syscall.h>
> +#include <sys/socket.h>
> +#include <unistd.h>
> +#include "netlink.h"
> +#include <stdio.h>
> +#include <poll.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) {
> + /* Wait if recv() timed out because response might
> not be queued in time */
> + if (r < 0 && (errno == EAGAIN || errno ==
> EWOULDBLOCK)) {
> + struct pollfd pfds[1];
> + pfds[0].fd = fd;
> + pfds[0].events = POLLIN;
> + pfds[0].revents = 0;
> + if (poll(pfds, 1, 1000) != 0)
> + continue;
> + }
> + 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/libc/network/netlink.h b/libc/network/netlink.h
> new file mode 100644
> index 0000000..20700ac
> --- /dev/null
> +++ b/libc/network/netlink.h
> @@ -0,0 +1,94 @@
> +#include <stdint.h>
> +
> +/* linux/netlink.h */
>
In the long run, maybe this stuff belongs in include/api/linux/netlink.h;
Don't you also need the same
definitions in the *implementation* of the netlink protocol, not just its
user in libc?
But if this fits your organization and doesn't cause duplication of the
definitions it can stay here for now.
+
> +#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);
> --
> 2.7.4
>
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