* Re: Re: if_nameindex, etc. [Re: Progress towards 1.1.4]
2014-07-22 8:58 ` Natanael Copa
@ 2014-07-22 9:04 ` Timo Teras
2014-07-22 13:45 ` Rich Felker
1 sibling, 0 replies; 9+ messages in thread
From: Timo Teras @ 2014-07-22 9:04 UTC (permalink / raw)
To: Natanael Copa; +Cc: Rich Felker, musl
On Tue, 22 Jul 2014 10:58:43 +0200
Natanael Copa <ncopa@alpinelinux.org> wrote:
> On Mon, 21 Jul 2014 12:13:42 -0400
> Rich Felker <dalias@libc.org> wrote:
>
> > On Mon, Jul 21, 2014 at 07:09:56PM +0300, Timo Teras wrote:
> > > So +300 bytes in text, but in return there is added functionality
> > > such as returning the link-level info in PF_PACKET dump (including
> > > statistics). I also expect the code to be a lot faster:
> >
> > One thing I forgot to ask: is there any regression in returning
> > old-style interface "alias" names, i.e. do things like "eth0:1"
> > still appear in the output of if_nameindex?
>
> Maybe this is an opportunity to get rid of the interface "alias"? it
> was a hack to make it possible to assign multiple addresses on a
> single NIC.
>
> Do we need support that kind of legacy?
Well, I think it might be desirable. For the record, glibc is funny in
this regard: if_nameindex() reports only real names (no aliases), but
getifaddrs() reports the alias name.
I have now updated the netlink patch and fixed:
- getifaddrs() to report alias names where approriate
- if_nameindex() fixed to report alias names (it also reports
duplicates like the current code)
- if_nameindex() calls realloc() less, but has now strdup() per
interface (i wonder if this should be made in to realloc() bucket,
and then merged in the end to return single allocated area again)
- optimized some bytes away
- few error case handling corrections
The size difference is now:
text data bss dec hex filename
544840 1920 11576 558336 88500 lib/libc.nonetlink.so
545022 1920 11576 558518 885b6 lib/libc.so
So now it's only +182 bytes with the added functionality (the earlier
patch was +320 or so).
Any comments?
From bc9f0408eda6f423c3d880cf72f764b2f2ec7001 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timo=20Ter=C3=A4s?= <timo.teras@iki.fi>
Date: Tue, 8 Apr 2014 14:03:16 +0000
Subject: [PATCH] reimplement if_nameindex and getifaddrs using netlink
---
src/network/__netlink.c | 52 +++++++
src/network/__netlink.h | 100 ++++++++++++++
src/network/getifaddrs.c | 307 ++++++++++++++++++++++-------------------
src/network/if_freenameindex.c | 4 +
src/network/if_nameindex.c | 89 ++++++------
5 files changed, 368 insertions(+), 184 deletions(-)
create mode 100644 src/network/__netlink.c
create mode 100644 src/network/__netlink.h
diff --git a/src/network/__netlink.c b/src/network/__netlink.c
new file mode 100644
index 0000000..78ab205
--- /dev/null
+++ b/src/network/__netlink.c
@@ -0,0 +1,52 @@
+#include <errno.h>
+#include <string.h>
+#include <syscall.h>
+#include <sys/socket.h>
+#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 = 0;
+
+ 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_ROOT | NLM_F_MATCH | 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 (ret == 0) {
+ 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 ret;
+ if (h->nlmsg_type == NLMSG_ERROR) return -1;
+ ret = cb(ctx, h);
+ }
+ }
+ 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 == 0) 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..04abfac
--- /dev/null
+++ b/src/network/__netlink.h
@@ -0,0 +1,100 @@
+#include <stdint.h>
+
+/* 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_ECHO 8
+#define NLM_F_DUMP_INTR 16
+
+#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) (NLMSG_DATA(nlh) <= (end) && \
+ (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
+ (void*)NLMSG_NEXT(nlh) <= (end))
+
+#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(rta,end) (RTA_DATA(rta) <= (void*)(end) && \
+ (rta)->rta_len >= sizeof(struct rtattr) && \
+ (void*)RTA_NEXT(rta) <= (void*)(end))
+
+#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);
diff --git a/src/network/getifaddrs.c b/src/network/getifaddrs.c
index 5a94cc7..ac2275f 100644
--- a/src/network/getifaddrs.c
+++ b/src/network/getifaddrs.c
@@ -1,181 +1,198 @@
-/* (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>
#include <errno.h>
-#include <arpa/inet.h> /* inet_pton */
+#include <string.h>
+#include <stdlib.h>
#include <unistd.h>
-#include <sys/ioctl.h>
-#include <sys/socket.h>
+#include <ifaddrs.h>
+#include <syscall.h>
+#include <net/if.h>
+#include "__netlink.h"
-typedef union {
- struct sockaddr_in6 v6;
+/* 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
+};
+
+#define IFADDRS_HASH_SIZE 64
+struct ifaddrs_ctx {
+ struct ifaddrs_storage *first;
+ struct ifaddrs_storage *last;
+ struct ifaddrs_storage *hash[IFADDRS_HASH_SIZE];
+};
-static stor* list_add(stor** list, stor** head, char* ifname)
+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 struct sockaddr* copy_lladdr(union sockany *sa, struct rtattr *rta, struct ifinfomsg *ifi)
{
- stor *head = (stor *) ifp;
- while(head) {
- void *p = head;
- head = (stor *) head->next;
- free(p);
- }
+ if (RTA_DATALEN(rta) > sizeof(sa->ll.sll_addr)) return 0;
+ sa->ll.sll_family = AF_PACKET;
+ sa->ll.sll_ifindex = ifi->ifi_index;
+ sa->ll.sll_hatype = ifi->ifi_type;
+ sa->ll.sll_halen = RTA_DATALEN(rta);
+ memcpy(sa->ll.sll_addr, RTA_DATA(rta), RTA_DATALEN(rta));
+ return &sa->sa;
}
-static void ipv6netmask(unsigned prefix_length, struct sockaddr_in6 *sa)
+static uint8_t *sockany_addr(int af, union sockany *sa, int *len)
{
- 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;
+ switch (af) {
+ case AF_INET: *len = 4; return (uint8_t*) &sa->v4.sin_addr;
+ case AF_INET6: *len = 16; return (uint8_t*) &sa->v6.sin6_addr;
}
+ return 0;
}
-static void dealwithipv6(stor **list, stor** head)
+static struct sockaddr* copy_addr(int af, union sockany *sa, struct rtattr *rta)
{
- 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;
- }
+ int len;
+ uint8_t *dst = sockany_addr(af, sa, &len);
+ if (!dst || RTA_DATALEN(rta) != len) return 0;
+ sa->sa.sa_family = af;
+ memcpy(dst, RTA_DATA(rta), len);
+ return &sa->sa;
+}
+
+static struct sockaddr *gen_netmask(int af, union sockany *sa, int prefixlen)
+{
+ int maxlen, i;
+ uint8_t *dst = sockany_addr(af, sa, &maxlen);
+ if (!dst) return 0;
+ sa->sa.sa_family = af;
+ if (prefixlen > 8*maxlen) prefixlen = 8*maxlen;
+ i = prefixlen / 8;
+ memset(dst, 0xff, i);
+ if (i<maxlen) {
+ dst[i++] = 0xff << (8 - (prefixlen % 8));
+ if (i<maxlen) memset(&dst[i+1], 0x00, maxlen-i);
}
- out:
- fclose(f);
+ return &sa->sa;
}
-int getifaddrs(struct ifaddrs **ifap)
+static int __handle(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:
+ ifs->ifa.ifa_addr = copy_lladdr(&ifs->addr, rta, ifi);
+ break;
+ case IFLA_BROADCAST:
+ ifs->ifa.ifa_broadaddr = copy_lladdr(&ifs->ifu, rta, ifi);
+ 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) {
+ ifs->hash_next = ctx->hash[ifs->index%IFADDRS_HASH_SIZE];
+ ctx->hash[ifs->index%IFADDRS_HASH_SIZE] = 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:
+ ifs->ifa.ifa_addr = copy_addr(ifa->ifa_family, &ifs->addr, rta);
+ if (ifs->ifa.ifa_addr)
+ ifs->ifa.ifa_netmask = gen_netmask(ifa->ifa_family, &ifs->netmask, ifa->ifa_prefixlen);
+ 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. */
+ ifs->ifa.ifa_broadaddr = copy_addr(ifa->ifa_family, &ifs->ifu, rta);
+ 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;
}
}
- close(sock);
- void* last = 0;
- for(head = list; head; head=(stor*)head->next) last=head;
- head = last;
- dealwithipv6(&list, &head);
- *ifap = (struct ifaddrs*) list;
+
+ 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;
- 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, __handle, ctx);
+ if (r == 0) *ifap = &ctx->first->ifa;
+ else freeifaddrs(&ctx->first->ifa);
+ return r;
+}
diff --git a/src/network/if_freenameindex.c b/src/network/if_freenameindex.c
index 89bafcc..bee80a7 100644
--- a/src/network/if_freenameindex.c
+++ b/src/network/if_freenameindex.c
@@ -3,5 +3,9 @@
void if_freenameindex(struct if_nameindex *idx)
{
+ struct if_nameindex *e;
+ if (!idx) return;
+ for (e = idx; e->if_name; e++)
+ free(e->if_name);
free(idx);
}
diff --git a/src/network/if_nameindex.c b/src/network/if_nameindex.c
index 53b80b2..53d5269 100644
--- a/src/network/if_nameindex.c
+++ b/src/network/if_nameindex.c
@@ -1,55 +1,66 @@
#define _GNU_SOURCE
#include <net/if.h>
-#include <stdlib.h>
-#include <sys/socket.h>
-#include <sys/ioctl.h>
#include <errno.h>
-#include "syscall.h"
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include "__netlink.h"
-static void *do_nameindex(int s, size_t n)
-{
- size_t i, len, k;
- struct ifconf conf;
- struct if_nameindex *idx;
+struct ifnameindexctx {
+ unsigned int num, allocated;
+ struct if_nameindex *list;
+};
- idx = malloc(n * (sizeof(struct if_nameindex)+sizeof(struct ifreq)));
- if (!idx) return 0;
+static int __handle(void *pctx, struct nlmsghdr *h)
+{
+ struct ifnameindexctx *ctx = pctx;
+ struct if_nameindex *e;
+ struct rtattr *rta;
+ int index, type;
- 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;
+ 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<n; i++) {
- if (ioctl(s, SIOCGIFINDEX, &conf.ifc_req[i]) < 0) {
- k++;
- continue;
+ /* Make sure the end-of-list record is always allocated */
+ if (ctx->num+1 >= ctx->allocated) {
+ size_t a = ctx->allocated ? ctx->allocated * 2 + 1 : 8;
+ if (a > SIZE_MAX/sizeof *e) return -1;
+ e = realloc(ctx->list, a * sizeof *e);
+ if (!e) return -1;
+ ctx->list = e;
+ ctx->allocated = a;
}
- idx[i-k].if_index = conf.ifc_req[i].ifr_ifindex;
- idx[i-k].if_name = conf.ifc_req[i].ifr_name;
+ e = &ctx->list[ctx->num++];
+ e->if_index = index;
+ e->if_name = strdup(RTA_DATA(rta));
+ if (!e->if_name) return -1;
+ return 0;
}
- idx[i-k].if_name = 0;
- idx[i-k].if_index = 0;
-
- return idx;
+ 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;
+ int r;
+
+ memset(ctx, 0, sizeof(*ctx));
+ r = __rtnetlink_enumerate(AF_UNSPEC, AF_INET, __handle, ctx);
+ if (ctx->list) memset(&ctx->list[ctx->num], 0, sizeof(struct if_nameindex));
+ if (r < 0) {
+ if_freenameindex(ctx->list);
+ return 0;
}
- errno = ENOBUFS;
- return p;
+ return realloc(ctx->list, sizeof(struct if_nameindex[ctx->num+1]));
}
--
2.0.2
^ permalink raw reply [flat|nested] 9+ messages in thread