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authorVincent Hou <vincent.houyi@gmail.com>2020-01-24 12:43:24 (GMT)
committerWaldemar Brodkorb <wbx@openadk.org>2020-01-30 08:44:41 (GMT)
commit6b21a5a5bd895e16ef57c4d0d89c806b2e0c22e8 (patch)
treea3289627f110c29e0457e96d74a94aaae0fb3804 /libc
parent24681d328c46df64062dc67d0af4ef2d7ca6da0c (diff)
Fix map_newlink abort when interface list changes during getifaddrs
map_newlink() may abort when interface list changed between netlink request for getting interfaces and getting addresses. This commit is ported from the same change from glibc commit. Signed-off-by: Vincent Hou <vincent.houyi@gmail.com>
Diffstat (limited to 'libc')
-rw-r--r--libc/inet/ifaddrs.c53
1 files changed, 42 insertions, 11 deletions
diff --git a/libc/inet/ifaddrs.c b/libc/inet/ifaddrs.c
index 0c93106..72771d3 100644
--- a/libc/inet/ifaddrs.c
+++ b/libc/inet/ifaddrs.c
@@ -339,17 +339,19 @@ map_newlink (int idx, struct ifaddrs_storage *ifas, int *map, int max)
else if (map[i] == idx)
return i;
}
- /* This should never be reached. If this will be reached, we have
- a very big problem. */
- abort ();
+
+ /* This means interfaces changed inbetween the reading of the
+ RTM_GETLINK and RTM_GETADDR information. We have to repeat
+ everything. */
+ return -1;
}
/* Create a linked list of `struct ifaddrs' structures, one for each
network interface on the host machine. If successful, store the
list in *IFAP and return 0. On errors, return -1 and set `errno'. */
-int
-getifaddrs (struct ifaddrs **ifap)
+static int
+getifaddrs_internal (struct ifaddrs **ifap)
{
struct netlink_handle nh = { 0, 0, 0, NULL, NULL };
struct netlink_res *nlp;
@@ -496,6 +498,13 @@ getifaddrs (struct ifaddrs **ifap)
kernel. */
ifa_index = map_newlink (ifim->ifi_index - 1, ifas,
map_newlink_data, newlink);
+ if (__builtin_expect (ifa_index == -1, 0))
+ {
+ try_again:
+ result = -EAGAIN;
+ free (ifas);
+ goto exit_free;
+ }
ifas[ifa_index].ifa.ifa_flags = ifim->ifi_flags;
while (RTA_OK (rta, rtasize))
@@ -580,9 +589,11 @@ getifaddrs (struct ifaddrs **ifap)
that we have holes in the interface part of the list,
but we always have already the interface for this address. */
ifa_index = newlink + newaddr_idx;
- ifas[ifa_index].ifa.ifa_flags
- = ifas[map_newlink (ifam->ifa_index - 1, ifas,
- map_newlink_data, newlink)].ifa.ifa_flags;
+ int idx = map_newlink (ifam->ifa_index - 1, ifas,
+ map_newlink_data, newlink);
+ if (__builtin_expect (idx == -1, 0))
+ goto try_again;
+ ifas[ifa_index].ifa.ifa_flags = ifas[idx].ifa.ifa_flags;
if (ifa_index > 0)
ifas[ifa_index - 1].ifa.ifa_next = &ifas[ifa_index].ifa;
++newaddr_idx;
@@ -768,9 +779,13 @@ getifaddrs (struct ifaddrs **ifap)
/* If we didn't get the interface name with the
address, use the name from the interface entry. */
if (ifas[ifa_index].ifa.ifa_name == NULL)
- ifas[ifa_index].ifa.ifa_name
- = ifas[map_newlink (ifam->ifa_index - 1, ifas,
- map_newlink_data, newlink)].ifa.ifa_name;
+ {
+ int idx = map_newlink (ifam->ifa_index - 1, ifas,
+ map_newlink_data, newlink);
+ if (__builtin_expect (idx == -1, 0))
+ goto try_again;
+ ifas[ifa_index].ifa.ifa_name = ifas[idx].ifa.ifa_name;
+ }
/* Calculate the netmask. */
if (ifas[ifa_index].ifa.ifa_addr
@@ -850,6 +865,22 @@ getifaddrs (struct ifaddrs **ifap)
return result;
}
+
+
+/* Create a linked list of `struct ifaddrs' structures, one for each
+ network interface on the host machine. If successful, store the
+ list in *IFAP and return 0. On errors, return -1 and set `errno'. */
+int
+getifaddrs (struct ifaddrs **ifap)
+{
+ int res;
+
+ do
+ res = getifaddrs_internal (ifap);
+ while (res == -EAGAIN);
+
+ return res;
+}
libc_hidden_def(getifaddrs)
void