00db10
commit c1f86a33ca32e26a9d6e29fc961e5ecb5e2e5eb4
00db10
Author: Daniel Alvarez <dalvarez@redhat.com>
00db10
Date:   Fri Jun 29 09:44:55 2018 +0200
00db10
00db10
    getifaddrs: Don't return ifa entries with NULL names [BZ #21812]
00db10
    
00db10
    A lookup operation in map_newlink could turn into an insert because of
00db10
    holes in the interface part of the map.  This leads to incorrectly set
00db10
    the name of the interface to NULL when the interface is not present
00db10
    for the address being processed (most likely because the interface was
00db10
    added between the RTM_GETLINK and RTM_GETADDR calls to the kernel).
00db10
    When such changes are detected by the kernel, it'll mark the dump as
00db10
    "inconsistent" by setting NLM_F_DUMP_INTR flag on the next netlink
00db10
    message.
00db10
    
00db10
    This patch checks this condition and retries the whole operation.
00db10
    Hopes are that next time the interface corresponding to the address
00db10
    entry is present in the list and correct name is returned.
00db10
00db10
diff --git a/sysdeps/unix/sysv/linux/ifaddrs.c b/sysdeps/unix/sysv/linux/ifaddrs.c
00db10
index c87e594e30a314fe..b1329dc4d4c63529 100644
00db10
--- a/sysdeps/unix/sysv/linux/ifaddrs.c
00db10
+++ b/sysdeps/unix/sysv/linux/ifaddrs.c
00db10
@@ -369,6 +369,14 @@ getifaddrs_internal (struct ifaddrs **ifap)
00db10
 	  if ((pid_t) nlh->nlmsg_pid != nh.pid || nlh->nlmsg_seq != nlp->seq)
00db10
 	    continue;
00db10
 
00db10
+	  /* If the dump got interrupted, we can't rely on the results
00db10
+	     so try again. */
00db10
+	  if (nlh->nlmsg_flags & NLM_F_DUMP_INTR)
00db10
+	    {
00db10
+	      result = -EAGAIN;
00db10
+	      goto exit_free;
00db10
+	    }
00db10
+
00db10
 	  if (nlh->nlmsg_type == NLMSG_DONE)
00db10
 	    break;		/* ok */
00db10