os_support: Don't try to return the service name as a string in getnameinfo

Some systems may be lacking getservbyport; the previous ifdef wasn't
quite enough since it still assumed that struct servent was defined,
as pointed out by Clément Gregoire.

Simply remove the possibility to return non-numeric services in
getnameinfo; no caller of getnameinfo within libavformat
currently try to use getnameinfo for retrieving the port number without
NI_NUMERICSERV, and falling back on getservbyport may be non-threadsafe.

Signed-off-by: Martin Storsjö <martin@martin.st>

1 files changed, 2 insertions, 9 deletions

diff --git a/libavformat/os_support.c b/libavformat/os_support.c
index 650baea0d0..e9b1f88fb8 100644
--- a/libavformat/os_support.c
+++ b/libavformat/os_support.c
@@ -204,16 +204,9 @@ int ff_getnameinfo(const struct sockaddr *sa, int salen,
     }
 
     if (serv && servlen > 0) {
-        struct servent *ent = NULL;
-#if HAVE_GETSERVBYPORT
         if (!(flags & NI_NUMERICSERV))
-            ent = getservbyport(sin->sin_port, flags & NI_DGRAM ? "udp" : "tcp");
-#endif /* HAVE_GETSERVBYPORT */
-
-        if (ent)
-            snprintf(serv, servlen, "%s", ent->s_name);
-        else
-            snprintf(serv, servlen, "%d", ntohs(sin->sin_port));
+            return EAI_FAIL;
+        snprintf(serv, servlen, "%d", ntohs(sin->sin_port));
     }
 
     return 0;