daemon: handle gethostbyname() error

If the user-supplied hostname can't be found then we should not use it.
We already avoid doing that in the non-NO_IPV6 case by checking if the
return value of getaddrinfo() is zero (success).  Do the same in the
NO_IPV6 case and make sure the return value of gethostbyname() isn't
NULL before dereferencing this pointer.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/daemon.c b/daemon.c
index 13608c07c674171ace754154c5d1cb7dea6c5e04..25af533b97ec1eeb74fef3d51e97dc99f248fa98 100644 (file)
--- a/daemon.c
+++ b/daemon.c
@@ -579,20 +579,21 @@ static void parse_host_arg(char *extra_args, int buflen)
                static char addrbuf[HOST_NAME_MAX + 1];
 
                hent = gethostbyname(hostname);
+               if (hent) {
+                       ap = hent->h_addr_list;
+                       memset(&sa, 0, sizeof sa);
+                       sa.sin_family = hent->h_addrtype;
+                       sa.sin_port = htons(0);
+                       memcpy(&sa.sin_addr, *ap, hent->h_length);
+
+                       inet_ntop(hent->h_addrtype, &sa.sin_addr,
+                                 addrbuf, sizeof(addrbuf));
 
-               ap = hent->h_addr_list;
-               memset(&sa, 0, sizeof sa);
-               sa.sin_family = hent->h_addrtype;
-               sa.sin_port = htons(0);
-               memcpy(&sa.sin_addr, *ap, hent->h_length);
-
-               inet_ntop(hent->h_addrtype, &sa.sin_addr,
-                         addrbuf, sizeof(addrbuf));
-
-               free(canon_hostname);
-               canon_hostname = xstrdup(hent->h_name);
-               free(ip_address);
-               ip_address = xstrdup(addrbuf);
+                       free(canon_hostname);
+                       canon_hostname = xstrdup(hent->h_name);
+                       free(ip_address);
+                       ip_address = xstrdup(addrbuf);
+               }
 #endif
        }
 }