Merge branch 'master' of git+ssh://gnunet.org/gnunet

[oweals/gnunet.git] / src / gns / nss / nss_gns_query.c

diff --git a/src/gns/nss/nss_gns_query.c b/src/gns/nss/nss_gns_query.c
index 094e25ed53f4331c2f220d553b313fde7aea8e45..380788d35d0cea3a761cbd87db8781edf050e26d 100644 (file)
--- a/src/gns/nss/nss_gns_query.c
+++ b/src/gns/nss/nss_gns_query.c
@@ -11,9 +11,11 @@
      WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      Affero General Public License for more details.
-    
+
      You should have received a copy of the GNU Affero General Public License
      along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+     SPDX-License-Identifier: AGPL3.0-or-later
 */
 #include <string.h>
 #include <stdio.h>
@@ -22,7 +24,23 @@
 #include <arpa/inet.h>
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <sys/wait.h>
 #include <netinet/in.h>
+#include <errno.h>
+#include <unistd.h>
+#include <signal.h>
+
+
+static void
+kwait (pid_t chld)
+{
+  int ret;
+
+  kill (chld, SIGKILL);
+  waitpid (chld,
+           &ret,
+           0);
+}
 
 
 /**
@@ -32,7 +50,10 @@
  * @param af address family
  * @param name the name to resolve
  * @param u the userdata (result struct)
- * @return -1 on error else 0
+ * @return -1 on internal error,
+ *         -2 if request is not for GNS,
+ *         -3 on timeout,
+ *          else 0
  */
 int
 gns_resolve_name (int af,
@@ -40,30 +61,46 @@ gns_resolve_name (int af,
                  struct userdata *u)
 {
   FILE *p;
-  char *cmd;
   char line[128];
   int ret;
+  int out[2];
+  pid_t pid;
 
-  if (AF_INET6 == af)
+  if (0 != pipe (out))
+    return -1;
+  pid = fork ();
+  if (-1 == pid)
+    return -1;
+  if (0 == pid)
   {
-    if (-1 == asprintf (&cmd,
-                       "%s -t AAAA -u %s\n",
-                       "gnunet-gns -r", name))
-      return -1;
+    char *argv[] = {
+      "gnunet-gns",
+      "-r",
+      "-t",
+      (AF_INET6 == af) ? "AAAA" : "A",
+      "-u",
+      (char *) name,
+      NULL
+    };
+
+    (void) close (STDOUT_FILENO);
+    if ( (0 != close (out[0])) ||
+         (STDOUT_FILENO != dup2 (out[1], STDOUT_FILENO)) )
+      _exit (1);
+    (void) execvp ("gnunet-gns",
+                   argv);
+    _exit (1);
   }
-  else
-  {
-    if (-1 == asprintf (&cmd,
-                       "%s %s\n",
-                       "gnunet-gns -r -u", name))
+  (void) close (out[1]);
+  p = fdopen (out[0], "r");
+  if (NULL == p)
+    {
+      kwait (pid);
       return -1;
-  }
-  if (NULL == (p = popen (cmd, "r")))
-  {
-    free (cmd);
-    return -1;
-  }
-  while (NULL != fgets (line, sizeof(line), p))
+    }
+  while (NULL != fgets (line,
+                        sizeof (line),
+                        p))
   {
     if (u->count >= MAX_ENTRIES)
       break;
@@ -72,40 +109,54 @@ gns_resolve_name (int af,
       line[strlen(line)-1] = '\0';
       if (AF_INET == af)
       {
-       if (inet_pton(af, line, &(u->data.ipv4[u->count])))
+       if (inet_pton(af,
+                      line,
+                      &u->data.ipv4[u->count]))
         {
          u->count++;
          u->data_len += sizeof(ipv4_address_t);
        }
        else
        {
-         pclose (p);
-         free (cmd);
+         (void) fclose (p);
+          kwait (pid);
+         errno = EINVAL;
          return -1;
        }
       }
       else if (AF_INET6 == af)
       {
-       if (inet_pton(af, line, &(u->data.ipv6[u->count])))
+       if (inet_pton(af,
+                      line,
+                      &u->data.ipv6[u->count]))
         {
          u->count++;
          u->data_len += sizeof(ipv6_address_t);
        }
        else
         {
-         pclose (p);
-         free (cmd);
+         (void) fclose (p);
+          kwait (pid);
+         errno = EINVAL;
          return -1;
        }
       }
     }
   }
-  ret = pclose (p);
-  free (cmd);
-  if (4 == ret)
+  (void) fclose (p);
+  waitpid (pid,
+           &ret,
+           0);
+  if (! WIFEXITED (ret))
+    return -1;
+  if (4 == WEXITSTATUS (ret))
     return -2; /* not for GNS */
   if (3 == ret)
-    return -3; /* timeout */
+    return -3; /* timeout -> not found */
+  if ( (2 == WEXITSTATUS (ret)) ||
+       (1 == WEXITSTATUS (ret)) )
+    return -2; /* launch failure -> service unavailable */
   return 0;
 }
+
 /* end of nss_gns_query.c */