1 files changed, 164 insertions, 0 deletions

diff --git a/src/service/gns/nss/nss_gns_query.c b/src/service/gns/nss/nss_gns_query.c
new file mode 100644
index 000000000..96e8e10da
--- /dev/null
+++ b/src/service/gns/nss/nss_gns_query.c
@@ -0,0 +1,164 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2012 GNUnet e.V.
+
+     GNUnet is free software: you can redistribute it and/or modify it
+     under the terms of the GNU Affero General Public License as published
+     by the Free Software Foundation, either version 3 of the License,
+     or (at your option) any later version.
+
+     GNUnet is distributed in the hope that it will be useful, but
+     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>
+#include <stdlib.h>
+#include "nss_gns_query.h"
+#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>
+
+#define TIMEOUT "5s"
+
+static void
+kwait (pid_t chld)
+{
+  int ret;
+
+  kill (chld, SIGKILL);
+  waitpid (chld, &ret, 0);
+}
+
+
+/**
+ * Wrapper function that uses gnunet-gns cli tool to resolve
+ * an IPv4/6 address.
+ *
+ * @param af address family
+ * @param name the name to resolve
+ * @param u the userdata (result struct)
+ * @return -1 on internal error,
+ *         -2 if request is not for GNS,
+ *         -3 on timeout,
+ *          else 0
+ */
+int
+gns_resolve_name (int af, const char *name, struct userdata *u)
+{
+  FILE *p;
+  char line[128];
+  int ret;
+  int retry = 0;
+  int out[2];
+  pid_t pid;
+
+  if (0 == getuid ())
+    return -2; /* GNS via NSS is NEVER for root */
+
+query_gns:
+  if (0 != pipe (out))
+    return -1;
+  pid = fork ();
+  if (-1 == pid)
+    return -1;
+  if (0 == pid)
+  {
+    char *argv[] = { "gnunet-gns",
+                     "-r", /* Raw output for easier parsing */
+                     "-d", /* DNS compatibility (allow IDNA names, no UTF-8) */
+                     "-t",
+                     (AF_INET6 == af) ? "AAAA" : "A",
+                     "-u",
+                     (char *) name,
+                     "-T",
+                     TIMEOUT,
+                     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);
+  }
+  (void) close (out[1]);
+  p = fdopen (out[0], "r");
+  if (NULL == p)
+  {
+    kwait (pid);
+    return -1;
+  }
+  while (NULL != fgets (line, sizeof(line), p))
+  {
+    if (u->count >= MAX_ENTRIES)
+      break;
+    if (line[strlen (line) - 1] == '\n')
+    {
+      line[strlen (line) - 1] = '\0';
+      if (AF_INET == af)
+      {
+        if (inet_pton (af, line, &u->data.ipv4[u->count]))
+        {
+          u->count++;
+          u->data_len += sizeof(ipv4_address_t);
+        }
+        else
+        {
+          (void) fclose (p);
+          kwait (pid);
+          errno = EINVAL;
+          return -1;
+        }
+      }
+      else if (AF_INET6 == af)
+      {
+        if (inet_pton (af, line, &u->data.ipv6[u->count]))
+        {
+          u->count++;
+          u->data_len += sizeof(ipv6_address_t);
+        }
+        else
+        {
+          (void) fclose (p);
+          kwait (pid);
+          errno = EINVAL;
+          return -1;
+        }
+      }
+    }
+  }
+  (void) fclose (p);
+  waitpid (pid, &ret, 0);
+  if (! WIFEXITED (ret))
+    return -1;
+  if (4 == WEXITSTATUS (ret))
+    return -2; /* not for GNS */
+  if (5 == WEXITSTATUS (ret))
+  {
+    if (1 == retry)
+      return -2; /* no go -> service unavailable */
+    retry = 1;
+    system ("gnunet-arm -s");
+    goto query_gns; /* Try again */
+  }
+  if (3 == WEXITSTATUS (ret))
+    return -2; /* timeout -> service unavailable */
+  if ((2 == WEXITSTATUS (ret)) || (1 == WEXITSTATUS (ret)))
+    return -2; /* launch failure -> service unavailable */
+  return 0;
+}
+
+
+/* end of nss_gns_query.c */