GNUnet  0.10.x
nss_gns_query.c
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1 /*
2  This file is part of GNUnet.
3  Copyright (C) 2012 GNUnet e.V.
4 
5  GNUnet is free software: you can redistribute it and/or modify it
6  under the terms of the GNU Affero General Public License as published
7  by the Free Software Foundation, either version 3 of the License,
8  or (at your option) any later version.
9 
10  GNUnet is distributed in the hope that it will be useful, but
11  WITHOUT ANY WARRANTY; without even the implied warranty of
12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  Affero General Public License for more details.
14 
15  You should have received a copy of the GNU Affero General Public License
16  along with this program. If not, see <http://www.gnu.org/licenses/>.
17 
18  SPDX-License-Identifier: AGPL3.0-or-later
19 */
20 #include <string.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include "nss_gns_query.h"
24 #include <arpa/inet.h>
25 #include <sys/types.h>
26 #include <sys/socket.h>
27 #include <sys/wait.h>
28 #include <netinet/in.h>
29 #include <errno.h>
30 #include <unistd.h>
31 #include <signal.h>
32 
33 #define TIMEOUT "5s"
34 
35 static void
36 kwait (pid_t chld)
37 {
38  int ret;
39 
40  kill (chld, SIGKILL);
41  waitpid (chld, &ret, 0);
42 }
43 
44 
57 int
58 gns_resolve_name (int af, const char *name, struct userdata *u)
59 {
60  FILE *p;
61  char line[128];
62  int ret;
63  int out[2];
64  pid_t pid;
65 
66  if (0 != pipe (out))
67  return -1;
68  pid = fork ();
69  if (-1 == pid)
70  return -1;
71  if (0 == pid)
72  {
73  char *argv[] = {"gnunet-gns",
74  "-r",
75  "-t",
76  (AF_INET6 == af) ? "AAAA" : "A",
77  "-u",
78  (char *) name,
79  "-T",
80  TIMEOUT,
81  NULL};
82 
83  (void) close (STDOUT_FILENO);
84  if ((0 != close (out[0])) ||
85  (STDOUT_FILENO != dup2 (out[1], STDOUT_FILENO)))
86  _exit (1);
87  (void) execvp ("gnunet-gns", argv);
88  _exit (1);
89  }
90  (void) close (out[1]);
91  p = fdopen (out[0], "r");
92  if (NULL == p)
93  {
94  kwait (pid);
95  return -1;
96  }
97  while (NULL != fgets (line, sizeof (line), p))
98  {
99  if (u->count >= MAX_ENTRIES)
100  break;
101  if (line[strlen (line) - 1] == '\n')
102  {
103  line[strlen (line) - 1] = '\0';
104  if (AF_INET == af)
105  {
106  if (inet_pton (af, line, &u->data.ipv4[u->count]))
107  {
108  u->count++;
109  u->data_len += sizeof (ipv4_address_t);
110  }
111  else
112  {
113  (void) fclose (p);
114  kwait (pid);
115  errno = EINVAL;
116  return -1;
117  }
118  }
119  else if (AF_INET6 == af)
120  {
121  if (inet_pton (af, line, &u->data.ipv6[u->count]))
122  {
123  u->count++;
124  u->data_len += sizeof (ipv6_address_t);
125  }
126  else
127  {
128  (void) fclose (p);
129  kwait (pid);
130  errno = EINVAL;
131  return -1;
132  }
133  }
134  }
135  }
136  (void) fclose (p);
137  waitpid (pid, &ret, 0);
138  if (! WIFEXITED (ret))
139  return -1;
140  if (4 == WEXITSTATUS (ret))
141  return -2; /* not for GNS */
142  if (3 == ret)
143  return -3; /* timeout -> not found */
144  if ((2 == WEXITSTATUS (ret)) || (1 == WEXITSTATUS (ret)))
145  return -2; /* launch failure -> service unavailable */
146  return 0;
147 }
148 
149 /* end of nss_gns_query.c */
ipv4_address_t ipv4[16]
Definition: nss_gns_query.h:48
#define MAX_ENTRIES
Parts taken from nss-mdns.
Definition: nss_gns_query.h:29
static int ret
Final status code.
Definition: gnunet-arm.c:89
static struct GNUNET_OS_Process * p
Helper process we started.
Definition: gnunet-qr.c:59
static char * line
Desired phone line (string to be converted to a hash).
int gns_resolve_name(int af, const char *name, struct userdata *u)
Wrapper function that uses gnunet-gns cli tool to resolve an IPv4/6 address.
Definition: nss_gns_query.c:58
union userdata::@24 data
ipv6_address_t ipv6[16]
Definition: nss_gns_query.h:49
#define TIMEOUT
Definition: nss_gns_query.c:33
const char * name
static void kwait(pid_t chld)
Definition: nss_gns_query.c:36
static int inet_pton(int af, const char *cp, struct in_addr *buf)
Convert IPv4 address from text to binary form.
int data_len
Definition: nss_gns_query.h:46
static struct GNUNET_PeerIdentity pid
Identity of the peer we transmit to / connect to.