GNUnet  0.11.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 retry = 0;
64  int out[2];
65  pid_t pid;
66 
67  if (0 == getuid ())
68  return -2; /* GNS via NSS is NEVER for root */
69 
70 query_gns:
71  if (0 != pipe (out))
72  return -1;
73  pid = fork ();
74  if (-1 == pid)
75  return -1;
76  if (0 == pid)
77  {
78  char *argv[] = { "gnunet-gns",
79  "-r", /* Raw output for easier parsing */
80  "-d", /* DNS compatibility (allow IDNA names, no UTF-8) */
81  "-t",
82  (AF_INET6 == af) ? "AAAA" : "A",
83  "-u",
84  (char *) name,
85  "-T",
86  TIMEOUT,
87  NULL };
88 
89  (void) close (STDOUT_FILENO);
90  if ((0 != close (out[0])) ||
91  (STDOUT_FILENO != dup2 (out[1], STDOUT_FILENO)))
92  _exit (1);
93  (void) execvp ("gnunet-gns", argv);
94  _exit (1);
95  }
96  (void) close (out[1]);
97  p = fdopen (out[0], "r");
98  if (NULL == p)
99  {
100  kwait (pid);
101  return -1;
102  }
103  while (NULL != fgets (line, sizeof(line), p))
104  {
105  if (u->count >= MAX_ENTRIES)
106  break;
107  if (line[strlen (line) - 1] == '\n')
108  {
109  line[strlen (line) - 1] = '\0';
110  if (AF_INET == af)
111  {
112  if (inet_pton (af, line, &u->data.ipv4[u->count]))
113  {
114  u->count++;
115  u->data_len += sizeof(ipv4_address_t);
116  }
117  else
118  {
119  (void) fclose (p);
120  kwait (pid);
121  errno = EINVAL;
122  return -1;
123  }
124  }
125  else if (AF_INET6 == af)
126  {
127  if (inet_pton (af, line, &u->data.ipv6[u->count]))
128  {
129  u->count++;
130  u->data_len += sizeof(ipv6_address_t);
131  }
132  else
133  {
134  (void) fclose (p);
135  kwait (pid);
136  errno = EINVAL;
137  return -1;
138  }
139  }
140  }
141  }
142  (void) fclose (p);
143  waitpid (pid, &ret, 0);
144  if (! WIFEXITED (ret))
145  return -1;
146  if (4 == WEXITSTATUS (ret))
147  return -2; /* not for GNS */
148  if (5 == WEXITSTATUS (ret))
149  {
150  if (1 == retry)
151  return -2; /* no go -> service unavailable */
152  retry = 1;
153  system ("gnunet-arm -s");
154  goto query_gns; /* Try again */
155  }
156  if (3 == WEXITSTATUS (ret))
157  return -2; /* timeout -> service unavailable */
158  if ((2 == WEXITSTATUS (ret)) || (1 == WEXITSTATUS (ret)))
159  return -2; /* launch failure -> service unavailable */
160  return 0;
161 }
162 
163 
164 /* end of nss_gns_query.c */
ipv4_address_t ipv4[16]
Definition: nss_gns_query.h:49
#define MAX_ENTRIES
Parts taken from nss-mdns.
Definition: nss_gns_query.h:29
static int ret
Return value of the commandline.
Definition: gnunet-abd.c:81
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
ipv6_address_t ipv6[16]
Definition: nss_gns_query.h:50
#define TIMEOUT
Definition: nss_gns_query.c:33
static void kwait(pid_t chld)
Definition: nss_gns_query.c:36
const char * name
int data_len
Definition: nss_gns_query.h:46
static struct GNUNET_PeerIdentity pid
Identity of the peer we transmit to / connect to.
union userdata::@21 data