xref: /third_party/curl/lib/if2ip.c (revision 13498266)
1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24
25#include "curl_setup.h"
26
27#ifdef HAVE_NETINET_IN_H
28#  include <netinet/in.h>
29#endif
30#ifdef HAVE_ARPA_INET_H
31#  include <arpa/inet.h>
32#endif
33#ifdef HAVE_NET_IF_H
34#  include <net/if.h>
35#endif
36#ifdef HAVE_SYS_IOCTL_H
37#  include <sys/ioctl.h>
38#endif
39#ifdef HAVE_NETDB_H
40#  include <netdb.h>
41#endif
42#ifdef HAVE_SYS_SOCKIO_H
43#  include <sys/sockio.h>
44#endif
45#ifdef HAVE_IFADDRS_H
46#  include <ifaddrs.h>
47#endif
48#ifdef HAVE_STROPTS_H
49#  include <stropts.h>
50#endif
51#ifdef __VMS
52#  include <inet.h>
53#endif
54
55#include "inet_ntop.h"
56#include "strcase.h"
57#include "if2ip.h"
58/* The last 3 #include files should be in this order */
59#include "curl_printf.h"
60#include "curl_memory.h"
61#include "memdebug.h"
62
63/* ------------------------------------------------------------------ */
64
65#ifdef ENABLE_IPV6
66/* Return the scope of the given address. */
67unsigned int Curl_ipv6_scope(const struct sockaddr *sa)
68{
69  if(sa->sa_family == AF_INET6) {
70    const struct sockaddr_in6 * sa6 = (const struct sockaddr_in6 *)(void *) sa;
71    const unsigned char *b = sa6->sin6_addr.s6_addr;
72    unsigned short w = (unsigned short) ((b[0] << 8) | b[1]);
73
74    if((b[0] & 0xFE) == 0xFC) /* Handle ULAs */
75      return IPV6_SCOPE_UNIQUELOCAL;
76    switch(w & 0xFFC0) {
77    case 0xFE80:
78      return IPV6_SCOPE_LINKLOCAL;
79    case 0xFEC0:
80      return IPV6_SCOPE_SITELOCAL;
81    case 0x0000:
82      w = b[1] | b[2] | b[3] | b[4] | b[5] | b[6] | b[7] | b[8] | b[9] |
83          b[10] | b[11] | b[12] | b[13] | b[14];
84      if(w || b[15] != 0x01)
85        break;
86      return IPV6_SCOPE_NODELOCAL;
87    default:
88      break;
89    }
90  }
91  return IPV6_SCOPE_GLOBAL;
92}
93#endif
94
95#ifndef CURL_DISABLE_BINDLOCAL
96
97#if defined(HAVE_GETIFADDRS)
98
99if2ip_result_t Curl_if2ip(int af,
100#ifdef ENABLE_IPV6
101                          unsigned int remote_scope,
102                          unsigned int local_scope_id,
103#endif
104                          const char *interf,
105                          char *buf, int buf_size)
106{
107  struct ifaddrs *iface, *head;
108  if2ip_result_t res = IF2IP_NOT_FOUND;
109
110#if defined(ENABLE_IPV6) && \
111    !defined(HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID)
112  (void) local_scope_id;
113#endif
114
115  if(getifaddrs(&head) >= 0) {
116    for(iface = head; iface != NULL; iface = iface->ifa_next) {
117      if(iface->ifa_addr) {
118        if(iface->ifa_addr->sa_family == af) {
119          if(strcasecompare(iface->ifa_name, interf)) {
120            void *addr;
121            const char *ip;
122            char scope[12] = "";
123            char ipstr[64];
124#ifdef ENABLE_IPV6
125            if(af == AF_INET6) {
126#ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID
127              unsigned int scopeid = 0;
128#endif
129              unsigned int ifscope = Curl_ipv6_scope(iface->ifa_addr);
130
131              if(ifscope != remote_scope) {
132                /* We are interested only in interface addresses whose scope
133                   matches the remote address we want to connect to: global
134                   for global, link-local for link-local, etc... */
135                if(res == IF2IP_NOT_FOUND)
136                  res = IF2IP_AF_NOT_SUPPORTED;
137                continue;
138              }
139
140              addr =
141                &((struct sockaddr_in6 *)(void *)iface->ifa_addr)->sin6_addr;
142#ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID
143              /* Include the scope of this interface as part of the address */
144              scopeid = ((struct sockaddr_in6 *)(void *)iface->ifa_addr)
145                            ->sin6_scope_id;
146
147              /* If given, scope id should match. */
148              if(local_scope_id && scopeid != local_scope_id) {
149                if(res == IF2IP_NOT_FOUND)
150                  res = IF2IP_AF_NOT_SUPPORTED;
151
152                continue;
153              }
154
155              if(scopeid)
156                msnprintf(scope, sizeof(scope), "%%%u", scopeid);
157#endif
158            }
159            else
160#endif
161              addr =
162                &((struct sockaddr_in *)(void *)iface->ifa_addr)->sin_addr;
163            res = IF2IP_FOUND;
164            ip = Curl_inet_ntop(af, addr, ipstr, sizeof(ipstr));
165            msnprintf(buf, buf_size, "%s%s", ip, scope);
166            break;
167          }
168        }
169        else if((res == IF2IP_NOT_FOUND) &&
170                strcasecompare(iface->ifa_name, interf)) {
171          res = IF2IP_AF_NOT_SUPPORTED;
172        }
173      }
174    }
175
176    freeifaddrs(head);
177  }
178
179  return res;
180}
181
182#elif defined(HAVE_IOCTL_SIOCGIFADDR)
183
184if2ip_result_t Curl_if2ip(int af,
185#ifdef ENABLE_IPV6
186                          unsigned int remote_scope,
187                          unsigned int local_scope_id,
188#endif
189                          const char *interf,
190                          char *buf, int buf_size)
191{
192  struct ifreq req;
193  struct in_addr in;
194  struct sockaddr_in *s;
195  curl_socket_t dummy;
196  size_t len;
197  const char *r;
198
199#ifdef ENABLE_IPV6
200  (void)remote_scope;
201  (void)local_scope_id;
202#endif
203
204  if(!interf || (af != AF_INET))
205    return IF2IP_NOT_FOUND;
206
207  len = strlen(interf);
208  if(len >= sizeof(req.ifr_name))
209    return IF2IP_NOT_FOUND;
210
211  dummy = socket(AF_INET, SOCK_STREAM, 0);
212  if(CURL_SOCKET_BAD == dummy)
213    return IF2IP_NOT_FOUND;
214
215  memset(&req, 0, sizeof(req));
216  memcpy(req.ifr_name, interf, len + 1);
217  req.ifr_addr.sa_family = AF_INET;
218
219  if(ioctl(dummy, SIOCGIFADDR, &req) < 0) {
220    sclose(dummy);
221    /* With SIOCGIFADDR, we cannot tell the difference between an interface
222       that does not exist and an interface that has no address of the
223       correct family. Assume the interface does not exist */
224    return IF2IP_NOT_FOUND;
225  }
226
227  s = (struct sockaddr_in *)(void *)&req.ifr_addr;
228  memcpy(&in, &s->sin_addr, sizeof(in));
229  r = Curl_inet_ntop(s->sin_family, &in, buf, buf_size);
230
231  sclose(dummy);
232  if(!r)
233    return IF2IP_NOT_FOUND;
234  return IF2IP_FOUND;
235}
236
237#else
238
239if2ip_result_t Curl_if2ip(int af,
240#ifdef ENABLE_IPV6
241                          unsigned int remote_scope,
242                          unsigned int local_scope_id,
243#endif
244                          const char *interf,
245                          char *buf, int buf_size)
246{
247    (void) af;
248#ifdef ENABLE_IPV6
249    (void) remote_scope;
250    (void) local_scope_id;
251#endif
252    (void) interf;
253    (void) buf;
254    (void) buf_size;
255    return IF2IP_NOT_FOUND;
256}
257
258#endif
259
260#endif /* CURL_DISABLE_BINDLOCAL */
261