1 /* -*- c-file-style: "linux" -*-
3 rsync -- fast file replication program
5 Copyright (C) 1992-2001 by Andrew Tridgell <tridge@samba.org>
6 Copyright (C) 2001, 2002 by Martin Pool <mbp@samba.org>
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 * Functions for looking up the remote name or addr of a socket.
28 * This file is now converted to use the new-style getaddrinfo()
29 * interface, which supports IPv6 but is also supported on recent
30 * IPv4-only machines. On systems that don't have that interface, we
31 * emulate it using the KAME implementation.
36 static const char default_name[] = "UNKNOWN";
42 * Return the IP addr of the client as a string
44 char *client_addr(int fd)
46 struct sockaddr_storage ss;
47 socklen_t length = sizeof ss;
50 static char addr_buf[100];
51 static int initialised;
58 if (am_server) { /* daemon over --rsh mode */
59 strcpy(addr_buf, "0.0.0.0");
60 if ((ssh_client = getenv("SSH_CLIENT")) != NULL) {
61 /* truncate SSH_CLIENT to just IP address */
62 if ((p = strchr(ssh_client, ' ')) != NULL) {
63 len = MIN((unsigned int) (p - ssh_client),
65 strncpy(addr_buf, ssh_client, len);
66 *(addr_buf + len) = '\0';
70 client_sockaddr(fd, &ss, &length);
71 getnameinfo((struct sockaddr *)&ss, length,
72 addr_buf, sizeof addr_buf, NULL, 0, NI_NUMERICHOST);
79 static int get_sockaddr_family(const struct sockaddr_storage *ss)
81 return ((struct sockaddr *) ss)->sa_family;
86 * Return the DNS name of the client.
88 * The name is statically cached so that repeated lookups are quick,
89 * so there is a limit of one lookup per customer.
91 * If anything goes wrong, including the name->addr->name check, then
92 * we just use "UNKNOWN", so you can use that value in hosts allow
95 * After translation from sockaddr to name we do a forward lookup to
96 * make sure nobody is spoofing PTR records.
98 char *client_name(int fd)
100 static char name_buf[100];
101 static char port_buf[100];
102 static int initialised;
103 struct sockaddr_storage ss;
109 strcpy(name_buf, default_name);
112 memset(&ss, 0, sizeof ss);
114 if (am_server) { /* daemon over --rsh mode */
115 char *addr = client_addr(fd);
116 struct addrinfo hint, *answer;
119 memset(&hint, 0, sizeof hint);
121 #ifdef AI_NUMERICHOST
122 hint.ai_flags = AI_NUMERICHOST;
124 hint.ai_socktype = SOCK_STREAM;
126 if ((err = getaddrinfo(addr, NULL, &hint, &answer)) != 0) {
127 rprintf(FERROR, RSYNC_NAME ": malformed address %s: %s\n",
128 addr, gai_strerror(err));
132 switch (answer->ai_family) {
134 ss_len = sizeof (struct sockaddr_in);
135 memcpy(&ss, answer->ai_addr, ss_len);
139 ss_len = sizeof (struct sockaddr_in6);
140 memcpy(&ss, answer->ai_addr, ss_len);
144 freeaddrinfo(answer);
147 client_sockaddr(fd, &ss, &ss_len);
150 if (!lookup_name(fd, &ss, ss_len, name_buf, sizeof name_buf,
151 port_buf, sizeof port_buf))
152 check_name(fd, &ss, name_buf);
160 * Get the sockaddr for the client.
162 * If it comes in as an ipv4 address mapped into IPv6 format then we
163 * convert it back to a regular IPv4.
165 void client_sockaddr(int fd,
166 struct sockaddr_storage *ss,
169 memset(ss, 0, sizeof *ss);
171 if (getpeername(fd, (struct sockaddr *) ss, ss_len)) {
172 /* FIXME: Can we really not continue? */
173 rprintf(FERROR, RSYNC_NAME ": getpeername on fd%d failed: %s\n",
174 fd, strerror(errno));
175 exit_cleanup(RERR_SOCKETIO);
179 if (get_sockaddr_family(ss) == AF_INET6 &&
180 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)ss)->sin6_addr)) {
181 /* OK, so ss is in the IPv6 family, but it is really
182 * an IPv4 address: something like
183 * "::ffff:10.130.1.2". If we use it as-is, then the
184 * reverse lookup might fail or perhaps something else
185 * bad might happen. So instead we convert it to an
186 * equivalent address in the IPv4 address family. */
187 struct sockaddr_in6 sin6;
188 struct sockaddr_in *sin;
190 memcpy(&sin6, ss, sizeof sin6);
191 sin = (struct sockaddr_in *)ss;
192 memset(sin, 0, sizeof *sin);
193 sin->sin_family = AF_INET;
194 *ss_len = sizeof (struct sockaddr_in);
195 #if HAVE_SOCKADDR_IN_LEN
196 sin->sin_len = *ss_len;
198 sin->sin_port = sin6.sin6_port;
200 /* There is a macro to extract the mapped part
201 * (IN6_V4MAPPED_TO_SINADDR ?), but it does not seem
202 * to be present in the Linux headers. */
203 memcpy(&sin->sin_addr, &sin6.sin6_addr.s6_addr[12],
204 sizeof sin->sin_addr);
211 * Look up a name from @p ss into @p name_buf.
213 * @param fd file descriptor for client socket.
215 int lookup_name(int fd, const struct sockaddr_storage *ss,
217 char *name_buf, size_t name_buf_len,
218 char *port_buf, size_t port_buf_len)
223 name_err = getnameinfo((struct sockaddr *) ss, ss_len,
224 name_buf, name_buf_len,
225 port_buf, port_buf_len,
226 NI_NAMEREQD | NI_NUMERICSERV);
228 strcpy(name_buf, default_name);
229 rprintf(FERROR, RSYNC_NAME ": name lookup failed for %s: %s\n",
231 gai_strerror(name_err));
241 * Compare an addrinfo from the resolver to a sockinfo.
243 * Like strcmp, returns 0 for identical.
245 int compare_addrinfo_sockaddr(const struct addrinfo *ai,
246 const struct sockaddr_storage *ss)
248 int ss_family = get_sockaddr_family(ss);
249 const char fn[] = "compare_addrinfo_sockaddr";
251 if (ai->ai_family != ss_family) {
253 "%s: response family %d != %d\n",
254 fn, ai->ai_family, ss_family);
258 /* The comparison method depends on the particular AF. */
259 if (ss_family == AF_INET) {
260 const struct sockaddr_in *sin1, *sin2;
262 sin1 = (const struct sockaddr_in *) ss;
263 sin2 = (const struct sockaddr_in *) ai->ai_addr;
265 return memcmp(&sin1->sin_addr, &sin2->sin_addr,
266 sizeof sin1->sin_addr);
270 if (ss_family == AF_INET6) {
271 const struct sockaddr_in6 *sin1, *sin2;
273 sin1 = (const struct sockaddr_in6 *) ss;
274 sin2 = (const struct sockaddr_in6 *) ai->ai_addr;
276 if (ai->ai_addrlen < sizeof (struct sockaddr_in6)) {
278 "%s: too short sockaddr_in6; length=%d\n",
283 if (memcmp(&sin1->sin6_addr, &sin2->sin6_addr,
284 sizeof sin1->sin6_addr))
287 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
288 if (sin1->sin6_scope_id != sin2->sin6_scope_id)
301 * Do a forward lookup on @p name_buf and make sure it corresponds to
302 * @p ss -- otherwise we may be being spoofed. If we suspect we are,
303 * then we don't abort the connection but just emit a warning, and
304 * change @p name_buf to be "UNKNOWN".
306 * We don't do anything with the service when checking the name,
307 * because it doesn't seem that it could be spoofed in any way, and
308 * getaddrinfo on random service names seems to cause problems on AIX.
310 int check_name(int fd,
311 const struct sockaddr_storage *ss,
314 struct addrinfo hints, *res, *res0;
316 int ss_family = get_sockaddr_family(ss);
318 memset(&hints, 0, sizeof hints);
319 hints.ai_family = ss_family;
320 hints.ai_flags = AI_CANONNAME;
321 hints.ai_socktype = SOCK_STREAM;
322 error = getaddrinfo(name_buf, NULL, &hints, &res0);
325 RSYNC_NAME ": forward name lookup for %s failed: %s\n",
326 name_buf, gai_strerror(error));
327 strcpy(name_buf, default_name);
332 /* Given all these results, we expect that one of them will be
333 * the same as ss. The comparison is a bit complicated. */
334 for (res = res0; res; res = res->ai_next) {
335 if (!compare_addrinfo_sockaddr(res, ss))
336 break; /* OK, identical */
340 /* We hit the end of the list without finding an
341 * address that was the same as ss. */
342 rprintf(FERROR, RSYNC_NAME
343 ": no known address for \"%s\": "
344 "spoofed address?\n",
346 strcpy(name_buf, default_name);
347 } else if (res == NULL) {
348 /* We hit the end of the list without finding an
349 * address that was the same as ss. */
350 rprintf(FERROR, RSYNC_NAME
351 ": %s is not a known address for \"%s\": "
352 "spoofed address?\n",
355 strcpy(name_buf, default_name);