fixed a bug that made us use only 16 bits of the file checksum when
[rsync/rsync.git] / socket.c
CommitLineData
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1/*
2 Copyright (C) Andrew Tridgell 1998
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17*/
18
19/*
20 socket functions used in rsync
21
22 */
23
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24#include "rsync.h"
25
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26
27/* establish a proxy connection on an open socket to a web roxy by using the CONNECT
28 method */
29static int establish_proxy_connection(int fd, char *host, int port)
30{
31 char buffer[1024];
32 char *cp;
33
34 slprintf(buffer, sizeof(buffer), "CONNECT %s:%d HTTP/1.0\r\n\r\n", host, port);
35 if (write(fd, buffer, strlen(buffer)) != strlen(buffer)) {
36 rprintf(FERROR, "failed to write to proxy - %s\n",
37 strerror(errno));
38 return -1;
39 }
40
41 for (cp = buffer; cp < &buffer[sizeof(buffer) - 1]; cp++) {
42 if (read(fd, cp, 1) != 1) {
43 rprintf(FERROR, "failed to read from proxy\n");
44 return -1;
45 }
46 if (*cp == '\n')
47 break;
48 }
49
50 if (*cp != '\n')
51 cp++;
52 *cp-- = '\0';
53 if (*cp == '\r')
54 *cp = '\0';
55 if (strncmp(buffer, "HTTP/", 5) != 0) {
56 rprintf(FERROR, "bad response from proxy - %s\n",
57 buffer);
58 return -1;
59 }
60 for (cp = &buffer[5]; isdigit(*cp) || (*cp == '.'); cp++)
61 ;
62 while (*cp == ' ')
63 cp++;
64 if (*cp != '2') {
65 rprintf(FERROR, "bad response from proxy - %s\n",
66 buffer);
67 return -1;
68 }
69 /* throw away the rest of the HTTP header */
70 while (1) {
71 for (cp = buffer; cp < &buffer[sizeof(buffer) - 1];
72 cp++) {
73 if (read(fd, cp, 1) != 1) {
74 rprintf(FERROR, "failed to read from proxy\n");
75 return -1;
76 }
77 if (*cp == '\n')
78 break;
79 }
80 if ((cp > buffer) && (*cp == '\n'))
81 cp--;
82 if ((cp == buffer) && ((*cp == '\n') || (*cp == '\r')))
83 break;
84 }
85 return 0;
86}
87
88
f0fca04e 89/* open a socket to a tcp remote host with the specified port
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90 based on code from Warren
91 proxy support by Stephen Rothwell */
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92int open_socket_out(char *host, int port)
93{
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94 int type = SOCK_STREAM;
95 struct sockaddr_in sock_out;
96 int res;
97 struct hostent *hp;
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98 char *h;
99 unsigned p;
100 int proxied = 0;
101 char buffer[1024];
102 char *cp;
103
104 /* if we have a RSYNC_PROXY env variable then redirect our connetcion via a web proxy
105 at the given address. The format is hostname:port */
106 h = getenv("RSYNC_PROXY");
107 proxied = (h != NULL) && (*h != '\0');
108
109 if (proxied) {
110 strlcpy(buffer, h, sizeof(buffer));
111 cp = strchr(buffer, ':');
112 if (cp == NULL) {
113 rprintf(FERROR, "invalid proxy specification\n");
114 return -1;
115 }
116 *cp++ = '\0';
117 p = atoi(cp);
118 h = buffer;
119 } else {
120 h = host;
121 p = port;
122 }
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123
124 res = socket(PF_INET, type, 0);
125 if (res == -1) {
126 return -1;
127 }
128
4c3b4b25 129 hp = gethostbyname(h);
f0fca04e 130 if (!hp) {
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131 rprintf(FERROR,"unknown host: %s\n", h);
132 close(res);
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133 return -1;
134 }
135
136 memcpy(&sock_out.sin_addr, hp->h_addr, hp->h_length);
4c3b4b25 137 sock_out.sin_port = htons(p);
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138 sock_out.sin_family = PF_INET;
139
140 if (connect(res,(struct sockaddr *)&sock_out,sizeof(sock_out))) {
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141 rprintf(FERROR,"failed to connect to %s - %s\n", h, strerror(errno));
142 close(res);
143 return -1;
144 }
145
146 if (proxied && establish_proxy_connection(res, host, port) != 0) {
f0fca04e 147 close(res);
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148 return -1;
149 }
150
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151 set_nonblocking(res);
152
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153 return res;
154}
155
156
157/****************************************************************************
158open a socket of the specified type, port and address for incoming data
159****************************************************************************/
160static int open_socket_in(int type, int port)
161{
162 struct hostent *hp;
163 struct sockaddr_in sock;
d41c7d02 164 char host_name[MAXHOSTNAMELEN];
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165 int res;
166 int one=1;
167
168 /* get my host name */
169 if (gethostname(host_name, sizeof(host_name)) == -1) {
170 rprintf(FERROR,"gethostname failed\n");
171 return -1;
172 }
173
174 /* get host info */
175 if ((hp = gethostbyname(host_name)) == 0) {
176 rprintf(FERROR,"gethostbyname: Unknown host %s\n",host_name);
177 return -1;
178 }
179
f5780433 180 memset((char *)&sock,0,sizeof(sock));
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181 memcpy((char *)&sock.sin_addr,(char *)hp->h_addr, hp->h_length);
182 sock.sin_port = htons(port);
183 sock.sin_family = hp->h_addrtype;
184 sock.sin_addr.s_addr = INADDR_ANY;
185 res = socket(hp->h_addrtype, type, 0);
186 if (res == -1) {
187 rprintf(FERROR,"socket failed\n");
188 return -1;
189 }
190
191 setsockopt(res,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one));
192
193 /* now we've got a socket - we need to bind it */
194 if (bind(res, (struct sockaddr * ) &sock,sizeof(sock)) == -1) {
195 rprintf(FERROR,"bind failed on port %d\n", port);
196 close(res);
197 return -1;
198 }
199
200 return res;
201}
202
203
204/****************************************************************************
205determine if a file descriptor is in fact a socket
206****************************************************************************/
207int is_a_socket(int fd)
208{
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209 int v,l;
210 l = sizeof(int);
211 return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0);
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212}
213
214
8ef4ffd6 215void start_accept_loop(int port, int (*fn)(int ))
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216{
217 int s;
218
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219 /* open an incoming socket */
220 s = open_socket_in(SOCK_STREAM, port);
221 if (s == -1)
65417579 222 exit_cleanup(RERR_SOCKETIO);
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223
224 /* ready to listen */
225 if (listen(s, 5) == -1) {
226 close(s);
65417579 227 exit_cleanup(RERR_SOCKETIO);
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228 }
229
230
231 /* now accept incoming connections - forking a new process
232 for each incoming connection */
233 while (1) {
234 fd_set fds;
235 int fd;
236 struct sockaddr addr;
237 int in_addrlen = sizeof(addr);
238
239 FD_ZERO(&fds);
240 FD_SET(s, &fds);
241
242 if (select(s+1, &fds, NULL, NULL, NULL) != 1) {
243 continue;
244 }
245
246 if(!FD_ISSET(s, &fds)) continue;
247
248 fd = accept(s,&addr,&in_addrlen);
249
250 if (fd == -1) continue;
251
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252 signal(SIGCHLD, SIG_IGN);
253
254 /* we shouldn't have any children left hanging around
255 but I have had reports that on Digital Unix zombies
256 are produced, so this ensures that they are reaped */
257#ifdef WNOHANG
258 waitpid(-1, NULL, WNOHANG);
259#endif
260
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261 if (fork()==0) {
262 close(s);
263
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264 set_nonblocking(fd);
265
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266 _exit(fn(fd));
267 }
268
269 close(fd);
270 }
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271}
272
273
274enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON};
275
276struct
277{
278 char *name;
279 int level;
280 int option;
281 int value;
282 int opttype;
283} socket_options[] = {
284 {"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL},
285 {"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL},
286 {"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL},
287#ifdef TCP_NODELAY
288 {"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL},
289#endif
290#ifdef IPTOS_LOWDELAY
291 {"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON},
292#endif
293#ifdef IPTOS_THROUGHPUT
294 {"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON},
295#endif
296#ifdef SO_SNDBUF
297 {"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT},
298#endif
299#ifdef SO_RCVBUF
300 {"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT},
301#endif
302#ifdef SO_SNDLOWAT
303 {"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT},
304#endif
305#ifdef SO_RCVLOWAT
306 {"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT},
307#endif
308#ifdef SO_SNDTIMEO
309 {"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT},
310#endif
311#ifdef SO_RCVTIMEO
312 {"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT},
313#endif
314 {NULL,0,0,0,0}};
315
316
317
318/****************************************************************************
319set user socket options
320****************************************************************************/
321void set_socket_options(int fd, char *options)
322{
323 char *tok;
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324 if (!options || !*options) return;
325
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326 options = strdup(options);
327
328 if (!options) out_of_memory("set_socket_options");
329
330 for (tok=strtok(options, " \t,"); tok; tok=strtok(NULL," \t,")) {
331 int ret=0,i;
332 int value = 1;
333 char *p;
334 int got_value = 0;
335
336 if ((p = strchr(tok,'='))) {
337 *p = 0;
338 value = atoi(p+1);
339 got_value = 1;
340 }
341
342 for (i=0;socket_options[i].name;i++)
343 if (strcmp(socket_options[i].name,tok)==0)
344 break;
345
346 if (!socket_options[i].name) {
347 rprintf(FERROR,"Unknown socket option %s\n",tok);
348 continue;
349 }
350
351 switch (socket_options[i].opttype) {
352 case OPT_BOOL:
353 case OPT_INT:
354 ret = setsockopt(fd,socket_options[i].level,
355 socket_options[i].option,(char *)&value,sizeof(int));
356 break;
357
358 case OPT_ON:
359 if (got_value)
360 rprintf(FERROR,"syntax error - %s does not take a value\n",tok);
361
362 {
363 int on = socket_options[i].value;
364 ret = setsockopt(fd,socket_options[i].level,
365 socket_options[i].option,(char *)&on,sizeof(int));
366 }
367 break;
368 }
369
370 if (ret != 0)
371 rprintf(FERROR,"Failed to set socket option %s\n",tok);
372 }
373
374 free(options);
375}
376
377/****************************************************************************
378become a daemon, discarding the controlling terminal
379****************************************************************************/
380void become_daemon(void)
381{
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382 int i;
383
c46ded46 384 if (fork()) {
f0fca04e 385 _exit(0);
c46ded46 386 }
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387
388 /* detach from the terminal */
389#ifdef HAVE_SETSID
390 setsid();
391#else
392#ifdef TIOCNOTTY
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393 i = open("/dev/tty", O_RDWR);
394 if (i >= 0) {
395 ioctl(i, (int) TIOCNOTTY, (char *)0);
396 close(i);
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397 }
398#endif /* TIOCNOTTY */
399#endif
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400 /* make sure that stdin, stdout an stderr don't stuff things
401 up (library functions, for example) */
402 for (i=0;i<3;i++) {
403 close(i);
404 open("/dev/null", O_RDWR);
405 }
bc2e93eb 406}
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407
408/*******************************************************************
409 return the IP addr of the client as a string
410 ******************************************************************/
411char *client_addr(int fd)
412{
413 struct sockaddr sa;
414 struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa);
415 int length = sizeof(sa);
416 static char addr_buf[100];
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417 static int initialised;
418
419 if (initialised) return addr_buf;
420
421 initialised = 1;
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422
423 if (getpeername(fd, &sa, &length)) {
65417579 424 exit_cleanup(RERR_SOCKETIO);
ff8b29b8 425 }
11a5a3c7 426
37f9805d 427 strlcpy(addr_buf,(char *)inet_ntoa(sockin->sin_addr), sizeof(addr_buf));
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428 return addr_buf;
429}
430
431
432/*******************************************************************
433 return the DNS name of the client
434 ******************************************************************/
435char *client_name(int fd)
436{
437 struct sockaddr sa;
438 struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa);
439 int length = sizeof(sa);
440 static char name_buf[100];
441 struct hostent *hp;
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442 char **p;
443 char *def = "UNKNOWN";
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444 static int initialised;
445
446 if (initialised) return name_buf;
447
448 initialised = 1;
ff8b29b8 449
de5fb374 450 strcpy(name_buf,def);
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451
452 if (getpeername(fd, &sa, &length)) {
65417579 453 exit_cleanup(RERR_SOCKETIO);
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454 }
455
456 /* Look up the remote host name. */
457 if ((hp = gethostbyaddr((char *) &sockin->sin_addr,
458 sizeof(sockin->sin_addr),
459 AF_INET))) {
37f9805d 460 strlcpy(name_buf,(char *)hp->h_name,sizeof(name_buf));
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461 }
462
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463
464 /* do a forward lookup as well to prevent spoofing */
465 hp = gethostbyname(name_buf);
466 if (!hp) {
467 strcpy(name_buf,def);
468 rprintf(FERROR,"reverse name lookup failed\n");
469 } else {
470 for (p=hp->h_addr_list;*p;p++) {
471 if (memcmp(*p, &sockin->sin_addr, hp->h_length) == 0) {
472 break;
473 }
474 }
475 if (!*p) {
476 strcpy(name_buf,def);
477 rprintf(FERROR,"reverse name lookup mismatch - spoofed address?\n");
478 }
479 }
480
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481 return name_buf;
482}