Commit | Line | Data |
---|---|---|
188d1201 FF |
1 | // Mosh: the mobile shell |
2 | // Copyright 2012 Keith Winstein | |
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 3 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, see <http://www.gnu.org/licenses/>. | |
16 | ||
17 | #include <limits.h> | |
18 | #include <unistd.h> | |
19 | #include <stdlib.h> | |
20 | #include <stdarg.h> | |
21 | #include <string.h> | |
22 | #include <vector> | |
23 | #include <map> | |
24 | #include <stdio.h> | |
25 | #include <string> | |
26 | #include <sys/socket.h> | |
27 | #include <getopt.h> | |
28 | #include <arpa/inet.h> | |
29 | #include <netdb.h> | |
30 | #include <signal.h> | |
31 | #include <errno.h> | |
32 | #include <sys/ioctl.h> | |
33 | #include <sys/types.h> | |
34 | #include <sys/wait.h> | |
35 | #include <termios.h> | |
36 | #include <pty.h> | |
37 | ||
38 | using namespace std; | |
39 | ||
40 | inline string shell_quote_string( const string &x ) | |
41 | { | |
42 | string result = "'"; | |
43 | string rest = x; | |
44 | while ( rest.size() ) { | |
45 | size_t good_part = rest.find( "'" ); | |
46 | result += rest.substr( 0, good_part ); | |
47 | if ( good_part != string::npos ) { | |
48 | result += "'\\''"; | |
49 | rest = rest.substr( good_part + 1 ); | |
50 | } else { | |
51 | break; | |
52 | } | |
53 | } | |
54 | return result + "'"; | |
55 | } | |
56 | ||
57 | template <typename SequenceT> | |
58 | inline string shell_quote( const SequenceT &sequence ) | |
59 | { | |
60 | string result; | |
61 | for ( typename SequenceT::const_iterator i = sequence.begin(); | |
62 | i != sequence.end(); | |
63 | i++ ) { | |
64 | result += shell_quote_string( *i ) + " "; | |
65 | } | |
66 | return result.substr( 0, result.size() - 1 ); | |
67 | } | |
68 | ||
69 | void die( const char *format, ... ) { | |
70 | va_list args; | |
71 | va_start( args, format ); | |
72 | vfprintf( stderr, format, args ); | |
73 | va_end( args ); | |
74 | fprintf( stderr, "\n" ); | |
75 | exit( 255 ); | |
76 | } | |
77 | ||
78 | static const char *usage_format = | |
79 | "Usage: %s [options] [--] [user@]host [command...]\n" | |
80 | " --client=PATH mosh client on local machine\n" | |
81 | " (default: \"mosh-client\")\n" | |
82 | " --server=COMMAND mosh server on remote machine\n" | |
83 | " (default: \"mosh-server\")\n" | |
84 | "\n" | |
85 | " --predict=adaptive local echo for slower links [default]\n" | |
86 | "-a --predict=always use local echo even on fast links\n" | |
87 | "-n --predict=never never use local echo\n" | |
257ccdad | 88 | "-6 use IPv6 only\n" |
188d1201 FF |
89 | "\n" |
90 | "-p NUM --port=NUM server-side UDP port\n" | |
91 | "\n" | |
92 | "-P NUM --ssh-port=NUM ssh server port\n" | |
93 | " (default: let the ssh command choose)\n" | |
94 | "\n" | |
95 | " --ssh=COMMAND ssh command to run when setting up session\n" | |
96 | " (example: \"ssh -p 2222\")\n" | |
97 | " (default: \"ssh\")\n" | |
98 | "\n" | |
9d1ea50b FF |
99 | " --no-init do not send terminal initialization string\n" |
100 | "\n" | |
188d1201 FF |
101 | " --help this message\n" |
102 | " --version version and copyright information\n" | |
103 | "\n" | |
104 | "Please report bugs to mosh-devel@mit.edu.\n" | |
105 | "Mosh home page: http://mosh.mit.edu"; | |
106 | ||
107 | static const char *version_format = | |
108 | "mosh %s\n" | |
109 | "Copyright 2012 Keith Winstein <mosh-devel@mit.edu>\n" | |
110 | "License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.\n" | |
111 | "This is free software: you are free to change and redistribute it.\n" | |
112 | "There is NO WARRANTY, to the extent permitted by law."; | |
113 | ||
114 | static const char *key_valid_char_set = | |
115 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789/+"; | |
116 | ||
117 | static char *argv0; | |
118 | ||
119 | void predict_check( const string &predict, bool env_set ) | |
120 | { | |
121 | if ( predict != "adaptive" && | |
122 | predict != "always" && | |
123 | predict != "never" ) { | |
124 | fprintf( stderr, "%s: Unknown mode \"%s\"%s.\n", argv0, predict.c_str(), | |
125 | env_set ? " (MOSH_PREDICTION_DISPLAY in environment)" : "" ); | |
126 | die( usage_format, argv0 ); | |
127 | } | |
128 | } | |
129 | ||
130 | void cat( int ifd, int ofd ) | |
131 | { | |
132 | char buf[4096]; | |
133 | ssize_t n; | |
134 | while ( 1 ) { | |
135 | n = read( ifd, buf, sizeof( buf ) ); | |
136 | if ( n==-1 ) { | |
137 | if (errno == EINTR ) { | |
138 | continue; | |
139 | } | |
140 | break; | |
141 | } | |
142 | if ( n==0 ) { | |
143 | break; | |
144 | } | |
145 | n = write( ofd, buf, n ); | |
146 | if ( n==-1 ) { | |
147 | break; | |
148 | } | |
149 | } | |
150 | } | |
151 | ||
152 | bool valid_port(string port) { | |
153 | if ( port.size() ) { | |
154 | return port.find_first_not_of( "0123456789" ) == string::npos && | |
155 | atoi( port.c_str() ) > 0 && | |
156 | atoi( port.c_str() ) <= 65535; | |
157 | } | |
158 | return true; // consider no port to be the default value | |
159 | } | |
160 | ||
161 | int main( int argc, char *argv[] ) | |
162 | { | |
163 | argv0 = argv[0]; | |
164 | string client = "mosh-client"; | |
165 | string server = "mosh-server"; | |
166 | string ssh = "ssh"; | |
167 | string predict, port_request, ssh_port; | |
e18a73fc | 168 | int help=0, version=0, fake_proxy=0, term_init=1; |
257ccdad | 169 | int force_ipv6 = 0; |
188d1201 FF |
170 | |
171 | static struct option long_options[] = | |
172 | { | |
173 | { "client", required_argument, 0, 'c' }, | |
174 | { "server", required_argument, 0, 's' }, | |
e18a73fc | 175 | { "no-init", no_argument, &term_init, 0 }, |
188d1201 FF |
176 | { "predict", required_argument, 0, 'r' }, |
177 | { "port", required_argument, 0, 'p' }, | |
178 | { "ssh-port", required_argument, 0, 'P' }, | |
179 | { "ssh", required_argument, 0, 'S' }, | |
180 | { "help", no_argument, &help, 1 }, | |
181 | { "version", no_argument, &version, 1 }, | |
e18a73fc | 182 | { "fake-proxy", no_argument, &fake_proxy, 1 }, |
188d1201 FF |
183 | { 0, 0, 0, 0 } |
184 | }; | |
185 | while ( 1 ) { | |
186 | int option_index = 0; | |
257ccdad | 187 | int c = getopt_long( argc, argv, "6anp:P:", |
188d1201 FF |
188 | long_options, &option_index ); |
189 | if ( c == -1 ) { | |
190 | break; | |
191 | } | |
192 | ||
193 | switch ( c ) { | |
194 | case 0: | |
195 | // flag has been set | |
196 | break; | |
197 | case 'c': | |
198 | client = optarg; | |
199 | break; | |
200 | case 's': | |
201 | server = optarg; | |
202 | break; | |
203 | case 'r': | |
204 | predict = optarg; | |
205 | break; | |
206 | case 'p': | |
207 | port_request = optarg; | |
208 | break; | |
209 | case 'P': | |
210 | ssh_port = optarg; | |
211 | break; | |
212 | case 'S': | |
213 | ssh = optarg; | |
214 | break; | |
215 | case 'a': | |
216 | predict = "always"; | |
217 | break; | |
218 | case 'n': | |
219 | predict = "never"; | |
220 | break; | |
257ccdad GS |
221 | case '6': |
222 | force_ipv6 = true; | |
223 | break; | |
188d1201 FF |
224 | default: |
225 | die( usage_format, argv[0] ); | |
226 | } | |
227 | } | |
228 | ||
229 | if ( help ) { | |
230 | die( usage_format, argv[0] ); | |
231 | } | |
232 | if ( version ) { | |
233 | die( version_format, PACKAGE_VERSION ); | |
234 | } | |
235 | ||
236 | if ( predict.size() ) { | |
237 | predict_check( predict, 0 ); | |
238 | } else if ( getenv( "MOSH_PREDICTION_DELAY" ) ) { | |
239 | predict = getenv( "MOSH_PREDICTION_DELAY" ); | |
240 | predict_check( predict, 1 ); | |
241 | } else { | |
242 | predict = "adaptive"; | |
243 | predict_check( predict, 0 ); | |
244 | } | |
245 | ||
246 | if(!valid_port(port_request)) { | |
247 | die( "%s: Server-side port (%s) must be within valid range [0..65535].", | |
248 | argv[0], | |
249 | port_request.c_str() ); | |
250 | } | |
251 | ||
252 | if(!valid_port(ssh_port)) { | |
253 | die( "%s: SSH port (%s) must be within valid range [0..65535].", | |
254 | argv[0], | |
255 | ssh_port.c_str() ); | |
256 | } | |
257 | ||
258 | unsetenv( "MOSH_PREDICTION_DISPLAY" ); | |
259 | ||
260 | if ( fake_proxy ) { | |
261 | string host = argv[optind++]; | |
262 | string port = argv[optind++]; | |
263 | ||
264 | int sockfd = -1; | |
265 | struct addrinfo hints, *servinfo, *p; | |
266 | int rv; | |
267 | ||
268 | memset( &hints, 0, sizeof( hints ) ); | |
269 | hints.ai_socktype = SOCK_STREAM; | |
257ccdad GS |
270 | if (force_ipv6) { |
271 | hints.ai_family = AF_INET6; | |
272 | } | |
188d1201 FF |
273 | |
274 | if ( ( rv = getaddrinfo( host.c_str(), | |
275 | port.c_str(), | |
276 | &hints, | |
277 | &servinfo ) ) != 0 ) { | |
278 | die( "%s: Could not resolve hostname %s: getaddrinfo: %s", | |
279 | argv[0], | |
280 | host.c_str(), | |
281 | gai_strerror( rv ) ); | |
282 | } | |
283 | ||
284 | int try_family = AF_INET; | |
257ccdad GS |
285 | if (force_ipv6) { |
286 | try_family = AF_INET6; | |
287 | } | |
188d1201 FF |
288 | // loop through all the results and connect to the first we can |
289 | for ( p = servinfo; p != NULL || try_family == AF_INET; p = p->ai_next ) { | |
290 | if(p == NULL && try_family == AF_INET) { // start over and try AF_INET6 | |
291 | p = servinfo; | |
292 | try_family = AF_INET6; | |
293 | } | |
294 | if(p == NULL) { | |
295 | break; // servinfo == NULL | |
296 | } | |
297 | ||
298 | if(p->ai_family != try_family) { | |
299 | continue; | |
300 | } | |
301 | ||
302 | if ( ( sockfd = socket( p->ai_family, SOCK_STREAM, IPPROTO_TCP ) ) == -1 ) { | |
303 | continue; | |
304 | } | |
305 | ||
306 | if ( connect( sockfd, p->ai_addr, p->ai_addrlen ) == -1 ) { | |
307 | close( sockfd ); | |
308 | continue; | |
309 | } | |
310 | ||
311 | char host[NI_MAXHOST], service[NI_MAXSERV]; | |
312 | if ( getnameinfo( p->ai_addr, p->ai_addrlen, | |
313 | host, NI_MAXHOST, | |
314 | service, NI_MAXSERV, | |
315 | NI_NUMERICSERV | NI_NUMERICHOST ) == -1 ) { | |
316 | die( "Couldn't get host name info" ); | |
317 | } | |
318 | ||
319 | fprintf( stderr, "MOSH IP %s\n", host ); | |
320 | break; // if we get here, we must have connected successfully | |
321 | } | |
322 | ||
323 | if ( p == NULL ) { | |
324 | // looped off the end of the list with no connection | |
325 | die( "%s: failed to connect to host %s port %s", | |
326 | argv[0], host.c_str(), port.c_str() ); | |
327 | } | |
328 | ||
329 | freeaddrinfo( servinfo ); // all done with this structure | |
330 | ||
331 | int pid = fork(); | |
1f87518b | 332 | if ( pid == -1 ) die( "%s: fork: %d", argv[0], errno ); |
188d1201 | 333 | if ( pid == 0 ) { |
3afa4f34 FF |
334 | close( STDIN_FILENO ); |
335 | cat( sockfd, STDOUT_FILENO ); | |
188d1201 FF |
336 | shutdown( sockfd, 0 ); |
337 | exit( 0 ); | |
338 | } | |
339 | signal( SIGHUP, SIG_IGN ); | |
3afa4f34 FF |
340 | close( STDOUT_FILENO ); |
341 | cat( STDIN_FILENO, sockfd ); | |
342 | shutdown( sockfd, SHUT_WR /* = 1 */ ); | |
343 | close( STDIN_FILENO ); | |
188d1201 FF |
344 | waitpid( pid, NULL, 0 ); |
345 | exit( 0 ); | |
346 | } | |
347 | ||
348 | if ( argc - optind < 1 ) { | |
349 | die( usage_format, argv[0] ); | |
350 | } | |
351 | ||
352 | string userhost = argv[optind++]; | |
353 | char **command = &argv[optind]; | |
354 | int commands = argc - optind; | |
355 | ||
188d1201 FF |
356 | char *buf = NULL; |
357 | size_t buf_sz = 0; | |
358 | ssize_t n; | |
188d1201 FF |
359 | |
360 | int pty, pty_slave; | |
361 | struct winsize ws; | |
362 | if ( ioctl( 0, TIOCGWINSZ, &ws ) == -1 ) { | |
363 | die( "%s: ioctl: %d", argv[0], errno ); | |
364 | } | |
365 | ||
366 | if ( openpty( &pty, &pty_slave, NULL, NULL, &ws ) == -1 ) { | |
367 | die( "%s: openpty: %d", argv[0], errno ); | |
368 | } | |
369 | ||
370 | int pid = fork(); | |
3afa4f34 | 371 | if ( pid == -1 ) die( "%s: fork: %d", argv[0], errno ); |
188d1201 FF |
372 | if ( pid == 0 ) { |
373 | close( pty ); | |
374 | if ( -1 == dup2( pty_slave, 1 ) || | |
375 | -1 == dup2( pty_slave, 2 ) ) { | |
376 | die( "%s: dup2: %d", argv[0], errno ); | |
377 | } | |
378 | close( pty_slave ); | |
379 | ||
380 | vector<string> server_args; | |
381 | server_args.push_back( "new" ); | |
188d1201 | 382 | server_args.push_back( "-c" ); |
df38a35b | 383 | server_args.push_back( "256" ); |
e18a73fc | 384 | server_args.push_back( "-s" ); |
188d1201 FF |
385 | if ( port_request.size() ) { |
386 | server_args.push_back( "-p" ); | |
387 | server_args.push_back( port_request ); | |
388 | } | |
32144b83 FF |
389 | |
390 | for (char const* env_name : { | |
391 | "LANG", "LANGUAGE", "LC_CTYPE", "LC_NUMERIC", | |
392 | "LC_TIME", "LC_COLLATE", "LC_MONETARY", "LC_MESSAGES", "LC_PAPER", | |
393 | "LC_NAME", "LC_ADDRESS", "LC_TELEPHONE", "LC_MEASUREMENT", | |
394 | "LC_IDENTIFICATION", "LC_ALL" }) { | |
395 | char* env_value = getenv(env_name); | |
396 | if (env_value) { | |
397 | server_args.push_back("-l"); | |
398 | server_args.push_back(string(env_name) + "=" + env_value); | |
399 | } | |
400 | } | |
401 | ||
188d1201 | 402 | if ( commands ) { |
e18a73fc | 403 | server_args.push_back( "--" ); |
188d1201 FF |
404 | server_args.insert( server_args.end(), command, command + commands ); |
405 | } | |
e18a73fc | 406 | |
188d1201 FF |
407 | string quoted_self = shell_quote_string( string( argv[0] ) ); |
408 | string quoted_server_args = shell_quote( server_args ); | |
409 | fflush( stdout ); | |
410 | ||
257ccdad GS |
411 | string proxy_arg = "ProxyCommand=" + quoted_self; |
412 | if (force_ipv6) { | |
413 | proxy_arg += " -6"; | |
414 | } | |
415 | proxy_arg += " --fake-proxy -- %h %p"; | |
188d1201 FF |
416 | string ssh_remote_command = server + " " + quoted_server_args; |
417 | ||
418 | vector<string> ssh_args; | |
e18a73fc FF |
419 | ssh_args.push_back( "-n" ); |
420 | ssh_args.push_back( "-tt" ); | |
188d1201 FF |
421 | ssh_args.push_back( "-S" ); |
422 | ssh_args.push_back( "none" ); | |
423 | ssh_args.push_back( "-o" ); | |
424 | ssh_args.push_back( proxy_arg ); | |
188d1201 FF |
425 | ssh_args.push_back( userhost ); |
426 | if ( ssh_port.size() ) { | |
427 | ssh_args.push_back( "-p" ); | |
428 | ssh_args.push_back( ssh_port ); | |
429 | } | |
257ccdad GS |
430 | if ( force_ipv6 ) { |
431 | ssh_args.push_back( "-6" ); | |
432 | } | |
188d1201 FF |
433 | ssh_args.push_back( "--" ); |
434 | ssh_args.push_back( ssh_remote_command ); | |
435 | ||
436 | string ssh_exec_string = ssh + " " + shell_quote( ssh_args ); | |
437 | ||
438 | int ret = execlp( "sh", "sh", "-c", ssh_exec_string.c_str(), (char *)NULL ); | |
439 | if ( ret == -1 ) { | |
440 | die( "Cannot exec ssh: %d", errno ); | |
441 | } | |
442 | } | |
443 | ||
444 | close( pty_slave ); | |
445 | string ip, port, key; | |
446 | ||
447 | FILE *pty_file = fdopen( pty, "r" ); | |
448 | string line; | |
449 | while ( ( n = getline( &buf, &buf_sz, pty_file ) ) >= 0 ) { | |
450 | line = string( buf, n ); | |
451 | line = line.erase( line.find_last_not_of( "\n" ) ); | |
452 | if ( line.compare( 0, 8, "MOSH IP " ) == 0 ) { | |
453 | size_t ip_end = line.find_last_not_of( " \t\n\r" ); | |
454 | if ( ip_end != string::npos && ip_end >= 8 ) { | |
455 | ip = line.substr( 8, ip_end + 1 - 8 ); | |
456 | } | |
457 | } else if ( line.compare( 0, 13, "MOSH CONNECT " ) == 0 ) { | |
458 | size_t port_end = line.find_first_not_of( "0123456789", 13 ); | |
459 | if ( port_end != string::npos && port_end >= 13 ) { | |
460 | port = line.substr( 13, port_end - 13 ); | |
461 | } | |
462 | string rest = line.substr( port_end + 1 ); | |
463 | size_t key_end = rest.find_last_not_of( " \t\n\r" ); | |
464 | size_t key_valid_end = rest.find_last_of( key_valid_char_set ); | |
465 | if ( key_valid_end == key_end && key_end + 1 == 22 ) { | |
466 | key = rest.substr( 0, key_end + 1 ); | |
467 | } | |
468 | break; | |
469 | } else { | |
470 | printf( "%s\n", line.c_str() ); | |
471 | } | |
472 | } | |
473 | waitpid( pid, NULL, 0 ); | |
474 | ||
475 | if ( !ip.size() ) { | |
476 | die( "%s: Did not find remote IP address (is SSH ProxyCommand disabled?).", | |
477 | argv[0] ); | |
478 | } | |
479 | ||
480 | if ( !key.size() || !port.size() ) { | |
481 | die( "%s: Did not find mosh server startup message.", argv[0] ); | |
482 | } | |
483 | ||
484 | setenv( "MOSH_KEY", key.c_str(), 1 ); | |
485 | setenv( "MOSH_PREDICTION_DISPLAY", predict.c_str(), 1 ); | |
9d1ea50b | 486 | if (!term_init) setenv( "MOSH_NO_TERM_INIT", "1", 1 ); |
188d1201 FF |
487 | execlp( client.c_str(), client.c_str(), ip.c_str(), port.c_str(), (char *)NULL ); |
488 | } |