1 // Mosh: the mobile shell
2 // Copyright 2012 Keith Winstein
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.
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.
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/>.
26 #include <sys/socket.h>
28 #include <arpa/inet.h>
32 #include <sys/ioctl.h>
33 #include <sys/types.h>
40 inline string
shell_quote_string( const string
&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
) {
49 rest
= rest
.substr( good_part
+ 1 );
57 template <typename SequenceT
>
58 inline string
shell_quote( const SequenceT
&sequence
)
61 for ( typename SequenceT
::const_iterator i
= sequence
.begin();
64 result
+= shell_quote_string( *i
) + " ";
66 return result
.substr( 0, result
.size() - 1 );
69 void die( const char *format
, ... ) {
71 va_start( args
, format
);
72 vfprintf( stderr
, format
, args
);
74 fprintf( stderr
, "\n" );
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"
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"
89 "-p NUM --port=NUM server-side UDP port\n"
91 "-P NUM --ssh-port=NUM ssh server port\n"
92 " (default: let the ssh command choose)\n"
94 " --ssh=COMMAND ssh command to run when setting up session\n"
95 " (example: \"ssh -p 2222\")\n"
96 " (default: \"ssh\")\n"
98 " --no-init do not send terminal initialization string\n"
100 " --help this message\n"
101 " --version version and copyright information\n"
103 "Please report bugs to mosh-devel@mit.edu.\n"
104 "Mosh home page: http://mosh.mit.edu";
106 static const char *version_format
=
108 "Copyright 2012 Keith Winstein <mosh-devel@mit.edu>\n"
109 "License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.\n"
110 "This is free software: you are free to change and redistribute it.\n"
111 "There is NO WARRANTY, to the extent permitted by law.";
113 static const char *key_valid_char_set
=
114 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789/+";
118 void predict_check( const string
&predict
, bool env_set
)
120 if ( predict
!= "adaptive" &&
121 predict
!= "always" &&
122 predict
!= "never" ) {
123 fprintf( stderr
, "%s: Unknown mode \"%s\"%s.\n", argv0
, predict
.c_str(),
124 env_set ?
" (MOSH_PREDICTION_DISPLAY in environment)" : "" );
125 die( usage_format
, argv0
);
129 void cat( int ifd
, int ofd
)
134 n
= read( ifd
, buf
, sizeof( buf
) );
136 if (errno
== EINTR
) {
144 n
= write( ofd
, buf
, n
);
151 bool valid_port(string port
) {
153 return port
.find_first_not_of( "0123456789" ) == string
::npos
&&
154 atoi( port
.c_str() ) > 0 &&
155 atoi( port
.c_str() ) <= 65535;
157 return true; // consider no port to be the default value
160 int main( int argc
, char *argv
[] )
163 string client
= "mosh-client";
164 string server
= "mosh-server";
166 string predict
, port_request
, ssh_port
;
167 int help
=0, version
=0, fake_proxy
=0, term_init
=1;
169 static struct option long_options
[] =
171 { "client", required_argument
, 0, 'c' },
172 { "server", required_argument
, 0, 's' },
173 { "no-init", no_argument
, &term_init
, 0 },
174 { "predict", required_argument
, 0, 'r' },
175 { "port", required_argument
, 0, 'p' },
176 { "ssh-port", required_argument
, 0, 'P' },
177 { "ssh", required_argument
, 0, 'S' },
178 { "help", no_argument
, &help
, 1 },
179 { "version", no_argument
, &version
, 1 },
180 { "fake-proxy", no_argument
, &fake_proxy
, 1 },
184 int option_index
= 0;
185 int c
= getopt_long( argc
, argv
, "anp:P:",
186 long_options
, &option_index
);
205 port_request
= optarg
;
220 die( usage_format
, argv
[0] );
225 die( usage_format
, argv
[0] );
228 die( version_format
, PACKAGE_VERSION
);
231 if ( predict
.size() ) {
232 predict_check( predict
, 0 );
233 } else if ( getenv( "MOSH_PREDICTION_DELAY" ) ) {
234 predict
= getenv( "MOSH_PREDICTION_DELAY" );
235 predict_check( predict
, 1 );
237 predict
= "adaptive";
238 predict_check( predict
, 0 );
241 if(!valid_port(port_request
)) {
242 die( "%s: Server-side port (%s) must be within valid range [0..65535].",
244 port_request
.c_str() );
247 if(!valid_port(ssh_port
)) {
248 die( "%s: SSH port (%s) must be within valid range [0..65535].",
253 unsetenv( "MOSH_PREDICTION_DISPLAY" );
256 string host
= argv
[optind
++];
257 string port
= argv
[optind
++];
260 struct addrinfo hints
, *servinfo
, *p
;
263 memset( &hints
, 0, sizeof( hints
) );
264 hints
.ai_socktype
= SOCK_STREAM
;
266 if ( ( rv
= getaddrinfo( host
.c_str(),
269 &servinfo
) ) != 0 ) {
270 die( "%s: Could not resolve hostname %s: getaddrinfo: %s",
273 gai_strerror( rv
) );
276 int try_family
= AF_INET
;
277 // loop through all the results and connect to the first we can
278 for ( p
= servinfo
; p
!= NULL
|| try_family
== AF_INET
; p
= p
->ai_next
) {
279 if(p
== NULL
&& try_family
== AF_INET
) { // start over and try AF_INET6
281 try_family
= AF_INET6
;
284 break; // servinfo == NULL
287 if(p
->ai_family
!= try_family
) {
291 if ( ( sockfd
= socket( p
->ai_family
, SOCK_STREAM
, IPPROTO_TCP
) ) == -1 ) {
295 if ( connect( sockfd
, p
->ai_addr
, p
->ai_addrlen
) == -1 ) {
300 char host
[NI_MAXHOST
], service
[NI_MAXSERV
];
301 if ( getnameinfo( p
->ai_addr
, p
->ai_addrlen
,
304 NI_NUMERICSERV
| NI_NUMERICHOST
) == -1 ) {
305 die( "Couldn't get host name info" );
308 fprintf( stderr
, "MOSH IP %s\n", host
);
309 break; // if we get here, we must have connected successfully
313 // looped off the end of the list with no connection
314 die( "%s: failed to connect to host %s port %s",
315 argv
[0], host
.c_str(), port
.c_str() );
318 freeaddrinfo( servinfo
); // all done with this structure
321 if ( pid
== -1 ) die( "%s: fork: %d", argv
[0], errno
);
323 close( STDIN_FILENO
);
324 cat( sockfd
, STDOUT_FILENO
);
325 shutdown( sockfd
, 0 );
328 signal( SIGHUP
, SIG_IGN
);
329 close( STDOUT_FILENO
);
330 cat( STDIN_FILENO
, sockfd
);
331 shutdown( sockfd
, SHUT_WR
/* = 1 */ );
332 close( STDIN_FILENO
);
333 waitpid( pid
, NULL
, 0 );
337 if ( argc
- optind
< 1 ) {
338 die( usage_format
, argv
[0] );
341 string userhost
= argv
[optind
++];
342 char **command
= &argv
[optind
];
343 int commands
= argc
- optind
;
351 if ( ioctl( 0, TIOCGWINSZ
, &ws
) == -1 ) {
352 die( "%s: ioctl: %d", argv
[0], errno
);
355 if ( openpty( &pty
, &pty_slave
, NULL
, NULL
, &ws
) == -1 ) {
356 die( "%s: openpty: %d", argv
[0], errno
);
360 if ( pid
== -1 ) die( "%s: fork: %d", argv
[0], errno
);
363 if ( -1 == dup2( pty_slave
, 1 ) ||
364 -1 == dup2( pty_slave
, 2 ) ) {
365 die( "%s: dup2: %d", argv
[0], errno
);
369 vector
<string
> server_args
;
370 server_args
.push_back( "new" );
371 server_args
.push_back( "-c" );
372 server_args
.push_back( "256" );
373 server_args
.push_back( "-s" );
374 if ( port_request
.size() ) {
375 server_args
.push_back( "-p" );
376 server_args
.push_back( port_request
);
379 for (char const* env_name
: {
380 "LANG", "LANGUAGE", "LC_CTYPE", "LC_NUMERIC",
381 "LC_TIME", "LC_COLLATE", "LC_MONETARY", "LC_MESSAGES", "LC_PAPER",
382 "LC_NAME", "LC_ADDRESS", "LC_TELEPHONE", "LC_MEASUREMENT",
383 "LC_IDENTIFICATION", "LC_ALL" }) {
384 char* env_value
= getenv(env_name
);
386 server_args
.push_back("-l");
387 server_args
.push_back(string(env_name
) + "=" + env_value
);
392 server_args
.push_back( "--" );
393 server_args
.insert( server_args
.end(), command
, command
+ commands
);
396 string quoted_self
= shell_quote_string( string( argv
[0] ) );
397 string quoted_server_args
= shell_quote( server_args
);
400 string proxy_arg
= "ProxyCommand=" + quoted_self
+ " --fake-proxy -- %h %p";
401 string ssh_remote_command
= server
+ " " + quoted_server_args
;
403 vector
<string
> ssh_args
;
404 ssh_args
.push_back( "-n" );
405 ssh_args
.push_back( "-tt" );
406 ssh_args
.push_back( "-S" );
407 ssh_args
.push_back( "none" );
408 ssh_args
.push_back( "-o" );
409 ssh_args
.push_back( proxy_arg
);
410 ssh_args
.push_back( userhost
);
411 if ( ssh_port
.size() ) {
412 ssh_args
.push_back( "-p" );
413 ssh_args
.push_back( ssh_port
);
415 ssh_args
.push_back( "--" );
416 ssh_args
.push_back( ssh_remote_command
);
418 string ssh_exec_string
= ssh
+ " " + shell_quote( ssh_args
);
420 int ret
= execlp( "sh", "sh", "-c", ssh_exec_string
.c_str(), (char *)NULL
);
422 die( "Cannot exec ssh: %d", errno
);
427 string ip
, port
, key
;
429 FILE *pty_file
= fdopen( pty
, "r" );
431 while ( ( n
= getline( &buf
, &buf_sz
, pty_file
) ) >= 0 ) {
432 line
= string( buf
, n
);
433 line
= line
.erase( line
.find_last_not_of( "\n" ) );
434 if ( line
.compare( 0, 8, "MOSH IP " ) == 0 ) {
435 size_t ip_end
= line
.find_last_not_of( " \t\n\r" );
436 if ( ip_end
!= string
::npos
&& ip_end
>= 8 ) {
437 ip
= line
.substr( 8, ip_end
+ 1 - 8 );
439 } else if ( line
.compare( 0, 13, "MOSH CONNECT " ) == 0 ) {
440 size_t port_end
= line
.find_first_not_of( "0123456789", 13 );
441 if ( port_end
!= string
::npos
&& port_end
>= 13 ) {
442 port
= line
.substr( 13, port_end
- 13 );
444 string rest
= line
.substr( port_end
+ 1 );
445 size_t key_end
= rest
.find_last_not_of( " \t\n\r" );
446 size_t key_valid_end
= rest
.find_last_of( key_valid_char_set
);
447 if ( key_valid_end
== key_end
&& key_end
+ 1 == 22 ) {
448 key
= rest
.substr( 0, key_end
+ 1 );
452 printf( "%s\n", line
.c_str() );
455 waitpid( pid
, NULL
, 0 );
458 die( "%s: Did not find remote IP address (is SSH ProxyCommand disabled?).",
462 if ( !key
.size() || !port
.size() ) {
463 die( "%s: Did not find mosh server startup message.", argv
[0] );
466 setenv( "MOSH_KEY", key
.c_str(), 1 );
467 setenv( "MOSH_PREDICTION_DISPLAY", predict
.c_str(), 1 );
468 if (!term_init
) setenv( "MOSH_NO_TERM_INIT", "1", 1 );
469 execlp( client
.c_str(), client
.c_str(), ip
.c_str(), port
.c_str(), (char *)NULL
);