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"
90 "-p NUM --port=NUM server-side UDP port\n"
92 "-P NUM --ssh-port=NUM ssh server port\n"
93 " (default: let the ssh command choose)\n"
95 " --ssh=COMMAND ssh command to run when setting up session\n"
96 " (example: \"ssh -p 2222\")\n"
97 " (default: \"ssh\")\n"
99 " --no-init do not send terminal initialization string\n"
101 " --help this message\n"
102 " --version version and copyright information\n"
104 "Please report bugs to mosh-devel@mit.edu.\n"
105 "Mosh home page: http://mosh.mit.edu";
107 static const char *version_format
=
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.";
114 static const char *key_valid_char_set
=
115 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789/+";
119 void predict_check( const string
&predict
, bool env_set
)
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
);
130 void cat( int ifd
, int ofd
)
135 n
= read( ifd
, buf
, sizeof( buf
) );
137 if (errno
== EINTR
) {
145 n
= write( ofd
, buf
, n
);
152 bool valid_port(string port
) {
154 return port
.find_first_not_of( "0123456789" ) == string
::npos
&&
155 atoi( port
.c_str() ) > 0 &&
156 atoi( port
.c_str() ) <= 65535;
158 return true; // consider no port to be the default value
161 int main( int argc
, char *argv
[] )
164 string client
= "mosh-client";
165 string server
= "mosh-server";
167 string predict
, port_request
, ssh_port
;
168 int help
=0, version
=0, fake_proxy
=0, term_init
=1;
171 static struct option long_options
[] =
173 { "client", required_argument
, 0, 'c' },
174 { "server", required_argument
, 0, 's' },
175 { "no-init", no_argument
, &term_init
, 0 },
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 },
182 { "fake-proxy", no_argument
, &fake_proxy
, 1 },
186 int option_index
= 0;
187 int c
= getopt_long( argc
, argv
, "6anp:P:",
188 long_options
, &option_index
);
207 port_request
= optarg
;
225 die( usage_format
, argv
[0] );
230 die( usage_format
, argv
[0] );
233 die( version_format
, PACKAGE_VERSION
);
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 );
242 predict
= "adaptive";
243 predict_check( predict
, 0 );
246 if(!valid_port(port_request
)) {
247 die( "%s: Server-side port (%s) must be within valid range [0..65535].",
249 port_request
.c_str() );
252 if(!valid_port(ssh_port
)) {
253 die( "%s: SSH port (%s) must be within valid range [0..65535].",
258 unsetenv( "MOSH_PREDICTION_DISPLAY" );
261 string host
= argv
[optind
++];
262 string port
= argv
[optind
++];
265 struct addrinfo hints
, *servinfo
, *p
;
268 memset( &hints
, 0, sizeof( hints
) );
269 hints
.ai_socktype
= SOCK_STREAM
;
271 hints
.ai_family
= AF_INET6
;
274 if ( ( rv
= getaddrinfo( host
.c_str(),
277 &servinfo
) ) != 0 ) {
278 die( "%s: Could not resolve hostname %s: getaddrinfo: %s",
281 gai_strerror( rv
) );
284 int try_family
= AF_INET
;
286 try_family
= AF_INET6
;
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
292 try_family
= AF_INET6
;
295 break; // servinfo == NULL
298 if(p
->ai_family
!= try_family
) {
302 if ( ( sockfd
= socket( p
->ai_family
, SOCK_STREAM
, IPPROTO_TCP
) ) == -1 ) {
306 if ( connect( sockfd
, p
->ai_addr
, p
->ai_addrlen
) == -1 ) {
311 char host
[NI_MAXHOST
], service
[NI_MAXSERV
];
312 if ( getnameinfo( p
->ai_addr
, p
->ai_addrlen
,
315 NI_NUMERICSERV
| NI_NUMERICHOST
) == -1 ) {
316 die( "Couldn't get host name info" );
319 fprintf( stderr
, "MOSH IP %s\n", host
);
320 break; // if we get here, we must have connected successfully
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() );
329 freeaddrinfo( servinfo
); // all done with this structure
332 if ( pid
== -1 ) die( "%s: fork: %d", argv
[0], errno
);
334 close( STDIN_FILENO
);
335 cat( sockfd
, STDOUT_FILENO
);
336 shutdown( sockfd
, 0 );
339 signal( SIGHUP
, SIG_IGN
);
340 close( STDOUT_FILENO
);
341 cat( STDIN_FILENO
, sockfd
);
342 shutdown( sockfd
, SHUT_WR
/* = 1 */ );
343 close( STDIN_FILENO
);
344 waitpid( pid
, NULL
, 0 );
348 if ( argc
- optind
< 1 ) {
349 die( usage_format
, argv
[0] );
352 string userhost
= argv
[optind
++];
353 char **command
= &argv
[optind
];
354 int commands
= argc
- optind
;
362 if ( ioctl( 0, TIOCGWINSZ
, &ws
) == -1 ) {
363 die( "%s: ioctl: %d", argv
[0], errno
);
366 if ( openpty( &pty
, &pty_slave
, NULL
, NULL
, &ws
) == -1 ) {
367 die( "%s: openpty: %d", argv
[0], errno
);
371 if ( pid
== -1 ) die( "%s: fork: %d", argv
[0], errno
);
374 if ( -1 == dup2( pty_slave
, 1 ) ||
375 -1 == dup2( pty_slave
, 2 ) ) {
376 die( "%s: dup2: %d", argv
[0], errno
);
380 vector
<string
> server_args
;
381 server_args
.push_back( "new" );
382 server_args
.push_back( "-c" );
383 server_args
.push_back( "256" );
384 server_args
.push_back( "-s" );
385 if ( port_request
.size() ) {
386 server_args
.push_back( "-p" );
387 server_args
.push_back( port_request
);
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
);
397 server_args
.push_back("-l");
398 server_args
.push_back(string(env_name
) + "=" + env_value
);
403 server_args
.push_back( "--" );
404 server_args
.insert( server_args
.end(), command
, command
+ commands
);
407 string quoted_self
= shell_quote_string( string( argv
[0] ) );
408 string quoted_server_args
= shell_quote( server_args
);
411 string proxy_arg
= "ProxyCommand=" + quoted_self
;
415 proxy_arg
+= " --fake-proxy -- %h %p";
416 string ssh_remote_command
= server
+ " " + quoted_server_args
;
418 vector
<string
> ssh_args
;
419 ssh_args
.push_back( "-n" );
420 ssh_args
.push_back( "-tt" );
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
);
425 ssh_args
.push_back( userhost
);
426 if ( ssh_port
.size() ) {
427 ssh_args
.push_back( "-p" );
428 ssh_args
.push_back( ssh_port
);
431 ssh_args
.push_back( "-6" );
433 ssh_args
.push_back( "--" );
434 ssh_args
.push_back( ssh_remote_command
);
436 string ssh_exec_string
= ssh
+ " " + shell_quote( ssh_args
);
438 int ret
= execlp( "sh", "sh", "-c", ssh_exec_string
.c_str(), (char *)NULL
);
440 die( "Cannot exec ssh: %d", errno
);
445 string ip
, port
, key
;
447 FILE *pty_file
= fdopen( pty
, "r" );
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 );
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 );
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 );
470 printf( "%s\n", line
.c_str() );
473 waitpid( pid
, NULL
, 0 );
476 die( "%s: Did not find remote IP address (is SSH ProxyCommand disabled?).",
480 if ( !key
.size() || !port
.size() ) {
481 die( "%s: Did not find mosh server startup message.", argv
[0] );
484 setenv( "MOSH_KEY", key
.c_str(), 1 );
485 setenv( "MOSH_PREDICTION_DISPLAY", predict
.c_str(), 1 );
486 if (!term_init
) setenv( "MOSH_NO_TERM_INIT", "1", 1 );
487 execlp( client
.c_str(), client
.c_str(), ip
.c_str(), port
.c_str(), (char *)NULL
);