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 " --help this message\n"
99 " --version version and copyright information\n"
101 "Please report bugs to mosh-devel@mit.edu.\n"
102 "Mosh home page: http://mosh.mit.edu";
104 static const char *version_format
=
106 "Copyright 2012 Keith Winstein <mosh-devel@mit.edu>\n"
107 "License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.\n"
108 "This is free software: you are free to change and redistribute it.\n"
109 "There is NO WARRANTY, to the extent permitted by law.";
111 static const char *key_valid_char_set
=
112 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789/+";
116 void predict_check( const string
&predict
, bool env_set
)
118 if ( predict
!= "adaptive" &&
119 predict
!= "always" &&
120 predict
!= "never" ) {
121 fprintf( stderr
, "%s: Unknown mode \"%s\"%s.\n", argv0
, predict
.c_str(),
122 env_set ?
" (MOSH_PREDICTION_DISPLAY in environment)" : "" );
123 die( usage_format
, argv0
);
127 void cat( int ifd
, int ofd
)
132 n
= read( ifd
, buf
, sizeof( buf
) );
134 if (errno
== EINTR
) {
142 n
= write( ofd
, buf
, n
);
149 bool valid_port(string port
) {
151 return port
.find_first_not_of( "0123456789" ) == string
::npos
&&
152 atoi( port
.c_str() ) > 0 &&
153 atoi( port
.c_str() ) <= 65535;
155 return true; // consider no port to be the default value
158 int main( int argc
, char *argv
[] )
161 string client
= "mosh-client";
162 string server
= "mosh-server";
164 string predict
, port_request
, ssh_port
;
165 int help
=0, version
=0, fake_proxy
=0;
167 static struct option long_options
[] =
169 { "client", required_argument
, 0, 'c' },
170 { "server", required_argument
, 0, 's' },
171 { "predict", required_argument
, 0, 'r' },
172 { "port", required_argument
, 0, 'p' },
173 { "ssh-port", required_argument
, 0, 'P' },
174 { "ssh", required_argument
, 0, 'S' },
175 { "help", no_argument
, &help
, 1 },
176 { "version", no_argument
, &version
, 1 },
177 { "fake-proxy!", no_argument
, &fake_proxy
, 1 },
181 int option_index
= 0;
182 int c
= getopt_long( argc
, argv
, "anp:P:",
183 long_options
, &option_index
);
202 port_request
= optarg
;
217 die( usage_format
, argv
[0] );
222 die( usage_format
, argv
[0] );
225 die( version_format
, PACKAGE_VERSION
);
228 if ( predict
.size() ) {
229 predict_check( predict
, 0 );
230 } else if ( getenv( "MOSH_PREDICTION_DELAY" ) ) {
231 predict
= getenv( "MOSH_PREDICTION_DELAY" );
232 predict_check( predict
, 1 );
234 predict
= "adaptive";
235 predict_check( predict
, 0 );
238 if(!valid_port(port_request
)) {
239 die( "%s: Server-side port (%s) must be within valid range [0..65535].",
241 port_request
.c_str() );
244 if(!valid_port(ssh_port
)) {
245 die( "%s: SSH port (%s) must be within valid range [0..65535].",
250 unsetenv( "MOSH_PREDICTION_DISPLAY" );
253 string host
= argv
[optind
++];
254 string port
= argv
[optind
++];
257 struct addrinfo hints
, *servinfo
, *p
;
260 memset( &hints
, 0, sizeof( hints
) );
261 hints
.ai_socktype
= SOCK_STREAM
;
263 if ( ( rv
= getaddrinfo( host
.c_str(),
266 &servinfo
) ) != 0 ) {
267 die( "%s: Could not resolve hostname %s: getaddrinfo: %s",
270 gai_strerror( rv
) );
273 int try_family
= AF_INET
;
274 // loop through all the results and connect to the first we can
275 for ( p
= servinfo
; p
!= NULL
|| try_family
== AF_INET
; p
= p
->ai_next
) {
276 if(p
== NULL
&& try_family
== AF_INET
) { // start over and try AF_INET6
278 try_family
= AF_INET6
;
281 break; // servinfo == NULL
284 if(p
->ai_family
!= try_family
) {
288 if ( ( sockfd
= socket( p
->ai_family
, SOCK_STREAM
, IPPROTO_TCP
) ) == -1 ) {
292 if ( connect( sockfd
, p
->ai_addr
, p
->ai_addrlen
) == -1 ) {
297 char host
[NI_MAXHOST
], service
[NI_MAXSERV
];
298 if ( getnameinfo( p
->ai_addr
, p
->ai_addrlen
,
301 NI_NUMERICSERV
| NI_NUMERICHOST
) == -1 ) {
302 die( "Couldn't get host name info" );
305 fprintf( stderr
, "MOSH IP %s\n", host
);
306 break; // if we get here, we must have connected successfully
310 // looped off the end of the list with no connection
311 die( "%s: failed to connect to host %s port %s",
312 argv
[0], host
.c_str(), port
.c_str() );
315 freeaddrinfo( servinfo
); // all done with this structure
318 if ( pid
== -1 ) die( "%s: fork: %d", argv
[0], errno
);
320 close( STDIN_FILENO
);
321 cat( sockfd
, STDOUT_FILENO
);
322 shutdown( sockfd
, 0 );
325 signal( SIGHUP
, SIG_IGN
);
326 close( STDOUT_FILENO
);
327 cat( STDIN_FILENO
, sockfd
);
328 shutdown( sockfd
, SHUT_WR
/* = 1 */ );
329 close( STDIN_FILENO
);
330 waitpid( pid
, NULL
, 0 );
334 if ( argc
- optind
< 1 ) {
335 die( usage_format
, argv
[0] );
338 string userhost
= argv
[optind
++];
339 char **command
= &argv
[optind
];
340 int commands
= argc
- optind
;
342 string color_invocation
= client
+ " -c";
343 FILE *color_file
= popen( color_invocation
.c_str(), "r" );
344 if ( !color_file
) die( "%s: popen: %d", argv
[0], errno
);
348 if ( ( n
= getline( &buf
, &buf_sz
, color_file
) ) < 0 ) {
349 die( "%s: Can't count colors: %d", argv
[0], errno
);
351 // Chomp the trailing newline:
352 if ( n
> 0 && buf
[n
- 1] == '\n' ) n
--;
353 string colors
= string( buf
, n
);
354 pclose( color_file
);
356 if ( !colors
.size() ||
357 colors
.find_first_not_of( "0123456789" ) != string
::npos
||
358 atoi( colors
.c_str() ) < 0 ) {
364 if ( ioctl( 0, TIOCGWINSZ
, &ws
) == -1 ) {
365 die( "%s: ioctl: %d", argv
[0], errno
);
368 if ( openpty( &pty
, &pty_slave
, NULL
, NULL
, &ws
) == -1 ) {
369 die( "%s: openpty: %d", argv
[0], errno
);
373 if ( pid
== -1 ) die( "%s: fork: %d", argv
[0], errno
);
376 if ( -1 == dup2( pty_slave
, 1 ) ||
377 -1 == dup2( pty_slave
, 2 ) ) {
378 die( "%s: dup2: %d", argv
[0], errno
);
382 vector
<string
> server_args
;
383 server_args
.push_back( "new" );
384 server_args
.push_back( "-s" );
385 server_args
.push_back( "-c" );
386 server_args
.push_back( colors
);
387 if ( port_request
.size() ) {
388 server_args
.push_back( "-p" );
389 server_args
.push_back( port_request
);
392 for (char const* env_name
: {
393 "LANG", "LANGUAGE", "LC_CTYPE", "LC_NUMERIC",
394 "LC_TIME", "LC_COLLATE", "LC_MONETARY", "LC_MESSAGES", "LC_PAPER",
395 "LC_NAME", "LC_ADDRESS", "LC_TELEPHONE", "LC_MEASUREMENT",
396 "LC_IDENTIFICATION", "LC_ALL" }) {
397 char* env_value
= getenv(env_name
);
399 server_args
.push_back("-l");
400 server_args
.push_back(string(env_name
) + "=" + env_value
);
405 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
+ " --fake-proxy -- %h %p";
412 string ssh_remote_command
= server
+ " " + quoted_server_args
;
414 vector
<string
> ssh_args
;
415 ssh_args
.push_back( "-S" );
416 ssh_args
.push_back( "none" );
417 ssh_args
.push_back( "-o" );
418 ssh_args
.push_back( proxy_arg
);
419 ssh_args
.push_back( "-t" );
420 ssh_args
.push_back( userhost
);
421 if ( ssh_port
.size() ) {
422 ssh_args
.push_back( "-p" );
423 ssh_args
.push_back( ssh_port
);
425 ssh_args
.push_back( "--" );
426 ssh_args
.push_back( ssh_remote_command
);
428 string ssh_exec_string
= ssh
+ " " + shell_quote( ssh_args
);
430 int ret
= execlp( "sh", "sh", "-c", ssh_exec_string
.c_str(), (char *)NULL
);
432 die( "Cannot exec ssh: %d", errno
);
437 string ip
, port
, key
;
439 FILE *pty_file
= fdopen( pty
, "r" );
441 while ( ( n
= getline( &buf
, &buf_sz
, pty_file
) ) >= 0 ) {
442 line
= string( buf
, n
);
443 line
= line
.erase( line
.find_last_not_of( "\n" ) );
444 if ( line
.compare( 0, 8, "MOSH IP " ) == 0 ) {
445 size_t ip_end
= line
.find_last_not_of( " \t\n\r" );
446 if ( ip_end
!= string
::npos
&& ip_end
>= 8 ) {
447 ip
= line
.substr( 8, ip_end
+ 1 - 8 );
449 } else if ( line
.compare( 0, 13, "MOSH CONNECT " ) == 0 ) {
450 size_t port_end
= line
.find_first_not_of( "0123456789", 13 );
451 if ( port_end
!= string
::npos
&& port_end
>= 13 ) {
452 port
= line
.substr( 13, port_end
- 13 );
454 string rest
= line
.substr( port_end
+ 1 );
455 size_t key_end
= rest
.find_last_not_of( " \t\n\r" );
456 size_t key_valid_end
= rest
.find_last_of( key_valid_char_set
);
457 if ( key_valid_end
== key_end
&& key_end
+ 1 == 22 ) {
458 key
= rest
.substr( 0, key_end
+ 1 );
462 printf( "%s\n", line
.c_str() );
465 waitpid( pid
, NULL
, 0 );
468 die( "%s: Did not find remote IP address (is SSH ProxyCommand disabled?).",
472 if ( !key
.size() || !port
.size() ) {
473 die( "%s: Did not find mosh server startup message.", argv
[0] );
476 setenv( "MOSH_KEY", key
.c_str(), 1 );
477 setenv( "MOSH_PREDICTION_DISPLAY", predict
.c_str(), 1 );
478 execlp( client
.c_str(), client
.c_str(), ip
.c_str(), port
.c_str(), (char *)NULL
);