| 1 | --- ../mosh/src/frontend/mosh.cc 2016-04-29 00:42:24.837700203 +1000 |
| 2 | +++ ./src/frontend/mosh.cc 2016-04-29 00:40:13.346294286 +1000 |
| 3 | @@ -0,0 +1,519 @@ |
| 4 | +// Mosh: the mobile shell |
| 5 | +// Copyright 2012 Keith Winstein |
| 6 | +// |
| 7 | +// This program is free software: you can redistribute it and/or modify |
| 8 | +// it under the terms of the GNU General Public License as published by |
| 9 | +// the Free Software Foundation, either version 3 of the License, or |
| 10 | +// (at your option) any later version. |
| 11 | +// |
| 12 | +// This program is distributed in the hope that it will be useful, |
| 13 | +// but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | +// GNU General Public License for more details. |
| 16 | +// |
| 17 | +// You should have received a copy of the GNU General Public License |
| 18 | +// along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 19 | + |
| 20 | +#include "config.h" |
| 21 | +#include <limits.h> |
| 22 | +#include <unistd.h> |
| 23 | +#include <stdlib.h> |
| 24 | +#include <stdarg.h> |
| 25 | +#include <string.h> |
| 26 | +#include <vector> |
| 27 | +#include <map> |
| 28 | +#include <stdio.h> |
| 29 | +#include <string> |
| 30 | +#include <sys/socket.h> |
| 31 | +#include <getopt.h> |
| 32 | +#include <arpa/inet.h> |
| 33 | +#include <netdb.h> |
| 34 | +#include <signal.h> |
| 35 | +#include <errno.h> |
| 36 | +#include <sys/ioctl.h> |
| 37 | +#include <sys/types.h> |
| 38 | +#include <sys/wait.h> |
| 39 | +#include <termios.h> |
| 40 | +#if HAVE_PTY_H |
| 41 | +#include <pty.h> |
| 42 | +#elif HAVE_UTIL_H |
| 43 | +#include <util.h> |
| 44 | +#endif |
| 45 | + |
| 46 | +#if OPENPTY_IN_LIBUTIL |
| 47 | +#include <libutil.h> |
| 48 | +#endif |
| 49 | + |
| 50 | +#if !HAVE_GETLINE |
| 51 | +ssize_t getline( char ** restrict linep, |
| 52 | + size_t * restrict linecapp, |
| 53 | + FILE * restrict stream ) { |
| 54 | + size_t num_read = 0; |
| 55 | + if ( !linep || !linecapp ) { |
| 56 | + errno = EINVAL; |
| 57 | + return -1; |
| 58 | + } |
| 59 | + if ( !*linep ) { |
| 60 | + *linecapp = 0; |
| 61 | + } |
| 62 | + while ( 1 ) { |
| 63 | + int ch = getc( stream ); |
| 64 | + if ( ch == EOF ) { |
| 65 | + return num_read ? (ssize_t)num_read : -1; |
| 66 | + } |
| 67 | + if ( num_read + 1 >= *linecapp ) { |
| 68 | + char *new_line = *linep; |
| 69 | + size_t new_linecap = *linecapp; |
| 70 | + if ( *linecapp > SSIZE_MAX - 4096 ) { |
| 71 | + errno = EOVERFLOW; |
| 72 | + return -1; |
| 73 | + } |
| 74 | + new_linecap += 4096; |
| 75 | + new_line = (char *)realloc( new_line, new_linecap ); |
| 76 | + if ( !new_line ) { |
| 77 | + return -1; |
| 78 | + } |
| 79 | + *linecapp = new_linecap; |
| 80 | + *linep = new_line; |
| 81 | + } |
| 82 | + (*linep)[num_read++] = ch; |
| 83 | + // so that we can safely return at any time, |
| 84 | + (*linep)[num_read] = '\0'; |
| 85 | + if (ch == '\n') { |
| 86 | + return num_read; |
| 87 | + } |
| 88 | + } |
| 89 | + return -1; |
| 90 | +} |
| 91 | +#endif |
| 92 | + |
| 93 | +using namespace std; |
| 94 | + |
| 95 | +inline string shell_quote_string( const string &x ) |
| 96 | +{ |
| 97 | + string result = "'"; |
| 98 | + string rest = x; |
| 99 | + while ( rest.size() ) { |
| 100 | + size_t good_part = rest.find( "'" ); |
| 101 | + result += rest.substr( 0, good_part ); |
| 102 | + if ( good_part != string::npos ) { |
| 103 | + result += "'\\''"; |
| 104 | + rest = rest.substr( good_part + 1 ); |
| 105 | + } else { |
| 106 | + break; |
| 107 | + } |
| 108 | + } |
| 109 | + return result + "'"; |
| 110 | +} |
| 111 | + |
| 112 | +template <typename SequenceT> |
| 113 | +inline string shell_quote( const SequenceT &sequence ) |
| 114 | +{ |
| 115 | + string result; |
| 116 | + for ( typename SequenceT::const_iterator i = sequence.begin(); |
| 117 | + i != sequence.end(); |
| 118 | + i++ ) { |
| 119 | + result += shell_quote_string( *i ) + " "; |
| 120 | + } |
| 121 | + return result.substr( 0, result.size() - 1 ); |
| 122 | +} |
| 123 | + |
| 124 | +void die( const char *format, ... ) { |
| 125 | + va_list args; |
| 126 | + va_start( args, format ); |
| 127 | + vfprintf( stderr, format, args ); |
| 128 | + va_end( args ); |
| 129 | + fprintf( stderr, "\n" ); |
| 130 | + exit( 255 ); |
| 131 | +} |
| 132 | + |
| 133 | +static const char *usage_format = |
| 134 | +"Usage: %s [options] [--] [user@]host [command...]\n" |
| 135 | +" --client=PATH mosh client on local machine\n" |
| 136 | +" (default: mosh-client)\n" |
| 137 | +" --server=PATH mosh server on remote machine\n" |
| 138 | +" (default: mosh-server)\n" |
| 139 | +"\n" |
| 140 | +" --predict=adaptive local echo for slower links [default]\n" |
| 141 | +"-a --predict=always use local echo even on fast links\n" |
| 142 | +"-n --predict=never never use local echo\n" |
| 143 | +"\n" |
| 144 | +"-p NUM --port=NUM server-side UDP port\n" |
| 145 | +"\n" |
| 146 | +"-P NUM --ssh-port=NUM ssh server port\n" |
| 147 | +" (default: let the ssh command choose)\n" |
| 148 | +"\n" |
| 149 | +" --ssh=COMMAND ssh command to run when setting up session\n" |
| 150 | +" (example: \"ssh -p 2222\")\n" |
| 151 | +" (default: \"ssh\")\n" |
| 152 | +"\n" |
| 153 | +" --help this message\n" |
| 154 | +" --version version and copyright information\n" |
| 155 | +"\n" |
| 156 | +"Please report bugs to mosh-devel@mit.edu.\n" |
| 157 | +"Mosh home page: http://mosh.mit.edu"; |
| 158 | + |
| 159 | +static const char *version_format = |
| 160 | +"mosh %s\n" |
| 161 | +"Copyright 2012 Keith Winstein <mosh-devel@mit.edu>\n" |
| 162 | +"License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.\n" |
| 163 | +"This is free software: you are free to change and redistribute it.\n" |
| 164 | +"There is NO WARRANTY, to the extent permitted by law."; |
| 165 | + |
| 166 | +static const char *key_valid_char_set = |
| 167 | +"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789/+"; |
| 168 | + |
| 169 | +static char *argv0; |
| 170 | + |
| 171 | +void predict_check( const string &predict, bool env_set ) |
| 172 | +{ |
| 173 | + if ( predict != "adaptive" && |
| 174 | + predict != "always" && |
| 175 | + predict != "never" ) { |
| 176 | + fprintf( stderr, "%s: Unknown mode \"%s\"%s.\n", argv0, predict.c_str(), |
| 177 | + env_set ? " (MOSH_PREDICTION_DISPLAY in environment)" : "" ); |
| 178 | + die( usage_format, argv0 ); |
| 179 | + } |
| 180 | +} |
| 181 | + |
| 182 | +void cat( int ifd, int ofd ) |
| 183 | +{ |
| 184 | + char buf[4096]; |
| 185 | + ssize_t n; |
| 186 | + while ( 1 ) { |
| 187 | + n = read( ifd, buf, sizeof( buf ) ); |
| 188 | + if ( n==-1 ) { |
| 189 | + if (errno == EINTR ) { |
| 190 | + continue; |
| 191 | + } |
| 192 | + break; |
| 193 | + } |
| 194 | + if ( n==0 ) { |
| 195 | + break; |
| 196 | + } |
| 197 | + n = write( ofd, buf, n ); |
| 198 | + if ( n==-1 ) { |
| 199 | + break; |
| 200 | + } |
| 201 | + } |
| 202 | +} |
| 203 | + |
| 204 | +bool valid_port(string port) { |
| 205 | + if ( port.size() ) { |
| 206 | + return port.find_first_not_of( "0123456789" ) == string::npos && |
| 207 | + atoi( port.c_str() ) > 0 && |
| 208 | + atoi( port.c_str() ) <= 65535; |
| 209 | + } |
| 210 | + return true; // consider no port to be the default value |
| 211 | +} |
| 212 | + |
| 213 | +int main( int argc, char *argv[] ) |
| 214 | +{ |
| 215 | + argv0 = argv[0]; |
| 216 | + string client = "mosh-client"; |
| 217 | + string server = "mosh-server"; |
| 218 | + string ssh = "ssh"; |
| 219 | + string predict, port_request, ssh_port; |
| 220 | + int help=0, version=0, fake_proxy=0; |
| 221 | + |
| 222 | + static struct option long_options[] = |
| 223 | + { |
| 224 | + { "client", required_argument, 0, 'c' }, |
| 225 | + { "server", required_argument, 0, 's' }, |
| 226 | + { "predict", required_argument, 0, 'r' }, |
| 227 | + { "port", required_argument, 0, 'p' }, |
| 228 | + { "ssh-port", required_argument, 0, 'P' }, |
| 229 | + { "ssh", required_argument, 0, 'S' }, |
| 230 | + { "help", no_argument, &help, 1 }, |
| 231 | + { "version", no_argument, &version, 1 }, |
| 232 | + { "fake-proxy!", no_argument, &fake_proxy, 1 }, |
| 233 | + { 0, 0, 0, 0 } |
| 234 | + }; |
| 235 | + while ( 1 ) { |
| 236 | + int option_index = 0; |
| 237 | + int c = getopt_long( argc, argv, "anp:P:", |
| 238 | + long_options, &option_index ); |
| 239 | + if ( c == -1 ) { |
| 240 | + break; |
| 241 | + } |
| 242 | + |
| 243 | + switch ( c ) { |
| 244 | + case 0: |
| 245 | + // flag has been set |
| 246 | + break; |
| 247 | + case 'c': |
| 248 | + client = optarg; |
| 249 | + break; |
| 250 | + case 's': |
| 251 | + server = optarg; |
| 252 | + break; |
| 253 | + case 'r': |
| 254 | + predict = optarg; |
| 255 | + break; |
| 256 | + case 'p': |
| 257 | + port_request = optarg; |
| 258 | + break; |
| 259 | + case 'P': |
| 260 | + ssh_port = optarg; |
| 261 | + break; |
| 262 | + case 'S': |
| 263 | + ssh = optarg; |
| 264 | + break; |
| 265 | + case 'a': |
| 266 | + predict = "always"; |
| 267 | + break; |
| 268 | + case 'n': |
| 269 | + predict = "never"; |
| 270 | + break; |
| 271 | + default: |
| 272 | + die( usage_format, argv[0] ); |
| 273 | + } |
| 274 | + } |
| 275 | + |
| 276 | + if ( help ) { |
| 277 | + die( usage_format, argv[0] ); |
| 278 | + } |
| 279 | + if ( version ) { |
| 280 | + die( version_format, PACKAGE_VERSION ); |
| 281 | + } |
| 282 | + |
| 283 | + if ( predict.size() ) { |
| 284 | + predict_check( predict, 0 ); |
| 285 | + } else if ( getenv( "MOSH_PREDICTION_DELAY" ) ) { |
| 286 | + predict = getenv( "MOSH_PREDICTION_DELAY" ); |
| 287 | + predict_check( predict, 1 ); |
| 288 | + } else { |
| 289 | + predict = "adaptive"; |
| 290 | + predict_check( predict, 0 ); |
| 291 | + } |
| 292 | + |
| 293 | + if(!valid_port(port_request)) { |
| 294 | + die( "%s: Server-side port (%s) must be within valid range [0..65535].", |
| 295 | + argv[0], |
| 296 | + port_request.c_str() ); |
| 297 | + } |
| 298 | + |
| 299 | + if(!valid_port(ssh_port)) { |
| 300 | + die( "%s: SSH port (%s) must be within valid range [0..65535].", |
| 301 | + argv[0], |
| 302 | + ssh_port.c_str() ); |
| 303 | + } |
| 304 | + |
| 305 | + unsetenv( "MOSH_PREDICTION_DISPLAY" ); |
| 306 | + |
| 307 | + if ( fake_proxy ) { |
| 308 | + string host = argv[optind++]; |
| 309 | + string port = argv[optind++]; |
| 310 | + |
| 311 | + int sockfd = -1; |
| 312 | + struct addrinfo hints, *servinfo, *p; |
| 313 | + int rv; |
| 314 | + |
| 315 | + memset( &hints, 0, sizeof( hints ) ); |
| 316 | + hints.ai_socktype = SOCK_STREAM; |
| 317 | + |
| 318 | + if ( ( rv = getaddrinfo( host.c_str(), |
| 319 | + port.c_str(), |
| 320 | + &hints, |
| 321 | + &servinfo ) ) != 0 ) { |
| 322 | + die( "%s: Could not resolve hostname %s: getaddrinfo: %s", |
| 323 | + argv[0], |
| 324 | + host.c_str(), |
| 325 | + gai_strerror( rv ) ); |
| 326 | + } |
| 327 | + |
| 328 | + int try_family = AF_INET; |
| 329 | + // loop through all the results and connect to the first we can |
| 330 | + for ( p = servinfo; p != NULL || try_family == AF_INET; p = p->ai_next ) { |
| 331 | + if(p == NULL && try_family == AF_INET) { // start over and try AF_INET6 |
| 332 | + p = servinfo; |
| 333 | + try_family = AF_INET6; |
| 334 | + } |
| 335 | + if(p == NULL) { |
| 336 | + break; // servinfo == NULL |
| 337 | + } |
| 338 | + |
| 339 | + if(p->ai_family != try_family) { |
| 340 | + continue; |
| 341 | + } |
| 342 | + |
| 343 | + if ( ( sockfd = socket( p->ai_family, SOCK_STREAM, IPPROTO_TCP ) ) == -1 ) { |
| 344 | + continue; |
| 345 | + } |
| 346 | + |
| 347 | + if ( connect( sockfd, p->ai_addr, p->ai_addrlen ) == -1 ) { |
| 348 | + close( sockfd ); |
| 349 | + continue; |
| 350 | + } |
| 351 | + |
| 352 | + char host[NI_MAXHOST], service[NI_MAXSERV]; |
| 353 | + if ( getnameinfo( p->ai_addr, p->ai_addrlen, |
| 354 | + host, NI_MAXHOST, |
| 355 | + service, NI_MAXSERV, |
| 356 | + NI_NUMERICSERV | NI_NUMERICHOST ) == -1 ) { |
| 357 | + die( "Couldn't get host name info" ); |
| 358 | + } |
| 359 | + |
| 360 | + fprintf( stderr, "MOSH IP %s\n", host ); |
| 361 | + break; // if we get here, we must have connected successfully |
| 362 | + } |
| 363 | + |
| 364 | + if ( p == NULL ) { |
| 365 | + // looped off the end of the list with no connection |
| 366 | + die( "%s: failed to connect to host %s port %s", |
| 367 | + argv[0], host.c_str(), port.c_str() ); |
| 368 | + } |
| 369 | + |
| 370 | + freeaddrinfo( servinfo ); // all done with this structure |
| 371 | + |
| 372 | + int pid = fork(); |
| 373 | + if ( pid == -1 ) { |
| 374 | + die( "%s: fork: %d", argv[0], errno ); |
| 375 | + } |
| 376 | + if ( pid == 0 ) { |
| 377 | + cat( sockfd, 1 ); |
| 378 | + shutdown( sockfd, 0 ); |
| 379 | + exit( 0 ); |
| 380 | + } |
| 381 | + signal( SIGHUP, SIG_IGN ); |
| 382 | + cat( 0, sockfd ); |
| 383 | + shutdown( sockfd, 1 ); |
| 384 | + waitpid( pid, NULL, 0 ); |
| 385 | + exit( 0 ); |
| 386 | + } |
| 387 | + |
| 388 | + if ( argc - optind < 1 ) { |
| 389 | + die( usage_format, argv[0] ); |
| 390 | + } |
| 391 | + |
| 392 | + string userhost = argv[optind++]; |
| 393 | + char **command = &argv[optind]; |
| 394 | + int commands = argc - optind; |
| 395 | + |
| 396 | + string color_invocation = client + " -c"; |
| 397 | + FILE *color_file = popen( color_invocation.c_str(), "r" ); |
| 398 | + if ( !color_file ) { |
| 399 | + die( "%s: popen: %d", argv[0], errno ); |
| 400 | + } |
| 401 | + char *buf = NULL; |
| 402 | + size_t buf_sz = 0; |
| 403 | + ssize_t n; |
| 404 | + if ( ( n = getline( &buf, &buf_sz, color_file ) ) < 0 ) { |
| 405 | + die( "%s: Can't count colors: %d", argv[0], errno ); |
| 406 | + } |
| 407 | + string colors = string( buf, n ); |
| 408 | + pclose( color_file ); |
| 409 | + |
| 410 | + if ( !colors.size() || |
| 411 | + colors.find_first_not_of( "0123456789" ) != string::npos || |
| 412 | + atoi( colors.c_str() ) < 0 ) { |
| 413 | + colors = "0"; |
| 414 | + } |
| 415 | + |
| 416 | + int pty, pty_slave; |
| 417 | + struct winsize ws; |
| 418 | + if ( ioctl( 0, TIOCGWINSZ, &ws ) == -1 ) { |
| 419 | + die( "%s: ioctl: %d", argv[0], errno ); |
| 420 | + } |
| 421 | + |
| 422 | + if ( openpty( &pty, &pty_slave, NULL, NULL, &ws ) == -1 ) { |
| 423 | + die( "%s: openpty: %d", argv[0], errno ); |
| 424 | + } |
| 425 | + |
| 426 | + int pid = fork(); |
| 427 | + if ( pid == -1 ) { |
| 428 | + die( "%s: fork: %d", argv[0], errno ); |
| 429 | + } |
| 430 | + if ( pid == 0 ) { |
| 431 | + close( pty ); |
| 432 | + if ( -1 == dup2( pty_slave, 1 ) || |
| 433 | + -1 == dup2( pty_slave, 2 ) ) { |
| 434 | + die( "%s: dup2: %d", argv[0], errno ); |
| 435 | + } |
| 436 | + close( pty_slave ); |
| 437 | + |
| 438 | + vector<string> server_args; |
| 439 | + server_args.push_back( "new" ); |
| 440 | + server_args.push_back( "-s" ); |
| 441 | + server_args.push_back( "-c" ); |
| 442 | + server_args.push_back( colors ); |
| 443 | + if ( port_request.size() ) { |
| 444 | + server_args.push_back( "-p" ); |
| 445 | + server_args.push_back( port_request ); |
| 446 | + } |
| 447 | + if ( commands ) { |
| 448 | + server_args.insert( server_args.end(), command, command + commands ); |
| 449 | + } |
| 450 | + string quoted_self = shell_quote_string( string( argv[0] ) ); |
| 451 | + string quoted_server_args = shell_quote( server_args ); |
| 452 | + fflush( stdout ); |
| 453 | + |
| 454 | + string proxy_arg = "ProxyCommand=" + quoted_self + " --fake-proxy -- %h %p"; |
| 455 | + string ssh_remote_command = server + " " + quoted_server_args; |
| 456 | + |
| 457 | + vector<string> ssh_args; |
| 458 | + ssh_args.push_back( "-S" ); |
| 459 | + ssh_args.push_back( "none" ); |
| 460 | + ssh_args.push_back( "-o" ); |
| 461 | + ssh_args.push_back( proxy_arg ); |
| 462 | + ssh_args.push_back( "-t" ); |
| 463 | + ssh_args.push_back( userhost ); |
| 464 | + if ( ssh_port.size() ) { |
| 465 | + ssh_args.push_back( "-p" ); |
| 466 | + ssh_args.push_back( ssh_port ); |
| 467 | + } |
| 468 | + ssh_args.push_back( "--" ); |
| 469 | + ssh_args.push_back( ssh_remote_command ); |
| 470 | + |
| 471 | + string ssh_exec_string = ssh + " " + shell_quote( ssh_args ); |
| 472 | + |
| 473 | + int ret = execlp( "sh", "sh", "-c", ssh_exec_string.c_str(), (char *)NULL ); |
| 474 | + if ( ret == -1 ) { |
| 475 | + die( "Cannot exec ssh: %d", errno ); |
| 476 | + } |
| 477 | + } |
| 478 | + |
| 479 | + close( pty_slave ); |
| 480 | + string ip, port, key; |
| 481 | + |
| 482 | + FILE *pty_file = fdopen( pty, "r" ); |
| 483 | + string line; |
| 484 | + while ( ( n = getline( &buf, &buf_sz, pty_file ) ) >= 0 ) { |
| 485 | + line = string( buf, n ); |
| 486 | + line = line.erase( line.find_last_not_of( "\n" ) ); |
| 487 | + if ( line.compare( 0, 8, "MOSH IP " ) == 0 ) { |
| 488 | + size_t ip_end = line.find_last_not_of( " \t\n\r" ); |
| 489 | + if ( ip_end != string::npos && ip_end >= 8 ) { |
| 490 | + ip = line.substr( 8, ip_end + 1 - 8 ); |
| 491 | + } |
| 492 | + } else if ( line.compare( 0, 13, "MOSH CONNECT " ) == 0 ) { |
| 493 | + size_t port_end = line.find_first_not_of( "0123456789", 13 ); |
| 494 | + if ( port_end != string::npos && port_end >= 13 ) { |
| 495 | + port = line.substr( 13, port_end - 13 ); |
| 496 | + } |
| 497 | + string rest = line.substr( port_end + 1 ); |
| 498 | + size_t key_end = rest.find_last_not_of( " \t\n\r" ); |
| 499 | + size_t key_valid_end = rest.find_last_of( key_valid_char_set ); |
| 500 | + if ( key_valid_end == key_end && key_end + 1 == 22 ) { |
| 501 | + key = rest.substr( 0, key_end + 1 ); |
| 502 | + } |
| 503 | + break; |
| 504 | + } else { |
| 505 | + printf( "%s\n", line.c_str() ); |
| 506 | + } |
| 507 | + } |
| 508 | + waitpid( pid, NULL, 0 ); |
| 509 | + |
| 510 | + if ( !ip.size() ) { |
| 511 | + die( "%s: Did not find remote IP address (is SSH ProxyCommand disabled?).", |
| 512 | + argv[0] ); |
| 513 | + } |
| 514 | + |
| 515 | + if ( !key.size() || !port.size() ) { |
| 516 | + die( "%s: Did not find mosh server startup message.", argv[0] ); |
| 517 | + } |
| 518 | + |
| 519 | + setenv( "MOSH_KEY", key.c_str(), 1 ); |
| 520 | + setenv( "MOSH_PREDICTION_DISPLAY", predict.c_str(), 1 ); |
| 521 | + execlp( client.c_str(), client.c_str(), ip.c_str(), port.c_str(), (char *)NULL ); |
| 522 | +} |