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--- ../mosh/src/frontend/mosh.cc 2016-04-29 00:42:24.837700203 +1000
+++ ./src/frontend/mosh.cc 2016-04-29 00:40:13.346294286 +1000
@@ -0,0 +1,519 @@
+// Mosh: the mobile shell
+// Copyright 2012 Keith Winstein
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+#include "config.h"
+#include <limits.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <vector>
+#include <map>
+#include <stdio.h>
+#include <string>
+#include <sys/socket.h>
+#include <getopt.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <signal.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <termios.h>
+#if HAVE_PTY_H
+#include <pty.h>
+#elif HAVE_UTIL_H
+#include <util.h>
+#endif
+
+#if OPENPTY_IN_LIBUTIL
+#include <libutil.h>
+#endif
+
+#if !HAVE_GETLINE
+ssize_t getline( char ** restrict linep,
+ size_t * restrict linecapp,
+ FILE * restrict stream ) {
+ size_t num_read = 0;
+ if ( !linep || !linecapp ) {
+ errno = EINVAL;
+ return -1;
+ }
+ if ( !*linep ) {
+ *linecapp = 0;
+ }
+ while ( 1 ) {
+ int ch = getc( stream );
+ if ( ch == EOF ) {
+ return num_read ? (ssize_t)num_read : -1;
+ }
+ if ( num_read + 1 >= *linecapp ) {
+ char *new_line = *linep;
+ size_t new_linecap = *linecapp;
+ if ( *linecapp > SSIZE_MAX - 4096 ) {
+ errno = EOVERFLOW;
+ return -1;
+ }
+ new_linecap += 4096;
+ new_line = (char *)realloc( new_line, new_linecap );
+ if ( !new_line ) {
+ return -1;
+ }
+ *linecapp = new_linecap;
+ *linep = new_line;
+ }
+ (*linep)[num_read++] = ch;
+ // so that we can safely return at any time,
+ (*linep)[num_read] = '\0';
+ if (ch == '\n') {
+ return num_read;
+ }
+ }
+ return -1;
+}
+#endif
+
+using namespace std;
+
+inline string shell_quote_string( const string &x )
+{
+ string result = "'";
+ string rest = x;
+ while ( rest.size() ) {
+ size_t good_part = rest.find( "'" );
+ result += rest.substr( 0, good_part );
+ if ( good_part != string::npos ) {
+ result += "'\\''";
+ rest = rest.substr( good_part + 1 );
+ } else {
+ break;
+ }
+ }
+ return result + "'";
+}
+
+template <typename SequenceT>
+inline string shell_quote( const SequenceT &sequence )
+{
+ string result;
+ for ( typename SequenceT::const_iterator i = sequence.begin();
+ i != sequence.end();
+ i++ ) {
+ result += shell_quote_string( *i ) + " ";
+ }
+ return result.substr( 0, result.size() - 1 );
+}
+
+void die( const char *format, ... ) {
+ va_list args;
+ va_start( args, format );
+ vfprintf( stderr, format, args );
+ va_end( args );
+ fprintf( stderr, "\n" );
+ exit( 255 );
+}
+
+static const char *usage_format =
+"Usage: %s [options] [--] [user@]host [command...]\n"
+" --client=PATH mosh client on local machine\n"
+" (default: mosh-client)\n"
+" --server=PATH mosh server on remote machine\n"
+" (default: mosh-server)\n"
+"\n"
+" --predict=adaptive local echo for slower links [default]\n"
+"-a --predict=always use local echo even on fast links\n"
+"-n --predict=never never use local echo\n"
+"\n"
+"-p NUM --port=NUM server-side UDP port\n"
+"\n"
+"-P NUM --ssh-port=NUM ssh server port\n"
+" (default: let the ssh command choose)\n"
+"\n"
+" --ssh=COMMAND ssh command to run when setting up session\n"
+" (example: \"ssh -p 2222\")\n"
+" (default: \"ssh\")\n"
+"\n"
+" --help this message\n"
+" --version version and copyright information\n"
+"\n"
+"Please report bugs to mosh-devel@mit.edu.\n"
+"Mosh home page: http://mosh.mit.edu";
+
+static const char *version_format =
+"mosh %s\n"
+"Copyright 2012 Keith Winstein <mosh-devel@mit.edu>\n"
+"License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.\n"
+"This is free software: you are free to change and redistribute it.\n"
+"There is NO WARRANTY, to the extent permitted by law.";
+
+static const char *key_valid_char_set =
+"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789/+";
+
+static char *argv0;
+
+void predict_check( const string &predict, bool env_set )
+{
+ if ( predict != "adaptive" &&
+ predict != "always" &&
+ predict != "never" ) {
+ fprintf( stderr, "%s: Unknown mode \"%s\"%s.\n", argv0, predict.c_str(),
+ env_set ? " (MOSH_PREDICTION_DISPLAY in environment)" : "" );
+ die( usage_format, argv0 );
+ }
+}
+
+void cat( int ifd, int ofd )
+{
+ char buf[4096];
+ ssize_t n;
+ while ( 1 ) {
+ n = read( ifd, buf, sizeof( buf ) );
+ if ( n==-1 ) {
+ if (errno == EINTR ) {
+ continue;
+ }
+ break;
+ }
+ if ( n==0 ) {
+ break;
+ }
+ n = write( ofd, buf, n );
+ if ( n==-1 ) {
+ break;
+ }
+ }
+}
+
+bool valid_port(string port) {
+ if ( port.size() ) {
+ return port.find_first_not_of( "0123456789" ) == string::npos &&
+ atoi( port.c_str() ) > 0 &&
+ atoi( port.c_str() ) <= 65535;
+ }
+ return true; // consider no port to be the default value
+}
+
+int main( int argc, char *argv[] )
+{
+ argv0 = argv[0];
+ string client = "mosh-client";
+ string server = "mosh-server";
+ string ssh = "ssh";
+ string predict, port_request, ssh_port;
+ int help=0, version=0, fake_proxy=0;
+
+ static struct option long_options[] =
+ {
+ { "client", required_argument, 0, 'c' },
+ { "server", required_argument, 0, 's' },
+ { "predict", required_argument, 0, 'r' },
+ { "port", required_argument, 0, 'p' },
+ { "ssh-port", required_argument, 0, 'P' },
+ { "ssh", required_argument, 0, 'S' },
+ { "help", no_argument, &help, 1 },
+ { "version", no_argument, &version, 1 },
+ { "fake-proxy!", no_argument, &fake_proxy, 1 },
+ { 0, 0, 0, 0 }
+ };
+ while ( 1 ) {
+ int option_index = 0;
+ int c = getopt_long( argc, argv, "anp:P:",
+ long_options, &option_index );
+ if ( c == -1 ) {
+ break;
+ }
+
+ switch ( c ) {
+ case 0:
+ // flag has been set
+ break;
+ case 'c':
+ client = optarg;
+ break;
+ case 's':
+ server = optarg;
+ break;
+ case 'r':
+ predict = optarg;
+ break;
+ case 'p':
+ port_request = optarg;
+ break;
+ case 'P':
+ ssh_port = optarg;
+ break;
+ case 'S':
+ ssh = optarg;
+ break;
+ case 'a':
+ predict = "always";
+ break;
+ case 'n':
+ predict = "never";
+ break;
+ default:
+ die( usage_format, argv[0] );
+ }
+ }
+
+ if ( help ) {
+ die( usage_format, argv[0] );
+ }
+ if ( version ) {
+ die( version_format, PACKAGE_VERSION );
+ }
+
+ if ( predict.size() ) {
+ predict_check( predict, 0 );
+ } else if ( getenv( "MOSH_PREDICTION_DELAY" ) ) {
+ predict = getenv( "MOSH_PREDICTION_DELAY" );
+ predict_check( predict, 1 );
+ } else {
+ predict = "adaptive";
+ predict_check( predict, 0 );
+ }
+
+ if(!valid_port(port_request)) {
+ die( "%s: Server-side port (%s) must be within valid range [0..65535].",
+ argv[0],
+ port_request.c_str() );
+ }
+
+ if(!valid_port(ssh_port)) {
+ die( "%s: SSH port (%s) must be within valid range [0..65535].",
+ argv[0],
+ ssh_port.c_str() );
+ }
+
+ unsetenv( "MOSH_PREDICTION_DISPLAY" );
+
+ if ( fake_proxy ) {
+ string host = argv[optind++];
+ string port = argv[optind++];
+
+ int sockfd = -1;
+ struct addrinfo hints, *servinfo, *p;
+ int rv;
+
+ memset( &hints, 0, sizeof( hints ) );
+ hints.ai_socktype = SOCK_STREAM;
+
+ if ( ( rv = getaddrinfo( host.c_str(),
+ port.c_str(),
+ &hints,
+ &servinfo ) ) != 0 ) {
+ die( "%s: Could not resolve hostname %s: getaddrinfo: %s",
+ argv[0],
+ host.c_str(),
+ gai_strerror( rv ) );
+ }
+
+ int try_family = AF_INET;
+ // loop through all the results and connect to the first we can
+ for ( p = servinfo; p != NULL || try_family == AF_INET; p = p->ai_next ) {
+ if(p == NULL && try_family == AF_INET) { // start over and try AF_INET6
+ p = servinfo;
+ try_family = AF_INET6;
+ }
+ if(p == NULL) {
+ break; // servinfo == NULL
+ }
+
+ if(p->ai_family != try_family) {
+ continue;
+ }
+
+ if ( ( sockfd = socket( p->ai_family, SOCK_STREAM, IPPROTO_TCP ) ) == -1 ) {
+ continue;
+ }
+
+ if ( connect( sockfd, p->ai_addr, p->ai_addrlen ) == -1 ) {
+ close( sockfd );
+ continue;
+ }
+
+ char host[NI_MAXHOST], service[NI_MAXSERV];
+ if ( getnameinfo( p->ai_addr, p->ai_addrlen,
+ host, NI_MAXHOST,
+ service, NI_MAXSERV,
+ NI_NUMERICSERV | NI_NUMERICHOST ) == -1 ) {
+ die( "Couldn't get host name info" );
+ }
+
+ fprintf( stderr, "MOSH IP %s\n", host );
+ break; // if we get here, we must have connected successfully
+ }
+
+ if ( p == NULL ) {
+ // looped off the end of the list with no connection
+ die( "%s: failed to connect to host %s port %s",
+ argv[0], host.c_str(), port.c_str() );
+ }
+
+ freeaddrinfo( servinfo ); // all done with this structure
+
+ int pid = fork();
+ if ( pid == -1 ) {
+ die( "%s: fork: %d", argv[0], errno );
+ }
+ if ( pid == 0 ) {
+ cat( sockfd, 1 );
+ shutdown( sockfd, 0 );
+ exit( 0 );
+ }
+ signal( SIGHUP, SIG_IGN );
+ cat( 0, sockfd );
+ shutdown( sockfd, 1 );
+ waitpid( pid, NULL, 0 );
+ exit( 0 );
+ }
+
+ if ( argc - optind < 1 ) {
+ die( usage_format, argv[0] );
+ }
+
+ string userhost = argv[optind++];
+ char **command = &argv[optind];
+ int commands = argc - optind;
+
+ string color_invocation = client + " -c";
+ FILE *color_file = popen( color_invocation.c_str(), "r" );
+ if ( !color_file ) {
+ die( "%s: popen: %d", argv[0], errno );
+ }
+ char *buf = NULL;
+ size_t buf_sz = 0;
+ ssize_t n;
+ if ( ( n = getline( &buf, &buf_sz, color_file ) ) < 0 ) {
+ die( "%s: Can't count colors: %d", argv[0], errno );
+ }
+ string colors = string( buf, n );
+ pclose( color_file );
+
+ if ( !colors.size() ||
+ colors.find_first_not_of( "0123456789" ) != string::npos ||
+ atoi( colors.c_str() ) < 0 ) {
+ colors = "0";
+ }
+
+ int pty, pty_slave;
+ struct winsize ws;
+ if ( ioctl( 0, TIOCGWINSZ, &ws ) == -1 ) {
+ die( "%s: ioctl: %d", argv[0], errno );
+ }
+
+ if ( openpty( &pty, &pty_slave, NULL, NULL, &ws ) == -1 ) {
+ die( "%s: openpty: %d", argv[0], errno );
+ }
+
+ int pid = fork();
+ if ( pid == -1 ) {
+ die( "%s: fork: %d", argv[0], errno );
+ }
+ if ( pid == 0 ) {
+ close( pty );
+ if ( -1 == dup2( pty_slave, 1 ) ||
+ -1 == dup2( pty_slave, 2 ) ) {
+ die( "%s: dup2: %d", argv[0], errno );
+ }
+ close( pty_slave );
+
+ vector<string> server_args;
+ server_args.push_back( "new" );
+ server_args.push_back( "-s" );
+ server_args.push_back( "-c" );
+ server_args.push_back( colors );
+ if ( port_request.size() ) {
+ server_args.push_back( "-p" );
+ server_args.push_back( port_request );
+ }
+ if ( commands ) {
+ server_args.insert( server_args.end(), command, command + commands );
+ }
+ string quoted_self = shell_quote_string( string( argv[0] ) );
+ string quoted_server_args = shell_quote( server_args );
+ fflush( stdout );
+
+ string proxy_arg = "ProxyCommand=" + quoted_self + " --fake-proxy -- %h %p";
+ string ssh_remote_command = server + " " + quoted_server_args;
+
+ vector<string> ssh_args;
+ ssh_args.push_back( "-S" );
+ ssh_args.push_back( "none" );
+ ssh_args.push_back( "-o" );
+ ssh_args.push_back( proxy_arg );
+ ssh_args.push_back( "-t" );
+ ssh_args.push_back( userhost );
+ if ( ssh_port.size() ) {
+ ssh_args.push_back( "-p" );
+ ssh_args.push_back( ssh_port );
+ }
+ ssh_args.push_back( "--" );
+ ssh_args.push_back( ssh_remote_command );
+
+ string ssh_exec_string = ssh + " " + shell_quote( ssh_args );
+
+ int ret = execlp( "sh", "sh", "-c", ssh_exec_string.c_str(), (char *)NULL );
+ if ( ret == -1 ) {
+ die( "Cannot exec ssh: %d", errno );
+ }
+ }
+
+ close( pty_slave );
+ string ip, port, key;
+
+ FILE *pty_file = fdopen( pty, "r" );
+ string line;
+ while ( ( n = getline( &buf, &buf_sz, pty_file ) ) >= 0 ) {
+ line = string( buf, n );
+ line = line.erase( line.find_last_not_of( "\n" ) );
+ if ( line.compare( 0, 8, "MOSH IP " ) == 0 ) {
+ size_t ip_end = line.find_last_not_of( " \t\n\r" );
+ if ( ip_end != string::npos && ip_end >= 8 ) {
+ ip = line.substr( 8, ip_end + 1 - 8 );
+ }
+ } else if ( line.compare( 0, 13, "MOSH CONNECT " ) == 0 ) {
+ size_t port_end = line.find_first_not_of( "0123456789", 13 );
+ if ( port_end != string::npos && port_end >= 13 ) {
+ port = line.substr( 13, port_end - 13 );
+ }
+ string rest = line.substr( port_end + 1 );
+ size_t key_end = rest.find_last_not_of( " \t\n\r" );
+ size_t key_valid_end = rest.find_last_of( key_valid_char_set );
+ if ( key_valid_end == key_end && key_end + 1 == 22 ) {
+ key = rest.substr( 0, key_end + 1 );
+ }
+ break;
+ } else {
+ printf( "%s\n", line.c_str() );
+ }
+ }
+ waitpid( pid, NULL, 0 );
+
+ if ( !ip.size() ) {
+ die( "%s: Did not find remote IP address (is SSH ProxyCommand disabled?).",
+ argv[0] );
+ }
+
+ if ( !key.size() || !port.size() ) {
+ die( "%s: Did not find mosh server startup message.", argv[0] );
+ }
+
+ setenv( "MOSH_KEY", key.c_str(), 1 );
+ setenv( "MOSH_PREDICTION_DISPLAY", predict.c_str(), 1 );
+ execlp( client.c_str(), client.c_str(), ip.c_str(), port.c_str(), (char *)NULL );
+}