aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/mosh-server.cc
diff options
context:
space:
mode:
Diffstat (limited to 'src/mosh-server.cc')
-rw-r--r--src/mosh-server.cc325
1 files changed, 325 insertions, 0 deletions
diff --git a/src/mosh-server.cc b/src/mosh-server.cc
new file mode 100644
index 0000000..8ecaffb
--- /dev/null
+++ b/src/mosh-server.cc
@@ -0,0 +1,325 @@
+#include <locale.h>
+#include <string.h>
+#include <langinfo.h>
+#include <termios.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <pty.h>
+#include <stdlib.h>
+#include <poll.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <typeinfo>
+#include <signal.h>
+#include <sys/signalfd.h>
+
+#include "completeterminal.h"
+#include "swrite.h"
+#include "user.h"
+
+#include "networktransport.cc"
+
+void serve( int host_fd, const char *desired_ip );
+
+using namespace std;
+
+int main( int argc, char *argv[] )
+{
+ char *desired_ip = NULL;
+ if ( argc == 1 ) {
+ desired_ip = NULL;
+ } else if ( argc == 2 ) {
+ desired_ip = argv[ 1 ];
+ } else {
+ fprintf( stderr, "Usage: %s [LOCALADDR]\n", argv[ 0 ] );
+ exit( 1 );
+ }
+
+ int master;
+ struct termios child_termios;
+
+ /* Adopt implementation locale */
+ if ( NULL == setlocale( LC_ALL, "" ) ) {
+ perror( "setlocale" );
+ exit( 1 );
+ }
+
+ /* Verify locale calls for UTF-8 */
+ if ( strcmp( nl_langinfo( CODESET ), "UTF-8" ) != 0 ) {
+ fprintf( stderr, "mosh requires a UTF-8 locale.\n" );
+ exit( 1 );
+ }
+
+ /* Verify terminal configuration */
+ if ( tcgetattr( STDIN_FILENO, &child_termios ) < 0 ) {
+ perror( "tcgetattr" );
+ exit( 1 );
+ }
+
+ if ( !(child_termios.c_iflag & IUTF8) ) {
+ /* SSH should also convey IUTF8 across connection. */
+ // fprintf( stderr, "Warning: Locale is UTF-8 but termios IUTF8 flag not set. Setting IUTF8 flag.\n" );
+ child_termios.c_iflag |= IUTF8;
+ }
+
+ /* Fork child process */
+ pid_t child = forkpty( &master, NULL, &child_termios, NULL );
+
+ if ( child == -1 ) {
+ perror( "forkpty" );
+ exit( 1 );
+ }
+
+ if ( child == 0 ) {
+ /* child */
+ if ( setenv( "TERM", "xterm", true ) < 0 ) {
+ perror( "setenv" );
+ exit( 1 );
+ }
+
+ /* ask ncurses to send UTF-8 instead of ISO 2022 for line-drawing chars */
+ if ( setenv( "NCURSES_NO_UTF8_ACS", "1", true ) < 0 ) {
+ perror( "setenv" );
+ exit( 1 );
+ }
+
+ /* clear STY environment variable so GNU screen regards us as top level */
+ if ( unsetenv( "STY" ) < 0 ) {
+ perror( "unsetenv" );
+ exit( 1 );
+ }
+
+ /* get shell name */
+ struct passwd *pw = getpwuid( geteuid() );
+ if ( pw == NULL ) {
+ perror( "getpwuid" );
+ exit( 1 );
+ }
+
+ char *my_argv[ 2 ];
+ my_argv[ 0 ] = strdup( pw->pw_shell );
+ assert( my_argv[ 0 ] );
+ my_argv[ 1 ] = NULL;
+
+ if ( execve( pw->pw_shell, my_argv, environ ) < 0 ) {
+ perror( "execve" );
+ exit( 1 );
+ }
+ exit( 0 );
+ } else {
+ /* parent */
+ serve( master, desired_ip );
+ if ( close( master ) < 0 ) {
+ perror( "close" );
+ exit( 1 );
+ }
+ }
+
+ printf( "\n[mosh-server is exiting.]\n" );
+
+ return 0;
+}
+
+void serve( int host_fd, const char *desired_ip )
+{
+ /* establish fd for shutdown signals */
+ sigset_t signal_mask;
+
+ assert( sigemptyset( &signal_mask ) == 0 );
+ assert( sigaddset( &signal_mask, SIGTERM ) == 0 );
+ assert( sigaddset( &signal_mask, SIGINT ) == 0 );
+
+ sigset_t signals_to_block = signal_mask;
+
+ assert( sigaddset( &signals_to_block, SIGHUP ) == 0 );
+ assert( sigaddset( &signals_to_block, SIGPIPE ) == 0 );
+
+ /* don't let signals kill us */
+ assert( sigprocmask( SIG_BLOCK, &signals_to_block, NULL ) == 0 );
+
+ int shutdown_signal_fd = signalfd( -1, &signal_mask, 0 );
+ if ( shutdown_signal_fd < 0 ) {
+ perror( "signalfd" );
+ return;
+ }
+
+ /* get initial window size */
+ struct winsize window_size;
+ if ( ioctl( STDIN_FILENO, TIOCGWINSZ, &window_size ) < 0 ) {
+ perror( "ioctl TIOCGWINSZ" );
+ return;
+ }
+
+ /* tell child process */
+ if ( ioctl( host_fd, TIOCSWINSZ, &window_size ) < 0 ) {
+ perror( "ioctl TIOCSWINSZ" );
+ return;
+ }
+
+ /* open parser and terminal */
+ Terminal::Complete terminal( window_size.ws_col, window_size.ws_row );
+
+ /* open network */
+ Network::UserStream blank;
+ Network::Transport< Terminal::Complete, Network::UserStream > network( terminal, blank, desired_ip );
+
+ /* network.set_verbose(); */
+
+ printf( "MOSH CONNECT %d %s\n", network.port(), network.get_key().c_str() );
+ fflush( stdout );
+
+ /* detach from terminal */
+ pid_t the_pid = fork();
+ if ( the_pid < 0 ) {
+ perror( "fork" );
+ } else if ( the_pid > 0 ) {
+ _exit( 0 );
+ }
+
+ fprintf( stderr, "[mosh-server detached, pid=%d.]\n", (int)getpid() );
+
+ /* prepare to poll for events */
+ struct pollfd pollfds[ 3 ];
+
+ pollfds[ 0 ].fd = network.fd();
+ pollfds[ 0 ].events = POLLIN;
+
+ pollfds[ 1 ].fd = host_fd;
+ pollfds[ 1 ].events = POLLIN;
+
+ pollfds[ 2 ].fd = shutdown_signal_fd;
+ pollfds[ 2 ].events = POLLIN;
+
+ uint64_t last_remote_num = network.get_remote_state_num();
+
+ while ( 1 ) {
+ try {
+ int active_fds = poll( pollfds, 3, network.wait_time() );
+ if ( active_fds < 0 ) {
+ perror( "poll" );
+ break;
+ }
+
+ if ( pollfds[ 0 ].revents & POLLIN ) {
+ /* packet received from the network */
+ network.recv();
+
+ /* is new user input available for the terminal? */
+ if ( network.get_remote_state_num() != last_remote_num ) {
+ string terminal_to_host;
+
+ Network::UserStream us;
+ us.apply_string( network.get_remote_diff() );
+ /* apply userstream to terminal */
+ for ( size_t i = 0; i < us.size(); i++ ) {
+ terminal_to_host += terminal.act( us.get_action( i ) );
+ if ( typeid( *us.get_action( i ) ) == typeid( Parser::Resize ) ) {
+ /* tell child process of resize */
+ const Parser::Resize *res = static_cast<const Parser::Resize *>( us.get_action( i ) );
+ window_size.ws_col = res->width;
+ window_size.ws_row = res->height;
+ if ( ioctl( host_fd, TIOCSWINSZ, &window_size ) < 0 ) {
+ perror( "ioctl TIOCSWINSZ" );
+ return;
+ }
+ }
+ }
+
+ /* update client with new state of terminal */
+ if ( !network.shutdown_in_progress() ) {
+ network.set_current_state( terminal );
+ }
+
+ /* write any writeback octets back to the host */
+ if ( swrite( host_fd, terminal_to_host.c_str(), terminal_to_host.length() ) < 0 ) {
+ break;
+ }
+ }
+ }
+
+ if ( pollfds[ 1 ].revents & POLLIN ) {
+ /* input from the host needs to be fed to the terminal */
+ const int buf_size = 16384;
+ char buf[ buf_size ];
+
+ /* fill buffer if possible */
+ ssize_t bytes_read = read( pollfds[ 1 ].fd, buf, buf_size );
+ if ( bytes_read == 0 ) { /* EOF */
+ return;
+ } else if ( bytes_read < 0 ) {
+ perror( "read" );
+ return;
+ }
+
+ string terminal_to_host = terminal.act( string( buf, bytes_read ) );
+
+ /* update client with new state of terminal */
+ if ( !network.shutdown_in_progress() ) {
+ network.set_current_state( terminal );
+ }
+
+ /* write any writeback octets back to the host */
+ if ( swrite( host_fd, terminal_to_host.c_str(), terminal_to_host.length() ) < 0 ) {
+ break;
+ }
+ }
+
+ if ( pollfds[ 2 ].revents & POLLIN ) {
+ /* shutdown signal */
+ struct signalfd_siginfo the_siginfo;
+ ssize_t bytes_read = read( pollfds[ 2 ].fd, &the_siginfo, sizeof( the_siginfo ) );
+ if ( bytes_read == 0 ) {
+ break;
+ } else if ( bytes_read < 0 ) {
+ perror( "read" );
+ break;
+ }
+
+ if ( network.attached() && (!network.shutdown_in_progress()) ) {
+ network.start_shutdown();
+ } else {
+ break;
+ }
+ }
+
+ if ( (pollfds[ 0 ].revents)
+ & (POLLERR | POLLHUP | POLLNVAL) ) {
+ /* network problem */
+ break;
+ }
+
+ if ( (pollfds[ 1 ].revents)
+ & (POLLERR | POLLHUP | POLLNVAL) ) {
+ /* host problem */
+ if ( network.attached() ) {
+ network.start_shutdown();
+ } else {
+ break;
+ }
+ }
+
+ /* quit if our shutdown has been acknowledged */
+ if ( network.shutdown_in_progress() && network.shutdown_acknowledged() ) {
+ break;
+ }
+
+ /* quit after shutdown acknowledgement timeout */
+ if ( network.shutdown_in_progress() && network.shutdown_ack_timed_out() ) {
+ break;
+ }
+
+ /* quit if we received and acknowledged a shutdown request */
+ if ( network.counterparty_shutdown_ack_sent() ) {
+ break;
+ }
+
+ network.tick();
+ } catch ( Network::NetworkException e ) {
+ fprintf( stderr, "%s: %s\n", e.function.c_str(), strerror( e.the_errno ) );
+ sleep( 1 );
+ } catch ( Crypto::CryptoException e ) {
+ fprintf( stderr, "Crypto exception: %s\n", e.text.c_str() );
+ }
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-08 22:54:14 +0000