void server_loop2(Authctxt *authctxt) { fd_set *readset = NULL, *writeset = NULL; int rekeying = 0, max_fd, nalloc = 0; debug("Entering interactive session for SSH2."); mysignal(SIGCHLD, sigchld_handler); child_terminated = 0; connection_in = packet_get_connection_in(); connection_out = packet_get_connection_out(); notify_setup(); max_fd = MAX(connection_in, connection_out); max_fd = MAX(max_fd, notify_pipe[0]); xxx_authctxt = authctxt; server_init_dispatch(); for (;;) { process_buffered_input_packets(); rekeying = (xxx_kex != NULL && !xxx_kex->done); if (!rekeying && packet_not_very_much_data_to_write()) channel_output_poll(); wait_until_can_do_something(&readset, &writeset, &max_fd, &nalloc, 0); collect_children(); if (!rekeying) { channel_after_select(readset, writeset); if (packet_need_rekeying()) { debug("need rekeying"); xxx_kex->done = 0; kex_send_kexinit(xxx_kex); } } process_input(readset); if (connection_closed) break; process_output(writeset); } collect_children(); if (readset) xfree(readset); if (writeset) xfree(writeset); /* free all channels, no more reads and writes */ channel_free_all(); /* free remaining sessions, e.g. remove wtmp entries */ session_destroy_all(NULL); }
void server_loop2(Authctxt *authctxt) { fd_set *readset = NULL, *writeset = NULL; int rekeying = 0, max_fd; u_int nalloc = 0; u_int64_t rekey_timeout_ms = 0; debug("Entering interactive session for SSH2."); mysignal(SIGCHLD, sigchld_handler); child_terminated = 0; connection_in = packet_get_connection_in(); connection_out = packet_get_connection_out(); if (!use_privsep) { signal(SIGTERM, sigterm_handler); signal(SIGINT, sigterm_handler); signal(SIGQUIT, sigterm_handler); } notify_setup(); max_fd = MAX(connection_in, connection_out); max_fd = MAX(max_fd, notify_pipe[0]); server_init_dispatch(); for (;;) { process_buffered_input_packets(); rekeying = (xxx_kex != NULL && !xxx_kex->done); if (!rekeying && packet_not_very_much_data_to_write()) channel_output_poll(); if (options.rekey_interval > 0 && compat20 && !rekeying) rekey_timeout_ms = packet_get_rekey_timeout() * 1000; else rekey_timeout_ms = 0; wait_until_can_do_something(&readset, &writeset, &max_fd, &nalloc, rekey_timeout_ms); if (received_sigterm) { logit("Exiting on signal %d", (int)received_sigterm); /* Clean up sessions, utmp, etc. */ cleanup_exit(255); } collect_children(); if (!rekeying) { channel_after_select(readset, writeset); if (packet_need_rekeying()) { debug("need rekeying"); xxx_kex->done = 0; kex_send_kexinit(xxx_kex); } } process_input(readset); if (connection_closed) break; process_output(writeset); } collect_children(); free(readset); free(writeset); /* free all channels, no more reads and writes */ channel_free_all(); /* free remaining sessions, e.g. remove wtmp entries */ session_destroy_all(NULL); }
/* * Performs the interactive session. This handles data transmission between * the client and the program. Note that the notion of stdin, stdout, and * stderr in this function is sort of reversed: this function writes to * stdin (of the child program), and reads from stdout and stderr (of the * child program). */ void server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg) { fd_set *readset = NULL, *writeset = NULL; int max_fd = 0; u_int nalloc = 0; int wait_status; /* Status returned by wait(). */ pid_t wait_pid; /* pid returned by wait(). */ int waiting_termination = 0; /* Have displayed waiting close message. */ u_int64_t max_time_milliseconds; u_int previous_stdout_buffer_bytes; u_int stdout_buffer_bytes; int type; debug("Entering interactive session."); /* Initialize the SIGCHLD kludge. */ child_terminated = 0; mysignal(SIGCHLD, sigchld_handler); if (!use_privsep) { signal(SIGTERM, sigterm_handler); signal(SIGINT, sigterm_handler); signal(SIGQUIT, sigterm_handler); } /* Initialize our global variables. */ fdin = fdin_arg; fdout = fdout_arg; fderr = fderr_arg; /* nonblocking IO */ set_nonblock(fdin); set_nonblock(fdout); /* we don't have stderr for interactive terminal sessions, see below */ if (fderr != -1) set_nonblock(fderr); if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin)) fdin_is_tty = 1; connection_in = packet_get_connection_in(); connection_out = packet_get_connection_out(); notify_setup(); previous_stdout_buffer_bytes = 0; /* Set approximate I/O buffer size. */ if (packet_is_interactive()) buffer_high = 4096; else buffer_high = 64 * 1024; #if 0 /* Initialize max_fd to the maximum of the known file descriptors. */ max_fd = MAX(connection_in, connection_out); max_fd = MAX(max_fd, fdin); max_fd = MAX(max_fd, fdout); if (fderr != -1) max_fd = MAX(max_fd, fderr); #endif /* Initialize Initialize buffers. */ buffer_init(&stdin_buffer); buffer_init(&stdout_buffer); buffer_init(&stderr_buffer); /* * If we have no separate fderr (which is the case when we have a pty * - there we cannot make difference between data sent to stdout and * stderr), indicate that we have seen an EOF from stderr. This way * we don't need to check the descriptor everywhere. */ if (fderr == -1) fderr_eof = 1; server_init_dispatch(); /* Main loop of the server for the interactive session mode. */ for (;;) { /* Process buffered packets from the client. */ process_buffered_input_packets(); /* * If we have received eof, and there is no more pending * input data, cause a real eof by closing fdin. */ if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) { if (fdin != fdout) close(fdin); else shutdown(fdin, SHUT_WR); /* We will no longer send. */ fdin = -1; } /* Make packets from buffered stderr data to send to the client. */ make_packets_from_stderr_data(); /* * Make packets from buffered stdout data to send to the * client. If there is very little to send, this arranges to * not send them now, but to wait a short while to see if we * are getting more data. This is necessary, as some systems * wake up readers from a pty after each separate character. */ max_time_milliseconds = 0; stdout_buffer_bytes = buffer_len(&stdout_buffer); if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 && stdout_buffer_bytes != previous_stdout_buffer_bytes) { /* try again after a while */ max_time_milliseconds = 10; } else { /* Send it now. */ make_packets_from_stdout_data(); } previous_stdout_buffer_bytes = buffer_len(&stdout_buffer); /* Send channel data to the client. */ if (packet_not_very_much_data_to_write()) channel_output_poll(); /* * Bail out of the loop if the program has closed its output * descriptors, and we have no more data to send to the * client, and there is no pending buffered data. */ if (fdout_eof && fderr_eof && !packet_have_data_to_write() && buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) { if (!channel_still_open()) break; if (!waiting_termination) { const char *s = "Waiting for forwarded connections to terminate... (press ~& to background)\r\n"; char *cp; waiting_termination = 1; buffer_append(&stderr_buffer, s, strlen(s)); /* Display list of open channels. */ cp = channel_open_message(); buffer_append(&stderr_buffer, cp, strlen(cp)); free(cp); } } max_fd = MAX(connection_in, connection_out); max_fd = MAX(max_fd, fdin); max_fd = MAX(max_fd, fdout); max_fd = MAX(max_fd, fderr); max_fd = MAX(max_fd, notify_pipe[0]); /* Sleep in select() until we can do something. */ wait_until_can_do_something(&readset, &writeset, &max_fd, &nalloc, max_time_milliseconds); if (received_sigterm) { logit("Exiting on signal %d", (int)received_sigterm); /* Clean up sessions, utmp, etc. */ cleanup_exit(255); } /* Process any channel events. */ channel_after_select(readset, writeset); /* Process input from the client and from program stdout/stderr. */ process_input(readset); /* Process output to the client and to program stdin. */ process_output(writeset); } free(readset); free(writeset); /* Cleanup and termination code. */ /* Wait until all output has been sent to the client. */ drain_output(); debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.", stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes); /* Free and clear the buffers. */ buffer_free(&stdin_buffer); buffer_free(&stdout_buffer); buffer_free(&stderr_buffer); /* Close the file descriptors. */ if (fdout != -1) close(fdout); fdout = -1; fdout_eof = 1; if (fderr != -1) close(fderr); fderr = -1; fderr_eof = 1; if (fdin != -1) close(fdin); fdin = -1; channel_free_all(); /* We no longer want our SIGCHLD handler to be called. */ mysignal(SIGCHLD, SIG_DFL); while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0) if (errno != EINTR) packet_disconnect("wait: %.100s", strerror(errno)); if (wait_pid != pid) error("Strange, wait returned pid %ld, expected %ld", (long)wait_pid, (long)pid); /* Check if it exited normally. */ if (WIFEXITED(wait_status)) { /* Yes, normal exit. Get exit status and send it to the client. */ debug("Command exited with status %d.", WEXITSTATUS(wait_status)); packet_start(SSH_SMSG_EXITSTATUS); packet_put_int(WEXITSTATUS(wait_status)); packet_send(); packet_write_wait(); /* * Wait for exit confirmation. Note that there might be * other packets coming before it; however, the program has * already died so we just ignore them. The client is * supposed to respond with the confirmation when it receives * the exit status. */ do { type = packet_read(); } while (type != SSH_CMSG_EXIT_CONFIRMATION); debug("Received exit confirmation."); return; } /* Check if the program terminated due to a signal. */ if (WIFSIGNALED(wait_status)) packet_disconnect("Command terminated on signal %d.", WTERMSIG(wait_status)); /* Some weird exit cause. Just exit. */ packet_disconnect("wait returned status %04x.", wait_status); /* NOTREACHED */ }
void server_loop2(Authctxt *authctxt) { fd_set *readset = NULL, *writeset = NULL; int rekeying = 0, max_fd, nalloc = 0; double start_time, total_time; debug("Entering interactive session for SSH2."); start_time = get_current_time(); mysignal(SIGCHLD, sigchld_handler); child_terminated = 0; connection_in = packet_get_connection_in(); connection_out = packet_get_connection_out(); if (!use_privsep) { signal(SIGTERM, sigterm_handler); signal(SIGINT, sigterm_handler); signal(SIGQUIT, sigterm_handler); } notify_setup(); max_fd = MAX(connection_in, connection_out); max_fd = MAX(max_fd, notify_pipe[0]); server_init_dispatch(); for (;;) { process_buffered_input_packets(); rekeying = (xxx_kex != NULL && !xxx_kex->done); if (!rekeying && packet_not_very_much_data_to_write()) channel_output_poll(); wait_until_can_do_something(&readset, &writeset, &max_fd, &nalloc, 0); if (received_sigterm) { logit("Exiting on signal %d", received_sigterm); /* Clean up sessions, utmp, etc. */ cleanup_exit(255); } collect_children(); if (!rekeying) { channel_after_select(readset, writeset); if (packet_need_rekeying()) { debug("need rekeying"); xxx_kex->done = 0; kex_send_kexinit(xxx_kex); } } process_input(readset); if (connection_closed) break; process_output(writeset); } collect_children(); if (readset) xfree(readset); if (writeset) xfree(writeset); /* free all channels, no more reads and writes */ channel_free_all(); /* free remaining sessions, e.g. remove wtmp entries */ session_destroy_all(NULL); total_time = get_current_time() - start_time; logit("SSH: Server;LType: Throughput;Remote: %s-%d;IN: %lu;OUT: %lu;Duration: %.1f;tPut_in: %.1f;tPut_out: %.1f", get_remote_ipaddr(), get_remote_port(), stdin_bytes, fdout_bytes, total_time, stdin_bytes / total_time, fdout_bytes / total_time); }