diff options
Diffstat (limited to 'serverloop.c')
| -rw-r--r-- | serverloop.c | 1242 |
1 files changed, 403 insertions, 839 deletions
diff --git a/serverloop.c b/serverloop.c index 306ac36b..340b19a5 100644 --- a/serverloop.c +++ b/serverloop.c @@ -1,4 +1,4 @@ -/* $OpenBSD: serverloop.c,v 1.178 2015/02/20 22:17:21 djm Exp $ */ +/* $OpenBSD: serverloop.c,v 1.222 2020/01/30 07:21:38 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -37,7 +37,6 @@ #include "includes.h" -#include <sys/param.h> /* MIN MAX */ #include <sys/types.h> #include <sys/wait.h> #include <sys/socket.h> @@ -50,6 +49,7 @@ #include <errno.h> #include <fcntl.h> #include <pwd.h> +#include <limits.h> #include <signal.h> #include <string.h> #include <termios.h> @@ -59,7 +59,7 @@ #include "openbsd-compat/sys-queue.h" #include "xmalloc.h" #include "packet.h" -#include "buffer.h" +#include "sshbuf.h" #include "log.h" #include "misc.h" #include "servconf.h" @@ -67,9 +67,8 @@ #include "sshpty.h" #include "channels.h" #include "compat.h" -#include "ssh1.h" #include "ssh2.h" -#include "key.h" +#include "sshkey.h" #include "cipher.h" #include "kex.h" #include "hostfile.h" @@ -78,34 +77,15 @@ #include "dispatch.h" #include "auth-options.h" #include "serverloop.h" -#include "roaming.h" #include "ssherr.h" extern ServerOptions options; /* XXX */ extern Authctxt *the_authctxt; +extern struct sshauthopt *auth_opts; extern int use_privsep; -static Buffer stdin_buffer; /* Buffer for stdin data. */ -static Buffer stdout_buffer; /* Buffer for stdout data. */ -static Buffer stderr_buffer; /* Buffer for stderr data. */ -static int fdin; /* Descriptor for stdin (for writing) */ -static int fdout; /* Descriptor for stdout (for reading); - May be same number as fdin. */ -static int fderr; /* Descriptor for stderr. May be -1. */ -static long stdin_bytes = 0; /* Number of bytes written to stdin. */ -static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */ -static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */ -static long fdout_bytes = 0; /* Number of stdout bytes read from program. */ -static int stdin_eof = 0; /* EOF message received from client. */ -static int fdout_eof = 0; /* EOF encountered reading from fdout. */ -static int fderr_eof = 0; /* EOF encountered readung from fderr. */ -static int fdin_is_tty = 0; /* fdin points to a tty. */ -static int connection_in; /* Connection to client (input). */ -static int connection_out; /* Connection to client (output). */ -static int connection_closed = 0; /* Connection to client closed. */ -static u_int buffer_high; /* "Soft" max buffer size. */ static int no_more_sessions = 0; /* Disallow further sessions. */ /* @@ -119,7 +99,21 @@ static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. static volatile sig_atomic_t received_sigterm = 0; /* prototypes */ -static void server_init_dispatch(void); +static void server_init_dispatch(struct ssh *); + +/* requested tunnel forwarding interface(s), shared with session.c */ +char *tun_fwd_ifnames = NULL; + +/* returns 1 if bind to specified port by specified user is permitted */ +static int +bind_permitted(int port, uid_t uid) +{ + if (use_privsep) + return 1; /* allow system to decide */ + if (port < IPPORT_RESERVED && uid != 0) + return 0; + return 1; +} /* * we write to this pipe if a SIGCHLD is caught in order to avoid @@ -129,7 +123,7 @@ static int notify_pipe[2]; static void notify_setup(void) { - if (pipe(notify_pipe) < 0) { + if (pipe(notify_pipe) == -1) { error("pipe(notify_pipe) failed %s", strerror(errno)); } else if ((fcntl(notify_pipe[0], F_SETFD, FD_CLOEXEC) == -1) || (fcntl(notify_pipe[1], F_SETFD, FD_CLOEXEC) == -1)) { @@ -163,7 +157,7 @@ notify_done(fd_set *readset) if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset)) while (read(notify_pipe[0], &c, 1) != -1) - debug2("notify_done: reading"); + debug2("%s: reading", __func__); } /*ARGSUSED*/ @@ -172,9 +166,6 @@ sigchld_handler(int sig) { int save_errno = errno; child_terminated = 1; -#ifndef _UNICOS - mysignal(SIGCHLD, sigchld_handler); -#endif notify_parent(); errno = save_errno; } @@ -186,72 +177,18 @@ sigterm_handler(int sig) received_sigterm = sig; } -/* - * Make packets from buffered stderr data, and buffer it for sending - * to the client. - */ -static void -make_packets_from_stderr_data(void) -{ - u_int len; - - /* Send buffered stderr data to the client. */ - while (buffer_len(&stderr_buffer) > 0 && - packet_not_very_much_data_to_write()) { - len = buffer_len(&stderr_buffer); - if (packet_is_interactive()) { - if (len > 512) - len = 512; - } else { - /* Keep the packets at reasonable size. */ - if (len > packet_get_maxsize()) - len = packet_get_maxsize(); - } - packet_start(SSH_SMSG_STDERR_DATA); - packet_put_string(buffer_ptr(&stderr_buffer), len); - packet_send(); - buffer_consume(&stderr_buffer, len); - stderr_bytes += len; - } -} - -/* - * Make packets from buffered stdout data, and buffer it for sending to the - * client. - */ static void -make_packets_from_stdout_data(void) +client_alive_check(struct ssh *ssh) { - u_int len; - - /* Send buffered stdout data to the client. */ - while (buffer_len(&stdout_buffer) > 0 && - packet_not_very_much_data_to_write()) { - len = buffer_len(&stdout_buffer); - if (packet_is_interactive()) { - if (len > 512) - len = 512; - } else { - /* Keep the packets at reasonable size. */ - if (len > packet_get_maxsize()) - len = packet_get_maxsize(); - } - packet_start(SSH_SMSG_STDOUT_DATA); - packet_put_string(buffer_ptr(&stdout_buffer), len); - packet_send(); - buffer_consume(&stdout_buffer, len); - stdout_bytes += len; - } -} - -static void -client_alive_check(void) -{ - int channel_id; + char remote_id[512]; + int r, channel_id; /* timeout, check to see how many we have had */ - if (packet_inc_alive_timeouts() > options.client_alive_count_max) { - logit("Timeout, client not responding."); + if (options.client_alive_count_max > 0 && + ssh_packet_inc_alive_timeouts(ssh) > + options.client_alive_count_max) { + sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id)); + logit("Timeout, client not responding from %s", remote_id); cleanup_exit(255); } @@ -259,14 +196,18 @@ client_alive_check(void) * send a bogus global/channel request with "wantreply", * we should get back a failure */ - if ((channel_id = channel_find_open()) == -1) { - packet_start(SSH2_MSG_GLOBAL_REQUEST); - packet_put_cstring("keepalive@openssh.com"); - packet_put_char(1); /* boolean: want reply */ + if ((channel_id = channel_find_open(ssh)) == -1) { + if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || + (r = sshpkt_put_cstring(ssh, "keepalive@openssh.com")) + != 0 || + (r = sshpkt_put_u8(ssh, 1)) != 0) /* boolean: want reply */ + fatal("%s: %s", __func__, ssh_err(r)); } else { - channel_request_start(channel_id, "keepalive@openssh.com", 1); + channel_request_start(ssh, channel_id, + "keepalive@openssh.com", 1); } - packet_send(); + if ((r = sshpkt_send(ssh)) != 0) + fatal("%s: %s", __func__, ssh_err(r)); } /* @@ -276,22 +217,25 @@ client_alive_check(void) * for the duration of the wait (0 = infinite). */ static void -wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp, - u_int *nallocp, u_int64_t max_time_milliseconds) +wait_until_can_do_something(struct ssh *ssh, + int connection_in, int connection_out, + fd_set **readsetp, fd_set **writesetp, int *maxfdp, + u_int *nallocp, u_int64_t max_time_ms) { struct timeval tv, *tvp; int ret; time_t minwait_secs = 0; int client_alive_scheduled = 0; - int program_alive_scheduled = 0; + /* time we last heard from the client OR sent a keepalive */ + static time_t last_client_time; /* Allocate and update select() masks for channel descriptors. */ - channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, - &minwait_secs, 0); + channel_prepare_select(ssh, readsetp, writesetp, maxfdp, + nallocp, &minwait_secs); + /* XXX need proper deadline system for rekey/client alive */ if (minwait_secs != 0) - max_time_milliseconds = MIN(max_time_milliseconds, - (u_int)minwait_secs * 1000); + max_time_ms = MINIMUM(max_time_ms, (u_int)minwait_secs * 1000); /* * if using client_alive, set the max timeout accordingly, @@ -301,67 +245,43 @@ wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp, * this could be randomized somewhat to make traffic * analysis more difficult, but we're not doing it yet. */ - if (compat20 && - max_time_milliseconds == 0 && options.client_alive_interval) { - client_alive_scheduled = 1; - max_time_milliseconds = - (u_int64_t)options.client_alive_interval * 1000; + if (options.client_alive_interval) { + uint64_t keepalive_ms = + (uint64_t)options.client_alive_interval * 1000; + + if (max_time_ms == 0 || max_time_ms > keepalive_ms) { + max_time_ms = keepalive_ms; + client_alive_scheduled = 1; + } } - if (compat20) { #if 0 - /* wrong: bad condition XXX */ - if (channel_not_very_much_buffered_data()) + /* wrong: bad condition XXX */ + if (channel_not_very_much_buffered_data()) #endif - FD_SET(connection_in, *readsetp); - } else { - /* - * Read packets from the client unless we have too much - * buffered stdin or channel data. - */ - if (buffer_len(&stdin_buffer) < buffer_high && - channel_not_very_much_buffered_data()) - FD_SET(connection_in, *readsetp); - /* - * If there is not too much data already buffered going to - * the client, try to get some more data from the program. - */ - if (packet_not_very_much_data_to_write()) { - program_alive_scheduled = child_terminated; - if (!fdout_eof) - FD_SET(fdout, *readsetp); - if (!fderr_eof) - FD_SET(fderr, *readsetp); - } - /* - * If we have buffered data, try to write some of that data - * to the program. - */ - if (fdin != -1 && buffer_len(&stdin_buffer) > 0) - FD_SET(fdin, *writesetp); - } + FD_SET(connection_in, *readsetp); notify_prepare(*readsetp); /* * If we have buffered packet data going to the client, mark that * descriptor. */ - if (packet_have_data_to_write()) + if (ssh_packet_have_data_to_write(ssh)) FD_SET(connection_out, *writesetp); /* * If child has terminated and there is enough buffer space to read * from it, then read as much as is available and exit. */ - if (child_terminated && packet_not_very_much_data_to_write()) - if (max_time_milliseconds == 0 || client_alive_scheduled) - max_time_milliseconds = 100; + if (child_terminated && ssh_packet_not_very_much_data_to_write(ssh)) + if (max_time_ms == 0 || client_alive_scheduled) + max_time_ms = 100; - if (max_time_milliseconds == 0) + if (max_time_ms == 0) tvp = NULL; else { - tv.tv_sec = max_time_milliseconds / 1000; - tv.tv_usec = 1000 * (max_time_milliseconds % 1000); + tv.tv_sec = max_time_ms / 1000; + tv.tv_usec = 1000 * (max_time_ms % 1000); tvp = &tv; } @@ -373,14 +293,19 @@ wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp, memset(*writesetp, 0, *nallocp); if (errno != EINTR) error("select: %.100s", strerror(errno)); - } else { - if (ret == 0 && client_alive_scheduled) - client_alive_check(); - if (!compat20 && program_alive_scheduled && fdin_is_tty) { - if (!fdout_eof) - FD_SET(fdout, *readsetp); - if (!fderr_eof) - FD_SET(fderr, *readsetp); + } else if (client_alive_scheduled) { + time_t now = monotime(); + + /* + * If the select timed out, or returned for some other reason + * but we haven't heard from the client in time, send keepalive. + */ + if (ret == 0 || (last_client_time != 0 && last_client_time + + options.client_alive_interval <= now)) { + client_alive_check(ssh); + last_client_time = now; + } else if (FD_ISSET(connection_in, *readsetp)) { + last_client_time = now; } } @@ -391,415 +316,64 @@ wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp, * Processes input from the client and the program. Input data is stored * in buffers and processed later. */ -static void -process_input(fd_set *readset) +static int +process_input(struct ssh *ssh, fd_set *readset, int connection_in) { - int len; + int r, len; char buf[16384]; /* Read and buffer any input data from the client. */ if (FD_ISSET(connection_in, readset)) { - int cont = 0; - len = roaming_read(connection_in, buf, sizeof(buf), &cont); + len = read(connection_in, buf, sizeof(buf)); if (len == 0) { - if (cont) - return; - verbose("Connection closed by %.100s", - get_remote_ipaddr()); - connection_closed = 1; - if (compat20) - return; - cleanup_exit(255); - } else if (len < 0) { + verbose("Connection closed by %.100s port %d", + ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); + return -1; + } else if (len == -1) { if (errno != EINTR && errno != EAGAIN && errno != EWOULDBLOCK) { verbose("Read error from remote host " - "%.100s: %.100s", - get_remote_ipaddr(), strerror(errno)); + "%.100s port %d: %.100s", + ssh_remote_ipaddr(ssh), + ssh_remote_port(ssh), strerror(errno)); cleanup_exit(255); } } else { /* Buffer any received data. */ - packet_process_incoming(buf, len); - } - } - if (compat20) - return; - - /* Read and buffer any available stdout data from the program. */ - if (!fdout_eof && FD_ISSET(fdout, readset)) { - errno = 0; - len = read(fdout, buf, sizeof(buf)); - if (len < 0 && (errno == EINTR || ((errno == EAGAIN || - errno == EWOULDBLOCK) && !child_terminated))) { - /* do nothing */ -#ifndef PTY_ZEROREAD - } else if (len <= 0) { -#else - } else if ((!isatty(fdout) && len <= 0) || - (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) { -#endif - fdout_eof = 1; - } else { - buffer_append(&stdout_buffer, buf, len); - fdout_bytes += len; - } - } - /* Read and buffer any available stderr data from the program. */ - if (!fderr_eof && FD_ISSET(fderr, readset)) { - errno = 0; - len = read(fderr, buf, sizeof(buf)); - if (len < 0 && (errno == EINTR || ((errno == EAGAIN || - errno == EWOULDBLOCK) && !child_terminated))) { - /* do nothing */ -#ifndef PTY_ZEROREAD - } else if (len <= 0) { -#else - } else if ((!isatty(fderr) && len <= 0) || - (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) { -#endif - fderr_eof = 1; - } else { - buffer_append(&stderr_buffer, buf, len); + if ((r = ssh_packet_process_incoming(ssh, buf, len)) + != 0) + fatal("%s: ssh_packet_process_incoming: %s", + __func__, ssh_err(r)); } } + return 0; } /* * Sends data from internal buffers to client program stdin. */ static void -process_output(fd_set *writeset) +process_output(struct ssh *ssh, fd_set *writeset, int connection_out) { - struct termios tio; - u_char *data; - u_int dlen; - int len; - - /* Write buffered data to program stdin. */ - if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) { - data = buffer_ptr(&stdin_buffer); - dlen = buffer_len(&stdin_buffer); - len = write(fdin, data, dlen); - if (len < 0 && - (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)) { - /* do nothing */ - } else if (len <= 0) { - if (fdin != fdout) - close(fdin); - else - shutdown(fdin, SHUT_WR); /* We will no longer send. */ - fdin = -1; - } else { - /* Successful write. */ - if (fdin_is_tty && dlen >= 1 && data[0] != '\r' && - tcgetattr(fdin, &tio) == 0 && - !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { - /* - * Simulate echo to reduce the impact of - * traffic analysis - */ - packet_send_ignore(len); - packet_send(); - } - /* Consume the data from the buffer. */ - buffer_consume(&stdin_buffer, len); - /* Update the count of bytes written to the program. */ - stdin_bytes += len; + int r; + + /* Send any buffered packet data to the client. */ + if (FD_ISSET(connection_out, writeset)) { + if ((r = ssh_packet_write_poll(ssh)) != 0) { + sshpkt_fatal(ssh, r, "%s: ssh_packet_write_poll", + __func__); } } - /* Send any buffered packet data to the client. */ - if (FD_ISSET(connection_out, writeset)) - packet_write_poll(); } -/* - * Wait until all buffered output has been sent to the client. - * This is used when the program terminates. - */ static void -drain_output(void) +process_buffered_input_packets(struct ssh *ssh) { - /* Send any buffered stdout data to the client. */ - if (buffer_len(&stdout_buffer) > 0) { - packet_start(SSH_SMSG_STDOUT_DATA); - packet_put_string(buffer_ptr(&stdout_buffer), - buffer_len(&stdout_buffer)); - packet_send(); - /* Update the count of sent bytes. */ - stdout_bytes += buffer_len(&stdout_buffer); - } - /* Send any buffered stderr data to the client. */ - if (buffer_len(&stderr_buffer) > 0) { - packet_start(SSH_SMSG_STDERR_DATA); - packet_put_string(buffer_ptr(&stderr_buffer), - buffer_len(&stderr_buffer)); - packet_send(); - /* Update the count of sent bytes. */ - stderr_bytes += buffer_len(&stderr_buffer); - } - /* Wait until all buffered data has been written to the client. */ - packet_write_wait(); + ssh_dispatch_run_fatal(ssh, DISPATCH_NONBLOCK, NULL); } static void -process_buffered_input_packets(void) -{ - dispatch_run(DISPATCH_NONBLOCK, NULL, active_state); -} - -/* - * 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...\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 */ -} - -static void -collect_children(void) +collect_children(struct ssh *ssh) { pid_t pid; sigset_t oset, nset; @@ -812,56 +386,58 @@ collect_children(void) if (child_terminated) { debug("Received SIGCHLD."); while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || - (pid < 0 && errno == EINTR)) + (pid == -1 && errno == EINTR)) if (pid > 0) - session_close_by_pid(pid, status); + session_close_by_pid(ssh, pid, status); child_terminated = 0; } sigprocmask(SIG_SETMASK, &oset, NULL); } void -server_loop2(Authctxt *authctxt) +server_loop2(struct ssh *ssh, Authctxt *authctxt) { fd_set *readset = NULL, *writeset = NULL; - int rekeying = 0, max_fd; - u_int nalloc = 0; + int max_fd; + u_int nalloc = 0, connection_in, connection_out; u_int64_t rekey_timeout_ms = 0; debug("Entering interactive session for SSH2."); - mysignal(SIGCHLD, sigchld_handler); + ssh_signal(SIGCHLD, sigchld_handler); child_terminated = 0; - connection_in = packet_get_connection_in(); - connection_out = packet_get_connection_out(); + connection_in = ssh_packet_get_connection_in(ssh); + connection_out = ssh_packet_get_connection_out(ssh); if (!use_privsep) { - signal(SIGTERM, sigterm_handler); - signal(SIGINT, sigterm_handler); - signal(SIGQUIT, sigterm_handler); + ssh_signal(SIGTERM, sigterm_handler); + ssh_signal(SIGINT, sigterm_handler); + ssh_signal(SIGQUIT, sigterm_handler); } notify_setup(); - max_fd = MAX(connection_in, connection_out); - max_fd = MAX(max_fd, notify_pipe[0]); + max_fd = MAXIMUM(connection_in, connection_out); + max_fd = MAXIMUM(max_fd, notify_pipe[0]); - server_init_dispatch(); + server_init_dispatch(ssh); for (;;) { - process_buffered_input_packets(); - - rekeying = (active_state->kex != NULL && !active_state->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 + process_buffered_input_packets(ssh); + + if (!ssh_packet_is_rekeying(ssh) && + ssh_packet_not_very_much_data_to_write(ssh)) + channel_output_poll(ssh); + if (options.rekey_interval > 0 && + !ssh_packet_is_rekeying(ssh)) { + rekey_timeout_ms = ssh_packet_get_rekey_timeout(ssh) * + 1000; + } else { rekey_timeout_ms = 0; + } - wait_until_can_do_something(&readset, &writeset, &max_fd, - &nalloc, rekey_timeout_ms); + wait_until_can_do_something(ssh, connection_in, connection_out, + &readset, &writeset, &max_fd, &nalloc, rekey_timeout_ms); if (received_sigterm) { logit("Exiting on signal %d", (int)received_sigterm); @@ -869,34 +445,27 @@ server_loop2(Authctxt *authctxt) cleanup_exit(255); } - collect_children(); - if (!rekeying) { - channel_after_select(readset, writeset); - if (packet_need_rekeying()) { - debug("need rekeying"); - active_state->kex->done = 0; - kex_send_kexinit(active_state); - } - } - process_input(readset); - if (connection_closed) + collect_children(ssh); + if (!ssh_packet_is_rekeying(ssh)) + channel_after_select(ssh, readset, writeset); + if (process_input(ssh, readset, connection_in) < 0) break; - process_output(writeset); + process_output(ssh, writeset, connection_out); } - collect_children(); + collect_children(ssh); free(readset); free(writeset); /* free all channels, no more reads and writes */ - channel_free_all(); + channel_free_all(ssh); /* free remaining sessions, e.g. remove wtmp entries */ - session_destroy_all(NULL); + session_destroy_all(ssh, NULL); } static int -server_input_keep_alive(int type, u_int32_t seq, void *ctxt) +server_input_keep_alive(int type, u_int32_t seq, struct ssh *ssh) { debug("Got %d/%u for keepalive", type, seq); /* @@ -904,109 +473,88 @@ server_input_keep_alive(int type, u_int32_t seq, void *ctxt) * even if this was generated by something other than * the bogus CHANNEL_REQUEST we send for keepalives. */ - packet_set_alive_timeouts(0); - return 0; -} - -static int -server_input_stdin_data(int type, u_int32_t seq, void *ctxt) -{ - char *data; - u_int data_len; - - /* Stdin data from the client. Append it to the buffer. */ - /* Ignore any data if the client has closed stdin. */ - if (fdin == -1) - return 0; - data = packet_get_string(&data_len); - packet_check_eom(); - buffer_append(&stdin_buffer, data, data_len); - explicit_bzero(data, data_len); - free(data); - return 0; -} - -static int -server_input_eof(int type, u_int32_t seq, void *ctxt) -{ - /* - * Eof from the client. The stdin descriptor to the - * program will be closed when all buffered data has - * drained. - */ - debug("EOF received for stdin."); - packet_check_eom(); - stdin_eof = 1; - return 0; -} - -static int -server_input_window_size(int type, u_int32_t seq, void *ctxt) -{ - u_int row = packet_get_int(); - u_int col = packet_get_int(); - u_int xpixel = packet_get_int(); - u_int ypixel = packet_get_int(); - - debug("Window change received."); - packet_check_eom(); - if (fdin != -1) - pty_change_window_size(fdin, row, col, xpixel, ypixel); + ssh_packet_set_alive_timeouts(ssh, 0); return 0; } static Channel * -server_request_direct_tcpip(void) +server_request_direct_tcpip(struct ssh *ssh, int *reason, const char **errmsg) { Channel *c = NULL; - char *target, *originator; - u_short target_port, originator_port; - - target = packet_get_string(NULL); - target_port = packet_get_int(); - originator = packet_get_string(NULL); - originator_port = packet_get_int(); - packet_check_eom(); - - debug("server_request_direct_tcpip: originator %s port %d, target %s " - "port %d", originator, originator_port, target, target_port); + char *target = NULL, *originator = NULL; + u_int target_port = 0, originator_port = 0; + int r; + + if ((r = sshpkt_get_cstring(ssh, &target, NULL)) != 0 || + (r = sshpkt_get_u32(ssh, &target_port)) != 0 || + (r = sshpkt_get_cstring(ssh, &originator, NULL)) != 0 || + (r = sshpkt_get_u32(ssh, &originator_port)) != 0 || + (r = sshpkt_get_end(ssh)) != 0) + sshpkt_fatal(ssh, r, "%s: parse packet", __func__); + if (target_port > 0xFFFF) { + error("%s: invalid target port", __func__); + *reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED; + goto out; + } + if (originator_port > 0xFFFF) { + error("%s: invalid originator port", __func__); + *reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED; + goto out; + } + + debug("%s: originator %s port %u, target %s port %u", __func__, + originator, originator_port, target, target_port); /* XXX fine grained permissions */ if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0 && - !no_port_forwarding_flag) { - c = channel_connect_to_port(target, target_port, - "direct-tcpip", "direct-tcpip"); + auth_opts->permit_port_forwarding_flag && + !options.disable_forwarding) { + c = channel_connect_to_port(ssh, target, target_port, + "direct-tcpip", "direct-tcpip", reason, errmsg); } else { logit("refused local port forward: " "originator %s port %d, target %s port %d", originator, originator_port, target, target_port); + if (reason != NULL) + *reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED; } + out: free(originator); free(target); - return c; } static Channel * -server_request_direct_streamlocal(void) +server_request_direct_streamlocal(struct ssh *ssh) { Channel *c = NULL; - char *target, *originator; - u_short originator_port; + char *target = NULL, *originator = NULL; + u_int originator_port = 0; + struct passwd *pw = the_authctxt->pw; + int r; + + if (pw == NULL || !the_authctxt->valid) + fatal("%s: no/invalid user", __func__); - target = packet_get_string(NULL); - originator = packet_get_string(NULL); - originator_port = packet_get_int(); - packet_check_eom(); + if ((r = sshpkt_get_cstring(ssh, &target, NULL)) != 0 || + (r = sshpkt_get_cstring(ssh, &originator, NULL)) != 0 || + (r = sshpkt_get_u32(ssh, &originator_port)) != 0 || + (r = sshpkt_get_end(ssh)) != 0) + sshpkt_fatal(ssh, r, "%s: parse packet", __func__); + if (originator_port > 0xFFFF) { + error("%s: invalid originator port", __func__); + goto out; + } - debug("server_request_direct_streamlocal: originator %s port %d, target %s", + debug("%s: originator %s port %d, target %s", __func__, originator, originator_port, target); /* XXX fine grained permissions */ if ((options.allow_streamlocal_forwarding & FORWARD_LOCAL) != 0 && - !no_port_forwarding_flag) { - c = channel_connect_to_path(target, + auth_opts->permit_port_forwarding_flag && + !options.disable_forwarding && (pw->pw_uid == 0 || use_privsep)) { + c = channel_connect_to_path(ssh, target, "direct-streamlocal@openssh.com", "direct-streamlocal"); } else { logit("refused streamlocal port forward: " @@ -1014,69 +562,94 @@ server_request_direct_streamlocal(void) originator, originator_port, target); } +out: free(originator); free(target); - return c; } static Channel * -server_request_tun(void) +server_request_tun(struct ssh *ssh) { Channel *c = NULL; - int mode, tun; - int sock; + u_int mode, tun; + int r, sock; + char *tmp, *ifname = NULL; - mode = packet_get_int(); + if ((r = sshpkt_get_u32(ssh, &mode)) != 0) + sshpkt_fatal(ssh, r, "%s: parse mode", __func__); switch (mode) { case SSH_TUNMODE_POINTOPOINT: case SSH_TUNMODE_ETHERNET: break; default: - packet_send_debug("Unsupported tunnel device mode."); + ssh_packet_send_debug(ssh, "Unsupported tunnel device mode."); return NULL; } if ((options.permit_tun & mode) == 0) { - packet_send_debug("Server has rejected tunnel device " + ssh_packet_send_debug(ssh, "Server has rejected tunnel device " "forwarding"); return NULL; } - tun = packet_get_int(); - if (forced_tun_device != -1) { - if (tun != SSH_TUNID_ANY && forced_tun_device != tun) + if ((r = sshpkt_get_u32(ssh, &tun)) != 0) + sshpkt_fatal(ssh, r, "%s: parse device", __func__); + if (tun > INT_MAX) { + debug("%s: invalid tun", __func__); + goto done; + } + if (auth_opts->force_tun_device != -1) { + if (tun != SSH_TUNID_ANY && + auth_opts->force_tun_device != (int)tun) goto done; - tun = forced_tun_device; + tun = auth_opts->force_tun_device; } - sock = tun_open(tun, mode); + sock = tun_open(tun, mode, &ifname); if (sock < 0) goto done; - c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1, + debug("Tunnel forwarding using interface %s", ifname); + + c = channel_new(ssh, "tun", SSH_CHANNEL_OPEN, sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); c->datagram = 1; #if defined(SSH_TUN_FILTER) if (mode == SSH_TUNMODE_POINTOPOINT) - channel_register_filter(c->self, sys_tun_infilter, + channel_register_filter(ssh, c->self, sys_tun_infilter, sys_tun_outfilter, NULL, NULL); #endif + /* + * Update the list of names exposed to the session + * XXX remove these if the tunnels are closed (won't matter + * much if they are already in the environment though) + */ + tmp = tun_fwd_ifnames; + xasprintf(&tun_fwd_ifnames, "%s%s%s", + tun_fwd_ifnames == NULL ? "" : tun_fwd_ifnames, + tun_fwd_ifnames == NULL ? "" : ",", + ifname); + free(tmp); + free(ifname); + done: if (c == NULL) - packet_send_debug("Failed to open the tunnel device."); + ssh_packet_send_debug(ssh, "Failed to open the tunnel device."); return c; } static Channel * -server_request_session(void) +server_request_session(struct ssh *ssh) { Channel *c; + int r; debug("input_session_request"); - packet_check_eom(); + if ((r = sshpkt_get_end(ssh)) != 0) + sshpkt_fatal(ssh, r, "%s: parse packet", __func__); if (no_more_sessions) { - packet_disconnect("Possible attack: attempt to open a session " - "after additional sessions disabled"); + ssh_packet_disconnect(ssh, "Possible attack: attempt to open a " + "session after additional sessions disabled"); } /* @@ -1085,79 +658,84 @@ server_request_session(void) * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all * CHANNEL_REQUEST messages is registered. */ - c = channel_new("session", SSH_CHANNEL_LARVAL, + c = channel_new(ssh, "session", SSH_CHANNEL_LARVAL, -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT, 0, "server-session", 1); if (session_open(the_authctxt, c->self) != 1) { debug("session open failed, free channel %d", c->self); - channel_free(c); + channel_free(ssh, c); return NULL; } - channel_register_cleanup(c->self, session_close_by_channel, 0); + channel_register_cleanup(ssh, c->self, session_close_by_channel, 0); return c; } static int -server_input_channel_open(int type, u_int32_t seq, void *ctxt) +server_input_channel_open(int type, u_int32_t seq, struct ssh *ssh) { Channel *c = NULL; - char *ctype; - int rchan; - u_int rmaxpack, rwindow, len; - - ctype = packet_get_string(&len); - rchan = packet_get_int(); - rwindow = packet_get_int(); - rmaxpack = packet_get_int(); - - debug("server_input_channel_open: ctype %s rchan %d win %d max %d", + char *ctype = NULL; + const char *errmsg = NULL; + int r, reason = SSH2_OPEN_CONNECT_FAILED; + u_int rchan = 0, rmaxpack = 0, rwindow = 0; + + if ((r = sshpkt_get_cstring(ssh, &ctype, NULL)) != 0 || + (r = sshpkt_get_u32(ssh, &rchan)) != 0 || + (r = sshpkt_get_u32(ssh, &rwindow)) != 0 || + (r = sshpkt_get_u32(ssh, &rmaxpack)) != 0) + sshpkt_fatal(ssh, r, "%s: parse packet", __func__); + debug("%s: ctype %s rchan %u win %u max %u", __func__, ctype, rchan, rwindow, rmaxpack); if (strcmp(ctype, "session") == 0) { - c = server_request_session(); + c = server_request_session(ssh); } else if (strcmp(ctype, "direct-tcpip") == 0) { - c = server_request_direct_tcpip(); + c = server_request_direct_tcpip(ssh, &reason, &errmsg); } else if (strcmp(ctype, "direct-streamlocal@openssh.com") == 0) { - c = server_request_direct_streamlocal(); + c = server_request_direct_streamlocal(ssh); } else if (strcmp(ctype, "tun@openssh.com") == 0) { - c = server_request_tun(); + c = server_request_tun(ssh); } if (c != NULL) { - debug("server_input_channel_open: confirm %s", ctype); + debug("%s: confirm %s", __func__, ctype); c->remote_id = rchan; + c->have_remote_id = 1; c->remote_window = rwindow; c->remote_maxpacket = rmaxpack; if (c->type != SSH_CHANNEL_CONNECTING) { - packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); - packet_put_int(c->remote_id); - packet_put_int(c->self); - packet_put_int(c->local_window); - packet_put_int(c->local_maxpacket); - packet_send(); + if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 || + (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 || + (r = sshpkt_put_u32(ssh, c->self)) != 0 || + (r = sshpkt_put_u32(ssh, c->local_window)) != 0 || + (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 || + (r = sshpkt_send(ssh)) != 0) { + sshpkt_fatal(ssh, r, + "%s: send open confirm", __func__); + } } } else { - debug("server_input_channel_open: failure %s", ctype); - packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); - packet_put_int(rchan); - packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); - if (!(datafellows & SSH_BUG_OPENFAILURE)) { - packet_put_cstring("open failed"); - packet_put_cstring(""); + debug("%s: failure %s", __func__, ctype); + if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 || + (r = sshpkt_put_u32(ssh, rchan)) != 0 || + (r = sshpkt_put_u32(ssh, reason)) != 0 || + (r = sshpkt_put_cstring(ssh, errmsg ? errmsg : "open failed")) != 0 || + (r = sshpkt_put_cstring(ssh, "")) != 0 || + (r = sshpkt_send(ssh)) != 0) { + sshpkt_fatal(ssh, r, + "%s: send open failure", __func__); } - packet_send(); } free(ctype); return 0; } static int -server_input_hostkeys_prove(struct sshbuf **respp) +server_input_hostkeys_prove(struct ssh *ssh, struct sshbuf **respp) { - struct ssh *ssh = active_state; /* XXX */ struct sshbuf *resp = NULL; struct sshbuf *sigbuf = NULL; struct sshkey *key = NULL, *key_pub = NULL, *key_prv = NULL; - int r, ndx, success = 0; + int r, ndx, kexsigtype, use_kexsigtype, success = 0; const u_char *blob; u_char *sig = 0; size_t blen, slen; @@ -1165,6 +743,8 @@ server_input_hostkeys_prove(struct sshbuf **respp) if ((resp = sshbuf_new()) == NULL || (sigbuf = sshbuf_new()) == NULL) fatal("%s: sshbuf_new", __func__); + kexsigtype = sshkey_type_plain( + sshkey_type_from_name(ssh->kex->hostkey_alg)); while (ssh_packet_remaining(ssh) > 0) { sshkey_free(key); key = NULL; @@ -1195,13 +775,20 @@ server_input_hostkeys_prove(struct sshbuf **respp) sshbuf_reset(sigbuf); free(sig); sig = NULL; + /* + * For RSA keys, prefer to use the signature type negotiated + * during KEX to the default (SHA1). + */ + use_kexsigtype = kexsigtype == KEY_RSA && + sshkey_type_plain(key->type) == KEY_RSA; if ((r = sshbuf_put_cstring(sigbuf, "hostkeys-prove-00@openssh.com")) != 0 || (r = sshbuf_put_string(sigbuf, ssh->kex->session_id, ssh->kex->session_id_len)) != 0 || (r = sshkey_puts(key, sigbuf)) != 0 || - (r = ssh->kex->sign(key_prv, key_pub, &sig, &slen, - sshbuf_ptr(sigbuf), sshbuf_len(sigbuf), 0)) != 0 || + (r = ssh->kex->sign(ssh, key_prv, key_pub, &sig, &slen, + sshbuf_ptr(sigbuf), sshbuf_len(sigbuf), + use_kexsigtype ? ssh->kex->hostkey_alg : NULL)) != 0 || (r = sshbuf_put_string(resp, sig, slen)) != 0) { error("%s: couldn't prepare signature: %s", __func__, ssh_err(r)); @@ -1221,198 +808,175 @@ server_input_hostkeys_prove(struct sshbuf **respp) } static int -server_input_global_request(int type, u_int32_t seq, void *ctxt) +server_input_global_request(int type, u_int32_t seq, struct ssh *ssh) { - char *rtype; - int want_reply; + char *rtype = NULL; + u_char want_reply = 0; int r, success = 0, allocated_listen_port = 0; + u_int port = 0; struct sshbuf *resp = NULL; + struct passwd *pw = the_authctxt->pw; + struct Forward fwd; + + memset(&fwd, 0, sizeof(fwd)); + if (pw == NULL || !the_authctxt->valid) + fatal("%s: no/invalid user", __func__); - rtype = packet_get_string(NULL); - want_reply = packet_get_char(); - debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply); + if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 || + (r = sshpkt_get_u8(ssh, &want_reply)) != 0) + sshpkt_fatal(ssh, r, "%s: parse packet", __func__); + debug("%s: rtype %s want_reply %d", __func__, rtype, want_reply); /* -R style forwarding */ if (strcmp(rtype, "tcpip-forward") == 0) { - struct passwd *pw; - struct Forward fwd; - - pw = the_authctxt->pw; - if (pw == NULL || !the_authctxt->valid) - fatal("server_input_global_request: no/invalid user"); - memset(&fwd, 0, sizeof(fwd)); - fwd.listen_host = packet_get_string(NULL); - fwd.listen_port = (u_short)packet_get_int(); - debug("server_input_global_request: tcpip-forward listen %s port %d", - fwd.listen_host, fwd.listen_port); - + if ((r = sshpkt_get_cstring(ssh, &fwd.listen_host, NULL)) != 0 || + (r = sshpkt_get_u32(ssh, &port)) != 0) + sshpkt_fatal(ssh, r, "%s: parse tcpip-forward", __func__); + debug("%s: tcpip-forward listen %s port %u", __func__, + fwd.listen_host, port); + if (port <= INT_MAX) + fwd.listen_port = (int)port; /* check permissions */ - if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 || - no_port_forwarding_flag || - (!want_reply && fwd.listen_port == 0) -#ifndef NO_IPPORT_RESERVED_CONCEPT - || (fwd.listen_port != 0 && fwd.listen_port < IPPORT_RESERVED && - pw->pw_uid != 0) -#endif - ) { + if (port > INT_MAX || + (options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 || + !auth_opts->permit_port_forwarding_flag || + options.disable_forwarding || + (!want_reply && fwd.listen_port == 0) || + (fwd.listen_port != 0 && + !bind_permitted(fwd.listen_port, pw->pw_uid))) { success = 0; - packet_send_debug("Server has disabled port forwarding."); + ssh_packet_send_debug(ssh, "Server has disabled port forwarding."); } else { /* Start listening on the port */ - success = channel_setup_remote_fwd_listener(&fwd, + success = channel_setup_remote_fwd_listener(ssh, &fwd, &allocated_listen_port, &options.fwd_opts); } - free(fwd.listen_host); if ((resp = sshbuf_new()) == NULL) fatal("%s: sshbuf_new", __func__); - if ((r = sshbuf_put_u32(resp, allocated_listen_port)) != 0) + if (allocated_listen_port != 0 && + (r = sshbuf_put_u32(resp, allocated_listen_port)) != 0) fatal("%s: sshbuf_put_u32: %s", __func__, ssh_err(r)); } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) { - struct Forward fwd; + if ((r = sshpkt_get_cstring(ssh, &fwd.listen_host, NULL)) != 0 || + (r = sshpkt_get_u32(ssh, &port)) != 0) + sshpkt_fatal(ssh, r, "%s: parse cancel-tcpip-forward", __func__); - memset(&fwd, 0, sizeof(fwd)); - fwd.listen_host = packet_get_string(NULL); - fwd.listen_port = (u_short)packet_get_int(); debug("%s: cancel-tcpip-forward addr %s port %d", __func__, - fwd.listen_host, fwd.listen_port); - - success = channel_cancel_rport_listener(&fwd); - free(fwd.listen_host); + fwd.listen_host, port); + if (port <= INT_MAX) { + fwd.listen_port = (int)port; + success = channel_cancel_rport_listener(ssh, &fwd); + } } else if (strcmp(rtype, "streamlocal-forward@openssh.com") == 0) { - struct Forward fwd; - - memset(&fwd, 0, sizeof(fwd)); - fwd.listen_path = packet_get_string(NULL); - debug("server_input_global_request: streamlocal-forward listen path %s", + if ((r = sshpkt_get_cstring(ssh, &fwd.listen_path, NULL)) != 0) + sshpkt_fatal(ssh, r, "%s: parse streamlocal-forward@openssh.com", __func__); + debug("%s: streamlocal-forward listen path %s", __func__, fwd.listen_path); /* check permissions */ if ((options.allow_streamlocal_forwarding & FORWARD_REMOTE) == 0 - || no_port_forwarding_flag) { + || !auth_opts->permit_port_forwarding_flag || + options.disable_forwarding || + (pw->pw_uid != 0 && !use_privsep)) { success = 0; - packet_send_debug("Server has disabled port forwarding."); + ssh_packet_send_debug(ssh, "Server has disabled " + "streamlocal forwarding."); } else { /* Start listening on the socket */ - success = channel_setup_remote_fwd_listener( + success = channel_setup_remote_fwd_listener(ssh, &fwd, NULL, &options.fwd_opts); } - free(fwd.listen_path); } else if (strcmp(rtype, "cancel-streamlocal-forward@openssh.com") == 0) { - struct Forward fwd; - - memset(&fwd, 0, sizeof(fwd)); - fwd.listen_path = packet_get_string(NULL); + if ((r = sshpkt_get_cstring(ssh, &fwd.listen_path, NULL)) != 0) + sshpkt_fatal(ssh, r, "%s: parse cancel-streamlocal-forward@openssh.com", __func__); debug("%s: cancel-streamlocal-forward path %s", __func__, fwd.listen_path); - success = channel_cancel_rport_listener(&fwd); - free(fwd.listen_path); + success = channel_cancel_rport_listener(ssh, &fwd); } else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) { no_more_sessions = 1; success = 1; } else if (strcmp(rtype, "hostkeys-prove-00@openssh.com") == 0) { - success = server_input_hostkeys_prove(&resp); + success = server_input_hostkeys_prove(ssh, &resp); } + /* XXX sshpkt_get_end() */ if (want_reply) { - packet_start(success ? - SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); - if (success && resp != NULL) - ssh_packet_put_raw(active_state, sshbuf_ptr(resp), - sshbuf_len(resp)); - packet_send(); - packet_write_wait(); - } + if ((r = sshpkt_start(ssh, success ? + SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE)) != 0 || + (success && resp != NULL && (r = sshpkt_putb(ssh, resp)) != 0) || + (r = sshpkt_send(ssh)) != 0 || + (r = ssh_packet_write_wait(ssh)) != 0) + sshpkt_fatal(ssh, r, "%s: send reply", __func__); + } + free(fwd.listen_host); + free(fwd.listen_path); free(rtype); sshbuf_free(resp); return 0; } static int -server_input_channel_req(int type, u_int32_t seq, void *ctxt) +server_input_channel_req(int type, u_int32_t seq, struct ssh *ssh) { Channel *c; - int id, reply, success = 0; - char *rtype; + int r, success = 0; + char *rtype = NULL; + u_char want_reply = 0; + u_int id = 0; - id = packet_get_int(); - rtype = packet_get_string(NULL); - reply = packet_get_char(); + if ((r = sshpkt_get_u32(ssh, &id)) != 0 || + (r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 || + (r = sshpkt_get_u8(ssh, &want_reply)) != 0) + sshpkt_fatal(ssh, r, "%s: parse packet", __func__); - debug("server_input_channel_req: channel %d request %s reply %d", - id, rtype, reply); + debug("server_input_channel_req: channel %u request %s reply %d", + id, rtype, want_reply); - if ((c = channel_lookup(id)) == NULL) - packet_disconnect("server_input_channel_req: " - "unknown channel %d", id); + if (id >= INT_MAX || (c = channel_lookup(ssh, (int)id)) == NULL) { + ssh_packet_disconnect(ssh, "%s: unknown channel %d", + __func__, id); + } if (!strcmp(rtype, "eow@openssh.com")) { - packet_check_eom(); - chan_rcvd_eow(c); + if ((r = sshpkt_get_end(ssh)) != 0) + sshpkt_fatal(ssh, r, "%s: parse packet", __func__); + chan_rcvd_eow(ssh, c); } else if ((c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0) - success = session_input_channel_req(c, rtype); - if (reply && !(c->flags & CHAN_CLOSE_SENT)) { - packet_start(success ? - SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); - packet_put_int(c->remote_id); - packet_send(); + success = session_input_channel_req(ssh, c, rtype); + if (want_reply && !(c->flags & CHAN_CLOSE_SENT)) { + if (!c->have_remote_id) + fatal("%s: channel %d: no remote_id", + __func__, c->self); + if ((r = sshpkt_start(ssh, success ? + SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE)) != 0 || + (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 || + (r = sshpkt_send(ssh)) != 0) + sshpkt_fatal(ssh, r, "%s: send reply", __func__); } free(rtype); return 0; } static void -server_init_dispatch_20(void) -{ - debug("server_init_dispatch_20"); - dispatch_init(&dispatch_protocol_error); - dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); - dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); - dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); - dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); - dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open); - dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); - dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); - dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req); - dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); - dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request); +server_init_dispatch(struct ssh *ssh) +{ + debug("server_init_dispatch"); + ssh_dispatch_init(ssh, &dispatch_protocol_error); + ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); + ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_DATA, &channel_input_data); + ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); + ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); + ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open); + ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); + ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); + ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req); + ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); + ssh_dispatch_set(ssh, SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request); /* client_alive */ - dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive); - dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive); - dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive); - dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive); + ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive); + ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive); + ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive); + ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive); /* rekeying */ - dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); -} -static void -server_init_dispatch_13(void) -{ - debug("server_init_dispatch_13"); - dispatch_init(NULL); - dispatch_set(SSH_CMSG_EOF, &server_input_eof); - dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data); - dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size); - dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); - dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); - dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); - dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); - dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); - dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); -} -static void -server_init_dispatch_15(void) -{ - server_init_dispatch_13(); - debug("server_init_dispatch_15"); - dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); - dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose); -} -static void -server_init_dispatch(void) -{ - if (compat20) - server_init_dispatch_20(); - else if (compat13) - server_init_dispatch_13(); - else - server_init_dispatch_15(); + ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit); } |