diff options
Diffstat (limited to 'crypto/openssh/serverloop.c')
| -rw-r--r-- | crypto/openssh/serverloop.c | 409 |
1 files changed, 291 insertions, 118 deletions
diff --git a/crypto/openssh/serverloop.c b/crypto/openssh/serverloop.c index a5ecfe97d5d7..9bf31275beaf 100644 --- a/crypto/openssh/serverloop.c +++ b/crypto/openssh/serverloop.c @@ -5,6 +5,10 @@ * Created: Sun Sep 10 00:30:37 1995 ylo * Server main loop for handling the interactive session. */ +/* + * SSH2 support by Markus Friedl. + * Copyright (c) 2000 Markus Friedl. All rights reserved. + */ #include "includes.h" #include "xmalloc.h" @@ -13,6 +17,12 @@ #include "buffer.h" #include "servconf.h" #include "pty.h" +#include "channels.h" + +#include "compat.h" +#include "ssh2.h" +#include "session.h" +#include "dispatch.h" static Buffer stdin_buffer; /* Buffer for stdin data. */ static Buffer stdout_buffer; /* Buffer for stdout data. */ @@ -38,15 +48,18 @@ static int max_fd; /* Max file descriptor number for select(). */ * will exit after that, as soon as forwarded connections have terminated. */ -static int child_pid; /* Pid of the child. */ +static pid_t child_pid; /* Pid of the child. */ static volatile int child_terminated; /* The child has terminated. */ static volatile int child_wait_status; /* Status from wait(). */ -void +void server_init_dispatch(void); + +void sigchld_handler(int sig) { int save_errno = errno; - int wait_pid; + pid_t wait_pid; + debug("Received SIGCHLD."); wait_pid = wait((int *) &child_wait_status); if (wait_pid != -1) { @@ -60,110 +73,21 @@ sigchld_handler(int sig) signal(SIGCHLD, sigchld_handler); errno = save_errno; } - -/* - * Process any buffered packets that have been received from the client. - */ -void -process_buffered_input_packets() +void +sigchld_handler2(int sig) { - int type; - char *data; - unsigned int data_len; - int row, col, xpixel, ypixel; - int payload_len; - - /* Process buffered packets from the client. */ - while ((type = packet_read_poll(&payload_len)) != SSH_MSG_NONE) { - switch (type) { - case SSH_CMSG_STDIN_DATA: - /* Stdin data from the client. Append it to the buffer. */ - /* Ignore any data if the client has closed stdin. */ - if (fdin == -1) - break; - data = packet_get_string(&data_len); - packet_integrity_check(payload_len, (4 + data_len), type); - buffer_append(&stdin_buffer, data, data_len); - memset(data, 0, data_len); - xfree(data); - break; - - case SSH_CMSG_EOF: - /* - * 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_integrity_check(payload_len, 0, type); - stdin_eof = 1; - break; - - case SSH_CMSG_WINDOW_SIZE: - debug("Window change received."); - packet_integrity_check(payload_len, 4 * 4, type); - row = packet_get_int(); - col = packet_get_int(); - xpixel = packet_get_int(); - ypixel = packet_get_int(); - if (fdin != -1) - pty_change_window_size(fdin, row, col, xpixel, ypixel); - break; - - case SSH_MSG_PORT_OPEN: - debug("Received port open request."); - channel_input_port_open(payload_len); - break; - - case SSH_MSG_CHANNEL_OPEN_CONFIRMATION: - debug("Received channel open confirmation."); - packet_integrity_check(payload_len, 4 + 4, type); - channel_input_open_confirmation(); - break; - - case SSH_MSG_CHANNEL_OPEN_FAILURE: - debug("Received channel open failure."); - packet_integrity_check(payload_len, 4, type); - channel_input_open_failure(); - break; - - case SSH_MSG_CHANNEL_DATA: - channel_input_data(payload_len); - break; - - case SSH_MSG_CHANNEL_CLOSE: - debug("Received channel close."); - packet_integrity_check(payload_len, 4, type); - channel_input_close(); - break; - - case SSH_MSG_CHANNEL_CLOSE_CONFIRMATION: - debug("Received channel close confirmation."); - packet_integrity_check(payload_len, 4, type); - channel_input_close_confirmation(); - break; - - default: - /* - * In this phase, any unexpected messages cause a - * protocol error. This is to ease debugging; also, - * since no confirmations are sent messages, - * unprocessed unknown messages could cause strange - * problems. Any compatible protocol extensions must - * be negotiated before entering the interactive - * session. - */ - packet_disconnect("Protocol error during session: type %d", - type); - } - } + int save_errno = errno; + debug("Received SIGCHLD."); + child_terminated = 1; + signal(SIGCHLD, sigchld_handler2); + errno = save_errno; } /* * Make packets from buffered stderr data, and buffer it for sending * to the client. */ -void +void make_packets_from_stderr_data() { int len; @@ -192,7 +116,7 @@ make_packets_from_stderr_data() * Make packets from buffered stdout data, and buffer it for sending to the * client. */ -void +void make_packets_from_stdout_data() { int len; @@ -223,7 +147,7 @@ make_packets_from_stdout_data() * have data or can accept data. Optionally, a maximum time can be specified * for the duration of the wait (0 = infinite). */ -void +void wait_until_can_do_something(fd_set * readset, fd_set * writeset, unsigned int max_time_milliseconds) { @@ -240,15 +164,21 @@ retry_select: * Read packets from the client unless we have too much buffered * stdin or channel data. */ - if (buffer_len(&stdin_buffer) < 4096 && - channel_not_very_much_buffered_data()) - FD_SET(connection_in, readset); + if (compat20) { + /* wrong: bad condition XXX */ + if (channel_not_very_much_buffered_data()) + FD_SET(connection_in, readset); + } else { + if (buffer_len(&stdin_buffer) < 4096 && + channel_not_very_much_buffered_data()) + FD_SET(connection_in, readset); + } /* * 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()) { + if (!compat20 && packet_not_very_much_data_to_write()) { if (!fdout_eof) FD_SET(fdout, readset); if (!fderr_eof) @@ -268,7 +198,7 @@ retry_select: /* If we have buffered data, try to write some of that data to the program. */ - if (fdin != -1 && buffer_len(&stdin_buffer) > 0) + if (!compat20 && fdin != -1 && buffer_len(&stdin_buffer) > 0) FD_SET(fdin, writeset); /* Update the maximum descriptor number if appropriate. */ @@ -290,6 +220,8 @@ retry_select: tv.tv_usec = 1000 * (max_time_milliseconds % 1000); tvp = &tv; } + if (tvp!=NULL) + debug("tvp!=NULL kid %d mili %d", child_terminated, max_time_milliseconds); /* Wait for something to happen, or the timeout to expire. */ ret = select(max_fd + 1, readset, writeset, NULL, tvp); @@ -306,7 +238,7 @@ retry_select: * Processes input from the client and the program. Input data is stored * in buffers and processed later. */ -void +void process_input(fd_set * readset) { int len; @@ -333,6 +265,9 @@ process_input(fd_set * readset) /* 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)) { len = read(fdout, buf, sizeof(buf)); @@ -356,20 +291,20 @@ process_input(fd_set * readset) /* * Sends data from internal buffers to client program stdin. */ -void +void process_output(fd_set * writeset) { int len; /* Write buffered data to program stdin. */ - if (fdin != -1 && FD_ISSET(fdin, writeset)) { + if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) { len = write(fdin, buffer_ptr(&stdin_buffer), buffer_len(&stdin_buffer)); if (len <= 0) { #ifdef USE_PIPES close(fdin); #else - if (fdout == -1) + if (fdin != fdout) close(fdin); else shutdown(fdin, SHUT_WR); /* We will no longer send. */ @@ -391,7 +326,7 @@ process_output(fd_set * writeset) * Wait until all buffered output has been sent to the client. * This is used when the program terminates. */ -void +void drain_output() { /* Send any buffered stdout data to the client. */ @@ -416,6 +351,12 @@ drain_output() packet_write_wait(); } +void +process_buffered_input_packets() +{ + dispatch_run(DISPATCH_NONBLOCK, NULL); +} + /* * Performs the interactive session. This handles data transmission between * the client and the program. Note that the notion of stdin, stdout, and @@ -423,10 +364,11 @@ drain_output() * stdin (of the child program), and reads from stdout and stderr (of the * child program). */ -void -server_loop(int pid, int fdin_arg, int fdout_arg, int fderr_arg) +void +server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg) { - int wait_status, wait_pid; /* Status and pid returned by wait(). */ + int wait_status; /* Status returned by wait(). */ + pid_t wait_pid; /* pid returned by wait(). */ int waiting_termination = 0; /* Have displayed waiting close message. */ unsigned int max_time_milliseconds; unsigned int previous_stdout_buffer_bytes; @@ -480,6 +422,8 @@ server_loop(int pid, int fdin_arg, int fdout_arg, int fderr_arg) if (fderr == -1) fderr_eof = 1; + server_init_dispatch(); + /* Main loop of the server for the interactive session mode. */ for (;;) { fd_set readset, writeset; @@ -495,7 +439,7 @@ server_loop(int pid, int fdin_arg, int fdout_arg, int fderr_arg) #ifdef USE_PIPES close(fdin); #else - if (fdout == -1) + if (fdin != fdout) close(fdin); else shutdown(fdin, SHUT_WR); /* We will no longer send. */ @@ -536,7 +480,7 @@ server_loop(int pid, int fdin_arg, int fdout_arg, int fderr_arg) if (fdout_eof && fderr_eof && !packet_have_data_to_write() && buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) { if (!channel_still_open()) - goto quit; + break; if (!waiting_termination) { const char *s = "Waiting for forwarded connections to terminate...\r\n"; char *cp; @@ -563,7 +507,6 @@ server_loop(int pid, int fdin_arg, int fdout_arg, int fderr_arg) process_output(&writeset); } -quit: /* Cleanup and termination code. */ /* Wait until all output has been sent to the client. */ @@ -649,3 +592,233 @@ quit: packet_disconnect("wait returned status %04x.", wait_status); /* NOTREACHED */ } + +void +server_loop2(void) +{ + fd_set readset, writeset; + int had_channel = 0; + int status; + pid_t pid; + + debug("Entering interactive session for SSH2."); + + signal(SIGCHLD, sigchld_handler2); + child_terminated = 0; + connection_in = packet_get_connection_in(); + connection_out = packet_get_connection_out(); + max_fd = connection_in; + if (connection_out > max_fd) + max_fd = connection_out; + server_init_dispatch(); + + for (;;) { + process_buffered_input_packets(); + if (!had_channel && channel_still_open()) + had_channel = 1; + if (had_channel && !channel_still_open()) { + debug("!channel_still_open."); + break; + } + if (packet_not_very_much_data_to_write()) + channel_output_poll(); + wait_until_can_do_something(&readset, &writeset, 0); + if (child_terminated) { + while ((pid = waitpid(-1, &status, WNOHANG)) > 0) + session_close_by_pid(pid, status); + child_terminated = 0; + } + channel_after_select(&readset, &writeset); + process_input(&readset); + process_output(&writeset); + } + signal(SIGCHLD, SIG_DFL); + while ((pid = waitpid(-1, &status, WNOHANG)) > 0) + session_close_by_pid(pid, status); + channel_stop_listening(); +} + +void +server_input_stdin_data(int type, int plen) +{ + char *data; + unsigned 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; + data = packet_get_string(&data_len); + packet_integrity_check(plen, (4 + data_len), type); + buffer_append(&stdin_buffer, data, data_len); + memset(data, 0, data_len); + xfree(data); +} + +void +server_input_eof(int type, int plen) +{ + /* + * 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_integrity_check(plen, 0, type); + stdin_eof = 1; +} + +void +server_input_window_size(int type, int plen) +{ + int row = packet_get_int(); + int col = packet_get_int(); + int xpixel = packet_get_int(); + int ypixel = packet_get_int(); + + debug("Window change received."); + packet_integrity_check(plen, 4 * 4, type); + if (fdin != -1) + pty_change_window_size(fdin, row, col, xpixel, ypixel); +} + +int +input_direct_tcpip(void) +{ + int sock; + char *target, *originator; + int 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_done(); + /* XXX check permission */ + sock = channel_connect_to(target, target_port); + xfree(target); + xfree(originator); + if (sock < 0) + return -1; + return channel_new("direct-tcpip", SSH_CHANNEL_OPEN, + sock, sock, -1, 4*1024, 32*1024, 0, xstrdup("direct-tcpip")); +} + +void +server_input_channel_open(int type, int plen) +{ + Channel *c = NULL; + char *ctype; + int id; + unsigned int len; + int rchan; + int rmaxpack; + int rwindow; + + ctype = packet_get_string(&len); + rchan = packet_get_int(); + rwindow = packet_get_int(); + rmaxpack = packet_get_int(); + + debug("channel_input_open: ctype %s rchan %d win %d max %d", + ctype, rchan, rwindow, rmaxpack); + + if (strcmp(ctype, "session") == 0) { + debug("open session"); + packet_done(); + /* + * A server session has no fd to read or write + * until a CHANNEL_REQUEST for a shell is made, + * so we set the type to SSH_CHANNEL_LARVAL. + * Additionally, a callback for handling all + * CHANNEL_REQUEST messages is registered. + */ + id = channel_new(ctype, SSH_CHANNEL_LARVAL, + -1, -1, -1, 0, 32*1024, 0, xstrdup("server-session")); + if (session_open(id) == 1) { + channel_register_callback(id, SSH2_MSG_CHANNEL_REQUEST, + session_input_channel_req, (void *)0); + channel_register_cleanup(id, session_close_by_channel); + c = channel_lookup(id); + } else { + debug("session open failed, free channel %d", id); + channel_free(id); + } + } else if (strcmp(ctype, "direct-tcpip") == 0) { + debug("open direct-tcpip"); + id = input_direct_tcpip(); + if (id >= 0) + c = channel_lookup(id); + } + if (c != NULL) { + debug("confirm %s", ctype); + c->remote_id = rchan; + c->remote_window = rwindow; + c->remote_maxpacket = rmaxpack; + + 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(); + } else { + debug("failure %s", ctype); + packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); + packet_put_int(rchan); + packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); + packet_put_cstring("bla bla"); + packet_put_cstring(""); + packet_send(); + } + xfree(ctype); +} + +void +server_init_dispatch_20() +{ + 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, &channel_input_channel_request); + dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); +} +void +server_init_dispatch_13() +{ + 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); +} +void +server_init_dispatch_15() +{ + 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); +} +void +server_init_dispatch() +{ + if (compat20) + server_init_dispatch_20(); + else if (compat13) + server_init_dispatch_13(); + else + server_init_dispatch_15(); +} |