X-Git-Url: http://andersk.mit.edu/gitweb/gssapi-openssh.git/blobdiff_plain/6a9b319871ee85eeada2a0511e9436d0bfa6aab8..d89322b8b73f64b1c6692a7e2f205caf86385278:/openssh/serverloop.c diff --git a/openssh/serverloop.c b/openssh/serverloop.c index f4df9cc..6e5fdc2 100644 --- a/openssh/serverloop.c +++ b/openssh/serverloop.c @@ -1,3 +1,4 @@ +/* $OpenBSD: serverloop.c,v 1.144 2006/08/03 03:34:42 deraadt Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -35,7 +36,25 @@ */ #include "includes.h" -RCSID("$OpenBSD: serverloop.c,v 1.106 2003/04/01 10:22:21 markus Exp $"); + +#include +#include +#include +#include +#ifdef HAVE_SYS_TIME_H +# include +#endif + +#include + +#include +#include +#include +#include +#include +#include +#include +#include #include "xmalloc.h" #include "packet.h" @@ -48,19 +67,23 @@ RCSID("$OpenBSD: serverloop.c,v 1.106 2003/04/01 10:22:21 markus Exp $"); #include "compat.h" #include "ssh1.h" #include "ssh2.h" +#include "key.h" +#include "cipher.h" +#include "kex.h" +#include "hostfile.h" #include "auth.h" #include "session.h" #include "dispatch.h" #include "auth-options.h" #include "serverloop.h" #include "misc.h" -#include "kex.h" extern ServerOptions options; /* XXX */ extern Kex *xxx_kex; -static Authctxt *xxx_authctxt; +extern Authctxt *the_authctxt; +extern int use_privsep; static Buffer stdin_buffer; /* Buffer for stdin data. */ static Buffer stdout_buffer; /* Buffer for stdout data. */ @@ -90,6 +113,9 @@ static int client_alive_timeouts = 0; static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */ +/* Cleanup on signals (!use_privsep case only) */ +static volatile sig_atomic_t received_sigterm = 0; + /* prototypes */ static void server_init_dispatch(void); @@ -138,11 +164,11 @@ notify_done(fd_set *readset) debug2("notify_done: reading"); } +/*ARGSUSED*/ static void sigchld_handler(int sig) { int save_errno = errno; - debug("Received SIGCHLD."); child_terminated = 1; #ifndef _UNICOS mysignal(SIGCHLD, sigchld_handler); @@ -151,6 +177,13 @@ sigchld_handler(int sig) errno = save_errno; } +/*ARGSUSED*/ +static void +sigterm_handler(int sig) +{ + received_sigterm = sig; +} + /* * Make packets from buffered stderr data, and buffer it for sending * to the client. @@ -158,7 +191,7 @@ sigchld_handler(int sig) static void make_packets_from_stderr_data(void) { - int len; + u_int len; /* Send buffered stderr data to the client. */ while (buffer_len(&stderr_buffer) > 0 && @@ -187,7 +220,7 @@ make_packets_from_stderr_data(void) static void make_packets_from_stdout_data(void) { - int len; + u_int len; /* Send buffered stdout data to the client. */ while (buffer_len(&stdout_buffer) > 0 && @@ -212,26 +245,23 @@ make_packets_from_stdout_data(void) static void client_alive_check(void) { - static int had_channel = 0; - int id; - - id = channel_find_open(); - if (id == -1) { - if (!had_channel) - return; - packet_disconnect("No open channels after timeout!"); - } - had_channel = 1; + int channel_id; /* timeout, check to see how many we have had */ if (++client_alive_timeouts > options.client_alive_count_max) packet_disconnect("Timeout, your session not responding."); /* - * send a bogus channel request with "wantreply", + * send a bogus global/channel request with "wantreply", * we should get back a failure */ - channel_request_start(id, "keepalive@openssh.com", 1); + 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 */ + } else { + channel_request_start(channel_id, "keepalive@openssh.com", 1); + } packet_send(); } @@ -243,7 +273,7 @@ client_alive_check(void) */ static void wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp, - int *nallocp, u_int max_time_milliseconds) + u_int *nallocp, u_int max_time_milliseconds) { struct timeval tv, *tvp; int ret; @@ -341,7 +371,7 @@ wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp, * in buffers and processed later. */ static void -process_input(fd_set * readset) +process_input(fd_set *readset) { int len; char buf[16384]; @@ -355,13 +385,13 @@ process_input(fd_set * readset) connection_closed = 1; if (compat20) return; - fatal_cleanup(); + cleanup_exit(255); } else if (len < 0) { if (errno != EINTR && errno != EAGAIN) { verbose("Read error from remote host " "%.100s: %.100s", get_remote_ipaddr(), strerror(errno)); - fatal_cleanup(); + cleanup_exit(255); } } else { /* Buffer any received data. */ @@ -373,10 +403,16 @@ process_input(fd_set * readset) /* 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)) { /* 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); @@ -385,10 +421,16 @@ process_input(fd_set * readset) } /* 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)) { /* 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); @@ -400,7 +442,7 @@ process_input(fd_set * readset) * Sends data from internal buffers to client program stdin. */ static void -process_output(fd_set * writeset) +process_output(fd_set *writeset) { struct termios tio; u_char *data; @@ -489,7 +531,8 @@ 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, nalloc = 0; + 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. */ @@ -504,6 +547,12 @@ server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg) 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; @@ -550,7 +599,7 @@ server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg) * 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. + * we don't need to check the descriptor everywhere. */ if (fderr == -1) fderr_eof = 1; @@ -631,6 +680,12 @@ server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg) wait_until_can_do_something(&readset, &writeset, &max_fd, &nalloc, max_time_milliseconds); + if (received_sigterm) { + logit("Exiting on signal %d", received_sigterm); + /* Clean up sessions, utmp, etc. */ + cleanup_exit(255); + } + /* Process any channel events. */ channel_after_select(readset, writeset); @@ -729,6 +784,7 @@ collect_children(void) sigaddset(&nset, SIGCHLD); sigprocmask(SIG_BLOCK, &nset, &oset); if (child_terminated) { + debug("Received SIGCHLD."); while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || (pid < 0 && errno == EINTR)) if (pid > 0) @@ -751,13 +807,17 @@ server_loop2(Authctxt *authctxt) 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]); - xxx_authctxt = authctxt; - server_init_dispatch(); for (;;) { @@ -770,9 +830,21 @@ server_loop2(Authctxt *authctxt) 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) + 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; @@ -793,9 +865,9 @@ server_loop2(Authctxt *authctxt) } static void -server_input_channel_failure(int type, u_int32_t seq, void *ctxt) +server_input_keep_alive(int type, u_int32_t seq, void *ctxt) { - debug("Got CHANNEL_FAILURE for keepalive"); + debug("Got %d/%u for keepalive", type, seq); /* * reset timeout, since we got a sane answer from the client. * even if this was generated by something other than @@ -804,7 +876,6 @@ server_input_channel_failure(int type, u_int32_t seq, void *ctxt) client_alive_timeouts = 0; } - static void server_input_stdin_data(int type, u_int32_t seq, void *ctxt) { @@ -838,10 +909,10 @@ server_input_eof(int type, u_int32_t seq, void *ctxt) static void server_input_window_size(int type, u_int32_t seq, void *ctxt) { - int row = packet_get_int(); - int col = packet_get_int(); - int xpixel = packet_get_int(); - int ypixel = packet_get_int(); + 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(); @@ -850,7 +921,7 @@ server_input_window_size(int type, u_int32_t seq, void *ctxt) } static Channel * -server_request_direct_tcpip(char *ctype) +server_request_direct_tcpip(void) { Channel *c; int sock; @@ -864,7 +935,7 @@ server_request_direct_tcpip(char *ctype) packet_check_eom(); debug("server_request_direct_tcpip: originator %s port %d, target %s port %d", - originator, originator_port, target, target_port); + originator, originator_port, target, target_port); /* XXX check permission */ sock = channel_connect_to(target, target_port); @@ -872,14 +943,60 @@ server_request_direct_tcpip(char *ctype) xfree(originator); if (sock < 0) return NULL; - c = channel_new(ctype, SSH_CHANNEL_CONNECTING, + c = channel_new("direct-tcpip", SSH_CHANNEL_CONNECTING, sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT, - CHAN_TCP_PACKET_DEFAULT, 0, xstrdup("direct-tcpip"), 1); + CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1); + return c; +} + +static Channel * +server_request_tun(void) +{ + Channel *c = NULL; + int mode, tun; + int sock; + + mode = packet_get_int(); + switch (mode) { + case SSH_TUNMODE_POINTOPOINT: + case SSH_TUNMODE_ETHERNET: + break; + default: + packet_send_debug("Unsupported tunnel device mode."); + return NULL; + } + if ((options.permit_tun & mode) == 0) { + packet_send_debug("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) + goto done; + tun = forced_tun_device; + } + sock = tun_open(tun, mode); + if (sock < 0) + goto done; + c = channel_new("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, + sys_tun_outfilter); +#endif + + done: + if (c == NULL) + packet_send_debug("Failed to open the tunnel device."); return c; } static Channel * -server_request_session(char *ctype) +server_request_session(void) { Channel *c; @@ -891,15 +1008,15 @@ server_request_session(char *ctype) * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all * CHANNEL_REQUEST messages is registered. */ - c = channel_new(ctype, SSH_CHANNEL_LARVAL, + c = channel_new("session", SSH_CHANNEL_LARVAL, -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT, - 0, xstrdup("server-session"), 1); - if (session_open(xxx_authctxt, c->self) != 1) { + 0, "server-session", 1); + if (session_open(the_authctxt, c->self) != 1) { debug("session open failed, free channel %d", c->self); channel_free(c); return NULL; } - channel_register_cleanup(c->self, session_close_by_channel); + channel_register_cleanup(c->self, session_close_by_channel, 0); return c; } @@ -920,9 +1037,11 @@ server_input_channel_open(int type, u_int32_t seq, void *ctxt) ctype, rchan, rwindow, rmaxpack); if (strcmp(ctype, "session") == 0) { - c = server_request_session(ctype); + c = server_request_session(); } else if (strcmp(ctype, "direct-tcpip") == 0) { - c = server_request_direct_tcpip(ctype); + c = server_request_direct_tcpip(); + } else if (strcmp(ctype, "tun@openssh.com") == 0) { + c = server_request_tun(); } if (c != NULL) { debug("server_input_channel_open: confirm %s", ctype); @@ -968,10 +1087,10 @@ server_input_global_request(int type, u_int32_t seq, void *ctxt) char *listen_address; u_short listen_port; - pw = auth_get_user(); - if (pw == NULL) - fatal("server_input_global_request: no user"); - listen_address = packet_get_string(NULL); /* XXX currently ignored */ + pw = the_authctxt->pw; + if (pw == NULL || !the_authctxt->valid) + fatal("server_input_global_request: no/invalid user"); + listen_address = packet_get_string(NULL); listen_port = (u_short)packet_get_int(); debug("server_input_global_request: tcpip-forward listen %s port %d", listen_address, listen_port); @@ -982,7 +1101,7 @@ server_input_global_request(int type, u_int32_t seq, void *ctxt) #ifndef NO_IPPORT_RESERVED_CONCEPT || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0) #endif - ) { + ) { success = 0; packet_send_debug("Server has disabled port forwarding."); } else { @@ -991,6 +1110,18 @@ server_input_global_request(int type, u_int32_t seq, void *ctxt) listen_address, listen_port, options.gateway_ports); } xfree(listen_address); + } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) { + char *cancel_address; + u_short cancel_port; + + cancel_address = packet_get_string(NULL); + cancel_port = (u_short)packet_get_int(); + debug("%s: cancel-tcpip-forward addr %s port %d", __func__, + cancel_address, cancel_port); + + success = channel_cancel_rport_listener(cancel_address, + cancel_port); + xfree(cancel_address); } if (want_reply) { packet_start(success ? @@ -1000,6 +1131,7 @@ server_input_global_request(int type, u_int32_t seq, void *ctxt) } xfree(rtype); } + static void server_input_channel_req(int type, u_int32_t seq, void *ctxt) { @@ -1044,7 +1176,9 @@ server_init_dispatch_20(void) dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request); /* client_alive */ - dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_channel_failure); + 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); /* rekeying */ dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); }