diff options
| -rw-r--r-- | ChangeLog | 12 | ||||
| -rw-r--r-- | PROTOCOL.mux | 11 | ||||
| -rw-r--r-- | clientloop.c | 53 | ||||
| -rw-r--r-- | clientloop.h | 4 | ||||
| -rw-r--r-- | mux.c | 60 |
5 files changed, 111 insertions, 29 deletions
@@ -50,6 +50,18 @@ - jmc@cvs.openbsd.org 2011/05/07 23:20:25 [ssh.1] +.It RequestTTY + - djm@cvs.openbsd.org 2011/05/08 12:52:01 + [PROTOCOL.mux clientloop.c clientloop.h mux.c] + improve our behaviour when TTY allocation fails: if we are in + RequestTTY=auto mode (the default), then do not treat at TTY + allocation error as fatal but rather just restore the local TTY + to cooked mode and continue. This is more graceful on devices that + never allocate TTYs. + + If RequestTTY is set to "yes" or "force", then failure to allocate + a TTY is fatal. + + ok markus@ 20110510 - (dtucker) [openbsd-compat/openssl-compat.{c,h}] Bug #1882: fix diff --git a/PROTOCOL.mux b/PROTOCOL.mux index 3da9e37a..9ad25660 100644 --- a/PROTOCOL.mux +++ b/PROTOCOL.mux @@ -73,6 +73,13 @@ non-multiplexed ssh(1) connection. Two additional cases that the client must cope with are it receiving a signal itself and the server disconnecting without sending an exit message. +A master may also send a MUX_S_TTY_ALLOC_FAIL before MUX_S_EXIT_MESSAGE +if remote TTY allocation was unsuccessful. The client may use this to +return its local tty to "cooked" mode. + + uint32 MUX_S_TTY_ALLOC_FAIL + uint32 session id + 3. Health checks The client may request a health check/PID report from a server: @@ -197,6 +204,7 @@ The MUX_S_PERMISSION_DENIED and MUX_S_FAILURE include a reason: #define MUX_S_ALIVE 0x80000005 #define MUX_S_SESSION_OPENED 0x80000006 #define MUX_S_REMOTE_PORT 0x80000007 +#define MUX_S_TTY_ALLOC_FAIL 0x80000008 #define MUX_FWD_LOCAL 1 #define MUX_FWD_REMOTE 2 @@ -208,7 +216,6 @@ XXX lock (maybe) XXX watch in/out traffic (pre/post crypto) XXX inject packet (what about replies) XXX server->client error/warning notifications -XXX port0 rfwd (need custom response message) XXX send signals via mux -$OpenBSD: PROTOCOL.mux,v 1.6 2011/05/06 22:20:10 djm Exp $ +$OpenBSD: PROTOCOL.mux,v 1.7 2011/05/08 12:52:01 djm Exp $ diff --git a/clientloop.c b/clientloop.c index 5bd757df..ed1d8a23 100644 --- a/clientloop.c +++ b/clientloop.c @@ -1,4 +1,4 @@ -/* $OpenBSD: clientloop.c,v 1.233 2011/05/06 21:34:32 djm Exp $ */ +/* $OpenBSD: clientloop.c,v 1.234 2011/05/08 12:52:01 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -174,9 +174,11 @@ struct escape_filter_ctx { }; /* Context for channel confirmation replies */ +enum confirm_action { CONFIRM_WARN = 0, CONFIRM_CLOSE, CONFIRM_TTY }; struct channel_reply_ctx { const char *request_type; - int id, do_close; + int id; + enum confirm_action action; }; /* Global request success/failure callbacks */ @@ -739,6 +741,15 @@ client_status_confirm(int type, Channel *c, void *ctx) char errmsg[256]; int tochan; + /* + * If a TTY was explicitly requested, then a failure to allocate + * one is fatal. + */ + if (cr->action == CONFIRM_TTY && + (options.request_tty == REQUEST_TTY_FORCE || + options.request_tty == REQUEST_TTY_YES)) + cr->action = CONFIRM_CLOSE; + /* XXX supress on mux _client_ quietmode */ tochan = options.log_level >= SYSLOG_LEVEL_ERROR && c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE; @@ -756,14 +767,27 @@ client_status_confirm(int type, Channel *c, void *ctx) cr->request_type, c->self); } /* If error occurred on primary session channel, then exit */ - if (cr->do_close && c->self == session_ident) + if (cr->action == CONFIRM_CLOSE && c->self == session_ident) fatal("%s", errmsg); - /* If error occurred on mux client, append to their stderr */ - if (tochan) - buffer_append(&c->extended, errmsg, strlen(errmsg)); - else + /* + * If error occurred on mux client, append to + * their stderr. + */ + if (tochan) { + buffer_append(&c->extended, errmsg, + strlen(errmsg)); + } else error("%s", errmsg); - if (cr->do_close) { + if (cr->action == CONFIRM_TTY) { + /* + * If a TTY allocation error occurred, then arrange + * for the correct TTY to leave raw mode. + */ + if (c->self == session_ident) + leave_raw_mode(0); + else + mux_tty_alloc_failed(c); + } else if (cr->action == CONFIRM_CLOSE) { chan_read_failed(c); chan_write_failed(c); } @@ -778,12 +802,13 @@ client_abandon_status_confirm(Channel *c, void *ctx) } static void -client_expect_confirm(int id, const char *request, int do_close) +client_expect_confirm(int id, const char *request, + enum confirm_action action) { struct channel_reply_ctx *cr = xmalloc(sizeof(*cr)); cr->request_type = request; - cr->do_close = do_close; + cr->action = action; channel_register_status_confirm(id, client_status_confirm, client_abandon_status_confirm, cr); @@ -1983,7 +2008,7 @@ client_session2_setup(int id, int want_tty, int want_subsystem, memset(&ws, 0, sizeof(ws)); channel_request_start(id, "pty-req", 1); - client_expect_confirm(id, "PTY allocation", 1); + client_expect_confirm(id, "PTY allocation", CONFIRM_TTY); packet_put_cstring(term != NULL ? term : ""); packet_put_int((u_int)ws.ws_col); packet_put_int((u_int)ws.ws_row); @@ -2042,18 +2067,18 @@ client_session2_setup(int id, int want_tty, int want_subsystem, debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd)); channel_request_start(id, "subsystem", 1); - client_expect_confirm(id, "subsystem", 1); + client_expect_confirm(id, "subsystem", CONFIRM_CLOSE); } else { debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd)); channel_request_start(id, "exec", 1); - client_expect_confirm(id, "exec", 1); + client_expect_confirm(id, "exec", CONFIRM_CLOSE); } packet_put_string(buffer_ptr(cmd), buffer_len(cmd)); packet_send(); } else { channel_request_start(id, "shell", 1); - client_expect_confirm(id, "shell", 1); + client_expect_confirm(id, "shell", CONFIRM_CLOSE); packet_send(); } } diff --git a/clientloop.h b/clientloop.h index 37d07290..ad588d14 100644 --- a/clientloop.h +++ b/clientloop.h @@ -1,4 +1,4 @@ -/* $OpenBSD: clientloop.h,v 1.26 2011/04/17 22:42:41 djm Exp $ */ +/* $OpenBSD: clientloop.h,v 1.27 2011/05/08 12:52:01 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> @@ -70,3 +70,5 @@ void client_register_global_confirm(global_confirm_cb *, void *); void muxserver_listen(void); void muxclient(const char *); void mux_exit_message(Channel *, int); +void mux_tty_alloc_failed(Channel *); + @@ -1,4 +1,4 @@ -/* $OpenBSD: mux.c,v 1.27 2011/05/06 21:34:32 djm Exp $ */ +/* $OpenBSD: mux.c,v 1.28 2011/05/08 12:52:01 djm Exp $ */ /* * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org> * @@ -153,6 +153,7 @@ struct mux_master_state { #define MUX_S_ALIVE 0x80000005 #define MUX_S_SESSION_OPENED 0x80000006 #define MUX_S_REMOTE_PORT 0x80000007 +#define MUX_S_TTY_ALLOC_FAIL 0x80000008 /* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */ #define MUX_FWD_LOCAL 1 @@ -1054,6 +1055,27 @@ mux_exit_message(Channel *c, int exitval) buffer_free(&m); } +void +mux_tty_alloc_failed(Channel *c) +{ + Buffer m; + Channel *mux_chan; + + debug3("%s: channel %d: TTY alloc failed", __func__, c->self); + + if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL) + fatal("%s: channel %d missing mux channel %d", + __func__, c->self, c->ctl_chan); + + /* Append exit message packet to control socket output queue */ + buffer_init(&m); + buffer_put_int(&m, MUX_S_TTY_ALLOC_FAIL); + buffer_put_int(&m, c->self); + + buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m)); + buffer_free(&m); +} + /* Prepare a mux master to listen on a Unix domain socket. */ void muxserver_listen(void) @@ -1612,7 +1634,7 @@ mux_client_request_session(int fd) char *e, *term; u_int i, rid, sid, esid, exitval, type, exitval_seen; extern char **environ; - int devnull; + int devnull, rawmode; debug3("%s: entering", __func__); @@ -1708,6 +1730,7 @@ mux_client_request_session(int fd) signal(SIGTERM, control_client_sighandler); signal(SIGWINCH, control_client_sigrelay); + rawmode = tty_flag; if (tty_flag) enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE); @@ -1723,22 +1746,35 @@ mux_client_request_session(int fd) if (mux_client_read_packet(fd, &m) != 0) break; type = buffer_get_int(&m); - if (type != MUX_S_EXIT_MESSAGE) { + switch (type) { + case MUX_S_TTY_ALLOC_FAIL: + if ((esid = buffer_get_int(&m)) != sid) + fatal("%s: tty alloc fail on unknown session: " + "my id %u theirs %u", + __func__, sid, esid); + leave_raw_mode(options.request_tty == + REQUEST_TTY_FORCE); + rawmode = 0; + continue; + case MUX_S_EXIT_MESSAGE: + if ((esid = buffer_get_int(&m)) != sid) + fatal("%s: exit on unknown session: " + "my id %u theirs %u", + __func__, sid, esid); + if (exitval_seen) + fatal("%s: exitval sent twice", __func__); + exitval = buffer_get_int(&m); + exitval_seen = 1; + continue; + default: e = buffer_get_string(&m, NULL); fatal("%s: master returned error: %s", __func__, e); } - if ((esid = buffer_get_int(&m)) != sid) - fatal("%s: exit on unknown session: my id %u theirs %u", - __func__, sid, esid); - debug("%s: master session id: %u", __func__, sid); - if (exitval_seen) - fatal("%s: exitval sent twice", __func__); - exitval = buffer_get_int(&m); - exitval_seen = 1; } close(fd); - leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); + if (rawmode) + leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); if (muxclient_terminate) { debug2("Exiting on signal %d", muxclient_terminate); |