diff options
Diffstat (limited to 'mux.c')
| -rw-r--r-- | mux.c | 1307 |
1 files changed, 761 insertions, 546 deletions
@@ -1,4 +1,4 @@ -/* $OpenBSD: mux.c,v 1.50 2015/01/20 23:14:00 deraadt Exp $ */ +/* $OpenBSD: mux.c,v 1.82 2020/04/30 17:12:20 markus Exp $ */ /* * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org> * @@ -17,19 +17,6 @@ /* ssh session multiplexing support */ -/* - * TODO: - * - Better signalling from master to slave, especially passing of - * error messages - * - Better fall-back from mux slave error to new connection. - * - ExitOnForwardingFailure - * - Maybe extension mechanisms for multi-X11/multi-agent forwarding - * - Support ~^Z in mux slaves. - * - Inspect or control sessions in master. - * - If we ever support the "signal" channel request, send signals on - * sessions in master. - */ - #include "includes.h" #include <sys/types.h> @@ -70,15 +57,16 @@ #include "pathnames.h" #include "misc.h" #include "match.h" -#include "buffer.h" +#include "sshbuf.h" #include "channels.h" #include "msg.h" #include "packet.h" #include "monitor_fdpass.h" #include "sshpty.h" -#include "key.h" +#include "sshkey.h" #include "readconf.h" #include "clientloop.h" +#include "ssherr.h" /* from ssh.c */ extern int tty_flag; @@ -86,10 +74,8 @@ extern Options options; extern int stdin_null_flag; extern char *host; extern int subsystem_flag; -extern Buffer command; +extern struct sshbuf *command; extern volatile sig_atomic_t quit_pending; -extern char *stdio_forward_host; -extern int stdio_forward_port; /* Context for session open confirmation callback */ struct mux_session_confirm_ctx { @@ -97,7 +83,7 @@ struct mux_session_confirm_ctx { u_int want_subsys; u_int want_x_fwd; u_int want_agent_fwd; - Buffer cmd; + struct sshbuf *cmd; char *term; struct termios tio; char **env; @@ -146,6 +132,7 @@ struct mux_master_state { #define MUX_C_CLOSE_FWD 0x10000007 #define MUX_C_NEW_STDIO_FWD 0x10000008 #define MUX_C_STOP_LISTENING 0x10000009 +#define MUX_C_PROXY 0x1000000f #define MUX_S_OK 0x80000001 #define MUX_S_PERMISSION_DENIED 0x80000002 #define MUX_S_FAILURE 0x80000003 @@ -154,88 +141,103 @@ struct mux_master_state { #define MUX_S_SESSION_OPENED 0x80000006 #define MUX_S_REMOTE_PORT 0x80000007 #define MUX_S_TTY_ALLOC_FAIL 0x80000008 +#define MUX_S_PROXY 0x8000000f /* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */ #define MUX_FWD_LOCAL 1 #define MUX_FWD_REMOTE 2 #define MUX_FWD_DYNAMIC 3 -static void mux_session_confirm(int, int, void *); -static void mux_stdio_confirm(int, int, void *); - -static int process_mux_master_hello(u_int, Channel *, Buffer *, Buffer *); -static int process_mux_new_session(u_int, Channel *, Buffer *, Buffer *); -static int process_mux_alive_check(u_int, Channel *, Buffer *, Buffer *); -static int process_mux_terminate(u_int, Channel *, Buffer *, Buffer *); -static int process_mux_open_fwd(u_int, Channel *, Buffer *, Buffer *); -static int process_mux_close_fwd(u_int, Channel *, Buffer *, Buffer *); -static int process_mux_stdio_fwd(u_int, Channel *, Buffer *, Buffer *); -static int process_mux_stop_listening(u_int, Channel *, Buffer *, Buffer *); +static void mux_session_confirm(struct ssh *, int, int, void *); +static void mux_stdio_confirm(struct ssh *, int, int, void *); + +static int mux_master_process_hello(struct ssh *, u_int, + Channel *, struct sshbuf *, struct sshbuf *); +static int mux_master_process_new_session(struct ssh *, u_int, + Channel *, struct sshbuf *, struct sshbuf *); +static int mux_master_process_alive_check(struct ssh *, u_int, + Channel *, struct sshbuf *, struct sshbuf *); +static int mux_master_process_terminate(struct ssh *, u_int, + Channel *, struct sshbuf *, struct sshbuf *); +static int mux_master_process_open_fwd(struct ssh *, u_int, + Channel *, struct sshbuf *, struct sshbuf *); +static int mux_master_process_close_fwd(struct ssh *, u_int, + Channel *, struct sshbuf *, struct sshbuf *); +static int mux_master_process_stdio_fwd(struct ssh *, u_int, + Channel *, struct sshbuf *, struct sshbuf *); +static int mux_master_process_stop_listening(struct ssh *, u_int, + Channel *, struct sshbuf *, struct sshbuf *); +static int mux_master_process_proxy(struct ssh *, u_int, + Channel *, struct sshbuf *, struct sshbuf *); static const struct { u_int type; - int (*handler)(u_int, Channel *, Buffer *, Buffer *); + int (*handler)(struct ssh *, u_int, Channel *, + struct sshbuf *, struct sshbuf *); } mux_master_handlers[] = { - { MUX_MSG_HELLO, process_mux_master_hello }, - { MUX_C_NEW_SESSION, process_mux_new_session }, - { MUX_C_ALIVE_CHECK, process_mux_alive_check }, - { MUX_C_TERMINATE, process_mux_terminate }, - { MUX_C_OPEN_FWD, process_mux_open_fwd }, - { MUX_C_CLOSE_FWD, process_mux_close_fwd }, - { MUX_C_NEW_STDIO_FWD, process_mux_stdio_fwd }, - { MUX_C_STOP_LISTENING, process_mux_stop_listening }, + { MUX_MSG_HELLO, mux_master_process_hello }, + { MUX_C_NEW_SESSION, mux_master_process_new_session }, + { MUX_C_ALIVE_CHECK, mux_master_process_alive_check }, + { MUX_C_TERMINATE, mux_master_process_terminate }, + { MUX_C_OPEN_FWD, mux_master_process_open_fwd }, + { MUX_C_CLOSE_FWD, mux_master_process_close_fwd }, + { MUX_C_NEW_STDIO_FWD, mux_master_process_stdio_fwd }, + { MUX_C_STOP_LISTENING, mux_master_process_stop_listening }, + { MUX_C_PROXY, mux_master_process_proxy }, { 0, NULL } }; /* Cleanup callback fired on closure of mux slave _session_ channel */ /* ARGSUSED */ static void -mux_master_session_cleanup_cb(int cid, void *unused) +mux_master_session_cleanup_cb(struct ssh *ssh, int cid, void *unused) { - Channel *cc, *c = channel_by_id(cid); + Channel *cc, *c = channel_by_id(ssh, cid); debug3("%s: entering for channel %d", __func__, cid); if (c == NULL) fatal("%s: channel_by_id(%i) == NULL", __func__, cid); if (c->ctl_chan != -1) { - if ((cc = channel_by_id(c->ctl_chan)) == NULL) + if ((cc = channel_by_id(ssh, c->ctl_chan)) == NULL) fatal("%s: channel %d missing control channel %d", __func__, c->self, c->ctl_chan); c->ctl_chan = -1; - cc->remote_id = -1; - chan_rcvd_oclose(cc); + cc->remote_id = 0; + cc->have_remote_id = 0; + chan_rcvd_oclose(ssh, cc); } - channel_cancel_cleanup(c->self); + channel_cancel_cleanup(ssh, c->self); } /* Cleanup callback fired on closure of mux slave _control_ channel */ /* ARGSUSED */ static void -mux_master_control_cleanup_cb(int cid, void *unused) +mux_master_control_cleanup_cb(struct ssh *ssh, int cid, void *unused) { - Channel *sc, *c = channel_by_id(cid); + Channel *sc, *c = channel_by_id(ssh, cid); debug3("%s: entering for channel %d", __func__, cid); if (c == NULL) fatal("%s: channel_by_id(%i) == NULL", __func__, cid); - if (c->remote_id != -1) { - if ((sc = channel_by_id(c->remote_id)) == NULL) - fatal("%s: channel %d missing session channel %d", + if (c->have_remote_id) { + if ((sc = channel_by_id(ssh, c->remote_id)) == NULL) + fatal("%s: channel %d missing session channel %u", __func__, c->self, c->remote_id); - c->remote_id = -1; + c->remote_id = 0; + c->have_remote_id = 0; sc->ctl_chan = -1; if (sc->type != SSH_CHANNEL_OPEN && sc->type != SSH_CHANNEL_OPENING) { debug2("%s: channel %d: not open", __func__, sc->self); - chan_mark_dead(sc); + chan_mark_dead(ssh, sc); } else { if (sc->istate == CHAN_INPUT_OPEN) - chan_read_failed(sc); + chan_read_failed(ssh, sc); if (sc->ostate == CHAN_OUTPUT_OPEN) - chan_write_failed(sc); + chan_write_failed(ssh, sc); } } - channel_cancel_cleanup(c->self); + channel_cancel_cleanup(ssh, c->self); } /* Check mux client environment variables before passing them to mux master. */ @@ -249,7 +251,7 @@ env_permitted(char *env) return 0; ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env); if (ret <= 0 || (size_t)ret >= sizeof(name)) { - error("env_permitted: name '%.100s...' too long", env); + error("%s: name '%.100s...' too long", __func__, env); return 0; } @@ -263,10 +265,12 @@ env_permitted(char *env) /* Mux master protocol message handlers */ static int -process_mux_master_hello(u_int rid, Channel *c, Buffer *m, Buffer *r) +mux_master_process_hello(struct ssh *ssh, u_int rid, + Channel *c, struct sshbuf *m, struct sshbuf *reply) { u_int ver; struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx; + int r; if (state == NULL) fatal("%s: channel %d: c->mux_ctx == NULL", __func__, c->self); @@ -274,63 +278,86 @@ process_mux_master_hello(u_int rid, Channel *c, Buffer *m, Buffer *r) error("%s: HELLO received twice", __func__); return -1; } - if (buffer_get_int_ret(&ver, m) != 0) { - malf: - error("%s: malformed message", __func__); + if ((r = sshbuf_get_u32(m, &ver)) != 0) { + error("%s: malformed message: %s", __func__, ssh_err(r)); return -1; } if (ver != SSHMUX_VER) { - error("Unsupported multiplexing protocol version %d " - "(expected %d)", ver, SSHMUX_VER); + error("%s: unsupported multiplexing protocol version %u " + "(expected %u)", __func__, ver, SSHMUX_VER); return -1; } debug2("%s: channel %d slave version %u", __func__, c->self, ver); /* No extensions are presently defined */ - while (buffer_len(m) > 0) { - char *name = buffer_get_string_ret(m, NULL); - char *value = buffer_get_string_ret(m, NULL); - - if (name == NULL || value == NULL) { - free(name); - free(value); - goto malf; + while (sshbuf_len(m) > 0) { + char *name = NULL; + size_t value_len = 0; + + if ((r = sshbuf_get_cstring(m, &name, NULL)) != 0 || + (r = sshbuf_get_string_direct(m, NULL, &value_len)) != 0) { + error("%s: malformed extension: %s", + __func__, ssh_err(r)); + return -1; } - debug2("Unrecognised slave extension \"%s\"", name); + debug2("%s: Unrecognised extension \"%s\" length %zu", + __func__, name, value_len); free(name); - free(value); } state->hello_rcvd = 1; return 0; } +/* Enqueue a "ok" response to the reply buffer */ +static void +reply_ok(struct sshbuf *reply, u_int rid) +{ + int r; + + if ((r = sshbuf_put_u32(reply, MUX_S_OK)) != 0 || + (r = sshbuf_put_u32(reply, rid)) != 0) + fatal("%s: reply: %s", __func__, ssh_err(r)); +} + +/* Enqueue an error response to the reply buffer */ +static void +reply_error(struct sshbuf *reply, u_int type, u_int rid, const char *msg) +{ + int r; + + if ((r = sshbuf_put_u32(reply, type)) != 0 || + (r = sshbuf_put_u32(reply, rid)) != 0 || + (r = sshbuf_put_cstring(reply, msg)) != 0) + fatal("%s: reply: %s", __func__, ssh_err(r)); +} + static int -process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r) +mux_master_process_new_session(struct ssh *ssh, u_int rid, + Channel *c, struct sshbuf *m, struct sshbuf *reply) { Channel *nc; struct mux_session_confirm_ctx *cctx; - char *reserved, *cmd, *cp; - u_int i, j, len, env_len, escape_char, window, packetmax; - int new_fd[3]; + char *cmd, *cp; + u_int i, j, env_len, escape_char, window, packetmax; + int r, new_fd[3]; /* Reply for SSHMUX_COMMAND_OPEN */ cctx = xcalloc(1, sizeof(*cctx)); cctx->term = NULL; cctx->rid = rid; - cmd = reserved = NULL; + cmd = NULL; cctx->env = NULL; env_len = 0; - if ((reserved = buffer_get_string_ret(m, NULL)) == NULL || - buffer_get_int_ret(&cctx->want_tty, m) != 0 || - buffer_get_int_ret(&cctx->want_x_fwd, m) != 0 || - buffer_get_int_ret(&cctx->want_agent_fwd, m) != 0 || - buffer_get_int_ret(&cctx->want_subsys, m) != 0 || - buffer_get_int_ret(&escape_char, m) != 0 || - (cctx->term = buffer_get_string_ret(m, &len)) == NULL || - (cmd = buffer_get_string_ret(m, &len)) == NULL) { + if ((r = sshbuf_skip_string(m)) != 0 || /* reserved */ + (r = sshbuf_get_u32(m, &cctx->want_tty)) != 0 || + (r = sshbuf_get_u32(m, &cctx->want_x_fwd)) != 0 || + (r = sshbuf_get_u32(m, &cctx->want_agent_fwd)) != 0 || + (r = sshbuf_get_u32(m, &cctx->want_subsys)) != 0 || + (r = sshbuf_get_u32(m, &escape_char)) != 0 || + (r = sshbuf_get_cstring(m, &cctx->term, NULL)) != 0 || + (r = sshbuf_get_cstring(m, &cmd, NULL)) != 0) { malf: free(cmd); - free(reserved); for (j = 0; j < env_len; j++) free(cctx->env[j]); free(cctx->env); @@ -339,24 +366,22 @@ process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r) error("%s: malformed message", __func__); return -1; } - free(reserved); - reserved = NULL; - while (buffer_len(m) > 0) { #define MUX_MAX_ENV_VARS 4096 - if ((cp = buffer_get_string_ret(m, &len)) == NULL) + while (sshbuf_len(m) > 0) { + if ((r = sshbuf_get_cstring(m, &cp, NULL)) != 0) goto malf; if (!env_permitted(cp)) { free(cp); continue; } - cctx->env = xrealloc(cctx->env, env_len + 2, + cctx->env = xreallocarray(cctx->env, env_len + 2, sizeof(*cctx->env)); cctx->env[env_len++] = cp; cctx->env[env_len] = NULL; if (env_len > MUX_MAX_ENV_VARS) { - error(">%d environment variables received, ignoring " - "additional", MUX_MAX_ENV_VARS); + error("%s: >%d environment variables received, " + "ignoring additional", __func__, MUX_MAX_ENV_VARS); break; } } @@ -366,8 +391,10 @@ process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r) cctx->want_tty, cctx->want_x_fwd, cctx->want_agent_fwd, cctx->want_subsys, cctx->term, cmd, env_len); - buffer_init(&cctx->cmd); - buffer_append(&cctx->cmd, cmd, strlen(cmd)); + if ((cctx->cmd = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if ((r = sshbuf_put(cctx->cmd, cmd, strlen(cmd))) != 0) + fatal("%s: sshbuf_put: %s", __func__, ssh_err(r)); free(cmd); cmd = NULL; @@ -382,13 +409,9 @@ process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r) free(cctx->env[j]); free(cctx->env); free(cctx->term); - buffer_free(&cctx->cmd); + sshbuf_free(cctx->cmd); free(cctx); - - /* prepare reply */ - buffer_put_int(r, MUX_S_FAILURE); - buffer_put_int(r, rid); - buffer_put_cstring(r, + reply_error(reply, MUX_S_FAILURE, rid, "did not receive file descriptors"); return -1; } @@ -398,12 +421,10 @@ process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r) new_fd[0], new_fd[1], new_fd[2]); /* XXX support multiple child sessions in future */ - if (c->remote_id != -1) { + if (c->have_remote_id) { debug2("%s: session already open", __func__); - /* prepare reply */ - buffer_put_int(r, MUX_S_FAILURE); - buffer_put_int(r, rid); - buffer_put_cstring(r, "Multiple sessions not supported"); + reply_error(reply, MUX_S_FAILURE, rid, + "Multiple sessions not supported"); cleanup: close(new_fd[0]); close(new_fd[1]); @@ -414,7 +435,7 @@ process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r) free(cctx->env[i]); free(cctx->env); } - buffer_free(&cctx->cmd); + sshbuf_free(cctx->cmd); free(cctx); return 0; } @@ -423,10 +444,8 @@ process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r) options.control_master == SSHCTL_MASTER_AUTO_ASK) { if (!ask_permission("Allow shared connection to %s? ", host)) { debug2("%s: session refused by user", __func__); - /* prepare reply */ - buffer_put_int(r, MUX_S_PERMISSION_DENIED); - buffer_put_int(r, rid); - buffer_put_cstring(r, "Permission denied"); + reply_error(reply, MUX_S_PERMISSION_DENIED, rid, + "Permission denied"); goto cleanup; } } @@ -450,15 +469,16 @@ process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r) packetmax >>= 1; } - nc = channel_new("session", SSH_CHANNEL_OPENING, + nc = channel_new(ssh, "session", SSH_CHANNEL_OPENING, new_fd[0], new_fd[1], new_fd[2], window, packetmax, CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0); nc->ctl_chan = c->self; /* link session -> control channel */ c->remote_id = nc->self; /* link control -> session channel */ + c->have_remote_id = 1; if (cctx->want_tty && escape_char != 0xffffffff) { - channel_register_filter(nc->self, + channel_register_filter(ssh, nc->self, client_simple_escape_filter, NULL, client_filter_cleanup, client_new_escape_filter_ctx((int)escape_char)); @@ -467,30 +487,36 @@ process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r) debug2("%s: channel_new: %d linked to control channel %d", __func__, nc->self, nc->ctl_chan); - channel_send_open(nc->self); - channel_register_open_confirm(nc->self, mux_session_confirm, cctx); + channel_send_open(ssh, nc->self); + channel_register_open_confirm(ssh, nc->self, mux_session_confirm, cctx); c->mux_pause = 1; /* stop handling messages until open_confirm done */ - channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1); + channel_register_cleanup(ssh, nc->self, + mux_master_session_cleanup_cb, 1); /* reply is deferred, sent by mux_session_confirm */ return 0; } static int -process_mux_alive_check(u_int rid, Channel *c, Buffer *m, Buffer *r) +mux_master_process_alive_check(struct ssh *ssh, u_int rid, + Channel *c, struct sshbuf *m, struct sshbuf *reply) { + int r; + debug2("%s: channel %d: alive check", __func__, c->self); /* prepare reply */ - buffer_put_int(r, MUX_S_ALIVE); - buffer_put_int(r, rid); - buffer_put_int(r, (u_int)getpid()); + if ((r = sshbuf_put_u32(reply, MUX_S_ALIVE)) != 0 || + (r = sshbuf_put_u32(reply, rid)) != 0 || + (r = sshbuf_put_u32(reply, (u_int)getpid())) != 0) + fatal("%s: reply: %s", __func__, ssh_err(r)); return 0; } static int -process_mux_terminate(u_int rid, Channel *c, Buffer *m, Buffer *r) +mux_master_process_terminate(struct ssh *ssh, u_int rid, + Channel *c, struct sshbuf *m, struct sshbuf *reply) { debug2("%s: channel %d: terminate request", __func__, c->self); @@ -499,16 +525,14 @@ process_mux_terminate(u_int rid, Channel *c, Buffer *m, Buffer *r) if (!ask_permission("Terminate shared connection to %s? ", host)) { debug2("%s: termination refused by user", __func__); - buffer_put_int(r, MUX_S_PERMISSION_DENIED); - buffer_put_int(r, rid); - buffer_put_cstring(r, "Permission denied"); + reply_error(reply, MUX_S_PERMISSION_DENIED, rid, + "Permission denied"); return 0; } } quit_pending = 1; - buffer_put_int(r, MUX_S_OK); - buffer_put_int(r, rid); + reply_ok(reply, rid); /* XXX exit happens too soon - message never makes it to client */ return 0; } @@ -579,21 +603,26 @@ compare_forward(struct Forward *a, struct Forward *b) } static void -mux_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) +mux_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt) { struct mux_channel_confirm_ctx *fctx = ctxt; char *failmsg = NULL; struct Forward *rfwd; Channel *c; - Buffer out; + struct sshbuf *out; + u_int port; + int r; - if ((c = channel_by_id(fctx->cid)) == NULL) { + if ((c = channel_by_id(ssh, fctx->cid)) == NULL) { /* no channel for reply */ error("%s: unknown channel", __func__); return; } - buffer_init(&out); - if (fctx->fid >= options.num_remote_forwards) { + if ((out = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if (fctx->fid >= options.num_remote_forwards || + (options.remote_forwards[fctx->fid].connect_path == NULL && + options.remote_forwards[fctx->fid].connect_host == NULL)) { xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid); goto fail; } @@ -604,60 +633,83 @@ mux_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) rfwd->connect_host, rfwd->connect_port); if (type == SSH2_MSG_REQUEST_SUCCESS) { if (rfwd->listen_port == 0) { - rfwd->allocated_port = packet_get_int(); - logit("Allocated port %u for mux remote forward" + if ((r = sshpkt_get_u32(ssh, &port)) != 0) + fatal("%s: packet error: %s", + __func__, ssh_err(r)); + if (port > 65535) { + fatal("Invalid allocated port %u for " + "mux remote forward to %s:%d", port, + rfwd->connect_host, rfwd->connect_port); + } + rfwd->allocated_port = (int)port; + debug("Allocated port %u for mux remote forward" " to %s:%d", rfwd->allocated_port, rfwd->connect_host, rfwd->connect_port); - buffer_put_int(&out, MUX_S_REMOTE_PORT); - buffer_put_int(&out, fctx->rid); - buffer_put_int(&out, rfwd->allocated_port); - channel_update_permitted_opens(rfwd->handle, + if ((r = sshbuf_put_u32(out, + MUX_S_REMOTE_PORT)) != 0 || + (r = sshbuf_put_u32(out, fctx->rid)) != 0 || + (r = sshbuf_put_u32(out, + rfwd->allocated_port)) != 0) + fatal("%s: reply: %s", __func__, ssh_err(r)); + channel_update_permission(ssh, rfwd->handle, rfwd->allocated_port); } else { - buffer_put_int(&out, MUX_S_OK); - buffer_put_int(&out, fctx->rid); + reply_ok(out, fctx->rid); } goto out; } else { if (rfwd->listen_port == 0) - channel_update_permitted_opens(rfwd->handle, -1); + channel_update_permission(ssh, rfwd->handle, -1); if (rfwd->listen_path != NULL) xasprintf(&failmsg, "remote port forwarding failed for " "listen path %s", rfwd->listen_path); else xasprintf(&failmsg, "remote port forwarding failed for " "listen port %d", rfwd->listen_port); + + debug2("%s: clearing registered forwarding for listen %d, " + "connect %s:%d", __func__, rfwd->listen_port, + rfwd->connect_path ? rfwd->connect_path : + rfwd->connect_host, rfwd->connect_port); + + free(rfwd->listen_host); + free(rfwd->listen_path); + free(rfwd->connect_host); + free(rfwd->connect_path); + memset(rfwd, 0, sizeof(*rfwd)); } fail: error("%s: %s", __func__, failmsg); - buffer_put_int(&out, MUX_S_FAILURE); - buffer_put_int(&out, fctx->rid); - buffer_put_cstring(&out, failmsg); + reply_error(out, MUX_S_FAILURE, fctx->rid, failmsg); free(failmsg); out: - buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out)); - buffer_free(&out); + if ((r = sshbuf_put_stringb(c->output, out)) != 0) + fatal("%s: sshbuf_put_stringb: %s", __func__, ssh_err(r)); + sshbuf_free(out); if (c->mux_pause <= 0) fatal("%s: mux_pause %d", __func__, c->mux_pause); c->mux_pause = 0; /* start processing messages again */ } static int -process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) +mux_master_process_open_fwd(struct ssh *ssh, u_int rid, + Channel *c, struct sshbuf *m, struct sshbuf *reply) { struct Forward fwd; char *fwd_desc = NULL; char *listen_addr, *connect_addr; u_int ftype; u_int lport, cport; - int i, ret = 0, freefwd = 1; + int r, i, ret = 0, freefwd = 1; + + memset(&fwd, 0, sizeof(fwd)); /* XXX - lport/cport check redundant */ - if (buffer_get_int_ret(&ftype, m) != 0 || - (listen_addr = buffer_get_string_ret(m, NULL)) == NULL || - buffer_get_int_ret(&lport, m) != 0 || - (connect_addr = buffer_get_string_ret(m, NULL)) == NULL || - buffer_get_int_ret(&cport, m) != 0 || + if ((r = sshbuf_get_u32(m, &ftype)) != 0 || + (r = sshbuf_get_cstring(m, &listen_addr, NULL)) != 0 || + (r = sshbuf_get_u32(m, &lport)) != 0 || + (r = sshbuf_get_cstring(m, &connect_addr, NULL)) != 0 || + (r = sshbuf_get_u32(m, &cport)) != 0 || (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) || (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) { error("%s: malformed message", __func__); @@ -694,9 +746,8 @@ process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) invalid: free(listen_addr); free(connect_addr); - buffer_put_int(r, MUX_S_FAILURE); - buffer_put_int(r, rid); - buffer_put_cstring(r, "Invalid forwarding request"); + reply_error(reply, MUX_S_FAILURE, rid, + "Invalid forwarding request"); return 0; } if (ftype == MUX_FWD_DYNAMIC && fwd.listen_path) { @@ -709,13 +760,16 @@ process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) fwd.listen_port); goto invalid; } - if ((fwd.connect_port != PORT_STREAMLOCAL && fwd.connect_port >= 65536) - || (ftype != MUX_FWD_DYNAMIC && ftype != MUX_FWD_REMOTE && fwd.connect_port == 0)) { + if ((fwd.connect_port != PORT_STREAMLOCAL && + fwd.connect_port >= 65536) || + (ftype != MUX_FWD_DYNAMIC && ftype != MUX_FWD_REMOTE && + fwd.connect_port == 0)) { logit("%s: invalid connect port %u", __func__, fwd.connect_port); goto invalid; } - if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL && fwd.connect_path == NULL) { + if (ftype != MUX_FWD_DYNAMIC && fwd.connect_host == NULL && + fwd.connect_path == NULL) { logit("%s: missing connect host", __func__); goto invalid; } @@ -730,26 +784,25 @@ process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) exists: debug2("%s: found existing forwarding", __func__); - buffer_put_int(r, MUX_S_OK); - buffer_put_int(r, rid); + reply_ok(reply, rid); goto out; } } break; case MUX_FWD_REMOTE: for (i = 0; i < options.num_remote_forwards; i++) { - if (compare_forward(&fwd, - options.remote_forwards + i)) { - if (fwd.listen_port != 0) - goto exists; - debug2("%s: found allocated port", - __func__); - buffer_put_int(r, MUX_S_REMOTE_PORT); - buffer_put_int(r, rid); - buffer_put_int(r, - options.remote_forwards[i].allocated_port); - goto out; - } + if (!compare_forward(&fwd, options.remote_forwards + i)) + continue; + if (fwd.listen_port != 0) + goto exists; + debug2("%s: found allocated port", __func__); + if ((r = sshbuf_put_u32(reply, + MUX_S_REMOTE_PORT)) != 0 || + (r = sshbuf_put_u32(reply, rid)) != 0 || + (r = sshbuf_put_u32(reply, + options.remote_forwards[i].allocated_port)) != 0) + fatal("%s: reply: %s", __func__, ssh_err(r)); + goto out; } break; } @@ -758,21 +811,19 @@ process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) options.control_master == SSHCTL_MASTER_AUTO_ASK) { if (!ask_permission("Open %s on %s?", fwd_desc, host)) { debug2("%s: forwarding refused by user", __func__); - buffer_put_int(r, MUX_S_PERMISSION_DENIED); - buffer_put_int(r, rid); - buffer_put_cstring(r, "Permission denied"); + reply_error(reply, MUX_S_PERMISSION_DENIED, rid, + "Permission denied"); goto out; } } if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) { - if (!channel_setup_local_fwd_listener(&fwd, + if (!channel_setup_local_fwd_listener(ssh, &fwd, &options.fwd_opts)) { fail: - logit("slave-requested %s failed", fwd_desc); - buffer_put_int(r, MUX_S_FAILURE); - buffer_put_int(r, rid); - buffer_put_cstring(r, "Port forwarding failed"); + logit("%s: requested %s failed", __func__, fwd_desc); + reply_error(reply, MUX_S_FAILURE, rid, + "Port forwarding failed"); goto out; } add_local_forward(&options, &fwd); @@ -780,7 +831,7 @@ process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) } else { struct mux_channel_confirm_ctx *fctx; - fwd.handle = channel_request_remote_forwarding(&fwd); + fwd.handle = channel_request_remote_forwarding(ssh, &fwd); if (fwd.handle < 0) goto fail; add_remote_forward(&options, &fwd); @@ -795,8 +846,7 @@ process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) /* delayed reply in mux_confirm_remote_forward */ goto out; } - buffer_put_int(r, MUX_S_OK); - buffer_put_int(r, rid); + reply_ok(reply, rid); out: free(fwd_desc); if (freefwd) { @@ -809,21 +859,24 @@ process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) } static int -process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) +mux_master_process_close_fwd(struct ssh *ssh, u_int rid, + Channel *c, struct sshbuf *m, struct sshbuf *reply) { struct Forward fwd, *found_fwd; char *fwd_desc = NULL; const char *error_reason = NULL; char *listen_addr = NULL, *connect_addr = NULL; u_int ftype; - int i, ret = 0; + int r, i, ret = 0; u_int lport, cport; - if (buffer_get_int_ret(&ftype, m) != 0 || - (listen_addr = buffer_get_string_ret(m, NULL)) == NULL || - buffer_get_int_ret(&lport, m) != 0 || - (connect_addr = buffer_get_string_ret(m, NULL)) == NULL || - buffer_get_int_ret(&cport, m) != 0 || + memset(&fwd, 0, sizeof(fwd)); + + if ((r = sshbuf_get_u32(m, &ftype)) != 0 || + (r = sshbuf_get_cstring(m, &listen_addr, NULL)) != 0 || + (r = sshbuf_get_u32(m, &lport)) != 0 || + (r = sshbuf_get_cstring(m, &connect_addr, NULL)) != 0 || + (r = sshbuf_get_u32(m, &cport)) != 0 || (lport != (u_int)PORT_STREAMLOCAL && lport > 65535) || (cport != (u_int)PORT_STREAMLOCAL && cport > 65535)) { error("%s: malformed message", __func__); @@ -888,19 +941,19 @@ process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) * However, for dynamic allocated listen ports we need * to use the actual listen port. */ - if (channel_request_rforward_cancel(found_fwd) == -1) + if (channel_request_rforward_cancel(ssh, found_fwd) == -1) error_reason = "port not in permitted opens"; } else { /* local and dynamic forwards */ /* Ditto */ - if (channel_cancel_lport_listener(&fwd, fwd.connect_port, + if (channel_cancel_lport_listener(ssh, &fwd, fwd.connect_port, &options.fwd_opts) == -1) error_reason = "port not found"; } - if (error_reason == NULL) { - buffer_put_int(r, MUX_S_OK); - buffer_put_int(r, rid); - + if (error_reason != NULL) + reply_error(reply, MUX_S_FAILURE, rid, error_reason); + else { + reply_ok(reply, rid); free(found_fwd->listen_host); free(found_fwd->listen_path); free(found_fwd->connect_host); @@ -908,10 +961,6 @@ process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) found_fwd->listen_host = found_fwd->connect_host = NULL; found_fwd->listen_path = found_fwd->connect_path = NULL; found_fwd->listen_port = found_fwd->connect_port = 0; - } else { - buffer_put_int(r, MUX_S_FAILURE); - buffer_put_int(r, rid); - buffer_put_cstring(r, error_reason); } out: free(fwd_desc); @@ -922,24 +971,22 @@ process_mux_close_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) } static int -process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) +mux_master_process_stdio_fwd(struct ssh *ssh, u_int rid, + Channel *c, struct sshbuf *m, struct sshbuf *reply) { Channel *nc; - char *reserved, *chost; + char *chost = NULL; u_int cport, i, j; - int new_fd[2]; + int r, new_fd[2]; struct mux_stdio_confirm_ctx *cctx; - chost = reserved = NULL; - if ((reserved = buffer_get_string_ret(m, NULL)) == NULL || - (chost = buffer_get_string_ret(m, NULL)) == NULL || - buffer_get_int_ret(&cport, m) != 0) { - free(reserved); + if ((r = sshbuf_skip_string(m)) != 0 || /* reserved */ + (r = sshbuf_get_cstring(m, &chost, NULL)) != 0 || + (r = sshbuf_get_u32(m, &cport)) != 0) { free(chost); error("%s: malformed message", __func__); return -1; } - free(reserved); debug2("%s: channel %d: request stdio fwd to %s:%u", __func__, c->self, chost, cport); @@ -954,9 +1001,7 @@ process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) free(chost); /* prepare reply */ - buffer_put_int(r, MUX_S_FAILURE); - buffer_put_int(r, rid); - buffer_put_cstring(r, + reply_error(reply, MUX_S_FAILURE, rid, "did not receive file descriptors"); return -1; } @@ -966,12 +1011,10 @@ process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) new_fd[0], new_fd[1]); /* XXX support multiple child sessions in future */ - if (c->remote_id != -1) { + if (c->have_remote_id) { debug2("%s: session already open", __func__); - /* prepare reply */ - buffer_put_int(r, MUX_S_FAILURE); - buffer_put_int(r, rid); - buffer_put_cstring(r, "Multiple sessions not supported"); + reply_error(reply, MUX_S_FAILURE, rid, + "Multiple sessions not supported"); cleanup: close(new_fd[0]); close(new_fd[1]); @@ -984,10 +1027,8 @@ process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) if (!ask_permission("Allow forward to %s:%u? ", chost, cport)) { debug2("%s: stdio fwd refused by user", __func__); - /* prepare reply */ - buffer_put_int(r, MUX_S_PERMISSION_DENIED); - buffer_put_int(r, rid); - buffer_put_cstring(r, "Permission denied"); + reply_error(reply, MUX_S_PERMISSION_DENIED, rid, + "Permission denied"); goto cleanup; } } @@ -998,19 +1039,22 @@ process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) if (!isatty(new_fd[1])) set_nonblock(new_fd[1]); - nc = channel_connect_stdio_fwd(chost, cport, new_fd[0], new_fd[1]); + nc = channel_connect_stdio_fwd(ssh, chost, cport, new_fd[0], new_fd[1]); + free(chost); nc->ctl_chan = c->self; /* link session -> control channel */ c->remote_id = nc->self; /* link control -> session channel */ + c->have_remote_id = 1; debug2("%s: channel_new: %d linked to control channel %d", __func__, nc->self, nc->ctl_chan); - channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1); + channel_register_cleanup(ssh, nc->self, + mux_master_session_cleanup_cb, 1); cctx = xcalloc(1, sizeof(*cctx)); cctx->rid = rid; - channel_register_open_confirm(nc->self, mux_stdio_confirm, cctx); + channel_register_open_confirm(ssh, nc->self, mux_stdio_confirm, cctx); c->mux_pause = 1; /* stop handling messages until open_confirm done */ /* reply is deferred, sent by mux_session_confirm */ @@ -1019,41 +1063,43 @@ process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r) /* Callback on open confirmation in mux master for a mux stdio fwd session. */ static void -mux_stdio_confirm(int id, int success, void *arg) +mux_stdio_confirm(struct ssh *ssh, int id, int success, void *arg) { struct mux_stdio_confirm_ctx *cctx = arg; Channel *c, *cc; - Buffer reply; + struct sshbuf *reply; + int r; if (cctx == NULL) fatal("%s: cctx == NULL", __func__); - if ((c = channel_by_id(id)) == NULL) + if ((c = channel_by_id(ssh, id)) == NULL) fatal("%s: no channel for id %d", __func__, id); - if ((cc = channel_by_id(c->ctl_chan)) == NULL) + if ((cc = channel_by_id(ssh, c->ctl_chan)) == NULL) fatal("%s: channel %d lacks control channel %d", __func__, id, c->ctl_chan); + if ((reply = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); if (!success) { debug3("%s: sending failure reply", __func__); + reply_error(reply, MUX_S_FAILURE, cctx->rid, + "Session open refused by peer"); /* prepare reply */ - buffer_init(&reply); - buffer_put_int(&reply, MUX_S_FAILURE); - buffer_put_int(&reply, cctx->rid); - buffer_put_cstring(&reply, "Session open refused by peer"); goto done; } debug3("%s: sending success reply", __func__); /* prepare reply */ - buffer_init(&reply); - buffer_put_int(&reply, MUX_S_SESSION_OPENED); - buffer_put_int(&reply, cctx->rid); - buffer_put_int(&reply, c->self); + if ((r = sshbuf_put_u32(reply, MUX_S_SESSION_OPENED)) != 0 || + (r = sshbuf_put_u32(reply, cctx->rid)) != 0 || + (r = sshbuf_put_u32(reply, c->self)) != 0) + fatal("%s: reply: %s", __func__, ssh_err(r)); done: /* Send reply */ - buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply)); - buffer_free(&reply); + if ((r = sshbuf_put_stringb(cc->output, reply)) != 0) + fatal("%s: sshbuf_put_stringb: %s", __func__, ssh_err(r)); + sshbuf_free(reply); if (cc->mux_pause <= 0) fatal("%s: mux_pause %d", __func__, cc->mux_pause); @@ -1063,7 +1109,8 @@ mux_stdio_confirm(int id, int success, void *arg) } static int -process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r) +mux_master_process_stop_listening(struct ssh *ssh, u_int rid, + Channel *c, struct sshbuf *m, struct sshbuf *reply) { debug("%s: channel %d: stop listening", __func__, c->self); @@ -1072,15 +1119,14 @@ process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r) if (!ask_permission("Disable further multiplexing on shared " "connection to %s? ", host)) { debug2("%s: stop listen refused by user", __func__); - buffer_put_int(r, MUX_S_PERMISSION_DENIED); - buffer_put_int(r, rid); - buffer_put_cstring(r, "Permission denied"); + reply_error(reply, MUX_S_PERMISSION_DENIED, rid, + "Permission denied"); return 0; } } if (mux_listener_channel != NULL) { - channel_free(mux_listener_channel); + channel_free(ssh, mux_listener_channel); client_stop_mux(); free(options.control_path); options.control_path = NULL; @@ -1088,57 +1134,69 @@ process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r) muxserver_sock = -1; } - /* prepare reply */ - buffer_put_int(r, MUX_S_OK); - buffer_put_int(r, rid); + reply_ok(reply, rid); + return 0; +} + +static int +mux_master_process_proxy(struct ssh *ssh, u_int rid, + Channel *c, struct sshbuf *m, struct sshbuf *reply) +{ + int r; + + debug("%s: channel %d: proxy request", __func__, c->self); + + c->mux_rcb = channel_proxy_downstream; + if ((r = sshbuf_put_u32(reply, MUX_S_PROXY)) != 0 || + (r = sshbuf_put_u32(reply, rid)) != 0) + fatal("%s: reply: %s", __func__, ssh_err(r)); return 0; } /* Channel callbacks fired on read/write from mux slave fd */ static int -mux_master_read_cb(Channel *c) +mux_master_read_cb(struct ssh *ssh, Channel *c) { struct mux_master_state *state = (struct mux_master_state *)c->mux_ctx; - Buffer in, out; - const u_char *ptr; - u_int type, rid, have, i; - int ret = -1; + struct sshbuf *in = NULL, *out = NULL; + u_int type, rid, i; + int r, ret = -1; + + if ((out = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); /* Setup ctx and */ if (c->mux_ctx == NULL) { state = xcalloc(1, sizeof(*state)); c->mux_ctx = state; - channel_register_cleanup(c->self, + channel_register_cleanup(ssh, c->self, mux_master_control_cleanup_cb, 0); /* Send hello */ - buffer_init(&out); - buffer_put_int(&out, MUX_MSG_HELLO); - buffer_put_int(&out, SSHMUX_VER); + if ((r = sshbuf_put_u32(out, MUX_MSG_HELLO)) != 0 || + (r = sshbuf_put_u32(out, SSHMUX_VER)) != 0) + fatal("%s: reply: %s", __func__, ssh_err(r)); /* no extensions */ - buffer_put_string(&c->output, buffer_ptr(&out), - buffer_len(&out)); - buffer_free(&out); + if ((r = sshbuf_put_stringb(c->output, out)) != 0) + fatal("%s: sshbuf_put_stringb: %s", + __func__, ssh_err(r)); debug3("%s: channel %d: hello sent", __func__, c->self); - return 0; + ret = 0; + goto out; } - buffer_init(&in); - buffer_init(&out); - /* Channel code ensures that we receive whole packets */ - if ((ptr = buffer_get_string_ptr_ret(&c->input, &have)) == NULL) { + if ((r = sshbuf_froms(c->input, &in)) != 0) { malf: error("%s: malformed message", __func__); goto out; } - buffer_append(&in, ptr, have); - if (buffer_get_int_ret(&type, &in) != 0) + if ((r = sshbuf_get_u32(in, &type)) != 0) goto malf; - debug3("%s: channel %d packet type 0x%08x len %u", - __func__, c->self, type, buffer_len(&in)); + debug3("%s: channel %d packet type 0x%08x len %zu", + __func__, c->self, type, sshbuf_len(in)); if (type == MUX_MSG_HELLO) rid = 0; @@ -1148,81 +1206,85 @@ mux_master_read_cb(Channel *c) "received 0x%08x", __func__, MUX_MSG_HELLO, type); goto out; } - if (buffer_get_int_ret(&rid, &in) != 0) + if ((r = sshbuf_get_u32(in, &rid)) != 0) goto malf; } for (i = 0; mux_master_handlers[i].handler != NULL; i++) { if (type == mux_master_handlers[i].type) { - ret = mux_master_handlers[i].handler(rid, c, &in, &out); + ret = mux_master_handlers[i].handler(ssh, rid, + c, in, out); break; } } if (mux_master_handlers[i].handler == NULL) { error("%s: unsupported mux message 0x%08x", __func__, type); - buffer_put_int(&out, MUX_S_FAILURE); - buffer_put_int(&out, rid); - buffer_put_cstring(&out, "unsupported request"); + reply_error(out, MUX_S_FAILURE, rid, "unsupported request"); ret = 0; } /* Enqueue reply packet */ - if (buffer_len(&out) != 0) { - buffer_put_string(&c->output, buffer_ptr(&out), - buffer_len(&out)); + if (sshbuf_len(out) != 0) { + if ((r = sshbuf_put_stringb(c->output, out)) != 0) + fatal("%s: sshbuf_put_stringb: %s", + __func__, ssh_err(r)); } out: - buffer_free(&in); - buffer_free(&out); + sshbuf_free(in); + sshbuf_free(out); return ret; } void -mux_exit_message(Channel *c, int exitval) +mux_exit_message(struct ssh *ssh, Channel *c, int exitval) { - Buffer m; + struct sshbuf *m; Channel *mux_chan; + int r; debug3("%s: channel %d: exit message, exitval %d", __func__, c->self, exitval); - if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL) + if ((mux_chan = channel_by_id(ssh, 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_EXIT_MESSAGE); - buffer_put_int(&m, c->self); - buffer_put_int(&m, exitval); - - buffer_put_string(&mux_chan->output, buffer_ptr(&m), buffer_len(&m)); - buffer_free(&m); + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if ((r = sshbuf_put_u32(m, MUX_S_EXIT_MESSAGE)) != 0 || + (r = sshbuf_put_u32(m, c->self)) != 0 || + (r = sshbuf_put_u32(m, exitval)) != 0 || + (r = sshbuf_put_stringb(mux_chan->output, m)) != 0) + fatal("%s: reply: %s", __func__, ssh_err(r)); + sshbuf_free(m); } void -mux_tty_alloc_failed(Channel *c) +mux_tty_alloc_failed(struct ssh *ssh, Channel *c) { - Buffer m; + struct sshbuf *m; Channel *mux_chan; + int r; debug3("%s: channel %d: TTY alloc failed", __func__, c->self); - if ((mux_chan = channel_by_id(c->ctl_chan)) == NULL) + if ((mux_chan = channel_by_id(ssh, 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); + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if ((r = sshbuf_put_u32(m, MUX_S_TTY_ALLOC_FAIL)) != 0 || + (r = sshbuf_put_u32(m, c->self)) != 0 || + (r = sshbuf_put_stringb(mux_chan->output, m)) != 0) + fatal("%s: reply: %s", __func__, ssh_err(r)); + sshbuf_free(m); } /* Prepare a mux master to listen on a Unix domain socket. */ void -muxserver_listen(void) +muxserver_listen(struct ssh *ssh) { mode_t old_umask; char *orig_control_path = options.control_path; @@ -1280,7 +1342,7 @@ muxserver_listen(void) /* Now atomically "move" the mux socket into position */ if (link(options.control_path, orig_control_path) != 0) { if (errno != EEXIST) { - fatal("%s: link mux listener %s => %s: %s", __func__, + fatal("%s: link mux listener %s => %s: %s", __func__, options.control_path, orig_control_path, strerror(errno)); } @@ -1295,7 +1357,7 @@ muxserver_listen(void) set_nonblock(muxserver_sock); - mux_listener_channel = channel_new("mux listener", + mux_listener_channel = channel_new(ssh, "mux listener", SSH_CHANNEL_MUX_LISTENER, muxserver_sock, muxserver_sock, -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, options.control_path, 1); @@ -1306,29 +1368,28 @@ muxserver_listen(void) /* Callback on open confirmation in mux master for a mux client session. */ static void -mux_session_confirm(int id, int success, void *arg) +mux_session_confirm(struct ssh *ssh, int id, int success, void *arg) { struct mux_session_confirm_ctx *cctx = arg; const char *display; Channel *c, *cc; - int i; - Buffer reply; + int i, r; + struct sshbuf *reply; if (cctx == NULL) fatal("%s: cctx == NULL", __func__); - if ((c = channel_by_id(id)) == NULL) + if ((c = channel_by_id(ssh, id)) == NULL) fatal("%s: no channel for id %d", __func__, id); - if ((cc = channel_by_id(c->ctl_chan)) == NULL) + if ((cc = channel_by_id(ssh, c->ctl_chan)) == NULL) fatal("%s: channel %d lacks control channel %d", __func__, id, c->ctl_chan); + if ((reply = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); if (!success) { debug3("%s: sending failure reply", __func__); - /* prepare reply */ - buffer_init(&reply); - buffer_put_int(&reply, MUX_S_FAILURE); - buffer_put_int(&reply, cctx->rid); - buffer_put_cstring(&reply, "Session open refused by peer"); + reply_error(reply, MUX_S_FAILURE, cctx->rid, + "Session open refused by peer"); goto done; } @@ -1337,44 +1398,48 @@ mux_session_confirm(int id, int success, void *arg) char *proto, *data; /* Get reasonable local authentication information. */ - client_x11_get_proto(display, options.xauth_location, + if (client_x11_get_proto(ssh, display, options.xauth_location, options.forward_x11_trusted, options.forward_x11_timeout, - &proto, &data); - /* Request forwarding with authentication spoofing. */ - debug("Requesting X11 forwarding with authentication " - "spoofing."); - x11_request_forwarding_with_spoofing(id, display, proto, - data, 1); - client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN); - /* XXX exit_on_forward_failure */ + &proto, &data) == 0) { + /* Request forwarding with authentication spoofing. */ + debug("Requesting X11 forwarding with authentication " + "spoofing."); + x11_request_forwarding_with_spoofing(ssh, id, + display, proto, data, 1); + /* XXX exit_on_forward_failure */ + client_expect_confirm(ssh, id, "X11 forwarding", + CONFIRM_WARN); + } } if (cctx->want_agent_fwd && options.forward_agent) { debug("Requesting authentication agent forwarding."); - channel_request_start(id, "auth-agent-req@openssh.com", 0); - packet_send(); + channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0); + if ((r = sshpkt_send(ssh)) != 0) + fatal("%s: packet error: %s", __func__, ssh_err(r)); } - client_session2_setup(id, cctx->want_tty, cctx->want_subsys, - cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env); + client_session2_setup(ssh, id, cctx->want_tty, cctx->want_subsys, + cctx->term, &cctx->tio, c->rfd, cctx->cmd, cctx->env); debug3("%s: sending success reply", __func__); /* prepare reply */ - buffer_init(&reply); - buffer_put_int(&reply, MUX_S_SESSION_OPENED); - buffer_put_int(&reply, cctx->rid); - buffer_put_int(&reply, c->self); + if ((r = sshbuf_put_u32(reply, MUX_S_SESSION_OPENED)) != 0 || + (r = sshbuf_put_u32(reply, cctx->rid)) != 0 || + (r = sshbuf_put_u32(reply, c->self)) != 0) + fatal("%s: reply: %s", __func__, ssh_err(r)); done: /* Send reply */ - buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply)); - buffer_free(&reply); + if ((r = sshbuf_put_stringb(cc->output, reply)) != 0) + fatal("%s: sshbuf_put_stringb: %s", __func__, ssh_err(r)); + sshbuf_free(reply); if (cc->mux_pause <= 0) fatal("%s: mux_pause %d", __func__, cc->mux_pause); cc->mux_pause = 0; /* start processing messages again */ c->open_confirm_ctx = NULL; - buffer_free(&cctx->cmd); + sshbuf_free(cctx->cmd); free(cctx->term); if (cctx->env != NULL) { for (i = 0; cctx->env[i] != NULL; i++) @@ -1409,23 +1474,25 @@ control_client_sigrelay(int signo) } static int -mux_client_read(int fd, Buffer *b, u_int need) +mux_client_read(int fd, struct sshbuf *b, size_t need) { - u_int have; + size_t have; ssize_t len; u_char *p; struct pollfd pfd; + int r; pfd.fd = fd; pfd.events = POLLIN; - p = buffer_append_space(b, need); + if ((r = sshbuf_reserve(b, need, &p)) != 0) + fatal("%s: reserve: %s", __func__, ssh_err(r)); for (have = 0; have < need; ) { if (muxclient_terminate) { errno = EINTR; return -1; } len = read(fd, p + have, need - have); - if (len < 0) { + if (len == -1) { switch (errno) { #if defined(EWOULDBLOCK) && (EWOULDBLOCK != EAGAIN) case EWOULDBLOCK: @@ -1443,36 +1510,38 @@ mux_client_read(int fd, Buffer *b, u_int need) errno = EPIPE; return -1; } - have += (u_int)len; + have += (size_t)len; } return 0; } static int -mux_client_write_packet(int fd, Buffer *m) +mux_client_write_packet(int fd, struct sshbuf *m) { - Buffer queue; + struct sshbuf *queue; u_int have, need; - int oerrno, len; - u_char *ptr; + int r, oerrno, len; + const u_char *ptr; struct pollfd pfd; pfd.fd = fd; pfd.events = POLLOUT; - buffer_init(&queue); - buffer_put_string(&queue, buffer_ptr(m), buffer_len(m)); + if ((queue = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if ((r = sshbuf_put_stringb(queue, m)) != 0) + fatal("%s: sshbuf_put_stringb: %s", __func__, ssh_err(r)); - need = buffer_len(&queue); - ptr = buffer_ptr(&queue); + need = sshbuf_len(queue); + ptr = sshbuf_ptr(queue); for (have = 0; have < need; ) { if (muxclient_terminate) { - buffer_free(&queue); + sshbuf_free(queue); errno = EINTR; return -1; } len = write(fd, ptr + have, need - have); - if (len < 0) { + if (len == -1) { switch (errno) { #if defined(EWOULDBLOCK) && (EWOULDBLOCK != EAGAIN) case EWOULDBLOCK: @@ -1484,132 +1553,160 @@ mux_client_write_packet(int fd, Buffer *m) continue; default: oerrno = errno; - buffer_free(&queue); + sshbuf_free(queue); errno = oerrno; return -1; } } if (len == 0) { - buffer_free(&queue); + sshbuf_free(queue); errno = EPIPE; return -1; } have += (u_int)len; } - buffer_free(&queue); + sshbuf_free(queue); return 0; } static int -mux_client_read_packet(int fd, Buffer *m) +mux_client_read_packet(int fd, struct sshbuf *m) { - Buffer queue; - u_int need, have; + struct sshbuf *queue; + size_t need, have; const u_char *ptr; - int oerrno; + int r, oerrno; - buffer_init(&queue); - if (mux_client_read(fd, &queue, 4) != 0) { + if ((queue = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if (mux_client_read(fd, queue, 4) != 0) { if ((oerrno = errno) == EPIPE) debug3("%s: read header failed: %s", __func__, strerror(errno)); - buffer_free(&queue); + sshbuf_free(queue); errno = oerrno; return -1; } - need = get_u32(buffer_ptr(&queue)); - if (mux_client_read(fd, &queue, need) != 0) { + need = PEEK_U32(sshbuf_ptr(queue)); + if (mux_client_read(fd, queue, need) != 0) { oerrno = errno; debug3("%s: read body failed: %s", __func__, strerror(errno)); - buffer_free(&queue); + sshbuf_free(queue); errno = oerrno; return -1; } - ptr = buffer_get_string_ptr(&queue, &have); - buffer_append(m, ptr, have); - buffer_free(&queue); + if ((r = sshbuf_get_string_direct(queue, &ptr, &have)) != 0 || + (r = sshbuf_put(m, ptr, have)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + sshbuf_free(queue); return 0; } static int mux_client_hello_exchange(int fd) { - Buffer m; + struct sshbuf *m; u_int type, ver; + int r, ret = -1; - buffer_init(&m); - buffer_put_int(&m, MUX_MSG_HELLO); - buffer_put_int(&m, SSHMUX_VER); + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if ((r = sshbuf_put_u32(m, MUX_MSG_HELLO)) != 0 || + (r = sshbuf_put_u32(m, SSHMUX_VER)) != 0) + fatal("%s: hello: %s", __func__, ssh_err(r)); /* no extensions */ - if (mux_client_write_packet(fd, &m) != 0) - fatal("%s: write packet: %s", __func__, strerror(errno)); + if (mux_client_write_packet(fd, m) != 0) { + debug("%s: write packet: %s", __func__, strerror(errno)); + goto out; + } - buffer_clear(&m); + sshbuf_reset(m); /* Read their HELLO */ - if (mux_client_read_packet(fd, &m) != 0) { - buffer_free(&m); - return -1; + if (mux_client_read_packet(fd, m) != 0) { + debug("%s: read packet failed", __func__); + goto out; } - type = buffer_get_int(&m); - if (type != MUX_MSG_HELLO) - fatal("%s: expected HELLO (%u) received %u", + if ((r = sshbuf_get_u32(m, &type)) != 0) + fatal("%s: decode type: %s", __func__, ssh_err(r)); + if (type != MUX_MSG_HELLO) { + error("%s: expected HELLO (%u) received %u", __func__, MUX_MSG_HELLO, type); - ver = buffer_get_int(&m); - if (ver != SSHMUX_VER) - fatal("Unsupported multiplexing protocol version %d " + goto out; + } + if ((r = sshbuf_get_u32(m, &ver)) != 0) + fatal("%s: decode version: %s", __func__, ssh_err(r)); + if (ver != SSHMUX_VER) { + error("Unsupported multiplexing protocol version %d " "(expected %d)", ver, SSHMUX_VER); + goto out; + } debug2("%s: master version %u", __func__, ver); /* No extensions are presently defined */ - while (buffer_len(&m) > 0) { - char *name = buffer_get_string(&m, NULL); - char *value = buffer_get_string(&m, NULL); + while (sshbuf_len(m) > 0) { + char *name = NULL; + if ((r = sshbuf_get_cstring(m, &name, NULL)) != 0 || + (r = sshbuf_skip_string(m)) != 0) { /* value */ + error("%s: malformed extension: %s", + __func__, ssh_err(r)); + goto out; + } debug2("Unrecognised master extension \"%s\"", name); free(name); - free(value); } - buffer_free(&m); - return 0; + /* success */ + ret = 0; + out: + sshbuf_free(m); + return ret; } static u_int mux_client_request_alive(int fd) { - Buffer m; + struct sshbuf *m; char *e; u_int pid, type, rid; + int r; debug3("%s: entering", __func__); - buffer_init(&m); - buffer_put_int(&m, MUX_C_ALIVE_CHECK); - buffer_put_int(&m, muxclient_request_id); + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if ((r = sshbuf_put_u32(m, MUX_C_ALIVE_CHECK)) != 0 || + (r = sshbuf_put_u32(m, muxclient_request_id)) != 0) + fatal("%s: request: %s", __func__, ssh_err(r)); - if (mux_client_write_packet(fd, &m) != 0) + if (mux_client_write_packet(fd, m) != 0) fatal("%s: write packet: %s", __func__, strerror(errno)); - buffer_clear(&m); + sshbuf_reset(m); /* Read their reply */ - if (mux_client_read_packet(fd, &m) != 0) { - buffer_free(&m); + if (mux_client_read_packet(fd, m) != 0) { + sshbuf_free(m); return 0; } - type = buffer_get_int(&m); + if ((r = sshbuf_get_u32(m, &type)) != 0) + fatal("%s: decode type: %s", __func__, ssh_err(r)); if (type != MUX_S_ALIVE) { - e = buffer_get_string(&m, NULL); + if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0) + fatal("%s: decode error: %s", __func__, ssh_err(r)); fatal("%s: master returned error: %s", __func__, e); } - if ((rid = buffer_get_int(&m)) != muxclient_request_id) + if ((r = sshbuf_get_u32(m, &rid)) != 0) + fatal("%s: decode remote ID: %s", __func__, ssh_err(r)); + if (rid != muxclient_request_id) fatal("%s: out of sequence reply: my id %u theirs %u", __func__, muxclient_request_id, rid); - pid = buffer_get_int(&m); - buffer_free(&m); + if ((r = sshbuf_get_u32(m, &pid)) != 0) + fatal("%s: decode PID: %s", __func__, ssh_err(r)); + sshbuf_free(m); debug3("%s: done pid = %u", __func__, pid); @@ -1621,129 +1718,152 @@ mux_client_request_alive(int fd) static void mux_client_request_terminate(int fd) { - Buffer m; + struct sshbuf *m; char *e; u_int type, rid; + int r; debug3("%s: entering", __func__); - buffer_init(&m); - buffer_put_int(&m, MUX_C_TERMINATE); - buffer_put_int(&m, muxclient_request_id); + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if ((r = sshbuf_put_u32(m, MUX_C_TERMINATE)) != 0 || + (r = sshbuf_put_u32(m, muxclient_request_id)) != 0) + fatal("%s: request: %s", __func__, ssh_err(r)); - if (mux_client_write_packet(fd, &m) != 0) + if (mux_client_write_packet(fd, m) != 0) fatal("%s: write packet: %s", __func__, strerror(errno)); - buffer_clear(&m); + sshbuf_reset(m); /* Read their reply */ - if (mux_client_read_packet(fd, &m) != 0) { + if (mux_client_read_packet(fd, m) != 0) { /* Remote end exited already */ if (errno == EPIPE) { - buffer_free(&m); + sshbuf_free(m); return; } fatal("%s: read from master failed: %s", __func__, strerror(errno)); } - type = buffer_get_int(&m); - if ((rid = buffer_get_int(&m)) != muxclient_request_id) + if ((r = sshbuf_get_u32(m, &type)) != 0 || + (r = sshbuf_get_u32(m, &rid)) != 0) + fatal("%s: decode: %s", __func__, ssh_err(r)); + if (rid != muxclient_request_id) fatal("%s: out of sequence reply: my id %u theirs %u", __func__, muxclient_request_id, rid); switch (type) { case MUX_S_OK: break; case MUX_S_PERMISSION_DENIED: - e = buffer_get_string(&m, NULL); + if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0) + fatal("%s: decode error: %s", __func__, ssh_err(r)); fatal("Master refused termination request: %s", e); case MUX_S_FAILURE: - e = buffer_get_string(&m, NULL); + if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0) + fatal("%s: decode error: %s", __func__, ssh_err(r)); fatal("%s: termination request failed: %s", __func__, e); default: fatal("%s: unexpected response from master 0x%08x", __func__, type); } - buffer_free(&m); + sshbuf_free(m); muxclient_request_id++; } static int mux_client_forward(int fd, int cancel_flag, u_int ftype, struct Forward *fwd) { - Buffer m; + struct sshbuf *m; char *e, *fwd_desc; + const char *lhost, *chost; u_int type, rid; + int r; fwd_desc = format_forward(ftype, fwd); debug("Requesting %s %s", cancel_flag ? "cancellation of" : "forwarding of", fwd_desc); free(fwd_desc); - buffer_init(&m); - buffer_put_int(&m, cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD); - buffer_put_int(&m, muxclient_request_id); - buffer_put_int(&m, ftype); - if (fwd->listen_path != NULL) { - buffer_put_cstring(&m, fwd->listen_path); - } else { - buffer_put_cstring(&m, - fwd->listen_host == NULL ? "" : - (*fwd->listen_host == '\0' ? "*" : fwd->listen_host)); - } - buffer_put_int(&m, fwd->listen_port); - if (fwd->connect_path != NULL) { - buffer_put_cstring(&m, fwd->connect_path); - } else { - buffer_put_cstring(&m, - fwd->connect_host == NULL ? "" : fwd->connect_host); - } - buffer_put_int(&m, fwd->connect_port); + type = cancel_flag ? MUX_C_CLOSE_FWD : MUX_C_OPEN_FWD; + if (fwd->listen_path != NULL) + lhost = fwd->listen_path; + else if (fwd->listen_host == NULL) + lhost = ""; + else if (*fwd->listen_host == '\0') + lhost = "*"; + else + lhost = fwd->listen_host; - if (mux_client_write_packet(fd, &m) != 0) + if (fwd->connect_path != NULL) + chost = fwd->connect_path; + else if (fwd->connect_host == NULL) + chost = ""; + else + chost = fwd->connect_host; + + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if ((r = sshbuf_put_u32(m, type)) != 0 || + (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 || + (r = sshbuf_put_u32(m, ftype)) != 0 || + (r = sshbuf_put_cstring(m, lhost)) != 0 || + (r = sshbuf_put_u32(m, fwd->listen_port)) != 0 || + (r = sshbuf_put_cstring(m, chost)) != 0 || + (r = sshbuf_put_u32(m, fwd->connect_port)) != 0) + fatal("%s: request: %s", __func__, ssh_err(r)); + + if (mux_client_write_packet(fd, m) != 0) fatal("%s: write packet: %s", __func__, strerror(errno)); - buffer_clear(&m); + sshbuf_reset(m); /* Read their reply */ - if (mux_client_read_packet(fd, &m) != 0) { - buffer_free(&m); + if (mux_client_read_packet(fd, m) != 0) { + sshbuf_free(m); return -1; } - type = buffer_get_int(&m); - if ((rid = buffer_get_int(&m)) != muxclient_request_id) + if ((r = sshbuf_get_u32(m, &type)) != 0 || + (r = sshbuf_get_u32(m, &rid)) != 0) + fatal("%s: decode: %s", __func__, ssh_err(r)); + if (rid != muxclient_request_id) fatal("%s: out of sequence reply: my id %u theirs %u", __func__, muxclient_request_id, rid); + switch (type) { case MUX_S_OK: break; case MUX_S_REMOTE_PORT: if (cancel_flag) fatal("%s: got MUX_S_REMOTE_PORT for cancel", __func__); - fwd->allocated_port = buffer_get_int(&m); - logit("Allocated port %u for remote forward to %s:%d", + if ((r = sshbuf_get_u32(m, &fwd->allocated_port)) != 0) + fatal("%s: decode port: %s", __func__, ssh_err(r)); + verbose("Allocated port %u for remote forward to %s:%d", fwd->allocated_port, fwd->connect_host ? fwd->connect_host : "", fwd->connect_port); if (muxclient_command == SSHMUX_COMMAND_FORWARD) - fprintf(stdout, "%u\n", fwd->allocated_port); + fprintf(stdout, "%i\n", fwd->allocated_port); break; case MUX_S_PERMISSION_DENIED: - e = buffer_get_string(&m, NULL); - buffer_free(&m); + if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0) + fatal("%s: decode error: %s", __func__, ssh_err(r)); + sshbuf_free(m); error("Master refused forwarding request: %s", e); return -1; case MUX_S_FAILURE: - e = buffer_get_string(&m, NULL); - buffer_free(&m); + if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0) + fatal("%s: decode error: %s", __func__, ssh_err(r)); + sshbuf_free(m); error("%s: forwarding request failed: %s", __func__, e); return -1; default: fatal("%s: unexpected response from master 0x%08x", __func__, type); } - buffer_free(&m); + sshbuf_free(m); muxclient_request_id++; return 0; @@ -1777,11 +1897,12 @@ mux_client_forwards(int fd, int cancel_flag) static int mux_client_request_session(int fd) { - Buffer m; - char *e, *term; - u_int i, rid, sid, esid, exitval, type, exitval_seen; + struct sshbuf *m; + char *e; + const char *term; + u_int echar, rid, sid, esid, exitval, type, exitval_seen; extern char **environ; - int devnull, rawmode; + int r, i, devnull, rawmode; debug3("%s: entering", __func__); @@ -1790,7 +1911,7 @@ mux_client_request_session(int fd) return -1; } - signal(SIGPIPE, SIG_IGN); + ssh_signal(SIGPIPE, SIG_IGN); if (stdin_null_flag) { if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1) @@ -1801,31 +1922,41 @@ mux_client_request_session(int fd) close(devnull); } - term = getenv("TERM"); - - buffer_init(&m); - buffer_put_int(&m, MUX_C_NEW_SESSION); - buffer_put_int(&m, muxclient_request_id); - buffer_put_cstring(&m, ""); /* reserved */ - buffer_put_int(&m, tty_flag); - buffer_put_int(&m, options.forward_x11); - buffer_put_int(&m, options.forward_agent); - buffer_put_int(&m, subsystem_flag); - buffer_put_int(&m, options.escape_char == SSH_ESCAPECHAR_NONE ? - 0xffffffff : (u_int)options.escape_char); - buffer_put_cstring(&m, term == NULL ? "" : term); - buffer_put_string(&m, buffer_ptr(&command), buffer_len(&command)); - + if ((term = getenv("TERM")) == NULL) + term = ""; + echar = 0xffffffff; + if (options.escape_char != SSH_ESCAPECHAR_NONE) + echar = (u_int)options.escape_char; + + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if ((r = sshbuf_put_u32(m, MUX_C_NEW_SESSION)) != 0 || + (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 || + (r = sshbuf_put_string(m, NULL, 0)) != 0 || /* reserved */ + (r = sshbuf_put_u32(m, tty_flag)) != 0 || + (r = sshbuf_put_u32(m, options.forward_x11)) != 0 || + (r = sshbuf_put_u32(m, options.forward_agent)) != 0 || + (r = sshbuf_put_u32(m, subsystem_flag)) != 0 || + (r = sshbuf_put_u32(m, echar)) != 0 || + (r = sshbuf_put_cstring(m, term)) != 0 || + (r = sshbuf_put_stringb(m, command)) != 0) + fatal("%s: request: %s", __func__, ssh_err(r)); + + /* Pass environment */ if (options.num_send_env > 0 && environ != NULL) { - /* Pass environment */ for (i = 0; environ[i] != NULL; i++) { - if (env_permitted(environ[i])) { - buffer_put_cstring(&m, environ[i]); - } + if (!env_permitted(environ[i])) + continue; + if ((r = sshbuf_put_cstring(m, environ[i])) != 0) + fatal("%s: request: %s", __func__, ssh_err(r)); } } + for (i = 0; i < options.num_setenv; i++) { + if ((r = sshbuf_put_cstring(m, options.setenv[i])) != 0) + fatal("%s: request: %s", __func__, ssh_err(r)); + } - if (mux_client_write_packet(fd, &m) != 0) + if (mux_client_write_packet(fd, m) != 0) fatal("%s: write packet: %s", __func__, strerror(errno)); /* Send the stdio file descriptors */ @@ -1837,45 +1968,55 @@ mux_client_request_session(int fd) debug3("%s: session request sent", __func__); /* Read their reply */ - buffer_clear(&m); - if (mux_client_read_packet(fd, &m) != 0) { + sshbuf_reset(m); + if (mux_client_read_packet(fd, m) != 0) { error("%s: read from master failed: %s", __func__, strerror(errno)); - buffer_free(&m); + sshbuf_free(m); return -1; } - type = buffer_get_int(&m); - if ((rid = buffer_get_int(&m)) != muxclient_request_id) + if ((r = sshbuf_get_u32(m, &type)) != 0 || + (r = sshbuf_get_u32(m, &rid)) != 0) + fatal("%s: decode: %s", __func__, ssh_err(r)); + if (rid != muxclient_request_id) fatal("%s: out of sequence reply: my id %u theirs %u", __func__, muxclient_request_id, rid); + switch (type) { case MUX_S_SESSION_OPENED: - sid = buffer_get_int(&m); + if ((r = sshbuf_get_u32(m, &sid)) != 0) + fatal("%s: decode ID: %s", __func__, ssh_err(r)); debug("%s: master session id: %u", __func__, sid); break; case MUX_S_PERMISSION_DENIED: - e = buffer_get_string(&m, NULL); - buffer_free(&m); + if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0) + fatal("%s: decode error: %s", __func__, ssh_err(r)); error("Master refused session request: %s", e); + sshbuf_free(m); return -1; case MUX_S_FAILURE: - e = buffer_get_string(&m, NULL); - buffer_free(&m); + if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0) + fatal("%s: decode error: %s", __func__, ssh_err(r)); error("%s: session request failed: %s", __func__, e); + sshbuf_free(m); return -1; default: - buffer_free(&m); + sshbuf_free(m); error("%s: unexpected response from master 0x%08x", __func__, type); return -1; } muxclient_request_id++; - signal(SIGHUP, control_client_sighandler); - signal(SIGINT, control_client_sighandler); - signal(SIGTERM, control_client_sighandler); - signal(SIGWINCH, control_client_sigrelay); + if (pledge("stdio proc tty", NULL) == -1) + fatal("%s pledge(): %s", __func__, strerror(errno)); + platform_pledge_mux(); + + ssh_signal(SIGHUP, control_client_sighandler); + ssh_signal(SIGINT, control_client_sighandler); + ssh_signal(SIGTERM, control_client_sighandler); + ssh_signal(SIGWINCH, control_client_sigrelay); rawmode = tty_flag; if (tty_flag) @@ -1889,13 +2030,17 @@ mux_client_request_session(int fd) * terminate early too (possibly losing data). */ for (exitval = 255, exitval_seen = 0;;) { - buffer_clear(&m); - if (mux_client_read_packet(fd, &m) != 0) + sshbuf_reset(m); + if (mux_client_read_packet(fd, m) != 0) break; - type = buffer_get_int(&m); + if ((r = sshbuf_get_u32(m, &type)) != 0) + fatal("%s: decode type: %s", __func__, ssh_err(r)); switch (type) { case MUX_S_TTY_ALLOC_FAIL: - if ((esid = buffer_get_int(&m)) != sid) + if ((r = sshbuf_get_u32(m, &esid)) != 0) + fatal("%s: decode ID: %s", + __func__, ssh_err(r)); + if (esid != sid) fatal("%s: tty alloc fail on unknown session: " "my id %u theirs %u", __func__, sid, esid); @@ -1904,17 +2049,24 @@ mux_client_request_session(int fd) rawmode = 0; continue; case MUX_S_EXIT_MESSAGE: - if ((esid = buffer_get_int(&m)) != sid) + if ((r = sshbuf_get_u32(m, &esid)) != 0) + fatal("%s: decode ID: %s", + __func__, ssh_err(r)); + if (esid != 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); + if ((r = sshbuf_get_u32(m, &exitval)) != 0) + fatal("%s: decode exit value: %s", + __func__, ssh_err(r)); exitval_seen = 1; continue; default: - e = buffer_get_string(&m, NULL); + if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0) + fatal("%s: decode error: %s", + __func__, ssh_err(r)); fatal("%s: master returned error: %s", __func__, e); } } @@ -1924,7 +2076,7 @@ mux_client_request_session(int fd) leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE); if (muxclient_terminate) { - debug2("Exiting on signal %d", muxclient_terminate); + debug2("Exiting on signal: %s", strsignal(muxclient_terminate)); exitval = 255; } else if (!exitval_seen) { debug2("Control master terminated unexpectedly"); @@ -1939,12 +2091,53 @@ mux_client_request_session(int fd) } static int +mux_client_proxy(int fd) +{ + struct sshbuf *m; + char *e; + u_int type, rid; + int r; + + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if ((r = sshbuf_put_u32(m, MUX_C_PROXY)) != 0 || + (r = sshbuf_put_u32(m, muxclient_request_id)) != 0) + fatal("%s: request: %s", __func__, ssh_err(r)); + if (mux_client_write_packet(fd, m) != 0) + fatal("%s: write packet: %s", __func__, strerror(errno)); + + sshbuf_reset(m); + + /* Read their reply */ + if (mux_client_read_packet(fd, m) != 0) { + sshbuf_free(m); + return 0; + } + if ((r = sshbuf_get_u32(m, &type)) != 0 || + (r = sshbuf_get_u32(m, &rid)) != 0) + fatal("%s: decode: %s", __func__, ssh_err(r)); + if (rid != muxclient_request_id) + fatal("%s: out of sequence reply: my id %u theirs %u", + __func__, muxclient_request_id, rid); + if (type != MUX_S_PROXY) { + if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0) + fatal("%s: decode error: %s", __func__, ssh_err(r)); + fatal("%s: master returned error: %s", __func__, e); + } + sshbuf_free(m); + + debug3("%s: done", __func__); + muxclient_request_id++; + return 0; +} + +static int mux_client_request_stdio_fwd(int fd) { - Buffer m; + struct sshbuf *m; char *e; u_int type, rid, sid; - int devnull; + int r, devnull; debug3("%s: entering", __func__); @@ -1953,7 +2146,7 @@ mux_client_request_stdio_fwd(int fd) return -1; } - signal(SIGPIPE, SIG_IGN); + ssh_signal(SIGPIPE, SIG_IGN); if (stdin_null_flag) { if ((devnull = open(_PATH_DEVNULL, O_RDONLY)) == -1) @@ -1964,14 +2157,16 @@ mux_client_request_stdio_fwd(int fd) close(devnull); } - buffer_init(&m); - buffer_put_int(&m, MUX_C_NEW_STDIO_FWD); - buffer_put_int(&m, muxclient_request_id); - buffer_put_cstring(&m, ""); /* reserved */ - buffer_put_cstring(&m, stdio_forward_host); - buffer_put_int(&m, stdio_forward_port); + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if ((r = sshbuf_put_u32(m, MUX_C_NEW_STDIO_FWD)) != 0 || + (r = sshbuf_put_u32(m, muxclient_request_id)) != 0 || + (r = sshbuf_put_string(m, NULL, 0)) != 0 || /* reserved */ + (r = sshbuf_put_cstring(m, options.stdio_forward_host)) != 0 || + (r = sshbuf_put_u32(m, options.stdio_forward_port)) != 0) + fatal("%s: request: %s", __func__, ssh_err(r)); - if (mux_client_write_packet(fd, &m) != 0) + if (mux_client_write_packet(fd, m) != 0) fatal("%s: write packet: %s", __func__, strerror(errno)); /* Send the stdio file descriptors */ @@ -1979,53 +2174,62 @@ mux_client_request_stdio_fwd(int fd) mm_send_fd(fd, STDOUT_FILENO) == -1) fatal("%s: send fds failed", __func__); + if (pledge("stdio proc tty", NULL) == -1) + fatal("%s pledge(): %s", __func__, strerror(errno)); + platform_pledge_mux(); + debug3("%s: stdio forward request sent", __func__); /* Read their reply */ - buffer_clear(&m); + sshbuf_reset(m); - if (mux_client_read_packet(fd, &m) != 0) { + if (mux_client_read_packet(fd, m) != 0) { error("%s: read from master failed: %s", __func__, strerror(errno)); - buffer_free(&m); + sshbuf_free(m); return -1; } - type = buffer_get_int(&m); - if ((rid = buffer_get_int(&m)) != muxclient_request_id) + if ((r = sshbuf_get_u32(m, &type)) != 0 || + (r = sshbuf_get_u32(m, &rid)) != 0) + fatal("%s: decode: %s", __func__, ssh_err(r)); + if (rid != muxclient_request_id) fatal("%s: out of sequence reply: my id %u theirs %u", __func__, muxclient_request_id, rid); switch (type) { case MUX_S_SESSION_OPENED: - sid = buffer_get_int(&m); + if ((r = sshbuf_get_u32(m, &sid)) != 0) + fatal("%s: decode ID: %s", __func__, ssh_err(r)); debug("%s: master session id: %u", __func__, sid); break; case MUX_S_PERMISSION_DENIED: - e = buffer_get_string(&m, NULL); - buffer_free(&m); + if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0) + fatal("%s: decode error: %s", __func__, ssh_err(r)); + sshbuf_free(m); fatal("Master refused stdio forwarding request: %s", e); case MUX_S_FAILURE: - e = buffer_get_string(&m, NULL); - buffer_free(&m); + if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0) + fatal("%s: decode error: %s", __func__, ssh_err(r)); + sshbuf_free(m); fatal("Stdio forwarding request failed: %s", e); default: - buffer_free(&m); + sshbuf_free(m); error("%s: unexpected response from master 0x%08x", __func__, type); return -1; } muxclient_request_id++; - signal(SIGHUP, control_client_sighandler); - signal(SIGINT, control_client_sighandler); - signal(SIGTERM, control_client_sighandler); - signal(SIGWINCH, control_client_sigrelay); + ssh_signal(SIGHUP, control_client_sighandler); + ssh_signal(SIGINT, control_client_sighandler); + ssh_signal(SIGTERM, control_client_sighandler); + ssh_signal(SIGWINCH, control_client_sigrelay); /* * Stick around until the controlee closes the client_fd. */ - buffer_clear(&m); - if (mux_client_read_packet(fd, &m) != 0) { + sshbuf_reset(m); + if (mux_client_read_packet(fd, m) != 0) { if (errno == EPIPE || (errno == EINTR && muxclient_terminate != 0)) return 0; @@ -2038,58 +2242,65 @@ mux_client_request_stdio_fwd(int fd) static void mux_client_request_stop_listening(int fd) { - Buffer m; + struct sshbuf *m; char *e; u_int type, rid; + int r; debug3("%s: entering", __func__); - buffer_init(&m); - buffer_put_int(&m, MUX_C_STOP_LISTENING); - buffer_put_int(&m, muxclient_request_id); + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new", __func__); + if ((r = sshbuf_put_u32(m, MUX_C_STOP_LISTENING)) != 0 || + (r = sshbuf_put_u32(m, muxclient_request_id)) != 0) + fatal("%s: request: %s", __func__, ssh_err(r)); - if (mux_client_write_packet(fd, &m) != 0) + if (mux_client_write_packet(fd, m) != 0) fatal("%s: write packet: %s", __func__, strerror(errno)); - buffer_clear(&m); + sshbuf_reset(m); /* Read their reply */ - if (mux_client_read_packet(fd, &m) != 0) + if (mux_client_read_packet(fd, m) != 0) fatal("%s: read from master failed: %s", __func__, strerror(errno)); - type = buffer_get_int(&m); - if ((rid = buffer_get_int(&m)) != muxclient_request_id) + if ((r = sshbuf_get_u32(m, &type)) != 0 || + (r = sshbuf_get_u32(m, &rid)) != 0) + fatal("%s: decode: %s", __func__, ssh_err(r)); + if (rid != muxclient_request_id) fatal("%s: out of sequence reply: my id %u theirs %u", __func__, muxclient_request_id, rid); + switch (type) { case MUX_S_OK: break; case MUX_S_PERMISSION_DENIED: - e = buffer_get_string(&m, NULL); + if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0) + fatal("%s: decode error: %s", __func__, ssh_err(r)); fatal("Master refused stop listening request: %s", e); case MUX_S_FAILURE: - e = buffer_get_string(&m, NULL); + if ((r = sshbuf_get_cstring(m, &e, NULL)) != 0) + fatal("%s: decode error: %s", __func__, ssh_err(r)); fatal("%s: stop listening request failed: %s", __func__, e); default: fatal("%s: unexpected response from master 0x%08x", __func__, type); } - buffer_free(&m); + sshbuf_free(m); muxclient_request_id++; } /* Multiplex client main loop. */ -void +int muxclient(const char *path) { struct sockaddr_un addr; - socklen_t sun_len; int sock; u_int pid; if (muxclient_command == 0) { - if (stdio_forward_host != NULL) + if (options.stdio_forward_host != NULL) muxclient_command = SSHMUX_COMMAND_STDIO_FWD; else muxclient_command = SSHMUX_COMMAND_OPEN; @@ -2103,22 +2314,21 @@ muxclient(const char *path) case SSHCTL_MASTER_NO: break; default: - return; + return -1; } memset(&addr, '\0', sizeof(addr)); addr.sun_family = AF_UNIX; - sun_len = offsetof(struct sockaddr_un, sun_path) + - strlen(path) + 1; if (strlcpy(addr.sun_path, path, sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) - fatal("ControlPath too long"); + fatal("ControlPath too long ('%s' >= %u bytes)", path, + (unsigned int)sizeof(addr.sun_path)); - if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) + if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) fatal("%s socket(): %s", __func__, strerror(errno)); - if (connect(sock, (struct sockaddr *)&addr, sun_len) == -1) { + if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) { switch (muxclient_command) { case SSHMUX_COMMAND_OPEN: case SSHMUX_COMMAND_STDIO_FWD: @@ -2138,25 +2348,26 @@ muxclient(const char *path) strerror(errno)); } close(sock); - return; + return -1; } set_nonblock(sock); if (mux_client_hello_exchange(sock) != 0) { error("%s: master hello exchange failed", __func__); close(sock); - return; + return -1; } switch (muxclient_command) { case SSHMUX_COMMAND_ALIVE_CHECK: if ((pid = mux_client_request_alive(sock)) == 0) fatal("%s: master alive check failed", __func__); - fprintf(stderr, "Master running (pid=%d)\r\n", pid); + fprintf(stderr, "Master running (pid=%u)\r\n", pid); exit(0); case SSHMUX_COMMAND_TERMINATE: mux_client_request_terminate(sock); - fprintf(stderr, "Exit request sent.\r\n"); + if (options.log_level != SYSLOG_LEVEL_QUIET) + fprintf(stderr, "Exit request sent.\r\n"); exit(0); case SSHMUX_COMMAND_FORWARD: if (mux_client_forwards(sock, 0) != 0) @@ -2165,22 +2376,26 @@ muxclient(const char *path) case SSHMUX_COMMAND_OPEN: if (mux_client_forwards(sock, 0) != 0) { error("%s: master forward request failed", __func__); - return; + return -1; } mux_client_request_session(sock); - return; + return -1; case SSHMUX_COMMAND_STDIO_FWD: mux_client_request_stdio_fwd(sock); exit(0); case SSHMUX_COMMAND_STOP: mux_client_request_stop_listening(sock); - fprintf(stderr, "Stop listening request sent.\r\n"); + if (options.log_level != SYSLOG_LEVEL_QUIET) + fprintf(stderr, "Stop listening request sent.\r\n"); exit(0); case SSHMUX_COMMAND_CANCEL_FWD: if (mux_client_forwards(sock, 1) != 0) error("%s: master cancel forward request failed", __func__); exit(0); + case SSHMUX_COMMAND_PROXY: + mux_client_proxy(sock); + return (sock); default: fatal("unrecognised muxclient_command %d", muxclient_command); } |