upstream: convert serverloop.c to new packet API

with & ok markus@

OpenBSD-Commit-ID: c92dd19b55457541478f95c0d6b318426d86d885

1 files changed, 204 insertions, 152 deletions

diff --git a/serverloop.c b/serverloop.c
index e0c26bbb..c60758e8 100644
--- a/serverloop.c
+++ b/serverloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: serverloop.c,v 1.210 2019/01/19 21:31:32 djm Exp $ */
+/* $OpenBSD: serverloop.c,v 1.211 2019/01/19 21:40:48 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -49,6 +49,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <pwd.h>
+#include <limits.h>
 #include <signal.h>
 #include <string.h>
 #include <termios.h>
@@ -78,9 +79,6 @@
 #include "serverloop.h"
 #include "ssherr.h"
 
-#include "opacket.h" /* XXX */
-extern struct ssh *active_state; /* XXX */
-
 extern ServerOptions options;
 
 /* XXX */
@@ -101,7 +99,7 @@ static volatile sig_atomic_t child_terminated = 0;	/* The child has terminated.
 static volatile sig_atomic_t received_sigterm = 0;
 
 /* prototypes */
-static void server_init_dispatch(void);
+static void server_init_dispatch(struct ssh *);
 
 /* requested tunnel forwarding interface(s), shared with session.c */
 char *tun_fwd_ifnames = NULL;
@@ -182,11 +180,12 @@ sigterm_handler(int sig)
 static void
 client_alive_check(struct ssh *ssh)
 {
-	int channel_id;
 	char remote_id[512];
+	int r, channel_id;
 
 	/* timeout, check to see how many we have had */
-	if (packet_inc_alive_timeouts() > options.client_alive_count_max) {
+	if (ssh_packet_inc_alive_timeouts(ssh) >
+	    options.client_alive_count_max) {
 		sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
 		logit("Timeout, client not responding from %s", remote_id);
 		cleanup_exit(255);
@@ -197,14 +196,17 @@ client_alive_check(struct ssh *ssh)
 	 * we should get back a failure
 	 */
 	if ((channel_id = channel_find_open(ssh)) == -1) {
-		packet_start(SSH2_MSG_GLOBAL_REQUEST);
-		packet_put_cstring("keepalive@openssh.com");
-		packet_put_char(1);	/* boolean: want reply */
+		if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
+		    (r = sshpkt_put_cstring(ssh, "keepalive@openssh.com"))
+		    != 0 ||
+		    (r = sshpkt_put_u8(ssh, 1)) != 0) /* boolean: want reply */
+			fatal("%s: %s", __func__, ssh_err(r));
 	} else {
 		channel_request_start(ssh, channel_id,
 		    "keepalive@openssh.com", 1);
 	}
-	packet_send();
+	if ((r = sshpkt_send(ssh)) != 0)
+		fatal("%s: %s", __func__, ssh_err(r));
 }
 
 /*
@@ -261,14 +263,14 @@ wait_until_can_do_something(struct ssh *ssh,
 	 * If we have buffered packet data going to the client, mark that
 	 * descriptor.
 	 */
-	if (packet_have_data_to_write())
+	if (ssh_packet_have_data_to_write(ssh))
 		FD_SET(connection_out, *writesetp);
 
 	/*
 	 * If child has terminated and there is enough buffer space to read
 	 * from it, then read as much as is available and exit.
 	 */
-	if (child_terminated && packet_not_very_much_data_to_write())
+	if (child_terminated && ssh_packet_not_very_much_data_to_write(ssh))
 		if (max_time_ms == 0 || client_alive_scheduled)
 			max_time_ms = 100;
 
@@ -312,7 +314,7 @@ wait_until_can_do_something(struct ssh *ssh,
 static int
 process_input(struct ssh *ssh, fd_set *readset, int connection_in)
 {
-	int len;
+	int r, len;
 	char buf[16384];
 
 	/* Read and buffer any input data from the client. */
@@ -333,7 +335,10 @@ process_input(struct ssh *ssh, fd_set *readset, int connection_in)
 			}
 		} else {
 			/* Buffer any received data. */
-			packet_process_incoming(buf, len);
+			if ((r = ssh_packet_process_incoming(ssh, buf, len))
+			    != 0)
+				fatal("%s: ssh_packet_process_incoming: %s",
+				    __func__, ssh_err(r));
 		}
 	}
 	return 0;
@@ -343,11 +348,16 @@ process_input(struct ssh *ssh, fd_set *readset, int connection_in)
  * Sends data from internal buffers to client program stdin.
  */
 static void
-process_output(fd_set *writeset, int connection_out)
+process_output(struct ssh *ssh, fd_set *writeset, int connection_out)
 {
+	int r;
+
 	/* Send any buffered packet data to the client. */
-	if (FD_ISSET(connection_out, writeset))
-		packet_write_poll();
+	if (FD_ISSET(connection_out, writeset)) {
+		if ((r = ssh_packet_write_poll(ssh)) != 0)
+			fatal("%s: ssh_packet_write_poll: %s",
+			    __func__, ssh_err(r));
+	}
 }
 
 static void
@@ -390,8 +400,8 @@ server_loop2(struct ssh *ssh, Authctxt *authctxt)
 
 	signal(SIGCHLD, sigchld_handler);
 	child_terminated = 0;
-	connection_in = packet_get_connection_in();
-	connection_out = packet_get_connection_out();
+	connection_in = ssh_packet_get_connection_in(ssh);
+	connection_out = ssh_packet_get_connection_out(ssh);
 
 	if (!use_privsep) {
 		signal(SIGTERM, sigterm_handler);
@@ -404,18 +414,21 @@ server_loop2(struct ssh *ssh, Authctxt *authctxt)
 	max_fd = MAXIMUM(connection_in, connection_out);
 	max_fd = MAXIMUM(max_fd, notify_pipe[0]);
 
-	server_init_dispatch();
+	server_init_dispatch(ssh);
 
 	for (;;) {
 		process_buffered_input_packets(ssh);
 
 		if (!ssh_packet_is_rekeying(ssh) &&
-		    packet_not_very_much_data_to_write())
+		    ssh_packet_not_very_much_data_to_write(ssh))
 			channel_output_poll(ssh);
-		if (options.rekey_interval > 0 && !ssh_packet_is_rekeying(ssh))
-			rekey_timeout_ms = packet_get_rekey_timeout() * 1000;
-		else
+		if (options.rekey_interval > 0 &&
+		    !ssh_packet_is_rekeying(ssh)) {
+			rekey_timeout_ms = ssh_packet_get_rekey_timeout(ssh) *
+			    1000;
+		} else {
 			rekey_timeout_ms = 0;
+		}
 
 		wait_until_can_do_something(ssh, connection_in, connection_out,
 		    &readset, &writeset, &max_fd, &nalloc, rekey_timeout_ms);
@@ -431,7 +444,7 @@ server_loop2(struct ssh *ssh, Authctxt *authctxt)
 			channel_after_select(ssh, readset, writeset);
 		if (process_input(ssh, readset, connection_in) < 0)
 			break;
-		process_output(writeset, connection_out);
+		process_output(ssh, writeset, connection_out);
 	}
 	collect_children(ssh);
 
@@ -454,7 +467,7 @@ server_input_keep_alive(int type, u_int32_t seq, struct ssh *ssh)
 	 * even if this was generated by something other than
 	 * the bogus CHANNEL_REQUEST we send for keepalives.
 	 */
-	packet_set_alive_timeouts(0);
+	ssh_packet_set_alive_timeouts(ssh, 0);
 	return 0;
 }
 
@@ -462,16 +475,28 @@ static Channel *
 server_request_direct_tcpip(struct ssh *ssh, int *reason, const char **errmsg)
 {
 	Channel *c = NULL;
-	char *target, *originator;
-	u_short target_port, originator_port;
-
-	target = packet_get_string(NULL);
-	target_port = packet_get_int();
-	originator = packet_get_string(NULL);
-	originator_port = packet_get_int();
-	packet_check_eom();
+	char *target = NULL, *originator = NULL;
+	u_int target_port = 0, originator_port = 0;
+	int r;
+
+	if ((r = sshpkt_get_cstring(ssh, &target, NULL)) != 0 ||
+	    (r = sshpkt_get_u32(ssh, &target_port)) != 0 ||
+	    (r = sshpkt_get_cstring(ssh, &originator, NULL)) != 0 ||
+	    (r = sshpkt_get_u32(ssh, &originator_port)) != 0 ||
+	    (r = sshpkt_get_end(ssh)) != 0)
+		sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
+	if (target_port > 0xFFFF) {
+		error("%s: invalid target port", __func__);
+		*reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
+		goto out;
+	}
+	if (originator_port > 0xFFFF) {
+		error("%s: invalid originator port", __func__);
+		*reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
+		goto out;
+	}
 
-	debug("%s: originator %s port %d, target %s port %d", __func__,
+	debug("%s: originator %s port %u, target %s port %u", __func__,
 	    originator, originator_port, target, target_port);
 
 	/* XXX fine grained permissions */
@@ -488,9 +513,9 @@ server_request_direct_tcpip(struct ssh *ssh, int *reason, const char **errmsg)
 			*reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
 	}
 
+ out:
 	free(originator);
 	free(target);
-
 	return c;
 }
 
@@ -498,17 +523,23 @@ static Channel *
 server_request_direct_streamlocal(struct ssh *ssh)
 {
 	Channel *c = NULL;
-	char *target, *originator;
-	u_short originator_port;
+	char *target = NULL, *originator = NULL;
+	u_int originator_port = 0;
 	struct passwd *pw = the_authctxt->pw;
+	int r;
 
 	if (pw == NULL || !the_authctxt->valid)
 		fatal("%s: no/invalid user", __func__);
 
-	target = packet_get_string(NULL);
-	originator = packet_get_string(NULL);
-	originator_port = packet_get_int();
-	packet_check_eom();
+	if ((r = sshpkt_get_cstring(ssh, &target, NULL)) != 0 ||
+	    (r = sshpkt_get_cstring(ssh, &originator, NULL)) != 0 ||
+	    (r = sshpkt_get_u32(ssh, &originator_port)) != 0 ||
+	    (r = sshpkt_get_end(ssh)) != 0)
+		sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
+	if (originator_port > 0xFFFF) {
+		error("%s: invalid originator port", __func__);
+		goto out;
+	}
 
 	debug("%s: originator %s port %d, target %s", __func__,
 	    originator, originator_port, target);
@@ -525,9 +556,9 @@ server_request_direct_streamlocal(struct ssh *ssh)
 		    originator, originator_port, target);
 	}
 
+out:
 	free(originator);
 	free(target);
-
 	return c;
 }
 
@@ -535,27 +566,35 @@ static Channel *
 server_request_tun(struct ssh *ssh)
 {
 	Channel *c = NULL;
-	int mode, tun, sock;
+	u_int mode, tun;
+	int r, sock;
 	char *tmp, *ifname = NULL;
 
-	mode = packet_get_int();
+	if ((r = sshpkt_get_u32(ssh, &mode)) != 0)
+		sshpkt_fatal(ssh, r, "%s: parse mode", __func__);
 	switch (mode) {
 	case SSH_TUNMODE_POINTOPOINT:
 	case SSH_TUNMODE_ETHERNET:
 		break;
 	default:
-		packet_send_debug("Unsupported tunnel device mode.");
+		ssh_packet_send_debug(ssh, "Unsupported tunnel device mode.");
 		return NULL;
 	}
 	if ((options.permit_tun & mode) == 0) {
-		packet_send_debug("Server has rejected tunnel device "
+		ssh_packet_send_debug(ssh, "Server has rejected tunnel device "
 		    "forwarding");
 		return NULL;
 	}
 
-	tun = packet_get_int();
+	if ((r = sshpkt_get_u32(ssh, &tun)) != 0)
+		sshpkt_fatal(ssh, r, "%s: parse device", __func__);
+	if (tun > INT_MAX) {
+		debug("%s: invalid tun", __func__);
+		goto done;
+	}
 	if (auth_opts->force_tun_device != -1) {
-		if (tun != SSH_TUNID_ANY && auth_opts->force_tun_device != tun)
+		if (tun != SSH_TUNID_ANY &&
+		    auth_opts->force_tun_device != (int)tun)
 			goto done;
 		tun = auth_opts->force_tun_device;
 	}
@@ -588,7 +627,7 @@ server_request_tun(struct ssh *ssh)
 
  done:
 	if (c == NULL)
-		packet_send_debug("Failed to open the tunnel device.");
+		ssh_packet_send_debug(ssh, "Failed to open the tunnel device.");
 	return c;
 }
 
@@ -596,13 +635,15 @@ static Channel *
 server_request_session(struct ssh *ssh)
 {
 	Channel *c;
+	int r;
 
 	debug("input_session_request");
-	packet_check_eom();
+	if ((r = sshpkt_get_end(ssh)) != 0)
+		sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
 
 	if (no_more_sessions) {
-		packet_disconnect("Possible attack: attempt to open a session "
-		    "after additional sessions disabled");
+		sshpkt_disconnect(ssh, "Possible attack: attempt to open a "
+		    "session after additional sessions disabled");
 	}
 
 	/*
@@ -627,20 +668,22 @@ static int
 server_input_channel_open(int type, u_int32_t seq, struct ssh *ssh)
 {
 	Channel *c = NULL;
-	char *ctype;
+	char *ctype = NULL;
 	const char *errmsg = NULL;
-	int rchan, reason = SSH2_OPEN_CONNECT_FAILED;
-	u_int rmaxpack, rwindow, len;
-
-	ctype = packet_get_string(&len);
-	rchan = packet_get_int();
-	rwindow = packet_get_int();
-	rmaxpack = packet_get_int();
-
-	debug("%s: ctype %s rchan %d win %d max %d", __func__,
+	int r, reason = SSH2_OPEN_CONNECT_FAILED;
+	u_int rchan = 0, rmaxpack = 0, rwindow = 0;
+
+	if ((r = sshpkt_get_cstring(ssh, &ctype, NULL)) != 0 ||
+	    (r = sshpkt_get_u32(ssh, &rchan)) != 0 ||
+	    (r = sshpkt_get_u32(ssh, &rwindow)) != 0 ||
+	    (r = sshpkt_get_u32(ssh, &rmaxpack)) != 0)
+		sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
+	debug("%s: ctype %s rchan %u win %u max %u", __func__,
 	    ctype, rchan, rwindow, rmaxpack);
 
-	if (strcmp(ctype, "session") == 0) {
+	if (rchan > INT_MAX) {
+		error("%s: invalid remote channel ID", __func__);
+	} else if (strcmp(ctype, "session") == 0) {
 		c = server_request_session(ssh);
 	} else if (strcmp(ctype, "direct-tcpip") == 0) {
 		c = server_request_direct_tcpip(ssh, &reason, &errmsg);
@@ -651,26 +694,32 @@ server_input_channel_open(int type, u_int32_t seq, struct ssh *ssh)
 	}
 	if (c != NULL) {
 		debug("%s: confirm %s", __func__, ctype);
-		c->remote_id = rchan;
+		c->remote_id = (int)rchan;
 		c->have_remote_id = 1;
 		c->remote_window = rwindow;
 		c->remote_maxpacket = rmaxpack;
 		if (c->type != SSH_CHANNEL_CONNECTING) {
-			packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
-			packet_put_int(c->remote_id);
-			packet_put_int(c->self);
-			packet_put_int(c->local_window);
-			packet_put_int(c->local_maxpacket);
-			packet_send();
+			if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
+			    (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
+			    (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
+			    (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
+			    (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 ||
+			    (r = sshpkt_send(ssh)) != 0) {
+				sshpkt_fatal(ssh, r,
+				    "%s: send open confirm", __func__);
+			}
 		}
 	} else {
 		debug("%s: failure %s", __func__, ctype);
-		packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
-		packet_put_int(rchan);
-		packet_put_int(reason);
-		packet_put_cstring(errmsg ? errmsg : "open failed");
-		packet_put_cstring("");
-		packet_send();
+		if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 ||
+		    (r = sshpkt_put_u32(ssh, rchan)) != 0 ||
+		    (r = sshpkt_put_u32(ssh, reason)) != 0 ||
+		    (r = sshpkt_put_cstring(ssh, errmsg ? errmsg : "open failed")) != 0 ||
+		    (r = sshpkt_put_cstring(ssh, "")) != 0 ||
+		    (r = sshpkt_send(ssh)) != 0) {
+			sshpkt_fatal(ssh, r,
+			    "%s: send open failure", __func__);
+		}
 	}
 	free(ctype);
 	return 0;
@@ -757,65 +806,66 @@ server_input_hostkeys_prove(struct ssh *ssh, struct sshbuf **respp)
 static int
 server_input_global_request(int type, u_int32_t seq, struct ssh *ssh)
 {
-	char *rtype;
-	int want_reply;
+	char *rtype = NULL;
+	u_char want_reply = 0;
 	int r, success = 0, allocated_listen_port = 0;
+	u_int port = 0;
 	struct sshbuf *resp = NULL;
 	struct passwd *pw = the_authctxt->pw;
+	struct Forward fwd;
 
+	memset(&fwd, 0, sizeof(fwd));
 	if (pw == NULL || !the_authctxt->valid)
 		fatal("%s: no/invalid user", __func__);
 
-	rtype = packet_get_string(NULL);
-	want_reply = packet_get_char();
+	if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 ||
+	    (r = sshpkt_get_u8(ssh, &want_reply)) != 0)
+		sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
 	debug("%s: rtype %s want_reply %d", __func__, rtype, want_reply);
 
 	/* -R style forwarding */
 	if (strcmp(rtype, "tcpip-forward") == 0) {
-		struct Forward fwd;
-
-		memset(&fwd, 0, sizeof(fwd));
-		fwd.listen_host = packet_get_string(NULL);
-		fwd.listen_port = (u_short)packet_get_int();
-		debug("%s: tcpip-forward listen %s port %d", __func__,
-		    fwd.listen_host, fwd.listen_port);
-
+		if ((r = sshpkt_get_cstring(ssh, &fwd.listen_host, NULL)) != 0 ||
+		    (r = sshpkt_get_u32(ssh, &port)) != 0)
+			sshpkt_fatal(ssh, r, "%s: parse tcpip-forward", __func__);
+		debug("%s: tcpip-forward listen %s port %u", __func__,
+		    fwd.listen_host, port);
+		if (port <= INT_MAX)
+			fwd.listen_port = (int)port;
 		/* check permissions */
-		if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 ||
+		if (port > INT_MAX ||
+		    (options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 ||
 		    !auth_opts->permit_port_forwarding_flag ||
 		    options.disable_forwarding ||
 		    (!want_reply && fwd.listen_port == 0) ||
 		    (fwd.listen_port != 0 &&
 		     !bind_permitted(fwd.listen_port, pw->pw_uid))) {
 			success = 0;
-			packet_send_debug("Server has disabled port forwarding.");
+			ssh_packet_send_debug(ssh, "Server has disabled port forwarding.");
 		} else {
 			/* Start listening on the port */
 			success = channel_setup_remote_fwd_listener(ssh, &fwd,
 			    &allocated_listen_port, &options.fwd_opts);
 		}
-		free(fwd.listen_host);
 		if ((resp = sshbuf_new()) == NULL)
 			fatal("%s: sshbuf_new", __func__);
 		if (allocated_listen_port != 0 &&
 		    (r = sshbuf_put_u32(resp, allocated_listen_port)) != 0)
 			fatal("%s: sshbuf_put_u32: %s", __func__, ssh_err(r));
 	} else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
-		struct Forward fwd;
+		if ((r = sshpkt_get_cstring(ssh, &fwd.listen_host, NULL)) != 0 ||
+		    (r = sshpkt_get_u32(ssh, &port)) != 0)
+			sshpkt_fatal(ssh, r, "%s: parse cancel-tcpip-forward", __func__);
 
-		memset(&fwd, 0, sizeof(fwd));
-		fwd.listen_host = packet_get_string(NULL);
-		fwd.listen_port = (u_short)packet_get_int();
 		debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
-		    fwd.listen_host, fwd.listen_port);
-
-		success = channel_cancel_rport_listener(ssh, &fwd);
-		free(fwd.listen_host);
+		    fwd.listen_host, port);
+		if (port <= INT_MAX) {
+			fwd.listen_port = (int)port;
+			success = channel_cancel_rport_listener(ssh, &fwd);
+		}
 	} else if (strcmp(rtype, "streamlocal-forward@openssh.com") == 0) {
-		struct Forward fwd;
-
-		memset(&fwd, 0, sizeof(fwd));
-		fwd.listen_path = packet_get_string(NULL);
+		if ((r = sshpkt_get_cstring(ssh, &fwd.listen_path, NULL)) != 0)
+			sshpkt_fatal(ssh, r, "%s: parse streamlocal-forward@openssh.com", __func__);
 		debug("%s: streamlocal-forward listen path %s", __func__,
 		    fwd.listen_path);
 
@@ -825,39 +875,37 @@ server_input_global_request(int type, u_int32_t seq, struct ssh *ssh)
 		    options.disable_forwarding ||
 		    (pw->pw_uid != 0 && !use_privsep)) {
 			success = 0;
-			packet_send_debug("Server has disabled "
+			ssh_packet_send_debug(ssh, "Server has disabled "
 			    "streamlocal forwarding.");
 		} else {
 			/* Start listening on the socket */
 			success = channel_setup_remote_fwd_listener(ssh,
 			    &fwd, NULL, &options.fwd_opts);
 		}
-		free(fwd.listen_path);
 	} else if (strcmp(rtype, "cancel-streamlocal-forward@openssh.com") == 0) {
-		struct Forward fwd;
-
-		memset(&fwd, 0, sizeof(fwd));
-		fwd.listen_path = packet_get_string(NULL);
+		if ((r = sshpkt_get_cstring(ssh, &fwd.listen_path, NULL)) != 0)
+			sshpkt_fatal(ssh, r, "%s: parse cancel-streamlocal-forward@openssh.com", __func__);
 		debug("%s: cancel-streamlocal-forward path %s", __func__,
 		    fwd.listen_path);
 
 		success = channel_cancel_rport_listener(ssh, &fwd);
-		free(fwd.listen_path);
 	} else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) {
 		no_more_sessions = 1;
 		success = 1;
 	} else if (strcmp(rtype, "hostkeys-prove-00@openssh.com") == 0) {
 		success = server_input_hostkeys_prove(ssh, &resp);
 	}
+	/* XXX sshpkt_get_end() */
 	if (want_reply) {
-		packet_start(success ?
-		    SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
-		if (success && resp != NULL)
-			ssh_packet_put_raw(ssh, sshbuf_ptr(resp),
-			    sshbuf_len(resp));
-		packet_send();
-		packet_write_wait();
+		if ((r = sshpkt_start(ssh, success ?
+		    SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE)) != 0 ||
+		    (success && resp != NULL && (r = sshpkt_putb(ssh, resp)) != 0) ||
+		    (r = sshpkt_send(ssh)) != 0 ||
+		    (r = ssh_packet_write_wait(ssh)) != 0)
+			sshpkt_fatal(ssh, r, "%s: send reply", __func__);
 	}
+	free(fwd.listen_host);
+	free(fwd.listen_path);
 	free(rtype);
 	sshbuf_free(resp);
 	return 0;
@@ -867,58 +915,62 @@ static int
 server_input_channel_req(int type, u_int32_t seq, struct ssh *ssh)
 {
 	Channel *c;
-	int id, reply, success = 0;
-	char *rtype;
+	int r, success = 0;
+	char *rtype = NULL;
+	u_char want_reply = 0;
+	u_int id = 0;
 
-	id = packet_get_int();
-	rtype = packet_get_string(NULL);
-	reply = packet_get_char();
+	if ((r = sshpkt_get_u32(ssh, &id)) != 0 ||
+	    (r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 ||
+	    (r = sshpkt_get_u8(ssh, &want_reply)) != 0)
+		sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
 
-	debug("server_input_channel_req: channel %d request %s reply %d",
-	    id, rtype, reply);
+	debug("server_input_channel_req: channel %u request %s reply %d",
+	    id, rtype, want_reply);
 
-	if ((c = channel_lookup(ssh, id)) == NULL)
-		packet_disconnect("server_input_channel_req: "
-		    "unknown channel %d", id);
+	if (id >= INT_MAX || (c = channel_lookup(ssh, (int)id)) == NULL)
+		sshpkt_disconnect(ssh, "%s: unknown channel %d", __func__, id);
 	if (!strcmp(rtype, "eow@openssh.com")) {
-		packet_check_eom();
+		if ((r = sshpkt_get_end(ssh)) != 0)
+			sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
 		chan_rcvd_eow(ssh, c);
 	} else if ((c->type == SSH_CHANNEL_LARVAL ||
 	    c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0)
 		success = session_input_channel_req(ssh, c, rtype);
-	if (reply && !(c->flags & CHAN_CLOSE_SENT)) {
+	if (want_reply && !(c->flags & CHAN_CLOSE_SENT)) {
 		if (!c->have_remote_id)
 			fatal("%s: channel %d: no remote_id",
 			    __func__, c->self);
-		packet_start(success ?
-		    SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
-		packet_put_int(c->remote_id);
-		packet_send();
+		if ((r = sshpkt_start(ssh, success ?
+		    SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE)) != 0 ||
+		    (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
+		    (r = sshpkt_send(ssh)) != 0)
+			sshpkt_fatal(ssh, r, "%s: send reply", __func__);
 	}
 	free(rtype);
 	return 0;
 }
 
 static void
-server_init_dispatch(void)
+server_init_dispatch(struct ssh *ssh)
 {
 	debug("server_init_dispatch");
-	dispatch_init(&dispatch_protocol_error);
-	dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
-	dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
-	dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
-	dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
-	dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
-	dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
-	dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
-	dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
-	dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
-	dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
+	ssh_dispatch_init(ssh, &dispatch_protocol_error);
+	ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
+	ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_DATA, &channel_input_data);
+	ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
+	ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
+	ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
+	ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
+	ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
+	ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
+	ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
+	ssh_dispatch_set(ssh, SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
 	/* client_alive */
-	dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive);
-	dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
-	dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
-	dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
+	ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive);
+	ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
+	ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
+	ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
 	/* rekeying */
-	dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
+	ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit);
 }