- Big OpenBSD CVS update (mainly beginnings of SSH2 infrastructure)

   - [auth.c session.c sshd.c auth.h]
     split sshd.c -> auth.c session.c sshd.c plus cleanup and goto-removal
   - [bufaux.c bufaux.h]
     support ssh2 bignums
   - [channels.c channels.h clientloop.c sshd.c nchan.c nchan.h packet.c]
     [readconf.c ssh.c ssh.h serverloop.c]
     replace big switch() with function tables (prepare for ssh2)
   - [ssh2.h]
     ssh2 message type codes
   - [sshd.8]
     reorder Xr to avoid cutting
   - [serverloop.c]
     close(fdin) if fdin != fdout, shutdown otherwise, ok theo@
   - [channels.c]
     missing close
     allow bigger packets
   - [cipher.c cipher.h]
     support ssh2 ciphers
   - [compress.c]
     cleanup, less code
   - [dispatch.c dispatch.h]
     function tables for different message types
   - [log-server.c]
     do not log() if debuggin to stderr
     rename a cpp symbol, to avoid param.h collision
   - [mpaux.c]
     KNF
   - [nchan.c]
     sync w/ channels.c

1 files changed, 682 insertions, 512 deletions

diff --git a/channels.c b/channels.c
index e60ecc61..b87ff9f4 100644
--- a/channels.c
+++ b/channels.c
@@ -16,7 +16,7 @@
  */
 
 #include "includes.h"
-RCSID("$Id: channels.c,v 1.19 2000/03/17 12:40:15 damien Exp $");
+RCSID("$Id: channels.c,v 1.20 2000/04/01 01:09:23 damien Exp $");
 
 #include "ssh.h"
 #include "packet.h"
@@ -37,6 +37,10 @@ RCSID("$Id: channels.c,v 1.19 2000/03/17 12:40:15 damien Exp $");
 /* Max len of agent socket */
 #define MAX_SOCKET_NAME 100
 
+/* default buffer for tcp-fwd-channel */
+#define CHAN_WINDOW_DEFAULT      (8*1024)
+#define CHAN_PACKET_DEFAULT	 (CHAN_WINDOW_DEFAULT/2)
+
 /*
  * Pointer to an array containing all allocated channels.  The array is
  * dynamically extended as needed.
@@ -81,8 +85,9 @@ unsigned int x11_fake_data_len;
  * network (which might be behind a firewall).
  */
 typedef struct {
-	char *host;		/* Host name. */
-	u_short port;		/* Port number. */
+	char *host_to_connect;		/* Connect to 'host'. */
+	u_short port_to_connect;	/* Connect to 'port'. */
+	u_short listen_port;		/* Remote side should listen port number. */
 } ForwardPermission;
 
 /* List of all permitted host/port pairs to connect. */
@@ -119,20 +124,43 @@ channel_permit_all_opens()
 	all_opens_permitted = 1;
 }
 
+/* lookup channel by id */
+
+Channel *
+channel_lookup(int id)
+{
+	Channel *c;
+	if (id < 0 && id > channels_alloc) {
+		log("channel_lookup: %d: bad id", id);
+		return NULL;
+	}
+	c = &channels[id];
+	if (c->type == SSH_CHANNEL_FREE) {
+		log("channel_lookup: %d: bad id: channel free", id);
+		return NULL;
+	}
+	return c;
+}
+
 /*
  * Allocate a new channel object and set its type and socket. This will cause
  * remote_name to be freed.
  */
 
 int 
-channel_allocate(int type, int sock, char *remote_name)
+channel_new(char *ctype, int type, int rfd, int wfd, int efd,
+    int window, int maxpack, int extended_usage, char *remote_name)
 {
 	int i, found;
 	Channel *c;
 
 	/* Update the maximum file descriptor value. */
-	if (sock > channel_max_fd_value)
-		channel_max_fd_value = sock;
+	if (rfd > channel_max_fd_value)
+		channel_max_fd_value = rfd;
+	if (wfd > channel_max_fd_value)
+		channel_max_fd_value = wfd;
+	if (efd > channel_max_fd_value)
+		channel_max_fd_value = efd;
 	/* XXX set close-on-exec -markus */
 
 	/* Do initial allocation if this is the first call. */
@@ -167,388 +195,514 @@ channel_allocate(int type, int sock, char *remote_name)
 	c = &channels[found];
 	buffer_init(&c->input);
 	buffer_init(&c->output);
+	buffer_init(&c->extended);
 	chan_init_iostates(c);
 	c->self = found;
 	c->type = type;
-	c->sock = sock;
+	c->ctype = ctype;
+	c->local_window = window;
+	c->local_window_max = window;
+	c->local_consumed = 0;
+	c->local_maxpacket = maxpack;
+	c->remote_window = 0;
+	c->remote_maxpacket = 0;
+	c->rfd = rfd;
+	c->wfd = wfd;
+	c->sock = (rfd == wfd) ? rfd : -1;
+	c->efd = efd;
+	c->extended_usage = extended_usage;
 	c->remote_id = -1;
 	c->remote_name = remote_name;
+	c->remote_window = 0;
+	c->remote_maxpacket = 0;
+	c->cb_fn = NULL;
+	c->cb_arg = NULL;
+	c->cb_event = 0;
+	c->dettach_user = NULL;
 	debug("channel %d: new [%s]", found, remote_name);
 	return found;
 }
+int 
+channel_allocate(int type, int sock, char *remote_name)
+{
+	return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name);
+}
 
 /* Free the channel and close its socket. */
 
 void 
-channel_free(int channel)
+channel_free(int id)
 {
-	if (channel < 0 || channel >= channels_alloc ||
-	    channels[channel].type == SSH_CHANNEL_FREE)
-		packet_disconnect("channel free: bad local channel %d", channel);
-
-	if (compat13)
-		shutdown(channels[channel].sock, SHUT_RDWR);
-	close(channels[channel].sock);
-	buffer_free(&channels[channel].input);
-	buffer_free(&channels[channel].output);
-	channels[channel].type = SSH_CHANNEL_FREE;
-	if (channels[channel].remote_name) {
-		xfree(channels[channel].remote_name);
-		channels[channel].remote_name = NULL;
+	Channel *c = channel_lookup(id);
+	if (c == NULL)
+		packet_disconnect("channel free: bad local channel %d", id);
+	debug("channel_free: channel %d: status: %s", id, channel_open_message());
+	if (c->sock != -1) {
+		shutdown(c->sock, SHUT_RDWR);
+		close(c->sock);
+	}
+	buffer_free(&c->input);
+	buffer_free(&c->output);
+	buffer_free(&c->extended);
+	c->type = SSH_CHANNEL_FREE;
+	if (c->remote_name) {
+		xfree(c->remote_name);
+		c->remote_name = NULL;
 	}
 }
 
 /*
- * This is called just before select() to add any bits relevant to channels
- * in the select bitmasks.
+ * 'channel_pre*' are called just before select() to add any bits relevant to
+ * channels in the select bitmasks.
+ */
+/*
+ * 'channel_post*': perform any appropriate operations for channels which
+ * have events pending.
  */
+typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
+chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
+chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
 
-void 
-channel_prepare_select(fd_set * readset, fd_set * writeset)
+void
+channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
 {
-	int i;
-	Channel *ch;
-	unsigned char *ucp;
-	unsigned int proto_len, data_len;
+	FD_SET(c->sock, readset);
+}
 
-	for (i = 0; i < channels_alloc; i++) {
-		ch = &channels[i];
-redo:
-		switch (ch->type) {
-		case SSH_CHANNEL_X11_LISTENER:
-		case SSH_CHANNEL_PORT_LISTENER:
-		case SSH_CHANNEL_AUTH_SOCKET:
-			FD_SET(ch->sock, readset);
-			break;
+void
+channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	if (buffer_len(&c->input) < packet_get_maxsize())
+		FD_SET(c->sock, readset);
+	if (buffer_len(&c->output) > 0)
+		FD_SET(c->sock, writeset);
+}
 
-		case SSH_CHANNEL_OPEN:
-			if (compat13) {
-				if (buffer_len(&ch->input) < packet_get_maxsize())
-					FD_SET(ch->sock, readset);
-				if (buffer_len(&ch->output) > 0)
-					FD_SET(ch->sock, writeset);
-				break;
-			}
-			/* test whether sockets are 'alive' for read/write */
-			if (ch->istate == CHAN_INPUT_OPEN)
-				if (buffer_len(&ch->input) < packet_get_maxsize())
-					FD_SET(ch->sock, readset);
-			if (ch->ostate == CHAN_OUTPUT_OPEN ||
-			    ch->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
-				if (buffer_len(&ch->output) > 0) {
-					FD_SET(ch->sock, writeset);
-				} else if (ch->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
-					chan_obuf_empty(ch);
-				}
-			}
-			break;
+void
+channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	/* test whether sockets are 'alive' for read/write */
+	if (c->istate == CHAN_INPUT_OPEN)
+		if (buffer_len(&c->input) < packet_get_maxsize())
+			FD_SET(c->sock, readset);
+	if (c->ostate == CHAN_OUTPUT_OPEN ||
+	    c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
+		if (buffer_len(&c->output) > 0) {
+			FD_SET(c->sock, writeset);
+		} else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
+			chan_obuf_empty(c);
+		}
+	}
+}
 
-		case SSH_CHANNEL_INPUT_DRAINING:
-			if (!compat13)
-				fatal("cannot happen: IN_DRAIN");
-			if (buffer_len(&ch->input) == 0) {
-				packet_start(SSH_MSG_CHANNEL_CLOSE);
-				packet_put_int(ch->remote_id);
-				packet_send();
-				ch->type = SSH_CHANNEL_CLOSED;
-				debug("Closing channel %d after input drain.", ch->self);
-				break;
-			}
-			break;
+void
+channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	if (buffer_len(&c->input) == 0) {
+		packet_start(SSH_MSG_CHANNEL_CLOSE);
+		packet_put_int(c->remote_id);
+		packet_send();
+		c->type = SSH_CHANNEL_CLOSED;
+		debug("Closing channel %d after input drain.", c->self);
+	}
+}
 
-		case SSH_CHANNEL_OUTPUT_DRAINING:
-			if (!compat13)
-				fatal("cannot happen: OUT_DRAIN");
-			if (buffer_len(&ch->output) == 0) {
-				channel_free(i);
-				break;
-			}
-			FD_SET(ch->sock, writeset);
-			break;
+void
+channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	if (buffer_len(&c->output) == 0)
+		channel_free(c->self);
+	else 
+		FD_SET(c->sock, writeset);
+}
 
-		case SSH_CHANNEL_X11_OPEN:
-			/*
-			 * This is a special state for X11 authentication
-			 * spoofing.  An opened X11 connection (when
-			 * authentication spoofing is being done) remains in
-			 * this state until the first packet has been
-			 * completely read.  The authentication data in that
-			 * packet is then substituted by the real data if it
-			 * matches the fake data, and the channel is put into
-			 * normal mode.
-			 */
-			/* Check if the fixed size part of the packet is in buffer. */
-			if (buffer_len(&ch->output) < 12)
-				break;
+/*
+ * This is a special state for X11 authentication spoofing.  An opened X11
+ * connection (when authentication spoofing is being done) remains in this
+ * state until the first packet has been completely read.  The authentication
+ * data in that packet is then substituted by the real data if it matches the
+ * fake data, and the channel is put into normal mode.
+ */
+int
+x11_open_helper(Channel *c)
+{
+	unsigned char *ucp;
+	unsigned int proto_len, data_len;
 
-			/* Parse the lengths of variable-length fields. */
-			ucp = (unsigned char *) buffer_ptr(&ch->output);
-			if (ucp[0] == 0x42) {	/* Byte order MSB first. */
-				proto_len = 256 * ucp[6] + ucp[7];
-				data_len = 256 * ucp[8] + ucp[9];
-			} else if (ucp[0] == 0x6c) {	/* Byte order LSB first. */
-				proto_len = ucp[6] + 256 * ucp[7];
-				data_len = ucp[8] + 256 * ucp[9];
-			} else {
-				debug("Initial X11 packet contains bad byte order byte: 0x%x",
-				      ucp[0]);
-				ch->type = SSH_CHANNEL_OPEN;
-				goto reject;
-			}
+	/* Check if the fixed size part of the packet is in buffer. */
+	if (buffer_len(&c->output) < 12)
+		return 0;
+
+	/* Parse the lengths of variable-length fields. */
+	ucp = (unsigned char *) buffer_ptr(&c->output);
+	if (ucp[0] == 0x42) {	/* Byte order MSB first. */
+		proto_len = 256 * ucp[6] + ucp[7];
+		data_len = 256 * ucp[8] + ucp[9];
+	} else if (ucp[0] == 0x6c) {	/* Byte order LSB first. */
+		proto_len = ucp[6] + 256 * ucp[7];
+		data_len = ucp[8] + 256 * ucp[9];
+	} else {
+		debug("Initial X11 packet contains bad byte order byte: 0x%x",
+		      ucp[0]);
+		return -1;
+	}
 
-			/* Check if the whole packet is in buffer. */
-			if (buffer_len(&ch->output) <
-			    12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
-				break;
+	/* Check if the whole packet is in buffer. */
+	if (buffer_len(&c->output) <
+	    12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
+		return 0;
 
-			/* Check if authentication protocol matches. */
-			if (proto_len != strlen(x11_saved_proto) ||
-			    memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
-				debug("X11 connection uses different authentication protocol.");
-				ch->type = SSH_CHANNEL_OPEN;
-				goto reject;
-			}
-			/* Check if authentication data matches our fake data. */
-			if (data_len != x11_fake_data_len ||
-			    memcmp(ucp + 12 + ((proto_len + 3) & ~3),
-				x11_fake_data, x11_fake_data_len) != 0) {
-				debug("X11 auth data does not match fake data.");
-				ch->type = SSH_CHANNEL_OPEN;
-				goto reject;
-			}
-			/* Check fake data length */
-			if (x11_fake_data_len != x11_saved_data_len) {
-				error("X11 fake_data_len %d != saved_data_len %d",
-				  x11_fake_data_len, x11_saved_data_len);
-				ch->type = SSH_CHANNEL_OPEN;
-				goto reject;
-			}
-			/*
-			 * Received authentication protocol and data match
-			 * our fake data. Substitute the fake data with real
-			 * data.
-			 */
-			memcpy(ucp + 12 + ((proto_len + 3) & ~3),
-			       x11_saved_data, x11_saved_data_len);
+	/* Check if authentication protocol matches. */
+	if (proto_len != strlen(x11_saved_proto) ||
+	    memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
+		debug("X11 connection uses different authentication protocol.");
+		return -1;
+	}
+	/* Check if authentication data matches our fake data. */
+	if (data_len != x11_fake_data_len ||
+	    memcmp(ucp + 12 + ((proto_len + 3) & ~3),
+		x11_fake_data, x11_fake_data_len) != 0) {
+		debug("X11 auth data does not match fake data.");
+		return -1;
+	}
+	/* Check fake data length */
+	if (x11_fake_data_len != x11_saved_data_len) {
+		error("X11 fake_data_len %d != saved_data_len %d",
+		    x11_fake_data_len, x11_saved_data_len);
+		return -1;
+	}
+	/*
+	 * Received authentication protocol and data match
+	 * our fake data. Substitute the fake data with real
+	 * data.
+	 */
+	memcpy(ucp + 12 + ((proto_len + 3) & ~3),
+	    x11_saved_data, x11_saved_data_len);
+	return 1;
+}
 
-			/* Start normal processing for the channel. */
-			ch->type = SSH_CHANNEL_OPEN;
-			goto redo;
+void
+channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	int ret = x11_open_helper(c);
+	if (ret == 1) {
+		/* Start normal processing for the channel. */
+		c->type = SSH_CHANNEL_OPEN;
+	} else if (ret == -1) {
+		/*
+		 * We have received an X11 connection that has bad
+		 * authentication information.
+		 */
+		log("X11 connection rejected because of wrong authentication.\r\n");
+		buffer_clear(&c->input);
+		buffer_clear(&c->output);
+		close(c->sock);
+		c->sock = -1;
+		c->type = SSH_CHANNEL_CLOSED;
+		packet_start(SSH_MSG_CHANNEL_CLOSE);
+		packet_put_int(c->remote_id);
+		packet_send();
+	}
+}
 
-	reject:
-			/*
-			 * We have received an X11 connection that has bad
-			 * authentication information.
-			 */
-			log("X11 connection rejected because of wrong authentication.\r\n");
-			buffer_clear(&ch->input);
-			buffer_clear(&ch->output);
-			if (compat13) {
-				close(ch->sock);
-				ch->sock = -1;
-				ch->type = SSH_CHANNEL_CLOSED;
-				packet_start(SSH_MSG_CHANNEL_CLOSE);
-				packet_put_int(ch->remote_id);
-				packet_send();
-			} else {
-				debug("X11 rejected %d i%d/o%d", ch->self, ch->istate, ch->ostate);
-				chan_read_failed(ch);
-				chan_write_failed(ch);
-				debug("X11 rejected %d i%d/o%d", ch->self, ch->istate, ch->ostate);
-			}
-			break;
+void
+channel_pre_x11_open_15(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	int ret = x11_open_helper(c);
+	if (ret == 1) {
+		c->type = SSH_CHANNEL_OPEN;
+	} else if (ret == -1) {
+		debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
+		chan_read_failed(c);
+		chan_write_failed(c);
+		debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
+	}
+}
 
-		case SSH_CHANNEL_FREE:
-		default:
-			continue;
+/* This is our fake X11 server socket. */
+void
+channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	struct sockaddr addr;
+	int newsock, newch;
+	socklen_t addrlen;
+	char buf[16384], *remote_hostname;
+
+	if (FD_ISSET(c->sock, readset)) {
+		debug("X11 connection requested.");
+		addrlen = sizeof(addr);
+		newsock = accept(c->sock, &addr, &addrlen);
+		if (newsock < 0) {
+			error("accept: %.100s", strerror(errno));
+			return;
 		}
+		remote_hostname = get_remote_hostname(newsock);
+		snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
+		remote_hostname, get_peer_port(newsock));
+		xfree(remote_hostname);
+		newch = channel_allocate(SSH_CHANNEL_OPENING, newsock,
+					 xstrdup(buf));
+		packet_start(SSH_SMSG_X11_OPEN);
+		packet_put_int(newch);
+		if (have_hostname_in_open)
+			packet_put_string(buf, strlen(buf));
+		packet_send();
 	}
 }
 
 /*
- * After select, perform any appropriate operations for channels which have
- * events pending.
+ * This socket is listening for connections to a forwarded TCP/IP port.
  */
+void
+channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	struct sockaddr addr;
+	int newsock, newch;
+	socklen_t addrlen;
+	char buf[1024], *remote_hostname;
+	int remote_port;
+
+	if (FD_ISSET(c->sock, readset)) {
+		debug("Connection to port %d forwarding "
+		    "to %.100s port %d requested.",
+		    c->listening_port, c->path, c->host_port);
+		addrlen = sizeof(addr);
+		newsock = accept(c->sock, &addr, &addrlen);
+		if (newsock < 0) {
+			error("accept: %.100s", strerror(errno));
+			return;
+		}
+		remote_hostname = get_remote_hostname(newsock);
+		remote_port = get_peer_port(newsock);
+		snprintf(buf, sizeof buf,
+		    "listen port %d for %.100s port %d, "
+		    "connect from %.200s port %d",
+		    c->listening_port, c->path, c->host_port,
+		    remote_hostname, remote_port);
+		newch = channel_new("direct-tcpip",
+		    SSH_CHANNEL_OPENING, newsock, newsock, -1,
+		    c->local_window_max, c->local_maxpacket,
+		    0, xstrdup(buf));
+
+		packet_start(SSH_MSG_PORT_OPEN);
+		packet_put_int(newch);
+		packet_put_string(c->path, strlen(c->path));
+		packet_put_int(c->host_port);
+		if (have_hostname_in_open) {
+			packet_put_string(buf, strlen(buf));
+		}
+		packet_send();
+		xfree(remote_hostname);
+	}
+}
 
-void 
-channel_after_select(fd_set * readset, fd_set * writeset)
+/*
+ * This is the authentication agent socket listening for connections from
+ * clients.
+ */
+void
+channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
 {
 	struct sockaddr addr;
-	int newsock, i, newch, len;
+	int newsock, newch;
 	socklen_t addrlen;
-	Channel *ch;
-	char buf[16384], *remote_hostname;
 
-	/* Loop over all channels... */
-	for (i = 0; i < channels_alloc; i++) {
-		ch = &channels[i];
-		switch (ch->type) {
-		case SSH_CHANNEL_X11_LISTENER:
-			/* This is our fake X11 server socket. */
-			if (FD_ISSET(ch->sock, readset)) {
-				debug("X11 connection requested.");
-				addrlen = sizeof(addr);
-				newsock = accept(ch->sock, &addr, &addrlen);
-				if (newsock < 0) {
-					error("accept: %.100s", strerror(errno));
-					break;
-				}
-				remote_hostname = get_remote_hostname(newsock);
-				snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
-				remote_hostname, get_peer_port(newsock));
-				xfree(remote_hostname);
-				newch = channel_allocate(SSH_CHANNEL_OPENING, newsock,
-							 xstrdup(buf));
-				packet_start(SSH_SMSG_X11_OPEN);
-				packet_put_int(newch);
-				if (have_hostname_in_open)
-					packet_put_string(buf, strlen(buf));
-				packet_send();
-			}
-			break;
+	if (FD_ISSET(c->sock, readset)) {
+		addrlen = sizeof(addr);
+		newsock = accept(c->sock, &addr, &addrlen);
+		if (newsock < 0) {
+			error("accept from auth socket: %.100s", strerror(errno));
+			return;
+		}
+		newch = channel_allocate(SSH_CHANNEL_OPENING, newsock,
+		    xstrdup("accepted auth socket"));
+		packet_start(SSH_SMSG_AGENT_OPEN);
+		packet_put_int(newch);
+		packet_send();
+	}
+}
 
-		case SSH_CHANNEL_PORT_LISTENER:
-			/*
-			 * This socket is listening for connections to a
-			 * forwarded TCP/IP port.
-			 */
-			if (FD_ISSET(ch->sock, readset)) {
-				debug("Connection to port %d forwarding to %.100s port %d requested.",
-				      ch->listening_port, ch->path, ch->host_port);
-				addrlen = sizeof(addr);
-				newsock = accept(ch->sock, &addr, &addrlen);
-				if (newsock < 0) {
-					error("accept: %.100s", strerror(errno));
-					break;
-				}
-				remote_hostname = get_remote_hostname(newsock);
-				snprintf(buf, sizeof buf, "listen port %d for %.100s port %d, connect from %.200s port %d",
-					 ch->listening_port, ch->path, ch->host_port,
-				remote_hostname, get_peer_port(newsock));
-				xfree(remote_hostname);
-				newch = channel_allocate(SSH_CHANNEL_OPENING, newsock,
-							 xstrdup(buf));
-				packet_start(SSH_MSG_PORT_OPEN);
-				packet_put_int(newch);
-				packet_put_string(ch->path, strlen(ch->path));
-				packet_put_int(ch->host_port);
-				if (have_hostname_in_open)
-					packet_put_string(buf, strlen(buf));
-				packet_send();
+int
+channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	char buf[16*1024];
+	int len;
+
+	if (c->rfd != -1 &&
+	    FD_ISSET(c->rfd, readset)) {
+		len = read(c->rfd, buf, sizeof(buf));
+		if (len <= 0) {
+			debug("channel %d: read<0 rfd %d len %d",
+			    c->self, c->rfd, len);
+			if (compat13) {
+				buffer_consume(&c->output, buffer_len(&c->output));
+				c->type = SSH_CHANNEL_INPUT_DRAINING;
+				debug("Channel %d status set to input draining.", c->self);
+			} else {
+				chan_read_failed(c);
 			}
-			break;
-
-		case SSH_CHANNEL_AUTH_SOCKET:
-			/*
-			 * This is the authentication agent socket listening
-			 * for connections from clients.
-			 */
-			if (FD_ISSET(ch->sock, readset)) {
-				addrlen = sizeof(addr);
-				newsock = accept(ch->sock, &addr, &addrlen);
-				if (newsock < 0) {
-					error("accept from auth socket: %.100s", strerror(errno));
-					break;
-				}
-				newch = channel_allocate(SSH_CHANNEL_OPENING, newsock,
-					xstrdup("accepted auth socket"));
-				packet_start(SSH_SMSG_AGENT_OPEN);
-				packet_put_int(newch);
-				packet_send();
+			return -1;
+		}
+		buffer_append(&c->input, buf, len);
+	}
+	return 1;
+}
+int
+channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	int len;
+
+	/* Send buffered output data to the socket. */
+	if (c->wfd != -1 &&
+	    FD_ISSET(c->wfd, writeset) &&
+	    buffer_len(&c->output) > 0) {
+		len = write(c->wfd, buffer_ptr(&c->output),
+			    buffer_len(&c->output));
+		if (len <= 0) {
+			if (compat13) {
+				buffer_consume(&c->output, buffer_len(&c->output));
+				debug("Channel %d status set to input draining.", c->self);
+				c->type = SSH_CHANNEL_INPUT_DRAINING;
+			} else {
+				chan_write_failed(c);
 			}
-			break;
+			return -1;
+		}
+		buffer_consume(&c->output, len);
+	}
+	return 1;
+}
 
-		case SSH_CHANNEL_OPEN:
-			/*
-			 * This is an open two-way communication channel. It
-			 * is not of interest to us at this point what kind
-			 * of data is being transmitted.
-			 */
+void
+channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	channel_handle_rfd(c, readset, writeset);
+	channel_handle_wfd(c, readset, writeset);
+}
 
-			/*
-			 * Read available incoming data and append it to
-			 * buffer; shutdown socket, if read or write failes
-			 */
-			if (FD_ISSET(ch->sock, readset)) {
-				len = read(ch->sock, buf, sizeof(buf));
-				if (len <= 0) {
-					if (compat13) {
-						buffer_consume(&ch->output, buffer_len(&ch->output));
-						ch->type = SSH_CHANNEL_INPUT_DRAINING;
-						debug("Channel %d status set to input draining.", i);
-					} else {
-						chan_read_failed(ch);
-					}
-					break;
-				}
-				buffer_append(&ch->input, buf, len);
-			}
-			/* Send buffered output data to the socket. */
-			if (FD_ISSET(ch->sock, writeset) && buffer_len(&ch->output) > 0) {
-				len = write(ch->sock, buffer_ptr(&ch->output),
-					    buffer_len(&ch->output));
-				if (len <= 0) {
-					if (compat13) {
-						buffer_consume(&ch->output, buffer_len(&ch->output));
-						debug("Channel %d status set to input draining.", i);
-						ch->type = SSH_CHANNEL_INPUT_DRAINING;
-					} else {
-						chan_write_failed(ch);
-					}
-					break;
-				}
-				buffer_consume(&ch->output, len);
-			}
-			break;
+void
+channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
+{
+	int len;
+	/* Send buffered output data to the socket. */
+	if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
+		len = write(c->sock, buffer_ptr(&c->output),
+			    buffer_len(&c->output));
+		if (len <= 0)
+			buffer_consume(&c->output, buffer_len(&c->output));
+		else
+			buffer_consume(&c->output, len);
+	}
+}
 
-		case SSH_CHANNEL_OUTPUT_DRAINING:
-			if (!compat13)
-				fatal("cannot happen: OUT_DRAIN");
-			/* Send buffered output data to the socket. */
-			if (FD_ISSET(ch->sock, writeset) && buffer_len(&ch->output) > 0) {
-				len = write(ch->sock, buffer_ptr(&ch->output),
-					    buffer_len(&ch->output));
-				if (len <= 0)
-					buffer_consume(&ch->output, buffer_len(&ch->output));
-				else
-					buffer_consume(&ch->output, len);
-			}
-			break;
+void
+channel_handler_init_13(void)
+{
+	channel_pre[SSH_CHANNEL_OPEN] =			&channel_pre_open_13;
+	channel_pre[SSH_CHANNEL_X11_OPEN] =		&channel_pre_x11_open_13;
+	channel_pre[SSH_CHANNEL_X11_LISTENER] =		&channel_pre_listener;
+	channel_pre[SSH_CHANNEL_PORT_LISTENER] =	&channel_pre_listener;
+	channel_pre[SSH_CHANNEL_AUTH_SOCKET] =		&channel_pre_listener;
+	channel_pre[SSH_CHANNEL_INPUT_DRAINING] =	&channel_pre_input_draining;
+	channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] =	&channel_pre_output_draining;
+
+	channel_post[SSH_CHANNEL_OPEN] =		&channel_post_open_1;
+	channel_post[SSH_CHANNEL_X11_LISTENER] =	&channel_post_x11_listener;
+	channel_post[SSH_CHANNEL_PORT_LISTENER] =	&channel_post_port_listener;
+	channel_post[SSH_CHANNEL_AUTH_SOCKET] =		&channel_post_auth_listener;
+	channel_post[SSH_CHANNEL_OUTPUT_DRAINING] =	&channel_post_output_drain_13;
+}
 
-		case SSH_CHANNEL_X11_OPEN:
-		case SSH_CHANNEL_FREE:
-		default:
+void
+channel_handler_init_15(void)
+{
+	channel_pre[SSH_CHANNEL_OPEN] =			&channel_pre_open_15;
+	channel_pre[SSH_CHANNEL_X11_OPEN] =		&channel_pre_x11_open_15;
+	channel_pre[SSH_CHANNEL_X11_LISTENER] =		&channel_pre_listener;
+	channel_pre[SSH_CHANNEL_PORT_LISTENER] =	&channel_pre_listener;
+	channel_pre[SSH_CHANNEL_AUTH_SOCKET] =		&channel_pre_listener;
+
+	channel_post[SSH_CHANNEL_X11_LISTENER] =	&channel_post_x11_listener;
+	channel_post[SSH_CHANNEL_PORT_LISTENER] =	&channel_post_port_listener;
+	channel_post[SSH_CHANNEL_AUTH_SOCKET] =		&channel_post_auth_listener;
+	channel_post[SSH_CHANNEL_OPEN] =		&channel_post_open_1;
+}
+
+void
+channel_handler_init(void)
+{
+	int i;
+	for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
+		channel_pre[i] = NULL;
+		channel_post[i] = NULL;
+	}
+	if (compat13)
+		channel_handler_init_13();
+	else
+		channel_handler_init_15();
+}
+
+void 
+channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
+{
+	static int did_init = 0;
+	int i;
+	Channel *c;
+
+	if (!did_init) {
+		channel_handler_init();
+		did_init = 1;
+	}
+	for (i = 0; i < channels_alloc; i++) {
+		c = &channels[i];
+		if (c->type == SSH_CHANNEL_FREE)
 			continue;
-		}
+		if (ftab[c->type] == NULL)
+			continue;
+		(*ftab[c->type])(c, readset, writeset);
+		if (!compat13)
+			chan_delete_if_full_closed(c);
 	}
 }
 
+void 
+channel_prepare_select(fd_set * readset, fd_set * writeset)
+{
+	channel_handler(channel_pre, readset, writeset);
+}
+
+void 
+channel_after_select(fd_set * readset, fd_set * writeset)
+{
+	channel_handler(channel_post, readset, writeset);
+}
+
 /* If there is data to send to the connection, send some of it now. */
 
 void 
 channel_output_poll()
 {
 	int len, i;
-	Channel *ch;
+	Channel *c;
 
 	for (i = 0; i < channels_alloc; i++) {
-		ch = &channels[i];
+		c = &channels[i];
 
 		/* We are only interested in channels that can have buffered incoming data. */
 		if (compat13) {
-			if (ch->type != SSH_CHANNEL_OPEN &&
-			    ch->type != SSH_CHANNEL_INPUT_DRAINING)
+			if (c->type != SSH_CHANNEL_OPEN &&
+			    c->type != SSH_CHANNEL_INPUT_DRAINING)
 				continue;
 		} else {
-			if (ch->type != SSH_CHANNEL_OPEN)
+			if (c->type != SSH_CHANNEL_OPEN)
 				continue;
-			if (ch->istate != CHAN_INPUT_OPEN &&
-			    ch->istate != CHAN_INPUT_WAIT_DRAIN)
+			if (c->istate != CHAN_INPUT_OPEN &&
+			    c->istate != CHAN_INPUT_WAIT_DRAIN)
 				continue;
 		}
 
 		/* Get the amount of buffered data for this channel. */
-		len = buffer_len(&ch->input);
+		len = buffer_len(&c->input);
 		if (len > 0) {
 			/* Send some data for the other side over the secure connection. */
 			if (packet_is_interactive()) {
@@ -556,22 +710,26 @@ channel_output_poll()
 					len = 512;
 			} else {
 				/* Keep the packets at reasonable size. */
-				if (len > packet_get_maxsize()/2)
+				if (len > packet_get_maxsize())
 					len = packet_get_maxsize()/2;
 			}
-			packet_start(SSH_MSG_CHANNEL_DATA);
-			packet_put_int(ch->remote_id);
-			packet_put_string(buffer_ptr(&ch->input), len);
-			packet_send();
-			buffer_consume(&ch->input, len);
-		} else if (ch->istate == CHAN_INPUT_WAIT_DRAIN) {
+			if (len > 0) {
+				packet_start(SSH_MSG_CHANNEL_DATA);
+				packet_put_int(c->remote_id);
+				packet_put_string(buffer_ptr(&c->input), len);
+				packet_send();
+				buffer_consume(&c->input, len);
+				c->remote_window -= len;
+debug("channel %d: send data len %d", c->self, len);
+			}
+		} else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
 			if (compat13)
 				fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
 			/*
 			 * input-buffer is empty and read-socket shutdown:
 			 * tell peer, that we will not send more data: send IEOF
 			 */
-			chan_ibuf_empty(ch);
+			chan_ibuf_empty(c);
 		}
 	}
 }
@@ -583,35 +741,33 @@ channel_output_poll()
  */
 
 void 
-channel_input_data(int payload_len)
+channel_input_data(int type, int plen)
 {
 	int id;
 	char *data;
 	unsigned int data_len;
-	Channel *ch;
+	Channel *c;
 
 	/* Get the channel number and verify it. */
 	id = packet_get_int();
-	if (id < 0 || id >= channels_alloc)
+	c = channel_lookup(id);
+	if (c == NULL)
 		packet_disconnect("Received data for nonexistent channel %d.", id);
-	ch = &channels[id];
-
-	if (ch->type == SSH_CHANNEL_FREE)
-		packet_disconnect("Received data for free channel %d.", ch->self);
 
 	/* Ignore any data for non-open channels (might happen on close) */
-	if (ch->type != SSH_CHANNEL_OPEN &&
-	    ch->type != SSH_CHANNEL_X11_OPEN)
+	if (c->type != SSH_CHANNEL_OPEN &&
+	    c->type != SSH_CHANNEL_X11_OPEN)
 		return;
 
 	/* same for protocol 1.5 if output end is no longer open */
-	if (!compat13 && ch->ostate != CHAN_OUTPUT_OPEN)
+	if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
 		return;
 
 	/* Get the data. */
 	data = packet_get_string(&data_len);
-	packet_integrity_check(payload_len, 4 + 4 + data_len, SSH_MSG_CHANNEL_DATA);
-	buffer_append(&ch->output, data, data_len);
+
+	packet_integrity_check(plen, 4 + 4 + data_len, SSH_MSG_CHANNEL_DATA);
+	buffer_append(&c->output, data, data_len);
 	xfree(data);
 }
 
@@ -624,45 +780,60 @@ int
 channel_not_very_much_buffered_data()
 {
 	unsigned int i;
-	Channel *ch;
+	Channel *c;
 
 	for (i = 0; i < channels_alloc; i++) {
-		ch = &channels[i];
-		if (ch->type == SSH_CHANNEL_OPEN) {
-			if (buffer_len(&ch->input) > packet_get_maxsize())
+		c = &channels[i];
+		if (c->type == SSH_CHANNEL_OPEN) {
+			if (buffer_len(&c->input) > packet_get_maxsize()) {
+				debug("channel %d: big input buffer %d",
+				    c->self, buffer_len(&c->input));
 				return 0;
-			if (buffer_len(&ch->output) > packet_get_maxsize())
+			}
+			if (buffer_len(&c->output) > packet_get_maxsize()) {
+				debug("channel %d: big output buffer %d",
+				    c->self, buffer_len(&c->output));
 				return 0;
+			}
 		}
 	}
 	return 1;
 }
 
-/* This is called after receiving CHANNEL_CLOSE/IEOF. */
+void 
+channel_input_ieof(int type, int plen)
+{
+	int id;
+	Channel *c;
+
+	packet_integrity_check(plen, 4, type);
+
+	id = packet_get_int();
+	c = channel_lookup(id);
+	if (c == NULL)
+		packet_disconnect("Received ieof for nonexistent channel %d.", id);
+	chan_rcvd_ieof(c);
+}
 
 void 
-channel_input_close()
+channel_input_close(int type, int plen)
 {
-	int channel;
+	int id;
+	Channel *c;
 
-	/* Get the channel number and verify it. */
-	channel = packet_get_int();
-	if (channel < 0 || channel >= channels_alloc ||