]> andersk Git - openssh.git/blobdiff - channels.c
- Big OpenBSD CVS update (mainly beginnings of SSH2 infrastructure)
[openssh.git] / channels.c
index 16e3df3980ef3a64f6f18e7da858636e5bf0d3a5..0becd4ca0555e75315e929811c30475a326240ed 100644 (file)
@@ -37,6 +37,10 @@ RCSID("$Id$");
 /* 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 ||
-           channels[channel].type == SSH_CHANNEL_FREE)
-               packet_disconnect("Received data for nonexistent channel %d.", channel);
-
-       if (!compat13) {
-               /* proto version 1.5 overloads CLOSE with IEOF */
-               chan_rcvd_ieof(&channels[channel]);
-               return;
-       }
+       packet_integrity_check(plen, 4, type);
+
+       id = packet_get_int();
+       c = channel_lookup(id);
+       if (c == NULL)
+               packet_disconnect("Received close for nonexistent channel %d.", id);
 
        /*
         * Send a confirmation that we have closed the channel and no more
         * data is coming for it.
         */
        packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
-       packet_put_int(channels[channel].remote_id);
+       packet_put_int(c->remote_id);
        packet_send();
 
        /*
@@ -672,81 +843,80 @@ channel_input_close()
         * no-one to receive the confirmation.  The channel gets freed when
         * the confirmation arrives.
         */
-       if (channels[channel].type != SSH_CHANNEL_CLOSED) {
+       if (c->type != SSH_CHANNEL_CLOSED) {
                /*
                 * Not a closed channel - mark it as draining, which will
                 * cause it to be freed later.
                 */
-               buffer_consume(&channels[channel].input,
-                              buffer_len(&channels[channel].input));
-               channels[channel].type = SSH_CHANNEL_OUTPUT_DRAINING;
+               buffer_consume(&c->input, buffer_len(&c->input));
+               c->type = SSH_CHANNEL_OUTPUT_DRAINING;
        }
 }
 
-/* This is called after receiving CHANNEL_CLOSE_CONFIRMATION/OCLOSE. */
-
+/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
 void 
-channel_input_close_confirmation()
+channel_input_oclose(int type, int plen)
 {
-       int channel;
-
-       /* Get the channel number and verify it. */
-       channel = packet_get_int();
-       if (channel < 0 || channel >= channels_alloc)
-               packet_disconnect("Received close confirmation for out-of-range channel %d.",
-                                 channel);
-
-       if (!compat13) {
-               /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
-               chan_rcvd_oclose(&channels[channel]);
-               return;
-       }
-       if (channels[channel].type != SSH_CHANNEL_CLOSED)
-               packet_disconnect("Received close confirmation for non-closed channel %d (type %d).",
-                                 channel, channels[channel].type);
-
-       /* Free the channel. */
-       channel_free(channel);
+       int id = packet_get_int();
+       Channel *c = channel_lookup(id);
+       packet_integrity_check(plen, 4, type);
+       if (c == NULL)
+               packet_disconnect("Received oclose for nonexistent channel %d.", id);
+       chan_rcvd_oclose(c);
 }
 
-/* This is called after receiving CHANNEL_OPEN_CONFIRMATION. */
+void 
+channel_input_close_confirmation(int type, int plen)
+{
+       int id = packet_get_int();
+       Channel *c = channel_lookup(id);
+
+       if (c == NULL)
+               packet_disconnect("Received close confirmation for "
+                   "out-of-range channel %d.", id);
+       if (c->type != SSH_CHANNEL_CLOSED)
+               packet_disconnect("Received close confirmation for "
+                   "non-closed channel %d (type %d).", id, c->type);
+       channel_free(c->self);
+}
 
 void 
-channel_input_open_confirmation()
+channel_input_open_confirmation(int type, int plen)
 {
-       int channel, remote_channel;
+       int id, remote_id;
+       Channel *c;
 
-       /* Get the channel number and verify it. */
-       channel = packet_get_int();
-       if (channel < 0 || channel >= channels_alloc ||
-           channels[channel].type != SSH_CHANNEL_OPENING)
-               packet_disconnect("Received open confirmation for non-opening channel %d.",
-                                 channel);
+       packet_integrity_check(plen, 4 + 4, type);
 
-       /* Get remote side's id for this channel. */
-       remote_channel = packet_get_int();
+       id = packet_get_int();
+       c = channel_lookup(id);
 
+       if (c==NULL || c->type != SSH_CHANNEL_OPENING)
+               packet_disconnect("Received open confirmation for "
+                   "non-opening channel %d.", id);
+       remote_id = packet_get_int();
        /* Record the remote channel number and mark that the channel is now open. */
-       channels[channel].remote_id = remote_channel;
-       channels[channel].type = SSH_CHANNEL_OPEN;
+       c->remote_id = remote_id;
+       c->type = SSH_CHANNEL_OPEN;
 }
 
-/* This is called after receiving CHANNEL_OPEN_FAILURE from the other side. */
-
 void 
-channel_input_open_failure()
+channel_input_open_failure(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 ||
-           channels[channel].type != SSH_CHANNEL_OPENING)
-               packet_disconnect("Received open failure for non-opening channel %d.",
-                                 channel);
+       packet_integrity_check(plen, 4, type);
+
+       id = packet_get_int();
+       c = channel_lookup(id);
+
+       if (c==NULL || c->type != SSH_CHANNEL_OPENING)
+               packet_disconnect("Received open failure for "
+                   "non-opening channel %d.", id);
 
        /* Free the channel.  This will also close the socket. */
-       channel_free(channel);
+       channel_free(id);
 }
 
 /*
@@ -859,15 +1029,16 @@ channel_open_message()
                case SSH_CHANNEL_X11_OPEN:
                case SSH_CHANNEL_INPUT_DRAINING:
                case SSH_CHANNEL_OUTPUT_DRAINING:
-                       snprintf(buf, sizeof buf, "  #%d %.300s (t%d r%d i%d/%d o%d/%d)\r\n",
+                       snprintf(buf, sizeof buf, "  #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n",
                            c->self, c->remote_name,
                            c->type, c->remote_id,
                            c->istate, buffer_len(&c->input),
-                           c->ostate, buffer_len(&c->output));
+                           c->ostate, buffer_len(&c->output),
+                           c->rfd, c->wfd);
                        buffer_append(&buffer, buf, strlen(buf));
                        continue;
                default:
-                       fatal("channel_still_open: bad channel type %d", c->type);
+                       fatal("channel_open_message: bad channel type %d", c->type);
                        /* NOTREACHED */
                }
        }
@@ -950,8 +1121,11 @@ channel_request_local_forwarding(u_short port, const char *host,
                        continue;
                }
                /* Allocate a channel number for the socket. */
-               ch = channel_allocate(SSH_CHANNEL_PORT_LISTENER, sock,
-                   xstrdup("port listener"));
+               ch = channel_new(
+                   "port listener", SSH_CHANNEL_PORT_LISTENER,
+                   sock, sock, -1,
+                   CHAN_WINDOW_DEFAULT, CHAN_PACKET_DEFAULT,
+                   0, xstrdup("port listener"));
                strlcpy(channels[ch].path, host, sizeof(channels[ch].path));
                channels[ch].host_port = host_port;
                channels[ch].listening_port = port;
@@ -968,26 +1142,26 @@ channel_request_local_forwarding(u_short port, const char *host,
  */
 
 void 
-channel_request_remote_forwarding(u_short port, const char *host,
-                                 u_short remote_port)
+channel_request_remote_forwarding(u_short listen_port, const char *host_to_connect,
+                                 u_short port_to_connect)
 {
        int payload_len;
        /* Record locally that connection to this host/port is permitted. */
        if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
                fatal("channel_request_remote_forwarding: too many forwards");
 
-       permitted_opens[num_permitted_opens].host = xstrdup(host);
-       permitted_opens[num_permitted_opens].port = remote_port;
+       permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
+       permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
+       permitted_opens[num_permitted_opens].listen_port = listen_port;
        num_permitted_opens++;
 
        /* Send the forward request to the remote side. */
        packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
-       packet_put_int(port);
-       packet_put_string(host, strlen(host));
-       packet_put_int(remote_port);
+       packet_put_int(port_to_connect);
+       packet_put_string(host_to_connect, strlen(host_to_connect));
+       packet_put_int(listen_port);
        packet_send();
        packet_write_wait();
-
        /*
         * Wait for response from the remote side.  It will send a disconnect
         * message on failure, and we will never see it here.
@@ -1029,63 +1203,14 @@ channel_input_port_forward_request(int is_root)
        xfree(hostname);
 }
 
-/*
- * This is called after receiving PORT_OPEN message.  This attempts to
- * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
- * or CHANNEL_OPEN_FAILURE.
- */
-
-void 
-channel_input_port_open(int payload_len)
+/* XXX move to aux.c */
+int
+channel_connect_to(const char *host, u_short host_port)
 {
-       int remote_channel, sock = 0, newch, i;
-       u_short host_port;
-       char *host, *originator_string;
-       unsigned int host_len, originator_len;
        struct addrinfo hints, *ai, *aitop;
        char ntop[NI_MAXHOST], strport[NI_MAXSERV];
        int gaierr;
-
-       /* Get remote channel number. */
-       remote_channel = packet_get_int();
-
-       /* Get host name to connect to. */
-       host = packet_get_string(&host_len);
-
-       /* Get port to connect to. */
-       host_port = packet_get_int();
-
-       /* Get remote originator name. */
-       if (have_hostname_in_open) {
-               originator_string = packet_get_string(&originator_len);
-               originator_len += 4;    /* size of packet_int */
-       } else {
-               originator_string = xstrdup("unknown (remote did not supply name)");
-               originator_len = 0;     /* no originator supplied */
-       }
-
-       packet_integrity_check(payload_len,
-                              4 + 4 + host_len + 4 + originator_len,
-                              SSH_MSG_PORT_OPEN);
-
-       /* Check if opening that port is permitted. */
-       if (!all_opens_permitted) {
-               /* Go trough all permitted ports. */
-               for (i = 0; i < num_permitted_opens; i++)
-                       if (permitted_opens[i].port == host_port &&
-                           strcmp(permitted_opens[i].host, host) == 0)
-                               break;
-
-               /* Check if we found the requested port among those permitted. */
-               if (i >= num_permitted_opens) {
-                       /* The port is not permitted. */
-                       log("Received request to connect to %.100s:%d, but the request was denied.",
-                           host, host_port);
-                       packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
-                       packet_put_int(remote_channel);
-                       packet_send();
-               }
-       }
+       int sock = -1;
 
        memset(&hints, 0, sizeof(hints));
        hints.ai_family = IPv4or6;
@@ -1093,15 +1218,14 @@ channel_input_port_open(int payload_len)
        snprintf(strport, sizeof strport, "%d", host_port);
        if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
                error("%.100s: unknown host (%s)", host, gai_strerror(gaierr));
-               goto fail;
+               return -1;
        }
-
        for (ai = aitop; ai; ai = ai->ai_next) {
                if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
                        continue;
                if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
                    strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
-                       error("channel_input_port_open: getnameinfo failed");
+                       error("channel_connect_to: getnameinfo failed");
                        continue;
                }
                /* Create the socket. */
@@ -1121,37 +1245,82 @@ channel_input_port_open(int payload_len)
 
        }
        freeaddrinfo(aitop);
-
        if (!ai) {
                error("connect %.100s port %d: failed.", host, host_port);      
-               goto fail;
+               return -1;
        }
+       /* success */
+       return sock;
+}
 
-       /* Successful connection. */
+/*
+ * This is called after receiving PORT_OPEN message.  This attempts to
+ * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
+ * or CHANNEL_OPEN_FAILURE.
+ */
 
-       /* Allocate a channel for this connection. */
-       newch = channel_allocate(SSH_CHANNEL_OPEN, sock, originator_string);
-       channels[newch].remote_id = remote_channel;
+void 
+channel_input_port_open(int type, int plen)
+{
+       u_short host_port;
+       char *host, *originator_string;
+       int remote_channel, sock = -1, newch, i, denied;
+       unsigned int host_len, originator_len;
 
-       /* Send a confirmation to the remote host. */
-       packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
-       packet_put_int(remote_channel);
-       packet_put_int(newch);
-       packet_send();
+       /* Get remote channel number. */
+       remote_channel = packet_get_int();
 
-       /* Free the argument string. */
-       xfree(host);
+       /* Get host name to connect to. */
+       host = packet_get_string(&host_len);
 
-       return;
+       /* Get port to connect to. */
+       host_port = packet_get_int();
 
-fail:
-       /* Free the argument string. */
-       xfree(host);
+       /* Get remote originator name. */
+       if (have_hostname_in_open) {
+               originator_string = packet_get_string(&originator_len);
+               originator_len += 4;    /* size of packet_int */
+       } else {
+               originator_string = xstrdup("unknown (remote did not supply name)");
+               originator_len = 0;     /* no originator supplied */
+       }
 
-       /* Send refusal to the remote host. */
-       packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
-       packet_put_int(remote_channel);
-       packet_send();
+       packet_integrity_check(plen,
+           4 + 4 + host_len + 4 + originator_len, SSH_MSG_PORT_OPEN);
+
+       /* Check if opening that port is permitted. */
+       denied = 0;
+       if (!all_opens_permitted) {
+               /* Go trough all permitted ports. */
+               for (i = 0; i < num_permitted_opens; i++)
+                       if (permitted_opens[i].port_to_connect == host_port &&
+                           strcmp(permitted_opens[i].host_to_connect, host) == 0)
+                               break;
+
+               /* Check if we found the requested port among those permitted. */
+               if (i >= num_permitted_opens) {
+                       /* The port is not permitted. */
+                       log("Received request to connect to %.100s:%d, but the request was denied.",
+                           host, host_port);
+                       denied = 1;
+               }
+       }
+       sock = denied ? -1 : channel_connect_to(host, host_port);
+       if (sock > 0) {
+               /* Allocate a channel for this connection. */
+               newch = channel_allocate(SSH_CHANNEL_OPEN, sock, originator_string);
+               channels[newch].remote_id = remote_channel;
+
+               packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
+               packet_put_int(remote_channel);
+               packet_put_int(newch);
+               packet_send();
+       } else {
+               packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
+               packet_put_int(remote_channel);
+               packet_send();
+       }
+       xfree(host);
 }
 
 /*
@@ -1336,7 +1505,7 @@ connect_local_xsocket(unsigned int dnr)
  */
 
 void 
-x11_input_open(int payload_len)
+x11_input_open(int type, int plen)
 {
        int remote_channel, display_number, sock = 0, newch;
        const char *display;
@@ -1359,7 +1528,7 @@ x11_input_open(int payload_len)
        }
 
        debug("Received X11 open request.");
-       packet_integrity_check(payload_len, 4 + remote_len, SSH_SMSG_X11_OPEN);
+       packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN);
 
        /* Try to open a socket for the local X server. */
        display = getenv("DISPLAY");
@@ -1425,19 +1594,18 @@ x11_input_open(int payload_len)
                sock = socket(ai->ai_family, SOCK_STREAM, 0);
                if (sock < 0) {
                        debug("socket: %.100s", strerror(errno));
-               continue;
-       }
-       /* Connect it to the display. */
-       if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
-               debug("connect %.100s port %d: %.100s", buf, 6000 + display_number, 
-                   strerror(errno));
-               close(sock);
-               continue;
+                       continue;
+               }
+               /* Connect it to the display. */
+               if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
+                       debug("connect %.100s port %d: %.100s", buf,
+                           6000 + display_number, strerror(errno));
+                       close(sock);
+                       continue;
+               }
+               /* Success */
+               break;
        }
-       /* Success */
-       break;
-
-       } /* (ai = aitop, ai; ai = ai->ai_next) */
        freeaddrinfo(aitop);
        if (!ai) {
                error("connect %.100s port %d: %.100s", buf, 6000 + display_number, 
@@ -1625,11 +1793,13 @@ auth_input_request_forwarding(struct passwd * pw)
 /* This is called to process an SSH_SMSG_AGENT_OPEN message. */
 
 void 
-auth_input_open_request()
+auth_input_open_request(int type, int plen)
 {
        int remch, sock, newch;
        char *dummyname;
 
+       packet_integrity_check(plen, 4, type);
+
        /* Read the remote channel number from the message. */
        remch = packet_get_int();
 
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