]> andersk Git - openssh.git/blobdiff - channels.c
[configure.ac] Make sure -lcrypto is before -lsocket for sco3. ok mouring@
[openssh.git] / channels.c
index ad879cc61bb3c8ed61c755ec5105f8f6ffcad695..e663c21596c2065a2cd6cec5810f8df5c00264c7 100644 (file)
@@ -39,7 +39,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: channels.c,v 1.190 2003/05/11 20:30:24 markus Exp $");
+RCSID("$OpenBSD: channels.c,v 1.200 2004/01/19 09:24:21 markus Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -54,7 +54,7 @@ RCSID("$OpenBSD: channels.c,v 1.190 2003/05/11 20:30:24 markus Exp $");
 #include "key.h"
 #include "authfd.h"
 #include "pathnames.h"
-
+#include "bufaux.h"
 
 /* -- channel core */
 
@@ -177,7 +177,7 @@ channel_register_fds(Channel *c, int rfd, int wfd, int efd,
 
        /* XXX ugly hack: nonblock is only set by the server */
        if (nonblock && isatty(c->rfd)) {
-               debug("channel %d: rfd %d isatty", c->self, c->rfd);
+               debug2("channel %d: rfd %d isatty", c->self, c->rfd);
                c->isatty = 1;
                if (!isatty(c->wfd)) {
                        error("channel %d: wfd %d is not a tty?",
@@ -217,7 +217,6 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd,
                channels = xmalloc(channels_alloc * sizeof(Channel *));
                for (i = 0; i < channels_alloc; i++)
                        channels[i] = NULL;
-               fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL);
        }
        /* Try to find a free slot where to put the new channel. */
        for (found = -1, i = 0; i < channels_alloc; i++)
@@ -229,12 +228,13 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd,
        if (found == -1) {
                /* There are no free slots.  Take last+1 slot and expand the array.  */
                found = channels_alloc;
-               channels_alloc += 10;
                if (channels_alloc > 10000)
                        fatal("channel_new: internal error: channels_alloc %d "
                            "too big.", channels_alloc);
+               channels = xrealloc(channels,
+                   (channels_alloc + 10) * sizeof(Channel *));
+               channels_alloc += 10;
                debug2("channel: expanding %d", channels_alloc);
-               channels = xrealloc(channels, channels_alloc * sizeof(Channel *));
                for (i = found; i < channels_alloc; i++)
                        channels[i] = NULL;
        }
@@ -304,7 +304,7 @@ channel_close_fd(int *fdp)
 static void
 channel_close_fds(Channel *c)
 {
-       debug3("channel_close_fds: channel %d: r %d w %d e %d",
+       debug3("channel %d: close_fds r %d w %d e %d",
            c->self, c->rfd, c->wfd, c->efd);
 
        channel_close_fd(&c->sock);
@@ -324,11 +324,11 @@ channel_free(Channel *c)
        for (n = 0, i = 0; i < channels_alloc; i++)
                if (channels[i])
                        n++;
-       debug("channel_free: channel %d: %s, nchannels %d", c->self,
+       debug("channel %d: free: %s, nchannels %d", c->self,
            c->remote_name ? c->remote_name : "???", n);
 
        s = channel_open_message();
-       debug3("channel_free: status: %s", s);
+       debug3("channel %d: status: %s", c->self, s);
        xfree(s);
 
        if (c->sock != -1)
@@ -419,7 +419,7 @@ channel_not_very_much_buffered_data(void)
                        }
 #endif
                        if (buffer_len(&c->output) > packet_get_maxsize()) {
-                               debug2("channel %d: big output buffer %d > %d",
+                               debug2("channel %d: big output buffer %u > %u",
                                    c->self, buffer_len(&c->output),
                                    packet_get_maxsize());
                                return 0;
@@ -596,7 +596,7 @@ channel_request_start(int id, char *service, int wantconfirm)
                logit("channel_request_start: %d: unknown channel id", id);
                return;
        }
-       debug("channel %d: request %s", id, service) ;
+       debug2("channel %d: request %s", id, service) ;
        packet_start(SSH2_MSG_CHANNEL_REQUEST);
        packet_put_int(c->remote_id);
        packet_put_cstring(service);
@@ -739,7 +739,7 @@ channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
                packet_put_int(c->remote_id);
                packet_send();
                c->type = SSH_CHANNEL_CLOSED;
-               debug("channel %d: closing after input drain.", c->self);
+               debug2("channel %d: closing after input drain.", c->self);
        }
 }
 
@@ -780,7 +780,7 @@ x11_open_helper(Buffer *b)
                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",
+               debug2("Initial X11 packet contains bad byte order byte: 0x%x",
                    ucp[0]);
                return -1;
        }
@@ -793,14 +793,14 @@ x11_open_helper(Buffer *b)
        /* 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.");
+               debug2("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.");
+               debug2("X11 auth data does not match fake data.");
                return -1;
        }
        /* Check fake data length */
@@ -857,7 +857,7 @@ channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
                channel_pre_open(c, readset, writeset);
        } else if (ret == -1) {
                logit("X11 connection rejected because of wrong authentication.");
-               debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
+               debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
                chan_read_failed(c);
                buffer_clear(&c->input);
                chan_ibuf_empty(c);
@@ -867,7 +867,7 @@ channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
                        chan_write_failed(c);
                else
                        c->type = SSH_CHANNEL_OPEN;
-               debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
+               debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
        }
 }
 
@@ -925,7 +925,7 @@ channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
        strlcpy(c->path, host, sizeof(c->path));
        c->host_port = ntohs(s4_req.dest_port);
 
-       debug("channel %d: dynamic request: socks4 host %s port %u command %u",
+       debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
            c->self, host, c->host_port, s4_req.command);
 
        if (s4_req.command != 1) {
@@ -941,6 +941,117 @@ channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
        return 1;
 }
 
+/* try to decode a socks5 header */
+#define SSH_SOCKS5_AUTHDONE    0x1000
+#define SSH_SOCKS5_NOAUTH      0x00
+#define SSH_SOCKS5_IPV4                0x01
+#define SSH_SOCKS5_DOMAIN      0x03
+#define SSH_SOCKS5_IPV6                0x04
+#define SSH_SOCKS5_CONNECT     0x01
+#define SSH_SOCKS5_SUCCESS     0x00
+
+static int
+channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset)
+{
+       struct {
+               u_int8_t version;
+               u_int8_t command;
+               u_int8_t reserved;
+               u_int8_t atyp;
+       } s5_req, s5_rsp;
+       u_int16_t dest_port;
+       u_char *p, dest_addr[255+1];
+       int i, have, found, nmethods, addrlen, af;
+
+       debug2("channel %d: decode socks5", c->self);
+       p = buffer_ptr(&c->input);
+       if (p[0] != 0x05)
+               return -1;
+       have = buffer_len(&c->input);
+       if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
+               /* format: ver | nmethods | methods */
+               if (have < 2)
+                       return 0;
+               nmethods = p[1];
+               if (have < nmethods + 2)
+                       return 0;
+               /* look for method: "NO AUTHENTICATION REQUIRED" */
+               for (found = 0, i = 2 ; i < nmethods + 2; i++) {
+                       if (p[i] == SSH_SOCKS5_NOAUTH ) {
+                               found = 1;
+                               break;
+                       }
+               }
+               if (!found) {
+                       debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
+                           c->self);
+                       return -1;
+               }
+               buffer_consume(&c->input, nmethods + 2);
+               buffer_put_char(&c->output, 0x05);              /* version */
+               buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
+               FD_SET(c->sock, writeset);
+               c->flags |= SSH_SOCKS5_AUTHDONE;
+               debug2("channel %d: socks5 auth done", c->self);
+               return 0;                               /* need more */
+       }
+       debug2("channel %d: socks5 post auth", c->self);
+       if (have < sizeof(s5_req)+1)
+               return 0;                       /* need more */
+       memcpy((char *)&s5_req, p, sizeof(s5_req));
+       if (s5_req.version != 0x05 ||
+           s5_req.command != SSH_SOCKS5_CONNECT ||
+           s5_req.reserved != 0x00) {
+               debug2("channel %d: only socks5 connect supported", c->self);
+               return -1;
+       }
+       switch(s5_req.atyp){
+       case SSH_SOCKS5_IPV4:
+               addrlen = 4;
+               af = AF_INET;
+               break;
+       case SSH_SOCKS5_DOMAIN:
+               addrlen = p[sizeof(s5_req)];
+               af = -1;
+               break;
+       case SSH_SOCKS5_IPV6:
+               addrlen = 16;
+               af = AF_INET6;
+               break;
+       default:
+               debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
+               return -1;
+       }
+       if (have < 4 + addrlen + 2)
+               return 0;
+       buffer_consume(&c->input, sizeof(s5_req));
+       if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
+               buffer_consume(&c->input, 1);    /* host string length */
+       buffer_get(&c->input, (char *)&dest_addr, addrlen);
+       buffer_get(&c->input, (char *)&dest_port, 2);
+       dest_addr[addrlen] = '\0';
+       if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
+               strlcpy(c->path, dest_addr, sizeof(c->path));
+       else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
+               return -1;
+       c->host_port = ntohs(dest_port);
+
+       debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
+           c->self, c->path, c->host_port, s5_req.command);
+
+       s5_rsp.version = 0x05;
+       s5_rsp.command = SSH_SOCKS5_SUCCESS;
+       s5_rsp.reserved = 0;                    /* ignored */
+       s5_rsp.atyp = SSH_SOCKS5_IPV4;
+       ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
+       dest_port = 0;                          /* ignored */
+
+       buffer_append(&c->output, (char *)&s5_rsp, sizeof(s5_rsp));
+       buffer_append(&c->output, (char *)&dest_addr, sizeof(struct in_addr));
+       buffer_append(&c->output, (char *)&dest_port, sizeof(dest_port));
+       return 1;
+}
+
 /* dynamic port forwarding */
 static void
 channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
@@ -953,7 +1064,7 @@ channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
        debug2("channel %d: pre_dynamic: have %d", c->self, have);
        /* buffer_dump(&c->input); */
        /* check if the fixed size part of the packet is in buffer. */
-       if (have < 4) {
+       if (have < 3) {
                /* need more */
                FD_SET(c->sock, readset);
                return;
@@ -964,6 +1075,9 @@ channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
        case 0x04:
                ret = channel_decode_socks4(c, readset, writeset);
                break;
+       case 0x05:
+               ret = channel_decode_socks5(c, readset, writeset);
+               break;
        default:
                ret = -1;
                break;
@@ -997,7 +1111,7 @@ channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
                addrlen = sizeof(addr);
                newsock = accept(c->sock, &addr, &addrlen);
                if (c->single_connection) {
-                       debug("single_connection: closing X11 listener.");
+                       debug2("single_connection: closing X11 listener.");
                        channel_close_fd(&c->sock);
                        chan_mark_dead(c);
                }
@@ -1023,7 +1137,7 @@ channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
                        /* originator ipaddr and port */
                        packet_put_cstring(remote_ipaddr);
                        if (datafellows & SSH_BUG_X11FWD) {
-                               debug("ssh2 x11 bug compat mode");
+                               debug2("ssh2 x11 bug compat mode");
                        } else {
                                packet_put_int(remote_port);
                        }
@@ -1242,16 +1356,16 @@ channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
                if (len < 0 && (errno == EINTR || errno == EAGAIN))
                        return 1;
                if (len <= 0) {
-                       debug("channel %d: read<=0 rfd %d len %d",
+                       debug2("channel %d: read<=0 rfd %d len %d",
                            c->self, c->rfd, len);
                        if (c->type != SSH_CHANNEL_OPEN) {
-                               debug("channel %d: not open", c->self);
+                               debug2("channel %d: not open", c->self);
                                chan_mark_dead(c);
                                return -1;
                        } else if (compat13) {
                                buffer_clear(&c->output);
                                c->type = SSH_CHANNEL_INPUT_DRAINING;
-                               debug("channel %d: input draining.", c->self);
+                               debug2("channel %d: input draining.", c->self);
                        } else {
                                chan_read_failed(c);
                        }
@@ -1259,7 +1373,7 @@ channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
                }
                if (c->input_filter != NULL) {
                        if (c->input_filter(c, buf, len) == -1) {
-                               debug("channel %d: filter stops", c->self);
+                               debug2("channel %d: filter stops", c->self);
                                chan_read_failed(c);
                        }
                } else {
@@ -1283,21 +1397,21 @@ channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
                data = buffer_ptr(&c->output);
                dlen = buffer_len(&c->output);
 #ifdef _AIX
-               /* XXX: Later AIX versions can't push as much data to tty */ 
-               if (compat20 && c->wfd_isatty && dlen > 8*1024)
-                       dlen = 8*1024;
+               /* XXX: Later AIX versions can't push as much data to tty */
+               if (compat20 && c->wfd_isatty)
+                       dlen = MIN(dlen, 8*1024);
 #endif
                len = write(c->wfd, data, dlen);
                if (len < 0 && (errno == EINTR || errno == EAGAIN))
                        return 1;
                if (len <= 0) {
                        if (c->type != SSH_CHANNEL_OPEN) {
-                               debug("channel %d: not open", c->self);
+                               debug2("channel %d: not open", c->self);
                                chan_mark_dead(c);
                                return -1;
                        } else if (compat13) {
                                buffer_clear(&c->output);
-                               debug("channel %d: input draining.", c->self);
+                               debug2("channel %d: input draining.", c->self);
                                c->type = SSH_CHANNEL_INPUT_DRAINING;
                        } else {
                                chan_write_failed(c);
@@ -1504,16 +1618,16 @@ channel_garbage_collect(Channel *c)
        if (c->detach_user != NULL) {
                if (!chan_is_dead(c, 0))
                        return;
-               debug("channel %d: gc: notify user", c->self);
+               debug2("channel %d: gc: notify user", c->self);
                c->detach_user(c->self, NULL);
                /* if we still have a callback */
                if (c->detach_user != NULL)
                        return;
-               debug("channel %d: gc: user detached", c->self);
+               debug2("channel %d: gc: user detached", c->self);
        }
        if (!chan_is_dead(c, 1))
                return;
-       debug("channel %d: garbage collecting", c->self);
+       debug2("channel %d: garbage collecting", c->self);
        channel_free(c);
 }
 
@@ -1703,13 +1817,25 @@ channel_input_data(int type, u_int32_t seq, void *ctxt)
            c->type != SSH_CHANNEL_X11_OPEN)
                return;
 
-       /* same for protocol 1.5 if output end is no longer open */
-       if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN)
-               return;
-
        /* Get the data. */
        data = packet_get_string(&data_len);
 
+       /*
+        * Ignore data for protocol > 1.3 if output end is no longer open.
+        * For protocol 2 the sending side is reducing its window as it sends
+        * data, so we must 'fake' consumption of the data in order to ensure
+        * that window updates are sent back.  Otherwise the connection might
+        * deadlock.
+        */
+       if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
+               if (compat20) {
+                       c->local_window -= data_len;
+                       c->local_consumed += data_len;
+               }
+               xfree(data);
+               return;
+       }
+
        if (compat20) {
                if (data_len > c->local_maxpacket) {
                        logit("channel %d: rcvd big packet %d, maxpack %d",
@@ -1888,7 +2014,7 @@ channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
                        c->confirm(c->self, NULL);
                        debug2("callback done");
                }
-               debug("channel %d: open confirm rwindow %u rmax %u", c->self,
+               debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
                    c->remote_window, c->remote_maxpacket);
        }
        packet_check_eom();
@@ -2081,7 +2207,7 @@ channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_por
                        continue;
                }
                /* Start listening for connections on the socket. */
-               if (listen(sock, 5) < 0) {
+               if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
                        error("listen: %.100s", strerror(errno));
                        close(sock);
                        continue;
@@ -2201,9 +2327,13 @@ channel_input_port_forward_request(int is_root, int gateway_ports)
         * privileged port.
         */
        if (port < IPPORT_RESERVED && !is_root)
-               packet_disconnect("Requested forwarding of port %d but user is not root.",
-                                 port);
+               packet_disconnect(
+                   "Requested forwarding of port %d but user is not root.",
+                   port);
+       if (host_port == 0)
+               packet_disconnect("Dynamic forwarding denied.");
 #endif
+
        /* Initiate forwarding */
        channel_setup_local_fwd_listener(port, hostname, host_port, gateway_ports);
 
@@ -2396,7 +2526,7 @@ x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
                        }
 #endif
                        if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
-                               debug("bind port %d: %.100s", port, strerror(errno));
+                               debug2("bind port %d: %.100s", port, strerror(errno));
                                close(sock);
 
                                if (ai->ai_next)
@@ -2432,7 +2562,7 @@ x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
        /* Start listening for connections on the socket. */
        for (n = 0; n < num_socks; n++) {
                sock = socks[n];
-               if (listen(sock, 5) < 0) {
+               if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
                        error("listen: %.100s", strerror(errno));
                        close(sock);
                        return -1;
@@ -2545,12 +2675,12 @@ x11_connect_display(void)
                /* Create a socket. */
                sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
                if (sock < 0) {
-                       debug("socket: %.100s", strerror(errno));
+                       debug2("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,
+                       debug2("connect %.100s port %d: %.100s", buf,
                            6000 + display_number, strerror(errno));
                        close(sock);
                        continue;
@@ -2720,46 +2850,3 @@ auth_request_forwarding(void)
        packet_send();
        packet_write_wait();
 }
-
-/* This is called to process an SSH_SMSG_AGENT_OPEN message. */
-
-void
-auth_input_open_request(int type, u_int32_t seq, void *ctxt)
-{
-       Channel *c = NULL;
-       int remote_id, sock;
-
-       /* Read the remote channel number from the message. */
-       remote_id = packet_get_int();
-       packet_check_eom();
-
-       /*
-        * Get a connection to the local authentication agent (this may again
-        * get forwarded).
-        */
-       sock = ssh_get_authentication_socket();
-
-       /*
-        * If we could not connect the agent, send an error message back to
-        * the server. This should never happen unless the agent dies,
-        * because authentication forwarding is only enabled if we have an
-        * agent.
-        */
-       if (sock >= 0) {
-               c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
-                   -1, 0, 0, 0, "authentication agent connection", 1);
-               c->remote_id = remote_id;
-               c->force_drain = 1;
-       }
-       if (c == NULL) {
-               packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
-               packet_put_int(remote_id);
-       } else {
-               /* Send a confirmation to the remote host. */
-               debug("Forwarding authentication connection.");
-               packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
-               packet_put_int(remote_id);
-               packet_put_int(c->self);
-       }
-       packet_send();
-}
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