]> andersk Git - openssh.git/blobdiff - channels.c
- markus@cvs.openbsd.org 2003/07/02 14:51:16
[openssh.git] / channels.c
index 1937b02446b5a9357b6f92532a888794893ffec2..e5b2b8c515580a92c9b832cca66850430a3761ae 100644 (file)
@@ -39,7 +39,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: channels.c,v 1.187 2003/03/05 22:33:43 markus Exp $");
+RCSID("$OpenBSD: channels.c,v 1.193 2003/07/02 14:51:16 markus Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -54,7 +54,7 @@ RCSID("$OpenBSD: channels.c,v 1.187 2003/03/05 22:33:43 markus Exp $");
 #include "key.h"
 #include "authfd.h"
 #include "pathnames.h"
-
+#include "bufaux.h"
 
 /* -- channel core */
 
@@ -142,12 +142,12 @@ channel_lookup(int id)
        Channel *c;
 
        if (id < 0 || id >= channels_alloc) {
-               log("channel_lookup: %d: bad id", id);
+               logit("channel_lookup: %d: bad id", id);
                return NULL;
        }
        c = channels[id];
        if (c == NULL) {
-               log("channel_lookup: %d: bad id: channel free", id);
+               logit("channel_lookup: %d: bad id: channel free", id);
                return NULL;
        }
        return c;
@@ -256,7 +256,7 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd,
        c->local_consumed = 0;
        c->local_maxpacket = maxpack;
        c->remote_id = -1;
-       c->remote_name = remote_name;
+       c->remote_name = xstrdup(remote_name);
        c->remote_window = 0;
        c->remote_maxpacket = 0;
        c->force_drain = 0;
@@ -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;
@@ -575,7 +575,7 @@ channel_send_open(int id)
        Channel *c = channel_lookup(id);
 
        if (c == NULL) {
-               log("channel_send_open: %d: bad id", id);
+               logit("channel_send_open: %d: bad id", id);
                return;
        }
        debug2("channel %d: send open", id);
@@ -593,7 +593,7 @@ channel_request_start(int id, char *service, int wantconfirm)
        Channel *c = channel_lookup(id);
 
        if (c == NULL) {
-               log("channel_request_start: %d: unknown channel id", id);
+               logit("channel_request_start: %d: unknown channel id", id);
                return;
        }
        debug("channel %d: request %s", id, service) ;
@@ -608,7 +608,7 @@ channel_register_confirm(int id, channel_callback_fn *fn)
        Channel *c = channel_lookup(id);
 
        if (c == NULL) {
-               log("channel_register_comfirm: %d: bad id", id);
+               logit("channel_register_comfirm: %d: bad id", id);
                return;
        }
        c->confirm = fn;
@@ -619,7 +619,7 @@ channel_register_cleanup(int id, channel_callback_fn *fn)
        Channel *c = channel_lookup(id);
 
        if (c == NULL) {
-               log("channel_register_cleanup: %d: bad id", id);
+               logit("channel_register_cleanup: %d: bad id", id);
                return;
        }
        c->detach_user = fn;
@@ -630,7 +630,7 @@ channel_cancel_cleanup(int id)
        Channel *c = channel_lookup(id);
 
        if (c == NULL) {
-               log("channel_cancel_cleanup: %d: bad id", id);
+               logit("channel_cancel_cleanup: %d: bad id", id);
                return;
        }
        c->detach_user = NULL;
@@ -641,7 +641,7 @@ channel_register_filter(int id, channel_filter_fn *fn)
        Channel *c = channel_lookup(id);
 
        if (c == NULL) {
-               log("channel_register_filter: %d: bad id", id);
+               logit("channel_register_filter: %d: bad id", id);
                return;
        }
        c->input_filter = fn;
@@ -833,7 +833,7 @@ channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
                 * We have received an X11 connection that has bad
                 * authentication information.
                 */
-               log("X11 connection rejected because of wrong authentication.");
+               logit("X11 connection rejected because of wrong authentication.");
                buffer_clear(&c->input);
                buffer_clear(&c->output);
                channel_close_fd(&c->sock);
@@ -856,7 +856,7 @@ channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
                c->type = SSH_CHANNEL_OPEN;
                channel_pre_open(c, readset, writeset);
        } else if (ret == -1) {
-               log("X11 connection rejected because of wrong authentication.");
+               logit("X11 connection rejected because of wrong authentication.");
                debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
                chan_read_failed(c);
                buffer_clear(&c->input);
@@ -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) {
+               debug("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:
+               debug("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);
+       
+       debug("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;
@@ -1013,8 +1127,7 @@ channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
 
                nc = channel_new("accepted x11 socket",
                    SSH_CHANNEL_OPENING, newsock, newsock, -1,
-                   c->local_window_max, c->local_maxpacket,
-                   0, xstrdup(buf), 1);
+                   c->local_window_max, c->local_maxpacket, 0, buf, 1);
                if (compat20) {
                        packet_start(SSH2_MSG_CHANNEL_OPEN);
                        packet_put_cstring("x11");
@@ -1129,10 +1242,8 @@ channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
                        return;
                }
                set_nodelay(newsock);
-               nc = channel_new(rtype,
-                   nextstate, newsock, newsock, -1,
-                   c->local_window_max, c->local_maxpacket,
-                   0, xstrdup(rtype), 1);
+               nc = channel_new(rtype, nextstate, newsock, newsock, -1,
+                   c->local_window_max, c->local_maxpacket, 0, rtype, 1);
                nc->listening_port = c->listening_port;
                nc->host_port = c->host_port;
                strlcpy(nc->path, c->path, sizeof(nc->path));
@@ -1158,7 +1269,6 @@ static void
 channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
 {
        Channel *nc;
-       char *name;
        int newsock;
        struct sockaddr addr;
        socklen_t addrlen;
@@ -1170,11 +1280,10 @@ channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
                        error("accept from auth socket: %.100s", strerror(errno));
                        return;
                }
-               name = xstrdup("accepted auth socket");
                nc = channel_new("accepted auth socket",
                    SSH_CHANNEL_OPENING, newsock, newsock, -1,
                    c->local_window_max, c->local_maxpacket,
-                   0, name, 1);
+                   0, "accepted auth socket", 1);
                if (compat20) {
                        packet_start(SSH2_MSG_CHANNEL_OPEN);
                        packet_put_cstring("auth-agent@openssh.com");
@@ -1717,11 +1826,11 @@ channel_input_data(int type, u_int32_t seq, void *ctxt)
 
        if (compat20) {
                if (data_len > c->local_maxpacket) {
-                       log("channel %d: rcvd big packet %d, maxpack %d",
+                       logit("channel %d: rcvd big packet %d, maxpack %d",
                            c->self, data_len, c->local_maxpacket);
                }
                if (data_len > c->local_window) {
-                       log("channel %d: rcvd too much data %d, win %d",
+                       logit("channel %d: rcvd too much data %d, win %d",
                            c->self, data_len, c->local_window);
                        xfree(data);
                        return;
@@ -1748,7 +1857,7 @@ channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
        if (c == NULL)
                packet_disconnect("Received extended_data for bad channel %d.", id);
        if (c->type != SSH_CHANNEL_OPEN) {
-               log("channel %d: ext data for non open", id);
+               logit("channel %d: ext data for non open", id);
                return;
        }
        if (c->flags & CHAN_EOF_RCVD) {
@@ -1762,13 +1871,13 @@ channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
        if (c->efd == -1 ||
            c->extended_usage != CHAN_EXTENDED_WRITE ||
            tcode != SSH2_EXTENDED_DATA_STDERR) {
-               log("channel %d: bad ext data", c->self);
+               logit("channel %d: bad ext data", c->self);
                return;
        }
        data = packet_get_string(&data_len);
        packet_check_eom();
        if (data_len > c->local_window) {
-               log("channel %d: rcvd too much extended_data %d, win %d",
+               logit("channel %d: rcvd too much extended_data %d, win %d",
                    c->self, data_len, c->local_window);
                xfree(data);
                return;
@@ -1934,7 +2043,7 @@ channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
                        msg  = packet_get_string(NULL);
                        lang = packet_get_string(NULL);
                }
-               log("channel %d: open failed: %s%s%s", id,
+               logit("channel %d: open failed: %s%s%s", id,
                    reason2txt(reason), msg ? ": ": "", msg ? msg : "");
                if (msg != NULL)
                        xfree(msg);
@@ -1961,7 +2070,7 @@ channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
        c = channel_lookup(id);
 
        if (c == NULL || c->type != SSH_CHANNEL_OPEN) {
-               log("Received window adjust for "
+               logit("Received window adjust for "
                    "non-open channel %d.", id);
                return;
        }
@@ -1996,8 +2105,8 @@ channel_input_port_open(int type, u_int32_t seq, void *ctxt)
                    originator_string, 1);
                c->remote_id = remote_id;
        }
+       xfree(originator_string);
        if (c == NULL) {
-               xfree(originator_string);
                packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
                packet_put_int(remote_id);
                packet_send();
@@ -2058,7 +2167,7 @@ channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_por
                        continue;
                }
                /* Create a port to listen for the host. */
-               sock = socket(ai->ai_family, SOCK_STREAM, 0);
+               sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
                if (sock < 0) {
                        /* this is no error since kernel may not support ipv6 */
                        verbose("socket: %.100s", strerror(errno));
@@ -2094,7 +2203,7 @@ channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_por
                /* Allocate a channel number for the socket. */
                c = channel_new("port listener", type, sock, sock, -1,
                    CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
-                   0, xstrdup("port listener"), 1);
+                   0, "port listener", 1);
                strlcpy(c->path, host, sizeof(c->path));
                c->host_port = port_to_connect;
                c->listening_port = listen_port;
@@ -2167,7 +2276,7 @@ channel_request_remote_forwarding(u_short listen_port,
                        success = 1;
                        break;
                case SSH_SMSG_FAILURE:
-                       log("Warning: Server denied remote port forwarding.");
+                       logit("Warning: Server denied remote port forwarding.");
                        break;
                default:
                        /* Unknown packet */
@@ -2206,9 +2315,13 @@ 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);
 
@@ -2280,7 +2393,7 @@ connect_to(const char *host, u_short port)
                        error("connect_to: getnameinfo failed");
                        continue;
                }
-               sock = socket(ai->ai_family, SOCK_STREAM, 0);
+               sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
                if (sock < 0) {
                        if (ai->ai_next == NULL)
                                error("socket: %.100s", strerror(errno));
@@ -2340,7 +2453,7 @@ channel_connect_to(const char *host, u_short port)
 
        }
        if (!permit) {
-               log("Received request to connect to host %.100s port %d, "
+               logit("Received request to connect to host %.100s port %d, "
                    "but the request was denied.", host, port);
                return -1;
        }
@@ -2381,7 +2494,8 @@ x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
                for (ai = aitop; ai; ai = ai->ai_next) {
                        if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
                                continue;
-                       sock = socket(ai->ai_family, SOCK_STREAM, 0);
+                       sock = socket(ai->ai_family, ai->ai_socktype,
+                           ai->ai_protocol);
                        if (sock < 0) {
                                if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) {
                                        error("socket: %.100s", strerror(errno));
@@ -2449,7 +2563,7 @@ x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
                nc = channel_new("x11 listener",
                    SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
                    CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
-                   0, xstrdup("X11 inet listener"), 1);
+                   0, "X11 inet listener", 1);
                nc->single_connection = single_connection;
        }
 
@@ -2547,7 +2661,7 @@ x11_connect_display(void)
        }
        for (ai = aitop; ai; ai = ai->ai_next) {
                /* Create a socket. */
-               sock = socket(ai->ai_family, SOCK_STREAM, 0);
+               sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
                if (sock < 0) {
                        debug("socket: %.100s", strerror(errno));
                        continue;
@@ -2606,11 +2720,11 @@ x11_input_open(int type, u_int32_t seq, void *ctxt)
                c->remote_id = remote_id;
                c->force_drain = 1;
        }
+       xfree(remote_host);
        if (c == NULL) {
                /* Send refusal to the remote host. */
                packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
                packet_put_int(remote_id);
-               xfree(remote_host);
        } else {
                /* Send a confirmation to the remote host. */
                packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
@@ -2732,7 +2846,6 @@ auth_input_open_request(int type, u_int32_t seq, void *ctxt)
 {
        Channel *c = NULL;
        int remote_id, sock;
-       char *name;
 
        /* Read the remote channel number from the message. */
        remote_id = packet_get_int();
@@ -2751,9 +2864,8 @@ auth_input_open_request(int type, u_int32_t seq, void *ctxt)
         * agent.
         */
        if (sock >= 0) {
-               name = xstrdup("authentication agent connection");
                c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
-                   -1, 0, 0, 0, name, 1);
+                   -1, 0, 0, 0, "authentication agent connection", 1);
                c->remote_id = remote_id;
                c->force_drain = 1;
        }
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