+
+static void
+collect_children(void)
+{
+ pid_t pid;
+ sigset_t oset, nset;
+ int status;
+
+ /* block SIGCHLD while we check for dead children */
+ sigemptyset(&nset);
+ sigaddset(&nset, SIGCHLD);
+ sigprocmask(SIG_BLOCK, &nset, &oset);
+ if (child_terminated) {
+ while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
+ (pid < 0 && errno == EINTR))
+ if (pid > 0)
+ session_close_by_pid(pid, status);
+ child_terminated = 0;
+ }
+ sigprocmask(SIG_SETMASK, &oset, NULL);
+}
+
+void
+server_loop2(Authctxt *authctxt)
+{
+ fd_set *readset = NULL, *writeset = NULL;
+ int rekeying = 0, max_fd, nalloc = 0;
+
+ debug("Entering interactive session for SSH2.");
+
+ mysignal(SIGCHLD, sigchld_handler);
+ child_terminated = 0;
+ connection_in = packet_get_connection_in();
+ connection_out = packet_get_connection_out();
+
+ notify_setup();
+
+ max_fd = MAX(connection_in, connection_out);
+ max_fd = MAX(max_fd, notify_pipe[0]);
+
+ server_init_dispatch();
+
+ for (;;) {
+ process_buffered_input_packets();
+
+ rekeying = (xxx_kex != NULL && !xxx_kex->done);
+
+ if (!rekeying && packet_not_very_much_data_to_write())
+ channel_output_poll();
+ wait_until_can_do_something(&readset, &writeset, &max_fd,
+ &nalloc, 0);
+
+ collect_children();
+ if (!rekeying) {
+ channel_after_select(readset, writeset);
+ if (packet_need_rekeying()) {
+ debug("need rekeying");
+ xxx_kex->done = 0;
+ kex_send_kexinit(xxx_kex);
+ }
+ }
+ process_input(readset);
+ if (connection_closed)
+ break;
+ process_output(writeset);
+ }
+ collect_children();
+
+ if (readset)
+ xfree(readset);
+ if (writeset)
+ xfree(writeset);
+
+ /* free all channels, no more reads and writes */
+ channel_free_all();
+
+ /* free remaining sessions, e.g. remove wtmp entries */
+ session_destroy_all(NULL);
+}
+
+static void
+server_input_keep_alive(int type, u_int32_t seq, void *ctxt)
+{
+ debug("Got %d/%u for keepalive", type, seq);
+ /*
+ * reset timeout, since we got a sane answer from the client.
+ * even if this was generated by something other than
+ * the bogus CHANNEL_REQUEST we send for keepalives.
+ */
+ client_alive_timeouts = 0;
+}
+
+static void
+server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
+{
+ char *data;
+ u_int data_len;
+
+ /* Stdin data from the client. Append it to the buffer. */
+ /* Ignore any data if the client has closed stdin. */
+ if (fdin == -1)
+ return;
+ data = packet_get_string(&data_len);
+ packet_check_eom();
+ buffer_append(&stdin_buffer, data, data_len);
+ memset(data, 0, data_len);
+ xfree(data);
+}
+
+static void
+server_input_eof(int type, u_int32_t seq, void *ctxt)
+{
+ /*
+ * Eof from the client. The stdin descriptor to the
+ * program will be closed when all buffered data has
+ * drained.
+ */
+ debug("EOF received for stdin.");
+ packet_check_eom();
+ stdin_eof = 1;
+}
+
+static void
+server_input_window_size(int type, u_int32_t seq, void *ctxt)
+{
+ int row = packet_get_int();
+ int col = packet_get_int();
+ int xpixel = packet_get_int();
+ int ypixel = packet_get_int();
+
+ debug("Window change received.");
+ packet_check_eom();
+ if (fdin != -1)
+ pty_change_window_size(fdin, row, col, xpixel, ypixel);
+}
+
+static Channel *
+server_request_direct_tcpip(void)
+{
+ Channel *c;
+ int sock;
+ char *target, *originator;
+ int target_port, originator_port;
+
+ target = packet_get_string(NULL);
+ target_port = packet_get_int();
+ originator = packet_get_string(NULL);
+ originator_port = packet_get_int();
+ packet_check_eom();
+
+ debug("server_request_direct_tcpip: originator %s port %d, target %s port %d",
+ originator, originator_port, target, target_port);
+
+ /* XXX check permission */
+ sock = channel_connect_to(target, target_port);
+ xfree(target);
+ xfree(originator);
+ if (sock < 0)
+ return NULL;
+ c = channel_new("direct-tcpip", SSH_CHANNEL_CONNECTING,
+ sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT,
+ CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1);
+ return c;
+}
+
+static Channel *
+server_request_session(void)
+{
+ Channel *c;
+
+ debug("input_session_request");
+ packet_check_eom();
+ /*
+ * A server session has no fd to read or write until a
+ * CHANNEL_REQUEST for a shell is made, so we set the type to
+ * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all
+ * CHANNEL_REQUEST messages is registered.
+ */
+ c = channel_new("session", SSH_CHANNEL_LARVAL,
+ -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
+ 0, "server-session", 1);
+ if (session_open(the_authctxt, c->self) != 1) {
+ debug("session open failed, free channel %d", c->self);
+ channel_free(c);
+ return NULL;
+ }
+ channel_register_cleanup(c->self, session_close_by_channel);
+ return c;
+}
+
+static void
+server_input_channel_open(int type, u_int32_t seq, void *ctxt)
+{
+ Channel *c = NULL;
+ char *ctype;
+ int rchan;
+ u_int rmaxpack, rwindow, len;
+
+ ctype = packet_get_string(&len);
+ rchan = packet_get_int();
+ rwindow = packet_get_int();
+ rmaxpack = packet_get_int();
+
+ debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
+ ctype, rchan, rwindow, rmaxpack);
+
+ if (strcmp(ctype, "session") == 0) {
+ c = server_request_session();
+ } else if (strcmp(ctype, "direct-tcpip") == 0) {
+ c = server_request_direct_tcpip();
+ }
+ if (c != NULL) {
+ debug("server_input_channel_open: confirm %s", ctype);
+ c->remote_id = rchan;
+ c->remote_window = rwindow;
+ c->remote_maxpacket = rmaxpack;
+ if (c->type != SSH_CHANNEL_CONNECTING) {
+ packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
+ packet_put_int(c->remote_id);
+ packet_put_int(c->self);
+ packet_put_int(c->local_window);
+ packet_put_int(c->local_maxpacket);
+ packet_send();
+ }
+ } else {
+ debug("server_input_channel_open: failure %s", ctype);
+ packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
+ packet_put_int(rchan);
+ packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
+ if (!(datafellows & SSH_BUG_OPENFAILURE)) {
+ packet_put_cstring("open failed");
+ packet_put_cstring("");
+ }
+ packet_send();
+ }
+ xfree(ctype);
+}
+
+static void
+server_input_global_request(int type, u_int32_t seq, void *ctxt)
+{
+ char *rtype;
+ int want_reply;
+ int success = 0;
+
+ rtype = packet_get_string(NULL);
+ want_reply = packet_get_char();
+ debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
+
+ /* -R style forwarding */
+ if (strcmp(rtype, "tcpip-forward") == 0) {
+ struct passwd *pw;
+ char *listen_address;
+ u_short listen_port;
+
+ pw = the_authctxt->pw;
+ if (pw == NULL || !the_authctxt->valid)
+ fatal("server_input_global_request: no/invalid user");
+ listen_address = packet_get_string(NULL);
+ listen_port = (u_short)packet_get_int();
+ debug("server_input_global_request: tcpip-forward listen %s port %d",
+ listen_address, listen_port);
+
+ /* check permissions */
+ if (!options.allow_tcp_forwarding ||
+ no_port_forwarding_flag
+#ifndef NO_IPPORT_RESERVED_CONCEPT
+ || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0)
+#endif
+ ) {
+ success = 0;
+ packet_send_debug("Server has disabled port forwarding.");
+ } else {
+ /* Start listening on the port */
+ success = channel_setup_remote_fwd_listener(
+ listen_address, listen_port, options.gateway_ports);
+ }
+ xfree(listen_address);
+ } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
+ char *cancel_address;
+ u_short cancel_port;
+
+ cancel_address = packet_get_string(NULL);
+ cancel_port = (u_short)packet_get_int();
+ debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
+ cancel_address, cancel_port);
+
+ success = channel_cancel_rport_listener(cancel_address,
+ cancel_port);
+ }
+ if (want_reply) {
+ packet_start(success ?
+ SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
+ packet_send();
+ packet_write_wait();
+ }
+ xfree(rtype);
+}
+static void
+server_input_channel_req(int type, u_int32_t seq, void *ctxt)
+{
+ Channel *c;
+ int id, reply, success = 0;
+ char *rtype;
+
+ id = packet_get_int();
+ rtype = packet_get_string(NULL);
+ reply = packet_get_char();
+
+ debug("server_input_channel_req: channel %d request %s reply %d",
+ id, rtype, reply);
+
+ if ((c = channel_lookup(id)) == NULL)
+ packet_disconnect("server_input_channel_req: "
+ "unknown channel %d", id);
+ if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN)
+ success = session_input_channel_req(c, rtype);
+ if (reply) {
+ packet_start(success ?
+ SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
+ packet_put_int(c->remote_id);
+ packet_send();
+ }
+ xfree(rtype);
+}
+
+static void
+server_init_dispatch_20(void)
+{
+ debug("server_init_dispatch_20");
+ dispatch_init(&dispatch_protocol_error);
+ dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
+ dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
+ dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
+ dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
+ dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
+ dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
+ dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
+ dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
+ dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
+ dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
+ /* client_alive */
+ dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
+ dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
+ dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
+ /* rekeying */
+ dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
+}
+static void
+server_init_dispatch_13(void)
+{
+ debug("server_init_dispatch_13");
+ dispatch_init(NULL);
+ dispatch_set(SSH_CMSG_EOF, &server_input_eof);
+ dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
+ dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
+ dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
+ dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
+ dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
+ dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
+ dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
+ dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
+}
+static void
+server_init_dispatch_15(void)
+{
+ server_init_dispatch_13();
+ debug("server_init_dispatch_15");
+ dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
+ dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
+}
+static void
+server_init_dispatch(void)
+{
+ if (compat20)
+ server_init_dispatch_20();
+ else if (compat13)
+ server_init_dispatch_13();
+ else
+ server_init_dispatch_15();
+}