| /* (C) 2009-2010 by Holger Hans Peter Freyther <zecke@selfish.org> |
| * (C) 2010 by Sylvain Munaut <tnt@246tNt.com> |
| * All Rights Reserved |
| * |
| * SPDX-License-Identifier: GPL-2.0+ |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| */ |
| |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <unistd.h> |
| |
| #include <osmocom/core/msgb.h> |
| #include <osmocom/core/socket.h> |
| #include <osmocom/core/talloc.h> |
| #include <osmocom/core/logging.h> |
| #include <osmocom/core/signal.h> |
| |
| #include <osmocom/vty/telnet_interface.h> |
| #include <osmocom/vty/buffer.h> |
| #include <osmocom/vty/command.h> |
| |
| /*! \file telnet_interface.c |
| * Telnet interface towards Osmocom VTY |
| * |
| * This module contains the code implementing a telnet server for VTY |
| * access. This telnet server gets linked into each libosmovty-using |
| * process in order to enable interactive command-line introspection, |
| * interaction and configuration. |
| * |
| * You typically call \ref telnet_init or \ref telnet_init_dynif once |
| * from your application code to enable this. |
| */ |
| |
| /* per connection data */ |
| LLIST_HEAD(active_connections); |
| |
| static void *tall_telnet_ctx; |
| |
| /* per network data */ |
| static int telnet_new_connection(struct osmo_fd *fd, unsigned int what); |
| |
| static struct osmo_fd server_socket = { |
| .when = OSMO_FD_READ, |
| .cb = telnet_new_connection, |
| .priv_nr = 0, |
| }; |
| |
| /*! Initialize telnet based VTY interface listening to 127.0.0.1 |
| * \param[in] tall_ctx \ref talloc context |
| * \param[in] priv private data to be passed to callback |
| * \param[in] port TCP port number to bind to |
| */ |
| int telnet_init(void *tall_ctx, void *priv, int port) |
| { |
| return telnet_init_dynif(tall_ctx, priv, "127.0.0.1", port); |
| } |
| |
| /*! Initialize telnet based VTY interface |
| * \param[in] tall_ctx \ref talloc context |
| * \param[in] priv private data to be passed to callback |
| * \param[in] ip IP to listen to ('::1' for localhost, '::0' for all, ...) |
| * \param[in] port TCP port number to bind to |
| */ |
| int telnet_init_dynif(void *tall_ctx, void *priv, const char *ip, int port) |
| { |
| int rc; |
| |
| tall_telnet_ctx = talloc_named_const(tall_ctx, 1, |
| "telnet_connection"); |
| |
| rc = osmo_sock_init_ofd( |
| &server_socket, |
| AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, |
| ip, port, OSMO_SOCK_F_BIND |
| ); |
| |
| server_socket.data = priv; |
| |
| if (rc < 0) { |
| LOGP(DLGLOBAL, LOGL_ERROR, "Cannot bind telnet at %s %d\n", |
| ip, port); |
| return -1; |
| } |
| |
| LOGP(DLGLOBAL, LOGL_NOTICE, "Available via telnet %s %d\n", ip, port); |
| return 0; |
| } |
| |
| /*! Initializes telnet based VTY interface using the configured bind addr/port. |
| * \param[in] tall_ctx \ref talloc context |
| * \param[in] priv private data to be passed to callback |
| * \param[in] default_port TCP port number to bind to if not explicitely configured |
| */ |
| int telnet_init_default(void *tall_ctx, void *priv, int default_port) |
| { |
| return telnet_init_dynif(tall_ctx, priv, vty_get_bind_addr(), |
| vty_get_bind_port(default_port)); |
| } |
| |
| |
| extern struct host host; |
| |
| /*! close a telnet connection */ |
| int telnet_close_client(struct osmo_fd *fd) |
| { |
| struct telnet_connection *conn = (struct telnet_connection*)fd->data; |
| char sock_name_buf[OSMO_SOCK_NAME_MAXLEN]; |
| int rc; |
| |
| /* FIXME: getsockname() always fails: "Bad file descriptor" */ |
| rc = osmo_sock_get_name_buf(sock_name_buf, OSMO_SOCK_NAME_MAXLEN, fd->fd); |
| LOGP(DLGLOBAL, LOGL_INFO, "Closing telnet connection %s\n", |
| (rc <= 0) ? "r=NULL<->l=NULL" : sock_name_buf); |
| |
| close(fd->fd); |
| osmo_fd_unregister(fd); |
| |
| if (conn->dbg) { |
| log_del_target(conn->dbg); |
| talloc_free(conn->dbg); |
| } |
| |
| llist_del(&conn->entry); |
| talloc_free(conn); |
| return 0; |
| } |
| |
| static int client_data(struct osmo_fd *fd, unsigned int what) |
| { |
| struct telnet_connection *conn = fd->data; |
| int rc = 0; |
| |
| if (what & OSMO_FD_READ) { |
| conn->fd.when &= ~OSMO_FD_READ; |
| rc = vty_read(conn->vty); |
| } |
| |
| /* vty might have been closed from vithin vty_read() */ |
| if (rc == -EBADF) |
| return rc; |
| |
| if (what & OSMO_FD_WRITE) { |
| rc = buffer_flush_all(conn->vty->obuf, fd->fd); |
| if (rc == BUFFER_EMPTY) |
| conn->fd.when &= ~OSMO_FD_WRITE; |
| } |
| |
| return rc; |
| } |
| |
| static int telnet_new_connection(struct osmo_fd *fd, unsigned int what) |
| { |
| struct telnet_connection *connection; |
| struct sockaddr_in sockaddr; |
| socklen_t len = sizeof(sockaddr); |
| int new_connection = accept(fd->fd, (struct sockaddr*)&sockaddr, &len); |
| char sock_name_buf[OSMO_SOCK_NAME_MAXLEN]; |
| int rc; |
| |
| if (new_connection < 0) { |
| LOGP(DLGLOBAL, LOGL_ERROR, "telnet accept failed\n"); |
| return new_connection; |
| } |
| |
| rc = osmo_sock_get_name_buf(sock_name_buf, OSMO_SOCK_NAME_MAXLEN, new_connection); |
| LOGP(DLGLOBAL, LOGL_INFO, "Accept()ed new telnet connection %s\n", |
| (rc <= 0) ? "r=NULL<->l=NULL" : sock_name_buf); |
| |
| connection = talloc_zero(tall_telnet_ctx, struct telnet_connection); |
| connection->priv = fd->data; |
| connection->fd.data = connection; |
| connection->fd.fd = new_connection; |
| connection->fd.when = OSMO_FD_READ; |
| connection->fd.cb = client_data; |
| rc = osmo_fd_register(&connection->fd); |
| if (rc < 0) { |
| talloc_free(connection); |
| return rc; |
| } |
| llist_add_tail(&connection->entry, &active_connections); |
| |
| connection->vty = vty_create(new_connection, connection); |
| if (!connection->vty) { |
| LOGP(DLGLOBAL, LOGL_ERROR, "couldn't create VTY\n"); |
| /* vty_create() is already closing the fd if it returns NULL */ |
| talloc_free(connection); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| bool vty_is_active(struct vty *vty) |
| { |
| struct telnet_connection *connection; |
| llist_for_each_entry(connection, &active_connections, entry) { |
| if (connection->vty == vty) |
| return true; |
| } |
| return false; |
| } |
| |
| /*! callback from core VTY code about VTY related events */ |
| void vty_event(enum event event, int sock, struct vty *vty) |
| { |
| struct vty_signal_data sig_data; |
| struct telnet_connection *connection = vty->priv; |
| struct osmo_fd *bfd; |
| |
| if (vty->type != VTY_TERM) |
| return; |
| |
| sig_data.event = event; |
| sig_data.sock = sock; |
| sig_data.vty = vty; |
| osmo_signal_dispatch(SS_L_VTY, S_VTY_EVENT, &sig_data); |
| |
| if (!connection) |
| return; |
| |
| bfd = &connection->fd; |
| |
| switch (event) { |
| case VTY_READ: |
| bfd->when |= OSMO_FD_READ; |
| break; |
| case VTY_WRITE: |
| bfd->when |= OSMO_FD_WRITE; |
| break; |
| case VTY_CLOSED: |
| /* vty layer is about to free() vty */ |
| telnet_close_client(bfd); |
| break; |
| default: |
| break; |
| } |
| } |
| |
| /*! Close all telnet connections and release the telnet socket */ |
| void telnet_exit(void) |
| { |
| struct telnet_connection *tc, *tc2; |
| |
| llist_for_each_entry_safe(tc, tc2, &active_connections, entry) |
| telnet_close_client(&tc->fd); |
| |
| osmo_fd_unregister(&server_socket); |
| close(server_socket.fd); |
| talloc_free(tall_telnet_ctx); |
| } |