osmo-el2tpd/src/l2tpd_socket.c

155 lines
4.0 KiB
C

/* generic unix socket interface */
/* (C) 2016 by sysmocom - s.f.m.c. GmbH, Author: Alexander Couzens <lynxis@fe80.eu>
*
* 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 <errno.h>
#include <stdio.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
#include <osmocom/core/write_queue.h>
#include <osmocom/core/logging.h>
#include <osmocom/core/loggingrb.h>
#include <osmocom/core/socket.h>
#include "l2tpd_socket.h"
static int l2tp_sock_write(struct osmo_fd *bfd, struct msgb *msg)
{
int rc;
rc = write(bfd->fd, msg->data, msg->len);
if (rc != msg->len)
LOGP(DLCTRL, LOGL_ERROR, "Failed to write message to the unix connection.\n");
return rc;
}
int l2tp_sock_cleanup(struct osmo_fd *bfd)
{
int rc;
struct osmo_wqueue *wq = container_of(bfd, struct osmo_wqueue, bfd);
osmo_wqueue_clear(wq);
rc = close(bfd->fd);
osmo_fd_unregister(bfd);
bfd->fd = -1;
return rc;
}
/* accept a new connection */
static int l2tp_sock_accept(struct osmo_fd *bfd, unsigned int flags)
{
struct l2tp_socket_state *state = container_of(bfd, struct l2tp_socket_state, listen_bfd);
struct osmo_fd *conn_bfd = &state->wqueue.bfd;
struct sockaddr_un un_addr;
socklen_t len;
int rc;
len = sizeof(un_addr);
rc = accept(bfd->fd, (struct sockaddr *) &un_addr, &len);
if (rc < 0) {
LOGP(state->log_class, LOGL_ERROR, "Failed to accept a new connection\n");
return -1;
}
if (conn_bfd->fd >= 0) {
LOGP(state->log_class, LOGL_NOTICE, "There is already one connection to the socket\n");
l2tp_sock_cleanup(conn_bfd);
return 0;
}
osmo_fd_setup(conn_bfd, rc, OSMO_FD_READ, conn_bfd->cb, conn_bfd->data, conn_bfd->priv_nr);
if (osmo_fd_register(conn_bfd) != 0) {
LOGP(state->log_class, LOGL_ERROR, "Failed to register new connection fd\n");
close(conn_bfd->fd);
conn_bfd->fd = -1;
return -1;
}
state->wqueue.write_cb = l2tp_sock_write;
state->wqueue.except_cb = l2tp_sock_cleanup;
LOGP(state->log_class, LOGL_NOTICE, "Unix Socket has connection with external "
"call control application\n");
return 0;
}
void l2tp_set_read_callback(struct l2tp_socket_state *state, int (*read_cb)(struct osmo_fd *fd))
{
state->wqueue.read_cb = read_cb;
}
/*!
* \brief l2tp_enqueue_data
* \param sock
* \return 0 on success
*/
int l2tp_socket_enqueue(struct l2tp_socket_state *state, struct msgb *msg)
{
return osmo_wqueue_enqueue(&state->wqueue, msg);
}
/*!
* \brief l2tp_socket_init
* \param sock
* \param sock_path
* \return 0 on success
*/
int l2tp_socket_init(struct l2tp_socket_state *state, const char *sock_path, int queue_len, int log_class)
{
struct osmo_fd *bfd;
int rc;
state->log_class = log_class;
osmo_wqueue_init(&state->wqueue, queue_len);
state->wqueue.bfd.fd = -1;
bfd = &state->listen_bfd;
bfd->fd = osmo_sock_unix_init(SOCK_SEQPACKET, 0, sock_path,
OSMO_SOCK_F_BIND);
if (bfd->fd < 0) {
LOGP(state->log_class, LOGL_ERROR, "Could not create unix socket: %s: %s\n",
sock_path, strerror(errno));
talloc_free(state);
return -1;
}
osmo_fd_setup(bfd, bfd->fd, OSMO_FD_READ, l2tp_sock_accept, NULL, 0);
rc = osmo_fd_register(bfd);
if (rc < 0) {
LOGP(state->log_class, LOGL_ERROR, "Could not register listen fd: %d\n", rc);
close(bfd->fd);
talloc_free(state);
return rc;
}
LOGP(state->log_class, LOGL_NOTICE, "unix domain socket at %s\n", sock_path);
return 0;
}