input_conn.c

/*
  Copyright(c) 2010-2016 Intel Corporation.
  All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:

    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in
      the documentation and/or other materials provided with the
      distribution.
    * Neither the name of Intel Corporation nor the names of its
      contributors may be used to endorse or promote products derived
      from this software without specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <string.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>

#include "input_conn.h"
#include "input.h"
#include "run.h"
#include "cmd_parser.h"

static struct input tcp_server;
int tcp_server_started;
static struct input uds_server;
int uds_server_started;

/* Active clients */
struct client_conn {
	struct input input;
	int          enabled;
	int          n_buf;
	char         buf[32768];
};

struct client_conn clients[32];

static int start_listen_tcp(void)
{
	struct sockaddr_in server;
	int ret, sock;
	int optval = 1;

	memset(&server, 0, sizeof(server));
	sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);

	if (sock == -1)
		return -1;

	server.sin_family = AF_INET;
	server.sin_port = ntohs(8474);
	server.sin_addr.s_addr = ntohl(INADDR_ANY);

	ret = setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(int));

	if (ret)
		return -1;

	if (bind(sock, (struct sockaddr *) &server, sizeof(server)) == -1)
		return -1;

	if (listen(sock, 1) == -1)
		return -1;

	return sock;
}

static int start_listen_uds(void)
{
	int sock;
	struct sockaddr_un server = {
		.sun_path = "/tmp/prox.sock",
		.sun_family = AF_UNIX
	};

	sock = socket(AF_UNIX, SOCK_STREAM, 0);
	if (sock == -1)
		return -1;

	/* Unlink can fail, i.e. when /tmp/prox.sock does not
	   exists. This is not fatal. */
	unlink(server.sun_path);

	if (bind(sock, (struct sockaddr *) &server, sizeof(server)) == -1)
		return -1;

	if (listen(sock, 1) == -1)
		return -1;

	return sock;
}

static void write_client(struct input *input, const char *buf, size_t len)
{
	int ret;

	while ((ret = write(input->fd, buf, len)) != (int)len) {
		buf += ret;
		len -= ret;
	}
}

static void handle_client(struct input* client_input)
{
	char cur[1024];
	size_t i;
	int ret;
	struct client_conn *c = NULL;

	/* Get the client structure that uses this input */
	for (i = 0; i < sizeof(clients)/sizeof(clients[0]); ++i) {
		if (&clients[i].input == client_input) {
			c = &clients[i];
			break;
		}
	}

	/* handle_client function called non-tcp client */
	if (c == NULL)
		return ;

	ret = read(c->input.fd, cur, sizeof(cur));

	if (ret == 0) {
		c->enabled = 0;
		unreg_input(&c->input);
		return ;
	}

	/* Scan in data until \n (\r skipped if followed by \n) */
	for (int i = 0; i < ret; ++i) {
		if (cur[i] == '\r' && i + 1 < ret && cur[i + 1] == '\n')
			continue;

		if (cur[i] == '\n') {
			c->buf[c->n_buf] = 0;
			if (c->n_buf)
				cmd_parser_parse(c->buf, client_input);
			c->n_buf = 0;
		}
		else if (c->n_buf + 1 < (int)sizeof(c->buf))
			c->buf[c->n_buf++] = cur[i];
		else
			c->n_buf = 0;
	}
}

static void handle_new_client(struct input* server)
{
	size_t i;

	int new_client = accept(server->fd, NULL, NULL);

	for (i = 0; i < sizeof(clients)/sizeof(clients[0]); ++i) {
		if (clients[i].enabled == 0) {
			break;
		}
	}

	if (i == sizeof(clients)/sizeof(clients[0])) {
		close(new_client);
		return ;
	}

	clients[i].enabled = 1;
	clients[i].n_buf = 0;
	clients[i].input.fd = new_client;
	clients[i].input.reply = server->reply;
	clients[i].input.proc_input = handle_client;

	reg_input(&clients[i].input);
}

int reg_input_tcp(void)
{
	int fd;

	if (tcp_server_started)
		return -1;
	if ((fd = start_listen_tcp()) < 0)
		return -1;

	tcp_server.fd = fd;
	tcp_server.proc_input = handle_new_client;
	tcp_server.reply = write_client;
	if (reg_input(&tcp_server) != 0) {
		close(fd);
		return -1;
	}
	tcp_server_started = 1;
	return 0;
}

int reg_input_uds(void)
{
	int fd;

	if (uds_server_started)
		return -1;

	if ((fd = start_listen_uds()) < 0)
		return -1;

	uds_server.fd = fd;
	uds_server.proc_input = handle_new_client;
	uds_server.reply = write_client;
	if (reg_input(&uds_server) != 0) {
		close(fd);
		return -1;
	}
	uds_server_started = 1;
	return 0;
}

void unreg_input_tcp(void)
{
	if (!tcp_server_started)
		return;
	tcp_server_started = 0;
	close(tcp_server.fd);
	unreg_input(&tcp_server);
}

void unreg_input_uds(void)
{
	if (!uds_server_started)
		return;
	uds_server_started = 0;
	close(tcp_server.fd);
	unreg_input(&tcp_server);
}