multipathd/uxlsnr.c

/*
 * Original author : tridge@samba.org, January 2002
 *
 * Copyright (c) 2005 Christophe Varoqui
 * Copyright (c) 2005 Benjamin Marzinski, Redhat
 */

/*
 * A simple domain socket listener
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdarg.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/poll.h>

#include <checkers.h>

#include <memory.h>
#include <debug.h>
#include <vector.h>
#include <structs.h>
#include <uxsock.h>
#include <defaults.h>

#include "cli.h"
#include "uxlsnr.h"

#define SLEEP_TIME 5000

struct client {
	int fd;
	struct client *next, *prev;
};

static struct client *clients;
static unsigned num_clients;
struct pollfd *polls;

/*
 * handle a new client joining
 */
static void new_client(int ux_sock)
{
	struct client *c;
	struct sockaddr addr;
	socklen_t len = sizeof(addr);
	int fd;

	fd = accept(ux_sock, &addr, &len);

	if (fd == -1)
		return;

	/* put it in our linked list */
	c = (struct client *)MALLOC(sizeof(*c));
	memset(c, 0, sizeof(*c));
	c->fd = fd;
	c->next = clients;
	if (c->next) c->next->prev = c;
	clients = c;
	num_clients++;
}

/*
 * kill off a dead client
 */
static void dead_client(struct client *c)
{
	close(c->fd);
	if (c->prev) c->prev->next = c->next;
	if (c->next) c->next->prev = c->prev;
	if (c == clients) clients = c->next;
	FREE(c);
	num_clients--;
}

void free_polls (void)
{
	if (polls)
		FREE(polls);
}

void uxsock_cleanup(void *arg)
{
	cli_exit();
	free_polls();
}

/*
 * entry point
 */
void * uxsock_listen(int (*uxsock_trigger)(char *, char **, int *, void *),
			void * trigger_data)
{
	int ux_sock;
	size_t len;
	int rlen;
	char *inbuf;
	char *reply;

	ux_sock = ux_socket_listen(DEFAULT_SOCKET);

	if (ux_sock == -1) {
		condlog(0, "ux_socket_listen error");
		exit(1);
	}

	pthread_cleanup_push(uxsock_cleanup, NULL);

	polls = (struct pollfd *)MALLOC(0);

	while (1) {
		struct client *c;
		int i, poll_count;

		/* setup for a poll */
		polls = REALLOC(polls, (1+num_clients) * sizeof(*polls));
		polls[0].fd = ux_sock;
		polls[0].events = POLLIN;

		/* setup the clients */
		for (i=1, c = clients; c; i++, c = c->next) {
			polls[i].fd = c->fd;
			polls[i].events = POLLIN;
		}

		/* most of our life is spent in this call */
		poll_count = poll(polls, i, SLEEP_TIME);

		if (poll_count == -1) {
			if (errno == EINTR)
				continue;

			/* something went badly wrong! */
			condlog(0, "poll");
			pthread_exit(NULL);
		}

		if (poll_count == 0)
			continue;

		/* see if a client wants to speak to us */
		for (i=1, c = clients; c; i++) {
			struct client *next = c->next;

			if (polls[i].revents & POLLIN) {
				if (recv_packet(c->fd, &inbuf, &len) != 0) {
					dead_client(c);
				} else {
					inbuf[len - 1] = 0;
					condlog(4, "Got request [%s]", inbuf);
					uxsock_trigger(inbuf, &reply, &rlen,
						       trigger_data);
					if (reply) {
						if (send_packet(c->fd, reply,
								rlen) != 0) {
							dead_client(c);
						}
						condlog(4, "Reply [%d bytes]",
							rlen);
						FREE(reply);
						reply = NULL;
					}
					FREE(inbuf);
				}
			}
			c = next;
		}

		/* see if we got a new client */
		if (polls[0].revents & POLLIN) {
			new_client(ux_sock);
		}
	}

	pthread_cleanup_pop(1);
	close(ux_sock);
	return NULL;
}