source: rtems-libbsd/dhcpcd/control.c @ 7e52ab9

/*
 * dhcpcd - DHCP client daemon
 * Copyright (c) 2006-2012 Roy Marples <roy@marples.name>
 * All rights reserved

 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 <sys/stat.h>
#include <sys/un.h>

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "config.h"
#include "common.h"
#include "dhcpcd.h"
#include "control.h"
#include "eloop.h"

static int fd = -1;
static char buffer[1024];
static char *argvp[255];

static struct sockaddr_un sun;
struct fd_list *control_fds = NULL;

#ifdef DEBUG_MEMORY
static void
cleanup(void)
{
        struct fd_list *f;

        f = control_fds;
        while (f) {
                control_fds = f->next;
                free(f);
                f = control_fds;
        }
}
#endif

static void
control_remove(void *arg)
{
        struct fd_list *l, *n, *last = NULL;

        l = control_fds;
        while (l) {
                n = l->next;
                if (l == arg) {
                        close(l->fd);
                        eloop_event_delete(l->fd);
                        if (last == NULL)
                                control_fds = l->next;
                        else
                                last->next = l->next;
                        free(l);
                        break;
                }
                last = l;
                l = n;
        }
}

static void
control_handle_data(void *arg)
{
        struct fd_list *l = arg;
        ssize_t bytes;
        int argc;
        char *e, *p;
        char **ap;

        bytes = read(l->fd, buffer, sizeof(buffer) - 1);
        if (bytes == -1 || bytes == 0) {
                control_remove(l);
                return;
        }
        buffer[bytes] = '\0';
        p = buffer;
        e = buffer + bytes;
        argc = 0;
        ap = argvp;
        while (p < e && (size_t)argc < sizeof(argvp)) {
                argc++;
                *ap++ = p;
                p += strlen(p) + 1;
        }
        handle_args(l, argc, argvp);
}

/* ARGSUSED */
static void
control_handle(__unused void *arg)
{
        struct sockaddr_un run;
        socklen_t len;
        struct fd_list *l;
        int f;

        len = sizeof(run);
        if ((f = accept(fd, (struct sockaddr *)&run, &len)) == -1)
                return;
        set_cloexec(f);
        l = malloc(sizeof(*l));
        if (l) {
                l->fd = f;
                l->listener = 0;
                l->next = control_fds;
                control_fds = l;
                eloop_event_add(l->fd, control_handle_data, l);
        }
}

static int
make_sock(void)
{
        if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
                return -1;
        memset(&sun, 0, sizeof(sun));
        sun.sun_family = AF_UNIX;
        strlcpy(sun.sun_path, CONTROLSOCKET, sizeof(sun.sun_path));
        return sizeof(sun.sun_family) + strlen(sun.sun_path) + 1;
}

int
control_start(void)
{
        int len;

        if ((len = make_sock()) == -1)
                return -1;
        unlink(CONTROLSOCKET);
        if (bind(fd, (struct sockaddr *)&sun, len) == -1 ||
            chmod(CONTROLSOCKET,
                S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP) == -1 ||
            set_cloexec(fd) == -1 ||
            set_nonblock(fd) == -1 ||
            listen(fd, sizeof(control_fds)) == -1)
        {
                close(fd);
                return -1;
        }
        eloop_event_add(fd, control_handle, NULL);
        return fd;
}

int
control_stop(void)
{
        int retval = 0;
        struct fd_list *l;

        eloop_event_delete(fd);
        if (shutdown(fd, SHUT_RDWR) == -1)
                retval = 1;
        fd = -1;
        if (unlink(CONTROLSOCKET) == -1)
                retval = -1;

        l = control_fds;
        while (l != NULL) {
                control_fds = l->next;
                eloop_event_delete(l->fd);
                shutdown(l->fd, SHUT_RDWR);
                free(l);
                l = control_fds;
        }

        return retval;
}

int
control_open(void)
{
        int len;

        if ((len = make_sock()) == -1)
                return -1;
#ifdef DEBUG_MEMORY
        atexit(cleanup);
#endif
        return connect(fd, (struct sockaddr *)&sun, len);
}

int
control_send(int argc, char * const *argv)
{
        char *p = buffer;
        int i;
        size_t len;

        if (argc > 255) {
                errno = ENOBUFS;
                return -1;
        }
        for (i = 0; i < argc; i++) {
                len = strlen(argv[i]) + 1;
                if ((p - buffer) + len > sizeof(buffer)) {
                        errno = ENOBUFS;
                        return -1;
                }
                memcpy(p, argv[i], len);
                p += len;
        }
        return write(fd, buffer, p - buffer);
}