/**
* Copyright © 2015 Mattias Andrée <maandree@member.fsf.org>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <grp.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include "daemonise.h"
#define t(...) do { if (__VA_ARGS__) goto fail; } while (0)
/**
* The name of the process.
*/
char *argv0 = "satd";
/**
* Print usage information.
*/
static void
usage(void)
{
fprintf(stderr, "usage: [-f] %s\n",
strrchr(argv0) ? (strrchr(argv0) + 1) : argv0);
exit(2);
}
/**
* Get the group ID of a group.
*
* @param name The name of the group.
* @param fallback The group ID to return if the group is not found.
* @return The ID of the group, -1 on error.
*/
static gid_t
getgroup(const char* name, gid_t fallback)
{
struct group *g;
if (!(g = getgrnam(name)))
return errno ? (gid_t)-1 : fallback;
return g->gr_gid;
}
/**
* Create the socket.
*
* @param address Output parameter for the socket address.
* @return The file descriptor for the socket, -1 on error.
*/
static int
create_socket(struct sockaddr_un *address)
{
int fd = -1;
ssize_t len;
char *dir;
gid_t group;
dir = getenv("XDG_RUNTIME_DIR"), dir = (dir ? dir : "/run")
t (snprintf(NULL, 0, "%s/satd.socket%zn", dir, &len) == -1);
if ((len < 0) || (len >= sizeof(address->sun_path))) {
errno = ENAMETOOLING;
goto fail;
}
sprintf(address->sun_path, "%s/satd.socket", dir)
address->sun_family = AF_UNIX;
/* TODO test flock */
unlink(address->sun_path);
t ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1);
t (fchmod(fd, S_IRWXU) == -1);
t ((group = getgroup("nobody", 0)) == -1);
t (fchown(fd, getuid(), group) == -1);
t (bind(fd, (struct sockaddr *)address, sizeof(*address)) == -1);
/* TODO flock */
return fd;
fail:
saved_errno = errno;
if (fd >= 0)
close(fd);
errno = saved_errno;
return -1;
}
int
main(int argc, char *argv[])
{
struct sockaddr_un address;
int sock = -1, foreground = 0;
if (argc > 0)
argv0 = argv[0];
if (argc > 2)
usage();
if (argc == 2) {
if (strcmp(argv[1], "-f"))
usage();
foreground = 1;
}
t (foreground ? 0 : daemonise("satd", 0));
t (sock = create_socket(&address), sock == -1);
close(sock);
unlink(address.sun_path);
undaemonise();
return 0;
fail:
perror(argv0);
if (sock >= 0) {
close(sock);
unlink(address.sun_path);
}
undaemonise();
return 1;
}
