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#include <errno.h>
#include <grp.h>
#include <poll.h>
#include <pwd.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include "client.h"
#include "log.h"
#include "poller.h"
#include "server.h"
#define LISTEN_BACKLOG 16
static int open_socket(const char *path, int uid, int gid) {
union {
struct sockaddr_un unix;
struct sockaddr generic;
} addr = {{0}};
int fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0);
if (fd == -1) {
log_errorf("Could not create socket: %s", strerror(errno));
return -1;
}
addr.unix.sun_family = AF_UNIX;
strncpy(addr.unix.sun_path, path, sizeof addr.unix.sun_path - 1);
socklen_t size = offsetof(struct sockaddr_un, sun_path) + strlen(addr.unix.sun_path);
if (bind(fd, &addr.generic, size) == -1) {
log_errorf("Could not bind socket: %s", strerror(errno));
goto error;
}
if (listen(fd, LISTEN_BACKLOG) == -1) {
log_errorf("Could not listen on socket: %s", strerror(errno));
goto error;
}
if (uid != -1 || gid != -1) {
if (chmod(path, 0770) == -1) {
log_errorf("Could not chmod socket: %s", strerror(errno));
goto error;
}
if (chown(path, uid, gid) == -1) {
log_errorf("Could not chown socket to uid %d, gid %d: %s", uid, gid,
strerror(errno));
goto error;
}
}
return fd;
error:
close(fd);
return -1;
}
int main(int argc, char *argv[]) {
const char *usage = "Usage: seatd [options]\n"
"\n"
" -h Show this help message\n"
" -n <fd> FD to notify readiness on\n"
" -u <user> User to own the seatd socket\n"
" -g <group> Group to own the seatd socket\n"
" -l <loglevel> Log-level, one of debug, info, error or silent\n"
" -v Show the version number\n"
"\n";
int c;
int uid = -1, gid = -1;
int readiness = -1;
bool unlink_existing_socket = true;
bool chown_socket = true;
enum libseat_log_level level = LIBSEAT_LOG_LEVEL_INFO;
while ((c = getopt(argc, argv, "vhn:g:u:l:z")) != -1) {
switch (c) {
case 'n':
readiness = atoi(optarg);
if (readiness < 0) {
fprintf(stderr, "Invalid readiness fd: %s\n", optarg);
return 1;
}
break;
case 'u': {
if (!chown_socket) {
fprintf(stderr, "-u/-g and -z are mutually exclusive\n");
return 1;
}
struct passwd *pw = getpwnam(optarg);
if (pw == NULL) {
fprintf(stderr, "Could not find user by name '%s'.\n", optarg);
return 1;
} else {
uid = pw->pw_uid;
}
break;
}
case 'g': {
if (!chown_socket) {
fprintf(stderr, "-u/-g and -z are mutually exclusive\n");
return 1;
}
struct group *gr = getgrnam(optarg);
if (gr == NULL) {
fprintf(stderr, "Could not find group by name '%s'.\n", optarg);
return 1;
} else {
gid = gr->gr_gid;
}
break;
}
case 'l':
if (strcmp(optarg, "debug") == 0) {
level = LIBSEAT_LOG_LEVEL_DEBUG;
} else if (strcmp(optarg, "info") == 0) {
level = LIBSEAT_LOG_LEVEL_INFO;
} else if (strcmp(optarg, "error") == 0) {
level = LIBSEAT_LOG_LEVEL_ERROR;
} else if (strcmp(optarg, "silent") == 0) {
level = LIBSEAT_LOG_LEVEL_SILENT;
} else {
fprintf(stderr, "Invalid loglevel: %s\n", optarg);
return 1;
}
break;
case 'z':
// Running under seatd-launch. We do not unlink files
// to protect against multiple instances, and
// seatd-launch takes care of ownership.
if (uid != -1 || gid != -1) {
fprintf(stderr, "-u/-g and -z are mutually exclusive\n");
return 1;
}
unlink_existing_socket = false;
chown_socket = false;
break;
case 'v':
printf("seatd version %s\n", SEATD_VERSION);
return 0;
case 'h':
printf("%s", usage);
return 0;
case '?':
fprintf(stderr, "Try '%s -h' for more information.\n", argv[0]);
return 1;
default:
abort();
}
}
log_init();
libseat_set_log_level(level);
struct stat st;
if (lstat(SEATD_DEFAULTPATH, &st) == 0) {
if (!S_ISSOCK(st.st_mode)) {
log_errorf("Non-socket file found at socket path %s, refusing to start",
SEATD_DEFAULTPATH);
return 1;
} else if (!unlink_existing_socket) {
log_errorf("Socket file found at socket path %s, refusing to start",
SEATD_DEFAULTPATH);
return 1;
} else {
// We only do this if the socket path is not user specified
log_infof("Removing leftover socket at %s", SEATD_DEFAULTPATH);
if (unlink(SEATD_DEFAULTPATH) == -1) {
log_errorf("Could not remove leftover socket: %s", strerror(errno));
return 1;
}
}
}
struct server server = {0};
if (server_init(&server) == -1) {
log_errorf("server_init failed: %s", strerror(errno));
return 1;
}
int ret = 1;
int socket_fd = open_socket(SEATD_DEFAULTPATH, uid, gid);
if (socket_fd == -1) {
log_error("Could not create server socket");
goto error_server;
}
if (poller_add_fd(&server.poller, socket_fd, EVENT_READABLE, server_handle_connection,
&server) == NULL) {
log_errorf("Could not add socket to poller: %s", strerror(errno));
close(socket_fd);
goto error_socket;
}
log_info("seatd started");
if (readiness != -1) {
if (write(readiness, "\n", 1) == -1) {
log_errorf("Could not write readiness signal: %s\n", strerror(errno));
}
close(readiness);
}
while (server.running) {
if (poller_poll(&server.poller) == -1) {
log_errorf("Poller failed: %s", strerror(errno));
goto error_socket;
}
}
ret = 0;
error_socket:
if (unlink(SEATD_DEFAULTPATH) == -1) {
log_errorf("Could not remove socket: %s", strerror(errno));
}
error_server:
server_finish(&server);
log_info("seatd stopped");
return ret;
}
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