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util-linux/misc-utils/uuidd.c

714 lines
18 KiB

/*
* uuidd.c --- UUID-generation daemon
*
* Copyright (C) 2007 Theodore Ts'o
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Public
* License.
* %End-Header%
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <inttypes.h>
#include <errno.h>
#include <err.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <fcntl.h>
#include <signal.h>
#include <string.h>
#include <getopt.h>
#include <sys/signalfd.h>
#include <poll.h>
#include "uuid.h"
#include "uuidd.h"
#include "all-io.h"
#include "c.h"
#include "closestream.h"
#include "strutils.h"
#include "optutils.h"
#include "monotonic.h"
#include "timer.h"
#ifdef HAVE_LIBSYSTEMD
# include <systemd/sd-daemon.h>
#endif
#include "nls.h"
/* length of binary representation of UUID */
#define UUID_LEN (sizeof(uuid_t))
/* server loop control structure */
struct uuidd_cxt_t {
const char *cleanup_pidfile;
const char *cleanup_socket;
uint32_t timeout;
unsigned int debug: 1,
quiet: 1,
no_fork: 1,
no_sock: 1;
};
static void __attribute__((__noreturn__)) usage(void)
{
FILE *out = stdout;
fputs(USAGE_HEADER, out);
fprintf(out, _(" %s [options]\n"), program_invocation_short_name);
fputs(USAGE_SEPARATOR, out);
fputs(_("A daemon for generating UUIDs.\n"), out);
fputs(USAGE_OPTIONS, out);
fputs(_(" -p, --pid <path> path to pid file\n"), out);
fputs(_(" -s, --socket <path> path to socket\n"), out);
fputs(_(" -T, --timeout <sec> specify inactivity timeout\n"), out);
fputs(_(" -k, --kill kill running daemon\n"), out);
fputs(_(" -r, --random test random-based generation\n"), out);
fputs(_(" -t, --time test time-based generation\n"), out);
fputs(_(" -n, --uuids <num> request number of uuids\n"), out);
fputs(_(" -P, --no-pid do not create pid file\n"), out);
fputs(_(" -F, --no-fork do not daemonize using double-fork\n"), out);
fputs(_(" -S, --socket-activation do not create listening socket\n"), out);
fputs(_(" -d, --debug run in debugging mode\n"), out);
fputs(_(" -q, --quiet turn on quiet mode\n"), out);
fputs(USAGE_SEPARATOR, out);
printf(USAGE_HELP_OPTIONS(25));
printf(USAGE_MAN_TAIL("uuidd(8)"));
exit(EXIT_SUCCESS);
}
static void create_daemon(void)
{
uid_t euid;
if (daemon(0, 0))
err(EXIT_FAILURE, "daemon");
euid = geteuid();
if (setreuid(euid, euid) < 0)
err(EXIT_FAILURE, "setreuid");
}
static int call_daemon(const char *socket_path, int op, char *buf,
size_t buflen, int *num, const char **err_context)
{
char op_buf[8];
int op_len;
int s;
ssize_t ret;
int32_t reply_len = 0;
struct sockaddr_un srv_addr;
if (((op == UUIDD_OP_BULK_TIME_UUID) ||
(op == UUIDD_OP_BULK_RANDOM_UUID)) && !num) {
if (err_context)
*err_context = _("bad arguments");
errno = EINVAL;
return -1;
}
if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
if (err_context)
*err_context = _("socket");
return -1;
}
srv_addr.sun_family = AF_UNIX;
assert(strlen(socket_path) < sizeof(srv_addr.sun_path));
xstrncpy(srv_addr.sun_path, socket_path, sizeof(srv_addr.sun_path));
if (connect(s, (const struct sockaddr *) &srv_addr,
sizeof(struct sockaddr_un)) < 0) {
if (err_context)
*err_context = _("connect");
close(s);
return -1;
}
if (op == UUIDD_OP_BULK_RANDOM_UUID) {
if ((*num) * UUID_LEN > buflen - 4)
*num = (buflen - 4) / UUID_LEN;
}
op_buf[0] = op;
op_len = 1;
if ((op == UUIDD_OP_BULK_TIME_UUID) ||
(op == UUIDD_OP_BULK_RANDOM_UUID)) {
memcpy(op_buf + 1, num, sizeof(int));
op_len += sizeof(int);
}
ret = write_all(s, op_buf, op_len);
if (ret < 0) {
if (err_context)
*err_context = _("write");
close(s);
return -1;
}
ret = read_all(s, (char *) &reply_len, sizeof(reply_len));
if (ret < 0) {
if (err_context)
*err_context = _("read count");
close(s);
return -1;
}
if (reply_len < 0 || (size_t) reply_len > buflen) {
if (err_context)
*err_context = _("bad response length");
close(s);
return -1;
}
ret = read_all(s, (char *) buf, reply_len);
if ((ret > 0) && (op == UUIDD_OP_BULK_TIME_UUID)) {
if (reply_len >= (int) (UUID_LEN + sizeof(int)))
memcpy(buf + UUID_LEN, num, sizeof(int));
else
*num = -1;
}
if ((ret > 0) && (op == UUIDD_OP_BULK_RANDOM_UUID)) {
if (reply_len >= (int) sizeof(int))
memcpy(buf, num, sizeof(int));
else
*num = -1;
}
close(s);
return ret;
}
/*
* Exclusively create and open a pid file with path @pidfile_path
*
* Return file descriptor of the created pid_file.
*/
static int create_pidfile(struct uuidd_cxt_t *cxt, const char *pidfile_path)
{
int fd_pidfile;
struct flock fl;
fd_pidfile = open(pidfile_path, O_CREAT | O_RDWR, 0664);
if (fd_pidfile < 0) {
if (!cxt->quiet)
warn(_("cannot open %s"), pidfile_path);
exit(EXIT_FAILURE);
}
cxt->cleanup_pidfile = pidfile_path;
fl.l_type = F_WRLCK;
fl.l_whence = SEEK_SET;
fl.l_start = 0;
fl.l_len = 0;
fl.l_pid = 0;
while (fcntl(fd_pidfile, F_SETLKW, &fl) < 0) {
if ((errno == EAGAIN) || (errno == EINTR))
continue;
if (!cxt->quiet)
warn(_("cannot lock %s"), pidfile_path);
exit(EXIT_FAILURE);
}
return fd_pidfile;
}
/*
* Create AF_UNIX, SOCK_STREAM socket and bind to @socket_path
*
* If @will_fork is true, then make sure the descriptor
* of the socket is >2, so that it won't be later closed
* during create_daemon().
*
* Return file descriptor corresponding to created socket.
*/
static int create_socket(struct uuidd_cxt_t *uuidd_cxt,
const char *socket_path, int will_fork)
{
struct sockaddr_un my_addr;
mode_t save_umask;
int s;
if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
if (!uuidd_cxt->quiet)
warn(_("couldn't create unix stream socket"));
exit(EXIT_FAILURE);
}
/*
* Make sure the socket isn't using fd numbers 0-2 to avoid it
* getting closed by create_daemon()
*/
while (will_fork && s <= 2) {
s = dup(s);
if (s < 0)
err(EXIT_FAILURE, "dup");
}
/*
* Create the address we will be binding to.
*/
my_addr.sun_family = AF_UNIX;
assert(strlen(socket_path) < sizeof(my_addr.sun_path));
xstrncpy(my_addr.sun_path, socket_path, sizeof(my_addr.sun_path));
unlink(socket_path);
save_umask = umask(0);
if (bind(s, (const struct sockaddr *) &my_addr,
sizeof(struct sockaddr_un)) < 0) {
if (!uuidd_cxt->quiet)
warn(_("couldn't bind unix socket %s"), socket_path);
exit(EXIT_FAILURE);
}
umask(save_umask);
uuidd_cxt->cleanup_socket = socket_path;
return s;
}
static void __attribute__((__noreturn__)) all_done(const struct uuidd_cxt_t *uuidd_cxt, int ret)
{
if (uuidd_cxt->cleanup_pidfile)
unlink(uuidd_cxt->cleanup_pidfile);
if (uuidd_cxt->cleanup_socket)
unlink(uuidd_cxt->cleanup_socket);
exit(ret);
}
static void handle_signal(const struct uuidd_cxt_t *uuidd_cxt, int fd)
{
struct signalfd_siginfo info;
ssize_t bytes;
bytes = read(fd, &info, sizeof(info));
if (bytes != sizeof(info)) {
if (errno == EAGAIN)
return;
warn(_("receiving signal failed"));
info.ssi_signo = 0;
}
if (info.ssi_signo == SIGPIPE)
return; /* ignored */
all_done(uuidd_cxt, EXIT_SUCCESS);
}
static void timeout_handler(int sig __attribute__((__unused__)),
siginfo_t * info,
void *context __attribute__((__unused__)))
{
#ifdef HAVE_TIMER_CREATE
if (info->si_code == SI_TIMER)
#endif
errx(EXIT_FAILURE, _("timed out"));
}
static void server_loop(const char *socket_path, const char *pidfile_path,
struct uuidd_cxt_t *uuidd_cxt)
{
struct sockaddr_un from_addr;
socklen_t fromlen;
int32_t reply_len = 0;
uuid_t uu;
char reply_buf[1024], *cp;
char op, str[UUID_STR_LEN];
int i, ns, len, num;
int s = 0;
int fd_pidfile = -1;
int ret;
struct pollfd pfd[2];
sigset_t sigmask;
int sigfd;
enum {
POLLFD_SIGNAL = 0,
POLLFD_SOCKET
};
#ifdef HAVE_LIBSYSTEMD
if (!uuidd_cxt->no_sock) /* no_sock implies no_fork and no_pid */
#endif
{
struct ul_timer timer;
struct itimerval timeout;
memset(&timeout, 0, sizeof timeout);
timeout.it_value.tv_sec = 30;
if (setup_timer(&timer, &timeout, &timeout_handler))
err(EXIT_FAILURE, _("cannot set up timer"));
if (pidfile_path)
fd_pidfile = create_pidfile(uuidd_cxt, pidfile_path);
ret = call_daemon(socket_path, UUIDD_OP_GETPID, reply_buf,
sizeof(reply_buf), 0, NULL);
cancel_timer(&timer);
if (ret > 0) {
if (!uuidd_cxt->quiet)
warnx(_("uuidd daemon is already running at pid %s"),
reply_buf);
exit(EXIT_FAILURE);
}
s = create_socket(uuidd_cxt, socket_path,
(!uuidd_cxt->debug || !uuidd_cxt->no_fork));
if (listen(s, SOMAXCONN) < 0) {
if (!uuidd_cxt->quiet)
warn(_("couldn't listen on unix socket %s"), socket_path);
exit(EXIT_FAILURE);
}
if (!uuidd_cxt->debug && !uuidd_cxt->no_fork)
create_daemon();
if (pidfile_path) {
sprintf(reply_buf, "%8d\n", getpid());
if (ftruncate(fd_pidfile, 0))
err(EXIT_FAILURE, _("could not truncate file: %s"), pidfile_path);
write_all(fd_pidfile, reply_buf, strlen(reply_buf));
if (fd_pidfile > 1 && close_fd(fd_pidfile) != 0)
err(EXIT_FAILURE, _("write failed: %s"), pidfile_path);
}
}
#ifdef HAVE_LIBSYSTEMD
if (uuidd_cxt->no_sock) {
const int r = sd_listen_fds(0);
if (r < 0) {
errno = r * -1;
err(EXIT_FAILURE, _("sd_listen_fds() failed"));
} else if (r == 0)
errx(EXIT_FAILURE,
_("no file descriptors received, check systemctl status uuidd.socket"));
else if (1 < r)
errx(EXIT_FAILURE,
_("too many file descriptors received, check uuidd.socket"));
s = SD_LISTEN_FDS_START + 0;
}
#endif
sigemptyset(&sigmask);
sigaddset(&sigmask, SIGHUP);
sigaddset(&sigmask, SIGINT);
sigaddset(&sigmask, SIGTERM);
sigaddset(&sigmask, SIGALRM);
sigaddset(&sigmask, SIGPIPE);
/* Block signals so that they aren't handled according to their
* default dispositions */
sigprocmask(SIG_BLOCK, &sigmask, NULL);
if ((sigfd = signalfd(-1, &sigmask, 0)) < 0)
err(EXIT_FAILURE, _("cannot set signal handler"));
pfd[POLLFD_SIGNAL].fd = sigfd;
pfd[POLLFD_SOCKET].fd = s;
pfd[POLLFD_SIGNAL].events = pfd[POLLFD_SOCKET].events = POLLIN | POLLERR | POLLHUP;
while (1) {
ret = poll(pfd, ARRAY_SIZE(pfd),
uuidd_cxt->timeout ?
(int) uuidd_cxt->timeout * 1000 : -1);
if (ret < 0) {
if (errno == EAGAIN)
continue;
warn(_("poll failed"));
all_done(uuidd_cxt, EXIT_FAILURE);
}
if (ret == 0) { /* true when poll() times out */
if (uuidd_cxt->debug)
fprintf(stderr, _("timeout [%d sec]\n"), uuidd_cxt->timeout),
all_done(uuidd_cxt, EXIT_SUCCESS);
}
if (pfd[POLLFD_SIGNAL].revents != 0)
handle_signal(uuidd_cxt, sigfd);
if (pfd[POLLFD_SOCKET].revents == 0)
continue;
fromlen = sizeof(from_addr);
ns = accept(s, (struct sockaddr *) &from_addr, &fromlen);
if (ns < 0) {
if ((errno == EAGAIN) || (errno == EINTR))
continue;
else
err(EXIT_FAILURE, "accept");
}
len = read(ns, &op, 1);
if (len != 1) {
if (len < 0)
warn(_("read failed"));
else
warnx(_("error reading from client, len = %d"),
len);
goto shutdown_socket;
}
if ((op == UUIDD_OP_BULK_TIME_UUID) ||
(op == UUIDD_OP_BULK_RANDOM_UUID)) {
if (read_all(ns, (char *) &num, sizeof(num)) != 4)
goto shutdown_socket;
if (uuidd_cxt->debug)
fprintf(stderr, _("operation %d, incoming num = %d\n"),
op, num);
} else if (uuidd_cxt->debug)
fprintf(stderr, _("operation %d\n"), op);
switch (op) {
case UUIDD_OP_GETPID:
sprintf(reply_buf, "%d", getpid());
reply_len = strlen(reply_buf) + 1;
break;
case UUIDD_OP_GET_MAXOP:
sprintf(reply_buf, "%d", UUIDD_MAX_OP);
reply_len = strlen(reply_buf) + 1;
break;
case UUIDD_OP_TIME_UUID:
num = 1;
__uuid_generate_time(uu, &num);
if (uuidd_cxt->debug) {
uuid_unparse(uu, str);
fprintf(stderr, _("Generated time UUID: %s\n"), str);
}
memcpy(reply_buf, uu, sizeof(uu));
reply_len = sizeof(uu);
break;
case UUIDD_OP_RANDOM_UUID:
num = 1;
__uuid_generate_random(uu, &num);
if (uuidd_cxt->debug) {
uuid_unparse(uu, str);
fprintf(stderr, _("Generated random UUID: %s\n"), str);
}
memcpy(reply_buf, uu, sizeof(uu));
reply_len = sizeof(uu);
break;
case UUIDD_OP_BULK_TIME_UUID:
__uuid_generate_time(uu, &num);
if (uuidd_cxt->debug) {
uuid_unparse(uu, str);
fprintf(stderr, P_("Generated time UUID %s "
"and %d following\n",
"Generated time UUID %s "
"and %d following\n", num - 1),
str, num - 1);
}
memcpy(reply_buf, uu, sizeof(uu));
reply_len = sizeof(uu);
memcpy(reply_buf + reply_len, &num, sizeof(num));
reply_len += sizeof(num);
break;
case UUIDD_OP_BULK_RANDOM_UUID:
if (num < 0)
num = 1;
if (num > 1000)
num = 1000;
if (num * UUID_LEN > (int) (sizeof(reply_buf) - sizeof(num)))
num = (sizeof(reply_buf) - sizeof(num)) / UUID_LEN;
__uuid_generate_random((unsigned char *) reply_buf +
sizeof(num), &num);
if (uuidd_cxt->debug) {
fprintf(stderr, P_("Generated %d UUID:\n",
"Generated %d UUIDs:\n", num), num);
for (i = 0, cp = reply_buf + sizeof(num);
i < num;
i++, cp += UUID_LEN) {
uuid_unparse((unsigned char *)cp, str);
fprintf(stderr, "\t%s\n", str);
}
}
reply_len = (num * UUID_LEN) + sizeof(num);
memcpy(reply_buf, &num, sizeof(num));
break;
default:
if (uuidd_cxt->debug)
fprintf(stderr, _("Invalid operation %d\n"), op);
goto shutdown_socket;
}
write_all(ns, (char *) &reply_len, sizeof(reply_len));
write_all(ns, reply_buf, reply_len);
shutdown_socket:
close(ns);
}
}
static void __attribute__ ((__noreturn__)) unexpected_size(int size)
{
errx(EXIT_FAILURE, _("Unexpected reply length from server %d"), size);
}
int main(int argc, char **argv)
{
const char *socket_path = UUIDD_SOCKET_PATH;
const char *pidfile_path = NULL;
const char *err_context = NULL;
char buf[1024], *cp;
char str[UUID_STR_LEN];
uuid_t uu;
int i, c, ret;
int do_type = 0, do_kill = 0, num = 0;
int no_pid = 0;
int s_flag = 0;
struct uuidd_cxt_t uuidd_cxt = { .timeout = 0 };
static const struct option longopts[] = {
{"pid", required_argument, NULL, 'p'},
{"socket", required_argument, NULL, 's'},
{"timeout", required_argument, NULL, 'T'},
{"kill", no_argument, NULL, 'k'},
{"random", no_argument, NULL, 'r'},
{"time", no_argument, NULL, 't'},
{"uuids", required_argument, NULL, 'n'},
{"no-pid", no_argument, NULL, 'P'},
{"no-fork", no_argument, NULL, 'F'},
{"socket-activation", no_argument, NULL, 'S'},
{"debug", no_argument, NULL, 'd'},
{"quiet", no_argument, NULL, 'q'},
{"version", no_argument, NULL, 'V'},
{"help", no_argument, NULL, 'h'},
{NULL, 0, NULL, 0}
};
static const ul_excl_t excl[] = {
{ 'P', 'p' },
{ 'd', 'q' },
{ 'r', 't' },
{ 0 }
};
int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
atexit(close_stdout);
while ((c =
getopt_long(argc, argv, "p:s:T:krtn:PFSdqVh", longopts,
NULL)) != -1) {
err_exclusive_options(c, longopts, excl, excl_st);
switch (c) {
case 'd':
uuidd_cxt.debug = 1;
break;
case 'k':
do_kill++;
break;
case 'n':
num = strtou32_or_err(optarg,
_("failed to parse --uuids"));
break;
case 'p':
pidfile_path = optarg;
break;
case 'P':
no_pid = 1;
break;
case 'F':
uuidd_cxt.no_fork = 1;
break;
case 'S':
#ifdef HAVE_LIBSYSTEMD
uuidd_cxt.no_sock = 1;
uuidd_cxt.no_fork = 1;
no_pid = 1;
#else
errx(EXIT_FAILURE, _("uuidd has been built without "
"support for socket activation"));
#endif
break;
case 'q':
uuidd_cxt.quiet = 1;
break;
case 'r':
do_type = UUIDD_OP_RANDOM_UUID;
break;
case 's':
socket_path = optarg;
s_flag = 1;
break;
case 't':
do_type = UUIDD_OP_TIME_UUID;
break;
case 'T':
uuidd_cxt.timeout = strtou32_or_err(optarg,
_("failed to parse --timeout"));
break;
case 'V':
printf(UTIL_LINUX_VERSION);
return EXIT_SUCCESS;
case 'h':
usage();
default:
errtryhelp(EXIT_FAILURE);
}
}
if (strlen(socket_path) >= sizeof(((struct sockaddr_un *)0)->sun_path))
errx(EXIT_FAILURE, _("socket name too long: %s"), socket_path);
if (!no_pid && !pidfile_path)
pidfile_path = UUIDD_PIDFILE_PATH;
/* custom socket path and socket-activation make no sense */
if (s_flag && uuidd_cxt.no_sock && !uuidd_cxt.quiet)
warnx(_("Both --socket-activation and --socket specified. "
"Ignoring --socket."));
if (num && do_type) {
ret = call_daemon(socket_path, do_type + 2, buf,
sizeof(buf), &num, &err_context);
if (ret < 0)
err(EXIT_FAILURE, _("error calling uuidd daemon (%s)"),
err_context ? : _("unexpected error"));
if (do_type == UUIDD_OP_TIME_UUID) {
if (ret != sizeof(uu) + sizeof(num))
unexpected_size(ret);
uuid_unparse((unsigned char *) buf, str);
printf(P_("%s and %d subsequent UUID\n",
"%s and %d subsequent UUIDs\n", num - 1),
str, num - 1);
} else {
printf(_("List of UUIDs:\n"));
cp = buf + 4;
if (ret != (int) (sizeof(num) + num * sizeof(uu)))
unexpected_size(ret);
for (i = 0; i < num; i++, cp += UUID_LEN) {
uuid_unparse((unsigned char *) cp, str);
printf("\t%s\n", str);
}
}
return EXIT_SUCCESS;
}
if (do_type) {
ret = call_daemon(socket_path, do_type, (char *) &uu,
sizeof(uu), 0, &err_context);
if (ret < 0)
err(EXIT_FAILURE, _("error calling uuidd daemon (%s)"),
err_context ? : _("unexpected error"));
if (ret != sizeof(uu))
unexpected_size(ret);
uuid_unparse(uu, str);
printf("%s\n", str);
return EXIT_SUCCESS;
}
if (do_kill) {
ret = call_daemon(socket_path, UUIDD_OP_GETPID, buf, sizeof(buf), 0, NULL);
if ((ret > 0) && ((do_kill = atoi((char *) buf)) > 0)) {
ret = kill(do_kill, SIGTERM);
if (ret < 0) {
if (!uuidd_cxt.quiet)
warn(_("couldn't kill uuidd running "
"at pid %d"), do_kill);
return EXIT_FAILURE;
}
if (!uuidd_cxt.quiet)
printf(_("Killed uuidd running at pid %d.\n"),
do_kill);
}
return EXIT_SUCCESS;
}
server_loop(socket_path, pidfile_path, &uuidd_cxt);
return EXIT_SUCCESS;
}