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authorDavid Oberhollenzer <david.oberhollenzer@tele2.at>2018-08-19 13:37:42 +0200
committerDavid Oberhollenzer <david.oberhollenzer@tele2.at>2018-08-20 12:31:51 +0200
commit73404a09d4f26522902a11b02f27896fa1a23d37 (patch)
treefd902bedd6222a4c11196bee4c3b6ea1e9bcded8 /syslogd/syslogd.c
parent325f919847cb23044d203501140d9030903cfe12 (diff)
usyslogd: minor header restructuring/file structure cleanup
Signed-off-by: David Oberhollenzer <david.oberhollenzer@tele2.at>
Diffstat (limited to 'syslogd/syslogd.c')
-rw-r--r--syslogd/syslogd.c285
1 files changed, 285 insertions, 0 deletions
diff --git a/syslogd/syslogd.c b/syslogd/syslogd.c
new file mode 100644
index 0000000..03f4b55
--- /dev/null
+++ b/syslogd/syslogd.c
@@ -0,0 +1,285 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * Copyright (C) 2018 - David Oberhollenzer
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <getopt.h>
+#include <errno.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <pwd.h>
+#include <grp.h>
+
+#include "syslogd.h"
+#include "util.h"
+
+
+#define GPL_URL "https://gnu.org/licenses/gpl.html"
+
+
+static const struct option long_opts[] = {
+ { "help", no_argument, NULL, 'h' },
+ { "version", no_argument, NULL, 'V' },
+ { "rotate-replace", no_argument, NULL, 'r' },
+ { "max-size", required_argument, NULL, 'm' },
+ { "user", required_argument, NULL, 'u' },
+ { "group", required_argument, NULL, 'g' },
+ { "chroot", required_argument, NULL, 'c' },
+ { NULL, 0, NULL, 0 },
+};
+
+const char *short_opts = "hVrm:";
+
+const char *version_string =
+"usyslogd (pygos init) " PACKAGE_VERSION "\n"
+"Copyright (C) 2018 David Oberhollenzer\n\n"
+"License GPLv3+: GNU GPL version 3 or later <" GPL_URL ">.\n"
+"This is free software: you are free to change and redistribute it.\n"
+"There is NO WARRANTY, to the extent permitted by law.\n";
+
+const char *usage_string =
+"Usage: usyslogd [OPTIONS..]\n\n"
+"The following options are supported:\n"
+" -h, --help Print this help text and exit\n"
+" -V, --version Print version information and exit\n"
+" -r, --rotate-replace Replace old log files when doing log rotation.\n"
+" -m, --max-size <size> Automatically rotate log files bigger than this.\n"
+" -u, --user <name> Run the syslog daemon as this user. If not set,\n"
+" try to use the user '" DEFAULT_USER "'.\n"
+" -g, --group <name> Run the syslog daemon as this group. If not set,\n"
+" try to use the group '" DEFAULT_GROUP "'.\n"
+" -c, --chroot If set, do a chroot into the log file path.\n";
+
+
+
+static volatile sig_atomic_t syslog_run = 1;
+static volatile sig_atomic_t syslog_rotate = 0;
+static int log_flags = 0;
+static size_t max_size = 0;
+static uid_t uid = 0;
+static gid_t gid = 0;
+static bool dochroot = false;
+
+
+
+static void sighandler(int signo)
+{
+ switch (signo) {
+ case SIGINT:
+ case SIGTERM:
+ syslog_run = 0;
+ break;
+ case SIGHUP:
+ syslog_rotate = 1;
+ break;
+ default:
+ break;
+ }
+}
+
+static void signal_setup(void)
+{
+ struct sigaction act;
+
+ memset(&act, 0, sizeof(act));
+ act.sa_handler = sighandler;
+
+ sigaction(SIGINT, &act, NULL);
+ sigaction(SIGTERM, &act, NULL);
+ sigaction(SIGHUP, &act, NULL);
+}
+
+static int handle_data(int fd)
+{
+ char buffer[2048];
+ syslog_msg_t msg;
+ ssize_t ret;
+
+ memset(buffer, 0, sizeof(buffer));
+
+ ret = read(fd, buffer, sizeof(buffer));
+ if (ret <= 0)
+ return -1;
+
+ if (syslog_msg_parse(&msg, buffer))
+ return -1;
+
+ return logmgr->write(logmgr, &msg);
+}
+
+static void process_options(int argc, char **argv)
+{
+ struct passwd *pw = getpwnam(DEFAULT_USER);
+ struct group *grp = getgrnam(DEFAULT_GROUP);
+ char *end;
+ int i;
+
+ if (pw != NULL)
+ uid = pw->pw_uid;
+
+ if (grp != NULL)
+ gid = grp->gr_gid;
+
+ for (;;) {
+ i = getopt_long(argc, argv, short_opts, long_opts, NULL);
+ if (i == -1)
+ break;
+
+ switch (i) {
+ case 'r':
+ log_flags |= LOG_ROTATE_OVERWRITE;
+ break;
+ case 'm':
+ log_flags |= LOG_ROTATE_SIZE_LIMIT;
+ max_size = strtol(optarg, &end, 10);
+ if (max_size == 0 || *end != '\0') {
+ fputs("Numeric argument > 0 expected for -m\n",
+ stderr);
+ goto fail;
+ }
+ break;
+ case 'u':
+ pw = getpwnam(optarg);
+ if (pw == NULL) {
+ fprintf(stderr, "Cannot get UID for user %s\n",
+ optarg);
+ goto fail;
+ }
+ uid = pw->pw_uid;
+ break;
+ case 'g':
+ grp = getgrnam(optarg);
+ if (grp == NULL) {
+ fprintf(stderr,
+ "Cannot get GID for group %s\n",
+ optarg);
+ goto fail;
+ }
+ gid = grp->gr_gid;
+ break;
+ case 'c':
+ dochroot = true;
+ break;
+ case 'h':
+ fputs(usage_string, stdout);
+ exit(EXIT_SUCCESS);
+ case 'V':
+ fputs(version_string, stdout);
+ exit(EXIT_SUCCESS);
+ default:
+ goto fail;
+ }
+ }
+ return;
+fail:
+ fputs("Try `usyslogd --help' for more information\n", stderr);
+ exit(EXIT_FAILURE);
+}
+
+static int chroot_setup(void)
+{
+ if (mkdir(SYSLOG_PATH, 0750)) {
+ if (errno != EEXIST) {
+ perror("mkdir " SYSLOG_PATH);
+ return -1;
+ }
+ }
+
+ if (uid > 0 && gid > 0 && chown(SYSLOG_PATH, uid, gid) != 0) {
+ perror("chown " SYSLOG_PATH);
+ return -1;
+ }
+
+ if (chmod(SYSLOG_PATH, 0750)) {
+ perror("chmod " SYSLOG_PATH);
+ return -1;
+ }
+
+ if (chdir(SYSLOG_PATH)) {
+ perror("cd " SYSLOG_PATH);
+ return -1;
+ }
+
+ if (dochroot && chroot(SYSLOG_PATH) != 0) {
+ perror("chroot " SYSLOG_PATH);
+ return -1;
+ }
+
+ return 0;
+}
+
+static int user_setup(void)
+{
+ if (gid > 0 && setresgid(gid, gid, gid) != 0) {
+ perror("setgid");
+ return -1;
+ }
+ if (uid > 0 && setresuid(uid, uid, uid) != 0) {
+ perror("setuid");
+ return -1;
+ }
+ return 0;
+}
+
+int main(int argc, char **argv)
+{
+ int sfd, status = EXIT_FAILURE;
+
+ process_options(argc, argv);
+
+ signal_setup();
+
+ sfd = mksock(SYSLOG_SOCKET, SOCK_FLAG_EVERYONE | SOCK_FLAG_DGRAM);
+ if (sfd < 0)
+ return EXIT_FAILURE;
+
+ if (uid > 0 && gid > 0 && chown(SYSLOG_SOCKET, uid, gid) != 0) {
+ perror("chown " SYSLOG_SOCKET);
+ return -1;
+ }
+
+ if (chroot_setup())
+ return EXIT_FAILURE;
+
+ if (user_setup())
+ return EXIT_FAILURE;
+
+ if (logmgr->init(logmgr, log_flags, max_size))
+ goto out;
+
+ while (syslog_run) {
+ if (syslog_rotate) {
+ logmgr->rotate(logmgr);
+ syslog_rotate = 0;
+ }
+
+ handle_data(sfd);
+ }
+
+ status = EXIT_SUCCESS;
+out:
+ logmgr->cleanup(logmgr);
+ if (sfd > 0)
+ close(sfd);
+ unlink(SYSLOG_SOCKET);
+ return status;
+}