Add logit v1.0 to Finit distribution

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

src/Makefile.am

@@ -7,7 +7,12 @@ else
 AM_LDFLAGS         = -export-dynamic
 endif
 
+bin_PROGRAMS       = logit
 sbin_PROGRAMS      = finit initctl reboot
+
+logit_SOURCES      = logit.c
+logit_CFLAGS       = -W -Wall -Wextra -Wno-unused-parameter -std=gnu99
+
 finit_SOURCES      = api.c					\
 		     cond.c	cond-w.c	cond.h		\
 		     telinit.c					\

src/logit.c

@@ -0,0 +1,281 @@
+/*
+ * Copyright (c) 2018  Joachim Nilsson <troglobit@gmail.com>
+ *
+ * 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 <config.h>
+#include <errno.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#define SYSLOG_NAMES
+#include <syslog.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+static const char version_info[] = PACKAGE_NAME " v" PACKAGE_VERSION;
+
+
+static int create(char *path, mode_t mode, uid_t uid, gid_t gid)
+{
+	return mknod(path, S_IFREG | mode, 0) || chown(path, uid, gid);
+}
+
+/*
+ * This function triggers a log rotates of @file when size >= @sz bytes
+ * At most @num old versions are kept and by default it starts gzipping
+ * .2 and older log files.  If gzip is not available in $PATH then @num
+ * files are kept uncompressed.
+ */
+static int logrotate(char *file, int num, off_t sz)
+{
+	int cnt;
+	struct stat st;
+
+	if (stat(file, &st))
+		return 1;
+
+	if (sz > 0 && S_ISREG(st.st_mode) && st.st_size > sz) {
+		if (num > 0) {
+			size_t len = strlen(file) + 10 + 1;
+			char   ofile[len];
+			char   nfile[len];
+
+			/* First age zipped log files */
+			for (cnt = num; cnt > 2; cnt--) {
+				snprintf(ofile, len, "%s.%d.gz", file, cnt - 1);
+				snprintf(nfile, len, "%s.%d.gz", file, cnt);
+
+				/* May fail because ofile doesn't exist yet, ignore. */
+				rename(ofile, nfile);
+			}
+
+			for (cnt = num; cnt > 0; cnt--) {
+				snprintf(ofile, len, "%s.%d", file, cnt - 1);
+				snprintf(nfile, len, "%s.%d", file, cnt);
+
+				/* May fail because ofile doesn't exist yet, ignore. */
+				(void)rename(ofile, nfile);
+
+				if (cnt == 2 && !access(nfile, F_OK)) {
+					size_t len = 5 + strlen(nfile) + 1;
+					char cmd[len];
+
+					snprintf(cmd, len, "gzip %s", nfile);
+					system(cmd);
+
+					remove(nfile);
+				}
+			}
+
+			rename(file, nfile);
+			create(file, st.st_mode, st.st_uid, st.st_gid);
+		} else {
+			if (truncate(file, 0))
+				syslog(LOG_ERR | LOG_PERROR, "Failed truncating %s during logrotate: %s", file, strerror(errno));
+		}
+	}
+
+	return 0;
+}
+
+static int checksz(FILE *fp, off_t sz)
+{
+	struct stat st;
+
+	if (sz <= 0)
+		return 0;
+
+	if (!fstat(fileno(fp), &st) && st.st_size > sz) {
+		fclose(fp);
+		return 1;
+	}
+
+	return 0;
+}
+
+static int flogit(char *logfile, int num, off_t sz, char *buf, size_t len)
+{
+	FILE *fp;
+
+reopen:
+	fp = fopen(logfile, "a");
+	if (!fp) {
+		syslog(LOG_ERR | LOG_PERROR, "Failed opening %s: %s", logfile, strerror(errno));
+		return 1;
+	}
+
+	if (buf[0]) {
+		fprintf(fp, "%s\n", buf);
+		if (checksz(fp, sz))
+			return logrotate(logfile, num, sz);
+	} else {
+		while ((fgets(buf, len, stdin))) {
+			fputs(buf, fp);
+
+			if (checksz(fp, sz)) {
+				logrotate(logfile, num, sz);
+				buf[0] = 0;
+				goto reopen;
+			}
+		}
+	}
+
+	return fclose(fp);
+}
+
+static int logit(int level, char *buf, size_t len)
+{
+	if (buf[0]) {
+		syslog(level, "%s", buf);
+		return 0;
+	}
+
+	while ((fgets(buf, len, stdin)))
+		syslog(level, "%s", buf);
+
+	return 0;
+}
+
+static int parse_prio(char *arg, int *f, int *l)
+{
+	char *ptr;
+
+	ptr = strchr(arg, '.');
+	if (ptr) {
+		*ptr++ = 0;
+
+		for (int i = 0; facilitynames[i].c_name; i++) {
+			if (!strcmp(facilitynames[i].c_name, arg)) {
+				*f = facilitynames[i].c_val;
+				break;
+			}
+		}
+
+		arg = ptr;
+	}
+
+	for (int i = 0; prioritynames[i].c_name; i++) {
+		if (!strcmp(prioritynames[i].c_name, arg)) {
+			*l = prioritynames[i].c_val;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static int usage(int code)
+{
+	fprintf(stderr, "Usage: %s [OPTIONS] [MESSAGE]\n"
+		"\n"
+		"Write MESSAGE (or stdin) to syslog, or file (with logrotate)\n"
+		"\n"
+		"  -h       This help text\n"
+		"  -p PRIO  Priority (numeric or facility.level pair)\n"
+		"  -t TAG   Log using the specified tag (defaults to user name)\n"
+		"  -s       Log to stderr as well as the system log\n"
+		"\n"
+		"  -f FILE  File to write log messages to, instead of syslog\n"
+		"  -n SIZE  Number of bytes before rotating, default: 200 kB\n"
+		"  -r NUM   Number of rotated files to keep, default: 5\n"
+		"  -v        Show program version\n"
+		"\n"
+		"Bug report address: %s\n", PACKAGE, PACKAGE_BUGREPORT);
+
+	return code;
+}
+
+int main(int argc, char *argv[])
+{
+	int c, rc, num = 5;
+	int facility = LOG_USER;
+	int level = LOG_INFO;
+	int log_opts = LOG_NOWAIT;
+	off_t size = 200 * 1024;
+	char *ident = NULL, *logfile = NULL;
+	char buf[512] = "";
+
+	while ((c = getopt(argc, argv, "f:hn:p:r:st:v")) != EOF) {
+		switch (c) {
+		case 'f':
+			logfile = optarg;
+			break;
+
+		case 'h':
+			return usage(0);
+
+		case 'n':
+			size = atoi(optarg);
+			break;
+
+		case 'p':
+			if (parse_prio(optarg, &facility, &level))
+				return usage(1);
+			break;
+
+		case 'r':
+			num = atoi(optarg);
+			break;
+
+		case 's':
+			log_opts |= LOG_PERROR;
+			break;
+
+		case 't':
+			ident = optarg;
+			break;
+
+		case 'v':	/* version */
+			fprintf(stderr, "%s\n", version_info);
+			return 0;
+
+		default:
+			return usage(1);
+		}
+	}
+
+	if (!ident)
+		ident = getenv("LOGNAME") ?: getenv("USER");
+
+	if (optind < argc) {
+		size_t pos = 0, len = sizeof(buf);
+
+		while (optind < argc) {
+			size_t bytes;
+
+			bytes = snprintf(&buf[pos], len, "%s ", argv[optind++]);
+			pos += bytes;
+			len -= bytes;
+		}
+	}
+
+	openlog(ident, log_opts, facility);
+
+	if (logfile)
+		rc = flogit(logfile, num, size, buf, sizeof(buf));
+	else
+		rc = logit(level, buf, sizeof(buf));
+
+	closelog();
+
+	return rc;
+}