Refactor, reduce code duplication

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

configure.ac

@@ -153,6 +153,8 @@ AS_IF([test "x$enable_logit" != "xno"], [
 AS_IF([test "x$enable_logrotate" != "xno"], [
 	AC_DEFINE(LOGROTATE_ENABLED, 1, [Enable built-in rotation of /var/log/wtmp et al.])])
 
+AM_CONDITIONAL(LOGROTATE, [test "x$enable_logrotate" = "xyes"])
+
 ### With features ##############################################################################
 AS_IF([test "x$with_config" != "xno"], [
 	AS_IF([test "x$conf" = "xyes"], [

src/Makefile.am

@@ -19,7 +19,7 @@ endif
 
 if LOGIT
 pkglibexec_PROGRAMS = logit
-logit_SOURCES       = logit.c
+logit_SOURCES       = logit.c logrotate.c
 logit_CFLAGS        = -W -Wall -Wextra -Wno-unused-parameter -std=gnu99
 logit_CFLAGS       += $(lite_CFLAGS)
 logit_LDADD         = $(lite_LIBS)
@@ -44,6 +44,10 @@ finit_SOURCES      = api.c	cgroup.c	cgroup.h	\
 		     tty.c	tty.h				\
 		     util.c	util.h				\
 		     utmp-api.c	utmp-api.h
+if LOGROTATE
+finit_SOURCES     += logrotate.c
+endif
+
 pkginclude_HEADERS = cond.h finit.h helpers.h log.h plugin.h svc.h
 
 finit_CFLAGS       = -W -Wall -Wextra -Wno-unused-parameter -std=gnu99

src/logit.c

@@ -33,77 +33,9 @@
 #include <lite/lite.h>
 
 static const char version_info[] = PACKAGE_NAME " v" PACKAGE_VERSION;
+extern int logrotate(char *file, int num, off_t sz);
 
 
-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. */
-				if (rename(ofile, nfile) && errno != ENOENT)
-					syslog(LOG_ERR, "Failed logrotate %s: %s",
-					       ofile, strerror(errno));
-			}
-
-			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. */
-				if (rename(ofile, nfile) && errno != ENOENT) {
-					syslog(LOG_ERR, "Failed logrotate %s: %s",
-					       ofile, strerror(errno));
-					continue;
-				}
-
-				if (cnt == 2 && fexist(nfile)) {
-					if (systemf("gzip %s", nfile))
-						continue; /* no gzip, probably */
-
-					(void)remove(nfile);
-				}
-			}
-
-			if (rename(file, nfile))
-				goto fallback;
-			create(file, st.st_mode, st.st_uid, st.st_gid);
-		} else {
-		fallback:
-			if (truncate(file, 0))
-				syslog(LOG_ERR, "Failed truncating %s during logrotate: %s",
-				       file, strerror(errno));
-		}
-	}
-
-	return 0;
-}
-
 static int checksz(FILE *fp, off_t sz)
 {
 	struct stat st;

src/logrotate.c

@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2018-2021  Joachim Wiberg <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 <lite/lite.h>
+#include <stdio.h>
+#include <syslog.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+static int recreate(char *path, mode_t mode, uid_t uid, gid_t gid)
+{
+	if (mknod(path, S_IFREG | mode, 0) || chown(path, uid, gid)) {
+		syslog(LOG_ERR, "Failed recreating %s: %s", path, strerror(errno));
+		return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * 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.
+ */
+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. */
+				if (rename(ofile, nfile) && errno != ENOENT)
+					syslog(LOG_ERR, "Failed logrotate %s: %s",
+					       ofile, strerror(errno));
+			}
+
+			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. */
+				if (rename(ofile, nfile) && errno != ENOENT) {
+					syslog(LOG_ERR, "Failed logrotate %s: %s",
+					       ofile, strerror(errno));
+					continue;
+				}
+
+				if (cnt == 2 && fexist(nfile)) {
+					if (systemf("gzip %s", nfile))
+						continue; /* no gzip, probably */
+
+					(void)remove(nfile);
+				}
+			}
+
+			if (rename(file, nfile))
+				goto fallback;
+			recreate(file, st.st_mode, st.st_uid, st.st_gid);
+		} else {
+		fallback:
+			if (truncate(file, 0))
+				syslog(LOG_ERR, "Failed truncating %s during logrotate: %s",
+				       file, strerror(errno));
+		}
+	}
+
+	return 0;
+}

src/utmp-api.c

@@ -35,6 +35,9 @@
 #define MAX_NO 5
 #define MAX_SZ 100 * 1024
 
+extern int logrotate(char *file, int num, off_t sz);
+
+
 static void utmp_strncpy(char *dst, const char *src, size_t dlen)
 {
 	size_t i;
@@ -46,72 +49,6 @@ static void utmp_strncpy(char *dst, const char *src, size_t dlen)
 		dst[i] = 0;
 }
 
-#ifdef LOGROTATE_ENABLED
-/*
- * 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. */
-				if (rename(ofile, nfile) && errno != ENOENT)
-					logit(LOG_ERR, "Failed logrotate %s: %s",
-					       ofile, strerror(errno));
-			}
-
-			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. */
-				if (rename(ofile, nfile) && errno != ENOENT) {
-					logit(LOG_ERR, "Failed logrotate %s: %s",
-					       ofile, strerror(errno));
-					continue;
-				}
-
-				if (cnt == 2 && fexist(nfile)) {
-					if (systemf("gzip %s", nfile))
-						continue; /* no gzip, probably */
-
-					(void)remove(nfile);
-				}
-			}
-
-			if (rename(file, nfile))
-				goto fallback;
-			create(file, st.st_mode, st.st_uid, st.st_gid);
-		} else {
-		fallback:
-			if (truncate(file, 0))
-				logit(LOG_ERR, "Failed truncating %s during logrotate: %s",
-				      file, strerror(errno));
-		}
-	}
-
-	return 0;
-}
-#endif /* LOGROTATE_ENABLED */
-
 /*
  * Rotate /var/log/wtmp (+ btmp?) and /run/utmp
  *