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-rw-r--r--runtime/operatingstate.c177
1 files changed, 177 insertions, 0 deletions
diff --git a/runtime/operatingstate.c b/runtime/operatingstate.c
new file mode 100644
index 0000000..04b4cbd
--- /dev/null
+++ b/runtime/operatingstate.c
@@ -0,0 +1,177 @@
+/* OperatingStateFile Handler.
+ *
+ * Copyright 2018 Adiscon GmbH.
+ *
+ * This file is part of the rsyslog runtime library.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * -or-
+ * see COPYING.ASL20 in the source distribution
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "config.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <assert.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "rsyslog.h"
+#include "errmsg.h"
+#include "operatingstate.h"
+#include "rsconf.h"
+
+#ifndef O_LARGEFILE
+#define O_LARGEFILE 0
+#endif
+#ifndef HAVE_LSEEK64
+# define lseek64(fd, offset, whence) lseek(fd, offset, whence)
+#endif
+
+/* some important standard states */
+#define STATE_INITIALIZING "INITIALIZING"
+#define STATE_CLEAN_CLOSE "CLEAN CLOSE"
+
+static int fd_osf = -1;
+
+/* check if old osf points to a problem and, if so, report */
+static void
+osf_checkOnStartup(void)
+{
+ int do_rename = 1;
+ const char *fn_osf = (const char*) glblGetOperatingStateFile(loadConf);
+ char iobuf[sizeof(STATE_CLEAN_CLOSE)];
+ const int len_clean_close = sizeof(STATE_CLEAN_CLOSE) - 1;
+ assert(fn_osf != NULL);
+
+ const int fd = open(fn_osf, O_RDONLY|O_LARGEFILE|O_CLOEXEC, 0);
+ if(fd == -1) {
+ if(errno != ENOENT) {
+ LogError(errno, RS_RET_ERR, "error opening existing operatingStateFile '%s' - "
+ "this may be an indication of a problem; ignoring", fn_osf);
+ }
+ do_rename = 0;
+ goto done;
+ }
+ assert(fd != -1);
+ int offs = lseek64(fd, -(len_clean_close + 1), SEEK_END);
+ if(offs == -1){
+ LogError(errno, RS_RET_IO_ERROR, "error seeking to end of existing operatingStateFile "
+ "'%s' - this may be an indication of a problem, e.g. empty file", fn_osf);
+ goto done;
+ }
+ int rd = read(fd, iobuf, len_clean_close);
+ if(rd == -1) {
+ LogError(errno, RS_RET_IO_ERROR, "error reading existing operatingStateFile "
+ "'%s' - this probably indicates an improper shutdown", fn_osf);
+ goto done;
+ } else {
+ assert(rd <= len_clean_close);
+ iobuf[rd] = '\0';
+ if(rd != len_clean_close || strcmp(iobuf, STATE_CLEAN_CLOSE) != 0) {
+ LogError(errno, RS_RET_IO_ERROR, "existing operatingStateFile '%s' does not end "
+ "with '%s, instead it has '%s' - this probably indicates an "
+ "improper shutdown", fn_osf, STATE_CLEAN_CLOSE, iobuf);
+ goto done;
+ }
+ }
+
+ /* all ok! */
+ do_rename = 0;
+done:
+ if(fd != -1) {
+ close(fd);
+ }
+ if(do_rename) {
+ char newname[MAXFNAME];
+ snprintf(newname, sizeof(newname)-1, "%s.previous", fn_osf);
+ newname[MAXFNAME-1] = '\0';
+ if(rename(fn_osf, newname) != 0) {
+ LogError(errno, RS_RET_IO_ERROR, "could not rename existing operatingStateFile "
+ "'%s' to '%s' - ignored, but will probably be overwritten now",
+ fn_osf, newname);
+ } else {
+ LogMsg(errno, RS_RET_OK, LOG_INFO, "existing state file '%s' renamed "
+ "to '%s' - you may want to review it", fn_osf, newname);
+ }
+ }
+ return;
+}
+
+void
+osf_open(void)
+{
+ assert(fd_osf == -1);
+ const char *fn_osf = (const char*) glblGetOperatingStateFile(loadConf);
+ assert(fn_osf != NULL);
+
+ osf_checkOnStartup();
+
+ fd_osf = open(fn_osf, O_WRONLY|O_CREAT|O_APPEND|O_LARGEFILE|O_CLOEXEC,
+ S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP);
+ if(fd_osf == -1) {
+ LogError(errno, RS_RET_ERR, "error opening operatingStateFile '%s' for write - "
+ "ignoring it", fn_osf);
+ goto done;
+ }
+ assert(fd_osf != -1);
+
+ osf_write(OSF_TAG_STATE, STATE_INITIALIZING " " VERSION);
+done:
+ return;
+}
+
+
+void ATTR_NONNULL()
+osf_write(const char *const tag, const char *const line)
+{
+ char buf[1024]; /* intentionally small */
+ time_t tt;
+ ssize_t wr;
+ size_t len;
+ struct tm tm;
+
+ DBGPRINTF("osf: %s %s: ", tag, line); /* ensure everything is inside the debug log */
+
+ if(fd_osf == -1)
+ return;
+
+ time(&tt);
+ localtime_r(&tt, &tm);
+ len = snprintf(buf, sizeof(buf)-1, "%d%2.2d%2.2d-%2.2d%2.2d%2.2d: %-5.5s %s\n",
+ tm.tm_year+1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
+ tag, line);
+ if(len > sizeof(buf)-1) {
+ len = sizeof(buf)-1; /* overflow, truncate */
+ }
+ wr = write(fd_osf, buf, len);
+ // TODO: handle EINTR
+ if(wr != (ssize_t) len) {
+ LogError(errno, RS_RET_IO_ERROR, "error writing operating state file - line lost");
+ }
+}
+
+
+void
+osf_close(void)
+{
+ if(fd_osf == -1)
+ return;
+ osf_write(OSF_TAG_STATE, STATE_CLEAN_CLOSE);
+ close(fd_osf);
+}