diff options
Diffstat (limited to 'runtime/operatingstate.c')
| -rw-r--r-- | runtime/operatingstate.c | 177 |
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); +} |