rotatelogs.c revision 4a13940dc2990df0a798718d3a3f9cf1566c2217
/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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
*
* 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.
*/
/*
* Simple program to rotate Apache logs without having to kill the server.
*
* Contributed by Ben Laurie <ben algroup.co.uk>
*
* 12 Mar 1996
*
* Ported to APR by Mladen Turk <mturk mappingsoft.com>
*
* 23 Sep 2001
*
* -l option added 2004-06-11
*
* -l causes the use of local time rather than GMT as the base for the
* interval. NB: Using -l in an environment which changes the GMT offset
* (such as for BST or DST) can lead to unpredictable results!
*
* -f option added Feb, 2008. This causes rotatelog to open/create
* the logfile as soon as it's started, not as soon as it sees
* data.
*
* -v option added Feb, 2008. Verbose output of command line parsing.
*/
#include "apr.h"
#include "apr_lib.h"
#include "apr_strings.h"
#include "apr_errno.h"
#include "apr_file_io.h"
#include "apr_file_info.h"
#include "apr_general.h"
#include "apr_time.h"
#include "apr_getopt.h"
#if APR_HAVE_STDLIB_H
#include <stdlib.h>
#endif
#define APR_WANT_STRFUNC
#include "apr_want.h"
#define BUFSIZE 65536
#define ERRMSGSZ 256
#ifndef MAX_PATH
#define MAX_PATH 1024
#endif
#define ROTATE_NONE 0
#define ROTATE_NEW 1
#define ROTATE_TIME 2
#define ROTATE_SIZE 3
#define ROTATE_FORCE 4
static const char *ROTATE_REASONS[] = {
"None",
"Open a new file",
"Time interval expired",
"Maximum size reached",
"Forced rotation",
NULL
};
typedef struct rotate_config rotate_config_t;
struct rotate_config {
unsigned int sRotation;
int tRotation;
int utc_offset;
int use_localtime;
int use_strftime;
int force_open;
int verbose;
const char *szLogRoot;
};
typedef struct rotate_status rotate_status_t;
struct rotate_status {
apr_pool_t *pool;
apr_pool_t *pfile;
apr_pool_t *pfile_prev;
apr_file_t *nLogFD;
apr_file_t *nLogFDprev;
char filename[MAX_PATH];
char errbuf[ERRMSGSZ];
int rotateReason;
int tLogEnd;
int nMessCount;
};
static rotate_config_t config;
static rotate_status_t status;
static void usage(const char *argv0, const char *reason)
{
if (reason) {
fprintf(stderr, "%s\n", reason);
}
fprintf(stderr,
"Usage: %s [-v] [-l] [-f] <logfile> "
"{<rotation time in seconds>|<rotation size>(B|K|M|G)} "
"[offset minutes from UTC]\n\n",
argv0);
#ifdef OS2
fprintf(stderr,
"Add this:\n\nTransferLog \"|%s.exe /some/where 86400\"\n\n",
argv0);
#else
fprintf(stderr,
"Add this:\n\nTransferLog \"|%s /some/where 86400\"\n\n",
argv0);
fprintf(stderr,
"or \n\nTransferLog \"|%s /some/where 5M\"\n\n", argv0);
#endif
fprintf(stderr,
"to httpd.conf. The generated name will be /some/where.nnnn "
"where nnnn is the\nsystem time at which the log nominally "
"starts (N.B. if using a rotation time,\nthe time will always "
"be a multiple of the rotation time, so you can synchronize\n"
"cron scripts with it). At the end of each rotation time or "
"when the file size\nis reached a new log is started.\n");
exit(1);
}
/*
* Get the unix time with timezone corrections
* given in the config struct.
*/
static int get_now(rotate_config_t *config)
{
apr_time_t tNow = apr_time_now();
int utc_offset = config->utc_offset;
if (config->use_localtime) {
/* Check for our UTC offset before using it, since it might
* change if there's a switch between standard and daylight
* savings time.
*/
apr_time_exp_t lt;
apr_time_exp_lt(&lt, tNow);
utc_offset = lt.tm_gmtoff;
}
return (int)apr_time_sec(tNow) + utc_offset;
}
/*
* Close a file and destroy the associated pool.
*/
static void closeFile(rotate_config_t *config, apr_pool_t *pool, apr_file_t *file)
{
if (file != NULL) {
if (config->verbose) {
apr_finfo_t finfo;
apr_int32_t wanted = APR_FINFO_NAME;
if (apr_file_info_get(&finfo, wanted, file) == APR_SUCCESS) {
fprintf(stderr, "Closing file %s (%s)\n", finfo.name, finfo.fname);
}
}
apr_file_close(file);
if (pool) {
apr_pool_destroy(pool);
}
}
}
/*
* Dump the configuration parsing result to STDERR.
*/
static void dumpConfig (rotate_config_t *config)
{
fprintf(stderr, "Rotation time interval: %12d\n", config->tRotation);
fprintf(stderr, "Rotation size interval: %12d\n", config->sRotation);
fprintf(stderr, "Rotation time UTC offset: %12d\n", config->utc_offset);
fprintf(stderr, "Rotation based on localtime: %12s\n", config->use_localtime ? "yes" : "no");
fprintf(stderr, "Rotation file date pattern: %12s\n", config->use_strftime ? "yes" : "no");
fprintf(stderr, "Rotation file forced open: %12s\n", config->force_open ? "yes" : "no");
fprintf(stderr, "Rotation verbose: %12s\n", config->verbose ? "yes" : "no");
fprintf(stderr, "Rotation file name: %21s\n", config->szLogRoot);
}
/*
* Check whether we need to rotate.
* Possible reasons are:
* - No log file open (ROTATE_NEW)
* - User forces us to rotate (ROTATE_FORCE)
* - Our log file size is already bigger than the
* allowed maximum (ROTATE_SIZE)
* - The next log time interval expired (ROTATE_TIME)
*
* When size and time constraints are both given,
* it suffices that one of them is fulfilled.
*/
static void checkRotate(rotate_config_t *config, rotate_status_t *status)
{
if (status->nLogFD == NULL) {
status->rotateReason = ROTATE_NEW;
}
else if (config->sRotation) {
apr_finfo_t finfo;
apr_off_t current_size = -1;
if (apr_file_info_get(&finfo, APR_FINFO_SIZE, status->nLogFD) == APR_SUCCESS) {
current_size = finfo.size;
}
if (current_size > config->sRotation) {
status->rotateReason = ROTATE_SIZE;
}
else if (config->tRotation) {
if (get_now(config) >= status->tLogEnd) {
status->rotateReason = ROTATE_TIME;
}
}
}
else if (config->tRotation) {
if (get_now(config) >= status->tLogEnd) {
status->rotateReason = ROTATE_TIME;
}
}
else {
fprintf(stderr, "No rotation time or size specified\n");
exit(2);
}
if (status->rotateReason != ROTATE_NONE && config->verbose) {
fprintf(stderr, "File rotation needed, reason: %s\n", ROTATE_REASONS[status->rotateReason]);
}
return;
}
/*
* Open a new log file, and if successful
* also close the old one.
*
* The timestamp for the calculation of the file
* name of the new log file will be the actual millisecond
* timestamp, except when a regular rotation based on a time
* interval is configured and the previous interval
* is over. Then the timestamp is the starting time
* of the actual interval.
*/
static void doRotate(rotate_config_t *config, rotate_status_t *status)
{
int now = get_now(config);
int tLogStart;
apr_status_t rv;
status->rotateReason = ROTATE_NONE;
status->nLogFDprev = status->nLogFD;
status->nLogFD = NULL;
status->pfile_prev = status->pfile;
if (config->tRotation) {
int tLogEnd;
tLogStart = (now / config->tRotation) * config->tRotation;
tLogEnd = tLogStart + config->tRotation;
/*
* Check if rotation was forced and the last rotation
* interval is not yet over. Use the value of now instead
* of the time interval boundary for the file name then.
*/
if (tLogStart < status->tLogEnd) {
tLogStart = now;
}
status->tLogEnd = tLogEnd;
}
else {
tLogStart = now;
}
if (config->use_strftime) {
apr_time_t tNow = apr_time_from_sec(tLogStart);
apr_time_exp_t e;
apr_size_t rs;
apr_time_exp_gmt(&e, tNow);
apr_strftime(status->filename, &rs, sizeof(status->filename), config->szLogRoot, &e);
}
else {
sprintf(status->filename, "%s.%010d", config->szLogRoot, tLogStart);
}
apr_pool_create(&status->pfile, status->pool);
if (config->verbose) {
fprintf(stderr, "Opening file %s\n", status->filename);
}
rv = apr_file_open(&status->nLogFD, status->filename, APR_WRITE | APR_CREATE | APR_APPEND,
APR_OS_DEFAULT, status->pfile);
if (rv != APR_SUCCESS) {
char error[120];
apr_strerror(rv, error, sizeof error);
/* Uh-oh. Failed to open the new log file. Try to clear
* the previous log file, note the lost log entries,
* and keep on truckin'. */
if (status->nLogFDprev == NULL) {
fprintf(stderr, "Could not open log file '%s' (%s)\n", status->filename, error);
exit(2);
}
else {
apr_size_t nWrite;
status->nLogFD = status->nLogFDprev;
apr_pool_destroy(status->pfile);
status->pfile = status->pfile_prev;
/* Try to keep this error message constant length
* in case it occurs several times. */
apr_snprintf(status->errbuf, sizeof status->errbuf,
"Resetting log file due to error opening "
"new log file, %10d messages lost: %-25.25s\n",
status->nMessCount, error);
nWrite = strlen(status->errbuf);
apr_file_trunc(status->nLogFD, 0);
if (apr_file_write(status->nLogFD, status->errbuf, &nWrite) != APR_SUCCESS) {
fprintf(stderr, "Error writing to the file %s\n", status->filename);
exit(2);
}
}
}
else {
closeFile(config, status->pfile_prev, status->nLogFDprev);
status->nLogFDprev = NULL;
status->pfile_prev = NULL;
}
status->nMessCount = 0;
}
/*
* Get a size or time param from a string.
* Parameter 'last' indicates, whether the
* argument is the last commadnline argument.
* UTC offset is only allowed as a last argument
* in order to make is distinguishable from the
* rotation interval time.
*/
static const char *get_time_or_size(rotate_config_t *config,
const char *arg, int last) {
char *ptr = NULL;
/* Byte multiplier */
unsigned int mult = 1;
if ((ptr = strchr(arg, 'B')) != NULL) { /* Found KB size */
mult = 1;
}
else if ((ptr = strchr(arg, 'K')) != NULL) { /* Found KB size */
mult = 1024;
}
else if ((ptr = strchr(arg, 'M')) != NULL) { /* Found MB size */
mult = 1024 * 1024;
}
else if ((ptr = strchr(arg, 'G')) != NULL) { /* Found GB size */
mult = 1024 * 1024 * 1024;
}
if (ptr) { /* rotation based on file size */
if (config->sRotation > 0) {
return "Rotation size parameter allowed only once";
}
if (*(ptr+1) == '\0') {
config->sRotation = atoi(arg) * mult;
}
if (config->sRotation == 0) {
return "Invalid rotation size parameter";
}
}
else if ((config->sRotation > 0 || config->tRotation > 0) && last) {
/* rotation based on elapsed time */
if (config->use_localtime) {
return "UTC offset parameter is not valid with -l";
}
config->utc_offset = atoi(arg) * 60;
}
else { /* rotation based on elapsed time */
if (config->tRotation > 0) {
return "Rotation time parameter allowed only once";
}
config->tRotation = atoi(arg);
if (config->tRotation <= 0) {
return "Invalid rotation time parameter";
}
}
return NULL;
}
int main (int argc, const char * const argv[])
{
char buf[BUFSIZE];
apr_size_t nRead, nWrite;
apr_file_t *f_stdin;
apr_getopt_t *opt;
apr_status_t rv;
char c;
const char *optarg;
const char *err = NULL;
apr_app_initialize(&argc, &argv, NULL);
atexit(apr_terminate);
config.sRotation = 0;
config.tRotation = 0;
config.utc_offset = 0;
config.use_localtime = 0;
config.use_strftime = 0;
config.force_open = 0;
config.verbose = 0;
status.pool = NULL;
status.pfile = NULL;
status.pfile_prev = NULL;
status.nLogFD = NULL;
status.nLogFDprev = NULL;
status.tLogEnd = 0;
status.rotateReason = ROTATE_NONE;
status.nMessCount = 0;
apr_pool_create(&status.pool, NULL);
apr_getopt_init(&opt, status.pool, argc, argv);
while ((rv = apr_getopt(opt, "lfv", &c, &optarg)) == APR_SUCCESS) {
switch (c) {
case 'l':
config.use_localtime = 1;
break;
case 'f':
config.force_open = 1;
break;
case 'v':
config.verbose = 1;
break;
}
}
if (rv != APR_EOF) {
usage(argv[0], NULL /* specific error message already issued */ );
}
/*
* After the initial flags we need 2 to 4 arguments,
* the file name, either the rotation interval time or size
* or both of them, and optionally the UTC offset.
*/
if ((argc - opt->ind < 2) || (argc - opt->ind > 4) ) {
usage(argv[0], "Incorrect number of arguments");
}
config.szLogRoot = argv[opt->ind++];
/* Read in the remaining flags, namely time, size and UTC offset. */
for(; opt->ind < argc; opt->ind++) {
if ((err = get_time_or_size(&config, argv[opt->ind],
opt->ind < argc - 1 ? 0 : 1)) != NULL) {
usage(argv[0], err);
}
}
config.use_strftime = (strchr(config.szLogRoot, '%') != NULL);
if (apr_file_open_stdin(&f_stdin, status.pool) != APR_SUCCESS) {
fprintf(stderr, "Unable to open stdin\n");
exit(1);
}
/*
* Write out result of config parsing if verbose is set.
*/
if (config.verbose) {
dumpConfig(&config);
}
/*
* Immediately open the logfile as we start, if we were forced
* to do so via '-f'.
*/
if (config.force_open) {
doRotate(&config, &status);
}
for (;;) {
nRead = sizeof(buf);
rv = apr_file_read(f_stdin, buf, &nRead);
if (rv != APR_SUCCESS) {
exit(3);
}
checkRotate(&config, &status);
if (status.rotateReason != ROTATE_NONE) {
doRotate(&config, &status);
}
nWrite = nRead;
rv = apr_file_write(status.nLogFD, buf, &nWrite);
if (rv == APR_SUCCESS && nWrite != nRead) {
/* buffer partially written, which for rotatelogs means we encountered
* an error such as out of space or quota or some other limit reached;
* try to write the rest so we get the real error code
*/
apr_size_t nWritten = nWrite;
nRead = nRead - nWritten;
nWrite = nRead;
rv = apr_file_write(status.nLogFD, buf + nWritten, &nWrite);
}
if (nWrite != nRead) {
char strerrbuf[120];
apr_off_t cur_offset;
cur_offset = 0;
if (apr_file_seek(status.nLogFD, APR_CUR, &cur_offset) != APR_SUCCESS) {
cur_offset = -1;
}
apr_strerror(rv, strerrbuf, sizeof strerrbuf);
status.nMessCount++;
apr_snprintf(status.errbuf, sizeof status.errbuf,
"Error %d writing to log file at offset %" APR_OFF_T_FMT ". "
"%10d messages lost (%s)\n",
rv, cur_offset, status.nMessCount, strerrbuf);
nWrite = strlen(status.errbuf);
apr_file_trunc(status.nLogFD, 0);
if (apr_file_write(status.nLogFD, status.errbuf, &nWrite) != APR_SUCCESS) {
fprintf(stderr, "Error writing to the file %s\n", status.filename);
exit(2);
}
}
else {
status.nMessCount++;
}
}
/* Of course we never, but prevent compiler warnings */
return 0;
}