ntp_filegen.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* Copyright (c) 1996,1999 by Sun Microsystems, Inc.
* All rights reserved.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* ntp_filegen.c,v 3.12 1994/01/25 19:06:11 kardel Exp
*
* implements file generations support for NTP
* logfiles and statistic files
*
*
* Copyright (C) 1992, 1996 by Rainer Pruy
* Friedrich-Alexander Universit�t Erlangen-N�rnberg, Germany
*
* This code may be modified and used freely
* provided credits remain intact.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include "ntpd.h"
#include "ntp_io.h"
#include "ntp_string.h"
#include "ntp_calendar.h"
#include "ntp_filegen.h"
#include "ntp_stdlib.h"
/*
* NTP is intended to run long periods of time without restart.
* Thus log and statistic files generated by NTP will grow large.
*
* this set of routines provides a central interface
* to generating files using file generations
*
* the generation of a file is changed according to file generation type
*/
/*
* to check reason on open failure
*/
#ifndef SYS_WINNT
extern int errno;
#endif /* SYS_WINNT */
/*
* imported from timer
*/
extern u_long current_time;
/*
* redefine this if your system dislikes filename suffixes like
* X.19910101 or X.1992W50 or ....
*/
#define SUFFIX_SEP '.'
/*
* other constants
*/
#define FGEN_AGE_SECS (24*60*60) /* life time of FILEGEN_AGE in seconds */
#ifdef DEBUG
extern int debug;
#endif
static void filegen_open P((FILEGEN *, u_long));
static int valid_fileref P((char *, char *));
#ifdef UNUSED
static FILEGEN *filegen_unregister P((char *));
#endif /* UNUSED */
/*
* open a file generation according to the current settings of gen
* will also provide a link to basename if requested to do so
*/
static void
filegen_open(gen, newid)
FILEGEN *gen;
u_long newid;
{
char *filename;
char *basename;
u_int len;
FILE *fp;
struct calendar cal;
len = strlen(gen->prefix) + strlen(gen->basename) + 1;
basename = emalloc(len);
sprintf(basename, "%s%s", gen->prefix, gen->basename);
switch(gen->type) {
default:
msyslog(LOG_ERR, "unsupported file generations type %d for \"%s\" - reverting to FILEGEN_NONE",
gen->type, basename);
gen->type = FILEGEN_NONE;
/*FALLTHROUGH*/
case FILEGEN_NONE:
filename = emalloc(len);
sprintf(filename,"%s", basename);
break;
case FILEGEN_PID:
filename = emalloc(len + 1 + 1 + 10);
sprintf(filename,"%s%c#%ld", basename, SUFFIX_SEP, newid);
break;
case FILEGEN_DAY:
/* You can argue here in favor of using MJD, but
* I would assume it to be easier for humans to interpret dates
* in a format they are used to in everyday life.
*/
caljulian(newid,&cal);
filename = emalloc(len + 1 + 4 + 2 + 2);
sprintf(filename, "%s%c%04d%02d%02d",
basename, SUFFIX_SEP, cal.year, cal.month, cal.monthday);
break;
case FILEGEN_WEEK:
/*
* This is still a hack
* - the term week is not correlated to week as it is used
* normally - it just refers to a period of 7 days
* starting at Jan 1 - 'weeks' are counted starting from zero
*/
caljulian(newid,&cal);
filename = emalloc(len + 1 + 4 + 1 + 2);
sprintf(filename, "%s%c%04dw%02d",
basename, SUFFIX_SEP, cal.year, cal.yearday / 7);
break;
case FILEGEN_MONTH:
caljulian(newid,&cal);
filename = emalloc(len + 1 + 4 + 2);
sprintf(filename, "%s%c%04d%02d",
basename, SUFFIX_SEP, cal.year, cal.month);
break;
case FILEGEN_YEAR:
caljulian(newid,&cal);
filename = emalloc(len + 1 + 4);
sprintf(filename, "%s%c%04d", basename, SUFFIX_SEP, cal.year);
break;
case FILEGEN_AGE:
filename = emalloc(len + 1 + 2 + 10);
sprintf(filename, "%s%ca%08ld", basename, SUFFIX_SEP, newid);
break;
}
if (gen->type != FILEGEN_NONE) {
/*
* check for existence of a file with name 'basename'
* as we disallow such a file
* if FGEN_FLAG_LINK is set create a link
*/
struct stat stats;
/*
* try to resolve name collisions
*/
static u_long conflicts = 0;
#ifndef S_ISREG
#define S_ISREG(mode) (((mode) & S_IFREG) == S_IFREG)
#endif
if (stat(basename, &stats) == 0) {
/* Hm, file exists... */
if (S_ISREG(stats.st_mode)) {
if (stats.st_nlink <= 1) {
/*
* Oh, it is not linked - try to save it
*/
char *savename = emalloc(len + 1 + 1 + 10 + 10);
sprintf(savename, "%s%c%dC%lu",
basename,
SUFFIX_SEP,
(int) getpid(),
(u_long)conflicts++);
if (rename(basename, savename) != 0)
msyslog(LOG_ERR," couldn't save %s: %m", basename);
free(savename);
} else {
/*
* there is at least a second link tpo this file
* just remove the conflicting one
*/
#if !defined(VMS)
if (unlink(basename) != 0)
#else
if (delete(basename) != 0)
#endif
msyslog(LOG_ERR, "couldn't unlink %s: %m", basename);
}
} else {
/*
* Ehh? Not a regular file ?? strange !!!!
*/
msyslog(LOG_ERR, "expected regular file for %s (found mode 0%o)",
basename, stats.st_mode);
}
} else {
/*
* stat(..) failed, but it is absolutely correct for
* 'basename' not to exist
*/
if (errno != ENOENT)
msyslog(LOG_ERR,"stat(%s) failed: %m", basename);
}
}
/*
* now, try to open new file generation...
*/
fp = fopen(filename, "a");
#ifdef DEBUG
if (debug > 3)
printf("opening filegen (type=%d/id=%lu) \"%s\"\n",
gen->type, (u_long)newid, filename);
#endif
if (fp == NULL) {
/* open failed -- keep previous state
*
* If the file was open before keep the previous generation.
* This will cause output to end up in the 'wrong' file,
* but I think this is still better than loosing output
*
* ignore errors due to missing directories
*/
if (errno != ENOENT)
msyslog(LOG_ERR, "can't open %s: %m", filename);
} else {
if (gen->fp != NULL) {
fclose(gen->fp);
}
gen->fp = fp;
gen->id = newid;
if (gen->flag & FGEN_FLAG_LINK) {
/*
* need to link file to basename
* have to use hardlink for now as I want to allow
* gen->basename spanning directory levels
* this would make it more complex to get the correct filename
* for symlink
*
* Ok, it would just mean taking the part following the last '/'
* in the name.... Should add it later....
*/
/* Windows NT does not support file links -Greg Schueman 1/18/97 */
#if !defined(VMS) && !defined(SYS_WINNT) && !defined (SYS_VXWORKS)
if (link(filename, basename) != 0) {
if (errno != EEXIST)
#else
{
#ifndef SYS_WINNT
errno = 0; /* On VMS, don't support FGEN_FLAG_LINK */
#else
SetLastError(0); /* On WinNT, don't support FGEN_FLAG_LINK */
#endif /* SYS_WINNT */
#endif /* VMS */
msyslog(LOG_ERR, "can't link(%s, %s): %m", filename, basename);
}
} /* flags & FGEN_FLAG_LINK */
} /* else fp == NULL */
free(basename);
free(filename);
return;
}
/*
* this function sets up gen->fp to point to the correct
* generation of the file for the time specified by 'now'
*
* 'now' usually is interpreted as second part of a l_fp as is in the cal...
* library routines
*/
void
filegen_setup(gen,now)
FILEGEN *gen;
u_long now;
{
u_long new_gen = ~ (u_long) 0;
struct calendar cal;
if (!(gen->flag & FGEN_FLAG_ENABLED)) {
if (gen->fp != NULL)
fclose(gen->fp);
return;
}
switch (gen->type) {
case FILEGEN_NONE:
if (gen->fp != NULL) return; /* file already open */
break;
case FILEGEN_PID:
new_gen = getpid();
break;
case FILEGEN_DAY:
caljulian(now, &cal);
cal.hour = cal.minute = cal.second = 0;
new_gen = caltontp(&cal);
break;
case FILEGEN_WEEK:
/* Would be nice to have a calweekstart() routine */
/* so just use a hack ... */
/* just round time to integral 7 days period for actual year */
new_gen = now - (now - calyearstart(now)) % TIMES7(SECSPERDAY)
+ 60;
/*
* just to be sure -
* the computation above would fail in the presence of leap seconds
* so at least carry the date to the next day (+60 (seconds))
* and go back to the start of the day via calendar computations
*/
caljulian(new_gen, &cal);
cal.hour = cal.minute = cal.second = 0;
new_gen = caltontp(&cal);
break;
case FILEGEN_MONTH:
caljulian(now, &cal);
cal.yearday -= cal.monthday - 1;
cal.monthday = 1;
cal.hour = cal.minute = cal.second = 0;
new_gen = caltontp(&cal);
break;
case FILEGEN_YEAR:
new_gen = calyearstart(now);
break;
case FILEGEN_AGE:
new_gen = current_time - (current_time % FGEN_AGE_SECS);
break;
}
/*
* try to open file if not yet open
* reopen new file generation file on change of generation id
*/
if (gen->fp == NULL || gen->id != new_gen) {
filegen_open(gen, new_gen);
}
}
/*
* change settings for filegen files
*/
void
filegen_config(gen,basename,type,flag)
FILEGEN *gen;
char *basename;
u_int type;
u_int flag;
{
/*
* if nothing would be changed...
*/
if ((basename == gen->basename || strcmp(basename,gen->basename) == 0) &&
type == gen->type &&
flag == gen->flag)
return;
/*
* validate parameters
*/
if (!valid_fileref(gen->prefix,basename))
return;
if (gen->fp != NULL)
fclose(gen->fp);
#ifdef DEBUG
if (debug > 2)
printf("configuring filegen:\n\tprefix:\t%s\n\tbasename:\t%s -> %s\n\ttype:\t%d -> %d\n\tflag: %x -> %x\n",
gen->prefix, gen->basename, basename, gen->type, type, gen->flag, flag);
#endif
if (gen->basename != basename || strcmp(gen->basename, basename) != 0) {
free(gen->basename);
gen->basename = emalloc(strlen(basename) + 1);
strcpy(gen->basename, basename);
}
gen->type = type;
gen->flag = flag;
/*
* make filegen use the new settings
* special action is only required when a generation file
* is currently open
* otherwise the new settings will be used anyway at the next open
*/
if (gen->fp != NULL) {
l_fp now;
get_systime(&now);
filegen_setup(gen, now.l_ui);
}
}
/*
* check whether concatenating prefix and basename
* yields a legal filename
*/
static int
valid_fileref(prefix,basename)
char *prefix, *basename;
{
/*
* prefix cannot be changed dynamically
* (within the context of filegen)
* so just reject basenames containing '..'
*
* ASSUMPTION:
* file system parts 'below' prefix may be
* specified without infringement of security
*
* restricing prefix to legal values
* has to be ensured by other means
* (however, it would be possible to perform some checks here...)
*/
register char *p = basename;
/*
* Just to catch, dumb errors opening up the world...
*/
if (prefix == NULL || *prefix == '\0')
return 0;
if (basename == NULL)
return 0;
for (p = basename; p; p = strchr(p, '/')) {
if (*p == '.' && *(p+1) == '.' && (*(p+2) == '\0' || *(p+2) == '/'))
return 0;
}
return 1;
}
/*
* filegen registry
*/
static struct filegen_entry {
char *name;
FILEGEN *filegen;
struct filegen_entry *next;
} *filegen_registry = NULL;
FILEGEN *
filegen_get(name)
char *name;
{
struct filegen_entry *f = filegen_registry;
while(f) {
if (f->name == name || strcmp(name, f->name) == 0) {
#ifdef XXX /* this gives the Alpha compiler fits */
if (debug > 3)
printf("filegen_get(\"%s\") = %x\n", name,
(u_int)f->filegen);
#endif
return f->filegen;
}
f = f->next;
}
#ifdef DEBUG
if (debug > 3)
printf("filegen_get(\"%s\") = NULL\n", name);
#endif
return NULL;
}
void
filegen_register(name, filegen)
char *name;
FILEGEN *filegen;
{
struct filegen_entry **f = &filegen_registry;
#ifdef XXX /* this gives the Alpha compiler fits */
if (debug > 3)
printf("filegen_register(\"%s\",%x)\n", name, (u_int)filegen);
#endif
while (*f) {
if ((*f)->name == name || strcmp(name, (*f)->name) == 0) {
#ifdef XXX /* this gives the Alpha compiler fits */
if (debug > 4) {
printf("replacing filegen %x\n", (u_int)(*f)->filegen);
}
#endif
(*f)->filegen = filegen;
return;
}
f = &((*f)->next);
}
*f = (struct filegen_entry *) emalloc(sizeof(struct filegen_entry));
if (*f) {
(*f)->next = NULL;
(*f)->name = emalloc(strlen(name) + 1);
strcpy((*f)->name, name);
(*f)->filegen = filegen;
#ifdef DEBUG
if (debug > 5) {
printf("adding new filegen\n");
}
#endif
}
return;
}
#ifdef UNUSED
static FILEGEN *
filegen_unregister(name)
char *name;
{
struct filegen_entry **f = &filegen_registry;
#ifdef DEBUG
if (debug > 3)
printf("filegen_unregister(\"%s\")\n", name);
#endif
while (*f) {
if (strcmp((*f)->name,name) == 0) {
struct filegen_entry *ff = *f;
FILEGEN *fg;
*f = (*f)->next;
fg = ff->filegen;
free(ff->name);
free(ff);
return fg;
}
f = &((*f)->next);
}
return NULL;
}
#endif /* UNUSED */