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Merge pull request #5264 from rgerhards/i5161
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imkmsg: add params parseKernelTimestamp and fixKernelTimeStamp
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@rgerhards
rgerhards committed Nov 10, 2023
2 parents 0ba9d5d + b38b7c6 commit ef1bd6b
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Showing 3 changed files with 128 additions and 32 deletions.
66 changes: 63 additions & 3 deletions contrib/imkmsg/imkmsg.c
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Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,7 @@
* To test under Linux:
* echo test1 > /dev/kmsg
*
* Copyright (C) 2008-2014 Adiscon GmbH
* Copyright (C) 2008-2023 Adiscon GmbH
*
* This file is part of rsyslog.
*
Expand Down Expand Up @@ -70,6 +70,16 @@ static modConfData_t *loadModConf = NULL;/* modConf ptr to use for the current l
static modConfData_t *runModConf = NULL;/* modConf ptr to use for the current load process */
static int bLegacyCnfModGlobalsPermitted;/* are legacy module-global config parameters permitted? */

/* module-global parameters */
static struct cnfparamdescr modpdescr[] = {
{ "parsekerneltimestamp", eCmdHdlrGetWord, 0 }
};
static struct cnfparamblk modpblk =
{ CNFPARAMBLK_VERSION,
sizeof(modpdescr)/sizeof(struct cnfparamdescr),
modpdescr
};

static prop_t *pInputName = NULL;
/* there is only one global inputName for all messages generated by this module */
static prop_t *pLocalHostIP = NULL; /* a pseudo-constant propterty for 127.0.0.1 */
Expand Down Expand Up @@ -182,13 +192,64 @@ CODESTARTbeginCnfLoad
pModConf->pConf = pConf;
/* init our settings */
pModConf->iFacilIntMsg = klogFacilIntMsg();
pModConf->parseKernelStamp = KMSG_PARSE_TS_STARTUP_ONLY;
loadModConf->configSetViaV2Method = 0;
bLegacyCnfModGlobalsPermitted = 1;
/* init legacy config vars */
initConfigSettings();
ENDbeginCnfLoad


BEGINsetModCnf
struct cnfparamvals *pvals = NULL;
int i;
CODESTARTsetModCnf
pvals = nvlstGetParams(lst, &modpblk, NULL);
if(pvals == NULL) {
LogError(0, RS_RET_MISSING_CNFPARAMS, "error processing module "
"config parameters [module(...)]");
ABORT_FINALIZE(RS_RET_MISSING_CNFPARAMS);
}

if(Debug) {
dbgprintf("module (global) param blk for imkmsg:\n");
cnfparamsPrint(&modpblk, pvals);
}

for(i = 0 ; i < modpblk.nParams ; ++i) {
if(!pvals[i].bUsed)
continue;
if(!strcmp(modpblk.descr[i].name, "parsekerneltimestamp")) {
if( !es_strconstcmp(pvals[i].val.d.estr, "on")
|| !es_strconstcmp(pvals[i].val.d.estr, "always")) {
loadModConf->parseKernelStamp = KMSG_PARSE_TS_ALWAYS;
} else if(!es_strconstcmp(pvals[i].val.d.estr, "startup")) {
loadModConf->parseKernelStamp = KMSG_PARSE_TS_STARTUP_ONLY;
} else if(!es_strconstcmp(pvals[i].val.d.estr, "off")) {
loadModConf->parseKernelStamp = KMSG_PARSE_TS_OFF;
} else {
const char *const cstr = es_str2cstr(pvals[i].val.d.estr, NULL);
LogError(0, RS_RET_PARAM_ERROR, "imkmsg: unknown "
"parse mode '%s'", cstr);
free((void*)cstr);
}
} else {
LogMsg(0, RS_RET_INTERNAL_ERROR, LOG_WARNING,
"imkmsg: RSYSLOG BUG, non-handled param '%s' in "
"beginCnfLoad\n", modpblk.descr[i].name);
}
}

/* disable legacy module-global config directives */
bLegacyCnfModGlobalsPermitted = 0;
loadModConf->configSetViaV2Method = 1;

finalize_it:
if(pvals != NULL)
cnfparamvalsDestruct(pvals, &modpblk);
ENDsetModCnf


BEGINendCnfLoad
CODESTARTendCnfLoad
if(!loadModConf->configSetViaV2Method) {
Expand Down Expand Up @@ -254,6 +315,7 @@ CODESTARTqueryEtryPt
CODEqueryEtryPt_STD_IMOD_QUERIES
CODEqueryEtryPt_STD_CONF2_QUERIES
CODEqueryEtryPt_STD_CONF2_PREPRIVDROP_QUERIES
CODEqueryEtryPt_STD_CONF2_setModCnf_QUERIES
ENDqueryEtryPt

static rsRetVal resetConfigVariables(uchar __attribute__((unused)) *pp, void __attribute__((unused)) *pVal)
Expand Down Expand Up @@ -289,5 +351,3 @@ CODEmodInit_QueryRegCFSLineHdlr
CHKiRet(omsdRegCFSLineHdlr((uchar *)"resetconfigvariables", 1, eCmdHdlrCustomHandler,
resetConfigVariables, NULL, STD_LOADABLE_MODULE_ID));
ENDmodInit
/* vim:set ai:
*/
13 changes: 9 additions & 4 deletions contrib/imkmsg/imkmsg.h
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Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
/* imkmsg.h
* These are the definitions for the kmsg message generation module.
*
* Copyright 2007-2012 Rainer Gerhards and Adiscon GmbH.
* Copyright 2007-2023 Rainer Gerhards and Adiscon GmbH.
*
* This file is part of rsyslog.
*
Expand All @@ -25,13 +25,20 @@
#include "rsyslog.h"
#include "dirty.h"

typedef enum _kernel_ts_parse_mods {
KMSG_PARSE_TS_OFF = 0,
KMSG_PARSE_TS_ALWAYS = 1,
KMSG_PARSE_TS_STARTUP_ONLY = 2
} t_kernel_ts_parse_mode;

/* we need to have the modConf type present in all submodules */
struct modConfData_s {
rsconf_t *pConf;
int iFacilIntMsg;
uchar *pszPath;
int console_log_level;
sbool bPermitNonKernel;
t_kernel_ts_parse_mode parseKernelStamp;
sbool bFixKernelStamp;
sbool configSetViaV2Method;
};

Expand Down Expand Up @@ -62,5 +69,3 @@ extern char * ExpandKadds(char *, char *);
extern void SetParanoiaLevel(int);

#endif /* #ifndef IMKLOG_H_INCLUDED */
/* vi:set ai:
*/
81 changes: 56 additions & 25 deletions contrib/imkmsg/kmsg.c
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Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,7 @@
* For a general overview, see head comment in imkmsg.c.
* This is heavily based on imklog bsd.c file.
*
* Copyright 2008-2014 Adiscon GmbH
* Copyright 2008-2023 Adiscon GmbH
*
* This file is part of rsyslog.
*
Expand Down Expand Up @@ -44,6 +44,18 @@

/* globals */
static int fklog = -1; /* kernel log fd */
static int bInInitialReading = 1; /* are we in the intial kmsg reading phase? */
/* Note: There is a problem with kernel log time.
* See https://github.com/troglobit/sysklogd/commit/9f6fbb3301e571d8af95f8d771469291384e9e95
* We use the same work-around if bFixKernelStamp is on, and use the kernel log time
* only for past records, which we assume to be from recent boot. Later on, we do not
* use them but system time.
* UNFORTUNATELY, with /dev/kmsg, we always get old messages on startup. That means we
* may also pull old messages. We do not address this right now, as for 10 years "old
* messages" was pretty acceptable. So we wait until someone complains. Hint: we could
* do a seek to the end of kmsg if desired to not pull old messages.
* 2023-10-31 rgerhards
*/

#ifndef _PATH_KLOG
# define _PATH_KLOG "/dev/kmsg"
Expand All @@ -54,10 +66,11 @@ static int fklog = -1; /* kernel log fd */
* from the rest.
*/
static void
submitSyslog(uchar *buf)
submitSyslog(modConfData_t *const pModConf, const uchar *buf)
{
long offs = 0;
struct timeval tv;
struct timeval *tp = NULL;
struct sysinfo info;
unsigned long int timestamp = 0;
char name[1024];
Expand Down Expand Up @@ -129,27 +142,32 @@ submitSyslog(uchar *buf)
json_object_object_add(json, name, jval);
}

/* calculate timestamp */
sysinfo(&info);
gettimeofday(&tv, NULL);
if( (pModConf->parseKernelStamp == KMSG_PARSE_TS_ALWAYS)
|| ((pModConf->parseKernelStamp == KMSG_PARSE_TS_STARTUP_ONLY) && bInInitialReading) ) {
/* calculate timestamp */
sysinfo(&info);
gettimeofday(&tv, NULL);

/* get boot time */
tv.tv_sec -= info.uptime;
/* get boot time */
tv.tv_sec -= info.uptime;

tv.tv_sec += timestamp / 1000000;
tv.tv_usec += timestamp % 1000000;
tv.tv_sec += timestamp / 1000000;
tv.tv_usec += timestamp % 1000000;

while (tv.tv_usec < 0) {
tv.tv_sec--;
tv.tv_usec += 1000000;
}
while (tv.tv_usec < 0) {
tv.tv_sec--;
tv.tv_usec += 1000000;
}

while (tv.tv_usec >= 1000000) {
tv.tv_sec++;
tv.tv_usec -= 1000000;
while (tv.tv_usec >= 1000000) {
tv.tv_sec++;
tv.tv_usec -= 1000000;
}

tp = &tv;
}

Syslog(priority, (uchar *)msg, &tv, json);
Syslog(priority, (uchar *)msg, tp, json);
}


Expand All @@ -161,7 +179,7 @@ klogWillRunPrePrivDrop(modConfData_t __attribute__((unused)) *pModConf)
char errmsg[2048];
DEFiRet;

fklog = open(_PATH_KLOG, O_RDONLY, 0);
fklog = open(_PATH_KLOG, O_RDONLY | O_NONBLOCK, 0);
if (fklog < 0) {
imkmsgLogIntMsg(LOG_ERR, "imkmsg: cannot open kernel log (%s): %s.",
_PATH_KLOG, rs_strerror_r(errno, errmsg, sizeof(errmsg)));
Expand All @@ -184,7 +202,7 @@ klogWillRunPostPrivDrop(modConfData_t __attribute__((unused)) *pModConf)
/* this normally returns EINVAL */
/* on an OpenVZ VM, we get EPERM */
r = read(fklog, NULL, 0);
if (r < 0 && errno != EINVAL) {
if (r < 0 && errno != EINVAL && errno != EAGAIN && errno != EWOULDBLOCK) {
imkmsgLogIntMsg(LOG_ERR, "imkmsg: cannot open kernel log (%s): %s.",
_PATH_KLOG, rs_strerror_r(errno, errmsg, sizeof(errmsg)));
fklog = -1;
Expand All @@ -195,11 +213,19 @@ klogWillRunPostPrivDrop(modConfData_t __attribute__((unused)) *pModConf)
RETiRet;
}


static void
change_reads_to_blocking(const int fd)
{
const int flags = fcntl(fd, F_GETFL, 0);
fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
}

/* Read kernel log while data are available, each read() reads one
* record of printk buffer.
*/
static void
readkmsg(void)
readkmsg(modConfData_t *const pModConf)
{
int i;
uchar pRcv[8192+1];
Expand All @@ -210,7 +236,6 @@ readkmsg(void)

/* every read() from the opened device node receives one record of the printk buffer */
i = read(fklog, pRcv, 8192);

if (i > 0) {
/* successful read of message of nonzero length */
pRcv[i] = '\0';
Expand All @@ -220,7 +245,13 @@ readkmsg(void)
continue;
} else {
/* something went wrong - error or zero length message */
if (i < 0 && errno != EINTR && errno != EAGAIN) {
if(i < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) {
DBGPRINTF("imkmsg: initial read done, changing to blocking mode\n");
change_reads_to_blocking(fklog);
bInInitialReading = 0;
continue;
}
if(i < 0 && errno != EINTR && errno != EAGAIN) {
/* error occurred */
imkmsgLogIntMsg(LOG_ERR,
"imkmsg: error reading kernel log - shutting down: %s",
Expand All @@ -230,7 +261,7 @@ readkmsg(void)
break;
}

submitSyslog(pRcv);
submitSyslog(pModConf, pRcv);
}
}

Expand All @@ -254,10 +285,10 @@ rsRetVal klogAfterRun(modConfData_t *pModConf)
* "message pull" mechanism.
* rgerhards, 2008-04-09
*/
rsRetVal klogLogKMsg(modConfData_t __attribute__((unused)) *pModConf)
rsRetVal klogLogKMsg(modConfData_t *const pModConf)
{
DEFiRet;
readkmsg();
readkmsg(pModConf);
RETiRet;
}

Expand Down

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