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libvirt/src/util/logging.c
Daniel P. Berrange e7df360d56 Add a virLogMessage alternative taking va_list args 
Allow the logging APIs to be called with a va_list for format
args, instead of requiring var-args usage.

* src/util/logging.h, src/util/logging.c: Add virLogVMessage
2012-05-16 17:13:13 +01:00

1265 lines
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/*
* logging.c: internal logging and debugging
*
* Copyright (C) 2008, 2010-2012 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <config.h>
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <time.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
#if HAVE_SYSLOG_H
# include <syslog.h>
#endif
#ifdef HAVE_EXECINFO_H
# include <execinfo.h>
#endif
#include "ignore-value.h"
#include "virterror_internal.h"
#include "logging.h"
#include "memory.h"
#include "util.h"
#include "buf.h"
#include "threads.h"
#include "virfile.h"
#include "virtime.h"
#define VIR_FROM_THIS VIR_FROM_NONE
/*
* A logging buffer to keep some history over logs
*/
static int virLogSize = 64 * 1024;
static char *virLogBuffer = NULL;
static int virLogLen = 0;
static int virLogStart = 0;
static int virLogEnd = 0;
/*
* Filters are used to refine the rules on what to keep or drop
* based on a matching pattern (currently a substring)
*/
struct _virLogFilter {
const char *match;
int priority;
unsigned int flags;
};
typedef struct _virLogFilter virLogFilter;
typedef virLogFilter *virLogFilterPtr;
static virLogFilterPtr virLogFilters = NULL;
static int virLogNbFilters = 0;
/*
* Outputs are used to emit the messages retained
* after filtering, multiple output can be used simultaneously
*/
struct _virLogOutput {
bool logVersion;
void *data;
virLogOutputFunc f;
virLogCloseFunc c;
int priority;
virLogDestination dest;
const char *name;
};
typedef struct _virLogOutput virLogOutput;
typedef virLogOutput *virLogOutputPtr;
static virLogOutputPtr virLogOutputs = NULL;
static int virLogNbOutputs = 0;
/*
* Default priorities
*/
static virLogPriority virLogDefaultPriority = VIR_LOG_DEFAULT;
static int virLogResetFilters(void);
static int virLogResetOutputs(void);
static int virLogOutputToFd(const char *category, int priority,
const char *funcname, long long linenr,
const char *timestamp,
unsigned int flags,
const char *str,
void *data);
/*
* Logs accesses must be serialized though a mutex
*/
virMutex virLogMutex;
void virLogLock(void)
{
virMutexLock(&virLogMutex);
}
void virLogUnlock(void)
{
virMutexUnlock(&virLogMutex);
}
static const char *virLogOutputString(virLogDestination ldest) {
switch (ldest) {
case VIR_LOG_TO_STDERR:
return "stderr";
case VIR_LOG_TO_SYSLOG:
return "syslog";
case VIR_LOG_TO_FILE:
return "file";
}
return "unknown";
}
static const char *virLogPriorityString(virLogPriority lvl) {
switch (lvl) {
case VIR_LOG_DEBUG:
return "debug";
case VIR_LOG_INFO:
return "info";
case VIR_LOG_WARN:
return "warning";
case VIR_LOG_ERROR:
return "error";
}
return "unknown";
}
static int virLogInitialized = 0;
/**
* virLogStartup:
*
* Initialize the logging module
*
* Returns 0 if successful, and -1 in case or error
*/
int virLogStartup(void) {
const char *pbm = NULL;
if (virLogInitialized)
return -1;
if (virMutexInit(&virLogMutex) < 0)
return -1;
virLogInitialized = 1;
virLogLock();
if (VIR_ALLOC_N(virLogBuffer, virLogSize + 1) < 0) {
/*
* The debug buffer is not a critical component, allow startup
* even in case of failure to allocate it in case of a
* configuration mistake.
*/
virLogSize = 64 * 1024;
if (VIR_ALLOC_N(virLogBuffer, virLogSize + 1) < 0) {
pbm = "Failed to allocate debug buffer: deactivating debug log\n";
virLogSize = 0;
} else {
pbm = "Failed to allocate debug buffer: reduced to 64 kB\n";
}
}
virLogLen = 0;
virLogStart = 0;
virLogEnd = 0;
virLogDefaultPriority = VIR_LOG_DEFAULT;
virLogUnlock();
if (pbm)
VIR_WARN("%s", pbm);
return 0;
}
/**
* virLogSetBufferSize:
* @size: size of the buffer in kilobytes or <= 0 to deactivate
*
* Dynamically set the size or deactivate the logging buffer used to keep
* a trace of all recent debug output. Note that the content of the buffer
* is lost if it gets reallocated.
*
* Return -1 in case of failure or 0 in case of success
*/
extern int
virLogSetBufferSize(int size) {
int ret = 0;
int oldsize;
char *oldLogBuffer;
const char *pbm = NULL;
if (size < 0)
size = 0;
if ((virLogInitialized == 0) || (size * 1024 == virLogSize))
return ret;
virLogLock();
oldsize = virLogSize;
oldLogBuffer = virLogBuffer;
if (INT_MAX / 1024 <= size) {
pbm = "Requested log size of %d kB too large\n";
ret = -1;
goto error;
}
virLogSize = size * 1024;
if (VIR_ALLOC_N(virLogBuffer, virLogSize + 1) < 0) {
pbm = "Failed to allocate debug buffer of %d kB\n";
virLogBuffer = oldLogBuffer;
virLogSize = oldsize;
ret = -1;
goto error;
}
VIR_FREE(oldLogBuffer);
virLogLen = 0;
virLogStart = 0;
virLogEnd = 0;
error:
virLogUnlock();
if (pbm)
VIR_ERROR(pbm, size);
return ret;
}
/**
* virLogReset:
*
* Reset the logging module to its default initial state
*
* Returns 0 if successful, and -1 in case or error
*/
int virLogReset(void) {
if (!virLogInitialized)
return virLogStartup();
virLogLock();
virLogResetFilters();
virLogResetOutputs();
virLogLen = 0;
virLogStart = 0;
virLogEnd = 0;
virLogDefaultPriority = VIR_LOG_DEFAULT;
virLogUnlock();
return 0;
}
/**
* virLogShutdown:
*
* Shutdown the logging module
*/
void virLogShutdown(void) {
if (!virLogInitialized)
return;
virLogLock();
virLogResetFilters();
virLogResetOutputs();
virLogLen = 0;
virLogStart = 0;
virLogEnd = 0;
VIR_FREE(virLogBuffer);
virLogUnlock();
virMutexDestroy(&virLogMutex);
virLogInitialized = 0;
}
/*
* Store a string in the ring buffer
*/
static void virLogStr(const char *str)
{
int tmp;
int len;
if ((str == NULL) || (virLogBuffer == NULL) || (virLogSize <= 0))
return;
len = strlen(str);
if (len >= virLogSize)
return;
/*
* copy the data and reset the end, we cycle over the end of the buffer
*/
if (virLogEnd + len >= virLogSize) {
tmp = virLogSize - virLogEnd;
memcpy(&virLogBuffer[virLogEnd], str, tmp);
memcpy(&virLogBuffer[0], &str[tmp], len - tmp);
virLogEnd = len - tmp;
} else {
memcpy(&virLogBuffer[virLogEnd], str, len);
virLogEnd += len;
}
virLogBuffer[virLogEnd] = 0;
/*
* Update the log length, and if full move the start index
*/
virLogLen += len;
if (virLogLen > virLogSize) {
tmp = virLogLen - virLogSize;
virLogLen = virLogSize;
virLogStart += tmp;
if (virLogStart >= virLogSize)
virLogStart -= virLogSize;
}
}
static void virLogDumpAllFD(const char *msg, int len) {
int i, found = 0;
if (len <= 0)
len = strlen(msg);
for (i = 0; i < virLogNbOutputs;i++) {
if (virLogOutputs[i].f == virLogOutputToFd) {
int fd = (intptr_t) virLogOutputs[i].data;
if (fd >= 0) {
ignore_value (safewrite(fd, msg, len));
found = 1;
}
}
}
if (!found)
ignore_value (safewrite(STDERR_FILENO, msg, len));
}
/**
* virLogEmergencyDumpAll:
* @signum: the signal number
*
* Emergency function called, possibly from a signal handler.
* It need to output the debug ring buffer through the log
* output which are safe to use from a signal handler.
* In case none is found it is emitted to standard error.
*/
void
virLogEmergencyDumpAll(int signum) {
int len;
int oldLogStart, oldLogLen;
switch (signum) {
#ifdef SIGFPE
case SIGFPE:
virLogDumpAllFD( "Caught signal Floating-point exception", -1);
break;
#endif
#ifdef SIGSEGV
case SIGSEGV:
virLogDumpAllFD( "Caught Segmentation violation", -1);
break;
#endif
#ifdef SIGILL
case SIGILL:
virLogDumpAllFD( "Caught illegal instruction", -1);
break;
#endif
#ifdef SIGABRT
case SIGABRT:
virLogDumpAllFD( "Caught abort signal", -1);
break;
#endif
#ifdef SIGBUS
case SIGBUS:
virLogDumpAllFD( "Caught bus error", -1);
break;
#endif
#ifdef SIGUSR2
case SIGUSR2:
virLogDumpAllFD( "Caught User-defined signal 2", -1);
break;
#endif
default:
virLogDumpAllFD( "Caught unexpected signal", -1);
break;
}
if ((virLogBuffer == NULL) || (virLogSize <= 0)) {
virLogDumpAllFD(" internal log buffer deactivated\n", -1);
return;
}
virLogDumpAllFD(" dumping internal log buffer:\n", -1);
virLogDumpAllFD("\n\n ====== start of log =====\n\n", -1);
/*
* Since we can't lock the buffer safely from a signal handler
* we mark it as empty in case of concurrent access, and proceed
* with the data, at worse we will output something a bit weird
* if another thread start logging messages at the same time.
* Note that virLogStr() uses virLogEnd for the computations and
* writes to the buffer and only then updates virLogLen and virLogStart
* so it's best to reset it first.
*/
oldLogStart = virLogStart;
oldLogLen = virLogLen;
virLogEnd = 0;
virLogLen = 0;
virLogStart = 0;
while (oldLogLen > 0) {
if (oldLogStart + oldLogLen < virLogSize) {
virLogBuffer[oldLogStart + oldLogLen] = 0;
virLogDumpAllFD(&virLogBuffer[oldLogStart], oldLogLen);
oldLogStart += oldLogLen;
oldLogLen = 0;
} else {
len = virLogSize - oldLogStart;
virLogBuffer[virLogSize] = 0;
virLogDumpAllFD(&virLogBuffer[oldLogStart], len);
oldLogLen -= len;
oldLogStart = 0;
}
}
virLogDumpAllFD("\n\n ====== end of log =====\n\n", -1);
}
/**
* virLogSetDefaultPriority:
* @priority: the default priority level
*
* Set the default priority level, i.e. any logged data of a priority
* equal or superior to this level will be logged, unless a specific rule
* was defined for the log category of the message.
*
* Returns 0 if successful, -1 in case of error.
*/
int virLogSetDefaultPriority(int priority) {
if ((priority < VIR_LOG_DEBUG) || (priority > VIR_LOG_ERROR)) {
VIR_WARN("Ignoring invalid log level setting.");
return -1;
}
if (!virLogInitialized)
virLogStartup();
virLogDefaultPriority = priority;
return 0;
}
/**
* virLogResetFilters:
*
* Removes the set of logging filters defined.
*
* Returns the number of filters removed
*/
static int virLogResetFilters(void) {
int i;
for (i = 0; i < virLogNbFilters;i++)
VIR_FREE(virLogFilters[i].match);
VIR_FREE(virLogFilters);
virLogNbFilters = 0;
return i;
}
/**
* virLogDefineFilter:
* @match: the pattern to match
* @priority: the priority to give to messages matching the pattern
* @flags: extra flags, see virLogFilterFlags enum
*
* Defines a pattern used for log filtering, it allow to select or
* reject messages independently of the default priority.
* The filter defines a rules that will apply only to messages matching
* the pattern (currently if @match is a substring of the message category)
*
* Returns -1 in case of failure or the filter number if successful
*/
int virLogDefineFilter(const char *match, int priority,
unsigned int flags)
{
int i;
char *mdup = NULL;
virCheckFlags(VIR_LOG_STACK_TRACE, -1);
if ((match == NULL) || (priority < VIR_LOG_DEBUG) ||
(priority > VIR_LOG_ERROR))
return -1;
virLogLock();
for (i = 0;i < virLogNbFilters;i++) {
if (STREQ(virLogFilters[i].match, match)) {
virLogFilters[i].priority = priority;
goto cleanup;
}
}
mdup = strdup(match);
if (mdup == NULL) {
i = -1;
goto cleanup;
}
i = virLogNbFilters;
if (VIR_REALLOC_N(virLogFilters, virLogNbFilters + 1)) {
i = -1;
VIR_FREE(mdup);
goto cleanup;
}
virLogFilters[i].match = mdup;
virLogFilters[i].priority = priority;
virLogFilters[i].flags = flags;
virLogNbFilters++;
cleanup:
virLogUnlock();
return i;
}
/**
* virLogFiltersCheck:
* @input: the input string
*
* Check the input of the message against the existing filters. Currently
* the match is just a substring check of the category used as the input
* string, a more subtle approach could be used instead
*
* Returns 0 if not matched or the new priority if found.
*/
static int virLogFiltersCheck(const char *input,
unsigned int *flags) {
int ret = 0;
int i;
virLogLock();
for (i = 0;i < virLogNbFilters;i++) {
if (strstr(input, virLogFilters[i].match)) {
ret = virLogFilters[i].priority;
*flags = virLogFilters[i].flags;
break;
}
}
virLogUnlock();
return ret;
}
/**
* virLogResetOutputs:
*
* Removes the set of logging output defined.
*
* Returns the number of output removed
*/
static int virLogResetOutputs(void) {
int i;
for (i = 0;i < virLogNbOutputs;i++) {
if (virLogOutputs[i].c != NULL)
virLogOutputs[i].c(virLogOutputs[i].data);
VIR_FREE(virLogOutputs[i].name);
}
VIR_FREE(virLogOutputs);
i = virLogNbOutputs;
virLogNbOutputs = 0;
return i;
}
/**
* virLogDefineOutput:
* @f: the function to call to output a message
* @c: the function to call to close the output (or NULL)
* @data: extra data passed as first arg to the function
* @priority: minimal priority for this filter, use 0 for none
* @dest: where to send output of this priority
* @name: optional name data associated with an output
* @flags: extra flag, currently unused
*
* Defines an output function for log messages. Each message once
* gone though filtering is emitted through each registered output.
*
* Returns -1 in case of failure or the output number if successful
*/
int virLogDefineOutput(virLogOutputFunc f, virLogCloseFunc c, void *data,
int priority, int dest, const char *name,
unsigned int flags)
{
int ret = -1;
char *ndup = NULL;
virCheckFlags(0, -1);
if (f == NULL)
return -1;
if (dest == VIR_LOG_TO_SYSLOG || dest == VIR_LOG_TO_FILE) {
if (name == NULL)
return -1;
ndup = strdup(name);
if (ndup == NULL)
return -1;
}
virLogLock();
if (VIR_REALLOC_N(virLogOutputs, virLogNbOutputs + 1)) {
VIR_FREE(ndup);
goto cleanup;
}
ret = virLogNbOutputs++;
virLogOutputs[ret].logVersion = true;
virLogOutputs[ret].f = f;
virLogOutputs[ret].c = c;
virLogOutputs[ret].data = data;
virLogOutputs[ret].priority = priority;
virLogOutputs[ret].dest = dest;
virLogOutputs[ret].name = ndup;
cleanup:
virLogUnlock();
return ret;
}
static int
virLogFormatString(char **msg,
const char *funcname,
long long linenr,
int priority,
const char *str)
{
int ret;
/*
* Be careful when changing the following log message formatting, we rely
* on it when stripping libvirt debug messages from qemu log files. So when
* changing this, you might also need to change the code there.
* virLogFormatString() function name is mentioned there so it's sufficient
* to just grep for it to find the right place.
*/
if ((funcname != NULL)) {
ret = virAsprintf(msg, "%d: %s : %s:%lld : %s\n",
virThreadSelfID(), virLogPriorityString(priority),
funcname, linenr, str);
} else {
ret = virAsprintf(msg, "%d: %s : %s\n",
virThreadSelfID(), virLogPriorityString(priority),
str);
}
return ret;
}
static int
virLogVersionString(char **msg)
{
#ifdef PACKAGER_VERSION
# ifdef PACKAGER
# define LOG_VERSION_STRING \
"libvirt version: " VERSION ", package: " PACKAGER_VERSION " (" PACKAGER ")"
# else
# define LOG_VERSION_STRING \
"libvirt version: " VERSION ", package: " PACKAGER_VERSION
# endif
#else
# define LOG_VERSION_STRING \
"libvirt version: " VERSION
#endif
return virLogFormatString(msg, NULL, 0, VIR_LOG_INFO, LOG_VERSION_STRING);
}
/**
* virLogMessage:
* @category: where is that message coming from
* @priority: the priority level
* @funcname: the function emitting the (debug) message
* @linenr: line where the message was emitted
* @flags: extra flags, 1 if coming from the error handler
* @fmt: the string format
* @...: the arguments
*
* Call the libvirt logger with some information. Based on the configuration
* the message may be stored, sent to output or just discarded
*/
void virLogMessage(const char *category, int priority, const char *funcname,
long long linenr, unsigned int flags, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
virLogVMessage(category, priority, funcname, linenr, flags, fmt, ap);
va_end(ap);
}
/**
* virLogVMessage:
* @category: where is that message coming from
* @priority: the priority level
* @funcname: the function emitting the (debug) message
* @linenr: line where the message was emitted
* @flags: extra flags, 1 if coming from the error handler
* @fmt: the string format
* @vargs: format args
*
* Call the libvirt logger with some information. Based on the configuration
* the message may be stored, sent to output or just discarded
*/
void virLogVMessage(const char *category, int priority, const char *funcname,
long long linenr, unsigned int flags, const char *fmt,
va_list vargs)
{
static bool logVersionStderr = true;
char *str = NULL;
char *msg = NULL;
char timestamp[VIR_TIME_STRING_BUFLEN];
int fprio, i, ret;
int saved_errno = errno;
int emit = 1;
unsigned int filterflags = 0;
if (!virLogInitialized)
virLogStartup();
if (fmt == NULL)
goto cleanup;
/*
* check against list of specific logging patterns
*/
fprio = virLogFiltersCheck(category, &filterflags);
if (fprio == 0) {
if (priority < virLogDefaultPriority)
emit = 0;
} else if (priority < fprio) {
emit = 0;
}
if ((emit == 0) && ((virLogBuffer == NULL) || (virLogSize <= 0)))
goto cleanup;
/*
* serialize the error message, add level and timestamp
*/
if (virVasprintf(&str, fmt, vargs) < 0) {
goto cleanup;
}
ret = virLogFormatString(&msg, funcname, linenr, priority, str);
VIR_FREE(str);
if (ret < 0)
goto cleanup;
if (virTimeStringNowRaw(timestamp) < 0)
timestamp[0] = '\0';
/*
* Log based on defaults, first store in the history buffer,
* then if emit push the message on the outputs defined, if none
* use stderr.
* NOTE: the locking is a single point of contention for multiple
* threads, but avoid intermixing. Maybe set up locks per output
* to improve paralellism.
*/
virLogLock();
virLogStr(timestamp);
virLogStr(msg);
virLogUnlock();
if (emit == 0)
goto cleanup;
virLogLock();
for (i = 0; i < virLogNbOutputs; i++) {
if (priority >= virLogOutputs[i].priority) {
if (virLogOutputs[i].logVersion) {
char *ver = NULL;
if (virLogVersionString(&ver) >= 0)
virLogOutputs[i].f(category, VIR_LOG_INFO,
__func__, __LINE__,
timestamp, 0, ver,
virLogOutputs[i].data);
VIR_FREE(ver);
virLogOutputs[i].logVersion = false;
}
virLogOutputs[i].f(category, priority, funcname, linenr,
timestamp, filterflags,
msg, virLogOutputs[i].data);
}
}
if ((virLogNbOutputs == 0) && (flags != 1)) {
if (logVersionStderr) {
char *ver = NULL;
if (virLogVersionString(&ver) >= 0)
virLogOutputToFd(category, VIR_LOG_INFO,
__func__, __LINE__,
timestamp, 0, ver,
(void *) STDERR_FILENO);
VIR_FREE(ver);
logVersionStderr = false;
}
virLogOutputToFd(category, priority, funcname, linenr,
timestamp, filterflags,
msg, (void *) STDERR_FILENO);
}
virLogUnlock();
cleanup:
VIR_FREE(msg);
errno = saved_errno;
}
static void virLogStackTraceToFd(int fd)
{
#ifdef HAVE_EXECINFO_H
void *array[100];
int size;
# define STRIP_DEPTH 3
size = backtrace(array, ARRAY_CARDINALITY(array));
backtrace_symbols_fd(array + STRIP_DEPTH, size - STRIP_DEPTH, fd);
ignore_value(safewrite(fd, "\n", 1));
#else
static bool doneWarning = false;
const char *msg = "Stack trace not available on this platform\n";
if (!doneWarning) {
ignore_value(safewrite(fd, msg, strlen(msg)));
doneWarning = true;
}
#endif
}
static int virLogOutputToFd(const char *category ATTRIBUTE_UNUSED,
int priority ATTRIBUTE_UNUSED,
const char *funcname ATTRIBUTE_UNUSED,
long long linenr ATTRIBUTE_UNUSED,
const char *timestamp,
unsigned int flags,
const char *str,
void *data)
{
int fd = (intptr_t) data;
int ret;
char *msg;
if (fd < 0)
return -1;
if (virAsprintf(&msg, "%s: %s", timestamp, str) < 0)
return -1;
ret = safewrite(fd, msg, strlen(msg));
VIR_FREE(msg);
if (flags & VIR_LOG_STACK_TRACE)
virLogStackTraceToFd(fd);
return ret;
}
static void virLogCloseFd(void *data) {
int fd = (intptr_t) data;
VIR_FORCE_CLOSE(fd);
}
static int virLogAddOutputToStderr(int priority) {
if (virLogDefineOutput(virLogOutputToFd, NULL, (void *)2L, priority,
VIR_LOG_TO_STDERR, NULL, 0) < 0)
return -1;
return 0;
}
static int virLogAddOutputToFile(int priority, const char *file) {
int fd;
fd = open(file, O_CREAT | O_APPEND | O_WRONLY, S_IRUSR | S_IWUSR);
if (fd < 0)
return -1;
if (virLogDefineOutput(virLogOutputToFd, virLogCloseFd,
(void *)(intptr_t)fd,
priority, VIR_LOG_TO_FILE, file, 0) < 0) {
VIR_FORCE_CLOSE(fd);
return -1;
}
return 0;
}
#if HAVE_SYSLOG_H
static int virLogOutputToSyslog(const char *category ATTRIBUTE_UNUSED,
int priority,
const char *funcname ATTRIBUTE_UNUSED,
long long linenr ATTRIBUTE_UNUSED,
const char *timestamp ATTRIBUTE_UNUSED,
unsigned int flags,
const char *str,
void *data ATTRIBUTE_UNUSED)
{
int prio;
virCheckFlags(VIR_LOG_STACK_TRACE, -1);
switch (priority) {
case VIR_LOG_DEBUG:
prio = LOG_DEBUG;
break;
case VIR_LOG_INFO:
prio = LOG_INFO;
break;
case VIR_LOG_WARN:
prio = LOG_WARNING;
break;
case VIR_LOG_ERROR:
prio = LOG_ERR;
break;
default:
prio = LOG_ERR;
}
syslog(prio, "%s", str);
return strlen(str);
}
static char *current_ident = NULL;
static void virLogCloseSyslog(void *data ATTRIBUTE_UNUSED) {
closelog();
VIR_FREE(current_ident);
}
static int virLogAddOutputToSyslog(int priority, const char *ident) {
/*
* ident needs to be kept around on Solaris
*/
VIR_FREE(current_ident);
current_ident = strdup(ident);
if (current_ident == NULL)
return -1;
openlog(current_ident, 0, 0);
if (virLogDefineOutput(virLogOutputToSyslog, virLogCloseSyslog, NULL,
priority, VIR_LOG_TO_SYSLOG, ident, 0) < 0) {
closelog();
VIR_FREE(current_ident);
return -1;
}
return 0;
}
#endif /* HAVE_SYSLOG_H */
#define IS_SPACE(cur) \
((*cur == ' ') || (*cur == '\t') || (*cur == '\n') || \
(*cur == '\r') || (*cur == '\\'))
/**
* virLogParseOutputs:
* @outputs: string defining a (set of) output(s)
*
* The format for an output can be:
* x:stderr
* output goes to stderr
* x:syslog:name
* use syslog for the output and use the given name as the ident
* x:file:file_path
* output to a file, with the given filepath
* In all case the x prefix is the minimal level, acting as a filter
* 0: everything
* 1: DEBUG
* 2: INFO
* 3: WARNING
* 4: ERROR
*
* Multiple output can be defined in a single @output, they just need to be
* separated by spaces.
*
* Returns the number of output parsed and installed or -1 in case of error
*/
int virLogParseOutputs(const char *outputs) {
const char *cur = outputs, *str;
char *name;
char *abspath;
int prio;
int ret = -1;
int count = 0;
if (cur == NULL)
return -1;
virSkipSpaces(&cur);
while (*cur != 0) {
prio= virParseNumber(&cur);
if ((prio < VIR_LOG_DEBUG) || (prio > VIR_LOG_ERROR))
goto cleanup;
if (*cur != ':')
goto cleanup;
cur++;
if (STREQLEN(cur, "stderr", 6)) {
cur += 6;
if (virLogAddOutputToStderr(prio) == 0)
count++;
} else if (STREQLEN(cur, "syslog", 6)) {
cur += 6;
if (*cur != ':')
goto cleanup;
cur++;
str = cur;
while ((*cur != 0) && (!IS_SPACE(cur)))
cur++;
if (str == cur)
goto cleanup;
#if HAVE_SYSLOG_H
name = strndup(str, cur - str);
if (name == NULL)
goto cleanup;
if (virLogAddOutputToSyslog(prio, name) == 0)
count++;
VIR_FREE(name);
#endif /* HAVE_SYSLOG_H */
} else if (STREQLEN(cur, "file", 4)) {
cur += 4;
if (*cur != ':')
goto cleanup;
cur++;
str = cur;
while ((*cur != 0) && (!IS_SPACE(cur)))
cur++;
if (str == cur)
goto cleanup;
name = strndup(str, cur - str);
if (name == NULL)
goto cleanup;
if (virFileAbsPath(name, &abspath) < 0) {
VIR_FREE(name);
return -1; /* skip warning here because setting was fine */
}
if (virLogAddOutputToFile(prio, abspath) == 0)
count++;
VIR_FREE(name);
VIR_FREE(abspath);
} else {
goto cleanup;
}
virSkipSpaces(&cur);
}
ret = count;
cleanup:
if (ret == -1)
VIR_WARN("Ignoring invalid log output setting.");
return ret;
}
/**
* virLogParseFilters:
* @filters: string defining a (set of) filter(s)
*
* The format for a filter is:
* x:name
* where name is a match string
* the x prefix is the minimal level where the messages should be logged
* 1: DEBUG
* 2: INFO
* 3: WARNING
* 4: ERROR
*
* Multiple filter can be defined in a single @filters, they just need to be
* separated by spaces.
*
* Returns the number of filter parsed and installed or -1 in case of error
*/
int virLogParseFilters(const char *filters) {
const char *cur = filters, *str;
char *name;
int prio;
int ret = -1;
int count = 0;
if (cur == NULL)
return -1;
virSkipSpaces(&cur);
while (*cur != 0) {
unsigned int flags = 0;
prio= virParseNumber(&cur);
if ((prio < VIR_LOG_DEBUG) || (prio > VIR_LOG_ERROR))
goto cleanup;
if (*cur != ':')
goto cleanup;
cur++;
if (*cur == '+') {
flags |= VIR_LOG_STACK_TRACE;
cur++;
}
str = cur;
while ((*cur != 0) && (!IS_SPACE(cur)))
cur++;
if (str == cur)
goto cleanup;
name = strndup(str, cur - str);
if (name == NULL)
goto cleanup;
if (virLogDefineFilter(name, prio, flags) >= 0)
count++;
VIR_FREE(name);
virSkipSpaces(&cur);
}
ret = count;
cleanup:
if (ret == -1)
VIR_WARN("Ignoring invalid log filter setting.");
return ret;
}
/**
* virLogGetDefaultPriority:
*
* Returns the current logging priority level.
*/
int virLogGetDefaultPriority(void) {
return virLogDefaultPriority;
}
/**
* virLogGetFilters:
*
* Returns a string listing the current filters, in the format originally
* specified in the config file or environment. Caller must free the
* result.
*/
char *virLogGetFilters(void) {
int i;
virBuffer filterbuf = VIR_BUFFER_INITIALIZER;
virLogLock();
for (i = 0; i < virLogNbFilters; i++) {
const char *sep = ":";
if (virLogFilters[i].flags & VIR_LOG_STACK_TRACE)
sep = ":+";
virBufferAsprintf(&filterbuf, "%d%s%s ",
virLogFilters[i].priority,
sep,
virLogFilters[i].match);
}
virLogUnlock();
if (virBufferError(&filterbuf)) {
virBufferFreeAndReset(&filterbuf);
return NULL;
}
return virBufferContentAndReset(&filterbuf);
}
/**
* virLogGetOutputs:
*
* Returns a string listing the current outputs, in the format originally
* specified in the config file or environment. Caller must free the
* result.
*/
char *virLogGetOutputs(void) {
int i;
virBuffer outputbuf = VIR_BUFFER_INITIALIZER;
virLogLock();
for (i = 0; i < virLogNbOutputs; i++) {
int dest = virLogOutputs[i].dest;
if (i)
virBufferAsprintf(&outputbuf, " ");
switch (dest) {
case VIR_LOG_TO_SYSLOG:
case VIR_LOG_TO_FILE:
virBufferAsprintf(&outputbuf, "%d:%s:%s",
virLogOutputs[i].priority,
virLogOutputString(dest),
virLogOutputs[i].name);
break;
default:
virBufferAsprintf(&outputbuf, "%d:%s",
virLogOutputs[i].priority,
virLogOutputString(dest));
}
}
virLogUnlock();
if (virBufferError(&outputbuf)) {
virBufferFreeAndReset(&outputbuf);
return NULL;
}
return virBufferContentAndReset(&outputbuf);
}
/**
* virLogGetNbFilters:
*
* Returns the current number of defined log filters.
*/
int virLogGetNbFilters(void) {
return virLogNbFilters;
}
/**
* virLogGetNbOutputs:
*
* Returns the current number of defined log outputs.
*/
int virLogGetNbOutputs(void) {
return virLogNbOutputs;
}
/**
* virLogParseDefaultPriority:
* @priority: string defining the desired logging level
*
* Parses and sets the default log priority level. It can take a string or
* number corresponding to the following levels:
* 1: DEBUG
* 2: INFO
* 3: WARNING
* 4: ERROR
*
* Returns the parsed log level or -1 on error.
*/
int virLogParseDefaultPriority(const char *priority) {
int ret = -1;
if (STREQ(priority, "1") || STREQ(priority, "debug"))
ret = virLogSetDefaultPriority(VIR_LOG_DEBUG);
else if (STREQ(priority, "2") || STREQ(priority, "info"))
ret = virLogSetDefaultPriority(VIR_LOG_INFO);
else if (STREQ(priority, "3") || STREQ(priority, "warning"))
ret = virLogSetDefaultPriority(VIR_LOG_WARN);
else if (STREQ(priority, "4") || STREQ(priority, "error"))
ret = virLogSetDefaultPriority(VIR_LOG_ERROR);
else
VIR_WARN("Ignoring invalid log level setting");
return ret;
}
/**
* virLogSetFromEnv:
*
* Sets virLogDefaultPriority, virLogFilters and virLogOutputs based on
* environment variables.
*/
void virLogSetFromEnv(void) {
char *debugEnv;
debugEnv = getenv("LIBVIRT_DEBUG");
if (debugEnv && *debugEnv)
virLogParseDefaultPriority(debugEnv);
debugEnv = getenv("LIBVIRT_LOG_FILTERS");
if (debugEnv && *debugEnv)
virLogParseFilters(debugEnv);
debugEnv = getenv("LIBVIRT_LOG_OUTPUTS");
if (debugEnv && *debugEnv)
virLogParseOutputs(debugEnv);
}
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