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libvirt/src/util/logging.c
Miloslav Trmač 39c814ff46 Use helper functions to format the journal iov array 
This simplifies the top-level code, at the cost of using a little more
stack space.  The primary benefit is being able to send more fields
without knowing in advance how many of them, and of which types, these
fields will be, and without having to individually add buffer variables.

The code imposes an upper limit on the total number of iovs/buffers
used, and fields that wouldn't fit are silently dropped.  This is not
significant in this patch, but will affect the following one.

Signed-off-by: Miloslav Trmač <mitr@redhat.com>
2012-11-14 20:20:02 -07:00

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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, see
* <http://www.gnu.org/licenses/>.
*
*/
#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>
#include <execinfo.h>
#if HAVE_SYSLOG_H
# include <syslog.h>
#endif
#include <sys/socket.h>
#if HAVE_SYS_UN_H
# include <sys/un.h>
#endif
#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"
#include "intprops.h"
/* Journald output is only supported on Linux new enough to expose
* htole64. */
#if HAVE_SYSLOG_H && defined(__linux__) && HAVE_DECL_HTOLE64
# define USE_JOURNALD 1
#endif
#define VIR_FROM_THIS VIR_FROM_NONE
VIR_ENUM_DECL(virLogSource)
VIR_ENUM_IMPL(virLogSource, VIR_LOG_FROM_LAST,
"file",
"error",
"audit",
"trace",
"library");
/*
* 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;
virLogPriority 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;
virLogPriority 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 void virLogOutputToFd(virLogSource src,
virLogPriority priority,
const char *filename,
int linenr,
const char *funcname,
const char *timestamp,
virLogMetadataPtr metadata,
unsigned int flags,
const char *rawstr,
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";
case VIR_LOG_TO_JOURNALD:
return "journald";
}
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
virLogOnceInit(void)
{
const char *pbm = NULL;
if (virMutexInit(&virLogMutex) < 0)
return -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;
}
VIR_ONCE_GLOBAL_INIT(virLog)
/**
* 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
*/
int
virLogSetBufferSize(int size)
{
int ret = 0;
int oldsize;
char *oldLogBuffer;
const char *pbm = NULL;
if (size < 0)
size = 0;
if (virLogInitialize() < 0)
return -1;
if (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 (virLogInitialize() < 0)
return -1;
virLogLock();
virLogResetFilters();
virLogResetOutputs();
virLogLen = 0;
virLogStart = 0;
virLogEnd = 0;
virLogDefaultPriority = VIR_LOG_DEFAULT;
virLogUnlock();
return 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(virLogPriority priority)
{
if ((priority < VIR_LOG_DEBUG) || (priority > VIR_LOG_ERROR)) {
VIR_WARN("Ignoring invalid log level setting.");
return -1;
}
if (virLogInitialize() < 0)
return -1;
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,
virLogPriority 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,
virLogPriority priority,
virLogDestination 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,
int linenr,
const char *funcname,
virLogPriority 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:%d : %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(const char **rawmsg,
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
*rawmsg = LOG_VERSION_STRING;
return virLogFormatString(msg, 0, NULL, VIR_LOG_INFO, LOG_VERSION_STRING);
}
/**
* virLogMessage:
* @source: where is that message coming from
* @priority: the priority level
* @filename: file where the message was emitted
* @linenr: line where the message was emitted
* @funcname: the function emitting the (debug) message
* @metadata: NULL or metadata array, terminated by an item with NULL key
* @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(virLogSource source,
virLogPriority priority,
const char *filename,
int linenr,
const char *funcname,
virLogMetadataPtr metadata,
const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
virLogVMessage(source, priority,
filename, linenr, funcname,
metadata, fmt, ap);
va_end(ap);
}
/**
* virLogVMessage:
* @source: where is that message coming from
* @priority: the priority level
* @filename: file where the message was emitted
* @linenr: line where the message was emitted
* @funcname: the function emitting the (debug) message
* @metadata: NULL or metadata array, terminated by an item with NULL key
* @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(virLogSource source,
virLogPriority priority,
const char *filename,
int linenr,
const char *funcname,
virLogMetadataPtr metadata,
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 (virLogInitialize() < 0)
return;
if (fmt == NULL)
goto cleanup;
/*
* check against list of specific logging patterns
*/
fprio = virLogFiltersCheck(filename, &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, linenr, funcname, priority, 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) {
const char *rawver;
char *ver = NULL;
if (virLogVersionString(&rawver, &ver) >= 0)
virLogOutputs[i].f(VIR_LOG_FROM_FILE, VIR_LOG_INFO,
__FILE__, __LINE__, __func__,
timestamp, NULL, 0, rawver, ver,
virLogOutputs[i].data);
VIR_FREE(ver);
virLogOutputs[i].logVersion = false;
}
virLogOutputs[i].f(source, priority,
filename, linenr, funcname,
timestamp, metadata, filterflags,
str, msg, virLogOutputs[i].data);
}
}
if ((virLogNbOutputs == 0) && (source != VIR_LOG_FROM_ERROR)) {
if (logVersionStderr) {
const char *rawver;
char *ver = NULL;
if (virLogVersionString(&rawver, &ver) >= 0)
virLogOutputToFd(VIR_LOG_FROM_FILE, VIR_LOG_INFO,
__FILE__, __LINE__, __func__,
timestamp, NULL, 0, rawver, ver,
(void *) STDERR_FILENO);
VIR_FREE(ver);
logVersionStderr = false;
}
virLogOutputToFd(source, priority,
filename, linenr, funcname,
timestamp, metadata, filterflags,
str, msg, (void *) STDERR_FILENO);
}
virLogUnlock();
cleanup:
VIR_FREE(str);
VIR_FREE(msg);
errno = saved_errno;
}
static void
virLogStackTraceToFd(int fd)
{
void *array[100];
int size;
static bool doneWarning = false;
const char *msg = "Stack trace not available on this platform\n";
#define STRIP_DEPTH 3
size = backtrace(array, ARRAY_CARDINALITY(array));
if (size) {
backtrace_symbols_fd(array + STRIP_DEPTH, size - STRIP_DEPTH, fd);
ignore_value(safewrite(fd, "\n", 1));
} else if (!doneWarning) {
ignore_value(safewrite(fd, msg, strlen(msg)));
doneWarning = true;
}
#undef STRIP_DEPTH
}
static void
virLogOutputToFd(virLogSource source ATTRIBUTE_UNUSED,
virLogPriority priority ATTRIBUTE_UNUSED,
const char *filename ATTRIBUTE_UNUSED,
int linenr ATTRIBUTE_UNUSED,
const char *funcname ATTRIBUTE_UNUSED,
const char *timestamp,
virLogMetadataPtr metadata ATTRIBUTE_UNUSED,
unsigned int flags,
const char *rawstr ATTRIBUTE_UNUSED,
const char *str,
void *data)
{
int fd = (intptr_t) data;
char *msg;
if (fd < 0)
return;
if (virAsprintf(&msg, "%s: %s", timestamp, str) < 0)
return;
ignore_value(safewrite(fd, msg, strlen(msg)));
VIR_FREE(msg);
if (flags & VIR_LOG_STACK_TRACE)
virLogStackTraceToFd(fd);
}
static void
virLogCloseFd(void *data)
{
int fd = (intptr_t) data;
VIR_LOG_CLOSE(fd);
}
static int
virLogAddOutputToStderr(virLogPriority priority)
{
if (virLogDefineOutput(virLogOutputToFd, NULL, (void *)2L, priority,
VIR_LOG_TO_STDERR, NULL, 0) < 0)
return -1;
return 0;
}
static int
virLogAddOutputToFile(virLogPriority 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
virLogPrioritySyslog(virLogPriority priority)
{
switch (priority) {
case VIR_LOG_DEBUG:
return LOG_DEBUG;
case VIR_LOG_INFO:
return LOG_INFO;
case VIR_LOG_WARN:
return LOG_WARNING;
case VIR_LOG_ERROR:
return LOG_ERR;
default:
return LOG_ERR;
}
}
static void
virLogOutputToSyslog(virLogSource source ATTRIBUTE_UNUSED,
virLogPriority priority,
const char *filename ATTRIBUTE_UNUSED,
int linenr ATTRIBUTE_UNUSED,
const char *funcname ATTRIBUTE_UNUSED,
const char *timestamp ATTRIBUTE_UNUSED,
virLogMetadataPtr metadata ATTRIBUTE_UNUSED,
unsigned int flags,
const char *rawstr ATTRIBUTE_UNUSED,
const char *str,
void *data ATTRIBUTE_UNUSED)
{
virCheckFlags(VIR_LOG_STACK_TRACE,);
syslog(virLogPrioritySyslog(priority), "%s", str);
}
static char *current_ident = NULL;
static void
virLogCloseSyslog(void *data ATTRIBUTE_UNUSED)
{
closelog();
VIR_FREE(current_ident);
}
static int
virLogAddOutputToSyslog(virLogPriority 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;
}
# if USE_JOURNALD
# define IOVEC_SET(iov, data, size) \
do { \
struct iovec *_i = &(iov); \
_i->iov_base = (void*)(data); \
_i->iov_len = (size); \
} while (0)
# define IOVEC_SET_STRING(iov, str) IOVEC_SET(iov, str, strlen(str))
/* Used for conversion of numbers to strings, and for length of binary data */
# define JOURNAL_BUF_SIZE (MAX(INT_BUFSIZE_BOUND(int), sizeof(uint64_t)))
struct journalState
{
struct iovec *iov, *iov_end;
char (*bufs)[JOURNAL_BUF_SIZE], (*bufs_end)[JOURNAL_BUF_SIZE];
};
static void
journalAddString(struct journalState *state, const char *field,
const char *value)
{
static const char newline = '\n', equals = '=';
if (strchr(value, '\n') != NULL) {
uint64_t nstr;
/* If 'str' contains a newline, then we must
* encode the string length, since we can't
* rely on the newline for the field separator
*/
if (state->iov_end - state->iov < 5 || state->bufs == state->bufs_end)
return; /* Silently drop */
nstr = htole64(strlen(value));
memcpy(state->bufs[0], &nstr, sizeof(nstr));
IOVEC_SET_STRING(state->iov[0], field);
IOVEC_SET(state->iov[1], &newline, sizeof(newline));
IOVEC_SET(state->iov[2], state->bufs[0], sizeof(nstr));
state->bufs++;
state->iov += 3;
} else {
if (state->iov_end - state->iov < 4)
return; /* Silently drop */
IOVEC_SET_STRING(state->iov[0], field);
IOVEC_SET(state->iov[1], (void *)&equals, sizeof(equals));
state->iov += 2;
}
IOVEC_SET_STRING(state->iov[0], value);
IOVEC_SET(state->iov[1], (void *)&newline, sizeof(newline));
state->iov += 2;
}
static void
journalAddInt(struct journalState *state, const char *field, int value)
{
static const char newline = '\n', equals = '=';
char *num;
if (state->iov_end - state->iov < 4 || state->bufs == state->bufs_end)
return; /* Silently drop */
num = virFormatIntDecimal(state->bufs[0], sizeof(state->bufs[0]), value);
IOVEC_SET_STRING(state->iov[0], field);
IOVEC_SET(state->iov[1], (void *)&equals, sizeof(equals));
IOVEC_SET_STRING(state->iov[2], num);
IOVEC_SET(state->iov[3], (void *)&newline, sizeof(newline));
state->bufs++;
state->iov += 4;
}
static int journalfd = -1;
static void
virLogOutputToJournald(virLogSource source,
virLogPriority priority,
const char *filename,
int linenr,
const char *funcname,
const char *timestamp ATTRIBUTE_UNUSED,
virLogMetadataPtr metadata ATTRIBUTE_UNUSED,
unsigned int flags,
const char *rawstr,
const char *str ATTRIBUTE_UNUSED,
void *data ATTRIBUTE_UNUSED)
{
virCheckFlags(VIR_LOG_STACK_TRACE,);
int buffd = -1;
struct msghdr mh;
struct sockaddr_un sa;
union {
struct cmsghdr cmsghdr;
uint8_t buf[CMSG_SPACE(sizeof(int))];
} control;
struct cmsghdr *cmsg;
/* We use /dev/shm instead of /tmp here, since we want this to
* be a tmpfs, and one that is available from early boot on
* and where unprivileged users can create files. */
char path[] = "/dev/shm/journal.XXXXXX";
# define NUM_FIELDS 6
struct iovec iov[NUM_FIELDS * 5];
char iov_bufs[NUM_FIELDS][JOURNAL_BUF_SIZE];
struct journalState state;
state.iov = iov;
state.iov_end = iov + ARRAY_CARDINALITY(iov);
state.bufs = iov_bufs;
state.bufs_end = iov_bufs + ARRAY_CARDINALITY(iov_bufs);
journalAddString(&state ,"MESSAGE", rawstr);
journalAddInt(&state, "PRIORITY", priority);
journalAddString(&state, "LIBVIRT_SOURCE",
virLogSourceTypeToString(source));
journalAddString(&state, "CODE_FILE", filename);
journalAddInt(&state, "CODE_LINE", linenr);
journalAddString(&state, "CODE_FUNC", funcname);
memset(&sa, 0, sizeof(sa));
sa.sun_family = AF_UNIX;
if (!virStrcpy(sa.sun_path, "/run/systemd/journal/socket", sizeof(sa.sun_path)))
return;
memset(&mh, 0, sizeof(mh));
mh.msg_name = &sa;
mh.msg_namelen = offsetof(struct sockaddr_un, sun_path) + strlen(sa.sun_path);
mh.msg_iov = iov;
mh.msg_iovlen = state.iov - iov;
if (sendmsg(journalfd, &mh, MSG_NOSIGNAL) >= 0)
return;
if (errno != EMSGSIZE && errno != ENOBUFS)
return;
/* Message was too large, so dump to temporary file
* and pass an FD to the journal
*/
/* NB: mkostemp is not declared async signal safe by
* POSIX, but this is Linux only code and the GLibc
* impl is safe enough, only using open() and inline
* asm to read a timestamp (falling back to gettimeofday
* on some arches
*/
if ((buffd = mkostemp(path, O_CLOEXEC|O_RDWR)) < 0)
return;
if (unlink(path) < 0)
goto cleanup;
if (writev(buffd, iov, state.iov - iov) < 0)
goto cleanup;
mh.msg_iov = NULL;
mh.msg_iovlen = 0;
memset(&control, 0, sizeof(control));
mh.msg_control = &control;
mh.msg_controllen = sizeof(control);
cmsg = CMSG_FIRSTHDR(&mh);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
memcpy(CMSG_DATA(cmsg), &buffd, sizeof(int));
mh.msg_controllen = cmsg->cmsg_len;
sendmsg(journalfd, &mh, MSG_NOSIGNAL);
cleanup:
VIR_LOG_CLOSE(buffd);
}
static void virLogCloseJournald(void *data ATTRIBUTE_UNUSED)
{
VIR_LOG_CLOSE(journalfd);
}
static int virLogAddOutputToJournald(int priority)
{
if ((journalfd = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0)
return -1;
if (virSetInherit(journalfd, false) < 0) {
VIR_LOG_CLOSE(journalfd);
return -1;
}
if (virLogDefineOutput(virLogOutputToJournald, virLogCloseJournald, NULL,
priority, VIR_LOG_TO_JOURNALD, NULL, 0) < 0) {
return -1;
}
return 0;
}
# endif /* USE_JOURNALD */
#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;
virLogPriority prio;
int ret = -1;
int count = 0;
if (cur == NULL)
return -1;
VIR_DEBUG("outputs=%s", outputs);
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 if (STREQLEN(cur, "journald", 8)) {
cur += 8;
#if USE_JOURNALD
if (virLogAddOutputToJournald(prio) == 0)
count++;
#endif /* USE_JOURNALD */
} 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;
virLogPriority 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.
*/
virLogPriority
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++) {
virLogDestination 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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