libvirt/src/util/virconf.c
Daniel P. Berrange a8412f868b Fix leak of comment string if virConfAddEntry fails on OOM
The code parsing comments in config files called virConfAddEntry
but did not check for failure. This caused the comment string to
leak on OOM.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-09-25 18:12:09 +01:00

1012 lines
25 KiB
C

/*
* virconf.c: parser for a subset of the Python encoded Xen configuration files
*
* Copyright (C) 2006-2013 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/>.
*
* Daniel Veillard <veillard@redhat.com>
*/
#include <config.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "virerror.h"
#include "virbuffer.h"
#include "virconf.h"
#include "virutil.h"
#include "c-ctype.h"
#include "virlog.h"
#include "viralloc.h"
#include "virfile.h"
#include "virstring.h"
#define VIR_FROM_THIS VIR_FROM_CONF
/************************************************************************
* *
* Structures and macros used by the mini parser *
* *
************************************************************************/
typedef struct _virConfParserCtxt virConfParserCtxt;
typedef virConfParserCtxt *virConfParserCtxtPtr;
struct _virConfParserCtxt {
const char* filename;
const char* base;
const char* cur;
const char *end;
int line;
virConfPtr conf;
};
#define CUR (*ctxt->cur)
#define NEXT if (ctxt->cur < ctxt->end) ctxt->cur++;
#define IS_EOL(c) (((c) == '\n') || ((c) == '\r'))
#define SKIP_BLANKS_AND_EOL \
do { while ((ctxt->cur < ctxt->end) && (c_isblank(CUR) || IS_EOL(CUR))) { \
if (CUR == '\n') ctxt->line++; \
ctxt->cur++; } } while (0)
#define SKIP_BLANKS \
do { while ((ctxt->cur < ctxt->end) && (c_isblank(CUR))) \
ctxt->cur++; } while (0)
/************************************************************************
* *
* Structures used by configuration data *
* *
************************************************************************/
typedef struct _virConfEntry virConfEntry;
typedef virConfEntry *virConfEntryPtr;
struct _virConfEntry {
virConfEntryPtr next;
char* name;
char* comment;
virConfValuePtr value;
};
struct _virConf {
const char* filename;
unsigned int flags;
virConfEntryPtr entries;
};
/**
* virConfError:
* @ctxt: the parser context if available or NULL
* @error: the error number
* @info: extra information string
*
* Handle an error at the xend daemon interface
*/
#define virConfError(ctxt, error, info) \
virConfErrorHelper(__FILE__, __FUNCTION__, __LINE__, ctxt, error, info)
static void
virConfErrorHelper(const char *file, const char *func, size_t line,
virConfParserCtxtPtr ctxt,
virErrorNumber error, const char *info)
{
if (error == VIR_ERR_OK)
return;
/* Construct the string 'filename:line: info' if we have that. */
if (ctxt && ctxt->filename) {
virReportErrorHelper(VIR_FROM_CONF, error, file, func, line,
_("%s:%d: %s"), ctxt->filename, ctxt->line, info);
} else {
virReportErrorHelper(VIR_FROM_CONF, error, file, func, line,
"%s", info);
}
}
/************************************************************************
* *
* Structures allocations and deallocations *
* *
************************************************************************/
/**
* virConfFreeList:
* @list: the list to free
*
* Free a list
*/
static void
virConfFreeList(virConfValuePtr list)
{
virConfValuePtr next;
while (list != NULL) {
next = list->next;
list->next = NULL;
virConfFreeValue(list);
list = next;
}
}
/**
* virConfFreeValue:
* @val: the value to free
*
* Free a value
*/
void
virConfFreeValue(virConfValuePtr val)
{
if (val == NULL)
return;
if (val->type == VIR_CONF_STRING &&
val->str != NULL)
VIR_FREE(val->str);
if (val->type == VIR_CONF_LIST &&
val->list != NULL)
virConfFreeList(val->list);
VIR_FREE(val);
}
virConfPtr
virConfNew(void)
{
virConfPtr ret;
if (VIR_ALLOC(ret) < 0)
return NULL;
ret->filename = NULL;
ret->flags = 0;
return ret;
}
/**
* virConfCreate:
* @filename: the name to report errors
* @flags: combination of virConfFlag(s)
*
* Create a configuration internal structure
*
* Returns a pointer or NULL in case of error.
*/
static virConfPtr
virConfCreate(const char *filename, unsigned int flags)
{
virConfPtr ret = virConfNew();
if (ret) {
ret->filename = filename;
ret->flags = flags;
}
return ret;
}
/**
* virConfAddEntry:
* @conf: the conf structure
* @name: name of the entry or NULL for comment
* @value: the value if any
* @comm: extra comment for that entry if any
*
* add one entry to the conf, the parameters are included in the conf
* if successful and freed on virConfFree()
*
* Returns a pointer to the entry or NULL in case of failure
*/
static virConfEntryPtr
virConfAddEntry(virConfPtr conf, char *name, virConfValuePtr value, char *comm)
{
virConfEntryPtr ret, prev;
if (conf == NULL)
return NULL;
if ((comm == NULL) && (name == NULL))
return NULL;
if (VIR_ALLOC(ret) < 0)
return NULL;
ret->name = name;
ret->value = value;
ret->comment = comm;
if (conf->entries == NULL) {
conf->entries = ret;
} else {
prev = conf->entries;
while (prev->next != NULL)
prev = prev->next;
prev->next = ret;
}
return ret;
}
/************************************************************************
* *
* Serialization *
* *
************************************************************************/
/**
* virConfSaveValue:
* @buf: output buffer
* @val: a value
*
* Serialize the value to the buffer
*
* Returns 0 in case of success, -1 in case of error.
*/
static int
virConfSaveValue(virBufferPtr buf, virConfValuePtr val)
{
if (val == NULL)
return -1;
switch (val->type) {
case VIR_CONF_NONE:
return -1;
case VIR_CONF_LONG:
virBufferAsprintf(buf, "%ld", val->l);
break;
case VIR_CONF_STRING:
if (strchr(val->str, '\n') != NULL) {
virBufferAsprintf(buf, "\"\"\"%s\"\"\"", val->str);
} else if (strchr(val->str, '"') == NULL) {
virBufferAsprintf(buf, "\"%s\"", val->str);
} else if (strchr(val->str, '\'') == NULL) {
virBufferAsprintf(buf, "'%s'", val->str);
} else {
virBufferAsprintf(buf, "\"\"\"%s\"\"\"", val->str);
}
break;
case VIR_CONF_LIST: {
virConfValuePtr cur;
cur = val->list;
virBufferAddLit(buf, "[ ");
if (cur != NULL) {
virConfSaveValue(buf, cur);
cur = cur->next;
while (cur != NULL) {
virBufferAddLit(buf, ", ");
virConfSaveValue(buf, cur);
cur = cur->next;
}
}
virBufferAddLit(buf, " ]");
break;
}
default:
return -1;
}
return 0;
}
/**
* virConfSaveEntry:
* @buf: output buffer
* @cur: a conf entry
*
* Serialize the entry to the buffer
*
* Returns 0 in case of success, -1 in case of error.
*/
static int
virConfSaveEntry(virBufferPtr buf, virConfEntryPtr cur)
{
if (cur->name != NULL) {
virBufferAdd(buf, cur->name, -1);
virBufferAddLit(buf, " = ");
virConfSaveValue(buf, cur->value);
if (cur->comment != NULL) {
virBufferAddLit(buf, " #");
virBufferAdd(buf, cur->comment, -1);
}
} else if (cur->comment != NULL) {
virBufferAddLit(buf, "#");
virBufferAdd(buf, cur->comment, -1);
}
virBufferAddLit(buf, "\n");
return 0;
}
/************************************************************************
* *
* The parser core *
* *
************************************************************************/
/**
* virConfParseLong:
* @ctxt: the parsing context
* @val: the result
*
* Parse one long int value
*
* Returns 0 in case of success and -1 in case of error
*/
static int
virConfParseLong(virConfParserCtxtPtr ctxt, long *val)
{
long l = 0;
int neg = 0;
if (CUR == '-') {
neg = 1;
NEXT;
} else if (CUR == '+') {
NEXT;
}
if ((ctxt->cur >= ctxt->end) || (!c_isdigit(CUR))) {
virConfError(ctxt, VIR_ERR_CONF_SYNTAX, _("unterminated number"));
return -1;
}
while ((ctxt->cur < ctxt->end) && (c_isdigit(CUR))) {
l = l * 10 + (CUR - '0');
NEXT;
}
if (neg)
l = -l;
*val = l;
return 0;
}
/**
* virConfParseString:
* @ctxt: the parsing context
*
* Parse one string
*
* Returns a pointer to the string or NULL in case of error
*/
static char *
virConfParseString(virConfParserCtxtPtr ctxt)
{
const char *base;
char *ret = NULL;
if (CUR == '\'') {
NEXT;
base = ctxt->cur;
while ((ctxt->cur < ctxt->end) && (CUR != '\'') && (!IS_EOL(CUR)))
NEXT;
if (CUR != '\'') {
virConfError(ctxt, VIR_ERR_CONF_SYNTAX, _("unterminated string"));
return NULL;
}
if (VIR_STRNDUP(ret, base, ctxt->cur - base) < 0)
return NULL;
NEXT;
} else if ((ctxt->cur + 6 < ctxt->end) &&
(STRPREFIX(ctxt->cur, "\"\"\""))) {
/* String starts with python-style triple quotes """ */
ctxt->cur += 3;
base = ctxt->cur;
/* Find the ending triple quotes */
while ((ctxt->cur + 2 < ctxt->end) &&
!(STRPREFIX(ctxt->cur, "\"\"\""))) {
if (CUR == '\n')
ctxt->line++;
NEXT;
}
if (!STRPREFIX(ctxt->cur, "\"\"\"")) {
virConfError(ctxt, VIR_ERR_CONF_SYNTAX, _("unterminated string"));
return NULL;
}
if (VIR_STRNDUP(ret, base, ctxt->cur - base) < 0)
return NULL;
ctxt->cur += 3;
} else if (CUR == '"') {
NEXT;
base = ctxt->cur;
while ((ctxt->cur < ctxt->end) && (CUR != '"') && (!IS_EOL(CUR)))
NEXT;
if (CUR != '"') {
virConfError(ctxt, VIR_ERR_CONF_SYNTAX, _("unterminated string"));
return NULL;
}
if (VIR_STRNDUP(ret, base, ctxt->cur - base) < 0)
return NULL;
NEXT;
}
return ret;
}
/**
* virConfParseValue:
* @ctxt: the parsing context
*
* Parse one value
*
* Returns a pointer to the value or NULL in case of error
*/
static virConfValuePtr
virConfParseValue(virConfParserCtxtPtr ctxt)
{
virConfValuePtr ret, lst = NULL, tmp, prev;
virConfType type = VIR_CONF_NONE;
char *str = NULL;
long l = 0;
SKIP_BLANKS;
if (ctxt->cur >= ctxt->end) {
virConfError(ctxt, VIR_ERR_CONF_SYNTAX, _("expecting a value"));
return NULL;
}
if ((CUR == '"') || (CUR == '\'')) {
type = VIR_CONF_STRING;
str = virConfParseString(ctxt);
if (str == NULL)
return NULL;
} else if (CUR == '[') {
if (ctxt->conf->flags & VIR_CONF_FLAG_VMX_FORMAT) {
virConfError(ctxt, VIR_ERR_CONF_SYNTAX,
_("lists not allowed in VMX format"));
return NULL;
}
type = VIR_CONF_LIST;
NEXT;
SKIP_BLANKS_AND_EOL;
if ((ctxt->cur < ctxt->end) && (CUR != ']')) {
if ((lst = virConfParseValue(ctxt)) == NULL)
return NULL;
SKIP_BLANKS_AND_EOL;
}
while ((ctxt->cur < ctxt->end) && (CUR != ']')) {
/* Tell Clang that when execution reaches this point
"lst" is guaranteed to be non-NULL. This stops it
from issuing an invalid NULL-dereference warning about
"prev = lst; while (prev->next..." below. */
sa_assert(lst);
if (CUR != ',') {
virConfError(ctxt, VIR_ERR_CONF_SYNTAX,
_("expecting a separator in list"));
virConfFreeList(lst);
return NULL;
}
NEXT;
SKIP_BLANKS_AND_EOL;
if (CUR == ']') {
break;
}
tmp = virConfParseValue(ctxt);
if (tmp == NULL) {
virConfFreeList(lst);
return NULL;
}
prev = lst;
while (prev->next != NULL) prev = prev->next;
prev->next = tmp;
SKIP_BLANKS_AND_EOL;
}
if (CUR == ']') {
NEXT;
} else {
virConfError(ctxt, VIR_ERR_CONF_SYNTAX,
_("list is not closed with ]"));
virConfFreeList(lst);
return NULL;
}
} else if (c_isdigit(CUR) || (CUR == '-') || (CUR == '+')) {
if (ctxt->conf->flags & VIR_CONF_FLAG_VMX_FORMAT) {
virConfError(ctxt, VIR_ERR_CONF_SYNTAX,
_("numbers not allowed in VMX format"));
return NULL;
}
if (virConfParseLong(ctxt, &l) < 0) {
return NULL;
}
type = VIR_CONF_LONG;
} else {
virConfError(ctxt, VIR_ERR_CONF_SYNTAX, _("expecting a value"));
return NULL;
}
if (VIR_ALLOC(ret) < 0) {
virConfFreeList(lst);
VIR_FREE(str);
return NULL;
}
ret->type = type;
ret->l = l;
ret->str = str;
ret->list = lst;
return ret;
}
/**
* virConfParseName:
* @ctxt: the parsing context
*
* Parse one name
*
* Returns a copy of the new string, NULL in case of error
*/
static char *
virConfParseName(virConfParserCtxtPtr ctxt)
{
const char *base;
char *ret;
SKIP_BLANKS;
base = ctxt->cur;
/* TODO: probably need encoding support and UTF-8 parsing ! */
if (!c_isalpha(CUR) &&
!((ctxt->conf->flags & VIR_CONF_FLAG_VMX_FORMAT) && (CUR == '.'))) {
virConfError(ctxt, VIR_ERR_CONF_SYNTAX, _("expecting a name"));
return NULL;
}
while ((ctxt->cur < ctxt->end) &&
(c_isalnum(CUR) || (CUR == '_') ||
((ctxt->conf->flags & VIR_CONF_FLAG_VMX_FORMAT) &&
((CUR == ':') || (CUR == '.') || (CUR == '-')))))
NEXT;
if (VIR_STRNDUP(ret, base, ctxt->cur - base) < 0)
return NULL;
return ret;
}
/**
* virConfParseComment:
* @ctxt: the parsing context
*
* Parse one standalone comment in the configuration file
*
* Returns 0 in case of success and -1 in case of error
*/
static int
virConfParseComment(virConfParserCtxtPtr ctxt)
{
const char *base;
char *comm;
if (CUR != '#')
return -1;
NEXT;
base = ctxt->cur;
while ((ctxt->cur < ctxt->end) && (!IS_EOL(CUR))) NEXT;
if (VIR_STRNDUP(comm, base, ctxt->cur - base) < 0)
return -1;
if (virConfAddEntry(ctxt->conf, NULL, NULL, comm) == NULL) {
VIR_FREE(comm);
return -1;
}
return 0;
}
/**
* virConfParseSeparator:
* @ctxt: the parsing context
*
* Parse one separator between statement if not at the end.
*
* Returns 0 in case of success and -1 in case of error
*/
static int
virConfParseSeparator(virConfParserCtxtPtr ctxt)
{
SKIP_BLANKS;
if (ctxt->cur >= ctxt->end)
return 0;
if (IS_EOL(CUR)) {
SKIP_BLANKS_AND_EOL;
} else if (CUR == ';') {
NEXT;
SKIP_BLANKS_AND_EOL;
} else {
virConfError(ctxt, VIR_ERR_CONF_SYNTAX, _("expecting a separator"));
return -1;
}
return 0;
}
/**
* virConfParseStatement:
* @ctxt: the parsing context
*
* Parse one statement in the conf file
*
* Returns 0 in case of success and -1 in case of error
*/
static int
virConfParseStatement(virConfParserCtxtPtr ctxt)
{
const char *base;
char *name;
virConfValuePtr value;
char *comm = NULL;
SKIP_BLANKS_AND_EOL;
if (CUR == '#') {
return virConfParseComment(ctxt);
}
name = virConfParseName(ctxt);
if (name == NULL)
return -1;
SKIP_BLANKS;
if (CUR != '=') {
virConfError(ctxt, VIR_ERR_CONF_SYNTAX, _("expecting an assignment"));
VIR_FREE(name);
return -1;
}
NEXT;
SKIP_BLANKS;
value = virConfParseValue(ctxt);
if (value == NULL) {
VIR_FREE(name);
return -1;
}
SKIP_BLANKS;
if (CUR == '#') {
NEXT;
base = ctxt->cur;
while ((ctxt->cur < ctxt->end) && (!IS_EOL(CUR))) NEXT;
if (VIR_STRNDUP(comm, base, ctxt->cur - base) < 0) {
VIR_FREE(name);
virConfFreeValue(value);
return -1;
}
}
if (virConfAddEntry(ctxt->conf, name, value, comm) == NULL) {
VIR_FREE(name);
virConfFreeValue(value);
VIR_FREE(comm);
return -1;
}
return 0;
}
/**
* virConfParse:
* @filename: the name to report errors
* @content: the configuration content in memory
* @len: the length in bytes
* @flags: combination of virConfFlag(s)
*
* Parse the subset of the Python language needed to handle simple
* Xen configuration files.
*
* Returns a handle to lookup settings or NULL if it failed to
* read or parse the file, use virConfFree() to free the data.
*/
static virConfPtr
virConfParse(const char *filename, const char *content, int len,
unsigned int flags) {
virConfParserCtxt ctxt;
ctxt.filename = filename;
ctxt.base = ctxt.cur = content;
ctxt.end = content + len - 1;
ctxt.line = 1;
ctxt.conf = virConfCreate(filename, flags);
if (ctxt.conf == NULL)
return NULL;
while (ctxt.cur < ctxt.end) {
if (virConfParseStatement(&ctxt) < 0)
goto error;
if (virConfParseSeparator(&ctxt) < 0)
goto error;
}
return ctxt.conf;
error:
virConfFree(ctxt.conf);
return NULL;
}
/************************************************************************
* *
* The module entry points *
* *
************************************************************************/
/* 10 MB limit on config file size as a sanity check */
#define MAX_CONFIG_FILE_SIZE (1024*1024*10)
/**
* virConfReadFile:
* @filename: the path to the configuration file.
* @flags: combination of virConfFlag(s)
*
* Reads a configuration file.
*
* Returns a handle to lookup settings or NULL if it failed to
* read or parse the file, use virConfFree() to free the data.
*/
virConfPtr
virConfReadFile(const char *filename, unsigned int flags)
{
char *content;
int len;
virConfPtr conf;
VIR_DEBUG("filename=%s", NULLSTR(filename));
if (filename == NULL) {
virConfError(NULL, VIR_ERR_INVALID_ARG, __FUNCTION__);
return NULL;
}
if ((len = virFileReadAll(filename, MAX_CONFIG_FILE_SIZE, &content)) < 0) {
return NULL;
}
conf = virConfParse(filename, content, len, flags);
VIR_FREE(content);
return conf;
}
/**
* virConfReadMem:
* @memory: pointer to the content of the configuration file
* @len: length in byte
* @flags: combination of virConfFlag(s)
*
* Reads a configuration file loaded in memory. The string can be
* zero terminated in which case @len can be 0
*
* Returns a handle to lookup settings or NULL if it failed to
* parse the content, use virConfFree() to free the data.
*/
virConfPtr
virConfReadMem(const char *memory, int len, unsigned int flags)
{
if ((memory == NULL) || (len < 0)) {
virConfError(NULL, VIR_ERR_INVALID_ARG, __FUNCTION__);
return NULL;
}
if (len == 0)
len = strlen(memory);
return virConfParse("memory conf", memory, len, flags);
}
/**
* virConfFree:
* @conf: a configuration file handle
*
* Frees all data associated to the handle
*
* Returns 0 in case of success, -1 in case of error.
*/
int
virConfFree(virConfPtr conf)
{
virConfEntryPtr tmp;
if (conf == NULL)
return 0;
tmp = conf->entries;
while (tmp) {
virConfEntryPtr next;
VIR_FREE(tmp->name);
virConfFreeValue(tmp->value);
VIR_FREE(tmp->comment);
next = tmp->next;
VIR_FREE(tmp);
tmp = next;
}
VIR_FREE(conf);
return 0;
}
/**
* virConfGetValue:
* @conf: a configuration file handle
* @entry: the name of the entry
*
* Lookup the value associated to this entry in the configuration file
*
* Returns a pointer to the value or NULL if the lookup failed, the data
* associated will be freed when virConfFree() is called
*/
virConfValuePtr
virConfGetValue(virConfPtr conf, const char *setting)
{
virConfEntryPtr cur;
if (conf == NULL)
return NULL;
cur = conf->entries;
while (cur != NULL) {
if ((cur->name != NULL) &&
((conf->flags & VIR_CONF_FLAG_VMX_FORMAT &&
STRCASEEQ(cur->name, setting)) ||
STREQ(cur->name, setting)))
return cur->value;
cur = cur->next;
}
return NULL;
}
/**
* virConfSetValue:
* @conf: a configuration file handle
* @entry: the name of the entry
* @value: the new configuration value
*
* Set (or replace) the value associated to this entry in the configuration
* file. The passed in 'value' will be owned by the conf object upon return
* of this method, even in case of error. It should not be referenced again
* by the caller.
*
* Returns 0 on success, or -1 on failure.
*/
int
virConfSetValue(virConfPtr conf,
const char *setting,
virConfValuePtr value)
{
virConfEntryPtr cur, prev = NULL;
if (value && value->type == VIR_CONF_STRING && value->str == NULL)
return -1;
cur = conf->entries;
while (cur != NULL) {
if ((cur->name != NULL) && (STREQ(cur->name, setting))) {
break;
}
prev = cur;
cur = cur->next;
}
if (!cur) {
if (VIR_ALLOC(cur) < 0) {
virConfFreeValue(value);
return -1;
}
cur->comment = NULL;
if (VIR_STRDUP(cur->name, setting) < 0) {
virConfFreeValue(value);
VIR_FREE(cur);
return -1;
}
cur->value = value;
if (prev) {
cur->next = prev->next;
prev->next = cur;
} else {
cur->next = conf->entries;
conf->entries = cur;
}
} else {
virConfFreeValue(cur->value);
cur->value = value;
}
return 0;
}
/**
* virConfWriteFile:
* @filename: the path to the configuration file.
* @conf: the conf
*
* Writes a configuration file back to a file.
*
* Returns the number of bytes written or -1 in case of error.
*/
int
virConfWriteFile(const char *filename, virConfPtr conf)
{
virBuffer buf = VIR_BUFFER_INITIALIZER;
virConfEntryPtr cur;
int ret;
int fd;
char *content;
unsigned int use;
if (conf == NULL)
return -1;
cur = conf->entries;
while (cur != NULL) {
virConfSaveEntry(&buf, cur);
cur = cur->next;
}
if (virBufferError(&buf)) {
virBufferFreeAndReset(&buf);
virReportOOMError();
return -1;
}
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
if (fd < 0) {
virBufferFreeAndReset(&buf);
virConfError(NULL, VIR_ERR_WRITE_FAILED, _("failed to open file"));
return -1;
}
use = virBufferUse(&buf);
content = virBufferContentAndReset(&buf);
ret = safewrite(fd, content, use);
VIR_FREE(content);
VIR_FORCE_CLOSE(fd);
if (ret != (int)use) {
virConfError(NULL, VIR_ERR_WRITE_FAILED, _("failed to save content"));
return -1;
}
return ret;
}
/**
* virConfWriteMem:
* @memory: pointer to the memory to store the config file
* @len: pointer to the length in bytes of the store, on output the size
* @conf: the conf
*
* Writes a configuration file back to a memory area. @len is an IN/OUT
* parameter, it indicates the size available in bytes, and on output the
* size required for the configuration file (even if the call fails due to
* insufficient space).
*
* Returns the number of bytes written or -1 in case of error.
*/
int
virConfWriteMem(char *memory, int *len, virConfPtr conf)
{
virBuffer buf = VIR_BUFFER_INITIALIZER;
virConfEntryPtr cur;
char *content;
unsigned int use;
if ((memory == NULL) || (len == NULL) || (*len <= 0) || (conf == NULL))
return -1;
cur = conf->entries;
while (cur != NULL) {
virConfSaveEntry(&buf, cur);
cur = cur->next;
}
if (virBufferError(&buf)) {
virBufferFreeAndReset(&buf);
virReportOOMError();
return -1;
}
use = virBufferUse(&buf);
content = virBufferContentAndReset(&buf);
if ((int)use >= *len) {
*len = (int)use;
VIR_FREE(content);
return -1;
}
memcpy(memory, content, use);
VIR_FREE(content);
*len = use;
return use;
}