libvirt/src/util/virmacmap.c

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/*
* virmacmap.c: MAC address <-> Domain name mapping
*
* Copyright (C) 2016 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 "virmacmap.h"
#include "virobject.h"
#include "virlog.h"
#include "virjson.h"
#include "virfile.h"
#include "virhash.h"
#include "virstring.h"
#include "viralloc.h"
#define VIR_FROM_THIS VIR_FROM_NETWORK
VIR_LOG_INIT("util.virmacmap");
/**
* VIR_MAC_MAP_FILE_SIZE_MAX:
*
* Macro providing the upper limit on the size of mac maps file
*/
#define VIR_MAC_MAP_FILE_SIZE_MAX (32 * 1024 * 1024)
struct virMacMap {
virObjectLockable parent;
GHashTable *macs;
};
static virClassPtr virMacMapClass;
static void
virmacmap: Don't use hash table dataFree callback Due to nature of operations we do over the string list (more precisely due to how virStringListRemove() works), it is not the best idea to use dataFree callback. Problem is, on MAC address remove, the string list remove function modifies the original list in place. Then, virHashUpdateEntry() is called which frees all the data stored in the list rendering @newMacsList point to freed data. ==16002== Invalid read of size 8 ==16002== at 0x50BC083: virFree (viralloc.c:582) ==16002== by 0x513DC39: virStringListFree (virstring.c:251) ==16002== by 0x51089B4: virMacMapHashFree (virmacmap.c:67) ==16002== by 0x50EF30B: virHashAddOrUpdateEntry (virhash.c:352) ==16002== by 0x50EF4FD: virHashUpdateEntry (virhash.c:415) ==16002== by 0x5108BED: virMacMapRemoveLocked (virmacmap.c:129) ==16002== by 0x51092D5: virMacMapRemove (virmacmap.c:346) ==16002== by 0x402F02: testMACRemove (virmacmaptest.c:107) ==16002== by 0x403F15: virTestRun (testutils.c:180) ==16002== by 0x4032C4: mymain (virmacmaptest.c:205) ==16002== by 0x405A3B: virTestMain (testutils.c:992) ==16002== by 0x403D87: main (virmacmaptest.c:237) ==16002== Address 0xdd5a4d0 is 0 bytes inside a block of size 24 free'd ==16002== at 0x4C2AD6F: realloc (vg_replace_malloc.c:693) ==16002== by 0x50BB99B: virReallocN (viralloc.c:245) ==16002== by 0x513DC0B: virStringListRemove (virstring.c:235) ==16002== by 0x5108BA6: virMacMapRemoveLocked (virmacmap.c:124) ==16002== by 0x51092D5: virMacMapRemove (virmacmap.c:346) ==16002== by 0x402F02: testMACRemove (virmacmaptest.c:107) ==16002== by 0x403F15: virTestRun (testutils.c:180) ==16002== by 0x4032C4: mymain (virmacmaptest.c:205) ==16002== by 0x405A3B: virTestMain (testutils.c:992) ==16002== by 0x403D87: main (virmacmaptest.c:237) Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-02 09:35:33 +00:00
virMacMapDispose(void *obj)
{
virmacmap: Don't use hash table dataFree callback Due to nature of operations we do over the string list (more precisely due to how virStringListRemove() works), it is not the best idea to use dataFree callback. Problem is, on MAC address remove, the string list remove function modifies the original list in place. Then, virHashUpdateEntry() is called which frees all the data stored in the list rendering @newMacsList point to freed data. ==16002== Invalid read of size 8 ==16002== at 0x50BC083: virFree (viralloc.c:582) ==16002== by 0x513DC39: virStringListFree (virstring.c:251) ==16002== by 0x51089B4: virMacMapHashFree (virmacmap.c:67) ==16002== by 0x50EF30B: virHashAddOrUpdateEntry (virhash.c:352) ==16002== by 0x50EF4FD: virHashUpdateEntry (virhash.c:415) ==16002== by 0x5108BED: virMacMapRemoveLocked (virmacmap.c:129) ==16002== by 0x51092D5: virMacMapRemove (virmacmap.c:346) ==16002== by 0x402F02: testMACRemove (virmacmaptest.c:107) ==16002== by 0x403F15: virTestRun (testutils.c:180) ==16002== by 0x4032C4: mymain (virmacmaptest.c:205) ==16002== by 0x405A3B: virTestMain (testutils.c:992) ==16002== by 0x403D87: main (virmacmaptest.c:237) ==16002== Address 0xdd5a4d0 is 0 bytes inside a block of size 24 free'd ==16002== at 0x4C2AD6F: realloc (vg_replace_malloc.c:693) ==16002== by 0x50BB99B: virReallocN (viralloc.c:245) ==16002== by 0x513DC0B: virStringListRemove (virstring.c:235) ==16002== by 0x5108BA6: virMacMapRemoveLocked (virmacmap.c:124) ==16002== by 0x51092D5: virMacMapRemove (virmacmap.c:346) ==16002== by 0x402F02: testMACRemove (virmacmaptest.c:107) ==16002== by 0x403F15: virTestRun (testutils.c:180) ==16002== by 0x4032C4: mymain (virmacmaptest.c:205) ==16002== by 0x405A3B: virTestMain (testutils.c:992) ==16002== by 0x403D87: main (virmacmaptest.c:237) Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-02 09:35:33 +00:00
virMacMapPtr mgr = obj;
GHashTableIter htitr;
void *value;
g_hash_table_iter_init(&htitr, mgr->macs);
while (g_hash_table_iter_next(&htitr, NULL, &value))
g_slist_free_full(value, g_free);
virmacmap: Don't use hash table dataFree callback Due to nature of operations we do over the string list (more precisely due to how virStringListRemove() works), it is not the best idea to use dataFree callback. Problem is, on MAC address remove, the string list remove function modifies the original list in place. Then, virHashUpdateEntry() is called which frees all the data stored in the list rendering @newMacsList point to freed data. ==16002== Invalid read of size 8 ==16002== at 0x50BC083: virFree (viralloc.c:582) ==16002== by 0x513DC39: virStringListFree (virstring.c:251) ==16002== by 0x51089B4: virMacMapHashFree (virmacmap.c:67) ==16002== by 0x50EF30B: virHashAddOrUpdateEntry (virhash.c:352) ==16002== by 0x50EF4FD: virHashUpdateEntry (virhash.c:415) ==16002== by 0x5108BED: virMacMapRemoveLocked (virmacmap.c:129) ==16002== by 0x51092D5: virMacMapRemove (virmacmap.c:346) ==16002== by 0x402F02: testMACRemove (virmacmaptest.c:107) ==16002== by 0x403F15: virTestRun (testutils.c:180) ==16002== by 0x4032C4: mymain (virmacmaptest.c:205) ==16002== by 0x405A3B: virTestMain (testutils.c:992) ==16002== by 0x403D87: main (virmacmaptest.c:237) ==16002== Address 0xdd5a4d0 is 0 bytes inside a block of size 24 free'd ==16002== at 0x4C2AD6F: realloc (vg_replace_malloc.c:693) ==16002== by 0x50BB99B: virReallocN (viralloc.c:245) ==16002== by 0x513DC0B: virStringListRemove (virstring.c:235) ==16002== by 0x5108BA6: virMacMapRemoveLocked (virmacmap.c:124) ==16002== by 0x51092D5: virMacMapRemove (virmacmap.c:346) ==16002== by 0x402F02: testMACRemove (virmacmaptest.c:107) ==16002== by 0x403F15: virTestRun (testutils.c:180) ==16002== by 0x4032C4: mymain (virmacmaptest.c:205) ==16002== by 0x405A3B: virTestMain (testutils.c:992) ==16002== by 0x403D87: main (virmacmaptest.c:237) Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-01-02 09:35:33 +00:00
virHashFree(mgr->macs);
}
static int virMacMapOnceInit(void)
{
if (!VIR_CLASS_NEW(virMacMap, virClassForObjectLockable()))
return -1;
return 0;
}
VIR_ONCE_GLOBAL_INIT(virMacMap);
static void
virMacMapAddLocked(virMacMapPtr mgr,
const char *domain,
const char *mac)
{
GSList *orig_list;
GSList *list;
GSList *next;
list = orig_list = g_hash_table_lookup(mgr->macs, domain);
for (next = list; next; next = next->next) {
if (STREQ((const char *) next->data, mac))
return;
}
list = g_slist_append(list, g_strdup(mac));
if (list != orig_list)
g_hash_table_insert(mgr->macs, g_strdup(domain), list);
}
static void
virMacMapRemoveLocked(virMacMapPtr mgr,
const char *domain,
const char *mac)
{
GSList *orig_list;
GSList *list;
GSList *next;
list = orig_list = g_hash_table_lookup(mgr->macs, domain);
if (!orig_list)
return;
for (next = list; next; next = next->next) {
if (STREQ((const char *) next->data, mac)) {
list = g_slist_remove_link(list, next);
g_slist_free_full(next, g_free);
break;
}
}
if (list != orig_list) {
if (list)
g_hash_table_insert(mgr->macs, g_strdup(domain), list);
else
g_hash_table_remove(mgr->macs, domain);
}
}
static int
virMacMapLoadFile(virMacMapPtr mgr,
const char *file)
{
g_autofree char *map_str = NULL;
g_autoptr(virJSONValue) map = NULL;
int map_str_len = 0;
size_t i;
if (virFileExists(file) &&
(map_str_len = virFileReadAll(file,
VIR_MAC_MAP_FILE_SIZE_MAX,
&map_str)) < 0)
return -1;
if (map_str_len == 0)
return 0;
if (!(map = virJSONValueFromString(map_str))) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("invalid json in file: %s"),
file);
return -1;
}
if (!virJSONValueIsArray(map)) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Malformed file structure: %s"),
file);
return -1;
}
for (i = 0; i < virJSONValueArraySize(map); i++) {
virJSONValuePtr tmp = virJSONValueArrayGet(map, i);
virJSONValuePtr macs;
const char *domain;
size_t j;
GSList *vals = NULL;
if (!(domain = virJSONValueObjectGetString(tmp, "domain"))) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Missing domain"));
return -1;
}
if (!(macs = virJSONValueObjectGetArray(tmp, "macs"))) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Missing macs"));
return -1;
}
if (g_hash_table_contains(mgr->macs, domain)) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("duplicate domain '%s'"), domain);
return -1;
}
for (j = 0; j < virJSONValueArraySize(macs); j++) {
virJSONValuePtr macJSON = virJSONValueArrayGet(macs, j);
vals = g_slist_prepend(vals, g_strdup(virJSONValueGetString(macJSON)));
}
vals = g_slist_reverse(vals);
g_hash_table_insert(mgr->macs, g_strdup(domain), vals);
}
return 0;
}
static int
virMACMapHashDumper(void *payload,
const char *name,
void *data)
{
g_autoptr(virJSONValue) obj = virJSONValueNewObject();
g_autoptr(virJSONValue) arr = virJSONValueNewArray();
GSList *macs = payload;
GSList *next;
for (next = macs; next; next = next->next) {
g_autoptr(virJSONValue) m = virJSONValueNewString((const char *) next->data);
if (virJSONValueArrayAppend(arr, &m) < 0)
return -1;
}
if (virJSONValueObjectAppendString(obj, "domain", name) < 0 ||
virJSONValueObjectAppend(obj, "macs", &arr) < 0)
return -1;
if (virJSONValueArrayAppend(data, &obj) < 0)
return -1;
return 0;
}
static int
virMacMapDumpStrLocked(virMacMapPtr mgr,
char **str)
{
g_autoptr(virJSONValue) arr = virJSONValueNewArray();
if (virHashForEachSorted(mgr->macs, virMACMapHashDumper, arr) < 0)
return -1;
if (!(*str = virJSONValueToString(arr, true)))
return -1;
return 0;
}
static int
virMacMapWriteFileLocked(virMacMapPtr mgr,
const char *file)
{
g_autofree char *str = NULL;
if (virMacMapDumpStrLocked(mgr, &str) < 0)
return -1;
if (virFileRewriteStr(file, 0644, str) < 0)
return -1;
return 0;
}
char *
virMacMapFileName(const char *dnsmasqStateDir,
const char *bridge)
{
char *filename;
filename = g_strdup_printf("%s/%s.macs", dnsmasqStateDir, bridge);
return filename;
}
#define VIR_MAC_HASH_TABLE_SIZE 10
virMacMapPtr
virMacMapNew(const char *file)
{
virMacMapPtr mgr;
if (virMacMapInitialize() < 0)
return NULL;
if (!(mgr = virObjectLockableNew(virMacMapClass)))
return NULL;
virObjectLock(mgr);
mgr->macs = virHashNew(NULL);
if (file &&
virMacMapLoadFile(mgr, file) < 0)
goto error;
virObjectUnlock(mgr);
return mgr;
error:
virObjectUnlock(mgr);
virObjectUnref(mgr);
return NULL;
}
int
virMacMapAdd(virMacMapPtr mgr,
const char *domain,
const char *mac)
{
virObjectLock(mgr);
virMacMapAddLocked(mgr, domain, mac);
virObjectUnlock(mgr);
return 0;
}
int
virMacMapRemove(virMacMapPtr mgr,
const char *domain,
const char *mac)
{
virObjectLock(mgr);
virMacMapRemoveLocked(mgr, domain, mac);
virObjectUnlock(mgr);
return 0;
}
/* note that the returned pointer may be invalidated by other APIs in this module */
GSList *
virMacMapLookup(virMacMapPtr mgr,
const char *domain)
{
GSList *ret;
virObjectLock(mgr);
ret = virHashLookup(mgr->macs, domain);
virObjectUnlock(mgr);
return ret;
}
int
virMacMapWriteFile(virMacMapPtr mgr,
const char *filename)
{
int ret;
virObjectLock(mgr);
ret = virMacMapWriteFileLocked(mgr, filename);
virObjectUnlock(mgr);
return ret;
}
int
virMacMapDumpStr(virMacMapPtr mgr,
char **str)
{
int ret;
virObjectLock(mgr);
ret = virMacMapDumpStrLocked(mgr, str);
virObjectUnlock(mgr);
return ret;
}