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Go Back   Linux Archive > ArchLinux > ArchLinux Pacman Development

 
 
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Old 02-07-2011, 01:59 PM
Pang Yan Han
 
Default Handle null pkgcache for db_populate, refactor hash

In sync_db_populate() and local_db_populate(), a NULL
db->pkgcache is not handled. This not only involves unnecessary
operations, but also potentially merge sorting
db->pkgcache->list which does not even exist in the case that
db->pkgcache is NULL.

This may lead to serious issues since alpm_list_msort calls
alpm_list_nth which will dereference invalid pointers.
Thus, db->pkgcache is checked during local/sync db_populate
calls.

For this purpose, PM_ERR_DB_PKGCACHE_NULL error is added to
_pmerrno_t and taken care of in alpm_strerror().

In addition, common code between _alpm_pkghash_add() and
_alpm_pkghash_add_sorted() is refactored out to
_alpm_pkghash_add_pkg(). The 2 functions are now wrappers
around _alpm_pkghash_add_pkg().

Signed-off-by: Pang Yan Han <pangyanhan@gmail.com>
---
Please give me advice on this as to whether it needs tweaking
or if it won't be accepted. Thanks!

lib/libalpm/alpm.h | 1 +
lib/libalpm/be_local.c | 4 ++++
lib/libalpm/be_sync.c | 8 +++++++-
lib/libalpm/db.c | 1 +
lib/libalpm/error.c | 2 ++
lib/libalpm/pkghash.c | 46 +++++++++++++++-------------------------------
lib/libalpm/pkghash.h | 1 +
7 files changed, 31 insertions(+), 32 deletions(-)

diff --git a/lib/libalpm/alpm.h b/lib/libalpm/alpm.h
index 7fec293..57c68bd 100644
--- a/lib/libalpm/alpm.h
+++ b/lib/libalpm/alpm.h
@@ -501,6 +501,7 @@ enum _pmerrno_t {
PM_ERR_DB_NOT_FOUND,
PM_ERR_DB_WRITE,
PM_ERR_DB_REMOVE,
+ PM_ERR_DB_PKGCACHE_NULL,
/* Servers */
PM_ERR_SERVER_BAD_URL,
PM_ERR_SERVER_NONE,
diff --git a/lib/libalpm/be_local.c b/lib/libalpm/be_local.c
index c5b2498..c7980f9 100644
--- a/lib/libalpm/be_local.c
+++ b/lib/libalpm/be_local.c
@@ -393,6 +393,10 @@ static int local_db_populate(pmdb_t *db)

/* initialize hash at 50% full */
db->pkgcache = _alpm_pkghash_create(est_count * 2);
+ if(db->pkgcache == NULL){
+ closedir(dbdir);
+ RET_ERR(PM_ERR_DB_PKGCACHE_NULL, -1);
+ }

while((ent = readdir(dbdir)) != NULL) {
const char *name = ent->d_name;
diff --git a/lib/libalpm/be_sync.c b/lib/libalpm/be_sync.c
index 4ad045c..853ad30 100644
--- a/lib/libalpm/be_sync.c
+++ b/lib/libalpm/be_sync.c
@@ -234,6 +234,9 @@ static int sync_db_populate(pmdb_t *db)

/* initialize hash at 66% full */
db->pkgcache = _alpm_pkghash_create(est_count * 3 / 2);
+ if(db->pkgcache == NULL) {
+ RET_ERR(PM_ERR_DB_PKGCACHE_NULL, -1);
+ }

while(archive_read_next_header(archive, &entry) == ARCHIVE_OK) {
const struct stat *st;
@@ -348,6 +351,9 @@ static int sync_db_read(pmdb_t *db, struct archive *archive,
if(likely_pkg && strcmp(likely_pkg->name, pkgname) == 0) {
pkg = likely_pkg;
} else {
+ if(db->pkgcache == NULL) {
+ RET_ERR(PM_ERR_DB_PKGCACHE_NULL, -1);
+ }
pkg = _alpm_pkghash_find(db->pkgcache, pkgname);
}
if(pkg == NULL) {
@@ -459,10 +465,10 @@ pmdb_t *_alpm_db_register_sync(const char *treename)
_alpm_log(PM_LOG_DEBUG, "registering sync database '%s'
", treename);

db = _alpm_db_new(treename, 0);
- db->ops = &sync_db_ops;
if(db == NULL) {
RET_ERR(PM_ERR_DB_CREATE, NULL);
}
+ db->ops = &sync_db_ops;

handle->dbs_sync = alpm_list_add(handle->dbs_sync, db);
return(db);
diff --git a/lib/libalpm/db.c b/lib/libalpm/db.c
index 02f8282..d43a16b 100644
--- a/lib/libalpm/db.c
+++ b/lib/libalpm/db.c
@@ -370,6 +370,7 @@ pmdb_t *_alpm_db_new(const char *treename, int is_local)
CALLOC(db, 1, sizeof(pmdb_t), RET_ERR(PM_ERR_MEMORY, NULL));
STRDUP(db->treename, treename, RET_ERR(PM_ERR_MEMORY, NULL));
db->is_local = is_local;
+ db->pkgcache_loaded = 0;

return(db);
}
diff --git a/lib/libalpm/error.c b/lib/libalpm/error.c
index 2cc6685..5b48c89 100644
--- a/lib/libalpm/error.c
+++ b/lib/libalpm/error.c
@@ -81,6 +81,8 @@ const char SYMEXPORT *alpm_strerror(int err)
return _("could not update database");
case PM_ERR_DB_REMOVE:
return _("could not remove database entry");
+ case PM_ERR_DB_PKGCACHE_NULL:
+ return _("could not initialize database package cache");
/* Servers */
case PM_ERR_SERVER_BAD_URL:
return _("invalid url for server");
diff --git a/lib/libalpm/pkghash.c b/lib/libalpm/pkghash.c
index 5480527..7006888 100644
--- a/lib/libalpm/pkghash.c
+++ b/lib/libalpm/pkghash.c
@@ -150,6 +150,16 @@ static pmpkghash_t *rehash(pmpkghash_t *oldhash)

pmpkghash_t *_alpm_pkghash_add(pmpkghash_t *hash, pmpkg_t *pkg)
{
+ return(_alpm_pkghash_add_pkg(hash, pkg, 0));
+}
+
+pmpkghash_t *_alpm_pkghash_add_sorted(pmpkghash_t *hash, pmpkg_t *pkg)
+{
+ return(_alpm_pkghash_add_pkg(hash, pkg, 1));
+}
+
+pmpkghash_t *_alpm_pkghash_add_pkg(pmpkghash_t *hash, pmpkg_t *pkg, int sorted)
+{
alpm_list_t *ptr;
size_t position;

@@ -173,40 +183,13 @@ pmpkghash_t *_alpm_pkghash_add(pmpkghash_t *hash, pmpkg_t *pkg)
ptr->prev = ptr;

hash->hash_table[position] = ptr;
- hash->list = alpm_list_join(hash->list, ptr);
- hash->entries += 1;
-
- return(hash);
-}
-
-pmpkghash_t *_alpm_pkghash_add_sorted(pmpkghash_t *hash, pmpkg_t *pkg)
-{
- if(!hash) {
- return(_alpm_pkghash_add(hash, pkg));
- }
-
- alpm_list_t *ptr;
- size_t position;
-
- if((hash->entries + 1) / MAX_HASH_LOAD > hash->buckets) {
- hash = rehash(hash);
+ if(!sorted){
+ hash->list = alpm_list_join(hash->list, ptr);
+ }else{
+ hash->list = alpm_list_mmerge(hash->list, ptr, _alpm_pkg_cmp);
}

- position = get_hash_position(pkg->name_hash, hash);
-
- ptr = calloc(1, sizeof(alpm_list_t));
- if(ptr == NULL) {
- return(hash);
- }
-
- ptr->data = pkg;
- ptr->next = NULL;
- ptr->prev = ptr;
-
- hash->hash_table[position] = ptr;
- hash->list = alpm_list_mmerge(hash->list, ptr, _alpm_pkg_cmp);
hash->entries += 1;
-
return(hash);
}

@@ -344,3 +327,4 @@ pmpkg_t *_alpm_pkghash_find(pmpkghash_t *hash, const char *name)

return(NULL);
}
+/* vim: set ts=2 sw=2 noet: */
diff --git a/lib/libalpm/pkghash.h b/lib/libalpm/pkghash.h
index a6c1db7..d63c6f0 100644
--- a/lib/libalpm/pkghash.h
+++ b/lib/libalpm/pkghash.h
@@ -47,6 +47,7 @@ pmpkghash_t *_alpm_pkghash_create(size_t size);

pmpkghash_t *_alpm_pkghash_add(pmpkghash_t *hash, pmpkg_t *pkg);
pmpkghash_t *_alpm_pkghash_add_sorted(pmpkghash_t *hash, pmpkg_t *pkg);
+pmpkghash_t *_alpm_pkghash_add_pkg(pmpkghash_t *hash, pmpkg_t *pkg, int sorted);
pmpkghash_t *_alpm_pkghash_remove(pmpkghash_t *hash, pmpkg_t *pkg, pmpkg_t **data);

void _alpm_pkghash_free(pmpkghash_t *hash);
--
1.7.4
 

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