diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/pwcache.c | 134 |
1 files changed, 80 insertions, 54 deletions
diff --git a/src/pwcache.c b/src/pwcache.c index 9f32eb0..a9acfc0 100644 --- a/src/pwcache.c +++ b/src/pwcache.c @@ -17,54 +17,56 @@ static void *MISSING = &MISSING; /** Callback type for bfs_getent(). */ -typedef void *bfs_getent_fn(const void *key, void *ent, void *buf, size_t bufsize); +typedef void *bfs_getent_fn(const void *key, void *ptr, size_t bufsize); /** Shared scaffolding for get{pw,gr}{nam,?id}_r(). */ -static void *bfs_getent(struct trie_leaf *leaf, bfs_getent_fn *fn, const void *key, size_t entsize, size_t bufsize) { +static void *bfs_getent(bfs_getent_fn *fn, const void *key, struct trie_leaf *leaf, struct varena *varena, size_t bufsize) { if (leaf->value) { errno = 0; return leaf->value == MISSING ? NULL : leaf->value; } - void *buf = NULL; - while (true) { - void *result = buf; - buf = realloc(buf, entsize + bufsize); - if (!buf) { - free(result); - return NULL; - } + void *ptr = varena_alloc(varena, bufsize); + if (!ptr) { + return NULL; + } - result = fn(key, buf, (char *)buf + entsize, bufsize); - if (result) { - leaf->value = result; - return result; + while (true) { + void *ret = fn(key, ptr, bufsize); + if (ret) { + leaf->value = ret; + return ret; } else if (errno == 0) { - free(buf); leaf->value = MISSING; - return NULL; + break; } else if (errno == ERANGE) { - bufsize *= 2; + void *next = varena_grow(varena, ptr, &bufsize); + if (!next) { + break; + } + ptr = next; } else { - free(buf); - return NULL; + break; } } -} -/** Flush a single cache. */ -static void bfs_pwcache_flush(struct trie *trie) { - TRIE_FOR_EACH(trie, leaf) { - if (leaf->value != MISSING) { - free(leaf->value); - } - trie_remove(trie, leaf); - } + varena_free(varena, ptr, bufsize); + return NULL; } +/** + * An arena-allocated struct passwd. + */ +struct bfs_passwd { + struct passwd pwd; + char buf[]; +}; + struct bfs_users { /** Initial buffer size for getpw*_r(). */ size_t bufsize; + /** bfs_passwd arena. */ + struct varena varena; /** A map from usernames to entries. */ struct trie by_name; /** A map from UIDs to entries. */ @@ -84,16 +86,19 @@ struct bfs_users *bfs_users_new(void) { users->bufsize = 1024; } + VARENA_INIT(&users->varena, struct bfs_passwd, buf); trie_init(&users->by_name); trie_init(&users->by_uid); return users; } /** bfs_getent() callback for getpwnam_r(). */ -static void *bfs_getpwnam_impl(const void *key, void *ent, void *buf, size_t bufsize) { - struct passwd *result; - errno = getpwnam_r(key, ent, buf, bufsize, &result); - return result; +static void *bfs_getpwnam_impl(const void *key, void *ptr, size_t bufsize) { + struct bfs_passwd *storage = ptr; + + struct passwd *ret; + errno = getpwnam_r(key, &storage->pwd, storage->buf, bufsize, &ret); + return ret; } const struct passwd *bfs_getpwnam(struct bfs_users *users, const char *name) { @@ -102,14 +107,17 @@ const struct passwd *bfs_getpwnam(struct bfs_users *users, const char *name) { return NULL; } - return bfs_getent(leaf, bfs_getpwnam_impl, name, sizeof(struct passwd), users->bufsize); + return bfs_getent(bfs_getpwnam_impl, name, leaf, &users->varena, users->bufsize); } /** bfs_getent() callback for getpwuid_r(). */ -static void *bfs_getpwuid_impl(const void *key, void *ent, void *buf, size_t bufsize) { - struct passwd *result; - errno = getpwuid_r(*(const uid_t *)key, ent, buf, bufsize, &result); - return result; +static void *bfs_getpwuid_impl(const void *key, void *ptr, size_t bufsize) { + const uid_t *uid = key; + struct bfs_passwd *storage = ptr; + + struct passwd *ret; + errno = getpwuid_r(*uid, &storage->pwd, storage->buf, bufsize, &ret); + return ret; } const struct passwd *bfs_getpwuid(struct bfs_users *users, uid_t uid) { @@ -118,26 +126,37 @@ const struct passwd *bfs_getpwuid(struct bfs_users *users, uid_t uid) { return NULL; } - return bfs_getent(leaf, bfs_getpwuid_impl, &uid, sizeof(struct passwd), users->bufsize); + return bfs_getent(bfs_getpwuid_impl, &uid, leaf, &users->varena, users->bufsize); } void bfs_users_flush(struct bfs_users *users) { - bfs_pwcache_flush(&users->by_name); - bfs_pwcache_flush(&users->by_uid); + trie_clear(&users->by_uid); + trie_clear(&users->by_name); + varena_clear(&users->varena); } void bfs_users_free(struct bfs_users *users) { if (users) { - bfs_users_flush(users); trie_destroy(&users->by_uid); trie_destroy(&users->by_name); + varena_destroy(&users->varena); free(users); } } +/** + * An arena-allocated struct group. + */ +struct bfs_group { + struct group grp; + char buf[]; +}; + struct bfs_groups { /** Initial buffer size for getgr*_r(). */ size_t bufsize; + /** bfs_group arena. */ + struct varena varena; /** A map from group names to entries. */ struct trie by_name; /** A map from GIDs to entries. */ @@ -157,16 +176,19 @@ struct bfs_groups *bfs_groups_new(void) { groups->bufsize = 1024; } + VARENA_INIT(&groups->varena, struct bfs_group, buf); trie_init(&groups->by_name); trie_init(&groups->by_gid); return groups; } /** bfs_getent() callback for getgrnam_r(). */ -static void *bfs_getgrnam_impl(const void *key, void *ent, void *buf, size_t bufsize) { - struct group *result; - errno = getgrnam_r(key, ent, buf, bufsize, &result); - return result; +static void *bfs_getgrnam_impl(const void *key, void *ptr, size_t bufsize) { + struct bfs_group *storage = ptr; + + struct group *ret; + errno = getgrnam_r(key, &storage->grp, storage->buf, bufsize, &ret); + return ret; } const struct group *bfs_getgrnam(struct bfs_groups *groups, const char *name) { @@ -175,14 +197,17 @@ const struct group *bfs_getgrnam(struct bfs_groups *groups, const char *name) { return NULL; } - return bfs_getent(leaf, bfs_getgrnam_impl, name, sizeof(struct group), groups->bufsize); + return bfs_getent(bfs_getgrnam_impl, name, leaf, &groups->varena, groups->bufsize); } /** bfs_getent() callback for getgrgid_r(). */ -static void *bfs_getgrgid_impl(const void *key, void *ent, void *buf, size_t bufsize) { - struct group *result; - errno = getgrgid_r(*(const gid_t *)key, ent, buf, bufsize, &result); - return result; +static void *bfs_getgrgid_impl(const void *key, void *ptr, size_t bufsize) { + const gid_t *gid = key; + struct bfs_group *storage = ptr; + + struct group *ret; + errno = getgrgid_r(*gid, &storage->grp, storage->buf, bufsize, &ret); + return ret; } const struct group *bfs_getgrgid(struct bfs_groups *groups, gid_t gid) { @@ -191,19 +216,20 @@ const struct group *bfs_getgrgid(struct bfs_groups *groups, gid_t gid) { return NULL; } - return bfs_getent(leaf, bfs_getgrgid_impl, &gid, sizeof(struct group), groups->bufsize); + return bfs_getent(bfs_getgrgid_impl, &gid, leaf, &groups->varena, groups->bufsize); } void bfs_groups_flush(struct bfs_groups *groups) { - bfs_pwcache_flush(&groups->by_name); - bfs_pwcache_flush(&groups->by_gid); + trie_clear(&groups->by_gid); + trie_clear(&groups->by_name); + varena_clear(&groups->varena); } void bfs_groups_free(struct bfs_groups *groups) { if (groups) { - bfs_groups_flush(groups); trie_destroy(&groups->by_gid); trie_destroy(&groups->by_name); + varena_destroy(&groups->varena); free(groups); } } |