From fc63f1b33fb438e8f7690db9bd84e3c69fe86b51 Mon Sep 17 00:00:00 2001
From: Tavian Barnes <tavianator@tavianator.com>
Date: Wed, 9 Nov 2022 11:35:53 -0500
Subject: ctx: Flush the user/group caches when executing commands
This fixes (admittedly uncommon) commands like
$ bfs -nouser -exec add-missing-user.sh {} \;
---
src/ctx.c | 5 +++++
src/pwcache.c | 46 ++++++++++++++++++++++------------------------
src/pwcache.h | 16 ++++++++++++++++
3 files changed, 43 insertions(+), 24 deletions(-)
diff --git a/src/ctx.c b/src/ctx.c
index 8d80691..4b373a1 100644
--- a/src/ctx.c
+++ b/src/ctx.c
@@ -186,6 +186,11 @@ void bfs_ctx_flush(const struct bfs_ctx *ctx) {
// We do not check errors here, but they will be caught at cleanup time
// with ferror().
fflush(NULL);
+
+ // Flush the user/group caches, in case the executed command edits the
+ // user/group tables
+ bfs_users_flush(ctx->users);
+ bfs_groups_flush(ctx->groups);
}
/** Flush a file and report any errors. */
diff --git a/src/pwcache.c b/src/pwcache.c
index 7071f59..868ec8f 100644
--- a/src/pwcache.c
+++ b/src/pwcache.c
@@ -64,6 +64,16 @@ static void *bfs_getent(struct trie_leaf *leaf, bfs_getent_fn *fn, const void *k
}
}
+/** 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);
+ }
+}
+
struct bfs_users {
/** Initial buffer size for getpw*_r(). */
size_t bufsize;
@@ -123,22 +133,16 @@ const struct passwd *bfs_getpwuid(struct bfs_users *users, uid_t uid) {
return bfs_getent(leaf, bfs_getpwuid_impl, &uid, sizeof(struct passwd), users->bufsize);
}
+void bfs_users_flush(struct bfs_users *users) {
+ bfs_pwcache_flush(&users->by_name);
+ bfs_pwcache_flush(&users->by_uid);
+}
+
void bfs_users_free(struct bfs_users *users) {
if (users) {
- TRIE_FOR_EACH(&users->by_uid, leaf) {
- if (leaf->value != MISSING) {
- free(leaf->value);
- }
- }
+ bfs_users_flush(users);
trie_destroy(&users->by_uid);
-
- TRIE_FOR_EACH(&users->by_name, leaf) {
- if (leaf->value != MISSING) {
- free(leaf->value);
- }
- }
trie_destroy(&users->by_name);
-
free(users);
}
}
@@ -202,22 +206,16 @@ const struct group *bfs_getgrgid(struct bfs_groups *groups, gid_t gid) {
return bfs_getent(leaf, bfs_getgrgid_impl, &gid, sizeof(struct group), groups->bufsize);
}
+void bfs_groups_flush(struct bfs_groups *groups) {
+ bfs_pwcache_flush(&groups->by_name);
+ bfs_pwcache_flush(&groups->by_gid);
+}
+
void bfs_groups_free(struct bfs_groups *groups) {
if (groups) {
- TRIE_FOR_EACH(&groups->by_gid, leaf) {
- if (leaf->value != MISSING) {
- free(leaf->value);
- }
- }
+ bfs_groups_flush(groups);
trie_destroy(&groups->by_gid);
-
- TRIE_FOR_EACH(&groups->by_name, leaf) {
- if (leaf->value != MISSING) {
- free(leaf->value);
- }
- }
trie_destroy(&groups->by_name);
-
free(groups);
}
}
diff --git a/src/pwcache.h b/src/pwcache.h
index 6ae8bea..f1ca0bf 100644
--- a/src/pwcache.h
+++ b/src/pwcache.h
@@ -63,6 +63,14 @@ const struct passwd *bfs_getpwnam(struct bfs_users *users, const char *name);
*/
const struct passwd *bfs_getpwuid(struct bfs_users *users, uid_t uid);
+/**
+ * Flush a user cache.
+ *
+ * @param users
+ * The cache to flush.
+ */
+void bfs_users_flush(struct bfs_users *users);
+
/**
* Free a user cache.
*
@@ -110,6 +118,14 @@ const struct group *bfs_getgrnam(struct bfs_groups *groups, const char *name);
*/
const struct group *bfs_getgrgid(struct bfs_groups *groups, gid_t gid);
+/**
+ * Flush a group cache.
+ *
+ * @param groups
+ * The cache to flush.
+ */
+void bfs_groups_flush(struct bfs_groups *groups);
+
/**
* Free a group cache.
*
--
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