From 88e92967a7b4e3e4501b17f21812467effa331c7 Mon Sep 17 00:00:00 2001
From: Alexey Tikhonov <atikhono@redhat.com>
Date: Tue, 16 Jun 2020 13:51:28 +0200
Subject: [PATCH] NEGCACHE: skip permanent entries in [users/groups] reset
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Files provider calling `sss_ncache_reset_[users/groups]()`
during cache rebuilding was breaking neg-cache prepopulation.

Resolves: https://github.com/SSSD/sssd/issues/1024

Reviewed-by: Tomáš Halman <thalman@redhat.com>
---
 src/responder/common/negcache.c | 9 +++++++++
 src/responder/common/negcache.h | 1 +
 2 files changed, 10 insertions(+)

diff --git a/src/responder/common/negcache.c b/src/responder/common/negcache.c
index d9545aef6..ce1c0ab8c 100644
--- a/src/responder/common/negcache.c
+++ b/src/responder/common/negcache.c
@@ -900,12 +900,21 @@ static int delete_prefix(struct tdb_context *tdb,
                          TDB_DATA key, TDB_DATA data, void *state)
 {
     const char *prefix = (const char *) state;
+    unsigned long long int timestamp;
+    char *ep = NULL;
 
     if (strncmp((char *)key.dptr, prefix, strlen(prefix) - 1) != 0) {
         /* not interested in this key */
         return 0;
     }
 
+    errno = 0;
+    timestamp = strtoull((const char *)data.dptr, &ep, 10);
+    if ((errno == 0) && (*ep == '\0') && (timestamp == 0)) {
+        /* skip permanent entries */
+        return 0;
+    }
+
     return tdb_delete(tdb, key);
 }
 
diff --git a/src/responder/common/negcache.h b/src/responder/common/negcache.h
index a80412215..4dcfb5e8f 100644
--- a/src/responder/common/negcache.h
+++ b/src/responder/common/negcache.h
@@ -146,6 +146,7 @@ int sss_ncache_set_locate_uid(struct sss_nc_ctx *ctx,
                               uid_t uid);
 
 int sss_ncache_reset_permanent(struct sss_nc_ctx *ctx);
+/* sss_ncache_reset_[users/groups] skips permanent entries */
 int sss_ncache_reset_users(struct sss_nc_ctx *ctx);
 int sss_ncache_reset_groups(struct sss_nc_ctx *ctx);
 
-- 
2.21.3