Revert "cache: recycle existing cache with incremental updates"

This reverts commit e791dbe109b6dd891a63a4236df5dc29d7a4b863.

Eric Garver reported two issues:

- index with rule breaks, because NFT_CACHE_REFRESH is missing.
- simple set updates.

Moreover, the current process could populate the cache with objects for
listing commands (no generation ID is bumped), while another process
could update the ruleset. Leading to a inconsistent cache due to the
genid + 1 check.

This optimization needs more work and more tests for -i/--interactive,
revert it.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/src/cache.c b/src/cache.c
index 4b797ec79ae54c7572750dc3c5af4df2bdb8985c..e88cbae2ad9598a85ee0f4b79ed9e27d34137ac1 100644 (file)
--- a/src/cache.c
+++ b/src/cache.c
@@ -1184,21 +1184,9 @@ static bool nft_cache_needs_refresh(struct nft_cache *cache, unsigned int flags)
               (flags & NFT_CACHE_REFRESH);
 }
 
-static bool nft_cache_is_updated(struct nft_cache *cache, unsigned int flags,
-                                uint16_t genid)
+static bool nft_cache_is_updated(struct nft_cache *cache, uint16_t genid)
 {
-       if (!genid)
-               return false;
-
-       if (genid == cache->genid)
-               return true;
-
-       if (genid == cache->genid + 1) {
-               cache->genid++;
-               return true;
-       }
-
-       return false;
+       return genid && genid == cache->genid;
 }
 
 bool nft_cache_needs_update(struct nft_cache *cache)
@@ -1223,7 +1211,7 @@ replay:
        genid = mnl_genid_get(&ctx);
        if (!nft_cache_needs_refresh(cache, flags) &&
            nft_cache_is_complete(cache, flags) &&
-           nft_cache_is_updated(cache, flags, genid))
+           nft_cache_is_updated(cache, genid))
                return 0;
 
        if (cache->genid)