netfilter: nft_compat: skip family comparison in case of NFPROTO_UNSPEC

Fix lookup of existing match/target structures in the corresponding list
by skipping the family check if NFPROTO_UNSPEC is used.

This is resulting in the allocation and insertion of one match/target
structure for each use of them. So this not only bloats memory
consumption but also severely affects the time to reload the ruleset
from the iptables-compat utility.

After this patch, iptables-compat-restore and iptables-compat take
almost the same time to reload large rulesets.

Fixes: 0ca743a55991 ("netfilter: nf_tables: add compatibility layer for x_tables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nft_compat.c b/net/netfilter/nft_compat.c
index 66def315eb5619a26b64da8a1a5525af7d4a5e3f..9c8fab00164b5b6f3e43b3fc6fe983e39f89e64e 100644 (file)
--- a/net/netfilter/nft_compat.c
+++ b/net/netfilter/nft_compat.c
@@ -619,6 +619,13 @@ struct nft_xt {
 
 static struct nft_expr_type nft_match_type;
 
+static bool nft_match_cmp(const struct xt_match *match,
+                         const char *name, u32 rev, u32 family)
+{
+       return strcmp(match->name, name) == 0 && match->revision == rev &&
+              (match->family == NFPROTO_UNSPEC || match->family == family);
+}
+
 static const struct nft_expr_ops *
 nft_match_select_ops(const struct nft_ctx *ctx,
                     const struct nlattr * const tb[])
@@ -626,7 +633,7 @@ nft_match_select_ops(const struct nft_ctx *ctx,
        struct nft_xt *nft_match;
        struct xt_match *match;
        char *mt_name;
-       __u32 rev, family;
+       u32 rev, family;
 
        if (tb[NFTA_MATCH_NAME] == NULL ||
            tb[NFTA_MATCH_REV] == NULL ||
@@ -641,8 +648,7 @@ nft_match_select_ops(const struct nft_ctx *ctx,
        list_for_each_entry(nft_match, &nft_match_list, head) {
                struct xt_match *match = nft_match->ops.data;
 
-               if (strcmp(match->name, mt_name) == 0 &&
-                   match->revision == rev && match->family == family) {
+               if (nft_match_cmp(match, mt_name, rev, family)) {
                        if (!try_module_get(match->me))
                                return ERR_PTR(-ENOENT);
 
@@ -693,6 +699,13 @@ static LIST_HEAD(nft_target_list);
 
 static struct nft_expr_type nft_target_type;
 
+static bool nft_target_cmp(const struct xt_target *tg,
+                          const char *name, u32 rev, u32 family)
+{
+       return strcmp(tg->name, name) == 0 && tg->revision == rev &&
+              (tg->family == NFPROTO_UNSPEC || tg->family == family);
+}
+
 static const struct nft_expr_ops *
 nft_target_select_ops(const struct nft_ctx *ctx,
                      const struct nlattr * const tb[])
@@ -700,7 +713,7 @@ nft_target_select_ops(const struct nft_ctx *ctx,
        struct nft_xt *nft_target;
        struct xt_target *target;
        char *tg_name;
-       __u32 rev, family;
+       u32 rev, family;
 
        if (tb[NFTA_TARGET_NAME] == NULL ||
            tb[NFTA_TARGET_REV] == NULL ||
@@ -715,8 +728,7 @@ nft_target_select_ops(const struct nft_ctx *ctx,
        list_for_each_entry(nft_target, &nft_target_list, head) {
                struct xt_target *target = nft_target->ops.data;
 
-               if (strcmp(target->name, tg_name) == 0 &&
-                   target->revision == rev && target->family == family) {
+               if (nft_target_cmp(target, tg_name, rev, family)) {
                        if (!try_module_get(target->me))
                                return ERR_PTR(-ENOENT);