[PATCH 4.2 126/258] netfilter: nft_compat: skip family comparison in case of NFPROTO_UNSPEC

From: Greg Kroah-Hartman
Date: Sun Oct 18 2015 - 00:36:24 EST


4.2-stable review patch. If anyone has any objections, please let me know.

------------------

From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>

commit ba378ca9c04a5fc1b2cf0f0274a9d02eb3d1bad9 upstream.

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@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/netfilter/nft_compat.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)

--- 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_ct
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_ct
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_c
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_c
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);



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