From: Phil Sutter <phil@xxxxxx>
If just a table name was given, nf_tables_dump_rules() continued over
the list of tables even after a match was found. The simple fix is to
exit the loop if it reached the bottom and ctx->table was not NULL.
When iterating over the table's chains, the same problem as above
existed. But worse than that, if a chain name was given the hash table
wasn't used to find the corresponding chain. Fix this by introducing a
helper function iterating over a chain's rules (and taking care of the
cb->args handling), then introduce a shortcut to it if a chain name was
given.
Signed-off-by: Phil Sutter <phil@xxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/nf_tables_api.c | 90 +++++++++++++++++++++++++++++--------------
1 file changed, 62 insertions(+), 28 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 42487d01a3ed..200751a49745 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2291,15 +2291,52 @@ struct nft_rule_dump_ctx {
char *chain;
};
+static int __nf_tables_dump_rules(struct sk_buff *skb,
+ unsigned int *idx,
+ struct netlink_callback *cb,
+ const struct nft_table *table,
+ const struct nft_chain *chain)
+{
+ struct net *net = sock_net(skb->sk);
+ unsigned int s_idx = cb->args[0];
+ const struct nft_rule *rule;
+ int rc = 1;
+
+ list_for_each_entry_rcu(rule, &chain->rules, list) {
+ if (!nft_is_active(net, rule))
+ goto cont;
+ if (*idx < s_idx)
+ goto cont;
+ if (*idx > s_idx) {
+ memset(&cb->args[1], 0,
+ sizeof(cb->args) - sizeof(cb->args[0]));
+ }
+ if (nf_tables_fill_rule_info(skb, net, NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq,
+ NFT_MSG_NEWRULE,
+ NLM_F_MULTI | NLM_F_APPEND,
+ table->family,
+ table, chain, rule) < 0)
+ goto out_unfinished;
+
+ nl_dump_check_consistent(cb, nlmsg_hdr(skb));
+cont:
+ (*idx)++;
+ }
+ rc = 0;
+out_unfinished:
+ cb->args[0] = *idx;
+ return rc;
+}
+
static int nf_tables_dump_rules(struct sk_buff *skb,
struct netlink_callback *cb)
{
const struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh);
const struct nft_rule_dump_ctx *ctx = cb->data;
- const struct nft_table *table;
+ struct nft_table *table;
const struct nft_chain *chain;
- const struct nft_rule *rule;
- unsigned int idx = 0, s_idx = cb->args[0];
+ unsigned int idx = 0;
struct net *net = sock_net(skb->sk);
int family = nfmsg->nfgen_family;
@@ -2313,37 +2350,34 @@ static int nf_tables_dump_rules(struct sk_buff *skb,
if (ctx && ctx->table && strcmp(ctx->table, table->name) != 0)
continue;
- list_for_each_entry_rcu(chain, &table->chains, list) {
- if (ctx && ctx->chain &&
- strcmp(ctx->chain, chain->name) != 0)
- continue;
+ if (ctx && ctx->chain) {
+ struct rhlist_head *list, *tmp;
- list_for_each_entry_rcu(rule, &chain->rules, list) {
- if (!nft_is_active(net, rule))
- goto cont;
- if (idx < s_idx)
- goto cont;
- if (idx > s_idx)
- memset(&cb->args[1], 0,
- sizeof(cb->args) - sizeof(cb->args[0]));
- if (nf_tables_fill_rule_info(skb, net, NETLINK_CB(cb->skb).portid,
- cb->nlh->nlmsg_seq,
- NFT_MSG_NEWRULE,
- NLM_F_MULTI | NLM_F_APPEND,
- table->family,
- table, chain, rule) < 0)
- goto done;
-
- nl_dump_check_consistent(cb, nlmsg_hdr(skb));
-cont:
- idx++;
+ list = rhltable_lookup(&table->chains_ht, ctx->chain,
+ nft_chain_ht_params);
+ if (!list)
+ goto done;
+
+ rhl_for_each_entry_rcu(chain, tmp, list, rhlhead) {
+ if (!nft_is_active(net, chain))
+ continue;
+ __nf_tables_dump_rules(skb, &idx,
+ cb, table, chain);
+ break;
}
+ goto done;
}
+
+ list_for_each_entry_rcu(chain, &table->chains, list) {
+ if (__nf_tables_dump_rules(skb, &idx, cb, table, chain))
+ goto done;
+ }
+
+ if (ctx && ctx->table)
+ break;
}
done:
rcu_read_unlock();
-
- cb->args[0] = idx;
return skb->len;
}
--
2.11.0
