From: Phil Sutter Date: Wed, 12 Dec 2018 18:29:07 +0000 (+0100) Subject: netfilter: nf_tables: Speed up selective rule dumps X-Git-Tag: v5.15~7332^2~14^2~13 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=241faeceb849cb02c6439ecb2a08f14bf409dd30;p=mirror_ubuntu-kernels.git netfilter: nf_tables: Speed up selective rule dumps 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 Signed-off-by: Pablo Neira Ayuso --- 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; }