diff options
Diffstat (limited to 'src/cache.c')
-rw-r--r-- | src/cache.c | 207 |
1 files changed, 205 insertions, 2 deletions
diff --git a/src/cache.c b/src/cache.c index ed260900..63971e86 100644 --- a/src/cache.c +++ b/src/cache.c @@ -15,6 +15,7 @@ #include <netlink.h> #include <mnl.h> #include <libnftnl/chain.h> +#include <linux/netfilter.h> static unsigned int evaluate_cache_add(struct cmd *cmd, unsigned int flags) { @@ -204,8 +205,8 @@ static int chain_cache_cb(struct nftnl_chain *nlc, void *arg) return 0; } -int chain_cache_init(struct netlink_ctx *ctx, struct table *table, - struct nftnl_chain_list *chain_list) +static int chain_cache_init(struct netlink_ctx *ctx, struct table *table, + struct nftnl_chain_list *chain_list) { struct chain_cache_dump_ctx dump_ctx = { .nlctx = ctx, @@ -256,3 +257,205 @@ struct chain *chain_cache_find(const struct table *table, return NULL; } + +static int cache_init_tables(struct netlink_ctx *ctx, struct handle *h, + struct nft_cache *cache) +{ + int ret; + + ret = netlink_list_tables(ctx, h); + if (ret < 0) + return -1; + + list_splice_tail_init(&ctx->list, &cache->list); + + return 0; +} + +static int cache_init_objects(struct netlink_ctx *ctx, unsigned int flags) +{ + struct nftnl_chain_list *chain_list = NULL; + struct rule *rule, *nrule; + struct table *table; + struct chain *chain; + struct set *set; + int ret = 0; + + if (flags & NFT_CACHE_CHAIN_BIT) { + chain_list = chain_cache_dump(ctx, &ret); + if (!chain_list) + return ret; + } + + list_for_each_entry(table, &ctx->nft->cache.list, list) { + if (flags & NFT_CACHE_SET_BIT) { + ret = netlink_list_sets(ctx, &table->handle); + list_splice_tail_init(&ctx->list, &table->sets); + if (ret < 0) { + ret = -1; + goto cache_fails; + } + } + if (flags & NFT_CACHE_SETELEM_BIT) { + list_for_each_entry(set, &table->sets, list) { + ret = netlink_list_setelems(ctx, &set->handle, + set); + if (ret < 0) { + ret = -1; + goto cache_fails; + } + } + } + if (flags & NFT_CACHE_CHAIN_BIT) { + ret = chain_cache_init(ctx, table, chain_list); + if (ret < 0) { + ret = -1; + goto cache_fails; + } + } + if (flags & NFT_CACHE_FLOWTABLE_BIT) { + ret = netlink_list_flowtables(ctx, &table->handle); + if (ret < 0) { + ret = -1; + goto cache_fails; + } + list_splice_tail_init(&ctx->list, &table->flowtables); + } + if (flags & NFT_CACHE_OBJECT_BIT) { + ret = netlink_list_objs(ctx, &table->handle); + if (ret < 0) { + ret = -1; + goto cache_fails; + } + list_splice_tail_init(&ctx->list, &table->objs); + } + + if (flags & NFT_CACHE_RULE_BIT) { + ret = netlink_list_rules(ctx, &table->handle); + list_for_each_entry_safe(rule, nrule, &ctx->list, list) { + chain = chain_cache_find(table, &rule->handle); + if (!chain) + chain = chain_binding_lookup(table, + rule->handle.chain.name); + list_move_tail(&rule->list, &chain->rules); + } + if (ret < 0) { + ret = -1; + goto cache_fails; + } + } + } + +cache_fails: + if (flags & NFT_CACHE_CHAIN_BIT) + nftnl_chain_list_free(chain_list); + + return ret; +} + +int cache_init(struct netlink_ctx *ctx, unsigned int flags) +{ + struct handle handle = { + .family = NFPROTO_UNSPEC, + }; + int ret; + + if (flags == NFT_CACHE_EMPTY) + return 0; + + /* assume NFT_CACHE_TABLE is always set. */ + ret = cache_init_tables(ctx, &handle, &ctx->nft->cache); + if (ret < 0) + return ret; + ret = cache_init_objects(ctx, flags); + if (ret < 0) + return ret; + + return 0; +} + +static bool cache_is_complete(struct nft_cache *cache, unsigned int flags) +{ + return (cache->flags & flags) == flags; +} + +static bool cache_needs_refresh(struct nft_cache *cache) +{ + return cache->flags & NFT_CACHE_REFRESH; +} + +static bool cache_is_updated(struct nft_cache *cache, uint16_t genid) +{ + return genid && genid == cache->genid; +} + +bool cache_needs_update(struct nft_cache *cache) +{ + return cache->flags & NFT_CACHE_UPDATE; +} + +int cache_update(struct nft_ctx *nft, unsigned int flags, struct list_head *msgs) +{ + struct netlink_ctx ctx = { + .list = LIST_HEAD_INIT(ctx.list), + .nft = nft, + .msgs = msgs, + }; + struct nft_cache *cache = &nft->cache; + uint32_t genid, genid_stop, oldflags; + int ret; +replay: + ctx.seqnum = cache->seqnum++; + genid = mnl_genid_get(&ctx); + if (!cache_needs_refresh(cache) && + cache_is_complete(cache, flags) && + cache_is_updated(cache, genid)) + return 0; + + if (cache->genid) + cache_release(cache); + + if (flags & NFT_CACHE_FLUSHED) { + oldflags = flags; + flags = NFT_CACHE_EMPTY; + if (oldflags & NFT_CACHE_UPDATE) + flags |= NFT_CACHE_UPDATE; + goto skip; + } + + ret = cache_init(&ctx, flags); + if (ret < 0) { + cache_release(cache); + if (errno == EINTR) + goto replay; + + return -1; + } + + genid_stop = mnl_genid_get(&ctx); + if (genid != genid_stop) { + cache_release(cache); + goto replay; + } +skip: + cache->genid = genid; + cache->flags = flags; + return 0; +} + +static void __cache_flush(struct list_head *table_list) +{ + struct table *table, *next; + + list_for_each_entry_safe(table, next, table_list, list) { + list_del(&table->list); + table_free(table); + } +} + +void cache_release(struct nft_cache *cache) +{ + __cache_flush(&cache->list); + cache->genid = 0; + cache->flags = NFT_CACHE_EMPTY; +} |