Implement 'reset rule' and 'reset rules' commands

Reset rule counters and quotas in kernel, i.e. without having to reload
them. Requires respective kernel patch to support NFT_MSG_GETRULE_RESET
message type.

Signed-off-by: Phil Sutter <phil@nwl.cc>

9 files changed, 164 insertions, 11 deletions

diff --git a/src/cache.c b/src/cache.c
index 85de970f..0f5d1099 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -263,6 +263,30 @@ static unsigned int evaluate_cache_list(struct nft_ctx *nft, struct cmd *cmd,
 	return flags;
 }
 
+static unsigned int evaluate_cache_reset(struct cmd *cmd, unsigned int flags,
+					 struct nft_cache_filter *filter)
+{
+	switch (cmd->obj) {
+	case CMD_OBJ_RULES:
+		if (filter) {
+			if (cmd->handle.table.name) {
+				filter->list.family = cmd->handle.family;
+				filter->list.table = cmd->handle.table.name;
+			}
+			if (cmd->handle.chain.name)
+				filter->list.chain = cmd->handle.chain.name;
+		}
+		flags |= NFT_CACHE_SET | NFT_CACHE_FLOWTABLE |
+			 NFT_CACHE_OBJECT | NFT_CACHE_CHAIN;
+		break;
+	default:
+		flags |= NFT_CACHE_TABLE;
+		break;
+	}
+
+	return flags;
+}
+
 static int nft_handle_validate(const struct cmd *cmd, struct list_head *msgs)
 {
 	const struct handle *h = &cmd->handle;
@@ -277,6 +301,7 @@ static int nft_handle_validate(const struct cmd *cmd, struct list_head *msgs)
 		}
 		break;
 	case CMD_OBJ_RULE:
+	case CMD_OBJ_RULES:
 	case CMD_OBJ_CHAIN:
 	case CMD_OBJ_CHAINS:
 		if (h->table.name &&
@@ -403,7 +428,7 @@ int nft_cache_evaluate(struct nft_ctx *nft, struct list_head *cmds,
 			flags = evaluate_cache_get(cmd, flags);
 			break;
 		case CMD_RESET:
-			flags |= NFT_CACHE_TABLE;
+			flags |= evaluate_cache_reset(cmd, flags, filter);
 			break;
 		case CMD_LIST:
 			flags |= evaluate_cache_list(nft, cmd, flags, filter);
@@ -591,8 +616,8 @@ static int list_rule_cb(struct nftnl_rule *nlr, void *data)
 	table  = nftnl_rule_get_str(nlr, NFTNL_RULE_TABLE);
 	chain  = nftnl_rule_get_str(nlr, NFTNL_RULE_CHAIN);
 
-	if (h->family != family ||
-	    strcmp(table, h->table.name) != 0 ||
+	if ((h->family != NFPROTO_UNSPEC && h->family != family) ||
+	    (h->table.name && strcmp(table, h->table.name) != 0) ||
 	    (h->chain.name && strcmp(chain, h->chain.name) != 0))
 		return 0;
 
@@ -604,19 +629,23 @@ static int list_rule_cb(struct nftnl_rule *nlr, void *data)
 	return 0;
 }
 
-static int rule_cache_dump(struct netlink_ctx *ctx, const struct handle *h,
-			   const struct nft_cache_filter *filter)
+int rule_cache_dump(struct netlink_ctx *ctx, const struct handle *h,
+		    const struct nft_cache_filter *filter,
+		    bool dump, bool reset)
 {
 	struct nftnl_rule_list *rule_cache;
 	const char *table = NULL;
 	const char *chain = NULL;
+	uint64_t rule_handle = 0;
 
 	if (filter) {
 		table = filter->list.table;
 		chain = filter->list.chain;
+		rule_handle = filter->list.rule_handle;
 	}
 
-	rule_cache = mnl_nft_rule_dump(ctx, h->family, table, chain);
+	rule_cache = mnl_nft_rule_dump(ctx, h->family,
+				       table, chain, rule_handle, dump, reset);
 	if (rule_cache == NULL) {
 		if (errno == EINTR)
 			return -1;
@@ -948,7 +977,7 @@ static int rule_init_cache(struct netlink_ctx *ctx, struct table *table,
 	struct chain *chain;
 	int ret;
 
-	ret = rule_cache_dump(ctx, &table->handle, filter);
+	ret = rule_cache_dump(ctx, &table->handle, filter, true, false);
 
 	list_for_each_entry_safe(rule, nrule, &ctx->list, list) {
 		chain = chain_cache_find(table, rule->handle.chain.name);
diff --git a/src/evaluate.c b/src/evaluate.c
index 21de1840..61ebcbfc 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -5286,6 +5286,8 @@ static int cmd_evaluate_reset(struct eval_ctx *ctx, struct cmd *cmd)
 	case CMD_OBJ_QUOTA:
 	case CMD_OBJ_COUNTERS:
 	case CMD_OBJ_QUOTAS:
+	case CMD_OBJ_RULES:
+	case CMD_OBJ_RULE:
 		if (cmd->handle.table.name == NULL)
 			return 0;
 		if (!table_cache_find(&ctx->nft->cache.table_cache,
diff --git a/src/json.c b/src/json.c
index f57f2f77..f15461d3 100644
--- a/src/json.c
+++ b/src/json.c
@@ -1911,6 +1911,7 @@ int do_command_list_json(struct netlink_ctx *ctx, struct cmd *cmd)
 	case CMD_OBJ_SET:
 		root = do_list_set_json(ctx, cmd, table);
 		break;
+	case CMD_OBJ_RULES:
 	case CMD_OBJ_RULESET:
 		root = do_list_ruleset_json(ctx, cmd);
 		break;
diff --git a/src/mnl.c b/src/mnl.c
index 46d86f0f..ca01516c 100644
--- a/src/mnl.c
+++ b/src/mnl.c
@@ -654,13 +654,21 @@ err_free:
 }
 
 struct nftnl_rule_list *mnl_nft_rule_dump(struct netlink_ctx *ctx, int family,
-					  const char *table, const char *chain)
+					  const char *table, const char *chain,
+					  uint64_t rule_handle,
+					  bool dump, bool reset)
 {
+	uint16_t nl_flags = dump ? NLM_F_DUMP : NLM_F_ACK;
 	char buf[MNL_SOCKET_BUFFER_SIZE];
 	struct nftnl_rule_list *nlr_list;
 	struct nftnl_rule *nlr = NULL;
 	struct nlmsghdr *nlh;
-	int ret;
+	int msg_type, ret;
+
+	if (reset)
+		msg_type = NFT_MSG_GETRULE_RESET;
+	else
+		msg_type = NFT_MSG_GETRULE;
 
 	if (table) {
 		nlr = nftnl_rule_alloc();
@@ -670,14 +678,16 @@ struct nftnl_rule_list *mnl_nft_rule_dump(struct netlink_ctx *ctx, int family,
 		nftnl_rule_set_str(nlr, NFTNL_RULE_TABLE, table);
 		if (chain)
 			nftnl_rule_set_str(nlr, NFTNL_RULE_CHAIN, chain);
+		if (rule_handle)
+			nftnl_rule_set_u64(nlr, NFTNL_RULE_HANDLE, rule_handle);
 	}
 
 	nlr_list = nftnl_rule_list_alloc();
 	if (nlr_list == NULL)
 		memory_allocation_error();
 
-	nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_GETRULE, family,
-				    NLM_F_DUMP, ctx->seqnum);
+	nlh = nftnl_nlmsg_build_hdr(buf, msg_type, family,
+				    nl_flags, ctx->seqnum);
 	if (nlr) {
 		nftnl_rule_nlmsg_build_payload(nlh, nlr);
 		nftnl_rule_free(nlr);
diff --git a/src/netlink.c b/src/netlink.c
index efae1251..f1452d48 100644
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -1767,6 +1767,55 @@ int netlink_reset_objs(struct netlink_ctx *ctx, const struct cmd *cmd,
 	return err;
 }
 
+int netlink_reset_rules(struct netlink_ctx *ctx, const struct cmd *cmd,
+		        bool dump)
+{
+	const struct handle *h = &cmd->handle;
+	struct nft_cache_filter f = {
+		.list.table		= h->table.name,
+		.list.chain		= h->chain.name,
+		.list.rule_handle	= h->handle.id,
+	};
+	struct rule *rule, *next, *crule, *cnext;
+	struct table *table;
+	struct chain *chain;
+	int ret;
+
+	ret = rule_cache_dump(ctx, h, &f, dump, true);
+
+	list_for_each_entry_safe(rule, next, &ctx->list, list) {
+		table = table_cache_find(&ctx->nft->cache.table_cache,
+					 rule->handle.table.name,
+					 rule->handle.family);
+		if (!table)
+			continue;
+
+		chain = chain_cache_find(table, rule->handle.chain.name);
+		if (!chain)
+			continue;
+
+		list_del(&rule->list);
+		list_for_each_entry_safe(crule, cnext, &chain->rules, list) {
+			if (crule->handle.handle.id != rule->handle.handle.id)
+				continue;
+
+			list_replace(&crule->list, &rule->list);
+			rule_free(crule);
+			rule = NULL;
+			break;
+		}
+		if (rule) {
+			list_add_tail(&rule->list, &chain->rules);
+		}
+	}
+	list_for_each_entry_safe(rule, next, &ctx->list, list) {
+		list_del(&rule->list);
+		rule_free(rule);
+	}
+
+	return ret;
+}
+
 struct flowtable *
 netlink_delinearize_flowtable(struct netlink_ctx *ctx,
 			      struct nftnl_flowtable *nlo)
diff --git a/src/parser_bison.y b/src/parser_bison.y
index ccf07a30..62a4809b 100644
--- a/src/parser_bison.y
+++ b/src/parser_bison.y
@@ -1597,6 +1597,22 @@ reset_cmd		:	COUNTERS	ruleset_spec
 			{
 				$$ = cmd_alloc(CMD_RESET, CMD_OBJ_QUOTA, &$2, &@$, NULL);
 			}
+			|	RULES		ruleset_spec
+			{
+				$$ = cmd_alloc(CMD_RESET, CMD_OBJ_RULES, &$2, &@$, NULL);
+			}
+			|	RULES		TABLE	table_spec
+			{
+				$$ = cmd_alloc(CMD_RESET, CMD_OBJ_RULES, &$3, &@$, NULL);
+			}
+			|	RULES		CHAIN	chain_spec
+			{
+				$$ = cmd_alloc(CMD_RESET, CMD_OBJ_RULES, &$3, &@$, NULL);
+			}
+			|	RULE		ruleid_spec
+			{
+				$$ = cmd_alloc(CMD_RESET, CMD_OBJ_RULE, &$2, &@$, NULL);
+			}
 			;
 
 flush_cmd		:	TABLE		table_spec
diff --git a/src/parser_json.c b/src/parser_json.c
index ae683314..dfab3f9c 100644
--- a/src/parser_json.c
+++ b/src/parser_json.c
@@ -3763,6 +3763,39 @@ static struct cmd *json_parse_cmd_list(struct json_ctx *ctx,
 	return NULL;
 }
 
+static struct cmd *json_parse_cmd_reset_rule(struct json_ctx *ctx,
+					     json_t *root, enum cmd_ops op,
+					     enum cmd_obj obj)
+{
+	struct handle h = {
+		.family = NFPROTO_UNSPEC,
+	};
+	const char *family = NULL, *table = NULL, *chain = NULL;
+
+
+	if (obj == CMD_OBJ_RULE &&
+	    json_unpack_err(ctx, root, "{s:s, s:s, s:s, s:I}",
+			    "family", &family, "table", &table,
+			    "chain", &chain, "handle", &h.handle.id))
+		return NULL;
+	else if (obj == CMD_OBJ_RULES) {
+		json_unpack(root, "{s:s}", "family", &family);
+		json_unpack(root, "{s:s}", "table", &table);
+		json_unpack(root, "{s:s}", "chain", &chain);
+	}
+
+	if (family && parse_family(family, &h.family)) {
+		json_error(ctx, "Unknown family '%s'.", family);
+		return NULL;
+	}
+	if (table) {
+		h.table.name = xstrdup(table);
+		if (chain)
+			h.chain.name = xstrdup(chain);
+	}
+	return cmd_alloc(op, obj, &h, int_loc, NULL);
+}
+
 static struct cmd *json_parse_cmd_reset(struct json_ctx *ctx,
 				        json_t *root, enum cmd_ops op)
 {
@@ -3776,6 +3809,8 @@ static struct cmd *json_parse_cmd_reset(struct json_ctx *ctx,
 		{ "counters", CMD_OBJ_COUNTERS, json_parse_cmd_list_multiple },
 		{ "quota", CMD_OBJ_QUOTA, json_parse_cmd_add_object },
 		{ "quotas", CMD_OBJ_QUOTAS, json_parse_cmd_list_multiple },
+		{ "rule", CMD_OBJ_RULE, json_parse_cmd_reset_rule },
+		{ "rules", CMD_OBJ_RULES, json_parse_cmd_reset_rule },
 	};
 	unsigned int i;
 	json_t *tmp;
diff --git a/src/rule.c b/src/rule.c
index 903c01f5..371c803a 100644
--- a/src/rule.c
+++ b/src/rule.c
@@ -2504,6 +2504,8 @@ static int do_command_list(struct netlink_ctx *ctx, struct cmd *cmd)
 	case CMD_OBJ_SET:
 		return do_list_set(ctx, cmd, table);
 	case CMD_OBJ_RULESET:
+	case CMD_OBJ_RULES:
+	case CMD_OBJ_RULE:
 		return do_list_ruleset(ctx, cmd);
 	case CMD_OBJ_METERS:
 		return do_list_sets(ctx, cmd);
@@ -2611,6 +2613,14 @@ static int do_command_reset(struct netlink_ctx *ctx, struct cmd *cmd)
 	case CMD_OBJ_QUOTA:
 		type = NFT_OBJECT_QUOTA;
 		break;
+	case CMD_OBJ_RULES:
+		ret = netlink_reset_rules(ctx, cmd, true);
+		if (ret < 0)
+			return ret;
+
+		return do_command_list(ctx, cmd);
+	case CMD_OBJ_RULE:
+		return netlink_reset_rules(ctx, cmd, false);
 	default:
 		BUG("invalid command object type %u\n", cmd->obj);
 	}
diff --git a/src/scanner.l b/src/scanner.l
index 9c85ee37..aa0a0a9f 100644
--- a/src/scanner.l
+++ b/src/scanner.l
@@ -402,6 +402,7 @@ addrstring	({macaddr}|{ip4addr}|{ip6addr})
 <SCANSTATE_CMD_LIST,SCANSTATE_CMD_RESET>{
 	"counters"		{ return COUNTERS; }
 	"quotas"		{ return QUOTAS; }
+	"rules"			{ return RULES; }
 }
 
 "log"			{ scanner_push_start_cond(yyscanner, SCANSTATE_STMT_LOG); return LOG; }