nftables: fix supression of "permission denied" errors

Introduction of batch support broke displaying of EPERM since those are
generated by the kernel before batch processing starts and thus have the
sequence number of the NFNL_MSG_BATCH_BEGIN message instead of the
command messages. Also only a single error message is generated for the
entire batch.

This patch fixes this by noting the batch sequence number and displaying
the error for all commands since this is what would happen if the
permission check was inside batch processing as every other check.

Signed-off-by: Patrick McHardy <kaber@trash.net>

3 files changed, 14 insertions, 8 deletions

diff --git a/include/mnl.h b/include/mnl.h
index fe2fb400..a6306058 100644
--- a/include/mnl.h
+++ b/include/mnl.h
@@ -18,7 +18,7 @@ void mnl_err_list_free(struct mnl_err *err);
 void mnl_batch_init(void);
 bool mnl_batch_ready(void);
 void mnl_batch_reset(void);
-void mnl_batch_begin(void);
+uint32_t mnl_batch_begin(void);
 void mnl_batch_end(void);
 int mnl_batch_talk(struct mnl_socket *nl, struct list_head *err_list);
 int mnl_nft_rule_batch_add(struct nft_rule *nlr, unsigned int flags,
diff --git a/src/main.c b/src/main.c
index 0c97120b..32a991a6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -156,9 +156,10 @@ static int nft_netlink(struct parser_state *state, struct list_head *msgs)
 	struct cmd *cmd, *next;
 	struct mnl_err *err, *tmp;
 	LIST_HEAD(err_list);
+	uint32_t batch_seqnum;
 	int ret = 0;
 
-	mnl_batch_begin();
+	batch_seqnum = mnl_batch_begin();
 	list_for_each_entry(cmd, &state->cmds, list) {
 		memset(&ctx, 0, sizeof(ctx));
 		ctx.msgs = msgs;
@@ -179,12 +180,15 @@ static int nft_netlink(struct parser_state *state, struct list_head *msgs)
 
 	list_for_each_entry_safe(err, tmp, &err_list, head) {
 		list_for_each_entry(cmd, &state->cmds, list) {
-			if (err->seqnum == cmd->seqnum) {
+			if (err->seqnum == cmd->seqnum ||
+			    err->seqnum == batch_seqnum) {
 				netlink_io_error(&ctx, &cmd->location,
 					"Could not process rule in batch: %s",
 					strerror(err->err));
-				mnl_err_list_free(err);
-				break;
+				if (err->seqnum == cmd->seqnum) {
+					mnl_err_list_free(err);
+					break;
+				}
 			}
 		}
 	}
diff --git a/src/mnl.c b/src/mnl.c
index a711b5e2..a4a4c4af 100644
--- a/src/mnl.c
+++ b/src/mnl.c
@@ -106,7 +106,7 @@ static void mnl_batch_page_add(void)
 	batch = mnl_batch_alloc();
 }
 
-static void mnl_batch_put(int type)
+static uint32_t mnl_batch_put(int type)
 {
 	struct nlmsghdr *nlh;
 	struct nfgenmsg *nfg;
@@ -123,11 +123,13 @@ static void mnl_batch_put(int type)
 
 	if (!mnl_nlmsg_batch_next(batch))
 		mnl_batch_page_add();
+
+	return nlh->nlmsg_seq;
 }
 
-void mnl_batch_begin(void)
+uint32_t mnl_batch_begin(void)
 {
-	mnl_batch_put(NFNL_MSG_BATCH_BEGIN);
+	return mnl_batch_put(NFNL_MSG_BATCH_BEGIN);
 }
 
 void mnl_batch_end(void)