[PATCH nft v2 1/2] libnftables: got rid of repeated initialization of netlink_ctx variable in loop.

[Jeremy Sowden]

Most members in the context doesn't change, so there is no need to
memset it and reassign them on every iteration.  Moved that code out of
the loop.

Fixes: a72315d2bad4 ("src: add rule batching support")
Reported-by: Pablo Neira Ayuso <pa...@netfilter.org>
Signed-off-by: Jeremy Sowden <jer...@azazel.net>
---
 src/libnftables.c | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/src/libnftables.c b/src/libnftables.c
index 2f77a7709e2c..4a139c58b2b3 100644
--- a/src/libnftables.c
+++ b/src/libnftables.c
@@ -22,8 +22,12 @@ static int nft_netlink(struct nft_ctx *nft,
                       struct mnl_socket *nf_sock)
 {
        uint32_t batch_seqnum, seqnum = 0, num_cmds = 0;
-       struct nftnl_batch *batch;
-       struct netlink_ctx ctx;
+       struct netlink_ctx ctx = {
+               .nft  = nft,
+               .msgs = msgs,
+               .list = LIST_HEAD_INIT(ctx.list),
+               .batch = mnl_batch_init(),
+       };
        struct cmd *cmd;
        struct mnl_err *err, *tmp;
        LIST_HEAD(err_list);
@@ -32,16 +36,9 @@ static int nft_netlink(struct nft_ctx *nft,
        if (list_empty(cmds))
                return 0;
 
-       batch = mnl_batch_init();
-
-       batch_seqnum = mnl_batch_begin(batch, mnl_seqnum_alloc(&seqnum));
+       batch_seqnum = mnl_batch_begin(ctx.batch, mnl_seqnum_alloc(&seqnum));
        list_for_each_entry(cmd, cmds, list) {
-               memset(&ctx, 0, sizeof(ctx));
-               ctx.msgs = msgs;
                ctx.seqnum = cmd->seqnum = mnl_seqnum_alloc(&seqnum);
-               ctx.batch = batch;
-               ctx.nft = nft;
-               init_list_head(&ctx.list);
                ret = do_command(&ctx, cmd);
                if (ret < 0) {
                        netlink_io_error(&ctx, &cmd->location,
@@ -52,9 +49,9 @@ static int nft_netlink(struct nft_ctx *nft,
                num_cmds++;
        }
        if (!nft->check)
-               mnl_batch_end(batch, mnl_seqnum_alloc(&seqnum));
+               mnl_batch_end(ctx.batch, mnl_seqnum_alloc(&seqnum));
 
-       if (!mnl_batch_ready(batch))
+       if (!mnl_batch_ready(ctx.batch))
                goto out;
 
        ret = mnl_batch_talk(&ctx, &err_list, num_cmds);
@@ -83,7 +80,7 @@ static int nft_netlink(struct nft_ctx *nft,
                }
        }
 out:
-       mnl_batch_reset(batch);
+       mnl_batch_reset(ctx.batch);
        return ret;
 }
 
-- 
2.20.1