This code example doesn't work, as the kernel API is only listening to messages
in batches.
This patch updates the example to add the needed batching support.
Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@xxxxxxxxx>
---
examples/nft-chain-add.c | 59 +++++++++++++++++++++++++++++++++++++---------
1 file changed, 47 insertions(+), 12 deletions(-)
diff --git a/examples/nft-chain-add.c b/examples/nft-chain-add.c
index 3edff86..ac55b4f 100644
--- a/examples/nft-chain-add.c
+++ b/examples/nft-chain-add.c
@@ -15,14 +15,32 @@
#include <netinet/in.h>
#include <linux/netfilter.h>
+#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nf_tables.h>
#include <libmnl/libmnl.h>
#include <libnftnl/chain.h>
+static void nft_mnl_batch_put(char *buf, uint16_t type, uint32_t seq)
+{
+ struct nlmsghdr *nlh;
+ struct nfgenmsg *nfg;
+
+ nlh = mnl_nlmsg_put_header(buf);
+ nlh->nlmsg_type = type;
+ nlh->nlmsg_flags = NLM_F_REQUEST;
+ nlh->nlmsg_seq = seq;
+
+ nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg));
+ nfg->nfgen_family = AF_INET;
+ nfg->version = NFNETLINK_V0;
+ nfg->res_id = NFNL_SUBSYS_NFTABLES;
+}
+
int main(int argc, char *argv[])
{
struct mnl_socket *nl;
+ struct mnl_nlmsg_batch *batch;
char buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh;
uint32_t portid, seq;
@@ -72,9 +90,17 @@ int main(int argc, char *argv[])
perror("OOM");
exit(EXIT_FAILURE);
}
+
seq = time(NULL);
- nlh = nft_chain_nlmsg_build_hdr(buf, NFT_MSG_NEWCHAIN, family,
- NLM_F_EXCL|NLM_F_ACK, seq);
+ batch = mnl_nlmsg_batch_start(buf, sizeof(buf));
+
+ nft_mnl_batch_put(mnl_nlmsg_batch_current(batch),
+ NFNL_MSG_BATCH_BEGIN, seq++);
+ mnl_nlmsg_batch_next(batch);
+
+ nlh = nft_chain_nlmsg_build_hdr(mnl_nlmsg_batch_current(batch),
+ NFT_MSG_NEWCHAIN, family,
+ NLM_F_ACK, seq++);
nft_chain_attr_set(t, NFT_CHAIN_ATTR_TABLE, argv[2]);
nft_chain_attr_set(t, NFT_CHAIN_ATTR_NAME, argv[3]);
if (argc == 6) {
@@ -83,6 +109,11 @@ int main(int argc, char *argv[])
}
nft_chain_nlmsg_build_payload(nlh, t);
nft_chain_free(t);
+ mnl_nlmsg_batch_next(batch);
+
+ nft_mnl_batch_put(mnl_nlmsg_batch_current(batch), NFNL_MSG_BATCH_END,
+ seq++);
+ mnl_nlmsg_batch_next(batch);
nl = mnl_socket_open(NETLINK_NETFILTER);
if (nl == NULL) {
@@ -96,23 +127,27 @@ int main(int argc, char *argv[])
}
portid = mnl_socket_get_portid(nl);
- if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
- perror("mnl_socket_send");
+ ret = mnl_socket_sendto(nl, mnl_nlmsg_batch_head(batch),
+ mnl_nlmsg_batch_size(batch));
+ if (ret == -1) {
+ perror("mnl_socket_sendto");
exit(EXIT_FAILURE);
}
+ mnl_nlmsg_batch_stop(batch);
+
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
- while (ret > 0) {
- ret = mnl_cb_run(buf, ret, seq, portid, NULL, NULL);
- if (ret <= 0)
- break;
- ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
- }
if (ret == -1) {
- perror("error");
+ perror("mnl_socket_recvfrom");
exit(EXIT_FAILURE);
}
- mnl_socket_close(nl);
+ ret = mnl_cb_run(buf, ret, 0, portid, NULL, NULL);
+ if (ret < 0) {
+ perror("mnl_cb_run");
+ exit(EXIT_FAILURE);
+ }
+
+ mnl_socket_close(nl);
return EXIT_SUCCESS;
}
--
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