static __set_verdict() uses mnl-API calls in enough places that the path
for no (mangled) data doesn't use any nfnl-API functions.
With no data, __set_verdict() uses sendto() (faster than sendmsg()).
nfq_set_verdict2() must not use htonl() on the packet mark.
Signed-off-by: Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx>
---
v3:
- rebased
- defer removal of libnfnetlink/libnfnetlink.h include to 13/15
v2:
- rebase to account for updated patches 1 - 3
- fix checkpatch warning re block comment termination
src/libnetfilter_queue.c | 36 +++++++++++++++++-------------------
1 file changed, 17 insertions(+), 19 deletions(-)
diff --git a/src/libnetfilter_queue.c b/src/libnetfilter_queue.c
index 6500fec..3fa8d2d 100644
--- a/src/libnetfilter_queue.c
+++ b/src/libnetfilter_queue.c
@@ -951,13 +951,8 @@ static int __set_verdict(struct nfq_q_handle *qh, uint32_t id,
uint32_t data_len, const unsigned char *data,
enum nfqnl_msg_types type)
{
- struct nfqnl_msg_verdict_hdr vh;
- union {
- char buf[NFNL_HEADER_LEN
- +NFA_LENGTH(sizeof(mark))
- +NFA_LENGTH(sizeof(vh))];
- struct nlmsghdr nmh;
- } u;
+ char buf[MNL_SOCKET_BUFFER_SIZE];
+ struct nlmsghdr *nlh;
struct iovec iov[3];
int nvecs;
@@ -968,20 +963,23 @@ static int __set_verdict(struct nfq_q_handle *qh, uint32_t id,
memset(iov, 0, sizeof(iov));
- vh.verdict = htonl(verdict);
- vh.id = htonl(id);
-
- nfnl_fill_hdr(qh->h->nfnlssh, &u.nmh, 0, AF_UNSPEC, qh->id,
- type, NLM_F_REQUEST);
+ nlh = nfq_nlmsg_put(buf, NFQNL_MSG_VERDICT, qh->id);
/* add verdict header */
- nfnl_addattr_l(&u.nmh, sizeof(u), NFQA_VERDICT_HDR, &vh, sizeof(vh));
+ nfq_nlmsg_verdict_put(nlh, id, verdict);
if (set_mark)
- nfnl_addattr32(&u.nmh, sizeof(u), NFQA_MARK, mark);
+ nfq_nlmsg_verdict_put_mark(nlh, mark);
+
+ /* Efficiency gain: when there is only 1 iov,
+ * sendto() is faster than sendmsg() because the kernel only has
+ * 1 userspace address to validate instead of 2.
+ */
+ if (!data_len)
+ return mnl_socket_sendto(qh->h->nl, nlh, nlh->nlmsg_len);
- iov[0].iov_base = &u.nmh;
- iov[0].iov_len = NLMSG_TAIL(&u.nmh) - (void *)&u.nmh;
+ iov[0].iov_base = nlh;
+ iov[0].iov_len = NLMSG_TAIL(nlh) - (void *)nlh;
nvecs = 1;
if (data_len) {
@@ -995,7 +993,7 @@ static int __set_verdict(struct nfq_q_handle *qh, uint32_t id,
* header. The size of the attribute is given in the
* nla_len field and is set in the nfnl_build_nfa_iovec()
* function. */
- u.nmh.nlmsg_len += data_attr.nla_len;
+ nlh->nlmsg_len += data_attr.nla_len;
}
return nfnl_sendiov(qh->h->nfnlh, iov, nvecs, 0);
@@ -1052,7 +1050,7 @@ int nfq_set_verdict2(struct nfq_q_handle *qh, uint32_t id,
uint32_t verdict, uint32_t mark,
uint32_t data_len, const unsigned char *buf)
{
- return __set_verdict(qh, id, verdict, htonl(mark), 1, data_len,
+ return __set_verdict(qh, id, verdict, mark, 1, data_len,
buf, NFQNL_MSG_VERDICT);
}
--
2.35.8
