tcp: Improve interface to tcp_l2_buf_flush()

Currently this takes a msghdr, but the only thing we actually care
about in there is the io vector.  Make it take an io vector directly.
We also have a weird side effect of zeroing @buf_used.  Just pass this
by value and zero it in the caller instead.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
David Gibson 2023-01-06 11:43:09 +11:00 committed by Stefano Brivio
parent f1d2d35416
commit a79e774770

63
tcp.c
View file

@ -1417,22 +1417,27 @@ static int tcp_l2_buf_write_one(struct ctx *c, const struct iovec *iov)
/**
* tcp_l2_buf_flush_passt() - Send a message on the passt tap interface
* @c: Execution context
* @mh: Message header that was partially sent by sendmsg()
* @iov: Pointer to array of buffers, one per frame
* @n: Number of buffers/frames to flush
*/
static void tcp_l2_buf_flush_passt(const struct ctx *c, const struct msghdr *mh)
static void tcp_l2_buf_flush_passt(const struct ctx *c,
const struct iovec *iov, size_t n)
{
struct msghdr mh = {
.msg_iov = (void *)iov,
.msg_iovlen = n,
};
size_t end = 0, missing;
struct iovec *iov;
unsigned int i;
ssize_t sent;
char *p;
sent = sendmsg(c->fd_tap, mh, MSG_NOSIGNAL | MSG_DONTWAIT);
sent = sendmsg(c->fd_tap, &mh, MSG_NOSIGNAL | MSG_DONTWAIT);
if (sent < 0)
return;
/* Ensure a complete last message on partial sendmsg() */
for (i = 0, iov = mh->msg_iov; i < mh->msg_iovlen; i++, iov++) {
for (i = 0; i < n; i++, iov++) {
end += iov->iov_len;
if (end >= (size_t)sent)
break;
@ -1450,30 +1455,24 @@ static void tcp_l2_buf_flush_passt(const struct ctx *c, const struct msghdr *mh)
/**
* tcp_l2_flags_buf_flush() - Send out buffers for segments with or without data
* @c: Execution context
* @mh: Message header pointing to buffers, msg_iovlen not set
* @buf_used: Pointer to count of used buffers, set to 0 on return
*/
static void tcp_l2_buf_flush(struct ctx *c, struct msghdr *mh,
unsigned int *buf_used)
static void tcp_l2_buf_flush(struct ctx *c, const struct iovec *iov, size_t n)
{
if (!(mh->msg_iovlen = *buf_used))
size_t i;
if (!n)
return;
if (c->mode == MODE_PASST) {
tcp_l2_buf_flush_passt(c, mh);
tcp_l2_buf_flush_passt(c, iov, n);
} else {
size_t i;
for (i = 0; i < mh->msg_iovlen; i++) {
struct iovec *iov = &mh->msg_iov[i];
if (tcp_l2_buf_write_one(c, iov))
for (i = 0; i < n; i++) {
if (tcp_l2_buf_write_one(c, iov + i))
i--;
}
}
*buf_used = 0;
pcap_multiple(mh->msg_iov, mh->msg_iovlen, sizeof(uint32_t));
pcap_multiple(iov, n, sizeof(uint32_t));
}
/**
@ -1482,16 +1481,11 @@ static void tcp_l2_buf_flush(struct ctx *c, struct msghdr *mh,
*/
static void tcp_l2_flags_buf_flush(struct ctx *c)
{
struct msghdr mh = { 0 };
unsigned int *buf_used;
tcp_l2_buf_flush(c, tcp6_l2_flags_iov, tcp6_l2_flags_buf_used);
tcp6_l2_flags_buf_used = 0;
mh.msg_iov = tcp6_l2_flags_iov;
buf_used = &tcp6_l2_flags_buf_used;
tcp_l2_buf_flush(c, &mh, buf_used);
mh.msg_iov = tcp4_l2_flags_iov;
buf_used = &tcp4_l2_flags_buf_used;
tcp_l2_buf_flush(c, &mh, buf_used);
tcp_l2_buf_flush(c, tcp4_l2_flags_iov, tcp4_l2_flags_buf_used);
tcp4_l2_flags_buf_used = 0;
}
/**
@ -1500,16 +1494,11 @@ static void tcp_l2_flags_buf_flush(struct ctx *c)
*/
static void tcp_l2_data_buf_flush(struct ctx *c)
{
struct msghdr mh = { 0 };
unsigned int *buf_used;
tcp_l2_buf_flush(c, tcp6_l2_iov, tcp6_l2_buf_used);
tcp6_l2_buf_used = 0;
mh.msg_iov = tcp6_l2_iov;
buf_used = &tcp6_l2_buf_used;
tcp_l2_buf_flush(c, &mh, buf_used);
mh.msg_iov = tcp4_l2_iov;
buf_used = &tcp4_l2_buf_used;
tcp_l2_buf_flush(c, &mh, buf_used);
tcp_l2_buf_flush(c, tcp4_l2_iov, tcp4_l2_buf_used);
tcp4_l2_buf_used = 0;
}
/**