mirrors/passt
1
0
Fork 0
mirror of https://passt.top/passt synced 2025-06-15 03:45:34 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

tap, tcp: Move tap send path to tap.c

Browse source 
The functions which do the final steps of sending TCP packets on through
the tap interface - tcp_l2_buf_flush*() - no longer have anything that's
actually specific to TCP in them, other than comments and names.  Move them
all to tap.c.

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 11:43:11 +11:00 • committed by Stefano Brivio
parent e21ee41ac3
commit 6d011c1faa
3 changed files with 89 additions and 81 deletions

84
tap.c
View file

@ -53,6 +53,7 @@
#include "netlink.h"
#include "pasta.h"
#include "packet.h"
#include "tap.h"
#include "log.h"
/* IPv4 (plus ARP) and IPv6 message batches from tap/guest to IP handlers */
@ -302,6 +303,89 @@ void tap_icmp6_send(const struct ctx *c,
debug("tap: failed to send %lu bytes (IPv6)", len);
}
/**
* tap_send_frames_pasta() - Send multiple frames to the pasta tap
* @c: Execution context
* @iov: Array of buffers, each containing one frame
* @n: Number of buffers/frames in @iov
*
* #syscalls:pasta write
*/
static void tap_send_frames_pasta(struct ctx *c,
const struct iovec *iov, size_t n)
{
size_t i;
for (i = 0; i < n; i++) {
if (write(c->fd_tap, (char *)iov->iov_base + 4,
iov->iov_len - 4) < 0) {
debug("tap write: %s", strerror(errno));
if (errno != EAGAIN && errno != EWOULDBLOCK)
tap_handler(c, c->fd_tap, EPOLLERR, NULL);
i--;
}
}
}
/**
* tap_send_frames_passt() - Send multiple frames to the passt tap
* @c: Execution context
* @iov: Array of buffers, each containing one frame
* @n: Number of buffers/frames in @iov
*
* #syscalls:passt sendmsg send
*/
static void tap_send_frames_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;
unsigned int i;
ssize_t sent;
char *p;
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; i < n; i++, iov++) {
end += iov->iov_len;
if (end >= (size_t)sent)
break;
}
missing = end - sent;
if (!missing)
return;
p = (char *)iov->iov_base + iov->iov_len - missing;
if (send(c->fd_tap, p, missing, MSG_NOSIGNAL))
debug("tap: failed to flush %lu missing bytes to tap", missing);
}
/**
* tap_send_frames() - Send out multiple prepared frames
* @c: Execution context
* @iov: Array of buffers, each containing one frame (with L2 headers)
* @n: Number of buffers/frames in @iov
*/
void tap_send_frames(struct ctx *c, const struct iovec *iov, size_t n)
{
if (!n)
return;
if (c->mode == MODE_PASST)
tap_send_frames_passt(c, iov, n);
else
tap_send_frames_pasta(c, iov, n);
pcap_multiple(iov, n, sizeof(uint32_t));
}
PACKET_POOL_DECL(pool_l4, UIO_MAXIOV, pkt_buf);
/**