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Diffstat (limited to 'tap.c')
-rw-r--r--tap.c83
1 files changed, 52 insertions, 31 deletions
diff --git a/tap.c b/tap.c
index f4051ce..8e0cda3 100644
--- a/tap.c
+++ b/tap.c
@@ -309,21 +309,28 @@ void tap_icmp6_send(const struct ctx *c,
/**
* 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
+ * @c: Execution context
+ * @iov: Array of buffers
+ * @bufs_per_frame: Number of buffers (iovec entries) per frame
+ * @nframes: Number of frames to send
+ *
+ * @iov must have total length @bufs_per_frame * @nframes, with each set of
+ * @bufs_per_frame contiguous buffers representing a single frame.
*
* Return: number of frames successfully sent
*
* #syscalls:pasta write
*/
static size_t tap_send_frames_pasta(const struct ctx *c,
- const struct iovec *iov, size_t n)
+ const struct iovec *iov,
+ size_t bufs_per_frame, size_t nframes)
{
+ size_t nbufs = bufs_per_frame * nframes;
size_t i;
- for (i = 0; i < n; i++) {
- ssize_t rc = write(c->fd_tap, iov[i].iov_base, iov[i].iov_len);
+ for (i = 0; i < nbufs; i += bufs_per_frame) {
+ ssize_t rc = writev(c->fd_tap, iov + i, bufs_per_frame);
+ size_t framelen = iov_size(iov + i, bufs_per_frame);
if (rc < 0) {
debug("tap write: %s", strerror(errno));
@@ -340,32 +347,37 @@ static size_t tap_send_frames_pasta(const struct ctx *c,
default:
die("Write error on tap device, exiting");
}
- } else if ((size_t)rc < iov[i].iov_len) {
- debug("short write on tuntap: %zd/%zu",
- rc, iov[i].iov_len);
+ } else if ((size_t)rc < framelen) {
+ debug("short write on tuntap: %zd/%zu", rc, framelen);
break;
}
}
- return i;
+ return i / bufs_per_frame;
}
/**
* 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
+ * @c: Execution context
+ * @iov: Array of buffers, each containing one frame
+ * @bufs_per_frame: Number of buffers (iovec entries) per frame
+ * @nframes: Number of frames to send
+ *
+ * @iov must have total length @bufs_per_frame * @nframes, with each set of
+ * @bufs_per_frame contiguous buffers representing a single frame.
*
* Return: number of frames successfully sent
*
* #syscalls:passt sendmsg
*/
static size_t tap_send_frames_passt(const struct ctx *c,
- const struct iovec *iov, size_t n)
+ const struct iovec *iov,
+ size_t bufs_per_frame, size_t nframes)
{
+ size_t nbufs = bufs_per_frame * nframes;
struct msghdr mh = {
.msg_iov = (void *)iov,
- .msg_iovlen = n,
+ .msg_iovlen = nbufs,
};
size_t buf_offset;
unsigned int i;
@@ -376,44 +388,53 @@ static size_t tap_send_frames_passt(const struct ctx *c,
return 0;
/* Check for any partial frames due to short send */
- i = iov_skip_bytes(iov, n, sent, &buf_offset);
+ i = iov_skip_bytes(iov, nbufs, sent, &buf_offset);
- if (i < n && buf_offset) {
- /* A partial frame was sent */
- if (write_remainder(c->fd_tap, &iov[i], 1, buf_offset) < 0) {
+ if (i < nbufs && (buf_offset || (i % bufs_per_frame))) {
+ /* Number of unsent or partially sent buffers for the frame */
+ size_t rembufs = bufs_per_frame - (i % bufs_per_frame);
+
+ if (write_remainder(c->fd_tap, &iov[i], rembufs, buf_offset) < 0) {
err("tap: partial frame send: %s", strerror(errno));
return i;
}
- i++;
+ i += rembufs;
}
- return i;
+ return i / bufs_per_frame;
}
/**
* 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
+ * @c: Execution context
+ * @iov: Array of buffers, each containing one frame (with L2 headers)
+ * @bufs_per_frame: Number of buffers (iovec entries) per frame
+ * @nframes: Number of frames to send
+ *
+ * @iov must have total length @bufs_per_frame * @nframes, with each set of
+ * @bufs_per_frame contiguous buffers representing a single frame.
*
* Return: number of frames actually sent
*/
-size_t tap_send_frames(const struct ctx *c, const struct iovec *iov, size_t n)
+size_t tap_send_frames(const struct ctx *c, const struct iovec *iov,
+ size_t bufs_per_frame, size_t nframes)
{
size_t m;
- if (!n)
+ if (!nframes)
return 0;
if (c->mode == MODE_PASST)
- m = tap_send_frames_passt(c, iov, n);
+ m = tap_send_frames_passt(c, iov, bufs_per_frame, nframes);
else
- m = tap_send_frames_pasta(c, iov, n);
+ m = tap_send_frames_pasta(c, iov, bufs_per_frame, nframes);
- if (m < n)
- debug("tap: failed to send %zu frames of %zu", n - m, n);
+ if (m < nframes)
+ debug("tap: failed to send %zu frames of %zu",
+ nframes - m, nframes);
- pcap_multiple(iov, 1, m, c->mode == MODE_PASST ? sizeof(uint32_t) : 0);
+ pcap_multiple(iov, bufs_per_frame, m,
+ c->mode == MODE_PASST ? sizeof(uint32_t) : 0);
return m;
}