From: David Gibson <david@gibson.dropbear.id.au>
To: Stefano Brivio <sbrivio@redhat.com>, passt-dev@passt.top
Cc: David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH v3 03/18] tcp: Combine two parts of passt tap send path together
Date: Fri, 6 Jan 2023 11:43:07 +1100 [thread overview]
Message-ID: <20230106004322.985665-4-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20230106004322.985665-1-david@gibson.dropbear.id.au>
tcp_l2_buf_flush() open codes the "primary" send of message to the passt
tap interface, but calls tcp_l2_buf_flush_part() to handle the case of a
short send. Combine these two passt-specific operations into
tcp_l2_buf_flush_passt() which is a little cleaner and will enable furrther
cleanups.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
tcp.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/tcp.c b/tcp.c
index ed65a9e..6a59c85 100644
--- a/tcp.c
+++ b/tcp.c
@@ -1415,19 +1415,25 @@ static int tcp_l2_buf_write_one(struct ctx *c, const struct iovec *iov)
}
/**
- * tcp_l2_buf_flush_part() - Ensure a complete last message on partial sendmsg()
+ * 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()
- * @sent: Bytes already sent
+ * @buf_bytes: Total number of bytes to send
*/
-static void tcp_l2_buf_flush_part(const struct ctx *c,
- const struct msghdr *mh, size_t sent)
+static void tcp_l2_buf_flush_passt(const struct ctx *c,
+ const struct msghdr *mh, size_t buf_bytes)
{
- size_t end = 0, missing;
+ size_t end = 0, missing, sent;
struct iovec *iov;
unsigned int i;
+ ssize_t n;
char *p;
+ n = sendmsg(c->fd_tap, mh, MSG_NOSIGNAL | MSG_DONTWAIT);
+ if (n < 0 || ((sent = (size_t)n) == buf_bytes))
+ return;
+
+ /* Ensure a complete last message on partial sendmsg() */
for (i = 0, iov = mh->msg_iov; i < mh->msg_iovlen; i++, iov++) {
end += iov->iov_len;
if (end >= sent)
@@ -1454,9 +1460,7 @@ static void tcp_l2_buf_flush(struct ctx *c, struct msghdr *mh,
return;
if (c->mode == MODE_PASST) {
- size_t n = sendmsg(c->fd_tap, mh, MSG_NOSIGNAL | MSG_DONTWAIT);
- if (n > 0 && n < *buf_bytes)
- tcp_l2_buf_flush_part(c, mh, n);
+ tcp_l2_buf_flush_passt(c, mh, *buf_bytes);
} else {
size_t i;
--
@@ -1415,19 +1415,25 @@ static int tcp_l2_buf_write_one(struct ctx *c, const struct iovec *iov)
}
/**
- * tcp_l2_buf_flush_part() - Ensure a complete last message on partial sendmsg()
+ * 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()
- * @sent: Bytes already sent
+ * @buf_bytes: Total number of bytes to send
*/
-static void tcp_l2_buf_flush_part(const struct ctx *c,
- const struct msghdr *mh, size_t sent)
+static void tcp_l2_buf_flush_passt(const struct ctx *c,
+ const struct msghdr *mh, size_t buf_bytes)
{
- size_t end = 0, missing;
+ size_t end = 0, missing, sent;
struct iovec *iov;
unsigned int i;
+ ssize_t n;
char *p;
+ n = sendmsg(c->fd_tap, mh, MSG_NOSIGNAL | MSG_DONTWAIT);
+ if (n < 0 || ((sent = (size_t)n) == buf_bytes))
+ return;
+
+ /* Ensure a complete last message on partial sendmsg() */
for (i = 0, iov = mh->msg_iov; i < mh->msg_iovlen; i++, iov++) {
end += iov->iov_len;
if (end >= sent)
@@ -1454,9 +1460,7 @@ static void tcp_l2_buf_flush(struct ctx *c, struct msghdr *mh,
return;
if (c->mode == MODE_PASST) {
- size_t n = sendmsg(c->fd_tap, mh, MSG_NOSIGNAL | MSG_DONTWAIT);
- if (n > 0 && n < *buf_bytes)
- tcp_l2_buf_flush_part(c, mh, n);
+ tcp_l2_buf_flush_passt(c, mh, *buf_bytes);
} else {
size_t i;
--
2.39.0
next prev parent reply other threads:[~2023-01-06 0:43 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-06 0:43 [PATCH v3 00/18] RFC: Unify and simplify tap send path David Gibson
2023-01-06 0:43 ` [PATCH v3 01/18] pcap: Introduce pcap_frame() helper David Gibson
2023-01-06 0:43 ` [PATCH v3 02/18] pcap: Replace pcapm() with pcap_multiple() David Gibson
2023-01-06 0:43 ` David Gibson [this message]
2023-01-06 0:43 ` [PATCH v3 04/18] tcp: Don't compute total bytes in a message until we need it David Gibson
2023-01-06 0:43 ` [PATCH v3 05/18] tcp: Improve interface to tcp_l2_buf_flush() David Gibson
2023-01-06 0:43 ` [PATCH v3 06/18] tcp: Combine two parts of pasta tap send path together David Gibson
2023-02-13 1:13 ` Stefano Brivio
2023-01-06 0:43 ` [PATCH v3 07/18] tap, tcp: Move tap send path to tap.c David Gibson
2023-01-06 0:43 ` [PATCH v3 08/18] util: Introduce hton*_constant() in place of #ifdefs David Gibson
2023-01-06 0:43 ` [PATCH v3 09/18] tcp, udp: Use named field initializers in iov_init functions David Gibson
2023-01-06 0:43 ` [PATCH v3 10/18] util: Parameterize ethernet header initializer macro David Gibson
2023-01-06 0:43 ` [PATCH v3 11/18] tcp: Remove redundant and incorrect initialization from *_iov_init() David Gibson
2023-01-06 0:43 ` [PATCH v3 12/18] tcp: Consolidate calculation of total frame size David Gibson
2023-01-06 0:43 ` [PATCH v3 13/18] tap: Add "tap headers" abstraction David Gibson
2023-01-06 0:43 ` [PATCH v3 14/18] tcp: Use abstracted tap header David Gibson
2023-01-06 0:43 ` [PATCH v3 15/18] tap: Use different io vector bases depending on tap type David Gibson
2023-01-06 0:43 ` [PATCH v3 16/18] udp: Use abstracted tap header David Gibson
2023-01-06 0:43 ` [PATCH v3 17/18] tap: Improve handling of partial frame sends David Gibson
2023-01-06 0:43 ` [PATCH v3 18/18] udp: Use tap_send_frames() David Gibson
2023-01-24 21:20 ` [PATCH v3 00/18] RFC: Unify and simplify tap send path Stefano Brivio
2023-01-25 3:13 ` David Gibson
2023-01-25 23:21 ` Stefano Brivio
2023-02-13 1:14 ` Stefano Brivio
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