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 08/10] tcp,tap: Use different io vector bases depending on tap type
Date: Thu, 8 Dec 2022 19:55:49 +1100 [thread overview]
Message-ID: <20221208085551.1433829-9-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20221208085551.1433829-1-david@gibson.dropbear.id.au>
Currently tap_send_frames() expects the frames it is given to include the
vnet_len field, even in pasta mode which doesn't use it (although it need
not be initialized in that case). This will inconvenience future changes,
so alter it to expect just the frame as appropriate for the tap backend
type. We alter the TCP code which uses it to match, setting up the base
of iovec to include or exclude the vnet_len as needed.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
tap.c | 5 ++---
tcp.c | 30 ++++++++++++++++++++++--------
2 files changed, 24 insertions(+), 11 deletions(-)
diff --git a/tap.c b/tap.c
index 558a734..2dd14f1 100644
--- a/tap.c
+++ b/tap.c
@@ -317,8 +317,7 @@ static void tap_send_frames_pasta(struct ctx *c,
size_t i;
for (i = 0; i < n; i++) {
- if (write(c->fd_tap, (char *)iov->iov_base + 4,
- iov->iov_len - 4) < 0) {
+ if (write(c->fd_tap, (char *)iov->iov_base, iov->iov_len) < 0) {
debug("tap write: %s", strerror(errno));
if (errno != EAGAIN && errno != EWOULDBLOCK)
tap_handler(c, c->fd_tap, EPOLLERR, NULL);
@@ -383,7 +382,7 @@ void tap_send_frames(struct ctx *c, const struct iovec *iov, size_t n)
else
tap_send_frames_pasta(c, iov, n);
- pcap_multiple(iov, n, sizeof(uint32_t));
+ pcap_multiple(iov, n, c->mode == MODE_PASST ? sizeof(uint32_t) : 0);
}
PACKET_POOL_DECL(pool_l4, UIO_MAXIOV, pkt_buf);
diff --git a/tcp.c b/tcp.c
index f560b96..e5fa5ae 100644
--- a/tcp.c
+++ b/tcp.c
@@ -1053,8 +1053,9 @@ void tcp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s,
/**
* tcp_sock4_iov_init() - Initialise scatter-gather L2 buffers for IPv4 sockets
+ * @ctx: Execution context
*/
-static void tcp_sock4_iov_init(void)
+static void tcp_sock4_iov_init(const struct ctx *c)
{
struct iovec *iov;
int i;
@@ -1076,18 +1077,25 @@ static void tcp_sock4_iov_init(void)
}
for (i = 0, iov = tcp4_l2_iov; i < TCP_FRAMES_MEM; i++, iov++) {
- iov->iov_base = &tcp4_l2_buf[i].vnet_len;
+ if (c->mode == MODE_PASTA)
+ iov->iov_base = &tcp4_l2_buf[i].eh;
+ else
+ iov->iov_base = &tcp4_l2_buf[i].vnet_len;
iov->iov_len = MSS_DEFAULT;
}
for (i = 0, iov = tcp4_l2_flags_iov; i < TCP_FRAMES_MEM; i++, iov++)
- iov->iov_base = &tcp4_l2_flags_buf[i].vnet_len;
+ if (c->mode == MODE_PASTA)
+ iov->iov_base = &tcp4_l2_flags_buf[i].eh;
+ else
+ iov->iov_base = &tcp4_l2_flags_buf[i].vnet_len;
}
/**
* tcp_sock6_iov_init() - Initialise scatter-gather L2 buffers for IPv6 sockets
+ * @ctx: Execution context
*/
-static void tcp_sock6_iov_init(void)
+static void tcp_sock6_iov_init(const struct ctx *c)
{
struct iovec *iov;
int i;
@@ -1109,12 +1117,18 @@ static void tcp_sock6_iov_init(void)
}
for (i = 0, iov = tcp6_l2_iov; i < TCP_FRAMES_MEM; i++, iov++) {
- iov->iov_base = &tcp6_l2_buf[i].vnet_len;
+ if (c->mode == MODE_PASTA)
+ iov->iov_base = &tcp6_l2_buf[i].eh;
+ else
+ iov->iov_base = &tcp6_l2_buf[i].vnet_len;
iov->iov_len = MSS_DEFAULT;
}
for (i = 0, iov = tcp6_l2_flags_iov; i < TCP_FRAMES_MEM; i++, iov++)
- iov->iov_base = &tcp6_l2_flags_buf[i].vnet_len;
+ if (c->mode == MODE_PASTA)
+ iov->iov_base = &tcp6_l2_flags_buf[i].eh;
+ else
+ iov->iov_base = &tcp6_l2_flags_buf[i].vnet_len;
}
/**
@@ -3131,10 +3145,10 @@ int tcp_init(struct ctx *c)
tcp_l2_mh[i] = (struct mmsghdr) { .msg_hdr.msg_iovlen = 1 };
if (c->ifi4)
- tcp_sock4_iov_init();
+ tcp_sock4_iov_init(c);
if (c->ifi6)
- tcp_sock6_iov_init();
+ tcp_sock6_iov_init(c);
memset(init_sock_pool4, 0xff, sizeof(init_sock_pool4));
memset(init_sock_pool6, 0xff, sizeof(init_sock_pool6));
--
@@ -1053,8 +1053,9 @@ void tcp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s,
/**
* tcp_sock4_iov_init() - Initialise scatter-gather L2 buffers for IPv4 sockets
+ * @ctx: Execution context
*/
-static void tcp_sock4_iov_init(void)
+static void tcp_sock4_iov_init(const struct ctx *c)
{
struct iovec *iov;
int i;
@@ -1076,18 +1077,25 @@ static void tcp_sock4_iov_init(void)
}
for (i = 0, iov = tcp4_l2_iov; i < TCP_FRAMES_MEM; i++, iov++) {
- iov->iov_base = &tcp4_l2_buf[i].vnet_len;
+ if (c->mode == MODE_PASTA)
+ iov->iov_base = &tcp4_l2_buf[i].eh;
+ else
+ iov->iov_base = &tcp4_l2_buf[i].vnet_len;
iov->iov_len = MSS_DEFAULT;
}
for (i = 0, iov = tcp4_l2_flags_iov; i < TCP_FRAMES_MEM; i++, iov++)
- iov->iov_base = &tcp4_l2_flags_buf[i].vnet_len;
+ if (c->mode == MODE_PASTA)
+ iov->iov_base = &tcp4_l2_flags_buf[i].eh;
+ else
+ iov->iov_base = &tcp4_l2_flags_buf[i].vnet_len;
}
/**
* tcp_sock6_iov_init() - Initialise scatter-gather L2 buffers for IPv6 sockets
+ * @ctx: Execution context
*/
-static void tcp_sock6_iov_init(void)
+static void tcp_sock6_iov_init(const struct ctx *c)
{
struct iovec *iov;
int i;
@@ -1109,12 +1117,18 @@ static void tcp_sock6_iov_init(void)
}
for (i = 0, iov = tcp6_l2_iov; i < TCP_FRAMES_MEM; i++, iov++) {
- iov->iov_base = &tcp6_l2_buf[i].vnet_len;
+ if (c->mode == MODE_PASTA)
+ iov->iov_base = &tcp6_l2_buf[i].eh;
+ else
+ iov->iov_base = &tcp6_l2_buf[i].vnet_len;
iov->iov_len = MSS_DEFAULT;
}
for (i = 0, iov = tcp6_l2_flags_iov; i < TCP_FRAMES_MEM; i++, iov++)
- iov->iov_base = &tcp6_l2_flags_buf[i].vnet_len;
+ if (c->mode == MODE_PASTA)
+ iov->iov_base = &tcp6_l2_flags_buf[i].eh;
+ else
+ iov->iov_base = &tcp6_l2_flags_buf[i].vnet_len;
}
/**
@@ -3131,10 +3145,10 @@ int tcp_init(struct ctx *c)
tcp_l2_mh[i] = (struct mmsghdr) { .msg_hdr.msg_iovlen = 1 };
if (c->ifi4)
- tcp_sock4_iov_init();
+ tcp_sock4_iov_init(c);
if (c->ifi6)
- tcp_sock6_iov_init();
+ tcp_sock6_iov_init(c);
memset(init_sock_pool4, 0xff, sizeof(init_sock_pool4));
memset(init_sock_pool6, 0xff, sizeof(init_sock_pool6));
--
2.38.1
next prev parent reply other threads:[~2022-12-08 8:56 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-08 8:55 [PATCH 00/10] RFC: Unify and simplify tap send path David Gibson
2022-12-08 8:55 ` [PATCH 01/10] pcap: Introduce pcap_frame() helper David Gibson
2022-12-08 8:55 ` [PATCH 02/10] pcap: Replace pcapm() with pcap_multiple() David Gibson
2022-12-08 8:55 ` [PATCH 03/10] tcp: Combine two parts of passt tap send path together David Gibson
2022-12-08 8:55 ` [PATCH 04/10] tcp: Don't keep compute total bytes in a message until we need it David Gibson
2022-12-08 8:55 ` [PATCH 05/10] tcp: Improve interface to tcp_l2_buf_flush() David Gibson
2022-12-08 8:55 ` [PATCH 06/10] tcp: Combine two parts of pasta tap send path together David Gibson
2022-12-08 8:55 ` [PATCH 07/10] tap, tcp: Move tap send path to tap.c David Gibson
2022-12-08 8:55 ` David Gibson [this message]
2022-12-08 8:55 ` [PATCH 09/10] udp: Use tap_send_frames() David Gibson
2022-12-08 8:55 ` [PATCH 10/10] tap: Improve handling of partial frame sends David Gibson
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