* [PATCH v4 1/5] tcp: Use tcp_payload_t rather than tcphdr
2024-09-26 14:04 [PATCH v4 0/5] tcp: use csum_iov() in tcp_update_check_tcp[4|6]() Laurent Vivier
@ 2024-09-26 14:04 ` Laurent Vivier
2024-09-26 14:04 ` [PATCH v4 2/5] pcap: Add an offset argument in pcap_iov() Laurent Vivier
` (3 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: Laurent Vivier @ 2024-09-26 14:04 UTC (permalink / raw)
To: passt-dev; +Cc: Laurent Vivier, David Gibson
As tcp_update_check_tcp4() and tcp_update_check_tcp6() compute the
checksum using the TCP header and the TCP payload, it is clearer
to use a pointer to tcp_payload_t that includes tcphdr and payload
rather than a pointer to tcphdr (and guessing TCP header is
followed by the payload).
Move tcp_payload_t and tcp_flags_t to tcp_internal.h.
(They will be used also by vhost-user).
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
---
tcp.c | 42 ++++++++++++++++++++++--------------------
tcp_buf.c | 29 -----------------------------
tcp_internal.h | 29 +++++++++++++++++++++++++++++
3 files changed, 51 insertions(+), 49 deletions(-)
diff --git a/tcp.c b/tcp.c
index 1962fcc469ed..c9472d905520 100644
--- a/tcp.c
+++ b/tcp.c
@@ -757,32 +757,34 @@ static void tcp_sock_set_bufsize(const struct ctx *c, int s)
/**
* tcp_update_check_tcp4() - Update TCP checksum from stored one
* @iph: IPv4 header
- * @th: TCP header followed by TCP payload
+ * @bp: TCP header followed by TCP payload
*/
-static void tcp_update_check_tcp4(const struct iphdr *iph, struct tcphdr *th)
+static void tcp_update_check_tcp4(const struct iphdr *iph,
+ struct tcp_payload_t *bp)
{
uint16_t l4len = ntohs(iph->tot_len) - sizeof(struct iphdr);
struct in_addr saddr = { .s_addr = iph->saddr };
struct in_addr daddr = { .s_addr = iph->daddr };
uint32_t sum = proto_ipv4_header_psum(l4len, IPPROTO_TCP, saddr, daddr);
- th->check = 0;
- th->check = csum(th, l4len, sum);
+ bp->th.check = 0;
+ bp->th.check = csum(bp, l4len, sum);
}
/**
* tcp_update_check_tcp6() - Calculate TCP checksum for IPv6
* @ip6h: IPv6 header
- * @th: TCP header followed by TCP payload
+ * @bp: TCP header followed by TCP payload
*/
-static void tcp_update_check_tcp6(struct ipv6hdr *ip6h, struct tcphdr *th)
+static void tcp_update_check_tcp6(const struct ipv6hdr *ip6h,
+ struct tcp_payload_t *bp)
{
uint16_t l4len = ntohs(ip6h->payload_len);
uint32_t sum = proto_ipv6_header_psum(l4len, IPPROTO_TCP,
&ip6h->saddr, &ip6h->daddr);
- th->check = 0;
- th->check = csum(th, l4len, sum);
+ bp->th.check = 0;
+ bp->th.check = csum(bp, l4len, sum);
}
/**
@@ -902,7 +904,7 @@ static void tcp_fill_header(struct tcphdr *th,
* @conn: Connection pointer
* @taph: tap backend specific header
* @iph: Pointer to IPv4 header
- * @th: Pointer to TCP header
+ * @bp: Pointer to TCP header followed by TCP payload
* @dlen: TCP payload length
* @check: Checksum, if already known
* @seq: Sequence number for this segment
@@ -912,14 +914,14 @@ static void tcp_fill_header(struct tcphdr *th,
*/
static size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
struct tap_hdr *taph,
- struct iphdr *iph, struct tcphdr *th,
+ struct iphdr *iph, struct tcp_payload_t *bp,
size_t dlen, const uint16_t *check,
uint32_t seq, bool no_tcp_csum)
{
const struct flowside *tapside = TAPFLOW(conn);
const struct in_addr *src4 = inany_v4(&tapside->oaddr);
const struct in_addr *dst4 = inany_v4(&tapside->eaddr);
- size_t l4len = dlen + sizeof(*th);
+ size_t l4len = dlen + sizeof(bp->th);
size_t l3len = l4len + sizeof(*iph);
ASSERT(src4 && dst4);
@@ -931,12 +933,12 @@ static size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
iph->check = check ? *check :
csum_ip4_header(l3len, IPPROTO_TCP, *src4, *dst4);
- tcp_fill_header(th, conn, seq);
+ tcp_fill_header(&bp->th, conn, seq);
if (no_tcp_csum)
- th->check = 0;
+ bp->th.check = 0;
else
- tcp_update_check_tcp4(iph, th);
+ tcp_update_check_tcp4(iph, bp);
tap_hdr_update(taph, l3len + sizeof(struct ethhdr));
@@ -948,7 +950,7 @@ static size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
* @conn: Connection pointer
* @taph: tap backend specific header
* @ip6h: Pointer to IPv6 header
- * @th: Pointer to TCP header
+ * @bp: Pointer to TCP header followed by TCP payload
* @dlen: TCP payload length
* @check: Checksum, if already known
* @seq: Sequence number for this segment
@@ -958,11 +960,11 @@ static size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
*/
static size_t tcp_fill_headers6(const struct tcp_tap_conn *conn,
struct tap_hdr *taph,
- struct ipv6hdr *ip6h, struct tcphdr *th,
+ struct ipv6hdr *ip6h, struct tcp_payload_t *bp,
size_t dlen, uint32_t seq, bool no_tcp_csum)
{
const struct flowside *tapside = TAPFLOW(conn);
- size_t l4len = dlen + sizeof(*th);
+ size_t l4len = dlen + sizeof(bp->th);
ip6h->payload_len = htons(l4len);
ip6h->saddr = tapside->oaddr.a6;
@@ -976,12 +978,12 @@ static size_t tcp_fill_headers6(const struct tcp_tap_conn *conn,
ip6h->flow_lbl[1] = (conn->sock >> 8) & 0xff;
ip6h->flow_lbl[2] = (conn->sock >> 0) & 0xff;
- tcp_fill_header(th, conn, seq);
+ tcp_fill_header(&bp->th, conn, seq);
if (no_tcp_csum)
- th->check = 0;
+ bp->th.check = 0;
else
- tcp_update_check_tcp6(ip6h, th);
+ tcp_update_check_tcp6(ip6h, bp);
tap_hdr_update(taph, l4len + sizeof(*ip6h) + sizeof(struct ethhdr));
diff --git a/tcp_buf.c b/tcp_buf.c
index ffbff5e4b485..238827b01d90 100644
--- a/tcp_buf.c
+++ b/tcp_buf.c
@@ -38,35 +38,6 @@
(c->mode == MODE_PASTA ? 1 : TCP_FRAMES_MEM)
/* Static buffers */
-/**
- * struct tcp_payload_t - TCP header and data to send segments with payload
- * @th: TCP header
- * @data: TCP data
- */
-struct tcp_payload_t {
- struct tcphdr th;
- uint8_t data[IP_MAX_MTU - sizeof(struct tcphdr)];
-#ifdef __AVX2__
-} __attribute__ ((packed, aligned(32))); /* For AVX2 checksum routines */
-#else
-} __attribute__ ((packed, aligned(__alignof__(unsigned int))));
-#endif
-
-/**
- * struct tcp_flags_t - TCP header and data to send zero-length
- * segments (flags)
- * @th: TCP header
- * @opts TCP options
- */
-struct tcp_flags_t {
- struct tcphdr th;
- char opts[OPT_MSS_LEN + OPT_WS_LEN + 1];
-#ifdef __AVX2__
-} __attribute__ ((packed, aligned(32)));
-#else
-} __attribute__ ((packed, aligned(__alignof__(unsigned int))));
-#endif
-
/* Ethernet header for IPv4 frames */
static struct ethhdr tcp4_eth_src;
diff --git a/tcp_internal.h b/tcp_internal.h
index de06db1438d6..2f74ffeff8f3 100644
--- a/tcp_internal.h
+++ b/tcp_internal.h
@@ -63,6 +63,35 @@ enum tcp_iov_parts {
TCP_NUM_IOVS
};
+/**
+ * struct tcp_payload_t - TCP header and data to send segments with payload
+ * @th: TCP header
+ * @data: TCP data
+ */
+struct tcp_payload_t {
+ struct tcphdr th;
+ uint8_t data[IP_MAX_MTU - sizeof(struct tcphdr)];
+#ifdef __AVX2__
+} __attribute__ ((packed, aligned(32))); /* For AVX2 checksum routines */
+#else
+} __attribute__ ((packed, aligned(__alignof__(unsigned int))));
+#endif
+
+/**
+ * struct tcp_flags_t - TCP header and data to send zero-length
+ * segments (flags)
+ * @th: TCP header
+ * @opts TCP options
+ */
+struct tcp_flags_t {
+ struct tcphdr th;
+ char opts[OPT_MSS_LEN + OPT_WS_LEN + 1];
+#ifdef __AVX2__
+} __attribute__ ((packed, aligned(32)));
+#else
+} __attribute__ ((packed, aligned(__alignof__(unsigned int))));
+#endif
+
extern char tcp_buf_discard [MAX_WINDOW];
void conn_flag_do(const struct ctx *c, struct tcp_tap_conn *conn,
--
@@ -63,6 +63,35 @@ enum tcp_iov_parts {
TCP_NUM_IOVS
};
+/**
+ * struct tcp_payload_t - TCP header and data to send segments with payload
+ * @th: TCP header
+ * @data: TCP data
+ */
+struct tcp_payload_t {
+ struct tcphdr th;
+ uint8_t data[IP_MAX_MTU - sizeof(struct tcphdr)];
+#ifdef __AVX2__
+} __attribute__ ((packed, aligned(32))); /* For AVX2 checksum routines */
+#else
+} __attribute__ ((packed, aligned(__alignof__(unsigned int))));
+#endif
+
+/**
+ * struct tcp_flags_t - TCP header and data to send zero-length
+ * segments (flags)
+ * @th: TCP header
+ * @opts TCP options
+ */
+struct tcp_flags_t {
+ struct tcphdr th;
+ char opts[OPT_MSS_LEN + OPT_WS_LEN + 1];
+#ifdef __AVX2__
+} __attribute__ ((packed, aligned(32)));
+#else
+} __attribute__ ((packed, aligned(__alignof__(unsigned int))));
+#endif
+
extern char tcp_buf_discard [MAX_WINDOW];
void conn_flag_do(const struct ctx *c, struct tcp_tap_conn *conn,
--
2.46.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v4 2/5] pcap: Add an offset argument in pcap_iov()
2024-09-26 14:04 [PATCH v4 0/5] tcp: use csum_iov() in tcp_update_check_tcp[4|6]() Laurent Vivier
2024-09-26 14:04 ` [PATCH v4 1/5] tcp: Use tcp_payload_t rather than tcphdr Laurent Vivier
@ 2024-09-26 14:04 ` Laurent Vivier
2024-09-26 14:04 ` [PATCH v4 3/5] checksum: Add an offset argument in csum_iov() Laurent Vivier
` (2 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: Laurent Vivier @ 2024-09-26 14:04 UTC (permalink / raw)
To: passt-dev; +Cc: Laurent Vivier, David Gibson
The offset is passed directly to pcap_frame() and allows
any headers that are not part of the frame to
capture to be skipped.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
---
pcap.c | 5 +++--
pcap.h | 2 +-
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/pcap.c b/pcap.c
index e6b5ced4a9f8..6ee6cdfd261a 100644
--- a/pcap.c
+++ b/pcap.c
@@ -138,9 +138,10 @@ void pcap_multiple(const struct iovec *iov, size_t frame_parts, unsigned int n,
* @iov: Pointer to the array of struct iovec describing the I/O vector
* containing packet data to write, including L2 header
* @iovcnt: Number of buffers (@iov entries)
+ * @offset: Offset of the L2 frame within the full data length
*/
/* cppcheck-suppress unusedFunction */
-void pcap_iov(const struct iovec *iov, size_t iovcnt)
+void pcap_iov(const struct iovec *iov, size_t iovcnt, size_t offset)
{
struct timespec now;
@@ -148,7 +149,7 @@ void pcap_iov(const struct iovec *iov, size_t iovcnt)
return;
clock_gettime(CLOCK_REALTIME, &now);
- pcap_frame(iov, iovcnt, 0, &now);
+ pcap_frame(iov, iovcnt, offset, &now);
}
/**
diff --git a/pcap.h b/pcap.h
index 533923749222..9795f2e8adc5 100644
--- a/pcap.h
+++ b/pcap.h
@@ -9,7 +9,7 @@
void pcap(const char *pkt, size_t l2len);
void pcap_multiple(const struct iovec *iov, size_t frame_parts, unsigned int n,
size_t offset);
-void pcap_iov(const struct iovec *iov, size_t iovcnt);
+void pcap_iov(const struct iovec *iov, size_t iovcnt, size_t offset);
void pcap_init(struct ctx *c);
#endif /* PCAP_H */
--
@@ -9,7 +9,7 @@
void pcap(const char *pkt, size_t l2len);
void pcap_multiple(const struct iovec *iov, size_t frame_parts, unsigned int n,
size_t offset);
-void pcap_iov(const struct iovec *iov, size_t iovcnt);
+void pcap_iov(const struct iovec *iov, size_t iovcnt, size_t offset);
void pcap_init(struct ctx *c);
#endif /* PCAP_H */
--
2.46.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v4 3/5] checksum: Add an offset argument in csum_iov()
2024-09-26 14:04 [PATCH v4 0/5] tcp: use csum_iov() in tcp_update_check_tcp[4|6]() Laurent Vivier
2024-09-26 14:04 ` [PATCH v4 1/5] tcp: Use tcp_payload_t rather than tcphdr Laurent Vivier
2024-09-26 14:04 ` [PATCH v4 2/5] pcap: Add an offset argument in pcap_iov() Laurent Vivier
@ 2024-09-26 14:04 ` Laurent Vivier
2024-09-26 14:04 ` [PATCH v4 4/5] tcp: Update TCP checksum using an iovec array Laurent Vivier
2024-09-26 14:04 ` [PATCH v4 5/5] udp: Update UDP " Laurent Vivier
4 siblings, 0 replies; 7+ messages in thread
From: Laurent Vivier @ 2024-09-26 14:04 UTC (permalink / raw)
To: passt-dev; +Cc: Laurent Vivier
The offset allows any headers that are not part of the data
to checksum to be skipped.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
Notes:
v3:
- reorder @offset and @init
v2:
- check iov_skip_bytes() return value
checksum.c | 16 ++++++++++++++--
checksum.h | 3 ++-
2 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/checksum.c b/checksum.c
index 006614fcbb28..16b834641604 100644
--- a/checksum.c
+++ b/checksum.c
@@ -59,6 +59,7 @@
#include "util.h"
#include "ip.h"
#include "checksum.h"
+#include "iov.h"
/* Checksums are optional for UDP over IPv4, so we usually just set
* them to 0. Change this to 1 to calculate real UDP over IPv4
@@ -497,16 +498,27 @@ uint16_t csum(const void *buf, size_t len, uint32_t init)
*
* @iov Pointer to the array of IO vectors
* @n Length of the array
+ * @offset: Offset of the data to checksum within the full data length
* @init Initial 32-bit checksum, 0 for no pre-computed checksum
*
* Return: 16-bit folded, complemented checksum
*/
/* cppcheck-suppress unusedFunction */
-uint16_t csum_iov(const struct iovec *iov, size_t n, uint32_t init)
+uint16_t csum_iov(const struct iovec *iov, size_t n, size_t offset,
+ uint32_t init)
{
unsigned int i;
+ size_t first;
- for (i = 0; i < n; i++)
+ i = iov_skip_bytes(iov, n, offset, &first);
+ if (i >= n)
+ return (uint16_t)~csum_fold(init);
+
+ init = csum_unfolded((char *)iov[i].iov_base + first,
+ iov[i].iov_len, init);
+ i++;
+
+ for (; i < n; i++)
init = csum_unfolded(iov[i].iov_base, iov[i].iov_len, init);
return (uint16_t)~csum_fold(init);
diff --git a/checksum.h b/checksum.h
index c5964ac78921..49f7472dd1b6 100644
--- a/checksum.h
+++ b/checksum.h
@@ -32,6 +32,7 @@ void csum_icmp6(struct icmp6hdr *icmp6hr,
const void *payload, size_t dlen);
uint32_t csum_unfolded(const void *buf, size_t len, uint32_t init);
uint16_t csum(const void *buf, size_t len, uint32_t init);
-uint16_t csum_iov(const struct iovec *iov, size_t n, uint32_t init);
+uint16_t csum_iov(const struct iovec *iov, size_t n, size_t offset,
+ uint32_t init);
#endif /* CHECKSUM_H */
--
@@ -32,6 +32,7 @@ void csum_icmp6(struct icmp6hdr *icmp6hr,
const void *payload, size_t dlen);
uint32_t csum_unfolded(const void *buf, size_t len, uint32_t init);
uint16_t csum(const void *buf, size_t len, uint32_t init);
-uint16_t csum_iov(const struct iovec *iov, size_t n, uint32_t init);
+uint16_t csum_iov(const struct iovec *iov, size_t n, size_t offset,
+ uint32_t init);
#endif /* CHECKSUM_H */
--
2.46.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v4 4/5] tcp: Update TCP checksum using an iovec array
2024-09-26 14:04 [PATCH v4 0/5] tcp: use csum_iov() in tcp_update_check_tcp[4|6]() Laurent Vivier
` (2 preceding siblings ...)
2024-09-26 14:04 ` [PATCH v4 3/5] checksum: Add an offset argument in csum_iov() Laurent Vivier
@ 2024-09-26 14:04 ` Laurent Vivier
2024-09-27 6:22 ` Stefano Brivio
2024-09-26 14:04 ` [PATCH v4 5/5] udp: Update UDP " Laurent Vivier
4 siblings, 1 reply; 7+ messages in thread
From: Laurent Vivier @ 2024-09-26 14:04 UTC (permalink / raw)
To: passt-dev; +Cc: Laurent Vivier
TCP header and payload are supposed to be in the same buffer,
and tcp_update_check_tcp4()/tcp_update_check_tcp6() compute
the checksum from the base address of the header using the
length of the IP payload.
In the future (for vhost-user) we need to dispatch the TCP header and
the TCP payload through several buffers. To be able to manage that, we
provide an iovec array that points to the data of the TCP frame.
We provide also an offset to be able to provide an array that contains
the TCP frame embedded in an lower level frame, and this offset points
to the TCP header inside the iovec array.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
Notes:
v4:
- replace die() by err() in tcp_update_check_tcp6() too
v3:
- replace die() by err() and return
- add more information in the error message
v2:
- s/payload_offset/l4offset/
- check memory address of the checksum (alignment, iovec boundaries)
checksum.c | 1 -
tcp.c | 138 ++++++++++++++++++++++++++++++++++++++++++-----------
2 files changed, 110 insertions(+), 29 deletions(-)
diff --git a/checksum.c b/checksum.c
index 16b834641604..19579323cf1e 100644
--- a/checksum.c
+++ b/checksum.c
@@ -503,7 +503,6 @@ uint16_t csum(const void *buf, size_t len, uint32_t init)
*
* Return: 16-bit folded, complemented checksum
*/
-/* cppcheck-suppress unusedFunction */
uint16_t csum_iov(const struct iovec *iov, size_t n, size_t offset,
uint32_t init)
{
diff --git a/tcp.c b/tcp.c
index c9472d905520..9db2e283d571 100644
--- a/tcp.c
+++ b/tcp.c
@@ -755,36 +755,103 @@ static void tcp_sock_set_bufsize(const struct ctx *c, int s)
}
/**
- * tcp_update_check_tcp4() - Update TCP checksum from stored one
- * @iph: IPv4 header
- * @bp: TCP header followed by TCP payload
- */
-static void tcp_update_check_tcp4(const struct iphdr *iph,
- struct tcp_payload_t *bp)
+ * tcp_update_check_tcp4() - Calculate TCP checksum for IPv6
+ * @src: IPv4 source address
+ * @dst: IPv4 destination address
+ * @iov: Pointer to the array of IO vectors
+ * @iov_cnt: Length of the array
+ * @l4offset: IPv4 payload offset in the iovec array
+ */
+void tcp_update_check_tcp4(struct in_addr src,
+ struct in_addr dst,
+ const struct iovec *iov, int iov_cnt,
+ size_t l4offset)
{
- uint16_t l4len = ntohs(iph->tot_len) - sizeof(struct iphdr);
- struct in_addr saddr = { .s_addr = iph->saddr };
- struct in_addr daddr = { .s_addr = iph->daddr };
- uint32_t sum = proto_ipv4_header_psum(l4len, IPPROTO_TCP, saddr, daddr);
+ size_t check_ofs;
+ __sum16 *check;
+ int check_idx;
+ uint32_t sum;
+
+ sum = proto_ipv4_header_psum(iov_size(iov, iov_cnt) - l4offset,
+ IPPROTO_TCP, src, dst);
+
+ check_idx = iov_skip_bytes(iov, iov_cnt,
+ l4offset + offsetof(struct tcphdr, check),
+ &check_ofs);
+
+ if (check_idx >= iov_cnt) {
+ err("TCP4 buffer is too small, iov size %zd, check offset %zd",
+ iov_size(iov, iov_cnt),
+ l4offset + offsetof(struct tcphdr, check));
+ return;
+ }
+
+ if (check_ofs + sizeof(*check) > iov[check_idx].iov_len) {
+ err("TCP4 checksum field memory is not contiguous "
+ "check_ofs %zd check_idx %d iov_len %zd",
+ check_ofs, check_idx, iov[check_idx].iov_len);
+ return;
+ }
+
+ check = (__sum16 *)((char *)iov[check_idx].iov_base + check_ofs);
- bp->th.check = 0;
- bp->th.check = csum(bp, l4len, sum);
+ if ((uintptr_t)check & (__alignof__(*check) - 1)) {
+ err("TCP4 checksum field is not correctly aligned in memory");
+ return;
+ }
+
+ *check = 0;
+ *check = csum_iov(iov, iov_cnt, l4offset, sum);
}
/**
* tcp_update_check_tcp6() - Calculate TCP checksum for IPv6
- * @ip6h: IPv6 header
- * @bp: TCP header followed by TCP payload
- */
-static void tcp_update_check_tcp6(const struct ipv6hdr *ip6h,
- struct tcp_payload_t *bp)
+ * @src: IPv6 source address
+ * @dst: IPv6 destination address
+ * @iov: Pointer to the array of IO vectors
+ * @iov_cnt: Length of the array
+ * @l4offset: IPv6 payload offset in the iovec array
+ */
+void tcp_update_check_tcp6(const struct in6_addr *src,
+ const struct in6_addr *dst,
+ const struct iovec *iov, int iov_cnt,
+ size_t l4offset)
{
- uint16_t l4len = ntohs(ip6h->payload_len);
- uint32_t sum = proto_ipv6_header_psum(l4len, IPPROTO_TCP,
- &ip6h->saddr, &ip6h->daddr);
+ size_t check_ofs;
+ __sum16 *check;
+ int check_idx;
+ uint32_t sum;
+
+ sum = proto_ipv6_header_psum(iov_size(iov, iov_cnt) - l4offset,
+ IPPROTO_TCP, src, dst);
+
+ check_idx = iov_skip_bytes(iov, iov_cnt,
+ l4offset + offsetof(struct tcphdr, check),
+ &check_ofs);
+
+ if (check_idx >= iov_cnt) {
+ err("TCP6 buffer is too small, iov size %zd, check offset %zd",
+ iov_size(iov, iov_cnt),
+ l4offset + offsetof(struct tcphdr, check));
+ return;
+ }
- bp->th.check = 0;
- bp->th.check = csum(bp, l4len, sum);
+ if (check_ofs + sizeof(*check) > iov[check_idx].iov_len) {
+ err("TCP6 checksum field memory is not contiguous "
+ "check_ofs %zd check_idx %d iov_len %zd",
+ check_ofs, check_idx, iov[check_idx].iov_len);
+ return;
+ }
+
+ check = (__sum16 *)((char *)iov[check_idx].iov_base + check_ofs);
+
+ if ((uintptr_t)check & (__alignof__(*check) - 1)) {
+ err("TCP6 checksum field is not correctly aligned in memory");
+ return;
+ }
+
+ *check = 0;
+ *check = csum_iov(iov, iov_cnt, l4offset, sum);
}
/**
@@ -935,10 +1002,18 @@ static size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
tcp_fill_header(&bp->th, conn, seq);
- if (no_tcp_csum)
+ if (no_tcp_csum) {
bp->th.check = 0;
- else
- tcp_update_check_tcp4(iph, bp);
+ } else {
+ const struct iovec iov = {
+ .iov_base = bp,
+ .iov_len = ntohs(iph->tot_len) - sizeof(struct iphdr),
+ };
+ struct in_addr saddr = { .s_addr = iph->saddr };
+ struct in_addr daddr = { .s_addr = iph->daddr };
+
+ tcp_update_check_tcp4(saddr, daddr, &iov, 1, 0);
+ }
tap_hdr_update(taph, l3len + sizeof(struct ethhdr));
@@ -980,10 +1055,17 @@ static size_t tcp_fill_headers6(const struct tcp_tap_conn *conn,
tcp_fill_header(&bp->th, conn, seq);
- if (no_tcp_csum)
+ if (no_tcp_csum) {
bp->th.check = 0;
- else
- tcp_update_check_tcp6(ip6h, bp);
+ } else {
+ const struct iovec iov = {
+ .iov_base = bp,
+ .iov_len = ntohs(ip6h->payload_len)
+ };
+
+ tcp_update_check_tcp6(&ip6h->saddr, &ip6h->daddr,
+ &iov, 1, 0);
+ }
tap_hdr_update(taph, l4len + sizeof(*ip6h) + sizeof(struct ethhdr));
--
@@ -755,36 +755,103 @@ static void tcp_sock_set_bufsize(const struct ctx *c, int s)
}
/**
- * tcp_update_check_tcp4() - Update TCP checksum from stored one
- * @iph: IPv4 header
- * @bp: TCP header followed by TCP payload
- */
-static void tcp_update_check_tcp4(const struct iphdr *iph,
- struct tcp_payload_t *bp)
+ * tcp_update_check_tcp4() - Calculate TCP checksum for IPv6
+ * @src: IPv4 source address
+ * @dst: IPv4 destination address
+ * @iov: Pointer to the array of IO vectors
+ * @iov_cnt: Length of the array
+ * @l4offset: IPv4 payload offset in the iovec array
+ */
+void tcp_update_check_tcp4(struct in_addr src,
+ struct in_addr dst,
+ const struct iovec *iov, int iov_cnt,
+ size_t l4offset)
{
- uint16_t l4len = ntohs(iph->tot_len) - sizeof(struct iphdr);
- struct in_addr saddr = { .s_addr = iph->saddr };
- struct in_addr daddr = { .s_addr = iph->daddr };
- uint32_t sum = proto_ipv4_header_psum(l4len, IPPROTO_TCP, saddr, daddr);
+ size_t check_ofs;
+ __sum16 *check;
+ int check_idx;
+ uint32_t sum;
+
+ sum = proto_ipv4_header_psum(iov_size(iov, iov_cnt) - l4offset,
+ IPPROTO_TCP, src, dst);
+
+ check_idx = iov_skip_bytes(iov, iov_cnt,
+ l4offset + offsetof(struct tcphdr, check),
+ &check_ofs);
+
+ if (check_idx >= iov_cnt) {
+ err("TCP4 buffer is too small, iov size %zd, check offset %zd",
+ iov_size(iov, iov_cnt),
+ l4offset + offsetof(struct tcphdr, check));
+ return;
+ }
+
+ if (check_ofs + sizeof(*check) > iov[check_idx].iov_len) {
+ err("TCP4 checksum field memory is not contiguous "
+ "check_ofs %zd check_idx %d iov_len %zd",
+ check_ofs, check_idx, iov[check_idx].iov_len);
+ return;
+ }
+
+ check = (__sum16 *)((char *)iov[check_idx].iov_base + check_ofs);
- bp->th.check = 0;
- bp->th.check = csum(bp, l4len, sum);
+ if ((uintptr_t)check & (__alignof__(*check) - 1)) {
+ err("TCP4 checksum field is not correctly aligned in memory");
+ return;
+ }
+
+ *check = 0;
+ *check = csum_iov(iov, iov_cnt, l4offset, sum);
}
/**
* tcp_update_check_tcp6() - Calculate TCP checksum for IPv6
- * @ip6h: IPv6 header
- * @bp: TCP header followed by TCP payload
- */
-static void tcp_update_check_tcp6(const struct ipv6hdr *ip6h,
- struct tcp_payload_t *bp)
+ * @src: IPv6 source address
+ * @dst: IPv6 destination address
+ * @iov: Pointer to the array of IO vectors
+ * @iov_cnt: Length of the array
+ * @l4offset: IPv6 payload offset in the iovec array
+ */
+void tcp_update_check_tcp6(const struct in6_addr *src,
+ const struct in6_addr *dst,
+ const struct iovec *iov, int iov_cnt,
+ size_t l4offset)
{
- uint16_t l4len = ntohs(ip6h->payload_len);
- uint32_t sum = proto_ipv6_header_psum(l4len, IPPROTO_TCP,
- &ip6h->saddr, &ip6h->daddr);
+ size_t check_ofs;
+ __sum16 *check;
+ int check_idx;
+ uint32_t sum;
+
+ sum = proto_ipv6_header_psum(iov_size(iov, iov_cnt) - l4offset,
+ IPPROTO_TCP, src, dst);
+
+ check_idx = iov_skip_bytes(iov, iov_cnt,
+ l4offset + offsetof(struct tcphdr, check),
+ &check_ofs);
+
+ if (check_idx >= iov_cnt) {
+ err("TCP6 buffer is too small, iov size %zd, check offset %zd",
+ iov_size(iov, iov_cnt),
+ l4offset + offsetof(struct tcphdr, check));
+ return;
+ }
- bp->th.check = 0;
- bp->th.check = csum(bp, l4len, sum);
+ if (check_ofs + sizeof(*check) > iov[check_idx].iov_len) {
+ err("TCP6 checksum field memory is not contiguous "
+ "check_ofs %zd check_idx %d iov_len %zd",
+ check_ofs, check_idx, iov[check_idx].iov_len);
+ return;
+ }
+
+ check = (__sum16 *)((char *)iov[check_idx].iov_base + check_ofs);
+
+ if ((uintptr_t)check & (__alignof__(*check) - 1)) {
+ err("TCP6 checksum field is not correctly aligned in memory");
+ return;
+ }
+
+ *check = 0;
+ *check = csum_iov(iov, iov_cnt, l4offset, sum);
}
/**
@@ -935,10 +1002,18 @@ static size_t tcp_fill_headers4(const struct tcp_tap_conn *conn,
tcp_fill_header(&bp->th, conn, seq);
- if (no_tcp_csum)
+ if (no_tcp_csum) {
bp->th.check = 0;
- else
- tcp_update_check_tcp4(iph, bp);
+ } else {
+ const struct iovec iov = {
+ .iov_base = bp,
+ .iov_len = ntohs(iph->tot_len) - sizeof(struct iphdr),
+ };
+ struct in_addr saddr = { .s_addr = iph->saddr };
+ struct in_addr daddr = { .s_addr = iph->daddr };
+
+ tcp_update_check_tcp4(saddr, daddr, &iov, 1, 0);
+ }
tap_hdr_update(taph, l3len + sizeof(struct ethhdr));
@@ -980,10 +1055,17 @@ static size_t tcp_fill_headers6(const struct tcp_tap_conn *conn,
tcp_fill_header(&bp->th, conn, seq);
- if (no_tcp_csum)
+ if (no_tcp_csum) {
bp->th.check = 0;
- else
- tcp_update_check_tcp6(ip6h, bp);
+ } else {
+ const struct iovec iov = {
+ .iov_base = bp,
+ .iov_len = ntohs(ip6h->payload_len)
+ };
+
+ tcp_update_check_tcp6(&ip6h->saddr, &ip6h->daddr,
+ &iov, 1, 0);
+ }
tap_hdr_update(taph, l4len + sizeof(*ip6h) + sizeof(struct ethhdr));
--
2.46.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH v4 4/5] tcp: Update TCP checksum using an iovec array
2024-09-26 14:04 ` [PATCH v4 4/5] tcp: Update TCP checksum using an iovec array Laurent Vivier
@ 2024-09-27 6:22 ` Stefano Brivio
0 siblings, 0 replies; 7+ messages in thread
From: Stefano Brivio @ 2024-09-27 6:22 UTC (permalink / raw)
To: Laurent Vivier; +Cc: passt-dev, David Gibson
On Thu, 26 Sep 2024 16:04:14 +0200
Laurent Vivier <lvivier@redhat.com> wrote:
> TCP header and payload are supposed to be in the same buffer,
> and tcp_update_check_tcp4()/tcp_update_check_tcp6() compute
> the checksum from the base address of the header using the
> length of the IP payload.
>
> In the future (for vhost-user) we need to dispatch the TCP header and
> the TCP payload through several buffers. To be able to manage that, we
> provide an iovec array that points to the data of the TCP frame.
> We provide also an offset to be able to provide an array that contains
> the TCP frame embedded in an lower level frame, and this offset points
> to the TCP header inside the iovec array.
>
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
It looks like you missed David's comments from:
ZvS8wXSMfoexsqXr@zatzit.fritz.box
https://archives.passt.top/passt-dev/ZvS8wXSMfoexsqXr@zatzit.fritz.box/
Other than those, this looks good to me.
--
Stefano
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v4 5/5] udp: Update UDP checksum using an iovec array
2024-09-26 14:04 [PATCH v4 0/5] tcp: use csum_iov() in tcp_update_check_tcp[4|6]() Laurent Vivier
` (3 preceding siblings ...)
2024-09-26 14:04 ` [PATCH v4 4/5] tcp: Update TCP checksum using an iovec array Laurent Vivier
@ 2024-09-26 14:04 ` Laurent Vivier
4 siblings, 0 replies; 7+ messages in thread
From: Laurent Vivier @ 2024-09-26 14:04 UTC (permalink / raw)
To: passt-dev; +Cc: Laurent Vivier
As for tcp_update_check_tcp4()/tcp_update_check_tcp6(),
change csum_udp4() and csum_udp6() to use an iovec array.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
checksum.c | 29 ++++++++++++++++++-----------
checksum.h | 4 ++--
tap.c | 14 +++++++++++---
tap.h | 2 +-
udp.c | 17 +++++++++++++----
5 files changed, 45 insertions(+), 21 deletions(-)
diff --git a/checksum.c b/checksum.c
index 19579323cf1e..01b590c09ba8 100644
--- a/checksum.c
+++ b/checksum.c
@@ -166,22 +166,24 @@ uint32_t proto_ipv4_header_psum(uint16_t l4len, uint8_t protocol,
* @udp4hr: UDP header, initialised apart from checksum
* @saddr: IPv4 source address
* @daddr: IPv4 destination address
- * @payload: UDP packet payload
- * @dlen: Length of @payload (not including UDP header)
+ * @iov: Pointer to the array of IO vectors
+ * @iov_cnt: Length of the array
+ * @offset: UDP payload offset in the iovec array
*/
void csum_udp4(struct udphdr *udp4hr,
struct in_addr saddr, struct in_addr daddr,
- const void *payload, size_t dlen)
+ const struct iovec *iov, int iov_cnt, size_t offset)
{
/* UDP checksums are optional, so don't bother */
udp4hr->check = 0;
if (UDP4_REAL_CHECKSUMS) {
- uint16_t l4len = dlen + sizeof(struct udphdr);
+ uint16_t l4len = iov_size(iov, iov_cnt) - offset +
+ sizeof(struct udphdr);
uint32_t psum = proto_ipv4_header_psum(l4len, IPPROTO_UDP,
saddr, daddr);
psum = csum_unfolded(udp4hr, sizeof(struct udphdr), psum);
- udp4hr->check = csum(payload, dlen, psum);
+ udp4hr->check = csum_iov(iov, iov_cnt, offset, psum);
}
}
@@ -227,19 +229,24 @@ uint32_t proto_ipv6_header_psum(uint16_t payload_len, uint8_t protocol,
/**
* csum_udp6() - Calculate and set checksum for a UDP over IPv6 packet
* @udp6hr: UDP header, initialised apart from checksum
- * @payload: UDP packet payload
- * @dlen: Length of @payload (not including UDP header)
+ * @saddr: Source address
+ * @daddr: Destination address
+ * @iov: Pointer to the array of IO vectors
+ * @iov_cnt: Length of the array
+ * @offset: UDP payload offset in the iovec array
*/
void csum_udp6(struct udphdr *udp6hr,
const struct in6_addr *saddr, const struct in6_addr *daddr,
- const void *payload, size_t dlen)
+ const struct iovec *iov, int iov_cnt, size_t offset)
{
- uint32_t psum = proto_ipv6_header_psum(dlen + sizeof(struct udphdr),
- IPPROTO_UDP, saddr, daddr);
+ uint16_t l4len = iov_size(iov, iov_cnt) - offset +
+ sizeof(struct udphdr);
+ uint32_t psum = proto_ipv6_header_psum(l4len, IPPROTO_UDP,
+ saddr, daddr);
udp6hr->check = 0;
psum = csum_unfolded(udp6hr, sizeof(struct udphdr), psum);
- udp6hr->check = csum(payload, dlen, psum);
+ udp6hr->check = csum_iov(iov, iov_cnt, offset, psum);
}
/**
diff --git a/checksum.h b/checksum.h
index 49f7472dd1b6..31ba322fa98c 100644
--- a/checksum.h
+++ b/checksum.h
@@ -19,14 +19,14 @@ uint32_t proto_ipv4_header_psum(uint16_t l4len, uint8_t protocol,
struct in_addr saddr, struct in_addr daddr);
void csum_udp4(struct udphdr *udp4hr,
struct in_addr saddr, struct in_addr daddr,
- const void *payload, size_t dlen);
+ const struct iovec *iov, int iov_cnt, size_t offset);
void csum_icmp4(struct icmphdr *icmp4hr, const void *payload, size_t dlen);
uint32_t proto_ipv6_header_psum(uint16_t payload_len, uint8_t protocol,
const struct in6_addr *saddr,
const struct in6_addr *daddr);
void csum_udp6(struct udphdr *udp6hr,
const struct in6_addr *saddr, const struct in6_addr *daddr,
- const void *payload, size_t dlen);
+ const struct iovec *iov, int iov_cnt, size_t offset);
void csum_icmp6(struct icmp6hdr *icmp6hr,
const struct in6_addr *saddr, const struct in6_addr *daddr,
const void *payload, size_t dlen);
diff --git a/tap.c b/tap.c
index 41af6a6d0c85..c53a39b79e62 100644
--- a/tap.c
+++ b/tap.c
@@ -172,11 +172,15 @@ void tap_udp4_send(const struct ctx *c, struct in_addr src, in_port_t sport,
struct iphdr *ip4h = tap_push_l2h(c, buf, ETH_P_IP);
struct udphdr *uh = tap_push_ip4h(ip4h, src, dst, l4len, IPPROTO_UDP);
char *data = (char *)(uh + 1);
+ const struct iovec iov = {
+ .iov_base = (void *)in,
+ .iov_len = dlen
+ };
uh->source = htons(sport);
uh->dest = htons(dport);
uh->len = htons(l4len);
- csum_udp4(uh, src, dst, in, dlen);
+ csum_udp4(uh, src, dst, &iov, 1, 0);
memcpy(data, in, dlen);
tap_send_single(c, buf, dlen + (data - buf));
@@ -247,7 +251,7 @@ static void *tap_push_ip6h(struct ipv6hdr *ip6h,
void tap_udp6_send(const struct ctx *c,
const struct in6_addr *src, in_port_t sport,
const struct in6_addr *dst, in_port_t dport,
- uint32_t flow, const void *in, size_t dlen)
+ uint32_t flow, void *in, size_t dlen)
{
size_t l4len = dlen + sizeof(struct udphdr);
char buf[USHRT_MAX];
@@ -255,11 +259,15 @@ void tap_udp6_send(const struct ctx *c,
struct udphdr *uh = tap_push_ip6h(ip6h, src, dst,
l4len, IPPROTO_UDP, flow);
char *data = (char *)(uh + 1);
+ const struct iovec iov = {
+ .iov_base = in,
+ .iov_len = dlen
+ };
uh->source = htons(sport);
uh->dest = htons(dport);
uh->len = htons(l4len);
- csum_udp6(uh, src, dst, in, dlen);
+ csum_udp6(uh, src, dst, &iov, 1, 0);
memcpy(data, in, dlen);
tap_send_single(c, buf, dlen + (data - buf));
diff --git a/tap.h b/tap.h
index ec9e2acec460..85f1e8473711 100644
--- a/tap.h
+++ b/tap.h
@@ -53,7 +53,7 @@ const struct in6_addr *tap_ip6_daddr(const struct ctx *c,
void tap_udp6_send(const struct ctx *c,
const struct in6_addr *src, in_port_t sport,
const struct in6_addr *dst, in_port_t dport,
- uint32_t flow, const void *in, size_t dlen);
+ uint32_t flow, void *in, size_t dlen);
void tap_icmp6_send(const struct ctx *c,
const struct in6_addr *src, const struct in6_addr *dst,
const void *in, size_t l4len);
diff --git a/udp.c b/udp.c
index 7b2831386db8..ac34279db253 100644
--- a/udp.c
+++ b/udp.c
@@ -321,10 +321,15 @@ static size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp,
bp->uh.source = htons(toside->oport);
bp->uh.dest = htons(toside->eport);
bp->uh.len = htons(l4len);
- if (no_udp_csum)
+ if (no_udp_csum) {
bp->uh.check = 0;
- else
- csum_udp4(&bp->uh, *src, *dst, bp->data, dlen);
+ } else {
+ const struct iovec iov = {
+ .iov_base = bp->data,
+ .iov_len = dlen
+ };
+ csum_udp4(&bp->uh, *src, *dst, &iov, 1, 0);
+ }
return l4len;
}
@@ -363,8 +368,12 @@ static size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp,
*/
bp->uh.check = 0xffff;
} else {
+ const struct iovec iov = {
+ .iov_base = bp->data,
+ .iov_len = dlen
+ };
csum_udp6(&bp->uh, &toside->oaddr.a6, &toside->eaddr.a6,
- bp->data, dlen);
+ &iov, 1, 0);
}
return l4len;
--
@@ -321,10 +321,15 @@ static size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp,
bp->uh.source = htons(toside->oport);
bp->uh.dest = htons(toside->eport);
bp->uh.len = htons(l4len);
- if (no_udp_csum)
+ if (no_udp_csum) {
bp->uh.check = 0;
- else
- csum_udp4(&bp->uh, *src, *dst, bp->data, dlen);
+ } else {
+ const struct iovec iov = {
+ .iov_base = bp->data,
+ .iov_len = dlen
+ };
+ csum_udp4(&bp->uh, *src, *dst, &iov, 1, 0);
+ }
return l4len;
}
@@ -363,8 +368,12 @@ static size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp,
*/
bp->uh.check = 0xffff;
} else {
+ const struct iovec iov = {
+ .iov_base = bp->data,
+ .iov_len = dlen
+ };
csum_udp6(&bp->uh, &toside->oaddr.a6, &toside->eaddr.a6,
- bp->data, dlen);
+ &iov, 1, 0);
}
return l4len;
--
2.46.0
^ permalink raw reply related [flat|nested] 7+ messages in thread