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udp: Update UDP checksum using an iovec array

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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>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Laurent Vivier 2024-10-03 16:51:08 +02:00 committed by Stefano Brivio
parent 3d484aa370
commit 151dbe0d3d
5 changed files with 45 additions and 21 deletions
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29
checksum.c
View file

@ -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);
}
/**

4
checksum.h
View file

@ -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);

14
tap.c
View file

@ -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));

2
tap.h
View file

@ -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);

17
udp.c
View file

@ -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;