Change udp_update_hdr4() and udp_update_hdr6() to take a separate
struct udphdr pointer and an iov_tail for the payload, instead of a
struct udp_payload_t pointer and an explicit data length.
This decouples the header update functions from the udp_payload_t memory
layout, which assumes all headers and data sit in a single contiguous
buffer. The vhost-user path uses virtqueue-provided scatter-gather
buffers where this assumption does not hold; passing an iov_tail lets
both the tap path and the vhost-user path share the same functions
without casting through layout-specific helpers.
Signed-off-by: Laurent Vivier
---
udp.c | 72 +++++++++++++++++++++++---------------------------
udp_internal.h | 10 ++++---
udp_vu.c | 14 ++++++++--
3 files changed, 51 insertions(+), 45 deletions(-)
diff --git a/udp.c b/udp.c
index 464aa09365cc..6840e8843e68 100644
--- a/udp.c
+++ b/udp.c
@@ -255,20 +255,20 @@ static void udp_iov_init(const struct ctx *c)
/**
* udp_update_hdr4() - Update headers for one IPv4 datagram
* @ip4h: Pre-filled IPv4 header (except for tot_len and saddr)
- * @bp: Pointer to udp_payload_t to update
+ * @uh: UDP header to update
+ * @payload: UDP payload
* @toside: Flowside for destination side
- * @dlen: Length of UDP payload
* @no_udp_csum: Do not set UDP checksum
*
* Return: size of IPv4 payload (UDP header + data)
*/
-size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp,
- const struct flowside *toside, size_t dlen,
- bool no_udp_csum)
+size_t udp_update_hdr4(struct iphdr *ip4h, struct udphdr *uh,
+ struct iov_tail *payload,
+ const struct flowside *toside, bool no_udp_csum)
{
const struct in_addr *src = inany_v4(&toside->oaddr);
const struct in_addr *dst = inany_v4(&toside->eaddr);
- size_t l4len = dlen + sizeof(bp->uh);
+ size_t l4len = iov_tail_size(payload) + sizeof(*uh);
size_t l3len = l4len + sizeof(*ip4h);
ASSERT(src && dst);
@@ -278,19 +278,13 @@ size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp,
ip4h->saddr = src->s_addr;
ip4h->check = csum_ip4_header(l3len, IPPROTO_UDP, *src, *dst);
- bp->uh.source = htons(toside->oport);
- bp->uh.dest = htons(toside->eport);
- bp->uh.len = htons(l4len);
- if (no_udp_csum) {
- bp->uh.check = 0;
- } else {
- const struct iovec iov = {
- .iov_base = bp->data,
- .iov_len = dlen
- };
- struct iov_tail data = IOV_TAIL(&iov, 1, 0);
- csum_udp4(&bp->uh, *src, *dst, &data);
- }
+ uh->source = htons(toside->oport);
+ uh->dest = htons(toside->eport);
+ uh->len = htons(l4len);
+ if (no_udp_csum)
+ uh->check = 0;
+ else
+ csum_udp4(uh, *src, *dst, payload);
return l4len;
}
@@ -299,18 +293,18 @@ size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp,
* udp_update_hdr6() - Update headers for one IPv6 datagram
* @ip6h: Pre-filled IPv6 header (except for payload_len and
* addresses)
- * @bp: Pointer to udp_payload_t to update
+ * @uh: UDP header to update
+ * @payload: UDP payload
* @toside: Flowside for destination side
- * @dlen: Length of UDP payload
* @no_udp_csum: Do not set UDP checksum
*
* Return: size of IPv6 payload (UDP header + data)
*/
-size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp,
- const struct flowside *toside, size_t dlen,
- bool no_udp_csum)
+size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udphdr *uh,
+ struct iov_tail *payload,
+ const struct flowside *toside, bool no_udp_csum)
{
- uint16_t l4len = dlen + sizeof(bp->uh);
+ uint16_t l4len = iov_tail_size(payload) + sizeof(*uh);
ip6h->payload_len = htons(l4len);
ip6h->daddr = toside->eaddr.a6;
@@ -319,22 +313,17 @@ size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp,
ip6h->nexthdr = IPPROTO_UDP;
ip6h->hop_limit = 255;
- bp->uh.source = htons(toside->oport);
- bp->uh.dest = htons(toside->eport);
- bp->uh.len = ip6h->payload_len;
+ uh->source = htons(toside->oport);
+ uh->dest = htons(toside->eport);
+ uh->len = ip6h->payload_len;
if (no_udp_csum) {
/* 0 is an invalid checksum for UDP IPv6 and dropped by
* the kernel stack, even if the checksum is disabled by virtio
* flags. We need to put any non-zero value here.
*/
- bp->uh.check = 0xffff;
+ uh->check = 0xffff;
} else {
- const struct iovec iov = {
- .iov_base = bp->data,
- .iov_len = dlen
- };
- struct iov_tail data = IOV_TAIL(&iov, 1, 0);
- csum_udp6(&bp->uh, &toside->oaddr.a6, &toside->eaddr.a6, &data);
+ csum_udp6(uh, &toside->oaddr.a6, &toside->eaddr.a6, payload);
}
return l4len;
@@ -374,12 +363,17 @@ static void udp_tap_prepare(const struct mmsghdr *mmh,
struct ethhdr *eh = (*tap_iov)[UDP_IOV_ETH].iov_base;
struct udp_payload_t *bp = &udp_payload[idx];
struct udp_meta_t *bm = &udp_meta[idx];
+ const struct iovec iov = {
+ .iov_base = bp->data,
+ .iov_len = mmh[idx].msg_len,
+ };
+ struct iov_tail payload = IOV_TAIL(&iov, 1, 0);
size_t l4len, l2len;
eth_update_mac(eh, NULL, tap_omac);
if (!inany_v4(&toside->eaddr) || !inany_v4(&toside->oaddr)) {
- l4len = udp_update_hdr6(&bm->ip6h, bp, toside,
- mmh[idx].msg_len, no_udp_csum);
+ l4len = udp_update_hdr6(&bm->ip6h, &bp->uh, &payload, toside,
+ no_udp_csum);
l2len = MAX(l4len + sizeof(bm->ip6h) + ETH_HLEN, ETH_ZLEN);
tap_hdr_update(&bm->taph, l2len);
@@ -387,8 +381,8 @@ static void udp_tap_prepare(const struct mmsghdr *mmh,
eh->h_proto = htons_constant(ETH_P_IPV6);
(*tap_iov)[UDP_IOV_IP] = IOV_OF_LVALUE(bm->ip6h);
} else {
- l4len = udp_update_hdr4(&bm->ip4h, bp, toside,
- mmh[idx].msg_len, no_udp_csum);
+ l4len = udp_update_hdr4(&bm->ip4h, &bp->uh, &payload, toside,
+ no_udp_csum);
l2len = MAX(l4len + sizeof(bm->ip4h) + ETH_HLEN, ETH_ZLEN);
tap_hdr_update(&bm->taph, l2len);
diff --git a/udp_internal.h b/udp_internal.h
index 64e457748324..fba5ef33cf99 100644
--- a/udp_internal.h
+++ b/udp_internal.h
@@ -25,11 +25,13 @@ struct udp_payload_t {
} __attribute__ ((packed, aligned(__alignof__(unsigned int))));
#endif
-size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp,
- const struct flowside *toside, size_t dlen,
+size_t udp_update_hdr4(struct iphdr *ip4h, struct udphdr *uh,
+ struct iov_tail *payload,
+ const struct flowside *toside,
bool no_udp_csum);
-size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp,
- const struct flowside *toside, size_t dlen,
+size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udphdr *uh,
+ struct iov_tail *payload,
+ const struct flowside *toside,
bool no_udp_csum);
void udp_sock_fwd(const struct ctx *c, int s, int rule_hint,
uint8_t frompif, in_port_t port, const struct timespec *now);
diff --git a/udp_vu.c b/udp_vu.c
index 27ae93de4420..2a5d3f822bf6 100644
--- a/udp_vu.c
+++ b/udp_vu.c
@@ -122,21 +122,31 @@ static size_t udp_vu_prepare(const struct ctx *c, const struct iov_tail *data,
if (inany_v4(&toside->eaddr) && inany_v4(&toside->oaddr)) {
struct iphdr *iph = vu_ip(iov[0].iov_base);
struct udp_payload_t *bp = vu_payloadv4(iov[0].iov_base);
+ const struct iovec payload_iov = {
+ .iov_base = bp->data,
+ .iov_len = dlen,
+ };
+ struct iov_tail payload = IOV_TAIL(&payload_iov, 1, 0);
eh->h_proto = htons(ETH_P_IP);
*iph = (struct iphdr)L2_BUF_IP4_INIT(IPPROTO_UDP);
- l4len = udp_update_hdr4(iph, bp, toside, dlen, true);
+ l4len = udp_update_hdr4(iph, &bp->uh, &payload, toside, true);
} else {
struct ipv6hdr *ip6h = vu_ip(iov[0].iov_base);
struct udp_payload_t *bp = vu_payloadv6(iov[0].iov_base);
+ const struct iovec payload_iov = {
+ .iov_base = bp->data,
+ .iov_len = dlen,
+ };
+ struct iov_tail payload = IOV_TAIL(&payload_iov, 1, 0);
eh->h_proto = htons(ETH_P_IPV6);
*ip6h = (struct ipv6hdr)L2_BUF_IP6_INIT(IPPROTO_UDP);
- l4len = udp_update_hdr6(ip6h, bp, toside, dlen, true);
+ l4len = udp_update_hdr6(ip6h, &bp->uh, &payload, toside, true);
}
return l4len;
--
2.53.0