Change udp_update_hdr4() and udp_update_hdr6() to take an iov_tail
covering the full L3 frame (IP header + UDP header + data), instead of
separate IP header, udp_payload_t, and data-length parameters. The
functions now use with_header() and IOV_DROP_HEADER() to access the IP
and UDP headers directly from the iov_tail, and derive sizes via
iov_tail_size() rather than an explicit length argument.
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 layout-specific helpers.
On the vhost-user side, udp_vu_prepare() likewise switches to
with_header() for the Ethernet header, and its caller now drops the
vnet header before calling udp_vu_prepare() instead of having the
function deal with it internally.
Signed-off-by: Laurent Vivier
---
iov.c | 1 -
udp.c | 129 +++++++++++++++++++++++++++----------------------
udp_internal.h | 6 +--
udp_vu.c | 51 +++++++++----------
4 files changed, 97 insertions(+), 90 deletions(-)
diff --git a/iov.c b/iov.c
index 41e418aab2cc..d92f28995004 100644
--- a/iov.c
+++ b/iov.c
@@ -315,7 +315,6 @@ void *iov_peek_header_(struct iov_tail *tail, void *v, size_t len, size_t align)
*
* Return: number of bytes written
*/
-/* cppcheck-suppress unusedFunction */
size_t iov_put_header_(const struct iov_tail *tail, const void *v, size_t len)
{
size_t l = len;
diff --git a/udp.c b/udp.c
index 2275c16b19f3..ec764a4a3969 100644
--- a/udp.c
+++ b/udp.c
@@ -254,42 +254,42 @@ 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
+ * @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,
+size_t udp_update_hdr4(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 l3len = l4len + sizeof(*ip4h);
+ size_t l3len = iov_tail_size(payload);
+ size_t l4len = l3len - sizeof(struct iphdr);
ASSERT(src && dst);
- ip4h->tot_len = htons(l3len);
- ip4h->daddr = dst->s_addr;
- ip4h->saddr = src->s_addr;
- ip4h->check = csum_ip4_header(l3len, IPPROTO_UDP, *src, *dst);
+ with_header(struct iphdr, ip4h, payload) {
+ ip4h->tot_len = htons(l3len);
+ ip4h->daddr = dst->s_addr;
+ ip4h->saddr = src->s_addr;
+ ip4h->check = csum_ip4_header(l3len, IPPROTO_UDP, *src, *dst);
+ }
+ IOV_DROP_HEADER(payload, struct iphdr);
+
+ with_header(struct udphdr, uh, payload) {
+ uh->source = htons(toside->oport);
+ uh->dest = htons(toside->eport);
+ uh->len = htons(l4len);
+ if (no_udp_csum) {
+ uh->check = 0;
+ } else {
+ struct iov_tail data = *payload;
- 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);
+ IOV_DROP_HEADER(&data, struct udphdr);
+ csum_udp4(uh, *src, *dst, &data);
+ }
}
return l4len;
@@ -297,44 +297,45 @@ 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
+ * @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,
+size_t udp_update_hdr6(struct iov_tail *payload, const struct flowside *toside,
bool no_udp_csum)
{
- uint16_t l4len = dlen + sizeof(bp->uh);
-
- ip6h->payload_len = htons(l4len);
- ip6h->daddr = toside->eaddr.a6;
- ip6h->saddr = toside->oaddr.a6;
- ip6h->version = 6;
- 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;
- 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;
- } 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);
+ uint16_t l4len = iov_tail_size(payload) - sizeof(struct ipv6hdr);
+
+ with_header(struct ipv6hdr, ip6h, payload) {
+ ip6h->payload_len = htons(l4len);
+ ip6h->daddr = toside->eaddr.a6;
+ ip6h->saddr = toside->oaddr.a6;
+ ip6h->version = 6;
+ ip6h->nexthdr = IPPROTO_UDP;
+ ip6h->hop_limit = 255;
+ }
+ IOV_DROP_HEADER(payload, struct ipv6hdr);
+
+ with_header(struct udphdr, uh, payload) {
+ uh->source = htons(toside->oport);
+ uh->dest = htons(toside->eport);
+ uh->len = htons(l4len);
+ 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.
+ */
+ uh->check = 0xffff;
+ } else {
+ struct iov_tail data = *payload;
+
+ IOV_DROP_HEADER(&data, struct udphdr);
+ csum_udp6(uh, &toside->oaddr.a6, &toside->eaddr.a6,
+ &data);
+ }
}
return l4len;
@@ -374,12 +375,22 @@ 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];
+ struct iovec iov[3];
+ struct iov_tail payload = IOV_TAIL(iov, ARRAY_SIZE(iov), 0);
size_t l4len, l2len;
+ iov[1].iov_base = &bp->uh;
+ iov[1].iov_len = sizeof(bp->uh);
+ iov[2].iov_base = bp->data;
+ iov[2].iov_len = mmh[idx].msg_len;
+
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);
+
+ iov[0].iov_base = &bm->ip6h;
+ iov[0].iov_len = sizeof(bm->ip6h);
+
+ l4len = udp_update_hdr6(&payload, toside, no_udp_csum);
l2len = MAX(l4len + sizeof(bm->ip6h) + ETH_HLEN, ETH_ZLEN);
tap_hdr_update(&bm->taph, l2len);
@@ -387,8 +398,10 @@ 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);
+ iov[0].iov_base = &bm->ip4h;
+ iov[0].iov_len = sizeof(bm->ip4h);
+
+ l4len = udp_update_hdr4(&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..fb3017ae3251 100644
--- a/udp_internal.h
+++ b/udp_internal.h
@@ -25,11 +25,9 @@ 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 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 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 7f6561f83505..f4023c765b6b 100644
--- a/udp_vu.c
+++ b/udp_vu.c
@@ -93,42 +93,39 @@ static ssize_t udp_vu_sock_recv(struct iovec *iov, size_t *cnt, int s, bool v6)
* @c: Execution context
* @data: IO vector tail for the frame
* @toside: Address information for one side of the flow
- * @dlen: Packet data length
*
* Return: Layer-4 length
*/
static size_t udp_vu_prepare(const struct ctx *c, const struct iov_tail *data,
- const struct flowside *toside, ssize_t dlen)
+ const struct flowside *toside)
{
- const struct iovec *iov = data->iov;
- struct ethhdr *eh;
+ bool ipv4 = inany_v4(&toside->eaddr) && inany_v4(&toside->oaddr);
+ struct iov_tail payload = *data;
size_t l4len;
/* ethernet header */
- eh = vu_eth(iov[0].iov_base);
-
- memcpy(eh->h_dest, c->guest_mac, sizeof(eh->h_dest));
- memcpy(eh->h_source, c->our_tap_mac, sizeof(eh->h_source));
+ with_header(struct ethhdr, eh, &payload) {
+ memcpy(eh->h_dest, c->guest_mac, sizeof(eh->h_dest));
+ memcpy(eh->h_source, c->our_tap_mac, sizeof(eh->h_source));
+
+ if (ipv4)
+ eh->h_proto = htons(ETH_P_IP);
+ else
+ eh->h_proto = htons(ETH_P_IPV6);
+ }
+ IOV_DROP_HEADER(&payload, struct ethhdr);
/* initialize header */
- 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);
+ if (ipv4) {
+ with_header(struct iphdr, iph, &payload)
+ *iph = (struct iphdr)L2_BUF_IP4_INIT(IPPROTO_UDP);
- 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(&payload, toside, true);
} else {
- struct ipv6hdr *ip6h = vu_ip(iov[0].iov_base);
- struct udp_payload_t *bp = vu_payloadv6(iov[0].iov_base);
-
- eh->h_proto = htons(ETH_P_IPV6);
-
- *ip6h = (struct ipv6hdr)L2_BUF_IP6_INIT(IPPROTO_UDP);
+ with_header(struct ipv6hdr, ip6h, &payload)
+ *ip6h = (struct ipv6hdr)L2_BUF_IP6_INIT(IPPROTO_UDP);
- l4len = udp_update_hdr6(ip6h, bp, toside, dlen, true);
+ l4len = udp_update_hdr6(&payload, toside, true);
}
return l4len;
@@ -137,7 +134,7 @@ static size_t udp_vu_prepare(const struct ctx *c, const struct iov_tail *data,
/**
* udp_vu_csum() - Calculate and set checksum for a UDP packet
* @toside: Address information for one side of the flow
- * @data: IO vector tail for the frame (including vnet header)
+ * @data: IO vector tail for the L2 frame
*/
static void udp_vu_csum(const struct flowside *toside,
const struct iov_tail *data)
@@ -148,7 +145,6 @@ static void udp_vu_csum(const struct flowside *toside,
struct udphdr *uh, uh_storage;
bool ipv4 = src4 && dst4;
- IOV_DROP_HEADER(&payload, struct virtio_net_hdr_mrg_rxbuf);
IOV_DROP_HEADER(&payload, struct ethhdr);
if (ipv4)
IOV_DROP_HEADER(&payload, struct iphdr);
@@ -225,10 +221,11 @@ void udp_vu_sock_to_tap(const struct ctx *c, int s, int n, flow_sidx_t tosidx)
if (iov_cnt > 0) {
struct iov_tail data = IOV_TAIL(iov_vu, iov_cnt, 0);
vu_set_vnethdr(iov_vu[0].iov_base, elem_used);
- udp_vu_prepare(c, &data, toside, dlen);
+ iov_drop_header(&data, VNET_HLEN);
+ udp_vu_prepare(c, &data, toside);
if (*c->pcap) {
udp_vu_csum(toside, &data);
- pcap_iov(data.iov, data.cnt, VNET_HLEN);
+ pcap_iov(data.iov, data.cnt, data.off);
}
vu_flush(vdev, vq, elem, elem_used);
}
--
2.53.0