On Wed, 5 Jun 2024 17:21:25 +0200 Laurent Vivier <lvivier(a)redhat.com> wrote:This commit refactors the udp_update_hdr4() and udp_update_hdr6() functions to improve code portability by replacing the udp_meta_t parameter with more specific parameters for the IPv4 and IPv6 headers (iphdr/ipv6hdr) and the source socket address (sockaddr_in/sockaddr_in6). It also moves the tap_hdr_update() function call inside the udp_tap_send() function not to have to pass the TAP header to udp_update_hdr4() and udp_update_hdr6() This refactor reduces complexity by making the functions more modular and ensuring that each function operates on more narrowly scoped data structures. This will facilitate future backend introduction like vhost-user. Signed-off-by: Laurent Vivier <lvivier(a)redhat.com> --- udp.c | 60 +++++++++++++++++++++++++++++++++-------------------------- 1 file changed, 34 insertions(+), 26 deletions(-) diff --git a/udp.c b/udp.c index 3abafc994537..4295d48046a6 100644 --- a/udp.c +++ b/udp.c @@ -556,7 +556,8 @@ static void udp_splice_sendfrom(const struct ctx *c, unsigned start, unsigned n, /** * udp_update_hdr4() - Update headers for one IPv4 datagram * @c: Execution context - * @bm: Pointer to udp_meta_t to update + * @ip4h: Pre-filled IPv4 header (except for tot_len and saddr) + * @s_in: Source socket address, filled in by recvmmsg() * @bp: Pointer to udp_payload_t to update * @dstport: Destination port number * @dlen: Length of UDP payload @@ -565,15 +566,16 @@ static void udp_splice_sendfrom(const struct ctx *c, unsigned start, unsigned n, * Return: size of IPv4 payload (UDP header + data) */ static size_t udp_update_hdr4(const struct ctx *c, - struct udp_meta_t *bm, struct udp_payload_t *bp, + struct iphdr *ip4h, const struct sockaddr_in *s_in, + struct udp_payload_t *bp, in_port_t dstport, size_t dlen, const struct timespec *now) { - in_port_t srcport = ntohs(bm->s_in.sa4.sin_port); + in_port_t srcport = ntohs(s_in->sin_port); const struct in_addr dst = c->ip4.addr_seen; - struct in_addr src = bm->s_in.sa4.sin_addr; + struct in_addr src = s_in->sin_addr; size_t l4len = dlen + sizeof(bp->uh); - size_t l3len = l4len + sizeof(bm->ip4h); + size_t l3len = l4len + sizeof(*ip4h);Nit: while at it, it would be nice to reorder declarations from longest to shortest, as well.if (!IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns_match) && IN4_ARE_ADDR_EQUAL(&src, &c->ip4.dns_host) && srcport == 53 && @@ -594,24 +596,24 @@ static size_t udp_update_hdr4(const struct ctx *c, src = c->ip4.gw; } - bm->ip4h.tot_len = htons(l3len); - bm->ip4h.daddr = dst.s_addr; - bm->ip4h.saddr = src.s_addr; - bm->ip4h.check = csum_ip4_header(l3len, IPPROTO_UDP, 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); - bp->uh.source = bm->s_in.sa4.sin_port; + bp->uh.source = s_in->sin_port; bp->uh.dest = htons(dstport); bp->uh.len = htons(l4len); csum_udp4(&bp->uh, src, dst, bp->data, dlen); - tap_hdr_update(&bm->taph, l3len + sizeof(udp4_eth_hdr)); return l4len; } /** * udp_update_hdr6() - Update headers for one IPv6 datagram * @c: Execution context - * @bm: Pointer to udp_meta_t to update + * @ip6h: Pre-filled IPv6 header (except for payload_len and addresses) + * @s_in: Source socket address, filled in by recvmmsg() * @bp: Pointer to udp_payload_t to update * @dstport: Destination port number * @dlen: Length of UDP payload @@ -620,13 +622,14 @@ static size_t udp_update_hdr4(const struct ctx *c, * Return: size of IPv6 payload (UDP header + data) */ static size_t udp_update_hdr6(const struct ctx *c, - struct udp_meta_t *bm, struct udp_payload_t *bp, + struct ipv6hdr *ip6h, struct sockaddr_in6 *s_in6, + struct udp_payload_t *bp, in_port_t dstport, size_t dlen, const struct timespec *now) { - const struct in6_addr *src = &bm->s_in.sa6.sin6_addr; + const struct in6_addr *src = &s_in6->sin6_addr; const struct in6_addr *dst = &c->ip6.addr_seen; - in_port_t srcport = ntohs(bm->s_in.sa6.sin6_port); + in_port_t srcport = ntohs(s_in6->sin6_port);Same here.uint16_t l4len = dlen + sizeof(bp->uh); if (IN6_IS_ADDR_LINKLOCAL(src)) { @@ -663,19 +666,18 @@ static size_t udp_update_hdr6(const struct ctx *c, } - bm->ip6h.payload_len = htons(l4len); - bm->ip6h.daddr = *dst; - bm->ip6h.saddr = *src; - bm->ip6h.version = 6; - bm->ip6h.nexthdr = IPPROTO_UDP; - bm->ip6h.hop_limit = 255; + ip6h->payload_len = htons(l4len); + ip6h->daddr = *dst; + ip6h->saddr = *src; + ip6h->version = 6; + ip6h->nexthdr = IPPROTO_UDP; + ip6h->hop_limit = 255; - bp->uh.source = bm->s_in.sa6.sin6_port; + bp->uh.source = s_in6->sin6_port; bp->uh.dest = htons(dstport); - bp->uh.len = bm->ip6h.payload_len; + bp->uh.len = ip6h->payload_len; csum_udp6(&bp->uh, src, dst, bp->data, dlen); - tap_hdr_update(&bm->taph, l4len + sizeof(bm->ip6h) + sizeof(udp6_eth_hdr)); return l4len; } @@ -708,11 +710,17 @@ static void udp_tap_send(const struct ctx *c, size_t l4len; if (v6) { - l4len = udp_update_hdr6(c, bm, bp, dstport, + l4len = udp_update_hdr6(c, &bm->ip6h, + &bm->s_in.sa6, bp, dstport, udp6_l2_mh_sock[i].msg_len, now); + tap_hdr_update(&bm->taph, l4len + sizeof(bm->ip6h) + + sizeof(udp6_eth_hdr));You're summing sizeof(udp6_eth_hdr) to l4len + sizeof(bm->ip6h), so this should be aligned as follows: tap_hdr_update(&bm->taph, l4len + sizeof(bm->ip6h) + sizeof(udp6_eth_hdr));} else { - l4len = udp_update_hdr4(c, bm, bp, dstport, + l4len = udp_update_hdr4(c, &bm->ip4h, + &bm->s_in.sa4, bp, dstport, udp4_l2_mh_sock[i].msg_len, now); + tap_hdr_update(&bm->taph, l4len + sizeof(bm->ip4h) + + sizeof(udp4_eth_hdr));Same here: tap_hdr_update(&bm->taph, l4len + sizeof(bm->ip4h) + sizeof(udp4_eth_hdr));} tap_iov[i][UDP_IOV_PAYLOAD].iov_len = l4len; }-- Stefano