From e82b4fe5fc8f62fd7e0045395ad7d4260be2f35d Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Wed, 6 Mar 2024 16:58:34 +1100 Subject: [PATCH] udp: little cleanup in udp_update_hdrX() to prepare future changes in udp_update_hdr4(): Assign the source address to src, either b->s_in.sin_addr, c->ip4.dns_match or c->ip4.gw and then set b->iph.saddr to src->s_addr. in udp_update_hdr6(): Assign the source address to src, either b->s_in6.sin6_addr, c->ip6.dns_match, c->ip6.gw or c->ip6.addr_ll. Assign the destination to dst, either c->ip6.addr_seen or &c->ip6.addr_ll_seen. Then set dst to b->ip6h.daddr and src to b->ip6h.saddr. Signed-off-by: Laurent Vivier Message-ID: <20240303135114.1023026-6-lvivier@redhat.com> Signed-off-by: David Gibson Signed-off-by: Stefano Brivio --- udp.c | 39 +++++++++++++++++++-------------------- 1 file changed, 19 insertions(+), 20 deletions(-) diff --git a/udp.c b/udp.c index 26774df..2b41a1b 100644 --- a/udp.c +++ b/udp.c @@ -588,7 +588,7 @@ static size_t udp_update_hdr4(const struct ctx *c, int n, in_port_t dstport, const struct timespec *now) { struct udp4_l2_buf_t *b = &udp4_l2_buf[n]; - struct in_addr *src; + const struct in_addr *src; in_port_t src_port; size_t ip_len; @@ -602,10 +602,9 @@ static size_t udp_update_hdr4(const struct ctx *c, int n, in_port_t dstport, if (!IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns_match) && IN4_ARE_ADDR_EQUAL(src, &c->ip4.dns_host) && src_port == 53) { - b->iph.saddr = c->ip4.dns_match.s_addr; + src = &c->ip4.dns_match; } else if (IN4_IS_ADDR_LOOPBACK(src) || IN4_ARE_ADDR_EQUAL(src, &c->ip4.addr_seen)) { - b->iph.saddr = c->ip4.gw.s_addr; udp_tap_map[V4][src_port].ts = now->tv_sec; udp_tap_map[V4][src_port].flags |= PORT_LOCAL; @@ -615,9 +614,10 @@ static size_t udp_update_hdr4(const struct ctx *c, int n, in_port_t dstport, udp_tap_map[V4][src_port].flags &= ~PORT_LOOPBACK; bitmap_set(udp_act[V4][UDP_ACT_TAP], src_port); - } else { - b->iph.saddr = src->s_addr; + + src = &c->ip4.gw; } + b->iph.saddr = src->s_addr; udp_update_check4(b); b->uh.source = b->s_in.sin_port; @@ -640,10 +640,11 @@ static size_t udp_update_hdr6(const struct ctx *c, int n, in_port_t dstport, const struct timespec *now) { struct udp6_l2_buf_t *b = &udp6_l2_buf[n]; - struct in6_addr *src; + const struct in6_addr *src, *dst; in_port_t src_port; size_t ip_len; + dst = &c->ip6.addr_seen; src = &b->s_in6.sin6_addr; src_port = ntohs(b->s_in6.sin6_port); @@ -652,23 +653,14 @@ static size_t udp_update_hdr6(const struct ctx *c, int n, in_port_t dstport, b->ip6h.payload_len = htons(udp6_l2_mh_sock[n].msg_len + sizeof(b->uh)); if (IN6_IS_ADDR_LINKLOCAL(src)) { - b->ip6h.daddr = c->ip6.addr_ll_seen; - b->ip6h.saddr = b->s_in6.sin6_addr; + dst = &c->ip6.addr_ll_seen; } else if (!IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns_match) && IN6_ARE_ADDR_EQUAL(src, &c->ip6.dns_host) && src_port == 53) { - b->ip6h.daddr = c->ip6.addr_seen; - b->ip6h.saddr = c->ip6.dns_match; + src = &c->ip6.dns_match; } else if (IN6_IS_ADDR_LOOPBACK(src) || IN6_ARE_ADDR_EQUAL(src, &c->ip6.addr_seen) || IN6_ARE_ADDR_EQUAL(src, &c->ip6.addr)) { - b->ip6h.daddr = c->ip6.addr_ll_seen; - - if (IN6_IS_ADDR_LINKLOCAL(&c->ip6.gw)) - b->ip6h.saddr = c->ip6.gw; - else - b->ip6h.saddr = c->ip6.addr_ll; - udp_tap_map[V6][src_port].ts = now->tv_sec; udp_tap_map[V6][src_port].flags |= PORT_LOCAL; @@ -683,10 +675,17 @@ static size_t udp_update_hdr6(const struct ctx *c, int n, in_port_t dstport, udp_tap_map[V6][src_port].flags &= ~PORT_GUA; bitmap_set(udp_act[V6][UDP_ACT_TAP], src_port); - } else { - b->ip6h.daddr = c->ip6.addr_seen; - b->ip6h.saddr = b->s_in6.sin6_addr; + + dst = &c->ip6.addr_ll_seen; + + if (IN6_IS_ADDR_LINKLOCAL(&c->ip6.gw)) + src = &c->ip6.gw; + else + src = &c->ip6.addr_ll; + } + b->ip6h.daddr = *dst; + b->ip6h.saddr = *src; b->uh.source = b->s_in6.sin6_port; b->uh.dest = htons(dstport);