diff --git a/udp.c b/udp.c index bb7d161..cc938bb 100644 --- a/udp.c +++ b/udp.c @@ -592,6 +592,7 @@ static size_t udp_update_hdr4(const struct ctx *c, struct udp4_l2_buf_t *b, in_port_t dstport, size_t dlen, const struct timespec *now) { + const struct in_addr dst = c->ip4.addr_seen; size_t l4len = dlen + sizeof(b->uh); size_t l3len = l4len + sizeof(b->iph); in_port_t srcport = ntohs(b->s_in.sin_port); @@ -617,14 +618,14 @@ static size_t udp_update_hdr4(const struct ctx *c, struct udp4_l2_buf_t *b, } b->iph.tot_len = htons(l3len); - b->iph.daddr = c->ip4.addr_seen.s_addr; + b->iph.daddr = dst.s_addr; b->iph.saddr = src.s_addr; - b->iph.check = csum_ip4_header(l3len, IPPROTO_UDP, - src, c->ip4.addr_seen); + b->iph.check = csum_ip4_header(l3len, IPPROTO_UDP, src, dst); b->uh.source = b->s_in.sin_port; b->uh.dest = htons(dstport); b->uh.len = htons(l4len); + csum_udp4(&b->uh, src, dst, b->data, dlen); tap_hdr_update(&b->taph, l3len + sizeof(b->eh)); return l4len;