These functions take an index to the L2 buffer whose header information to
update. They use that for two things: to locate the buffer pointer itself,
and to retrieve the length of the received message from the paralllel
udp[46]_l2_mh_sock array. The latter is arguably a failure to separate
concerns. Change these functions to explicitly take a buffer pointer and
payload length as parameters.
Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au>
---
udp.c | 46 ++++++++++++++++++++--------------------------
1 file changed, 20 insertions(+), 26 deletions(-)
diff --git a/udp.c b/udp.c
index 092d343e..e3c51bae 100644
--- a/udp.c
+++ b/udp.c
@@ -576,28 +576,24 @@ 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
- * @n: Index of buffer in udp4_l2_buf pool
+ * @b: Pointer to udp4_l2_buf to update
* @dstport: Destination port number
+ * @datalen: Length of UDP payload
* @now: Current timestamp
*
* Return: size of tap frame with headers
*/
-static size_t udp_update_hdr4(const struct ctx *c, int n, in_port_t dstport,
+static size_t udp_update_hdr4(const struct ctx *c, struct udp4_l2_buf_t *b,
+ in_port_t dstport, size_t datalen,
const struct timespec *now)
{
- struct udp4_l2_buf_t *b = &udp4_l2_buf[n];
- struct in_addr *src;
- in_port_t src_port;
- size_t ip_len;
-
- ip_len = udp4_l2_mh_sock[n].msg_len + sizeof(b->iph) + sizeof(b->uh);
+ size_t ip_len = datalen + sizeof(b->iph) + sizeof(b->uh);
+ in_port_t src_port = ntohs(b->s_in.sin_port);
+ struct in_addr *src = &b->s_in.sin_addr;
b->iph.tot_len = htons(ip_len);
b->iph.daddr = c->ip4.addr_seen.s_addr;
- src = &b->s_in.sin_addr;
- src_port = ntohs(b->s_in.sin_port);
-
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;
@@ -620,7 +616,7 @@ static size_t udp_update_hdr4(const struct ctx *c, int n, in_port_t
dstport,
udp_update_check4(b);
b->uh.source = b->s_in.sin_port;
b->uh.dest = htons(dstport);
- b->uh.len = htons(udp4_l2_mh_sock[n].msg_len + sizeof(b->uh));
+ b->uh.len = htons(datalen + sizeof(b->uh));
return tap_iov_len(c, &b->taph, ip_len);
}
@@ -628,26 +624,22 @@ static size_t udp_update_hdr4(const struct ctx *c, int n, in_port_t
dstport,
/**
* udp_update_hdr6() - Update headers for one IPv6 datagram
* @c: Execution context
- * @n: Index of buffer in udp6_l2_buf pool
+ * @b: Pointer to udp6_l2_buf to update
* @dstport: Destination port number
+ * @datalen: Length of UDP payload
* @now: Current timestamp
*
* Return: size of tap frame with headers
*/
-static size_t udp_update_hdr6(const struct ctx *c, int n, in_port_t dstport,
+static size_t udp_update_hdr6(const struct ctx *c, struct udp6_l2_buf_t *b,
+ in_port_t dstport, size_t datalen,
const struct timespec *now)
{
- struct udp6_l2_buf_t *b = &udp6_l2_buf[n];
- struct in6_addr *src;
- in_port_t src_port;
- size_t ip_len;
-
- src = &b->s_in6.sin6_addr;
- src_port = ntohs(b->s_in6.sin6_port);
-
- ip_len = udp6_l2_mh_sock[n].msg_len + sizeof(b->ip6h) + sizeof(b->uh);
+ size_t ip_len = datalen + sizeof(b->ip6h) + sizeof(b->uh);
+ in_port_t src_port = ntohs(b->s_in6.sin6_port);
+ struct in6_addr *src = &b->s_in6.sin6_addr;
- b->ip6h.payload_len = htons(udp6_l2_mh_sock[n].msg_len + sizeof(b->uh));
+ b->ip6h.payload_len = htons(datalen + sizeof(b->uh));
if (IN6_IS_ADDR_LINKLOCAL(src)) {
b->ip6h.daddr = c->ip6.addr_ll_seen;
@@ -727,9 +719,11 @@ static void udp_tap_send(const struct ctx *c,
size_t buf_len;
if (v6)
- buf_len = udp_update_hdr6(c, i, dstport, now);
+ buf_len = udp_update_hdr6(c, &udp6_l2_buf[i], dstport,
+ udp6_l2_mh_sock[i].msg_len, now);
else
- buf_len = udp_update_hdr4(c, i, dstport, now);
+ buf_len = udp_update_hdr4(c, &udp4_l2_buf[i], dstport,
+ udp4_l2_mh_sock[i].msg_len, now);
tap_iov[i].iov_len = buf_len;
}
--
2.44.0