Even ICMP needs to be updated to use the external MAC address instead
of just the own tap address when applicable. We do that here.
Signed-off-by: Jon Maloy
---
v3: - Adapted to the move of external MAC address from struct flowside
to struct flow_common
v4: - Adapted to name changes in previous commits in this series
v5: - Added conditional lookup in ARP/NDP if the flow's tap_omac is
undefined
---
icmp.c | 8 ++++++--
ndp.c | 2 +-
tap.c | 10 ++++++----
tap.h | 4 ++--
udp.c | 12 ++++++++----
5 files changed, 23 insertions(+), 13 deletions(-)
diff --git a/icmp.c b/icmp.c
index 6dffafb..2d5bf0c 100644
--- a/icmp.c
+++ b/icmp.c
@@ -125,17 +125,21 @@ void icmp_sock_handler(const struct ctx *c, union epoll_ref ref)
flow_dbg(pingf, "echo reply to tap, ID: %"PRIu16", seq: %"PRIu16,
ini->eport, seq);
+ /* Try to find true MAC address in ARP/NDP table if needed */
+ if (mac_undefined(pingf->f.tap_omac))
+ fwd_neigh_mac_get(c, &ini->oaddr, pingf->f.tap_omac);
+
if (pingf->f.type == FLOW_PING4) {
const struct in_addr *saddr = inany_v4(&ini->oaddr);
const struct in_addr *daddr = inany_v4(&ini->eaddr);
ASSERT(saddr && daddr); /* Must have IPv4 addresses */
- tap_icmp4_send(c, *saddr, *daddr, buf, n);
+ tap_icmp4_send(c, *saddr, *daddr, buf, pingf->f.tap_omac, n);
} else if (pingf->f.type == FLOW_PING6) {
const struct in6_addr *saddr = &ini->oaddr.a6;
const struct in6_addr *daddr = &ini->eaddr.a6;
- tap_icmp6_send(c, saddr, daddr, buf, n);
+ tap_icmp6_send(c, saddr, daddr, buf, pingf->f.tap_omac, n);
}
return;
diff --git a/ndp.c b/ndp.c
index 820c556..e0e8938 100644
--- a/ndp.c
+++ b/ndp.c
@@ -184,7 +184,7 @@ static void ndp_send(const struct ctx *c, const struct in6_addr *dst,
{
const struct in6_addr *src = &c->ip6.our_tap_ll;
- tap_icmp6_send(c, src, dst, buf, l4len);
+ tap_icmp6_send(c, src, dst, buf, c->our_tap_mac, l4len);
}
/**
diff --git a/tap.c b/tap.c
index 05429aa..6443812 100644
--- a/tap.c
+++ b/tap.c
@@ -278,13 +278,14 @@ void tap_udp4_send(const struct ctx *c, struct in_addr src, in_port_t sport,
* @src: IPv4 source address
* @dst: IPv4 destination address
* @in: ICMP packet, including ICMP header
+ * @src_mac: MAC address to be used as source for message
* @l4len: ICMP packet length, including ICMP header
*/
void tap_icmp4_send(const struct ctx *c, struct in_addr src, struct in_addr dst,
- const void *in, size_t l4len)
+ const void *in, const void *src_mac, size_t l4len)
{
char buf[USHRT_MAX];
- struct iphdr *ip4h = tap_push_l2h(c, buf, c->our_tap_mac, ETH_P_IP);
+ struct iphdr *ip4h = tap_push_l2h(c, buf, src_mac, ETH_P_IP);
struct icmphdr *icmp4h = tap_push_ip4h(ip4h, src, dst,
l4len, IPPROTO_ICMP);
@@ -385,14 +386,15 @@ void tap_udp6_send(const struct ctx *c,
* @src: IPv6 source address
* @dst: IPv6 destination address
* @in: ICMP packet, including ICMP header
+ * @src_mac: MAC address to be used as source for message
* @l4len: ICMP packet length, including ICMP header
*/
void tap_icmp6_send(const struct ctx *c,
const struct in6_addr *src, const struct in6_addr *dst,
- const void *in, size_t l4len)
+ const void *in, const void *src_mac, size_t l4len)
{
char buf[USHRT_MAX];
- struct ipv6hdr *ip6h = tap_push_l2h(c, buf, c->our_tap_mac, ETH_P_IPV6);
+ struct ipv6hdr *ip6h = tap_push_l2h(c, buf, src_mac, ETH_P_IPV6);
struct icmp6hdr *icmp6h = tap_push_ip6h(ip6h, src, dst, l4len,
IPPROTO_ICMPV6, 0);
diff --git a/tap.h b/tap.h
index 02f7761..1864173 100644
--- a/tap.h
+++ b/tap.h
@@ -91,7 +91,7 @@ void tap_udp4_send(const struct ctx *c, struct in_addr src, in_port_t sport,
struct in_addr dst, in_port_t dport,
const void *in, size_t dlen);
void tap_icmp4_send(const struct ctx *c, struct in_addr src, struct in_addr dst,
- const void *in, size_t l4len);
+ const void *in, const void *src_mac, size_t l4len);
const struct in6_addr *tap_ip6_daddr(const struct ctx *c,
const struct in6_addr *src);
void *tap_push_ip6h(struct ipv6hdr *ip6h,
@@ -103,7 +103,7 @@ void tap_udp6_send(const struct ctx *c,
uint32_t flow, void *in, size_t dlen);
void tap_icmp6_send(const struct ctx *c,
const struct in6_addr *src, const struct in6_addr *dst,
- const void *in, size_t l4len);
+ const void *in, const void *src_mac, size_t l4len);
void tap_send_single(const struct ctx *c, const void *data, size_t l2len);
size_t tap_send_frames(const struct ctx *c, const struct iovec *iov,
size_t bufs_per_frame, size_t nframes);
diff --git a/udp.c b/udp.c
index 7d98845..26f8c22 100644
--- a/udp.c
+++ b/udp.c
@@ -385,6 +385,7 @@ static void udp_tap_prepare(const struct mmsghdr *mmh,
* udp_send_tap_icmp4() - Construct and send ICMPv4 to local peer
* @c: Execution context
* @ee: Extended error descriptor
+ * @uflow: UDP flow
* @toside: Destination side of flow
* @saddr: Address of ICMP generating node
* @in: First bytes (max 8) of original UDP message body
@@ -392,6 +393,7 @@ static void udp_tap_prepare(const struct mmsghdr *mmh,
*/
static void udp_send_tap_icmp4(const struct ctx *c,
const struct sock_extended_err *ee,
+ const struct udp_flow *uflow,
const struct flowside *toside,
struct in_addr saddr,
const void *in, size_t dlen)
@@ -421,7 +423,7 @@ static void udp_send_tap_icmp4(const struct ctx *c,
tap_push_uh4(&msg.uh, eaddr, eport, oaddr, oport, in, dlen);
memcpy(&msg.data, in, dlen);
- tap_icmp4_send(c, saddr, eaddr, &msg, msglen);
+ tap_icmp4_send(c, saddr, eaddr, &msg, uflow->f.tap_omac, msglen);
}
@@ -429,6 +431,7 @@ static void udp_send_tap_icmp4(const struct ctx *c,
* udp_send_tap_icmp6() - Construct and send ICMPv6 to local peer
* @c: Execution context
* @ee: Extended error descriptor
+ * @uflow: UDP flow
* @toside: Destination side of flow
* @saddr: Address of ICMP generating node
* @in: First bytes (max 1232) of original UDP message body
@@ -437,6 +440,7 @@ static void udp_send_tap_icmp4(const struct ctx *c,
*/
static void udp_send_tap_icmp6(const struct ctx *c,
const struct sock_extended_err *ee,
+ const struct udp_flow *uflow,
const struct flowside *toside,
const struct in6_addr *saddr,
void *in, size_t dlen, uint32_t flow)
@@ -466,7 +470,7 @@ static void udp_send_tap_icmp6(const struct ctx *c,
tap_push_uh6(&msg.uh, eaddr, eport, oaddr, oport, in, dlen);
memcpy(&msg.data, in, dlen);
- tap_icmp6_send(c, saddr, eaddr, &msg, msglen);
+ tap_icmp6_send(c, saddr, eaddr, &msg, uflow->f.tap_omac, msglen);
}
/**
@@ -626,12 +630,12 @@ static int udp_sock_recverr(const struct ctx *c, int s, flow_sidx_t sidx,
if (hdr->cmsg_level == IPPROTO_IP &&
(o4 = inany_v4(&otap)) && inany_v4(&toside->eaddr)) {
dlen = MIN(dlen, ICMP4_MAX_DLEN);
- udp_send_tap_icmp4(c, ee, toside, *o4, data, dlen);
+ udp_send_tap_icmp4(c, ee, uflow, toside, *o4, data, dlen);
return 1;
}
if (hdr->cmsg_level == IPPROTO_IPV6 && !inany_v4(&toside->eaddr)) {
- udp_send_tap_icmp6(c, ee, toside, &otap.a6, data, dlen,
+ udp_send_tap_icmp6(c, ee, uflow, toside, &otap.a6, data, dlen,
FLOW_IDX(uflow));
return 1;
}
--
2.50.1