Merge "Set mark on non-offloaded ingress clat traffic" am: 49bcf60592 am: 3bc334e71b
Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2052985
Change-Id: Ifa10a9ea4a364ab36a59b50e3ca7435d0e92069a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/bpf_progs/clatd.c b/bpf_progs/clatd.c
index dc646c3..55165b1 100644
--- a/bpf_progs/clatd.c
+++ b/bpf_progs/clatd.c
@@ -37,6 +37,12 @@
// From kernel:include/net/ip.h
#define IP_DF 0x4000 // Flag: "Don't Fragment"
+// Used for iptables drops ingress clat packet. Beware of clat mark change may break the device
+// which is using the old clat mark in netd platform code. The reason is that the clat mark is a
+// mainline constant since T+ but netd iptable rules (ex: bandwidth control, firewall, and so on)
+// are set in stone.
+#define CLAT_MARK 0xdeadc1a7
+
DEFINE_BPF_MAP_GRW(clat_ingress6_map, HASH, ClatIngress6Key, ClatIngress6Value, 16, AID_SYSTEM)
static inline __always_inline int nat64(struct __sk_buff* skb, bool is_ethernet) {
@@ -64,17 +70,6 @@
// Maximum IPv6 payload length that can be translated to IPv4
if (ntohs(ip6->payload_len) > 0xFFFF - sizeof(struct iphdr)) return TC_ACT_PIPE;
- switch (ip6->nexthdr) {
- case IPPROTO_TCP: // For TCP & UDP the checksum neutrality of the chosen IPv6
- case IPPROTO_UDP: // address means there is no need to update their checksums.
- case IPPROTO_GRE: // We do not need to bother looking at GRE/ESP headers,
- case IPPROTO_ESP: // since there is never a checksum to update.
- break;
-
- default: // do not know how to handle anything else
- return TC_ACT_PIPE;
- }
-
ClatIngress6Key k = {
.iif = skb->ifindex,
.pfx96.in6_u.u6_addr32 =
@@ -90,6 +85,21 @@
if (!v) return TC_ACT_PIPE;
+ switch (ip6->nexthdr) {
+ case IPPROTO_TCP: // For TCP & UDP the checksum neutrality of the chosen IPv6
+ case IPPROTO_UDP: // address means there is no need to update their checksums.
+ case IPPROTO_GRE: // We do not need to bother looking at GRE/ESP headers,
+ case IPPROTO_ESP: // since there is never a checksum to update.
+ break;
+
+ default: // do not know how to handle anything else
+ // Mark ingress non-offloaded clat packet for dropping in ip6tables bw_raw_PREROUTING.
+ // Non-offloaded clat packet is going to be handled by clat daemon and ip6tables. The
+ // duplicate one in ip6tables is not necessary.
+ skb->mark = CLAT_MARK;
+ return TC_ACT_PIPE;
+ }
+
struct ethhdr eth2; // used iff is_ethernet
if (is_ethernet) {
eth2 = *eth; // Copy over the ethernet header (src/dst mac)
@@ -132,7 +142,13 @@
// Packet mutations begin - point of no return, but if this first modification fails
// the packet is probably still pristine, so let clatd handle it.
- if (bpf_skb_change_proto(skb, htons(ETH_P_IP), 0)) return TC_ACT_PIPE;
+ if (bpf_skb_change_proto(skb, htons(ETH_P_IP), 0)) {
+ // Mark ingress non-offloaded clat packet for dropping in ip6tables bw_raw_PREROUTING.
+ // Non-offloaded clat packet is going to be handled by clat daemon and ip6tables. The
+ // duplicate one in ip6tables is not necessary.
+ skb->mark = CLAT_MARK;
+ return TC_ACT_PIPE;
+ }
// This takes care of updating the skb->csum field for a CHECKSUM_COMPLETE packet.
//