Merge changes I67ba0379,Iced00bb4
* changes:
clatd - preparation for ipv6 to ipv4 fragmentation translation
clatd - pull in more fragmentation related stuff from kernel headers
diff --git a/bpf_progs/clatd.c b/bpf_progs/clatd.c
index d0e41ee..3ac0603 100644
--- a/bpf_progs/clatd.c
+++ b/bpf_progs/clatd.c
@@ -38,8 +38,19 @@
#include "bpf_shared.h"
#include "clat_mark.h"
-// From kernel:include/net/ip.h
-#define IP_DF 0x4000 // Flag: "Don't Fragment"
+// IP flags. (from kernel's include/net/ip.h)
+#define IP_CE 0x8000 // Flag: "Congestion" (really reserved 'evil bit')
+#define IP_DF 0x4000 // Flag: "Don't Fragment"
+#define IP_MF 0x2000 // Flag: "More Fragments"
+#define IP_OFFSET 0x1FFF // "Fragment Offset" part
+
+// from kernel's include/net/ipv6.h
+struct frag_hdr {
+ __u8 nexthdr;
+ __u8 reserved; // always zero
+ __be16 frag_off; // 13 bit offset, 2 bits zero, 1 bit "More Fragments"
+ __be32 identification;
+};
DEFINE_BPF_MAP_GRW(clat_ingress6_map, HASH, ClatIngress6Key, ClatIngress6Value, 16, AID_SYSTEM)
@@ -89,7 +100,11 @@
if (!v) return TC_ACT_PIPE;
- switch (ip6->nexthdr) {
+ __u8 proto = ip6->nexthdr;
+ __be16 ip_id = 0;
+ __be16 frag_off = htons(IP_DF);
+
+ switch (proto) {
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,
@@ -114,14 +129,14 @@
.version = 4, // u4
.ihl = sizeof(struct iphdr) / sizeof(__u32), // u4
.tos = (ip6->priority << 4) + (ip6->flow_lbl[0] >> 4), // u8
- .tot_len = htons(ntohs(ip6->payload_len) + sizeof(struct iphdr)), // u16
- .id = 0, // u16
- .frag_off = htons(IP_DF), // u16
+ .tot_len = htons(ntohs(ip6->payload_len) + sizeof(struct iphdr)), // be16
+ .id = ip_id, // be16
+ .frag_off = frag_off, // be16
.ttl = ip6->hop_limit, // u8
- .protocol = ip6->nexthdr, // u8
+ .protocol = proto, // u8
.check = 0, // u16
- .saddr = ip6->saddr.in6_u.u6_addr32[3], // u32
- .daddr = v->local4.s_addr, // u32
+ .saddr = ip6->saddr.in6_u.u6_addr32[3], // be32
+ .daddr = v->local4.s_addr, // be32
};
// Calculate the IPv4 one's complement checksum of the IPv4 header.