DO NOT MERGE: Support translating fragmented packets.

Bug: 11542311
Change-Id: I5dd29805e12b919ae3105b6128aaedefd7e78b48
diff --git a/translate.h b/translate.h
index 3378254..5efa817 100644
--- a/translate.h
+++ b/translate.h
@@ -36,9 +36,11 @@
 // The CLAT_POS_XXX constants represent the array indices within the clat_packet that contain
 // specific parts of the packet. The packet_* functions operate on all the packet segments past a
 // given position.
-enum clat_packet_index { CLAT_POS_TUNHDR, CLAT_POS_IPHDR, CLAT_POS_TRANSPORTHDR,
-                         CLAT_POS_ICMPERR_IPHDR, CLAT_POS_ICMPERR_TRANSPORTHDR,
-                         CLAT_POS_PAYLOAD, CLAT_POS_MAX };
+enum clat_packet_index {
+    CLAT_POS_TUNHDR, CLAT_POS_IPHDR, CLAT_POS_FRAGHDR, CLAT_POS_TRANSPORTHDR,
+    CLAT_POS_ICMPERR_IPHDR, CLAT_POS_ICMPERR_FRAGHDR, CLAT_POS_ICMPERR_TRANSPORTHDR,
+    CLAT_POS_PAYLOAD, CLAT_POS_MAX
+};
 typedef struct iovec clat_packet[CLAT_POS_MAX];
 
 // Calculates the checksum over all the packet components starting from pos.
@@ -65,6 +67,11 @@
 int ipv4_packet(clat_packet out, int pos, const char *packet, size_t len);
 int ipv6_packet(clat_packet out, int pos, const char *packet, size_t len);
 
+// Deal with fragmented packets.
+size_t maybe_fill_frag_header(struct ip6_frag *frag_hdr, struct ip6_hdr *ip6_targ,
+                              const struct iphdr *old_header);
+uint8_t parse_frag_header(const struct ip6_frag *frag_hdr, struct iphdr *ip_targ);
+
 // Translate ICMP packets.
 int icmp_to_icmp6(clat_packet out, int pos, const struct icmphdr *icmp, uint32_t checksum,
                   const char *payload, size_t payload_size);