+ int tcp_len;
+
+ if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr))))
+ return false;
+
+ tcp_len = tcp_hdrlen(skb);
+ if (unlikely(tcp_len < sizeof(struct tcphdr) ||
+ skb->len < th_ofs + tcp_len))
+ return false;
+
+ return true;
+}
+
+static bool udphdr_ok(struct sk_buff *skb)
+{
+ return pskb_may_pull(skb, skb_transport_offset(skb) +
+ sizeof(struct udphdr));
+}
+
+static bool icmphdr_ok(struct sk_buff *skb)
+{
+ return pskb_may_pull(skb, skb_transport_offset(skb) +
+ sizeof(struct icmphdr));
+}
+
+u64 flow_used_time(unsigned long flow_jiffies)
+{
+ struct timespec cur_ts;
+ u64 cur_ms, idle_ms;
+
+ ktime_get_ts(&cur_ts);
+ idle_ms = jiffies_to_msecs(jiffies - flow_jiffies);
+ cur_ms = (u64)cur_ts.tv_sec * MSEC_PER_SEC +
+ cur_ts.tv_nsec / NSEC_PER_MSEC;
+
+ return cur_ms - idle_ms;
+}
+
+#define SW_FLOW_KEY_OFFSET(field) \
+ (offsetof(struct sw_flow_key, field) + \
+ FIELD_SIZEOF(struct sw_flow_key, field))
+
+/**
+ * skip_exthdr - skip any IPv6 extension headers
+ * @skb: skbuff to parse
+ * @start: offset of first extension header
+ * @nexthdrp: Initially, points to the type of the extension header at @start.
+ * This function updates it to point to the extension header at the final
+ * offset.
+ * @frag: Points to the @frag member in a &struct sw_flow_key. This
+ * function sets an appropriate %OVS_FRAG_TYPE_* value.
+ *
+ * This is based on ipv6_skip_exthdr() but adds the updates to *@frag.
+ *
+ * When there is more than one fragment header, this version reports whether
+ * the final fragment header that it examines is a first fragment.
+ *
+ * Returns the final payload offset, or -1 on error.
+ */
+static int skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp,
+ u8 *frag)
+{
+ u8 nexthdr = *nexthdrp;
+
+ while (ipv6_ext_hdr(nexthdr)) {
+ struct ipv6_opt_hdr _hdr, *hp;
+ int hdrlen;
+
+ if (nexthdr == NEXTHDR_NONE)
+ return -1;
+ hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
+ if (hp == NULL)
+ return -1;
+ if (nexthdr == NEXTHDR_FRAGMENT) {
+ __be16 _frag_off, *fp;
+ fp = skb_header_pointer(skb,
+ start+offsetof(struct frag_hdr,
+ frag_off),
+ sizeof(_frag_off),
+ &_frag_off);
+ if (fp == NULL)
+ return -1;
+
+ if (ntohs(*fp) & ~0x7) {
+ *frag = OVS_FRAG_TYPE_LATER;
+ break;
+ }
+ *frag = OVS_FRAG_TYPE_FIRST;
+ hdrlen = 8;
+ } else if (nexthdr == NEXTHDR_AUTH)
+ hdrlen = (hp->hdrlen+2)<<2;
+ else
+ hdrlen = ipv6_optlen(hp);
+
+ nexthdr = hp->nexthdr;
+ start += hdrlen;