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flow_dissector: Move GRE dissection into a separate function
Make the main flow_dissect function a bit smaller and move the GRE dissection into a separate function. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jiri Pirko
David S. Miller
parent
c5ef188e93
commit
7c92de8eaa
@ -116,6 +116,7 @@ EXPORT_SYMBOL(__skb_flow_get_ports);
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enum flow_dissect_ret {
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FLOW_DISSECT_RET_OUT_GOOD,
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FLOW_DISSECT_RET_OUT_BAD,
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FLOW_DISSECT_RET_OUT_PROTO_AGAIN,
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};
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static enum flow_dissect_ret
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@ -200,6 +201,128 @@ __skb_flow_dissect_arp(const struct sk_buff *skb,
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return FLOW_DISSECT_RET_OUT_GOOD;
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}
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static enum flow_dissect_ret
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__skb_flow_dissect_gre(const struct sk_buff *skb,
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struct flow_dissector_key_control *key_control,
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struct flow_dissector *flow_dissector,
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void *target_container, void *data,
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__be16 *p_proto, int *p_nhoff, int *p_hlen,
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unsigned int flags)
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{
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struct flow_dissector_key_keyid *key_keyid;
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struct gre_base_hdr *hdr, _hdr;
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int offset = 0;
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u16 gre_ver;
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hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
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data, *p_hlen, &_hdr);
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if (!hdr)
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return FLOW_DISSECT_RET_OUT_BAD;
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/* Only look inside GRE without routing */
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if (hdr->flags & GRE_ROUTING)
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return FLOW_DISSECT_RET_OUT_GOOD;
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/* Only look inside GRE for version 0 and 1 */
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gre_ver = ntohs(hdr->flags & GRE_VERSION);
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if (gre_ver > 1)
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return FLOW_DISSECT_RET_OUT_GOOD;
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*p_proto = hdr->protocol;
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if (gre_ver) {
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/* Version1 must be PPTP, and check the flags */
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if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
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return FLOW_DISSECT_RET_OUT_GOOD;
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}
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offset += sizeof(struct gre_base_hdr);
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if (hdr->flags & GRE_CSUM)
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offset += sizeof(((struct gre_full_hdr *) 0)->csum) +
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sizeof(((struct gre_full_hdr *) 0)->reserved1);
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if (hdr->flags & GRE_KEY) {
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const __be32 *keyid;
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__be32 _keyid;
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keyid = __skb_header_pointer(skb, *p_nhoff + offset,
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sizeof(_keyid),
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data, *p_hlen, &_keyid);
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if (!keyid)
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return FLOW_DISSECT_RET_OUT_BAD;
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if (dissector_uses_key(flow_dissector,
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FLOW_DISSECTOR_KEY_GRE_KEYID)) {
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key_keyid = skb_flow_dissector_target(flow_dissector,
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FLOW_DISSECTOR_KEY_GRE_KEYID,
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target_container);
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if (gre_ver == 0)
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key_keyid->keyid = *keyid;
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else
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key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
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}
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offset += sizeof(((struct gre_full_hdr *) 0)->key);
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}
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if (hdr->flags & GRE_SEQ)
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offset += sizeof(((struct pptp_gre_header *) 0)->seq);
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if (gre_ver == 0) {
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if (*p_proto == htons(ETH_P_TEB)) {
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const struct ethhdr *eth;
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struct ethhdr _eth;
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eth = __skb_header_pointer(skb, *p_nhoff + offset,
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sizeof(_eth),
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data, *p_hlen, &_eth);
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if (!eth)
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return FLOW_DISSECT_RET_OUT_BAD;
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*p_proto = eth->h_proto;
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offset += sizeof(*eth);
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/* Cap headers that we access via pointers at the
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* end of the Ethernet header as our maximum alignment
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* at that point is only 2 bytes.
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*/
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if (NET_IP_ALIGN)
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*p_hlen = *p_nhoff + offset;
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}
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} else { /* version 1, must be PPTP */
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u8 _ppp_hdr[PPP_HDRLEN];
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u8 *ppp_hdr;
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if (hdr->flags & GRE_ACK)
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offset += sizeof(((struct pptp_gre_header *) 0)->ack);
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ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
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sizeof(_ppp_hdr),
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data, *p_hlen, _ppp_hdr);
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if (!ppp_hdr)
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return FLOW_DISSECT_RET_OUT_BAD;
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switch (PPP_PROTOCOL(ppp_hdr)) {
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case PPP_IP:
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*p_proto = htons(ETH_P_IP);
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break;
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case PPP_IPV6:
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*p_proto = htons(ETH_P_IPV6);
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break;
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default:
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/* Could probably catch some more like MPLS */
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break;
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}
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offset += PPP_HDRLEN;
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}
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*p_nhoff += offset;
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key_control->flags |= FLOW_DIS_ENCAPSULATION;
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if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
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return FLOW_DISSECT_RET_OUT_GOOD;
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return FLOW_DISSECT_RET_OUT_PROTO_AGAIN;
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}
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/**
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* __skb_flow_dissect - extract the flow_keys struct and return it
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* @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
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@ -229,7 +352,6 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
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struct flow_dissector_key_icmp *key_icmp;
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struct flow_dissector_key_tags *key_tags;
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struct flow_dissector_key_vlan *key_vlan;
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struct flow_dissector_key_keyid *key_keyid;
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bool skip_vlan = false;
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u8 ip_proto = 0;
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bool ret;
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@ -443,6 +565,7 @@ mpls:
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case FLOW_DISSECT_RET_OUT_GOOD:
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goto out_good;
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case FLOW_DISSECT_RET_OUT_BAD:
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default:
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goto out_bad;
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}
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case htons(ETH_P_FCOE):
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@ -460,6 +583,7 @@ mpls:
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case FLOW_DISSECT_RET_OUT_GOOD:
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goto out_good;
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case FLOW_DISSECT_RET_OUT_BAD:
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default:
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goto out_bad;
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}
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default:
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@ -468,117 +592,17 @@ mpls:
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ip_proto_again:
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switch (ip_proto) {
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case IPPROTO_GRE: {
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struct gre_base_hdr *hdr, _hdr;
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u16 gre_ver;
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int offset = 0;
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hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
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if (!hdr)
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case IPPROTO_GRE:
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switch (__skb_flow_dissect_gre(skb, key_control, flow_dissector,
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target_container, data,
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&proto, &nhoff, &hlen, flags)) {
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case FLOW_DISSECT_RET_OUT_GOOD:
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goto out_good;
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case FLOW_DISSECT_RET_OUT_BAD:
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goto out_bad;
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/* Only look inside GRE without routing */
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if (hdr->flags & GRE_ROUTING)
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goto out_good;
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/* Only look inside GRE for version 0 and 1 */
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gre_ver = ntohs(hdr->flags & GRE_VERSION);
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if (gre_ver > 1)
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goto out_good;
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proto = hdr->protocol;
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if (gre_ver) {
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/* Version1 must be PPTP, and check the flags */
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if (!(proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
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goto out_good;
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case FLOW_DISSECT_RET_OUT_PROTO_AGAIN:
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goto proto_again;
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}
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offset += sizeof(struct gre_base_hdr);
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if (hdr->flags & GRE_CSUM)
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offset += sizeof(((struct gre_full_hdr *)0)->csum) +
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sizeof(((struct gre_full_hdr *)0)->reserved1);
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if (hdr->flags & GRE_KEY) {
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const __be32 *keyid;
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__be32 _keyid;
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keyid = __skb_header_pointer(skb, nhoff + offset, sizeof(_keyid),
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data, hlen, &_keyid);
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if (!keyid)
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goto out_bad;
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if (dissector_uses_key(flow_dissector,
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FLOW_DISSECTOR_KEY_GRE_KEYID)) {
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key_keyid = skb_flow_dissector_target(flow_dissector,
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FLOW_DISSECTOR_KEY_GRE_KEYID,
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target_container);
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if (gre_ver == 0)
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key_keyid->keyid = *keyid;
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else
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key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
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}
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offset += sizeof(((struct gre_full_hdr *)0)->key);
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}
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if (hdr->flags & GRE_SEQ)
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offset += sizeof(((struct pptp_gre_header *)0)->seq);
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if (gre_ver == 0) {
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if (proto == htons(ETH_P_TEB)) {
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const struct ethhdr *eth;
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struct ethhdr _eth;
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eth = __skb_header_pointer(skb, nhoff + offset,
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sizeof(_eth),
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data, hlen, &_eth);
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if (!eth)
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goto out_bad;
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proto = eth->h_proto;
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offset += sizeof(*eth);
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/* Cap headers that we access via pointers at the
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* end of the Ethernet header as our maximum alignment
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* at that point is only 2 bytes.
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*/
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if (NET_IP_ALIGN)
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hlen = (nhoff + offset);
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}
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} else { /* version 1, must be PPTP */
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u8 _ppp_hdr[PPP_HDRLEN];
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u8 *ppp_hdr;
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if (hdr->flags & GRE_ACK)
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offset += sizeof(((struct pptp_gre_header *)0)->ack);
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ppp_hdr = __skb_header_pointer(skb, nhoff + offset,
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sizeof(_ppp_hdr),
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data, hlen, _ppp_hdr);
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if (!ppp_hdr)
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goto out_bad;
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switch (PPP_PROTOCOL(ppp_hdr)) {
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case PPP_IP:
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proto = htons(ETH_P_IP);
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break;
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case PPP_IPV6:
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proto = htons(ETH_P_IPV6);
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break;
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default:
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/* Could probably catch some more like MPLS */
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break;
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}
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offset += PPP_HDRLEN;
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}
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nhoff += offset;
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key_control->flags |= FLOW_DIS_ENCAPSULATION;
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if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
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goto out_good;
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goto proto_again;
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}
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case NEXTHDR_HOP:
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case NEXTHDR_ROUTING:
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case NEXTHDR_DEST: {
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