- return NULL;
-
-found:
- *mutable = lookup.mutable;
- return gre_vport_to_vport(gre_vport_table_cast(tbl_node));
-}
-
-static bool
-check_ipv4_address(__be32 addr)
-{
- if (ipv4_is_multicast(addr) || ipv4_is_lbcast(addr)
- || ipv4_is_loopback(addr) || ipv4_is_zeronet(addr))
- return false;
-
- return true;
-}
-
-static bool
-ipv4_should_icmp(struct sk_buff *skb)
-{
- struct iphdr *old_iph = ip_hdr(skb);
-
- /* Don't respond to L2 broadcast. */
- if (is_multicast_ether_addr(eth_hdr(skb)->h_dest))
- return false;
-
- /* Don't respond to L3 broadcast or invalid addresses. */
- if (!check_ipv4_address(old_iph->daddr) ||
- !check_ipv4_address(old_iph->saddr))
- return false;
-
- /* Only respond to the first fragment. */
- if (old_iph->frag_off & htons(IP_OFFSET))
- return false;
-
- /* Don't respond to ICMP error messages. */
- if (old_iph->protocol == IPPROTO_ICMP) {
- u8 icmp_type, *icmp_typep;
-
- icmp_typep = skb_header_pointer(skb, (u8 *)old_iph +
- (old_iph->ihl << 2) +
- offsetof(struct icmphdr, type) -
- skb->data, sizeof(icmp_type),
- &icmp_type);
-
- if (!icmp_typep)
- return false;
-
- if (*icmp_typep > NR_ICMP_TYPES
- || (*icmp_typep <= ICMP_PARAMETERPROB
- && *icmp_typep != ICMP_ECHOREPLY
- && *icmp_typep != ICMP_ECHO))
- return false;
- }
-
- return true;
-}
-
-static void
-ipv4_build_icmp(struct sk_buff *skb, struct sk_buff *nskb,
- unsigned int mtu, unsigned int payload_length)
-{
- struct iphdr *iph, *old_iph = ip_hdr(skb);
- struct icmphdr *icmph;
- u8 *payload;
-
- iph = (struct iphdr *)skb_put(nskb, sizeof(struct iphdr));
- icmph = (struct icmphdr *)skb_put(nskb, sizeof(struct icmphdr));
- payload = skb_put(nskb, payload_length);
-
- /* IP */
- iph->version = 4;
- iph->ihl = sizeof(struct iphdr) >> 2;
- iph->tos = (old_iph->tos & IPTOS_TOS_MASK) |
- IPTOS_PREC_INTERNETCONTROL;
- iph->tot_len = htons(sizeof(struct iphdr)
- + sizeof(struct icmphdr)
- + payload_length);
- get_random_bytes(&iph->id, sizeof(iph->id));
- iph->frag_off = 0;
- iph->ttl = IPDEFTTL;
- iph->protocol = IPPROTO_ICMP;
- iph->daddr = old_iph->saddr;
- iph->saddr = old_iph->daddr;
-
- ip_send_check(iph);
-
- /* ICMP */
- icmph->type = ICMP_DEST_UNREACH;
- icmph->code = ICMP_FRAG_NEEDED;
- icmph->un.gateway = htonl(mtu);
- icmph->checksum = 0;
-
- nskb->csum = csum_partial((u8 *)icmph, sizeof(struct icmphdr), 0);
- nskb->csum = skb_copy_and_csum_bits(skb, (u8 *)old_iph - skb->data,
- payload, payload_length,
- nskb->csum);
- icmph->checksum = csum_fold(nskb->csum);
-}
-
-static bool
-ipv6_should_icmp(struct sk_buff *skb)
-{
- struct ipv6hdr *old_ipv6h = ipv6_hdr(skb);
- int addr_type;
- int payload_off = (u8 *)(old_ipv6h + 1) - skb->data;
- u8 nexthdr = ipv6_hdr(skb)->nexthdr;
-
- /* Check source address is valid. */
- addr_type = ipv6_addr_type(&old_ipv6h->saddr);
- if (addr_type & IPV6_ADDR_MULTICAST || addr_type == IPV6_ADDR_ANY)
- return false;
-
- /* Don't reply to unspecified addresses. */
- if (ipv6_addr_type(&old_ipv6h->daddr) == IPV6_ADDR_ANY)
- return false;
-
- /* Don't respond to ICMP error messages. */
- payload_off = ipv6_skip_exthdr(skb, payload_off, &nexthdr);
- if (payload_off < 0)
- return false;
-
- if (nexthdr == NEXTHDR_ICMP) {
- u8 icmp_type, *icmp_typep;
-
- icmp_typep = skb_header_pointer(skb, payload_off +
- offsetof(struct icmp6hdr,
- icmp6_type),
- sizeof(icmp_type), &icmp_type);
-
- if (!icmp_typep || !(*icmp_typep & ICMPV6_INFOMSG_MASK))
- return false;
- }
-
- return true;
-}
-
-static void
-ipv6_build_icmp(struct sk_buff *skb, struct sk_buff *nskb, unsigned int mtu,
- unsigned int payload_length)
-{
- struct ipv6hdr *ipv6h, *old_ipv6h = ipv6_hdr(skb);
- struct icmp6hdr *icmp6h;
- u8 *payload;
-
- ipv6h = (struct ipv6hdr *)skb_put(nskb, sizeof(struct ipv6hdr));
- icmp6h = (struct icmp6hdr *)skb_put(nskb, sizeof(struct icmp6hdr));
- payload = skb_put(nskb, payload_length);
-
- /* IPv6 */
- ipv6h->version = 6;
- ipv6h->priority = 0;
- memset(&ipv6h->flow_lbl, 0, sizeof(ipv6h->flow_lbl));
- ipv6h->payload_len = htons(sizeof(struct icmp6hdr)
- + payload_length);
- ipv6h->nexthdr = NEXTHDR_ICMP;
- ipv6h->hop_limit = IPV6_DEFAULT_HOPLIMIT;
- ipv6_addr_copy(&ipv6h->daddr, &old_ipv6h->saddr);
- ipv6_addr_copy(&ipv6h->saddr, &old_ipv6h->daddr);
-
- /* ICMPv6 */
- icmp6h->icmp6_type = ICMPV6_PKT_TOOBIG;
- icmp6h->icmp6_code = 0;
- icmp6h->icmp6_cksum = 0;
- icmp6h->icmp6_mtu = htonl(mtu);
-
- nskb->csum = csum_partial((u8 *)icmp6h, sizeof(struct icmp6hdr), 0);
- nskb->csum = skb_copy_and_csum_bits(skb, (u8 *)old_ipv6h - skb->data,
- payload, payload_length,
- nskb->csum);
- icmp6h->icmp6_cksum = csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
- sizeof(struct icmp6hdr)
- + payload_length,
- ipv6h->nexthdr, nskb->csum);
-}
-
-static bool
-send_frag_needed(struct vport *vport, const struct mutable_config *mutable,
- struct sk_buff *skb, unsigned int mtu, __be32 flow_key)
-{
- unsigned int eth_hdr_len = ETH_HLEN;
- unsigned int total_length, header_length, payload_length;
- struct ethhdr *eh, *old_eh = eth_hdr(skb);
- struct sk_buff *nskb;
-
- /* Sanity check */
- if (skb->protocol == htons(ETH_P_IP)) {
- if (mtu < IP_MIN_MTU)
- return false;
-
- if (!ipv4_should_icmp(skb))
- return true;
- } else {
- if (mtu < IPV6_MIN_MTU)
- return false;
-
- /* In theory we should do PMTUD on IPv6 multicast messages but
- * we don't have an address to send from so just fragment. */
- if (ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST)
- return false;
-
- if (!ipv6_should_icmp(skb))
- return true;
- }
-
- /* Allocate */
- if (old_eh->h_proto == htons(ETH_P_8021Q))
- eth_hdr_len = VLAN_ETH_HLEN;
-
- payload_length = skb->len - eth_hdr_len;
- if (skb->protocol == htons(ETH_P_IP)) {
- header_length = sizeof(struct iphdr) + sizeof(struct icmphdr);
- total_length = min_t(unsigned int, header_length +
- payload_length, 576);
- } else {
- header_length = sizeof(struct ipv6hdr) +
- sizeof(struct icmp6hdr);
- total_length = min_t(unsigned int, header_length +
- payload_length, IPV6_MIN_MTU);
- }
- total_length = min(total_length, mutable->mtu);
- payload_length = total_length - header_length;
-
- nskb = dev_alloc_skb(NET_IP_ALIGN + eth_hdr_len + header_length +
- payload_length);
- if (!nskb)
- return false;
-
- skb_reserve(nskb, NET_IP_ALIGN);
-
- /* Ethernet / VLAN */
- eh = (struct ethhdr *)skb_put(nskb, eth_hdr_len);
- memcpy(eh->h_dest, old_eh->h_source, ETH_ALEN);
- memcpy(eh->h_source, mutable->eth_addr, ETH_ALEN);
- nskb->protocol = eh->h_proto = old_eh->h_proto;
- if (old_eh->h_proto == htons(ETH_P_8021Q)) {
- struct vlan_ethhdr *vh = (struct vlan_ethhdr *)eh;
-
- vh->h_vlan_TCI = vlan_eth_hdr(skb)->h_vlan_TCI;
- vh->h_vlan_encapsulated_proto = skb->protocol;
- }
- skb_reset_mac_header(nskb);
-
- /* Protocol */
- if (skb->protocol == htons(ETH_P_IP))
- ipv4_build_icmp(skb, nskb, mtu, payload_length);
- else
- ipv6_build_icmp(skb, nskb, mtu, payload_length);
-
- /* Assume that flow based keys are symmetric with respect to input
- * and output and use the key that we were going to put on the
- * outgoing packet for the fake received packet. If the keys are
- * not symmetric then PMTUD needs to be disabled since we won't have
- * any way of synthesizing packets. */
- if (mutable->port_config.flags & GRE_F_IN_KEY_MATCH &&
- mutable->port_config.flags & GRE_F_OUT_KEY_ACTION)
- OVS_CB(nskb)->tun_id = flow_key;
-
- vport_receive(vport, nskb);
-
- return true;
-}
-
-static struct sk_buff *
-check_headroom(struct sk_buff *skb, int headroom)
-{
- if (skb_headroom(skb) < headroom ||
- (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
- struct sk_buff *nskb = skb_realloc_headroom(skb, headroom);
- if (!nskb) {
- kfree_skb(skb);
- return ERR_PTR(-ENOMEM);
- }
-
- set_skb_csum_bits(skb, nskb);
-
- if (skb->sk)
- skb_set_owner_w(nskb, skb->sk);
-
- dev_kfree_skb(skb);
- return nskb;
- }