--- /dev/null
+/*
+ * Copyright (c) 2010 Nicira Networks.
+ * Distributed under the terms of the GNU GPL version 2.
+ *
+ * Significant portions of this file may be copied from parts of the Linux
+ * kernel, by Linus Torvalds and others.
+ */
+
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <linux/if_tunnel.h>
+#include <linux/if_vlan.h>
+#include <linux/in.h>
+#include <linux/in_route.h>
+#include <linux/jhash.h>
+#include <linux/kernel.h>
+#include <linux/version.h>
+
+#include <net/dsfield.h>
+#include <net/dst.h>
+#include <net/icmp.h>
+#include <net/inet_ecn.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <net/xfrm.h>
+
+#include "actions.h"
+#include "datapath.h"
+#include "openvswitch/gre.h"
+#include "table.h"
+#include "vport.h"
+
+/* The absolute minimum fragment size. Note that there are many other
+ * definitions of the minimum MTU. */
+#define IP_MIN_MTU 68
+
+/* The GRE header is composed of a series of sections: a base and then a variable
+ * number of options. */
+#define GRE_HEADER_SECTION 4
+
+struct mutable_config {
+ struct rcu_head rcu;
+
+ unsigned char eth_addr[ETH_ALEN];
+ unsigned int mtu;
+ struct gre_port_config port_config;
+
+ int tunnel_hlen; /* Tunnel header length. */
+};
+
+struct gre_vport {
+ struct tbl_node tbl_node;
+
+ char name[IFNAMSIZ];
+
+ /* Protected by RCU. */
+ struct mutable_config *mutable;
+};
+
+struct vport_ops gre_vport_ops;
+
+/* Protected by RCU. */
+static struct tbl *port_table;
+
+/* These are just used as an optimization: they don't require any kind of
+ * synchronization because we could have just as easily read the value before
+ * the port change happened. */
+static unsigned int key_local_remote_ports;
+static unsigned int key_remote_ports;
+static unsigned int local_remote_ports;
+static unsigned int remote_ports;
+
+static inline struct gre_vport *
+gre_vport_priv(const struct vport *vport)
+{
+ return vport_priv(vport);
+}
+
+static inline struct vport *
+gre_vport_to_vport(const struct gre_vport *gre_vport)
+{
+ return vport_from_priv(gre_vport);
+}
+
+static inline struct gre_vport *
+gre_vport_table_cast(const struct tbl_node *node)
+{
+ return container_of(node, struct gre_vport, tbl_node);
+}
+
+/* RCU callback. */
+static void
+free_config(struct rcu_head *rcu)
+{
+ struct mutable_config *c = container_of(rcu, struct mutable_config, rcu);
+ kfree(c);
+}
+
+static void
+assign_config_rcu(struct vport *vport, struct mutable_config *new_config)
+{
+ struct gre_vport *gre_vport = gre_vport_priv(vport);
+ struct mutable_config *old_config;
+
+ old_config = rcu_dereference(gre_vport->mutable);
+ rcu_assign_pointer(gre_vport->mutable, new_config);
+ call_rcu(&old_config->rcu, free_config);
+}
+
+static unsigned int *
+find_port_pool(const struct mutable_config *mutable)
+{
+ if (mutable->port_config.flags & GRE_F_IN_KEY_MATCH) {
+ if (mutable->port_config.saddr)
+ return &local_remote_ports;
+ else
+ return &remote_ports;
+ } else {
+ if (mutable->port_config.saddr)
+ return &key_local_remote_ports;
+ else
+ return &key_remote_ports;
+ }
+}
+
+enum lookup_key {
+ LOOKUP_SADDR = 0,
+ LOOKUP_DADDR = 1,
+ LOOKUP_KEY = 2,
+ LOOKUP_KEY_MATCH = 3
+};
+
+struct port_lookup_key {
+ u32 vals[4]; /* Contains enum lookup_key keys. */
+ const struct mutable_config *mutable;
+};
+
+/* Modifies 'target' to store the rcu_dereferenced pointer that was used to do
+ * the comparision. */
+static int
+port_cmp(const struct tbl_node *node, void *target)
+{
+ const struct gre_vport *gre_vport = gre_vport_table_cast(node);
+ struct port_lookup_key *lookup = target;
+
+ lookup->mutable = rcu_dereference(gre_vport->mutable);
+
+ return ((lookup->mutable->port_config.flags & GRE_F_IN_KEY_MATCH) ==
+ lookup->vals[LOOKUP_KEY_MATCH]) &&
+ lookup->mutable->port_config.daddr == lookup->vals[LOOKUP_DADDR] &&
+ lookup->mutable->port_config.in_key == lookup->vals[LOOKUP_KEY] &&
+ lookup->mutable->port_config.saddr == lookup->vals[LOOKUP_SADDR];
+}
+
+static u32
+port_hash(struct port_lookup_key *lookup)
+{
+ return jhash2(lookup->vals, ARRAY_SIZE(lookup->vals), 0);
+}
+
+static int
+add_port(struct vport *vport)
+{
+ struct gre_vport *gre_vport = gre_vport_priv(vport);
+ struct port_lookup_key lookup;
+ int err;
+
+ if (!port_table) {
+ struct tbl *new_table;
+
+ new_table = tbl_create(0);
+ if (!new_table)
+ return -ENOMEM;
+
+ rcu_assign_pointer(port_table, new_table);
+
+ } else if (tbl_count(port_table) > tbl_n_buckets(port_table)) {
+ struct tbl *old_table = port_table;
+ struct tbl *new_table;
+
+ new_table = tbl_expand(old_table);
+ if (IS_ERR(new_table))
+ return PTR_ERR(new_table);
+
+ rcu_assign_pointer(port_table, new_table);
+ tbl_deferred_destroy(old_table, NULL);
+ }
+
+ lookup.vals[LOOKUP_SADDR] = gre_vport->mutable->port_config.saddr;
+ lookup.vals[LOOKUP_DADDR] = gre_vport->mutable->port_config.daddr;
+ lookup.vals[LOOKUP_KEY] = gre_vport->mutable->port_config.in_key;
+ lookup.vals[LOOKUP_KEY_MATCH] = gre_vport->mutable->port_config.flags & GRE_F_IN_KEY_MATCH;
+
+ err = tbl_insert(port_table, &gre_vport->tbl_node, port_hash(&lookup));
+ if (err)
+ return err;
+
+ (*find_port_pool(gre_vport->mutable))++;
+
+ return 0;
+}
+
+static int
+del_port(struct vport *vport)
+{
+ struct gre_vport *gre_vport = gre_vport_priv(vport);
+ int err;
+
+ err = tbl_remove(port_table, &gre_vport->tbl_node);
+ if (err)
+ return err;
+
+ (*find_port_pool(gre_vport->mutable))--;
+
+ return 0;
+}
+
+#define FIND_PORT_KEY (1 << 0)
+#define FIND_PORT_MATCH (1 << 1)
+#define FIND_PORT_ANY (FIND_PORT_KEY | FIND_PORT_MATCH)
+
+static struct vport *
+find_port(__be32 saddr, __be32 daddr, __be32 key, int port_type,
+ const struct mutable_config **mutable)
+{
+ struct port_lookup_key lookup;
+ struct tbl *table = rcu_dereference(port_table);
+ struct tbl_node *tbl_node;
+
+ if (!table)
+ return NULL;
+
+ lookup.vals[LOOKUP_SADDR] = saddr;
+ lookup.vals[LOOKUP_DADDR] = daddr;
+
+ if (port_type & FIND_PORT_KEY) {
+ lookup.vals[LOOKUP_KEY] = key;
+ lookup.vals[LOOKUP_KEY_MATCH] = 0;
+
+ if (key_local_remote_ports) {
+ tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
+ if (tbl_node)
+ goto found;
+ }
+
+ if (key_remote_ports) {
+ lookup.vals[LOOKUP_SADDR] = 0;
+
+ tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
+ if (tbl_node)
+ goto found;
+
+ lookup.vals[LOOKUP_SADDR] = saddr;
+ }
+ }
+
+ if (port_type & FIND_PORT_MATCH) {
+ lookup.vals[LOOKUP_KEY] = 0;
+ lookup.vals[LOOKUP_KEY_MATCH] = GRE_F_IN_KEY_MATCH;
+
+ if (local_remote_ports) {
+ tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
+ if (tbl_node)
+ goto found;
+ }
+
+ if (remote_ports) {
+ lookup.vals[LOOKUP_SADDR] = 0;
+
+ tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
+ if (tbl_node)
+ goto found;
+ }
+ }
+
+ 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)
+{
+ 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) {
+ if (mutable->port_config.flags & GRE_F_OUT_KEY_ACTION)
+ OVS_CB(nskb)->tun_id = OVS_CB(skb)->tun_id;
+ else
+ OVS_CB(nskb)->tun_id = mutable->port_config.out_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;
+ }
+
+ return skb;
+}
+
+static void
+create_gre_header(struct sk_buff *skb, const struct mutable_config *mutable)
+{
+ struct iphdr *iph = ip_hdr(skb);
+ __be16 *flags = (__be16 *)(iph + 1);
+ __be16 *protocol = flags + 1;
+ __be32 *options = (__be32 *)((u8 *)iph + mutable->tunnel_hlen
+ - GRE_HEADER_SECTION);
+
+ *protocol = htons(ETH_P_TEB);
+ *flags = 0;
+
+ /* Work backwards over the options so the checksum is last. */
+ if (mutable->port_config.out_key ||
+ mutable->port_config.flags & GRE_F_OUT_KEY_ACTION) {
+ *flags |= GRE_KEY;
+
+ if (mutable->port_config.flags & GRE_F_OUT_KEY_ACTION)
+ *options = OVS_CB(skb)->tun_id;
+ else
+ *options = mutable->port_config.out_key;
+
+ options--;
+ }
+
+ if (mutable->port_config.flags & GRE_F_OUT_CSUM) {
+ *flags |= GRE_CSUM;
+
+ *options = 0;
+ *(__sum16 *)options = csum_fold(skb_checksum(skb,
+ sizeof(struct iphdr),
+ skb->len - sizeof(struct iphdr),
+ 0));
+ }
+}
+
+static int
+check_checksum(struct sk_buff *skb)
+{
+ struct iphdr *iph = ip_hdr(skb);
+ __be16 flags = *(__be16 *)(iph + 1);
+ __sum16 csum = 0;
+
+ if (flags & GRE_CSUM) {
+ switch (skb->ip_summed) {
+ case CHECKSUM_COMPLETE:
+ csum = csum_fold(skb->csum);
+
+ if (!csum)
+ break;
+ /* Fall through. */
+
+ case CHECKSUM_NONE:
+ skb->csum = 0;
+ csum = __skb_checksum_complete(skb);
+ skb->ip_summed = CHECKSUM_COMPLETE;
+ break;
+ }
+ }
+
+ return (csum == 0);
+}
+
+static int
+parse_gre_header(struct iphdr *iph, __be16 *flags, __be32 *key)
+{
+ __be16 *flagsp = (__be16 *)(iph + 1);
+ __be16 *protocol = flagsp + 1;
+ __be32 *options = (__be32 *)(protocol + 1);
+ int hdr_len;
+
+ *flags = *flagsp;
+
+ if (*flags & (GRE_VERSION | GRE_ROUTING))
+ return -EINVAL;
+
+ if (*protocol != htons(ETH_P_TEB))
+ return -EINVAL;
+
+ hdr_len = GRE_HEADER_SECTION;
+
+ if (*flags & GRE_CSUM) {
+ hdr_len += GRE_HEADER_SECTION;
+ options++;
+ }
+
+ if (*flags & GRE_KEY) {
+ hdr_len += GRE_HEADER_SECTION;
+
+ *key = *options;
+ options++;
+ } else
+ *key = 0;
+
+ if (*flags & GRE_SEQ)
+ hdr_len += GRE_HEADER_SECTION;
+
+ return hdr_len;
+}
+
+static inline u8
+ecn_encapsulate(u8 tos, struct sk_buff *skb)
+{
+ u8 inner;
+
+ if (skb->protocol == htons(ETH_P_IP))
+ inner = ((struct iphdr *)skb_network_header(skb))->tos;
+ else if (skb->protocol == htons(ETH_P_IPV6))
+ inner = ipv6_get_dsfield((struct ipv6hdr *)skb_network_header(skb));
+ else
+ inner = 0;
+
+ return INET_ECN_encapsulate(tos, inner);
+}
+
+static inline void
+ecn_decapsulate(u8 tos, struct sk_buff *skb)
+{
+ if (INET_ECN_is_ce(tos)) {
+ __be16 protocol = skb->protocol;
+ unsigned int nw_header = skb_network_header(skb) - skb->data;
+
+ if (skb->protocol == htons(ETH_P_8021Q)) {
+ if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
+ return;
+
+ protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
+ nw_header += VLAN_HLEN;
+ }
+
+ if (protocol == htons(ETH_P_IP)) {
+ if (unlikely(!pskb_may_pull(skb, nw_header
+ + sizeof(struct iphdr))))
+ return;
+
+ IP_ECN_set_ce((struct iphdr *)(nw_header + skb->data));
+ } else if (protocol == htons(ETH_P_IPV6)) {
+ if (unlikely(!pskb_may_pull(skb, nw_header
+ + sizeof(struct ipv6hdr))))
+ return;
+
+ IP6_ECN_set_ce((struct ipv6hdr *)(nw_header
+ + skb->data));
+ }
+ }
+}
+
+static struct sk_buff *
+handle_gso(struct sk_buff *skb)
+{
+ if (skb_is_gso(skb)) {
+ struct sk_buff *nskb = skb_gso_segment(skb, NETIF_F_SG);
+
+ dev_kfree_skb(skb);
+ return nskb;
+ }
+
+ return skb;
+}
+
+static int
+handle_csum_offload(struct sk_buff *skb)
+{
+ if (skb->ip_summed == CHECKSUM_PARTIAL)
+ return skb_checksum_help(skb);
+ else
+ return 0;
+}
+
+/* Called with rcu_read_lock and bottom-halves disabled. */
+static void
+gre_err(struct sk_buff *skb, u32 info)
+{
+ struct vport *vport;
+ const struct mutable_config *mutable;
+ const int type = icmp_hdr(skb)->type;
+ const int code = icmp_hdr(skb)->code;
+ int mtu = ntohs(icmp_hdr(skb)->un.frag.mtu);
+
+ struct iphdr *iph;
+ __be16 flags;
+ __be32 key;
+ int tunnel_hdr_len, tot_hdr_len;
+ unsigned int orig_mac_header;
+ unsigned int orig_nw_header;
+
+ if (type != ICMP_DEST_UNREACH || code != ICMP_FRAG_NEEDED)
+ return;
+
+ /* The mimimum size packet that we would actually be able to process:
+ * encapsulating IP header, minimum GRE header, Ethernet header,
+ * inner IPv4 header. */
+ if (!pskb_may_pull(skb, sizeof(struct iphdr) + GRE_HEADER_SECTION +
+ ETH_HLEN + sizeof(struct iphdr)))
+ return;
+
+ iph = (struct iphdr *)skb->data;
+
+ tunnel_hdr_len = parse_gre_header(iph, &flags, &key);
+ if (tunnel_hdr_len < 0)
+ return;
+
+ vport = find_port(iph->saddr, iph->daddr, key, FIND_PORT_ANY, &mutable);
+ if (!vport)
+ return;
+
+ if ((mutable->port_config.flags & GRE_F_IN_CSUM) && !(flags & GRE_CSUM))
+ return;
+
+ tot_hdr_len = sizeof(struct iphdr) + tunnel_hdr_len;
+
+ orig_mac_header = skb_mac_header(skb) - skb->data;
+ orig_nw_header = skb_network_header(skb) - skb->data;
+ skb_set_mac_header(skb, tot_hdr_len);
+
+ tot_hdr_len += ETH_HLEN;
+
+ skb->protocol = eth_hdr(skb)->h_proto;
+ if (skb->protocol == htons(ETH_P_8021Q)) {
+ tot_hdr_len += VLAN_HLEN;
+ skb->protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
+ }
+
+ if (skb->protocol == htons(ETH_P_IP))
+ tot_hdr_len += sizeof(struct iphdr);
+ else if (skb->protocol == htons(ETH_P_IP))
+ tot_hdr_len += sizeof(struct ipv6hdr);
+ else
+ goto out;
+
+ if (!pskb_may_pull(skb, tot_hdr_len))
+ goto out;
+
+ skb_set_network_header(skb, tot_hdr_len);
+ mtu -= tot_hdr_len;
+
+ if (skb->protocol == htons(ETH_P_IP)) {
+ if (mtu < IP_MIN_MTU) {
+ if (ntohs(ip_hdr(skb)->tot_len) >= IP_MIN_MTU)
+ mtu = IP_MIN_MTU;
+ else
+ goto out;
+ }
+
+ } else if (skb->protocol == htons(ETH_P_IPV6)) {
+ if (mtu < IPV6_MIN_MTU) {
+ unsigned int packet_length = sizeof(struct ipv6hdr) +
+ ntohs(ipv6_hdr(skb)->payload_len);
+
+ if (packet_length >= IPV6_MIN_MTU
+ || ntohs(ipv6_hdr(skb)->payload_len) == 0)
+ mtu = IPV6_MIN_MTU;
+ else
+ goto out;
+ }
+ }
+
+ __pskb_pull(skb, tunnel_hdr_len);
+ send_frag_needed(vport, mutable, skb, mtu);
+ skb_push(skb, tunnel_hdr_len);
+
+out:
+ skb_set_mac_header(skb, orig_mac_header);
+ skb_set_network_header(skb, orig_nw_header);
+ skb->protocol = htons(ETH_P_IP);
+}
+
+/* Called with rcu_read_lock and bottom-halves disabled. */
+static int
+gre_rcv(struct sk_buff *skb)
+{
+ struct vport *vport;
+ const struct mutable_config *mutable;
+ int hdr_len;
+ struct iphdr *iph;
+ __be16 flags;
+ __be32 key;
+
+ if (!pskb_may_pull(skb, GRE_HEADER_SECTION + ETH_HLEN))
+ goto error;
+
+ if (!check_checksum(skb))
+ goto error;
+
+ iph = ip_hdr(skb);
+
+ hdr_len = parse_gre_header(iph, &flags, &key);
+ if (hdr_len < 0)
+ goto error;
+
+ vport = find_port(iph->daddr, iph->saddr, key, FIND_PORT_ANY, &mutable);
+ if (!vport) {
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+ goto error;
+ }
+
+ if ((mutable->port_config.flags & GRE_F_IN_CSUM) && !(flags & GRE_CSUM)) {
+ vport_record_error(vport, VPORT_E_RX_CRC);
+ goto error;
+ }
+
+ if (!pskb_pull(skb, hdr_len) || !pskb_may_pull(skb, ETH_HLEN)) {
+ vport_record_error(vport, VPORT_E_RX_ERROR);
+ goto error;
+ }
+
+ skb->pkt_type = PACKET_HOST;
+ skb->protocol = eth_type_trans(skb, skb->dev);
+ skb_postpull_rcsum(skb, skb_transport_header(skb), hdr_len + ETH_HLEN);
+
+ skb_dst_drop(skb);
+ nf_reset(skb);
+ secpath_reset(skb);
+ skb_reset_network_header(skb);
+
+ ecn_decapsulate(iph->tos, skb);
+
+ if (mutable->port_config.flags & GRE_F_IN_KEY_MATCH)
+ OVS_CB(skb)->tun_id = key;
+ else
+ OVS_CB(skb)->tun_id = 0;
+
+ skb_push(skb, ETH_HLEN);
+ vport_receive(vport, skb);
+
+ return 0;
+
+error:
+ kfree_skb(skb);
+ return 0;
+}
+
+static int
+build_packet(struct vport *vport, const struct mutable_config *mutable,
+ struct iphdr *iph, struct rtable *rt, int max_headroom, int mtu,
+ struct sk_buff *skb)
+{
+ int err;
+ struct iphdr *new_iph;
+ int orig_len = skb->len;
+ __be16 frag_off = iph->frag_off;
+
+ skb = check_headroom(skb, max_headroom);
+ if (unlikely(IS_ERR(skb)))
+ goto error;
+
+ err = handle_csum_offload(skb);
+ if (err)
+ goto error_free;
+
+ if (skb->protocol == htons(ETH_P_IP)) {
+ struct iphdr *old_iph = ip_hdr(skb);
+
+ if ((old_iph->frag_off & htons(IP_DF)) &&
+ mtu < ntohs(old_iph->tot_len)) {
+ if (send_frag_needed(vport, mutable, skb, mtu))
+ goto error_free;
+ }
+
+ } else if (skb->protocol == htons(ETH_P_IPV6)) {
+ unsigned int packet_length = skb->len - ETH_HLEN
+ - (eth_hdr(skb)->h_proto == htons(ETH_P_8021Q) ? VLAN_HLEN : 0);
+
+ /* IPv6 requires PMTUD if the packet is above the minimum MTU. */
+ if (packet_length > IPV6_MIN_MTU)
+ frag_off = htons(IP_DF);
+
+ if (mtu < packet_length) {
+ if (send_frag_needed(vport, mutable, skb, mtu))
+ goto error_free;
+ }
+ }
+
+ skb_reset_transport_header(skb);
+ new_iph = (struct iphdr *)skb_push(skb, mutable->tunnel_hlen);
+ skb_reset_network_header(skb);
+
+ memcpy(new_iph, iph, sizeof(struct iphdr));
+ new_iph->frag_off = frag_off;
+ ip_select_ident(new_iph, &rt->u.dst, NULL);
+
+ create_gre_header(skb, mutable);
+
+ memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+ IPCB(skb)->flags = 0;
+
+ err = ip_local_out(skb);
+ if (likely(net_xmit_eval(err) == 0))
+ return orig_len;
+ else {
+ vport_record_error(vport, VPORT_E_TX_ERROR);
+ return 0;
+ }
+
+error_free:
+ kfree_skb(skb);
+error:
+ vport_record_error(vport, VPORT_E_TX_DROPPED);
+
+ return 0;
+}
+
+static int
+gre_send(struct vport *vport, struct sk_buff *skb)
+{
+ struct gre_vport *gre_vport = gre_vport_priv(vport);
+ const struct mutable_config *mutable = rcu_dereference(gre_vport->mutable);
+
+ struct iphdr *old_iph;
+ struct ipv6hdr *old_ipv6h;
+ int orig_len;
+ struct iphdr iph;
+ struct rtable *rt;
+ int max_headroom;
+ int mtu;
+
+ /* Validate the protocol headers before we try to use them. */
+ if (skb->protocol == htons(ETH_P_8021Q)) {
+ if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
+ goto error_free;
+
+ skb->protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
+ skb_set_network_header(skb, VLAN_ETH_HLEN);
+ }
+
+ if (skb->protocol == htons(ETH_P_IP)) {
+ if (unlikely(!pskb_may_pull(skb, skb_network_header(skb)
+ + sizeof(struct iphdr) - skb->data)))
+ skb->protocol = 0;
+ } else if (skb->protocol == htons(ETH_P_IPV6)) {
+ if (unlikely(!pskb_may_pull(skb, skb_network_header(skb)
+ + sizeof(struct ipv6hdr) - skb->data)))
+ skb->protocol = 0;
+ }
+
+ old_iph = ip_hdr(skb);
+ old_ipv6h = ipv6_hdr(skb);
+
+ iph.tos = mutable->port_config.tos;
+ if (mutable->port_config.flags & GRE_F_TOS_INHERIT) {
+ if (skb->protocol == htons(ETH_P_IP))
+ iph.tos = old_iph->tos;
+ else if (skb->protocol == htons(ETH_P_IPV6))
+ iph.tos = ipv6_get_dsfield(ipv6_hdr(skb));
+ }
+ iph.tos = ecn_encapsulate(iph.tos, skb);
+
+ {
+ struct flowi fl = { .nl_u = { .ip4_u =
+ { .daddr = mutable->port_config.daddr,
+ .saddr = mutable->port_config.saddr,
+ .tos = RT_TOS(iph.tos) } },
+ .proto = IPPROTO_GRE };
+
+ if (ip_route_output_key(&init_net, &rt, &fl))
+ goto error_free;
+ }
+
+ iph.ttl = mutable->port_config.ttl;
+ if (mutable->port_config.flags & GRE_F_TTL_INHERIT) {
+ if (skb->protocol == htons(ETH_P_IP))
+ iph.ttl = old_iph->ttl;
+ else if (skb->protocol == htons(ETH_P_IPV6))
+ iph.ttl = old_ipv6h->hop_limit;
+ }
+ if (!iph.ttl)
+ iph.ttl = dst_metric(&rt->u.dst, RTAX_HOPLIMIT);
+
+ iph.frag_off = (mutable->port_config.flags & GRE_F_PMTUD) ? htons(IP_DF) : 0;
+ if (iph.frag_off)
+ mtu = dst_mtu(&rt->u.dst)
+ - ETH_HLEN
+ - mutable->tunnel_hlen
+ - (eth_hdr(skb)->h_proto == htons(ETH_P_8021Q) ? VLAN_HLEN : 0);
+ else
+ mtu = mutable->mtu;
+
+ if (skb->protocol == htons(ETH_P_IP)) {
+ iph.frag_off |= old_iph->frag_off & htons(IP_DF);
+ mtu = max(mtu, IP_MIN_MTU);
+
+ } else if (skb->protocol == htons(ETH_P_IPV6))
+ mtu = max(mtu, IPV6_MIN_MTU);
+
+ iph.version = 4;
+ iph.ihl = sizeof(struct iphdr) >> 2;
+ iph.protocol = IPPROTO_GRE;
+ iph.daddr = rt->rt_dst;
+ iph.saddr = rt->rt_src;
+
+ /* Allow our local IP stack to fragment the outer packet even if the
+ * DF bit is set as a last resort. */
+ skb->local_df = 1;
+
+ nf_reset(skb);
+ secpath_reset(skb);
+ skb_dst_drop(skb);
+ skb_dst_set(skb, &rt->u.dst);
+ skb->ip_summed = CHECKSUM_NONE;
+
+ /* If we are doing GSO on a pskb it is better to make sure that the
+ * headroom is correct now. We will only have to copy the portion in
+ * the linear data area and GSO will preserve headroom when it creates
+ * the segments. This is particularly beneficial on Xen where we get
+ * lots of GSO pskbs. Conversely, we delay copying if it is just to
+ * get our own writable clone because GSO may do the copy for us. */
+ max_headroom = LL_RESERVED_SPACE(rt->u.dst.dev) + mutable->tunnel_hlen;
+ if (skb_headroom(skb) < max_headroom) {
+ skb = check_headroom(skb, max_headroom);
+ if (unlikely(IS_ERR(skb))) {
+ vport_record_error(vport, VPORT_E_TX_DROPPED);
+ goto error;
+ }
+ }
+
+ vswitch_skb_checksum_setup(skb);
+ skb = handle_gso(skb);
+ if (unlikely(IS_ERR(skb))) {
+ vport_record_error(vport, VPORT_E_TX_DROPPED);
+ goto error;
+ }
+
+ /* Process GSO segments. Try to do any work on the entire packet that
+ * doesn't involve actually writing to it before this point. */
+ orig_len = 0;
+ do {
+ struct sk_buff *next_skb = skb->next;
+ skb->next = NULL;
+
+ orig_len += build_packet(vport, mutable, &iph, rt, max_headroom, mtu, skb);
+
+ skb = next_skb;
+ } while (skb);
+
+ return orig_len;
+
+error_free:
+ kfree_skb(skb);
+ vport_record_error(vport, VPORT_E_TX_ERROR);
+error:
+ return 0;
+}
+
+static struct net_protocol gre_protocol_handlers = {
+ .handler = gre_rcv,
+ .err_handler = gre_err,
+};
+
+static int
+gre_init(void)
+{
+ int err;
+
+ err = inet_add_protocol(&gre_protocol_handlers, IPPROTO_GRE);
+ if (err)
+ printk(KERN_WARNING "openvswitch: cannot register gre protocol handler\n");
+
+ return err;
+}
+
+static void
+gre_exit(void)
+{
+ tbl_destroy(port_table, NULL);
+ inet_del_protocol(&gre_protocol_handlers, IPPROTO_GRE);
+}
+
+static int
+set_config(const struct vport *cur_vport, struct mutable_config *mutable,
+ const void __user *uconfig)
+{
+ const struct vport *old_vport;
+ const struct mutable_config *old_mutable;
+ int port_type;
+
+ if (copy_from_user(&mutable->port_config, uconfig, sizeof(struct gre_port_config)))
+ return -EFAULT;
+
+ if (mutable->port_config.daddr == 0)
+ return -EINVAL;
+
+ if (mutable->port_config.flags & GRE_F_IN_KEY_MATCH) {
+ port_type = FIND_PORT_MATCH;
+ mutable->port_config.in_key = 0;
+ } else
+ port_type = FIND_PORT_KEY;
+
+ old_vport = find_port(mutable->port_config.saddr,
+ mutable->port_config.daddr,
+ mutable->port_config.in_key, port_type,
+ &old_mutable);
+
+ if (old_vport && old_vport != cur_vport)
+ return -EEXIST;
+
+ mutable->tunnel_hlen = sizeof(struct iphdr) + GRE_HEADER_SECTION;
+
+ if (mutable->port_config.flags & GRE_F_OUT_CSUM)
+ mutable->tunnel_hlen += GRE_HEADER_SECTION;
+
+ if (mutable->port_config.out_key ||
+ mutable->port_config.flags & GRE_F_OUT_KEY_ACTION)
+ mutable->tunnel_hlen += GRE_HEADER_SECTION;
+
+ return 0;
+}
+
+static struct vport *
+gre_create(const char *name, const void __user *config)
+{
+ struct vport *vport;
+ struct gre_vport *gre_vport;
+ int err;
+
+ vport = vport_alloc(sizeof(struct gre_vport), &gre_vport_ops);
+ if (IS_ERR(vport)) {
+ err = PTR_ERR(vport);
+ goto error;
+ }
+
+ gre_vport = gre_vport_priv(vport);
+
+ strcpy(gre_vport->name, name);
+
+ gre_vport->mutable = kmalloc(sizeof(struct mutable_config), GFP_KERNEL);
+ if (!gre_vport->mutable) {
+ err = -ENOMEM;
+ goto error_free_vport;
+ }
+
+ vport_gen_ether_addr(gre_vport->mutable->eth_addr);
+ gre_vport->mutable->mtu = ETH_DATA_LEN;
+
+ err = set_config(NULL, gre_vport->mutable, config);
+ if (err)
+ goto error_free_mutable;
+
+ err = add_port(vport);
+ if (err)
+ goto error_free_mutable;
+
+ return vport;
+
+error_free_mutable:
+ kfree(gre_vport->mutable);
+error_free_vport:
+ vport_free(vport);
+error:
+ return ERR_PTR(err);
+}
+
+static int
+gre_modify(struct vport *vport, const void __user *config)
+{
+ struct gre_vport *gre_vport = gre_vport_priv(vport);
+ struct mutable_config *mutable;
+ int err;
+ int update_hash = 0;
+
+ mutable = kmemdup(gre_vport->mutable, sizeof(struct mutable_config), GFP_KERNEL);
+ if (!mutable) {
+ err = -ENOMEM;
+ goto error;
+ }
+
+ err = set_config(vport, mutable, config);
+ if (err)
+ goto error_free;
+
+ /* Only remove the port from the hash table if something that would
+ * affect the lookup has changed. */
+ if (gre_vport->mutable->port_config.saddr != mutable->port_config.saddr ||
+ gre_vport->mutable->port_config.daddr != mutable->port_config.daddr ||
+ gre_vport->mutable->port_config.in_key != mutable->port_config.in_key ||
+ (gre_vport->mutable->port_config.flags & GRE_F_IN_KEY_MATCH) !=
+ (mutable->port_config.flags & GRE_F_IN_KEY_MATCH))
+ update_hash = 1;
+
+
+ /* This update is not atomic but the lookup uses the config, which
+ * serves as an inherent double check. */
+ if (update_hash) {
+ err = del_port(vport);
+ if (err)
+ goto error_free;
+ }
+
+ assign_config_rcu(vport, mutable);
+
+ if (update_hash) {
+ err = add_port(vport);
+ if (err)
+ goto error_free;
+ }
+
+ return 0;
+
+error_free:
+ kfree(mutable);
+error:
+ return err;
+}
+
+static int
+gre_destroy(struct vport *vport)
+{
+ struct gre_vport *gre_vport = gre_vport_priv(vport);
+ int port_type;
+ const struct mutable_config *old_mutable;
+
+ /* Do a hash table lookup to make sure that the port exists. It should
+ * exist but might not if a modify failed earlier. */
+ if (gre_vport->mutable->port_config.flags & GRE_F_IN_KEY_MATCH)
+ port_type = FIND_PORT_MATCH;
+ else
+ port_type = FIND_PORT_KEY;
+
+ if (vport == find_port(gre_vport->mutable->port_config.saddr,
+ gre_vport->mutable->port_config.daddr,
+ gre_vport->mutable->port_config.in_key, port_type, &old_mutable))
+ del_port(vport);
+
+ kfree(gre_vport->mutable);
+ vport_free(vport);
+
+ return 0;
+}
+
+static int
+gre_set_mtu(struct vport *vport, int mtu)
+{
+ struct gre_vport *gre_vport = gre_vport_priv(vport);
+ struct mutable_config *mutable;
+ struct dp_port *dp_port;
+
+ mutable = kmemdup(gre_vport->mutable, sizeof(struct mutable_config), GFP_KERNEL);
+ if (!mutable)
+ return -ENOMEM;
+
+ mutable->mtu = mtu;
+ assign_config_rcu(vport, mutable);
+
+ dp_port = vport_get_dp_port(vport);
+ if (dp_port)
+ set_internal_devs_mtu(dp_port->dp);
+
+ return 0;
+}
+
+static int
+gre_set_addr(struct vport *vport, const unsigned char *addr)
+{
+ struct gre_vport *gre_vport = gre_vport_priv(vport);
+ struct mutable_config *mutable;
+
+ mutable = kmemdup(gre_vport->mutable, sizeof(struct mutable_config), GFP_KERNEL);
+ if (!mutable)
+ return -ENOMEM;
+
+ memcpy(mutable->eth_addr, addr, ETH_ALEN);
+ assign_config_rcu(vport, mutable);
+
+ return 0;
+}
+
+
+static const char *
+gre_get_name(const struct vport *vport)
+{
+ const struct gre_vport *gre_vport = gre_vport_priv(vport);
+ return gre_vport->name;
+}
+
+static const unsigned char *
+gre_get_addr(const struct vport *vport)
+{
+ const struct gre_vport *gre_vport = gre_vport_priv(vport);
+ return rcu_dereference(gre_vport->mutable)->eth_addr;
+}
+
+static unsigned
+gre_get_dev_flags(const struct vport *vport)
+{
+ return IFF_UP | IFF_RUNNING | IFF_LOWER_UP;
+}
+
+static int
+gre_is_running(const struct vport *vport)
+{
+ return 1;
+}
+
+static unsigned char
+gre_get_operstate(const struct vport *vport)
+{
+ return IF_OPER_UP;
+}
+
+static int
+gre_get_mtu(const struct vport *vport)
+{
+ const struct gre_vport *gre_vport = gre_vport_priv(vport);
+ return rcu_dereference(gre_vport->mutable)->mtu;
+}
+
+struct vport_ops gre_vport_ops = {
+ .type = "gre",
+ .flags = VPORT_F_GEN_STATS | VPORT_F_TUN_ID,
+ .init = gre_init,
+ .exit = gre_exit,
+ .create = gre_create,
+ .modify = gre_modify,
+ .destroy = gre_destroy,
+ .set_mtu = gre_set_mtu,
+ .set_addr = gre_set_addr,
+ .get_name = gre_get_name,
+ .get_addr = gre_get_addr,
+ .get_dev_flags = gre_get_dev_flags,
+ .is_running = gre_is_running,
+ .get_operstate = gre_get_operstate,
+ .get_mtu = gre_get_mtu,
+ .send = gre_send,
+};
projects / openvswitch / commitdiff