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OpenCloudOS-Kernel/net/openvswitch/flow.c

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/*
* Copyright (c) 2007-2011 Nicira, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
*/
#include "flow.h"
#include "datapath.h"
#include <linux/uaccess.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <net/llc_pdu.h>
#include <linux/kernel.h>
#include <linux/jhash.h>
#include <linux/jiffies.h>
#include <linux/llc.h>
#include <linux/module.h>
#include <linux/in.h>
#include <linux/rcupdate.h>
#include <linux/if_arp.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/icmp.h>
#include <linux/icmpv6.h>
#include <linux/rculist.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/ndisc.h>
static struct kmem_cache *flow_cache;
static int check_header(struct sk_buff *skb, int len)
{
if (unlikely(skb->len < len))
return -EINVAL;
if (unlikely(!pskb_may_pull(skb, len)))
return -ENOMEM;
return 0;
}
static bool arphdr_ok(struct sk_buff *skb)
{
return pskb_may_pull(skb, skb_network_offset(skb) +
sizeof(struct arp_eth_header));
}
static int check_iphdr(struct sk_buff *skb)
{
unsigned int nh_ofs = skb_network_offset(skb);
unsigned int ip_len;
int err;
err = check_header(skb, nh_ofs + sizeof(struct iphdr));
if (unlikely(err))
return err;
ip_len = ip_hdrlen(skb);
if (unlikely(ip_len < sizeof(struct iphdr) ||
skb->len < nh_ofs + ip_len))
return -EINVAL;
skb_set_transport_header(skb, nh_ofs + ip_len);
return 0;
}
static bool tcphdr_ok(struct sk_buff *skb)
{
int th_ofs = skb_transport_offset(skb);
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 ovs_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))
static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key,
int *key_lenp)
{
unsigned int nh_ofs = skb_network_offset(skb);
unsigned int nh_len;
int payload_ofs;
struct ipv6hdr *nh;
uint8_t nexthdr;
__be16 frag_off;
int err;
*key_lenp = SW_FLOW_KEY_OFFSET(ipv6.label);
err = check_header(skb, nh_ofs + sizeof(*nh));
if (unlikely(err))
return err;
nh = ipv6_hdr(skb);
nexthdr = nh->nexthdr;
payload_ofs = (u8 *)(nh + 1) - skb->data;
key->ip.proto = NEXTHDR_NONE;
key->ip.tos = ipv6_get_dsfield(nh);
key->ip.ttl = nh->hop_limit;
key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
key->ipv6.addr.src = nh->saddr;
key->ipv6.addr.dst = nh->daddr;
payload_ofs = ipv6_skip_exthdr(skb, payload_ofs, &nexthdr, &frag_off);
if (unlikely(payload_ofs < 0))
return -EINVAL;
if (frag_off) {
if (frag_off & htons(~0x7))
key->ip.frag = OVS_FRAG_TYPE_LATER;
else
key->ip.frag = OVS_FRAG_TYPE_FIRST;
}
nh_len = payload_ofs - nh_ofs;
skb_set_transport_header(skb, nh_ofs + nh_len);
key->ip.proto = nexthdr;
return nh_len;
}
static bool icmp6hdr_ok(struct sk_buff *skb)
{
return pskb_may_pull(skb, skb_transport_offset(skb) +
sizeof(struct icmp6hdr));
}
#define TCP_FLAGS_OFFSET 13
#define TCP_FLAG_MASK 0x3f
void ovs_flow_used(struct sw_flow *flow, struct sk_buff *skb)
{
u8 tcp_flags = 0;
if ((flow->key.eth.type == htons(ETH_P_IP) ||
flow->key.eth.type == htons(ETH_P_IPV6)) &&
flow->key.ip.proto == IPPROTO_TCP &&
likely(skb->len >= skb_transport_offset(skb) + sizeof(struct tcphdr))) {
u8 *tcp = (u8 *)tcp_hdr(skb);
tcp_flags = *(tcp + TCP_FLAGS_OFFSET) & TCP_FLAG_MASK;
}
spin_lock(&flow->lock);
flow->used = jiffies;
flow->packet_count++;
flow->byte_count += skb->len;
flow->tcp_flags |= tcp_flags;
spin_unlock(&flow->lock);
}
struct sw_flow_actions *ovs_flow_actions_alloc(const struct nlattr *actions)
{
int actions_len = nla_len(actions);
struct sw_flow_actions *sfa;
/* At least DP_MAX_PORTS actions are required to be able to flood a
* packet to every port. Factor of 2 allows for setting VLAN tags,
* etc. */
if (actions_len > 2 * DP_MAX_PORTS * nla_total_size(4))
return ERR_PTR(-EINVAL);
sfa = kmalloc(sizeof(*sfa) + actions_len, GFP_KERNEL);
if (!sfa)
return ERR_PTR(-ENOMEM);
sfa->actions_len = actions_len;
memcpy(sfa->actions, nla_data(actions), actions_len);
return sfa;
}
struct sw_flow *ovs_flow_alloc(void)
{
struct sw_flow *flow;
flow = kmem_cache_alloc(flow_cache, GFP_KERNEL);
if (!flow)
return ERR_PTR(-ENOMEM);
spin_lock_init(&flow->lock);
flow->sf_acts = NULL;
return flow;
}
static struct hlist_head *find_bucket(struct flow_table *table, u32 hash)
{
hash = jhash_1word(hash, table->hash_seed);
return flex_array_get(table->buckets,
(hash & (table->n_buckets - 1)));
}
static struct flex_array *alloc_buckets(unsigned int n_buckets)
{
struct flex_array *buckets;
int i, err;
buckets = flex_array_alloc(sizeof(struct hlist_head *),
n_buckets, GFP_KERNEL);
if (!buckets)
return NULL;
err = flex_array_prealloc(buckets, 0, n_buckets, GFP_KERNEL);
if (err) {
flex_array_free(buckets);
return NULL;
}
for (i = 0; i < n_buckets; i++)
INIT_HLIST_HEAD((struct hlist_head *)
flex_array_get(buckets, i));
return buckets;
}
static void free_buckets(struct flex_array *buckets)
{
flex_array_free(buckets);
}
struct flow_table *ovs_flow_tbl_alloc(int new_size)
{
struct flow_table *table = kmalloc(sizeof(*table), GFP_KERNEL);
if (!table)
return NULL;
table->buckets = alloc_buckets(new_size);
if (!table->buckets) {
kfree(table);
return NULL;
}
table->n_buckets = new_size;
table->count = 0;
table->node_ver = 0;
table->keep_flows = false;
get_random_bytes(&table->hash_seed, sizeof(u32));
return table;
}
void ovs_flow_tbl_destroy(struct flow_table *table)
{
int i;
if (!table)
return;
if (table->keep_flows)
goto skip_flows;
for (i = 0; i < table->n_buckets; i++) {
struct sw_flow *flow;
struct hlist_head *head = flex_array_get(table->buckets, i);
struct hlist_node *node, *n;
int ver = table->node_ver;
hlist_for_each_entry_safe(flow, node, n, head, hash_node[ver]) {
hlist_del_rcu(&flow->hash_node[ver]);
ovs_flow_free(flow);
}
}
skip_flows:
free_buckets(table->buckets);
kfree(table);
}
static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
{
struct flow_table *table = container_of(rcu, struct flow_table, rcu);
ovs_flow_tbl_destroy(table);
}
void ovs_flow_tbl_deferred_destroy(struct flow_table *table)
{
if (!table)
return;
call_rcu(&table->rcu, flow_tbl_destroy_rcu_cb);
}
struct sw_flow *ovs_flow_tbl_next(struct flow_table *table, u32 *bucket, u32 *last)
{
struct sw_flow *flow;
struct hlist_head *head;
struct hlist_node *n;
int ver;
int i;
ver = table->node_ver;
while (*bucket < table->n_buckets) {
i = 0;
head = flex_array_get(table->buckets, *bucket);
hlist_for_each_entry_rcu(flow, n, head, hash_node[ver]) {
if (i < *last) {
i++;
continue;
}
*last = i + 1;
return flow;
}
(*bucket)++;
*last = 0;
}
return NULL;
}
static void flow_table_copy_flows(struct flow_table *old, struct flow_table *new)
{
int old_ver;
int i;
old_ver = old->node_ver;
new->node_ver = !old_ver;
/* Insert in new table. */
for (i = 0; i < old->n_buckets; i++) {
struct sw_flow *flow;
struct hlist_head *head;
struct hlist_node *n;
head = flex_array_get(old->buckets, i);
hlist_for_each_entry(flow, n, head, hash_node[old_ver])
ovs_flow_tbl_insert(new, flow);
}
old->keep_flows = true;
}
static struct flow_table *__flow_tbl_rehash(struct flow_table *table, int n_buckets)
{
struct flow_table *new_table;
new_table = ovs_flow_tbl_alloc(n_buckets);
if (!new_table)
return ERR_PTR(-ENOMEM);
flow_table_copy_flows(table, new_table);
return new_table;
}
struct flow_table *ovs_flow_tbl_rehash(struct flow_table *table)
{
return __flow_tbl_rehash(table, table->n_buckets);
}
struct flow_table *ovs_flow_tbl_expand(struct flow_table *table)
{
return __flow_tbl_rehash(table, table->n_buckets * 2);
}
void ovs_flow_free(struct sw_flow *flow)
{
if (unlikely(!flow))
return;
kfree((struct sf_flow_acts __force *)flow->sf_acts);
kmem_cache_free(flow_cache, flow);
}
/* RCU callback used by ovs_flow_deferred_free. */
static void rcu_free_flow_callback(struct rcu_head *rcu)
{
struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
ovs_flow_free(flow);
}
/* Schedules 'flow' to be freed after the next RCU grace period.
* The caller must hold rcu_read_lock for this to be sensible. */
void ovs_flow_deferred_free(struct sw_flow *flow)
{
call_rcu(&flow->rcu, rcu_free_flow_callback);
}
/* RCU callback used by ovs_flow_deferred_free_acts. */
static void rcu_free_acts_callback(struct rcu_head *rcu)
{
struct sw_flow_actions *sf_acts = container_of(rcu,
struct sw_flow_actions, rcu);
kfree(sf_acts);
}
/* Schedules 'sf_acts' to be freed after the next RCU grace period.
* The caller must hold rcu_read_lock for this to be sensible. */
void ovs_flow_deferred_free_acts(struct sw_flow_actions *sf_acts)
{
call_rcu(&sf_acts->rcu, rcu_free_acts_callback);
}
static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
{
struct qtag_prefix {
__be16 eth_type; /* ETH_P_8021Q */
__be16 tci;
};
struct qtag_prefix *qp;
if (unlikely(skb->len < sizeof(struct qtag_prefix) + sizeof(__be16)))
return 0;
if (unlikely(!pskb_may_pull(skb, sizeof(struct qtag_prefix) +
sizeof(__be16))))
return -ENOMEM;
qp = (struct qtag_prefix *) skb->data;
key->eth.tci = qp->tci | htons(VLAN_TAG_PRESENT);
__skb_pull(skb, sizeof(struct qtag_prefix));
return 0;
}
static __be16 parse_ethertype(struct sk_buff *skb)
{
struct llc_snap_hdr {
u8 dsap; /* Always 0xAA */
u8 ssap; /* Always 0xAA */
u8 ctrl;
u8 oui[3];
__be16 ethertype;
};
struct llc_snap_hdr *llc;
__be16 proto;
proto = *(__be16 *) skb->data;
__skb_pull(skb, sizeof(__be16));
if (ntohs(proto) >= 1536)
return proto;
if (skb->len < sizeof(struct llc_snap_hdr))
return htons(ETH_P_802_2);
if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr))))
return htons(0);
llc = (struct llc_snap_hdr *) skb->data;
if (llc->dsap != LLC_SAP_SNAP ||
llc->ssap != LLC_SAP_SNAP ||
(llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0)
return htons(ETH_P_802_2);
__skb_pull(skb, sizeof(struct llc_snap_hdr));
return llc->ethertype;
}
static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key,
int *key_lenp, int nh_len)
{
struct icmp6hdr *icmp = icmp6_hdr(skb);
int error = 0;
int key_len;
/* The ICMPv6 type and code fields use the 16-bit transport port
* fields, so we need to store them in 16-bit network byte order.
*/
key->ipv6.tp.src = htons(icmp->icmp6_type);
key->ipv6.tp.dst = htons(icmp->icmp6_code);
key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
if (icmp->icmp6_code == 0 &&
(icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) {
int icmp_len = skb->len - skb_transport_offset(skb);
struct nd_msg *nd;
int offset;
key_len = SW_FLOW_KEY_OFFSET(ipv6.nd);
/* In order to process neighbor discovery options, we need the
* entire packet.
*/
if (unlikely(icmp_len < sizeof(*nd)))
goto out;
if (unlikely(skb_linearize(skb))) {
error = -ENOMEM;
goto out;
}
nd = (struct nd_msg *)skb_transport_header(skb);
key->ipv6.nd.target = nd->target;
key_len = SW_FLOW_KEY_OFFSET(ipv6.nd);
icmp_len -= sizeof(*nd);
offset = 0;
while (icmp_len >= 8) {
struct nd_opt_hdr *nd_opt =
(struct nd_opt_hdr *)(nd->opt + offset);
int opt_len = nd_opt->nd_opt_len * 8;
if (unlikely(!opt_len || opt_len > icmp_len))
goto invalid;
/* Store the link layer address if the appropriate
* option is provided. It is considered an error if
* the same link layer option is specified twice.
*/
if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR
&& opt_len == 8) {
if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll)))
goto invalid;
memcpy(key->ipv6.nd.sll,
&nd->opt[offset+sizeof(*nd_opt)], ETH_ALEN);
} else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR
&& opt_len == 8) {
if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll)))
goto invalid;
memcpy(key->ipv6.nd.tll,
&nd->opt[offset+sizeof(*nd_opt)], ETH_ALEN);
}
icmp_len -= opt_len;
offset += opt_len;
}
}
goto out;
invalid:
memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target));
memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll));
memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll));
out:
*key_lenp = key_len;
return error;
}
/**
* ovs_flow_extract - extracts a flow key from an Ethernet frame.
* @skb: sk_buff that contains the frame, with skb->data pointing to the
* Ethernet header
* @in_port: port number on which @skb was received.
* @key: output flow key
* @key_lenp: length of output flow key
*
* The caller must ensure that skb->len >= ETH_HLEN.
*
* Returns 0 if successful, otherwise a negative errno value.
*
* Initializes @skb header pointers as follows:
*
* - skb->mac_header: the Ethernet header.
*
* - skb->network_header: just past the Ethernet header, or just past the
* VLAN header, to the first byte of the Ethernet payload.
*
* - skb->transport_header: If key->dl_type is ETH_P_IP or ETH_P_IPV6
* on output, then just past the IP header, if one is present and
* of a correct length, otherwise the same as skb->network_header.
* For other key->dl_type values it is left untouched.
*/
int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key,
int *key_lenp)
{
int error = 0;
int key_len = SW_FLOW_KEY_OFFSET(eth);
struct ethhdr *eth;
memset(key, 0, sizeof(*key));
key->phy.priority = skb->priority;
key->phy.in_port = in_port;
skb_reset_mac_header(skb);
/* Link layer. We are guaranteed to have at least the 14 byte Ethernet
* header in the linear data area.
*/
eth = eth_hdr(skb);
memcpy(key->eth.src, eth->h_source, ETH_ALEN);
memcpy(key->eth.dst, eth->h_dest, ETH_ALEN);
__skb_pull(skb, 2 * ETH_ALEN);
if (vlan_tx_tag_present(skb))
key->eth.tci = htons(skb->vlan_tci);
else if (eth->h_proto == htons(ETH_P_8021Q))
if (unlikely(parse_vlan(skb, key)))
return -ENOMEM;
key->eth.type = parse_ethertype(skb);
if (unlikely(key->eth.type == htons(0)))
return -ENOMEM;
skb_reset_network_header(skb);
__skb_push(skb, skb->data - skb_mac_header(skb));
/* Network layer. */
if (key->eth.type == htons(ETH_P_IP)) {
struct iphdr *nh;
__be16 offset;
key_len = SW_FLOW_KEY_OFFSET(ipv4.addr);
error = check_iphdr(skb);
if (unlikely(error)) {
if (error == -EINVAL) {
skb->transport_header = skb->network_header;
error = 0;
}
goto out;
}
nh = ip_hdr(skb);
key->ipv4.addr.src = nh->saddr;
key->ipv4.addr.dst = nh->daddr;
key->ip.proto = nh->protocol;
key->ip.tos = nh->tos;
key->ip.ttl = nh->ttl;
offset = nh->frag_off & htons(IP_OFFSET);
if (offset) {
key->ip.frag = OVS_FRAG_TYPE_LATER;
goto out;
}
if (nh->frag_off & htons(IP_MF) ||
skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
key->ip.frag = OVS_FRAG_TYPE_FIRST;
/* Transport layer. */
if (key->ip.proto == IPPROTO_TCP) {
key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
if (tcphdr_ok(skb)) {
struct tcphdr *tcp = tcp_hdr(skb);
key->ipv4.tp.src = tcp->source;
key->ipv4.tp.dst = tcp->dest;
}
} else if (key->ip.proto == IPPROTO_UDP) {
key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
if (udphdr_ok(skb)) {
struct udphdr *udp = udp_hdr(skb);
key->ipv4.tp.src = udp->source;
key->ipv4.tp.dst = udp->dest;
}
} else if (key->ip.proto == IPPROTO_ICMP) {
key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
if (icmphdr_ok(skb)) {
struct icmphdr *icmp = icmp_hdr(skb);
/* The ICMP type and code fields use the 16-bit
* transport port fields, so we need to store
* them in 16-bit network byte order. */
key->ipv4.tp.src = htons(icmp->type);
key->ipv4.tp.dst = htons(icmp->code);
}
}
} else if (key->eth.type == htons(ETH_P_ARP) && arphdr_ok(skb)) {
struct arp_eth_header *arp;
arp = (struct arp_eth_header *)skb_network_header(skb);
if (arp->ar_hrd == htons(ARPHRD_ETHER)
&& arp->ar_pro == htons(ETH_P_IP)
&& arp->ar_hln == ETH_ALEN
&& arp->ar_pln == 4) {
/* We only match on the lower 8 bits of the opcode. */
if (ntohs(arp->ar_op) <= 0xff)
key->ip.proto = ntohs(arp->ar_op);
if (key->ip.proto == ARPOP_REQUEST
|| key->ip.proto == ARPOP_REPLY) {
memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
memcpy(key->ipv4.arp.sha, arp->ar_sha, ETH_ALEN);
memcpy(key->ipv4.arp.tha, arp->ar_tha, ETH_ALEN);
key_len = SW_FLOW_KEY_OFFSET(ipv4.arp);
}
}
} else if (key->eth.type == htons(ETH_P_IPV6)) {
int nh_len; /* IPv6 Header + Extensions */
nh_len = parse_ipv6hdr(skb, key, &key_len);
if (unlikely(nh_len < 0)) {
if (nh_len == -EINVAL)
skb->transport_header = skb->network_header;
else
error = nh_len;
goto out;
}
if (key->ip.frag == OVS_FRAG_TYPE_LATER)
goto out;
if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
key->ip.frag = OVS_FRAG_TYPE_FIRST;
/* Transport layer. */
if (key->ip.proto == NEXTHDR_TCP) {
key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
if (tcphdr_ok(skb)) {
struct tcphdr *tcp = tcp_hdr(skb);
key->ipv6.tp.src = tcp->source;
key->ipv6.tp.dst = tcp->dest;
}
} else if (key->ip.proto == NEXTHDR_UDP) {
key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
if (udphdr_ok(skb)) {
struct udphdr *udp = udp_hdr(skb);
key->ipv6.tp.src = udp->source;
key->ipv6.tp.dst = udp->dest;
}
} else if (key->ip.proto == NEXTHDR_ICMP) {
key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
if (icmp6hdr_ok(skb)) {
error = parse_icmpv6(skb, key, &key_len, nh_len);
if (error < 0)
goto out;
}
}
}
out:
*key_lenp = key_len;
return error;
}
u32 ovs_flow_hash(const struct sw_flow_key *key, int key_len)
{
return jhash2((u32 *)key, DIV_ROUND_UP(key_len, sizeof(u32)), 0);
}
struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *table,
struct sw_flow_key *key, int key_len)
{
struct sw_flow *flow;
struct hlist_node *n;
struct hlist_head *head;
u32 hash;
hash = ovs_flow_hash(key, key_len);
head = find_bucket(table, hash);
hlist_for_each_entry_rcu(flow, n, head, hash_node[table->node_ver]) {
if (flow->hash == hash &&
!memcmp(&flow->key, key, key_len)) {
return flow;
}
}
return NULL;
}
void ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow)
{
struct hlist_head *head;
head = find_bucket(table, flow->hash);
hlist_add_head_rcu(&flow->hash_node[table->node_ver], head);
table->count++;
}
void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
{
hlist_del_rcu(&flow->hash_node[table->node_ver]);
table->count--;
BUG_ON(table->count < 0);
}
/* The size of the argument for each %OVS_KEY_ATTR_* Netlink attribute. */
const int ovs_key_lens[OVS_KEY_ATTR_MAX + 1] = {
[OVS_KEY_ATTR_ENCAP] = -1,
[OVS_KEY_ATTR_PRIORITY] = sizeof(u32),
[OVS_KEY_ATTR_IN_PORT] = sizeof(u32),
[OVS_KEY_ATTR_ETHERNET] = sizeof(struct ovs_key_ethernet),
[OVS_KEY_ATTR_VLAN] = sizeof(__be16),
[OVS_KEY_ATTR_ETHERTYPE] = sizeof(__be16),
[OVS_KEY_ATTR_IPV4] = sizeof(struct ovs_key_ipv4),
[OVS_KEY_ATTR_IPV6] = sizeof(struct ovs_key_ipv6),
[OVS_KEY_ATTR_TCP] = sizeof(struct ovs_key_tcp),
[OVS_KEY_ATTR_UDP] = sizeof(struct ovs_key_udp),
[OVS_KEY_ATTR_ICMP] = sizeof(struct ovs_key_icmp),
[OVS_KEY_ATTR_ICMPV6] = sizeof(struct ovs_key_icmpv6),
[OVS_KEY_ATTR_ARP] = sizeof(struct ovs_key_arp),
[OVS_KEY_ATTR_ND] = sizeof(struct ovs_key_nd),
};
static int ipv4_flow_from_nlattrs(struct sw_flow_key *swkey, int *key_len,
const struct nlattr *a[], u32 *attrs)
{
const struct ovs_key_icmp *icmp_key;
const struct ovs_key_tcp *tcp_key;
const struct ovs_key_udp *udp_key;
switch (swkey->ip.proto) {
case IPPROTO_TCP:
if (!(*attrs & (1 << OVS_KEY_ATTR_TCP)))
return -EINVAL;
*attrs &= ~(1 << OVS_KEY_ATTR_TCP);
*key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
tcp_key = nla_data(a[OVS_KEY_ATTR_TCP]);
swkey->ipv4.tp.src = tcp_key->tcp_src;
swkey->ipv4.tp.dst = tcp_key->tcp_dst;
break;
case IPPROTO_UDP:
if (!(*attrs & (1 << OVS_KEY_ATTR_UDP)))
return -EINVAL;
*attrs &= ~(1 << OVS_KEY_ATTR_UDP);
*key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
udp_key = nla_data(a[OVS_KEY_ATTR_UDP]);
swkey->ipv4.tp.src = udp_key->udp_src;
swkey->ipv4.tp.dst = udp_key->udp_dst;
break;
case IPPROTO_ICMP:
if (!(*attrs & (1 << OVS_KEY_ATTR_ICMP)))
return -EINVAL;
*attrs &= ~(1 << OVS_KEY_ATTR_ICMP);
*key_len = SW_FLOW_KEY_OFFSET(ipv4.tp);
icmp_key = nla_data(a[OVS_KEY_ATTR_ICMP]);
swkey->ipv4.tp.src = htons(icmp_key->icmp_type);
swkey->ipv4.tp.dst = htons(icmp_key->icmp_code);
break;
}
return 0;
}
static int ipv6_flow_from_nlattrs(struct sw_flow_key *swkey, int *key_len,
const struct nlattr *a[], u32 *attrs)
{
const struct ovs_key_icmpv6 *icmpv6_key;
const struct ovs_key_tcp *tcp_key;
const struct ovs_key_udp *udp_key;
switch (swkey->ip.proto) {
case IPPROTO_TCP:
if (!(*attrs & (1 << OVS_KEY_ATTR_TCP)))
return -EINVAL;
*attrs &= ~(1 << OVS_KEY_ATTR_TCP);
*key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
tcp_key = nla_data(a[OVS_KEY_ATTR_TCP]);
swkey->ipv6.tp.src = tcp_key->tcp_src;
swkey->ipv6.tp.dst = tcp_key->tcp_dst;
break;
case IPPROTO_UDP:
if (!(*attrs & (1 << OVS_KEY_ATTR_UDP)))
return -EINVAL;
*attrs &= ~(1 << OVS_KEY_ATTR_UDP);
*key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
udp_key = nla_data(a[OVS_KEY_ATTR_UDP]);
swkey->ipv6.tp.src = udp_key->udp_src;
swkey->ipv6.tp.dst = udp_key->udp_dst;
break;
case IPPROTO_ICMPV6:
if (!(*attrs & (1 << OVS_KEY_ATTR_ICMPV6)))
return -EINVAL;
*attrs &= ~(1 << OVS_KEY_ATTR_ICMPV6);
*key_len = SW_FLOW_KEY_OFFSET(ipv6.tp);
icmpv6_key = nla_data(a[OVS_KEY_ATTR_ICMPV6]);
swkey->ipv6.tp.src = htons(icmpv6_key->icmpv6_type);
swkey->ipv6.tp.dst = htons(icmpv6_key->icmpv6_code);
if (swkey->ipv6.tp.src == htons(NDISC_NEIGHBOUR_SOLICITATION) ||
swkey->ipv6.tp.src == htons(NDISC_NEIGHBOUR_ADVERTISEMENT)) {
const struct ovs_key_nd *nd_key;
if (!(*attrs & (1 << OVS_KEY_ATTR_ND)))
return -EINVAL;
*attrs &= ~(1 << OVS_KEY_ATTR_ND);
*key_len = SW_FLOW_KEY_OFFSET(ipv6.nd);
nd_key = nla_data(a[OVS_KEY_ATTR_ND]);
memcpy(&swkey->ipv6.nd.target, nd_key->nd_target,
sizeof(swkey->ipv6.nd.target));
memcpy(swkey->ipv6.nd.sll, nd_key->nd_sll, ETH_ALEN);
memcpy(swkey->ipv6.nd.tll, nd_key->nd_tll, ETH_ALEN);
}
break;
}
return 0;
}
static int parse_flow_nlattrs(const struct nlattr *attr,
const struct nlattr *a[], u32 *attrsp)
{
const struct nlattr *nla;
u32 attrs;
int rem;
attrs = 0;
nla_for_each_nested(nla, attr, rem) {
u16 type = nla_type(nla);
int expected_len;
if (type > OVS_KEY_ATTR_MAX || attrs & (1 << type))
return -EINVAL;
expected_len = ovs_key_lens[type];
if (nla_len(nla) != expected_len && expected_len != -1)
return -EINVAL;
attrs |= 1 << type;
a[type] = nla;
}
if (rem)
return -EINVAL;
*attrsp = attrs;
return 0;
}
/**
* ovs_flow_from_nlattrs - parses Netlink attributes into a flow key.
* @swkey: receives the extracted flow key.
* @key_lenp: number of bytes used in @swkey.
* @attr: Netlink attribute holding nested %OVS_KEY_ATTR_* Netlink attribute
* sequence.
*/
int ovs_flow_from_nlattrs(struct sw_flow_key *swkey, int *key_lenp,
const struct nlattr *attr)
{
const struct nlattr *a[OVS_KEY_ATTR_MAX + 1];
const struct ovs_key_ethernet *eth_key;
int key_len;
u32 attrs;
int err;
memset(swkey, 0, sizeof(struct sw_flow_key));
key_len = SW_FLOW_KEY_OFFSET(eth);
err = parse_flow_nlattrs(attr, a, &attrs);
if (err)
return err;
/* Metadata attributes. */
if (attrs & (1 << OVS_KEY_ATTR_PRIORITY)) {
swkey->phy.priority = nla_get_u32(a[OVS_KEY_ATTR_PRIORITY]);
attrs &= ~(1 << OVS_KEY_ATTR_PRIORITY);
}
if (attrs & (1 << OVS_KEY_ATTR_IN_PORT)) {
u32 in_port = nla_get_u32(a[OVS_KEY_ATTR_IN_PORT]);
if (in_port >= DP_MAX_PORTS)
return -EINVAL;
swkey->phy.in_port = in_port;
attrs &= ~(1 << OVS_KEY_ATTR_IN_PORT);
} else {
swkey->phy.in_port = USHRT_MAX;
}
/* Data attributes. */
if (!(attrs & (1 << OVS_KEY_ATTR_ETHERNET)))
return -EINVAL;
attrs &= ~(1 << OVS_KEY_ATTR_ETHERNET);
eth_key = nla_data(a[OVS_KEY_ATTR_ETHERNET]);
memcpy(swkey->eth.src, eth_key->eth_src, ETH_ALEN);
memcpy(swkey->eth.dst, eth_key->eth_dst, ETH_ALEN);
if (attrs & (1u << OVS_KEY_ATTR_ETHERTYPE) &&
nla_get_be16(a[OVS_KEY_ATTR_ETHERTYPE]) == htons(ETH_P_8021Q)) {
const struct nlattr *encap;
__be16 tci;
if (attrs != ((1 << OVS_KEY_ATTR_VLAN) |
(1 << OVS_KEY_ATTR_ETHERTYPE) |
(1 << OVS_KEY_ATTR_ENCAP)))
return -EINVAL;
encap = a[OVS_KEY_ATTR_ENCAP];
tci = nla_get_be16(a[OVS_KEY_ATTR_VLAN]);
if (tci & htons(VLAN_TAG_PRESENT)) {
swkey->eth.tci = tci;
err = parse_flow_nlattrs(encap, a, &attrs);
if (err)
return err;
} else if (!tci) {
/* Corner case for truncated 802.1Q header. */
if (nla_len(encap))
return -EINVAL;
swkey->eth.type = htons(ETH_P_8021Q);
*key_lenp = key_len;
return 0;
} else {
return -EINVAL;
}
}
if (attrs & (1 << OVS_KEY_ATTR_ETHERTYPE)) {
swkey->eth.type = nla_get_be16(a[OVS_KEY_ATTR_ETHERTYPE]);
if (ntohs(swkey->eth.type) < 1536)
return -EINVAL;
attrs &= ~(1 << OVS_KEY_ATTR_ETHERTYPE);
} else {
swkey->eth.type = htons(ETH_P_802_2);
}
if (swkey->eth.type == htons(ETH_P_IP)) {
const struct ovs_key_ipv4 *ipv4_key;
if (!(attrs & (1 << OVS_KEY_ATTR_IPV4)))
return -EINVAL;
attrs &= ~(1 << OVS_KEY_ATTR_IPV4);
key_len = SW_FLOW_KEY_OFFSET(ipv4.addr);
ipv4_key = nla_data(a[OVS_KEY_ATTR_IPV4]);
if (ipv4_key->ipv4_frag > OVS_FRAG_TYPE_MAX)
return -EINVAL;
swkey->ip.proto = ipv4_key->ipv4_proto;
swkey->ip.tos = ipv4_key->ipv4_tos;
swkey->ip.ttl = ipv4_key->ipv4_ttl;
swkey->ip.frag = ipv4_key->ipv4_frag;
swkey->ipv4.addr.src = ipv4_key->ipv4_src;
swkey->ipv4.addr.dst = ipv4_key->ipv4_dst;
if (swkey->ip.frag != OVS_FRAG_TYPE_LATER) {
err = ipv4_flow_from_nlattrs(swkey, &key_len, a, &attrs);
if (err)
return err;
}
} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
const struct ovs_key_ipv6 *ipv6_key;
if (!(attrs & (1 << OVS_KEY_ATTR_IPV6)))
return -EINVAL;
attrs &= ~(1 << OVS_KEY_ATTR_IPV6);
key_len = SW_FLOW_KEY_OFFSET(ipv6.label);
ipv6_key = nla_data(a[OVS_KEY_ATTR_IPV6]);
if (ipv6_key->ipv6_frag > OVS_FRAG_TYPE_MAX)
return -EINVAL;
swkey->ipv6.label = ipv6_key->ipv6_label;
swkey->ip.proto = ipv6_key->ipv6_proto;
swkey->ip.tos = ipv6_key->ipv6_tclass;
swkey->ip.ttl = ipv6_key->ipv6_hlimit;
swkey->ip.frag = ipv6_key->ipv6_frag;
memcpy(&swkey->ipv6.addr.src, ipv6_key->ipv6_src,
sizeof(swkey->ipv6.addr.src));
memcpy(&swkey->ipv6.addr.dst, ipv6_key->ipv6_dst,
sizeof(swkey->ipv6.addr.dst));
if (swkey->ip.frag != OVS_FRAG_TYPE_LATER) {
err = ipv6_flow_from_nlattrs(swkey, &key_len, a, &attrs);
if (err)
return err;
}
} else if (swkey->eth.type == htons(ETH_P_ARP)) {
const struct ovs_key_arp *arp_key;
if (!(attrs & (1 << OVS_KEY_ATTR_ARP)))
return -EINVAL;
attrs &= ~(1 << OVS_KEY_ATTR_ARP);
key_len = SW_FLOW_KEY_OFFSET(ipv4.arp);
arp_key = nla_data(a[OVS_KEY_ATTR_ARP]);
swkey->ipv4.addr.src = arp_key->arp_sip;
swkey->ipv4.addr.dst = arp_key->arp_tip;
if (arp_key->arp_op & htons(0xff00))
return -EINVAL;
swkey->ip.proto = ntohs(arp_key->arp_op);
memcpy(swkey->ipv4.arp.sha, arp_key->arp_sha, ETH_ALEN);
memcpy(swkey->ipv4.arp.tha, arp_key->arp_tha, ETH_ALEN);
}
if (attrs)
return -EINVAL;
*key_lenp = key_len;
return 0;
}
/**
* ovs_flow_metadata_from_nlattrs - parses Netlink attributes into a flow key.
* @in_port: receives the extracted input port.
* @key: Netlink attribute holding nested %OVS_KEY_ATTR_* Netlink attribute
* sequence.
*
* This parses a series of Netlink attributes that form a flow key, which must
* take the same form accepted by flow_from_nlattrs(), but only enough of it to
* get the metadata, that is, the parts of the flow key that cannot be
* extracted from the packet itself.
*/
int ovs_flow_metadata_from_nlattrs(u32 *priority, u16 *in_port,
const struct nlattr *attr)
{
const struct nlattr *nla;
int rem;
*in_port = USHRT_MAX;
*priority = 0;
nla_for_each_nested(nla, attr, rem) {
int type = nla_type(nla);
if (type <= OVS_KEY_ATTR_MAX && ovs_key_lens[type] > 0) {
if (nla_len(nla) != ovs_key_lens[type])
return -EINVAL;
switch (type) {
case OVS_KEY_ATTR_PRIORITY:
*priority = nla_get_u32(nla);
break;
case OVS_KEY_ATTR_IN_PORT:
if (nla_get_u32(nla) >= DP_MAX_PORTS)
return -EINVAL;
*in_port = nla_get_u32(nla);
break;
}
}
}
if (rem)
return -EINVAL;
return 0;
}
int ovs_flow_to_nlattrs(const struct sw_flow_key *swkey, struct sk_buff *skb)
{
struct ovs_key_ethernet *eth_key;
struct nlattr *nla, *encap;
if (swkey->phy.priority &&
nla_put_u32(skb, OVS_KEY_ATTR_PRIORITY, swkey->phy.priority))
goto nla_put_failure;
if (swkey->phy.in_port != USHRT_MAX &&
nla_put_u32(skb, OVS_KEY_ATTR_IN_PORT, swkey->phy.in_port))
goto nla_put_failure;
nla = nla_reserve(skb, OVS_KEY_ATTR_ETHERNET, sizeof(*eth_key));
if (!nla)
goto nla_put_failure;
eth_key = nla_data(nla);
memcpy(eth_key->eth_src, swkey->eth.src, ETH_ALEN);
memcpy(eth_key->eth_dst, swkey->eth.dst, ETH_ALEN);
if (swkey->eth.tci || swkey->eth.type == htons(ETH_P_8021Q)) {
if (nla_put_be16(skb, OVS_KEY_ATTR_ETHERTYPE, htons(ETH_P_8021Q)) ||
nla_put_be16(skb, OVS_KEY_ATTR_VLAN, swkey->eth.tci))
goto nla_put_failure;
encap = nla_nest_start(skb, OVS_KEY_ATTR_ENCAP);
if (!swkey->eth.tci)
goto unencap;
} else {
encap = NULL;
}
if (swkey->eth.type == htons(ETH_P_802_2))
goto unencap;
if (nla_put_be16(skb, OVS_KEY_ATTR_ETHERTYPE, swkey->eth.type))
goto nla_put_failure;
if (swkey->eth.type == htons(ETH_P_IP)) {
struct ovs_key_ipv4 *ipv4_key;
nla = nla_reserve(skb, OVS_KEY_ATTR_IPV4, sizeof(*ipv4_key));
if (!nla)
goto nla_put_failure;
ipv4_key = nla_data(nla);
ipv4_key->ipv4_src = swkey->ipv4.addr.src;
ipv4_key->ipv4_dst = swkey->ipv4.addr.dst;
ipv4_key->ipv4_proto = swkey->ip.proto;
ipv4_key->ipv4_tos = swkey->ip.tos;
ipv4_key->ipv4_ttl = swkey->ip.ttl;
ipv4_key->ipv4_frag = swkey->ip.frag;
} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
struct ovs_key_ipv6 *ipv6_key;
nla = nla_reserve(skb, OVS_KEY_ATTR_IPV6, sizeof(*ipv6_key));
if (!nla)
goto nla_put_failure;
ipv6_key = nla_data(nla);
memcpy(ipv6_key->ipv6_src, &swkey->ipv6.addr.src,
sizeof(ipv6_key->ipv6_src));
memcpy(ipv6_key->ipv6_dst, &swkey->ipv6.addr.dst,
sizeof(ipv6_key->ipv6_dst));
ipv6_key->ipv6_label = swkey->ipv6.label;
ipv6_key->ipv6_proto = swkey->ip.proto;
ipv6_key->ipv6_tclass = swkey->ip.tos;
ipv6_key->ipv6_hlimit = swkey->ip.ttl;
ipv6_key->ipv6_frag = swkey->ip.frag;
} else if (swkey->eth.type == htons(ETH_P_ARP)) {
struct ovs_key_arp *arp_key;
nla = nla_reserve(skb, OVS_KEY_ATTR_ARP, sizeof(*arp_key));
if (!nla)
goto nla_put_failure;
arp_key = nla_data(nla);
memset(arp_key, 0, sizeof(struct ovs_key_arp));
arp_key->arp_sip = swkey->ipv4.addr.src;
arp_key->arp_tip = swkey->ipv4.addr.dst;
arp_key->arp_op = htons(swkey->ip.proto);
memcpy(arp_key->arp_sha, swkey->ipv4.arp.sha, ETH_ALEN);
memcpy(arp_key->arp_tha, swkey->ipv4.arp.tha, ETH_ALEN);
}
if ((swkey->eth.type == htons(ETH_P_IP) ||
swkey->eth.type == htons(ETH_P_IPV6)) &&
swkey->ip.frag != OVS_FRAG_TYPE_LATER) {
if (swkey->ip.proto == IPPROTO_TCP) {
struct ovs_key_tcp *tcp_key;
nla = nla_reserve(skb, OVS_KEY_ATTR_TCP, sizeof(*tcp_key));
if (!nla)
goto nla_put_failure;
tcp_key = nla_data(nla);
if (swkey->eth.type == htons(ETH_P_IP)) {
tcp_key->tcp_src = swkey->ipv4.tp.src;
tcp_key->tcp_dst = swkey->ipv4.tp.dst;
} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
tcp_key->tcp_src = swkey->ipv6.tp.src;
tcp_key->tcp_dst = swkey->ipv6.tp.dst;
}
} else if (swkey->ip.proto == IPPROTO_UDP) {
struct ovs_key_udp *udp_key;
nla = nla_reserve(skb, OVS_KEY_ATTR_UDP, sizeof(*udp_key));
if (!nla)
goto nla_put_failure;
udp_key = nla_data(nla);
if (swkey->eth.type == htons(ETH_P_IP)) {
udp_key->udp_src = swkey->ipv4.tp.src;
udp_key->udp_dst = swkey->ipv4.tp.dst;
} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
udp_key->udp_src = swkey->ipv6.tp.src;
udp_key->udp_dst = swkey->ipv6.tp.dst;
}
} else if (swkey->eth.type == htons(ETH_P_IP) &&
swkey->ip.proto == IPPROTO_ICMP) {
struct ovs_key_icmp *icmp_key;
nla = nla_reserve(skb, OVS_KEY_ATTR_ICMP, sizeof(*icmp_key));
if (!nla)
goto nla_put_failure;
icmp_key = nla_data(nla);
icmp_key->icmp_type = ntohs(swkey->ipv4.tp.src);
icmp_key->icmp_code = ntohs(swkey->ipv4.tp.dst);
} else if (swkey->eth.type == htons(ETH_P_IPV6) &&
swkey->ip.proto == IPPROTO_ICMPV6) {
struct ovs_key_icmpv6 *icmpv6_key;
nla = nla_reserve(skb, OVS_KEY_ATTR_ICMPV6,
sizeof(*icmpv6_key));
if (!nla)
goto nla_put_failure;
icmpv6_key = nla_data(nla);
icmpv6_key->icmpv6_type = ntohs(swkey->ipv6.tp.src);
icmpv6_key->icmpv6_code = ntohs(swkey->ipv6.tp.dst);
if (icmpv6_key->icmpv6_type == NDISC_NEIGHBOUR_SOLICITATION ||
icmpv6_key->icmpv6_type == NDISC_NEIGHBOUR_ADVERTISEMENT) {
struct ovs_key_nd *nd_key;
nla = nla_reserve(skb, OVS_KEY_ATTR_ND, sizeof(*nd_key));
if (!nla)
goto nla_put_failure;
nd_key = nla_data(nla);
memcpy(nd_key->nd_target, &swkey->ipv6.nd.target,
sizeof(nd_key->nd_target));
memcpy(nd_key->nd_sll, swkey->ipv6.nd.sll, ETH_ALEN);
memcpy(nd_key->nd_tll, swkey->ipv6.nd.tll, ETH_ALEN);
}
}
}
unencap:
if (encap)
nla_nest_end(skb, encap);
return 0;
nla_put_failure:
return -EMSGSIZE;
}
/* Initializes the flow module.
* Returns zero if successful or a negative error code. */
int ovs_flow_init(void)
{
flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow), 0,
0, NULL);
if (flow_cache == NULL)
return -ENOMEM;
return 0;
}
/* Uninitializes the flow module. */
void ovs_flow_exit(void)
{
kmem_cache_destroy(flow_cache);
}
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