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flow.c
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/*
* Copyright (c) 2007-2013 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/ip_tunnels.h>
#include <net/ipv6.h>
#include <net/ndisc.h>
static struct kmem_cache *flow_cache;
static void ovs_sw_flow_mask_set(struct sw_flow_mask *mask,
struct sw_flow_key_range *range, u8 val);
static void update_range__(struct sw_flow_match *match,
size_t offset, size_t size, bool is_mask)
{
struct sw_flow_key_range *range = NULL;
size_t start = offset;
size_t end = offset + size;
if (!is_mask)
range = &match->range;
else if (match->mask)
range = &match->mask->range;
if (!range)
return;
if (range->start == range->end) {
range->start = start;
range->end = end;
return;
}
if (range->start > start)
range->start = start;
if (range->end < end)
range->end = end;
}
#define SW_FLOW_KEY_PUT(match, field, value, is_mask) \
do { \
update_range__(match, offsetof(struct sw_flow_key, field), \
sizeof((match)->key->field), is_mask); \
if (is_mask) { \
if ((match)->mask) \
(match)->mask->key.field = value; \
} else { \
(match)->key->field = value; \
} \
} while (0)
#define SW_FLOW_KEY_MEMCPY(match, field, value_p, len, is_mask) \
do { \
update_range__(match, offsetof(struct sw_flow_key, field), \
len, is_mask); \
if (is_mask) { \
if ((match)->mask) \
memcpy(&(match)->mask->key.field, value_p, len);\
} else { \
memcpy(&(match)->key->field, value_p, len); \
} \
} while (0)
void ovs_match_init(struct sw_flow_match *match,
struct sw_flow_key *key,
struct sw_flow_mask *mask)
{
memset(match, 0, sizeof(*match));
match->key = key;
match->mask = mask;
memset(key, 0, sizeof(*key));
if (mask) {
memset(&mask->key, 0, sizeof(mask->key));
mask->range.start = mask->range.end = 0;
}
}
static bool ovs_match_validate(const struct sw_flow_match *match,
u64 key_attrs, u64 mask_attrs)
{
u64 key_expected = 1 << OVS_KEY_ATTR_ETHERNET;
u64 mask_allowed = key_attrs; /* At most allow all key attributes */
/* The following mask attributes allowed only if they
* pass the validation tests. */
mask_allowed &= ~((1 << OVS_KEY_ATTR_IPV4)
| (1 << OVS_KEY_ATTR_IPV6)
| (1 << OVS_KEY_ATTR_TCP)
| (1 << OVS_KEY_ATTR_UDP)
| (1 << OVS_KEY_ATTR_ICMP)
| (1 << OVS_KEY_ATTR_ICMPV6)
| (1 << OVS_KEY_ATTR_ARP)
| (1 << OVS_KEY_ATTR_ND));
/* Always allowed mask fields. */
mask_allowed |= ((1 << OVS_KEY_ATTR_TUNNEL)
| (1 << OVS_KEY_ATTR_IN_PORT)
| (1 << OVS_KEY_ATTR_ETHERTYPE));
/* Check key attributes. */
if (match->key->eth.type == htons(ETH_P_ARP)
|| match->key->eth.type == htons(ETH_P_RARP)) {
key_expected |= 1 << OVS_KEY_ATTR_ARP;
if (match->mask && (match->mask->key.eth.type == htons(0xffff)))
mask_allowed |= 1 << OVS_KEY_ATTR_ARP;
}
if (match->key->eth.type == htons(ETH_P_IP)) {
key_expected |= 1 << OVS_KEY_ATTR_IPV4;
if (match->mask && (match->mask->key.eth.type == htons(0xffff)))
mask_allowed |= 1 << OVS_KEY_ATTR_IPV4;
if (match->key->ip.frag != OVS_FRAG_TYPE_LATER) {
if (match->key->ip.proto == IPPROTO_UDP) {
key_expected |= 1 << OVS_KEY_ATTR_UDP;
if (match->mask && (match->mask->key.ip.proto == 0xff))
mask_allowed |= 1 << OVS_KEY_ATTR_UDP;
}
if (match->key->ip.proto == IPPROTO_TCP) {
key_expected |= 1 << OVS_KEY_ATTR_TCP;
if (match->mask && (match->mask->key.ip.proto == 0xff))
mask_allowed |= 1 << OVS_KEY_ATTR_TCP;
}
if (match->key->ip.proto == IPPROTO_ICMP) {
key_expected |= 1 << OVS_KEY_ATTR_ICMP;
if (match->mask && (match->mask->key.ip.proto == 0xff))
mask_allowed |= 1 << OVS_KEY_ATTR_ICMP;
}
}
}
if (match->key->eth.type == htons(ETH_P_IPV6)) {
key_expected |= 1 << OVS_KEY_ATTR_IPV6;
if (match->mask && (match->mask->key.eth.type == htons(0xffff)))
mask_allowed |= 1 << OVS_KEY_ATTR_IPV6;
if (match->key->ip.frag != OVS_FRAG_TYPE_LATER) {
if (match->key->ip.proto == IPPROTO_UDP) {
key_expected |= 1 << OVS_KEY_ATTR_UDP;
if (match->mask && (match->mask->key.ip.proto == 0xff))
mask_allowed |= 1 << OVS_KEY_ATTR_UDP;
}
if (match->key->ip.proto == IPPROTO_TCP) {
key_expected |= 1 << OVS_KEY_ATTR_TCP;
if (match->mask && (match->mask->key.ip.proto == 0xff))
mask_allowed |= 1 << OVS_KEY_ATTR_TCP;
}
if (match->key->ip.proto == IPPROTO_ICMPV6) {
key_expected |= 1 << OVS_KEY_ATTR_ICMPV6;
if (match->mask && (match->mask->key.ip.proto == 0xff))
mask_allowed |= 1 << OVS_KEY_ATTR_ICMPV6;
if (match->key->ipv6.tp.src ==
htons(NDISC_NEIGHBOUR_SOLICITATION) ||
match->key->ipv6.tp.src == htons(NDISC_NEIGHBOUR_ADVERTISEMENT)) {
key_expected |= 1 << OVS_KEY_ATTR_ND;
if (match->mask && (match->mask->key.ipv6.tp.src == htons(0xffff)))
mask_allowed |= 1 << OVS_KEY_ATTR_ND;
}
}
}
}
if ((key_attrs & key_expected) != key_expected) {
/* Key attributes check failed. */
OVS_NLERR("Missing expected key attributes (key_attrs=%llx, expected=%llx).\n",
key_attrs, key_expected);
return false;
}
if ((mask_attrs & mask_allowed) != mask_attrs) {
/* Mask attributes check failed. */
OVS_NLERR("Contain more than allowed mask fields (mask_attrs=%llx, mask_allowed=%llx).\n",
mask_attrs, mask_allowed);
return false;
}
return true;
}
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;
}
static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key)
{
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;
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));
}
void ovs_flow_key_mask(struct sw_flow_key *dst, const struct sw_flow_key *src,
const struct sw_flow_mask *mask)
{
u8 *m = (u8 *)&mask->key + mask->range.start;
u8 *s = (u8 *)src + mask->range.start;
u8 *d = (u8 *)dst + mask->range.start;
int i;
memset(dst, 0, sizeof(*dst));
for (i = 0; i < ovs_sw_flow_mask_size_roundup(mask); i++) {
*d = *s & *m;
d++, s++, m++;
}
}
#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(int size)
{
struct sw_flow_actions *sfa;
if (size > MAX_ACTIONS_BUFSIZE)
return ERR_PTR(-EINVAL);
sfa = kmalloc(sizeof(*sfa) + size, GFP_KERNEL);
if (!sfa)
return ERR_PTR(-ENOMEM);
sfa->actions_len = 0;
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;
flow->mask = 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);
}
static struct flow_table *__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));
table->mask_list = NULL;
return table;
}
static void __flow_tbl_destroy(struct flow_table *table)
{
int i;
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 *n;
int ver = table->node_ver;
hlist_for_each_entry_safe(flow, n, head, hash_node[ver]) {
hlist_del(&flow->hash_node[ver]);
ovs_flow_free(flow, false);
}
}
BUG_ON(!list_empty(table->mask_list));
kfree(table->mask_list);
skip_flows:
free_buckets(table->buckets);
kfree(table);
}
struct flow_table *ovs_flow_tbl_alloc(int new_size)
{
struct flow_table *table = __flow_tbl_alloc(new_size);
if (!table)
return NULL;
table->mask_list = kmalloc(sizeof(struct list_head), GFP_KERNEL);
if (!table->mask_list) {
table->keep_flows = true;
__flow_tbl_destroy(table);
return NULL;
}
INIT_LIST_HEAD(table->mask_list);
return table;
}
static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
{
struct flow_table *table = container_of(rcu, struct flow_table, rcu);
__flow_tbl_destroy(table);
}
void ovs_flow_tbl_destroy(struct flow_table *table, bool deferred)
{
if (!table)
return;
if (deferred)
call_rcu(&table->rcu, flow_tbl_destroy_rcu_cb);
else
__flow_tbl_destroy(table);
}
struct sw_flow *ovs_flow_dump_next(struct flow_table *table, u32 *bucket, u32 *last)
{
struct sw_flow *flow;
struct hlist_head *head;
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, head, hash_node[ver]) {
if (i < *last) {
i++;
continue;
}
*last = i + 1;
return flow;
}
(*bucket)++;
*last = 0;
}
return NULL;
}
static void __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++;
}
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;
head = flex_array_get(old->buckets, i);
hlist_for_each_entry(flow, head, hash_node[old_ver])
__tbl_insert(new, flow);
}
new->mask_list = old->mask_list;
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 = __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);
}
static void __flow_free(struct sw_flow *flow)
{
kfree((struct sf_flow_acts __force *)flow->sf_acts);
kmem_cache_free(flow_cache, flow);
}
static void rcu_free_flow_callback(struct rcu_head *rcu)
{
struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
__flow_free(flow);
}
void ovs_flow_free(struct sw_flow *flow, bool deferred)
{
if (!flow)
return;
ovs_sw_flow_mask_del_ref(flow->mask, deferred);
if (deferred)
call_rcu(&flow->rcu, rcu_free_flow_callback);
else
__flow_free(flow);
}
/* 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)
{
kfree_rcu(sf_acts, rcu);
}
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) >= ETH_P_802_3_MIN)
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));
if (ntohs(llc->ethertype) >= ETH_P_802_3_MIN)
return llc->ethertype;
return htons(ETH_P_802_2);
}
static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key,
int nh_len)
{
struct icmp6hdr *icmp = icmp6_hdr(skb);
/* 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);
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;
/* In order to process neighbor discovery options, we need the
* entire packet.
*/
if (unlikely(icmp_len < sizeof(*nd)))
return 0;
if (unlikely(skb_linearize(skb)))
return -ENOMEM;
nd = (struct nd_msg *)skb_transport_header(skb);
key->ipv6.nd.target = nd->target;
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))
return 0;
/* 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;
}
}
return 0;
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));
return 0;
}
/**
* 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
*
* 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->eth.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->eth.type values it is left untouched.
*/
int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key)
{
int error;
struct ethhdr *eth;
memset(key, 0, sizeof(*key));
key->phy.priority = skb->priority;
if (OVS_CB(skb)->tun_key)
memcpy(&key->tun_key, OVS_CB(skb)->tun_key, sizeof(key->tun_key));
key->phy.in_port = in_port;
key->phy.skb_mark = skb->mark;
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);
/* We are going to push all headers that we pull, so no need to
* update skb->csum here.
*/
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;
error = check_iphdr(skb);
if (unlikely(error)) {
if (error == -EINVAL) {
skb->transport_header = skb->network_header;
error = 0;
}
return error;
}
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;
return 0;
}
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) {
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) {
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) {
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) ||
key->eth.type == htons(ETH_P_RARP)) && 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);
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);
}
} else if (key->eth.type == htons(ETH_P_IPV6)) {
int nh_len; /* IPv6 Header + Extensions */
nh_len = parse_ipv6hdr(skb, key);
if (unlikely(nh_len < 0)) {
if (nh_len == -EINVAL) {
skb->transport_header = skb->network_header;
error = 0;
} else {
error = nh_len;
}
return error;
}
if (key->ip.frag == OVS_FRAG_TYPE_LATER)
return 0;
if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
key->ip.frag = OVS_FRAG_TYPE_FIRST;
/* Transport layer. */
if (key->ip.proto == NEXTHDR_TCP) {
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) {
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) {
if (icmp6hdr_ok(skb)) {
error = parse_icmpv6(skb, key, nh_len);
if (error)
return error;
}
}
}
return 0;
}
static u32 ovs_flow_hash(const struct sw_flow_key *key, int key_start, int key_len)
{
return jhash2((u32 *)((u8 *)key + key_start),
DIV_ROUND_UP(key_len - key_start, sizeof(u32)), 0);
}
static int flow_key_start(const struct sw_flow_key *key)
{
if (key->tun_key.ipv4_dst)
return 0;
else
return offsetof(struct sw_flow_key, phy);
}
static bool __cmp_key(const struct sw_flow_key *key1,
const struct sw_flow_key *key2, int key_start, int key_len)
{
return !memcmp((u8 *)key1 + key_start,
(u8 *)key2 + key_start, (key_len - key_start));
}
static bool __flow_cmp_key(const struct sw_flow *flow,
const struct sw_flow_key *key, int key_start, int key_len)
{
return __cmp_key(&flow->key, key, key_start, key_len);
}
static bool __flow_cmp_unmasked_key(const struct sw_flow *flow,
const struct sw_flow_key *key, int key_start, int key_len)
{
return __cmp_key(&flow->unmasked_key, key, key_start, key_len);
}