+#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/export.h>
#include <linux/ip.h>
#include <linux/if_tunnel.h>
#include <linux/if_pppox.h>
#include <linux/ppp_defs.h>
+#include <linux/stddef.h>
+#include <linux/if_ether.h>
#include <net/flow_dissector.h>
#include <scsi/fc/fc_fcoe.h>
-/* copy saddr & daddr, possibly using 64bit load/store
- * Equivalent to : flow->src = iph->saddr;
- * flow->dst = iph->daddr;
- */
-static void iph_to_flow_copy_addrs(struct flow_keys *flow, const struct iphdr *iph)
+static bool skb_flow_dissector_uses_key(struct flow_dissector *flow_dissector,
+ enum flow_dissector_key_id key_id)
+{
+ return flow_dissector->used_keys & (1 << key_id);
+}
+
+static void skb_flow_dissector_set_key(struct flow_dissector *flow_dissector,
+ enum flow_dissector_key_id key_id)
+{
+ flow_dissector->used_keys |= (1 << key_id);
+}
+
+static void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
+ enum flow_dissector_key_id key_id,
+ void *target_container)
{
- BUILD_BUG_ON(offsetof(typeof(*flow), dst) !=
- offsetof(typeof(*flow), src) + sizeof(flow->src));
- memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst));
+ return ((char *) target_container) + flow_dissector->offset[key_id];
}
+void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
+ const struct flow_dissector_key *key,
+ unsigned int key_count)
+{
+ unsigned int i;
+
+ memset(flow_dissector, 0, sizeof(*flow_dissector));
+
+ for (i = 0; i < key_count; i++, key++) {
+ /* User should make sure that every key target offset is withing
+ * boundaries of unsigned short.
+ */
+ BUG_ON(key->offset > USHRT_MAX);
+ BUG_ON(skb_flow_dissector_uses_key(flow_dissector,
+ key->key_id));
+
+ skb_flow_dissector_set_key(flow_dissector, key->key_id);
+ flow_dissector->offset[key->key_id] = key->offset;
+ }
+
+ /* Ensure that the dissector always includes basic key. That way
+ * we are able to avoid handling lack of it in fast path.
+ */
+ BUG_ON(!skb_flow_dissector_uses_key(flow_dissector,
+ FLOW_DISSECTOR_KEY_BASIC));
+}
+EXPORT_SYMBOL(skb_flow_dissector_init);
+
/**
* __skb_flow_get_ports - extract the upper layer ports and return them
* @skb: sk_buff to extract the ports from
/**
* __skb_flow_dissect - extract the flow_keys struct and return it
* @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
+ * @flow_dissector: list of keys to dissect
+ * @target_container: target structure to put dissected values into
* @data: raw buffer pointer to the packet, if NULL use skb->data
* @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
* @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
* @hlen: packet header length, if @data is NULL use skb_headlen(skb)
*
- * The function will try to retrieve the struct flow_keys from either the skbuff
- * or a raw buffer specified by the rest parameters
+ * The function will try to retrieve individual keys into target specified
+ * by flow_dissector from either the skbuff or a raw buffer specified by the
+ * rest parameters.
+ *
+ * Caller must take care of zeroing target container memory.
*/
-bool __skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow,
+bool __skb_flow_dissect(const struct sk_buff *skb,
+ struct flow_dissector *flow_dissector,
+ void *target_container,
void *data, __be16 proto, int nhoff, int hlen)
{
+ struct flow_dissector_key_basic *key_basic;
+ struct flow_dissector_key_addrs *key_addrs;
+ struct flow_dissector_key_ports *key_ports;
u8 ip_proto;
if (!data) {
hlen = skb_headlen(skb);
}
- memset(flow, 0, sizeof(*flow));
+ /* It is ensured by skb_flow_dissector_init() that basic key will
+ * be always present.
+ */
+ key_basic = skb_flow_dissector_target(flow_dissector,
+ FLOW_DISSECTOR_KEY_BASIC,
+ target_container);
+
+ if (skb_flow_dissector_uses_key(flow_dissector,
+ FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
+ struct ethhdr *eth = eth_hdr(skb);
+ struct flow_dissector_key_eth_addrs *key_eth_addrs;
+
+ key_eth_addrs = skb_flow_dissector_target(flow_dissector,
+ FLOW_DISSECTOR_KEY_ETH_ADDRS,
+ target_container);
+ memcpy(key_eth_addrs, ð->h_dest, sizeof(*key_eth_addrs));
+ }
again:
switch (proto) {
if (ip_is_fragment(iph))
ip_proto = 0;
- /* skip the address processing if skb is NULL. The assumption
- * here is that if there is no skb we are not looking for flow
- * info but lengths and protocols.
- */
- if (!skb)
+ if (!skb_flow_dissector_uses_key(flow_dissector,
+ FLOW_DISSECTOR_KEY_IPV4_ADDRS))
break;
-
- iph_to_flow_copy_addrs(flow, iph);
+ key_addrs = skb_flow_dissector_target(flow_dissector,
+ FLOW_DISSECTOR_KEY_IPV4_ADDRS,
+ target_container);
+ memcpy(key_addrs, &iph->saddr, sizeof(*key_addrs));
break;
}
case htons(ETH_P_IPV6): {
ip_proto = iph->nexthdr;
nhoff += sizeof(struct ipv6hdr);
- /* see comment above in IPv4 section */
- if (!skb)
- break;
+ if (skb_flow_dissector_uses_key(flow_dissector,
+ FLOW_DISSECTOR_KEY_IPV6_HASH_ADDRS)) {
+ key_addrs = skb_flow_dissector_target(flow_dissector,
+ FLOW_DISSECTOR_KEY_IPV6_HASH_ADDRS,
+ target_container);
- flow->src = (__force __be32)ipv6_addr_hash(&iph->saddr);
- flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr);
+ key_addrs->src = (__force __be32)ipv6_addr_hash(&iph->saddr);
+ key_addrs->dst = (__force __be32)ipv6_addr_hash(&iph->daddr);
+ goto flow_label;
+ }
+ if (skb_flow_dissector_uses_key(flow_dissector,
+ FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
+ struct flow_dissector_key_ipv6_addrs *key_ipv6_addrs;
+
+ key_ipv6_addrs = skb_flow_dissector_target(flow_dissector,
+ FLOW_DISSECTOR_KEY_IPV6_ADDRS,
+ target_container);
+ memcpy(key_ipv6_addrs, &iph->saddr, sizeof(*key_ipv6_addrs));
+ goto flow_label;
+ }
+ break;
+flow_label:
flow_label = ip6_flowlabel(iph);
if (flow_label) {
/* Awesome, IPv6 packet has a flow label so we can
* use that to represent the ports without any
* further dissection.
*/
- flow->n_proto = proto;
- flow->ip_proto = ip_proto;
- flow->ports = flow_label;
- flow->thoff = (u16)nhoff;
+
+ key_basic->n_proto = proto;
+ key_basic->ip_proto = ip_proto;
+ key_basic->thoff = (u16)nhoff;
+
+ if (skb_flow_dissector_uses_key(flow_dissector,
+ FLOW_DISSECTOR_KEY_PORTS)) {
+ key_ports = skb_flow_dissector_target(flow_dissector,
+ FLOW_DISSECTOR_KEY_PORTS,
+ target_container);
+ key_ports->ports = flow_label;
+ }
return true;
}
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
if (!hdr)
return false;
- flow->src = hdr->srcnode;
- flow->dst = 0;
- flow->n_proto = proto;
- flow->thoff = (u16)nhoff;
+ key_basic->n_proto = proto;
+ key_basic->thoff = (u16)nhoff;
+
+ if (skb_flow_dissector_uses_key(flow_dissector,
+ FLOW_DISSECTOR_KEY_IPV6_HASH_ADDRS)) {
+ key_addrs = skb_flow_dissector_target(flow_dissector,
+ FLOW_DISSECTOR_KEY_IPV6_HASH_ADDRS,
+ target_container);
+ key_addrs->src = hdr->srcnode;
+ key_addrs->dst = 0;
+ }
return true;
}
case htons(ETH_P_FCOE):
- flow->thoff = (u16)(nhoff + FCOE_HEADER_LEN);
+ key_basic->thoff = (u16)(nhoff + FCOE_HEADER_LEN);
/* fall through */
default:
return false;
break;
}
- flow->n_proto = proto;
- flow->ip_proto = ip_proto;
- flow->thoff = (u16) nhoff;
-
- /* unless skb is set we don't need to record port info */
- if (skb)
- flow->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
- data, hlen);
+ /* It is ensured by skb_flow_dissector_init() that basic key will
+ * be always present.
+ */
+ key_basic = skb_flow_dissector_target(flow_dissector,
+ FLOW_DISSECTOR_KEY_BASIC,
+ target_container);
+ key_basic->n_proto = proto;
+ key_basic->ip_proto = ip_proto;
+ key_basic->thoff = (u16) nhoff;
+
+ if (skb_flow_dissector_uses_key(flow_dissector,
+ FLOW_DISSECTOR_KEY_PORTS)) {
+ key_ports = skb_flow_dissector_target(flow_dissector,
+ FLOW_DISSECTOR_KEY_PORTS,
+ target_container);
+ key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
+ data, hlen);
+ }
return true;
}
u32 hash;
/* get a consistent hash (same value on both flow directions) */
- if (((__force u32)keys->dst < (__force u32)keys->src) ||
- (((__force u32)keys->dst == (__force u32)keys->src) &&
- ((__force u16)keys->port16[1] < (__force u16)keys->port16[0]))) {
- swap(keys->dst, keys->src);
- swap(keys->port16[0], keys->port16[1]);
+ if (((__force u32)keys->addrs.dst < (__force u32)keys->addrs.src) ||
+ (((__force u32)keys->addrs.dst == (__force u32)keys->addrs.src) &&
+ ((__force u16)keys->ports.dst < (__force u16)keys->ports.src))) {
+ swap(keys->addrs.dst, keys->addrs.src);
+ swap(keys->ports.src, keys->ports.dst);
}
- hash = __flow_hash_3words((__force u32)keys->dst,
- (__force u32)keys->src,
- (__force u32)keys->ports,
+ hash = __flow_hash_3words((__force u32)keys->addrs.dst,
+ (__force u32)keys->addrs.src,
+ (__force u32)keys->ports.ports,
keyval);
if (!hash)
hash = 1;
static inline u32 ___skb_get_hash(const struct sk_buff *skb,
struct flow_keys *keys, u32 keyval)
{
- if (!skb_flow_dissect(skb, keys))
+ if (!skb_flow_dissect_flow_keys(skb, keys))
return 0;
return __flow_hash_from_keys(keys, keyval);
memset(digest, 0, sizeof(*digest));
- data->n_proto = flow->n_proto;
- data->ip_proto = flow->ip_proto;
- data->ports = flow->ports;
- data->src = flow->src;
- data->dst = flow->dst;
+ data->n_proto = flow->basic.n_proto;
+ data->ip_proto = flow->basic.ip_proto;
+ data->ports = flow->ports.ports;
+ data->src = flow->addrs.src;
+ data->dst = flow->addrs.dst;
}
EXPORT_SYMBOL(make_flow_keys_digest);
hash = ___skb_get_hash(skb, &keys, hashrnd);
if (!hash)
return;
- if (keys.ports)
+ if (keys.ports.ports)
skb->l4_hash = 1;
skb->sw_hash = 1;
skb->hash = hash;
u32 __skb_get_poff(const struct sk_buff *skb, void *data,
const struct flow_keys *keys, int hlen)
{
- u32 poff = keys->thoff;
+ u32 poff = keys->basic.thoff;
- switch (keys->ip_proto) {
+ switch (keys->basic.ip_proto) {
case IPPROTO_TCP: {
/* access doff as u8 to avoid unaligned access */
const u8 *doff;
{
struct flow_keys keys;
- if (!skb_flow_dissect(skb, &keys))
+ if (!skb_flow_dissect_flow_keys(skb, &keys))
return 0;
return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
}
+
+static const struct flow_dissector_key flow_keys_dissector_keys[] = {
+ {
+ .key_id = FLOW_DISSECTOR_KEY_BASIC,
+ .offset = offsetof(struct flow_keys, basic),
+ },
+ {
+ .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
+ .offset = offsetof(struct flow_keys, addrs),
+ },
+ {
+ .key_id = FLOW_DISSECTOR_KEY_IPV6_HASH_ADDRS,
+ .offset = offsetof(struct flow_keys, addrs),
+ },
+ {
+ .key_id = FLOW_DISSECTOR_KEY_PORTS,
+ .offset = offsetof(struct flow_keys, ports),
+ },
+};
+
+static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
+ {
+ .key_id = FLOW_DISSECTOR_KEY_BASIC,
+ .offset = offsetof(struct flow_keys, basic),
+ },
+};
+
+struct flow_dissector flow_keys_dissector __read_mostly;
+EXPORT_SYMBOL(flow_keys_dissector);
+
+struct flow_dissector flow_keys_buf_dissector __read_mostly;
+
+static int __init init_default_flow_dissectors(void)
+{
+ skb_flow_dissector_init(&flow_keys_dissector,
+ flow_keys_dissector_keys,
+ ARRAY_SIZE(flow_keys_dissector_keys));
+ skb_flow_dissector_init(&flow_keys_buf_dissector,
+ flow_keys_buf_dissector_keys,
+ ARRAY_SIZE(flow_keys_buf_dissector_keys));
+ return 0;
+}
+
+late_initcall_sync(init_default_flow_dissectors);
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