1 files changed, 405 insertions, 0 deletions

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
new file mode 100644
index 00000000000..107ed12a532
--- /dev/null
+++ b/net/core/flow_dissector.c
@@ -0,0 +1,405 @@
+#include <linux/skbuff.h>
+#include <linux/export.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/if_vlan.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+#include <linux/igmp.h>
+#include <linux/icmp.h>
+#include <linux/sctp.h>
+#include <linux/dccp.h>
+#include <linux/if_tunnel.h>
+#include <linux/if_pppox.h>
+#include <linux/ppp_defs.h>
+#include <net/flow_keys.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)
+{
+	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));
+}
+
+/**
+ * skb_flow_get_ports - extract the upper layer ports and return them
+ * @skb: buffer to extract the ports from
+ * @thoff: transport header offset
+ * @ip_proto: protocol for which to get port offset
+ *
+ * The function will try to retrieve the ports at offset thoff + poff where poff
+ * is the protocol port offset returned from proto_ports_offset
+ */
+__be32 skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto)
+{
+	int poff = proto_ports_offset(ip_proto);
+
+	if (poff >= 0) {
+		__be32 *ports, _ports;
+
+		ports = skb_header_pointer(skb, thoff + poff,
+					   sizeof(_ports), &_ports);
+		if (ports)
+			return *ports;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(skb_flow_get_ports);
+
+bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow)
+{
+	int nhoff = skb_network_offset(skb);
+	u8 ip_proto;
+	__be16 proto = skb->protocol;
+
+	memset(flow, 0, sizeof(*flow));
+
+again:
+	switch (proto) {
+	case htons(ETH_P_IP): {
+		const struct iphdr *iph;
+		struct iphdr _iph;
+ip:
+		iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
+		if (!iph || iph->ihl < 5)
+			return false;
+		nhoff += iph->ihl * 4;
+
+		ip_proto = iph->protocol;
+		if (ip_is_fragment(iph))
+			ip_proto = 0;
+
+		iph_to_flow_copy_addrs(flow, iph);
+		break;
+	}
+	case htons(ETH_P_IPV6): {
+		const struct ipv6hdr *iph;
+		struct ipv6hdr _iph;
+ipv6:
+		iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
+		if (!iph)
+			return false;
+
+		ip_proto = iph->nexthdr;
+		flow->src = (__force __be32)ipv6_addr_hash(&iph->saddr);
+		flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr);
+		nhoff += sizeof(struct ipv6hdr);
+		break;
+	}
+	case htons(ETH_P_8021AD):
+	case htons(ETH_P_8021Q): {
+		const struct vlan_hdr *vlan;
+		struct vlan_hdr _vlan;
+
+		vlan = skb_header_pointer(skb, nhoff, sizeof(_vlan), &_vlan);
+		if (!vlan)
+			return false;
+
+		proto = vlan->h_vlan_encapsulated_proto;
+		nhoff += sizeof(*vlan);
+		goto again;
+	}
+	case htons(ETH_P_PPP_SES): {
+		struct {
+			struct pppoe_hdr hdr;
+			__be16 proto;
+		} *hdr, _hdr;
+		hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
+		if (!hdr)
+			return false;
+		proto = hdr->proto;
+		nhoff += PPPOE_SES_HLEN;
+		switch (proto) {
+		case htons(PPP_IP):
+			goto ip;
+		case htons(PPP_IPV6):
+			goto ipv6;
+		default:
+			return false;
+		}
+	}
+	default:
+		return false;
+	}
+
+	switch (ip_proto) {
+	case IPPROTO_GRE: {
+		struct gre_hdr {
+			__be16 flags;
+			__be16 proto;
+		} *hdr, _hdr;
+
+		hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
+		if (!hdr)
+			return false;
+		/*
+		 * Only look inside GRE if version zero and no
+		 * routing
+		 */
+		if (!(hdr->flags & (GRE_VERSION|GRE_ROUTING))) {
+			proto = hdr->proto;
+			nhoff += 4;
+			if (hdr->flags & GRE_CSUM)
+				nhoff += 4;
+			if (hdr->flags & GRE_KEY)
+				nhoff += 4;
+			if (hdr->flags & GRE_SEQ)
+				nhoff += 4;
+			if (proto == htons(ETH_P_TEB)) {
+				const struct ethhdr *eth;
+				struct ethhdr _eth;
+
+				eth = skb_header_pointer(skb, nhoff,
+							 sizeof(_eth), &_eth);
+				if (!eth)
+					return false;
+				proto = eth->h_proto;
+				nhoff += sizeof(*eth);
+			}
+			goto again;
+		}
+		break;
+	}
+	case IPPROTO_IPIP:
+		proto = htons(ETH_P_IP);
+		goto ip;
+	case IPPROTO_IPV6:
+		proto = htons(ETH_P_IPV6);
+		goto ipv6;
+	default:
+		break;
+	}
+
+	flow->ip_proto = ip_proto;
+	flow->ports = skb_flow_get_ports(skb, nhoff, ip_proto);
+	flow->thoff = (u16) nhoff;
+
+	return true;
+}
+EXPORT_SYMBOL(skb_flow_dissect);
+
+static u32 hashrnd __read_mostly;
+static __always_inline void __flow_hash_secret_init(void)
+{
+	net_get_random_once(&hashrnd, sizeof(hashrnd));
+}
+
+static __always_inline u32 __flow_hash_3words(u32 a, u32 b, u32 c)
+{
+	__flow_hash_secret_init();
+	return jhash_3words(a, b, c, hashrnd);
+}
+
+static __always_inline u32 __flow_hash_1word(u32 a)
+{
+	__flow_hash_secret_init();
+	return jhash_1word(a, hashrnd);
+}
+
+/*
+ * __skb_get_hash: calculate a flow hash based on src/dst addresses
+ * and src/dst port numbers.  Sets hash in skb to non-zero hash value
+ * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
+ * if hash is a canonical 4-tuple hash over transport ports.
+ */
+void __skb_get_hash(struct sk_buff *skb)
+{
+	struct flow_keys keys;
+	u32 hash;
+
+	if (!skb_flow_dissect(skb, &keys))
+		return;
+
+	if (keys.ports)
+		skb->l4_hash = 1;
+
+	/* 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]);
+	}
+
+	hash = __flow_hash_3words((__force u32)keys.dst,
+				  (__force u32)keys.src,
+				  (__force u32)keys.ports);
+	if (!hash)
+		hash = 1;
+
+	skb->hash = hash;
+}
+EXPORT_SYMBOL(__skb_get_hash);
+
+/*
+ * Returns a Tx hash based on the given packet descriptor a Tx queues' number
+ * to be used as a distribution range.
+ */
+u16 __skb_tx_hash(const struct net_device *dev, const struct sk_buff *skb,
+		  unsigned int num_tx_queues)
+{
+	u32 hash;
+	u16 qoffset = 0;
+	u16 qcount = num_tx_queues;
+
+	if (skb_rx_queue_recorded(skb)) {
+		hash = skb_get_rx_queue(skb);
+		while (unlikely(hash >= num_tx_queues))
+			hash -= num_tx_queues;
+		return hash;
+	}
+
+	if (dev->num_tc) {
+		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
+		qoffset = dev->tc_to_txq[tc].offset;
+		qcount = dev->tc_to_txq[tc].count;
+	}
+
+	if (skb->sk && skb->sk->sk_hash)
+		hash = skb->sk->sk_hash;
+	else
+		hash = (__force u16) skb->protocol;
+	hash = __flow_hash_1word(hash);
+
+	return (u16) (((u64) hash * qcount) >> 32) + qoffset;
+}
+EXPORT_SYMBOL(__skb_tx_hash);
+
+/* __skb_get_poff() returns the offset to the payload as far as it could
+ * be dissected. The main user is currently BPF, so that we can dynamically
+ * truncate packets without needing to push actual payload to the user
+ * space and can analyze headers only, instead.
+ */
+u32 __skb_get_poff(const struct sk_buff *skb)
+{
+	struct flow_keys keys;
+	u32 poff = 0;
+
+	if (!skb_flow_dissect(skb, &keys))
+		return 0;
+
+	poff += keys.thoff;
+	switch (keys.ip_proto) {
+	case IPPROTO_TCP: {
+		const struct tcphdr *tcph;
+		struct tcphdr _tcph;
+
+		tcph = skb_header_pointer(skb, poff, sizeof(_tcph), &_tcph);
+		if (!tcph)
+			return poff;
+
+		poff += max_t(u32, sizeof(struct tcphdr), tcph->doff * 4);
+		break;
+	}
+	case IPPROTO_UDP:
+	case IPPROTO_UDPLITE:
+		poff += sizeof(struct udphdr);
+		break;
+	/* For the rest, we do not really care about header
+	 * extensions at this point for now.
+	 */
+	case IPPROTO_ICMP:
+		poff += sizeof(struct icmphdr);
+		break;
+	case IPPROTO_ICMPV6:
+		poff += sizeof(struct icmp6hdr);
+		break;
+	case IPPROTO_IGMP:
+		poff += sizeof(struct igmphdr);
+		break;
+	case IPPROTO_DCCP:
+		poff += sizeof(struct dccp_hdr);
+		break;
+	case IPPROTO_SCTP:
+		poff += sizeof(struct sctphdr);
+		break;
+	}
+
+	return poff;
+}
+
+static inline int get_xps_queue(struct net_device *dev, struct sk_buff *skb)
+{
+#ifdef CONFIG_XPS
+	struct xps_dev_maps *dev_maps;
+	struct xps_map *map;
+	int queue_index = -1;
+
+	rcu_read_lock();
+	dev_maps = rcu_dereference(dev->xps_maps);
+	if (dev_maps) {
+		map = rcu_dereference(
+		    dev_maps->cpu_map[raw_smp_processor_id()]);
+		if (map) {
+			if (map->len == 1)
+				queue_index = map->queues[0];
+			else {
+				u32 hash;
+				if (skb->sk && skb->sk->sk_hash)
+					hash = skb->sk->sk_hash;
+				else
+					hash = (__force u16) skb->protocol ^
+					    skb->hash;
+				hash = __flow_hash_1word(hash);
+				queue_index = map->queues[
+				    ((u64)hash * map->len) >> 32];
+			}
+			if (unlikely(queue_index >= dev->real_num_tx_queues))
+				queue_index = -1;
+		}
+	}
+	rcu_read_unlock();
+
+	return queue_index;
+#else
+	return -1;
+#endif
+}
+
+static u16 __netdev_pick_tx(struct net_device *dev, struct sk_buff *skb)
+{
+	struct sock *sk = skb->sk;
+	int queue_index = sk_tx_queue_get(sk);
+
+	if (queue_index < 0 || skb->ooo_okay ||
+	    queue_index >= dev->real_num_tx_queues) {
+		int new_index = get_xps_queue(dev, skb);
+		if (new_index < 0)
+			new_index = skb_tx_hash(dev, skb);
+
+		if (queue_index != new_index && sk &&
+		    rcu_access_pointer(sk->sk_dst_cache))
+			sk_tx_queue_set(sk, new_index);
+
+		queue_index = new_index;
+	}
+
+	return queue_index;
+}
+
+struct netdev_queue *netdev_pick_tx(struct net_device *dev,
+				    struct sk_buff *skb,
+				    void *accel_priv)
+{
+	int queue_index = 0;
+
+	if (dev->real_num_tx_queues != 1) {
+		const struct net_device_ops *ops = dev->netdev_ops;
+		if (ops->ndo_select_queue)
+			queue_index = ops->ndo_select_queue(dev, skb, accel_priv,
+							    __netdev_pick_tx);
+		else
+			queue_index = __netdev_pick_tx(dev, skb);
+
+		if (!accel_priv)
+			queue_index = netdev_cap_txqueue(dev, queue_index);
+	}
+
+	skb_set_queue_mapping(skb, queue_index);
+	return netdev_get_tx_queue(dev, queue_index);
+}