[GitHub/MotorolaMobilityLLC/kernel-slsi.git] / net / core / flow_dissector.c

#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: sk_buff to extract the ports from
 * @thoff: transport header offset
 * @ip_proto: protocol for which to get port offset
 * @data: raw buffer pointer to the packet, if NULL use skb->data
 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 *
 * 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,
			    void *data, int hlen)
{
	int poff = proto_ports_offset(ip_proto);

	if (!data) {
		data = skb->data;
		hlen = skb_headlen(skb);
	}

	if (poff >= 0) {
		__be32 *ports, _ports;

		ports = __skb_header_pointer(skb, thoff + poff,
					     sizeof(_ports), data, hlen, &_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, void *data, int hlen)
{
	int nhoff = skb_network_offset(skb);
	u8 ip_proto;
	__be16 proto = skb->protocol;

	if (!data) {
		data = skb->data;
		hlen = skb_headlen(skb);
	}

	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), data, hlen, &_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;
		__be32 flow_label;

ipv6:
		iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_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);

		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;

			return true;
		}

		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), data, hlen, &_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), data, hlen, &_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), data, hlen, &_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),
							   data, hlen, &_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->n_proto = proto;
	flow->ip_proto = ip_proto;
	flow->ports = __skb_flow_get_ports(skb, nhoff, ip_proto, data, hlen);
	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 inline u32 __flow_hash_from_keys(struct flow_keys *keys)
{
	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]);
	}

	hash = __flow_hash_3words((__force u32)keys->dst,
				  (__force u32)keys->src,
				  (__force u32)keys->ports);
	if (!hash)
		hash = 1;

	return hash;
}

u32 flow_hash_from_keys(struct flow_keys *keys)
{
	return __flow_hash_from_keys(keys);
}
EXPORT_SYMBOL(flow_hash_from_keys);

/*
 * __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;

	if (!skb_flow_dissect(skb, &keys))
		return;

	if (keys.ports)
		skb->l4_hash = 1;

	skb->sw_hash = 1;

	skb->hash = __flow_hash_from_keys(&keys);
}
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, 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;
	}

	return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + 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
				queue_index = map->queues[reciprocal_scale(skb_get_hash(skb),
									   map->len)];
			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);
}
Commit	Line	Data
0744dd00	1	#include <linux/skbuff.h>
c452ed70	2	#include <linux/export.h>
0744dd00 ED	3	#include <linux/ip.h>
	4	#include <linux/ipv6.h>
	5	#include <linux/if_vlan.h>
	6	#include <net/ip.h>
ddbe5032	7	#include <net/ipv6.h>
f77668dc DB	8	#include <linux/igmp.h>
	9	#include <linux/icmp.h>
	10	#include <linux/sctp.h>
	11	#include <linux/dccp.h>
0744dd00 ED	12	#include <linux/if_tunnel.h>
	13	#include <linux/if_pppox.h>
	14	#include <linux/ppp_defs.h>
	15	#include <net/flow_keys.h>
	16
4d77d2b5 ED	17	/* copy saddr & daddr, possibly using 64bit load/store
	18	* Equivalent to : flow->src = iph->saddr;
	19	* flow->dst = iph->daddr;
	20	*/
	21	static void iph_to_flow_copy_addrs(struct flow_keys flow, const struct iphdr iph)
	22	{
	23	BUILD_BUG_ON(offsetof(typeof(*flow), dst) !=
	24	offsetof(typeof(*flow), src) + sizeof(flow->src));
	25	memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst));
	26	}
0744dd00	27
357afe9c	28	/**
6451b3f5 WC	29	* __skb_flow_get_ports - extract the upper layer ports and return them
6451b3f5 WC	30	* @skb: sk_buff to extract the ports from
357afe9c NA	31	* @thoff: transport header offset
357afe9c NA	32	* @ip_proto: protocol for which to get port offset
6451b3f5 WC	33	* @data: raw buffer pointer to the packet, if NULL use skb->data
6451b3f5 WC	34	* @hlen: packet header length, if @data is NULL use skb_headlen(skb)
357afe9c NA	35	*
	36	* The function will try to retrieve the ports at offset thoff + poff where poff
	37	* is the protocol port offset returned from proto_ports_offset
	38	*/
690e36e7 DM	39	__be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
690e36e7 DM	40	void *data, int hlen)
357afe9c NA	41	{
	42	int poff = proto_ports_offset(ip_proto);
	43
690e36e7 DM	44	if (!data) {
	45	data = skb->data;
	46	hlen = skb_headlen(skb);
	47	}
	48
357afe9c NA	49	if (poff >= 0) {
	50	__be32 *ports, _ports;
	51
690e36e7 DM	52	ports = __skb_header_pointer(skb, thoff + poff,
690e36e7 DM	53	sizeof(_ports), data, hlen, &_ports);
357afe9c NA	54	if (ports)
	55	return *ports;
	56	}
	57
	58	return 0;
	59	}
690e36e7	60	EXPORT_SYMBOL(__skb_flow_get_ports);
357afe9c	61
690e36e7	62	bool __skb_flow_dissect(const struct sk_buff skb, struct flow_keys flow, void *data, int hlen)
0744dd00	63	{
357afe9c	64	int nhoff = skb_network_offset(skb);
0744dd00 ED	65	u8 ip_proto;
	66	__be16 proto = skb->protocol;
	67
690e36e7 DM	68	if (!data) {
	69	data = skb->data;
	70	hlen = skb_headlen(skb);
	71	}
	72
0744dd00 ED	73	memset(flow, 0, sizeof(*flow));
	74
	75	again:
	76	switch (proto) {
2b8837ae	77	case htons(ETH_P_IP): {
0744dd00 ED	78	const struct iphdr *iph;
	79	struct iphdr _iph;
	80	ip:
690e36e7	81	iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
6f092343	82	if (!iph \|\| iph->ihl < 5)
0744dd00	83	return false;
3797d3e8	84	nhoff += iph->ihl * 4;
0744dd00	85
3797d3e8	86	ip_proto = iph->protocol;
0744dd00 ED	87	if (ip_is_fragment(iph))
0744dd00 ED	88	ip_proto = 0;
3797d3e8	89
4d77d2b5	90	iph_to_flow_copy_addrs(flow, iph);
0744dd00 ED	91	break;
0744dd00 ED	92	}
2b8837ae	93	case htons(ETH_P_IPV6): {
0744dd00 ED	94	const struct ipv6hdr *iph;
0744dd00 ED	95	struct ipv6hdr _iph;
19469a87 TH	96	__be32 flow_label;
19469a87 TH	97
0744dd00	98	ipv6:
690e36e7	99	iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
0744dd00 ED	100	if (!iph)
	101	return false;
	102
	103	ip_proto = iph->nexthdr;
ddbe5032 ED	104	flow->src = (__force __be32)ipv6_addr_hash(&iph->saddr);
ddbe5032 ED	105	flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr);
0744dd00	106	nhoff += sizeof(struct ipv6hdr);
19469a87 TH	107
	108	flow_label = ip6_flowlabel(iph);
	109	if (flow_label) {
	110	/* Awesome, IPv6 packet has a flow label so we can
	111	* use that to represent the ports without any
	112	* further dissection.
	113	*/
	114	flow->n_proto = proto;
	115	flow->ip_proto = ip_proto;
	116	flow->ports = flow_label;
	117	flow->thoff = (u16)nhoff;
	118
	119	return true;
	120	}
	121
0744dd00 ED	122	break;
0744dd00 ED	123	}
2b8837ae JP	124	case htons(ETH_P_8021AD):
2b8837ae JP	125	case htons(ETH_P_8021Q): {
0744dd00 ED	126	const struct vlan_hdr *vlan;
	127	struct vlan_hdr _vlan;
	128
690e36e7	129	vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan);
0744dd00 ED	130	if (!vlan)
	131	return false;
	132
	133	proto = vlan->h_vlan_encapsulated_proto;
	134	nhoff += sizeof(*vlan);
	135	goto again;
	136	}
2b8837ae	137	case htons(ETH_P_PPP_SES): {
0744dd00 ED	138	struct {
	139	struct pppoe_hdr hdr;
	140	__be16 proto;
	141	} *hdr, _hdr;
690e36e7	142	hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
0744dd00 ED	143	if (!hdr)
	144	return false;
	145	proto = hdr->proto;
	146	nhoff += PPPOE_SES_HLEN;
	147	switch (proto) {
2b8837ae	148	case htons(PPP_IP):
0744dd00	149	goto ip;
2b8837ae	150	case htons(PPP_IPV6):
0744dd00 ED	151	goto ipv6;
	152	default:
	153	return false;
	154	}
	155	}
	156	default:
	157	return false;
	158	}
	159
	160	switch (ip_proto) {
	161	case IPPROTO_GRE: {
	162	struct gre_hdr {
	163	__be16 flags;
	164	__be16 proto;
	165	} *hdr, _hdr;
	166
690e36e7	167	hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
0744dd00 ED	168	if (!hdr)
	169	return false;
	170	/*
	171	* Only look inside GRE if version zero and no
	172	* routing
	173	*/
	174	if (!(hdr->flags & (GRE_VERSION\|GRE_ROUTING))) {
	175	proto = hdr->proto;
	176	nhoff += 4;
	177	if (hdr->flags & GRE_CSUM)
	178	nhoff += 4;
	179	if (hdr->flags & GRE_KEY)
	180	nhoff += 4;
	181	if (hdr->flags & GRE_SEQ)
	182	nhoff += 4;
e1733de2 MD	183	if (proto == htons(ETH_P_TEB)) {
	184	const struct ethhdr *eth;
	185	struct ethhdr _eth;
	186
690e36e7 DM	187	eth = __skb_header_pointer(skb, nhoff,
	188	sizeof(_eth),
	189	data, hlen, &_eth);
e1733de2 MD	190	if (!eth)
	191	return false;
	192	proto = eth->h_proto;
	193	nhoff += sizeof(*eth);
	194	}
0744dd00 ED	195	goto again;
	196	}
	197	break;
	198	}
	199	case IPPROTO_IPIP:
fca41895 TH	200	proto = htons(ETH_P_IP);
fca41895 TH	201	goto ip;
b438f940 TH	202	case IPPROTO_IPV6:
	203	proto = htons(ETH_P_IPV6);
	204	goto ipv6;
0744dd00 ED	205	default:
	206	break;
	207	}
	208
e0f31d84	209	flow->n_proto = proto;
0744dd00	210	flow->ip_proto = ip_proto;
690e36e7	211	flow->ports = __skb_flow_get_ports(skb, nhoff, ip_proto, data, hlen);
8ed78166 DB	212	flow->thoff = (u16) nhoff;
8ed78166 DB	213
0744dd00 ED	214	return true;
0744dd00 ED	215	}
690e36e7	216	EXPORT_SYMBOL(__skb_flow_dissect);
441d9d32 CW	217
441d9d32 CW	218	static u32 hashrnd __read_mostly;
66415cf8 HFS	219	static __always_inline void __flow_hash_secret_init(void)
	220	{
	221	net_get_random_once(&hashrnd, sizeof(hashrnd));
	222	}
	223
	224	static __always_inline u32 __flow_hash_3words(u32 a, u32 b, u32 c)
	225	{
	226	__flow_hash_secret_init();
	227	return jhash_3words(a, b, c, hashrnd);
	228	}
	229
5ed20a68 TH	230	static inline u32 __flow_hash_from_keys(struct flow_keys *keys)
	231	{
	232	u32 hash;
	233
	234	/* get a consistent hash (same value on both flow directions) */
	235	if (((__force u32)keys->dst < (__force u32)keys->src) \|\|
	236	(((__force u32)keys->dst == (__force u32)keys->src) &&
	237	((__force u16)keys->port16[1] < (__force u16)keys->port16[0]))) {
	238	swap(keys->dst, keys->src);
	239	swap(keys->port16[0], keys->port16[1]);
	240	}
	241
	242	hash = __flow_hash_3words((__force u32)keys->dst,
	243	(__force u32)keys->src,
	244	(__force u32)keys->ports);
	245	if (!hash)
	246	hash = 1;
	247
	248	return hash;
	249	}
	250
	251	u32 flow_hash_from_keys(struct flow_keys *keys)
	252	{
	253	return __flow_hash_from_keys(keys);
	254	}
	255	EXPORT_SYMBOL(flow_hash_from_keys);
	256
441d9d32	257	/*
3958afa1	258	* __skb_get_hash: calculate a flow hash based on src/dst addresses
61b905da TH	259	* and src/dst port numbers. Sets hash in skb to non-zero hash value
61b905da TH	260	* on success, zero indicates no valid hash. Also, sets l4_hash in skb
441d9d32 CW	261	* if hash is a canonical 4-tuple hash over transport ports.
441d9d32 CW	262	*/
3958afa1	263	void __skb_get_hash(struct sk_buff *skb)
441d9d32 CW	264	{
441d9d32 CW	265	struct flow_keys keys;
441d9d32 CW	266
	267	if (!skb_flow_dissect(skb, &keys))
	268	return;
	269
	270	if (keys.ports)
61b905da	271	skb->l4_hash = 1;
441d9d32	272
a3b18ddb TH	273	skb->sw_hash = 1;
a3b18ddb TH	274
5ed20a68	275	skb->hash = __flow_hash_from_keys(&keys);
441d9d32	276	}
3958afa1	277	EXPORT_SYMBOL(__skb_get_hash);
441d9d32 CW	278
	279	/*
	280	* Returns a Tx hash based on the given packet descriptor a Tx queues' number
	281	* to be used as a distribution range.
	282	*/
0e001614	283	u16 __skb_tx_hash(const struct net_device dev, struct sk_buff skb,
441d9d32 CW	284	unsigned int num_tx_queues)
	285	{
	286	u32 hash;
	287	u16 qoffset = 0;
	288	u16 qcount = num_tx_queues;
	289
	290	if (skb_rx_queue_recorded(skb)) {
	291	hash = skb_get_rx_queue(skb);
	292	while (unlikely(hash >= num_tx_queues))
	293	hash -= num_tx_queues;
	294	return hash;
	295	}
	296
	297	if (dev->num_tc) {
	298	u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
	299	qoffset = dev->tc_to_txq[tc].offset;
	300	qcount = dev->tc_to_txq[tc].count;
	301	}
	302
8fc54f68	303	return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
441d9d32 CW	304	}
	305	EXPORT_SYMBOL(__skb_tx_hash);
	306
f77668dc DB	307	/* __skb_get_poff() returns the offset to the payload as far as it could
	308	* be dissected. The main user is currently BPF, so that we can dynamically
	309	* truncate packets without needing to push actual payload to the user
	310	* space and can analyze headers only, instead.
	311	*/
	312	u32 __skb_get_poff(const struct sk_buff *skb)
	313	{
	314	struct flow_keys keys;
	315	u32 poff = 0;
	316
	317	if (!skb_flow_dissect(skb, &keys))
	318	return 0;
	319
	320	poff += keys.thoff;
	321	switch (keys.ip_proto) {
	322	case IPPROTO_TCP: {
	323	const struct tcphdr *tcph;
	324	struct tcphdr _tcph;
	325
	326	tcph = skb_header_pointer(skb, poff, sizeof(_tcph), &_tcph);
	327	if (!tcph)
	328	return poff;
	329
	330	poff += max_t(u32, sizeof(struct tcphdr), tcph->doff * 4);
	331	break;
	332	}
	333	case IPPROTO_UDP:
	334	case IPPROTO_UDPLITE:
	335	poff += sizeof(struct udphdr);
	336	break;
	337	/* For the rest, we do not really care about header
	338	* extensions at this point for now.
	339	*/
	340	case IPPROTO_ICMP:
	341	poff += sizeof(struct icmphdr);
	342	break;
	343	case IPPROTO_ICMPV6:
	344	poff += sizeof(struct icmp6hdr);
	345	break;
	346	case IPPROTO_IGMP:
	347	poff += sizeof(struct igmphdr);
	348	break;
	349	case IPPROTO_DCCP:
	350	poff += sizeof(struct dccp_hdr);
	351	break;
	352	case IPPROTO_SCTP:
	353	poff += sizeof(struct sctphdr);
	354	break;
	355	}
	356
	357	return poff;
	358	}
	359
441d9d32 CW	360	static inline int get_xps_queue(struct net_device dev, struct sk_buff skb)
	361	{
	362	#ifdef CONFIG_XPS
	363	struct xps_dev_maps *dev_maps;
	364	struct xps_map *map;
	365	int queue_index = -1;
	366
	367	rcu_read_lock();
	368	dev_maps = rcu_dereference(dev->xps_maps);
	369	if (dev_maps) {
	370	map = rcu_dereference(
	371	dev_maps->cpu_map[raw_smp_processor_id()]);
	372	if (map) {
	373	if (map->len == 1)
	374	queue_index = map->queues[0];
0e001614	375	else
8fc54f68 DB	376	queue_index = map->queues[reciprocal_scale(skb_get_hash(skb),
8fc54f68 DB	377	map->len)];
441d9d32 CW	378	if (unlikely(queue_index >= dev->real_num_tx_queues))
	379	queue_index = -1;
	380	}
	381	}
	382	rcu_read_unlock();
	383
	384	return queue_index;
	385	#else
	386	return -1;
	387	#endif
	388	}
	389
99932d4f	390	static u16 __netdev_pick_tx(struct net_device dev, struct sk_buff skb)
441d9d32 CW	391	{
	392	struct sock *sk = skb->sk;
	393	int queue_index = sk_tx_queue_get(sk);
	394
	395	if (queue_index < 0 \|\| skb->ooo_okay \|\|
	396	queue_index >= dev->real_num_tx_queues) {
	397	int new_index = get_xps_queue(dev, skb);
	398	if (new_index < 0)
	399	new_index = skb_tx_hash(dev, skb);
	400
702821f4 ED	401	if (queue_index != new_index && sk &&
702821f4 ED	402	rcu_access_pointer(sk->sk_dst_cache))
50d1784e	403	sk_tx_queue_set(sk, new_index);
441d9d32 CW	404
	405	queue_index = new_index;
	406	}
	407
	408	return queue_index;
	409	}
441d9d32 CW	410
441d9d32 CW	411	struct netdev_queue netdev_pick_tx(struct net_device dev,
f663dd9a JW	412	struct sk_buff *skb,
f663dd9a JW	413	void *accel_priv)
441d9d32 CW	414	{
	415	int queue_index = 0;
	416
	417	if (dev->real_num_tx_queues != 1) {
	418	const struct net_device_ops *ops = dev->netdev_ops;
	419	if (ops->ndo_select_queue)
99932d4f DB	420	queue_index = ops->ndo_select_queue(dev, skb, accel_priv,
99932d4f DB	421	__netdev_pick_tx);
441d9d32 CW	422	else
441d9d32 CW	423	queue_index = __netdev_pick_tx(dev, skb);
f663dd9a JW	424
f663dd9a JW	425	if (!accel_priv)
b9507bda	426	queue_index = netdev_cap_txqueue(dev, queue_index);
441d9d32 CW	427	}
	428
	429	skb_set_queue_mapping(skb, queue_index);
	430	return netdev_get_tx_queue(dev, queue_index);
	431	}