[GitHub/mt8127/android_kernel_alcatel_ttab.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/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));
}

bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow)
{
	int poff, nhoff = skb_network_offset(skb);
	u8 ip_proto;
	__be16 proto = skb->protocol;

	memset(flow, 0, sizeof(*flow));

again:
	switch (proto) {
	case __constant_htons(ETH_P_IP): {
		const struct iphdr *iph;
		struct iphdr _iph;
ip:
		iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
		if (!iph)
			return false;

		if (ip_is_fragment(iph))
			ip_proto = 0;
		else
			ip_proto = iph->protocol;
		iph_to_flow_copy_addrs(flow, iph);
		nhoff += iph->ihl * 4;
		break;
	}
	case __constant_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 __constant_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 __constant_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 __constant_htons(PPP_IP):
			goto ip;
		case __constant_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;
			goto again;
		}
		break;
	}
	case IPPROTO_IPIP:
		goto again;
	default:
		break;
	}

	flow->ip_proto = ip_proto;
	poff = proto_ports_offset(ip_proto);
	if (poff >= 0) {
		__be32 *ports, _ports;

		nhoff += poff;
		ports = skb_header_pointer(skb, nhoff, sizeof(_ports), &_ports);
		if (ports)
			flow->ports = *ports;
	}

	return true;
}
EXPORT_SYMBOL(skb_flow_dissect);
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>
0744dd00 ED	8	#include <linux/if_tunnel.h>
	9	#include <linux/if_pppox.h>
	10	#include <linux/ppp_defs.h>
	11	#include <net/flow_keys.h>
	12
4d77d2b5 ED	13	/* copy saddr & daddr, possibly using 64bit load/store
	14	* Equivalent to : flow->src = iph->saddr;
	15	* flow->dst = iph->daddr;
	16	*/
	17	static void iph_to_flow_copy_addrs(struct flow_keys flow, const struct iphdr iph)
	18	{
	19	BUILD_BUG_ON(offsetof(typeof(*flow), dst) !=
	20	offsetof(typeof(*flow), src) + sizeof(flow->src));
	21	memcpy(&flow->src, &iph->saddr, sizeof(flow->src) + sizeof(flow->dst));
	22	}
0744dd00 ED	23
	24	bool skb_flow_dissect(const struct sk_buff skb, struct flow_keys flow)
	25	{
	26	int poff, nhoff = skb_network_offset(skb);
	27	u8 ip_proto;
	28	__be16 proto = skb->protocol;
	29
	30	memset(flow, 0, sizeof(*flow));
	31
	32	again:
	33	switch (proto) {
	34	case __constant_htons(ETH_P_IP): {
	35	const struct iphdr *iph;
	36	struct iphdr _iph;
	37	ip:
	38	iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
	39	if (!iph)
	40	return false;
	41
	42	if (ip_is_fragment(iph))
	43	ip_proto = 0;
	44	else
	45	ip_proto = iph->protocol;
4d77d2b5	46	iph_to_flow_copy_addrs(flow, iph);
0744dd00 ED	47	nhoff += iph->ihl * 4;
	48	break;
	49	}
	50	case __constant_htons(ETH_P_IPV6): {
	51	const struct ipv6hdr *iph;
	52	struct ipv6hdr _iph;
	53	ipv6:
	54	iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
	55	if (!iph)
	56	return false;
	57
	58	ip_proto = iph->nexthdr;
ddbe5032 ED	59	flow->src = (__force __be32)ipv6_addr_hash(&iph->saddr);
ddbe5032 ED	60	flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr);
0744dd00 ED	61	nhoff += sizeof(struct ipv6hdr);
	62	break;
	63	}
	64	case __constant_htons(ETH_P_8021Q): {
	65	const struct vlan_hdr *vlan;
	66	struct vlan_hdr _vlan;
	67
	68	vlan = skb_header_pointer(skb, nhoff, sizeof(_vlan), &_vlan);
	69	if (!vlan)
	70	return false;
	71
	72	proto = vlan->h_vlan_encapsulated_proto;
	73	nhoff += sizeof(*vlan);
	74	goto again;
	75	}
	76	case __constant_htons(ETH_P_PPP_SES): {
	77	struct {
	78	struct pppoe_hdr hdr;
	79	__be16 proto;
	80	} *hdr, _hdr;
	81	hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
	82	if (!hdr)
	83	return false;
	84	proto = hdr->proto;
	85	nhoff += PPPOE_SES_HLEN;
	86	switch (proto) {
	87	case __constant_htons(PPP_IP):
	88	goto ip;
	89	case __constant_htons(PPP_IPV6):
	90	goto ipv6;
	91	default:
	92	return false;
	93	}
	94	}
	95	default:
	96	return false;
	97	}
	98
	99	switch (ip_proto) {
	100	case IPPROTO_GRE: {
	101	struct gre_hdr {
	102	__be16 flags;
	103	__be16 proto;
	104	} *hdr, _hdr;
	105
	106	hdr = skb_header_pointer(skb, nhoff, sizeof(_hdr), &_hdr);
	107	if (!hdr)
	108	return false;
	109	/*
	110	* Only look inside GRE if version zero and no
	111	* routing
	112	*/
	113	if (!(hdr->flags & (GRE_VERSION\|GRE_ROUTING))) {
	114	proto = hdr->proto;
	115	nhoff += 4;
	116	if (hdr->flags & GRE_CSUM)
	117	nhoff += 4;
	118	if (hdr->flags & GRE_KEY)
	119	nhoff += 4;
	120	if (hdr->flags & GRE_SEQ)
	121	nhoff += 4;
	122	goto again;
	123	}
	124	break;
125	}
126	case IPPROTO_IPIP:
127	goto again;
128	default:
129	break;
130	}
131
132	flow->ip_proto = ip_proto;
133	poff = proto_ports_offset(ip_proto);
134	if (poff >= 0) {
135	__be32 *ports, _ports;
136
137	nhoff += poff;
138	ports = skb_header_pointer(skb, nhoff, sizeof(_ports), &_ports);
139	if (ports)
140	flow->ports = *ports;
141	}
142
143	return true;
144	}
145	EXPORT_SYMBOL(skb_flow_dissect);