[deliverable/linux.git] / net / ipv6 / output_core.c

/*
 * IPv6 library code, needed by static components when full IPv6 support is
 * not configured or static.  These functions are needed by GSO/GRO implementation.
 */
#include <linux/export.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/ip6_fib.h>
#include <net/addrconf.h>
#include <net/secure_seq.h>
#include <linux/netfilter.h>

static u32 __ipv6_select_ident(struct net *net, u32 hashrnd,
			       const struct in6_addr *dst,
			       const struct in6_addr *src)
{
	u32 hash, id;

	hash = __ipv6_addr_jhash(dst, hashrnd);
	hash = __ipv6_addr_jhash(src, hash);
	hash ^= net_hash_mix(net);

	/* Treat id of 0 as unset and if we get 0 back from ip_idents_reserve,
	 * set the hight order instead thus minimizing possible future
	 * collisions.
	 */
	id = ip_idents_reserve(hash, 1);
	if (unlikely(!id))
		id = 1 << 31;

	return id;
}

/* This function exists only for tap drivers that must support broken
 * clients requesting UFO without specifying an IPv6 fragment ID.
 *
 * This is similar to ipv6_select_ident() but we use an independent hash
 * seed to limit information leakage.
 *
 * The network header must be set before calling this.
 */
void ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb)
{
	static u32 ip6_proxy_idents_hashrnd __read_mostly;
	struct in6_addr buf[2];
	struct in6_addr *addrs;
	u32 id;

	addrs = skb_header_pointer(skb,
				   skb_network_offset(skb) +
				   offsetof(struct ipv6hdr, saddr),
				   sizeof(buf), buf);
	if (!addrs)
		return;

	net_get_random_once(&ip6_proxy_idents_hashrnd,
			    sizeof(ip6_proxy_idents_hashrnd));

	id = __ipv6_select_ident(net, ip6_proxy_idents_hashrnd,
				 &addrs[1], &addrs[0]);
	skb_shinfo(skb)->ip6_frag_id = htonl(id);
}
EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);

__be32 ipv6_select_ident(struct net *net,
			 const struct in6_addr *daddr,
			 const struct in6_addr *saddr)
{
	static u32 ip6_idents_hashrnd __read_mostly;
	u32 id;

	net_get_random_once(&ip6_idents_hashrnd, sizeof(ip6_idents_hashrnd));

	id = __ipv6_select_ident(net, ip6_idents_hashrnd, daddr, saddr);
	return htonl(id);
}
EXPORT_SYMBOL(ipv6_select_ident);

int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
{
	u16 offset = sizeof(struct ipv6hdr);
	struct ipv6_opt_hdr *exthdr =
				(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
	unsigned int packet_len = skb_tail_pointer(skb) -
		skb_network_header(skb);
	int found_rhdr = 0;
	*nexthdr = &ipv6_hdr(skb)->nexthdr;

	while (offset + 1 <= packet_len) {

		switch (**nexthdr) {

		case NEXTHDR_HOP:
			break;
		case NEXTHDR_ROUTING:
			found_rhdr = 1;
			break;
		case NEXTHDR_DEST:
#if IS_ENABLED(CONFIG_IPV6_MIP6)
			if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
				break;
#endif
			if (found_rhdr)
				return offset;
			break;
		default:
			return offset;
		}

		offset += ipv6_optlen(exthdr);
		*nexthdr = &exthdr->nexthdr;
		exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
						 offset);
	}

	return offset;
}
EXPORT_SYMBOL(ip6_find_1stfragopt);

#if IS_ENABLED(CONFIG_IPV6)
int ip6_dst_hoplimit(struct dst_entry *dst)
{
	int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
	if (hoplimit == 0) {
		struct net_device *dev = dst->dev;
		struct inet6_dev *idev;

		rcu_read_lock();
		idev = __in6_dev_get(dev);
		if (idev)
			hoplimit = idev->cnf.hop_limit;
		else
			hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
		rcu_read_unlock();
	}
	return hoplimit;
}
EXPORT_SYMBOL(ip6_dst_hoplimit);
#endif

int __ip6_local_out(struct sock *sk, struct sk_buff *skb)
{
	struct net *net = dev_net(skb_dst(skb)->dev);
	int len;

	len = skb->len - sizeof(struct ipv6hdr);
	if (len > IPV6_MAXPLEN)
		len = 0;
	ipv6_hdr(skb)->payload_len = htons(len);
	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);

	return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
		       net, sk, skb, NULL, skb_dst(skb)->dev,
		       dst_output);
}
EXPORT_SYMBOL_GPL(__ip6_local_out);

int ip6_local_out(struct sock *sk, struct sk_buff *skb)
{
	struct net *net = dev_net(skb_dst(skb)->dev);
	int err;

	err = __ip6_local_out(sk, skb);
	if (likely(err == 1))
		err = dst_output(net, sk, skb);

	return err;
}
EXPORT_SYMBOL_GPL(ip6_local_out);
Commit	Line	Data
3c73a036 VY	1	/*
	2	* IPv6 library code, needed by static components when full IPv6 support is
	3	* not configured or static. These functions are needed by GSO/GRO implementation.
	4	*/
	5	#include <linux/export.h>
5188cd44	6	#include <net/ip.h>
3c73a036 VY	7	#include <net/ipv6.h>
3c73a036 VY	8	#include <net/ip6_fib.h>
3ce9b35f	9	#include <net/addrconf.h>
6dfac5c3	10	#include <net/secure_seq.h>
a263653e	11	#include <linux/netfilter.h>
3c73a036	12
5a352dd0	13	static u32 __ipv6_select_ident(struct net *net, u32 hashrnd,
fd0273d7 MKL	14	const struct in6_addr *dst,
fd0273d7 MKL	15	const struct in6_addr *src)
0508c07f VY	16	{
	17	u32 hash, id;
	18
	19	hash = __ipv6_addr_jhash(dst, hashrnd);
	20	hash = __ipv6_addr_jhash(src, hash);
5a352dd0	21	hash ^= net_hash_mix(net);
0508c07f VY	22
	23	/* Treat id of 0 as unset and if we get 0 back from ip_idents_reserve,
	24	* set the hight order instead thus minimizing possible future
	25	* collisions.
	26	*/
	27	id = ip_idents_reserve(hash, 1);
	28	if (unlikely(!id))
	29	id = 1 << 31;
	30
	31	return id;
	32	}
	33
5188cd44 BH	34	/* This function exists only for tap drivers that must support broken
	35	* clients requesting UFO without specifying an IPv6 fragment ID.
	36	*
	37	* This is similar to ipv6_select_ident() but we use an independent hash
	38	* seed to limit information leakage.
	39	*
	40	* The network header must be set before calling this.
	41	*/
5a352dd0	42	void ipv6_proxy_select_ident(struct net net, struct sk_buff skb)
5188cd44 BH	43	{
	44	static u32 ip6_proxy_idents_hashrnd __read_mostly;
	45	struct in6_addr buf[2];
	46	struct in6_addr *addrs;
0508c07f	47	u32 id;
5188cd44 BH	48
	49	addrs = skb_header_pointer(skb,
	50	skb_network_offset(skb) +
	51	offsetof(struct ipv6hdr, saddr),
	52	sizeof(buf), buf);
	53	if (!addrs)
	54	return;
	55
	56	net_get_random_once(&ip6_proxy_idents_hashrnd,
	57	sizeof(ip6_proxy_idents_hashrnd));
	58
5a352dd0	59	id = __ipv6_select_ident(net, ip6_proxy_idents_hashrnd,
0508c07f	60	&addrs[1], &addrs[0]);
51f30770	61	skb_shinfo(skb)->ip6_frag_id = htonl(id);
5188cd44 BH	62	}
	63	EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
	64
7f159867 ED	65	__be32 ipv6_select_ident(struct net *net,
	66	const struct in6_addr *daddr,
	67	const struct in6_addr *saddr)
0508c07f VY	68	{
	69	static u32 ip6_idents_hashrnd __read_mostly;
	70	u32 id;
	71
	72	net_get_random_once(&ip6_idents_hashrnd, sizeof(ip6_idents_hashrnd));
	73
fd0273d7	74	id = __ipv6_select_ident(net, ip6_idents_hashrnd, daddr, saddr);
286c2349	75	return htonl(id);
0508c07f VY	76	}
	77	EXPORT_SYMBOL(ipv6_select_ident);
	78
3c73a036 VY	79	int ip6_find_1stfragopt(struct sk_buff skb, u8 *nexthdr)
	80	{
	81	u16 offset = sizeof(struct ipv6hdr);
	82	struct ipv6_opt_hdr *exthdr =
	83	(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
29a3cad5 SH	84	unsigned int packet_len = skb_tail_pointer(skb) -
29a3cad5 SH	85	skb_network_header(skb);
3c73a036 VY	86	int found_rhdr = 0;
	87	*nexthdr = &ipv6_hdr(skb)->nexthdr;
	88
	89	while (offset + 1 <= packet_len) {
	90
	91	switch (**nexthdr) {
	92
	93	case NEXTHDR_HOP:
	94	break;
	95	case NEXTHDR_ROUTING:
	96	found_rhdr = 1;
	97	break;
	98	case NEXTHDR_DEST:
	99	#if IS_ENABLED(CONFIG_IPV6_MIP6)
	100	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
	101	break;
	102	#endif
	103	if (found_rhdr)
	104	return offset;
	105	break;
67ba4152	106	default:
3c73a036 VY	107	return offset;
	108	}
	109
	110	offset += ipv6_optlen(exthdr);
	111	*nexthdr = &exthdr->nexthdr;
	112	exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
	113	offset);
	114	}
	115
	116	return offset;
	117	}
	118	EXPORT_SYMBOL(ip6_find_1stfragopt);
3ce9b35f CW	119
	120	#if IS_ENABLED(CONFIG_IPV6)
	121	int ip6_dst_hoplimit(struct dst_entry *dst)
	122	{
	123	int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
	124	if (hoplimit == 0) {
	125	struct net_device *dev = dst->dev;
	126	struct inet6_dev *idev;
	127
	128	rcu_read_lock();
	129	idev = __in6_dev_get(dev);
	130	if (idev)
	131	hoplimit = idev->cnf.hop_limit;
	132	else
	133	hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
	134	rcu_read_unlock();
	135	}
	136	return hoplimit;
	137	}
	138	EXPORT_SYMBOL(ip6_dst_hoplimit);
	139	#endif
788787b5	140
9f8955cc	141	int __ip6_local_out(struct sock sk, struct sk_buff skb)
788787b5	142	{
29a26a56	143	struct net *net = dev_net(skb_dst(skb)->dev);
788787b5 CW	144	int len;
	145
	146	len = skb->len - sizeof(struct ipv6hdr);
	147	if (len > IPV6_MAXPLEN)
	148	len = 0;
	149	ipv6_hdr(skb)->payload_len = htons(len);
f6c20c59	150	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
788787b5	151
29a26a56 EB	152	return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
29a26a56 EB	153	net, sk, skb, NULL, skb_dst(skb)->dev,
13206b6b	154	dst_output);
788787b5 CW	155	}
	156	EXPORT_SYMBOL_GPL(__ip6_local_out);
	157
79288330	158	int ip6_local_out(struct sock sk, struct sk_buff skb)
788787b5	159	{
13206b6b	160	struct net *net = dev_net(skb_dst(skb)->dev);
788787b5 CW	161	int err;
788787b5 CW	162
9f8955cc	163	err = __ip6_local_out(sk, skb);
788787b5	164	if (likely(err == 1))
13206b6b	165	err = dst_output(net, sk, skb);
788787b5 CW	166
	167	return err;
	168	}
	169	EXPORT_SYMBOL_GPL(ip6_local_out);