[linux-2.6-block.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>

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

	hash = __ipv6_addr_jhash(dst, hashrnd);
	hash = __ipv6_addr_jhash(src, hash);

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

void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt)
{
	static u32 ip6_idents_hashrnd __read_mostly;
	u32 id;

	net_get_random_once(&ip6_idents_hashrnd, sizeof(ip6_idents_hashrnd));

	id = __ipv6_select_ident(ip6_idents_hashrnd, &rt->rt6i_dst.addr,
				 &rt->rt6i_src.addr);
	fhdr->identification = 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 sk_buff *skb)
{
	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, skb, NULL,
		       skb_dst(skb)->dev, dst_output);
}
EXPORT_SYMBOL_GPL(__ip6_local_out);

int ip6_local_out(struct sk_buff *skb)
{
	int err;

	err = __ip6_local_out(skb);
	if (likely(err == 1))
		err = dst_output(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>
3c73a036	11
8381eacf VY	12	static u32 __ipv6_select_ident(u32 hashrnd, struct in6_addr *dst,
8381eacf VY	13	struct in6_addr *src)
0508c07f VY	14	{
	15	u32 hash, id;
	16
	17	hash = __ipv6_addr_jhash(dst, hashrnd);
	18	hash = __ipv6_addr_jhash(src, hash);
	19
	20	/* Treat id of 0 as unset and if we get 0 back from ip_idents_reserve,
	21	* set the hight order instead thus minimizing possible future
	22	* collisions.
	23	*/
	24	id = ip_idents_reserve(hash, 1);
	25	if (unlikely(!id))
	26	id = 1 << 31;
	27
	28	return id;
	29	}
	30
5188cd44 BH	31	/* This function exists only for tap drivers that must support broken
	32	* clients requesting UFO without specifying an IPv6 fragment ID.
	33	*
	34	* This is similar to ipv6_select_ident() but we use an independent hash
	35	* seed to limit information leakage.
	36	*
	37	* The network header must be set before calling this.
	38	*/
	39	void ipv6_proxy_select_ident(struct sk_buff *skb)
	40	{
	41	static u32 ip6_proxy_idents_hashrnd __read_mostly;
	42	struct in6_addr buf[2];
	43	struct in6_addr *addrs;
0508c07f	44	u32 id;
5188cd44 BH	45
	46	addrs = skb_header_pointer(skb,
	47	skb_network_offset(skb) +
	48	offsetof(struct ipv6hdr, saddr),
	49	sizeof(buf), buf);
	50	if (!addrs)
	51	return;
	52
	53	net_get_random_once(&ip6_proxy_idents_hashrnd,
	54	sizeof(ip6_proxy_idents_hashrnd));
	55
0508c07f VY	56	id = __ipv6_select_ident(ip6_proxy_idents_hashrnd,
0508c07f VY	57	&addrs[1], &addrs[0]);
51f30770	58	skb_shinfo(skb)->ip6_frag_id = htonl(id);
5188cd44 BH	59	}
	60	EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
	61
0508c07f VY	62	void ipv6_select_ident(struct frag_hdr fhdr, struct rt6_info rt)
	63	{
	64	static u32 ip6_idents_hashrnd __read_mostly;
	65	u32 id;
	66
	67	net_get_random_once(&ip6_idents_hashrnd, sizeof(ip6_idents_hashrnd));
	68
	69	id = __ipv6_select_ident(ip6_idents_hashrnd, &rt->rt6i_dst.addr,
	70	&rt->rt6i_src.addr);
	71	fhdr->identification = htonl(id);
	72	}
	73	EXPORT_SYMBOL(ipv6_select_ident);
	74
3c73a036 VY	75	int ip6_find_1stfragopt(struct sk_buff skb, u8 *nexthdr)
	76	{
	77	u16 offset = sizeof(struct ipv6hdr);
	78	struct ipv6_opt_hdr *exthdr =
	79	(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
29a3cad5 SH	80	unsigned int packet_len = skb_tail_pointer(skb) -
29a3cad5 SH	81	skb_network_header(skb);
3c73a036 VY	82	int found_rhdr = 0;
	83	*nexthdr = &ipv6_hdr(skb)->nexthdr;
	84
	85	while (offset + 1 <= packet_len) {
	86
	87	switch (**nexthdr) {
	88
	89	case NEXTHDR_HOP:
	90	break;
	91	case NEXTHDR_ROUTING:
	92	found_rhdr = 1;
	93	break;
	94	case NEXTHDR_DEST:
	95	#if IS_ENABLED(CONFIG_IPV6_MIP6)
	96	if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
	97	break;
	98	#endif
	99	if (found_rhdr)
	100	return offset;
	101	break;
67ba4152	102	default:
3c73a036 VY	103	return offset;
	104	}
	105
	106	offset += ipv6_optlen(exthdr);
	107	*nexthdr = &exthdr->nexthdr;
	108	exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
	109	offset);
	110	}
	111
	112	return offset;
	113	}
	114	EXPORT_SYMBOL(ip6_find_1stfragopt);
3ce9b35f CW	115
	116	#if IS_ENABLED(CONFIG_IPV6)
	117	int ip6_dst_hoplimit(struct dst_entry *dst)
	118	{
	119	int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
	120	if (hoplimit == 0) {
	121	struct net_device *dev = dst->dev;
	122	struct inet6_dev *idev;
	123
	124	rcu_read_lock();
	125	idev = __in6_dev_get(dev);
	126	if (idev)
	127	hoplimit = idev->cnf.hop_limit;
	128	else
	129	hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
	130	rcu_read_unlock();
	131	}
	132	return hoplimit;
	133	}
	134	EXPORT_SYMBOL(ip6_dst_hoplimit);
	135	#endif
788787b5 CW	136
	137	int __ip6_local_out(struct sk_buff *skb)
	138	{
	139	int len;
	140
	141	len = skb->len - sizeof(struct ipv6hdr);
	142	if (len > IPV6_MAXPLEN)
	143	len = 0;
	144	ipv6_hdr(skb)->payload_len = htons(len);
f6c20c59	145	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
788787b5 CW	146
	147	return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
	148	skb_dst(skb)->dev, dst_output);
	149	}
	150	EXPORT_SYMBOL_GPL(__ip6_local_out);
	151
	152	int ip6_local_out(struct sk_buff *skb)
	153	{
	154	int err;
	155
	156	err = __ip6_local_out(skb);
	157	if (likely(err == 1))
	158	err = dst_output(skb);
	159
	160	return err;
	161	}
	162	EXPORT_SYMBOL_GPL(ip6_local_out);