1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef __NET_DST_METADATA_H
  3#define __NET_DST_METADATA_H 1
  4
  5#include <linux/skbuff.h>
  6#include <net/ip_tunnels.h>
  7#include <net/dst.h>
  8
  9enum metadata_type {
 10	METADATA_IP_TUNNEL,
 11	METADATA_HW_PORT_MUX,
 12};
 13
 14struct hw_port_info {
 15	struct net_device *lower_dev;
 16	u32 port_id;
 17};
 18
 19struct metadata_dst {
 20	struct dst_entry		dst;
 21	enum metadata_type		type;
 22	union {
 23		struct ip_tunnel_info	tun_info;
 24		struct hw_port_info	port_info;
 25	} u;
 26};
 27
 28static inline struct metadata_dst *skb_metadata_dst(const struct sk_buff *skb)
 29{
 30	struct metadata_dst *md_dst = (struct metadata_dst *) skb_dst(skb);
 31
 32	if (md_dst && md_dst->dst.flags & DST_METADATA)
 33		return md_dst;
 34
 35	return NULL;
 36}
 37
 38static inline struct ip_tunnel_info *
 39skb_tunnel_info(const struct sk_buff *skb)
 40{
 41	struct metadata_dst *md_dst = skb_metadata_dst(skb);
 42	struct dst_entry *dst;
 43
 44	if (md_dst && md_dst->type == METADATA_IP_TUNNEL)
 45		return &md_dst->u.tun_info;
 46
 47	dst = skb_dst(skb);
 48	if (dst && dst->lwtstate)
 49		return lwt_tun_info(dst->lwtstate);
 50
 51	return NULL;
 52}
 53
 54static inline bool skb_valid_dst(const struct sk_buff *skb)
 55{
 56	struct dst_entry *dst = skb_dst(skb);
 57
 58	return dst && !(dst->flags & DST_METADATA);
 59}
 60
 61static inline int skb_metadata_dst_cmp(const struct sk_buff *skb_a,
 62				       const struct sk_buff *skb_b)
 63{
 64	const struct metadata_dst *a, *b;
 65
 66	if (!(skb_a->_skb_refdst | skb_b->_skb_refdst))
 67		return 0;
 68
 69	a = (const struct metadata_dst *) skb_dst(skb_a);
 70	b = (const struct metadata_dst *) skb_dst(skb_b);
 71
 72	if (!a != !b || a->type != b->type)
 73		return 1;
 74
 75	switch (a->type) {
 76	case METADATA_HW_PORT_MUX:
 77		return memcmp(&a->u.port_info, &b->u.port_info,
 78			      sizeof(a->u.port_info));
 79	case METADATA_IP_TUNNEL:
 80		return memcmp(&a->u.tun_info, &b->u.tun_info,
 81			      sizeof(a->u.tun_info) +
 82					 a->u.tun_info.options_len);
 83	default:
 84		return 1;
 85	}
 86}
 87
 88void metadata_dst_free(struct metadata_dst *);
 89struct metadata_dst *metadata_dst_alloc(u8 optslen, enum metadata_type type,
 90					gfp_t flags);
 91void metadata_dst_free_percpu(struct metadata_dst __percpu *md_dst);
 92struct metadata_dst __percpu *
 93metadata_dst_alloc_percpu(u8 optslen, enum metadata_type type, gfp_t flags);
 94
 95static inline struct metadata_dst *tun_rx_dst(int md_size)
 96{
 97	struct metadata_dst *tun_dst;
 98
 99	tun_dst = metadata_dst_alloc(md_size, METADATA_IP_TUNNEL, GFP_ATOMIC);
100	if (!tun_dst)
101		return NULL;
102
103	tun_dst->u.tun_info.options_len = 0;
104	tun_dst->u.tun_info.mode = 0;
105	return tun_dst;
106}
107
108static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb)
109{
110	struct metadata_dst *md_dst = skb_metadata_dst(skb);
111	int md_size;
112	struct metadata_dst *new_md;
113
114	if (!md_dst || md_dst->type != METADATA_IP_TUNNEL)
115		return ERR_PTR(-EINVAL);
116
117	md_size = md_dst->u.tun_info.options_len;
118	new_md = metadata_dst_alloc(md_size, METADATA_IP_TUNNEL, GFP_ATOMIC);
119	if (!new_md)
120		return ERR_PTR(-ENOMEM);
121
122	memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,
123	       sizeof(struct ip_tunnel_info) + md_size);
124	skb_dst_drop(skb);
125	dst_hold(&new_md->dst);
126	skb_dst_set(skb, &new_md->dst);
127	return new_md;
128}
129
130static inline struct ip_tunnel_info *skb_tunnel_info_unclone(struct sk_buff *skb)
131{
132	struct metadata_dst *dst;
133
134	dst = tun_dst_unclone(skb);
135	if (IS_ERR(dst))
136		return NULL;
137
138	return &dst->u.tun_info;
139}
140
141static inline struct metadata_dst *__ip_tun_set_dst(__be32 saddr,
142						    __be32 daddr,
143						    __u8 tos, __u8 ttl,
144						    __be16 tp_dst,
145						    __be16 flags,
146						    __be64 tunnel_id,
147						    int md_size)
148{
149	struct metadata_dst *tun_dst;
150
151	tun_dst = tun_rx_dst(md_size);
152	if (!tun_dst)
153		return NULL;
154
155	ip_tunnel_key_init(&tun_dst->u.tun_info.key,
156			   saddr, daddr, tos, ttl,
157			   0, 0, tp_dst, tunnel_id, flags);
158	return tun_dst;
159}
160
161static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb,
162						 __be16 flags,
163						 __be64 tunnel_id,
164						 int md_size)
165{
166	const struct iphdr *iph = ip_hdr(skb);
167
168	return __ip_tun_set_dst(iph->saddr, iph->daddr, iph->tos, iph->ttl,
169				0, flags, tunnel_id, md_size);
170}
171
172static inline struct metadata_dst *__ipv6_tun_set_dst(const struct in6_addr *saddr,
173						      const struct in6_addr *daddr,
174						      __u8 tos, __u8 ttl,
175						      __be16 tp_dst,
176						      __be32 label,
177						      __be16 flags,
178						      __be64 tunnel_id,
179						      int md_size)
180{
181	struct metadata_dst *tun_dst;
182	struct ip_tunnel_info *info;
183
184	tun_dst = tun_rx_dst(md_size);
185	if (!tun_dst)
186		return NULL;
187
188	info = &tun_dst->u.tun_info;
189	info->mode = IP_TUNNEL_INFO_IPV6;
190	info->key.tun_flags = flags;
191	info->key.tun_id = tunnel_id;
192	info->key.tp_src = 0;
193	info->key.tp_dst = tp_dst;
194
195	info->key.u.ipv6.src = *saddr;
196	info->key.u.ipv6.dst = *daddr;
197
198	info->key.tos = tos;
199	info->key.ttl = ttl;
200	info->key.label = label;
201
202	return tun_dst;
203}
204
205static inline struct metadata_dst *ipv6_tun_rx_dst(struct sk_buff *skb,
206						   __be16 flags,
207						   __be64 tunnel_id,
208						   int md_size)
209{
210	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
211
212	return __ipv6_tun_set_dst(&ip6h->saddr, &ip6h->daddr,
213				  ipv6_get_dsfield(ip6h), ip6h->hop_limit,
214				  0, ip6_flowlabel(ip6h), flags, tunnel_id,
215				  md_size);
216}
217#endif /* __NET_DST_METADATA_H */