dst_metadata.h

  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.h>
  7#include <net/ip_tunnels.h>
  8#include <net/macsec.h>
  9#include <net/dst.h>
 10
 11enum metadata_type {
 12	METADATA_IP_TUNNEL,
 13	METADATA_HW_PORT_MUX,
 14	METADATA_MACSEC,
 15	METADATA_XFRM,
 16};
 17
 18struct hw_port_info {
 19	struct net_device *lower_dev;
 20	u32 port_id;
 21};
 22
 23struct macsec_info {
 24	sci_t sci;
 25};
 26
 27struct xfrm_md_info {
 28	u32 if_id;
 29	int link;
 30	struct dst_entry *dst_orig;
 31};
 32
 33struct metadata_dst {
 34	struct dst_entry		dst;
 35	enum metadata_type		type;
 36	union {
 37		struct ip_tunnel_info	tun_info;
 38		struct hw_port_info	port_info;
 39		struct macsec_info	macsec_info;
 40		struct xfrm_md_info	xfrm_info;
 41	} u;
 42};
 43
 44static inline struct metadata_dst *skb_metadata_dst(const struct sk_buff *skb)
 45{
 46	struct metadata_dst *md_dst = (struct metadata_dst *) skb_dst(skb);
 47
 48	if (md_dst && md_dst->dst.flags & DST_METADATA)
 49		return md_dst;
 50
 51	return NULL;
 52}
 53
 54static inline struct ip_tunnel_info *
 55skb_tunnel_info(const struct sk_buff *skb)
 56{
 57	struct metadata_dst *md_dst = skb_metadata_dst(skb);
 58	struct dst_entry *dst;
 59
 60	if (md_dst && md_dst->type == METADATA_IP_TUNNEL)
 61		return &md_dst->u.tun_info;
 62
 63	dst = skb_dst(skb);
 64	if (dst && dst->lwtstate &&
 65	    (dst->lwtstate->type == LWTUNNEL_ENCAP_IP ||
 66	     dst->lwtstate->type == LWTUNNEL_ENCAP_IP6))
 67		return lwt_tun_info(dst->lwtstate);
 68
 69	return NULL;
 70}
 71
 72static inline struct xfrm_md_info *lwt_xfrm_info(struct lwtunnel_state *lwt)
 73{
 74	return (struct xfrm_md_info *)lwt->data;
 75}
 76
 77static inline struct xfrm_md_info *skb_xfrm_md_info(const struct sk_buff *skb)
 78{
 79	struct metadata_dst *md_dst = skb_metadata_dst(skb);
 80	struct dst_entry *dst;
 81
 82	if (md_dst && md_dst->type == METADATA_XFRM)
 83		return &md_dst->u.xfrm_info;
 84
 85	dst = skb_dst(skb);
 86	if (dst && dst->lwtstate &&
 87	    dst->lwtstate->type == LWTUNNEL_ENCAP_XFRM)
 88		return lwt_xfrm_info(dst->lwtstate);
 89
 90	return NULL;
 91}
 92
 93static inline bool skb_valid_dst(const struct sk_buff *skb)
 94{
 95	struct dst_entry *dst = skb_dst(skb);
 96
 97	return dst && !(dst->flags & DST_METADATA);
 98}
 99
100static inline int skb_metadata_dst_cmp(const struct sk_buff *skb_a,
101				       const struct sk_buff *skb_b)
102{
103	const struct metadata_dst *a, *b;
104
105	if (!(skb_a->_skb_refdst | skb_b->_skb_refdst))
106		return 0;
107
108	a = (const struct metadata_dst *) skb_dst(skb_a);
109	b = (const struct metadata_dst *) skb_dst(skb_b);
110
111	if (!a != !b || a->type != b->type)
112		return 1;
113
114	switch (a->type) {
115	case METADATA_HW_PORT_MUX:
116		return memcmp(&a->u.port_info, &b->u.port_info,
117			      sizeof(a->u.port_info));
118	case METADATA_IP_TUNNEL:
119		return memcmp(&a->u.tun_info, &b->u.tun_info,
120			      sizeof(a->u.tun_info) +
121					 a->u.tun_info.options_len);
122	case METADATA_MACSEC:
123		return memcmp(&a->u.macsec_info, &b->u.macsec_info,
124			      sizeof(a->u.macsec_info));
125	case METADATA_XFRM:
126		return memcmp(&a->u.xfrm_info, &b->u.xfrm_info,
127			      sizeof(a->u.xfrm_info));
128	default:
129		return 1;
130	}
131}
132
133void metadata_dst_free(struct metadata_dst *);
134struct metadata_dst *metadata_dst_alloc(u8 optslen, enum metadata_type type,
135					gfp_t flags);
136void metadata_dst_free_percpu(struct metadata_dst __percpu *md_dst);
137struct metadata_dst __percpu *
138metadata_dst_alloc_percpu(u8 optslen, enum metadata_type type, gfp_t flags);
139
140static inline struct metadata_dst *tun_rx_dst(int md_size)
141{
142	struct metadata_dst *tun_dst;
143
144	tun_dst = metadata_dst_alloc(md_size, METADATA_IP_TUNNEL, GFP_ATOMIC);
145	if (!tun_dst)
146		return NULL;
147
148	tun_dst->u.tun_info.options_len = 0;
149	tun_dst->u.tun_info.mode = 0;
150	return tun_dst;
151}
152
153static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb)
154{
155	struct metadata_dst *md_dst = skb_metadata_dst(skb);
156	int md_size;
157	struct metadata_dst *new_md;
158
159	if (!md_dst || md_dst->type != METADATA_IP_TUNNEL)
160		return ERR_PTR(-EINVAL);
161
162	md_size = md_dst->u.tun_info.options_len;
163	new_md = metadata_dst_alloc(md_size, METADATA_IP_TUNNEL, GFP_ATOMIC);
164	if (!new_md)
165		return ERR_PTR(-ENOMEM);
166
167	memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,
168	       sizeof(struct ip_tunnel_info) + md_size);
169#ifdef CONFIG_DST_CACHE
170	/* Unclone the dst cache if there is one */
171	if (new_md->u.tun_info.dst_cache.cache) {
172		int ret;
173
174		ret = dst_cache_init(&new_md->u.tun_info.dst_cache, GFP_ATOMIC);
175		if (ret) {
176			metadata_dst_free(new_md);
177			return ERR_PTR(ret);
178		}
179	}
180#endif
181
182	skb_dst_drop(skb);
183	skb_dst_set(skb, &new_md->dst);
184	return new_md;
185}
186
187static inline struct ip_tunnel_info *skb_tunnel_info_unclone(struct sk_buff *skb)
188{
189	struct metadata_dst *dst;
190
191	dst = tun_dst_unclone(skb);
192	if (IS_ERR(dst))
193		return NULL;
194
195	return &dst->u.tun_info;
196}
197
198static inline struct metadata_dst *__ip_tun_set_dst(__be32 saddr,
199						    __be32 daddr,
200						    __u8 tos, __u8 ttl,
201						    __be16 tp_dst,
202						    const unsigned long *flags,
203						    __be64 tunnel_id,
204						    int md_size)
205{
206	struct metadata_dst *tun_dst;
207
208	tun_dst = tun_rx_dst(md_size);
209	if (!tun_dst)
210		return NULL;
211
212	ip_tunnel_key_init(&tun_dst->u.tun_info.key,
213			   saddr, daddr, tos, ttl,
214			   0, 0, tp_dst, tunnel_id, flags);
215	return tun_dst;
216}
217
218static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb,
219						 const unsigned long *flags,
220						 __be64 tunnel_id,
221						 int md_size)
222{
223	const struct iphdr *iph = ip_hdr(skb);
224	struct metadata_dst *tun_dst;
225
226	tun_dst = __ip_tun_set_dst(iph->saddr, iph->daddr, iph->tos, iph->ttl,
227				   0, flags, tunnel_id, md_size);
228
229	if (tun_dst && (iph->frag_off & htons(IP_DF)))
230		__set_bit(IP_TUNNEL_DONT_FRAGMENT_BIT,
231			  tun_dst->u.tun_info.key.tun_flags);
232	return tun_dst;
233}
234
235static inline struct metadata_dst *__ipv6_tun_set_dst(const struct in6_addr *saddr,
236						      const struct in6_addr *daddr,
237						      __u8 tos, __u8 ttl,
238						      __be16 tp_dst,
239						      __be32 label,
240						      const unsigned long *flags,
241						      __be64 tunnel_id,
242						      int md_size)
243{
244	struct metadata_dst *tun_dst;
245	struct ip_tunnel_info *info;
246
247	tun_dst = tun_rx_dst(md_size);
248	if (!tun_dst)
249		return NULL;
250
251	info = &tun_dst->u.tun_info;
252	info->mode = IP_TUNNEL_INFO_IPV6;
253	ip_tunnel_flags_copy(info->key.tun_flags, flags);
254	info->key.tun_id = tunnel_id;
255	info->key.tp_src = 0;
256	info->key.tp_dst = tp_dst;
257
258	info->key.u.ipv6.src = *saddr;
259	info->key.u.ipv6.dst = *daddr;
260
261	info->key.tos = tos;
262	info->key.ttl = ttl;
263	info->key.label = label;
264
265	return tun_dst;
266}
267
268static inline struct metadata_dst *ipv6_tun_rx_dst(struct sk_buff *skb,
269						   const unsigned long *flags,
270						   __be64 tunnel_id,
271						   int md_size)
272{
273	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
274
275	return __ipv6_tun_set_dst(&ip6h->saddr, &ip6h->daddr,
276				  ipv6_get_dsfield(ip6h), ip6h->hop_limit,
277				  0, ip6_flowlabel(ip6h), flags, tunnel_id,
278				  md_size);
279}
280#endif /* __NET_DST_METADATA_H */