xref: /linux/include/net/dst_metadata.h (revision 06a130e42a5bfc84795464bff023bff4c16f58c5)
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/macsec.h>
8 #include <net/dst.h>
9 
10 enum metadata_type {
11 	METADATA_IP_TUNNEL,
12 	METADATA_HW_PORT_MUX,
13 	METADATA_MACSEC,
14 	METADATA_XFRM,
15 };
16 
17 struct hw_port_info {
18 	struct net_device *lower_dev;
19 	u32 port_id;
20 };
21 
22 struct macsec_info {
23 	sci_t sci;
24 };
25 
26 struct xfrm_md_info {
27 	u32 if_id;
28 	int link;
29 	struct dst_entry *dst_orig;
30 };
31 
32 struct metadata_dst {
33 	struct dst_entry		dst;
34 	enum metadata_type		type;
35 	union {
36 		struct ip_tunnel_info	tun_info;
37 		struct hw_port_info	port_info;
38 		struct macsec_info	macsec_info;
39 		struct xfrm_md_info	xfrm_info;
40 	} u;
41 };
42 
43 static inline struct metadata_dst *skb_metadata_dst(const struct sk_buff *skb)
44 {
45 	struct metadata_dst *md_dst = (struct metadata_dst *) skb_dst(skb);
46 
47 	if (md_dst && md_dst->dst.flags & DST_METADATA)
48 		return md_dst;
49 
50 	return NULL;
51 }
52 
53 static inline struct ip_tunnel_info *
54 skb_tunnel_info(const struct sk_buff *skb)
55 {
56 	struct metadata_dst *md_dst = skb_metadata_dst(skb);
57 	struct dst_entry *dst;
58 
59 	if (md_dst && md_dst->type == METADATA_IP_TUNNEL)
60 		return &md_dst->u.tun_info;
61 
62 	dst = skb_dst(skb);
63 	if (dst && dst->lwtstate &&
64 	    (dst->lwtstate->type == LWTUNNEL_ENCAP_IP ||
65 	     dst->lwtstate->type == LWTUNNEL_ENCAP_IP6))
66 		return lwt_tun_info(dst->lwtstate);
67 
68 	return NULL;
69 }
70 
71 static inline struct xfrm_md_info *lwt_xfrm_info(struct lwtunnel_state *lwt)
72 {
73 	return (struct xfrm_md_info *)lwt->data;
74 }
75 
76 static inline struct xfrm_md_info *skb_xfrm_md_info(const struct sk_buff *skb)
77 {
78 	struct metadata_dst *md_dst = skb_metadata_dst(skb);
79 	struct dst_entry *dst;
80 
81 	if (md_dst && md_dst->type == METADATA_XFRM)
82 		return &md_dst->u.xfrm_info;
83 
84 	dst = skb_dst(skb);
85 	if (dst && dst->lwtstate &&
86 	    dst->lwtstate->type == LWTUNNEL_ENCAP_XFRM)
87 		return lwt_xfrm_info(dst->lwtstate);
88 
89 	return NULL;
90 }
91 
92 static inline bool skb_valid_dst(const struct sk_buff *skb)
93 {
94 	struct dst_entry *dst = skb_dst(skb);
95 
96 	return dst && !(dst->flags & DST_METADATA);
97 }
98 
99 static inline int skb_metadata_dst_cmp(const struct sk_buff *skb_a,
100 				       const struct sk_buff *skb_b)
101 {
102 	const struct metadata_dst *a, *b;
103 
104 	if (!(skb_a->_skb_refdst | skb_b->_skb_refdst))
105 		return 0;
106 
107 	a = (const struct metadata_dst *) skb_dst(skb_a);
108 	b = (const struct metadata_dst *) skb_dst(skb_b);
109 
110 	if (!a != !b || a->type != b->type)
111 		return 1;
112 
113 	switch (a->type) {
114 	case METADATA_HW_PORT_MUX:
115 		return memcmp(&a->u.port_info, &b->u.port_info,
116 			      sizeof(a->u.port_info));
117 	case METADATA_IP_TUNNEL:
118 		return memcmp(&a->u.tun_info, &b->u.tun_info,
119 			      sizeof(a->u.tun_info) +
120 					 a->u.tun_info.options_len);
121 	case METADATA_MACSEC:
122 		return memcmp(&a->u.macsec_info, &b->u.macsec_info,
123 			      sizeof(a->u.macsec_info));
124 	case METADATA_XFRM:
125 		return memcmp(&a->u.xfrm_info, &b->u.xfrm_info,
126 			      sizeof(a->u.xfrm_info));
127 	default:
128 		return 1;
129 	}
130 }
131 
132 void metadata_dst_free(struct metadata_dst *);
133 struct metadata_dst *metadata_dst_alloc(u8 optslen, enum metadata_type type,
134 					gfp_t flags);
135 void metadata_dst_free_percpu(struct metadata_dst __percpu *md_dst);
136 struct metadata_dst __percpu *
137 metadata_dst_alloc_percpu(u8 optslen, enum metadata_type type, gfp_t flags);
138 
139 static inline struct metadata_dst *tun_rx_dst(int md_size)
140 {
141 	struct metadata_dst *tun_dst;
142 
143 	tun_dst = metadata_dst_alloc(md_size, METADATA_IP_TUNNEL, GFP_ATOMIC);
144 	if (!tun_dst)
145 		return NULL;
146 
147 	tun_dst->u.tun_info.options_len = 0;
148 	tun_dst->u.tun_info.mode = 0;
149 	return tun_dst;
150 }
151 
152 static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb)
153 {
154 	struct metadata_dst *md_dst = skb_metadata_dst(skb);
155 	int md_size;
156 	struct metadata_dst *new_md;
157 
158 	if (!md_dst || md_dst->type != METADATA_IP_TUNNEL)
159 		return ERR_PTR(-EINVAL);
160 
161 	md_size = md_dst->u.tun_info.options_len;
162 	new_md = metadata_dst_alloc(md_size, METADATA_IP_TUNNEL, GFP_ATOMIC);
163 	if (!new_md)
164 		return ERR_PTR(-ENOMEM);
165 
166 	unsafe_memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,
167 		      sizeof(struct ip_tunnel_info) + md_size,
168 		      /* metadata_dst_alloc() reserves room (md_size bytes) for
169 		       * options right after the ip_tunnel_info struct.
170 		       */);
171 #ifdef CONFIG_DST_CACHE
172 	/* Unclone the dst cache if there is one */
173 	if (new_md->u.tun_info.dst_cache.cache) {
174 		int ret;
175 
176 		ret = dst_cache_init(&new_md->u.tun_info.dst_cache, GFP_ATOMIC);
177 		if (ret) {
178 			metadata_dst_free(new_md);
179 			return ERR_PTR(ret);
180 		}
181 	}
182 #endif
183 
184 	skb_dst_drop(skb);
185 	skb_dst_set(skb, &new_md->dst);
186 	return new_md;
187 }
188 
189 static inline struct ip_tunnel_info *skb_tunnel_info_unclone(struct sk_buff *skb)
190 {
191 	struct metadata_dst *dst;
192 
193 	dst = tun_dst_unclone(skb);
194 	if (IS_ERR(dst))
195 		return NULL;
196 
197 	return &dst->u.tun_info;
198 }
199 
200 static inline struct metadata_dst *__ip_tun_set_dst(__be32 saddr,
201 						    __be32 daddr,
202 						    __u8 tos, __u8 ttl,
203 						    __be16 tp_dst,
204 						    const unsigned long *flags,
205 						    __be64 tunnel_id,
206 						    int md_size)
207 {
208 	struct metadata_dst *tun_dst;
209 
210 	tun_dst = tun_rx_dst(md_size);
211 	if (!tun_dst)
212 		return NULL;
213 
214 	ip_tunnel_key_init(&tun_dst->u.tun_info.key,
215 			   saddr, daddr, tos, ttl,
216 			   0, 0, tp_dst, tunnel_id, flags);
217 	return tun_dst;
218 }
219 
220 static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb,
221 						 const unsigned long *flags,
222 						 __be64 tunnel_id,
223 						 int md_size)
224 {
225 	const struct iphdr *iph = ip_hdr(skb);
226 
227 	return __ip_tun_set_dst(iph->saddr, iph->daddr, iph->tos, iph->ttl,
228 				0, flags, tunnel_id, md_size);
229 }
230 
231 static inline struct metadata_dst *__ipv6_tun_set_dst(const struct in6_addr *saddr,
232 						      const struct in6_addr *daddr,
233 						      __u8 tos, __u8 ttl,
234 						      __be16 tp_dst,
235 						      __be32 label,
236 						      const unsigned long *flags,
237 						      __be64 tunnel_id,
238 						      int md_size)
239 {
240 	struct metadata_dst *tun_dst;
241 	struct ip_tunnel_info *info;
242 
243 	tun_dst = tun_rx_dst(md_size);
244 	if (!tun_dst)
245 		return NULL;
246 
247 	info = &tun_dst->u.tun_info;
248 	info->mode = IP_TUNNEL_INFO_IPV6;
249 	ip_tunnel_flags_copy(info->key.tun_flags, flags);
250 	info->key.tun_id = tunnel_id;
251 	info->key.tp_src = 0;
252 	info->key.tp_dst = tp_dst;
253 
254 	info->key.u.ipv6.src = *saddr;
255 	info->key.u.ipv6.dst = *daddr;
256 
257 	info->key.tos = tos;
258 	info->key.ttl = ttl;
259 	info->key.label = label;
260 
261 	return tun_dst;
262 }
263 
264 static inline struct metadata_dst *ipv6_tun_rx_dst(struct sk_buff *skb,
265 						   const unsigned long *flags,
266 						   __be64 tunnel_id,
267 						   int md_size)
268 {
269 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
270 
271 	return __ipv6_tun_set_dst(&ip6h->saddr, &ip6h->daddr,
272 				  ipv6_get_dsfield(ip6h), ip6h->hop_limit,
273 				  0, ip6_flowlabel(ip6h), flags, tunnel_id,
274 				  md_size);
275 }
276 #endif /* __NET_DST_METADATA_H */
277