xref: /linux/include/net/dst_metadata.h (revision 722ecdbce68a87de2d9296f91308f44ea900a039)
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 
9 enum metadata_type {
10 	METADATA_IP_TUNNEL,
11 	METADATA_HW_PORT_MUX,
12 };
13 
14 struct hw_port_info {
15 	struct net_device *lower_dev;
16 	u32 port_id;
17 };
18 
19 struct 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 
28 static 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 
38 static inline struct ip_tunnel_info *
39 skb_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 	    (dst->lwtstate->type == LWTUNNEL_ENCAP_IP ||
50 	     dst->lwtstate->type == LWTUNNEL_ENCAP_IP6))
51 		return lwt_tun_info(dst->lwtstate);
52 
53 	return NULL;
54 }
55 
56 static inline bool skb_valid_dst(const struct sk_buff *skb)
57 {
58 	struct dst_entry *dst = skb_dst(skb);
59 
60 	return dst && !(dst->flags & DST_METADATA);
61 }
62 
63 static inline int skb_metadata_dst_cmp(const struct sk_buff *skb_a,
64 				       const struct sk_buff *skb_b)
65 {
66 	const struct metadata_dst *a, *b;
67 
68 	if (!(skb_a->_skb_refdst | skb_b->_skb_refdst))
69 		return 0;
70 
71 	a = (const struct metadata_dst *) skb_dst(skb_a);
72 	b = (const struct metadata_dst *) skb_dst(skb_b);
73 
74 	if (!a != !b || a->type != b->type)
75 		return 1;
76 
77 	switch (a->type) {
78 	case METADATA_HW_PORT_MUX:
79 		return memcmp(&a->u.port_info, &b->u.port_info,
80 			      sizeof(a->u.port_info));
81 	case METADATA_IP_TUNNEL:
82 		return memcmp(&a->u.tun_info, &b->u.tun_info,
83 			      sizeof(a->u.tun_info) +
84 					 a->u.tun_info.options_len);
85 	default:
86 		return 1;
87 	}
88 }
89 
90 void metadata_dst_free(struct metadata_dst *);
91 struct metadata_dst *metadata_dst_alloc(u8 optslen, enum metadata_type type,
92 					gfp_t flags);
93 void metadata_dst_free_percpu(struct metadata_dst __percpu *md_dst);
94 struct metadata_dst __percpu *
95 metadata_dst_alloc_percpu(u8 optslen, enum metadata_type type, gfp_t flags);
96 
97 static inline struct metadata_dst *tun_rx_dst(int md_size)
98 {
99 	struct metadata_dst *tun_dst;
100 
101 	tun_dst = metadata_dst_alloc(md_size, METADATA_IP_TUNNEL, GFP_ATOMIC);
102 	if (!tun_dst)
103 		return NULL;
104 
105 	tun_dst->u.tun_info.options_len = 0;
106 	tun_dst->u.tun_info.mode = 0;
107 	return tun_dst;
108 }
109 
110 static inline struct metadata_dst *tun_dst_unclone(struct sk_buff *skb)
111 {
112 	struct metadata_dst *md_dst = skb_metadata_dst(skb);
113 	int md_size;
114 	struct metadata_dst *new_md;
115 
116 	if (!md_dst || md_dst->type != METADATA_IP_TUNNEL)
117 		return ERR_PTR(-EINVAL);
118 
119 	md_size = md_dst->u.tun_info.options_len;
120 	new_md = metadata_dst_alloc(md_size, METADATA_IP_TUNNEL, GFP_ATOMIC);
121 	if (!new_md)
122 		return ERR_PTR(-ENOMEM);
123 
124 	memcpy(&new_md->u.tun_info, &md_dst->u.tun_info,
125 	       sizeof(struct ip_tunnel_info) + md_size);
126 #ifdef CONFIG_DST_CACHE
127 	/* Unclone the dst cache if there is one */
128 	if (new_md->u.tun_info.dst_cache.cache) {
129 		int ret;
130 
131 		ret = dst_cache_init(&new_md->u.tun_info.dst_cache, GFP_ATOMIC);
132 		if (ret) {
133 			metadata_dst_free(new_md);
134 			return ERR_PTR(ret);
135 		}
136 	}
137 #endif
138 
139 	skb_dst_drop(skb);
140 	skb_dst_set(skb, &new_md->dst);
141 	return new_md;
142 }
143 
144 static inline struct ip_tunnel_info *skb_tunnel_info_unclone(struct sk_buff *skb)
145 {
146 	struct metadata_dst *dst;
147 
148 	dst = tun_dst_unclone(skb);
149 	if (IS_ERR(dst))
150 		return NULL;
151 
152 	return &dst->u.tun_info;
153 }
154 
155 static inline struct metadata_dst *__ip_tun_set_dst(__be32 saddr,
156 						    __be32 daddr,
157 						    __u8 tos, __u8 ttl,
158 						    __be16 tp_dst,
159 						    __be16 flags,
160 						    __be64 tunnel_id,
161 						    int md_size)
162 {
163 	struct metadata_dst *tun_dst;
164 
165 	tun_dst = tun_rx_dst(md_size);
166 	if (!tun_dst)
167 		return NULL;
168 
169 	ip_tunnel_key_init(&tun_dst->u.tun_info.key,
170 			   saddr, daddr, tos, ttl,
171 			   0, 0, tp_dst, tunnel_id, flags);
172 	return tun_dst;
173 }
174 
175 static inline struct metadata_dst *ip_tun_rx_dst(struct sk_buff *skb,
176 						 __be16 flags,
177 						 __be64 tunnel_id,
178 						 int md_size)
179 {
180 	const struct iphdr *iph = ip_hdr(skb);
181 
182 	return __ip_tun_set_dst(iph->saddr, iph->daddr, iph->tos, iph->ttl,
183 				0, flags, tunnel_id, md_size);
184 }
185 
186 static inline struct metadata_dst *__ipv6_tun_set_dst(const struct in6_addr *saddr,
187 						      const struct in6_addr *daddr,
188 						      __u8 tos, __u8 ttl,
189 						      __be16 tp_dst,
190 						      __be32 label,
191 						      __be16 flags,
192 						      __be64 tunnel_id,
193 						      int md_size)
194 {
195 	struct metadata_dst *tun_dst;
196 	struct ip_tunnel_info *info;
197 
198 	tun_dst = tun_rx_dst(md_size);
199 	if (!tun_dst)
200 		return NULL;
201 
202 	info = &tun_dst->u.tun_info;
203 	info->mode = IP_TUNNEL_INFO_IPV6;
204 	info->key.tun_flags = flags;
205 	info->key.tun_id = tunnel_id;
206 	info->key.tp_src = 0;
207 	info->key.tp_dst = tp_dst;
208 
209 	info->key.u.ipv6.src = *saddr;
210 	info->key.u.ipv6.dst = *daddr;
211 
212 	info->key.tos = tos;
213 	info->key.ttl = ttl;
214 	info->key.label = label;
215 
216 	return tun_dst;
217 }
218 
219 static inline struct metadata_dst *ipv6_tun_rx_dst(struct sk_buff *skb,
220 						   __be16 flags,
221 						   __be64 tunnel_id,
222 						   int md_size)
223 {
224 	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
225 
226 	return __ipv6_tun_set_dst(&ip6h->saddr, &ip6h->daddr,
227 				  ipv6_get_dsfield(ip6h), ip6h->hop_limit,
228 				  0, ip6_flowlabel(ip6h), flags, tunnel_id,
229 				  md_size);
230 }
231 #endif /* __NET_DST_METADATA_H */
232