1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Copyright (c) 2014 Mahesh Bandewar <maheshb@google.com>
3 */
4
5 #include "ipvlan.h"
6
7 static unsigned int ipvlan_netid __read_mostly;
8
9 struct ipvlan_netns {
10 unsigned int ipvl_nf_hook_refcnt;
11 };
12
ipvlan_skb_to_addr(struct sk_buff * skb,struct net_device * dev)13 static struct ipvl_addr *ipvlan_skb_to_addr(struct sk_buff *skb,
14 struct net_device *dev)
15 {
16 struct ipvl_addr *addr = NULL;
17 struct ipvl_port *port;
18 int addr_type;
19 void *lyr3h;
20
21 if (!dev || !netif_is_ipvlan_port(dev))
22 goto out;
23
24 port = ipvlan_port_get_rcu(dev);
25 if (!port || port->mode != IPVLAN_MODE_L3S)
26 goto out;
27
28 lyr3h = ipvlan_get_L3_hdr(port, skb, &addr_type);
29 if (!lyr3h)
30 goto out;
31
32 addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
33 out:
34 return addr;
35 }
36
ipvlan_l3_rcv(struct net_device * dev,struct sk_buff * skb,u16 proto)37 static struct sk_buff *ipvlan_l3_rcv(struct net_device *dev,
38 struct sk_buff *skb, u16 proto)
39 {
40 struct ipvl_addr *addr;
41 struct net_device *sdev;
42
43 addr = ipvlan_skb_to_addr(skb, dev);
44 if (!addr)
45 goto out;
46
47 sdev = addr->master->dev;
48 switch (proto) {
49 case AF_INET:
50 {
51 struct iphdr *ip4h = ip_hdr(skb);
52 int err;
53
54 err = ip_route_input_noref(skb, ip4h->daddr, ip4h->saddr,
55 ip4h->tos, sdev);
56 if (unlikely(err))
57 goto out;
58 break;
59 }
60 #if IS_ENABLED(CONFIG_IPV6)
61 case AF_INET6:
62 {
63 struct dst_entry *dst;
64 struct ipv6hdr *ip6h = ipv6_hdr(skb);
65 int flags = RT6_LOOKUP_F_HAS_SADDR;
66 struct flowi6 fl6 = {
67 .flowi6_iif = sdev->ifindex,
68 .daddr = ip6h->daddr,
69 .saddr = ip6h->saddr,
70 .flowlabel = ip6_flowinfo(ip6h),
71 .flowi6_mark = skb->mark,
72 .flowi6_proto = ip6h->nexthdr,
73 };
74
75 skb_dst_drop(skb);
76 dst = ip6_route_input_lookup(dev_net(sdev), sdev, &fl6,
77 skb, flags);
78 skb_dst_set(skb, dst);
79 break;
80 }
81 #endif
82 default:
83 break;
84 }
85 out:
86 return skb;
87 }
88
89 static const struct l3mdev_ops ipvl_l3mdev_ops = {
90 .l3mdev_l3_rcv = ipvlan_l3_rcv,
91 };
92
ipvlan_nf_input(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)93 static unsigned int ipvlan_nf_input(void *priv, struct sk_buff *skb,
94 const struct nf_hook_state *state)
95 {
96 struct ipvl_addr *addr;
97 unsigned int len;
98
99 addr = ipvlan_skb_to_addr(skb, skb->dev);
100 if (!addr)
101 goto out;
102
103 skb->dev = addr->master->dev;
104 skb->skb_iif = skb->dev->ifindex;
105 #if IS_ENABLED(CONFIG_IPV6)
106 if (addr->atype == IPVL_IPV6)
107 IP6CB(skb)->iif = skb->dev->ifindex;
108 #endif
109 len = skb->len + ETH_HLEN;
110 ipvlan_count_rx(addr->master, len, true, false);
111 out:
112 return NF_ACCEPT;
113 }
114
115 static const struct nf_hook_ops ipvl_nfops[] = {
116 {
117 .hook = ipvlan_nf_input,
118 .pf = NFPROTO_IPV4,
119 .hooknum = NF_INET_LOCAL_IN,
120 .priority = INT_MAX,
121 },
122 #if IS_ENABLED(CONFIG_IPV6)
123 {
124 .hook = ipvlan_nf_input,
125 .pf = NFPROTO_IPV6,
126 .hooknum = NF_INET_LOCAL_IN,
127 .priority = INT_MAX,
128 },
129 #endif
130 };
131
ipvlan_register_nf_hook(struct net * net)132 static int ipvlan_register_nf_hook(struct net *net)
133 {
134 struct ipvlan_netns *vnet = net_generic(net, ipvlan_netid);
135 int err = 0;
136
137 if (!vnet->ipvl_nf_hook_refcnt) {
138 err = nf_register_net_hooks(net, ipvl_nfops,
139 ARRAY_SIZE(ipvl_nfops));
140 if (!err)
141 vnet->ipvl_nf_hook_refcnt = 1;
142 } else {
143 vnet->ipvl_nf_hook_refcnt++;
144 }
145
146 return err;
147 }
148
ipvlan_unregister_nf_hook(struct net * net)149 static void ipvlan_unregister_nf_hook(struct net *net)
150 {
151 struct ipvlan_netns *vnet = net_generic(net, ipvlan_netid);
152
153 if (WARN_ON(!vnet->ipvl_nf_hook_refcnt))
154 return;
155
156 vnet->ipvl_nf_hook_refcnt--;
157 if (!vnet->ipvl_nf_hook_refcnt)
158 nf_unregister_net_hooks(net, ipvl_nfops,
159 ARRAY_SIZE(ipvl_nfops));
160 }
161
ipvlan_migrate_l3s_hook(struct net * oldnet,struct net * newnet)162 void ipvlan_migrate_l3s_hook(struct net *oldnet, struct net *newnet)
163 {
164 struct ipvlan_netns *old_vnet;
165
166 ASSERT_RTNL();
167
168 old_vnet = net_generic(oldnet, ipvlan_netid);
169 if (!old_vnet->ipvl_nf_hook_refcnt)
170 return;
171
172 ipvlan_register_nf_hook(newnet);
173 ipvlan_unregister_nf_hook(oldnet);
174 }
175
ipvlan_ns_exit(struct net * net)176 static void ipvlan_ns_exit(struct net *net)
177 {
178 struct ipvlan_netns *vnet = net_generic(net, ipvlan_netid);
179
180 if (WARN_ON_ONCE(vnet->ipvl_nf_hook_refcnt)) {
181 vnet->ipvl_nf_hook_refcnt = 0;
182 nf_unregister_net_hooks(net, ipvl_nfops,
183 ARRAY_SIZE(ipvl_nfops));
184 }
185 }
186
187 static struct pernet_operations ipvlan_net_ops = {
188 .id = &ipvlan_netid,
189 .size = sizeof(struct ipvlan_netns),
190 .exit = ipvlan_ns_exit,
191 };
192
ipvlan_l3s_init(void)193 int ipvlan_l3s_init(void)
194 {
195 return register_pernet_subsys(&ipvlan_net_ops);
196 }
197
ipvlan_l3s_cleanup(void)198 void ipvlan_l3s_cleanup(void)
199 {
200 unregister_pernet_subsys(&ipvlan_net_ops);
201 }
202
ipvlan_l3s_register(struct ipvl_port * port)203 int ipvlan_l3s_register(struct ipvl_port *port)
204 {
205 struct net_device *dev = port->dev;
206 int ret;
207
208 ASSERT_RTNL();
209
210 ret = ipvlan_register_nf_hook(read_pnet(&port->pnet));
211 if (!ret) {
212 dev->l3mdev_ops = &ipvl_l3mdev_ops;
213 dev->priv_flags |= IFF_L3MDEV_RX_HANDLER;
214 }
215
216 return ret;
217 }
218
ipvlan_l3s_unregister(struct ipvl_port * port)219 void ipvlan_l3s_unregister(struct ipvl_port *port)
220 {
221 struct net_device *dev = port->dev;
222
223 ASSERT_RTNL();
224
225 dev->priv_flags &= ~IFF_L3MDEV_RX_HANDLER;
226 ipvlan_unregister_nf_hook(read_pnet(&port->pnet));
227 dev->l3mdev_ops = NULL;
228 }
229