1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * xfrm6_policy.c: based on xfrm4_policy.c 4 * 5 * Authors: 6 * Mitsuru KANDA @USAGI 7 * Kazunori MIYAZAWA @USAGI 8 * Kunihiro Ishiguro <kunihiro@ipinfusion.com> 9 * IPv6 support 10 * YOSHIFUJI Hideaki 11 * Split up af-specific portion 12 * 13 */ 14 15 #include <linux/err.h> 16 #include <linux/kernel.h> 17 #include <linux/netdevice.h> 18 #include <net/addrconf.h> 19 #include <net/dst.h> 20 #include <net/xfrm.h> 21 #include <net/ip.h> 22 #include <net/ipv6.h> 23 #include <net/ip6_route.h> 24 #include <net/l3mdev.h> 25 26 static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, int oif, 27 const xfrm_address_t *saddr, 28 const xfrm_address_t *daddr, 29 u32 mark) 30 { 31 struct flowi6 fl6; 32 struct dst_entry *dst; 33 int err; 34 35 memset(&fl6, 0, sizeof(fl6)); 36 fl6.flowi6_l3mdev = l3mdev_master_ifindex_by_index(net, oif); 37 fl6.flowi6_mark = mark; 38 memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr)); 39 if (saddr) 40 memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr)); 41 42 dst = ip6_route_output(net, NULL, &fl6); 43 44 err = dst->error; 45 if (dst->error) { 46 dst_release(dst); 47 dst = ERR_PTR(err); 48 } 49 50 return dst; 51 } 52 53 static int xfrm6_get_saddr(struct net *net, int oif, 54 xfrm_address_t *saddr, xfrm_address_t *daddr, 55 u32 mark) 56 { 57 struct dst_entry *dst; 58 struct net_device *dev; 59 60 dst = xfrm6_dst_lookup(net, 0, oif, NULL, daddr, mark); 61 if (IS_ERR(dst)) 62 return -EHOSTUNREACH; 63 64 dev = ip6_dst_idev(dst)->dev; 65 ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6); 66 dst_release(dst); 67 return 0; 68 } 69 70 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 71 const struct flowi *fl) 72 { 73 struct rt6_info *rt = (struct rt6_info *)xdst->route; 74 75 xdst->u.dst.dev = dev; 76 netdev_hold(dev, &xdst->u.dst.dev_tracker, GFP_ATOMIC); 77 78 xdst->u.rt6.rt6i_idev = in6_dev_get(dev); 79 if (!xdst->u.rt6.rt6i_idev) { 80 netdev_put(dev, &xdst->u.dst.dev_tracker); 81 return -ENODEV; 82 } 83 84 /* Sheit... I remember I did this right. Apparently, 85 * it was magically lost, so this code needs audit */ 86 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST | 87 RTF_LOCAL); 88 xdst->route_cookie = rt6_get_cookie(rt); 89 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway; 90 xdst->u.rt6.rt6i_dst = rt->rt6i_dst; 91 xdst->u.rt6.rt6i_src = rt->rt6i_src; 92 rt6_uncached_list_add(&xdst->u.rt6); 93 94 return 0; 95 } 96 97 static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk, 98 struct sk_buff *skb, u32 mtu, 99 bool confirm_neigh) 100 { 101 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 102 struct dst_entry *path = xdst->route; 103 104 path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh); 105 } 106 107 static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk, 108 struct sk_buff *skb) 109 { 110 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 111 struct dst_entry *path = xdst->route; 112 113 path->ops->redirect(path, sk, skb); 114 } 115 116 static void xfrm6_dst_destroy(struct dst_entry *dst) 117 { 118 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 119 120 if (likely(xdst->u.rt6.rt6i_idev)) 121 in6_dev_put(xdst->u.rt6.rt6i_idev); 122 dst_destroy_metrics_generic(dst); 123 rt6_uncached_list_del(&xdst->u.rt6); 124 xfrm_dst_destroy(xdst); 125 } 126 127 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 128 int unregister) 129 { 130 struct xfrm_dst *xdst; 131 132 if (!unregister) 133 return; 134 135 xdst = (struct xfrm_dst *)dst; 136 if (xdst->u.rt6.rt6i_idev->dev == dev) { 137 struct inet6_dev *loopback_idev = 138 in6_dev_get(dev_net(dev)->loopback_dev); 139 140 do { 141 in6_dev_put(xdst->u.rt6.rt6i_idev); 142 xdst->u.rt6.rt6i_idev = loopback_idev; 143 in6_dev_hold(loopback_idev); 144 xdst = (struct xfrm_dst *)xfrm_dst_child(&xdst->u.dst); 145 } while (xdst->u.dst.xfrm); 146 147 __in6_dev_put(loopback_idev); 148 } 149 150 xfrm_dst_ifdown(dst, dev); 151 } 152 153 static struct dst_ops xfrm6_dst_ops_template = { 154 .family = AF_INET6, 155 .update_pmtu = xfrm6_update_pmtu, 156 .redirect = xfrm6_redirect, 157 .cow_metrics = dst_cow_metrics_generic, 158 .destroy = xfrm6_dst_destroy, 159 .ifdown = xfrm6_dst_ifdown, 160 .local_out = __ip6_local_out, 161 .gc_thresh = 32768, 162 }; 163 164 static const struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 165 .dst_ops = &xfrm6_dst_ops_template, 166 .dst_lookup = xfrm6_dst_lookup, 167 .get_saddr = xfrm6_get_saddr, 168 .fill_dst = xfrm6_fill_dst, 169 .blackhole_route = ip6_blackhole_route, 170 }; 171 172 static int __init xfrm6_policy_init(void) 173 { 174 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo, AF_INET6); 175 } 176 177 static void xfrm6_policy_fini(void) 178 { 179 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 180 } 181 182 #ifdef CONFIG_SYSCTL 183 static struct ctl_table xfrm6_policy_table[] = { 184 { 185 .procname = "xfrm6_gc_thresh", 186 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, 187 .maxlen = sizeof(int), 188 .mode = 0644, 189 .proc_handler = proc_dointvec, 190 }, 191 { } 192 }; 193 194 static int __net_init xfrm6_net_sysctl_init(struct net *net) 195 { 196 struct ctl_table *table; 197 struct ctl_table_header *hdr; 198 199 table = xfrm6_policy_table; 200 if (!net_eq(net, &init_net)) { 201 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL); 202 if (!table) 203 goto err_alloc; 204 205 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh; 206 } 207 208 hdr = register_net_sysctl(net, "net/ipv6", table); 209 if (!hdr) 210 goto err_reg; 211 212 net->ipv6.sysctl.xfrm6_hdr = hdr; 213 return 0; 214 215 err_reg: 216 if (!net_eq(net, &init_net)) 217 kfree(table); 218 err_alloc: 219 return -ENOMEM; 220 } 221 222 static void __net_exit xfrm6_net_sysctl_exit(struct net *net) 223 { 224 struct ctl_table *table; 225 226 if (!net->ipv6.sysctl.xfrm6_hdr) 227 return; 228 229 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg; 230 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr); 231 if (!net_eq(net, &init_net)) 232 kfree(table); 233 } 234 #else /* CONFIG_SYSCTL */ 235 static inline int xfrm6_net_sysctl_init(struct net *net) 236 { 237 return 0; 238 } 239 240 static inline void xfrm6_net_sysctl_exit(struct net *net) 241 { 242 } 243 #endif 244 245 static int __net_init xfrm6_net_init(struct net *net) 246 { 247 int ret; 248 249 memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template, 250 sizeof(xfrm6_dst_ops_template)); 251 ret = dst_entries_init(&net->xfrm.xfrm6_dst_ops); 252 if (ret) 253 return ret; 254 255 ret = xfrm6_net_sysctl_init(net); 256 if (ret) 257 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops); 258 259 return ret; 260 } 261 262 static void __net_exit xfrm6_net_exit(struct net *net) 263 { 264 xfrm6_net_sysctl_exit(net); 265 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops); 266 } 267 268 static struct pernet_operations xfrm6_net_ops = { 269 .init = xfrm6_net_init, 270 .exit = xfrm6_net_exit, 271 }; 272 273 int __init xfrm6_init(void) 274 { 275 int ret; 276 277 ret = xfrm6_policy_init(); 278 if (ret) 279 goto out; 280 ret = xfrm6_state_init(); 281 if (ret) 282 goto out_policy; 283 284 ret = xfrm6_protocol_init(); 285 if (ret) 286 goto out_state; 287 288 ret = register_pernet_subsys(&xfrm6_net_ops); 289 if (ret) 290 goto out_protocol; 291 out: 292 return ret; 293 out_protocol: 294 xfrm6_protocol_fini(); 295 out_state: 296 xfrm6_state_fini(); 297 out_policy: 298 xfrm6_policy_fini(); 299 goto out; 300 } 301 302 void xfrm6_fini(void) 303 { 304 unregister_pernet_subsys(&xfrm6_net_ops); 305 xfrm6_protocol_fini(); 306 xfrm6_policy_fini(); 307 xfrm6_state_fini(); 308 } 309