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 INIT_LIST_HEAD(&xdst->u.rt6.rt6i_uncached); 93 rt6_uncached_list_add(&xdst->u.rt6); 94 95 return 0; 96 } 97 98 static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk, 99 struct sk_buff *skb, u32 mtu, 100 bool confirm_neigh) 101 { 102 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 103 struct dst_entry *path = xdst->route; 104 105 path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh); 106 } 107 108 static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk, 109 struct sk_buff *skb) 110 { 111 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 112 struct dst_entry *path = xdst->route; 113 114 path->ops->redirect(path, sk, skb); 115 } 116 117 static void xfrm6_dst_destroy(struct dst_entry *dst) 118 { 119 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 120 121 if (likely(xdst->u.rt6.rt6i_idev)) 122 in6_dev_put(xdst->u.rt6.rt6i_idev); 123 dst_destroy_metrics_generic(dst); 124 if (xdst->u.rt6.rt6i_uncached_list) 125 rt6_uncached_list_del(&xdst->u.rt6); 126 xfrm_dst_destroy(xdst); 127 } 128 129 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 130 int unregister) 131 { 132 struct xfrm_dst *xdst; 133 134 if (!unregister) 135 return; 136 137 xdst = (struct xfrm_dst *)dst; 138 if (xdst->u.rt6.rt6i_idev->dev == dev) { 139 struct inet6_dev *loopback_idev = 140 in6_dev_get(dev_net(dev)->loopback_dev); 141 142 do { 143 in6_dev_put(xdst->u.rt6.rt6i_idev); 144 xdst->u.rt6.rt6i_idev = loopback_idev; 145 in6_dev_hold(loopback_idev); 146 xdst = (struct xfrm_dst *)xfrm_dst_child(&xdst->u.dst); 147 } while (xdst->u.dst.xfrm); 148 149 __in6_dev_put(loopback_idev); 150 } 151 152 xfrm_dst_ifdown(dst, dev); 153 } 154 155 static struct dst_ops xfrm6_dst_ops_template = { 156 .family = AF_INET6, 157 .update_pmtu = xfrm6_update_pmtu, 158 .redirect = xfrm6_redirect, 159 .cow_metrics = dst_cow_metrics_generic, 160 .destroy = xfrm6_dst_destroy, 161 .ifdown = xfrm6_dst_ifdown, 162 .local_out = __ip6_local_out, 163 .gc_thresh = 32768, 164 }; 165 166 static const struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 167 .dst_ops = &xfrm6_dst_ops_template, 168 .dst_lookup = xfrm6_dst_lookup, 169 .get_saddr = xfrm6_get_saddr, 170 .fill_dst = xfrm6_fill_dst, 171 .blackhole_route = ip6_blackhole_route, 172 }; 173 174 static int __init xfrm6_policy_init(void) 175 { 176 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo, AF_INET6); 177 } 178 179 static void xfrm6_policy_fini(void) 180 { 181 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 182 } 183 184 #ifdef CONFIG_SYSCTL 185 static struct ctl_table xfrm6_policy_table[] = { 186 { 187 .procname = "xfrm6_gc_thresh", 188 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, 189 .maxlen = sizeof(int), 190 .mode = 0644, 191 .proc_handler = proc_dointvec, 192 }, 193 { } 194 }; 195 196 static int __net_init xfrm6_net_sysctl_init(struct net *net) 197 { 198 struct ctl_table *table; 199 struct ctl_table_header *hdr; 200 201 table = xfrm6_policy_table; 202 if (!net_eq(net, &init_net)) { 203 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL); 204 if (!table) 205 goto err_alloc; 206 207 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh; 208 } 209 210 hdr = register_net_sysctl(net, "net/ipv6", table); 211 if (!hdr) 212 goto err_reg; 213 214 net->ipv6.sysctl.xfrm6_hdr = hdr; 215 return 0; 216 217 err_reg: 218 if (!net_eq(net, &init_net)) 219 kfree(table); 220 err_alloc: 221 return -ENOMEM; 222 } 223 224 static void __net_exit xfrm6_net_sysctl_exit(struct net *net) 225 { 226 struct ctl_table *table; 227 228 if (!net->ipv6.sysctl.xfrm6_hdr) 229 return; 230 231 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg; 232 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr); 233 if (!net_eq(net, &init_net)) 234 kfree(table); 235 } 236 #else /* CONFIG_SYSCTL */ 237 static inline int xfrm6_net_sysctl_init(struct net *net) 238 { 239 return 0; 240 } 241 242 static inline void xfrm6_net_sysctl_exit(struct net *net) 243 { 244 } 245 #endif 246 247 static int __net_init xfrm6_net_init(struct net *net) 248 { 249 int ret; 250 251 memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template, 252 sizeof(xfrm6_dst_ops_template)); 253 ret = dst_entries_init(&net->xfrm.xfrm6_dst_ops); 254 if (ret) 255 return ret; 256 257 ret = xfrm6_net_sysctl_init(net); 258 if (ret) 259 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops); 260 261 return ret; 262 } 263 264 static void __net_exit xfrm6_net_exit(struct net *net) 265 { 266 xfrm6_net_sysctl_exit(net); 267 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops); 268 } 269 270 static struct pernet_operations xfrm6_net_ops = { 271 .init = xfrm6_net_init, 272 .exit = xfrm6_net_exit, 273 }; 274 275 int __init xfrm6_init(void) 276 { 277 int ret; 278 279 ret = xfrm6_policy_init(); 280 if (ret) 281 goto out; 282 ret = xfrm6_state_init(); 283 if (ret) 284 goto out_policy; 285 286 ret = xfrm6_protocol_init(); 287 if (ret) 288 goto out_state; 289 290 register_pernet_subsys(&xfrm6_net_ops); 291 out: 292 return ret; 293 out_state: 294 xfrm6_state_fini(); 295 out_policy: 296 xfrm6_policy_fini(); 297 goto out; 298 } 299 300 void xfrm6_fini(void) 301 { 302 unregister_pernet_subsys(&xfrm6_net_ops); 303 xfrm6_protocol_fini(); 304 xfrm6_policy_fini(); 305 xfrm6_state_fini(); 306 } 307