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_oif = l3mdev_master_ifindex_by_index(net, oif); 37 fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF; 38 fl6.flowi6_mark = mark; 39 memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr)); 40 if (saddr) 41 memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr)); 42 43 dst = ip6_route_output(net, NULL, &fl6); 44 45 err = dst->error; 46 if (dst->error) { 47 dst_release(dst); 48 dst = ERR_PTR(err); 49 } 50 51 return dst; 52 } 53 54 static int xfrm6_get_saddr(struct net *net, int oif, 55 xfrm_address_t *saddr, xfrm_address_t *daddr, 56 u32 mark) 57 { 58 struct dst_entry *dst; 59 struct net_device *dev; 60 61 dst = xfrm6_dst_lookup(net, 0, oif, NULL, daddr, mark); 62 if (IS_ERR(dst)) 63 return -EHOSTUNREACH; 64 65 dev = ip6_dst_idev(dst)->dev; 66 ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6); 67 dst_release(dst); 68 return 0; 69 } 70 71 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 72 const struct flowi *fl) 73 { 74 struct rt6_info *rt = (struct rt6_info *)xdst->route; 75 76 xdst->u.dst.dev = dev; 77 dev_hold(dev); 78 79 xdst->u.rt6.rt6i_idev = in6_dev_get(dev); 80 if (!xdst->u.rt6.rt6i_idev) { 81 dev_put(dev); 82 return -ENODEV; 83 } 84 85 /* Sheit... I remember I did this right. Apparently, 86 * it was magically lost, so this code needs audit */ 87 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST | 88 RTF_LOCAL); 89 xdst->route_cookie = rt6_get_cookie(rt); 90 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway; 91 xdst->u.rt6.rt6i_dst = rt->rt6i_dst; 92 xdst->u.rt6.rt6i_src = rt->rt6i_src; 93 INIT_LIST_HEAD(&xdst->u.rt6.rt6i_uncached); 94 rt6_uncached_list_add(&xdst->u.rt6); 95 atomic_inc(&dev_net(dev)->ipv6.rt6_stats->fib_rt_uncache); 96 97 return 0; 98 } 99 100 static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk, 101 struct sk_buff *skb, u32 mtu) 102 { 103 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 104 struct dst_entry *path = xdst->route; 105 106 path->ops->update_pmtu(path, sk, skb, mtu); 107 } 108 109 static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk, 110 struct sk_buff *skb) 111 { 112 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 113 struct dst_entry *path = xdst->route; 114 115 path->ops->redirect(path, sk, skb); 116 } 117 118 static void xfrm6_dst_destroy(struct dst_entry *dst) 119 { 120 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 121 122 if (likely(xdst->u.rt6.rt6i_idev)) 123 in6_dev_put(xdst->u.rt6.rt6i_idev); 124 dst_destroy_metrics_generic(dst); 125 if (xdst->u.rt6.rt6i_uncached_list) 126 rt6_uncached_list_del(&xdst->u.rt6); 127 xfrm_dst_destroy(xdst); 128 } 129 130 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 131 int unregister) 132 { 133 struct xfrm_dst *xdst; 134 135 if (!unregister) 136 return; 137 138 xdst = (struct xfrm_dst *)dst; 139 if (xdst->u.rt6.rt6i_idev->dev == dev) { 140 struct inet6_dev *loopback_idev = 141 in6_dev_get(dev_net(dev)->loopback_dev); 142 143 do { 144 in6_dev_put(xdst->u.rt6.rt6i_idev); 145 xdst->u.rt6.rt6i_idev = loopback_idev; 146 in6_dev_hold(loopback_idev); 147 xdst = (struct xfrm_dst *)xfrm_dst_child(&xdst->u.dst); 148 } while (xdst->u.dst.xfrm); 149 150 __in6_dev_put(loopback_idev); 151 } 152 153 xfrm_dst_ifdown(dst, dev); 154 } 155 156 static struct dst_ops xfrm6_dst_ops_template = { 157 .family = AF_INET6, 158 .update_pmtu = xfrm6_update_pmtu, 159 .redirect = xfrm6_redirect, 160 .cow_metrics = dst_cow_metrics_generic, 161 .destroy = xfrm6_dst_destroy, 162 .ifdown = xfrm6_dst_ifdown, 163 .local_out = __ip6_local_out, 164 .gc_thresh = 32768, 165 }; 166 167 static const struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 168 .dst_ops = &xfrm6_dst_ops_template, 169 .dst_lookup = xfrm6_dst_lookup, 170 .get_saddr = xfrm6_get_saddr, 171 .fill_dst = xfrm6_fill_dst, 172 .blackhole_route = ip6_blackhole_route, 173 }; 174 175 static int __init xfrm6_policy_init(void) 176 { 177 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo, AF_INET6); 178 } 179 180 static void xfrm6_policy_fini(void) 181 { 182 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 183 } 184 185 #ifdef CONFIG_SYSCTL 186 static struct ctl_table xfrm6_policy_table[] = { 187 { 188 .procname = "xfrm6_gc_thresh", 189 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, 190 .maxlen = sizeof(int), 191 .mode = 0644, 192 .proc_handler = proc_dointvec, 193 }, 194 { } 195 }; 196 197 static int __net_init xfrm6_net_sysctl_init(struct net *net) 198 { 199 struct ctl_table *table; 200 struct ctl_table_header *hdr; 201 202 table = xfrm6_policy_table; 203 if (!net_eq(net, &init_net)) { 204 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL); 205 if (!table) 206 goto err_alloc; 207 208 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh; 209 } 210 211 hdr = register_net_sysctl(net, "net/ipv6", table); 212 if (!hdr) 213 goto err_reg; 214 215 net->ipv6.sysctl.xfrm6_hdr = hdr; 216 return 0; 217 218 err_reg: 219 if (!net_eq(net, &init_net)) 220 kfree(table); 221 err_alloc: 222 return -ENOMEM; 223 } 224 225 static void __net_exit xfrm6_net_sysctl_exit(struct net *net) 226 { 227 struct ctl_table *table; 228 229 if (!net->ipv6.sysctl.xfrm6_hdr) 230 return; 231 232 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg; 233 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr); 234 if (!net_eq(net, &init_net)) 235 kfree(table); 236 } 237 #else /* CONFIG_SYSCTL */ 238 static inline int xfrm6_net_sysctl_init(struct net *net) 239 { 240 return 0; 241 } 242 243 static inline void xfrm6_net_sysctl_exit(struct net *net) 244 { 245 } 246 #endif 247 248 static int __net_init xfrm6_net_init(struct net *net) 249 { 250 int ret; 251 252 memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template, 253 sizeof(xfrm6_dst_ops_template)); 254 ret = dst_entries_init(&net->xfrm.xfrm6_dst_ops); 255 if (ret) 256 return ret; 257 258 ret = xfrm6_net_sysctl_init(net); 259 if (ret) 260 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops); 261 262 return ret; 263 } 264 265 static void __net_exit xfrm6_net_exit(struct net *net) 266 { 267 xfrm6_net_sysctl_exit(net); 268 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops); 269 } 270 271 static struct pernet_operations xfrm6_net_ops = { 272 .init = xfrm6_net_init, 273 .exit = xfrm6_net_exit, 274 }; 275 276 int __init xfrm6_init(void) 277 { 278 int ret; 279 280 ret = xfrm6_policy_init(); 281 if (ret) 282 goto out; 283 ret = xfrm6_state_init(); 284 if (ret) 285 goto out_policy; 286 287 ret = xfrm6_protocol_init(); 288 if (ret) 289 goto out_state; 290 291 register_pernet_subsys(&xfrm6_net_ops); 292 out: 293 return ret; 294 out_state: 295 xfrm6_state_fini(); 296 out_policy: 297 xfrm6_policy_fini(); 298 goto out; 299 } 300 301 void xfrm6_fini(void) 302 { 303 unregister_pernet_subsys(&xfrm6_net_ops); 304 xfrm6_protocol_fini(); 305 xfrm6_policy_fini(); 306 xfrm6_state_fini(); 307 } 308