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