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 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 }; 189 190 static int __net_init xfrm6_net_sysctl_init(struct net *net) 191 { 192 struct ctl_table *table; 193 struct ctl_table_header *hdr; 194 195 table = xfrm6_policy_table; 196 if (!net_eq(net, &init_net)) { 197 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL); 198 if (!table) 199 goto err_alloc; 200 201 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh; 202 } 203 204 hdr = register_net_sysctl_sz(net, "net/ipv6", table, 205 ARRAY_SIZE(xfrm6_policy_table)); 206 if (!hdr) 207 goto err_reg; 208 209 net->ipv6.sysctl.xfrm6_hdr = hdr; 210 return 0; 211 212 err_reg: 213 if (!net_eq(net, &init_net)) 214 kfree(table); 215 err_alloc: 216 return -ENOMEM; 217 } 218 219 static void __net_exit xfrm6_net_sysctl_exit(struct net *net) 220 { 221 struct ctl_table *table; 222 223 if (!net->ipv6.sysctl.xfrm6_hdr) 224 return; 225 226 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg; 227 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr); 228 if (!net_eq(net, &init_net)) 229 kfree(table); 230 } 231 #else /* CONFIG_SYSCTL */ 232 static inline int xfrm6_net_sysctl_init(struct net *net) 233 { 234 return 0; 235 } 236 237 static inline void xfrm6_net_sysctl_exit(struct net *net) 238 { 239 } 240 #endif 241 242 static int __net_init xfrm6_net_init(struct net *net) 243 { 244 int ret; 245 246 memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template, 247 sizeof(xfrm6_dst_ops_template)); 248 ret = dst_entries_init(&net->xfrm.xfrm6_dst_ops); 249 if (ret) 250 return ret; 251 252 ret = xfrm6_net_sysctl_init(net); 253 if (ret) 254 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops); 255 256 return ret; 257 } 258 259 static void __net_exit xfrm6_net_exit(struct net *net) 260 { 261 xfrm6_net_sysctl_exit(net); 262 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops); 263 } 264 265 static struct pernet_operations xfrm6_net_ops = { 266 .init = xfrm6_net_init, 267 .exit = xfrm6_net_exit, 268 }; 269 270 int __init xfrm6_init(void) 271 { 272 int ret; 273 274 ret = xfrm6_policy_init(); 275 if (ret) 276 goto out; 277 ret = xfrm6_state_init(); 278 if (ret) 279 goto out_policy; 280 281 ret = xfrm6_protocol_init(); 282 if (ret) 283 goto out_state; 284 285 ret = register_pernet_subsys(&xfrm6_net_ops); 286 if (ret) 287 goto out_protocol; 288 out: 289 return ret; 290 out_protocol: 291 xfrm6_protocol_fini(); 292 out_state: 293 xfrm6_state_fini(); 294 out_policy: 295 xfrm6_policy_fini(); 296 goto out; 297 } 298 299 void xfrm6_fini(void) 300 { 301 unregister_pernet_subsys(&xfrm6_net_ops); 302 xfrm6_protocol_fini(); 303 xfrm6_policy_fini(); 304 xfrm6_state_fini(); 305 } 306