1 /* License: GPL */ 2 3 #include <linux/mutex.h> 4 #include <linux/socket.h> 5 #include <linux/skbuff.h> 6 #include <net/netlink.h> 7 #include <net/net_namespace.h> 8 #include <linux/module.h> 9 #include <net/sock.h> 10 #include <linux/kernel.h> 11 #include <linux/tcp.h> 12 #include <linux/workqueue.h> 13 #include <linux/nospec.h> 14 #include <linux/cookie.h> 15 #include <linux/inet_diag.h> 16 #include <linux/sock_diag.h> 17 18 static const struct sock_diag_handler *sock_diag_handlers[AF_MAX]; 19 static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh); 20 static DEFINE_MUTEX(sock_diag_table_mutex); 21 static struct workqueue_struct *broadcast_wq; 22 23 DEFINE_COOKIE(sock_cookie); 24 25 u64 __sock_gen_cookie(struct sock *sk) 26 { 27 while (1) { 28 u64 res = atomic64_read(&sk->sk_cookie); 29 30 if (res) 31 return res; 32 res = gen_cookie_next(&sock_cookie); 33 atomic64_cmpxchg(&sk->sk_cookie, 0, res); 34 } 35 } 36 37 int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie) 38 { 39 u64 res; 40 41 if (cookie[0] == INET_DIAG_NOCOOKIE && cookie[1] == INET_DIAG_NOCOOKIE) 42 return 0; 43 44 res = sock_gen_cookie(sk); 45 if ((u32)res != cookie[0] || (u32)(res >> 32) != cookie[1]) 46 return -ESTALE; 47 48 return 0; 49 } 50 EXPORT_SYMBOL_GPL(sock_diag_check_cookie); 51 52 void sock_diag_save_cookie(struct sock *sk, __u32 *cookie) 53 { 54 u64 res = sock_gen_cookie(sk); 55 56 cookie[0] = (u32)res; 57 cookie[1] = (u32)(res >> 32); 58 } 59 EXPORT_SYMBOL_GPL(sock_diag_save_cookie); 60 61 int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype) 62 { 63 u32 mem[SK_MEMINFO_VARS]; 64 65 sk_get_meminfo(sk, mem); 66 67 return nla_put(skb, attrtype, sizeof(mem), &mem); 68 } 69 EXPORT_SYMBOL_GPL(sock_diag_put_meminfo); 70 71 int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk, 72 struct sk_buff *skb, int attrtype) 73 { 74 struct sock_fprog_kern *fprog; 75 struct sk_filter *filter; 76 struct nlattr *attr; 77 unsigned int flen; 78 int err = 0; 79 80 if (!may_report_filterinfo) { 81 nla_reserve(skb, attrtype, 0); 82 return 0; 83 } 84 85 rcu_read_lock(); 86 filter = rcu_dereference(sk->sk_filter); 87 if (!filter) 88 goto out; 89 90 fprog = filter->prog->orig_prog; 91 if (!fprog) 92 goto out; 93 94 flen = bpf_classic_proglen(fprog); 95 96 attr = nla_reserve(skb, attrtype, flen); 97 if (attr == NULL) { 98 err = -EMSGSIZE; 99 goto out; 100 } 101 102 memcpy(nla_data(attr), fprog->filter, flen); 103 out: 104 rcu_read_unlock(); 105 return err; 106 } 107 EXPORT_SYMBOL(sock_diag_put_filterinfo); 108 109 struct broadcast_sk { 110 struct sock *sk; 111 struct work_struct work; 112 }; 113 114 static size_t sock_diag_nlmsg_size(void) 115 { 116 return NLMSG_ALIGN(sizeof(struct inet_diag_msg) 117 + nla_total_size(sizeof(u8)) /* INET_DIAG_PROTOCOL */ 118 + nla_total_size_64bit(sizeof(struct tcp_info))); /* INET_DIAG_INFO */ 119 } 120 121 static void sock_diag_broadcast_destroy_work(struct work_struct *work) 122 { 123 struct broadcast_sk *bsk = 124 container_of(work, struct broadcast_sk, work); 125 struct sock *sk = bsk->sk; 126 const struct sock_diag_handler *hndl; 127 struct sk_buff *skb; 128 const enum sknetlink_groups group = sock_diag_destroy_group(sk); 129 int err = -1; 130 131 WARN_ON(group == SKNLGRP_NONE); 132 133 skb = nlmsg_new(sock_diag_nlmsg_size(), GFP_KERNEL); 134 if (!skb) 135 goto out; 136 137 mutex_lock(&sock_diag_table_mutex); 138 hndl = sock_diag_handlers[sk->sk_family]; 139 if (hndl && hndl->get_info) 140 err = hndl->get_info(skb, sk); 141 mutex_unlock(&sock_diag_table_mutex); 142 143 if (!err) 144 nlmsg_multicast(sock_net(sk)->diag_nlsk, skb, 0, group, 145 GFP_KERNEL); 146 else 147 kfree_skb(skb); 148 out: 149 sk_destruct(sk); 150 kfree(bsk); 151 } 152 153 void sock_diag_broadcast_destroy(struct sock *sk) 154 { 155 /* Note, this function is often called from an interrupt context. */ 156 struct broadcast_sk *bsk = 157 kmalloc(sizeof(struct broadcast_sk), GFP_ATOMIC); 158 if (!bsk) 159 return sk_destruct(sk); 160 bsk->sk = sk; 161 INIT_WORK(&bsk->work, sock_diag_broadcast_destroy_work); 162 queue_work(broadcast_wq, &bsk->work); 163 } 164 165 void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) 166 { 167 mutex_lock(&sock_diag_table_mutex); 168 inet_rcv_compat = fn; 169 mutex_unlock(&sock_diag_table_mutex); 170 } 171 EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat); 172 173 void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) 174 { 175 mutex_lock(&sock_diag_table_mutex); 176 inet_rcv_compat = NULL; 177 mutex_unlock(&sock_diag_table_mutex); 178 } 179 EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat); 180 181 int sock_diag_register(const struct sock_diag_handler *hndl) 182 { 183 int err = 0; 184 185 if (hndl->family >= AF_MAX) 186 return -EINVAL; 187 188 mutex_lock(&sock_diag_table_mutex); 189 if (sock_diag_handlers[hndl->family]) 190 err = -EBUSY; 191 else 192 sock_diag_handlers[hndl->family] = hndl; 193 mutex_unlock(&sock_diag_table_mutex); 194 195 return err; 196 } 197 EXPORT_SYMBOL_GPL(sock_diag_register); 198 199 void sock_diag_unregister(const struct sock_diag_handler *hnld) 200 { 201 int family = hnld->family; 202 203 if (family >= AF_MAX) 204 return; 205 206 mutex_lock(&sock_diag_table_mutex); 207 BUG_ON(sock_diag_handlers[family] != hnld); 208 sock_diag_handlers[family] = NULL; 209 mutex_unlock(&sock_diag_table_mutex); 210 } 211 EXPORT_SYMBOL_GPL(sock_diag_unregister); 212 213 static int __sock_diag_cmd(struct sk_buff *skb, struct nlmsghdr *nlh) 214 { 215 int err; 216 struct sock_diag_req *req = nlmsg_data(nlh); 217 const struct sock_diag_handler *hndl; 218 219 if (nlmsg_len(nlh) < sizeof(*req)) 220 return -EINVAL; 221 222 if (req->sdiag_family >= AF_MAX) 223 return -EINVAL; 224 req->sdiag_family = array_index_nospec(req->sdiag_family, AF_MAX); 225 226 if (sock_diag_handlers[req->sdiag_family] == NULL) 227 sock_load_diag_module(req->sdiag_family, 0); 228 229 mutex_lock(&sock_diag_table_mutex); 230 hndl = sock_diag_handlers[req->sdiag_family]; 231 if (hndl == NULL) 232 err = -ENOENT; 233 else if (nlh->nlmsg_type == SOCK_DIAG_BY_FAMILY) 234 err = hndl->dump(skb, nlh); 235 else if (nlh->nlmsg_type == SOCK_DESTROY && hndl->destroy) 236 err = hndl->destroy(skb, nlh); 237 else 238 err = -EOPNOTSUPP; 239 mutex_unlock(&sock_diag_table_mutex); 240 241 return err; 242 } 243 244 static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, 245 struct netlink_ext_ack *extack) 246 { 247 int ret; 248 249 switch (nlh->nlmsg_type) { 250 case TCPDIAG_GETSOCK: 251 case DCCPDIAG_GETSOCK: 252 if (inet_rcv_compat == NULL) 253 sock_load_diag_module(AF_INET, 0); 254 255 mutex_lock(&sock_diag_table_mutex); 256 if (inet_rcv_compat != NULL) 257 ret = inet_rcv_compat(skb, nlh); 258 else 259 ret = -EOPNOTSUPP; 260 mutex_unlock(&sock_diag_table_mutex); 261 262 return ret; 263 case SOCK_DIAG_BY_FAMILY: 264 case SOCK_DESTROY: 265 return __sock_diag_cmd(skb, nlh); 266 default: 267 return -EINVAL; 268 } 269 } 270 271 static DEFINE_MUTEX(sock_diag_mutex); 272 273 static void sock_diag_rcv(struct sk_buff *skb) 274 { 275 mutex_lock(&sock_diag_mutex); 276 netlink_rcv_skb(skb, &sock_diag_rcv_msg); 277 mutex_unlock(&sock_diag_mutex); 278 } 279 280 static int sock_diag_bind(struct net *net, int group) 281 { 282 switch (group) { 283 case SKNLGRP_INET_TCP_DESTROY: 284 case SKNLGRP_INET_UDP_DESTROY: 285 if (!sock_diag_handlers[AF_INET]) 286 sock_load_diag_module(AF_INET, 0); 287 break; 288 case SKNLGRP_INET6_TCP_DESTROY: 289 case SKNLGRP_INET6_UDP_DESTROY: 290 if (!sock_diag_handlers[AF_INET6]) 291 sock_load_diag_module(AF_INET6, 0); 292 break; 293 } 294 return 0; 295 } 296 297 int sock_diag_destroy(struct sock *sk, int err) 298 { 299 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 300 return -EPERM; 301 302 if (!sk->sk_prot->diag_destroy) 303 return -EOPNOTSUPP; 304 305 return sk->sk_prot->diag_destroy(sk, err); 306 } 307 EXPORT_SYMBOL_GPL(sock_diag_destroy); 308 309 static int __net_init diag_net_init(struct net *net) 310 { 311 struct netlink_kernel_cfg cfg = { 312 .groups = SKNLGRP_MAX, 313 .input = sock_diag_rcv, 314 .bind = sock_diag_bind, 315 .flags = NL_CFG_F_NONROOT_RECV, 316 }; 317 318 net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg); 319 return net->diag_nlsk == NULL ? -ENOMEM : 0; 320 } 321 322 static void __net_exit diag_net_exit(struct net *net) 323 { 324 netlink_kernel_release(net->diag_nlsk); 325 net->diag_nlsk = NULL; 326 } 327 328 static struct pernet_operations diag_net_ops = { 329 .init = diag_net_init, 330 .exit = diag_net_exit, 331 }; 332 333 static int __init sock_diag_init(void) 334 { 335 broadcast_wq = alloc_workqueue("sock_diag_events", 0, 0); 336 BUG_ON(!broadcast_wq); 337 return register_pernet_subsys(&diag_net_ops); 338 } 339 device_initcall(sock_diag_init); 340