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 14 #include <linux/inet_diag.h> 15 #include <linux/sock_diag.h> 16 17 static const struct sock_diag_handler *sock_diag_handlers[AF_MAX]; 18 static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh); 19 static DEFINE_MUTEX(sock_diag_table_mutex); 20 static struct workqueue_struct *broadcast_wq; 21 22 static u64 sock_gen_cookie(struct sock *sk) 23 { 24 while (1) { 25 u64 res = atomic64_read(&sk->sk_cookie); 26 27 if (res) 28 return res; 29 res = atomic64_inc_return(&sock_net(sk)->cookie_gen); 30 atomic64_cmpxchg(&sk->sk_cookie, 0, res); 31 } 32 } 33 34 int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie) 35 { 36 u64 res; 37 38 if (cookie[0] == INET_DIAG_NOCOOKIE && cookie[1] == INET_DIAG_NOCOOKIE) 39 return 0; 40 41 res = sock_gen_cookie(sk); 42 if ((u32)res != cookie[0] || (u32)(res >> 32) != cookie[1]) 43 return -ESTALE; 44 45 return 0; 46 } 47 EXPORT_SYMBOL_GPL(sock_diag_check_cookie); 48 49 void sock_diag_save_cookie(struct sock *sk, __u32 *cookie) 50 { 51 u64 res = sock_gen_cookie(sk); 52 53 cookie[0] = (u32)res; 54 cookie[1] = (u32)(res >> 32); 55 } 56 EXPORT_SYMBOL_GPL(sock_diag_save_cookie); 57 58 int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype) 59 { 60 u32 mem[SK_MEMINFO_VARS]; 61 62 mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk); 63 mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf; 64 mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk); 65 mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf; 66 mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc; 67 mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued; 68 mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc); 69 mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len; 70 mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops); 71 72 return nla_put(skb, attrtype, sizeof(mem), &mem); 73 } 74 EXPORT_SYMBOL_GPL(sock_diag_put_meminfo); 75 76 int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk, 77 struct sk_buff *skb, int attrtype) 78 { 79 struct sock_fprog_kern *fprog; 80 struct sk_filter *filter; 81 struct nlattr *attr; 82 unsigned int flen; 83 int err = 0; 84 85 if (!may_report_filterinfo) { 86 nla_reserve(skb, attrtype, 0); 87 return 0; 88 } 89 90 rcu_read_lock(); 91 filter = rcu_dereference(sk->sk_filter); 92 if (!filter) 93 goto out; 94 95 fprog = filter->prog->orig_prog; 96 if (!fprog) 97 goto out; 98 99 flen = bpf_classic_proglen(fprog); 100 101 attr = nla_reserve(skb, attrtype, flen); 102 if (attr == NULL) { 103 err = -EMSGSIZE; 104 goto out; 105 } 106 107 memcpy(nla_data(attr), fprog->filter, flen); 108 out: 109 rcu_read_unlock(); 110 return err; 111 } 112 EXPORT_SYMBOL(sock_diag_put_filterinfo); 113 114 struct broadcast_sk { 115 struct sock *sk; 116 struct work_struct work; 117 }; 118 119 static size_t sock_diag_nlmsg_size(void) 120 { 121 return NLMSG_ALIGN(sizeof(struct inet_diag_msg) 122 + nla_total_size(sizeof(u8)) /* INET_DIAG_PROTOCOL */ 123 + nla_total_size_64bit(sizeof(struct tcp_info))); /* INET_DIAG_INFO */ 124 } 125 126 static void sock_diag_broadcast_destroy_work(struct work_struct *work) 127 { 128 struct broadcast_sk *bsk = 129 container_of(work, struct broadcast_sk, work); 130 struct sock *sk = bsk->sk; 131 const struct sock_diag_handler *hndl; 132 struct sk_buff *skb; 133 const enum sknetlink_groups group = sock_diag_destroy_group(sk); 134 int err = -1; 135 136 WARN_ON(group == SKNLGRP_NONE); 137 138 skb = nlmsg_new(sock_diag_nlmsg_size(), GFP_KERNEL); 139 if (!skb) 140 goto out; 141 142 mutex_lock(&sock_diag_table_mutex); 143 hndl = sock_diag_handlers[sk->sk_family]; 144 if (hndl && hndl->get_info) 145 err = hndl->get_info(skb, sk); 146 mutex_unlock(&sock_diag_table_mutex); 147 148 if (!err) 149 nlmsg_multicast(sock_net(sk)->diag_nlsk, skb, 0, group, 150 GFP_KERNEL); 151 else 152 kfree_skb(skb); 153 out: 154 sk_destruct(sk); 155 kfree(bsk); 156 } 157 158 void sock_diag_broadcast_destroy(struct sock *sk) 159 { 160 /* Note, this function is often called from an interrupt context. */ 161 struct broadcast_sk *bsk = 162 kmalloc(sizeof(struct broadcast_sk), GFP_ATOMIC); 163 if (!bsk) 164 return sk_destruct(sk); 165 bsk->sk = sk; 166 INIT_WORK(&bsk->work, sock_diag_broadcast_destroy_work); 167 queue_work(broadcast_wq, &bsk->work); 168 } 169 170 void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) 171 { 172 mutex_lock(&sock_diag_table_mutex); 173 inet_rcv_compat = fn; 174 mutex_unlock(&sock_diag_table_mutex); 175 } 176 EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat); 177 178 void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) 179 { 180 mutex_lock(&sock_diag_table_mutex); 181 inet_rcv_compat = NULL; 182 mutex_unlock(&sock_diag_table_mutex); 183 } 184 EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat); 185 186 int sock_diag_register(const struct sock_diag_handler *hndl) 187 { 188 int err = 0; 189 190 if (hndl->family >= AF_MAX) 191 return -EINVAL; 192 193 mutex_lock(&sock_diag_table_mutex); 194 if (sock_diag_handlers[hndl->family]) 195 err = -EBUSY; 196 else 197 sock_diag_handlers[hndl->family] = hndl; 198 mutex_unlock(&sock_diag_table_mutex); 199 200 return err; 201 } 202 EXPORT_SYMBOL_GPL(sock_diag_register); 203 204 void sock_diag_unregister(const struct sock_diag_handler *hnld) 205 { 206 int family = hnld->family; 207 208 if (family >= AF_MAX) 209 return; 210 211 mutex_lock(&sock_diag_table_mutex); 212 BUG_ON(sock_diag_handlers[family] != hnld); 213 sock_diag_handlers[family] = NULL; 214 mutex_unlock(&sock_diag_table_mutex); 215 } 216 EXPORT_SYMBOL_GPL(sock_diag_unregister); 217 218 static int __sock_diag_cmd(struct sk_buff *skb, struct nlmsghdr *nlh) 219 { 220 int err; 221 struct sock_diag_req *req = nlmsg_data(nlh); 222 const struct sock_diag_handler *hndl; 223 224 if (nlmsg_len(nlh) < sizeof(*req)) 225 return -EINVAL; 226 227 if (req->sdiag_family >= AF_MAX) 228 return -EINVAL; 229 230 if (sock_diag_handlers[req->sdiag_family] == NULL) 231 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, 232 NETLINK_SOCK_DIAG, req->sdiag_family); 233 234 mutex_lock(&sock_diag_table_mutex); 235 hndl = sock_diag_handlers[req->sdiag_family]; 236 if (hndl == NULL) 237 err = -ENOENT; 238 else if (nlh->nlmsg_type == SOCK_DIAG_BY_FAMILY) 239 err = hndl->dump(skb, nlh); 240 else if (nlh->nlmsg_type == SOCK_DESTROY && hndl->destroy) 241 err = hndl->destroy(skb, nlh); 242 else 243 err = -EOPNOTSUPP; 244 mutex_unlock(&sock_diag_table_mutex); 245 246 return err; 247 } 248 249 static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) 250 { 251 int ret; 252 253 switch (nlh->nlmsg_type) { 254 case TCPDIAG_GETSOCK: 255 case DCCPDIAG_GETSOCK: 256 if (inet_rcv_compat == NULL) 257 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, 258 NETLINK_SOCK_DIAG, AF_INET); 259 260 mutex_lock(&sock_diag_table_mutex); 261 if (inet_rcv_compat != NULL) 262 ret = inet_rcv_compat(skb, nlh); 263 else 264 ret = -EOPNOTSUPP; 265 mutex_unlock(&sock_diag_table_mutex); 266 267 return ret; 268 case SOCK_DIAG_BY_FAMILY: 269 case SOCK_DESTROY: 270 return __sock_diag_cmd(skb, nlh); 271 default: 272 return -EINVAL; 273 } 274 } 275 276 static DEFINE_MUTEX(sock_diag_mutex); 277 278 static void sock_diag_rcv(struct sk_buff *skb) 279 { 280 mutex_lock(&sock_diag_mutex); 281 netlink_rcv_skb(skb, &sock_diag_rcv_msg); 282 mutex_unlock(&sock_diag_mutex); 283 } 284 285 static int sock_diag_bind(struct net *net, int group) 286 { 287 switch (group) { 288 case SKNLGRP_INET_TCP_DESTROY: 289 case SKNLGRP_INET_UDP_DESTROY: 290 if (!sock_diag_handlers[AF_INET]) 291 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, 292 NETLINK_SOCK_DIAG, AF_INET); 293 break; 294 case SKNLGRP_INET6_TCP_DESTROY: 295 case SKNLGRP_INET6_UDP_DESTROY: 296 if (!sock_diag_handlers[AF_INET6]) 297 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, 298 NETLINK_SOCK_DIAG, AF_INET); 299 break; 300 } 301 return 0; 302 } 303 304 int sock_diag_destroy(struct sock *sk, int err) 305 { 306 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 307 return -EPERM; 308 309 if (!sk->sk_prot->diag_destroy) 310 return -EOPNOTSUPP; 311 312 return sk->sk_prot->diag_destroy(sk, err); 313 } 314 EXPORT_SYMBOL_GPL(sock_diag_destroy); 315 316 static int __net_init diag_net_init(struct net *net) 317 { 318 struct netlink_kernel_cfg cfg = { 319 .groups = SKNLGRP_MAX, 320 .input = sock_diag_rcv, 321 .bind = sock_diag_bind, 322 .flags = NL_CFG_F_NONROOT_RECV, 323 }; 324 325 net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg); 326 return net->diag_nlsk == NULL ? -ENOMEM : 0; 327 } 328 329 static void __net_exit diag_net_exit(struct net *net) 330 { 331 netlink_kernel_release(net->diag_nlsk); 332 net->diag_nlsk = NULL; 333 } 334 335 static struct pernet_operations diag_net_ops = { 336 .init = diag_net_init, 337 .exit = diag_net_exit, 338 }; 339 340 static int __init sock_diag_init(void) 341 { 342 broadcast_wq = alloc_workqueue("sock_diag_events", 0, 0); 343 BUG_ON(!broadcast_wq); 344 return register_pernet_subsys(&diag_net_ops); 345 } 346 device_initcall(sock_diag_init); 347