1 #include <linux/mutex.h> 2 #include <linux/socket.h> 3 #include <linux/skbuff.h> 4 #include <net/netlink.h> 5 #include <net/net_namespace.h> 6 #include <linux/module.h> 7 #include <net/sock.h> 8 #include <linux/kernel.h> 9 #include <linux/tcp.h> 10 #include <linux/workqueue.h> 11 12 #include <linux/inet_diag.h> 13 #include <linux/sock_diag.h> 14 15 static const struct sock_diag_handler *sock_diag_handlers[AF_MAX]; 16 static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh); 17 static DEFINE_MUTEX(sock_diag_table_mutex); 18 static struct workqueue_struct *broadcast_wq; 19 20 static u64 sock_gen_cookie(struct sock *sk) 21 { 22 while (1) { 23 u64 res = atomic64_read(&sk->sk_cookie); 24 25 if (res) 26 return res; 27 res = atomic64_inc_return(&sock_net(sk)->cookie_gen); 28 atomic64_cmpxchg(&sk->sk_cookie, 0, res); 29 } 30 } 31 32 int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie) 33 { 34 u64 res; 35 36 if (cookie[0] == INET_DIAG_NOCOOKIE && cookie[1] == INET_DIAG_NOCOOKIE) 37 return 0; 38 39 res = sock_gen_cookie(sk); 40 if ((u32)res != cookie[0] || (u32)(res >> 32) != cookie[1]) 41 return -ESTALE; 42 43 return 0; 44 } 45 EXPORT_SYMBOL_GPL(sock_diag_check_cookie); 46 47 void sock_diag_save_cookie(struct sock *sk, __u32 *cookie) 48 { 49 u64 res = sock_gen_cookie(sk); 50 51 cookie[0] = (u32)res; 52 cookie[1] = (u32)(res >> 32); 53 } 54 EXPORT_SYMBOL_GPL(sock_diag_save_cookie); 55 56 int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype) 57 { 58 u32 mem[SK_MEMINFO_VARS]; 59 60 mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk); 61 mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf; 62 mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk); 63 mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf; 64 mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc; 65 mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued; 66 mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc); 67 mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len; 68 69 return nla_put(skb, attrtype, sizeof(mem), &mem); 70 } 71 EXPORT_SYMBOL_GPL(sock_diag_put_meminfo); 72 73 int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk, 74 struct sk_buff *skb, int attrtype) 75 { 76 struct sock_fprog_kern *fprog; 77 struct sk_filter *filter; 78 struct nlattr *attr; 79 unsigned int flen; 80 int err = 0; 81 82 if (!may_report_filterinfo) { 83 nla_reserve(skb, attrtype, 0); 84 return 0; 85 } 86 87 rcu_read_lock(); 88 filter = rcu_dereference(sk->sk_filter); 89 if (!filter) 90 goto out; 91 92 fprog = filter->prog->orig_prog; 93 if (!fprog) 94 goto out; 95 96 flen = bpf_classic_proglen(fprog); 97 98 attr = nla_reserve(skb, attrtype, flen); 99 if (attr == NULL) { 100 err = -EMSGSIZE; 101 goto out; 102 } 103 104 memcpy(nla_data(attr), fprog->filter, flen); 105 out: 106 rcu_read_unlock(); 107 return err; 108 } 109 EXPORT_SYMBOL(sock_diag_put_filterinfo); 110 111 struct broadcast_sk { 112 struct sock *sk; 113 struct work_struct work; 114 }; 115 116 static size_t sock_diag_nlmsg_size(void) 117 { 118 return NLMSG_ALIGN(sizeof(struct inet_diag_msg) 119 + nla_total_size(sizeof(u8)) /* INET_DIAG_PROTOCOL */ 120 + nla_total_size(sizeof(struct tcp_info))); /* INET_DIAG_INFO */ 121 } 122 123 static void sock_diag_broadcast_destroy_work(struct work_struct *work) 124 { 125 struct broadcast_sk *bsk = 126 container_of(work, struct broadcast_sk, work); 127 struct sock *sk = bsk->sk; 128 const struct sock_diag_handler *hndl; 129 struct sk_buff *skb; 130 const enum sknetlink_groups group = sock_diag_destroy_group(sk); 131 int err = -1; 132 133 WARN_ON(group == SKNLGRP_NONE); 134 135 skb = nlmsg_new(sock_diag_nlmsg_size(), GFP_KERNEL); 136 if (!skb) 137 goto out; 138 139 mutex_lock(&sock_diag_table_mutex); 140 hndl = sock_diag_handlers[sk->sk_family]; 141 if (hndl && hndl->get_info) 142 err = hndl->get_info(skb, sk); 143 mutex_unlock(&sock_diag_table_mutex); 144 145 if (!err) 146 nlmsg_multicast(sock_net(sk)->diag_nlsk, skb, 0, group, 147 GFP_KERNEL); 148 else 149 kfree_skb(skb); 150 out: 151 sk_destruct(sk); 152 kfree(bsk); 153 } 154 155 void sock_diag_broadcast_destroy(struct sock *sk) 156 { 157 /* Note, this function is often called from an interrupt context. */ 158 struct broadcast_sk *bsk = 159 kmalloc(sizeof(struct broadcast_sk), GFP_ATOMIC); 160 if (!bsk) 161 return sk_destruct(sk); 162 bsk->sk = sk; 163 INIT_WORK(&bsk->work, sock_diag_broadcast_destroy_work); 164 queue_work(broadcast_wq, &bsk->work); 165 } 166 167 void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) 168 { 169 mutex_lock(&sock_diag_table_mutex); 170 inet_rcv_compat = fn; 171 mutex_unlock(&sock_diag_table_mutex); 172 } 173 EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat); 174 175 void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) 176 { 177 mutex_lock(&sock_diag_table_mutex); 178 inet_rcv_compat = NULL; 179 mutex_unlock(&sock_diag_table_mutex); 180 } 181 EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat); 182 183 int sock_diag_register(const struct sock_diag_handler *hndl) 184 { 185 int err = 0; 186 187 if (hndl->family >= AF_MAX) 188 return -EINVAL; 189 190 mutex_lock(&sock_diag_table_mutex); 191 if (sock_diag_handlers[hndl->family]) 192 err = -EBUSY; 193 else 194 sock_diag_handlers[hndl->family] = hndl; 195 mutex_unlock(&sock_diag_table_mutex); 196 197 return err; 198 } 199 EXPORT_SYMBOL_GPL(sock_diag_register); 200 201 void sock_diag_unregister(const struct sock_diag_handler *hnld) 202 { 203 int family = hnld->family; 204 205 if (family >= AF_MAX) 206 return; 207 208 mutex_lock(&sock_diag_table_mutex); 209 BUG_ON(sock_diag_handlers[family] != hnld); 210 sock_diag_handlers[family] = NULL; 211 mutex_unlock(&sock_diag_table_mutex); 212 } 213 EXPORT_SYMBOL_GPL(sock_diag_unregister); 214 215 static int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) 216 { 217 int err; 218 struct sock_diag_req *req = nlmsg_data(nlh); 219 const struct sock_diag_handler *hndl; 220 221 if (nlmsg_len(nlh) < sizeof(*req)) 222 return -EINVAL; 223 224 if (req->sdiag_family >= AF_MAX) 225 return -EINVAL; 226 227 if (sock_diag_handlers[req->sdiag_family] == NULL) 228 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, 229 NETLINK_SOCK_DIAG, req->sdiag_family); 230 231 mutex_lock(&sock_diag_table_mutex); 232 hndl = sock_diag_handlers[req->sdiag_family]; 233 if (hndl == NULL) 234 err = -ENOENT; 235 else 236 err = hndl->dump(skb, nlh); 237 mutex_unlock(&sock_diag_table_mutex); 238 239 return err; 240 } 241 242 static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) 243 { 244 int ret; 245 246 switch (nlh->nlmsg_type) { 247 case TCPDIAG_GETSOCK: 248 case DCCPDIAG_GETSOCK: 249 if (inet_rcv_compat == NULL) 250 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, 251 NETLINK_SOCK_DIAG, AF_INET); 252 253 mutex_lock(&sock_diag_table_mutex); 254 if (inet_rcv_compat != NULL) 255 ret = inet_rcv_compat(skb, nlh); 256 else 257 ret = -EOPNOTSUPP; 258 mutex_unlock(&sock_diag_table_mutex); 259 260 return ret; 261 case SOCK_DIAG_BY_FAMILY: 262 return __sock_diag_rcv_msg(skb, nlh); 263 default: 264 return -EINVAL; 265 } 266 } 267 268 static DEFINE_MUTEX(sock_diag_mutex); 269 270 static void sock_diag_rcv(struct sk_buff *skb) 271 { 272 mutex_lock(&sock_diag_mutex); 273 netlink_rcv_skb(skb, &sock_diag_rcv_msg); 274 mutex_unlock(&sock_diag_mutex); 275 } 276 277 static int sock_diag_bind(struct net *net, int group) 278 { 279 switch (group) { 280 case SKNLGRP_INET_TCP_DESTROY: 281 case SKNLGRP_INET_UDP_DESTROY: 282 if (!sock_diag_handlers[AF_INET]) 283 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, 284 NETLINK_SOCK_DIAG, AF_INET); 285 break; 286 case SKNLGRP_INET6_TCP_DESTROY: 287 case SKNLGRP_INET6_UDP_DESTROY: 288 if (!sock_diag_handlers[AF_INET6]) 289 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK, 290 NETLINK_SOCK_DIAG, AF_INET); 291 break; 292 } 293 return 0; 294 } 295 296 static int __net_init diag_net_init(struct net *net) 297 { 298 struct netlink_kernel_cfg cfg = { 299 .groups = SKNLGRP_MAX, 300 .input = sock_diag_rcv, 301 .bind = sock_diag_bind, 302 .flags = NL_CFG_F_NONROOT_RECV, 303 }; 304 305 net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg); 306 return net->diag_nlsk == NULL ? -ENOMEM : 0; 307 } 308 309 static void __net_exit diag_net_exit(struct net *net) 310 { 311 netlink_kernel_release(net->diag_nlsk); 312 net->diag_nlsk = NULL; 313 } 314 315 static struct pernet_operations diag_net_ops = { 316 .init = diag_net_init, 317 .exit = diag_net_exit, 318 }; 319 320 static int __init sock_diag_init(void) 321 { 322 broadcast_wq = alloc_workqueue("sock_diag_events", 0, 0); 323 BUG_ON(!broadcast_wq); 324 return register_pernet_subsys(&diag_net_ops); 325 } 326 327 static void __exit sock_diag_exit(void) 328 { 329 unregister_pernet_subsys(&diag_net_ops); 330 destroy_workqueue(broadcast_wq); 331 } 332 333 module_init(sock_diag_init); 334 module_exit(sock_diag_exit); 335 MODULE_LICENSE("GPL"); 336 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_SOCK_DIAG); 337