net/core/sock_diag.c

   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
   9 #include <linux/inet_diag.h>
  10 #include <linux/sock_diag.h>
  11
  12 static const struct sock_diag_handler *sock_diag_handlers[AF_MAX];
  13 static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh);
  14 static DEFINE_MUTEX(sock_diag_table_mutex);
  15
  16 int sock_diag_check_cookie(void *sk, __u32 *cookie)
  17 {
  18         if ((cookie[0] != INET_DIAG_NOCOOKIE ||
  19              cookie[1] != INET_DIAG_NOCOOKIE) &&
  20             ((u32)(unsigned long)sk != cookie[0] ||
  21              (u32)((((unsigned long)sk) >> 31) >> 1) != cookie[1]))
  22                 return -ESTALE;
  23         else
  24                 return 0;
  25 }
  26 EXPORT_SYMBOL_GPL(sock_diag_check_cookie);
  27
  28 void sock_diag_save_cookie(void *sk, __u32 *cookie)
  29 {
  30         cookie[0] = (u32)(unsigned long)sk;
  31         cookie[1] = (u32)(((unsigned long)sk >> 31) >> 1);
  32 }
  33 EXPORT_SYMBOL_GPL(sock_diag_save_cookie);
  34
  35 int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype)
  36 {
  37         u32 mem[SK_MEMINFO_VARS];
  38
  39         mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
  40         mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
  41         mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
  42         mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
  43         mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
  44         mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
  45         mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
  46         mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
  47
  48         return nla_put(skb, attrtype, sizeof(mem), &mem);
  49 }
  50 EXPORT_SYMBOL_GPL(sock_diag_put_meminfo);
  51
  52 void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
  53 {
  54         mutex_lock(&sock_diag_table_mutex);
  55         inet_rcv_compat = fn;
  56         mutex_unlock(&sock_diag_table_mutex);
  57 }
  58 EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);
  59
  60 void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
  61 {
  62         mutex_lock(&sock_diag_table_mutex);
  63         inet_rcv_compat = NULL;
  64         mutex_unlock(&sock_diag_table_mutex);
  65 }
  66 EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);
  67
  68 int sock_diag_register(const struct sock_diag_handler *hndl)
  69 {
  70         int err = 0;
  71
  72         if (hndl->family >= AF_MAX)
  73                 return -EINVAL;
  74
  75         mutex_lock(&sock_diag_table_mutex);
  76         if (sock_diag_handlers[hndl->family])
  77                 err = -EBUSY;
  78         else
  79                 sock_diag_handlers[hndl->family] = hndl;
  80         mutex_unlock(&sock_diag_table_mutex);
  81
  82         return err;
  83 }
  84 EXPORT_SYMBOL_GPL(sock_diag_register);
  85
  86 void sock_diag_unregister(const struct sock_diag_handler *hnld)
  87 {
  88         int family = hnld->family;
  89
  90         if (family >= AF_MAX)
  91                 return;
  92
  93         mutex_lock(&sock_diag_table_mutex);
  94         BUG_ON(sock_diag_handlers[family] != hnld);
  95         sock_diag_handlers[family] = NULL;
  96         mutex_unlock(&sock_diag_table_mutex);
  97 }
  98 EXPORT_SYMBOL_GPL(sock_diag_unregister);
  99
 100 static const inline struct sock_diag_handler *sock_diag_lock_handler(int family)
 101 {
 102         if (sock_diag_handlers[family] == NULL)
 103                 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
 104                                 NETLINK_SOCK_DIAG, family);
 105
 106         mutex_lock(&sock_diag_table_mutex);
 107         return sock_diag_handlers[family];
 108 }
 109
 110 static inline void sock_diag_unlock_handler(const struct sock_diag_handler *h)
 111 {
 112         mutex_unlock(&sock_diag_table_mutex);
 113 }
 114
 115 static int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 116 {
 117         int err;
 118         struct sock_diag_req *req = nlmsg_data(nlh);
 119         const struct sock_diag_handler *hndl;
 120
 121         if (nlmsg_len(nlh) < sizeof(*req))
 122                 return -EINVAL;
 123
 124         hndl = sock_diag_lock_handler(req->sdiag_family);
 125         if (hndl == NULL)
 126                 err = -ENOENT;
 127         else
 128                 err = hndl->dump(skb, nlh);
 129         sock_diag_unlock_handler(hndl);
 130
 131         return err;
 132 }
 133
 134 static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 135 {
 136         int ret;
 137
 138         switch (nlh->nlmsg_type) {
 139         case TCPDIAG_GETSOCK:
 140         case DCCPDIAG_GETSOCK:
 141                 if (inet_rcv_compat == NULL)
 142                         request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
 143                                         NETLINK_SOCK_DIAG, AF_INET);
 144
 145                 mutex_lock(&sock_diag_table_mutex);
 146                 if (inet_rcv_compat != NULL)
 147                         ret = inet_rcv_compat(skb, nlh);
 148                 else
 149                         ret = -EOPNOTSUPP;
 150                 mutex_unlock(&sock_diag_table_mutex);
 151
 152                 return ret;
 153         case SOCK_DIAG_BY_FAMILY:
 154                 return __sock_diag_rcv_msg(skb, nlh);
 155         default:
 156                 return -EINVAL;
 157         }
 158 }
 159
 160 static DEFINE_MUTEX(sock_diag_mutex);
 161
 162 static void sock_diag_rcv(struct sk_buff *skb)
 163 {
 164         mutex_lock(&sock_diag_mutex);
 165         netlink_rcv_skb(skb, &sock_diag_rcv_msg);
 166         mutex_unlock(&sock_diag_mutex);
 167 }
 168
 169 static int __net_init diag_net_init(struct net *net)
 170 {
 171         struct netlink_kernel_cfg cfg = {
 172                 .input  = sock_diag_rcv,
 173         };
 174
 175         net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg);
 176         return net->diag_nlsk == NULL ? -ENOMEM : 0;
 177 }
 178
 179 static void __net_exit diag_net_exit(struct net *net)
 180 {
 181         netlink_kernel_release(net->diag_nlsk);
 182         net->diag_nlsk = NULL;
 183 }
 184
 185 static struct pernet_operations diag_net_ops = {
 186         .init = diag_net_init,
 187         .exit = diag_net_exit,
 188 };
 189
 190 static int __init sock_diag_init(void)
 191 {
 192         return register_pernet_subsys(&diag_net_ops);
 193 }
 194
 195 static void __exit sock_diag_exit(void)
 196 {
 197         unregister_pernet_subsys(&diag_net_ops);
 198 }
 199
 200 module_init(sock_diag_init);
 201 module_exit(sock_diag_exit);
 202 MODULE_LICENSE("GPL");
 203 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_SOCK_DIAG);