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 int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 101 {
 102         int err;
 103         struct sock_diag_req *req = nlmsg_data(nlh);
 104         const struct sock_diag_handler *hndl;
 105
 106         if (nlmsg_len(nlh) < sizeof(*req))
 107                 return -EINVAL;
 108
 109         if (req->sdiag_family >= AF_MAX)
 110                 return -EINVAL;
 111
 112         if (sock_diag_handlers[req->sdiag_family] == NULL)
 113                 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
 114                                 NETLINK_SOCK_DIAG, req->sdiag_family);
 115
 116         mutex_lock(&sock_diag_table_mutex);
 117         hndl = sock_diag_handlers[req->sdiag_family];
 118         if (hndl == NULL)
 119                 err = -ENOENT;
 120         else
 121                 err = hndl->dump(skb, nlh);
 122         mutex_unlock(&sock_diag_table_mutex);
 123
 124         return err;
 125 }
 126
 127 static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 128 {
 129         int ret;
 130
 131         switch (nlh->nlmsg_type) {
 132         case TCPDIAG_GETSOCK:
 133         case DCCPDIAG_GETSOCK:
 134                 if (inet_rcv_compat == NULL)
 135                         request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
 136                                         NETLINK_SOCK_DIAG, AF_INET);
 137
 138                 mutex_lock(&sock_diag_table_mutex);
 139                 if (inet_rcv_compat != NULL)
 140                         ret = inet_rcv_compat(skb, nlh);
 141                 else
 142                         ret = -EOPNOTSUPP;
 143                 mutex_unlock(&sock_diag_table_mutex);
 144
 145                 return ret;
 146         case SOCK_DIAG_BY_FAMILY:
 147                 return __sock_diag_rcv_msg(skb, nlh);
 148         default:
 149                 return -EINVAL;
 150         }
 151 }
 152
 153 static DEFINE_MUTEX(sock_diag_mutex);
 154
 155 static void sock_diag_rcv(struct sk_buff *skb)
 156 {
 157         mutex_lock(&sock_diag_mutex);
 158         netlink_rcv_skb(skb, &sock_diag_rcv_msg);
 159         mutex_unlock(&sock_diag_mutex);
 160 }
 161
 162 static int __net_init diag_net_init(struct net *net)
 163 {
 164         struct netlink_kernel_cfg cfg = {
 165                 .input  = sock_diag_rcv,
 166         };
 167
 168         net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg);
 169         return net->diag_nlsk == NULL ? -ENOMEM : 0;
 170 }
 171
 172 static void __net_exit diag_net_exit(struct net *net)
 173 {
 174         netlink_kernel_release(net->diag_nlsk);
 175         net->diag_nlsk = NULL;
 176 }
 177
 178 static struct pernet_operations diag_net_ops = {
 179         .init = diag_net_init,
 180         .exit = diag_net_exit,
 181 };
 182
 183 static int __init sock_diag_init(void)
 184 {
 185         return register_pernet_subsys(&diag_net_ops);
 186 }
 187
 188 static void __exit sock_diag_exit(void)
 189 {
 190         unregister_pernet_subsys(&diag_net_ops);
 191 }
 192
 193 module_init(sock_diag_init);
 194 module_exit(sock_diag_exit);
 195 MODULE_LICENSE("GPL");
 196 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_SOCK_DIAG);