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 int sock_diag_put_filterinfo(struct user_namespace *user_ns, struct sock *sk,
  53                              struct sk_buff *skb, int attrtype)
  54 {
  55         struct nlattr *attr;
  56         struct sk_filter *filter;
  57         unsigned int len;
  58         int err = 0;
  59
  60         if (!ns_capable(user_ns, CAP_NET_ADMIN)) {
  61                 nla_reserve(skb, attrtype, 0);
  62                 return 0;
  63         }
  64
  65         rcu_read_lock();
  66
  67         filter = rcu_dereference(sk->sk_filter);
  68         len = filter ? filter->len * sizeof(struct sock_filter) : 0;
  69
  70         attr = nla_reserve(skb, attrtype, len);
  71         if (attr == NULL) {
  72                 err = -EMSGSIZE;
  73                 goto out;
  74         }
  75
  76         if (filter) {
  77                 struct sock_filter *fb = (struct sock_filter *)nla_data(attr);
  78                 int i;
  79
  80                 for (i = 0; i < filter->len; i++, fb++)
  81                         sk_decode_filter(&filter->insns[i], fb);
  82         }
  83
  84 out:
  85         rcu_read_unlock();
  86         return err;
  87 }
  88 EXPORT_SYMBOL(sock_diag_put_filterinfo);
  89
  90 void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
  91 {
  92         mutex_lock(&sock_diag_table_mutex);
  93         inet_rcv_compat = fn;
  94         mutex_unlock(&sock_diag_table_mutex);
  95 }
  96 EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);
  97
  98 void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
  99 {
 100         mutex_lock(&sock_diag_table_mutex);
 101         inet_rcv_compat = NULL;
 102         mutex_unlock(&sock_diag_table_mutex);
 103 }
 104 EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);
 105
 106 int sock_diag_register(const struct sock_diag_handler *hndl)
 107 {
 108         int err = 0;
 109
 110         if (hndl->family >= AF_MAX)
 111                 return -EINVAL;
 112
 113         mutex_lock(&sock_diag_table_mutex);
 114         if (sock_diag_handlers[hndl->family])
 115                 err = -EBUSY;
 116         else
 117                 sock_diag_handlers[hndl->family] = hndl;
 118         mutex_unlock(&sock_diag_table_mutex);
 119
 120         return err;
 121 }
 122 EXPORT_SYMBOL_GPL(sock_diag_register);
 123
 124 void sock_diag_unregister(const struct sock_diag_handler *hnld)
 125 {
 126         int family = hnld->family;
 127
 128         if (family >= AF_MAX)
 129                 return;
 130
 131         mutex_lock(&sock_diag_table_mutex);
 132         BUG_ON(sock_diag_handlers[family] != hnld);
 133         sock_diag_handlers[family] = NULL;
 134         mutex_unlock(&sock_diag_table_mutex);
 135 }
 136 EXPORT_SYMBOL_GPL(sock_diag_unregister);
 137
 138 static int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 139 {
 140         int err;
 141         struct sock_diag_req *req = nlmsg_data(nlh);
 142         const struct sock_diag_handler *hndl;
 143
 144         if (nlmsg_len(nlh) < sizeof(*req))
 145                 return -EINVAL;
 146
 147         if (req->sdiag_family >= AF_MAX)
 148                 return -EINVAL;
 149
 150         if (sock_diag_handlers[req->sdiag_family] == NULL)
 151                 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
 152                                 NETLINK_SOCK_DIAG, req->sdiag_family);
 153
 154         mutex_lock(&sock_diag_table_mutex);
 155         hndl = sock_diag_handlers[req->sdiag_family];
 156         if (hndl == NULL)
 157                 err = -ENOENT;
 158         else
 159                 err = hndl->dump(skb, nlh);
 160         mutex_unlock(&sock_diag_table_mutex);
 161
 162         return err;
 163 }
 164
 165 static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 166 {
 167         int ret;
 168
 169         switch (nlh->nlmsg_type) {
 170         case TCPDIAG_GETSOCK:
 171         case DCCPDIAG_GETSOCK:
 172                 if (inet_rcv_compat == NULL)
 173                         request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
 174                                         NETLINK_SOCK_DIAG, AF_INET);
 175
 176                 mutex_lock(&sock_diag_table_mutex);
 177                 if (inet_rcv_compat != NULL)
 178                         ret = inet_rcv_compat(skb, nlh);
 179                 else
 180                         ret = -EOPNOTSUPP;
 181                 mutex_unlock(&sock_diag_table_mutex);
 182
 183                 return ret;
 184         case SOCK_DIAG_BY_FAMILY:
 185                 return __sock_diag_rcv_msg(skb, nlh);
 186         default:
 187                 return -EINVAL;
 188         }
 189 }
 190
 191 static DEFINE_MUTEX(sock_diag_mutex);
 192
 193 static void sock_diag_rcv(struct sk_buff *skb)
 194 {
 195         mutex_lock(&sock_diag_mutex);
 196         netlink_rcv_skb(skb, &sock_diag_rcv_msg);
 197         mutex_unlock(&sock_diag_mutex);
 198 }
 199
 200 static int __net_init diag_net_init(struct net *net)
 201 {
 202         struct netlink_kernel_cfg cfg = {
 203                 .input  = sock_diag_rcv,
 204         };
 205
 206         net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg);
 207         return net->diag_nlsk == NULL ? -ENOMEM : 0;
 208 }
 209
 210 static void __net_exit diag_net_exit(struct net *net)
 211 {
 212         netlink_kernel_release(net->diag_nlsk);
 213         net->diag_nlsk = NULL;
 214 }
 215
 216 static struct pernet_operations diag_net_ops = {
 217         .init = diag_net_init,
 218         .exit = diag_net_exit,
 219 };
 220
 221 static int __init sock_diag_init(void)
 222 {
 223         return register_pernet_subsys(&diag_net_ops);
 224 }
 225
 226 static void __exit sock_diag_exit(void)
 227 {
 228         unregister_pernet_subsys(&diag_net_ops);
 229 }
 230
 231 module_init(sock_diag_init);
 232 module_exit(sock_diag_exit);
 233 MODULE_LICENSE("GPL");
 234 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_SOCK_DIAG);