net/netlink/diag.c

   1 #include <linux/module.h>
   2
   3 #include <net/sock.h>
   4 #include <linux/netlink.h>
   5 #include <linux/sock_diag.h>
   6 #include <linux/netlink_diag.h>
   7 #include <linux/rhashtable.h>
   8
   9 #include "af_netlink.h"
  10
  11 static int sk_diag_dump_groups(struct sock *sk, struct sk_buff *nlskb)
  12 {
  13         struct netlink_sock *nlk = nlk_sk(sk);
  14
  15         if (nlk->groups == NULL)
  16                 return 0;
  17
  18         return nla_put(nlskb, NETLINK_DIAG_GROUPS, NLGRPSZ(nlk->ngroups),
  19                        nlk->groups);
  20 }
  21
  22 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
  23                         struct netlink_diag_req *req,
  24                         u32 portid, u32 seq, u32 flags, int sk_ino)
  25 {
  26         struct nlmsghdr *nlh;
  27         struct netlink_diag_msg *rep;
  28         struct netlink_sock *nlk = nlk_sk(sk);
  29
  30         nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rep),
  31                         flags);
  32         if (!nlh)
  33                 return -EMSGSIZE;
  34
  35         rep = nlmsg_data(nlh);
  36         rep->ndiag_family       = AF_NETLINK;
  37         rep->ndiag_type         = sk->sk_type;
  38         rep->ndiag_protocol     = sk->sk_protocol;
  39         rep->ndiag_state        = sk->sk_state;
  40
  41         rep->ndiag_ino          = sk_ino;
  42         rep->ndiag_portid       = nlk->portid;
  43         rep->ndiag_dst_portid   = nlk->dst_portid;
  44         rep->ndiag_dst_group    = nlk->dst_group;
  45         sock_diag_save_cookie(sk, rep->ndiag_cookie);
  46
  47         if ((req->ndiag_show & NDIAG_SHOW_GROUPS) &&
  48             sk_diag_dump_groups(sk, skb))
  49                 goto out_nlmsg_trim;
  50
  51         if ((req->ndiag_show & NDIAG_SHOW_MEMINFO) &&
  52             sock_diag_put_meminfo(sk, skb, NETLINK_DIAG_MEMINFO))
  53                 goto out_nlmsg_trim;
  54
  55         nlmsg_end(skb, nlh);
  56         return 0;
  57
  58 out_nlmsg_trim:
  59         nlmsg_cancel(skb, nlh);
  60         return -EMSGSIZE;
  61 }
  62
  63 static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
  64                                 int protocol, int s_num)
  65 {
  66         struct rhashtable_iter *hti = (void *)cb->args[2];
  67         struct netlink_table *tbl = &nl_table[protocol];
  68         struct net *net = sock_net(skb->sk);
  69         struct netlink_diag_req *req;
  70         struct netlink_sock *nlsk;
  71         struct sock *sk;
  72         int num = 2;
  73         int ret = 0;
  74
  75         req = nlmsg_data(cb->nlh);
  76
  77         if (s_num > 1)
  78                 goto mc_list;
  79
  80         num--;
  81
  82         if (!hti) {
  83                 hti = kmalloc(sizeof(*hti), GFP_KERNEL);
  84                 if (!hti)
  85                         return -ENOMEM;
  86
  87                 cb->args[2] = (long)hti;
  88         }
  89
  90         if (!s_num)
  91                 rhashtable_walk_enter(&tbl->hash, hti);
  92
  93         ret = rhashtable_walk_start(hti);
  94         if (ret == -EAGAIN)
  95                 ret = 0;
  96         if (ret)
  97                 goto stop;
  98
  99         while ((nlsk = rhashtable_walk_next(hti))) {
 100                 if (IS_ERR(nlsk)) {
 101                         ret = PTR_ERR(nlsk);
 102                         if (ret == -EAGAIN) {
 103                                 ret = 0;
 104                                 continue;
 105                         }
 106                         break;
 107                 }
 108
 109                 sk = (struct sock *)nlsk;
 110
 111                 if (!net_eq(sock_net(sk), net))
 112                         continue;
 113
 114                 if (sk_diag_fill(sk, skb, req,
 115                                  NETLINK_CB(cb->skb).portid,
 116                                  cb->nlh->nlmsg_seq,
 117                                  NLM_F_MULTI,
 118                                  sock_i_ino(sk)) < 0) {
 119                         ret = 1;
 120                         break;
 121                 }
 122         }
 123
 124 stop:
 125         rhashtable_walk_stop(hti);
 126         if (ret)
 127                 goto done;
 128
 129         rhashtable_walk_exit(hti);
 130         num++;
 131
 132 mc_list:
 133         read_lock(&nl_table_lock);
 134         sk_for_each_bound(sk, &tbl->mc_list) {
 135                 if (sk_hashed(sk))
 136                         continue;
 137                 if (!net_eq(sock_net(sk), net))
 138                         continue;
 139                 if (num < s_num) {
 140                         num++;
 141                         continue;
 142                 }
 143
 144                 if (sk_diag_fill(sk, skb, req,
 145                                  NETLINK_CB(cb->skb).portid,
 146                                  cb->nlh->nlmsg_seq,
 147                                  NLM_F_MULTI,
 148                                  sock_i_ino(sk)) < 0) {
 149                         ret = 1;
 150                         break;
 151                 }
 152                 num++;
 153         }
 154         read_unlock(&nl_table_lock);
 155
 156 done:
 157         cb->args[0] = num;
 158
 159         return ret;
 160 }
 161
 162 static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 163 {
 164         struct netlink_diag_req *req;
 165         int s_num = cb->args[0];
 166         int err = 0;
 167
 168         req = nlmsg_data(cb->nlh);
 169
 170         if (req->sdiag_protocol == NDIAG_PROTO_ALL) {
 171                 int i;
 172
 173                 for (i = cb->args[1]; i < MAX_LINKS; i++) {
 174                         err = __netlink_diag_dump(skb, cb, i, s_num);
 175                         if (err)
 176                                 break;
 177                         s_num = 0;
 178                 }
 179                 cb->args[1] = i;
 180         } else {
 181                 if (req->sdiag_protocol >= MAX_LINKS) {
 182                         read_unlock(&nl_table_lock);
 183                         rcu_read_unlock();
 184                         return -ENOENT;
 185                 }
 186
 187                 err = __netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);
 188         }
 189
 190         return err < 0 ? err : skb->len;
 191 }
 192
 193 static int netlink_diag_dump_done(struct netlink_callback *cb)
 194 {
 195         struct rhashtable_iter *hti = (void *)cb->args[2];
 196
 197         if (cb->args[0] == 1)
 198                 rhashtable_walk_exit(hti);
 199
 200         kfree(hti);
 201
 202         return 0;
 203 }
 204
 205 static int netlink_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
 206 {
 207         int hdrlen = sizeof(struct netlink_diag_req);
 208         struct net *net = sock_net(skb->sk);
 209
 210         if (nlmsg_len(h) < hdrlen)
 211                 return -EINVAL;
 212
 213         if (h->nlmsg_flags & NLM_F_DUMP) {
 214                 struct netlink_dump_control c = {
 215                         .dump = netlink_diag_dump,
 216                         .done = netlink_diag_dump_done,
 217                 };
 218                 return netlink_dump_start(net->diag_nlsk, skb, h, &c);
 219         } else
 220                 return -EOPNOTSUPP;
 221 }
 222
 223 static const struct sock_diag_handler netlink_diag_handler = {
 224         .family = AF_NETLINK,
 225         .dump = netlink_diag_handler_dump,
 226 };
 227
 228 static int __init netlink_diag_init(void)
 229 {
 230         return sock_diag_register(&netlink_diag_handler);
 231 }
 232
 233 static void __exit netlink_diag_exit(void)
 234 {
 235         sock_diag_unregister(&netlink_diag_handler);
 236 }
 237
 238 module_init(netlink_diag_init);
 239 module_exit(netlink_diag_exit);
 240 MODULE_LICENSE("GPL");
 241 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 16 /* AF_NETLINK */);