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_put_flags(struct sock *sk, struct sk_buff *skb)
  23 {
  24         struct netlink_sock *nlk = nlk_sk(sk);
  25         u32 flags = 0;
  26
  27         if (nlk->cb_running)
  28                 flags |= NDIAG_FLAG_CB_RUNNING;
  29         if (nlk->flags & NETLINK_F_RECV_PKTINFO)
  30                 flags |= NDIAG_FLAG_PKTINFO;
  31         if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR)
  32                 flags |= NDIAG_FLAG_BROADCAST_ERROR;
  33         if (nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)
  34                 flags |= NDIAG_FLAG_NO_ENOBUFS;
  35         if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID)
  36                 flags |= NDIAG_FLAG_LISTEN_ALL_NSID;
  37         if (nlk->flags & NETLINK_F_CAP_ACK)
  38                 flags |= NDIAG_FLAG_CAP_ACK;
  39
  40         return nla_put_u32(skb, NETLINK_DIAG_FLAGS, flags);
  41 }
  42
  43 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
  44                         struct netlink_diag_req *req,
  45                         u32 portid, u32 seq, u32 flags, int sk_ino)
  46 {
  47         struct nlmsghdr *nlh;
  48         struct netlink_diag_msg *rep;
  49         struct netlink_sock *nlk = nlk_sk(sk);
  50
  51         nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rep),
  52                         flags);
  53         if (!nlh)
  54                 return -EMSGSIZE;
  55
  56         rep = nlmsg_data(nlh);
  57         rep->ndiag_family       = AF_NETLINK;
  58         rep->ndiag_type         = sk->sk_type;
  59         rep->ndiag_protocol     = sk->sk_protocol;
  60         rep->ndiag_state        = sk->sk_state;
  61
  62         rep->ndiag_ino          = sk_ino;
  63         rep->ndiag_portid       = nlk->portid;
  64         rep->ndiag_dst_portid   = nlk->dst_portid;
  65         rep->ndiag_dst_group    = nlk->dst_group;
  66         sock_diag_save_cookie(sk, rep->ndiag_cookie);
  67
  68         if ((req->ndiag_show & NDIAG_SHOW_GROUPS) &&
  69             sk_diag_dump_groups(sk, skb))
  70                 goto out_nlmsg_trim;
  71
  72         if ((req->ndiag_show & NDIAG_SHOW_MEMINFO) &&
  73             sock_diag_put_meminfo(sk, skb, NETLINK_DIAG_MEMINFO))
  74                 goto out_nlmsg_trim;
  75
  76         if ((req->ndiag_show & NDIAG_SHOW_FLAGS) &&
  77             sk_diag_put_flags(sk, skb))
  78                 goto out_nlmsg_trim;
  79
  80         nlmsg_end(skb, nlh);
  81         return 0;
  82
  83 out_nlmsg_trim:
  84         nlmsg_cancel(skb, nlh);
  85         return -EMSGSIZE;
  86 }
  87
  88 static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
  89                                 int protocol, int s_num)
  90 {
  91         struct rhashtable_iter *hti = (void *)cb->args[2];
  92         struct netlink_table *tbl = &nl_table[protocol];
  93         struct net *net = sock_net(skb->sk);
  94         struct netlink_diag_req *req;
  95         struct netlink_sock *nlsk;
  96         struct sock *sk;
  97         int num = 2;
  98         int ret = 0;
  99
 100         req = nlmsg_data(cb->nlh);
 101
 102         if (s_num > 1)
 103                 goto mc_list;
 104
 105         num--;
 106
 107         if (!hti) {
 108                 hti = kmalloc(sizeof(*hti), GFP_KERNEL);
 109                 if (!hti)
 110                         return -ENOMEM;
 111
 112                 cb->args[2] = (long)hti;
 113         }
 114
 115         if (!s_num)
 116                 rhashtable_walk_enter(&tbl->hash, hti);
 117
 118         ret = rhashtable_walk_start(hti);
 119         if (ret == -EAGAIN)
 120                 ret = 0;
 121         if (ret)
 122                 goto stop;
 123
 124         while ((nlsk = rhashtable_walk_next(hti))) {
 125                 if (IS_ERR(nlsk)) {
 126                         ret = PTR_ERR(nlsk);
 127                         if (ret == -EAGAIN) {
 128                                 ret = 0;
 129                                 continue;
 130                         }
 131                         break;
 132                 }
 133
 134                 sk = (struct sock *)nlsk;
 135
 136                 if (!net_eq(sock_net(sk), net))
 137                         continue;
 138
 139                 if (sk_diag_fill(sk, skb, req,
 140                                  NETLINK_CB(cb->skb).portid,
 141                                  cb->nlh->nlmsg_seq,
 142                                  NLM_F_MULTI,
 143                                  sock_i_ino(sk)) < 0) {
 144                         ret = 1;
 145                         break;
 146                 }
 147         }
 148
 149 stop:
 150         rhashtable_walk_stop(hti);
 151         if (ret)
 152                 goto done;
 153
 154         rhashtable_walk_exit(hti);
 155         num++;
 156
 157 mc_list:
 158         read_lock(&nl_table_lock);
 159         sk_for_each_bound(sk, &tbl->mc_list) {
 160                 if (sk_hashed(sk))
 161                         continue;
 162                 if (!net_eq(sock_net(sk), net))
 163                         continue;
 164                 if (num < s_num) {
 165                         num++;
 166                         continue;
 167                 }
 168
 169                 if (sk_diag_fill(sk, skb, req,
 170                                  NETLINK_CB(cb->skb).portid,
 171                                  cb->nlh->nlmsg_seq,
 172                                  NLM_F_MULTI,
 173                                  sock_i_ino(sk)) < 0) {
 174                         ret = 1;
 175                         break;
 176                 }
 177                 num++;
 178         }
 179         read_unlock(&nl_table_lock);
 180
 181 done:
 182         cb->args[0] = num;
 183
 184         return ret;
 185 }
 186
 187 static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 188 {
 189         struct netlink_diag_req *req;
 190         int s_num = cb->args[0];
 191         int err = 0;
 192
 193         req = nlmsg_data(cb->nlh);
 194
 195         if (req->sdiag_protocol == NDIAG_PROTO_ALL) {
 196                 int i;
 197
 198                 for (i = cb->args[1]; i < MAX_LINKS; i++) {
 199                         err = __netlink_diag_dump(skb, cb, i, s_num);
 200                         if (err)
 201                                 break;
 202                         s_num = 0;
 203                 }
 204                 cb->args[1] = i;
 205         } else {
 206                 if (req->sdiag_protocol >= MAX_LINKS)
 207                         return -ENOENT;
 208
 209                 err = __netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);
 210         }
 211
 212         return err < 0 ? err : skb->len;
 213 }
 214
 215 static int netlink_diag_dump_done(struct netlink_callback *cb)
 216 {
 217         struct rhashtable_iter *hti = (void *)cb->args[2];
 218
 219         if (cb->args[0] == 1)
 220                 rhashtable_walk_exit(hti);
 221
 222         kfree(hti);
 223
 224         return 0;
 225 }
 226
 227 static int netlink_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
 228 {
 229         int hdrlen = sizeof(struct netlink_diag_req);
 230         struct net *net = sock_net(skb->sk);
 231
 232         if (nlmsg_len(h) < hdrlen)
 233                 return -EINVAL;
 234
 235         if (h->nlmsg_flags & NLM_F_DUMP) {
 236                 struct netlink_dump_control c = {
 237                         .dump = netlink_diag_dump,
 238                         .done = netlink_diag_dump_done,
 239                 };
 240                 return netlink_dump_start(net->diag_nlsk, skb, h, &c);
 241         } else
 242                 return -EOPNOTSUPP;
 243 }
 244
 245 static const struct sock_diag_handler netlink_diag_handler = {
 246         .family = AF_NETLINK,
 247         .dump = netlink_diag_handler_dump,
 248 };
 249
 250 static int __init netlink_diag_init(void)
 251 {
 252         return sock_diag_register(&netlink_diag_handler);
 253 }
 254
 255 static void __exit netlink_diag_exit(void)
 256 {
 257         sock_diag_unregister(&netlink_diag_handler);
 258 }
 259
 260 module_init(netlink_diag_init);
 261 module_exit(netlink_diag_exit);
 262 MODULE_LICENSE("GPL");
 263 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 16 /* AF_NETLINK */);