net/packet/diag.c

   1 #include <linux/module.h>
   2 #include <linux/sock_diag.h>
   3 #include <linux/net.h>
   4 #include <linux/netdevice.h>
   5 #include <linux/packet_diag.h>
   6 #include <net/net_namespace.h>
   7 #include <net/sock.h>
   8
   9 #include "internal.h"
  10
  11 static int pdiag_put_info(const struct packet_sock *po, struct sk_buff *nlskb)
  12 {
  13         struct packet_diag_info pinfo;
  14
  15         pinfo.pdi_index = po->ifindex;
  16         pinfo.pdi_version = po->tp_version;
  17         pinfo.pdi_reserve = po->tp_reserve;
  18         pinfo.pdi_copy_thresh = po->copy_thresh;
  19         pinfo.pdi_tstamp = po->tp_tstamp;
  20
  21         pinfo.pdi_flags = 0;
  22         if (po->running)
  23                 pinfo.pdi_flags |= PDI_RUNNING;
  24         if (po->auxdata)
  25                 pinfo.pdi_flags |= PDI_AUXDATA;
  26         if (po->origdev)
  27                 pinfo.pdi_flags |= PDI_ORIGDEV;
  28         if (po->has_vnet_hdr)
  29                 pinfo.pdi_flags |= PDI_VNETHDR;
  30         if (po->tp_loss)
  31                 pinfo.pdi_flags |= PDI_LOSS;
  32
  33         return nla_put(nlskb, PACKET_DIAG_INFO, sizeof(pinfo), &pinfo);
  34 }
  35
  36 static int pdiag_put_mclist(const struct packet_sock *po, struct sk_buff *nlskb)
  37 {
  38         struct nlattr *mca;
  39         struct packet_mclist *ml;
  40
  41         mca = nla_nest_start(nlskb, PACKET_DIAG_MCLIST);
  42         if (!mca)
  43                 return -EMSGSIZE;
  44
  45         rtnl_lock();
  46         for (ml = po->mclist; ml; ml = ml->next) {
  47                 struct packet_diag_mclist *dml;
  48
  49                 dml = nla_reserve_nohdr(nlskb, sizeof(*dml));
  50                 if (!dml) {
  51                         rtnl_unlock();
  52                         nla_nest_cancel(nlskb, mca);
  53                         return -EMSGSIZE;
  54                 }
  55
  56                 dml->pdmc_index = ml->ifindex;
  57                 dml->pdmc_type = ml->type;
  58                 dml->pdmc_alen = ml->alen;
  59                 dml->pdmc_count = ml->count;
  60                 BUILD_BUG_ON(sizeof(dml->pdmc_addr) != sizeof(ml->addr));
  61                 memcpy(dml->pdmc_addr, ml->addr, sizeof(ml->addr));
  62         }
  63
  64         rtnl_unlock();
  65         nla_nest_end(nlskb, mca);
  66
  67         return 0;
  68 }
  69
  70 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct packet_diag_req *req,
  71                 u32 pid, u32 seq, u32 flags, int sk_ino)
  72 {
  73         struct nlmsghdr *nlh;
  74         struct packet_diag_msg *rp;
  75         const struct packet_sock *po = pkt_sk(sk);
  76
  77         nlh = nlmsg_put(skb, pid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rp), flags);
  78         if (!nlh)
  79                 return -EMSGSIZE;
  80
  81         rp = nlmsg_data(nlh);
  82         rp->pdiag_family = AF_PACKET;
  83         rp->pdiag_type = sk->sk_type;
  84         rp->pdiag_num = ntohs(po->num);
  85         rp->pdiag_ino = sk_ino;
  86         sock_diag_save_cookie(sk, rp->pdiag_cookie);
  87
  88         if ((req->pdiag_show & PACKET_SHOW_INFO) &&
  89                         pdiag_put_info(po, skb))
  90                 goto out_nlmsg_trim;
  91
  92         if ((req->pdiag_show & PACKET_SHOW_MCLIST) &&
  93                         pdiag_put_mclist(po, skb))
  94                 goto out_nlmsg_trim;
  95
  96         return nlmsg_end(skb, nlh);
  97
  98 out_nlmsg_trim:
  99         nlmsg_cancel(skb, nlh);
 100         return -EMSGSIZE;
 101 }
 102
 103 static int packet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 104 {
 105         int num = 0, s_num = cb->args[0];
 106         struct packet_diag_req *req;
 107         struct net *net;
 108         struct sock *sk;
 109         struct hlist_node *node;
 110
 111         net = sock_net(skb->sk);
 112         req = nlmsg_data(cb->nlh);
 113
 114         rcu_read_lock();
 115         sk_for_each_rcu(sk, node, &net->packet.sklist) {
 116                 if (!net_eq(sock_net(sk), net))
 117                         continue;
 118                 if (num < s_num)
 119                         goto next;
 120
 121                 if (sk_diag_fill(sk, skb, req, NETLINK_CB(cb->skb).pid,
 122                                         cb->nlh->nlmsg_seq, NLM_F_MULTI,
 123                                         sock_i_ino(sk)) < 0)
 124                         goto done;
 125 next:
 126                 num++;
 127         }
 128 done:
 129         rcu_read_unlock();
 130         cb->args[0] = num;
 131
 132         return skb->len;
 133 }
 134
 135 static int packet_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
 136 {
 137         int hdrlen = sizeof(struct packet_diag_req);
 138         struct net *net = sock_net(skb->sk);
 139         struct packet_diag_req *req;
 140
 141         if (nlmsg_len(h) < hdrlen)
 142                 return -EINVAL;
 143
 144         req = nlmsg_data(h);
 145         /* Make it possible to support protocol filtering later */
 146         if (req->sdiag_protocol)
 147                 return -EINVAL;
 148
 149         if (h->nlmsg_flags & NLM_F_DUMP) {
 150                 struct netlink_dump_control c = {
 151                         .dump = packet_diag_dump,
 152                 };
 153                 return netlink_dump_start(net->diag_nlsk, skb, h, &c);
 154         } else
 155                 return -EOPNOTSUPP;
 156 }
 157
 158 static const struct sock_diag_handler packet_diag_handler = {
 159         .family = AF_PACKET,
 160         .dump = packet_diag_handler_dump,
 161 };
 162
 163 static int __init packet_diag_init(void)
 164 {
 165         return sock_diag_register(&packet_diag_handler);
 166 }
 167
 168 static void __exit packet_diag_exit(void)
 169 {
 170         sock_diag_unregister(&packet_diag_handler);
 171 }
 172
 173 module_init(packet_diag_init);
 174 module_exit(packet_diag_exit);
 175 MODULE_LICENSE("GPL");
 176 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 17 /* AF_PACKET */);