net/packet/diag.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <linux/module.h>
   3 #include <linux/sock_diag.h>
   4 #include <linux/net.h>
   5 #include <linux/netdevice.h>
   6 #include <linux/packet_diag.h>
   7 #include <linux/percpu.h>
   8 #include <net/net_namespace.h>
   9 #include <net/sock.h>
  10
  11 #include "internal.h"
  12
  13 static int pdiag_put_info(const struct packet_sock *po, struct sk_buff *nlskb)
  14 {
  15         struct packet_diag_info pinfo;
  16
  17         pinfo.pdi_index = po->ifindex;
  18         pinfo.pdi_version = po->tp_version;
  19         pinfo.pdi_reserve = po->tp_reserve;
  20         pinfo.pdi_copy_thresh = po->copy_thresh;
  21         pinfo.pdi_tstamp = po->tp_tstamp;
  22
  23         pinfo.pdi_flags = 0;
  24         if (po->running)
  25                 pinfo.pdi_flags |= PDI_RUNNING;
  26         if (po->auxdata)
  27                 pinfo.pdi_flags |= PDI_AUXDATA;
  28         if (po->origdev)
  29                 pinfo.pdi_flags |= PDI_ORIGDEV;
  30         if (po->has_vnet_hdr)
  31                 pinfo.pdi_flags |= PDI_VNETHDR;
  32         if (po->tp_loss)
  33                 pinfo.pdi_flags |= PDI_LOSS;
  34
  35         return nla_put(nlskb, PACKET_DIAG_INFO, sizeof(pinfo), &pinfo);
  36 }
  37
  38 static int pdiag_put_mclist(const struct packet_sock *po, struct sk_buff *nlskb)
  39 {
  40         struct nlattr *mca;
  41         struct packet_mclist *ml;
  42
  43         mca = nla_nest_start_noflag(nlskb, PACKET_DIAG_MCLIST);
  44         if (!mca)
  45                 return -EMSGSIZE;
  46
  47         rtnl_lock();
  48         for (ml = po->mclist; ml; ml = ml->next) {
  49                 struct packet_diag_mclist *dml;
  50
  51                 dml = nla_reserve_nohdr(nlskb, sizeof(*dml));
  52                 if (!dml) {
  53                         rtnl_unlock();
  54                         nla_nest_cancel(nlskb, mca);
  55                         return -EMSGSIZE;
  56                 }
  57
  58                 dml->pdmc_index = ml->ifindex;
  59                 dml->pdmc_type = ml->type;
  60                 dml->pdmc_alen = ml->alen;
  61                 dml->pdmc_count = ml->count;
  62                 BUILD_BUG_ON(sizeof(dml->pdmc_addr) != sizeof(ml->addr));
  63                 memcpy(dml->pdmc_addr, ml->addr, sizeof(ml->addr));
  64         }
  65
  66         rtnl_unlock();
  67         nla_nest_end(nlskb, mca);
  68
  69         return 0;
  70 }
  71
  72 static int pdiag_put_ring(struct packet_ring_buffer *ring, int ver, int nl_type,
  73                 struct sk_buff *nlskb)
  74 {
  75         struct packet_diag_ring pdr;
  76
  77         if (!ring->pg_vec)
  78                 return 0;
  79
  80         pdr.pdr_block_size = ring->pg_vec_pages << PAGE_SHIFT;
  81         pdr.pdr_block_nr = ring->pg_vec_len;
  82         pdr.pdr_frame_size = ring->frame_size;
  83         pdr.pdr_frame_nr = ring->frame_max + 1;
  84
  85         if (ver > TPACKET_V2) {
  86                 pdr.pdr_retire_tmo = ring->prb_bdqc.retire_blk_tov;
  87                 pdr.pdr_sizeof_priv = ring->prb_bdqc.blk_sizeof_priv;
  88                 pdr.pdr_features = ring->prb_bdqc.feature_req_word;
  89         } else {
  90                 pdr.pdr_retire_tmo = 0;
  91                 pdr.pdr_sizeof_priv = 0;
  92                 pdr.pdr_features = 0;
  93         }
  94
  95         return nla_put(nlskb, nl_type, sizeof(pdr), &pdr);
  96 }
  97
  98 static int pdiag_put_rings_cfg(struct packet_sock *po, struct sk_buff *skb)
  99 {
 100         int ret;
 101
 102         mutex_lock(&po->pg_vec_lock);
 103         ret = pdiag_put_ring(&po->rx_ring, po->tp_version,
 104                         PACKET_DIAG_RX_RING, skb);
 105         if (!ret)
 106                 ret = pdiag_put_ring(&po->tx_ring, po->tp_version,
 107                                 PACKET_DIAG_TX_RING, skb);
 108         mutex_unlock(&po->pg_vec_lock);
 109
 110         return ret;
 111 }
 112
 113 static int pdiag_put_fanout(struct packet_sock *po, struct sk_buff *nlskb)
 114 {
 115         int ret = 0;
 116
 117         mutex_lock(&fanout_mutex);
 118         if (po->fanout) {
 119                 u32 val;
 120
 121                 val = (u32)po->fanout->id | ((u32)po->fanout->type << 16);
 122                 ret = nla_put_u32(nlskb, PACKET_DIAG_FANOUT, val);
 123         }
 124         mutex_unlock(&fanout_mutex);
 125
 126         return ret;
 127 }
 128
 129 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
 130                         struct packet_diag_req *req,
 131                         bool may_report_filterinfo,
 132                         struct user_namespace *user_ns,
 133                         u32 portid, u32 seq, u32 flags, int sk_ino)
 134 {
 135         struct nlmsghdr *nlh;
 136         struct packet_diag_msg *rp;
 137         struct packet_sock *po = pkt_sk(sk);
 138
 139         nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rp), flags);
 140         if (!nlh)
 141                 return -EMSGSIZE;
 142
 143         rp = nlmsg_data(nlh);
 144         rp->pdiag_family = AF_PACKET;
 145         rp->pdiag_type = sk->sk_type;
 146         rp->pdiag_num = ntohs(po->num);
 147         rp->pdiag_ino = sk_ino;
 148         sock_diag_save_cookie(sk, rp->pdiag_cookie);
 149
 150         if ((req->pdiag_show & PACKET_SHOW_INFO) &&
 151                         pdiag_put_info(po, skb))
 152                 goto out_nlmsg_trim;
 153
 154         if ((req->pdiag_show & PACKET_SHOW_INFO) &&
 155             nla_put_u32(skb, PACKET_DIAG_UID,
 156                         from_kuid_munged(user_ns, sock_i_uid(sk))))
 157                 goto out_nlmsg_trim;
 158
 159         if ((req->pdiag_show & PACKET_SHOW_MCLIST) &&
 160                         pdiag_put_mclist(po, skb))
 161                 goto out_nlmsg_trim;
 162
 163         if ((req->pdiag_show & PACKET_SHOW_RING_CFG) &&
 164                         pdiag_put_rings_cfg(po, skb))
 165                 goto out_nlmsg_trim;
 166
 167         if ((req->pdiag_show & PACKET_SHOW_FANOUT) &&
 168                         pdiag_put_fanout(po, skb))
 169                 goto out_nlmsg_trim;
 170
 171         if ((req->pdiag_show & PACKET_SHOW_MEMINFO) &&
 172             sock_diag_put_meminfo(sk, skb, PACKET_DIAG_MEMINFO))
 173                 goto out_nlmsg_trim;
 174
 175         if ((req->pdiag_show & PACKET_SHOW_FILTER) &&
 176             sock_diag_put_filterinfo(may_report_filterinfo, sk, skb,
 177                                      PACKET_DIAG_FILTER))
 178                 goto out_nlmsg_trim;
 179
 180         nlmsg_end(skb, nlh);
 181         return 0;
 182
 183 out_nlmsg_trim:
 184         nlmsg_cancel(skb, nlh);
 185         return -EMSGSIZE;
 186 }
 187
 188 static int packet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 189 {
 190         int num = 0, s_num = cb->args[0];
 191         struct packet_diag_req *req;
 192         struct net *net;
 193         struct sock *sk;
 194         bool may_report_filterinfo;
 195
 196         net = sock_net(skb->sk);
 197         req = nlmsg_data(cb->nlh);
 198         may_report_filterinfo = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
 199
 200         mutex_lock(&net->packet.sklist_lock);
 201         sk_for_each(sk, &net->packet.sklist) {
 202                 if (!net_eq(sock_net(sk), net))
 203                         continue;
 204                 if (num < s_num)
 205                         goto next;
 206
 207                 if (sk_diag_fill(sk, skb, req,
 208                                  may_report_filterinfo,
 209                                  sk_user_ns(NETLINK_CB(cb->skb).sk),
 210                                  NETLINK_CB(cb->skb).portid,
 211                                  cb->nlh->nlmsg_seq, NLM_F_MULTI,
 212                                  sock_i_ino(sk)) < 0)
 213                         goto done;
 214 next:
 215                 num++;
 216         }
 217 done:
 218         mutex_unlock(&net->packet.sklist_lock);
 219         cb->args[0] = num;
 220
 221         return skb->len;
 222 }
 223
 224 static int packet_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
 225 {
 226         int hdrlen = sizeof(struct packet_diag_req);
 227         struct net *net = sock_net(skb->sk);
 228         struct packet_diag_req *req;
 229
 230         if (nlmsg_len(h) < hdrlen)
 231                 return -EINVAL;
 232
 233         req = nlmsg_data(h);
 234         /* Make it possible to support protocol filtering later */
 235         if (req->sdiag_protocol)
 236                 return -EINVAL;
 237
 238         if (h->nlmsg_flags & NLM_F_DUMP) {
 239                 struct netlink_dump_control c = {
 240                         .dump = packet_diag_dump,
 241                 };
 242                 return netlink_dump_start(net->diag_nlsk, skb, h, &c);
 243         } else
 244                 return -EOPNOTSUPP;
 245 }
 246
 247 static const struct sock_diag_handler packet_diag_handler = {
 248         .family = AF_PACKET,
 249         .dump = packet_diag_handler_dump,
 250 };
 251
 252 static int __init packet_diag_init(void)
 253 {
 254         return sock_diag_register(&packet_diag_handler);
 255 }
 256
 257 static void __exit packet_diag_exit(void)
 258 {
 259         sock_diag_unregister(&packet_diag_handler);
 260 }
 261
 262 module_init(packet_diag_init);
 263 module_exit(packet_diag_exit);
 264 MODULE_LICENSE("GPL");
 265 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 17 /* AF_PACKET */);