net/xdp/xsk_diag.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* XDP sockets monitoring support
   3  *
   4  * Copyright(c) 2019 Intel Corporation.
   5  *
   6  * Author: Björn Töpel <bjorn.topel@intel.com>
   7  */
   8
   9 #include <linux/module.h>
  10 #include <net/xdp_sock.h>
  11 #include <linux/xdp_diag.h>
  12 #include <linux/sock_diag.h>
  13
  14 #include "xsk_queue.h"
  15 #include "xsk.h"
  16
  17 static int xsk_diag_put_info(const struct xdp_sock *xs, struct sk_buff *nlskb)
  18 {
  19         struct xdp_diag_info di = {};
  20
  21         di.ifindex = xs->dev ? xs->dev->ifindex : 0;
  22         di.queue_id = xs->queue_id;
  23         return nla_put(nlskb, XDP_DIAG_INFO, sizeof(di), &di);
  24 }
  25
  26 static int xsk_diag_put_ring(const struct xsk_queue *queue, int nl_type,
  27                              struct sk_buff *nlskb)
  28 {
  29         struct xdp_diag_ring dr = {};
  30
  31         dr.entries = queue->nentries;
  32         return nla_put(nlskb, nl_type, sizeof(dr), &dr);
  33 }
  34
  35 static int xsk_diag_put_rings_cfg(const struct xdp_sock *xs,
  36                                   struct sk_buff *nlskb)
  37 {
  38         int err = 0;
  39
  40         if (xs->rx)
  41                 err = xsk_diag_put_ring(xs->rx, XDP_DIAG_RX_RING, nlskb);
  42         if (!err && xs->tx)
  43                 err = xsk_diag_put_ring(xs->tx, XDP_DIAG_TX_RING, nlskb);
  44         return err;
  45 }
  46
  47 static int xsk_diag_put_umem(const struct xdp_sock *xs, struct sk_buff *nlskb)
  48 {
  49         struct xdp_umem *umem = xs->umem;
  50         struct xdp_diag_umem du = {};
  51         int err;
  52
  53         if (!umem)
  54                 return 0;
  55
  56         du.id = umem->id;
  57         du.size = umem->size;
  58         du.num_pages = umem->npgs;
  59         du.chunk_size = umem->chunk_size_nohr + umem->headroom;
  60         du.headroom = umem->headroom;
  61         du.ifindex = umem->dev ? umem->dev->ifindex : 0;
  62         du.queue_id = umem->queue_id;
  63         du.flags = 0;
  64         if (umem->zc)
  65                 du.flags |= XDP_DU_F_ZEROCOPY;
  66         du.refs = refcount_read(&umem->users);
  67
  68         err = nla_put(nlskb, XDP_DIAG_UMEM, sizeof(du), &du);
  69
  70         if (!err && umem->fq)
  71                 err = xsk_diag_put_ring(umem->fq, XDP_DIAG_UMEM_FILL_RING, nlskb);
  72         if (!err && umem->cq) {
  73                 err = xsk_diag_put_ring(umem->cq, XDP_DIAG_UMEM_COMPLETION_RING,
  74                                         nlskb);
  75         }
  76         return err;
  77 }
  78
  79 static int xsk_diag_fill(struct sock *sk, struct sk_buff *nlskb,
  80                          struct xdp_diag_req *req,
  81                          struct user_namespace *user_ns,
  82                          u32 portid, u32 seq, u32 flags, int sk_ino)
  83 {
  84         struct xdp_sock *xs = xdp_sk(sk);
  85         struct xdp_diag_msg *msg;
  86         struct nlmsghdr *nlh;
  87
  88         nlh = nlmsg_put(nlskb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*msg),
  89                         flags);
  90         if (!nlh)
  91                 return -EMSGSIZE;
  92
  93         msg = nlmsg_data(nlh);
  94         memset(msg, 0, sizeof(*msg));
  95         msg->xdiag_family = AF_XDP;
  96         msg->xdiag_type = sk->sk_type;
  97         msg->xdiag_ino = sk_ino;
  98         sock_diag_save_cookie(sk, msg->xdiag_cookie);
  99
 100         mutex_lock(&xs->mutex);
 101         if ((req->xdiag_show & XDP_SHOW_INFO) && xsk_diag_put_info(xs, nlskb))
 102                 goto out_nlmsg_trim;
 103
 104         if ((req->xdiag_show & XDP_SHOW_INFO) &&
 105             nla_put_u32(nlskb, XDP_DIAG_UID,
 106                         from_kuid_munged(user_ns, sock_i_uid(sk))))
 107                 goto out_nlmsg_trim;
 108
 109         if ((req->xdiag_show & XDP_SHOW_RING_CFG) &&
 110             xsk_diag_put_rings_cfg(xs, nlskb))
 111                 goto out_nlmsg_trim;
 112
 113         if ((req->xdiag_show & XDP_SHOW_UMEM) &&
 114             xsk_diag_put_umem(xs, nlskb))
 115                 goto out_nlmsg_trim;
 116
 117         if ((req->xdiag_show & XDP_SHOW_MEMINFO) &&
 118             sock_diag_put_meminfo(sk, nlskb, XDP_DIAG_MEMINFO))
 119                 goto out_nlmsg_trim;
 120
 121         mutex_unlock(&xs->mutex);
 122         nlmsg_end(nlskb, nlh);
 123         return 0;
 124
 125 out_nlmsg_trim:
 126         mutex_unlock(&xs->mutex);
 127         nlmsg_cancel(nlskb, nlh);
 128         return -EMSGSIZE;
 129 }
 130
 131 static int xsk_diag_dump(struct sk_buff *nlskb, struct netlink_callback *cb)
 132 {
 133         struct xdp_diag_req *req = nlmsg_data(cb->nlh);
 134         struct net *net = sock_net(nlskb->sk);
 135         int num = 0, s_num = cb->args[0];
 136         struct sock *sk;
 137
 138         mutex_lock(&net->xdp.lock);
 139
 140         sk_for_each(sk, &net->xdp.list) {
 141                 if (!net_eq(sock_net(sk), net))
 142                         continue;
 143                 if (num++ < s_num)
 144                         continue;
 145
 146                 if (xsk_diag_fill(sk, nlskb, req,
 147                                   sk_user_ns(NETLINK_CB(cb->skb).sk),
 148                                   NETLINK_CB(cb->skb).portid,
 149                                   cb->nlh->nlmsg_seq, NLM_F_MULTI,
 150                                   sock_i_ino(sk)) < 0) {
 151                         num--;
 152                         break;
 153                 }
 154         }
 155
 156         mutex_unlock(&net->xdp.lock);
 157         cb->args[0] = num;
 158         return nlskb->len;
 159 }
 160
 161 static int xsk_diag_handler_dump(struct sk_buff *nlskb, struct nlmsghdr *hdr)
 162 {
 163         struct netlink_dump_control c = { .dump = xsk_diag_dump };
 164         int hdrlen = sizeof(struct xdp_diag_req);
 165         struct net *net = sock_net(nlskb->sk);
 166
 167         if (nlmsg_len(hdr) < hdrlen)
 168                 return -EINVAL;
 169
 170         if (!(hdr->nlmsg_flags & NLM_F_DUMP))
 171                 return -EOPNOTSUPP;
 172
 173         return netlink_dump_start(net->diag_nlsk, nlskb, hdr, &c);
 174 }
 175
 176 static const struct sock_diag_handler xsk_diag_handler = {
 177         .family = AF_XDP,
 178         .dump = xsk_diag_handler_dump,
 179 };
 180
 181 static int __init xsk_diag_init(void)
 182 {
 183         return sock_diag_register(&xsk_diag_handler);
 184 }
 185
 186 static void __exit xsk_diag_exit(void)
 187 {
 188         sock_diag_unregister(&xsk_diag_handler);
 189 }
 190
 191 module_init(xsk_diag_init);
 192 module_exit(xsk_diag_exit);
 193 MODULE_LICENSE("GPL");
 194 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, AF_XDP);