linux/net/xdp/xsk_diag.c
Björn Töpel 25dc18ff9b xsk: lock the control mutex in sock_diag interface
When accessing the members of an XDP socket, the control mutex should
be held. This commit fixes that.

Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Fixes: a36b38aa2a ("xsk: add sock_diag interface for AF_XDP")
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-05 14:11:52 +02:00

195 lines
4.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* XDP sockets monitoring support
*
* Copyright(c) 2019 Intel Corporation.
*
* Author: Björn Töpel <bjorn.topel@intel.com>
*/
#include <linux/module.h>
#include <net/xdp_sock.h>
#include <linux/xdp_diag.h>
#include <linux/sock_diag.h>
#include "xsk_queue.h"
#include "xsk.h"
static int xsk_diag_put_info(const struct xdp_sock *xs, struct sk_buff *nlskb)
{
struct xdp_diag_info di = {};
di.ifindex = xs->dev ? xs->dev->ifindex : 0;
di.queue_id = xs->queue_id;
return nla_put(nlskb, XDP_DIAG_INFO, sizeof(di), &di);
}
static int xsk_diag_put_ring(const struct xsk_queue *queue, int nl_type,
struct sk_buff *nlskb)
{
struct xdp_diag_ring dr = {};
dr.entries = queue->nentries;
return nla_put(nlskb, nl_type, sizeof(dr), &dr);
}
static int xsk_diag_put_rings_cfg(const struct xdp_sock *xs,
struct sk_buff *nlskb)
{
int err = 0;
if (xs->rx)
err = xsk_diag_put_ring(xs->rx, XDP_DIAG_RX_RING, nlskb);
if (!err && xs->tx)
err = xsk_diag_put_ring(xs->tx, XDP_DIAG_TX_RING, nlskb);
return err;
}
static int xsk_diag_put_umem(const struct xdp_sock *xs, struct sk_buff *nlskb)
{
struct xdp_umem *umem = xs->umem;
struct xdp_diag_umem du = {};
int err;
if (!umem)
return 0;
du.id = umem->id;
du.size = umem->size;
du.num_pages = umem->npgs;
du.chunk_size = umem->chunk_size_nohr + umem->headroom;
du.headroom = umem->headroom;
du.ifindex = umem->dev ? umem->dev->ifindex : 0;
du.queue_id = umem->queue_id;
du.flags = 0;
if (umem->zc)
du.flags |= XDP_DU_F_ZEROCOPY;
du.refs = refcount_read(&umem->users);
err = nla_put(nlskb, XDP_DIAG_UMEM, sizeof(du), &du);
if (!err && umem->fq)
err = xsk_diag_put_ring(umem->fq, XDP_DIAG_UMEM_FILL_RING, nlskb);
if (!err && umem->cq) {
err = xsk_diag_put_ring(umem->cq, XDP_DIAG_UMEM_COMPLETION_RING,
nlskb);
}
return err;
}
static int xsk_diag_fill(struct sock *sk, struct sk_buff *nlskb,
struct xdp_diag_req *req,
struct user_namespace *user_ns,
u32 portid, u32 seq, u32 flags, int sk_ino)
{
struct xdp_sock *xs = xdp_sk(sk);
struct xdp_diag_msg *msg;
struct nlmsghdr *nlh;
nlh = nlmsg_put(nlskb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*msg),
flags);
if (!nlh)
return -EMSGSIZE;
msg = nlmsg_data(nlh);
memset(msg, 0, sizeof(*msg));
msg->xdiag_family = AF_XDP;
msg->xdiag_type = sk->sk_type;
msg->xdiag_ino = sk_ino;
sock_diag_save_cookie(sk, msg->xdiag_cookie);
mutex_lock(&xs->mutex);
if ((req->xdiag_show & XDP_SHOW_INFO) && xsk_diag_put_info(xs, nlskb))
goto out_nlmsg_trim;
if ((req->xdiag_show & XDP_SHOW_INFO) &&
nla_put_u32(nlskb, XDP_DIAG_UID,
from_kuid_munged(user_ns, sock_i_uid(sk))))
goto out_nlmsg_trim;
if ((req->xdiag_show & XDP_SHOW_RING_CFG) &&
xsk_diag_put_rings_cfg(xs, nlskb))
goto out_nlmsg_trim;
if ((req->xdiag_show & XDP_SHOW_UMEM) &&
xsk_diag_put_umem(xs, nlskb))
goto out_nlmsg_trim;
if ((req->xdiag_show & XDP_SHOW_MEMINFO) &&
sock_diag_put_meminfo(sk, nlskb, XDP_DIAG_MEMINFO))
goto out_nlmsg_trim;
mutex_unlock(&xs->mutex);
nlmsg_end(nlskb, nlh);
return 0;
out_nlmsg_trim:
mutex_unlock(&xs->mutex);
nlmsg_cancel(nlskb, nlh);
return -EMSGSIZE;
}
static int xsk_diag_dump(struct sk_buff *nlskb, struct netlink_callback *cb)
{
struct xdp_diag_req *req = nlmsg_data(cb->nlh);
struct net *net = sock_net(nlskb->sk);
int num = 0, s_num = cb->args[0];
struct sock *sk;
mutex_lock(&net->xdp.lock);
sk_for_each(sk, &net->xdp.list) {
if (!net_eq(sock_net(sk), net))
continue;
if (num++ < s_num)
continue;
if (xsk_diag_fill(sk, nlskb, req,
sk_user_ns(NETLINK_CB(cb->skb).sk),
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
sock_i_ino(sk)) < 0) {
num--;
break;
}
}
mutex_unlock(&net->xdp.lock);
cb->args[0] = num;
return nlskb->len;
}
static int xsk_diag_handler_dump(struct sk_buff *nlskb, struct nlmsghdr *hdr)
{
struct netlink_dump_control c = { .dump = xsk_diag_dump };
int hdrlen = sizeof(struct xdp_diag_req);
struct net *net = sock_net(nlskb->sk);
if (nlmsg_len(hdr) < hdrlen)
return -EINVAL;
if (!(hdr->nlmsg_flags & NLM_F_DUMP))
return -EOPNOTSUPP;
return netlink_dump_start(net->diag_nlsk, nlskb, hdr, &c);
}
static const struct sock_diag_handler xsk_diag_handler = {
.family = AF_XDP,
.dump = xsk_diag_handler_dump,
};
static int __init xsk_diag_init(void)
{
return sock_diag_register(&xsk_diag_handler);
}
static void __exit xsk_diag_exit(void)
{
sock_diag_unregister(&xsk_diag_handler);
}
module_init(xsk_diag_init);
module_exit(xsk_diag_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, AF_XDP);