xref: /linux/net/xdp/xsk_diag.c (revision 9a4e47ef98a3041f6d2869ba2cd3401701776275)
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 xsk_buff_pool *pool = xs->pool;
50 	struct xdp_umem *umem = xs->umem;
51 	struct xdp_diag_umem du = {};
52 	int err;
53 
54 	if (!umem)
55 		return 0;
56 
57 	du.id = umem->id;
58 	du.size = umem->size;
59 	du.num_pages = umem->npgs;
60 	du.chunk_size = umem->chunk_size;
61 	du.headroom = umem->headroom;
62 	du.ifindex = (pool && pool->netdev) ? pool->netdev->ifindex : 0;
63 	du.queue_id = pool ? pool->queue_id : 0;
64 	du.flags = 0;
65 	if (umem->zc)
66 		du.flags |= XDP_DU_F_ZEROCOPY;
67 	du.refs = refcount_read(&umem->users);
68 
69 	err = nla_put(nlskb, XDP_DIAG_UMEM, sizeof(du), &du);
70 	if (!err && pool && pool->fq)
71 		err = xsk_diag_put_ring(pool->fq,
72 					XDP_DIAG_UMEM_FILL_RING, nlskb);
73 	if (!err && pool && pool->cq)
74 		err = xsk_diag_put_ring(pool->cq,
75 					XDP_DIAG_UMEM_COMPLETION_RING, nlskb);
76 	return err;
77 }
78 
79 static int xsk_diag_put_stats(const struct xdp_sock *xs, struct sk_buff *nlskb)
80 {
81 	struct xdp_diag_stats du = {};
82 
83 	du.n_rx_dropped = xs->rx_dropped;
84 	du.n_rx_invalid = xskq_nb_invalid_descs(xs->rx);
85 	du.n_rx_full = xs->rx_queue_full;
86 	du.n_fill_ring_empty = xs->pool ? xskq_nb_queue_empty_descs(xs->pool->fq) : 0;
87 	du.n_tx_invalid = xskq_nb_invalid_descs(xs->tx);
88 	du.n_tx_ring_empty = xskq_nb_queue_empty_descs(xs->tx);
89 	return nla_put(nlskb, XDP_DIAG_STATS, sizeof(du), &du);
90 }
91 
92 static int xsk_diag_fill(struct sock *sk, struct sk_buff *nlskb,
93 			 struct xdp_diag_req *req,
94 			 struct user_namespace *user_ns,
95 			 u32 portid, u32 seq, u32 flags, int sk_ino)
96 {
97 	struct xdp_sock *xs = xdp_sk(sk);
98 	struct xdp_diag_msg *msg;
99 	struct nlmsghdr *nlh;
100 
101 	nlh = nlmsg_put(nlskb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*msg),
102 			flags);
103 	if (!nlh)
104 		return -EMSGSIZE;
105 
106 	msg = nlmsg_data(nlh);
107 	memset(msg, 0, sizeof(*msg));
108 	msg->xdiag_family = AF_XDP;
109 	msg->xdiag_type = sk->sk_type;
110 	msg->xdiag_ino = sk_ino;
111 	sock_diag_save_cookie(sk, msg->xdiag_cookie);
112 
113 	mutex_lock(&xs->mutex);
114 	if (READ_ONCE(xs->state) == XSK_UNBOUND)
115 		goto out_nlmsg_trim;
116 
117 	if ((req->xdiag_show & XDP_SHOW_INFO) && xsk_diag_put_info(xs, nlskb))
118 		goto out_nlmsg_trim;
119 
120 	if ((req->xdiag_show & XDP_SHOW_INFO) &&
121 	    nla_put_u32(nlskb, XDP_DIAG_UID,
122 			from_kuid_munged(user_ns, sock_i_uid(sk))))
123 		goto out_nlmsg_trim;
124 
125 	if ((req->xdiag_show & XDP_SHOW_RING_CFG) &&
126 	    xsk_diag_put_rings_cfg(xs, nlskb))
127 		goto out_nlmsg_trim;
128 
129 	if ((req->xdiag_show & XDP_SHOW_UMEM) &&
130 	    xsk_diag_put_umem(xs, nlskb))
131 		goto out_nlmsg_trim;
132 
133 	if ((req->xdiag_show & XDP_SHOW_MEMINFO) &&
134 	    sock_diag_put_meminfo(sk, nlskb, XDP_DIAG_MEMINFO))
135 		goto out_nlmsg_trim;
136 
137 	if ((req->xdiag_show & XDP_SHOW_STATS) &&
138 	    xsk_diag_put_stats(xs, nlskb))
139 		goto out_nlmsg_trim;
140 
141 	mutex_unlock(&xs->mutex);
142 	nlmsg_end(nlskb, nlh);
143 	return 0;
144 
145 out_nlmsg_trim:
146 	mutex_unlock(&xs->mutex);
147 	nlmsg_cancel(nlskb, nlh);
148 	return -EMSGSIZE;
149 }
150 
151 static int xsk_diag_dump(struct sk_buff *nlskb, struct netlink_callback *cb)
152 {
153 	struct xdp_diag_req *req = nlmsg_data(cb->nlh);
154 	struct net *net = sock_net(nlskb->sk);
155 	int num = 0, s_num = cb->args[0];
156 	struct sock *sk;
157 
158 	mutex_lock(&net->xdp.lock);
159 
160 	sk_for_each(sk, &net->xdp.list) {
161 		if (!net_eq(sock_net(sk), net))
162 			continue;
163 		if (num++ < s_num)
164 			continue;
165 
166 		if (xsk_diag_fill(sk, nlskb, req,
167 				  sk_user_ns(NETLINK_CB(cb->skb).sk),
168 				  NETLINK_CB(cb->skb).portid,
169 				  cb->nlh->nlmsg_seq, NLM_F_MULTI,
170 				  sock_i_ino(sk)) < 0) {
171 			num--;
172 			break;
173 		}
174 	}
175 
176 	mutex_unlock(&net->xdp.lock);
177 	cb->args[0] = num;
178 	return nlskb->len;
179 }
180 
181 static int xsk_diag_handler_dump(struct sk_buff *nlskb, struct nlmsghdr *hdr)
182 {
183 	struct netlink_dump_control c = { .dump = xsk_diag_dump };
184 	int hdrlen = sizeof(struct xdp_diag_req);
185 	struct net *net = sock_net(nlskb->sk);
186 
187 	if (nlmsg_len(hdr) < hdrlen)
188 		return -EINVAL;
189 
190 	if (!(hdr->nlmsg_flags & NLM_F_DUMP))
191 		return -EOPNOTSUPP;
192 
193 	return netlink_dump_start(net->diag_nlsk, nlskb, hdr, &c);
194 }
195 
196 static const struct sock_diag_handler xsk_diag_handler = {
197 	.family = AF_XDP,
198 	.dump = xsk_diag_handler_dump,
199 };
200 
201 static int __init xsk_diag_init(void)
202 {
203 	return sock_diag_register(&xsk_diag_handler);
204 }
205 
206 static void __exit xsk_diag_exit(void)
207 {
208 	sock_diag_unregister(&xsk_diag_handler);
209 }
210 
211 module_init(xsk_diag_init);
212 module_exit(xsk_diag_exit);
213 MODULE_LICENSE("GPL");
214 MODULE_DESCRIPTION("XDP socket monitoring via SOCK_DIAG");
215 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, AF_XDP);
216