xref: /linux/net/packet/diag.c (revision b1a54551dd9ed5ef1763b97b35a0999ca002b95c)
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 = READ_ONCE(po->tp_tstamp);
22 
23 	pinfo.pdi_flags = 0;
24 	if (packet_sock_flag(po, PACKET_SOCK_RUNNING))
25 		pinfo.pdi_flags |= PDI_RUNNING;
26 	if (packet_sock_flag(po, PACKET_SOCK_AUXDATA))
27 		pinfo.pdi_flags |= PDI_AUXDATA;
28 	if (packet_sock_flag(po, PACKET_SOCK_ORIGDEV))
29 		pinfo.pdi_flags |= PDI_ORIGDEV;
30 	if (READ_ONCE(po->vnet_hdr_sz))
31 		pinfo.pdi_flags |= PDI_VNETHDR;
32 	if (packet_sock_flag(po, PACKET_SOCK_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(READ_ONCE(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_DESCRIPTION("PACKET socket monitoring via SOCK_DIAG");
266 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 17 /* AF_PACKET */);
267