xref: /linux/net/ipv6/ping.c (revision a82ebb093fc7bdd88f8df17b2fa303d7535fa43b)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		"Ping" sockets
8  *
9  * Based on ipv4/ping.c code.
10  *
11  * Authors:	Lorenzo Colitti (IPv6 support)
12  *		Vasiliy Kulikov / Openwall (IPv4 implementation, for Linux 2.6),
13  *		Pavel Kankovsky (IPv4 implementation, for Linux 2.4.32)
14  */
15 
16 #include <net/addrconf.h>
17 #include <net/ipv6.h>
18 #include <net/ip6_route.h>
19 #include <net/protocol.h>
20 #include <net/udp.h>
21 #include <net/transp_v6.h>
22 #include <linux/proc_fs.h>
23 #include <net/ping.h>
24 
25 /* Compatibility glue so we can support IPv6 when it's compiled as a module */
26 static int dummy_ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
27 				 int *addr_len)
28 {
29 	return -EAFNOSUPPORT;
30 }
31 static void dummy_ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
32 				       struct sk_buff *skb)
33 {
34 }
35 static int dummy_icmpv6_err_convert(u8 type, u8 code, int *err)
36 {
37 	return -EAFNOSUPPORT;
38 }
39 static void dummy_ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
40 				  __be16 port, u32 info, u8 *payload) {}
41 static int dummy_ipv6_chk_addr(struct net *net, const struct in6_addr *addr,
42 			       const struct net_device *dev, int strict)
43 {
44 	return 0;
45 }
46 
47 static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
48 {
49 	struct inet_sock *inet = inet_sk(sk);
50 	struct ipv6_pinfo *np = inet6_sk(sk);
51 	struct icmp6hdr user_icmph;
52 	int addr_type;
53 	struct in6_addr *daddr;
54 	int oif = 0;
55 	struct flowi6 fl6;
56 	int err;
57 	struct dst_entry *dst;
58 	struct rt6_info *rt;
59 	struct pingfakehdr pfh;
60 	struct ipcm6_cookie ipc6;
61 
62 	err = ping_common_sendmsg(AF_INET6, msg, len, &user_icmph,
63 				  sizeof(user_icmph));
64 	if (err)
65 		return err;
66 
67 	if (msg->msg_name) {
68 		DECLARE_SOCKADDR(struct sockaddr_in6 *, u, msg->msg_name);
69 		if (msg->msg_namelen < sizeof(*u))
70 			return -EINVAL;
71 		if (u->sin6_family != AF_INET6) {
72 			return -EAFNOSUPPORT;
73 		}
74 		daddr = &(u->sin6_addr);
75 		if (__ipv6_addr_needs_scope_id(ipv6_addr_type(daddr)))
76 			oif = u->sin6_scope_id;
77 	} else {
78 		if (sk->sk_state != TCP_ESTABLISHED)
79 			return -EDESTADDRREQ;
80 		daddr = &sk->sk_v6_daddr;
81 	}
82 
83 	if (!oif)
84 		oif = sk->sk_bound_dev_if;
85 
86 	if (!oif)
87 		oif = np->sticky_pktinfo.ipi6_ifindex;
88 
89 	if (!oif && ipv6_addr_is_multicast(daddr))
90 		oif = np->mcast_oif;
91 	else if (!oif)
92 		oif = np->ucast_oif;
93 
94 	addr_type = ipv6_addr_type(daddr);
95 	if ((__ipv6_addr_needs_scope_id(addr_type) && !oif) ||
96 	    (addr_type & IPV6_ADDR_MAPPED) ||
97 	    (oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if))
98 		return -EINVAL;
99 
100 	ipcm6_init_sk(&ipc6, np);
101 	ipc6.sockc.tsflags = sk->sk_tsflags;
102 	ipc6.sockc.mark = sk->sk_mark;
103 
104 	if (msg->msg_controllen) {
105 		struct ipv6_txoptions opt = {};
106 
107 		opt.tot_len = sizeof(opt);
108 		ipc6.opt = &opt;
109 
110 		err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6);
111 		if (err < 0)
112 			return err;
113 
114 		/* Changes to txoptions and flow info are not implemented, yet.
115 		 * Drop the options, fl6 is wiped below.
116 		 */
117 		ipc6.opt = NULL;
118 	}
119 
120 	memset(&fl6, 0, sizeof(fl6));
121 
122 	fl6.flowi6_proto = IPPROTO_ICMPV6;
123 	fl6.saddr = np->saddr;
124 	fl6.daddr = *daddr;
125 	fl6.flowi6_oif = oif;
126 	fl6.flowi6_mark = ipc6.sockc.mark;
127 	fl6.flowi6_uid = sk->sk_uid;
128 	fl6.fl6_icmp_type = user_icmph.icmp6_type;
129 	fl6.fl6_icmp_code = user_icmph.icmp6_code;
130 	security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
131 
132 	fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
133 
134 	dst = ip6_sk_dst_lookup_flow(sk, &fl6, daddr, false);
135 	if (IS_ERR(dst))
136 		return PTR_ERR(dst);
137 	rt = (struct rt6_info *) dst;
138 
139 	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
140 		fl6.flowi6_oif = np->mcast_oif;
141 	else if (!fl6.flowi6_oif)
142 		fl6.flowi6_oif = np->ucast_oif;
143 
144 	pfh.icmph.type = user_icmph.icmp6_type;
145 	pfh.icmph.code = user_icmph.icmp6_code;
146 	pfh.icmph.checksum = 0;
147 	pfh.icmph.un.echo.id = inet->inet_sport;
148 	pfh.icmph.un.echo.sequence = user_icmph.icmp6_sequence;
149 	pfh.msg = msg;
150 	pfh.wcheck = 0;
151 	pfh.family = AF_INET6;
152 
153 	if (ipc6.hlimit < 0)
154 		ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
155 
156 	lock_sock(sk);
157 	err = ip6_append_data(sk, ping_getfrag, &pfh, len,
158 			      0, &ipc6, &fl6, rt,
159 			      MSG_DONTWAIT);
160 
161 	if (err) {
162 		ICMP6_INC_STATS(sock_net(sk), rt->rt6i_idev,
163 				ICMP6_MIB_OUTERRORS);
164 		ip6_flush_pending_frames(sk);
165 	} else {
166 		icmpv6_push_pending_frames(sk, &fl6,
167 					   (struct icmp6hdr *)&pfh.icmph, len);
168 	}
169 	release_sock(sk);
170 
171 	dst_release(dst);
172 
173 	if (err)
174 		return err;
175 
176 	return len;
177 }
178 
179 struct proto pingv6_prot = {
180 	.name =		"PINGv6",
181 	.owner =	THIS_MODULE,
182 	.init =		ping_init_sock,
183 	.close =	ping_close,
184 	.connect =	ip6_datagram_connect_v6_only,
185 	.disconnect =	__udp_disconnect,
186 	.setsockopt =	ipv6_setsockopt,
187 	.getsockopt =	ipv6_getsockopt,
188 	.sendmsg =	ping_v6_sendmsg,
189 	.recvmsg =	ping_recvmsg,
190 	.bind =		ping_bind,
191 	.backlog_rcv =	ping_queue_rcv_skb,
192 	.hash =		ping_hash,
193 	.unhash =	ping_unhash,
194 	.get_port =	ping_get_port,
195 	.put_port =	ping_unhash,
196 	.obj_size =	sizeof(struct raw6_sock),
197 };
198 EXPORT_SYMBOL_GPL(pingv6_prot);
199 
200 static struct inet_protosw pingv6_protosw = {
201 	.type =      SOCK_DGRAM,
202 	.protocol =  IPPROTO_ICMPV6,
203 	.prot =      &pingv6_prot,
204 	.ops =       &inet6_sockraw_ops,
205 	.flags =     INET_PROTOSW_REUSE,
206 };
207 
208 #ifdef CONFIG_PROC_FS
209 static void *ping_v6_seq_start(struct seq_file *seq, loff_t *pos)
210 {
211 	return ping_seq_start(seq, pos, AF_INET6);
212 }
213 
214 static int ping_v6_seq_show(struct seq_file *seq, void *v)
215 {
216 	if (v == SEQ_START_TOKEN) {
217 		seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
218 	} else {
219 		int bucket = ((struct ping_iter_state *) seq->private)->bucket;
220 		struct inet_sock *inet = inet_sk(v);
221 		__u16 srcp = ntohs(inet->inet_sport);
222 		__u16 destp = ntohs(inet->inet_dport);
223 		ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
224 	}
225 	return 0;
226 }
227 
228 static const struct seq_operations ping_v6_seq_ops = {
229 	.start		= ping_v6_seq_start,
230 	.show		= ping_v6_seq_show,
231 	.next		= ping_seq_next,
232 	.stop		= ping_seq_stop,
233 };
234 
235 static int __net_init ping_v6_proc_init_net(struct net *net)
236 {
237 	if (!proc_create_net("icmp6", 0444, net->proc_net, &ping_v6_seq_ops,
238 			sizeof(struct ping_iter_state)))
239 		return -ENOMEM;
240 	return 0;
241 }
242 
243 static void __net_exit ping_v6_proc_exit_net(struct net *net)
244 {
245 	remove_proc_entry("icmp6", net->proc_net);
246 }
247 
248 static struct pernet_operations ping_v6_net_ops = {
249 	.init = ping_v6_proc_init_net,
250 	.exit = ping_v6_proc_exit_net,
251 };
252 #endif
253 
254 int __init pingv6_init(void)
255 {
256 #ifdef CONFIG_PROC_FS
257 	int ret = register_pernet_subsys(&ping_v6_net_ops);
258 	if (ret)
259 		return ret;
260 #endif
261 	pingv6_ops.ipv6_recv_error = ipv6_recv_error;
262 	pingv6_ops.ip6_datagram_recv_common_ctl = ip6_datagram_recv_common_ctl;
263 	pingv6_ops.ip6_datagram_recv_specific_ctl =
264 		ip6_datagram_recv_specific_ctl;
265 	pingv6_ops.icmpv6_err_convert = icmpv6_err_convert;
266 	pingv6_ops.ipv6_icmp_error = ipv6_icmp_error;
267 	pingv6_ops.ipv6_chk_addr = ipv6_chk_addr;
268 	return inet6_register_protosw(&pingv6_protosw);
269 }
270 
271 /* This never gets called because it's not possible to unload the ipv6 module,
272  * but just in case.
273  */
274 void pingv6_exit(void)
275 {
276 	pingv6_ops.ipv6_recv_error = dummy_ipv6_recv_error;
277 	pingv6_ops.ip6_datagram_recv_common_ctl = dummy_ip6_datagram_recv_ctl;
278 	pingv6_ops.ip6_datagram_recv_specific_ctl = dummy_ip6_datagram_recv_ctl;
279 	pingv6_ops.icmpv6_err_convert = dummy_icmpv6_err_convert;
280 	pingv6_ops.ipv6_icmp_error = dummy_ipv6_icmp_error;
281 	pingv6_ops.ipv6_chk_addr = dummy_ipv6_chk_addr;
282 #ifdef CONFIG_PROC_FS
283 	unregister_pernet_subsys(&ping_v6_net_ops);
284 #endif
285 	inet6_unregister_protosw(&pingv6_protosw);
286 }
287