xref: /linux/net/ipv6/ping.c (revision 81499d338995fa288464c585f49211cfaa6ffdce)
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 	pr_debug("ping_v6_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
63 
64 	err = ping_common_sendmsg(AF_INET6, msg, len, &user_icmph,
65 				  sizeof(user_icmph));
66 	if (err)
67 		return err;
68 
69 	if (msg->msg_name) {
70 		DECLARE_SOCKADDR(struct sockaddr_in6 *, u, msg->msg_name);
71 		if (msg->msg_namelen < sizeof(*u))
72 			return -EINVAL;
73 		if (u->sin6_family != AF_INET6) {
74 			return -EAFNOSUPPORT;
75 		}
76 		daddr = &(u->sin6_addr);
77 		if (__ipv6_addr_needs_scope_id(ipv6_addr_type(daddr)))
78 			oif = u->sin6_scope_id;
79 	} else {
80 		if (sk->sk_state != TCP_ESTABLISHED)
81 			return -EDESTADDRREQ;
82 		daddr = &sk->sk_v6_daddr;
83 	}
84 
85 	if (!oif)
86 		oif = sk->sk_bound_dev_if;
87 
88 	if (!oif)
89 		oif = np->sticky_pktinfo.ipi6_ifindex;
90 
91 	if (!oif && ipv6_addr_is_multicast(daddr))
92 		oif = np->mcast_oif;
93 	else if (!oif)
94 		oif = np->ucast_oif;
95 
96 	addr_type = ipv6_addr_type(daddr);
97 	if ((__ipv6_addr_needs_scope_id(addr_type) && !oif) ||
98 	    (addr_type & IPV6_ADDR_MAPPED) ||
99 	    (oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if))
100 		return -EINVAL;
101 
102 	/* TODO: use ip6_datagram_send_ctl to get options from cmsg */
103 
104 	memset(&fl6, 0, sizeof(fl6));
105 
106 	fl6.flowi6_proto = IPPROTO_ICMPV6;
107 	fl6.saddr = np->saddr;
108 	fl6.daddr = *daddr;
109 	fl6.flowi6_oif = oif;
110 	fl6.flowi6_mark = sk->sk_mark;
111 	fl6.flowi6_uid = sk->sk_uid;
112 	fl6.fl6_icmp_type = user_icmph.icmp6_type;
113 	fl6.fl6_icmp_code = user_icmph.icmp6_code;
114 	security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
115 
116 	ipcm6_init_sk(&ipc6, np);
117 	ipc6.sockc.mark = sk->sk_mark;
118 	fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
119 
120 	dst = ip6_sk_dst_lookup_flow(sk, &fl6, daddr, false);
121 	if (IS_ERR(dst))
122 		return PTR_ERR(dst);
123 	rt = (struct rt6_info *) dst;
124 
125 	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
126 		fl6.flowi6_oif = np->mcast_oif;
127 	else if (!fl6.flowi6_oif)
128 		fl6.flowi6_oif = np->ucast_oif;
129 
130 	pfh.icmph.type = user_icmph.icmp6_type;
131 	pfh.icmph.code = user_icmph.icmp6_code;
132 	pfh.icmph.checksum = 0;
133 	pfh.icmph.un.echo.id = inet->inet_sport;
134 	pfh.icmph.un.echo.sequence = user_icmph.icmp6_sequence;
135 	pfh.msg = msg;
136 	pfh.wcheck = 0;
137 	pfh.family = AF_INET6;
138 
139 	ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
140 
141 	lock_sock(sk);
142 	err = ip6_append_data(sk, ping_getfrag, &pfh, len,
143 			      0, &ipc6, &fl6, rt,
144 			      MSG_DONTWAIT);
145 
146 	if (err) {
147 		ICMP6_INC_STATS(sock_net(sk), rt->rt6i_idev,
148 				ICMP6_MIB_OUTERRORS);
149 		ip6_flush_pending_frames(sk);
150 	} else {
151 		icmpv6_push_pending_frames(sk, &fl6,
152 					   (struct icmp6hdr *)&pfh.icmph, len);
153 	}
154 	release_sock(sk);
155 
156 	dst_release(dst);
157 
158 	if (err)
159 		return err;
160 
161 	return len;
162 }
163 
164 struct proto pingv6_prot = {
165 	.name =		"PINGv6",
166 	.owner =	THIS_MODULE,
167 	.init =		ping_init_sock,
168 	.close =	ping_close,
169 	.connect =	ip6_datagram_connect_v6_only,
170 	.disconnect =	__udp_disconnect,
171 	.setsockopt =	ipv6_setsockopt,
172 	.getsockopt =	ipv6_getsockopt,
173 	.sendmsg =	ping_v6_sendmsg,
174 	.recvmsg =	ping_recvmsg,
175 	.bind =		ping_bind,
176 	.backlog_rcv =	ping_queue_rcv_skb,
177 	.hash =		ping_hash,
178 	.unhash =	ping_unhash,
179 	.get_port =	ping_get_port,
180 	.obj_size =	sizeof(struct raw6_sock),
181 };
182 EXPORT_SYMBOL_GPL(pingv6_prot);
183 
184 static struct inet_protosw pingv6_protosw = {
185 	.type =      SOCK_DGRAM,
186 	.protocol =  IPPROTO_ICMPV6,
187 	.prot =      &pingv6_prot,
188 	.ops =       &inet6_sockraw_ops,
189 	.flags =     INET_PROTOSW_REUSE,
190 };
191 
192 #ifdef CONFIG_PROC_FS
193 static void *ping_v6_seq_start(struct seq_file *seq, loff_t *pos)
194 {
195 	return ping_seq_start(seq, pos, AF_INET6);
196 }
197 
198 static int ping_v6_seq_show(struct seq_file *seq, void *v)
199 {
200 	if (v == SEQ_START_TOKEN) {
201 		seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
202 	} else {
203 		int bucket = ((struct ping_iter_state *) seq->private)->bucket;
204 		struct inet_sock *inet = inet_sk(v);
205 		__u16 srcp = ntohs(inet->inet_sport);
206 		__u16 destp = ntohs(inet->inet_dport);
207 		ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
208 	}
209 	return 0;
210 }
211 
212 static const struct seq_operations ping_v6_seq_ops = {
213 	.start		= ping_v6_seq_start,
214 	.show		= ping_v6_seq_show,
215 	.next		= ping_seq_next,
216 	.stop		= ping_seq_stop,
217 };
218 
219 static int __net_init ping_v6_proc_init_net(struct net *net)
220 {
221 	if (!proc_create_net("icmp6", 0444, net->proc_net, &ping_v6_seq_ops,
222 			sizeof(struct ping_iter_state)))
223 		return -ENOMEM;
224 	return 0;
225 }
226 
227 static void __net_exit ping_v6_proc_exit_net(struct net *net)
228 {
229 	remove_proc_entry("icmp6", net->proc_net);
230 }
231 
232 static struct pernet_operations ping_v6_net_ops = {
233 	.init = ping_v6_proc_init_net,
234 	.exit = ping_v6_proc_exit_net,
235 };
236 #endif
237 
238 int __init pingv6_init(void)
239 {
240 #ifdef CONFIG_PROC_FS
241 	int ret = register_pernet_subsys(&ping_v6_net_ops);
242 	if (ret)
243 		return ret;
244 #endif
245 	pingv6_ops.ipv6_recv_error = ipv6_recv_error;
246 	pingv6_ops.ip6_datagram_recv_common_ctl = ip6_datagram_recv_common_ctl;
247 	pingv6_ops.ip6_datagram_recv_specific_ctl =
248 		ip6_datagram_recv_specific_ctl;
249 	pingv6_ops.icmpv6_err_convert = icmpv6_err_convert;
250 	pingv6_ops.ipv6_icmp_error = ipv6_icmp_error;
251 	pingv6_ops.ipv6_chk_addr = ipv6_chk_addr;
252 	return inet6_register_protosw(&pingv6_protosw);
253 }
254 
255 /* This never gets called because it's not possible to unload the ipv6 module,
256  * but just in case.
257  */
258 void pingv6_exit(void)
259 {
260 	pingv6_ops.ipv6_recv_error = dummy_ipv6_recv_error;
261 	pingv6_ops.ip6_datagram_recv_common_ctl = dummy_ip6_datagram_recv_ctl;
262 	pingv6_ops.ip6_datagram_recv_specific_ctl = dummy_ip6_datagram_recv_ctl;
263 	pingv6_ops.icmpv6_err_convert = dummy_icmpv6_err_convert;
264 	pingv6_ops.ipv6_icmp_error = dummy_ipv6_icmp_error;
265 	pingv6_ops.ipv6_chk_addr = dummy_ipv6_chk_addr;
266 #ifdef CONFIG_PROC_FS
267 	unregister_pernet_subsys(&ping_v6_net_ops);
268 #endif
269 	inet6_unregister_protosw(&pingv6_protosw);
270 }
271