xref: /linux/net/ipv6/ping.c (revision 5ef12cb4a3a78ffb331c03a795a15eea4ae35155)
1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		"Ping" sockets
7  *
8  *		This program is free software; you can redistribute it and/or
9  *		modify it under the terms of the GNU General Public License
10  *		as published by the Free Software Foundation; either version
11  *		2 of the License, or (at your option) any later version.
12  *
13  * Based on ipv4/ping.c code.
14  *
15  * Authors:	Lorenzo Colitti (IPv6 support)
16  *		Vasiliy Kulikov / Openwall (IPv4 implementation, for Linux 2.6),
17  *		Pavel Kankovsky (IPv4 implementation, for Linux 2.4.32)
18  *
19  */
20 
21 #include <net/addrconf.h>
22 #include <net/ipv6.h>
23 #include <net/ip6_route.h>
24 #include <net/protocol.h>
25 #include <net/udp.h>
26 #include <net/transp_v6.h>
27 #include <net/ping.h>
28 
29 /* Compatibility glue so we can support IPv6 when it's compiled as a module */
30 static int dummy_ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
31 				 int *addr_len)
32 {
33 	return -EAFNOSUPPORT;
34 }
35 static void dummy_ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
36 				       struct sk_buff *skb)
37 {
38 }
39 static int dummy_icmpv6_err_convert(u8 type, u8 code, int *err)
40 {
41 	return -EAFNOSUPPORT;
42 }
43 static void dummy_ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
44 				  __be16 port, u32 info, u8 *payload) {}
45 static int dummy_ipv6_chk_addr(struct net *net, const struct in6_addr *addr,
46 			       const struct net_device *dev, int strict)
47 {
48 	return 0;
49 }
50 
51 static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
52 {
53 	struct inet_sock *inet = inet_sk(sk);
54 	struct ipv6_pinfo *np = inet6_sk(sk);
55 	struct icmp6hdr user_icmph;
56 	int addr_type;
57 	struct in6_addr *daddr;
58 	int oif = 0;
59 	struct flowi6 fl6;
60 	int err;
61 	struct dst_entry *dst;
62 	struct rt6_info *rt;
63 	struct pingfakehdr pfh;
64 	struct sockcm_cookie junk = {0};
65 	struct ipcm6_cookie ipc6;
66 
67 	pr_debug("ping_v6_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
68 
69 	err = ping_common_sendmsg(AF_INET6, msg, len, &user_icmph,
70 				  sizeof(user_icmph));
71 	if (err)
72 		return err;
73 
74 	if (msg->msg_name) {
75 		DECLARE_SOCKADDR(struct sockaddr_in6 *, u, msg->msg_name);
76 		if (msg->msg_namelen < sizeof(*u))
77 			return -EINVAL;
78 		if (u->sin6_family != AF_INET6) {
79 			return -EAFNOSUPPORT;
80 		}
81 		daddr = &(u->sin6_addr);
82 		if (__ipv6_addr_needs_scope_id(ipv6_addr_type(daddr)))
83 			oif = u->sin6_scope_id;
84 	} else {
85 		if (sk->sk_state != TCP_ESTABLISHED)
86 			return -EDESTADDRREQ;
87 		daddr = &sk->sk_v6_daddr;
88 	}
89 
90 	if (!oif)
91 		oif = sk->sk_bound_dev_if;
92 
93 	if (!oif)
94 		oif = np->sticky_pktinfo.ipi6_ifindex;
95 
96 	if (!oif && ipv6_addr_is_multicast(daddr))
97 		oif = np->mcast_oif;
98 	else if (!oif)
99 		oif = np->ucast_oif;
100 
101 	addr_type = ipv6_addr_type(daddr);
102 	if ((__ipv6_addr_needs_scope_id(addr_type) && !oif) ||
103 	    (addr_type & IPV6_ADDR_MAPPED) ||
104 	    (oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if))
105 		return -EINVAL;
106 
107 	/* TODO: use ip6_datagram_send_ctl to get options from cmsg */
108 
109 	memset(&fl6, 0, sizeof(fl6));
110 
111 	fl6.flowi6_proto = IPPROTO_ICMPV6;
112 	fl6.saddr = np->saddr;
113 	fl6.daddr = *daddr;
114 	fl6.flowi6_oif = oif;
115 	fl6.flowi6_mark = sk->sk_mark;
116 	fl6.flowi6_uid = sk->sk_uid;
117 	fl6.fl6_icmp_type = user_icmph.icmp6_type;
118 	fl6.fl6_icmp_code = user_icmph.icmp6_code;
119 	security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
120 
121 	ipc6.tclass = np->tclass;
122 	fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
123 
124 	dst = ip6_sk_dst_lookup_flow(sk, &fl6, daddr, false);
125 	if (IS_ERR(dst))
126 		return PTR_ERR(dst);
127 	rt = (struct rt6_info *) dst;
128 
129 	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
130 		fl6.flowi6_oif = np->mcast_oif;
131 	else if (!fl6.flowi6_oif)
132 		fl6.flowi6_oif = np->ucast_oif;
133 
134 	pfh.icmph.type = user_icmph.icmp6_type;
135 	pfh.icmph.code = user_icmph.icmp6_code;
136 	pfh.icmph.checksum = 0;
137 	pfh.icmph.un.echo.id = inet->inet_sport;
138 	pfh.icmph.un.echo.sequence = user_icmph.icmp6_sequence;
139 	pfh.msg = msg;
140 	pfh.wcheck = 0;
141 	pfh.family = AF_INET6;
142 
143 	ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
144 	ipc6.dontfrag = np->dontfrag;
145 	ipc6.opt = NULL;
146 
147 	lock_sock(sk);
148 	err = ip6_append_data(sk, ping_getfrag, &pfh, len,
149 			      0, &ipc6, &fl6, rt,
150 			      MSG_DONTWAIT, &junk);
151 
152 	if (err) {
153 		ICMP6_INC_STATS(sock_net(sk), rt->rt6i_idev,
154 				ICMP6_MIB_OUTERRORS);
155 		ip6_flush_pending_frames(sk);
156 	} else {
157 		icmpv6_push_pending_frames(sk, &fl6,
158 					   (struct icmp6hdr *)&pfh.icmph, len);
159 	}
160 	release_sock(sk);
161 
162 	dst_release(dst);
163 
164 	if (err)
165 		return err;
166 
167 	return len;
168 }
169 
170 struct proto pingv6_prot = {
171 	.name =		"PINGv6",
172 	.owner =	THIS_MODULE,
173 	.init =		ping_init_sock,
174 	.close =	ping_close,
175 	.connect =	ip6_datagram_connect_v6_only,
176 	.disconnect =	__udp_disconnect,
177 	.setsockopt =	ipv6_setsockopt,
178 	.getsockopt =	ipv6_getsockopt,
179 	.sendmsg =	ping_v6_sendmsg,
180 	.recvmsg =	ping_recvmsg,
181 	.bind =		ping_bind,
182 	.backlog_rcv =	ping_queue_rcv_skb,
183 	.hash =		ping_hash,
184 	.unhash =	ping_unhash,
185 	.get_port =	ping_get_port,
186 	.obj_size =	sizeof(struct raw6_sock),
187 };
188 EXPORT_SYMBOL_GPL(pingv6_prot);
189 
190 static struct inet_protosw pingv6_protosw = {
191 	.type =      SOCK_DGRAM,
192 	.protocol =  IPPROTO_ICMPV6,
193 	.prot =      &pingv6_prot,
194 	.ops =       &inet6_sockraw_ops,
195 	.flags =     INET_PROTOSW_REUSE,
196 };
197 
198 #ifdef CONFIG_PROC_FS
199 static void *ping_v6_seq_start(struct seq_file *seq, loff_t *pos)
200 {
201 	return ping_seq_start(seq, pos, AF_INET6);
202 }
203 
204 static int ping_v6_seq_show(struct seq_file *seq, void *v)
205 {
206 	if (v == SEQ_START_TOKEN) {
207 		seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
208 	} else {
209 		int bucket = ((struct ping_iter_state *) seq->private)->bucket;
210 		struct inet_sock *inet = inet_sk(v);
211 		__u16 srcp = ntohs(inet->inet_sport);
212 		__u16 destp = ntohs(inet->inet_dport);
213 		ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
214 	}
215 	return 0;
216 }
217 
218 static struct ping_seq_afinfo ping_v6_seq_afinfo = {
219 	.name		= "icmp6",
220 	.family		= AF_INET6,
221 	.seq_fops       = &ping_seq_fops,
222 	.seq_ops	= {
223 		.start		= ping_v6_seq_start,
224 		.show		= ping_v6_seq_show,
225 		.next		= ping_seq_next,
226 		.stop		= ping_seq_stop,
227 	},
228 };
229 
230 static int __net_init ping_v6_proc_init_net(struct net *net)
231 {
232 	return ping_proc_register(net, &ping_v6_seq_afinfo);
233 }
234 
235 static void __net_init ping_v6_proc_exit_net(struct net *net)
236 {
237 	return ping_proc_unregister(net, &ping_v6_seq_afinfo);
238 }
239 
240 static struct pernet_operations ping_v6_net_ops = {
241 	.init = ping_v6_proc_init_net,
242 	.exit = ping_v6_proc_exit_net,
243 };
244 #endif
245 
246 int __init pingv6_init(void)
247 {
248 #ifdef CONFIG_PROC_FS
249 	int ret = register_pernet_subsys(&ping_v6_net_ops);
250 	if (ret)
251 		return ret;
252 #endif
253 	pingv6_ops.ipv6_recv_error = ipv6_recv_error;
254 	pingv6_ops.ip6_datagram_recv_common_ctl = ip6_datagram_recv_common_ctl;
255 	pingv6_ops.ip6_datagram_recv_specific_ctl =
256 		ip6_datagram_recv_specific_ctl;
257 	pingv6_ops.icmpv6_err_convert = icmpv6_err_convert;
258 	pingv6_ops.ipv6_icmp_error = ipv6_icmp_error;
259 	pingv6_ops.ipv6_chk_addr = ipv6_chk_addr;
260 	return inet6_register_protosw(&pingv6_protosw);
261 }
262 
263 /* This never gets called because it's not possible to unload the ipv6 module,
264  * but just in case.
265  */
266 void pingv6_exit(void)
267 {
268 	pingv6_ops.ipv6_recv_error = dummy_ipv6_recv_error;
269 	pingv6_ops.ip6_datagram_recv_common_ctl = dummy_ip6_datagram_recv_ctl;
270 	pingv6_ops.ip6_datagram_recv_specific_ctl = dummy_ip6_datagram_recv_ctl;
271 	pingv6_ops.icmpv6_err_convert = dummy_icmpv6_err_convert;
272 	pingv6_ops.ipv6_icmp_error = dummy_ipv6_icmp_error;
273 	pingv6_ops.ipv6_chk_addr = dummy_ipv6_chk_addr;
274 #ifdef CONFIG_PROC_FS
275 	unregister_pernet_subsys(&ping_v6_net_ops);
276 #endif
277 	inet6_unregister_protosw(&pingv6_protosw);
278 }
279