xref: /linux/net/ipv6/ping.c (revision f79e4d5f92a129a1159c973735007d4ddc8541f3)
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 <linux/proc_fs.h>
28 #include <net/ping.h>
29 
30 /* Compatibility glue so we can support IPv6 when it's compiled as a module */
31 static int dummy_ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
32 				 int *addr_len)
33 {
34 	return -EAFNOSUPPORT;
35 }
36 static void dummy_ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
37 				       struct sk_buff *skb)
38 {
39 }
40 static int dummy_icmpv6_err_convert(u8 type, u8 code, int *err)
41 {
42 	return -EAFNOSUPPORT;
43 }
44 static void dummy_ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
45 				  __be16 port, u32 info, u8 *payload) {}
46 static int dummy_ipv6_chk_addr(struct net *net, const struct in6_addr *addr,
47 			       const struct net_device *dev, int strict)
48 {
49 	return 0;
50 }
51 
52 static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
53 {
54 	struct inet_sock *inet = inet_sk(sk);
55 	struct ipv6_pinfo *np = inet6_sk(sk);
56 	struct icmp6hdr user_icmph;
57 	int addr_type;
58 	struct in6_addr *daddr;
59 	int oif = 0;
60 	struct flowi6 fl6;
61 	int err;
62 	struct dst_entry *dst;
63 	struct rt6_info *rt;
64 	struct pingfakehdr pfh;
65 	struct sockcm_cookie junk = {0};
66 	struct ipcm6_cookie ipc6;
67 
68 	pr_debug("ping_v6_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
69 
70 	err = ping_common_sendmsg(AF_INET6, msg, len, &user_icmph,
71 				  sizeof(user_icmph));
72 	if (err)
73 		return err;
74 
75 	if (msg->msg_name) {
76 		DECLARE_SOCKADDR(struct sockaddr_in6 *, u, msg->msg_name);
77 		if (msg->msg_namelen < sizeof(*u))
78 			return -EINVAL;
79 		if (u->sin6_family != AF_INET6) {
80 			return -EAFNOSUPPORT;
81 		}
82 		daddr = &(u->sin6_addr);
83 		if (__ipv6_addr_needs_scope_id(ipv6_addr_type(daddr)))
84 			oif = u->sin6_scope_id;
85 	} else {
86 		if (sk->sk_state != TCP_ESTABLISHED)
87 			return -EDESTADDRREQ;
88 		daddr = &sk->sk_v6_daddr;
89 	}
90 
91 	if (!oif)
92 		oif = sk->sk_bound_dev_if;
93 
94 	if (!oif)
95 		oif = np->sticky_pktinfo.ipi6_ifindex;
96 
97 	if (!oif && ipv6_addr_is_multicast(daddr))
98 		oif = np->mcast_oif;
99 	else if (!oif)
100 		oif = np->ucast_oif;
101 
102 	addr_type = ipv6_addr_type(daddr);
103 	if ((__ipv6_addr_needs_scope_id(addr_type) && !oif) ||
104 	    (addr_type & IPV6_ADDR_MAPPED) ||
105 	    (oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if))
106 		return -EINVAL;
107 
108 	/* TODO: use ip6_datagram_send_ctl to get options from cmsg */
109 
110 	memset(&fl6, 0, sizeof(fl6));
111 
112 	fl6.flowi6_proto = IPPROTO_ICMPV6;
113 	fl6.saddr = np->saddr;
114 	fl6.daddr = *daddr;
115 	fl6.flowi6_oif = oif;
116 	fl6.flowi6_mark = sk->sk_mark;
117 	fl6.flowi6_uid = sk->sk_uid;
118 	fl6.fl6_icmp_type = user_icmph.icmp6_type;
119 	fl6.fl6_icmp_code = user_icmph.icmp6_code;
120 	security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
121 
122 	ipc6.tclass = np->tclass;
123 	fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
124 
125 	dst = ip6_sk_dst_lookup_flow(sk, &fl6, daddr, false);
126 	if (IS_ERR(dst))
127 		return PTR_ERR(dst);
128 	rt = (struct rt6_info *) dst;
129 
130 	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
131 		fl6.flowi6_oif = np->mcast_oif;
132 	else if (!fl6.flowi6_oif)
133 		fl6.flowi6_oif = np->ucast_oif;
134 
135 	pfh.icmph.type = user_icmph.icmp6_type;
136 	pfh.icmph.code = user_icmph.icmp6_code;
137 	pfh.icmph.checksum = 0;
138 	pfh.icmph.un.echo.id = inet->inet_sport;
139 	pfh.icmph.un.echo.sequence = user_icmph.icmp6_sequence;
140 	pfh.msg = msg;
141 	pfh.wcheck = 0;
142 	pfh.family = AF_INET6;
143 
144 	ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
145 	ipc6.dontfrag = np->dontfrag;
146 	ipc6.opt = NULL;
147 
148 	lock_sock(sk);
149 	err = ip6_append_data(sk, ping_getfrag, &pfh, len,
150 			      0, &ipc6, &fl6, rt,
151 			      MSG_DONTWAIT, &junk);
152 
153 	if (err) {
154 		ICMP6_INC_STATS(sock_net(sk), rt->rt6i_idev,
155 				ICMP6_MIB_OUTERRORS);
156 		ip6_flush_pending_frames(sk);
157 	} else {
158 		icmpv6_push_pending_frames(sk, &fl6,
159 					   (struct icmp6hdr *)&pfh.icmph, len);
160 	}
161 	release_sock(sk);
162 
163 	dst_release(dst);
164 
165 	if (err)
166 		return err;
167 
168 	return len;
169 }
170 
171 struct proto pingv6_prot = {
172 	.name =		"PINGv6",
173 	.owner =	THIS_MODULE,
174 	.init =		ping_init_sock,
175 	.close =	ping_close,
176 	.connect =	ip6_datagram_connect_v6_only,
177 	.disconnect =	__udp_disconnect,
178 	.setsockopt =	ipv6_setsockopt,
179 	.getsockopt =	ipv6_getsockopt,
180 	.sendmsg =	ping_v6_sendmsg,
181 	.recvmsg =	ping_recvmsg,
182 	.bind =		ping_bind,
183 	.backlog_rcv =	ping_queue_rcv_skb,
184 	.hash =		ping_hash,
185 	.unhash =	ping_unhash,
186 	.get_port =	ping_get_port,
187 	.obj_size =	sizeof(struct raw6_sock),
188 };
189 EXPORT_SYMBOL_GPL(pingv6_prot);
190 
191 static struct inet_protosw pingv6_protosw = {
192 	.type =      SOCK_DGRAM,
193 	.protocol =  IPPROTO_ICMPV6,
194 	.prot =      &pingv6_prot,
195 	.ops =       &inet6_sockraw_ops,
196 	.flags =     INET_PROTOSW_REUSE,
197 };
198 
199 #ifdef CONFIG_PROC_FS
200 static void *ping_v6_seq_start(struct seq_file *seq, loff_t *pos)
201 {
202 	return ping_seq_start(seq, pos, AF_INET6);
203 }
204 
205 static int ping_v6_seq_show(struct seq_file *seq, void *v)
206 {
207 	if (v == SEQ_START_TOKEN) {
208 		seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
209 	} else {
210 		int bucket = ((struct ping_iter_state *) seq->private)->bucket;
211 		struct inet_sock *inet = inet_sk(v);
212 		__u16 srcp = ntohs(inet->inet_sport);
213 		__u16 destp = ntohs(inet->inet_dport);
214 		ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
215 	}
216 	return 0;
217 }
218 
219 static const struct seq_operations ping_v6_seq_ops = {
220 	.start		= ping_v6_seq_start,
221 	.show		= ping_v6_seq_show,
222 	.next		= ping_seq_next,
223 	.stop		= ping_seq_stop,
224 };
225 
226 static int __net_init ping_v6_proc_init_net(struct net *net)
227 {
228 	if (!proc_create_net("icmp6", 0444, net->proc_net, &ping_v6_seq_ops,
229 			sizeof(struct ping_iter_state)))
230 		return -ENOMEM;
231 	return 0;
232 }
233 
234 static void __net_init ping_v6_proc_exit_net(struct net *net)
235 {
236 	remove_proc_entry("icmp6", net->proc_net);
237 }
238 
239 static struct pernet_operations ping_v6_net_ops = {
240 	.init = ping_v6_proc_init_net,
241 	.exit = ping_v6_proc_exit_net,
242 };
243 #endif
244 
245 int __init pingv6_init(void)
246 {
247 #ifdef CONFIG_PROC_FS
248 	int ret = register_pernet_subsys(&ping_v6_net_ops);
249 	if (ret)
250 		return ret;
251 #endif
252 	pingv6_ops.ipv6_recv_error = ipv6_recv_error;
253 	pingv6_ops.ip6_datagram_recv_common_ctl = ip6_datagram_recv_common_ctl;
254 	pingv6_ops.ip6_datagram_recv_specific_ctl =
255 		ip6_datagram_recv_specific_ctl;
256 	pingv6_ops.icmpv6_err_convert = icmpv6_err_convert;
257 	pingv6_ops.ipv6_icmp_error = ipv6_icmp_error;
258 	pingv6_ops.ipv6_chk_addr = ipv6_chk_addr;
259 	return inet6_register_protosw(&pingv6_protosw);
260 }
261 
262 /* This never gets called because it's not possible to unload the ipv6 module,
263  * but just in case.
264  */
265 void pingv6_exit(void)
266 {
267 	pingv6_ops.ipv6_recv_error = dummy_ipv6_recv_error;
268 	pingv6_ops.ip6_datagram_recv_common_ctl = dummy_ip6_datagram_recv_ctl;
269 	pingv6_ops.ip6_datagram_recv_specific_ctl = dummy_ip6_datagram_recv_ctl;
270 	pingv6_ops.icmpv6_err_convert = dummy_icmpv6_err_convert;
271 	pingv6_ops.ipv6_icmp_error = dummy_ipv6_icmp_error;
272 	pingv6_ops.ipv6_chk_addr = dummy_ipv6_chk_addr;
273 #ifdef CONFIG_PROC_FS
274 	unregister_pernet_subsys(&ping_v6_net_ops);
275 #endif
276 	inet6_unregister_protosw(&pingv6_protosw);
277 }
278