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 */
 26static int dummy_ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
 27				 int *addr_len)
 28{
 29	return -EAFNOSUPPORT;
 30}
 31static void dummy_ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 32				       struct sk_buff *skb)
 33{
 34}
 35static int dummy_icmpv6_err_convert(u8 type, u8 code, int *err)
 36{
 37	return -EAFNOSUPPORT;
 38}
 39static void dummy_ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 40				  __be16 port, u32 info, u8 *payload) {}
 41static 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
 47static 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(&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
164struct 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};
182EXPORT_SYMBOL_GPL(pingv6_prot);
183
184static 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
193static void *ping_v6_seq_start(struct seq_file *seq, loff_t *pos)
194{
195	return ping_seq_start(seq, pos, AF_INET6);
196}
197
198static 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
212static 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
219static 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
227static void __net_exit ping_v6_proc_exit_net(struct net *net)
228{
229	remove_proc_entry("icmp6", net->proc_net);
230}
231
232static 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
238int __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 */
258void 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}