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 <linux/bpf-cgroup.h>
24 #include <net/ping.h>
25
26 /* Compatibility glue so we can support IPv6 when it's compiled as a module */
dummy_ipv6_recv_error(struct sock * sk,struct msghdr * msg,int len,int * addr_len)27 static int dummy_ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
28 int *addr_len)
29 {
30 return -EAFNOSUPPORT;
31 }
dummy_ip6_datagram_recv_ctl(struct sock * sk,struct msghdr * msg,struct sk_buff * skb)32 static void dummy_ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
33 struct sk_buff *skb)
34 {
35 }
dummy_icmpv6_err_convert(u8 type,u8 code,int * err)36 static int dummy_icmpv6_err_convert(u8 type, u8 code, int *err)
37 {
38 return -EAFNOSUPPORT;
39 }
dummy_ipv6_icmp_error(struct sock * sk,struct sk_buff * skb,int err,__be16 port,u32 info,u8 * payload)40 static void dummy_ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
41 __be16 port, u32 info, u8 *payload) {}
dummy_ipv6_chk_addr(struct net * net,const struct in6_addr * addr,const struct net_device * dev,int strict)42 static int dummy_ipv6_chk_addr(struct net *net, const struct in6_addr *addr,
43 const struct net_device *dev, int strict)
44 {
45 return 0;
46 }
47
ping_v6_pre_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)48 static int ping_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
49 int addr_len)
50 {
51 /* This check is replicated from __ip6_datagram_connect() and
52 * intended to prevent BPF program called below from accessing
53 * bytes that are out of the bound specified by user in addr_len.
54 */
55
56 if (addr_len < SIN6_LEN_RFC2133)
57 return -EINVAL;
58
59 return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr, &addr_len);
60 }
61
ping_v6_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)62 static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
63 {
64 struct inet_sock *inet = inet_sk(sk);
65 struct ipv6_pinfo *np = inet6_sk(sk);
66 struct icmp6hdr user_icmph;
67 int addr_type;
68 struct in6_addr *daddr;
69 int oif = 0;
70 struct flowi6 fl6;
71 int err;
72 struct dst_entry *dst;
73 struct rt6_info *rt;
74 struct pingfakehdr pfh;
75 struct ipcm6_cookie ipc6;
76
77 err = ping_common_sendmsg(AF_INET6, msg, len, &user_icmph,
78 sizeof(user_icmph));
79 if (err)
80 return err;
81
82 memset(&fl6, 0, sizeof(fl6));
83
84 if (msg->msg_name) {
85 DECLARE_SOCKADDR(struct sockaddr_in6 *, u, msg->msg_name);
86 if (msg->msg_namelen < sizeof(*u))
87 return -EINVAL;
88 if (u->sin6_family != AF_INET6) {
89 return -EAFNOSUPPORT;
90 }
91 daddr = &(u->sin6_addr);
92 if (inet6_test_bit(SNDFLOW, sk))
93 fl6.flowlabel = u->sin6_flowinfo & IPV6_FLOWINFO_MASK;
94 if (__ipv6_addr_needs_scope_id(ipv6_addr_type(daddr)))
95 oif = u->sin6_scope_id;
96 } else {
97 if (sk->sk_state != TCP_ESTABLISHED)
98 return -EDESTADDRREQ;
99 daddr = &sk->sk_v6_daddr;
100 fl6.flowlabel = np->flow_label;
101 }
102
103 if (!oif)
104 oif = sk->sk_bound_dev_if;
105
106 if (!oif)
107 oif = np->sticky_pktinfo.ipi6_ifindex;
108
109 if (!oif && ipv6_addr_is_multicast(daddr))
110 oif = READ_ONCE(np->mcast_oif);
111 else if (!oif)
112 oif = READ_ONCE(np->ucast_oif);
113
114 addr_type = ipv6_addr_type(daddr);
115 if ((__ipv6_addr_needs_scope_id(addr_type) && !oif) ||
116 (addr_type & IPV6_ADDR_MAPPED) ||
117 (oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if &&
118 l3mdev_master_ifindex_by_index(sock_net(sk), oif) != sk->sk_bound_dev_if))
119 return -EINVAL;
120
121 ipcm6_init_sk(&ipc6, sk);
122
123 fl6.flowi6_oif = oif;
124
125 if (msg->msg_controllen) {
126 struct ipv6_txoptions opt = {};
127
128 opt.tot_len = sizeof(opt);
129 ipc6.opt = &opt;
130
131 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6);
132 if (err < 0)
133 return err;
134
135 /* Changes to txoptions and flow info are not implemented, yet.
136 * Drop the options.
137 */
138 ipc6.opt = NULL;
139 }
140
141 fl6.flowi6_proto = IPPROTO_ICMPV6;
142 fl6.saddr = np->saddr;
143 fl6.daddr = *daddr;
144 fl6.flowi6_mark = ipc6.sockc.mark;
145 fl6.flowi6_uid = sk->sk_uid;
146 fl6.fl6_icmp_type = user_icmph.icmp6_type;
147 fl6.fl6_icmp_code = user_icmph.icmp6_code;
148 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
149
150 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
151
152 dst = ip6_sk_dst_lookup_flow(sk, &fl6, daddr, false);
153 if (IS_ERR(dst))
154 return PTR_ERR(dst);
155 rt = dst_rt6_info(dst);
156
157 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
158 fl6.flowi6_oif = READ_ONCE(np->mcast_oif);
159 else if (!fl6.flowi6_oif)
160 fl6.flowi6_oif = READ_ONCE(np->ucast_oif);
161
162 pfh.icmph.type = user_icmph.icmp6_type;
163 pfh.icmph.code = user_icmph.icmp6_code;
164 pfh.icmph.checksum = 0;
165 pfh.icmph.un.echo.id = inet->inet_sport;
166 pfh.icmph.un.echo.sequence = user_icmph.icmp6_sequence;
167 pfh.msg = msg;
168 pfh.wcheck = 0;
169 pfh.family = AF_INET6;
170
171 if (ipc6.hlimit < 0)
172 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
173
174 lock_sock(sk);
175 err = ip6_append_data(sk, ping_getfrag, &pfh, len,
176 sizeof(struct icmp6hdr), &ipc6, &fl6, rt,
177 MSG_DONTWAIT);
178
179 if (err) {
180 ICMP6_INC_STATS(sock_net(sk), rt->rt6i_idev,
181 ICMP6_MIB_OUTERRORS);
182 ip6_flush_pending_frames(sk);
183 } else {
184 icmpv6_push_pending_frames(sk, &fl6,
185 (struct icmp6hdr *)&pfh.icmph, len);
186 }
187 release_sock(sk);
188
189 dst_release(dst);
190
191 if (err)
192 return err;
193
194 return len;
195 }
196
197 struct proto pingv6_prot = {
198 .name = "PINGv6",
199 .owner = THIS_MODULE,
200 .init = ping_init_sock,
201 .close = ping_close,
202 .pre_connect = ping_v6_pre_connect,
203 .connect = ip6_datagram_connect_v6_only,
204 .disconnect = __udp_disconnect,
205 .setsockopt = ipv6_setsockopt,
206 .getsockopt = ipv6_getsockopt,
207 .sendmsg = ping_v6_sendmsg,
208 .recvmsg = ping_recvmsg,
209 .bind = ping_bind,
210 .backlog_rcv = ping_queue_rcv_skb,
211 .hash = ping_hash,
212 .unhash = ping_unhash,
213 .get_port = ping_get_port,
214 .put_port = ping_unhash,
215 .obj_size = sizeof(struct raw6_sock),
216 .ipv6_pinfo_offset = offsetof(struct raw6_sock, inet6),
217 };
218 EXPORT_SYMBOL_GPL(pingv6_prot);
219
220 static struct inet_protosw pingv6_protosw = {
221 .type = SOCK_DGRAM,
222 .protocol = IPPROTO_ICMPV6,
223 .prot = &pingv6_prot,
224 .ops = &inet6_sockraw_ops,
225 .flags = INET_PROTOSW_REUSE,
226 };
227
228 #ifdef CONFIG_PROC_FS
ping_v6_seq_start(struct seq_file * seq,loff_t * pos)229 static void *ping_v6_seq_start(struct seq_file *seq, loff_t *pos)
230 {
231 return ping_seq_start(seq, pos, AF_INET6);
232 }
233
ping_v6_seq_show(struct seq_file * seq,void * v)234 static int ping_v6_seq_show(struct seq_file *seq, void *v)
235 {
236 if (v == SEQ_START_TOKEN) {
237 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
238 } else {
239 int bucket = ((struct ping_iter_state *) seq->private)->bucket;
240 struct inet_sock *inet = inet_sk((struct sock *)v);
241 __u16 srcp = ntohs(inet->inet_sport);
242 __u16 destp = ntohs(inet->inet_dport);
243 ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
244 }
245 return 0;
246 }
247
248 static const struct seq_operations ping_v6_seq_ops = {
249 .start = ping_v6_seq_start,
250 .show = ping_v6_seq_show,
251 .next = ping_seq_next,
252 .stop = ping_seq_stop,
253 };
254
ping_v6_proc_init_net(struct net * net)255 static int __net_init ping_v6_proc_init_net(struct net *net)
256 {
257 if (!proc_create_net("icmp6", 0444, net->proc_net, &ping_v6_seq_ops,
258 sizeof(struct ping_iter_state)))
259 return -ENOMEM;
260 return 0;
261 }
262
ping_v6_proc_exit_net(struct net * net)263 static void __net_exit ping_v6_proc_exit_net(struct net *net)
264 {
265 remove_proc_entry("icmp6", net->proc_net);
266 }
267
268 static struct pernet_operations ping_v6_net_ops = {
269 .init = ping_v6_proc_init_net,
270 .exit = ping_v6_proc_exit_net,
271 };
272 #endif
273
pingv6_init(void)274 int __init pingv6_init(void)
275 {
276 #ifdef CONFIG_PROC_FS
277 int ret = register_pernet_subsys(&ping_v6_net_ops);
278 if (ret)
279 return ret;
280 #endif
281 pingv6_ops.ipv6_recv_error = ipv6_recv_error;
282 pingv6_ops.ip6_datagram_recv_common_ctl = ip6_datagram_recv_common_ctl;
283 pingv6_ops.ip6_datagram_recv_specific_ctl =
284 ip6_datagram_recv_specific_ctl;
285 pingv6_ops.icmpv6_err_convert = icmpv6_err_convert;
286 pingv6_ops.ipv6_icmp_error = ipv6_icmp_error;
287 pingv6_ops.ipv6_chk_addr = ipv6_chk_addr;
288 return inet6_register_protosw(&pingv6_protosw);
289 }
290
291 /* This never gets called because it's not possible to unload the ipv6 module,
292 * but just in case.
293 */
pingv6_exit(void)294 void pingv6_exit(void)
295 {
296 pingv6_ops.ipv6_recv_error = dummy_ipv6_recv_error;
297 pingv6_ops.ip6_datagram_recv_common_ctl = dummy_ip6_datagram_recv_ctl;
298 pingv6_ops.ip6_datagram_recv_specific_ctl = dummy_ip6_datagram_recv_ctl;
299 pingv6_ops.icmpv6_err_convert = dummy_icmpv6_err_convert;
300 pingv6_ops.ipv6_icmp_error = dummy_ipv6_icmp_error;
301 pingv6_ops.ipv6_chk_addr = dummy_ipv6_chk_addr;
302 #ifdef CONFIG_PROC_FS
303 unregister_pernet_subsys(&ping_v6_net_ops);
304 #endif
305 inet6_unregister_protosw(&pingv6_protosw);
306 }
307