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
ping_v6_destroy(struct sock * sk)26 static void ping_v6_destroy(struct sock *sk)
27 {
28 inet6_destroy_sock(sk);
29 }
30
31 /* 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)32 static int dummy_ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
33 int *addr_len)
34 {
35 return -EAFNOSUPPORT;
36 }
dummy_ip6_datagram_recv_ctl(struct sock * sk,struct msghdr * msg,struct sk_buff * skb)37 static void dummy_ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
38 struct sk_buff *skb)
39 {
40 }
dummy_icmpv6_err_convert(u8 type,u8 code,int * err)41 static int dummy_icmpv6_err_convert(u8 type, u8 code, int *err)
42 {
43 return -EAFNOSUPPORT;
44 }
dummy_ipv6_icmp_error(struct sock * sk,struct sk_buff * skb,int err,__be16 port,u32 info,u8 * payload)45 static void dummy_ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
46 __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)47 static int dummy_ipv6_chk_addr(struct net *net, const struct in6_addr *addr,
48 const struct net_device *dev, int strict)
49 {
50 return 0;
51 }
52
ping_v6_pre_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)53 static int ping_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
54 int addr_len)
55 {
56 /* This check is replicated from __ip6_datagram_connect() and
57 * intended to prevent BPF program called below from accessing
58 * bytes that are out of the bound specified by user in addr_len.
59 */
60
61 if (addr_len < SIN6_LEN_RFC2133)
62 return -EINVAL;
63
64 return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr);
65 }
66
ping_v6_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)67 static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
68 {
69 struct inet_sock *inet = inet_sk(sk);
70 struct ipv6_pinfo *np = inet6_sk(sk);
71 struct icmp6hdr user_icmph;
72 int addr_type;
73 struct in6_addr *daddr;
74 int oif = 0;
75 struct flowi6 fl6;
76 int err;
77 struct dst_entry *dst;
78 struct rt6_info *rt;
79 struct pingfakehdr pfh;
80 struct ipcm6_cookie ipc6;
81
82 err = ping_common_sendmsg(AF_INET6, msg, len, &user_icmph,
83 sizeof(user_icmph));
84 if (err)
85 return err;
86
87 memset(&fl6, 0, sizeof(fl6));
88
89 if (msg->msg_name) {
90 DECLARE_SOCKADDR(struct sockaddr_in6 *, u, msg->msg_name);
91 if (msg->msg_namelen < sizeof(*u))
92 return -EINVAL;
93 if (u->sin6_family != AF_INET6) {
94 return -EAFNOSUPPORT;
95 }
96 daddr = &(u->sin6_addr);
97 if (np->sndflow)
98 fl6.flowlabel = u->sin6_flowinfo & IPV6_FLOWINFO_MASK;
99 if (__ipv6_addr_needs_scope_id(ipv6_addr_type(daddr)))
100 oif = u->sin6_scope_id;
101 } else {
102 if (sk->sk_state != TCP_ESTABLISHED)
103 return -EDESTADDRREQ;
104 daddr = &sk->sk_v6_daddr;
105 fl6.flowlabel = np->flow_label;
106 }
107
108 if (!oif)
109 oif = sk->sk_bound_dev_if;
110
111 if (!oif)
112 oif = np->sticky_pktinfo.ipi6_ifindex;
113
114 if (!oif && ipv6_addr_is_multicast(daddr))
115 oif = np->mcast_oif;
116 else if (!oif)
117 oif = np->ucast_oif;
118
119 addr_type = ipv6_addr_type(daddr);
120 if ((__ipv6_addr_needs_scope_id(addr_type) && !oif) ||
121 (addr_type & IPV6_ADDR_MAPPED) ||
122 (oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if))
123 return -EINVAL;
124
125 ipcm6_init_sk(&ipc6, np);
126 ipc6.sockc.tsflags = sk->sk_tsflags;
127 ipc6.sockc.mark = sk->sk_mark;
128
129 fl6.flowi6_oif = oif;
130
131 if (msg->msg_controllen) {
132 struct ipv6_txoptions opt = {};
133
134 opt.tot_len = sizeof(opt);
135 ipc6.opt = &opt;
136
137 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6);
138 if (err < 0)
139 return err;
140
141 /* Changes to txoptions and flow info are not implemented, yet.
142 * Drop the options.
143 */
144 ipc6.opt = NULL;
145 }
146
147 fl6.flowi6_proto = IPPROTO_ICMPV6;
148 fl6.saddr = np->saddr;
149 fl6.daddr = *daddr;
150 fl6.flowi6_mark = ipc6.sockc.mark;
151 fl6.flowi6_uid = sk->sk_uid;
152 fl6.fl6_icmp_type = user_icmph.icmp6_type;
153 fl6.fl6_icmp_code = user_icmph.icmp6_code;
154 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
155
156 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
157
158 dst = ip6_sk_dst_lookup_flow(sk, &fl6, daddr, false);
159 if (IS_ERR(dst))
160 return PTR_ERR(dst);
161 rt = (struct rt6_info *) dst;
162
163 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
164 fl6.flowi6_oif = np->mcast_oif;
165 else if (!fl6.flowi6_oif)
166 fl6.flowi6_oif = np->ucast_oif;
167
168 pfh.icmph.type = user_icmph.icmp6_type;
169 pfh.icmph.code = user_icmph.icmp6_code;
170 pfh.icmph.checksum = 0;
171 pfh.icmph.un.echo.id = inet->inet_sport;
172 pfh.icmph.un.echo.sequence = user_icmph.icmp6_sequence;
173 pfh.msg = msg;
174 pfh.wcheck = 0;
175 pfh.family = AF_INET6;
176
177 if (ipc6.hlimit < 0)
178 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
179
180 lock_sock(sk);
181 err = ip6_append_data(sk, ping_getfrag, &pfh, len,
182 sizeof(struct icmp6hdr), &ipc6, &fl6, rt,
183 MSG_DONTWAIT);
184
185 if (err) {
186 ICMP6_INC_STATS(sock_net(sk), rt->rt6i_idev,
187 ICMP6_MIB_OUTERRORS);
188 ip6_flush_pending_frames(sk);
189 } else {
190 icmpv6_push_pending_frames(sk, &fl6,
191 (struct icmp6hdr *)&pfh.icmph, len);
192 }
193 release_sock(sk);
194
195 dst_release(dst);
196
197 if (err)
198 return err;
199
200 return len;
201 }
202
203 struct proto pingv6_prot = {
204 .name = "PINGv6",
205 .owner = THIS_MODULE,
206 .init = ping_init_sock,
207 .close = ping_close,
208 .destroy = ping_v6_destroy,
209 .pre_connect = ping_v6_pre_connect,
210 .connect = ip6_datagram_connect_v6_only,
211 .disconnect = __udp_disconnect,
212 .setsockopt = ipv6_setsockopt,
213 .getsockopt = ipv6_getsockopt,
214 .sendmsg = ping_v6_sendmsg,
215 .recvmsg = ping_recvmsg,
216 .bind = ping_bind,
217 .backlog_rcv = ping_queue_rcv_skb,
218 .hash = ping_hash,
219 .unhash = ping_unhash,
220 .get_port = ping_get_port,
221 .put_port = ping_unhash,
222 .obj_size = sizeof(struct raw6_sock),
223 };
224 EXPORT_SYMBOL_GPL(pingv6_prot);
225
226 static struct inet_protosw pingv6_protosw = {
227 .type = SOCK_DGRAM,
228 .protocol = IPPROTO_ICMPV6,
229 .prot = &pingv6_prot,
230 .ops = &inet6_sockraw_ops,
231 .flags = INET_PROTOSW_REUSE,
232 };
233
234 #ifdef CONFIG_PROC_FS
ping_v6_seq_start(struct seq_file * seq,loff_t * pos)235 static void *ping_v6_seq_start(struct seq_file *seq, loff_t *pos)
236 {
237 return ping_seq_start(seq, pos, AF_INET6);
238 }
239
ping_v6_seq_show(struct seq_file * seq,void * v)240 static int ping_v6_seq_show(struct seq_file *seq, void *v)
241 {
242 if (v == SEQ_START_TOKEN) {
243 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
244 } else {
245 int bucket = ((struct ping_iter_state *) seq->private)->bucket;
246 struct inet_sock *inet = inet_sk(v);
247 __u16 srcp = ntohs(inet->inet_sport);
248 __u16 destp = ntohs(inet->inet_dport);
249 ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
250 }
251 return 0;
252 }
253
254 static const struct seq_operations ping_v6_seq_ops = {
255 .start = ping_v6_seq_start,
256 .show = ping_v6_seq_show,
257 .next = ping_seq_next,
258 .stop = ping_seq_stop,
259 };
260
ping_v6_proc_init_net(struct net * net)261 static int __net_init ping_v6_proc_init_net(struct net *net)
262 {
263 if (!proc_create_net("icmp6", 0444, net->proc_net, &ping_v6_seq_ops,
264 sizeof(struct ping_iter_state)))
265 return -ENOMEM;
266 return 0;
267 }
268
ping_v6_proc_exit_net(struct net * net)269 static void __net_exit ping_v6_proc_exit_net(struct net *net)
270 {
271 remove_proc_entry("icmp6", net->proc_net);
272 }
273
274 static struct pernet_operations ping_v6_net_ops = {
275 .init = ping_v6_proc_init_net,
276 .exit = ping_v6_proc_exit_net,
277 };
278 #endif
279
pingv6_init(void)280 int __init pingv6_init(void)
281 {
282 #ifdef CONFIG_PROC_FS
283 int ret = register_pernet_subsys(&ping_v6_net_ops);
284 if (ret)
285 return ret;
286 #endif
287 pingv6_ops.ipv6_recv_error = ipv6_recv_error;
288 pingv6_ops.ip6_datagram_recv_common_ctl = ip6_datagram_recv_common_ctl;
289 pingv6_ops.ip6_datagram_recv_specific_ctl =
290 ip6_datagram_recv_specific_ctl;
291 pingv6_ops.icmpv6_err_convert = icmpv6_err_convert;
292 pingv6_ops.ipv6_icmp_error = ipv6_icmp_error;
293 pingv6_ops.ipv6_chk_addr = ipv6_chk_addr;
294 return inet6_register_protosw(&pingv6_protosw);
295 }
296
297 /* This never gets called because it's not possible to unload the ipv6 module,
298 * but just in case.
299 */
pingv6_exit(void)300 void pingv6_exit(void)
301 {
302 pingv6_ops.ipv6_recv_error = dummy_ipv6_recv_error;
303 pingv6_ops.ip6_datagram_recv_common_ctl = dummy_ip6_datagram_recv_ctl;
304 pingv6_ops.ip6_datagram_recv_specific_ctl = dummy_ip6_datagram_recv_ctl;
305 pingv6_ops.icmpv6_err_convert = dummy_icmpv6_err_convert;
306 pingv6_ops.ipv6_icmp_error = dummy_ipv6_icmp_error;
307 pingv6_ops.ipv6_chk_addr = dummy_ipv6_chk_addr;
308 #ifdef CONFIG_PROC_FS
309 unregister_pernet_subsys(&ping_v6_net_ops);
310 #endif
311 inet6_unregister_protosw(&pingv6_protosw);
312 }
313
