net/ipv6/ping.c

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