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