linux/net/ipv6/ping.c
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   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_common(&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}
 271