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         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              l3mdev_master_ifindex_by_index(sock_net(sk), oif) != sk->sk_bound_dev_if))
 101                 return -EINVAL;
 102
 103         /* TODO: use ip6_datagram_send_ctl to get options from cmsg */
 104
 105         memset(&fl6, 0, sizeof(fl6));
 106
 107         fl6.flowi6_proto = IPPROTO_ICMPV6;
 108         fl6.saddr = np->saddr;
 109         fl6.daddr = *daddr;
 110         fl6.flowi6_oif = oif;
 111         fl6.flowi6_mark = sk->sk_mark;
 112         fl6.flowi6_uid = sk->sk_uid;
 113         fl6.fl6_icmp_type = user_icmph.icmp6_type;
 114         fl6.fl6_icmp_code = user_icmph.icmp6_code;
 115         security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
 116
 117         ipcm6_init_sk(&ipc6, np);
 118         ipc6.sockc.mark = sk->sk_mark;
 119         fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
 120
 121         dst = ip6_sk_dst_lookup_flow(sk, &fl6, daddr, false);
 122         if (IS_ERR(dst))
 123                 return PTR_ERR(dst);
 124         rt = (struct rt6_info *) dst;
 125
 126         if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
 127                 fl6.flowi6_oif = np->mcast_oif;
 128         else if (!fl6.flowi6_oif)
 129                 fl6.flowi6_oif = np->ucast_oif;
 130
 131         pfh.icmph.type = user_icmph.icmp6_type;
 132         pfh.icmph.code = user_icmph.icmp6_code;
 133         pfh.icmph.checksum = 0;
 134         pfh.icmph.un.echo.id = inet->inet_sport;
 135         pfh.icmph.un.echo.sequence = user_icmph.icmp6_sequence;
 136         pfh.msg = msg;
 137         pfh.wcheck = 0;
 138         pfh.family = AF_INET6;
 139
 140         ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
 141
 142         lock_sock(sk);
 143         err = ip6_append_data(sk, ping_getfrag, &pfh, len,
 144                               0, &ipc6, &fl6, rt,
 145                               MSG_DONTWAIT);
 146
 147         if (err) {
 148                 ICMP6_INC_STATS(sock_net(sk), rt->rt6i_idev,
 149                                 ICMP6_MIB_OUTERRORS);
 150                 ip6_flush_pending_frames(sk);
 151         } else {
 152                 icmpv6_push_pending_frames(sk, &fl6,
 153                                            (struct icmp6hdr *)&pfh.icmph, len);
 154         }
 155         release_sock(sk);
 156
 157         dst_release(dst);
 158
 159         if (err)
 160                 return err;
 161
 162         return len;
 163 }
 164
 165 struct proto pingv6_prot = {
 166         .name =         "PINGv6",
 167         .owner =        THIS_MODULE,
 168         .init =         ping_init_sock,
 169         .close =        ping_close,
 170         .connect =      ip6_datagram_connect_v6_only,
 171         .disconnect =   __udp_disconnect,
 172         .setsockopt =   ipv6_setsockopt,
 173         .getsockopt =   ipv6_getsockopt,
 174         .sendmsg =      ping_v6_sendmsg,
 175         .recvmsg =      ping_recvmsg,
 176         .bind =         ping_bind,
 177         .backlog_rcv =  ping_queue_rcv_skb,
 178         .hash =         ping_hash,
 179         .unhash =       ping_unhash,
 180         .get_port =     ping_get_port,
 181         .obj_size =     sizeof(struct raw6_sock),
 182 };
 183 EXPORT_SYMBOL_GPL(pingv6_prot);
 184
 185 static struct inet_protosw pingv6_protosw = {
 186         .type =      SOCK_DGRAM,
 187         .protocol =  IPPROTO_ICMPV6,
 188         .prot =      &pingv6_prot,
 189         .ops =       &inet6_sockraw_ops,
 190         .flags =     INET_PROTOSW_REUSE,
 191 };
 192
 193 #ifdef CONFIG_PROC_FS
 194 static void *ping_v6_seq_start(struct seq_file *seq, loff_t *pos)
 195 {
 196         return ping_seq_start(seq, pos, AF_INET6);
 197 }
 198
 199 static int ping_v6_seq_show(struct seq_file *seq, void *v)
 200 {
 201         if (v == SEQ_START_TOKEN) {
 202                 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
 203         } else {
 204                 int bucket = ((struct ping_iter_state *) seq->private)->bucket;
 205                 struct inet_sock *inet = inet_sk(v);
 206                 __u16 srcp = ntohs(inet->inet_sport);
 207                 __u16 destp = ntohs(inet->inet_dport);
 208                 ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
 209         }
 210         return 0;
 211 }
 212
 213 static const struct seq_operations ping_v6_seq_ops = {
 214         .start          = ping_v6_seq_start,
 215         .show           = ping_v6_seq_show,
 216         .next           = ping_seq_next,
 217         .stop           = ping_seq_stop,
 218 };
 219
 220 static int __net_init ping_v6_proc_init_net(struct net *net)
 221 {
 222         if (!proc_create_net("icmp6", 0444, net->proc_net, &ping_v6_seq_ops,
 223                         sizeof(struct ping_iter_state)))
 224                 return -ENOMEM;
 225         return 0;
 226 }
 227
 228 static void __net_exit ping_v6_proc_exit_net(struct net *net)
 229 {
 230         remove_proc_entry("icmp6", net->proc_net);
 231 }
 232
 233 static struct pernet_operations ping_v6_net_ops = {
 234         .init = ping_v6_proc_init_net,
 235         .exit = ping_v6_proc_exit_net,
 236 };
 237 #endif
 238
 239 int __init pingv6_init(void)
 240 {
 241 #ifdef CONFIG_PROC_FS
 242         int ret = register_pernet_subsys(&ping_v6_net_ops);
 243         if (ret)
 244                 return ret;
 245 #endif
 246         pingv6_ops.ipv6_recv_error = ipv6_recv_error;
 247         pingv6_ops.ip6_datagram_recv_common_ctl = ip6_datagram_recv_common_ctl;
 248         pingv6_ops.ip6_datagram_recv_specific_ctl =
 249                 ip6_datagram_recv_specific_ctl;
 250         pingv6_ops.icmpv6_err_convert = icmpv6_err_convert;
 251         pingv6_ops.ipv6_icmp_error = ipv6_icmp_error;
 252         pingv6_ops.ipv6_chk_addr = ipv6_chk_addr;
 253         return inet6_register_protosw(&pingv6_protosw);
 254 }
 255
 256 /* This never gets called because it's not possible to unload the ipv6 module,
 257  * but just in case.
 258  */
 259 void pingv6_exit(void)
 260 {
 261         pingv6_ops.ipv6_recv_error = dummy_ipv6_recv_error;
 262         pingv6_ops.ip6_datagram_recv_common_ctl = dummy_ip6_datagram_recv_ctl;
 263         pingv6_ops.ip6_datagram_recv_specific_ctl = dummy_ip6_datagram_recv_ctl;
 264         pingv6_ops.icmpv6_err_convert = dummy_icmpv6_err_convert;
 265         pingv6_ops.ipv6_icmp_error = dummy_ipv6_icmp_error;
 266         pingv6_ops.ipv6_chk_addr = dummy_ipv6_chk_addr;
 267 #ifdef CONFIG_PROC_FS
 268         unregister_pernet_subsys(&ping_v6_net_ops);
 269 #endif
 270         inet6_unregister_protosw(&pingv6_protosw);
 271 }