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 <linux/bpf-cgroup.h>
  24 #include <net/ping.h>
  25
  26 /* Compatibility glue so we can support IPv6 when it's compiled as a module */
  27 static int dummy_ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
  28                                  int *addr_len)
  29 {
  30         return -EAFNOSUPPORT;
  31 }
  32 static void dummy_ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
  33                                        struct sk_buff *skb)
  34 {
  35 }
  36 static int dummy_icmpv6_err_convert(u8 type, u8 code, int *err)
  37 {
  38         return -EAFNOSUPPORT;
  39 }
  40 static void dummy_ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
  41                                   __be16 port, u32 info, u8 *payload) {}
  42 static int dummy_ipv6_chk_addr(struct net *net, const struct in6_addr *addr,
  43                                const struct net_device *dev, int strict)
  44 {
  45         return 0;
  46 }
  47
  48 static int ping_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
  49                                int addr_len)
  50 {
  51         /* This check is replicated from __ip6_datagram_connect() and
  52          * intended to prevent BPF program called below from accessing
  53          * bytes that are out of the bound specified by user in addr_len.
  54          */
  55
  56         if (addr_len < SIN6_LEN_RFC2133)
  57                 return -EINVAL;
  58
  59         return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr, &addr_len);
  60 }
  61
  62 static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
  63 {
  64         struct inet_sock *inet = inet_sk(sk);
  65         struct ipv6_pinfo *np = inet6_sk(sk);
  66         struct icmp6hdr user_icmph;
  67         int addr_type;
  68         struct in6_addr *daddr;
  69         int oif = 0;
  70         struct flowi6 fl6;
  71         int err;
  72         struct dst_entry *dst;
  73         struct rt6_info *rt;
  74         struct pingfakehdr pfh;
  75         struct ipcm6_cookie ipc6;
  76
  77         err = ping_common_sendmsg(AF_INET6, msg, len, &user_icmph,
  78                                   sizeof(user_icmph));
  79         if (err)
  80                 return err;
  81
  82         memset(&fl6, 0, sizeof(fl6));
  83
  84         if (msg->msg_name) {
  85                 DECLARE_SOCKADDR(struct sockaddr_in6 *, u, msg->msg_name);
  86                 if (msg->msg_namelen < sizeof(*u))
  87                         return -EINVAL;
  88                 if (u->sin6_family != AF_INET6) {
  89                         return -EAFNOSUPPORT;
  90                 }
  91                 daddr = &(u->sin6_addr);
  92                 if (inet6_test_bit(SNDFLOW, sk))
  93                         fl6.flowlabel = u->sin6_flowinfo & IPV6_FLOWINFO_MASK;
  94                 if (__ipv6_addr_needs_scope_id(ipv6_addr_type(daddr)))
  95                         oif = u->sin6_scope_id;
  96         } else {
  97                 if (sk->sk_state != TCP_ESTABLISHED)
  98                         return -EDESTADDRREQ;
  99                 daddr = &sk->sk_v6_daddr;
 100                 fl6.flowlabel = np->flow_label;
 101         }
 102
 103         if (!oif)
 104                 oif = sk->sk_bound_dev_if;
 105
 106         if (!oif)
 107                 oif = np->sticky_pktinfo.ipi6_ifindex;
 108
 109         if (!oif && ipv6_addr_is_multicast(daddr))
 110                 oif = READ_ONCE(np->mcast_oif);
 111         else if (!oif)
 112                 oif = READ_ONCE(np->ucast_oif);
 113
 114         addr_type = ipv6_addr_type(daddr);
 115         if ((__ipv6_addr_needs_scope_id(addr_type) && !oif) ||
 116             (addr_type & IPV6_ADDR_MAPPED) ||
 117             (oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if &&
 118              l3mdev_master_ifindex_by_index(sock_net(sk), oif) != sk->sk_bound_dev_if))
 119                 return -EINVAL;
 120
 121         ipcm6_init_sk(&ipc6, sk);
 122         ipc6.sockc.tsflags = READ_ONCE(sk->sk_tsflags);
 123         ipc6.sockc.mark = READ_ONCE(sk->sk_mark);
 124
 125         fl6.flowi6_oif = oif;
 126
 127         if (msg->msg_controllen) {
 128                 struct ipv6_txoptions opt = {};
 129
 130                 opt.tot_len = sizeof(opt);
 131                 ipc6.opt = &opt;
 132
 133                 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6);
 134                 if (err < 0)
 135                         return err;
 136
 137                 /* Changes to txoptions and flow info are not implemented, yet.
 138                  * Drop the options.
 139                  */
 140                 ipc6.opt = NULL;
 141         }
 142
 143         fl6.flowi6_proto = IPPROTO_ICMPV6;
 144         fl6.saddr = np->saddr;
 145         fl6.daddr = *daddr;
 146         fl6.flowi6_mark = ipc6.sockc.mark;
 147         fl6.flowi6_uid = sk->sk_uid;
 148         fl6.fl6_icmp_type = user_icmph.icmp6_type;
 149         fl6.fl6_icmp_code = user_icmph.icmp6_code;
 150         security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
 151
 152         fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
 153
 154         dst = ip6_sk_dst_lookup_flow(sk, &fl6, daddr, false);
 155         if (IS_ERR(dst))
 156                 return PTR_ERR(dst);
 157         rt = dst_rt6_info(dst);
 158
 159         if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
 160                 fl6.flowi6_oif = READ_ONCE(np->mcast_oif);
 161         else if (!fl6.flowi6_oif)
 162                 fl6.flowi6_oif = READ_ONCE(np->ucast_oif);
 163
 164         pfh.icmph.type = user_icmph.icmp6_type;
 165         pfh.icmph.code = user_icmph.icmp6_code;
 166         pfh.icmph.checksum = 0;
 167         pfh.icmph.un.echo.id = inet->inet_sport;
 168         pfh.icmph.un.echo.sequence = user_icmph.icmp6_sequence;
 169         pfh.msg = msg;
 170         pfh.wcheck = 0;
 171         pfh.family = AF_INET6;
 172
 173         if (ipc6.hlimit < 0)
 174                 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
 175
 176         lock_sock(sk);
 177         err = ip6_append_data(sk, ping_getfrag, &pfh, len,
 178                               sizeof(struct icmp6hdr), &ipc6, &fl6, rt,
 179                               MSG_DONTWAIT);
 180
 181         if (err) {
 182                 ICMP6_INC_STATS(sock_net(sk), rt->rt6i_idev,
 183                                 ICMP6_MIB_OUTERRORS);
 184                 ip6_flush_pending_frames(sk);
 185         } else {
 186                 icmpv6_push_pending_frames(sk, &fl6,
 187                                            (struct icmp6hdr *)&pfh.icmph, len);
 188         }
 189         release_sock(sk);
 190
 191         dst_release(dst);
 192
 193         if (err)
 194                 return err;
 195
 196         return len;
 197 }
 198
 199 struct proto pingv6_prot = {
 200         .name =         "PINGv6",
 201         .owner =        THIS_MODULE,
 202         .init =         ping_init_sock,
 203         .close =        ping_close,
 204         .pre_connect =  ping_v6_pre_connect,
 205         .connect =      ip6_datagram_connect_v6_only,
 206         .disconnect =   __udp_disconnect,
 207         .setsockopt =   ipv6_setsockopt,
 208         .getsockopt =   ipv6_getsockopt,
 209         .sendmsg =      ping_v6_sendmsg,
 210         .recvmsg =      ping_recvmsg,
 211         .bind =         ping_bind,
 212         .backlog_rcv =  ping_queue_rcv_skb,
 213         .hash =         ping_hash,
 214         .unhash =       ping_unhash,
 215         .get_port =     ping_get_port,
 216         .put_port =     ping_unhash,
 217         .obj_size =     sizeof(struct raw6_sock),
 218         .ipv6_pinfo_offset = offsetof(struct raw6_sock, inet6),
 219 };
 220 EXPORT_SYMBOL_GPL(pingv6_prot);
 221
 222 static struct inet_protosw pingv6_protosw = {
 223         .type =      SOCK_DGRAM,
 224         .protocol =  IPPROTO_ICMPV6,
 225         .prot =      &pingv6_prot,
 226         .ops =       &inet6_sockraw_ops,
 227         .flags =     INET_PROTOSW_REUSE,
 228 };
 229
 230 #ifdef CONFIG_PROC_FS
 231 static void *ping_v6_seq_start(struct seq_file *seq, loff_t *pos)
 232 {
 233         return ping_seq_start(seq, pos, AF_INET6);
 234 }
 235
 236 static int ping_v6_seq_show(struct seq_file *seq, void *v)
 237 {
 238         if (v == SEQ_START_TOKEN) {
 239                 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
 240         } else {
 241                 int bucket = ((struct ping_iter_state *) seq->private)->bucket;
 242                 struct inet_sock *inet = inet_sk((struct sock *)v);
 243                 __u16 srcp = ntohs(inet->inet_sport);
 244                 __u16 destp = ntohs(inet->inet_dport);
 245                 ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
 246         }
 247         return 0;
 248 }
 249
 250 static const struct seq_operations ping_v6_seq_ops = {
 251         .start          = ping_v6_seq_start,
 252         .show           = ping_v6_seq_show,
 253         .next           = ping_seq_next,
 254         .stop           = ping_seq_stop,
 255 };
 256
 257 static int __net_init ping_v6_proc_init_net(struct net *net)
 258 {
 259         if (!proc_create_net("icmp6", 0444, net->proc_net, &ping_v6_seq_ops,
 260                         sizeof(struct ping_iter_state)))
 261                 return -ENOMEM;
 262         return 0;
 263 }
 264
 265 static void __net_exit ping_v6_proc_exit_net(struct net *net)
 266 {
 267         remove_proc_entry("icmp6", net->proc_net);
 268 }
 269
 270 static struct pernet_operations ping_v6_net_ops = {
 271         .init = ping_v6_proc_init_net,
 272         .exit = ping_v6_proc_exit_net,
 273 };
 274 #endif
 275
 276 int __init pingv6_init(void)
 277 {
 278 #ifdef CONFIG_PROC_FS
 279         int ret = register_pernet_subsys(&ping_v6_net_ops);
 280         if (ret)
 281                 return ret;
 282 #endif
 283         pingv6_ops.ipv6_recv_error = ipv6_recv_error;
 284         pingv6_ops.ip6_datagram_recv_common_ctl = ip6_datagram_recv_common_ctl;
 285         pingv6_ops.ip6_datagram_recv_specific_ctl =
 286                 ip6_datagram_recv_specific_ctl;
 287         pingv6_ops.icmpv6_err_convert = icmpv6_err_convert;
 288         pingv6_ops.ipv6_icmp_error = ipv6_icmp_error;
 289         pingv6_ops.ipv6_chk_addr = ipv6_chk_addr;
 290         return inet6_register_protosw(&pingv6_protosw);
 291 }
 292
 293 /* This never gets called because it's not possible to unload the ipv6 module,
 294  * but just in case.
 295  */
 296 void pingv6_exit(void)
 297 {
 298         pingv6_ops.ipv6_recv_error = dummy_ipv6_recv_error;
 299         pingv6_ops.ip6_datagram_recv_common_ctl = dummy_ip6_datagram_recv_ctl;
 300         pingv6_ops.ip6_datagram_recv_specific_ctl = dummy_ip6_datagram_recv_ctl;
 301         pingv6_ops.icmpv6_err_convert = dummy_icmpv6_err_convert;
 302         pingv6_ops.ipv6_icmp_error = dummy_ipv6_icmp_error;
 303         pingv6_ops.ipv6_chk_addr = dummy_ipv6_chk_addr;
 304 #ifdef CONFIG_PROC_FS
 305         unregister_pernet_subsys(&ping_v6_net_ops);
 306 #endif
 307         inet6_unregister_protosw(&pingv6_protosw);
 308 }