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);
  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 (np->sndflow)
  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 = np->mcast_oif;
 111         else if (!oif)
 112                 oif = 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                 return -EINVAL;
 119
 120         ipcm6_init_sk(&ipc6, np);
 121         ipc6.sockc.tsflags = sk->sk_tsflags;
 122         ipc6.sockc.mark = sk->sk_mark;
 123
 124         fl6.flowi6_oif = oif;
 125
 126         if (msg->msg_controllen) {
 127                 struct ipv6_txoptions opt = {};
 128
 129                 opt.tot_len = sizeof(opt);
 130                 ipc6.opt = &opt;
 131
 132                 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6);
 133                 if (err < 0)
 134                         return err;
 135
 136                 /* Changes to txoptions and flow info are not implemented, yet.
 137                  * Drop the options.
 138                  */
 139                 ipc6.opt = NULL;
 140         }
 141
 142         fl6.flowi6_proto = IPPROTO_ICMPV6;
 143         fl6.saddr = np->saddr;
 144         fl6.daddr = *daddr;
 145         fl6.flowi6_mark = ipc6.sockc.mark;
 146         fl6.flowi6_uid = sk->sk_uid;
 147         fl6.fl6_icmp_type = user_icmph.icmp6_type;
 148         fl6.fl6_icmp_code = user_icmph.icmp6_code;
 149         security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
 150
 151         fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
 152
 153         dst = ip6_sk_dst_lookup_flow(sk, &fl6, daddr, false);
 154         if (IS_ERR(dst))
 155                 return PTR_ERR(dst);
 156         rt = (struct rt6_info *) dst;
 157
 158         if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
 159                 fl6.flowi6_oif = np->mcast_oif;
 160         else if (!fl6.flowi6_oif)
 161                 fl6.flowi6_oif = np->ucast_oif;
 162
 163         pfh.icmph.type = user_icmph.icmp6_type;
 164         pfh.icmph.code = user_icmph.icmp6_code;
 165         pfh.icmph.checksum = 0;
 166         pfh.icmph.un.echo.id = inet->inet_sport;
 167         pfh.icmph.un.echo.sequence = user_icmph.icmp6_sequence;
 168         pfh.msg = msg;
 169         pfh.wcheck = 0;
 170         pfh.family = AF_INET6;
 171
 172         if (ipc6.hlimit < 0)
 173                 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
 174
 175         lock_sock(sk);
 176         err = ip6_append_data(sk, ping_getfrag, &pfh, len,
 177                               sizeof(struct icmp6hdr), &ipc6, &fl6, rt,
 178                               MSG_DONTWAIT);
 179
 180         if (err) {
 181                 ICMP6_INC_STATS(sock_net(sk), rt->rt6i_idev,
 182                                 ICMP6_MIB_OUTERRORS);
 183                 ip6_flush_pending_frames(sk);
 184         } else {
 185                 icmpv6_push_pending_frames(sk, &fl6,
 186                                            (struct icmp6hdr *)&pfh.icmph, len);
 187         }
 188         release_sock(sk);
 189
 190         dst_release(dst);
 191
 192         if (err)
 193                 return err;
 194
 195         return len;
 196 }
 197
 198 struct proto pingv6_prot = {
 199         .name =         "PINGv6",
 200         .owner =        THIS_MODULE,
 201         .init =         ping_init_sock,
 202         .close =        ping_close,
 203         .pre_connect =  ping_v6_pre_connect,
 204         .connect =      ip6_datagram_connect_v6_only,
 205         .disconnect =   __udp_disconnect,
 206         .setsockopt =   ipv6_setsockopt,
 207         .getsockopt =   ipv6_getsockopt,
 208         .sendmsg =      ping_v6_sendmsg,
 209         .recvmsg =      ping_recvmsg,
 210         .bind =         ping_bind,
 211         .backlog_rcv =  ping_queue_rcv_skb,
 212         .hash =         ping_hash,
 213         .unhash =       ping_unhash,
 214         .get_port =     ping_get_port,
 215         .put_port =     ping_unhash,
 216         .obj_size =     sizeof(struct raw6_sock),
 217 };
 218 EXPORT_SYMBOL_GPL(pingv6_prot);
 219
 220 static struct inet_protosw pingv6_protosw = {
 221         .type =      SOCK_DGRAM,
 222         .protocol =  IPPROTO_ICMPV6,
 223         .prot =      &pingv6_prot,
 224         .ops =       &inet6_sockraw_ops,
 225         .flags =     INET_PROTOSW_REUSE,
 226 };
 227
 228 #ifdef CONFIG_PROC_FS
 229 static void *ping_v6_seq_start(struct seq_file *seq, loff_t *pos)
 230 {
 231         return ping_seq_start(seq, pos, AF_INET6);
 232 }
 233
 234 static int ping_v6_seq_show(struct seq_file *seq, void *v)
 235 {
 236         if (v == SEQ_START_TOKEN) {
 237                 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
 238         } else {
 239                 int bucket = ((struct ping_iter_state *) seq->private)->bucket;
 240                 struct inet_sock *inet = inet_sk(v);
 241                 __u16 srcp = ntohs(inet->inet_sport);
 242                 __u16 destp = ntohs(inet->inet_dport);
 243                 ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
 244         }
 245         return 0;
 246 }
 247
 248 static const struct seq_operations ping_v6_seq_ops = {
 249         .start          = ping_v6_seq_start,
 250         .show           = ping_v6_seq_show,
 251         .next           = ping_seq_next,
 252         .stop           = ping_seq_stop,
 253 };
 254
 255 static int __net_init ping_v6_proc_init_net(struct net *net)
 256 {
 257         if (!proc_create_net("icmp6", 0444, net->proc_net, &ping_v6_seq_ops,
 258                         sizeof(struct ping_iter_state)))
 259                 return -ENOMEM;
 260         return 0;
 261 }
 262
 263 static void __net_exit ping_v6_proc_exit_net(struct net *net)
 264 {
 265         remove_proc_entry("icmp6", net->proc_net);
 266 }
 267
 268 static struct pernet_operations ping_v6_net_ops = {
 269         .init = ping_v6_proc_init_net,
 270         .exit = ping_v6_proc_exit_net,
 271 };
 272 #endif
 273
 274 int __init pingv6_init(void)
 275 {
 276 #ifdef CONFIG_PROC_FS
 277         int ret = register_pernet_subsys(&ping_v6_net_ops);
 278         if (ret)
 279                 return ret;
 280 #endif
 281         pingv6_ops.ipv6_recv_error = ipv6_recv_error;
 282         pingv6_ops.ip6_datagram_recv_common_ctl = ip6_datagram_recv_common_ctl;
 283         pingv6_ops.ip6_datagram_recv_specific_ctl =
 284                 ip6_datagram_recv_specific_ctl;
 285         pingv6_ops.icmpv6_err_convert = icmpv6_err_convert;
 286         pingv6_ops.ipv6_icmp_error = ipv6_icmp_error;
 287         pingv6_ops.ipv6_chk_addr = ipv6_chk_addr;
 288         return inet6_register_protosw(&pingv6_protosw);
 289 }
 290
 291 /* This never gets called because it's not possible to unload the ipv6 module,
 292  * but just in case.
 293  */
 294 void pingv6_exit(void)
 295 {
 296         pingv6_ops.ipv6_recv_error = dummy_ipv6_recv_error;
 297         pingv6_ops.ip6_datagram_recv_common_ctl = dummy_ip6_datagram_recv_ctl;
 298         pingv6_ops.ip6_datagram_recv_specific_ctl = dummy_ip6_datagram_recv_ctl;
 299         pingv6_ops.icmpv6_err_convert = dummy_icmpv6_err_convert;
 300         pingv6_ops.ipv6_icmp_error = dummy_ipv6_icmp_error;
 301         pingv6_ops.ipv6_chk_addr = dummy_ipv6_chk_addr;
 302 #ifdef CONFIG_PROC_FS
 303         unregister_pernet_subsys(&ping_v6_net_ops);
 304 #endif
 305         inet6_unregister_protosw(&pingv6_protosw);
 306 }