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 static void ping_v6_destroy(struct sock *sk)
  27 {
  28         inet6_destroy_sock(sk);
  29 }
  30
  31 /* Compatibility glue so we can support IPv6 when it's compiled as a module */
  32 static int dummy_ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len,
  33                                  int *addr_len)
  34 {
  35         return -EAFNOSUPPORT;
  36 }
  37 static void dummy_ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
  38                                        struct sk_buff *skb)
  39 {
  40 }
  41 static int dummy_icmpv6_err_convert(u8 type, u8 code, int *err)
  42 {
  43         return -EAFNOSUPPORT;
  44 }
  45 static void dummy_ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
  46                                   __be16 port, u32 info, u8 *payload) {}
  47 static int dummy_ipv6_chk_addr(struct net *net, const struct in6_addr *addr,
  48                                const struct net_device *dev, int strict)
  49 {
  50         return 0;
  51 }
  52
  53 static int ping_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
  54                                int addr_len)
  55 {
  56         /* This check is replicated from __ip6_datagram_connect() and
  57          * intended to prevent BPF program called below from accessing
  58          * bytes that are out of the bound specified by user in addr_len.
  59          */
  60
  61         if (addr_len < SIN6_LEN_RFC2133)
  62                 return -EINVAL;
  63
  64         return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr);
  65 }
  66
  67 static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
  68 {
  69         struct inet_sock *inet = inet_sk(sk);
  70         struct ipv6_pinfo *np = inet6_sk(sk);
  71         struct icmp6hdr user_icmph;
  72         int addr_type;
  73         struct in6_addr *daddr;
  74         int oif = 0;
  75         struct flowi6 fl6;
  76         int err;
  77         struct dst_entry *dst;
  78         struct rt6_info *rt;
  79         struct pingfakehdr pfh;
  80         struct ipcm6_cookie ipc6;
  81
  82         err = ping_common_sendmsg(AF_INET6, msg, len, &user_icmph,
  83                                   sizeof(user_icmph));
  84         if (err)
  85                 return err;
  86
  87         memset(&fl6, 0, sizeof(fl6));
  88
  89         if (msg->msg_name) {
  90                 DECLARE_SOCKADDR(struct sockaddr_in6 *, u, msg->msg_name);
  91                 if (msg->msg_namelen < sizeof(*u))
  92                         return -EINVAL;
  93                 if (u->sin6_family != AF_INET6) {
  94                         return -EAFNOSUPPORT;
  95                 }
  96                 daddr = &(u->sin6_addr);
  97                 if (np->sndflow)
  98                         fl6.flowlabel = u->sin6_flowinfo & IPV6_FLOWINFO_MASK;
  99                 if (__ipv6_addr_needs_scope_id(ipv6_addr_type(daddr)))
 100                         oif = u->sin6_scope_id;
 101         } else {
 102                 if (sk->sk_state != TCP_ESTABLISHED)
 103                         return -EDESTADDRREQ;
 104                 daddr = &sk->sk_v6_daddr;
 105                 fl6.flowlabel = np->flow_label;
 106         }
 107
 108         if (!oif)
 109                 oif = sk->sk_bound_dev_if;
 110
 111         if (!oif)
 112                 oif = np->sticky_pktinfo.ipi6_ifindex;
 113
 114         if (!oif && ipv6_addr_is_multicast(daddr))
 115                 oif = np->mcast_oif;
 116         else if (!oif)
 117                 oif = np->ucast_oif;
 118
 119         addr_type = ipv6_addr_type(daddr);
 120         if ((__ipv6_addr_needs_scope_id(addr_type) && !oif) ||
 121             (addr_type & IPV6_ADDR_MAPPED) ||
 122             (oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if))
 123                 return -EINVAL;
 124
 125         ipcm6_init_sk(&ipc6, np);
 126         ipc6.sockc.tsflags = sk->sk_tsflags;
 127         ipc6.sockc.mark = sk->sk_mark;
 128
 129         fl6.flowi6_oif = oif;
 130
 131         if (msg->msg_controllen) {
 132                 struct ipv6_txoptions opt = {};
 133
 134                 opt.tot_len = sizeof(opt);
 135                 ipc6.opt = &opt;
 136
 137                 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6);
 138                 if (err < 0)
 139                         return err;
 140
 141                 /* Changes to txoptions and flow info are not implemented, yet.
 142                  * Drop the options.
 143                  */
 144                 ipc6.opt = NULL;
 145         }
 146
 147         fl6.flowi6_proto = IPPROTO_ICMPV6;
 148         fl6.saddr = np->saddr;
 149         fl6.daddr = *daddr;
 150         fl6.flowi6_mark = ipc6.sockc.mark;
 151         fl6.flowi6_uid = sk->sk_uid;
 152         fl6.fl6_icmp_type = user_icmph.icmp6_type;
 153         fl6.fl6_icmp_code = user_icmph.icmp6_code;
 154         security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
 155
 156         fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
 157
 158         dst = ip6_sk_dst_lookup_flow(sk, &fl6, daddr, false);
 159         if (IS_ERR(dst))
 160                 return PTR_ERR(dst);
 161         rt = (struct rt6_info *) dst;
 162
 163         if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
 164                 fl6.flowi6_oif = np->mcast_oif;
 165         else if (!fl6.flowi6_oif)
 166                 fl6.flowi6_oif = np->ucast_oif;
 167
 168         pfh.icmph.type = user_icmph.icmp6_type;
 169         pfh.icmph.code = user_icmph.icmp6_code;
 170         pfh.icmph.checksum = 0;
 171         pfh.icmph.un.echo.id = inet->inet_sport;
 172         pfh.icmph.un.echo.sequence = user_icmph.icmp6_sequence;
 173         pfh.msg = msg;
 174         pfh.wcheck = 0;
 175         pfh.family = AF_INET6;
 176
 177         if (ipc6.hlimit < 0)
 178                 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
 179
 180         lock_sock(sk);
 181         err = ip6_append_data(sk, ping_getfrag, &pfh, len,
 182                               sizeof(struct icmp6hdr), &ipc6, &fl6, rt,
 183                               MSG_DONTWAIT);
 184
 185         if (err) {
 186                 ICMP6_INC_STATS(sock_net(sk), rt->rt6i_idev,
 187                                 ICMP6_MIB_OUTERRORS);
 188                 ip6_flush_pending_frames(sk);
 189         } else {
 190                 icmpv6_push_pending_frames(sk, &fl6,
 191                                            (struct icmp6hdr *)&pfh.icmph, len);
 192         }
 193         release_sock(sk);
 194
 195         dst_release(dst);
 196
 197         if (err)
 198                 return err;
 199
 200         return len;
 201 }
 202
 203 struct proto pingv6_prot = {
 204         .name =         "PINGv6",
 205         .owner =        THIS_MODULE,
 206         .init =         ping_init_sock,
 207         .close =        ping_close,
 208         .destroy =      ping_v6_destroy,
 209         .pre_connect =  ping_v6_pre_connect,
 210         .connect =      ip6_datagram_connect_v6_only,
 211         .disconnect =   __udp_disconnect,
 212         .setsockopt =   ipv6_setsockopt,
 213         .getsockopt =   ipv6_getsockopt,
 214         .sendmsg =      ping_v6_sendmsg,
 215         .recvmsg =      ping_recvmsg,
 216         .bind =         ping_bind,
 217         .backlog_rcv =  ping_queue_rcv_skb,
 218         .hash =         ping_hash,
 219         .unhash =       ping_unhash,
 220         .get_port =     ping_get_port,
 221         .put_port =     ping_unhash,
 222         .obj_size =     sizeof(struct raw6_sock),
 223 };
 224 EXPORT_SYMBOL_GPL(pingv6_prot);
 225
 226 static struct inet_protosw pingv6_protosw = {
 227         .type =      SOCK_DGRAM,
 228         .protocol =  IPPROTO_ICMPV6,
 229         .prot =      &pingv6_prot,
 230         .ops =       &inet6_sockraw_ops,
 231         .flags =     INET_PROTOSW_REUSE,
 232 };
 233
 234 #ifdef CONFIG_PROC_FS
 235 static void *ping_v6_seq_start(struct seq_file *seq, loff_t *pos)
 236 {
 237         return ping_seq_start(seq, pos, AF_INET6);
 238 }
 239
 240 static int ping_v6_seq_show(struct seq_file *seq, void *v)
 241 {
 242         if (v == SEQ_START_TOKEN) {
 243                 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
 244         } else {
 245                 int bucket = ((struct ping_iter_state *) seq->private)->bucket;
 246                 struct inet_sock *inet = inet_sk(v);
 247                 __u16 srcp = ntohs(inet->inet_sport);
 248                 __u16 destp = ntohs(inet->inet_dport);
 249                 ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
 250         }
 251         return 0;
 252 }
 253
 254 static const struct seq_operations ping_v6_seq_ops = {
 255         .start          = ping_v6_seq_start,
 256         .show           = ping_v6_seq_show,
 257         .next           = ping_seq_next,
 258         .stop           = ping_seq_stop,
 259 };
 260
 261 static int __net_init ping_v6_proc_init_net(struct net *net)
 262 {
 263         if (!proc_create_net("icmp6", 0444, net->proc_net, &ping_v6_seq_ops,
 264                         sizeof(struct ping_iter_state)))
 265                 return -ENOMEM;
 266         return 0;
 267 }
 268
 269 static void __net_exit ping_v6_proc_exit_net(struct net *net)
 270 {
 271         remove_proc_entry("icmp6", net->proc_net);
 272 }
 273
 274 static struct pernet_operations ping_v6_net_ops = {
 275         .init = ping_v6_proc_init_net,
 276         .exit = ping_v6_proc_exit_net,
 277 };
 278 #endif
 279
 280 int __init pingv6_init(void)
 281 {
 282 #ifdef CONFIG_PROC_FS
 283         int ret = register_pernet_subsys(&ping_v6_net_ops);
 284         if (ret)
 285                 return ret;
 286 #endif
 287         pingv6_ops.ipv6_recv_error = ipv6_recv_error;
 288         pingv6_ops.ip6_datagram_recv_common_ctl = ip6_datagram_recv_common_ctl;
 289         pingv6_ops.ip6_datagram_recv_specific_ctl =
 290                 ip6_datagram_recv_specific_ctl;
 291         pingv6_ops.icmpv6_err_convert = icmpv6_err_convert;
 292         pingv6_ops.ipv6_icmp_error = ipv6_icmp_error;
 293         pingv6_ops.ipv6_chk_addr = ipv6_chk_addr;
 294         return inet6_register_protosw(&pingv6_protosw);
 295 }
 296
 297 /* This never gets called because it's not possible to unload the ipv6 module,
 298  * but just in case.
 299  */
 300 void pingv6_exit(void)
 301 {
 302         pingv6_ops.ipv6_recv_error = dummy_ipv6_recv_error;
 303         pingv6_ops.ip6_datagram_recv_common_ctl = dummy_ip6_datagram_recv_ctl;
 304         pingv6_ops.ip6_datagram_recv_specific_ctl = dummy_ip6_datagram_recv_ctl;
 305         pingv6_ops.icmpv6_err_convert = dummy_icmpv6_err_convert;
 306         pingv6_ops.ipv6_icmp_error = dummy_ipv6_icmp_error;
 307         pingv6_ops.ipv6_chk_addr = dummy_ipv6_chk_addr;
 308 #ifdef CONFIG_PROC_FS
 309         unregister_pernet_subsys(&ping_v6_net_ops);
 310 #endif
 311         inet6_unregister_protosw(&pingv6_protosw);
 312 }