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((struct sock *)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 } 307