Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / net / ipv4 / ping.c
diff --git a/kernel/net/ipv4/ping.c b/kernel/net/ipv4/ping.c
new file mode 100644 (file)
index 0000000..05ff44b
--- /dev/null
@@ -0,0 +1,1223 @@
+/*
+ * INET                An implementation of the TCP/IP protocol suite for the LINUX
+ *             operating system.  INET is implemented using the  BSD Socket
+ *             interface as the means of communication with the user level.
+ *
+ *             "Ping" sockets
+ *
+ *             This program is free software; you can redistribute it and/or
+ *             modify it under the terms of the GNU General Public License
+ *             as published by the Free Software Foundation; either version
+ *             2 of the License, or (at your option) any later version.
+ *
+ * Based on ipv4/udp.c code.
+ *
+ * Authors:    Vasiliy Kulikov / Openwall (for Linux 2.6),
+ *             Pavel Kankovsky (for Linux 2.4.32)
+ *
+ * Pavel gave all rights to bugs to Vasiliy,
+ * none of the bugs are Pavel's now.
+ *
+ */
+
+#include <linux/uaccess.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <net/snmp.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/protocol.h>
+#include <linux/skbuff.h>
+#include <linux/proc_fs.h>
+#include <linux/export.h>
+#include <net/sock.h>
+#include <net/ping.h>
+#include <net/udp.h>
+#include <net/route.h>
+#include <net/inet_common.h>
+#include <net/checksum.h>
+
+#if IS_ENABLED(CONFIG_IPV6)
+#include <linux/in6.h>
+#include <linux/icmpv6.h>
+#include <net/addrconf.h>
+#include <net/ipv6.h>
+#include <net/transp_v6.h>
+#endif
+
+struct ping_table {
+       struct hlist_nulls_head hash[PING_HTABLE_SIZE];
+       rwlock_t                lock;
+};
+
+static struct ping_table ping_table;
+struct pingv6_ops pingv6_ops;
+EXPORT_SYMBOL_GPL(pingv6_ops);
+
+static u16 ping_port_rover;
+
+static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
+{
+       u32 res = (num + net_hash_mix(net)) & mask;
+
+       pr_debug("hash(%u) = %u\n", num, res);
+       return res;
+}
+EXPORT_SYMBOL_GPL(ping_hash);
+
+static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
+                                            struct net *net, unsigned int num)
+{
+       return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
+}
+
+int ping_get_port(struct sock *sk, unsigned short ident)
+{
+       struct hlist_nulls_node *node;
+       struct hlist_nulls_head *hlist;
+       struct inet_sock *isk, *isk2;
+       struct sock *sk2 = NULL;
+
+       isk = inet_sk(sk);
+       write_lock_bh(&ping_table.lock);
+       if (ident == 0) {
+               u32 i;
+               u16 result = ping_port_rover + 1;
+
+               for (i = 0; i < (1L << 16); i++, result++) {
+                       if (!result)
+                               result++; /* avoid zero */
+                       hlist = ping_hashslot(&ping_table, sock_net(sk),
+                                           result);
+                       ping_portaddr_for_each_entry(sk2, node, hlist) {
+                               isk2 = inet_sk(sk2);
+
+                               if (isk2->inet_num == result)
+                                       goto next_port;
+                       }
+
+                       /* found */
+                       ping_port_rover = ident = result;
+                       break;
+next_port:
+                       ;
+               }
+               if (i >= (1L << 16))
+                       goto fail;
+       } else {
+               hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
+               ping_portaddr_for_each_entry(sk2, node, hlist) {
+                       isk2 = inet_sk(sk2);
+
+                       /* BUG? Why is this reuse and not reuseaddr? ping.c
+                        * doesn't turn off SO_REUSEADDR, and it doesn't expect
+                        * that other ping processes can steal its packets.
+                        */
+                       if ((isk2->inet_num == ident) &&
+                           (sk2 != sk) &&
+                           (!sk2->sk_reuse || !sk->sk_reuse))
+                               goto fail;
+               }
+       }
+
+       pr_debug("found port/ident = %d\n", ident);
+       isk->inet_num = ident;
+       if (sk_unhashed(sk)) {
+               pr_debug("was not hashed\n");
+               sock_hold(sk);
+               hlist_nulls_add_head(&sk->sk_nulls_node, hlist);
+               sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+       }
+       write_unlock_bh(&ping_table.lock);
+       return 0;
+
+fail:
+       write_unlock_bh(&ping_table.lock);
+       return 1;
+}
+EXPORT_SYMBOL_GPL(ping_get_port);
+
+void ping_hash(struct sock *sk)
+{
+       pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
+       BUG(); /* "Please do not press this button again." */
+}
+
+void ping_unhash(struct sock *sk)
+{
+       struct inet_sock *isk = inet_sk(sk);
+       pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
+       if (sk_hashed(sk)) {
+               write_lock_bh(&ping_table.lock);
+               hlist_nulls_del(&sk->sk_nulls_node);
+               sk_nulls_node_init(&sk->sk_nulls_node);
+               sock_put(sk);
+               isk->inet_num = 0;
+               isk->inet_sport = 0;
+               sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+               write_unlock_bh(&ping_table.lock);
+       }
+}
+EXPORT_SYMBOL_GPL(ping_unhash);
+
+static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
+{
+       struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
+       struct sock *sk = NULL;
+       struct inet_sock *isk;
+       struct hlist_nulls_node *hnode;
+       int dif = skb->dev->ifindex;
+
+       if (skb->protocol == htons(ETH_P_IP)) {
+               pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
+                        (int)ident, &ip_hdr(skb)->daddr, dif);
+#if IS_ENABLED(CONFIG_IPV6)
+       } else if (skb->protocol == htons(ETH_P_IPV6)) {
+               pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
+                        (int)ident, &ipv6_hdr(skb)->daddr, dif);
+#endif
+       }
+
+       read_lock_bh(&ping_table.lock);
+
+       ping_portaddr_for_each_entry(sk, hnode, hslot) {
+               isk = inet_sk(sk);
+
+               pr_debug("iterate\n");
+               if (isk->inet_num != ident)
+                       continue;
+
+               if (skb->protocol == htons(ETH_P_IP) &&
+                   sk->sk_family == AF_INET) {
+                       pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
+                                (int) isk->inet_num, &isk->inet_rcv_saddr,
+                                sk->sk_bound_dev_if);
+
+                       if (isk->inet_rcv_saddr &&
+                           isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
+                               continue;
+#if IS_ENABLED(CONFIG_IPV6)
+               } else if (skb->protocol == htons(ETH_P_IPV6) &&
+                          sk->sk_family == AF_INET6) {
+
+                       pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
+                                (int) isk->inet_num,
+                                &sk->sk_v6_rcv_saddr,
+                                sk->sk_bound_dev_if);
+
+                       if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
+                           !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
+                                            &ipv6_hdr(skb)->daddr))
+                               continue;
+#endif
+               } else {
+                       continue;
+               }
+
+               if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
+                       continue;
+
+               sock_hold(sk);
+               goto exit;
+       }
+
+       sk = NULL;
+exit:
+       read_unlock_bh(&ping_table.lock);
+
+       return sk;
+}
+
+static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
+                                         kgid_t *high)
+{
+       kgid_t *data = net->ipv4.ping_group_range.range;
+       unsigned int seq;
+
+       do {
+               seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
+
+               *low = data[0];
+               *high = data[1];
+       } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
+}
+
+
+int ping_init_sock(struct sock *sk)
+{
+       struct net *net = sock_net(sk);
+       kgid_t group = current_egid();
+       struct group_info *group_info;
+       int i, j, count;
+       kgid_t low, high;
+       int ret = 0;
+
+       if (sk->sk_family == AF_INET6)
+               sk->sk_ipv6only = 1;
+
+       inet_get_ping_group_range_net(net, &low, &high);
+       if (gid_lte(low, group) && gid_lte(group, high))
+               return 0;
+
+       group_info = get_current_groups();
+       count = group_info->ngroups;
+       for (i = 0; i < group_info->nblocks; i++) {
+               int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
+               for (j = 0; j < cp_count; j++) {
+                       kgid_t gid = group_info->blocks[i][j];
+                       if (gid_lte(low, gid) && gid_lte(gid, high))
+                               goto out_release_group;
+               }
+
+               count -= cp_count;
+       }
+
+       ret = -EACCES;
+
+out_release_group:
+       put_group_info(group_info);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(ping_init_sock);
+
+void ping_close(struct sock *sk, long timeout)
+{
+       pr_debug("ping_close(sk=%p,sk->num=%u)\n",
+                inet_sk(sk), inet_sk(sk)->inet_num);
+       pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
+
+       sk_common_release(sk);
+}
+EXPORT_SYMBOL_GPL(ping_close);
+
+/* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
+static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
+                               struct sockaddr *uaddr, int addr_len) {
+       struct net *net = sock_net(sk);
+       if (sk->sk_family == AF_INET) {
+               struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
+               int chk_addr_ret;
+
+               if (addr_len < sizeof(*addr))
+                       return -EINVAL;
+
+               if (addr->sin_family != AF_INET &&
+                   !(addr->sin_family == AF_UNSPEC &&
+                     addr->sin_addr.s_addr == htonl(INADDR_ANY)))
+                       return -EAFNOSUPPORT;
+
+               pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
+                        sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
+
+               chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
+
+               if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
+                       chk_addr_ret = RTN_LOCAL;
+
+               if ((net->ipv4.sysctl_ip_nonlocal_bind == 0 &&
+                   isk->freebind == 0 && isk->transparent == 0 &&
+                    chk_addr_ret != RTN_LOCAL) ||
+                   chk_addr_ret == RTN_MULTICAST ||
+                   chk_addr_ret == RTN_BROADCAST)
+                       return -EADDRNOTAVAIL;
+
+#if IS_ENABLED(CONFIG_IPV6)
+       } else if (sk->sk_family == AF_INET6) {
+               struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
+               int addr_type, scoped, has_addr;
+               struct net_device *dev = NULL;
+
+               if (addr_len < sizeof(*addr))
+                       return -EINVAL;
+
+               if (addr->sin6_family != AF_INET6)
+                       return -EAFNOSUPPORT;
+
+               pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
+                        sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
+
+               addr_type = ipv6_addr_type(&addr->sin6_addr);
+               scoped = __ipv6_addr_needs_scope_id(addr_type);
+               if ((addr_type != IPV6_ADDR_ANY &&
+                    !(addr_type & IPV6_ADDR_UNICAST)) ||
+                   (scoped && !addr->sin6_scope_id))
+                       return -EINVAL;
+
+               rcu_read_lock();
+               if (addr->sin6_scope_id) {
+                       dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
+                       if (!dev) {
+                               rcu_read_unlock();
+                               return -ENODEV;
+                       }
+               }
+               has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
+                                                   scoped);
+               rcu_read_unlock();
+
+               if (!(isk->freebind || isk->transparent || has_addr ||
+                     addr_type == IPV6_ADDR_ANY))
+                       return -EADDRNOTAVAIL;
+
+               if (scoped)
+                       sk->sk_bound_dev_if = addr->sin6_scope_id;
+#endif
+       } else {
+               return -EAFNOSUPPORT;
+       }
+       return 0;
+}
+
+static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
+{
+       if (saddr->sa_family == AF_INET) {
+               struct inet_sock *isk = inet_sk(sk);
+               struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
+               isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
+#if IS_ENABLED(CONFIG_IPV6)
+       } else if (saddr->sa_family == AF_INET6) {
+               struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
+               struct ipv6_pinfo *np = inet6_sk(sk);
+               sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
+#endif
+       }
+}
+
+static void ping_clear_saddr(struct sock *sk, int dif)
+{
+       sk->sk_bound_dev_if = dif;
+       if (sk->sk_family == AF_INET) {
+               struct inet_sock *isk = inet_sk(sk);
+               isk->inet_rcv_saddr = isk->inet_saddr = 0;
+#if IS_ENABLED(CONFIG_IPV6)
+       } else if (sk->sk_family == AF_INET6) {
+               struct ipv6_pinfo *np = inet6_sk(sk);
+               memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
+               memset(&np->saddr, 0, sizeof(np->saddr));
+#endif
+       }
+}
+/*
+ * We need our own bind because there are no privileged id's == local ports.
+ * Moreover, we don't allow binding to multi- and broadcast addresses.
+ */
+
+int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
+{
+       struct inet_sock *isk = inet_sk(sk);
+       unsigned short snum;
+       int err;
+       int dif = sk->sk_bound_dev_if;
+
+       err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
+       if (err)
+               return err;
+
+       lock_sock(sk);
+
+       err = -EINVAL;
+       if (isk->inet_num != 0)
+               goto out;
+
+       err = -EADDRINUSE;
+       ping_set_saddr(sk, uaddr);
+       snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
+       if (ping_get_port(sk, snum) != 0) {
+               ping_clear_saddr(sk, dif);
+               goto out;
+       }
+
+       pr_debug("after bind(): num = %d, dif = %d\n",
+                (int)isk->inet_num,
+                (int)sk->sk_bound_dev_if);
+
+       err = 0;
+       if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
+               sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
+#if IS_ENABLED(CONFIG_IPV6)
+       if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
+               sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
+#endif
+
+       if (snum)
+               sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
+       isk->inet_sport = htons(isk->inet_num);
+       isk->inet_daddr = 0;
+       isk->inet_dport = 0;
+
+#if IS_ENABLED(CONFIG_IPV6)
+       if (sk->sk_family == AF_INET6)
+               memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
+#endif
+
+       sk_dst_reset(sk);
+out:
+       release_sock(sk);
+       pr_debug("ping_v4_bind -> %d\n", err);
+       return err;
+}
+EXPORT_SYMBOL_GPL(ping_bind);
+
+/*
+ * Is this a supported type of ICMP message?
+ */
+
+static inline int ping_supported(int family, int type, int code)
+{
+       return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
+              (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
+}
+
+/*
+ * This routine is called by the ICMP module when it gets some
+ * sort of error condition.
+ */
+
+void ping_err(struct sk_buff *skb, int offset, u32 info)
+{
+       int family;
+       struct icmphdr *icmph;
+       struct inet_sock *inet_sock;
+       int type;
+       int code;
+       struct net *net = dev_net(skb->dev);
+       struct sock *sk;
+       int harderr;
+       int err;
+
+       if (skb->protocol == htons(ETH_P_IP)) {
+               family = AF_INET;
+               type = icmp_hdr(skb)->type;
+               code = icmp_hdr(skb)->code;
+               icmph = (struct icmphdr *)(skb->data + offset);
+       } else if (skb->protocol == htons(ETH_P_IPV6)) {
+               family = AF_INET6;
+               type = icmp6_hdr(skb)->icmp6_type;
+               code = icmp6_hdr(skb)->icmp6_code;
+               icmph = (struct icmphdr *) (skb->data + offset);
+       } else {
+               BUG();
+       }
+
+       /* We assume the packet has already been checked by icmp_unreach */
+
+       if (!ping_supported(family, icmph->type, icmph->code))
+               return;
+
+       pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
+                skb->protocol, type, code, ntohs(icmph->un.echo.id),
+                ntohs(icmph->un.echo.sequence));
+
+       sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
+       if (!sk) {
+               pr_debug("no socket, dropping\n");
+               return; /* No socket for error */
+       }
+       pr_debug("err on socket %p\n", sk);
+
+       err = 0;
+       harderr = 0;
+       inet_sock = inet_sk(sk);
+
+       if (skb->protocol == htons(ETH_P_IP)) {
+               switch (type) {
+               default:
+               case ICMP_TIME_EXCEEDED:
+                       err = EHOSTUNREACH;
+                       break;
+               case ICMP_SOURCE_QUENCH:
+                       /* This is not a real error but ping wants to see it.
+                        * Report it with some fake errno.
+                        */
+                       err = EREMOTEIO;
+                       break;
+               case ICMP_PARAMETERPROB:
+                       err = EPROTO;
+                       harderr = 1;
+                       break;
+               case ICMP_DEST_UNREACH:
+                       if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
+                               ipv4_sk_update_pmtu(skb, sk, info);
+                               if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
+                                       err = EMSGSIZE;
+                                       harderr = 1;
+                                       break;
+                               }
+                               goto out;
+                       }
+                       err = EHOSTUNREACH;
+                       if (code <= NR_ICMP_UNREACH) {
+                               harderr = icmp_err_convert[code].fatal;
+                               err = icmp_err_convert[code].errno;
+                       }
+                       break;
+               case ICMP_REDIRECT:
+                       /* See ICMP_SOURCE_QUENCH */
+                       ipv4_sk_redirect(skb, sk);
+                       err = EREMOTEIO;
+                       break;
+               }
+#if IS_ENABLED(CONFIG_IPV6)
+       } else if (skb->protocol == htons(ETH_P_IPV6)) {
+               harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
+#endif
+       }
+
+       /*
+        *      RFC1122: OK.  Passes ICMP errors back to application, as per
+        *      4.1.3.3.
+        */
+       if ((family == AF_INET && !inet_sock->recverr) ||
+           (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
+               if (!harderr || sk->sk_state != TCP_ESTABLISHED)
+                       goto out;
+       } else {
+               if (family == AF_INET) {
+                       ip_icmp_error(sk, skb, err, 0 /* no remote port */,
+                                     info, (u8 *)icmph);
+#if IS_ENABLED(CONFIG_IPV6)
+               } else if (family == AF_INET6) {
+                       pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
+                                                  info, (u8 *)icmph);
+#endif
+               }
+       }
+       sk->sk_err = err;
+       sk->sk_error_report(sk);
+out:
+       sock_put(sk);
+}
+EXPORT_SYMBOL_GPL(ping_err);
+
+/*
+ *     Copy and checksum an ICMP Echo packet from user space into a buffer
+ *     starting from the payload.
+ */
+
+int ping_getfrag(void *from, char *to,
+                int offset, int fraglen, int odd, struct sk_buff *skb)
+{
+       struct pingfakehdr *pfh = (struct pingfakehdr *)from;
+
+       if (offset == 0) {
+               fraglen -= sizeof(struct icmphdr);
+               if (fraglen < 0)
+                       BUG();
+               if (csum_and_copy_from_iter(to + sizeof(struct icmphdr),
+                           fraglen, &pfh->wcheck,
+                           &pfh->msg->msg_iter) != fraglen)
+                       return -EFAULT;
+       } else if (offset < sizeof(struct icmphdr)) {
+                       BUG();
+       } else {
+               if (csum_and_copy_from_iter(to, fraglen, &pfh->wcheck,
+                                           &pfh->msg->msg_iter) != fraglen)
+                       return -EFAULT;
+       }
+
+#if IS_ENABLED(CONFIG_IPV6)
+       /* For IPv6, checksum each skb as we go along, as expected by
+        * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
+        * wcheck, it will be finalized in ping_v4_push_pending_frames.
+        */
+       if (pfh->family == AF_INET6) {
+               skb->csum = pfh->wcheck;
+               skb->ip_summed = CHECKSUM_NONE;
+               pfh->wcheck = 0;
+       }
+#endif
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(ping_getfrag);
+
+static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
+                                      struct flowi4 *fl4)
+{
+       struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
+
+       pfh->wcheck = csum_partial((char *)&pfh->icmph,
+               sizeof(struct icmphdr), pfh->wcheck);
+       pfh->icmph.checksum = csum_fold(pfh->wcheck);
+       memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
+       skb->ip_summed = CHECKSUM_NONE;
+       return ip_push_pending_frames(sk, fl4);
+}
+
+int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
+                       void *user_icmph, size_t icmph_len) {
+       u8 type, code;
+
+       if (len > 0xFFFF)
+               return -EMSGSIZE;
+
+       /*
+        *      Check the flags.
+        */
+
+       /* Mirror BSD error message compatibility */
+       if (msg->msg_flags & MSG_OOB)
+               return -EOPNOTSUPP;
+
+       /*
+        *      Fetch the ICMP header provided by the userland.
+        *      iovec is modified! The ICMP header is consumed.
+        */
+       if (memcpy_from_msg(user_icmph, msg, icmph_len))
+               return -EFAULT;
+
+       if (family == AF_INET) {
+               type = ((struct icmphdr *) user_icmph)->type;
+               code = ((struct icmphdr *) user_icmph)->code;
+#if IS_ENABLED(CONFIG_IPV6)
+       } else if (family == AF_INET6) {
+               type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
+               code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
+#endif
+       } else {
+               BUG();
+       }
+
+       if (!ping_supported(family, type, code))
+               return -EINVAL;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(ping_common_sendmsg);
+
+static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
+{
+       struct net *net = sock_net(sk);
+       struct flowi4 fl4;
+       struct inet_sock *inet = inet_sk(sk);
+       struct ipcm_cookie ipc;
+       struct icmphdr user_icmph;
+       struct pingfakehdr pfh;
+       struct rtable *rt = NULL;
+       struct ip_options_data opt_copy;
+       int free = 0;
+       __be32 saddr, daddr, faddr;
+       u8  tos;
+       int err;
+
+       pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
+
+       err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
+                                 sizeof(user_icmph));
+       if (err)
+               return err;
+
+       /*
+        *      Get and verify the address.
+        */
+
+       if (msg->msg_name) {
+               DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
+               if (msg->msg_namelen < sizeof(*usin))
+                       return -EINVAL;
+               if (usin->sin_family != AF_INET)
+                       return -EAFNOSUPPORT;
+               daddr = usin->sin_addr.s_addr;
+               /* no remote port */
+       } else {
+               if (sk->sk_state != TCP_ESTABLISHED)
+                       return -EDESTADDRREQ;
+               daddr = inet->inet_daddr;
+               /* no remote port */
+       }
+
+       ipc.addr = inet->inet_saddr;
+       ipc.opt = NULL;
+       ipc.oif = sk->sk_bound_dev_if;
+       ipc.tx_flags = 0;
+       ipc.ttl = 0;
+       ipc.tos = -1;
+
+       sock_tx_timestamp(sk, &ipc.tx_flags);
+
+       if (msg->msg_controllen) {
+               err = ip_cmsg_send(sock_net(sk), msg, &ipc, false);
+               if (err)
+                       return err;
+               if (ipc.opt)
+                       free = 1;
+       }
+       if (!ipc.opt) {
+               struct ip_options_rcu *inet_opt;
+
+               rcu_read_lock();
+               inet_opt = rcu_dereference(inet->inet_opt);
+               if (inet_opt) {
+                       memcpy(&opt_copy, inet_opt,
+                              sizeof(*inet_opt) + inet_opt->opt.optlen);
+                       ipc.opt = &opt_copy.opt;
+               }
+               rcu_read_unlock();
+       }
+
+       saddr = ipc.addr;
+       ipc.addr = faddr = daddr;
+
+       if (ipc.opt && ipc.opt->opt.srr) {
+               if (!daddr)
+                       return -EINVAL;
+               faddr = ipc.opt->opt.faddr;
+       }
+       tos = get_rttos(&ipc, inet);
+       if (sock_flag(sk, SOCK_LOCALROUTE) ||
+           (msg->msg_flags & MSG_DONTROUTE) ||
+           (ipc.opt && ipc.opt->opt.is_strictroute)) {
+               tos |= RTO_ONLINK;
+       }
+
+       if (ipv4_is_multicast(daddr)) {
+               if (!ipc.oif)
+                       ipc.oif = inet->mc_index;
+               if (!saddr)
+                       saddr = inet->mc_addr;
+       } else if (!ipc.oif)
+               ipc.oif = inet->uc_index;
+
+       flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
+                          RT_SCOPE_UNIVERSE, sk->sk_protocol,
+                          inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
+
+       security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
+       rt = ip_route_output_flow(net, &fl4, sk);
+       if (IS_ERR(rt)) {
+               err = PTR_ERR(rt);
+               rt = NULL;
+               if (err == -ENETUNREACH)
+                       IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
+               goto out;
+       }
+
+       err = -EACCES;
+       if ((rt->rt_flags & RTCF_BROADCAST) &&
+           !sock_flag(sk, SOCK_BROADCAST))
+               goto out;
+
+       if (msg->msg_flags & MSG_CONFIRM)
+               goto do_confirm;
+back_from_confirm:
+
+       if (!ipc.addr)
+               ipc.addr = fl4.daddr;
+
+       lock_sock(sk);
+
+       pfh.icmph.type = user_icmph.type; /* already checked */
+       pfh.icmph.code = user_icmph.code; /* ditto */
+       pfh.icmph.checksum = 0;
+       pfh.icmph.un.echo.id = inet->inet_sport;
+       pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
+       pfh.msg = msg;
+       pfh.wcheck = 0;
+       pfh.family = AF_INET;
+
+       err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
+                       0, &ipc, &rt, msg->msg_flags);
+       if (err)
+               ip_flush_pending_frames(sk);
+       else
+               err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
+       release_sock(sk);
+
+out:
+       ip_rt_put(rt);
+       if (free)
+               kfree(ipc.opt);
+       if (!err) {
+               icmp_out_count(sock_net(sk), user_icmph.type);
+               return len;
+       }
+       return err;
+
+do_confirm:
+       dst_confirm(&rt->dst);
+       if (!(msg->msg_flags & MSG_PROBE) || len)
+               goto back_from_confirm;
+       err = 0;
+       goto out;
+}
+
+int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
+                int flags, int *addr_len)
+{
+       struct inet_sock *isk = inet_sk(sk);
+       int family = sk->sk_family;
+       struct sk_buff *skb;
+       int copied, err;
+
+       pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
+
+       err = -EOPNOTSUPP;
+       if (flags & MSG_OOB)
+               goto out;
+
+       if (flags & MSG_ERRQUEUE)
+               return inet_recv_error(sk, msg, len, addr_len);
+
+       skb = skb_recv_datagram(sk, flags, noblock, &err);
+       if (!skb)
+               goto out;
+
+       copied = skb->len;
+       if (copied > len) {
+               msg->msg_flags |= MSG_TRUNC;
+               copied = len;
+       }
+
+       /* Don't bother checking the checksum */
+       err = skb_copy_datagram_msg(skb, 0, msg, copied);
+       if (err)
+               goto done;
+
+       sock_recv_timestamp(msg, sk, skb);
+
+       /* Copy the address and add cmsg data. */
+       if (family == AF_INET) {
+               DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
+
+               if (sin) {
+                       sin->sin_family = AF_INET;
+                       sin->sin_port = 0 /* skb->h.uh->source */;
+                       sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
+                       memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
+                       *addr_len = sizeof(*sin);
+               }
+
+               if (isk->cmsg_flags)
+                       ip_cmsg_recv(msg, skb);
+
+#if IS_ENABLED(CONFIG_IPV6)
+       } else if (family == AF_INET6) {
+               struct ipv6_pinfo *np = inet6_sk(sk);
+               struct ipv6hdr *ip6 = ipv6_hdr(skb);
+               DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
+
+               if (sin6) {
+                       sin6->sin6_family = AF_INET6;
+                       sin6->sin6_port = 0;
+                       sin6->sin6_addr = ip6->saddr;
+                       sin6->sin6_flowinfo = 0;
+                       if (np->sndflow)
+                               sin6->sin6_flowinfo = ip6_flowinfo(ip6);
+                       sin6->sin6_scope_id =
+                               ipv6_iface_scope_id(&sin6->sin6_addr,
+                                                   inet6_iif(skb));
+                       *addr_len = sizeof(*sin6);
+               }
+
+               if (inet6_sk(sk)->rxopt.all)
+                       pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
+               if (skb->protocol == htons(ETH_P_IPV6) &&
+                   inet6_sk(sk)->rxopt.all)
+                       pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
+               else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
+                       ip_cmsg_recv(msg, skb);
+#endif
+       } else {
+               BUG();
+       }
+
+       err = copied;
+
+done:
+       skb_free_datagram(sk, skb);
+out:
+       pr_debug("ping_recvmsg -> %d\n", err);
+       return err;
+}
+EXPORT_SYMBOL_GPL(ping_recvmsg);
+
+int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+       pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
+                inet_sk(sk), inet_sk(sk)->inet_num, skb);
+       if (sock_queue_rcv_skb(sk, skb) < 0) {
+               kfree_skb(skb);
+               pr_debug("ping_queue_rcv_skb -> failed\n");
+               return -1;
+       }
+       return 0;
+}
+EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
+
+
+/*
+ *     All we need to do is get the socket.
+ */
+
+bool ping_rcv(struct sk_buff *skb)
+{
+       struct sock *sk;
+       struct net *net = dev_net(skb->dev);
+       struct icmphdr *icmph = icmp_hdr(skb);
+
+       /* We assume the packet has already been checked by icmp_rcv */
+
+       pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
+                skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
+
+       /* Push ICMP header back */
+       skb_push(skb, skb->data - (u8 *)icmph);
+
+       sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
+       if (sk) {
+               struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
+
+               pr_debug("rcv on socket %p\n", sk);
+               if (skb2)
+                       ping_queue_rcv_skb(sk, skb2);
+               sock_put(sk);
+               return true;
+       }
+       pr_debug("no socket, dropping\n");
+
+       return false;
+}
+EXPORT_SYMBOL_GPL(ping_rcv);
+
+struct proto ping_prot = {
+       .name =         "PING",
+       .owner =        THIS_MODULE,
+       .init =         ping_init_sock,
+       .close =        ping_close,
+       .connect =      ip4_datagram_connect,
+       .disconnect =   udp_disconnect,
+       .setsockopt =   ip_setsockopt,
+       .getsockopt =   ip_getsockopt,
+       .sendmsg =      ping_v4_sendmsg,
+       .recvmsg =      ping_recvmsg,
+       .bind =         ping_bind,
+       .backlog_rcv =  ping_queue_rcv_skb,
+       .release_cb =   ip4_datagram_release_cb,
+       .hash =         ping_hash,
+       .unhash =       ping_unhash,
+       .get_port =     ping_get_port,
+       .obj_size =     sizeof(struct inet_sock),
+};
+EXPORT_SYMBOL(ping_prot);
+
+#ifdef CONFIG_PROC_FS
+
+static struct sock *ping_get_first(struct seq_file *seq, int start)
+{
+       struct sock *sk;
+       struct ping_iter_state *state = seq->private;
+       struct net *net = seq_file_net(seq);
+
+       for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
+            ++state->bucket) {
+               struct hlist_nulls_node *node;
+               struct hlist_nulls_head *hslot;
+
+               hslot = &ping_table.hash[state->bucket];
+
+               if (hlist_nulls_empty(hslot))
+                       continue;
+
+               sk_nulls_for_each(sk, node, hslot) {
+                       if (net_eq(sock_net(sk), net) &&
+                           sk->sk_family == state->family)
+                               goto found;
+               }
+       }
+       sk = NULL;
+found:
+       return sk;
+}
+
+static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
+{
+       struct ping_iter_state *state = seq->private;
+       struct net *net = seq_file_net(seq);
+
+       do {
+               sk = sk_nulls_next(sk);
+       } while (sk && (!net_eq(sock_net(sk), net)));
+
+       if (!sk)
+               return ping_get_first(seq, state->bucket + 1);
+       return sk;
+}
+
+static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
+{
+       struct sock *sk = ping_get_first(seq, 0);
+
+       if (sk)
+               while (pos && (sk = ping_get_next(seq, sk)) != NULL)
+                       --pos;
+       return pos ? NULL : sk;
+}
+
+void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
+{
+       struct ping_iter_state *state = seq->private;
+       state->bucket = 0;
+       state->family = family;
+
+       read_lock_bh(&ping_table.lock);
+
+       return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
+}
+EXPORT_SYMBOL_GPL(ping_seq_start);
+
+static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
+{
+       return ping_seq_start(seq, pos, AF_INET);
+}
+
+void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+       struct sock *sk;
+
+       if (v == SEQ_START_TOKEN)
+               sk = ping_get_idx(seq, 0);
+       else
+               sk = ping_get_next(seq, v);
+
+       ++*pos;
+       return sk;
+}
+EXPORT_SYMBOL_GPL(ping_seq_next);
+
+void ping_seq_stop(struct seq_file *seq, void *v)
+{
+       read_unlock_bh(&ping_table.lock);
+}
+EXPORT_SYMBOL_GPL(ping_seq_stop);
+
+static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
+               int bucket)
+{
+       struct inet_sock *inet = inet_sk(sp);
+       __be32 dest = inet->inet_daddr;
+       __be32 src = inet->inet_rcv_saddr;
+       __u16 destp = ntohs(inet->inet_dport);
+       __u16 srcp = ntohs(inet->inet_sport);
+
+       seq_printf(f, "%5d: %08X:%04X %08X:%04X"
+               " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
+               bucket, src, srcp, dest, destp, sp->sk_state,
+               sk_wmem_alloc_get(sp),
+               sk_rmem_alloc_get(sp),
+               0, 0L, 0,
+               from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
+               0, sock_i_ino(sp),
+               atomic_read(&sp->sk_refcnt), sp,
+               atomic_read(&sp->sk_drops));
+}
+
+static int ping_v4_seq_show(struct seq_file *seq, void *v)
+{
+       seq_setwidth(seq, 127);
+       if (v == SEQ_START_TOKEN)
+               seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
+                          "rx_queue tr tm->when retrnsmt   uid  timeout "
+                          "inode ref pointer drops");
+       else {
+               struct ping_iter_state *state = seq->private;
+
+               ping_v4_format_sock(v, seq, state->bucket);
+       }
+       seq_pad(seq, '\n');
+       return 0;
+}
+
+static const struct seq_operations ping_v4_seq_ops = {
+       .show           = ping_v4_seq_show,
+       .start          = ping_v4_seq_start,
+       .next           = ping_seq_next,
+       .stop           = ping_seq_stop,
+};
+
+static int ping_seq_open(struct inode *inode, struct file *file)
+{
+       struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
+       return seq_open_net(inode, file, &afinfo->seq_ops,
+                          sizeof(struct ping_iter_state));
+}
+
+const struct file_operations ping_seq_fops = {
+       .open           = ping_seq_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = seq_release_net,
+};
+EXPORT_SYMBOL_GPL(ping_seq_fops);
+
+static struct ping_seq_afinfo ping_v4_seq_afinfo = {
+       .name           = "icmp",
+       .family         = AF_INET,
+       .seq_fops       = &ping_seq_fops,
+       .seq_ops        = {
+               .start          = ping_v4_seq_start,
+               .show           = ping_v4_seq_show,
+               .next           = ping_seq_next,
+               .stop           = ping_seq_stop,
+       },
+};
+
+int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
+{
+       struct proc_dir_entry *p;
+       p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
+                            afinfo->seq_fops, afinfo);
+       if (!p)
+               return -ENOMEM;
+       return 0;
+}
+EXPORT_SYMBOL_GPL(ping_proc_register);
+
+void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
+{
+       remove_proc_entry(afinfo->name, net->proc_net);
+}
+EXPORT_SYMBOL_GPL(ping_proc_unregister);
+
+static int __net_init ping_v4_proc_init_net(struct net *net)
+{
+       return ping_proc_register(net, &ping_v4_seq_afinfo);
+}
+
+static void __net_exit ping_v4_proc_exit_net(struct net *net)
+{
+       ping_proc_unregister(net, &ping_v4_seq_afinfo);
+}
+
+static struct pernet_operations ping_v4_net_ops = {
+       .init = ping_v4_proc_init_net,
+       .exit = ping_v4_proc_exit_net,
+};
+
+int __init ping_proc_init(void)
+{
+       return register_pernet_subsys(&ping_v4_net_ops);
+}
+
+void ping_proc_exit(void)
+{
+       unregister_pernet_subsys(&ping_v4_net_ops);
+}
+
+#endif
+
+void __init ping_init(void)
+{
+       int i;
+
+       for (i = 0; i < PING_HTABLE_SIZE; i++)
+               INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
+       rwlock_init(&ping_table.lock);
+}