Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1209 insertions, 0 deletions

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
new file mode 100644
index 000000000..2e7abad48
--- /dev/null
+++ b/net/ipv4/ping.c
@@ -0,0 +1,1209 @@
+/*
+ * 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);
+
+int 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." */
+
+	return 0;
+}
+
+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);
+	write_lock_bh(&ping_table.lock);
+	if (sk_hashed(sk)) {
+		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, sdif;
+
+	if (skb->protocol == htons(ETH_P_IP)) {
+		dif = inet_iif(skb);
+		sdif = inet_sdif(skb);
+		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)) {
+		dif = inet6_iif(skb);
+		sdif = inet6_sdif(skb);
+		pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
+			 (int)ident, &ipv6_hdr(skb)->daddr, dif);
+#endif
+	} else {
+		return NULL;
+	}
+
+	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 &&
+		    sk->sk_bound_dev_if != sdif)
+			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;
+	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();
+	for (i = 0; i < group_info->ngroups; i++) {
+		kgid_t gid = group_info->gid[i];
+
+		if (gid_lte(low, gid) && gid_lte(gid, high))
+			goto out_release_group;
+	}
+
+	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", refcount_read(&sk->sk_refcnt));
+
+	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;
+		u32 tb_id = RT_TABLE_LOCAL;
+		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));
+
+		tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
+		chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
+
+		if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
+			chk_addr_ret = RTN_LOCAL;
+
+		if ((!inet_can_nonlocal_bind(net, isk) &&
+		     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;
+			}
+		}
+
+		if (!dev && sk->sk_bound_dev_if) {
+			dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
+			if (!dev) {
+				rcu_read_unlock();
+				return -ENODEV;
+			}
+		}
+		has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
+						    scoped);
+		rcu_read_unlock();
+
+		if (!(ipv6_can_nonlocal_bind(net, isk) || 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 = %hu, dif = %d\n",
+		 isk->inet_num,
+		 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_full(to + sizeof(struct icmphdr),
+			    fraglen, &pfh->wcheck,
+			    &pfh->msg->msg_iter))
+			return -EFAULT;
+	} else if (offset < sizeof(struct icmphdr)) {
+			BUG();
+	} else {
+		if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck,
+					    &pfh->msg->msg_iter))
+			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);
+
+	if (!skb)
+		return 0;
+	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;
+
+	/* Must have at least a full ICMP header. */
+	if (len < icmph_len)
+		return -EINVAL;
+
+	/*
+	 *	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 */
+	}
+
+	ipcm_init_sk(&ipc, inet);
+
+	if (msg->msg_controllen) {
+		err = ip_cmsg_send(sk, msg, &ipc, false);
+		if (unlikely(err)) {
+			kfree(ipc.opt);
+			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) {
+			err = -EINVAL;
+			goto out_free;
+		}
+		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,
+			   sk->sk_uid);
+
+	fl4.fl4_icmp_type = user_icmph.type;
+	fl4.fl4_icmp_code = user_icmph.code;
+
+	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);
+out_free:
+	if (free)
+		kfree(ipc.opt);
+	if (!err) {
+		icmp_out_count(sock_net(sk), user_icmph.type);
+		return len;
+	}
+	return err;
+
+do_confirm:
+	if (msg->msg_flags & MSG_PROBE)
+		dst_confirm_neigh(&rt->dst, &fl4.daddr);
+	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);
+	bool rc = false;
+
+	/* 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))
+			rc = true;
+		sock_put(sk);
+	}
+
+	if (!rc)
+		pr_debug("no socket, dropping\n");
+
+	return rc;
+}
+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)
+	__acquires(ping_table.lock)
+{
+	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)
+	__releases(ping_table.lock)
+{
+	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),
+		refcount_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 = {
+	.start		= ping_v4_seq_start,
+	.show		= ping_v4_seq_show,
+	.next		= ping_seq_next,
+	.stop		= ping_seq_stop,
+};
+
+static int __net_init ping_v4_proc_init_net(struct net *net)
+{
+	if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops,
+			sizeof(struct ping_iter_state)))
+		return -ENOMEM;
+	return 0;
+}
+
+static void __net_exit ping_v4_proc_exit_net(struct net *net)
+{
+	remove_proc_entry("icmp", net->proc_net);
+}
+
+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);
+}