1 files changed, 392 insertions, 0 deletions
diff --git a/net/batman-adv/icmp_socket.c b/net/batman-adv/icmp_socket.c
new file mode 100644
index 000000000..8bdabc03b
--- /dev/null
+++ b/net/batman-adv/icmp_socket.c
@@ -0,0 +1,392 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2007-2020  B.A.T.M.A.N. contributors:
+ *
+ * Marek Lindner
+ */
+
+#include "icmp_socket.h"
+#include "main.h"
+
+#include <linux/atomic.h>
+#include <linux/compiler.h>
+#include <linux/debugfs.h>
+#include <linux/errno.h>
+#include <linux/etherdevice.h>
+#include <linux/eventpoll.h>
+#include <linux/export.h>
+#include <linux/fcntl.h>
+#include <linux/fs.h>
+#include <linux/gfp.h>
+#include <linux/if_ether.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/pkt_sched.h>
+#include <linux/poll.h>
+#include <linux/printk.h>
+#include <linux/sched.h> /* for linux/wait.h */
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/stddef.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <linux/wait.h>
+#include <uapi/linux/batadv_packet.h>
+
+#include "debugfs.h"
+#include "hard-interface.h"
+#include "log.h"
+#include "originator.h"
+#include "send.h"
+
+static struct batadv_socket_client *batadv_socket_client_hash[256];
+
+static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
+				     struct batadv_icmp_header *icmph,
+				     size_t icmp_len);
+
+/**
+ * batadv_socket_init() - Initialize soft interface independent socket data
+ */
+void batadv_socket_init(void)
+{
+	memset(batadv_socket_client_hash, 0, sizeof(batadv_socket_client_hash));
+}
+
+static int batadv_socket_open(struct inode *inode, struct file *file)
+{
+	unsigned int i;
+	struct batadv_socket_client *socket_client;
+
+	if (!try_module_get(THIS_MODULE))
+		return -EBUSY;
+
+	batadv_debugfs_deprecated(file, "");
+
+	stream_open(inode, file);
+
+	socket_client = kmalloc(sizeof(*socket_client), GFP_KERNEL);
+	if (!socket_client) {
+		module_put(THIS_MODULE);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(batadv_socket_client_hash); i++) {
+		if (!batadv_socket_client_hash[i]) {
+			batadv_socket_client_hash[i] = socket_client;
+			break;
+		}
+	}
+
+	if (i == ARRAY_SIZE(batadv_socket_client_hash)) {
+		pr_err("Error - can't add another packet client: maximum number of clients reached\n");
+		kfree(socket_client);
+		module_put(THIS_MODULE);
+		return -EXFULL;
+	}
+
+	INIT_LIST_HEAD(&socket_client->queue_list);
+	socket_client->queue_len = 0;
+	socket_client->index = i;
+	socket_client->bat_priv = inode->i_private;
+	spin_lock_init(&socket_client->lock);
+	init_waitqueue_head(&socket_client->queue_wait);
+
+	file->private_data = socket_client;
+
+	return 0;
+}
+
+static int batadv_socket_release(struct inode *inode, struct file *file)
+{
+	struct batadv_socket_client *client = file->private_data;
+	struct batadv_socket_packet *packet, *tmp;
+
+	spin_lock_bh(&client->lock);
+
+	/* for all packets in the queue ... */
+	list_for_each_entry_safe(packet, tmp, &client->queue_list, list) {
+		list_del(&packet->list);
+		kfree(packet);
+	}
+
+	batadv_socket_client_hash[client->index] = NULL;
+	spin_unlock_bh(&client->lock);
+
+	kfree(client);
+	module_put(THIS_MODULE);
+
+	return 0;
+}
+
+static ssize_t batadv_socket_read(struct file *file, char __user *buf,
+				  size_t count, loff_t *ppos)
+{
+	struct batadv_socket_client *socket_client = file->private_data;
+	struct batadv_socket_packet *socket_packet;
+	size_t packet_len;
+	int error;
+
+	if ((file->f_flags & O_NONBLOCK) && socket_client->queue_len == 0)
+		return -EAGAIN;
+
+	if (!buf || count < sizeof(struct batadv_icmp_packet))
+		return -EINVAL;
+
+	error = wait_event_interruptible(socket_client->queue_wait,
+					 socket_client->queue_len);
+
+	if (error)
+		return error;
+
+	spin_lock_bh(&socket_client->lock);
+
+	socket_packet = list_first_entry(&socket_client->queue_list,
+					 struct batadv_socket_packet, list);
+	list_del(&socket_packet->list);
+	socket_client->queue_len--;
+
+	spin_unlock_bh(&socket_client->lock);
+
+	packet_len = min(count, socket_packet->icmp_len);
+	error = copy_to_user(buf, &socket_packet->icmp_packet, packet_len);
+
+	kfree(socket_packet);
+
+	if (error)
+		return -EFAULT;
+
+	return packet_len;
+}
+
+static ssize_t batadv_socket_write(struct file *file, const char __user *buff,
+				   size_t len, loff_t *off)
+{
+	struct batadv_socket_client *socket_client = file->private_data;
+	struct batadv_priv *bat_priv = socket_client->bat_priv;
+	struct batadv_hard_iface *primary_if = NULL;
+	struct sk_buff *skb;
+	struct batadv_icmp_packet_rr *icmp_packet_rr;
+	struct batadv_icmp_header *icmp_header;
+	struct batadv_orig_node *orig_node = NULL;
+	struct batadv_neigh_node *neigh_node = NULL;
+	size_t packet_len = sizeof(struct batadv_icmp_packet);
+	u8 *addr;
+
+	if (len < sizeof(struct batadv_icmp_header)) {
+		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+			   "Error - can't send packet from char device: invalid packet size\n");
+		return -EINVAL;
+	}
+
+	primary_if = batadv_primary_if_get_selected(bat_priv);
+
+	if (!primary_if) {
+		len = -EFAULT;
+		goto out;
+	}
+
+	if (len >= BATADV_ICMP_MAX_PACKET_SIZE)
+		packet_len = BATADV_ICMP_MAX_PACKET_SIZE;
+	else
+		packet_len = len;
+
+	skb = netdev_alloc_skb_ip_align(NULL, packet_len + ETH_HLEN);
+	if (!skb) {
+		len = -ENOMEM;
+		goto out;
+	}
+
+	skb->priority = TC_PRIO_CONTROL;
+	skb_reserve(skb, ETH_HLEN);
+	icmp_header = skb_put(skb, packet_len);
+
+	if (copy_from_user(icmp_header, buff, packet_len)) {
+		len = -EFAULT;
+		goto free_skb;
+	}
+
+	if (icmp_header->packet_type != BATADV_ICMP) {
+		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+			   "Error - can't send packet from char device: got bogus packet type (expected: BAT_ICMP)\n");
+		len = -EINVAL;
+		goto free_skb;
+	}
+
+	switch (icmp_header->msg_type) {
+	case BATADV_ECHO_REQUEST:
+		if (len < sizeof(struct batadv_icmp_packet)) {
+			batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+				   "Error - can't send packet from char device: invalid packet size\n");
+			len = -EINVAL;
+			goto free_skb;
+		}
+
+		if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
+			goto dst_unreach;
+
+		orig_node = batadv_orig_hash_find(bat_priv, icmp_header->dst);
+		if (!orig_node)
+			goto dst_unreach;
+
+		neigh_node = batadv_orig_router_get(orig_node,
+						    BATADV_IF_DEFAULT);
+		if (!neigh_node)
+			goto dst_unreach;
+
+		if (!neigh_node->if_incoming)
+			goto dst_unreach;
+
+		if (neigh_node->if_incoming->if_status != BATADV_IF_ACTIVE)
+			goto dst_unreach;
+
+		icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmp_header;
+		if (packet_len == sizeof(*icmp_packet_rr)) {
+			addr = neigh_node->if_incoming->net_dev->dev_addr;
+			ether_addr_copy(icmp_packet_rr->rr[0], addr);
+		}
+
+		break;
+	default:
+		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+			   "Error - can't send packet from char device: got unknown message type\n");
+		len = -EINVAL;
+		goto free_skb;
+	}
+
+	icmp_header->uid = socket_client->index;
+
+	if (icmp_header->version != BATADV_COMPAT_VERSION) {
+		icmp_header->msg_type = BATADV_PARAMETER_PROBLEM;
+		icmp_header->version = BATADV_COMPAT_VERSION;
+		batadv_socket_add_packet(socket_client, icmp_header,
+					 packet_len);
+		goto free_skb;
+	}
+
+	ether_addr_copy(icmp_header->orig, primary_if->net_dev->dev_addr);
+
+	batadv_send_unicast_skb(skb, neigh_node);
+	goto out;
+
+dst_unreach:
+	icmp_header->msg_type = BATADV_DESTINATION_UNREACHABLE;
+	batadv_socket_add_packet(socket_client, icmp_header, packet_len);
+free_skb:
+	kfree_skb(skb);
+out:
+	if (primary_if)
+		batadv_hardif_put(primary_if);
+	if (neigh_node)
+		batadv_neigh_node_put(neigh_node);
+	if (orig_node)
+		batadv_orig_node_put(orig_node);
+	return len;
+}
+
+static __poll_t batadv_socket_poll(struct file *file, poll_table *wait)
+{
+	struct batadv_socket_client *socket_client = file->private_data;
+
+	poll_wait(file, &socket_client->queue_wait, wait);
+
+	if (socket_client->queue_len > 0)
+		return EPOLLIN | EPOLLRDNORM;
+
+	return 0;
+}
+
+static const struct file_operations batadv_fops = {
+	.owner = THIS_MODULE,
+	.open = batadv_socket_open,
+	.release = batadv_socket_release,
+	.read = batadv_socket_read,
+	.write = batadv_socket_write,
+	.poll = batadv_socket_poll,
+	.llseek = no_llseek,
+};
+
+/**
+ * batadv_socket_setup() - Create debugfs "socket" file
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+void batadv_socket_setup(struct batadv_priv *bat_priv)
+{
+	debugfs_create_file(BATADV_ICMP_SOCKET, 0600, bat_priv->debug_dir,
+			    bat_priv, &batadv_fops);
+}
+
+/**
+ * batadv_socket_add_packet() - schedule an icmp packet to be sent to
+ *  userspace on an icmp socket.
+ * @socket_client: the socket this packet belongs to
+ * @icmph: pointer to the header of the icmp packet
+ * @icmp_len: total length of the icmp packet
+ */
+static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
+				     struct batadv_icmp_header *icmph,
+				     size_t icmp_len)
+{
+	struct batadv_socket_packet *socket_packet;
+	size_t len;
+
+	socket_packet = kmalloc(sizeof(*socket_packet), GFP_ATOMIC);
+
+	if (!socket_packet)
+		return;
+
+	len = icmp_len;
+	/* check the maximum length before filling the buffer */
+	if (len > sizeof(socket_packet->icmp_packet))
+		len = sizeof(socket_packet->icmp_packet);
+
+	INIT_LIST_HEAD(&socket_packet->list);
+	memcpy(&socket_packet->icmp_packet, icmph, len);
+	socket_packet->icmp_len = len;
+
+	spin_lock_bh(&socket_client->lock);
+
+	/* while waiting for the lock the socket_client could have been
+	 * deleted
+	 */
+	if (!batadv_socket_client_hash[icmph->uid]) {
+		spin_unlock_bh(&socket_client->lock);
+		kfree(socket_packet);
+		return;
+	}
+
+	list_add_tail(&socket_packet->list, &socket_client->queue_list);
+	socket_client->queue_len++;
+
+	if (socket_client->queue_len > 100) {
+		socket_packet = list_first_entry(&socket_client->queue_list,
+						 struct batadv_socket_packet,
+						 list);
+
+		list_del(&socket_packet->list);
+		kfree(socket_packet);
+		socket_client->queue_len--;
+	}
+
+	spin_unlock_bh(&socket_client->lock);
+
+	wake_up(&socket_client->queue_wait);
+}
+
+/**
+ * batadv_socket_receive_packet() - schedule an icmp packet to be received
+ *  locally and sent to userspace.
+ * @icmph: pointer to the header of the icmp packet
+ * @icmp_len: total length of the icmp packet
+ */
+void batadv_socket_receive_packet(struct batadv_icmp_header *icmph,
+				  size_t icmp_len)
+{
+	struct batadv_socket_client *hash;
+
+	hash = batadv_socket_client_hash[icmph->uid];
+	if (hash)
+		batadv_socket_add_packet(hash, icmph, icmp_len);
+}