Staging: batman-adv: record route for ICMP messages

The standard layer 3 ping utility can use the record route (RR) option
of IP to collect route data for sent ping messages (ping -R). This
patch introduces comparable functionality for batman-adv ICMP messages.

The patch adds a second batman ICMP packet format (icmp_packet_rr) such
that up to 17 MAC addresses can be recorded (sufficient for up to 8
hops per direction). When no RR is wanted, the old icmp_packet without
the RR overhead can be sent.

Signed-off-by: Daniel Seither <post@tiwoc.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
[sven.eckelmann@gmx.de: Rework on top of current version]
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 27 insertions, 18 deletions

diff --git a/drivers/staging/batman-adv/icmp_socket.c b/drivers/staging/batman-adv/icmp_socket.c
index d4411cbe350..08a5f7b7b11 100644
--- a/drivers/staging/batman-adv/icmp_socket.c
+++ b/drivers/staging/batman-adv/icmp_socket.c
@@ -32,7 +32,8 @@
 static struct socket_client *socket_client_hash[256];
 
 static void bat_socket_add_packet(struct socket_client *socket_client,
-                                  struct icmp_packet *icmp_packet);
+                                  struct icmp_packet_rr *icmp_packet,
+                                  size_t icmp_len);
 
 void bat_socket_init(void)
 {
@@ -110,6 +111,7 @@ static ssize_t bat_socket_read(struct file *file, char __user *buf,
         struct socket_client *socket_client =
                 (struct socket_client *)file->private_data;
         struct socket_packet *socket_packet;
+        size_t packet_len;
         int error;
         unsigned long flags;
 
@@ -138,14 +140,15 @@ static ssize_t bat_socket_read(struct file *file, char __user *buf,
         spin_unlock_irqrestore(&socket_client->lock, flags);
 
         error = __copy_to_user(buf, &socket_packet->icmp_packet,
-                               sizeof(struct icmp_packet));
+                               socket_packet->icmp_len);
 
+        packet_len = socket_packet->icmp_len;
         kfree(socket_packet);
 
         if (error)
                 return -EFAULT;
 
-        return sizeof(struct icmp_packet);
+        return packet_len;
 }
 
 static ssize_t bat_socket_write(struct file *file, const char __user *buff,
@@ -153,9 +156,10 @@ static ssize_t bat_socket_write(struct file *file, const char __user *buff,
 {
         struct socket_client *socket_client =
                 (struct socket_client *)file->private_data;
-        struct icmp_packet icmp_packet;
+        struct icmp_packet_rr icmp_packet;
         struct orig_node *orig_node;
         struct batman_if *batman_if;
+        size_t packet_len = sizeof(struct icmp_packet);
         uint8_t dstaddr[ETH_ALEN];
         unsigned long flags;
 
@@ -166,10 +170,13 @@ static ssize_t bat_socket_write(struct file *file, const char __user *buff,
                 return -EINVAL;
         }
 
-        if (!access_ok(VERIFY_READ, buff, sizeof(struct icmp_packet)))
+        if (len >= sizeof(struct icmp_packet_rr))
+                packet_len = sizeof(struct icmp_packet_rr);
+
+        if (!access_ok(VERIFY_READ, buff, packet_len))
                 return -EFAULT;
 
-        if (__copy_from_user(&icmp_packet, buff, sizeof(icmp_packet)))
+        if (__copy_from_user(&icmp_packet, buff, packet_len))
                 return -EFAULT;
 
         if (icmp_packet.packet_type != BAT_ICMP) {
@@ -191,7 +198,7 @@ static ssize_t bat_socket_write(struct file *file, const char __user *buff,
         if (icmp_packet.version != COMPAT_VERSION) {
                 icmp_packet.msg_type = PARAMETER_PROBLEM;
                 icmp_packet.ttl = COMPAT_VERSION;
-                bat_socket_add_packet(socket_client, &icmp_packet);
+                bat_socket_add_packet(socket_client, &icmp_packet, packet_len);
                 goto out;
         }
 
@@ -218,13 +225,13 @@ static ssize_t bat_socket_write(struct file *file, const char __user *buff,
         if (batman_if->if_status != IF_ACTIVE)
                 goto dst_unreach;
 
-        memcpy(icmp_packet.orig,
-               batman_if->net_dev->dev_addr,
-               ETH_ALEN);
+        memcpy(icmp_packet.orig, batman_if->net_dev->dev_addr, ETH_ALEN);
+
+        if (packet_len == sizeof(struct icmp_packet_rr))
+                memcpy(icmp_packet.rr, batman_if->net_dev->dev_addr, ETH_ALEN);
 
         send_raw_packet((unsigned char *)&icmp_packet,
-                        sizeof(struct icmp_packet),
-                        batman_if, dstaddr);
+                        packet_len, batman_if, dstaddr);
 
         goto out;
 
@@ -232,7 +239,7 @@ unlock:
         spin_unlock_irqrestore(&orig_hash_lock, flags);
 dst_unreach:
         icmp_packet.msg_type = DESTINATION_UNREACHABLE;
-        bat_socket_add_packet(socket_client, &icmp_packet);
+        bat_socket_add_packet(socket_client, &icmp_packet, packet_len);
 out:
         return len;
 }
@@ -278,7 +285,8 @@ err:
 }
 
 static void bat_socket_add_packet(struct socket_client *socket_client,
-                                  struct icmp_packet *icmp_packet)
+                                  struct icmp_packet_rr *icmp_packet,
+                                  size_t icmp_len)
 {
         struct socket_packet *socket_packet;
         unsigned long flags;
@@ -289,8 +297,8 @@ static void bat_socket_add_packet(struct socket_client *socket_client,
                 return;
 
         INIT_LIST_HEAD(&socket_packet->list);
-        memcpy(&socket_packet->icmp_packet, icmp_packet,
-               sizeof(struct icmp_packet));
+        memcpy(&socket_packet->icmp_packet, icmp_packet, icmp_len);
+        socket_packet->icmp_len = icmp_len;
 
         spin_lock_irqsave(&socket_client->lock, flags);
 
@@ -319,10 +327,11 @@ static void bat_socket_add_packet(struct socket_client *socket_client,
         wake_up(&socket_client->queue_wait);
 }
 
-void bat_socket_receive_packet(struct icmp_packet *icmp_packet)
+void bat_socket_receive_packet(struct icmp_packet_rr *icmp_packet,
+                               size_t icmp_len)
 {
         struct socket_client *hash = socket_client_hash[icmp_packet->uid];
 
         if (hash)
-                bat_socket_add_packet(hash, icmp_packet);
+                bat_socket_add_packet(hash, icmp_packet, icmp_len);
 }