Commit 95a066d8 authored by Sven Eckelmann's avatar Sven Eckelmann Committed by Antonio Quartulli
Browse files

batman-adv: Add function to calculate crc32c for the skb payload 



Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
Signed-off-by: default avatarMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: default avatarAntonio Quartulli <ordex@autistici.org>
parent 60d8cce7

net/batman-adv/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ config BATMAN_ADV 
	tristate "B.A.T.M.A.N. Advanced Meshing Protocol"

	depends on NET

	select CRC16

	select LIBCRC32C

        default n

	help

          B.A.T.M.A.N. (better approach to mobile ad-hoc networking) is

net/batman-adv/main.c

+34 −0
Original line number Diff line number Diff line
@@ -17,6 +17,8 @@ 
 * 02110-1301, USA

 */



#include <linux/crc32c.h>

#include <linux/highmem.h>

#include "main.h"

#include "sysfs.h"

#include "debugfs.h"
@@ -420,6 +422,38 @@ int batadv_algo_seq_print_text(struct seq_file *seq, void *offset) 
	return 0;

}



/**

 * batadv_skb_crc32 - calculate CRC32 of the whole packet and skip bytes in

 *  the header

 * @skb: skb pointing to fragmented socket buffers

 * @payload_ptr: Pointer to position inside the head buffer of the skb

 *  marking the start of the data to be CRC'ed

 *

 * payload_ptr must always point to an address in the skb head buffer and not to

 * a fragment.

 */

__be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)

{

	u32 crc = 0;

	unsigned int from;

	unsigned int to = skb->len;

	struct skb_seq_state st;

	const u8 *data;

	unsigned int len;

	unsigned int consumed = 0;



	from = (unsigned int)(payload_ptr - skb->data);



	skb_prepare_seq_read(skb, from, to, &st);

	while ((len = skb_seq_read(consumed, &data, &st)) != 0) {

		crc = crc32c(crc, data, len);

		consumed += len;

	}

	skb_abort_seq_read(&st);



	return htonl(crc);

}



static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)

{

	struct batadv_algo_ops *bat_algo_ops;

net/batman-adv/main.h

+1 −0
Original line number Diff line number Diff line
@@ -174,6 +174,7 @@ void batadv_recv_handler_unregister(uint8_t packet_type); 
int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops);

int batadv_algo_select(struct batadv_priv *bat_priv, char *name);

int batadv_algo_seq_print_text(struct seq_file *seq, void *offset);

__be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr);



/**

 * enum batadv_dbg_level - available log levels