linux/net/llc/llc_output.c
Dave Jones 0f1a24c9a9 llc: remove noisy WARN from llc_mac_hdr_init
Sending malformed llc packets triggers this spew, which seems excessive.

WARNING: CPU: 1 PID: 6917 at net/llc/llc_output.c:46 llc_mac_hdr_init+0x85/0x90 [llc]()
device type not supported: 0
CPU: 1 PID: 6917 Comm: trinity-c1 Not tainted 3.13.0+ 
 0000000000000009 00000000007e257d ffff88009232fbe8 ffffffffac737325
 ffff88009232fc30 ffff88009232fc20 ffffffffac06d28d ffff88020e07f180
 ffff88009232fec0 00000000000000c8 0000000000000000 ffff88009232fe70
Call Trace:
 [<ffffffffac737325>] dump_stack+0x4e/0x7a
 [<ffffffffac06d28d>] warn_slowpath_common+0x7d/0xa0
 [<ffffffffac06d30c>] warn_slowpath_fmt+0x5c/0x80
 [<ffffffffc01736d5>] llc_mac_hdr_init+0x85/0x90 [llc]
 [<ffffffffc0173759>] llc_build_and_send_ui_pkt+0x79/0x90 [llc]
 [<ffffffffc057cdba>] llc_ui_sendmsg+0x23a/0x400 [llc2]
 [<ffffffffac605d8c>] sock_sendmsg+0x9c/0xe0
 [<ffffffffac185a37>] ? might_fault+0x47/0x50
 [<ffffffffac606321>] SYSC_sendto+0x121/0x1c0
 [<ffffffffac011847>] ? syscall_trace_enter+0x207/0x270
 [<ffffffffac6071ce>] SyS_sendto+0xe/0x10
 [<ffffffffac74aaa4>] tracesys+0xdd/0xe2

Until 2009, this was a printk, when it was changed in
bf9ae5386b: "llc: use dev_hard_header".

Let userland figure out what -EINVAL means by itself.

Signed-off-by: Dave Jones <davej@fedoraproject.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-28 18:01:32 -08:00

80 lines
2.3 KiB
C

/*
* llc_output.c - LLC minimal output path
*
* Copyright (c) 1997 by Procom Technology, Inc.
* 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
*
* This program can be redistributed or modified under the terms of the
* GNU General Public License version 2 as published by the Free Software
* Foundation.
* This program is distributed without any warranty or implied warranty
* of merchantability or fitness for a particular purpose.
*
* See the GNU General Public License version 2 for more details.
*/
#include <linux/if_arp.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/export.h>
#include <net/llc.h>
#include <net/llc_pdu.h>
/**
* llc_mac_hdr_init - fills MAC header fields
* @skb: Address of the frame to initialize its MAC header
* @sa: The MAC source address
* @da: The MAC destination address
*
* Fills MAC header fields, depending on MAC type. Returns 0, If MAC type
* is a valid type and initialization completes correctly 1, otherwise.
*/
int llc_mac_hdr_init(struct sk_buff *skb,
const unsigned char *sa, const unsigned char *da)
{
int rc = -EINVAL;
switch (skb->dev->type) {
case ARPHRD_ETHER:
case ARPHRD_LOOPBACK:
rc = dev_hard_header(skb, skb->dev, ETH_P_802_2, da, sa,
skb->len);
if (rc > 0)
rc = 0;
break;
default:
break;
}
return rc;
}
/**
* llc_build_and_send_ui_pkt - unitdata request interface for upper layers
* @sap: sap to use
* @skb: packet to send
* @dmac: destination mac address
* @dsap: destination sap
*
* Upper layers calls this function when upper layer wants to send data
* using connection-less mode communication (UI pdu).
*
* Accept data frame from network layer to be sent using connection-
* less mode communication; timeout/retries handled by network layer;
* package primitive as an event and send to SAP event handler
*/
int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb,
unsigned char *dmac, unsigned char dsap)
{
int rc;
llc_pdu_header_init(skb, LLC_PDU_TYPE_U, sap->laddr.lsap,
dsap, LLC_PDU_CMD);
llc_pdu_init_as_ui_cmd(skb);
rc = llc_mac_hdr_init(skb, skb->dev->dev_addr, dmac);
if (likely(!rc))
rc = dev_queue_xmit(skb);
return rc;
}
EXPORT_SYMBOL(llc_mac_hdr_init);
EXPORT_SYMBOL(llc_build_and_send_ui_pkt);