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linux/net/lapb/lapb_subr.c

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/*
* LAPB release 002
*
* This code REQUIRES 2.1.15 or higher/ NET3.038
*
* This module:
* This module 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.
*
* History
* LAPB 001 Jonathan Naylor Started Coding
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/inet.h>
#include <linux/skbuff.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 01:04:11 -07:00
#include <linux/slab.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <net/lapb.h>
/*
* This routine purges all the queues of frames.
*/
void lapb_clear_queues(struct lapb_cb *lapb)
{
skb_queue_purge(&lapb->write_queue);
skb_queue_purge(&lapb->ack_queue);
}
/*
* This routine purges the input queue of those frames that have been
* acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
* SDL diagram.
*/
void lapb_frames_acked(struct lapb_cb *lapb, unsigned short nr)
{
struct sk_buff *skb;
int modulus;
modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS;
/*
* Remove all the ack-ed frames from the ack queue.
*/
if (lapb->va != nr)
while (skb_peek(&lapb->ack_queue) && lapb->va != nr) {
skb = skb_dequeue(&lapb->ack_queue);
kfree_skb(skb);
lapb->va = (lapb->va + 1) % modulus;
}
}
void lapb_requeue_frames(struct lapb_cb *lapb)
{
struct sk_buff *skb, *skb_prev = NULL;
/*
* Requeue all the un-ack-ed frames on the output queue to be picked
* up by lapb_kick called from the timer. This arrangement handles the
* possibility of an empty output queue.
*/
while ((skb = skb_dequeue(&lapb->ack_queue)) != NULL) {
if (!skb_prev)
skb_queue_head(&lapb->write_queue, skb);
else
skb_append(skb_prev, skb, &lapb->write_queue);
skb_prev = skb;
}
}
/*
* Validate that the value of nr is between va and vs. Return true or
* false for testing.
*/
int lapb_validate_nr(struct lapb_cb *lapb, unsigned short nr)
{
unsigned short vc = lapb->va;
int modulus;
modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS;
while (vc != lapb->vs) {
if (nr == vc)
return 1;
vc = (vc + 1) % modulus;
}
return nr == lapb->vs;
}
/*
* This routine is the centralised routine for parsing the control
* information for the different frame formats.
*/
int lapb_decode(struct lapb_cb *lapb, struct sk_buff *skb,
struct lapb_frame *frame)
{
frame->type = LAPB_ILLEGAL;
lapb_dbg(2, "(%p) S%d RX %02X %02X %02X\n",
lapb->dev, lapb->state,
skb->data[0], skb->data[1], skb->data[2]);
/* We always need to look at 2 bytes, sometimes we need
* to look at 3 and those cases are handled below.
*/
if (!pskb_may_pull(skb, 2))
return -1;
if (lapb->mode & LAPB_MLP) {
if (lapb->mode & LAPB_DCE) {
if (skb->data[0] == LAPB_ADDR_D)
frame->cr = LAPB_COMMAND;
if (skb->data[0] == LAPB_ADDR_C)
frame->cr = LAPB_RESPONSE;
} else {
if (skb->data[0] == LAPB_ADDR_C)
frame->cr = LAPB_COMMAND;
if (skb->data[0] == LAPB_ADDR_D)
frame->cr = LAPB_RESPONSE;
}
} else {
if (lapb->mode & LAPB_DCE) {
if (skb->data[0] == LAPB_ADDR_B)
frame->cr = LAPB_COMMAND;
if (skb->data[0] == LAPB_ADDR_A)
frame->cr = LAPB_RESPONSE;
} else {
if (skb->data[0] == LAPB_ADDR_A)
frame->cr = LAPB_COMMAND;
if (skb->data[0] == LAPB_ADDR_B)
frame->cr = LAPB_RESPONSE;
}
}
skb_pull(skb, 1);
if (lapb->mode & LAPB_EXTENDED) {
if (!(skb->data[0] & LAPB_S)) {
if (!pskb_may_pull(skb, 2))
return -1;
/*
* I frame - carries NR/NS/PF
*/
frame->type = LAPB_I;
frame->ns = (skb->data[0] >> 1) & 0x7F;
frame->nr = (skb->data[1] >> 1) & 0x7F;
frame->pf = skb->data[1] & LAPB_EPF;
frame->control[0] = skb->data[0];
frame->control[1] = skb->data[1];
skb_pull(skb, 2);
} else if ((skb->data[0] & LAPB_U) == 1) {
if (!pskb_may_pull(skb, 2))
return -1;
/*
* S frame - take out PF/NR
*/
frame->type = skb->data[0] & 0x0F;
frame->nr = (skb->data[1] >> 1) & 0x7F;
frame->pf = skb->data[1] & LAPB_EPF;
frame->control[0] = skb->data[0];
frame->control[1] = skb->data[1];
skb_pull(skb, 2);
} else if ((skb->data[0] & LAPB_U) == 3) {
/*
* U frame - take out PF
*/
frame->type = skb->data[0] & ~LAPB_SPF;
frame->pf = skb->data[0] & LAPB_SPF;
frame->control[0] = skb->data[0];
frame->control[1] = 0x00;
skb_pull(skb, 1);
}
} else {
if (!(skb->data[0] & LAPB_S)) {
/*
* I frame - carries NR/NS/PF
*/
frame->type = LAPB_I;
frame->ns = (skb->data[0] >> 1) & 0x07;
frame->nr = (skb->data[0] >> 5) & 0x07;
frame->pf = skb->data[0] & LAPB_SPF;
} else if ((skb->data[0] & LAPB_U) == 1) {
/*
* S frame - take out PF/NR
*/
frame->type = skb->data[0] & 0x0F;
frame->nr = (skb->data[0] >> 5) & 0x07;
frame->pf = skb->data[0] & LAPB_SPF;
} else if ((skb->data[0] & LAPB_U) == 3) {
/*
* U frame - take out PF
*/
frame->type = skb->data[0] & ~LAPB_SPF;
frame->pf = skb->data[0] & LAPB_SPF;
}
frame->control[0] = skb->data[0];
skb_pull(skb, 1);
}
return 0;
}
/*
* This routine is called when the HDLC layer internally generates a
* command or response for the remote machine ( eg. RR, UA etc. ).
* Only supervisory or unnumbered frames are processed, FRMRs are handled
* by lapb_transmit_frmr below.
*/
void lapb_send_control(struct lapb_cb *lapb, int frametype,
int poll_bit, int type)
{
struct sk_buff *skb;
unsigned char *dptr;
if ((skb = alloc_skb(LAPB_HEADER_LEN + 3, GFP_ATOMIC)) == NULL)
return;
skb_reserve(skb, LAPB_HEADER_LEN + 1);
if (lapb->mode & LAPB_EXTENDED) {
if ((frametype & LAPB_U) == LAPB_U) {
dptr = skb_put(skb, 1);
*dptr = frametype;
*dptr |= poll_bit ? LAPB_SPF : 0;
} else {
dptr = skb_put(skb, 2);
dptr[0] = frametype;
dptr[1] = (lapb->vr << 1);
dptr[1] |= poll_bit ? LAPB_EPF : 0;
}
} else {
dptr = skb_put(skb, 1);
*dptr = frametype;
*dptr |= poll_bit ? LAPB_SPF : 0;
if ((frametype & LAPB_U) == LAPB_S) /* S frames carry NR */
*dptr |= (lapb->vr << 5);
}
lapb_transmit_buffer(lapb, skb, type);
}
/*
* This routine generates FRMRs based on information previously stored in
* the LAPB control block.
*/
void lapb_transmit_frmr(struct lapb_cb *lapb)
{
struct sk_buff *skb;
unsigned char *dptr;
if ((skb = alloc_skb(LAPB_HEADER_LEN + 7, GFP_ATOMIC)) == NULL)
return;
skb_reserve(skb, LAPB_HEADER_LEN + 1);
if (lapb->mode & LAPB_EXTENDED) {
dptr = skb_put(skb, 6);
*dptr++ = LAPB_FRMR;
*dptr++ = lapb->frmr_data.control[0];
*dptr++ = lapb->frmr_data.control[1];
*dptr++ = (lapb->vs << 1) & 0xFE;
*dptr = (lapb->vr << 1) & 0xFE;
if (lapb->frmr_data.cr == LAPB_RESPONSE)
*dptr |= 0x01;
dptr++;
*dptr++ = lapb->frmr_type;
lapb_dbg(1, "(%p) S%d TX FRMR %02X %02X %02X %02X %02X\n",
lapb->dev, lapb->state,
skb->data[1], skb->data[2], skb->data[3],
skb->data[4], skb->data[5]);
} else {
dptr = skb_put(skb, 4);
*dptr++ = LAPB_FRMR;
*dptr++ = lapb->frmr_data.control[0];
*dptr = (lapb->vs << 1) & 0x0E;
*dptr |= (lapb->vr << 5) & 0xE0;
if (lapb->frmr_data.cr == LAPB_RESPONSE)
*dptr |= 0x10;
dptr++;
*dptr++ = lapb->frmr_type;
lapb_dbg(1, "(%p) S%d TX FRMR %02X %02X %02X\n",
lapb->dev, lapb->state, skb->data[1],
skb->data[2], skb->data[3]);
}
lapb_transmit_buffer(lapb, skb, LAPB_RESPONSE);
}