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linux/drivers/isdn/pcbit/capi.c
Arnaldo Carvalho de Melo d626f62b11 [SK_BUFF]: Introduce skb_copy_from_linear_data{_offset} 
To clearly state the intent of copying from linear sk_buffs, _offset being a
overly long variant but interesting for the sake of saving some bytes.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2007-04-25 22:28:23 -07:00

655 lines
15 KiB
C
Raw Blame History

/*
* CAPI encoder/decoder for
* Portugal Telecom CAPI 2.0
*
* Copyright (C) 1996 Universidade de Lisboa
*
* Written by Pedro Roque Marques (roque@di.fc.ul.pt)
*
* This software may be used and distributed according to the terms of
* the GNU General Public License, incorporated herein by reference.
*
* Not compatible with the AVM Gmbh. CAPI 2.0
*
*/
/*
* Documentation:
* - "Common ISDN API - Perfil Português - Versão 2.1",
* Telecom Portugal, Fev 1992.
* - "Common ISDN API - Especificação de protocolos para
* acesso aos canais B", Inesc, Jan 1994.
*/
/*
* TODO: better decoding of Information Elements
* for debug purposes mainly
* encode our number in CallerPN and ConnectedPN
*/
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/skbuff.h>
#include <asm/io.h>
#include <asm/string.h>
#include <linux/isdnif.h>
#include "pcbit.h"
#include "edss1.h"
#include "capi.h"
/*
* Encoding of CAPI messages
*
*/
int capi_conn_req(const char * calledPN, struct sk_buff **skb, int proto)
{
ushort len;
/*
* length
* AppInfoMask - 2
* BC0 - 3
* BC1 - 1
* Chan - 2
* Keypad - 1
* CPN - 1
* CPSA - 1
* CalledPN - 2 + strlen
* CalledPSA - 1
* rest... - 4
* ----------------
* Total 18 + strlen
*/
len = 18 + strlen(calledPN);
if (proto == ISDN_PROTO_L2_TRANS)
len++;
if ((*skb = dev_alloc_skb(len)) == NULL) {
printk(KERN_WARNING "capi_conn_req: alloc_skb failed\n");
return -1;
}
/* InfoElmMask */
*((ushort*) skb_put(*skb, 2)) = AppInfoMask;
if (proto == ISDN_PROTO_L2_TRANS)
{
/* Bearer Capability - Mandatory*/
*(skb_put(*skb, 1)) = 3; /* BC0.Length */
*(skb_put(*skb, 1)) = 0x80; /* Speech */
*(skb_put(*skb, 1)) = 0x10; /* Circuit Mode */
*(skb_put(*skb, 1)) = 0x23; /* A-law */
}
else
{
/* Bearer Capability - Mandatory*/
*(skb_put(*skb, 1)) = 2; /* BC0.Length */
*(skb_put(*skb, 1)) = 0x88; /* Digital Information */
*(skb_put(*skb, 1)) = 0x90; /* BC0.Octect4 */
}
/* Bearer Capability - Optional*/
*(skb_put(*skb, 1)) = 0; /* BC1.Length = 0 */
*(skb_put(*skb, 1)) = 1; /* ChannelID.Length = 1 */
*(skb_put(*skb, 1)) = 0x83; /* Basic Interface - Any Channel */
*(skb_put(*skb, 1)) = 0; /* Keypad.Length = 0 */
*(skb_put(*skb, 1)) = 0; /* CallingPN.Length = 0 */
*(skb_put(*skb, 1)) = 0; /* CallingPSA.Length = 0 */
/* Called Party Number */
*(skb_put(*skb, 1)) = strlen(calledPN) + 1;
*(skb_put(*skb, 1)) = 0x81;
memcpy(skb_put(*skb, strlen(calledPN)), calledPN, strlen(calledPN));
/* '#' */
*(skb_put(*skb, 1)) = 0; /* CalledPSA.Length = 0 */
/* LLC.Length = 0; */
/* HLC0.Length = 0; */
/* HLC1.Length = 0; */
/* UTUS.Length = 0; */
memset(skb_put(*skb, 4), 0, 4);
return len;
}
int capi_conn_resp(struct pcbit_chan* chan, struct sk_buff **skb)
{
if ((*skb = dev_alloc_skb(5)) == NULL) {
printk(KERN_WARNING "capi_conn_resp: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2) ) = chan->callref;
*(skb_put(*skb, 1)) = 0x01; /* ACCEPT_CALL */
*(skb_put(*skb, 1)) = 0;
*(skb_put(*skb, 1)) = 0;
return 5;
}
int capi_conn_active_req(struct pcbit_chan* chan, struct sk_buff **skb)
{
/*
* 8 bytes
*/
if ((*skb = dev_alloc_skb(8)) == NULL) {
printk(KERN_WARNING "capi_conn_active_req: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2) ) = chan->callref;
#ifdef DEBUG
printk(KERN_DEBUG "Call Reference: %04x\n", chan->callref);
#endif
*(skb_put(*skb, 1)) = 0; /* BC.Length = 0; */
*(skb_put(*skb, 1)) = 0; /* ConnectedPN.Length = 0 */
*(skb_put(*skb, 1)) = 0; /* PSA.Length */
*(skb_put(*skb, 1)) = 0; /* LLC.Length = 0; */
*(skb_put(*skb, 1)) = 0; /* HLC.Length = 0; */
*(skb_put(*skb, 1)) = 0; /* UTUS.Length = 0; */
return 8;
}
int capi_conn_active_resp(struct pcbit_chan* chan, struct sk_buff **skb)
{
/*
* 2 bytes
*/
if ((*skb = dev_alloc_skb(2)) == NULL) {
printk(KERN_WARNING "capi_conn_active_resp: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2) ) = chan->callref;
return 2;
}
int capi_select_proto_req(struct pcbit_chan *chan, struct sk_buff **skb,
int outgoing)
{
/*
* 18 bytes
*/
if ((*skb = dev_alloc_skb(18)) == NULL) {
printk(KERN_WARNING "capi_select_proto_req: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2) ) = chan->callref;
/* Layer2 protocol */
switch (chan->proto) {
case ISDN_PROTO_L2_X75I:
*(skb_put(*skb, 1)) = 0x05; /* LAPB */
break;
case ISDN_PROTO_L2_HDLC:
*(skb_put(*skb, 1)) = 0x02;
break;
case ISDN_PROTO_L2_TRANS:
/*
* Voice (a-law)
*/
*(skb_put(*skb, 1)) = 0x06;
break;
default:
#ifdef DEBUG
printk(KERN_DEBUG "Transparent\n");
#endif
*(skb_put(*skb, 1)) = 0x03;
break;
}
*(skb_put(*skb, 1)) = (outgoing ? 0x02 : 0x42); /* Don't ask */
*(skb_put(*skb, 1)) = 0x00;
*((ushort *) skb_put(*skb, 2)) = MRU;
*(skb_put(*skb, 1)) = 0x08; /* Modulo */
*(skb_put(*skb, 1)) = 0x07; /* Max Window */
*(skb_put(*skb, 1)) = 0x01; /* No Layer3 Protocol */
/*
* 2 - layer3 MTU [10]
* - Modulo [12]
* - Window
* - layer1 proto [14]
* - bitrate
* - sub-channel [16]
* - layer1dataformat [17]
*/
memset(skb_put(*skb, 8), 0, 8);
return 18;
}
int capi_activate_transp_req(struct pcbit_chan *chan, struct sk_buff **skb)
{
if ((*skb = dev_alloc_skb(7)) == NULL) {
printk(KERN_WARNING "capi_activate_transp_req: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2) ) = chan->callref;
*(skb_put(*skb, 1)) = chan->layer2link; /* Layer2 id */
*(skb_put(*skb, 1)) = 0x00; /* Transmit by default */
*((ushort *) skb_put(*skb, 2)) = MRU;
*(skb_put(*skb, 1)) = 0x01; /* Enables reception*/
return 7;
}
int capi_tdata_req(struct pcbit_chan* chan, struct sk_buff *skb)
{
ushort data_len;
/*
* callref - 2
* layer2link - 1
* wBlockLength - 2
* data - 4
* sernum - 1
*/
data_len = skb->len;
if(skb_headroom(skb) < 10)
{
printk(KERN_CRIT "No headspace (%u) on headroom %p for capi header\n", skb_headroom(skb), skb);
}
else
{
skb_push(skb, 10);
}
*((u16 *) (skb->data)) = chan->callref;
skb->data[2] = chan->layer2link;
*((u16 *) (skb->data + 3)) = data_len;
chan->s_refnum = (chan->s_refnum + 1) % 8;
*((u32 *) (skb->data + 5)) = chan->s_refnum;
skb->data[9] = 0; /* HDLC frame number */
return 10;
}
int capi_tdata_resp(struct pcbit_chan *chan, struct sk_buff ** skb)
{
if ((*skb = dev_alloc_skb(4)) == NULL) {
printk(KERN_WARNING "capi_tdata_resp: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2) ) = chan->callref;
*(skb_put(*skb, 1)) = chan->layer2link;
*(skb_put(*skb, 1)) = chan->r_refnum;
return (*skb)->len;
}
int capi_disc_req(ushort callref, struct sk_buff **skb, u_char cause)
{
if ((*skb = dev_alloc_skb(6)) == NULL) {
printk(KERN_WARNING "capi_disc_req: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2) ) = callref;
*(skb_put(*skb, 1)) = 2; /* Cause.Length = 2; */
*(skb_put(*skb, 1)) = 0x80;
*(skb_put(*skb, 1)) = 0x80 | cause;
/*
* Change it: we should send 'Sic transit gloria Mundi' here ;-)
*/
*(skb_put(*skb, 1)) = 0; /* UTUS.Length = 0; */
return 6;
}
int capi_disc_resp(struct pcbit_chan *chan, struct sk_buff **skb)
{
if ((*skb = dev_alloc_skb(2)) == NULL) {
printk(KERN_WARNING "capi_disc_resp: alloc_skb failed\n");
return -1;
}
*((ushort*) skb_put(*skb, 2)) = chan->callref;
return 2;
}
/*
* Decoding of CAPI messages
*
*/
int capi_decode_conn_ind(struct pcbit_chan * chan,
struct sk_buff *skb,
struct callb_data *info)
{
int CIlen, len;
/* Call Reference [CAPI] */
chan->callref = *((ushort*) skb->data);
skb_pull(skb, 2);
#ifdef DEBUG
printk(KERN_DEBUG "Call Reference: %04x\n", chan->callref);
#endif
/* Channel Identification */
/* Expect
Len = 1
Octect 3 = 0100 10CC - [ 7 Basic, 4 , 2-1 chan ]
*/
CIlen = skb->data[0];
#ifdef DEBUG
if (CIlen == 1) {
if ( ((skb->data[1]) & 0xFC) == 0x48 )
printk(KERN_DEBUG "decode_conn_ind: chan ok\n");
printk(KERN_DEBUG "phyChan = %d\n", skb->data[1] & 0x03);
}
else
printk(KERN_DEBUG "conn_ind: CIlen = %d\n", CIlen);
#endif
skb_pull(skb, CIlen + 1);
/* Calling Party Number */
/* An "additional service" as far as Portugal Telecom is concerned */
len = skb->data[0];
if (len > 0) {
int count = 1;
#ifdef DEBUG
printk(KERN_DEBUG "CPN: Octect 3 %02x\n", skb->data[1]);
#endif
if ((skb->data[1] & 0x80) == 0)
count = 2;
if (!(info->data.setup.CallingPN = kmalloc(len - count + 1, GFP_ATOMIC)))
return -1;
skb_copy_from_linear_data_offset(skb, count + 1,
info->data.setup.CallingPN,
len - count);
info->data.setup.CallingPN[len - count] = 0;
}
else {
info->data.setup.CallingPN = NULL;
printk(KERN_DEBUG "NULL CallingPN\n");
}
skb_pull(skb, len + 1);
/* Calling Party Subaddress */
skb_pull(skb, skb->data[0] + 1);
/* Called Party Number */
len = skb->data[0];
if (len > 0) {
int count = 1;
if ((skb->data[1] & 0x80) == 0)
count = 2;
if (!(info->data.setup.CalledPN = kmalloc(len - count + 1, GFP_ATOMIC)))
return -1;
skb_copy_from_linear_data_offset(skb, count + 1,
info->data.setup.CalledPN,
len - count);
info->data.setup.CalledPN[len - count] = 0;
}
else {
info->data.setup.CalledPN = NULL;
printk(KERN_DEBUG "NULL CalledPN\n");
}
skb_pull(skb, len + 1);
/* Called Party Subaddress */
skb_pull(skb, skb->data[0] + 1);
/* LLC */
skb_pull(skb, skb->data[0] + 1);
/* HLC */
skb_pull(skb, skb->data[0] + 1);
/* U2U */
skb_pull(skb, skb->data[0] + 1);
return 0;
}
/*
* returns errcode
*/
int capi_decode_conn_conf(struct pcbit_chan * chan, struct sk_buff *skb,
int *complete)
{
int errcode;
chan->callref = *((ushort *) skb->data); /* Update CallReference */
skb_pull(skb, 2);
errcode = *((ushort *) skb->data); /* read errcode */
skb_pull(skb, 2);
*complete = *(skb->data);
skb_pull(skb, 1);
/* FIX ME */
/* This is actually a firmware bug */
if (!*complete)
{
printk(KERN_DEBUG "complete=%02x\n", *complete);
*complete = 1;
}
/* Optional Bearer Capability */
skb_pull(skb, *(skb->data) + 1);
/* Channel Identification */
skb_pull(skb, *(skb->data) + 1);
/* High Layer Compatibility follows */
skb_pull(skb, *(skb->data) + 1);
return errcode;
}
int capi_decode_conn_actv_ind(struct pcbit_chan * chan, struct sk_buff *skb)
{
ushort len;
#ifdef DEBUG
char str[32];
#endif
/* Yet Another Bearer Capability */
skb_pull(skb, *(skb->data) + 1);
/* Connected Party Number */
len=*(skb->data);
#ifdef DEBUG
if (len > 1 && len < 31) {
skb_copy_from_linear_data_offset(skb, 2, str, len - 1);
str[len] = 0;
printk(KERN_DEBUG "Connected Party Number: %s\n", str);
}
else
printk(KERN_DEBUG "actv_ind CPN len = %d\n", len);
#endif
skb_pull(skb, len + 1);
/* Connected Subaddress */
skb_pull(skb, *(skb->data) + 1);
/* Low Layer Capability */
skb_pull(skb, *(skb->data) + 1);
/* High Layer Capability */
skb_pull(skb, *(skb->data) + 1);
return 0;
}
int capi_decode_conn_actv_conf(struct pcbit_chan * chan, struct sk_buff *skb)
{
ushort errcode;
errcode = *((ushort*) skb->data);
skb_pull(skb, 2);
/* Channel Identification
skb_pull(skb, skb->data[0] + 1);
*/
return errcode;
}
int capi_decode_sel_proto_conf(struct pcbit_chan *chan, struct sk_buff *skb)
{
ushort errcode;
chan->layer2link = *(skb->data);
skb_pull(skb, 1);
errcode = *((ushort*) skb->data);
skb_pull(skb, 2);
return errcode;
}
int capi_decode_actv_trans_conf(struct pcbit_chan *chan, struct sk_buff *skb)
{
ushort errcode;
if (chan->layer2link != *(skb->data) )
printk("capi_decode_actv_trans_conf: layer2link doesn't match\n");
skb_pull(skb, 1);
errcode = *((ushort*) skb->data);
skb_pull(skb, 2);
return errcode;
}
int capi_decode_disc_ind(struct pcbit_chan *chan, struct sk_buff *skb)
{
ushort len;
#ifdef DEBUG
int i;
#endif
/* Cause */
len = *(skb->data);
skb_pull(skb, 1);
#ifdef DEBUG
for (i=0; i<len; i++)
printk(KERN_DEBUG "Cause Octect %d: %02x\n", i+3,
*(skb->data + i));
#endif
skb_pull(skb, len);
return 0;
}
#ifdef DEBUG
int capi_decode_debug_188(u_char *hdr, ushort hdrlen)
{
char str[64];
int len;
len = hdr[0];
if (len < 64 && len == hdrlen - 1) {
memcpy(str, hdr + 1, hdrlen - 1);
str[hdrlen - 1] = 0;
printk("%s\n", str);
}
else
printk("debug message incorrect\n");
return 0;
}
#endif
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