capi.c
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上传日期:2013-02-24
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- /*
- * 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 Portugu阺 - Vers鉶 2.1",
- * Telecom Portugal, Fev 1992.
- * - "Common ISDN API - Especifica玢o 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/sched.h>
- #include <linux/string.h>
- #include <linux/kernel.h>
- #include <linux/types.h>
- #include <linux/slab.h>
- #include <linux/mm.h>
- #include <linux/tqueue.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 failedn");
- 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 failedn");
- 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 failedn");
- return -1;
- }
- *((ushort*) skb_put(*skb, 2) ) = chan->callref;
- #ifdef DEBUG
- printk(KERN_DEBUG "Call Reference: %04xn", 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 failedn");
- 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 failedn");
- 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 "Transparentn");
- #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 failedn");
- 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 headern", 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 failedn");
- 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 failedn");
- 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 failedn");
- 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: %04xn", 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 okn");
- printk(KERN_DEBUG "phyChan = %dn", skb->data[1] & 0x03);
- }
- else
- printk(KERN_DEBUG "conn_ind: CIlen = %dn", 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 %02xn", 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;
-
- memcpy(info->data.setup.CallingPN, skb->data + count + 1,
- len - count);
- info->data.setup.CallingPN[len - count] = 0;
- }
- else {
- info->data.setup.CallingPN = NULL;
- printk(KERN_DEBUG "NULL CallingPNn");
- }
- 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;
-
- memcpy(info->data.setup.CalledPN, skb->data + count + 1,
- len - count);
- info->data.setup.CalledPN[len - count] = 0;
- }
- else {
- info->data.setup.CalledPN = NULL;
- printk(KERN_DEBUG "NULL CalledPNn");
- }
- 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=%02xn", *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) {
- memcpy(str, skb->data + 2, len - 1);
- str[len] = 0;
- printk(KERN_DEBUG "Connected Party Number: %sn", str);
- }
- else
- printk(KERN_DEBUG "actv_ind CPN len = %dn", 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 matchn");
- 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: %02xn", i+3,
- *(skb->data + i));
- #endif
- skb_pull(skb, len);
- return 0;
- }
- int capi_decode_disc_conf(struct pcbit_chan *chan, struct sk_buff *skb)
- {
- ushort errcode;
- errcode = *((ushort*) skb->data);
- skb_pull(skb, 2);
- return errcode;
- }
- #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("%sn", str);
- }
- else
- printk("debug message incorrectn");
- return 0;
- }
- #endif