--- /dev/null
+/* $Id: isdn_v110.c,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $
+ *
+ * Linux ISDN subsystem, V.110 related functions (linklevel).
+ *
+ * Copyright by Thomas Pfeiffer (pfeiffer@pds.de)
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ *
+ */
+
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+
+#include <linux/isdn.h>
+#include "isdn_v110.h"
+
+#undef ISDN_V110_DEBUG
+
+char *isdn_v110_revision = "$Revision: 1.1.2.2 $";
+
+#define V110_38400 255
+#define V110_19200 15
+#define V110_9600 3
+
+/*
+ * The following data are precoded matrices, online and offline matrix
+ * for 9600, 19200 und 38400, respectively
+ */
+static unsigned char V110_OnMatrix_9600[] =
+{0xfc, 0xfc, 0xfc, 0xfc, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff,
+ 0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd,
+ 0xfd, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff,
+ 0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd};
+
+static unsigned char V110_OffMatrix_9600[] =
+{0xfc, 0xfc, 0xfc, 0xfc, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xfd, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+
+static unsigned char V110_OnMatrix_19200[] =
+{0xf0, 0xf0, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7,
+ 0xfd, 0xff, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7};
+
+static unsigned char V110_OffMatrix_19200[] =
+{0xf0, 0xf0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xfd, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+
+static unsigned char V110_OnMatrix_38400[] =
+{0x00, 0x7f, 0x7f, 0x7f, 0x7f, 0xfd, 0x7f, 0x7f, 0x7f, 0x7f};
+
+static unsigned char V110_OffMatrix_38400[] =
+{0x00, 0xff, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, 0xff, 0xff};
+
+/*
+ * FlipBits reorders sequences of keylen bits in one byte.
+ * E.g. source order 7654321 will be converted to 45670123 when keylen = 4,
+ * and to 67452301 when keylen = 2. This is necessary because ordering on
+ * the isdn line is the other way.
+ */
+static inline unsigned char
+FlipBits(unsigned char c, int keylen)
+{
+ unsigned char b = c;
+ unsigned char bit = 128;
+ int i;
+ int j;
+ int hunks = (8 / keylen);
+
+ c = 0;
+ for (i = 0; i < hunks; i++) {
+ for (j = 0; j < keylen; j++) {
+ if (b & (bit >> j))
+ c |= bit >> (keylen - j - 1);
+ }
+ bit >>= keylen;
+ }
+ return c;
+}
+
+
+/* isdn_v110_open allocates and initializes private V.110 data
+ * structures and returns a pointer to these.
+ */
+static isdn_v110_stream *
+isdn_v110_open(unsigned char key, int hdrlen, int maxsize)
+{
+ int i;
+ isdn_v110_stream *v;
+
+ if ((v = kzalloc(sizeof(isdn_v110_stream), GFP_ATOMIC)) == NULL)
+ return NULL;
+ v->key = key;
+ v->nbits = 0;
+ for (i = 0; key & (1 << i); i++)
+ v->nbits++;
+
+ v->nbytes = 8 / v->nbits;
+ v->decodelen = 0;
+
+ switch (key) {
+ case V110_38400:
+ v->OnlineFrame = V110_OnMatrix_38400;
+ v->OfflineFrame = V110_OffMatrix_38400;
+ break;
+ case V110_19200:
+ v->OnlineFrame = V110_OnMatrix_19200;
+ v->OfflineFrame = V110_OffMatrix_19200;
+ break;
+ default:
+ v->OnlineFrame = V110_OnMatrix_9600;
+ v->OfflineFrame = V110_OffMatrix_9600;
+ break;
+ }
+ v->framelen = v->nbytes * 10;
+ v->SyncInit = 5;
+ v->introducer = 0;
+ v->dbit = 1;
+ v->b = 0;
+ v->skbres = hdrlen;
+ v->maxsize = maxsize - hdrlen;
+ if ((v->encodebuf = kmalloc(maxsize, GFP_ATOMIC)) == NULL) {
+ kfree(v);
+ return NULL;
+ }
+ return v;
+}
+
+/* isdn_v110_close frees private V.110 data structures */
+void
+isdn_v110_close(isdn_v110_stream *v)
+{
+ if (v == NULL)
+ return;
+#ifdef ISDN_V110_DEBUG
+ printk(KERN_DEBUG "v110 close\n");
+#endif
+ kfree(v->encodebuf);
+ kfree(v);
+}
+
+
+/*
+ * ValidHeaderBytes return the number of valid bytes in v->decodebuf
+ */
+static int
+ValidHeaderBytes(isdn_v110_stream *v)
+{
+ int i;
+ for (i = 0; (i < v->decodelen) && (i < v->nbytes); i++)
+ if ((v->decodebuf[i] & v->key) != 0)
+ break;
+ return i;
+}
+
+/*
+ * SyncHeader moves the decodebuf ptr to the next valid header
+ */
+static void
+SyncHeader(isdn_v110_stream *v)
+{
+ unsigned char *rbuf = v->decodebuf;
+ int len = v->decodelen;
+
+ if (len == 0)
+ return;
+ for (rbuf++, len--; len > 0; len--, rbuf++) /* such den SyncHeader in buf ! */
+ if ((*rbuf & v->key) == 0) /* erstes byte gefunden ? */
+ break; /* jupp! */
+ if (len)
+ memcpy(v->decodebuf, rbuf, len);
+
+ v->decodelen = len;
+#ifdef ISDN_V110_DEBUG
+ printk(KERN_DEBUG "isdn_v110: Header resync\n");
+#endif
+}
+
+/* DecodeMatrix takes n (n>=1) matrices (v110 frames, 10 bytes) where
+ len is the number of matrix-lines. len must be a multiple of 10, i.e.
+ only complete matices must be given.
+ From these, netto data is extracted and returned in buf. The return-value
+ is the bytecount of the decoded data.
+*/
+static int
+DecodeMatrix(isdn_v110_stream *v, unsigned char *m, int len, unsigned char *buf)
+{
+ int line = 0;
+ int buflen = 0;
+ int mbit = 64;
+ int introducer = v->introducer;
+ int dbit = v->dbit;
+ unsigned char b = v->b;
+
+ while (line < len) { /* Are we done with all lines of the matrix? */
+ if ((line % 10) == 0) { /* the 0. line of the matrix is always 0 ! */
+ if (m[line] != 0x00) { /* not 0 ? -> error! */
+#ifdef ISDN_V110_DEBUG
+ printk(KERN_DEBUG "isdn_v110: DecodeMatrix, V110 Bad Header\n");
+ /* returning now is not the right thing, though :-( */
+#endif
+ }
+ line++; /* next line of matrix */
+ continue;
+ } else if ((line % 10) == 5) { /* in line 5 there's only e-bits ! */
+ if ((m[line] & 0x70) != 0x30) { /* 011 has to be at the beginning! */
+#ifdef ISDN_V110_DEBUG
+ printk(KERN_DEBUG "isdn_v110: DecodeMatrix, V110 Bad 5th line\n");
+ /* returning now is not the right thing, though :-( */
+#endif
+ }
+ line++; /* next line */
+ continue;
+ } else if (!introducer) { /* every byte starts with 10 (stopbit, startbit) */
+ introducer = (m[line] & mbit) ? 0 : 1; /* current bit of the matrix */
+ next_byte:
+ if (mbit > 2) { /* was it the last bit in this line ? */
+ mbit >>= 1; /* no -> take next */
+ continue;
+ } /* otherwise start with leftmost bit in the next line */
+ mbit = 64;
+ line++;
+ continue;
+ } else { /* otherwise we need to set a data bit */
+ if (m[line] & mbit) /* was that bit set in the matrix ? */
+ b |= dbit; /* yes -> set it in the data byte */
+ else
+ b &= dbit - 1; /* no -> clear it in the data byte */
+ if (dbit < 128) /* is that data byte done ? */
+ dbit <<= 1; /* no, got the next bit */
+ else { /* data byte is done */
+ buf[buflen++] = b; /* copy byte into the output buffer */
+ introducer = b = 0; /* init of the intro sequence and of the data byte */
+ dbit = 1; /* next we look for the 0th bit */
+ }
+ goto next_byte; /* look for next bit in the matrix */
+ }
+ }
+ v->introducer = introducer;
+ v->dbit = dbit;
+ v->b = b;
+ return buflen; /* return number of bytes in the output buffer */
+}
+
+/*
+ * DecodeStream receives V.110 coded data from the input stream. It recovers the
+ * original frames.
+ * The input stream doesn't need to be framed
+ */
+struct sk_buff *
+isdn_v110_decode(isdn_v110_stream *v, struct sk_buff *skb)
+{
+ int i;
+ int j;
+ int len;
+ unsigned char *v110_buf;
+ unsigned char *rbuf;
+
+ if (!skb) {
+ printk(KERN_WARNING "isdn_v110_decode called with NULL skb!\n");
+ return NULL;
+ }
+ rbuf = skb->data;
+ len = skb->len;
+ if (v == NULL) {
+ /* invalid handle, no chance to proceed */
+ printk(KERN_WARNING "isdn_v110_decode called with NULL stream!\n");
+ dev_kfree_skb(skb);
+ return NULL;
+ }
+ if (v->decodelen == 0) /* cache empty? */
+ for (; len > 0; len--, rbuf++) /* scan for SyncHeader in buf */
+ if ((*rbuf & v->key) == 0)
+ break; /* found first byte */
+ if (len == 0) {
+ dev_kfree_skb(skb);
+ return NULL;
+ }
+ /* copy new data to decode-buffer */
+ memcpy(&(v->decodebuf[v->decodelen]), rbuf, len);
+ v->decodelen += len;
+ReSync:
+ if (v->decodelen < v->nbytes) { /* got a new header ? */
+ dev_kfree_skb(skb);
+ return NULL; /* no, try later */
+ }
+ if (ValidHeaderBytes(v) != v->nbytes) { /* is that a valid header? */
+ SyncHeader(v); /* no -> look for header */
+ goto ReSync;
+ }
+ len = (v->decodelen - (v->decodelen % (10 * v->nbytes))) / v->nbytes;
+ if ((v110_buf = kmalloc(len, GFP_ATOMIC)) == NULL) {
+ printk(KERN_WARNING "isdn_v110_decode: Couldn't allocate v110_buf\n");
+ dev_kfree_skb(skb);
+ return NULL;
+ }
+ for (i = 0; i < len; i++) {
+ v110_buf[i] = 0;
+ for (j = 0; j < v->nbytes; j++)
+ v110_buf[i] |= (v->decodebuf[(i * v->nbytes) + j] & v->key) << (8 - ((j + 1) * v->nbits));
+ v110_buf[i] = FlipBits(v110_buf[i], v->nbits);
+ }
+ v->decodelen = (v->decodelen % (10 * v->nbytes));
+ memcpy(v->decodebuf, &(v->decodebuf[len * v->nbytes]), v->decodelen);
+
+ skb_trim(skb, DecodeMatrix(v, v110_buf, len, skb->data));
+ kfree(v110_buf);
+ if (skb->len)
+ return skb;
+ else {
+ kfree_skb(skb);
+ return NULL;
+ }
+}
+
+/* EncodeMatrix takes input data in buf, len is the bytecount.
+ Data is encoded into v110 frames in m. Return value is the number of
+ matrix-lines generated.
+*/
+static int
+EncodeMatrix(unsigned char *buf, int len, unsigned char *m, int mlen)
+{
+ int line = 0;
+ int i = 0;
+ int mbit = 128;
+ int dbit = 1;
+ int introducer = 3;
+ int ibit[] = {0, 1, 1};
+
+ while ((i < len) && (line < mlen)) { /* while we still have input data */
+ switch (line % 10) { /* in which line of the matrix are we? */
+ case 0:
+ m[line++] = 0x00; /* line 0 is always 0 */
+ mbit = 128; /* go on with the 7th bit */
+ break;
+ case 5:
+ m[line++] = 0xbf; /* line 5 is always 10111111 */
+ mbit = 128; /* go on with the 7th bit */
+ break;
+ }
+ if (line >= mlen) {
+ printk(KERN_WARNING "isdn_v110 (EncodeMatrix): buffer full!\n");
+ return line;
+ }
+ next_bit:
+ switch (mbit) { /* leftmost or rightmost bit ? */
+ case 1:
+ line++; /* rightmost -> go to next line */
+ if (line >= mlen) {
+ printk(KERN_WARNING "isdn_v110 (EncodeMatrix): buffer full!\n");
+ return line;
+ }
+ case 128:
+ m[line] = 128; /* leftmost -> set byte to 1000000 */
+ mbit = 64; /* current bit in the matrix line */
+ continue;
+ }
+ if (introducer) { /* set 110 sequence ? */
+ introducer--; /* set on digit less */
+ m[line] |= ibit[introducer] ? mbit : 0; /* set corresponding bit */
+ mbit >>= 1; /* bit of matrix line >> 1 */
+ goto next_bit; /* and go on there */
+ } /* else push data bits into the matrix! */
+ m[line] |= (buf[i] & dbit) ? mbit : 0; /* set data bit in matrix */
+ if (dbit == 128) { /* was it the last one? */
+ dbit = 1; /* then go on with first bit of */
+ i++; /* next byte in input buffer */
+ if (i < len) /* input buffer done ? */
+ introducer = 3; /* no, write introducer 110 */
+ else { /* input buffer done ! */
+ m[line] |= (mbit - 1) & 0xfe; /* set remaining bits in line to 1 */
+ break;
+ }
+ } else /* not the last data bit */
+ dbit <<= 1; /* then go to next data bit */
+ mbit >>= 1; /* go to next bit of matrix */
+ goto next_bit;
+
+ }
+ /* if necessary, generate remaining lines of the matrix... */
+ if ((line) && ((line + 10) < mlen))
+ switch (++line % 10) {
+ case 1:
+ m[line++] = 0xfe;
+ case 2:
+ m[line++] = 0xfe;
+ case 3:
+ m[line++] = 0xfe;
+ case 4:
+ m[line++] = 0xfe;
+ case 5:
+ m[line++] = 0xbf;
+ case 6:
+ m[line++] = 0xfe;
+ case 7:
+ m[line++] = 0xfe;
+ case 8:
+ m[line++] = 0xfe;
+ case 9:
+ m[line++] = 0xfe;
+ }
+ return line; /* that's how many lines we have */
+}
+
+/*
+ * Build a sync frame.
+ */
+static struct sk_buff *
+isdn_v110_sync(isdn_v110_stream *v)
+{
+ struct sk_buff *skb;
+
+ if (v == NULL) {
+ /* invalid handle, no chance to proceed */
+ printk(KERN_WARNING "isdn_v110_sync called with NULL stream!\n");
+ return NULL;
+ }
+ if ((skb = dev_alloc_skb(v->framelen + v->skbres))) {
+ skb_reserve(skb, v->skbres);
+ memcpy(skb_put(skb, v->framelen), v->OfflineFrame, v->framelen);
+ }
+ return skb;
+}
+
+/*
+ * Build an idle frame.
+ */
+static struct sk_buff *
+isdn_v110_idle(isdn_v110_stream *v)
+{
+ struct sk_buff *skb;
+
+ if (v == NULL) {
+ /* invalid handle, no chance to proceed */
+ printk(KERN_WARNING "isdn_v110_sync called with NULL stream!\n");
+ return NULL;
+ }
+ if ((skb = dev_alloc_skb(v->framelen + v->skbres))) {
+ skb_reserve(skb, v->skbres);
+ memcpy(skb_put(skb, v->framelen), v->OnlineFrame, v->framelen);
+ }
+ return skb;
+}
+
+struct sk_buff *
+isdn_v110_encode(isdn_v110_stream *v, struct sk_buff *skb)
+{
+ int i;
+ int j;
+ int rlen;
+ int mlen;
+ int olen;
+ int size;
+ int sval1;
+ int sval2;
+ int nframes;
+ unsigned char *v110buf;
+ unsigned char *rbuf;
+ struct sk_buff *nskb;
+
+ if (v == NULL) {
+ /* invalid handle, no chance to proceed */
+ printk(KERN_WARNING "isdn_v110_encode called with NULL stream!\n");
+ return NULL;
+ }
+ if (!skb) {
+ /* invalid skb, no chance to proceed */
+ printk(KERN_WARNING "isdn_v110_encode called with NULL skb!\n");
+ return NULL;
+ }
+ rlen = skb->len;
+ nframes = (rlen + 3) / 4;
+ v110buf = v->encodebuf;
+ if ((nframes * 40) > v->maxsize) {
+ size = v->maxsize;
+ rlen = v->maxsize / 40;
+ } else
+ size = nframes * 40;
+ if (!(nskb = dev_alloc_skb(size + v->skbres + sizeof(int)))) {
+ printk(KERN_WARNING "isdn_v110_encode: Couldn't alloc skb\n");
+ return NULL;
+ }
+ skb_reserve(nskb, v->skbres + sizeof(int));
+ if (skb->len == 0) {
+ memcpy(skb_put(nskb, v->framelen), v->OnlineFrame, v->framelen);
+ *((int *)skb_push(nskb, sizeof(int))) = 0;
+ return nskb;
+ }
+ mlen = EncodeMatrix(skb->data, rlen, v110buf, size);
+ /* now distribute 2 or 4 bits each to the output stream! */
+ rbuf = skb_put(nskb, size);
+ olen = 0;
+ sval1 = 8 - v->nbits;
+ sval2 = v->key << sval1;
+ for (i = 0; i < mlen; i++) {
+ v110buf[i] = FlipBits(v110buf[i], v->nbits);
+ for (j = 0; j < v->nbytes; j++) {
+ if (size--)
+ *rbuf++ = ~v->key | (((v110buf[i] << (j * v->nbits)) & sval2) >> sval1);
+ else {
+ printk(KERN_WARNING "isdn_v110_encode: buffers full!\n");
+ goto buffer_full;
+ }
+ olen++;
+ }
+ }
+buffer_full:
+ skb_trim(nskb, olen);
+ *((int *)skb_push(nskb, sizeof(int))) = rlen;
+ return nskb;
+}
+
+int
+isdn_v110_stat_callback(int idx, isdn_ctrl *c)
+{
+ isdn_v110_stream *v = NULL;
+ int i;
+ int ret = 0;
+
+ if (idx < 0)
+ return 0;
+ switch (c->command) {
+ case ISDN_STAT_BSENT:
+ /* Keep the send-queue of the driver filled
+ * with frames:
+ * If number of outstanding frames < 3,
+ * send down an Idle-Frame (or an Sync-Frame, if
+ * v->SyncInit != 0).
+ */
+ if (!(v = dev->v110[idx]))
+ return 0;
+ atomic_inc(&dev->v110use[idx]);
+ for (i = 0; i * v->framelen < c->parm.length; i++) {
+ if (v->skbidle > 0) {
+ v->skbidle--;
+ ret = 1;
+ } else {
+ if (v->skbuser > 0)
+ v->skbuser--;
+ ret = 0;
+ }
+ }
+ for (i = v->skbuser + v->skbidle; i < 2; i++) {
+ struct sk_buff *skb;
+ if (v->SyncInit > 0)
+ skb = isdn_v110_sync(v);
+ else
+ skb = isdn_v110_idle(v);
+ if (skb) {
+ if (dev->drv[c->driver]->interface->writebuf_skb(c->driver, c->arg, 1, skb) <= 0) {
+ dev_kfree_skb(skb);
+ break;
+ } else {
+ if (v->SyncInit)
+ v->SyncInit--;
+ v->skbidle++;
+ }
+ } else
+ break;
+ }
+ atomic_dec(&dev->v110use[idx]);
+ return ret;
+ case ISDN_STAT_DHUP:
+ case ISDN_STAT_BHUP:
+ while (1) {
+ atomic_inc(&dev->v110use[idx]);
+ if (atomic_dec_and_test(&dev->v110use[idx])) {
+ isdn_v110_close(dev->v110[idx]);
+ dev->v110[idx] = NULL;
+ break;
+ }
+ mdelay(1);
+ }
+ break;
+ case ISDN_STAT_BCONN:
+ if (dev->v110emu[idx] && (dev->v110[idx] == NULL)) {
+ int hdrlen = dev->drv[c->driver]->interface->hl_hdrlen;
+ int maxsize = dev->drv[c->driver]->interface->maxbufsize;
+ atomic_inc(&dev->v110use[idx]);
+ switch (dev->v110emu[idx]) {
+ case ISDN_PROTO_L2_V11096:
+ dev->v110[idx] = isdn_v110_open(V110_9600, hdrlen, maxsize);
+ break;
+ case ISDN_PROTO_L2_V11019:
+ dev->v110[idx] = isdn_v110_open(V110_19200, hdrlen, maxsize);
+ break;
+ case ISDN_PROTO_L2_V11038:
+ dev->v110[idx] = isdn_v110_open(V110_38400, hdrlen, maxsize);
+ break;
+ default:;
+ }
+ if ((v = dev->v110[idx])) {
+ while (v->SyncInit) {
+ struct sk_buff *skb = isdn_v110_sync(v);
+ if (dev->drv[c->driver]->interface->writebuf_skb(c->driver, c->arg, 1, skb) <= 0) {
+ dev_kfree_skb(skb);
+ /* Unable to send, try later */
+ break;
+ }
+ v->SyncInit--;
+ v->skbidle++;
+ }
+ } else
+ printk(KERN_WARNING "isdn_v110: Couldn't open stream for chan %d\n", idx);
+ atomic_dec(&dev->v110use[idx]);
+ }
+ break;
+ default:
+ return 0;
+ }
+ return 0;
+}
Code Review / kvmfornfv.git / blobdiff