patch-2.1.111 linux/drivers/net/hamradio/mkiss.c

• Lines: 227
• Date: Wed Jul 22 13:45:52 1998
• Orig file: v2.1.110/linux/drivers/net/hamradio/mkiss.c
• Orig date: Sun Jun 7 11:16:32 1998

diff -u --recursive --new-file v2.1.110/linux/drivers/net/hamradio/mkiss.c linux/drivers/net/hamradio/mkiss.c
@@ -19,6 +19,9 @@
  *
  *	History
  *	Jonathan (G4KLX)	Fixed to match Linux networking changes - 2.1.15.
+ *	Matthias (DG2FEF)       Added support for FlexNet CRC (on special request)
+ *                              Fixed bug in ax25_close(): dev_lock_wait() was
+ *                              called twice, causing a deadlock.
  */
 
 #include <linux/config.h>
@@ -91,8 +94,80 @@
 static int mkiss_init(void);
 static int mkiss_write(struct tty_struct *, int, const unsigned char *, int);
 static int kiss_esc(unsigned char *, unsigned char *, int);
+static int kiss_esc_crc(unsigned char *, unsigned char *, unsigned short, int);
 static void kiss_unesc(struct ax_disp *, unsigned char);
 
+/*---------------------------------------------------------------------------*/
+
+static const unsigned short Crc_flex_table[] = {
+  0x0f87, 0x1e0e, 0x2c95, 0x3d1c, 0x49a3, 0x582a, 0x6ab1, 0x7b38,
+  0x83cf, 0x9246, 0xa0dd, 0xb154, 0xc5eb, 0xd462, 0xe6f9, 0xf770,
+  0x1f06, 0x0e8f, 0x3c14, 0x2d9d, 0x5922, 0x48ab, 0x7a30, 0x6bb9,
+  0x934e, 0x82c7, 0xb05c, 0xa1d5, 0xd56a, 0xc4e3, 0xf678, 0xe7f1,
+  0x2e85, 0x3f0c, 0x0d97, 0x1c1e, 0x68a1, 0x7928, 0x4bb3, 0x5a3a,
+  0xa2cd, 0xb344, 0x81df, 0x9056, 0xe4e9, 0xf560, 0xc7fb, 0xd672,
+  0x3e04, 0x2f8d, 0x1d16, 0x0c9f, 0x7820, 0x69a9, 0x5b32, 0x4abb,
+  0xb24c, 0xa3c5, 0x915e, 0x80d7, 0xf468, 0xe5e1, 0xd77a, 0xc6f3,
+  0x4d83, 0x5c0a, 0x6e91, 0x7f18, 0x0ba7, 0x1a2e, 0x28b5, 0x393c,
+  0xc1cb, 0xd042, 0xe2d9, 0xf350, 0x87ef, 0x9666, 0xa4fd, 0xb574,
+  0x5d02, 0x4c8b, 0x7e10, 0x6f99, 0x1b26, 0x0aaf, 0x3834, 0x29bd,
+  0xd14a, 0xc0c3, 0xf258, 0xe3d1, 0x976e, 0x86e7, 0xb47c, 0xa5f5,
+  0x6c81, 0x7d08, 0x4f93, 0x5e1a, 0x2aa5, 0x3b2c, 0x09b7, 0x183e,
+  0xe0c9, 0xf140, 0xc3db, 0xd252, 0xa6ed, 0xb764, 0x85ff, 0x9476,
+  0x7c00, 0x6d89, 0x5f12, 0x4e9b, 0x3a24, 0x2bad, 0x1936, 0x08bf,
+  0xf048, 0xe1c1, 0xd35a, 0xc2d3, 0xb66c, 0xa7e5, 0x957e, 0x84f7,
+  0x8b8f, 0x9a06, 0xa89d, 0xb914, 0xcdab, 0xdc22, 0xeeb9, 0xff30,
+  0x07c7, 0x164e, 0x24d5, 0x355c, 0x41e3, 0x506a, 0x62f1, 0x7378,
+  0x9b0e, 0x8a87, 0xb81c, 0xa995, 0xdd2a, 0xcca3, 0xfe38, 0xefb1,
+  0x1746, 0x06cf, 0x3454, 0x25dd, 0x5162, 0x40eb, 0x7270, 0x63f9,
+  0xaa8d, 0xbb04, 0x899f, 0x9816, 0xeca9, 0xfd20, 0xcfbb, 0xde32,
+  0x26c5, 0x374c, 0x05d7, 0x145e, 0x60e1, 0x7168, 0x43f3, 0x527a,
+  0xba0c, 0xab85, 0x991e, 0x8897, 0xfc28, 0xeda1, 0xdf3a, 0xceb3,
+  0x3644, 0x27cd, 0x1556, 0x04df, 0x7060, 0x61e9, 0x5372, 0x42fb,
+  0xc98b, 0xd802, 0xea99, 0xfb10, 0x8faf, 0x9e26, 0xacbd, 0xbd34,
+  0x45c3, 0x544a, 0x66d1, 0x7758, 0x03e7, 0x126e, 0x20f5, 0x317c,
+  0xd90a, 0xc883, 0xfa18, 0xeb91, 0x9f2e, 0x8ea7, 0xbc3c, 0xadb5,
+  0x5542, 0x44cb, 0x7650, 0x67d9, 0x1366, 0x02ef, 0x3074, 0x21fd,
+  0xe889, 0xf900, 0xcb9b, 0xda12, 0xaead, 0xbf24, 0x8dbf, 0x9c36,
+  0x64c1, 0x7548, 0x47d3, 0x565a, 0x22e5, 0x336c, 0x01f7, 0x107e,
+  0xf808, 0xe981, 0xdb1a, 0xca93, 0xbe2c, 0xafa5, 0x9d3e, 0x8cb7,
+  0x7440, 0x65c9, 0x5752, 0x46db, 0x3264, 0x23ed, 0x1176, 0x00ff
+};
+
+/*---------------------------------------------------------------------------*/
+
+static unsigned short 
+calc_crc_flex(unsigned char *cp, int size)
+{
+    unsigned short crc = 0xffff;
+    
+    while (size--)
+	crc = (crc << 8) ^ Crc_flex_table[((crc >> 8) ^ *cp++) & 0xff];
+
+    return crc;
+}
+
+/*---------------------------------------------------------------------------*/
+
+static int 
+check_crc_flex(unsigned char *cp, int size)
+{
+  unsigned short crc = 0xffff;
+
+  if (size < 3)
+      return -1;
+
+  while (size--)
+      crc = (crc << 8) ^ Crc_flex_table[((crc >> 8) ^ *cp++) & 0xff];
+
+  if ((crc & 0xffff) != 0x7070) 
+      return -1;
+
+  return 0;
+}
+
+/*---------------------------------------------------------------------------*/
+
 /* Find a free channel, and link in this `tty' line. */
 static inline struct ax_disp *ax_alloc(void)
 {
@@ -272,6 +347,13 @@
 			mkiss= ax->mkiss->tty->driver_data;
 			if (mkiss->magic == MKISS_DRIVER_MAGIC)
 				tmp_ax = ax->mkiss;
+		} else if (ax->rbuff[0] & 0x20) {
+		        ax->crcmode = CRC_MODE_FLEX;
+			if (check_crc_flex(ax->rbuff, ax->rcount) < 0) {
+			        ax->rx_errors++;
+				return;
+			}
+			ax->rcount -= 2;
 		}
  	}
 
@@ -312,7 +394,19 @@
 	p = icp;
 
 	if (mkiss->magic  != MKISS_DRIVER_MAGIC) {
-		count = kiss_esc(p, (unsigned char *)ax->xbuff, len);
+	        switch (ax->crcmode) {
+		         unsigned short crc;
+			 
+		case CRC_MODE_FLEX:
+		         *p |= 0x20;
+		         crc = calc_crc_flex(p, len);
+			 count = kiss_esc_crc(p, (unsigned char *)ax->xbuff, crc, len+2);
+			 break;
+
+		default:
+		         count = kiss_esc(p, (unsigned char *)ax->xbuff, len);
+			 break;
+		}
 		ax->tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
 		actual = ax->tty->driver.write(ax->tty, 0, ax->xbuff, count);
 		ax->tx_packets++;
@@ -629,12 +723,8 @@
 		return;
 
 	mkiss = ax->mode;
-	if (ax->dev->flags & IFF_UP)
-	{
-		dev_lock_wait();
-		dev_close(ax->dev);
-		dev_unlock_list();
-	}
+
+	dev_close(ax->dev);
 
 	tty->disc_data = 0;
 	ax->tty        = NULL;
@@ -704,6 +794,45 @@
 	return ptr - d;
 }
 
+/*
+ * MW:
+ * OK its ugly, but tell me a better solution without copying the
+ * packet to a temporary buffer :-)
+ */
+static int kiss_esc_crc(unsigned char *s, unsigned char *d, unsigned short crc, int len)
+{
+	unsigned char *ptr = d;
+	unsigned char c;
+
+	*ptr++ = END;
+	while (len > 0) {
+		if (len > 2) 
+			c = *s++;
+		else if (len > 1)
+			c = crc >> 8;
+		else if (len > 0)
+			c = crc & 0xff;
+
+		len--;
+
+		switch (c) {
+                        case END:
+                                *ptr++ = ESC;
+                                *ptr++ = ESC_END;
+                                break;
+                        case ESC:
+                                *ptr++ = ESC;
+                                *ptr++ = ESC_ESC;
+                                break;
+                        default:
+                                *ptr++ = c;
+                                break;
+		}
+	}
+	*ptr++ = END;
+	return ptr - d;		
+}
+
 static void kiss_unesc(struct ax_disp *ax, unsigned char s)
 {
 	switch (s) {
@@ -746,14 +875,8 @@
 
 int ax_set_mac_address(struct device *dev, void *addr)
 {
-	int err;
-
-	if ((err = verify_area(VERIFY_READ, addr, AX25_ADDR_LEN)) != 0)
-		return err;
-
-	/* addr is an AX.25 shifted ASCII mac address */
-	copy_from_user(dev->dev_addr, addr, AX25_ADDR_LEN);
-
+	if (copy_from_user(dev->dev_addr, addr, AX25_ADDR_LEN))
+		return -EFAULT;
 	return 0;
 }
 
@@ -780,20 +903,15 @@
 
 	switch (cmd) {
 	 	case SIOCGIFNAME:
-			if ((err = verify_area(VERIFY_WRITE, arg, strlen(ax->dev->name) + 1)) != 0)
-				return err;
-			copy_to_user(arg, ax->dev->name, strlen(ax->dev->name) + 1);
+			if (copy_to_user(arg, ax->dev->name, strlen(ax->dev->name) + 1))
+				return -EFAULT;
 			return 0;
 
 		case SIOCGIFENCAP:
-			if ((err = verify_area(VERIFY_WRITE, arg, sizeof(int))) != 0)
-				return err;
 			put_user(4, (int *)arg);
 			return 0;
 
 		case SIOCSIFENCAP:
-			if ((err = verify_area(VERIFY_READ, arg, sizeof(int))) != 0)
-				return err;
 			get_user(tmp, (int *)arg);
 	 		ax->mode = tmp;
 			ax->dev->addr_len        = AX25_ADDR_LEN;	  /* sizeof an AX.25 addr */