[X25] simplify facility negotiation.

net/x25/x25_facilities.c

 /*
  *	X.25 Packet Layer release 002
  *
- *	This is ALPHA test software. This code may break your machine, randomly fail to work with new 
- *	releases, misbehave and/or generally screw up. It might even work. 
+ *	This is ALPHA test software. This code may break your machine,
+ *	randomly fail to work with new releases, misbehave and/or generally
+ *	screw up. It might even work. 
  *
  *	This code REQUIRES 2.1.15 or higher
  *
@@ -42,65 +43,71 @@
  *	Parse a set of facilities into the facilities structure. Unrecognised
  *	facilities are written to the debug log file.
  */
-int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities, unsigned long *vc_fac_mask)
+int x25_parse_facilities(struct sk_buff *skb,
+			 struct x25_facilities *facilities,
+			 unsigned long *vc_fac_mask)
 {
-	unsigned int len;
 	unsigned char *p = skb->data;
+	unsigned int len = *p++;
 
-	len = *p++;
 	*vc_fac_mask = 0;
 
 	while (len > 0) {
 		switch (*p & X25_FAC_CLASS_MASK) {
-			case X25_FAC_CLASS_A:
-				switch (*p) {
-					case X25_FAC_REVERSE:
-						facilities->reverse = (p[1] & 0x01);
-						*vc_fac_mask |= X25_MASK_REVERSE;
-						break;
-					case X25_FAC_THROUGHPUT:
-						facilities->throughput = p[1];
-						*vc_fac_mask |= X25_MASK_THROUGHPUT;
-						break;
-					default:
-						printk(KERN_DEBUG "X.25: unknown facility %02X, value %02X\n", p[0], p[1]);
-						break;
-				}
-				p   += 2;
-				len -= 2;
+		case X25_FAC_CLASS_A:
+			switch (*p) {
+			case X25_FAC_REVERSE:
+				facilities->reverse = p[1] & 0x01;
+				*vc_fac_mask |= X25_MASK_REVERSE;
 				break;
-
-			case X25_FAC_CLASS_B:
-				switch (*p) {
-					case X25_FAC_PACKET_SIZE:
-						facilities->pacsize_in  = p[1];
-						facilities->pacsize_out = p[2];
-						*vc_fac_mask |= X25_MASK_PACKET_SIZE;
-						break;
-					case X25_FAC_WINDOW_SIZE:
-						facilities->winsize_in  = p[1];
-						facilities->winsize_out = p[2];
-						*vc_fac_mask |= X25_MASK_WINDOW_SIZE;
-						break;
-					default:
-						printk(KERN_DEBUG "X.25: unknown facility %02X, values %02X, %02X\n", p[0], p[1], p[2]);
-						break;
-				}
-				p   += 3;
-				len -= 3;
+			case X25_FAC_THROUGHPUT:
+				facilities->throughput = p[1];
+				*vc_fac_mask |= X25_MASK_THROUGHPUT;
 				break;
-
-			case X25_FAC_CLASS_C:
-				printk(KERN_DEBUG "X.25: unknown facility %02X, values %02X, %02X, %02X\n", p[0], p[1], p[2], p[3]);
-				p   += 4;
-				len -= 4;
+			default:
+				printk(KERN_DEBUG "X.25: unknown facility "
+				       "%02X, value %02X\n",
+				       p[0], p[1]);
 				break;
-
-			case X25_FAC_CLASS_D:
-				printk(KERN_DEBUG "X.25: unknown facility %02X, length %d, values %02X, %02X, %02X, %02X\n", p[0], p[1], p[2], p[3], p[4], p[5]);
-				p   += p[1] + 2;
-				len -= p[1] + 2;
+			}
+			p   += 2;
+			len -= 2;
+			break;
+		case X25_FAC_CLASS_B:
+			switch (*p) {
+			case X25_FAC_PACKET_SIZE:
+				facilities->pacsize_in  = p[1];
+				facilities->pacsize_out = p[2];
+				*vc_fac_mask |= X25_MASK_PACKET_SIZE;
+				break;
+			case X25_FAC_WINDOW_SIZE:
+				facilities->winsize_in  = p[1];
+				facilities->winsize_out = p[2];
+				*vc_fac_mask |= X25_MASK_WINDOW_SIZE;
 				break;
+			default:
+				printk(KERN_DEBUG "X.25: unknown facility "
+				       "%02X, values %02X, %02X\n",
+				       p[0], p[1], p[2]);
+				break;
+			}
+			p   += 3;
+			len -= 3;
+			break;
+		case X25_FAC_CLASS_C:
+			printk(KERN_DEBUG "X.25: unknown facility %02X, "
+			       "values %02X, %02X, %02X\n",
+			       p[0], p[1], p[2], p[3]);
+			p   += 4;
+			len -= 4;
+			break;
+		case X25_FAC_CLASS_D:
+			printk(KERN_DEBUG "X.25: unknown facility %02X, "
+			       "length %d, values %02X, %02X, %02X, %02X\n",
+			       p[0], p[1], p[2], p[3], p[4], p[5]);
+			p   += p[1] + 2;
+			len -= p[1] + 2;
+			break;
 		}
 	}
 
@@ -110,37 +117,45 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities,
 /*
  *	Create a set of facilities.
  */
-int x25_create_facilities(unsigned char *buffer, struct x25_facilities *facilities, unsigned long facil_mask)
+int x25_create_facilities(unsigned char *buffer,
+			  struct x25_facilities *facilities,
+			  unsigned long facil_mask)
 {
 	unsigned char *p = buffer + 1;
 	int len;
 
-	if (facil_mask == 0) {
-		buffer [0] = 0; /* length of the facilities field in call_req or call_accept packets */
+	if (!facil_mask) {
+		/*
+		 * Length of the facilities field in call_req or
+		 * call_accept packets
+		 */
+		buffer[0] = 0;
 		len = 1; /* 1 byte for the length field */
 		return len;
 	}
 
-	if ((facilities->reverse != 0) && (facil_mask & X25_MASK_REVERSE)) {
+	if (facilities->reverse && (facil_mask & X25_MASK_REVERSE)) {
 		*p++ = X25_FAC_REVERSE;
-		*p++ = (facilities->reverse) ? 0x01 : 0x00;
+		*p++ = !!facilities->reverse;
 	}
 
-	if ((facilities->throughput != 0) && (facil_mask & X25_MASK_THROUGHPUT)) {
+	if (facilities->throughput && (facil_mask & X25_MASK_THROUGHPUT)) {
 		*p++ = X25_FAC_THROUGHPUT;
 		*p++ = facilities->throughput;
 	}
 
-	if ((facilities->pacsize_in != 0 || facilities->pacsize_out != 0) && (facil_mask & X25_MASK_PACKET_SIZE)) {
+	if ((facilities->pacsize_in || facilities->pacsize_out) &&
+	    (facil_mask & X25_MASK_PACKET_SIZE)) {
 		*p++ = X25_FAC_PACKET_SIZE;
-		*p++ = (facilities->pacsize_in  == 0) ? facilities->pacsize_out : facilities->pacsize_in;
-		*p++ = (facilities->pacsize_out == 0) ? facilities->pacsize_in  : facilities->pacsize_out;
+		*p++ = facilities->pacsize_in ? : facilities->pacsize_out;
+		*p++ = facilities->pacsize_out ? : facilities->pacsize_in;
 	}
 
-	if ((facilities->winsize_in != 0 || facilities->winsize_out != 0) && (facil_mask & X25_MASK_WINDOW_SIZE)) {
+	if (facilities->winsize_in || facilities->winsize_out &&
+	    (facil_mask & X25_MASK_WINDOW_SIZE)) {
 		*p++ = X25_FAC_WINDOW_SIZE;
-		*p++ = (facilities->winsize_in  == 0) ? facilities->winsize_out : facilities->winsize_in;
-		*p++ = (facilities->winsize_out == 0) ? facilities->winsize_in  : facilities->winsize_out;
+		*p++ = facilities->winsize_in ? : facilities->winsize_out;
+		*p++ = facilities->winsize_out ? : facilities->winsize_in;
 	}
 
 	len       = p - buffer;
@@ -154,39 +169,37 @@ int x25_create_facilities(unsigned char *buffer, struct x25_facilities *faciliti
  *
  *	The only real problem is with reverse charging.
  */
-int x25_negotiate_facilities(struct sk_buff *skb, struct sock *sk, struct x25_facilities *new)
+int x25_negotiate_facilities(struct sk_buff *skb, struct sock *sk,
+			     struct x25_facilities *new)
 {
 	x25_cb *x25 = x25_sk(sk);
-	struct x25_facilities *ours;
+	struct x25_facilities *ours = &x25->facilities;
 	struct x25_facilities theirs;
 	int len;
 
-	memset(&theirs, 0x00, sizeof(struct x25_facilities));
-
-	ours = &x25->facilities;
-
-	*new = *ours;
+	memset(&theirs, 0, sizeof(theirs));
+	memcpy(new, ours, sizeof(*new));
 
 	len = x25_parse_facilities(skb, &theirs, &x25->vc_facil_mask);
 
 	/*
 	 *	They want reverse charging, we won't accept it.
 	 */
-	if (theirs.reverse != 0 && ours->reverse == 0) {
+	if (theirs.reverse && ours->reverse) {
 		SOCK_DEBUG(sk, "X.25: rejecting reverse charging request");
 		return -1;
 	}
 
 	new->reverse = theirs.reverse;
 
-	if (theirs.throughput != 0) {
+	if (theirs.throughput) {
 		if (theirs.throughput < ours->throughput) {
 			SOCK_DEBUG(sk, "X.25: throughput negotiated down");
 			new->throughput = theirs.throughput;
 		}
 	}
 
-	if (theirs.pacsize_in != 0 && theirs.pacsize_out != 0) {
+	if (theirs.pacsize_in && theirs.pacsize_out) {
 		if (theirs.pacsize_in < ours->pacsize_in) {
 			SOCK_DEBUG(sk, "X.25: packet size inwards negotiated down");
 			new->pacsize_in = theirs.pacsize_in;
@@ -197,7 +210,7 @@ int x25_negotiate_facilities(struct sk_buff *skb, struct sock *sk, struct x25_fa
 		}
 	}
 
-	if (theirs.winsize_in != 0 && theirs.winsize_out != 0) {
+	if (theirs.winsize_in && theirs.winsize_out) {
 		if (theirs.winsize_in < ours->winsize_in) {
 			SOCK_DEBUG(sk, "X.25: window size inwards negotiated down");
 			new->winsize_in = theirs.winsize_in;
@@ -219,12 +232,12 @@ void x25_limit_facilities(struct x25_facilities *facilities,
 			  struct x25_neigh *neighbour)
 {
 
-	if( ! neighbour->extended ){
-		if( facilities->winsize_in  > 7 ){
+	if (!neighbour->extended) {
+		if (facilities->winsize_in  > 7) {
 			printk(KERN_DEBUG "X.25: incoming winsize limited to 7\n");
 			facilities->winsize_in = 7;
 		}
-		if( facilities->winsize_out > 7 ){
+		if (facilities->winsize_out > 7) {
 			facilities->winsize_out = 7;
 			printk( KERN_DEBUG "X.25: outgoing winsize limited to 7\n");
 		}