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Commit a85122a7 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo Committed by David S. Miller
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[X25] simplify facility negotiation.

parent 6c546640
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Showing with 89 additions and 76 deletions
net/x25/x25_facilities.c
View file @ a85122a7
/*
* 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
*
......@@ -42,12 +43,13 @@
* 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) {
......@@ -55,7 +57,7 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities,
case X25_FAC_CLASS_A:
switch (*p) {
case X25_FAC_REVERSE:
facilities->reverse = (p[1] & 0x01);
facilities->reverse = p[1] & 0x01;
*vc_fac_mask |= X25_MASK_REVERSE;
break;
case X25_FAC_THROUGHPUT:
......@@ -63,13 +65,14 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities,
*vc_fac_mask |= X25_MASK_THROUGHPUT;
break;
default:
printk(KERN_DEBUG "X.25: unknown facility %02X, value %02X\n", p[0], p[1]);
printk(KERN_DEBUG "X.25: unknown facility "
"%02X, value %02X\n",
p[0], p[1]);
break;
}
p += 2;
len -= 2;
break;
case X25_FAC_CLASS_B:
switch (*p) {
case X25_FAC_PACKET_SIZE:
......@@ -83,21 +86,25 @@ int x25_parse_facilities(struct sk_buff *skb, struct x25_facilities *facilities,
*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]);
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]);
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]);
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");
}
......
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