1 // SPDX-License-Identifier: GPL-2.0-or-later
15  *	apr/14/05	Shaun Pereira - Allow fast select with no restriction
28  * x25_parse_facilities - Parse facilities from skb into the facilities structs
36  *  -1 - Parsing error, caller should drop call and clean up
37  *   0 - Parse OK, this skb has no facilities
38  *  >0 - Parse OK, returns the length of the facilities header
55 	dte_facs->calling_len = 0;  in x25_parse_facilities()
56 	dte_facs->called_len = 0;  in x25_parse_facilities()
57 	memset(dte_facs->called_ae, '\0', sizeof(dte_facs->called_ae));  in x25_parse_facilities()
58 	memset(dte_facs->calling_ae, '\0', sizeof(dte_facs->calling_ae));  in x25_parse_facilities()
63 	len = skb->data[0];  in x25_parse_facilities()
66 		return -1;  in x25_parse_facilities()
68 	p = skb->data + 1;  in x25_parse_facilities()
74 				return -1;  in x25_parse_facilities()
78 					facilities->reverse = p[1] & 0x81;  in x25_parse_facilities()
84 					facilities->reverse = p[1] & 0x01;  in x25_parse_facilities()
90 					facilities->reverse = p[1] & 0x80;  in x25_parse_facilities()
96 					facilities->reverse  in x25_parse_facilities()
103 				facilities->throughput = p[1];  in x25_parse_facilities()
115 			len -= 2;  in x25_parse_facilities()
119 				return -1;  in x25_parse_facilities()
122 				facilities->pacsize_in  = p[1];  in x25_parse_facilities()
123 				facilities->pacsize_out = p[2];  in x25_parse_facilities()
127 				facilities->winsize_in  = p[1];  in x25_parse_facilities()
128 				facilities->winsize_out = p[2];  in x25_parse_facilities()
138 			len -= 3;  in x25_parse_facilities()
142 				return -1;  in x25_parse_facilities()
147 			len -= 4;  in x25_parse_facilities()
151 				return -1;  in x25_parse_facilities()
155 					return -1;  in x25_parse_facilities()
157 					return -1;  in x25_parse_facilities()
158 				dte_facs->calling_len = p[2];  in x25_parse_facilities()
159 				memcpy(dte_facs->calling_ae, &p[3], p[1] - 1);  in x25_parse_facilities()
164 					return -1;  in x25_parse_facilities()
166 					return -1;  in x25_parse_facilities()
167 				dte_facs->called_len = p[2];  in x25_parse_facilities()
168 				memcpy(dte_facs->called_ae, &p[3], p[1] - 1);  in x25_parse_facilities()
176 			len -= p[1] + 2;  in x25_parse_facilities()
182 	return p - skb->data;  in x25_parse_facilities()
205 	if (facilities->reverse && (facil_mask & X25_MASK_REVERSE)) {  in x25_create_facilities()
207 		*p++ = facilities->reverse;  in x25_create_facilities()
210 	if (facilities->throughput && (facil_mask & X25_MASK_THROUGHPUT)) {  in x25_create_facilities()
212 		*p++ = facilities->throughput;  in x25_create_facilities()
215 	if ((facilities->pacsize_in || facilities->pacsize_out) &&  in x25_create_facilities()
218 		*p++ = facilities->pacsize_in ? : facilities->pacsize_out;  in x25_create_facilities()
219 		*p++ = facilities->pacsize_out ? : facilities->pacsize_in;  in x25_create_facilities()
222 	if ((facilities->winsize_in || facilities->winsize_out) &&  in x25_create_facilities()
225 		*p++ = facilities->winsize_in ? : facilities->winsize_out;  in x25_create_facilities()
226 		*p++ = facilities->winsize_out ? : facilities->winsize_in;  in x25_create_facilities()
234 	if (dte_facs->calling_len && (facil_mask & X25_MASK_CALLING_AE)) {  in x25_create_facilities()
235 		unsigned int bytecount = (dte_facs->calling_len + 1) >> 1;  in x25_create_facilities()
238 		*p++ = dte_facs->calling_len;  in x25_create_facilities()
239 		memcpy(p, dte_facs->calling_ae, bytecount);  in x25_create_facilities()
243 	if (dte_facs->called_len && (facil_mask & X25_MASK_CALLED_AE)) {  in x25_create_facilities()
244 		unsigned int bytecount = (dte_facs->called_len % 2) ?  in x25_create_facilities()
245 		dte_facs->called_len / 2 + 1 :  in x25_create_facilities()
246 		dte_facs->called_len / 2;  in x25_create_facilities()
249 		*p++ = dte_facs->called_len;  in x25_create_facilities()
250 		memcpy(p, dte_facs->called_ae, bytecount);  in x25_create_facilities()
254 	len       = p - buffer;  in x25_create_facilities()
255 	buffer[0] = len - 1;  in x25_create_facilities()
263  *	The only real problem is with reverse charging.
269 	struct x25_facilities *ours = &x25->facilities;  in x25_negotiate_facilities()
277 	len = x25_parse_facilities(skb, &theirs, dte, &x25->vc_facil_mask);  in x25_negotiate_facilities()
282 	 *	They want reverse charging, we won't accept it.  in x25_negotiate_facilities()
284 	if ((theirs.reverse & 0x01 ) && (ours->reverse & 0x01)) {  in x25_negotiate_facilities()
285 		SOCK_DEBUG(sk, "X.25: rejecting reverse charging request\n");  in x25_negotiate_facilities()
286 		return -1;  in x25_negotiate_facilities()
289 	new->reverse = theirs.reverse;  in x25_negotiate_facilities()
294 		int ours_in  = ours->throughput & 0x0f;  in x25_negotiate_facilities()
295 		int ours_out = ours->throughput & 0xf0;  in x25_negotiate_facilities()
298 			new->throughput = (new->throughput & 0xf0) | theirs_in;  in x25_negotiate_facilities()
303 			new->throughput = (new->throughput & 0x0f) | theirs_out;  in x25_negotiate_facilities()
308 		if (theirs.pacsize_in < ours->pacsize_in) {  in x25_negotiate_facilities()
310 			new->pacsize_in = theirs.pacsize_in;  in x25_negotiate_facilities()
312 		if (theirs.pacsize_out < ours->pacsize_out) {  in x25_negotiate_facilities()
314 			new->pacsize_out = theirs.pacsize_out;  in x25_negotiate_facilities()
319 		if (theirs.winsize_in < ours->winsize_in) {  in x25_negotiate_facilities()
321 			new->winsize_in = theirs.winsize_in;  in x25_negotiate_facilities()
323 		if (theirs.winsize_out < ours->winsize_out) {  in x25_negotiate_facilities()
325 			new->winsize_out = theirs.winsize_out;  in x25_negotiate_facilities()
340 	if (!nb->extended) {  in x25_limit_facilities()
341 		if (facilities->winsize_in  > 7) {  in x25_limit_facilities()
343 			facilities->winsize_in = 7;  in x25_limit_facilities()
345 		if (facilities->winsize_out > 7) {  in x25_limit_facilities()
346 			facilities->winsize_out = 7;  in x25_limit_facilities()