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1.1 root 1: /*
2: * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3: *
4: * @APPLE_LICENSE_HEADER_START@
5: *
6: * The contents of this file constitute Original Code as defined in and
7: * are subject to the Apple Public Source License Version 1.1 (the
8: * "License"). You may not use this file except in compliance with the
9: * License. Please obtain a copy of the License at
10: * http://www.apple.com/publicsource and read it before using this file.
11: *
12: * This Original Code and all software distributed under the License are
13: * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17: * License for the specific language governing rights and limitations
18: * under the License.
19: *
20: * @APPLE_LICENSE_HEADER_END@
21: */
22: /*
23: * Copyright (c) University of British Columbia, 1984
24: * Copyright (c) 1990, 1993
25: * The Regents of the University of California. All rights reserved.
26: *
27: * This code is derived from software contributed to Berkeley by
28: * the Laboratory for Computation Vision and the Computer Science Department
29: * of the University of British Columbia.
30: *
31: * Redistribution and use in source and binary forms, with or without
32: * modification, are permitted provided that the following conditions
33: * are met:
34: * 1. Redistributions of source code must retain the above copyright
35: * notice, this list of conditions and the following disclaimer.
36: * 2. Redistributions in binary form must reproduce the above copyright
37: * notice, this list of conditions and the following disclaimer in the
38: * documentation and/or other materials provided with the distribution.
39: * 3. All advertising materials mentioning features or use of this software
40: * must display the following acknowledgement:
41: * This product includes software developed by the University of
42: * California, Berkeley and its contributors.
43: * 4. Neither the name of the University nor the names of its contributors
44: * may be used to endorse or promote products derived from this software
45: * without specific prior written permission.
46: *
47: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
48: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
49: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
50: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
51: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
52: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
53: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
54: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
55: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
56: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
57: * SUCH DAMAGE.
58: *
59: * @(#)hd_output.c 8.1 (Berkeley) 6/10/93
60: */
61:
62: #include <sys/param.h>
63: #include <sys/systm.h>
64: #include <sys/mbuf.h>
65: #include <sys/domain.h>
66: #include <sys/socket.h>
67: #include <sys/syslog.h>
68: #include <sys/protosw.h>
69: #include <sys/errno.h>
70: #include <sys/time.h>
71: #include <sys/kernel.h>
72:
73: #include <net/if.h>
74:
75: #include <netccitt/hdlc.h>
76: #include <netccitt/hd_var.h>
77: #include <netccitt/x25.h>
78:
79: /*
80: * HDLC OUTPUT INTERFACE
81: *
82: * This routine is called when the X.25 packet layer output routine
83: * has a information frame (iframe) to write. It is also called
84: * by the input and control routines of the HDLC layer.
85: */
86:
87: hd_output (hdp, m0)
88: register struct hdcb *hdp;
89: struct mbuf *m0;
90: {
91: struct x25config *xcp;
92: register struct mbuf *m = m0;
93: int len;
94:
95: if (m == NULL)
96: panic ("hd_output");
97: if ((m->m_flags & M_PKTHDR) == 0)
98: panic ("hd_output 2");
99:
100: if (hdp->hd_state != ABM) {
101: m_freem (m);
102: return;
103: }
104:
105: /*
106: * Make room for the hdlc header either by prepending
107: * another mbuf, or by adjusting the offset and length
108: * of the first mbuf in the mbuf chain.
109: */
110:
111: M_PREPEND(m, HDHEADERLN, M_DONTWAIT);
112: if (m == NULL)
113: return;
114: for (len = 0; m; m = m->m_next)
115: len += m->m_len;
116: m = m0;
117: m->m_pkthdr.len = len;
118:
119: hd_append (&hdp->hd_txq, m);
120: hd_start (hdp);
121: }
122:
123: hd_start (hdp)
124: register struct hdcb *hdp;
125: {
126: register struct mbuf *m;
127:
128: /*
129: * The iframe is only transmitted if all these conditions are FALSE.
130: * The iframe remains queued (hdp->hd_txq) however and will be
131: * transmitted as soon as these conditions are cleared.
132: */
133:
134: while (!(hdp->hd_condition & (TIMER_RECOVERY_CONDITION | REMOTE_RNR_CONDITION | REJ_CONDITION))) {
135: if (hdp->hd_vs == (hdp->hd_lastrxnr + hdp->hd_xcp->xc_lwsize) % MODULUS) {
136:
137: /* We have now exceeded the maximum number of
138: outstanding iframes. Therefore, we must wait
139: until at least one is acknowledged if this
140: condition is not turned off before we are
141: requested to write another iframe. */
142: hdp->hd_window_condition++;
143: break;
144: }
145:
146: /* hd_remove top iframe from transmit queue. */
147: if ((m = hd_remove (&hdp->hd_txq)) == NULL)
148: break;
149:
150: hd_send_iframe (hdp, m, POLLOFF);
151: }
152: }
153:
154: /*
155: * This procedure is passed a buffer descriptor for an iframe. It builds
156: * the rest of the control part of the frame and then writes it out. It
157: * also starts the acknowledgement timer and keeps the iframe in the
158: * Retransmit queue (Retxq) just in case we have to do this again.
159: *
160: * Note: This routine is also called from hd_input.c when retransmission
161: * of old frames is required.
162: */
163:
164: hd_send_iframe (hdp, buf, poll_bit)
165: register struct hdcb *hdp;
166: register struct mbuf *buf;
167: int poll_bit;
168: {
169: register struct Hdlc_iframe *iframe;
170: struct mbuf *m;
171:
172: KILL_TIMER (hdp);
173:
174: if (buf == 0) {
175: printf ("hd_send_iframe: zero arg\n");
176: #ifdef HDLCDEBUG
177: hd_status (hdp);
178: hd_dumptrace (hdp);
179: #endif
180: hdp->hd_vs = (hdp->hd_vs + 7) % MODULUS;
181: return;
182: }
183: iframe = mtod (buf, struct Hdlc_iframe *);
184:
185: iframe -> hdlc_0 = 0;
186: iframe -> nr = hdp->hd_vr;
187: iframe -> pf = poll_bit;
188: iframe -> ns = hdp->hd_vs;
189: iframe -> address = ADDRESS_B;
190: hdp->hd_lasttxnr = hdp->hd_vr;
191: hdp->hd_rrtimer = 0;
192:
193: if (hdp->hd_vs == hdp->hd_retxqi) {
194: /* Check for retransmissions. */
195: /* Put iframe only once in the Retransmission queue. */
196: hdp->hd_retxq[hdp->hd_retxqi] = buf;
197: hdp->hd_retxqi = (hdp->hd_retxqi + 1) % MODULUS;
198: hdp->hd_iframes_out++;
199: }
200:
201: hdp->hd_vs = (hdp->hd_vs + 1) % MODULUS;
202:
203: hd_trace (hdp, TX, (struct Hdlc_frame *)iframe);
204:
205: /* Write buffer on device. */
206: m = hdp->hd_dontcopy ? buf : m_copy(buf, 0, (int)M_COPYALL);
207: if (m == 0) {
208: printf("hdlc: out of mbufs\n");
209: return;
210: }
211: (*hdp->hd_output)(hdp, m);
212: SET_TIMER (hdp);
213: }
214:
215: hd_ifoutput(hdp, m)
216: register struct mbuf *m;
217: register struct hdcb *hdp;
218: {
219: /*
220: * Queue message on interface, and start output if interface
221: * not yet active.
222: */
223: register struct ifnet *ifp = hdp->hd_ifp;
224: int s = splimp();
225:
226: if (IF_QFULL(&ifp->if_snd)) {
227: IF_DROP(&ifp->if_snd);
228: /* printf("%s%d: HDLC says OK to send but queue full, may hang\n",
229: ifp->if_name, ifp->if_unit);*/
230: m_freem(m);
231: } else {
232: IF_ENQUEUE(&ifp->if_snd, m);
233: if ((ifp->if_flags & IFF_OACTIVE) == 0)
234: (*ifp->if_start)(ifp);
235: }
236: splx(s);
237: }
238:
239:
240: /*
241: * This routine gets control when the timer expires because we have not
242: * received an acknowledgement for a iframe.
243: */
244:
245: hd_resend_iframe (hdp)
246: register struct hdcb *hdp;
247: {
248:
249: if (hdp->hd_retxcnt++ < hd_n2) {
250: if (!(hdp->hd_condition & TIMER_RECOVERY_CONDITION)) {
251: hdp->hd_xx = hdp->hd_vs;
252: hdp->hd_condition |= TIMER_RECOVERY_CONDITION;
253: }
254:
255: hdp->hd_vs = hdp->hd_lastrxnr;
256: hd_send_iframe (hdp, hdp->hd_retxq[hdp->hd_vs], POLLON);
257: } else {
258: /* At this point we have not received a RR even after N2
259: retries - attempt to reset link. */
260:
261: hd_initvars (hdp);
262: hd_writeinternal (hdp, SABM, POLLOFF);
263: hdp->hd_state = WAIT_UA;
264: SET_TIMER (hdp);
265: hd_message (hdp, "Timer recovery failed: link down");
266: (void) pk_ctlinput (PRC_LINKDOWN, hdp->hd_pkp);
267: }
268: }
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