Added functions for demand-dial support
authorPaul Mackerras <paulus@samba.org>
Mon, 1 Jan 1996 23:10:09 +0000 (23:10 +0000)
committerPaul Mackerras <paulus@samba.org>
Mon, 1 Jan 1996 23:10:09 +0000 (23:10 +0000)
pppd/demand.c [new file with mode: 0644]

diff --git a/pppd/demand.c b/pppd/demand.c
new file mode 100644 (file)
index 0000000..21a1f07
--- /dev/null
@@ -0,0 +1,296 @@
+/*
+ * auth.c - PPP authentication and phase control.
+ *
+ * Copyright (c) 1993 The Australian National University.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that the above copyright notice and this paragraph are
+ * duplicated in all such forms and that any documentation,
+ * advertising materials, and other materials related to such
+ * distribution and use acknowledge that the software was developed
+ * by the Australian National University.  The name of the University
+ * may not be used to endorse or promote products derived from this
+ * software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#ifndef lint
+static char rcsid[] = "$Id: demand.c,v 1.1 1996/01/01 23:10:09 paulus Exp $";
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <syslog.h>
+#include <netdb.h>
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <net/if.h>
+
+#include "pppd.h"
+#include "fsm.h"
+#include "ipcp.h"
+#include "lcp.h"
+
+char *frame;
+int framelen;
+int framemax;
+int escape_flag;
+int flush_flag;
+int fcs;
+
+struct packet {
+    int length;
+    struct packet *next;
+    unsigned char data[1];
+};
+
+struct packet *pend_q;
+struct packet *pend_qtail;
+
+/*
+ * demand_conf - configure the interface for doing dial-on-demand.
+ */
+void
+demand_conf()
+{
+    int i;
+    struct protent *protp;
+
+/*    framemax = lcp_allowoptions[0].mru;
+    if (framemax < PPP_MRU) */
+       framemax = PPP_MRU;
+    framemax += PPP_HDRLEN + PPP_FCSLEN;
+    frame = malloc(framemax);
+    if (frame == NULL)
+       novm("demand frame");
+    framelen = 0;
+    pend_q = NULL;
+    escape_flag = 0;
+    flush_flag = 0;
+    fcs = PPP_INITFCS;
+
+    ppp_send_config(0, PPP_MRU, (u_int32_t) 0, 0, 0);
+    ppp_recv_config(0, PPP_MRU, (u_int32_t) 0, 0, 0);
+
+    /*
+     * Call the demand_conf procedure for each protocol that's got one.
+     */
+    for (i = 0; (protp = protocols[i]) != NULL; ++i)
+       if (protp->enabled_flag && protp->demand_conf != NULL)
+           if (!((*protp->demand_conf)(0)))
+               die(1);
+}
+
+
+/*
+ * demand_block - set each network protocol to block further packets.
+ */
+void
+demand_block()
+{
+    int i;
+    struct protent *protp;
+
+    for (i = 0; (protp = protocols[i]) != NULL; ++i)
+       if (protp->enabled_flag && protp->demand_conf != NULL)
+           sifnpmode(0, protp->protocol, NPMODE_QUEUE);
+    get_loop_output();
+}
+
+/*
+ * demand_discard - set each network protocol to discard packets
+ * with an error.
+ */
+void
+demand_discard()
+{
+    struct packet *pkt, *nextpkt;
+    int i;
+    struct protent *protp;
+
+    for (i = 0; (protp = protocols[i]) != NULL; ++i)
+       if (protp->enabled_flag && protp->demand_conf != NULL)
+           sifnpmode(0, protp->protocol, NPMODE_ERROR);
+    get_loop_output();
+
+    /* discard all saved packets */
+    for (pkt = pend_q; pkt != NULL; pkt = nextpkt) {
+       nextpkt = pkt->next;
+       free(pkt);
+    }
+    pend_q = NULL;
+    framelen = 0;
+    flush_flag = 0;
+    escape_flag = 0;
+    fcs = PPP_INITFCS;
+}
+
+/*
+ * demand_unblock - set each enabled network protocol to pass packets.
+ */
+void
+demand_unblock()
+{
+    int i;
+    struct protent *protp;
+
+    for (i = 0; (protp = protocols[i]) != NULL; ++i)
+       if (protp->enabled_flag && protp->demand_conf != NULL)
+           sifnpmode(0, protp->protocol, NPMODE_PASS);
+}
+
+/*
+ * FCS lookup table as calculated by genfcstab.
+ */
+static u_short fcstab[256] = {
+       0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
+       0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
+       0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
+       0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
+       0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
+       0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
+       0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
+       0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
+       0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
+       0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
+       0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
+       0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
+       0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
+       0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
+       0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
+       0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
+       0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
+       0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
+       0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
+       0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
+       0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
+       0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
+       0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
+       0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
+       0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
+       0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
+       0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
+       0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
+       0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
+       0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
+       0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
+       0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
+};
+
+/*
+ * loop_chars - process characters received from the loopback.
+ * Calls loop_frame when a complete frame has been accumulated.
+ * Return value is 1 if we need to bring up the link, 0 otherwise.
+ */
+int
+loop_chars(p, n)
+    unsigned char *p;
+    int n;
+{
+    int c, rv;
+
+    rv = 0;
+    for (; n > 0; --n) {
+       c = *p++;
+       if (c == PPP_FLAG) {
+           if (!escape_flag && !flush_flag
+               && framelen > 2 && fcs == PPP_GOODFCS) {
+               framelen -= 2;
+               if (loop_frame(frame, framelen))
+                   rv = 1;
+           }
+           framelen = 0;
+           flush_flag = 0;
+           escape_flag = 0;
+           fcs = PPP_INITFCS;
+           continue;
+       }
+       if (flush_flag)
+           continue;
+       if (escape_flag) {
+           c ^= PPP_TRANS;
+           escape_flag = 0;
+       } else if (c == PPP_ESCAPE) {
+           escape_flag = 1;
+           continue;
+       }
+       if (framelen >= framemax) {
+           flush_flag = 1;
+           continue;
+       }
+       frame[framelen++] = c;
+       fcs = PPP_FCS(fcs, c);
+    }
+    return rv;
+}
+
+/*
+ * loop_frame - given a frame obtained from the loopback,
+ * decide whether to bring up the link or not, and, if we want
+ * to transmit this frame later, put it on the pending queue.
+ * Return value is 1 if we need to bring up the link, 0 otherwise.
+ */
+int
+loop_frame(frame, len)
+    unsigned char *frame;
+    int len;
+{
+    struct packet *pkt;
+
+    if (len < PPP_HDRLEN)
+       return 0;
+    if (PPP_PROTOCOL(frame) != PPP_IP)
+       return 0;
+    pkt = (struct packet *) malloc(sizeof(struct packet) + len);
+    if (pkt != NULL) {
+       pkt->length = len;
+       pkt->next = NULL;
+       memcpy(pkt->data, frame, len);
+       if (pend_q == NULL)
+           pend_q = pkt;
+       else
+           pend_qtail->next = pkt;
+       pend_qtail = pkt;
+    }
+    return 1;
+}
+
+/*
+ * demand_rexmit - Resend all those frames which we got via the
+ * loopback, now that the real serial link is up.
+ */
+void
+demand_rexmit(proto)
+    int proto;
+{
+    struct packet *pkt, *prev, *nextpkt;
+
+    prev = NULL;
+    pkt = pend_q;
+    pend_q = NULL;
+    for (; pkt != NULL; pkt = nextpkt) {
+       if (PPP_PROTOCOL(pkt->data) == proto) {
+           output(0, pkt->data, pkt->length);
+           nextpkt = pkt->next;
+           free(pkt);
+       } else {
+           if (prev == NULL)
+               pend_q = pkt;
+           else
+               prev->next = pkt;
+           prev = pkt;
+       }
+    }
+    pend_qtail = prev;
+}