From NetBSD: merge of 960317

1 files changed, 312 insertions, 0 deletions

diff --git a/usr.sbin/pppd/demand.c b/usr.sbin/pppd/demand.c
new file mode 100644
index 00000000000..0292ca43020
--- /dev/null
+++ b/usr.sbin/pppd/demand.c
@@ -0,0 +1,312 @@
+/*	$OpenBSD: demand.c,v 1.1 1996/03/25 15:55:37 niklas Exp $	*/
+
+/*
+ * demand.c - Dial on demand support.
+ *
+ * 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[] = "$OpenBSD: demand.c,v 1.1 1996/03/25 15:55:37 niklas 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 <net/bpf.h>
+
+#include "pppd.h"
+#include "fsm.h"
+#include "ipcp.h"
+#include "lcp.h"
+#include "bpf_compile.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);
+
+    set_filters(&pass_filter, &active_filter);
+
+    /*
+     * 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 & ~0x8000, 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 & ~0x8000, 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 & ~0x8000, 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.
+ * We assume that the kernel driver has already applied the
+ * pass_filter, so we won't get packets it rejected.
+ * We apply the active_filter to see if we want this packet to
+ * bring up the link.
+ */
+int
+loop_frame(frame, len)
+    unsigned char *frame;
+    int len;
+{
+    struct packet *pkt;
+
+    if (len < PPP_HDRLEN)
+	return 0;
+    if ((PPP_PROTOCOL(frame) & 0x8000) != 0)
+	return 0;		/* shouldn't get any of these anyway */
+    if (active_filter.bf_len != 0
+	&& bpf_filter(active_filter.bf_insns, frame, len, len) == 0)
+	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) {
+	nextpkt = pkt->next;
+	if (PPP_PROTOCOL(pkt->data) == proto) {
+	    output(0, pkt->data, pkt->length);
+	    free(pkt);
+	} else {
+	    if (prev == NULL)
+		pend_q = pkt;
+	    else
+		prev->next = pkt;
+	    prev = pkt;
+	}
+    }
+    pend_qtail = prev;
+    if (prev != NULL)
+	prev->next = NULL;
+}