Large patch from Frank Cusack <fcusack@fcusack.com> to add proper

[ppp.git] / pppd / demand.c

diff --git a/pppd/demand.c b/pppd/demand.c
index 21a1f07c0b320156f693a8d6783a5fbdf026a740..d46776692fa04f7158abcaac0fb4fd92af12fc22 100644 (file)
--- a/pppd/demand.c
+++ b/pppd/demand.c
@@ -1,5 +1,5 @@
 /*
- * auth.c - PPP authentication and phase control.
+ * demand.c - Support routines for demand-dialling.
  *
  * Copyright (c) 1993 The Australian National University.
  * All rights reserved.
@@ -17,16 +17,13 @@
  * 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 $";
-#endif
+#define RCSID  "$Id: demand.c,v 1.15 2001/03/08 05:14:26 paulus Exp $"
 
 #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>
@@ -35,13 +32,19 @@ static char rcsid[] = "$Id: demand.c,v 1.1 1996/01/01 23:10:09 paulus Exp $";
 #include <sys/resource.h>
 #include <sys/stat.h>
 #include <sys/socket.h>
+#ifdef PPP_FILTER
 #include <net/if.h>
+#include <net/bpf.h>
+#include <pcap.h>
+#endif
 
 #include "pppd.h"
 #include "fsm.h"
 #include "ipcp.h"
 #include "lcp.h"
 
+static const char rcsid[] = RCSID;
+
 char *frame;
 int framelen;
 int framemax;
@@ -58,6 +61,8 @@ struct packet {
 struct packet *pend_q;
 struct packet *pend_qtail;
 
+static int active_packet __P((unsigned char *, int));
+
 /*
  * demand_conf - configure the interface for doing dial-on-demand.
  */
@@ -80,9 +85,14 @@ demand_conf()
     flush_flag = 0;
     fcs = PPP_INITFCS;
 
+    netif_set_mtu(0, MIN(lcp_allowoptions[0].mru, PPP_MRU));
     ppp_send_config(0, PPP_MRU, (u_int32_t) 0, 0, 0);
     ppp_recv_config(0, PPP_MRU, (u_int32_t) 0, 0, 0);
 
+#ifdef PPP_FILTER
+    set_filters(&pass_filter, &active_filter);
+#endif
+
     /*
      * Call the demand_conf procedure for each protocol that's got one.
      */
@@ -104,7 +114,7 @@ demand_block()
 
     for (i = 0; (protp = protocols[i]) != NULL; ++i)
        if (protp->enabled_flag && protp->demand_conf != NULL)
-           sifnpmode(0, protp->protocol, NPMODE_QUEUE);
+           sifnpmode(0, protp->protocol & ~0x8000, NPMODE_QUEUE);
     get_loop_output();
 }
 
@@ -121,7 +131,7 @@ demand_discard()
 
     for (i = 0; (protp = protocols[i]) != NULL; ++i)
        if (protp->enabled_flag && protp->demand_conf != NULL)
-           sifnpmode(0, protp->protocol, NPMODE_ERROR);
+           sifnpmode(0, protp->protocol & ~0x8000, NPMODE_ERROR);
     get_loop_output();
 
     /* discard all saved packets */
@@ -147,7 +157,7 @@ demand_unblock()
 
     for (i = 0; (protp = protocols[i]) != NULL; ++i)
        if (protp->enabled_flag && protp->demand_conf != NULL)
-           sifnpmode(0, protp->protocol, NPMODE_PASS);
+           sifnpmode(0, protp->protocol & ~0x8000, NPMODE_PASS);
 }
 
 /*
@@ -207,7 +217,7 @@ loop_chars(p, n)
            if (!escape_flag && !flush_flag
                && framelen > 2 && fcs == PPP_GOODFCS) {
                framelen -= 2;
-               if (loop_frame(frame, framelen))
+               if (loop_frame((unsigned char *)frame, framelen))
                    rv = 1;
            }
            framelen = 0;
@@ -240,6 +250,10 @@ loop_chars(p, n)
  * 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)
@@ -248,10 +262,14 @@ loop_frame(frame, len)
 {
     struct packet *pkt;
 
+    /* dbglog("from loop: %P", frame, len); */
     if (len < PPP_HDRLEN)
        return 0;
-    if (PPP_PROTOCOL(frame) != PPP_IP)
+    if ((PPP_PROTOCOL(frame) & 0x8000) != 0)
+       return 0;               /* shouldn't get any of these anyway */
+    if (!active_packet(frame, len))
        return 0;
+
     pkt = (struct packet *) malloc(sizeof(struct packet) + len);
     if (pkt != NULL) {
        pkt->length = len;
@@ -280,9 +298,9 @@ demand_rexmit(proto)
     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);
-           nextpkt = pkt->next;
            free(pkt);
        } else {
            if (prev == NULL)
@@ -293,4 +311,41 @@ demand_rexmit(proto)
        }
     }
     pend_qtail = prev;
+    if (prev != NULL)
+       prev->next = NULL;
+}
+
+/*
+ * Scan a packet to decide whether it is an "active" packet,
+ * that is, whether it is worth bringing up the link for.
+ */
+static int
+active_packet(p, len)
+    unsigned char *p;
+    int len;
+{
+    int proto, i;
+    struct protent *protp;
+
+    if (len < PPP_HDRLEN)
+       return 0;
+    proto = PPP_PROTOCOL(p);
+#ifdef PPP_FILTER
+    if (pass_filter.bf_len != 0
+       && bpf_filter(pass_filter.bf_insns, p, len, len) == 0)
+       return 0;
+    if (active_filter.bf_len != 0
+       && bpf_filter(active_filter.bf_insns, p, len, len) == 0)
+       return 0;
+#endif
+    for (i = 0; (protp = protocols[i]) != NULL; ++i) {
+       if (protp->protocol < 0xC000 && (protp->protocol & ~0x8000) == proto) {
+           if (!protp->enabled_flag)
+               return 0;
+           if (protp->active_pkt == NULL)
+               return 1;
+           return (*protp->active_pkt)(p, len);
+       }
+    }
+    return 0;                  /* not a supported protocol !!?? */
 }