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fixed usage of libpcap

PATCH Arvin Schnell 1 participant 2 messages Feb 18, 2004 PPP protocol drivers and compressors

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Arvin Schnell

author
#0 lore raw

Hi,

while updating to libpcap 0.8.1 I realized that pppd uses it's own version of pcap-int.h that does not match the original version anymore.

Attached is a patch against ppp 2.4.2 to solve that problem. The rename from net/bpf.h to pcap-bpf.h happend somewhere between libpcap 0.7.2 and 0.8.1.

But I still have the problem that libpcap reports an error when using inbound or outbound:

error in active-filter expression: inbound/outbound not supported on linktype 9

Seems as if that's not supported anymore and was so far silently ignored. Does anyone know more about that?

ciao Arvin

Signature · 4 lines
Dipl.-Phys. Arvin Schnell
SuSE Linux AG
Research & Development
email: [email protected]
demand.c +1 -1
@@ -38,7 +38,7 @@
 #include <arpa/inet.h>
 #ifdef PPP_FILTER
 #include <net/if.h>
-#include <net/bpf.h>
+#include <pcap-bpf.h>
 #include <pcap.h>
 #endif
sys-linux.c +1 -1
@@ -85,7 +85,7 @@
 #endif /* IPX_CHANGE */
 
 #ifdef PPP_FILTER
-#include <net/bpf.h>
+#include <pcap-bpf.h>
 #include <linux/filter.h>
 #endif /* PPP_FILTER */
pppd/options.c renamed from pppd/options.c.orig +14 -10
@@ -56,7 +56,6 @@
 #endif
 #ifdef PPP_FILTER
 #include <pcap.h>
-#include <pcap-int.h>	/* XXX: To get struct pcap */
 #endif
 
 #include "pppd.h"

@@ -122,7 +121,6 @@
 #ifdef PPP_FILTER
 struct	bpf_program pass_filter;/* Filter program for packets to pass */
 struct	bpf_program active_filter; /* Filter program for link-active pkts */
-pcap_t  pc;			/* Fake struct pcap so we can compile expr */
 #endif
 
 char *current_option;		/* the name of the option being parsed */

@@ -1439,12 +1437,15 @@
 setpassfilter(argv)
     char **argv;
 {
-    pc.linktype = DLT_PPP;
-    pc.snapshot = PPP_HDRLEN;
+    pcap_t* pc = pcap_open_dead (DLT_PPP, PPP_HDRLEN);
  
-    if (pcap_compile(&pc, &pass_filter, *argv, 1, netmask) == 0)
+    if (pcap_compile(pc, &pass_filter, *argv, 1, netmask) == 0) {
+	pcap_close (pc);
 	return 1;
-    option_error("error in pass-filter expression: %s\n", pcap_geterr(&pc));
+    }
+
+    option_error("error in pass-filter expression: %s\n", pcap_geterr(pc));
+    pcap_close (pc);
     return 0;
 }
 

@@ -1455,12 +1456,15 @@
 setactivefilter(argv)
     char **argv;
 {
-    pc.linktype = DLT_PPP;
-    pc.snapshot = PPP_HDRLEN;
+    pcap_t* pc = pcap_open_dead (DLT_PPP, PPP_HDRLEN);
  
-    if (pcap_compile(&pc, &active_filter, *argv, 1, netmask) == 0)
+    if (pcap_compile(pc, &active_filter, *argv, 1, netmask) == 0) {
+	pcap_close (pc);
 	return 1;
-    option_error("error in active-filter expression: %s\n", pcap_geterr(&pc));
+    }
+
+    option_error("error in active-filter expression: %s\n", pcap_geterr(pc));
+    pcap_close (pc);
     return 0;
 }
 #endif
author
#1 lore raw
Quoted 10 lines · Arvin Schnell

Hi,

while updating to libpcap 0.8.1 I realized that pppd uses it's own version of pcap-int.h that does not match the original version anymore.

Attached is a patch against ppp 2.4.2 to solve that problem. The rename from net/bpf.h to pcap-bpf.h happend somewhere between libpcap 0.7.2 and 0.8.1.

Better also check the return value of pcap_open_dead.

ciao Arvin

demand.c +1 -1
@@ -38,7 +38,7 @@
 #include <arpa/inet.h>
 #ifdef PPP_FILTER
 #include <net/if.h>
-#include <net/bpf.h>
+#include <pcap-bpf.h>
 #include <pcap.h>
 #endif
sys-linux.c +1 -1
@@ -85,7 +85,7 @@
 #endif /* IPX_CHANGE */
 
 #ifdef PPP_FILTER
-#include <net/bpf.h>
+#include <pcap-bpf.h>
 #include <linux/filter.h>
 #endif /* PPP_FILTER */
pppd/options.c renamed from pppd/options.c.orig +24 -10
@@ -56,7 +56,6 @@
 #endif
 #ifdef PPP_FILTER
 #include <pcap.h>
-#include <pcap-int.h>	/* XXX: To get struct pcap */
 #endif
 
 #include "pppd.h"

@@ -122,7 +121,6 @@
 #ifdef PPP_FILTER
 struct	bpf_program pass_filter;/* Filter program for packets to pass */
 struct	bpf_program active_filter; /* Filter program for link-active pkts */
-pcap_t  pc;			/* Fake struct pcap so we can compile expr */
 #endif
 
 char *current_option;		/* the name of the option being parsed */

@@ -1439,12 +1437,20 @@
 setpassfilter(argv)
     char **argv;
 {
-    pc.linktype = DLT_PPP;
-    pc.snapshot = PPP_HDRLEN;
+    pcap_t* pc = pcap_open_dead (DLT_PPP, PPP_HDRLEN);
  
-    if (pcap_compile(&pc, &pass_filter, *argv, 1, netmask) == 0)
+    if (!pc) {
+	option_error("error in pass-filter expression: pcap_open_dead failed\n");
+	return 0;
+    }
+
+    if (pcap_compile(pc, &pass_filter, *argv, 1, netmask) == 0) {
+	pcap_close (pc);
 	return 1;
-    option_error("error in pass-filter expression: %s\n", pcap_geterr(&pc));
+    }
+
+    option_error("error in pass-filter expression: %s\n", pcap_geterr(pc));
+    pcap_close (pc);
     return 0;
 }
 

@@ -1455,12 +1461,20 @@
 setactivefilter(argv)
     char **argv;
 {
-    pc.linktype = DLT_PPP;
-    pc.snapshot = PPP_HDRLEN;
+    pcap_t* pc = pcap_open_dead (DLT_PPP, PPP_HDRLEN);
  
-    if (pcap_compile(&pc, &active_filter, *argv, 1, netmask) == 0)
+    if (!pc) {
+	option_error("error in active-filter expression: pcap_open_dead failed\n");
+	return 0;
+    }
+
+    if (pcap_compile(pc, &active_filter, *argv, 1, netmask) == 0) {
+	pcap_close (pc);
 	return 1;
-    option_error("error in active-filter expression: %s\n", pcap_geterr(&pc));
+    }
+
+    option_error("error in active-filter expression: %s\n", pcap_geterr(pc));
+    pcap_close (pc);
     return 0;
 }
 #endif