X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;f=pppd%2Foptions.c;h=a85239abb0c523908e2e51d69d2b296b79754fb2;hb=dd39af173ba7e20360fff462cd5848aeb9471a4c;hp=fb83dee1f8b092623d7d862613c10b638a7d932b;hpb=0b6b481854230b3ea1e613f05800f17eb4fcc204;p=ppp.git

diff --git a/pppd/options.c b/pppd/options.c
index fb83dee..a85239a 100644
--- a/pppd/options.c
+++ b/pppd/options.c
@@ -40,7 +40,7 @@
  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-#define RCSID	"$Id: options.c,v 1.97 2005/07/09 04:58:36 paulus Exp $"
+#define RCSID	"$Id: options.c,v 1.100 2006/06/18 11:26:00 paulus Exp $"
 
 #include <ctype.h>
 #include <stdio.h>
@@ -58,14 +58,19 @@
 #ifdef PPP_FILTER
 #include <pcap.h>
 /*
- * DLT_PPP_WITH_DIRECTION is in current libpcap cvs, and should be in
- * libpcap-0.8.4.  Until that is released, use DLT_PPP - but that means
+ * There have been 3 or 4 different names for this in libpcap CVS, but
+ * this seems to be what they have settled on...
+ * For older versions of libpcap, use DLT_PPP - but that means
  * we lose the inbound and outbound qualifiers.
  */
-#ifndef DLT_PPP_WITHDIRECTION
-#define DLT_PPP_WITHDIRECTION	DLT_PPP
+#ifndef DLT_PPP_PPPD
+#ifdef DLT_PPP_WITHDIRECTION
+#define DLT_PPP_PPPD	DLT_PPP_WITHDIRECTION
+#else
+#define DLT_PPP_PPPD	DLT_PPP
 #endif
 #endif
+#endif /* PPP_FILTER */
 
 #include "pppd.h"
 #include "pathnames.h"
@@ -394,16 +399,20 @@ options_from_file(filename, must_exist, check_prot, priv)
     option_t *opt;
     int oldpriv, n;
     char *oldsource;
+    uid_t euid;
     char *argv[MAXARGS];
     char args[MAXARGS][MAXWORDLEN];
     char cmd[MAXWORDLEN];
 
-    if (check_prot)
-	seteuid(getuid());
+    euid = geteuid();
+    if (check_prot && seteuid(getuid()) == -1) {
+	option_error("unable to drop privileges to open %s: %m", filename);
+	return 0;
+    }
     f = fopen(filename, "r");
     err = errno;
-    if (check_prot)
-	seteuid(0);
+    if (check_prot && seteuid(euid) == -1)
+	fatal("unable to regain privileges");
     if (f == NULL) {
 	errno = err;
 	if (!must_exist) {
@@ -1449,7 +1458,7 @@ setpassfilter(argv)
     pcap_t *pc;
     int ret = 1;
 
-    pc = pcap_open_dead(DLT_PPP_WITHDIRECTION, 65535);
+    pc = pcap_open_dead(DLT_PPP_PPPD, 65535);
     if (pcap_compile(pc, &pass_filter, *argv, 1, netmask) == -1) {
 	option_error("error in pass-filter expression: %s\n",
 		     pcap_geterr(pc));
@@ -1470,7 +1479,7 @@ setactivefilter(argv)
     pcap_t *pc;
     int ret = 1;
 
-    pc = pcap_open_dead(DLT_PPP_WITHDIRECTION, 65535);
+    pc = pcap_open_dead(DLT_PPP_PPPD, 65535);
     if (pcap_compile(pc, &active_filter, *argv, 1, netmask) == -1) {
 	option_error("error in active-filter expression: %s\n",
 		     pcap_geterr(pc));
@@ -1505,15 +1514,19 @@ setlogfile(argv)
     char **argv;
 {
     int fd, err;
+    uid_t euid;
 
-    if (!privileged_option)
-	seteuid(getuid());
+    euid = geteuid();
+    if (!privileged_option && seteuid(getuid()) == -1) {
+	option_error("unable to drop permissions to open %s: %m", *argv);
+	return 0;
+    }
     fd = open(*argv, O_WRONLY | O_APPEND | O_CREAT | O_EXCL, 0644);
     if (fd < 0 && errno == EEXIST)
 	fd = open(*argv, O_WRONLY | O_APPEND);
     err = errno;
-    if (!privileged_option)
-	seteuid(0);
+    if (!privileged_option && seteuid(euid) == -1)
+	fatal("unable to regain privileges: %m");
     if (fd < 0) {
 	errno = err;
 	option_error("Can't open log file %s: %m", *argv);