- drop privileges - taken from RH

Changed files:
    arpwatch-drop.patch -> 1.1

diff --git a/arpwatch-drop.patch b/arpwatch-drop.patch
new file mode 100644 (file)
index 0000000..916a4b1
--- /dev/null
+++ b/arpwatch-drop.patch
@@ -0,0 +1,93 @@
+--- arpwatch-2.1a10/arpwatch.c Sat Oct 14 05:07:35 2000
++++ arpwatch-2.1a10/arpwatch.c Sun Jun 10 16:22:57 2001
+@@ -62,7 +62,7 @@
+ #include <string.h>
+ #include <syslog.h>
+ #include <unistd.h>
+-
++#include <pwd.h>
+ #include <pcap.h>
+ 
+ #include "gnuc.h"
+@@ -141,6 +141,25 @@
+ int   sanity_fddi(struct fddi_header *, struct ether_arp *, int);
+ __dead        void usage(void) __attribute__((volatile));
+ 
++void dropprivileges(const char* user)
++{
++      struct passwd* pw;
++      pw = getpwnam( user );
++      if ( pw ) {
++              if ( initgroups(pw->pw_name, NULL) != 0 || setgid(pw->pw_gid) != 0 ||
++                               setuid(pw->pw_uid) != 0 ) {
++                      syslog(LOG_ERR, "Couldn't change to '%.32s' uid=%d gid=%d", user,
++                                               pw->pw_uid, pw->pw_gid);
++                      exit(1);
++              }
++      }
++      else {
++              syslog(LOG_ERR, "Couldn't find user '%.32s' in /etc/passwd", user);
++              exit(1);
++      }
++      syslog(LOG_DEBUG, "Running as uid=%d gid=%d", getuid(), getgid());
++}
++
+ int
+ main(int argc, char **argv)
+ {
+@@ -153,6 +172,7 @@
+       register char *interface, *rfilename;
+       struct bpf_program code;
+       char errbuf[PCAP_ERRBUF_SIZE];
++      char* serveruser = NULL;
+ 
+       if (argv[0] == NULL)
+               prog = "arpwatch";
+@@ -170,7 +190,7 @@
+       interface = NULL;
+       rfilename = NULL;
+       pd = NULL;
+-      while ((op = getopt(argc, argv, "df:i:n:Nr:")) != EOF)
++      while ((op = getopt(argc, argv, "df:i:n:Nr:u:")) != EOF)
+               switch (op) {
+ 
+               case 'd':
+@@ -202,6 +222,16 @@
+                       rfilename = optarg;
+                       break;
+ 
++              case 'u':
++                      if ( optarg ) {
++                              serveruser = strdup(optarg);
++                      }
++                      else {
++                              fprintf(stderr, "%s: Need username after -u\n", prog);
++                              usage();
++                      }
++                      break;
++
+               default:
+                       usage();
+               }
+@@ -283,8 +313,11 @@
+        * Revert to non-privileged user after opening sockets
+        * (not needed on most systems).
+        */
+-      setgid(getgid());
+-      setuid(getuid());
++      /*setgid(getgid());*/
++      /*setuid(getuid());*/
++      if ( serveruser ) {
++              dropprivileges( serveruser );
++      }
+ 
+       /* Must be ethernet or fddi */
+       linktype = pcap_datalink(pd);
+@@ -751,6 +784,6 @@
+ 
+       (void)fprintf(stderr, "Version %s\n", version);
+       (void)fprintf(stderr, "usage: %s [-dN] [-f datafile] [-i interface]"
+-          " [-n net[/width]] [-r file]\n", prog);
++          " [-n net[/width]] [-r file] [-u username]\n", prog);
+       exit(1);
+ }