r23393: Support BSD group semantics by making sure that the effective GID is always
authorJames Peach <jpeach@samba.org>
Fri, 8 Jun 2007 22:25:55 +0000 (22:25 +0000)
committerGerald (Jerry) Carter <jerry@samba.org>
Wed, 10 Oct 2007 17:23:12 +0000 (12:23 -0500)
passed as the first GID when calling setgroups(2).

source/lib/system.c
source/lib/system_smbd.c
source/smbd/sec_ctx.c

index d7321501ad59902a2dec8391eeed749deac42b61..2cc7ef6ca42eda7b7a146a2ca671f198f8e3487c 100644 (file)
@@ -889,15 +889,13 @@ int groups_max(void)
 }
 
 /**************************************************************************
- Wrapper for getgroups. Deals with broken (int) case.
+ Wrap setgroups and getgroups for systems that declare getgroups() as
+ returning an array of gid_t, but actuall return an array of int.
 ****************************************************************************/
 
-int sys_getgroups(int setlen, gid_t *gidset)
+#if defined(HAVE_BROKEN_GETGROUPS)
+static int sys_broken_getgroups(int setlen, gid_t *gidset)
 {
-#if !defined(HAVE_BROKEN_GETGROUPS)
-       return getgroups(setlen, gidset);
-#else
-
        GID_T gid;
        GID_T *group_list;
        int i, ngroups;
@@ -919,7 +917,7 @@ int sys_getgroups(int setlen, gid_t *gidset)
        if (setlen == 0)
                setlen = groups_max();
 
-       if((group_list = (GID_T *)malloc(setlen * sizeof(GID_T))) == NULL) {
+       if((group_list = SMB_MALLOC_ARRAY(GID_T, setlen)) == NULL) {
                DEBUG(0,("sys_getgroups: Malloc fail.\n"));
                return -1;
        }
@@ -936,26 +934,10 @@ int sys_getgroups(int setlen, gid_t *gidset)
 
        SAFE_FREE(group_list);
        return ngroups;
-#endif /* HAVE_BROKEN_GETGROUPS */
 }
 
-
-/**************************************************************************
- Wrapper for setgroups. Deals with broken (int) case. Automatically used
- if we have broken getgroups.
-****************************************************************************/
-
-int sys_setgroups(int setlen, gid_t *gidset)
+static int sys_broken_setgroups(gid_t primary_gid, int setlen, gid_t *gidset)
 {
-#if !defined(HAVE_SETGROUPS)
-       errno = ENOSYS;
-       return -1;
-#endif /* HAVE_SETGROUPS */
-
-#if !defined(HAVE_BROKEN_GETGROUPS)
-       return setgroups(setlen, gidset);
-#else
-
        GID_T *group_list;
        int i ; 
 
@@ -972,7 +954,7 @@ int sys_setgroups(int setlen, gid_t *gidset)
         * GID_T array of size setlen.
         */
 
-       if((group_list = (GID_T *)malloc(setlen * sizeof(GID_T))) == NULL) {
+       if((group_list = SMB_MALLOC_ARRAY(GID_T, setlen)) == NULL) {
                DEBUG(0,("sys_setgroups: Malloc fail.\n"));
                return -1;    
        }
@@ -989,7 +971,101 @@ int sys_setgroups(int setlen, gid_t *gidset)
  
        SAFE_FREE(group_list);
        return 0 ;
+}
+
 #endif /* HAVE_BROKEN_GETGROUPS */
+
+/* This is a list of systems that require the first GID passed to setgroups(2)
+ * to be the effective GID. If your system is one of these, add it here.
+ */
+#if defined (FREEBSD) || defined (DARWINOS)
+#define USE_BSD_SETGROUPS
+#endif
+
+#if defined(USE_BSD_SETGROUPS)
+/* Depending on the particular BSD implementation, the first GID that is
+ * passed to setgroups(2) will either be ignored or will set the credential's
+ * effective GID. In either case, the right thing to do is to guarantee that
+ * gidset[0] is the effective GID.
+ */
+static int sys_bsd_setgroups(gid_t primary_gid, int setlen, const gid_t *gidset)
+{
+       gid_t *new_gidset = NULL;
+       int max;
+       int ret;
+
+       /* setgroups(2) will fail with EINVAL if we pass too many groups. */
+       max = groups_max();
+
+       /* No group list, just make sure we are setting the efective GID. */
+       if (setlen == 0) {
+               return setgroups(1, &primary_gid);
+       }
+
+       /* If the primary gid is not the first array element, grow the array
+        * and insert it at the front.
+        */
+       if (gidset[0] != primary_gid) {
+               gid_t *new_gidset;
+
+               new_gidset = SMB_MALLOC_ARRAY(gid_t, setlen + 1);
+               if (new_gidset == NULL) {
+                       return -1;
+               }
+
+               memcpy(new_gidset + 1, gidset, ((setlen + 1) * sizeof(gid_t)));
+               new_gidset[0] = primary_gid;
+               setlen++;
+       }
+
+#if defined(BROKEN_GETGROUPS)
+       ret = sys_broken_setgroups(max, new_gidset ? new_gidset : gidset);
+#else
+       ret = setgroups(max, new_gidset ? new_gidset : gidset);
+#endif
+
+       if (new_gidset) {
+               int errsav = errno;
+               SAFE_FREE(new_gidset);
+               errno = errsav;
+       }
+
+       return ret;
+}
+
+#endif /* USE_BSD_SETGROUPS */
+
+/**************************************************************************
+ Wrapper for getgroups. Deals with broken (int) case.
+****************************************************************************/
+
+int sys_getgroups(int setlen, gid_t *gidset)
+{
+#if defined(HAVE_BROKEN_GETGROUPS)
+       return sys_broken_getgroups(setlen, gidset);
+#else
+       return getgroups(setlen, gidset);
+#endif
+}
+
+/**************************************************************************
+ Wrapper for setgroups. Deals with broken (int) case and BSD case.
+****************************************************************************/
+
+int sys_setgroups(gid_t UNUSED(primary_gid), int setlen, gid_t *gidset)
+{
+#if !defined(HAVE_SETGROUPS)
+       errno = ENOSYS;
+       return -1;
+#endif /* HAVE_SETGROUPS */
+
+#if defined(HAVE_BROKEN_GETGROUPS)
+       return sys_broken_setgroups(setlen, gidset);
+#elif defined(USE_BSD_SETGROUPS)
+       return sys_bsd_setgroups(primary_gid, setlen, gidset);
+#else
+       return setgroups(setlen, gidset);
+#endif
 }
 
 /**************************************************************************
index 509b2bbcb1e9e960cc9f3f6ab097b61921d2dc94..0d62360ca67e81fdf7640ab999d4fae6202a8cc7 100644 (file)
@@ -104,7 +104,7 @@ static int getgrouplist_internals(const char *user, gid_t gid, gid_t *groups,
 
        restore_re_gid();
 
-       if (sys_setgroups(ngrp_saved, gids_saved) != 0) {
+       if (sys_setgroups(gid, ngrp_saved, gids_saved) != 0) {
                /* yikes! */
                DEBUG(0,("ERROR: getgrouplist: failed to reset group list!\n"));
                smb_panic("getgrouplist: failed to reset group list!\n");
index fd79fbb7fe894dd0657a317332c039ab769e3493..19dac0d27fd166c0b4c979349b575a56aa24399a 100644 (file)
@@ -236,7 +236,7 @@ static void set_unix_security_ctx(uid_t uid, gid_t gid, int ngroups, gid_t *grou
        /* Start context switch */
        gain_root();
 #ifdef HAVE_SETGROUPS
-       sys_setgroups(ngroups, groups);
+       sys_setgroups(gid, ngroups, groups);
 #endif
        become_id(uid, gid);
        /* end context switch */