X-Git-Url: http://andersk.mit.edu/gitweb/nss_nonlocal.git/blobdiff_plain/3010a54bf00c67c780db74166f38b9d3fdfccd85..4893970472bd815b8dbb6f6058dd26358700110e:/nonlocal-group.c

diff --git a/nonlocal-group.c b/nonlocal-group.c
index 09fa6f2..9bbe156 100644
--- a/nonlocal-group.c
+++ b/nonlocal-group.c
@@ -24,23 +24,45 @@
  */
 
 #define _GNU_SOURCE
+
 #include <sys/types.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <stdint.h>
-#include <string.h>
 #include <dlfcn.h>
-#include <stdio.h>
-#include <syslog.h>
 #include <errno.h>
 #include <grp.h>
 #include <nss.h>
+#include <pwd.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <unistd.h>
+
 #include "nsswitch-internal.h"
 #include "nonlocal.h"
 
+/*
+ * If the MAGIC_NONLOCAL_GROUPNAME local group exists, then nonlocal
+ * users will be automatically added to it.  Furthermore, if a local
+ * user is added to this group, then that user will inherit any
+ * nonlocal gids from a nonlocal user of the same name, as
+ * supplementary gids.
+ */
 #define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users"
+
+/*
+ * If the MAGIC_LOCAL_GROUPNAME local group exists, then local users
+ * will be automatically added to it.
+ */
 #define MAGIC_LOCAL_GROUPNAME "nss-local-users"
 
+/*
+ * If the MAGIC_NONLOCAL_USERNAME local user is added to a local
+ * group, then the local group will inherit the nonlocal membership of
+ * a group of the same gid.
+ */
+#define MAGIC_NONLOCAL_USERNAME "nss-nonlocal-users"
+
 
 enum nss_status
 _nss_nonlocal_getgrnam_r(const char *name, struct group *grp,
@@ -71,7 +93,7 @@ __nss_group_nonlocal_lookup(service_user **ni, const char *fct_name,
 
 
 enum nss_status
-check_nonlocal_gid(const char *user, gid_t gid, int *errnop)
+check_nonlocal_gid(const char *user, const char *group, gid_t gid, int *errnop)
 {
     enum nss_status status;
     struct group gbuf;
@@ -86,15 +108,30 @@ check_nonlocal_gid(const char *user, gid_t gid, int *errnop)
 #include "walk_nss.h"
 #undef args
 
-    if (status == NSS_STATUS_SUCCESS) {
-	syslog(LOG_DEBUG, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user);
-	free(buf);
-	status = NSS_STATUS_NOTFOUND;
-    } else if (status != NSS_STATUS_TRYAGAIN) {
-	status = NSS_STATUS_SUCCESS;
+    if (status == NSS_STATUS_TRYAGAIN)
+	return status;
+    else if (status != NSS_STATUS_SUCCESS)
+	return NSS_STATUS_SUCCESS;
+
+    if (group == NULL || strcmp(gbuf.gr_name, group) == 0) {
+	char *const *mem;
+	for (mem = gbuf.gr_mem; *mem != NULL; mem++)
+	    if (strcmp(*mem, MAGIC_NONLOCAL_USERNAME) == 0) {
+		status = check_nonlocal_user(*mem, errnop);
+		if (status == NSS_STATUS_TRYAGAIN) {
+		    free(buf);
+		    return status;
+		} else if (status == NSS_STATUS_NOTFOUND) {
+		    free(buf);
+		    return NSS_STATUS_SUCCESS;
+		}
+		break;
+	    }
     }
 
-    return status;
+    syslog(LOG_DEBUG, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user);
+    free(buf);
+    return NSS_STATUS_NOTFOUND;
 }
 
 enum nss_status
@@ -109,13 +146,13 @@ check_nonlocal_group(const char *user, struct group *grp, int *errnop)
     gid = strtoul(grp->gr_name, &end, 10);
     if (errno == 0 && *end == '\0' && (gid_t)gid == gid) {
 	errno = old_errno;
-	status = check_nonlocal_gid(user, gid, errnop);
+	status = check_nonlocal_gid(user, grp->gr_name, gid, errnop);
     } else
 	errno = old_errno;
     if (status != NSS_STATUS_SUCCESS)
 	return status;
 
-    return check_nonlocal_gid(user, grp->gr_gid, errnop);
+    return check_nonlocal_gid(user, grp->gr_name, grp->gr_gid, errnop);
 }
 
 enum nss_status
@@ -134,6 +171,7 @@ get_local_group(const char *name, struct group *grp, char **buffer, int *errnop)
     return status;
 }
 
+static bool grent_initialized = false;
 static service_user *grent_startp, *grent_nip;
 static void *grent_fct_start;
 static union {
@@ -158,9 +196,12 @@ _nss_nonlocal_setgrent(int stayopen)
     if (status != NSS_STATUS_SUCCESS)
 	return status;
 
-    if (grent_fct_start == NULL)
+    if (!grent_initialized) {
 	__nss_group_nonlocal_lookup(&grent_startp, grent_fct_name,
 				    &grent_fct_start);
+	__sync_synchronize();
+	grent_initialized = true;
+    }
     grent_nip = grent_startp;
     grent_fct.ptr = grent_fct_start;
     return NSS_STATUS_SUCCESS;
@@ -325,16 +366,17 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
     const __typeof__(&_nss_nonlocal_initgroups_dyn) self = NULL;
 
     struct group local_users_group, nonlocal_users_group;
-    int is_local = 0;
+    bool is_nonlocal = true;
     char *buffer;
     int in, out, i;
 
-    /* Check that the user is a nonlocal user before adding any groups. */
+    /* Check that the user is a nonlocal user, or a member of the
+     * MAGIC_NONLOCAL_GROUPNAME group, before adding any groups. */
     status = check_nonlocal_user(user, errnop);
     if (status == NSS_STATUS_TRYAGAIN) {
 	return status;
     } else if (status != NSS_STATUS_SUCCESS) {
-	is_local = 1;
+	is_nonlocal = false;
 
 	status = get_local_group(MAGIC_LOCAL_GROUPNAME,
 				 &local_users_group, &buffer, errnop);
@@ -350,23 +392,57 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
 		   "nss_nonlocal: Group %s does not exist locally!",
 		   MAGIC_LOCAL_GROUPNAME);
 	}
-    } else {
- 	status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
-				 &nonlocal_users_group, &buffer, errnop);
-	if (status == NSS_STATUS_SUCCESS) {
-	    free(buffer);
+    }
+
+    status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
+			     &nonlocal_users_group, &buffer, errnop);
+    if (status == NSS_STATUS_SUCCESS) {
+	free(buffer);
+	if (is_nonlocal) {
 	    if (!add_group(nonlocal_users_group.gr_gid, start, size, groupsp,
 			   limit, errnop, &status))
 		return status;
-	} else if (status == NSS_STATUS_TRYAGAIN) {
-	    return status;
 	} else {
-	    syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
-		   MAGIC_NONLOCAL_GROUPNAME);
+	    int i;
+	    for (i = 0; i < *start; ++i) {
+		if ((*groupsp)[i] == nonlocal_users_group.gr_gid) {
+		    is_nonlocal = true;
+		    break;
+		}
+	    }
+
+	    if (is_nonlocal) {
+		struct passwd pwbuf;
+		char *buf;
+		int nonlocal_errno = *errnop;
+		status = get_nonlocal_passwd(user, &pwbuf, &buf, errnop);
+
+		if (status == NSS_STATUS_SUCCESS) {
+		    nonlocal_errno = *errnop;
+		    status = check_nonlocal_gid(user, NULL, pwbuf.pw_gid,
+						&nonlocal_errno);
+		    free(buf);
+		}
+
+		if (status == NSS_STATUS_SUCCESS) {
+		    if (!add_group(pwbuf.pw_gid, start, size, groupsp, limit,
+				   errnop, &status))
+			return status;
+		} else if (status == NSS_STATUS_TRYAGAIN) {
+		    *errnop = nonlocal_errno;
+		    return status;
+		}
+	    }
 	}
+    } else if (status == NSS_STATUS_TRYAGAIN) {
+	if (is_nonlocal)
+	    return status;
+    } else {
+	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
+	       MAGIC_NONLOCAL_GROUPNAME);
     }
 
-    if (is_local)
+    if (!is_nonlocal)
 	return NSS_STATUS_SUCCESS;
 
     in = out = *start;
@@ -386,7 +462,8 @@ _nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
 	if (i < out)
 	    continue;
 
-	status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
+	status = check_nonlocal_gid(user, NULL, (*groupsp)[in],
+				    &nonlocal_errno);
 	if (status == NSS_STATUS_SUCCESS) {
 	    (*groupsp)[out++] = (*groupsp)[in];
 	} else if (status == NSS_STATUS_TRYAGAIN) {