Attachment 403 Details for Bug 1081 – patch to sys_getgrouplist_internals

[patch] patch to sys_getgrouplist_internals

getgrouplist.patch (text/plain), 2.44 KB, created by Buck Huppmann on 2004-02-15 19:55:29 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Buck Huppmann

Created: 2004-02-15 19:55:29 UTC

Size: 2.44 KB

patch

obsolete

>--- samba-3.0.2/source/lib/system_smbd.c.orig	Fri Oct 10 14:08:35 2003
>+++ samba-3.0.2/source/lib/system_smbd.c	Wed Feb 11 17:18:37 2004
>@@ -38,7 +38,7 @@
>   */
> static int getgrouplist_internals(const char *user, gid_t gid, gid_t *groups, int *grpcnt)
> {
>-	gid_t *gids_saved;
>+	gid_t *gids_saved, *groups_tmp;
> 	int ret, ngrp_saved, num_gids;
> 
> 	if (non_root_mode()) {
>@@ -79,16 +79,82 @@
> 	setgid(gid);
> 
> 	num_gids = getgroups(0, NULL);
>-	if (num_gids + 1 > *grpcnt) {
>-		*grpcnt = num_gids + 1;
>-		ret = -1;
>-	} else {
>-		ret = getgroups(*grpcnt - 1, &groups[1]);
>-		if (ret >= 0) {
>-			groups[0] = gid;
>-			*grpcnt = ret + 1;
>+	
>+	/* see if we can use the buffer in place */
>+	if (num_gids <= *grpcnt) {
>+		groups_tmp = groups;
>+	}
>+	/* otherwise, allocate a buffer big enough so we can getgroups()
>+	 * and see whether or not gid is among them, so we can return the
>+	 * correct grpcnt (num_gids or num_gids + 1) */
>+	else {
>+		groups_tmp = (gid_t *)malloc(sizeof(gid_t) * (num_gids));
>+		if (!groups_tmp) {
>+			errno = ENOMEM;
>+			ret = -1;
>+			goto restore_gid;
>+		}
>+	}
>+	ret = getgroups(num_gids, groups_tmp);
>+	if (ret >= 0) {
>+		int i;
>+		int saw_gid = False;
>+		/* just in case this has changed in the interim; can only
>+		 * down-size, though */
>+		num_gids = ret < num_gids ? ret : num_gids;
>+		for (i = 0; i < num_gids; i++) {
>+			if (groups_tmp[i] == gid) {
>+				saw_gid = True;
>+				break;
>+			}
> 		}
>+		/* if the buffer wasn't big enough and we were just
>+		 * counting groups, return the number we found we
>+		 * needed */
>+		if (groups_tmp != groups) {
>+			if (!saw_gid) {
>+				/* one more for the gid arg, since it wasn't
>+				 * in the list */
>+				num_gids++;
>+			}
>+			/* unlikely: if (num_gids now <= *grpcnt) forge-ahead; */
>+			free(groups_tmp);
>+			/* cse: *grpcnt = num_gids; is below */
>+			ret = -1;
>+		}
>+		else {
>+			if (saw_gid) {
>+				if (i != 0) {
>+					/* pull gid arg up to front */
>+					memmove(&groups[1], &groups[0],
>+						sizeof(gid_t) * i);
>+					groups[0] = gid;
>+				}
>+				/* cse: *grpcnt = num_gids; is below */
>+			}
>+			else {
>+				num_gids++;
>+				ret++;
>+				/* cse: *grpcnt = num_gids; is below */
>+				if (num_gids > *grpcnt) {
>+					ret = -1;
>+				}
>+				else {
>+					/* avoid 0-length memmove() */
>+					if (num_gids > 1) {
>+						memmove(&groups[1],
>+							&groups[0],
>+							sizeof(gid_t)
>+							* (num_gids - 1));
>+					}
>+					groups[0] = gid;
>+				}
>+			}
>+		}
>+		*grpcnt = num_gids;
> 	}
>+
>+restore_gid:
> 
> 	restore_re_gid();
>

Actions: View

Attachments on bug 1081: 403