Attachment 550 Details for Bug 787 – NGROUPS patch with our own get_ngroups()

[patch] NGROUPS patch with our own get_ngroups()

openssh-NGROUPS-5.diff (text/plain), 3.92 KB, created by Tim Hockin on 2004-02-24 11:26:22 AEDT

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Creator: Tim Hockin

Created: 2004-02-24 11:26:22 AEDT

Size: 3.92 KB

patch

obsolete

>Index: uidswap.c
>===================================================================
>RCS file: /cvs/openssh/uidswap.c,v
>retrieving revision 1.42
>diff -u -u -r1.42 uidswap.c
>--- uidswap.c	17 Dec 2003 07:53:26 -0000	1.42
>+++ uidswap.c	24 Feb 2004 00:20:12 -0000
>@@ -16,6 +16,7 @@
> 
> #include "log.h"
> #include "uidswap.h"
>+#include "xmalloc.h"
> 
> /*
>  * Note: all these functions must work in all of the following cases:
>@@ -38,7 +39,7 @@
> /* Saved effective uid. */
> static int	privileged = 0;
> static int	temporarily_use_uid_effective = 0;
>-static gid_t	saved_egroups[NGROUPS_MAX], user_groups[NGROUPS_MAX];
>+static gid_t	*saved_egroups, *user_groups;
> static int	saved_egroupslen = -1, user_groupslen = -1;
> 
> /*
>@@ -68,18 +69,38 @@
> 
> 	privileged = 1;
> 	temporarily_use_uid_effective = 1;
>-	saved_egroupslen = getgroups(NGROUPS_MAX, saved_egroups);
>+
>+	saved_egroupslen = getgroups(0, NULL);
> 	if (saved_egroupslen < 0)
> 		fatal("getgroups: %.100s", strerror(errno));
>+	if (saved_egroupslen > 0) {
>+		saved_egroups = xrealloc(saved_egroups,
>+		    saved_egroupslen * sizeof(gid_t));
>+		if (getgroups(saved_egroupslen, saved_egroups) < 0)
>+			fatal("getgroups: %.100s", strerror(errno));
>+	} else { /* saved_egroupslen == 0 */
>+		if (saved_egroups)
>+			xfree(saved_egroups);
>+	}
> 
> 	/* set and save the user's groups */
> 	if (user_groupslen == -1) {
> 		if (initgroups(pw->pw_name, pw->pw_gid) < 0)
> 			fatal("initgroups: %s: %.100s", pw->pw_name,
> 			    strerror(errno));
>-		user_groupslen = getgroups(NGROUPS_MAX, user_groups);
>+
>+		user_groupslen = getgroups(0, NULL);
> 		if (user_groupslen < 0)
> 			fatal("getgroups: %.100s", strerror(errno));
>+		if (user_groupslen > 0) {
>+			user_groups = xrealloc(user_groups,
>+			    user_groupslen * sizeof(gid_t));
>+			if (getgroups(user_groupslen, user_groups) < 0)
>+				fatal("getgroups: %.100s", strerror(errno));
>+		} else { /* user_groupslen == 0 */
>+			if (user_groups)
>+				xfree(user_groups);
>+		}
> 	}
> 	/* Set the effective uid to the given (unprivileged) uid. */
> 	if (setgroups(user_groupslen, user_groups) < 0)
>Index: groupaccess.c
>===================================================================
>RCS file: /cvs/openssh/groupaccess.c,v
>retrieving revision 1.7
>diff -u -u -r1.7 groupaccess.c
>--- groupaccess.c	14 May 2003 03:40:07 -0000	1.7
>+++ groupaccess.c	24 Feb 2004 00:20:12 -0000
>@@ -31,7 +31,39 @@
> #include "log.h"
> 
> static int ngroups;
>-static char *groups_byname[NGROUPS_MAX + 1];	/* +1 for base/primary group */
>+static char **groups_byname;
>+
>+/*
>+ * Count group membership from the groups database.  Some implementations of
>+ * getgrouplist() are not happy to return the right number of groups.
>+ */
>+static int
>+get_ngroups(const char *user, gid_t base)
>+{
>+	int ngroups = 1;
>+
>+	while (1) {
>+		struct group *gr = getgrent();
>+		char **memberp;
>+
>+		if (gr == NULL)
>+			break;
>+
>+		/* we already know we're part of the base group */
>+		if (gr->gr_gid == base)
>+			continue;
>+
>+		memberp = gr->gr_mem;
>+		while (*memberp) {
>+			if (!strcmp(user, *memberp))
>+				ngroups++;
>+			memberp++;
>+		}
>+	}
>+	endgrent();
>+
>+	return ngroups;
>+}
> 
> /*
>  * Initialize group access list for user with primary (base) and
>@@ -40,19 +72,23 @@
> int
> ga_init(const char *user, gid_t base)
> {
>-	gid_t groups_bygid[NGROUPS_MAX + 1];
>+	gid_t *groups_bygid;
> 	int i, j;
> 	struct group *gr;
> 
> 	if (ngroups > 0)
> 		ga_free();
> 
>-	ngroups = sizeof(groups_bygid) / sizeof(gid_t);
>+	ngroups = get_ngroups(user, base);
>+	groups_bygid = xmalloc(ngroups * sizeof(*groups_bygid));
>+	groups_byname = xmalloc(ngroups * sizeof(*groups_byname));
>+
> 	if (getgrouplist(user, base, groups_bygid, &ngroups) == -1)
> 		logit("getgrouplist: groups list too small");
> 	for (i = 0, j = 0; i < ngroups; i++)
> 		if ((gr = getgrgid(groups_bygid[i])) != NULL)
> 			groups_byname[j++] = xstrdup(gr->gr_name);
>+	xfree(groups_bygid);
> 	return (ngroups = j);
> }
> 
>@@ -84,5 +120,6 @@
> 		for (i = 0; i < ngroups; i++)
> 			xfree(groups_byname[i]);
> 		ngroups = 0;
>+		xfree(groups_byname);
> 	}
> }

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