[PATCH] udev - simple klibc textual uid/gid handling

Here we get a very dumb getpwnam() and getgrnam() for klibc to
stop the confusion of not handling textual id's if klibc is used.

If used with  initrd we just need to copy the /etc/passwd and /etc/group
file and all should work well.

klibc_fixups.c

@@ -1,10 +1,110 @@
+/*
+ * klibc_fixups.c - very simple implementation of stuff missing in klibc
+ *
+ * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
+ * Copyright (C) 2004 Kay Sievers <kay@vrfy.org>
+ *
+ *	This program is free software; you can redistribute it and/or modify it
+ *	under the terms of the GNU General Public License as published by the
+ *	Free Software Foundation version 2 of the License.
+ * 
+ *	This program is distributed in the hope that it will be useful, but
+ *	WITHOUT ANY WARRANTY; without even the implied warranty of
+ *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *	General Public License for more details.
+ * 
+ *	You should have received a copy of the GNU General Public License along
+ *	with this program; if not, write to the Free Software Foundation, Inc.,
+ *	675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
 
 #ifdef __KLIBC__
 
 #include <stdlib.h>
+#include <stdio.h>
 #include <string.h>
 #include <ctype.h>
 #include <sys/types.h>
+
 #include "klibc_fixups.h"
+#include "logging.h"
+
+#define PW_FILE		"/etc/passwd"
+#define GR_FILE		"/etc/group"
+
+/* return the id of a passwd style line, selected by the users name */
+static unsigned long get_id_by_name(const char *uname, const char *dbfile)
+{
+	unsigned long id = -1;
+	FILE *file;
+	char buf[255];
+	char *pos;
+	char *name;
+	char *idstr;
+	char *tail;
+
+	file = fopen(dbfile, "r");
+	if (file == NULL) {
+		dbg("unable to open file '%s'", dbfile);
+		return -1;
+	}
+
+	while (1) {
+		pos = fgets(buf, sizeof(buf), file);
+		if (pos == NULL)
+			break;
+
+		/* get name */
+		name = strsep(&pos, ":");
+		if (name == NULL)
+			continue;
+
+		/* skip pass */
+		if (strsep(&pos, ":") == NULL)
+			continue;
+
+		/* get id */
+		idstr = strsep(&pos, ":");
+		if (idstr == NULL)
+			continue;
+
+		if (strcmp(uname, name) == 0) {
+			id = strtoul(idstr, &tail, 10);
+			if (tail == NULL)
+				id = -1;
+			else
+				dbg("id for '%s' is '%li'", name, id);
+			break;
+		}
+	}
+
+	fclose(file);
+	return id;
+}
+
+struct passwd *getpwnam(const char *name)
+{
+	static struct passwd pw;
+
+	memset(&pw, 0x00, sizeof(struct passwd));
+	pw.pw_uid = (uid_t) get_id_by_name(name, PW_FILE);
+	if (pw.pw_uid < 0)
+		return NULL;
+	else
+		return &pw;
+}
+
+struct group *getgrnam(const char *name)
+{
+	static struct group gr;
+
+	memset(&gr, 0x00, sizeof(struct group));
+	gr.gr_gid = (gid_t) get_id_by_name(name, GR_FILE);
+	if (gr.gr_gid < 0)
+		return NULL;
+	else
+		return &gr;
+}
 
 #endif

klibc_fixups.h

@@ -3,19 +3,6 @@
 #ifndef KLIBC_FIXUPS_H
 #define KLIBC_FIXUPS_H 
 
-struct group {
-	char	*gr_name;	/* group name */
-	char	*gr_passwd;	/* group password */
-	gid_t	gr_gid;		/* group id */
-	char	**gr_mem;	/* group members */
-};
-
-static inline struct group *getgrnam(const char *name)
-{
-	return NULL;
-}
-
-
 struct passwd {
 	char	*pw_name;	/* user name */
 	char	*pw_passwd;	/* user password */
@@ -26,11 +13,15 @@ struct passwd {
 	char	*pw_shell;	/* shell program */
 };
 
-static inline struct passwd *getpwnam(const char *name)
-{
-	return NULL;
-}
+struct group {
+	char	*gr_name;	/* group name */
+	char	*gr_passwd;	/* group password */
+	gid_t	gr_gid;		/* group id */
+	char	**gr_mem;	/* group members */
+};
 
+struct passwd *getpwnam(const char *name);
+struct group *getgrnam(const char *name);
 
 #endif