Tito writes,

"This patch fixes all the bugs in id previously spotted by vodz and me.
The binary size increased a bit,  but now it should work as expected."

6 files changed, 126 insertions, 108 deletions

diff --git a/coreutils/id.c b/coreutils/id.c
index 76331e48f..d5182b953 100644
--- a/coreutils/id.c
+++ b/coreutils/id.c
@@ -26,12 +26,9 @@
  */
 
 #include "busybox.h"
-#include "grp_.h"
 #include "pwd_.h"
 #include <stdio.h>
 #include <unistd.h>
-#include <getopt.h>
-#include <string.h>
 #include <sys/types.h>
 
 #ifdef CONFIG_SELINUX
@@ -44,21 +41,26 @@
 #define JUST_USER         4
 #define JUST_GROUP        8
 
-void printf_full(unsigned int id, char *arg, char prefix)
+static short printf_full(unsigned int id, const char *arg, const char prefix)
 {	
-	printf("%cid=%u",prefix, id);
-	if(arg)
-		printf("(%s) ", arg);
+	const char *fmt = "%cid=%u";
+	short status=EXIT_FAILURE;
+	
+	if(arg) {
+		fmt = "%cid=%u(%s)";
+		status=EXIT_SUCCESS;
+	}
+	bb_printf(fmt, prefix, id, arg);
+	return status;
 }
 
 extern int id_main(int argc, char **argv)
 {
 	struct passwd *p;
-	char *user;
-	char *group;
 	uid_t uid;
 	gid_t gid;
-	int flags;
+	unsigned long flags;
+	short status;
 #ifdef CONFIG_SELINUX
 	int is_flask_enabled_flag = is_flask_enabled();
 #endif
@@ -67,8 +69,9 @@ extern int id_main(int argc, char **argv)
 	flags = bb_getopt_ulflags(argc, argv, "rnug");
 
 	if ((flags & 0x80000000UL)
-	 /* Don't allow -n -r -nr */
+	/* Don't allow -n -r -nr */
 	|| (flags <= 3 && flags > 0) 
+	/* Don't allow more than one username */
 	|| (argc > optind + 1))
 		bb_show_usage();
 	
@@ -80,54 +83,45 @@ extern int id_main(int argc, char **argv)
 		gid = getgid();
 	}
 	
-	if(argv[optind])
-	{
-
+	if(argv[optind]) {
 		p=getpwnam(argv[optind]);
-		/* this is needed because it exits on failure */
+		/* my_getpwnam is needed because it exits on failure */
 		uid = my_getpwnam(argv[optind]);
 		gid = p->pw_gid;
 		/* in this case PRINT_REAL is the same */ 
 	}
-	
-	user=my_getpwuid(NULL, uid, (flags & JUST_USER) ? -1 : 0);
 
-	if(flags & JUST_USER)
-	{
-		gid=uid;
-		group=user;
-		goto PRINT; 
-	}
-	
-	group=my_getgrgid(NULL, gid, (flags & JUST_GROUP) ? -1 : 0);
-
-	if(flags & JUST_GROUP) 
-	{
-PRINT:		
-		if(flags & NAME_NOT_NUMBER)
-			puts(group);
-		else
-			printf ("%u\n", gid);
+	if(flags & (JUST_GROUP | JUST_USER)) {
+		/* JUST_GROUP and JUST_USER are mutually exclusive */
+		if(flags & NAME_NOT_NUMBER) {
+			/* my_getpwuid and my_getgrgid exit on failure so puts cannot segfault */
+			puts((flags & JUST_USER) ? my_getpwuid(NULL, uid, -1 ) : my_getgrgid(NULL, gid, -1 ));
+		} else {
+			bb_printf("%u\n",(flags & JUST_USER) ? uid : gid);
+		}
+		/* exit */ 
 		bb_fflush_stdout_and_exit(EXIT_SUCCESS);
 	}
-	
+
 	/* Print full info like GNU id */
-	printf_full(uid, user, 'u');
-	printf_full(gid, group, 'g');
+	/* my_getpwuid doesn't exit on failure here */
+	status=printf_full(uid, my_getpwuid(NULL, uid, 0), 'u');
+	putchar(' ');
+	/* my_getgrgid doesn't exit on failure here */
+	status|=printf_full(gid, my_getgrgid(NULL, gid, 0), 'g');
 #ifdef CONFIG_SELINUX
-	if(is_flask_enabled_flag)
-	{
+	if(is_flask_enabled_flag) {
 		security_id_t mysid = getsecsid();
 		char context[80];
 		int len = sizeof(context);
 		context[0] = '\0';
 		if(security_sid_to_context(mysid, context, &len))
 			strcpy(context, "unknown");
-		printf("context=%s", context);
+		bb_printf(" context=%s", context);
 	}
 #endif
-	puts("");
-	bb_fflush_stdout_and_exit((user && group) ? EXIT_SUCCESS : EXIT_FAILURE);
+	putchar('\n');
+	bb_fflush_stdout_and_exit(status);
 }
 
 /* END CODE */
diff --git a/include/libbb.h b/include/libbb.h
index 51afd1e9d..93ab5375c 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -230,6 +230,7 @@ extern unsigned long bb_xparse_number(const char *numstr,
  * increases target size and is often not needed embedded systems.  */
 extern long my_getpwnam(const char *name);
 extern long my_getgrnam(const char *name);
+extern char * my_getug(char *buffer, char *idname, long id, int bufsize, char prefix);
 extern char * my_getpwuid(char *name, long uid, int bufsize);
 extern char * my_getgrgid(char *group, long gid, int bufsize);
 extern char *bb_askpass(int timeout, const char * prompt);
diff --git a/libbb/Makefile.in b/libbb/Makefile.in
index 26ed5b132..f86664f15 100644
--- a/libbb/Makefile.in
+++ b/libbb/Makefile.in
@@ -34,7 +34,7 @@ LIBBB_SRC:= \
 	human_readable.c inet_common.c inode_hash.c interface.c isdirectory.c \
 	kernel_version.c last_char_is.c llist_add_to.c login.c loop.c \
 	make_directory.c mode_string.c module_syscalls.c mtab.c mtab_file.c \
-	my_getgrgid.c my_getgrnam.c my_getpwnam.c \
+	my_getgrgid.c my_getgrnam.c my_getpwnam.c my_getug.c\
 	my_getpwuid.c obscure.c parse_mode.c parse_number.c perror_msg.c \
 	perror_msg_and_die.c print_file.c get_console.c \
 	process_escape_sequence.c procps.c pwd2spwd.c pw_encrypt.c qmodule.c \
diff --git a/libbb/my_getgrgid.c b/libbb/my_getgrgid.c
index 8c530964c..9ac14a34e 100644
--- a/libbb/my_getgrgid.c
+++ b/libbb/my_getgrgid.c
@@ -22,48 +22,28 @@
   /* Hacked by Tito Ragusa (c) 2004 <farmatito@tiscali.it> to make it more
   * flexible :
   *
-  * if bufsize is > 0 char *group cannot be set to NULL
-  *                   on success groupname is written on static allocated buffer
-  *                   on failure gid as string is written to buffer and NULL is returned
-  * if bufsize is = 0 char *group can be set to NULL
-  *                   on success groupname is returned 
-  *                   on failure NULL is returned
-  * if bufsize is < 0 char *group can be set to NULL
-  *                   on success groupname is returned
-  *                   on failure an error message is printed and the program exits   
+  * if bufsize is > 0 char *group cannot be set to NULL.
+  *                   On success groupname is written on static allocated buffer group
+  *                   (and a pointer to it is returned).
+  *                   On failure gid as string is written to static allocated buffer 
+  *                   group and NULL is returned.
+  * if bufsize is = 0 char *group can be set to NULL.
+  *                   On success groupname is returned. 
+  *                   On failure NULL is returned.
+  * if bufsize is < 0 char *group can be set to NULL.
+  *                   On success groupname is returned.
+  *                   On failure an error message is printed and the program exits.   
   */
   
-#include <stdio.h>
-#include <string.h>
-#include <assert.h>
 #include "libbb.h"
-#include "pwd_.h"
 #include "grp_.h"
 
-
 /* gets a groupname given a gid */
 char * my_getgrgid(char *group, long gid, int bufsize)
 {
-	struct group *mygroup;
+	struct group *mygroup = getgrgid(gid);
 
-	mygroup  = getgrgid(gid);
-	if (mygroup==NULL) {
-		if(bufsize > 0) {
-			assert(group != NULL);
-			snprintf(group, bufsize, "%ld", (long)gid);
-		}
-		if( bufsize < 0 ) {
-			bb_error_msg_and_die("unknown gid %ld", (long)gid);
-		} 
-		return NULL;
-	} else {
-		if(bufsize > 0)
-		{
-			assert(group != NULL);
-			return safe_strncpy(group, mygroup->gr_name, bufsize);
-		}
-		return mygroup->gr_name;
-	}
+	return  my_getug(group, (mygroup) ? mygroup->gr_name : (char *)mygroup, gid, bufsize, 'g');
 }
 
 
diff --git a/libbb/my_getpwuid.c b/libbb/my_getpwuid.c
index 1e8b11a09..3195a2182 100644
--- a/libbb/my_getpwuid.c
+++ b/libbb/my_getpwuid.c
@@ -22,49 +22,28 @@
  /* Hacked by Tito Ragusa (c) 2004 <farmatito@tiscali.it> to make it more
   * flexible :
   *
-  * if bufsize is > 0 char *user can not be set to NULL
-  *                   on success username is written on static allocated buffer
-  *                   on failure uid as string is written to buffer and NULL is returned
-  * if bufsize is = 0 char *user can be set to NULL
-  *                   on success username is returned 
-  *                   on failure NULL is returned
+  * if bufsize is > 0 char *user can not be set to NULL.
+  *                   On success username is written on static allocated buffer name 
+  *                   (and a pointer to it is returned).
+  *                   On failure uid as string is written to static allocated buffer name
+  *                   and NULL is returned.
+  * if bufsize is = 0 char *user can be set to NULL.
+  *                   On success username is returned. 
+  *                   On failure NULL is returned.
   * if bufsize is < 0 char *user can be set to NULL
-  *                   on success username is returned
-  *                   on failure an error message is printed and the program exits   
+  *                   On success username is returned.
+  *                   On failure an error message is printed and the program exits.   
   */
   
-#include <stdio.h>
-#include <string.h>
-#include <assert.h>
 #include "libbb.h"
 #include "pwd_.h"
-#include "grp_.h"
-
-
 
 /* gets a username given a uid */
 char * my_getpwuid(char *name, long uid, int bufsize)
 {
-	struct passwd *myuser;
+	struct passwd *myuser = getpwuid(uid);
 
-	myuser  = getpwuid(uid);
-	if (myuser==NULL) {
-		if(bufsize > 0) {
-			assert(name != NULL);
-			snprintf(name, bufsize, "%ld", (long)uid);
-		}
-		if (bufsize < 0 ) {
-			bb_error_msg_and_die("unknown uid %ld", (long)uid); 
-		}
-		return NULL;
-	} else {
-		if(bufsize > 0 )
-		{
-			assert(name != NULL);
-			return safe_strncpy(name, myuser->pw_name, bufsize);
-		}
-		return myuser->pw_name;
-	}
+	return  my_getug(name, (myuser) ? myuser->pw_name : (char *)myuser , uid, bufsize, 'u');
 }
 
 /* END CODE */
diff --git a/libbb/my_getug.c b/libbb/my_getug.c
new file mode 100644
index 000000000..894dc5fdd
--- /dev/null
+++ b/libbb/my_getug.c
@@ -0,0 +1,64 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * Copyright (C) 2004 by Tito Ragusa <farmatito@tiscali.it>
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+ /* 
+  *
+  * if bufsize is > 0 char *idname can not be set to NULL.
+  *                   On success idname is written on static allocated buffer 
+  *                   (and a pointer to it is returned).
+  *                   On failure uid or gid as string is written to static allocated buffer
+  *                   and NULL is returned.
+  * if bufsize is = 0 char *idname can be set to NULL.
+  *                   On success idname is returned. 
+  *                   On failure NULL is returned.
+  * if bufsize is < 0 char *idname can be set to NULL.
+  *                   On success idname is returned.
+  *                   On failure an error message is printed and the program exits.   
+  */
+  
+#include <stdio.h>
+#include <assert.h>
+#include "libbb.h"
+
+
+/* internal function for my_getpwuid and my_getgrgid */
+char * my_getug(char *buffer, char *idname, long id, int bufsize, char prefix)
+{
+	if(bufsize > 0 ) {
+		assert(buffer!=NULL);
+		if(idname) {
+			return safe_strncpy(buffer, idname, bufsize);
+		}
+		snprintf(buffer, bufsize, "%ld", id);
+	} else if(bufsize < 0 && !idname) {
+		bb_error_msg_and_die("unknown %cid %ld", prefix, id); 
+	}
+	return idname;
+}
+
+/* END CODE */
+/*
+Local Variables:
+c-file-style: "linux"
+c-basic-offset: 4
+tab-width: 4
+End:
+*/