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:
+*/