adduser/addgroup: make system id range configurable.

By Tito (farmatito AT tiscali.it).

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/loginutils/Config.in b/loginutils/Config.in
index 9430bfa..e115036 100644
--- a/loginutils/Config.in
+++ b/loginutils/Config.in
@@ -152,6 +152,22 @@
 	help
 	  Support long options for the adduser applet.
 
+config FIRST_SYSTEM_ID
+	int "First valid system uid or gid for adduser and addgroup"
+	depends on ADDUSER || ADDGROUP
+	range 0 64900
+	default 100
+	help
+	  First valid system uid or gid for adduser and addgroup
+
+config LAST_SYSTEM_ID
+	int "Last valid system uid or gid for adduser and addgroup"
+	depends on ADDUSER || ADDGROUP
+	range 0 64900
+	default 999
+	help
+	  Last valid system uid or gid for adduser and addgroup
+
 config DELUSER
 	bool "deluser"
 	default n
diff --git a/loginutils/addgroup.c b/loginutils/addgroup.c
index cb83929..dc60788 100644
--- a/loginutils/addgroup.c
+++ b/loginutils/addgroup.c
@@ -11,6 +11,10 @@
  */
 #include "libbb.h"
 
+#if CONFIG_LAST_SYSTEM_ID < CONFIG_FIRST_SYSTEM_ID
+#error Bad LAST_SYSTEM_ID or FIRST_SYSTEM_ID in .config
+#endif
+
 #define OPT_GID                       (1 << 0)
 #define OPT_SYSTEM_ACCOUNT            (1 << 1)
 
@@ -30,11 +34,11 @@
 	/* gid values is set to [0, INT_MAX] */
 	if (!(option_mask32 & OPT_GID)) {
 		if (option_mask32 & OPT_SYSTEM_ACCOUNT) {
-			g->gr_gid = 100; /* FIRST_SYSTEM_GID */
-			max = 999;       /* LAST_SYSTEM_GID */
+			g->gr_gid = CONFIG_FIRST_SYSTEM_ID;
+			max = CONFIG_LAST_SYSTEM_ID;
 		} else {
-			g->gr_gid = 1000; /* FIRST_GID */
-			max = 64999;      /* LAST_GID */
+			g->gr_gid = CONFIG_LAST_SYSTEM_ID + 1;
+			max = 64999;
 		}
 	}
 	/* Check if the desired gid is free
diff --git a/loginutils/adduser.c b/loginutils/adduser.c
index a399d9e..0023237 100644
--- a/loginutils/adduser.c
+++ b/loginutils/adduser.c
@@ -9,6 +9,10 @@
  */
 #include "libbb.h"
 
+#if CONFIG_LAST_SYSTEM_ID < CONFIG_FIRST_SYSTEM_ID
+#error Bad LAST_SYSTEM_ID or FIRST_SYSTEM_ID in .config
+#endif
+
 /* #define OPT_HOME           (1 << 0) */ /* unused */
 /* #define OPT_GECOS          (1 << 1) */ /* unused */
 #define OPT_SHELL          (1 << 2)
@@ -32,11 +36,11 @@
 
 	if (!(option_mask32 & OPT_UID)) {
 		if (option_mask32 & OPT_SYSTEM_ACCOUNT) {
-			p->pw_uid = 100; /* FIRST_SYSTEM_UID */
-			max = 999;       /* LAST_SYSTEM_UID */
+			p->pw_uid = CONFIG_FIRST_SYSTEM_ID;
+			max = CONFIG_LAST_SYSTEM_ID;
 		} else {
-			p->pw_uid = 1000; /* FIRST_UID */
-			max = 64999;      /* LAST_UID */
+			p->pw_uid = CONFIG_LAST_SYSTEM_ID + 1;
+			max = 64999;
 		}
 	}
 	/* check for a free uid (and maybe gid) */