getsubids: system binary for user's sub*ids

Rename list_subid_ranges to getsubids to provide a system binary to
check the sub*ids of a user. The intention is to provide this binary
with any distribution that includes the subid feature, so that system
administrators can check the subid ranges of a given user.

Finally, add a man page to explain the behaviour of getsubids.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1980780

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>

man/Makefile.am

@@ -62,6 +62,7 @@ man_MANS += $(man_nopam)
 endif
 
 man_subids = \
+	man1/getsubids.1 \
 	man1/newgidmap.1 \
 	man1/newuidmap.1 \
 	man5/subgid.5 \
@@ -80,6 +81,7 @@ man_XMANS = \
 	expiry.1.xml \
 	faillog.5.xml \
 	faillog.8.xml \
+	getsubids.1.xml \
 	gpasswd.1.xml \
 	groupadd.8.xml \
 	groupdel.8.xml \

man/getsubids.1.xml

@@ -0,0 +1,141 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+   Copyright (c) 2021 Iker Pedrosa
+   All rights reserved.
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions
+   are met:
+   1. Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+   2. Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+   3. The name of the copyright holders or contributors may not be used to
+      endorse or promote products derived from this software without
+      specific prior written permission.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+   PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
+   HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.5//EN"
+  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
+<!-- SHADOW-CONFIG-HERE -->
+]>
+
+<refentry id='getsubids.1'>
+  <refentryinfo>
+    <author>
+      <firstname>Iker</firstname>
+      <surname>Pedrosa</surname>
+      <contrib>Creation, 2021</contrib>
+    </author>
+  </refentryinfo>
+  <refmeta>
+    <refentrytitle>getsubids</refentrytitle>
+    <manvolnum>1</manvolnum>
+    <refmiscinfo class="sectdesc">User Commands</refmiscinfo>
+    <refmiscinfo class="source">shadow-utils</refmiscinfo>
+    <refmiscinfo class="version">&SHADOW_UTILS_VERSION;</refmiscinfo>
+  </refmeta>
+  <refnamediv id='name'>
+    <refname>getsubids</refname>
+    <refpurpose>get the subordinate id ranges for a user</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv id='synopsis'>
+    <cmdsynopsis>
+      <command>getsubids</command>
+      <arg choice='opt'>
+        <replaceable>options</replaceable>
+      </arg>
+      <arg choice='plain'>
+        <replaceable>USER</replaceable>
+      </arg>
+    </cmdsynopsis>
+  </refsynopsisdiv>
+
+  <refsect1 id='description'>
+    <title>DESCRIPTION</title>
+    <para>
+      The <command>getsubids</command> command lists the subordinate user ID
+      ranges for a given user. The subordinate group IDs can be listed using
+      the <option>-g</option> option.
+    </para>
+  </refsect1>
+
+  <refsect1 id='options'>
+    <title>OPTIONS</title>
+    <para>
+      The options which apply to the <command>getsubids</command> command are:
+    </para>
+    <variablelist remap='IP'>
+      <varlistentry>
+        <term>
+          <option>-g</option>
+        </term>
+        <listitem>
+          <para>
+            List the subordinate group ID ranges.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+  </refsect1>
+
+  <refsect1 id='example'>
+    <title>EXAMPLE</title>
+    <para>
+      For example, to obtain the subordinate UIDs of the testuser:
+    </para>
+    <para>
+<programlisting>
+$ getsubids testuser
+0: testuser 100000 65536
+</programlisting>
+    </para>
+    <para>
+      This command output provides (in order from left to right) the list
+      index, username, UID range start, and number of UIDs in range.
+    </para>
+  </refsect1>
+
+  <refsect1 id='see_also'>
+    <title>SEE ALSO</title>
+    <para>
+      <citerefentry>
+        <refentrytitle>login.defs</refentrytitle><manvolnum>5</manvolnum>
+      </citerefentry>,
+      <citerefentry>
+        <refentrytitle>newgidmap</refentrytitle><manvolnum>1</manvolnum>
+      </citerefentry>,
+      <citerefentry>
+        <refentrytitle>newuidmap</refentrytitle><manvolnum>1</manvolnum>
+      </citerefentry>,
+      <citerefentry>
+        <refentrytitle>subgid</refentrytitle><manvolnum>5</manvolnum>
+      </citerefentry>,
+      <citerefentry>
+        <refentrytitle>subuid</refentrytitle><manvolnum>5</manvolnum>
+      </citerefentry>,
+      <citerefentry>
+        <refentrytitle>useradd</refentrytitle><manvolnum>8</manvolnum>
+      </citerefentry>,
+      <citerefentry>
+        <refentrytitle>userdel</refentrytitle><manvolnum>8</manvolnum>
+      </citerefentry>.
+      <citerefentry>
+        <refentrytitle>usermod</refentrytitle><manvolnum>8</manvolnum>
+      </citerefentry>,
+    </para>
+  </refsect1>
+</refentry>

src/.gitignore

@@ -34,7 +34,7 @@
 /usermod
 /vipw
 /get_subid_owners
-/list_subid_ranges
+/getsubids
 /new_subid_range
 /free_subid_range
 /check_subid_range

src/Makefile.am

@@ -158,8 +158,8 @@ if FCAPS
 	setcap cap_setgid+ep $(DESTDIR)$(ubindir)/newgidmap
 endif
 
-noinst_PROGRAMS += list_subid_ranges  \
+bin_PROGRAMS    +=  getsubids
-					get_subid_owners \
+noinst_PROGRAMS +=  get_subid_owners \
 					new_subid_range \
 					free_subid_range \
 					check_subid_range
@@ -175,13 +175,13 @@ MISCLIBS = \
 	$(LIBCRYPT) \
 	$(LIBTCB)
 
-list_subid_ranges_LDADD = \
+getsubids_LDADD = \
 	$(top_builddir)/lib/libshadow.la \
 	$(top_builddir)/libmisc/libmisc.la \
 	$(top_builddir)/libsubid/libsubid.la \
 	$(MISCLIBS) -ldl
 
-list_subid_ranges_CPPFLAGS = \
+getsubids_CPPFLAGS = \
 	-I$(top_srcdir)/lib \
 	-I$(top_srcdir)/libmisc \
 	-I$(top_srcdir) \

src/getsubids.c

@@ -1,6 +1,7 @@
 #include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
 #include "subid.h"
-#include "stdlib.h"
 #include "prototypes.h"
 
 const char *Prog;

tests/libsubid/01_list_ranges/list_ranges.test

@@ -17,8 +17,8 @@ trap 'log_status "$0" "FAILURE"; restore_config' 0
 change_config
 
 echo -n "list foo's ranges..."
-${build_path}/src/list_subid_ranges foo > /tmp/subuidlistout
+${build_path}/src/getsubids foo > /tmp/subuidlistout
-${build_path}/src/list_subid_ranges -g foo > /tmp/subgidlistout
+${build_path}/src/getsubids -g foo > /tmp/subgidlistout
 echo "OK"
 
 echo -n "Check the subuid ranges..."