Add s6-applyuidgid

author: Laurent Bercot <ska-skaware@skarnet.org> 2015-01-06 23:38:19 +0000
committer: Laurent Bercot <ska-skaware@skarnet.org> 2015-01-06 23:38:19 +0000
commit: f7033d3fee696a0d1a775686d1b229eae1b5a137 (patch)
tree: fc9c05f797271fb72765282ab169845a84a58679
parent: 861bed98658c79a55bcfea8e7f9e706c4d610c8a (diff)
download: s6-f7033d3fee696a0d1a775686d1b229eae1b5a137.tar.xz
7 files changed, 141 insertions, 1 deletions
diff --git a/doc/index.html b/doc/index.html
index 54e8925..bf8d0ae 100644
--- a/doc/index.html
+++ b/doc/index.html
@@ -138,6 +138,7 @@ counterpart.
 <li><a href="s6-setlock.html">The <tt>s6-setlock</tt> program</a></li>
 <li><a href="s6-setsid.html">The <tt>s6-setsid</tt> program</a></li>
 <li><a href="s6-setuidgid.html">The <tt>s6-setuidgid</tt> program</a></li>
+<li><a href="s6-applyuidgid.html">The <tt>s6-applyuidgid</tt> program</a></li>
 <li><a href="s6-softlimit.html">The <tt>s6-softlimit</tt> program</a></li>
 <li><a href="s6-tai64n.html">The <tt>s6-tai64n</tt> program</a></li>
 <li><a href="s6-tai64nlocal.html">The <tt>s6-tai64nlocal</tt> program</a></li>
diff --git a/doc/s6-applyuidgid.html b/doc/s6-applyuidgid.html
new file mode 100644
index 0000000..9b4293e
--- /dev/null
+++ b/doc/s6-applyuidgid.html
@@ -0,0 +1,63 @@
+<html>
+  <head>
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
+    <meta http-equiv="Content-Language" content="en" />
+    <title>s6: the s6-applyuidgid program</title>
+    <meta name="Description" content="s6: the s6-applyuidgid program" />
+    <meta name="Keywords" content="s6 command s6-applyuidgid uid gid groups privilege dropping loss user change su" />
+    <!-- <link rel="stylesheet" type="text/css" href="http://skarnet.org/default.css" /> -->
+  </head>
+<body>
+
+<p>
+<a href="index.html">s6</a><br />
+<a href="http://skarnet.org/software/">Software</a><br />
+<a href="http://skarnet.org/">skarnet.org</a>
+</p>
+
+<h1> The s6-applyuidgid program </h1>
+
+<p>
+ s6-applyuidgid executes a program with reduced privileges.
+</p>
+
+<h2> Interface </h2>
+
+<pre>
+     s6-applyuidgid [ -z ] [ -u <em>uid</em> ] [ -g <em>gid</em> ] [ -G <em>gidlist</em> ] [ -U ] <em>prog...</em>
+</pre>
+
+<ul>
+ <li> s6-applyuidgid sets its uid, gid and supplementary group list to the
+values given, then executes into <em>prog</em>. </li>
+</ul>
+
+<h2> Options </h2>
+
+<ul>
+ <li> <tt>-u&nbsp;<em>uid</em></tt>&nbsp;: set the process' user ID to <em>uid</em> </li>
+ <li> <tt>-g&nbsp;<em>gid</em></tt>&nbsp;: set the process' group ID to <em>gid</em> </li>
+ <li> <tt>-G&nbsp;<em>gidlist</em></tt>&nbsp;: set the process' supplementary group list
+to <em>gidlist</em>, which must be given as a comma-separated list of numeric GIDs,
+without spaces. </li>
+ <li> <tt>-U</tt>&nbsp;: set the process' user ID, group ID and supplementary group list
+to the values of the UID, GID and GIDLIST environment variables. If a <tt>-u</tt>,
+<tt>-g</tt> or <tt>-G</tt> option is given after <tt>-U</tt>, the command line
+value overrides the environment variable. </li>
+ <li> <tt>-z</tt>&nbsp;: unexport. The UID, GID and GIDLIST variables will be
+removed from the process environment. </li>
+</ul>
+	
+<h2> Notes </h2>
+
+<ul>
+ <li> s6-applyuidgid can only be run as root. Its main use is to drop root privileges before
+starting a daemon. </li>
+ <li> s6-applyuidgid is a more generic version of
+<a href="s6-setuidgid.html">s6-setuidgid</a>. It is used as a command line
+building block by some programs that rewrite their command line, such as
+<a href="http://skarnet.org/software/s6-networking/s6-tcpserver.html">s6-tcpserver</a> </li>
+</ul>
+
+</body>
+</html>
diff --git a/package/deps.mak b/package/deps.mak
index e728bb0..4b33279 100644
--- a/package/deps.mak
+++ b/package/deps.mak
@@ -5,6 +5,7 @@
 src/include/s6/ftrigr.h: src/include/s6/config.h
 src/include/s6/s6.h: src/include/s6/ftrigr.h src/include/s6/ftrigw.h src/include/s6/s6-supervise.h src/include/s6/s6lock.h
 src/include/s6/s6lock.h: src/include/s6/config.h
+src/daemontools-extras/s6-applyuidgid.o src/daemontools-extras/s6-applyuidgid.lo: src/daemontools-extras/s6-applyuidgid.c
 src/daemontools-extras/s6-envdir.o src/daemontools-extras/s6-envdir.lo: src/daemontools-extras/s6-envdir.c
 src/daemontools-extras/s6-envuidgid.o src/daemontools-extras/s6-envuidgid.lo: src/daemontools-extras/s6-envuidgid.c
 src/daemontools-extras/s6-fghack.o src/daemontools-extras/s6-fghack.lo: src/daemontools-extras/s6-fghack.c
@@ -69,6 +70,8 @@ src/supervision/s6-svscanctl.o src/supervision/s6-svscanctl.lo: src/supervision/
 src/supervision/s6-svstat.o src/supervision/s6-svstat.lo: src/supervision/s6-svstat.c src/include/s6/s6-supervise.h
 src/supervision/s6-svwait.o src/supervision/s6-svwait.lo: src/supervision/s6-svwait.c src/include/s6/ftrigr.h src/include/s6/s6-supervise.h
 
+s6-applyuidgid: private EXTRA_LIBS :=
+s6-applyuidgid: src/daemontools-extras/s6-applyuidgid.o -lskarnet
 s6-envdir: private EXTRA_LIBS :=
 s6-envdir: src/daemontools-extras/s6-envdir.o -lskarnet
 s6-envuidgid: private EXTRA_LIBS :=
diff --git a/package/modes b/package/modes
index d3fb2e0..4b86721 100644
--- a/package/modes
+++ b/package/modes
@@ -15,6 +15,7 @@ s6-svscanctl		0755
 s6-svok			0755
 s6-svstat		0755
 s6-svwait		0755
+s6-applyuidgid		0700
 s6-envdir		0755
 s6-envuidgid		0755
 s6-fghack		0755
diff --git a/package/targets.mak b/package/targets.mak
index 5353fc6..283cc67 100644
--- a/package/targets.mak
+++ b/package/targets.mak
@@ -21,12 +21,15 @@ s6-fghack \
 s6-log \
 s6-setlock \
 s6-setsid \
-s6-setuidgid \
 s6-softlimit \
 s6-tai64n \
 s6-tai64nlocal \
 ucspilogd
 
+SBIN_TARGETS := \
+s6-applyuidgid \
+s6-setuidgid
+
 LIBEXEC_TARGETS := s6lockd-helper
 
 ifdef DO_SHARED
diff --git a/src/daemontools-extras/deps-exe/s6-applyuidgid b/src/daemontools-extras/deps-exe/s6-applyuidgid
new file mode 100644
index 0000000..e7187fe
--- /dev/null
+++ b/src/daemontools-extras/deps-exe/s6-applyuidgid
@@ -0,0 +1 @@
+-lskarnet
diff --git a/src/daemontools-extras/s6-applyuidgid.c b/src/daemontools-extras/s6-applyuidgid.c
new file mode 100644
index 0000000..77beef2
--- /dev/null
+++ b/src/daemontools-extras/s6-applyuidgid.c
@@ -0,0 +1,68 @@
+/* ISC license. */
+
+#include <skalibs/nonposix.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <grp.h>
+#include <limits.h>
+#include <skalibs/uint.h>
+#include <skalibs/gidstuff.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/sgetopt.h>
+#include <skalibs/env.h>
+#include <skalibs/djbunix.h>
+
+#define USAGE "s6-applyuidgid [ -z ] [ -u uid ] [ -g gid ] [ -G gidlist ] [ -U ] prog..."
+#define dieusage() strerr_dieusage(100, USAGE)
+
+int main (int argc, char const *const *argv, char const *const *envp)
+{
+  unsigned int uid = 0, gid = 0 ;
+  gid_t gids[NGROUPS_MAX] ;
+  unsigned int gidn = (unsigned int)-1 ;
+  int unexport = 0 ;
+  PROG = "s6-applyuidgid" ;
+  {
+    subgetopt_t l = SUBGETOPT_ZERO ;
+    for (;;)
+    {
+      register int opt = subgetopt_r(argc, argv, "zUu:g:G:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case 'z' : unexport = 1 ; break ;
+        case 'u' : if (!uint0_scan(l.arg, &uid)) dieusage() ; break ;
+        case 'g' : if (!uint0_scan(l.arg, &gid)) dieusage() ; break ;
+        case 'G' : if (!gid_scanlist(gids, NGROUPS_MAX, l.arg, &gidn)) dieusage() ; break ;
+        case 'U' :
+        {
+          char const *x = env_get2(envp, "UID") ;
+          if (!x) strerr_dienotset(100, "UID") ;
+          if (!uint0_scan(x, &uid)) strerr_dieinvalid(100, "UID") ;
+          x = env_get2(envp, "GID") ;
+          if (!x) strerr_dienotset(100, "GID") ;
+          if (!uint0_scan(x, &gid)) strerr_dieinvalid(100, "GID") ;
+          x = env_get2(envp, "GIDLIST") ;
+          if (!x) strerr_dienotset(100, "GIDLIST") ;
+          if (!gid_scanlist(gids, NGROUPS_MAX, x, &gidn) && *x)
+            strerr_dieinvalid(100, "GIDLIST") ;
+          break ;
+        }
+        default : dieusage() ;
+      }
+    }
+    argc -= l.ind ; argv += l.ind ;
+  }
+  if (!argc) dieusage() ;
+
+  if (gidn != (unsigned int)-1 && setgroups(gidn, gids) < 0)
+    strerr_diefu1sys(111, "set supplementary group list") ;
+  if (gid && setgid(gid) < 0)
+    strerr_diefu1sys(111, "setgid") ;
+  if (uid && setuid(uid) < 0)
+    strerr_diefu1sys(111, "setuid") ;
+
+  if (unexport) pathexec_r(argv, envp, env_len(envp), "UID\0GID\0GIDLIST", 16) ;
+  else pathexec_run(argv[0], argv, envp) ;
+  strerr_dieexec(111, argv[0]) ;
+}
author	Laurent Bercot <ska-skaware@skarnet.org>	2015-01-06 23:38:19 +0000
committer	Laurent Bercot <ska-skaware@skarnet.org>	2015-01-06 23:38:19 +0000
commit	f7033d3fee696a0d1a775686d1b229eae1b5a137 (patch)
tree	fc9c05f797271fb72765282ab169845a84a58679
parent	861bed98658c79a55bcfea8e7f9e706c4d610c8a (diff)
download	s6-f7033d3fee696a0d1a775686d1b229eae1b5a137.tar.xz