1 files changed, 30 insertions, 0 deletions
diff --git a/src/daemontools-extras/s6-setuidgid.c b/src/daemontools-extras/s6-setuidgid.c
new file mode 100644
index 0000000..d2e7361
--- /dev/null
+++ b/src/daemontools-extras/s6-setuidgid.c
@@ -0,0 +1,30 @@
+/* ISC license. */
+
+#include <unistd.h>
+#include <skalibs/bytestr.h>
+#include <skalibs/uint.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/djbunix.h>
+
+#define USAGE "s6-setuidgid username prog..."
+#define dieusage() strerr_dieusage(100, USAGE)
+
+int main (int argc, char const *const *argv, char const *const *envp)
+{
+  unsigned int pos ;
+  PROG = "s6-setuidgid" ;
+  if (argc < 3) dieusage() ;
+  pos = str_chr(argv[1], ':') ;
+  if (argv[1][pos])
+  {
+    unsigned int uid = 0, gid = 0, len = uint_scan(argv[1], &uid) ;
+    if (len != pos) dieusage() ;
+    if (argv[1][pos+1] && !uint0_scan(argv[1]+pos+1, &gid)) dieusage() ;
+    if (gid && setgid(gid)) strerr_diefu1sys(111, "setgid") ;
+    if (uid && setuid(uid)) strerr_diefu1sys(111, "setuid") ;
+  }
+  else if (!prot_setuidgid(argv[1]))
+    strerr_diefu2sys(111, "change identity to ", argv[1]) ;
+  pathexec_run(argv[2], argv+2, envp) ;
+  strerr_dieexec(111, argv[2]) ;
+}