1 files changed, 65 insertions, 24 deletions

diff --git a/src/daemontools-extras/s6-envuidgid.c b/src/daemontools-extras/s6-envuidgid.c
index 64521b0..3a58c3c 100644
--- a/src/daemontools-extras/s6-envuidgid.c
+++ b/src/daemontools-extras/s6-envuidgid.c
@@ -3,42 +3,83 @@
 #include <sys/types.h>
 #include <pwd.h>
 #include <limits.h>
+#include <skalibs/uint64.h>
 #include <skalibs/gidstuff.h>
-#include <skalibs/env.h>
+#include <skalibs/bytestr.h>
+#include <skalibs/sgetopt.h>
 #include <skalibs/strerr2.h>
+#include <skalibs/env.h>
 #include <skalibs/fmtscan.h>
 #include <skalibs/djbunix.h>
 
-#define USAGE "s6-envuidgid username prog..."
+#define USAGE "s6-envuidgid [ -i | -D defaultuid:defaultgid ] username prog..."
+#define dieusage() strerr_dieusage(100, USAGE)
 
 int main (int argc, char const *const *argv, char const *const *envp)
 {
+  struct passwd *pw ;
+  uint64 uid ;
+  gid_t gid ;
+  gid_t tab[NGROUPS_MAX] ;
+  int n = 0 ;
+  int insist = 1 ;
   PROG = "s6-envuidgid" ;
-  if (argc < 3) strerr_dieusage(100, USAGE) ;
   {
-    char fmt[UINT64_FMT] ;
-    struct passwd *pw = getpwnam(argv[1]) ;
-    if (!pw) strerr_dief2x(1, "unknown user: ", argv[1]) ;
-    fmt[gid_fmt(fmt, pw->pw_gid)] = 0 ;
-    if (!pathexec_env("GID", fmt))
-      strerr_diefu1sys(111, "update environment") ;
-    fmt[uint64_fmt(fmt, pw->pw_uid)] = 0 ;
-    if (!pathexec_env("UID", fmt))
-      strerr_diefu1sys(111, "update environment") ;
+    subgetopt_t l = SUBGETOPT_ZERO ;
+    for (;;)
+    {
+      register int opt = subgetopt_r(argc, argv, "iD:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case 'i' : insist = 1 ; break ;
+        case 'D' :
+        {
+          unsigned int pos = uint64_scan(l.arg, &uid) ;
+          if (!pos)
+          {
+            if (l.arg[pos] != ':') dieusage() ;
+            uid = 0 ;
+          }
+          if (!l.arg[pos]) gid = 0 ;
+          else
+          {
+            if (l.arg[pos++] != ':') dieusage() ;
+            if (!l.arg[pos]) gid = 0 ;
+            else if (!gid0_scan(l.arg + pos, &gid)) dieusage() ;
+          }
+          insist = 0 ;
+          break ;
+        }
+        default : dieusage() ;
+      }
+    }
+    argc -= l.ind ; argv += l.ind ;
   }
-  
+  if (argc < 2) dieusage() ;
+
+  pw = getpwnam(argv[0]) ;
+  if (pw)
   {
-    gid_t tab[NGROUPS_MAX] ;
-    int n = prot_readgroups(argv[1], tab, NGROUPS_MAX) ;
+    uid = pw->pw_uid ;
+    gid = pw->pw_gid ;
+    n = prot_readgroups(argv[0], tab, NGROUPS_MAX) ;
     if (n < 0)
-      strerr_diefu2sys(111, "get supplementary groups for ", argv[1]) ;
-    {
-      char fmt[GID_FMT * n] ;
-      fmt[gid_fmtlist(fmt, tab, n)] = 0 ;
-      if (!pathexec_env("GIDLIST", fmt))
-        strerr_diefu1sys(111, "update environment") ;
-    }
+      strerr_diefu2sys(111, "get supplementary groups for ", argv[0]) ;
+  }
+  else if (insist) strerr_dief2x(1, "unknown user: ", argv[1]) ;
+
+  {
+    unsigned int pos = 0 ;
+    char fmt[19 + UINT64_FMT + (n+1) * GID_FMT] ;
+    byte_copy(fmt + pos, 4, "UID=") ; pos += 4 ;
+    pos += uint64_fmt(fmt + pos, uid) ;
+    byte_copy(fmt + pos, 5, "\0GID=") ; pos += 5 ;
+    pos += gid_fmt(fmt + pos, gid) ;
+    byte_copy(fmt + pos, 9, "\0GIDLIST=") ; pos += 9 ;
+    pos += gid_fmtlist(fmt + pos, tab, n) ;
+    fmt[pos++] = 0 ;
+    pathexec_r(argv+1, envp, env_len(envp), fmt, pos) ;
   }
-  pathexec_fromenv(argv+2, envp, env_len(envp)) ;
-  strerr_dieexec(111, argv[2]) ;
+  strerr_dieexec(111, argv[1]) ;
 }