pposix: Add setgid() function

diff --git a/util-src/pposix.c b/util-src/pposix.c
index 70c152818d3224df33dbf21a0ea5ae185a9b41ec..993e6e876becf361d6f098382c20700fc6078d55 100644 (file)
--- a/util-src/pposix.c
+++ b/util-src/pposix.c
@@ -25,6 +25,7 @@
 
 #include <syslog.h>
 #include <pwd.h>
+#include <grp.h>
 
 #include <string.h>
 #include <errno.h>
@@ -291,6 +292,64 @@ int lc_setuid(lua_State* L)
        return 2;
 }
 
+int lc_setgid(lua_State* L)
+{
+       int gid = -1;
+       if(lua_gettop(L) < 1)
+               return 0;
+       if(!lua_isnumber(L, 1) && lua_tostring(L, 1))
+       {
+               /* Passed GID is actually a string, so look up the GID */
+               struct group *g;
+               g = getgrnam(lua_tostring(L, 1));
+               if(!g)
+               {
+                       lua_pushboolean(L, 0);
+                       lua_pushstring(L, "no-such-group");
+                       return 2;
+               }
+               gid = g->gr_gid;
+       }
+       else
+       {
+               gid = lua_tonumber(L, 1);
+       }
+       
+       if(gid>-1)
+       {
+               /* Ok, attempt setgid */
+               errno = 0;
+               if(setgid(gid))
+               {
+                       /* Fail */
+                       lua_pushboolean(L, 0);
+                       switch(errno)
+                       {
+                       case EINVAL:
+                               lua_pushstring(L, "invalid-gid");
+                               break;
+                       case EPERM:
+                               lua_pushstring(L, "permission-denied");
+                               break;
+                       default:
+                               lua_pushstring(L, "unknown-error");
+                       }
+                       return 2;
+               }
+               else
+               {
+                       /* Success! */
+                       lua_pushboolean(L, 1);
+                       return 1;
+               }
+       }
+       
+       /* Seems we couldn't find a valid GID to switch to */
+       lua_pushboolean(L, 0);
+       lua_pushstring(L, "invalid-gid");
+       return 2;
+}
+
 /*     Like POSIX's setrlimit()/getrlimit() API functions.
  *     
  *     Syntax:
@@ -420,9 +479,13 @@ int luaopen_util_pposix(lua_State *L)
 
        lua_pushcfunction(L, lc_getuid);
        lua_setfield(L, -2, "getuid");
+       lua_pushcfunction(L, lc_getgid);
+       lua_setfield(L, -2, "getgid");
 
        lua_pushcfunction(L, lc_setuid);
        lua_setfield(L, -2, "setuid");
+       lua_pushcfunction(L, lc_setgid);
+       lua_setfield(L, -2, "setgid");
        
        lua_pushcfunction(L, lc_setrlimit);
        lua_setfield(L, -2, "setrlimit");