added ability to run as different user than root

git-svn-id: https://erlyaws.svn.sourceforge.net/svnroot/erlyaws/trunk/yaws@315 9fbdc01b-0d2c-0410-bfb7-fb27d70d8b52

Author: Claes Wikstrom

Makefile

@@ -1,4 +1,4 @@
-SUBDIRS	=	src scripts man www/shopingcart doc
+SUBDIRS	=	c_src src scripts man www/shopingcart doc
 APPS = webmail
 include ./include.mk
 

c_src/Makefile

@@ -0,0 +1,31 @@
+include ../include.mk
+
+
+PRIV_FILES= ../priv/setuid_drv.$(DLL) 
+
+CFLAGS += -I${ERLDIR}/usr/include
+
+#
+# Targets
+#
+
+all: $(PRIV_FILES) 
+
+clean:
+	-rm -f $(PRIV_FILES) setuid_drv.$(OBJ) 
+
+install:
+	install -d $(INSTALLPREFIX)/lib/yaws/priv
+	install ../priv/setuid_drv.$(DLL) $(INSTALLPREFIX)/lib/yaws/priv
+
+
+../priv/setuid_drv.$(DLL): setuid_drv.$(OBJ)
+	$(LD_SHARED) $(OUT)$@ setuid_drv.$(OBJ) $(DLL_LIBS)
+
+setuid_drv.$(OBJ):	setuid_drv.c
+	$(CC) -c $(FPIC) $(CFLAGS) -DDYNAMIC_DRIVER setuid_drv.c
+
+
+
+
+

c_src/setuid_drv.c

@@ -0,0 +1,85 @@
+/* author: [email protected]                                  */
+/* purpose, make us run under a different username           */
+
+#ifndef WIN32
+#include <unistd.h>
+#endif
+
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <pwd.h>
+
+#include "erl_driver.h"
+#ifndef ERL_DRV_NIL
+#include "erl_driver_compat.h"
+#endif
+
+
+
+static ErlDrvData setuid_start(ErlDrvPort port, char *buf);
+static void setuid_stop(ErlDrvData drv_data);
+
+static ErlDrvEntry setuid_driver_entry;
+
+
+/* buf is the name of the intented user */
+static ErlDrvData setuid_start(ErlDrvPort port, char *buf)
+{
+    char *t;
+    char xbuf[BUFSIZ];
+    struct passwd *pe;
+
+    if ((t = strchr(buf, ' ')) == NULL)
+	return (ErlDrvData) -1;
+    t++;
+
+    while ((pe = getpwent())) {
+	if (strcmp(pe->pw_name , t) == 0) {
+	    if ((setuid(pe->pw_uid)  != 0) ||
+		(setreuid(pe->pw_uid, pe->pw_uid) != 0)) {
+		return (ErlDrvData) -1;
+	    }
+	    sprintf(xbuf, "ok %d", pe->pw_uid);
+	    endpwent();
+	    driver_output(port,xbuf, strlen(xbuf));
+	    return (ErlDrvData) port;
+	}
+    }
+    endpwent();
+    return (ErlDrvData) -1;
+}
+
+
+static void setuid_stop(ErlDrvData drv_data)
+{
+}
+
+
+
+
+/*
+ * Initialize and return a driver entry struct
+ */
+
+
+
+
+DRIVER_INIT(setuid_drv)
+{
+    setuid_driver_entry.init         = NULL;   /* Not used */
+    setuid_driver_entry.start        = setuid_start;
+    setuid_driver_entry.stop         = setuid_stop;
+    setuid_driver_entry.output       = NULL;
+    setuid_driver_entry.ready_input  = NULL;
+    setuid_driver_entry.ready_output = NULL;
+    setuid_driver_entry.driver_name  = "setuid_drv";
+    setuid_driver_entry.finish       = NULL;
+    setuid_driver_entry.control      = NULL;
+    setuid_driver_entry.outputv      = NULL;
+    return (ErlDrvEntry*) &setuid_driver_entry;
+}
+
+