Factor the Cygwin password authentication hack out of program-agent into...

Factor the Cygwin password authentication hack out of program-agent into libtb, and use it in linktest as well.

event/linktest/GNUmakefile.in

@@ -54,7 +54,7 @@ ifeq ($(SYSTEM),Linux)
 LIBS     	+= -ldl
 endif
 
-LIBTB_OBJS	= $(LIBTBDIR)/log.o $(LIBTBDIR)/tbdefs.o
+LIBTB_OBJS	= $(LIBTBDIR)/log.o $(LIBTBDIR)/tbdefs.o $(LIBTBDIR)/be_user.o
 DAEMON_OBJS	= linktest.o version.o
 LTEVENT_OBJS	= ltevent.o
 

event/linktest/linktest.c

@@ -18,6 +18,7 @@
 #include <time.h>
 #include "tbdefs.h"
 #include "log.h"
+#include "be_user.h"
 #include "event.h"
 
 #define TRUE    1
@@ -362,6 +363,13 @@ exec_linktest(char *args, int buflen) {
 	argv[i] = NULL;
 	argv[0] = LINKTEST_SCRIPT;
 
+#ifdef __CYGWIN__
+	/*
+	 * Run as the swapper on Cygwin for access to the shared /proj dir.
+	 */
+	be_user(swapper);
+#endif /* __CYGWIN__ */
+
 	/*
 	 * Execute the script with the arguments from the event
 	 */

event/program-agent/program-agent.c

@@ -40,6 +40,7 @@
 #include "log.h"
 #include "popenf.h"
 #include "systemf.h"
+#include "be_user.h"
 #include "event.h"
 #include <elvin/elvin.h>
 #ifdef __CYGWIN__
@@ -556,48 +557,7 @@ main(int argc, char **argv)
 	/*
 	 * Flip to the user, but only if we are currently root.
 	 */
-	if (getuid() == 0) {
-
-#ifdef __CYGWIN__
-	/* 
-	 * Present the plain-text password from the tmcc accounts file
-	 * so remote Samba directory mounts like /proj can be accessed.
-	 */
-	FILE *pwd_file = fopen("/var/emulab/boot/tmcc/accounts", "r");
-	static char line[255], name[30], password[30];
-	int matched = 0;
-	while (pwd_file && fgets(line, 255, pwd_file)) {
-		if (sscanf(line, "ADDUSER LOGIN=%30s PSWD=%30s ",
-			   name, password) == 2 &&
-		   (matched = (strncmp(user, name, 30) == 0)))
-			break; /* Found it. */
-	}
-	fclose(pwd_file);
-	if (matched) {
-		info("cygwin_logon_user: name %s, password '%s'...",
-		     pw->pw_name, password);
-		HANDLE hToken = cygwin_logon_user(pw, password);
-		if (hToken != INVALID_HANDLE_VALUE) {
-			info(" suceeded\n");
-			/* This sets context for setuid() below. */
-			cygwin_set_impersonation_token(hToken);
-		}
-		else
-			info(" failed\n");
-	}
-	else
-		info("AGENT: user %s, %s", pw->pw_name, "password not found\n");
-#endif /* __CYGWIN__ */
-
-		/*
-		 * Initialize the group list, and then flip to uid.
-		 */
-		if (setgid(pw->pw_gid) ||
-		    initgroups(user, pw->pw_gid) ||
-		    setuid(pw->pw_uid)) {
-			fatal("Could not become user: %s", user);
-		}
-	}
+	be_user(user);
 
 	if (access(LOGDIR, W_OK) < 0) {
 		fatal("Cannot write to log directory: %s", LOGDIR);

lib/libtb/GNUmakefile.in

@@ -24,7 +24,7 @@ control-install: client
 
 include $(TESTBED_SRCDIR)/GNUmakerules
 
-OBJS		= log.o tbdefs.o popenf.o systemf.o
+OBJS		= log.o tbdefs.o popenf.o systemf.o be_user.o
 CFLAGS	       += -O -g -Wall -I${OBJDIR} -I/usr/local/include
 
 libtb.a:	$(OBJS) tbdb.o
@@ -40,6 +40,7 @@ tbdb.o:		tbdb.h log.h tbdefs.h
 tbdefs.o:	tbdefs.h
 popenf.o:	popenf.h
 systemf.o:	systemf.h
+be_user.o:	be_user.h
 
 install: all
 

lib/libtb/be_user.c

+/*
+ * EMULAB-COPYRIGHT
+ * Copyright (c) 2005 University of Utah and the Flux Group.
+ * All rights reserved.
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <errno.h>
+#include <assert.h>
+
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <pwd.h>
+#include <grp.h>
+
+#ifdef __CYGWIN__
+#include <w32api/windows.h>
+#include <sys/cygwin.h>
+#endif /* __CYGWIN__ */
+
+#include "be_user.h"
+#include "log.h"
+
+int be_user(const char *user)
+{
+	int retval = 1;
+	struct passwd *pw;
+
+	if ((pw = getpwnam(user)) == NULL) {
+		fatal("invalid user: %s", user);
+	}
+
+	if (getuid() == 0) {
+
+#ifdef __CYGWIN__
+	/* 
+	 * On Windows, present the plain-text password from the tmcc accounts
+	 * file so remote Samba directory mounts like /proj can be accessed.
+	 */
+	FILE *pwd_file = fopen("/var/emulab/boot/tmcc/accounts", "r");
+	static char line[255], name[30], password[30];
+	int matched = 0;
+	while (pwd_file && fgets(line, 255, pwd_file)) {
+		if (sscanf(line, "ADDUSER LOGIN=%30s PSWD=%30s ",
+			   name, password) == 2 &&
+		   (matched = (strncmp(user, name, 30) == 0)))
+			break; /* Found it. */
+	}
+	fclose(pwd_file);
+	if (matched) {
+		info("cygwin_logon_user: name %s, password '%s'...",
+		     pw->pw_name, password);
+		HANDLE hToken = cygwin_logon_user(pw, password);
+		if (hToken != INVALID_HANDLE_VALUE) {
+			info(" suceeded\n");
+			/* This sets context for setuid() below. */
+			cygwin_set_impersonation_token(hToken);
+
+			retval = 0;
+		}
+		else
+			info(" failed\n");
+	}
+	else
+		info("user %s, %s", pw->pw_name, "password not found\n");
+#endif /* __CYGWIN__ */
+
+		/*
+		 * Initialize the group list, and then flip to uid.
+		 */
+		if (setgid(pw->pw_gid) ||
+		    initgroups(user, pw->pw_gid) ||
+		    setuid(pw->pw_uid)) {
+			fatal("Could not become user: %s", user);
+		}
+	}
+
+	return retval;
+}

lib/libtb/be_user.h

+/*
+ * EMULAB-COPYRIGHT
+ * Copyright (c) 2005 University of Utah and the Flux Group.
+ * All rights reserved.
+ */
+
+/**
+ * @file be_user.h
+ */
+
+#ifndef _be_user_h
+#define _be_user_h
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Flip to the user, but only if we are currently root. */
+int be_user(const char *username);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif