2011-08-20 Jonathan Nieder <jrnieder@gmail.com>

* lib/Makefile.am: Added lib/spawn.c and lib/spawn.h.
	* lib/nscd.c, lib/spawn.c, lib/spawn.h: It is not possible to
	differentiate between an nscd failure, and a failure to execute
	due to no nscd with posix_spawn. Use our own run_command routine.
	* src/userdel.c: Use run_command()

ChangeLog

@@ -1,3 +1,11 @@
+2011-08-20  Jonathan Nieder  <jrnieder@gmail.com>
+
+	* lib/Makefile.am: Added lib/spawn.c and lib/spawn.h.
+	* lib/nscd.c, lib/spawn.c, lib/spawn.h: It is not possible to
+	differentiate between an nscd failure, and a failure to execute
+	due to no nscd with posix_spawn. Use our own run_command routine.
+	* src/userdel.c: Use run_command()
+
 2011-08-15  Nicolas François  <nicolas.francois@centraliens.net>
 
 	* src/groupmod.c: Ignore return value from snprintf.

lib/Makefile.am

@@ -48,6 +48,8 @@ libshadow_la_SOURCES = \
 	shadowio.c \
 	shadowio.h \
 	shadowmem.c \
+	spawn.c \
+	spawn.h \
 	utent.c
 
 if WITH_TCB

lib/nscd.c

@@ -16,7 +16,9 @@
 #include <errno.h>
 #include <sys/wait.h>
 #include <sys/types.h>
+#include "exitcodes.h"
 #include "defines.h"
+#include "spawn.h"
 #include "nscd.h"
 
 #define MSG_NSCD_FLUSH_CACHE_FAILED "Failed to flush the nscd cache.\n"
@@ -26,37 +28,32 @@
  */
 int nscd_flush_cache (const char *service)
 {
-	pid_t pid, termpid;
+	pid_t pid;
-	int err, status;
+	int err, status, code;
-	char *spawnedArgs[] = {"/usr/sbin/nscd", "nscd", "-i", service, NULL};
+	const char *spawnedArgs[] = {"/usr/sbin/nscd", "nscd", "-i", service, NULL};
-	char *spawnedEnv[] = {NULL};
+	const char *spawnedEnv[] = {NULL};
 
-	/* spawn process */
+	err = run_command (spawnedArgs[0], spawnedArgs, spawnedEnv, &status);
-	err = posix_spawn (&pid, spawnedArgs[0], NULL, NULL,
+	if (0 != err)
-	                   spawnedArgs, spawnedEnv);
-	if(0 != err)
 	{
+		/* run_command writes its own more detailed message. */
 		(void) fputs (_(MSG_NSCD_FLUSH_CACHE_FAILED), stderr);
-		(void) fprintf (stderr, "posix_spawn() error=%d\n", err);
 		return -1;
 	}
-
+	code = WIFEXITED (status) ? WEXITSTATUS (status)
-	/* Wait for the spawned process to exit */
+	                          : (WTERMSIG (status) + 128);
-	termpid = TEMP_FAILURE_RETRY (waitpid (pid, &status, 0));
+	if (code == E_CMD_NOTFOUND)
-	if (-1 == termpid)
 	{
+		/* nscd is not installed, or it is installed but uses an
+		   interpreter that is missing.  Probably the former. */
+		return 0;
+	}
+	if (code != 0)
+	{
+		(void) fprintf (stderr, "nscd exited with status %d", code);
 		(void) fputs (_(MSG_NSCD_FLUSH_CACHE_FAILED), stderr);
-		perror("waitpid");
 		return -1;
 	}
-	else if (termpid != pid)
-	{
-		(void) fputs (_(MSG_NSCD_FLUSH_CACHE_FAILED), stderr);
-		(void) fprintf (stderr, "waitpid returned %ld != %ld\n",
-		               (long int) termpid, (long int) pid);
-		return -1;
-	}
-
 	return 0;
 }
 #else				/* USE_NSCD */

lib/spawn.c

@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2011, Jonathan Nieder
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FREEBSD
+ * PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <config.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <errno.h>
+#include "exitcodes.h"
+#include "spawn.h"
+
+extern char **environ;
+
+int run_command (const char *cmd, const char *argv[], const char *envp[],
+                 int *status)
+{
+	pid_t pid, wpid;
+
+	if (!envp)
+		envp = (const char **)environ;
+	pid = fork ();
+	if (pid == 0) {
+		execve (cmd, (char * const *) argv, (char * const *) envp);
+		if (errno == ENOENT)
+			exit (E_CMD_NOTFOUND);
+		perror(cmd);
+		exit (E_CMD_NOEXEC);
+	} else if ((pid_t)-1 == pid) {
+		int saved_errno = errno;
+		perror ("fork");
+		errno = saved_errno;
+		return -1;
+	}
+
+	do {
+		wpid = waitpid (pid, status, 0);
+	} while ((pid_t)-1 == wpid && errno == EINTR);
+
+	if ((pid_t)-1 == wpid) {
+		int saved_errno = errno;
+		perror ("waitpid");
+		return -1;
+	} else if (wpid != pid) {
+		(void) fprintf (stderr, "waitpid returned %ld != %ld\n",
+		                (long int) wpid, (long int) pid);
+		errno = ECHILD;
+		return -1;
+	}
+	return 0;
+}

lib/spawn.h

@@ -0,0 +1,7 @@
+#ifndef _SPAWN_H
+#define _SPAWN_H
+
+extern int run_command (const char *cmd, const char *argv[],
+                        const char *envp[], int *status);
+
+#endif

src/userdel.c

@@ -59,6 +59,7 @@
 #ifdef	SHADOWGRP
 #include "sgroupio.h"
 #endif				/* SHADOWGRP */
+#include "spawn.h"
 #ifdef WITH_TCB
 #include <tcb.h>
 #include "tcbfuncs.h"
@@ -628,6 +629,7 @@ static void update_user (void)
 static void user_cancel (const char *user)
 {
 	const char *cmd;
+	const char *argv[3];
 	pid_t pid, wpid;
 	int status;
 
@@ -635,18 +637,10 @@ static void user_cancel (const char *user)
 	if (NULL == cmd) {
 		return;
 	}
-	pid = fork ();
+	argv[0] = cmd;
-	if (pid == 0) {
+	argv[1] = user;
-		execl (cmd, cmd, user, (char *) 0);
+	argv[2] = (char *)0;
-		perror (cmd);
+	(void) run_command (cmd, argv, NULL, &status);
-		exit (errno == ENOENT ? E_CMD_NOTFOUND : E_CMD_NOEXEC);
-	} else if ((pid_t)-1 == pid) {
-		perror ("fork");
-		return;
-	}
-	do {
-		wpid = wait (&status);
-	} while ((wpid != pid) && ((pid_t)-1 != wpid));
 }
 
 #ifdef EXTRA_CHECK_HOME_DIR