2009-03-27 Sebastian Huber <sebastian.huber@embedded-brains.de>

* Makefile.am, preinstall.am, libmisc/Makefile.am,
	libmisc/shell/shell.c, libmisc/shell/shell.h, telnetd/check_passwd.c,
	telnetd/telnetd.c, telnetd/telnetd.h:
	Generalized login check.
	* libmisc/shell/login.h, libmisc/shell/login_check.c,
	libmisc/shell/login_prompt.c: New files.
	* libmisc/stackchk/check.c: Changed format for blown stack message.
	* libcsupport/src/libio_sockets.c: Removed superfluous cast.
	* libnetworking/rtems/ftpfs.h: Documentation.

cpukit/libmisc/shell/login.h

@@ -0,0 +1,56 @@
+/**
+ * @file
+ *
+ * @author Sebastian Huber <sebastian.huber@embedded-brains.de>
+ *
+ * @brief Login types and functions.
+ */
+
+/*
+ * Copyright (c) 2009
+ * embedded brains GmbH
+ * Obere Lagerstr. 30
+ * D-82178 Puchheim
+ * Germany
+ * <rtems@embedded-brains.de>
+ *
+ * Based on work from Chris Johns, Fernando Ruiz and Till Straumann.
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#ifndef RTEMS_LOGIN_H
+#define RTEMS_LOGIN_H
+
+#include <stdio.h>
+
+#include <rtems.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+typedef bool (*rtems_login_check)(
+  const char * /* user */,
+  const char * /* passphrase */
+);
+
+bool rtems_shell_login_prompt(
+  FILE *in,
+  FILE *out,
+  const char *device,
+  rtems_login_check check
+);
+
+bool rtems_shell_login_check(
+  const char *user,
+  const char *passphrase
+);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* RTEMS_LOGIN_H */

cpukit/libmisc/shell/login_check.c

@@ -0,0 +1,58 @@
+/**
+ * @file
+ *
+ * @author Sebastian Huber <sebastian.huber@embedded-brains.de>
+ *
+ * @brief Shell login check function.
+ */
+
+/*
+ * Copyright (c) 2009
+ * Embedded Brains GmbH
+ * Obere Lagerstr. 30
+ * D-82178 Puchheim
+ * Germany
+ * rtems@embedded-brains.de
+ *
+ * Based on work from Chris Johns, Fernando Ruiz and Till Straumann.
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <pwd.h>
+
+#include <rtems/login.h>
+#include <rtems/shell.h>
+#include <rtems/userenv.h>
+
+bool rtems_shell_login_check(
+  const char *user,
+  const char *passphrase
+)
+{
+  struct passwd *pw = getpwnam( user);
+
+  /* Valid user? */
+  if (pw != NULL && strcmp( pw->pw_passwd, "!") != 0) {
+    setuid( pw->pw_uid);
+    setgid( pw->pw_gid);
+    rtems_current_user_env->euid = 0;
+    rtems_current_user_env->egid = 0;
+    chown( rtems_current_shell_env->devname, pw->pw_uid, 0);
+    rtems_current_user_env->euid = pw->pw_uid;
+    rtems_current_user_env->egid = pw->pw_gid;
+    if (strcmp( pw->pw_passwd, "*") == 0) {
+      /* TODO: /etc/shadow */
+      return true;
+    } else {
+      /* TODO: crypt() */
+      return true;
+    }
+  }
+
+  return false;
+}

cpukit/libmisc/shell/login_prompt.c

@@ -0,0 +1,162 @@
+/**
+ * @file
+ *
+ * @author Sebastian Huber <sebastian.huber@embedded-brains.de>
+ *
+ * @brief Shell login prompt functions.
+ */
+
+/*
+ * Copyright (c) 2009
+ * embedded brains GmbH
+ * Obere Lagerstr. 30
+ * D-82178 Puchheim
+ * Germany
+ * <rtems@embedded-brains.de>
+ *
+ * Based on work from Chris Johns, Fernando Ruiz and Till Straumann.
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#include <stdio.h>
+#include <termios.h>
+#include <unistd.h>
+#include <ctype.h>
+
+#include <rtems/login.h>
+
+static int rtems_shell_discard( int c, FILE *stream)
+{
+  return c;
+}
+
+static void rtems_shell_get_text(
+  FILE *in,
+  FILE *out,
+  char *line,
+  size_t size
+)
+{
+  int fd_in = fileno( in);
+  int (*put)( int, FILE *) =
+    out != NULL && isatty( fd_in)
+      ? fputc
+      : rtems_shell_discard;
+  size_t i = 0;
+
+  if (size < 1) {
+    return;
+  }
+
+  tcdrain( fd_in);
+  if (out != NULL){
+    tcdrain( fileno( out));
+  }
+
+  while (true) {
+    int c = fgetc( in);
+
+    switch (c) {
+      case EOF:
+        /* Here comes an ugly hack: The Termios driver's read() handler returns
+         * 0 to the C library's fgets() if it times out.  fgets() interprets
+         * this (correctly) as EOF, a condition we want to undo since it's not
+         * really true since we really have a read error (Termios bug?).
+         *
+         * As a workaround we push something back and read it again.  This
+         * should simply reset the EOF condition.
+         */
+        if (ungetc( '?', in) == '?') {
+          fgetc( in);
+        }
+        break;
+      case '\n':
+      case '\r':
+        put( '\n', out);
+        line [i] = '\0';
+        return;
+      case  127:
+      case '\b':
+        if (i > 0) {
+          put( '\b', out);
+          put( ' ', out);
+          put( '\b', out);
+          --i;
+        } else {
+          put( '\a', out);
+        }
+        break;
+      default:
+        if (!iscntrl( c)) {
+          if (i < size - 1) {
+            line [i] = (char) c;
+            ++i;
+            put( c, out);
+          } else {
+            put( '\a', out);
+          }
+        } else {
+          put( '\a', out);
+        }
+        break;
+    }
+  }
+}
+
+bool rtems_shell_login_prompt(
+  FILE *in,
+  FILE *out,
+  const char *device,
+  rtems_login_check check
+)
+{
+  int fd_in = fileno( in);
+  struct termios termios_previous;
+  bool restore_termios = false;
+  int i = 0;
+  bool result = false;
+
+  if (tcgetattr( fd_in, &termios_previous) == 0) {
+    struct termios termios_new = termios_previous;
+
+    termios_new.c_lflag &= ~ECHO;
+    termios_new.c_lflag &= ~ICANON;
+    termios_new.c_cc [VTIME] = 255;
+    termios_new.c_cc [VMIN] = 0;
+
+    restore_termios = tcsetattr( fd_in, TCSANOW, &termios_new) == 0;
+  }
+
+  for (i = 0; i < 3; ++i) {
+    char user [32];
+    char passphrase [128];
+
+    fprintf( out, "%s login: ", device);
+    fflush( out);
+    rtems_shell_get_text( in, out, user, sizeof( user));
+
+    fflush( in);
+    fprintf( out, "Password: ");
+    fflush( out);
+    rtems_shell_get_text( in, NULL, passphrase, sizeof( passphrase));
+    fputc( '\n', out);
+
+    result = check( user, passphrase);
+    if (result) {
+      break;
+    }
+
+    fprintf( out, "Login incorrect\n\n");
+    sleep( 2);
+  }
+
+  if (restore_termios) {
+    /* What to do if restoring the flags fails? */
+    tcsetattr( fd_in, TCSANOW, &termios_previous);
+  }
+
+  return result;
+}