Add support for "Defaults" line in sudoers to make configuration variables

changable at runtime (and on a global, per-host and per-user basis).
Both the names and the internal representation are still subject to change.
It was necessary to make sudo_user.runas but a char ** instead of a
char * since this value can be changed by a Defaults line.  There is a
similar (but more complicated) issue with sudo_user.prompt but it
is handled differently at the moment.

Add a "-L" flag to list the name of options with their descriptions.  This
may only be temporary.

Move some prototypes to parse.h

Be much less restrictive on what is allowed for a username.

defaults.h

@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 1999 Todd C. Miller <Todd.Miller@courtesan.com>
+ * All rights reserved.
+ *
+ * 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.
+ *
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * 4. Products derived from this software may not be called "Sudo" nor
+ *    may "Sudo" appear in their names without specific prior written
+ *    permission from the author.
+ *
+ * THIS SOFTWARE IS PROVIDED ``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 AUTHOR 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.
+ *
+ * $Sudo$
+ */
+
+#ifndef _SUDO_DEFAULTS_H
+#define _SUDO_DEFAULTS_H
+
+/*
+ * Four types of defaults: strings, integers, booleans, and flags.
+ * Note that flags have their value in the index field.
+ * Also, T_INT or T_STR may be ANDed with T_BOOL to indicate that
+ * a value is not required.
+ */
+#define T_INT	0x01
+#define T_STR	0x02
+#define T_FLAG	0x08
+#define T_MASK	0x0F
+#define T_BOOL	0x10
+
+/*
+ * Flag values
+ */
+#define FL_LONG_OTP_PROMPT	0x00001
+#define FL_IGNORE_DOT		0x00002
+#define FL_MAIL_ALWAYS		0x00004
+#define FL_MAIL_IF_NOUSER	0x00008
+#define FL_MAIL_IF_NOHOST	0x00010
+#define FL_MAIL_IF_NOPERMS	0x00020
+#define FL_TTY_TICKETS		0x00040
+#define FL_LECTURE		0x00080
+#define FL_AUTHENTICATE		0x00100
+#define FL_ROOT_SUDO		0x00200
+#define FL_LOG_HOST		0x00400
+#define FL_SHELL_NOARGS		0x00800
+#define FL_SET_HOME		0x01000
+#define FL_PATH_INFO		0x02000
+#define FL_FQDN			0x04000
+#define FL_INSULTS		0x08000
+#define FL_MAX			0xFFFFF
+
+/*
+ * Indexes into sudo_inttable
+ */
+#define	I_FLAGS		0	/* various flags, as listed above */
+#define	I_LOGFAC	1	/* syslog facility */
+#define	I_GOODPRI	2	/* syslog priority for successful auth */
+#define	I_BADPRI	3	/* syslog priority for unsuccessful auth */
+#define	I_LOGLEN	4	/* wrap log file line after N chars */
+#define	I_TS_TIMEOUT	5	/* timestamp stale after N minutes */
+#define	I_PW_TIMEOUT	6	/* exit if pass not entered in N minutes */
+#define	I_PW_TRIES	7	/* exit after N bad password tries */
+#define	I_UMASK		8	/* umask to use or 0777 to use user's */
+
+/*
+ * Indexes into sudo_strtable
+ */
+#define	I_LOGFILE	0	/* path to logfile (or NULL for none) */
+#define	I_MAILERPATH	1	/* path to sendmail or other mailer */
+#define	I_MAILERARGS	2	/* flags to pass to the mailer */
+#define	I_ALERTMAIL	3	/* who to send bitch mail to */
+#define	I_MAILSUB	4	/* subject line of mail msg */
+#define	I_BADPASS_MSG	5	/* what to say when passwd is wrong */
+#define	I_TIMESTAMPDIR	6	/* path to timestamp dir */
+#define	I_EXEMPT_GRP	7	/* no password or PATH override for these */
+#define	I_PASSPROMPT	8	/* password prompt */
+#define	I_RUNAS_DEF	9	/* default user to run commands as */
+#define	I_SECURE_PATH	10	/* set $PATH to this if not NULL */
+
+#define SUDO_INTTABLE_LAST	9
+#define SUDO_STRTABLE_LAST	11
+
+#define sudo_flag_set(_f)	(sudo_inttable[I_FLAGS] & (_f))
+
+extern unsigned int sudo_inttable[SUDO_INTTABLE_LAST];
+extern char *sudo_strtable[SUDO_STRTABLE_LAST];
+
+/*
+ * Prototypes
+ */
+void dump_default	__P((void));
+int set_default		__P((char *, char *, int));
+void init_defaults	__P((void));
+void list_options	__P((void));
+
+#endif /* _SUDO_DEFAULTS_H */