[unix-history] / usr / src / usr.sbin / sendmail / src / conf.c

# include <stdio.h>
# include <pwd.h>
# include "dlvrmail.h"

/*
**  CONF.C -- Delivermail Configuration Tables.
**
**	Defines the configuration of this installation.
**
**	Compilation Flags:
**		HASARPA -- set if this machine has a connection to
**			the Arpanet.
**		HASUUCP -- set if this machine has a connection to
**			the UUCP network.
**		NETV6MAIL -- set if you want to use "v6mail" that
**			comes with the Berkeley network.  Normally
**			/bin/mail will work fine, but around Berkeley
**			we use v6mail because it is a "fixed target".
**		V6 -- running on a version 6 system.  This determines
**			whether to define certain routines between
**			the two systems.  If you are running a funny
**			system, e.g., V6 with long tty names, this
**			should be checked carefully.
**
**	Configuration Variables:
**		ArpaHost -- the name of the host through which arpanet
**			mail will be sent.
**		MyLocName -- the name of the host on a local network.
**			This is used to disambiguate the contents of
**			ArpaHost among many hosts who may be sharing
**			a gateway.
**		Mailer -- a table of mailers known to the system.
**			The fields are:
**			- the pathname of the mailer.
**			- a list of flags describing the properties
**			  of this mailer:
**			   M_FOPT -- if set, the mailer has a picky "-f"
**				option.  In this mode, the mailer will
**				only accept the "-f" option if the
**				sender is actually "root", "network",
**				and possibly (but not necessarily) if
**				the -f argument matches the real sender.
**				The effect is that if the "-f" option
**				is given to delivermail then it will be
**				passed through (as arguments 1 & 2) to
**				the mailer.
**			   M_ROPT -- identical to M_FOPT, except uses
**				-r instead.
**			   M_QUIET -- if set, don't print a message if
**				the mailer returns bad status.
**			   M_RESTR -- if set, this mailer is restricted
**				to use by "daemon"; otherwise, we do a
**				setuid(getuid()) before calling the
**				mailer.
**			   M_HDR -- if set, the mailer wants us to
**				insert a UNIX "From" line before
**				outputing.
**			   M_NOHOST -- if set, this mailer doesn't care
**				about the host part (e.g., the local
**				mailer).
**			   M_STRIPQ -- if set, strip quote (`"')
**				characters out of parameters as you
**				transliterate them into the argument
**				vector.  For example, the local mailer
**				is called directly, so these should be
**				stripped, but the program-mailer (i.e.,
**				csh) should leave them in.
**			- an exit status to use as the code for the
**			  error message print if the mailer returns
**			  something we don't understand.
**			- A list of names that are to be considered
**			  "local" (and hence are stripped off) for
**			  this mailer.
**			- An argument vector to be passed to the
**			  mailer with the following substitutions:
**			   $f - the from person name.
**			   $u - the target user name.
**			   $h - the target user host.
**			   $c - the hop count.
**			>>>>>>>>>> Entry zero must be for the local
**			>> NOTE >> mailer and entry one must be for
**			>>>>>>>>>> the shell.
**		ParseTab -- a table driving the parsing process.  Each
**			entry contains:
**			- a character that will trigger this entry.
**			- an index into the Mailer table.
**			- a word of flags, described in dlvrmail.h.
**			- an argument.  If we have P_MAP, it is the
**			  character to turn the trigger character into.
**			  If we have P_MOVE, it is the site to send it
**			  to, using the mailer specified above.
*/


static char SccsId[] = "@(#)conf.c	1.8	%G%";


char	*ArpaHost = "Berkeley";	/* host name of gateway on Arpanet */
bool	UseMsgId = FALSE;	/* don't put message id's in anywhere */

# include <whoami.h>		/* definitions of machine id's at berkeley */

# ifdef ING70
static char	*BerkLocal[] = { "i", "ingres", "ing70", NULL };
# define ArpaLocal	NULL
char		*MyLocName = "Ing70";
# define HASARPA
# define V6
# endif ING70

# ifdef INGVAX
/* untested */
static char	*BerkLocal[] = { "j", "ingvax", NULL };
char		*MyLocName = "IngVax";
# endif INGVAX

# ifdef CSVAX
/* untested */
static char	*BerkLocal[] = { "v", "csvax", "vax", NULL };
static char	*UucpLocal[] = { "ucbvax", "ernie", NULL };
char		*MyLocName = "CSVAX";
# define HASUUCP
# define NETV6MAIL
# endif CSVAX

# ifdef CORY
/* untested */
static char	*BerkLocal[] = { "y", "cory", NULL };
char		*MyLocName = "Cory";
# endif CORY

# ifdef IMAGE
/* untested */
static char	*BerkLocal[] = { "m", "image", NULL };
char		*MyLocName = "Image";
# define V6
# endif IMAGE

# ifdef ESVAX
/* untested */
static char	*BerkLocal[] = { "o", "esvax", NULL };
char		*MyLocName = "ESVAX";
# endif ESVAX

# ifdef EECS40
/* untested */
static char	*BerkLocal[] = { "z", "eecs40", NULL };
char		*MyLocName = "EECS40";
# define V6
# endif EECS40


# ifndef HASARPA
# define ArpaLocal	NULL
# endif HASARPA

# ifndef HASUUCP
# define UucpLocal	NULL
# endif HASUUCP


struct mailer Mailer[] =
{
	/* local mail -- must be #0 */
	{
# ifdef NETV6MAIL
		"/usr/net/bin/v6mail",
# else
		"/bin/mail",
# endif
		M_ROPT|M_NOHOST|M_STRIPQ,	EX_NOUSER,	NULL,
		{ "...local%mail", "-d", "$u", NULL }
	},
	/* pipes through programs -- must be #1 */
	{
		"/bin/csh",
		M_HDR|M_NOHOST,			EX_UNAVAIL,	NULL,
		{ "...prog%mail", "-fc", "$u", NULL }
	},
	/* local berkeley mail */
	{
		"/usr/net/bin/sendberkmail",
		M_FOPT|M_HDR|M_STRIPQ,		EX_UNAVAIL,	BerkLocal,
		{ "...berk%mail", "-m", "$h", "-t", "$u", "-h", "$c", NULL }
	},
	/* arpanet mail */
	{
		"/usr/lib/mailers/arpa",
		M_STRIPQ,			0,		ArpaLocal,
		{ "...arpa%mail", "$f", "$h", "$u", NULL }
	},
	/* uucp mail (cheat & use Bell's v7 mail) */
	{
		"/bin/mail",
		M_ROPT|M_STRIPQ,		EX_NOUSER,	UucpLocal,
# ifdef DUMBMAIL
		{ "...uucp%mail", "$h!$u", NULL }
# else
		{ "...uucp%mail", "-d", "$h!$u", NULL }
# endif DUMBMAIL
	},
};

# define M_LOCAL	0
# define M_BERK		2
# define M_ARPA		3
# define M_UUCP		4


struct parsetab ParseTab[] =
{
	':',	M_BERK,		P_ONE,				NULL,
# ifdef HASARPA
	'@',	M_ARPA,		P_HLAST|P_USR_UPPER,		NULL,
# else
	'@',	M_BERK,		P_HLAST|P_USR_UPPER|P_MOVE,	"ing70",
# endif HASARPA
	'^',	-1,		P_MAP,				"!",
# ifdef HASUUCP
	'!',	M_UUCP,		0,				NULL,
# else
	'!',	M_BERK,		P_MOVE,				"csvax",
# endif HASUUCP
	'.',	-1,		P_MAP|P_ONE,			":",
	'\0',	M_LOCAL,	P_MOVE,				"",
};
\f/*
**  GETNAME -- Get the current users login name.
**
**	This is in config.c because it is somewhat machine dependent.
**	Examine it carefully for your installation.
**
**	Algorithm:
**		See if the person is logged in.  If so, return
**			the name s/he is logged in as.
**		Look up the user id in /etc/passwd.  If found,
**			return that name.
**		Return NULL.
**
**	Parameters:
**		none
**
**	Returns:
**		The login name of this user.
**		NULL if this person is noone.
**
**	Side Effects:
**		none
**
**	Called By:
**		main
*/

char *
getname()
{
	register char *p;
	register struct passwd *w;
	extern char *getlogin();
	extern struct passwd *getpwuid();
	static char namebuf[9];

	p = getlogin();
	if (p != NULL && p[0] != '\0')
		return (p);
# ifdef V6
	w = getpwuid(getuid() & 0377);
# else
	w = getpwuid(getuid());
# endif V6
	if (w != NULL)
	{
		strcpy(namebuf, w->pw_name);
		return (namebuf);
	}
	return (NULL);
}
\f
# ifdef V6
/*
**  TTYPATH -- Get the path of the user's tty -- Version 6 version.
**
**	Returns the pathname of the user's tty.  Returns NULL if
**	the user is not logged in or if s/he has write permission
**	denied.
**
**	Parameters:
**		none
**
**	Returns:
**		pathname of the user's tty.
**		NULL if not logged in or write permission denied.
**
**	Side Effects:
**		none.
**
**	WARNING:
**		Return value is in a local buffer.
**
**	Called By:
**		savemail
*/

# include <sys/types.h>
# include <sys/stat.h>

char *
ttypath()
{
	struct stat stbuf;
	register int i;
	static char pathn[] = "/dev/ttyx";
	extern int errno;

	/* compute the pathname of the controlling tty */
	if ((i = ttyn(2)) == 'x' && (i = ttyn(1)) == 'x' && (i = ttyn(0)) == 'x')
	{
		errno = 0;
		return (NULL);
	}
	pathn[8] = i;

	/* see if we have write permission */
	if (stat(pathn, &stbuf) < 0 || !flagset(02, stbuf.st_mode))
	{
		errno = 0;
		return (NULL);
	}

	/* see if the user is logged in */
	if (getlogin() == NULL)
		return (NULL);

	/* looks good */
	return (pathn);
}
\f/*
**  FDOPEN -- Open a stdio file given an open file descriptor.
**
**	This is included here because it is standard in v7, but we
**	need it in v6.
**
**	Algorithm:
**		Open /dev/null to create a descriptor.
**		Close that descriptor.
**		Copy the existing fd into the descriptor.
**
**	Parameters:
**		fd -- the open file descriptor.
**		type -- "r", "w", or whatever.
**
**	Returns:
**		The file descriptor it creates.
**
**	Side Effects:
**		none
**
**	Called By:
**		deliver
**
**	Notes:
**		The mode of fd must match "type".
*/

FILE *
fdopen(fd, type)
	int fd;
	char *type;
{
	register FILE *f;

	f = fopen("/dev/null", type);
	close(fileno(f));
	fileno(f) = fd;
	return (f);
}
\f/*
**  INDEX -- Return pointer to character in string
**
**	For V7 compatibility.
**
**	Parameters:
**		s -- a string to scan.
**		c -- a character to look for.
**
**	Returns:
**		If c is in s, returns the address of the first
**			instance of c in s.
**		NULL if c is not in s.
**
**	Side Effects:
**		none.
*/

index(s, c)
	register char *s;
	register char c;
{
	while (*s != '\0')
	{
		if (*s++ == c)
			return (--s);
	}
	return (NULL);
}
# endif V6
\f
# ifndef V6
/*
**  TTYPATH -- Get the path of the user's tty -- Version 7 version.
**
**	Returns the pathname of the user's tty.  Returns NULL if
**	the user is not logged in or if s/he has write permission
**	denied.
**
**	Parameters:
**		none
**
**	Returns:
**		pathname of the user's tty.
**		NULL if not logged in or write permission denied.
**
**	Side Effects:
**		none.
**
**	WARNING:
**		Return value is in a local buffer.
**
**	Called By:
**		savemail
*/

# include <sys/types.h>
# include <sys/stat.h>

char *
ttypath()
{
	struct stat stbuf;
	register char *pathn;
	extern int errno;
	extern char *ttyname();

	/* compute the pathname of the controlling tty */
	if ((pathn = ttyname(2)) == NULL && (pathn = ttyname(1)) == NULL && (pathn = ttyname(0)) == NULL)
	{
		errno = 0;
		return (NULL);
	}

	/* see if we have write permission */
	if (stat(pathn, &stbuf) < 0 || !flagset(02, stbuf.st_mode))
	{
		errno = 0;
		return (NULL);
	}

	/* see if the user is logged in */
	if (getlogin() == NULL)
		return (NULL);

	/* looks good */
	return (pathn);
}
# endif V6
Commit	Line	Data
b3cbe40f EA	1	# include <stdio.h>
	2	# include <pwd.h>
	3	# include "dlvrmail.h"
916b3375	4
b3cbe40f EA	5	/*
	6	** CONF.C -- Delivermail Configuration Tables.
	7	**
	8	** Defines the configuration of this installation.
	9	**
cb590f52 EA	10	** Compilation Flags:
	11	** HASARPA -- set if this machine has a connection to
	12	** the Arpanet.
	13	** HASUUCP -- set if this machine has a connection to
	14	** the UUCP network.
	15	** NETV6MAIL -- set if you want to use "v6mail" that
	16	** comes with the Berkeley network. Normally
	17	** /bin/mail will work fine, but around Berkeley
	18	** we use v6mail because it is a "fixed target".
	19	** V6 -- running on a version 6 system. This determines
	20	** whether to define certain routines between
	21	** the two systems. If you are running a funny
	22	** system, e.g., V6 with long tty names, this
	23	** should be checked carefully.
b3cbe40f	24	**
cb590f52 EA	25	** Configuration Variables:
	26	** ArpaHost -- the name of the host through which arpanet
	27	** mail will be sent.
	28	** MyLocName -- the name of the host on a local network.
	29	** This is used to disambiguate the contents of
	30	** ArpaHost among many hosts who may be sharing
	31	** a gateway.
	32	** Mailer -- a table of mailers known to the system.
	33	** The fields are:
	34	** - the pathname of the mailer.
	35	** - a list of flags describing the properties
	36	** of this mailer:
	37	** M_FOPT -- if set, the mailer has a picky "-f"
	38	** option. In this mode, the mailer will
	39	** only accept the "-f" option if the
	40	** sender is actually "root", "network",
	41	** and possibly (but not necessarily) if
	42	** the -f argument matches the real sender.
	43	** The effect is that if the "-f" option
	44	** is given to delivermail then it will be
	45	** passed through (as arguments 1 & 2) to
	46	** the mailer.
	47	** M_ROPT -- identical to M_FOPT, except uses
	48	** -r instead.
	49	** M_QUIET -- if set, don't print a message if
	50	** the mailer returns bad status.
	51	** M_RESTR -- if set, this mailer is restricted
	52	** to use by "daemon"; otherwise, we do a
	53	** setuid(getuid()) before calling the
	54	** mailer.
	55	** M_HDR -- if set, the mailer wants us to
	56	** insert a UNIX "From" line before
	57	** outputing.
	58	** M_NOHOST -- if set, this mailer doesn't care
	59	** about the host part (e.g., the local
	60	** mailer).
	61	** M_STRIPQ -- if set, strip quote (`"')
	62	** characters out of parameters as you
	63	** transliterate them into the argument
	64	** vector. For example, the local mailer
	65	** is called directly, so these should be
	66	** stripped, but the program-mailer (i.e.,
	67	** csh) should leave them in.
	68	** - an exit status to use as the code for the
	69	** error message print if the mailer returns
	70	** something we don't understand.
	71	** - A list of names that are to be considered
	72	** "local" (and hence are stripped off) for
	73	** this mailer.
	74	** - An argument vector to be passed to the
	75	** mailer with the following substitutions:
	76	** $f - the from person name.
	77	** $u - the target user name.
	78	** $h - the target user host.
	79	** $c - the hop count.
	80	** >>>>>>>>>> Entry zero must be for the local
	81	** >> NOTE >> mailer and entry one must be for
	82	** >>>>>>>>>> the shell.
	83	** ParseTab -- a table driving the parsing process. Each
	84	** entry contains:
	85	** - a character that will trigger this entry.
	86	** - an index into the Mailer table.
	87	** - a word of flags, described in dlvrmail.h.
	88	** - an argument. If we have P_MAP, it is the
89	** character to turn the trigger character into.
90	** If we have P_MOVE, it is the site to send it
91	** to, using the mailer specified above.
b3cbe40f EA	92	*/
	93
	94
	95
	96
cb590f52 EA	97	static char SccsId[] = "@(#)conf.c 1.8 %G%";
	98
	99
	100	char ArpaHost = "Berkeley"; / host name of gateway on Arpanet */
	101	bool UseMsgId = FALSE; /* don't put message id's in anywhere */
	102
	103	# include <whoami.h> /* definitions of machine id's at berkeley */
b3cbe40f EA	104
	105	# ifdef ING70
	106	static char *BerkLocal[] = { "i", "ingres", "ing70", NULL };
50e67097	107	# define ArpaLocal NULL
970cbdf3	108	char *MyLocName = "Ing70";
b3cbe40f EA	109	# define HASARPA
	110	# define V6
	111	# endif ING70
	112
	113	# ifdef INGVAX
	114	/* untested */
	115	static char *BerkLocal[] = { "j", "ingvax", NULL };
970cbdf3	116	char *MyLocName = "IngVax";
b3cbe40f EA	117	# endif INGVAX
	118
	119	# ifdef CSVAX
	120	/* untested */
	121	static char *BerkLocal[] = { "v", "csvax", "vax", NULL };
50e67097	122	static char *UucpLocal[] = { "ucbvax", "ernie", NULL };
970cbdf3	123	char *MyLocName = "CSVAX";
b3cbe40f EA	124	# define HASUUCP
	125	# define NETV6MAIL
	126	# endif CSVAX
	127
	128	# ifdef CORY
	129	/* untested */
	130	static char *BerkLocal[] = { "y", "cory", NULL };
970cbdf3	131	char *MyLocName = "Cory";
b3cbe40f EA	132	# endif CORY
	133
	134	# ifdef IMAGE
	135	/* untested */
	136	static char *BerkLocal[] = { "m", "image", NULL };
970cbdf3	137	char *MyLocName = "Image";
b3cbe40f EA	138	# define V6
	139	# endif IMAGE
	140
	141	# ifdef ESVAX
	142	/* untested */
	143	static char *BerkLocal[] = { "o", "esvax", NULL };
970cbdf3	144	char *MyLocName = "ESVAX";
b3cbe40f EA	145	# endif ESVAX
	146
	147	# ifdef EECS40
	148	/* untested */
	149	static char *BerkLocal[] = { "z", "eecs40", NULL };
970cbdf3	150	char *MyLocName = "EECS40";
b3cbe40f EA	151	# define V6
	152	# endif EECS40
	153
50e67097 EA	154
	155	# ifndef HASARPA
	156	# define ArpaLocal NULL
	157	# endif HASARPA
	158
	159	# ifndef HASUUCP
	160	# define UucpLocal NULL
	161	# endif HASUUCP
	162
	163
b3cbe40f EA	164	struct mailer Mailer[] =
	165	{
	166	/* local mail -- must be #0 */
	167	{
	168	# ifdef NETV6MAIL
	169	"/usr/net/bin/v6mail",
	170	# else
	171	"/bin/mail",
	172	# endif
	173	M_ROPT\|M_NOHOST\|M_STRIPQ, EX_NOUSER, NULL,
	174	{ "...local%mail", "-d", "$u", NULL }
	175	},
	176	/* pipes through programs -- must be #1 */
	177	{
	178	"/bin/csh",
	179	M_HDR\|M_NOHOST, EX_UNAVAIL, NULL,
	180	{ "...prog%mail", "-fc", "$u", NULL }
	181	},
	182	/* local berkeley mail */
	183	{
	184	"/usr/net/bin/sendberkmail",
cc7250b7	185	M_FOPT\|M_HDR\|M_STRIPQ, EX_UNAVAIL, BerkLocal,
b3cbe40f EA	186	{ "...berk%mail", "-m", "$h", "-t", "$u", "-h", "$c", NULL }
	187	},
	188	/* arpanet mail */
	189	{
	190	"/usr/lib/mailers/arpa",
50e67097	191	M_STRIPQ, 0, ArpaLocal,
b3cbe40f EA	192	{ "...arpa%mail", "$f", "$h", "$u", NULL }
	193	},
	194	/* uucp mail (cheat & use Bell's v7 mail) */
	195	{
b3cbe40f	196	"/bin/mail",
df2fb49b	197	M_ROPT\|M_STRIPQ, EX_NOUSER, UucpLocal,
b3cbe40f EA	198	# ifdef DUMBMAIL
	199	{ "...uucp%mail", "$h!$u", NULL }
	200	# else
	201	{ "...uucp%mail", "-d", "$h!$u", NULL }
	202	# endif DUMBMAIL
	203	},
	204	};
	205
	206	# define M_LOCAL 0
	207	# define M_BERK 2
	208	# define M_ARPA 3
	209	# define M_UUCP 4
	210
	211
	212
	213	struct parsetab ParseTab[] =
	214	{
	215	':', M_BERK, P_ONE, NULL,
	216	# ifdef HASARPA
	217	'@', M_ARPA, P_HLAST\|P_USR_UPPER, NULL,
	218	# else
	219	'@', M_BERK, P_HLAST\|P_USR_UPPER\|P_MOVE, "ing70",
	220	# endif HASARPA
	221	'^', -1, P_MAP, "!",
	222	# ifdef HASUUCP
	223	'!', M_UUCP, 0, NULL,
	224	# else
	225	'!', M_BERK, P_MOVE, "csvax",
	226	# endif HASUUCP
	227	'.', -1, P_MAP\|P_ONE, ":",
	228	'\0', M_LOCAL, P_MOVE, "",
	229	};
	230	\f/*
	231	** GETNAME -- Get the current users login name.
	232	**
	233	** This is in config.c because it is somewhat machine dependent.
	234	** Examine it carefully for your installation.
	235	**
	236	** Algorithm:
	237	** See if the person is logged in. If so, return
	238	** the name s/he is logged in as.
	239	** Look up the user id in /etc/passwd. If found,
	240	** return that name.
	241	** Return NULL.
	242	**
	243	** Parameters:
	244	** none
	245	**
	246	** Returns:
	247	** The login name of this user.
	248	** NULL if this person is noone.
	249	**
	250	** Side Effects:
	251	** none
	252	**
b3cbe40f EA	253	** Called By:
b3cbe40f EA	254	** main
b3cbe40f EA	255	*/
	256
	257	char *
	258	getname()
	259	{
	260	register char *p;
	261	register struct passwd *w;
	262	extern char *getlogin();
	263	extern struct passwd *getpwuid();
	264	static char namebuf[9];
	265
	266	p = getlogin();
	267	if (p != NULL && p[0] != '\0')
	268	return (p);
	269	# ifdef V6
	270	w = getpwuid(getuid() & 0377);
	271	# else
	272	w = getpwuid(getuid());
	273	# endif V6
	274	if (w != NULL)
	275	{
	276	strcpy(namebuf, w->pw_name);
	277	return (namebuf);
	278	}
	279	return (NULL);
	280	}
	281	\f
	282	# ifdef V6
	283	/*
	284	** TTYPATH -- Get the path of the user's tty -- Version 6 version.
	285	**
	286	** Returns the pathname of the user's tty. Returns NULL if
	287	** the user is not logged in or if s/he has write permission
	288	** denied.
	289	**
	290	** Parameters:
	291	** none
	292	**
	293	** Returns:
	294	** pathname of the user's tty.
	295	** NULL if not logged in or write permission denied.
	296	**
	297	** Side Effects:
	298	** none.
	299	**
	300	** WARNING:
	301	** Return value is in a local buffer.
	302	**
b3cbe40f EA	303	** Called By:
b3cbe40f EA	304	** savemail
b3cbe40f EA	305	*/
	306
	307	# include <sys/types.h>
	308	# include <sys/stat.h>
	309
	310	char *
	311	ttypath()
	312	{
	313	struct stat stbuf;
	314	register int i;
	315	static char pathn[] = "/dev/ttyx";
	316	extern int errno;
	317
	318	/* compute the pathname of the controlling tty */
	319	if ((i = ttyn(2)) == 'x' && (i = ttyn(1)) == 'x' && (i = ttyn(0)) == 'x')
	320	{
	321	errno = 0;
	322	return (NULL);
	323	}
	324	pathn[8] = i;
	325
	326	/* see if we have write permission */
	327	if (stat(pathn, &stbuf) < 0 \|\| !flagset(02, stbuf.st_mode))
	328	{
	329	errno = 0;
	330	return (NULL);
	331	}
	332
	333	/* see if the user is logged in */
	334	if (getlogin() == NULL)
	335	return (NULL);
	336
	337	/* looks good */
	338	return (pathn);
	339	}
	340	\f/*
	341	** FDOPEN -- Open a stdio file given an open file descriptor.
	342	**
	343	** This is included here because it is standard in v7, but we
	344	** need it in v6.
	345	**
	346	** Algorithm:
	347	** Open /dev/null to create a descriptor.
	348	** Close that descriptor.
	349	** Copy the existing fd into the descriptor.
	350	**
	351	** Parameters:
	352	** fd -- the open file descriptor.
	353	** type -- "r", "w", or whatever.
	354	**
	355	** Returns:
	356	** The file descriptor it creates.
	357	**
	358	** Side Effects:
	359	** none
	360	**
b3cbe40f EA	361	** Called By:
	362	** deliver
	363	**
	364	** Notes:
	365	** The mode of fd must match "type".
	366	*/
	367
	368	FILE *
	369	fdopen(fd, type)
	370	int fd;
	371	char *type;
	372	{
	373	register FILE *f;
	374
	375	f = fopen("/dev/null", type);
	376	close(fileno(f));
	377	fileno(f) = fd;
	378	return (f);
	379	}
	380	\f/*
	381	** INDEX -- Return pointer to character in string
	382	**
	383	** For V7 compatibility.
	384	**
	385	** Parameters:
	386	** s -- a string to scan.
	387	** c -- a character to look for.
	388	**
	389	** Returns:
	390	** If c is in s, returns the address of the first
	391	** instance of c in s.
	392	** NULL if c is not in s.
	393	**
	394	** Side Effects:
	395	** none.
b3cbe40f EA	396	*/
	397
	398	index(s, c)
	399	register char *s;
	400	register char c;
	401	{
	402	while (*s != '\0')
	403	{
	404	if (*s++ == c)
	405	return (--s);
	406	}
	407	return (NULL);
	408	}
	409	# endif V6
	410	\f
	411	# ifndef V6
	412	/*
	413	** TTYPATH -- Get the path of the user's tty -- Version 7 version.
	414	**
	415	** Returns the pathname of the user's tty. Returns NULL if
	416	** the user is not logged in or if s/he has write permission
	417	** denied.
	418	**
	419	** Parameters:
	420	** none
	421	**
	422	** Returns:
	423	** pathname of the user's tty.
	424	** NULL if not logged in or write permission denied.
	425	**
	426	** Side Effects:
	427	** none.
	428	**
	429	** WARNING:
	430	** Return value is in a local buffer.
	431	**
b3cbe40f EA	432	** Called By:
b3cbe40f EA	433	** savemail
b3cbe40f EA	434	*/
	435
	436	# include <sys/types.h>
	437	# include <sys/stat.h>
	438
	439	char *
	440	ttypath()
	441	{
	442	struct stat stbuf;
	443	register char *pathn;
	444	extern int errno;
	445	extern char *ttyname();
	446
	447	/* compute the pathname of the controlling tty */
	448	if ((pathn = ttyname(2)) == NULL && (pathn = ttyname(1)) == NULL && (pathn = ttyname(0)) == NULL)
	449	{
	450	errno = 0;
	451	return (NULL);
	452	}
	453
	454	/* see if we have write permission */
	455	if (stat(pathn, &stbuf) < 0 \|\| !flagset(02, stbuf.st_mode))
	456	{
	457	errno = 0;
	458	return (NULL);
	459	}
	460
	461	/* see if the user is logged in */
	462	if (getlogin() == NULL)
	463	return (NULL);
	464
	465	/* looks good */
	466	return (pathn);
	467	}
	468	# endif V6