parseaddr.c

< linux网络编程工具>>配套源码

/*
 * Copyright (c) 1998-2000 Sendmail, Inc. and its suppliers.
 *	All rights reserved.
 * Copyright (c) 1983, 1995-1997 Eric P. Allman.  All rights reserved.
 * Copyright (c) 1988, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * By using this file, you agree to the terms and conditions set
 * forth in the LICENSE file which can be found at the top level of
 * the sendmail distribution.
 *
 */

#ifndef lint
static char id[] = "@(#)$Id: parseaddr.c,v 8.234.4.5 2000/09/25 07:53:29 gshapiro Exp $";
#endif /* ! lint */

#include <sendmail.h>

static void	allocaddr __P((ADDRESS *, int, char *));
static int	callsubr __P((char**, int, ENVELOPE *));
static char	*map_lookup __P((STAB *, char *, char **, int *, ENVELOPE *));
static ADDRESS	*buildaddr __P((char **, ADDRESS *, int, ENVELOPE *));

/*
**  PARSEADDR -- Parse an address
**
**	Parses an address and breaks it up into three parts: a
**	net to transmit the message on, the host to transmit it
**	to, and a user on that host.  These are loaded into an
**	ADDRESS header with the values squirreled away if necessary.
**	The "user" part may not be a real user; the process may
**	just reoccur on that machine.  For example, on a machine
**	with an arpanet connection, the address
**		csvax.bill@berkeley
**	will break up to a "user" of 'csvax.bill' and a host
**	of 'berkeley' -- to be transmitted over the arpanet.
**
**	Parameters:
**		addr -- the address to parse.
**		a -- a pointer to the address descriptor buffer.
**			If NULL, a header will be created.
**		flags -- describe detail for parsing.  See RF_ definitions
**			in sendmail.h.
**		delim -- the character to terminate the address, passed
**			to prescan.
**		delimptr -- if non-NULL, set to the location of the
**			delim character that was found.
**		e -- the envelope that will contain this address.
**
**	Returns:
**		A pointer to the address descriptor header (`a' if
**			`a' is non-NULL).
**		NULL on error.
**
**	Side Effects:
**		none
*/

/* following delimiters are inherent to the internal algorithms */
#define DELIMCHARS	"()<>,;\r\n"	/* default word delimiters */

ADDRESS *
parseaddr(addr, a, flags, delim, delimptr, e)
	char *addr;
	register ADDRESS *a;
	int flags;
	int delim;
	char **delimptr;
	register ENVELOPE *e;
{
	register char **pvp;
	auto char *delimptrbuf;
	bool qup;
	char pvpbuf[PSBUFSIZE];

	/*
	**  Initialize and prescan address.
	*/

	e->e_to = addr;
	if (tTd(20, 1))
		dprintf("\n--parseaddr(%s)\n", addr);

	if (delimptr == NULL)
		delimptr = &delimptrbuf;

	pvp = prescan(addr, delim, pvpbuf, sizeof pvpbuf, delimptr, NULL);
	if (pvp == NULL)
	{
		if (tTd(20, 1))
			dprintf("parseaddr-->NULL\n");
		return NULL;
	}

	if (invalidaddr(addr, delim == '\0' ? NULL : *delimptr))
	{
		if (tTd(20, 1))
			dprintf("parseaddr-->bad address\n");
		return NULL;
	}

	/*
	**  Save addr if we are going to have to.
	**
	**	We have to do this early because there is a chance that
	**	the map lookups in the rewriting rules could clobber
	**	static memory somewhere.
	*/

	if (bitset(RF_COPYPADDR, flags) && addr != NULL)
	{
		char savec = **delimptr;

		if (savec != '\0')
			**delimptr = '\0';
		e->e_to = addr = newstr(addr);
		if (savec != '\0')
			**delimptr = savec;
	}

	/*
	**  Apply rewriting rules.
	**	Ruleset 0 does basic parsing.  It must resolve.
	*/

	qup = FALSE;
	if (rewrite(pvp, 3, 0, e) == EX_TEMPFAIL)
		qup = TRUE;
	if (rewrite(pvp, 0, 0, e) == EX_TEMPFAIL)
		qup = TRUE;


	/*
	**  Build canonical address from pvp.
	*/

	a = buildaddr(pvp, a, flags, e);

	/*
	**  Make local copies of the host & user and then
	**  transport them out.
	*/

	allocaddr(a, flags, addr);
	if (QS_IS_BADADDR(a->q_state))
		return a;

	/*
	**  If there was a parsing failure, mark it for queueing.
	*/

	if (qup && OpMode != MD_INITALIAS)
	{
		char *msg = "Transient parse error -- message queued for future delivery";

		if (e->e_sendmode == SM_DEFER)
			msg = "Deferring message until queue run";
		if (tTd(20, 1))
			dprintf("parseaddr: queuing message\n");
		message(msg);
		if (e->e_message == NULL && e->e_sendmode != SM_DEFER)
			e->e_message = newstr(msg);
		a->q_state = QS_QUEUEUP;
		a->q_status = "4.4.3";
	}

	/*
	**  Compute return value.
	*/

	if (tTd(20, 1))
	{
		dprintf("parseaddr-->");
		printaddr(a, FALSE);
	}

	return a;
}
/*
**  INVALIDADDR -- check for address containing meta-characters
**
**	Parameters:
**		addr -- the address to check.
**
**	Returns:
**		TRUE -- if the address has any "wierd" characters
**		FALSE -- otherwise.
*/

bool
invalidaddr(addr, delimptr)
	register char *addr;
	char *delimptr;
{
	char savedelim = '\0';

	if (delimptr != NULL)
	{
		savedelim = *delimptr;
		if (savedelim != '\0')
			*delimptr = '\0';
	}
	if (strlen(addr) > MAXNAME - 1)
	{
		usrerr("553 5.1.1 Address too long (%d bytes max)",
		       MAXNAME - 1);
		goto failure;
	}
	for (; *addr != '\0'; addr++)
	{
		if ((*addr & 0340) == 0200)
			break;
	}
	if (*addr == '\0')
	{
		if (delimptr != NULL && savedelim != '\0')
			*delimptr = savedelim;
		return FALSE;
	}
	setstat(EX_USAGE);
	usrerr("553 5.1.1 Address contained invalid control characters");
failure:
	if (delimptr != NULL && savedelim != '\0')
		*delimptr = savedelim;
	return TRUE;
}
/*
**  ALLOCADDR -- do local allocations of address on demand.
**
**	Also lowercases the host name if requested.
**
**	Parameters:
**		a -- the address to reallocate.
**		flags -- the copy flag (see RF_ definitions in sendmail.h
**			for a description).
**		paddr -- the printname of the address.
**
**	Returns:
**		none.
**
**	Side Effects:
**		Copies portions of a into local buffers as requested.
*/

static void
allocaddr(a, flags, paddr)
	register ADDRESS *a;
	int flags;
	char *paddr;
{
	if (tTd(24, 4))
		dprintf("allocaddr(flags=%x, paddr=%s)\n", flags, paddr);

	a->q_paddr = paddr;

	if (a->q_user == NULL)
		a->q_user = newstr("");
	if (a->q_host == NULL)
		a->q_host = newstr("");

	if (bitset(RF_COPYPARSE, flags))
	{
		a->q_host = newstr(a->q_host);
		if (a->q_user != a->q_paddr)
			a->q_user = newstr(a->q_user);
	}

	if (a->q_paddr == NULL)
		a->q_paddr = newstr(a->q_user);
}
/*
**  PRESCAN -- Prescan name and make it canonical
**
**	Scans a name and turns it into a set of tokens.  This process
**	deletes blanks and comments (in parentheses) (if the token type
**	for left paren is SPC).
**
**	This routine knows about quoted strings and angle brackets.
**
**	There are certain subtleties to this routine.  The one that
**	comes to mind now is that backslashes on the ends of names
**	are silently stripped off; this is intentional.  The problem
**	is that some versions of sndmsg (like at LBL) set the kill
**	character to something other than @ when reading addresses;
**	so people type "csvax.eric\@berkeley" -- which screws up the
**	berknet mailer.
**
**	Parameters:
**		addr -- the name to chomp.
**		delim -- the delimiter for the address, normally
**			'\0' or ','; \0 is accepted in any case.
**			If '\t' then we are reading the .cf file.
**		pvpbuf -- place to put the saved text -- note that
**			the pointers are static.
**		pvpbsize -- size of pvpbuf.
**		delimptr -- if non-NULL, set to the location of the
**			terminating delimiter.
**		toktab -- if set, a token table to use for parsing.
**			If NULL, use the default table.
**
**	Returns:
**		A pointer to a vector of tokens.
**		NULL on error.
*/

/* states and character types */
#define OPR		0	/* operator */
#define ATM		1	/* atom */
#define QST		2	/* in quoted string */
#define SPC		3	/* chewing up spaces */
#define ONE		4	/* pick up one character */
#define ILL		5	/* illegal character */

#define NSTATES	6	/* number of states */
#define TYPE		017	/* mask to select state type */

/* meta bits for table */
#define M		020	/* meta character; don't pass through */
#define B		040	/* cause a break */
#define MB		M|B	/* meta-break */

static short StateTab[NSTATES][NSTATES] =
{
   /*	oldst	chtype>	OPR	ATM	QST	SPC	ONE	ILL	*/
	/*OPR*/	{	OPR|B,	ATM|B,	QST|B,	SPC|MB,	ONE|B,	ILL|MB	},
	/*ATM*/	{	OPR|B,	ATM,	QST|B,	SPC|MB,	ONE|B,	ILL|MB	},
	/*QST*/	{	QST,	QST,	OPR,	QST,	QST,	QST	},
	/*SPC*/	{	OPR,	ATM,	QST,	SPC|M,	ONE,	ILL|MB	},
	/*ONE*/	{	OPR,	OPR,	OPR,	OPR,	OPR,	ILL|MB	},
	/*ILL*/	{	OPR|B,	ATM|B,	QST|B,	SPC|MB,	ONE|B,	ILL|M	},
};

/* token type table -- it gets modified with $o characters */
static u_char	TokTypeTab[256] =
{
    /*	nul soh stx etx eot enq ack bel  bs  ht  nl  vt  np  cr  so  si   */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,SPC,SPC,SPC,SPC,SPC,ATM,ATM,
    /*	dle dc1 dc2 dc3 dc4 nak syn etb  can em  sub esc fs  gs  rs  us   */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*  sp  !   "   #   $   %   &   '    (   )   *   +   ,   -   .   /    */
	SPC,ATM,QST,ATM,ATM,ATM,ATM,ATM, SPC,SPC,ATM,ATM,ATM,ATM,ATM,ATM,
    /*	0   1   2   3   4   5   6   7    8   9   :   ;   <   =   >   ?    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*	@   A   B   C   D   E   F   G    H   I   J   K   L   M   N   O    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*  P   Q   R   S   T   U   V   W    X   Y   Z   [   \   ]   ^   _    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*	`   a   b   c   d   e   f   g    h   i   j   k   l   m   n   o    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*  p   q   r   s   t   u   v   w    x   y   z   {   |   }   ~   del  */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,

    /*	nul soh stx etx eot enq ack bel  bs  ht  nl  vt  np  cr  so  si   */
	OPR,OPR,ONE,OPR,OPR,OPR,OPR,OPR, OPR,OPR,OPR,OPR,OPR,OPR,OPR,OPR,
    /*	dle dc1 dc2 dc3 dc4 nak syn etb  can em  sub esc fs  gs  rs  us   */
	OPR,OPR,OPR,ONE,ONE,ONE,OPR,OPR, OPR,OPR,OPR,OPR,OPR,OPR,OPR,OPR,
    /*  sp  !   "   #   $   %   &   '    (   )   *   +   ,   -   .   /    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*	0   1   2   3   4   5   6   7    8   9   :   ;   <   =   >   ?    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*	@   A   B   C   D   E   F   G    H   I   J   K   L   M   N   O    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*  P   Q   R   S   T   U   V   W    X   Y   Z   [   \   ]   ^   _    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*	`   a   b   c   d   e   f   g    h   i   j   k   l   m   n   o    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*  p   q   r   s   t   u   v   w    x   y   z   {   |   }   ~   del  */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
};

/* token type table for MIME parsing */
u_char	MimeTokenTab[256] =
{
    /*	nul soh stx etx eot enq ack bel  bs  ht  nl  vt  np  cr  so  si   */
	ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL, ILL,SPC,SPC,SPC,SPC,SPC,ILL,ILL,
    /*	dle dc1 dc2 dc3 dc4 nak syn etb  can em  sub esc fs  gs  rs  us   */
	ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL, ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL,
    /*  sp  !   "   #   $   %   &   '    (   )   *   +   ,   -   .   /    */
	SPC,ATM,QST,ATM,ATM,ATM,ATM,ATM, SPC,SPC,ATM,ATM,OPR,ATM,ATM,OPR,
    /*	0   1   2   3   4   5   6   7    8   9   :   ;   <   =   >   ?    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,OPR,OPR,OPR,OPR,OPR,OPR,
    /*	@   A   B   C   D   E   F   G    H   I   J   K   L   M   N   O    */
	OPR,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*  P   Q   R   S   T   U   V   W    X   Y   Z   [   \   ]   ^   _    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,OPR,OPR,OPR,ATM,ATM,
    /*	`   a   b   c   d   e   f   g    h   i   j   k   l   m   n   o    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*  p   q   r   s   t   u   v   w    x   y   z   {   |   }   ~   del  */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,

    /*	nul soh stx etx eot enq ack bel  bs  ht  nl  vt  np  cr  so  si   */
	ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL, ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL,
    /*	dle dc1 dc2 dc3 dc4 nak syn etb  can em  sub esc fs  gs  rs  us   */
	ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL, ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL,
    /*  sp  !   "   #   $   %   &   '    (   )   *   +   ,   -   .   /    */
	ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL, ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL,
    /*	0   1   2   3   4   5   6   7    8   9   :   ;   <   =   >   ?    */
	ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL, ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL,
    /*	@   A   B   C   D   E   F   G    H   I   J   K   L   M   N   O    */
	ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL, ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL,
    /*  P   Q   R   S   T   U   V   W    X   Y   Z   [   \   ]   ^   _    */
	ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL, ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL,
    /*	`   a   b   c   d   e   f   g    h   i   j   k   l   m   n   o    */
	ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL, ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL,
    /*  p   q   r   s   t   u   v   w    x   y   z   {   |   }   ~   del  */
	ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL, ILL,ILL,ILL,ILL,ILL,ILL,ILL,ILL,
};

/* token type table: don't strip comments */
u_char	TokTypeNoC[256] =
{
    /*	nul soh stx etx eot enq ack bel  bs  ht  nl  vt  np  cr  so  si   */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,SPC,SPC,SPC,SPC,SPC,ATM,ATM,
    /*	dle dc1 dc2 dc3 dc4 nak syn etb  can em  sub esc fs  gs  rs  us   */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*  sp  !   "   #   $   %   &   '    (   )   *   +   ,   -   .   /    */
	SPC,ATM,QST,ATM,ATM,ATM,ATM,ATM, OPR,OPR,ATM,ATM,ATM,ATM,ATM,ATM,
    /*	0   1   2   3   4   5   6   7    8   9   :   ;   <   =   >   ?    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*	@   A   B   C   D   E   F   G    H   I   J   K   L   M   N   O    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*  P   Q   R   S   T   U   V   W    X   Y   Z   [   \   ]   ^   _    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*	`   a   b   c   d   e   f   g    h   i   j   k   l   m   n   o    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*  p   q   r   s   t   u   v   w    x   y   z   {   |   }   ~   del  */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,

    /*	nul soh stx etx eot enq ack bel  bs  ht  nl  vt  np  cr  so  si   */
	OPR,OPR,ONE,OPR,OPR,OPR,OPR,OPR, OPR,OPR,OPR,OPR,OPR,OPR,OPR,OPR,
    /*	dle dc1 dc2 dc3 dc4 nak syn etb  can em  sub esc fs  gs  rs  us   */
	OPR,OPR,OPR,ONE,ONE,ONE,OPR,OPR, OPR,OPR,OPR,OPR,OPR,OPR,OPR,OPR,
    /*  sp  !   "   #   $   %   &   '    (   )   *   +   ,   -   .   /    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*	0   1   2   3   4   5   6   7    8   9   :   ;   <   =   >   ?    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*	@   A   B   C   D   E   F   G    H   I   J   K   L   M   N   O    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*  P   Q   R   S   T   U   V   W    X   Y   Z   [   \   ]   ^   _    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*	`   a   b   c   d   e   f   g    h   i   j   k   l   m   n   o    */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
    /*  p   q   r   s   t   u   v   w    x   y   z   {   |   }   ~   del  */
	ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM, ATM,ATM,ATM,ATM,ATM,ATM,ATM,ATM,
};


#define NOCHAR		-1	/* signal nothing in lookahead token */

char **
prescan(addr, delim, pvpbuf, pvpbsize, delimptr, toktab)
	char *addr;
	int delim;
	char pvpbuf[];
	int pvpbsize;
	char **delimptr;
	u_char *toktab;
{
	register char *p;
	register char *q;
	register int c;
	char **avp;
	bool bslashmode;
	bool route_syntax;
	int cmntcnt;
	int anglecnt;
	char *tok;
	int state;
	int newstate;
	char *saveto = CurEnv->e_to;
	static char *av[MAXATOM + 1];
	static char firsttime = TRUE;
	extern int errno;

	if (firsttime)
	{
		/* initialize the token type table */
		char obuf[50];

		firsttime = FALSE;
		if (OperatorChars == NULL)
		{
			if (ConfigLevel < 7)
				OperatorChars = macvalue('o', CurEnv);
			if (OperatorChars == NULL)
				OperatorChars = ".:@[]";
		}
		expand(OperatorChars, obuf, sizeof obuf - sizeof DELIMCHARS,
		       CurEnv);
		(void) strlcat(obuf, DELIMCHARS, sizeof obuf);
		for (p = obuf; *p != '\0'; p++)
		{
			if (TokTypeTab[*p & 0xff] == ATM)
				TokTypeTab[*p & 0xff] = OPR;
			if (TokTypeNoC[*p & 0xff] == ATM)
				TokTypeNoC[*p & 0xff] = OPR;
		}
	}
	if (toktab == NULL)
		toktab = TokTypeTab;

	/* make sure error messages don't have garbage on them */
	errno = 0;

	q = pvpbuf;
	bslashmode = FALSE;
	route_syntax = FALSE;
	cmntcnt = 0;
	anglecnt = 0;
	avp = av;
	state = ATM;
	c = NOCHAR;
	p = addr;
	CurEnv->e_to = p;
	if (tTd(22, 11))
	{
		dprintf("prescan: ");
		xputs(p);
		dprintf("\n");
	}

	do
	{
		/* read a token */
		tok = q;
		for (;;)
		{
			/* store away any old lookahead character */
			if (c != NOCHAR && !bslashmode)
			{
				/* see if there is room */
				if (q >= &pvpbuf[pvpbsize - 5])
				{
					usrerr("553 5.1.1 Address too long");
					if (strlen(addr) > (SIZE_T) MAXNAME)
						addr[MAXNAME] = '\0';
	returnnull:
					if (delimptr != NULL)
						*delimptr = p;
					CurEnv->e_to = saveto;
					return NULL;
				}

				/* squirrel it away */
				*q++ = c;
			}

			/* read a new input character */
			c = *p++;
			if (c == '\0')
			{
				/* diagnose and patch up bad syntax */
				if (state == QST)