parseaddr.c

操作系统SunOS 4.1.3版本的源码

/*
 * Copyright (c) 1983 Eric P. Allman
 * Copyright (c) 1988 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted provided
 * that: (1) source distributions retain this entire copyright notice and
 * comment, and (2) distributions including binaries display the following
 * acknowledgement:  ``This product includes software developed by the
 * University of California, Berkeley and its contributors'' in the
 * documentation or other materials provided with the distribution and in
 * all advertising materials mentioning features or use of this software.
 * Neither the name of the University nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

# include "sendmail.h"
# include "errno.h"

SCCSID(@(#)parseaddr.c 1.1 92/07/30 SMI); /* from UCB 5.8 3/13/88 */

/*
**  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.
**		copyf -- determines what shall be copied:
**			-1 -- don't copy anything.  The printname
**				(q_paddr) is just addr, and the
**				user & host are allocated internally
**				to parse.
**			0 -- copy out the parsed user & host, but
**				don't copy the printname.
**			+1 -- copy everything.
**		delim -- the character to terminate the address, passed
**			to prescan.
**
**	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	"\001()<>,;\\\"\r\n"	/* word delimiters */

ADDRESS *
parseaddr(addr, a, copyf, delim)
	char *addr;
	register ADDRESS *a;
	int copyf;
	char delim;
{
	register char **pvp;
	register struct mailer *m;
	char pvpbuf[PSBUFSIZE];
	extern char **prescan();
	extern ADDRESS *buildaddr();

	/*
	**  Initialize and prescan address.
	*/

	CurEnv->e_to = addr;
# ifdef DEBUG
	if (tTd(20, 1))
		printf("\n--parseaddr(%s)\n", addr);
# endif DEBUG

	pvp = prescan(addr, delim, pvpbuf);
	if (pvp == NULL)
		return (NULL);

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

	rewrite(pvp, 3);
	rewrite(pvp, 0);

	/*
	**  See if we resolved to a real mailer.
	*/

	if (pvp[0][0] != CANONNET)
	{
		setstat(EX_USAGE);
		usrerr("cannot resolve name");
		return (NULL);
	}

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

	a = buildaddr(pvp, a);
	if (a == NULL)
		return (NULL);
	m = a->q_mailer;

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

	if (copyf > 0)
	{
		extern char *DelimChar;
		char savec = *DelimChar;

		*DelimChar = '\0';
		a->q_paddr = newstr(addr);
		*DelimChar = savec;
	}
	else
		a->q_paddr = addr;

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

	if (copyf >= 0)
	{
		a->q_host = newstr(a->q_host);
		if (a->q_user != a->q_paddr)
			a->q_user = newstr(a->q_user);
	}

	/*
	**  Convert host name to lower case if requested.
	**	User name will be done later.
	*/

	if (!bitnset(M_HST_UPPER, m->m_flags))
		makelower(a->q_host);

	/*
	**  Compute return value.
	*/

# ifdef DEBUG
	if (tTd(20, 1))
	{
		printf("parseaddr-->");
		printaddr(a, FALSE);
	}
# endif DEBUG

	return (a);
}
/*
**  LOWERADDR -- map UPPER->lower case on addresses as requested.
**
**	Parameters:
**		a -- address to be mapped.
**
**	Returns:
**		none.
**
**	Side Effects:
**		none.
*/

loweraddr(a)
	register ADDRESS *a;
{
	register MAILER *m = a->q_mailer;

	if (m != NULL && !bitnset(M_USR_UPPER, m->m_flags))
		makelower(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).
**
**	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.
**
**	Returns:
**		A pointer to a vector of tokens.
**		NULL on error.
**
**	Side Effects:
**		sets DelimChar to point to the character matching 'delim'.
*/

/* 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 NSTATES	5	/* 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	*/
	/*OPR*/		OPR|B,	ATM|B,	QST|B,	SPC|MB,	ONE|B,
	/*ATM*/		OPR|B,	ATM,	QST|B,	SPC|MB,	ONE|B,
	/*QST*/		QST,	QST,	OPR,	QST,	QST,
	/*SPC*/		OPR,	ATM,	QST,	SPC|M,	ONE,
	/*ONE*/		OPR,	OPR,	OPR,	OPR,	OPR,
};

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

char	*DelimChar;		/* set to point to the delimiter */

char **
prescan(addr, delim, pvpbuf)
	char *addr;
	char delim;
	char pvpbuf[];
{
	register char *p;
	register char *q;
	register int c;
	char **avp;
	bool bslashmode;
	int cmntcnt;
	int anglecnt;
	char *tok;
	int state;
	int newstate;
	static char *av[MAXATOM+1];
	extern int errno;

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

	q = pvpbuf;
	bslashmode = FALSE;
	cmntcnt = 0;
	anglecnt = 0;
	avp = av;
	state = OPR;
	c = NOCHAR;
	p = addr;
# ifdef DEBUG
	if (tTd(22, 45))
	{
		printf("prescan: ");
		xputs(p);
		(void) putchar('\n');
	}
# endif DEBUG

	do
	{
		/* read a token */
		tok = q;
		for (;;)
		{
			/* store away any old lookahead character */
			if (c != NOCHAR)
			{
				/* see if there is room */
				if (q >= &pvpbuf[PSBUFSIZE - 5])
				{
					usrerr("Address too long");
					DelimChar = p;
					return (NULL);
				}

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

			/* read a new input character */
			c = *p++;
			if (c == '\0')
				break;
			c &= ~0200;

# ifdef DEBUG
			if (tTd(22, 101))
				printf("c=%c, s=%d; ", c, state);
# endif DEBUG

			/* chew up special characters */
			*q = '\0';
			/* kludge \! for naive users (violates RFC 822) */
			if ((c == '!') && bslashmode)
				bslashmode = FALSE;
				
			if (bslashmode)
			{
				c |= 0200;
				bslashmode = FALSE;
			}
			else if (c == '\\')
			{
				bslashmode = TRUE;
				c = NOCHAR;
			}
			else if (state == QST)
			{
				/* do nothing, just avoid next clauses */
			}
			else if (c == '(')
			{
				cmntcnt++;
				c = NOCHAR;
			}
			else if (c == ')')
			{
				if (cmntcnt <= 0)
				{
					usrerr("Unbalanced ')'");
					DelimChar = p;
					return (NULL);
				}
				else
					cmntcnt--;
			}
			else if (cmntcnt > 0)
				c = NOCHAR;
			else if (c == '<')
				anglecnt++;
			else if (c == '>')
			{
				if (anglecnt <= 0)
				{
					usrerr("Unbalanced '>'");
					DelimChar = p;
					return (NULL);
				}
				anglecnt--;
			}
			else if (delim == ' ' && isspace(c))
				c = ' ';

			if (c == NOCHAR)
				continue;

			/* see if this is end of input */
			if (c == delim && anglecnt <= 0 && state != QST)
				break;

			newstate = StateTab[state][toktype(c)];
# ifdef DEBUG
			if (tTd(22, 101))
				printf("ns=%02o\n", newstate);
# endif DEBUG
			state = newstate & TYPE;
			if (bitset(M, newstate))
				c = NOCHAR;
			if (bitset(B, newstate))
				break;
		}

		/* new token */
		if (tok != q)
		{
			*q++ = '\0';
# ifdef DEBUG
			if (tTd(22, 36))
			{
				printf("tok=");
				xputs(tok);
				(void) putchar('\n');
			}
# endif DEBUG
			if (avp >= &av[MAXATOM])
			{
				syserr("prescan: too many tokens");
				DelimChar = p;
				return (NULL);
			}
			*avp++ = tok;
		}
	} while (c != '\0' && (c != delim || anglecnt > 0));
	*avp = NULL;
	DelimChar = --p;
	if (cmntcnt > 0)
		usrerr("Unbalanced '('");
	else if (anglecnt > 0)
		usrerr("Unbalanced '<'");
	else if (state == QST)
		usrerr("Unbalanced '\"'");
	else if (av[0] != NULL)
		return (av);
	return (NULL);
}
/*
**  TOKTYPE -- return token type
**
**	Parameters:
**		c -- the character in question.
**
**	Returns:
**		Its type.
**
**	Side Effects:
**		none.
*/

toktype(c)
	register char c;
{
	static char buf[50];
	static bool firstime = TRUE;

	if (firstime)
	{
		firstime = FALSE;
		expand("\001o", buf, &buf[sizeof buf - 1], CurEnv);
		(void) strcat(buf, DELIMCHARS);
	}
	if (c == MATCHCLASS || c == MATCHREPL || c == MATCHNCLASS ||
		 c == MATCHYELLOW || c == MATCHNYELLOW)
		return (ONE);
	if (c == '"')
		return (QST);
	if (!isascii(c))
		return (ATM);
	if (isspace(c) || c == ')')
		return (SPC);
	if (iscntrl(c) || index(buf, c) != NULL)
		return (OPR);
	return (ATM);
}
/*
**  REWRITE -- apply rewrite rules to token vector.
**
**	This routine is an ordered production system.  Each rewrite
**	rule has a LHS (called the pattern) and a RHS (called the
**	rewrite); 'rwr' points the the current rewrite rule.
**
**	For each rewrite rule, 'avp' points the address vector we
**	are trying to match against, and 'pvp' points to the pattern.
**	If pvp points to a special match value (MATCHZANY, MATCHANY,
**	MATCHONE, MATCHCLASS, MATCHNCLASS) then the address in avp
**	matched is saved away in the match vector (pointed to by 'mvp').
**
**	When a match between avp & pvp does not match, we try to
**	back out.  If we back up over MATCHONE, MATCHCLASS, or MATCHNCLASS
**	we must also back out the match in mvp.  If we reach a
**	MATCHANY or MATCHZANY we just extend the match and start
**	over again.
**
**	When we finally match, we rewrite the address vector
**	and try over again.
**
**	Parameters:
**		pvp -- pointer to token vector.
**
**	Returns:
**		none.
**
**	Side Effects:
**		pvp is modified.
*/

struct match
{
	char	**first;	/* first token matched */
	char	**last;		/* last token matched */
};

# define MAXMATCH	9	/* max params per rewrite */

rewrite(pvp, ruleset)
	char **pvp;
	int ruleset;
{
	register char *ap;		/* address pointer */
	register char *rp;		/* rewrite pointer */
	register char **avp;		/* address vector pointer */
	register char **rvp;		/* rewrite vector pointer */
	register struct match *mlp;	/* cur ptr into mlist */
	register struct rewrite *rwr;	/* pointer to current rewrite rule */
	struct match mlist[MAXMATCH];	/* stores match on LHS */
	char *npvp[MAXATOM+1];		/* temporary space for rebuild */
	char tokbuf[MAXNAME+1];		/* for concatenated class tokens */

	if (OpMode == MD_TEST || tTd(21, 2))
	{
		printf("rewrite: ruleset %2d   input:", ruleset);
		printav(pvp);
	}
	if (pvp == NULL)
		return;

	/*
	**  Run through the list of rewrite rules, applying
	**	any that match.
	*/

	for (rwr = RewriteRules[ruleset]; rwr != NULL; )
	{
# ifdef DEBUG
		if (tTd(21, 12))
		{
			printf("-----trying rule:");
			printav(rwr->r_lhs);
		}
# endif DEBUG

		/* try to match on this rule */
		mlp = mlist;
		rvp = rwr->r_lhs;
		avp = pvp;
		while ((ap = *avp) != NULL || *rvp != NULL)
		{
			rp = *rvp;
# ifdef DEBUG
			if (tTd(21, 35))
			{
				printf("ap=");
				xputs(ap);
				printf(", rp=");
				xputs(rp);
				printf("\n");
			}
# endif DEBUG
			if (rp == NULL)
			{
				/* end-of-pattern before end-of-address */
				goto backup;
			}
			if (ap == NULL && *rp != MATCHZANY)
			{
				/* end-of-input */
				break;
			}

			switch (*rp)
			{
				register STAB *s;
				char **oldavp;

			  case MATCHNCLASS:
				/* match any single token not in a class */
				s = stab(ap, ST_CLASS, ST_FIND);
				if (s != NULL && bitnset(rp[1], s->s_class))
					goto backup;

				/* match exactly one token */
				mlp->first = avp;
				mlp->last = avp++;
				mlp++;
				break;

			  case MATCHCLASS:
				/* match any token in a class */
				/* from [e-mail] */
				oldavp = avp;
				*tokbuf = NULL;
				do
				{
					if (*avp == NULL)
					{
						avp = oldavp;
						goto backup;
					}
					(void) strcat(tokbuf, *avp++);
					s = stab(tokbuf, ST_CLASS, ST_FIND);
				} while (s == NULL ||
					!bitnset(rp[1], s->s_class));
				mlp->first = oldavp;
				mlp->last = avp-1;
				mlp++;
				break;

			  case MATCHONE:
			  case MATCHANY:
				/* match exactly one token */
				mlp->first = avp;
				mlp->last = avp++;
				mlp++;
				break;

			  case MATCHZANY:
				/* match zero or more tokens */
				mlp->first = avp;
				mlp->last = avp - 1;
				mlp++;
				break;

# ifdef YELLOW
			  case MATCHNYELLOW:
			  case MATCHYELLOW:
				/* match any token in (not in) a NIS map. */
				if (yellowmatch(ap,rp[1]))
				{
					if (*rp == MATCHNYELLOW)
						goto backup;
				}
				else if (*rp == MATCHYELLOW)
					goto backup;
				mlp->first = avp;
				mlp->last = avp++;
				mlp++;
				break;
# endif YELLOW

			  default:
				/* must have exact match */
				if (strcasecmp(rp, ap))
					goto backup;
				avp++;
				break;
			}

			/* successful match on this token */
			rvp++;
			continue;

		  backup:
			/* match failed -- back up */
			while (--rvp >= rwr->r_lhs)
			{
				rp = *rvp;
	                        if (*rp == MATCHCLASS) {
	                          register STAB *s;
	                          char **oldavp;
 
	                          /* attempt to extend binding */
	                          /* slow, concat version by [e-mail] */
 
	                          oldavp = avp;
	                          *tokbuf = NULL;
	                          for (avp = mlp[-1].first;
	                               avp <= mlp[-1].last; avp++)
	                            (void)strcat(tokbuf, *avp);
 
	                          do {
	                            if (*avp == NULL) {
	                              /* back out binding */
	                              avp = oldavp;
	                              mlp--;
	                              goto cantextend;