Adding upstream version 3.4.23.upstream/3.4.23upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 726 insertions, 0 deletions

diff --git a/src/global/tok822_parse.c b/src/global/tok822_parse.c
new file mode 100644
index 0000000..4376802
--- /dev/null
+++ b/src/global/tok822_parse.c
@@ -0,0 +1,726 @@
+/*++
+/* NAME
+/*	tok822_parse 3
+/* SUMMARY
+/*	RFC 822 address parser
+/* SYNOPSIS
+/*	#include <tok822.h>
+/*
+/*	TOK822 *tok822_scan_limit(str, tailp, limit)
+/*	const char *str;
+/*	TOK822	**tailp;
+/*	int	limit;
+/*
+/*	TOK822 *tok822_scan(str, tailp)
+/*	const char *str;
+/*	TOK822	**tailp;
+/*
+/*	TOK822	*tok822_parse_limit(str, limit)
+/*	const char *str;
+/*	int	limit;
+/*
+/*	TOK822	*tok822_parse(str)
+/*	const char *str;
+/*
+/*	TOK822	*tok822_scan_addr(str)
+/*	const char *str;
+/*
+/*	VSTRING	*tok822_externalize(buffer, tree, flags)
+/*	VSTRING	*buffer;
+/*	TOK822	*tree;
+/*	int	flags;
+/*
+/*	VSTRING	*tok822_internalize(buffer, tree, flags)
+/*	VSTRING	*buffer;
+/*	TOK822	*tree;
+/*	int	flags;
+/* DESCRIPTION
+/*	This module converts address lists between string form and parse
+/*	tree formats. The string form can appear in two different ways:
+/*	external (or quoted) form, as used in message headers, and internal
+/*	(unquoted) form, as used internally by the mail software.
+/*	Although RFC 822 expects 7-bit data, these routines pay no
+/*	special attention to 8-bit characters.
+/*
+/*	tok822_scan() converts the external-form string in \fIstr\fR
+/*	to a linear token list. The \fItailp\fR argument is a null pointer
+/*	or receives the pointer value of the last result list element.
+/*
+/*	tok822_scan_limit() implements tok822_scan(), which is a macro.
+/*	The \fIlimit\fR argument is either zero or an upper bound on the
+/*	number of tokens produced.
+/*
+/*	tok822_parse() converts the external-form address list in
+/*	\fIstr\fR to the corresponding token tree. The parser is permissive
+/*	and will not throw away information that it does not understand.
+/*	The parser adds missing commas between addresses.
+/*
+/*	tok822_parse_limit() implements tok822_parse(), which is a macro.
+/*	The \fIlimit\fR argument is either zero or an upper bound on the
+/*	number of tokens produced.
+/*
+/*	tok822_scan_addr() converts the external-form string in
+/*	\fIstr\fR to an address token tree. This is just string to
+/*	token list conversion; no parsing is done. This routine is
+/*	suitable for data that should contain just one address and no
+/*	other information.
+/*
+/*	tok822_externalize() converts a token list to external form.
+/*	Where appropriate, characters and strings are quoted and white
+/*	space is inserted. The \fIflags\fR argument is the binary OR of
+/*	zero or more of the following:
+/* .IP TOK822_STR_WIPE
+/*	Initially, truncate the result to zero length.
+/* .IP TOK822_STR_TERM
+/*	Append a null terminator to the result when done.
+/* .IP TOK822_STR_LINE
+/*	Append a line break after each comma token, instead of appending
+/*	whitespace.  It is up to the caller to concatenate short lines to
+/*	produce longer ones.
+/* .IP TOK822_STR_TRNC
+/*	Truncate non-address information to 250 characters per address, to
+/*	protect Sendmail systems that are vulnerable to the problem in CERT
+/*	advisory CA-2003-07.
+/*	This flag has effect with tok822_externalize() only.
+/* .PP
+/*	The macro TOK_822_NONE expresses that none of the above features
+/*	should be activated.
+/*
+/*	The macro TOK822_STR_DEFL combines the TOK822_STR_WIPE and
+/*	TOK822_STR_TERM flags. This is useful for most token to string
+/*	conversions.
+/*
+/*	The macro TOK822_STR_HEAD combines the TOK822_STR_TERM,
+/*	TOK822_STR_LINE and TOK822_STR_TRNC flags. This is useful for
+/*	the special case of token to mail header conversion.
+/*
+/*	tok822_internalize() converts a token list to string form,
+/*	without quoting. White space is inserted where appropriate.
+/*	The \fIflags\fR argument is as with tok822_externalize().
+/* STANDARDS
+/* .ad
+/* .fi
+/*	RFC 822 (ARPA Internet Text Messages). In addition to this standard
+/*	this module implements additional operators such as % and !. These
+/*	are needed because the real world is not all RFC 822. Also, the ':'
+/*	operator is allowed to appear inside addresses, to accommodate DECnet.
+/*	In addition, 8-bit data is not given special treatment.
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <ctype.h>
+#include <string.h>
+
+/* Utility library. */
+
+#include <vstring.h>
+#include <msg.h>
+#include <stringops.h>
+
+/* Global library. */
+
+#include "lex_822.h"
+#include "quote_822_local.h"
+#include "tok822.h"
+
+ /*
+  * I suppose this is my favorite macro. Used heavily for tokenizing.
+  */
+#define COLLECT(t,s,c,cond) { \
+	while ((c = *(unsigned char *) s) != 0) { \
+	    if (c == '\\') { \
+		if ((c = *(unsigned char *)++s) == 0) \
+		    break; \
+	    } else if (!(cond)) { \
+		break; \
+	    } \
+	    VSTRING_ADDCH(t->vstr, IS_SPACE_TAB_CR_LF(c) ? ' ' : c); \
+	    s++; \
+	} \
+	VSTRING_TERMINATE(t->vstr); \
+    }
+
+#define COLLECT_SKIP_LAST(t,s,c,cond) { COLLECT(t,s,c,cond); if (*s) s++; }
+
+ /*
+  * Not quite as complex. The parser depends heavily on it.
+  */
+#define SKIP(tp, cond) { \
+	while (tp->type && (cond)) \
+	    tp = tp->prev; \
+    }
+
+#define MOVE_COMMENT_AND_CONTINUE(tp, right) { \
+	TOK822 *prev = tok822_unlink(tp); \
+	right = tok822_prepend(right, tp); \
+	tp = prev; \
+	continue; \
+    }
+
+#define SKIP_MOVE_COMMENT(tp, cond, right) { \
+	while (tp->type && (cond)) { \
+	    if (tp->type == TOK822_COMMENT) \
+		MOVE_COMMENT_AND_CONTINUE(tp, right); \
+	    tp = tp->prev; \
+	} \
+    }
+
+ /*
+  * Single-character operators. We include the % and ! operators because not
+  * all the world is RFC822. XXX Make this operator list configurable when we
+  * have a real rewriting language. Include | for aliases file parsing.
+  */
+static char tok822_opchar[] = "|%!" LEX_822_SPECIALS;
+static void tok822_quote_atom(TOK822 *);
+static const char *tok822_comment(TOK822 *, const char *);
+static TOK822 *tok822_group(int, TOK822 *, TOK822 *, int);
+static void tok822_copy_quoted(VSTRING *, char *, char *);
+static int tok822_append_space(TOK822 *);
+
+#define DO_WORD		(1<<0)		/* finding a word is ok here */
+#define DO_GROUP	(1<<1)		/* doing an address group */
+
+#define ADD_COMMA	','		/* resynchronize */
+#define NO_MISSING_COMMA 0
+
+/* tok822_internalize - token tree to string, internal form */
+
+VSTRING *tok822_internalize(VSTRING *vp, TOK822 *tree, int flags)
+{
+    TOK822 *tp;
+
+    if (flags & TOK822_STR_WIPE)
+	VSTRING_RESET(vp);
+
+    for (tp = tree; tp; tp = tp->next) {
+	switch (tp->type) {
+	case ',':
+	    VSTRING_ADDCH(vp, tp->type);
+	    if (flags & TOK822_STR_LINE) {
+		VSTRING_ADDCH(vp, '\n');
+		continue;
+	    }
+	    break;
+	case TOK822_ADDR:
+	    tok822_internalize(vp, tp->head, TOK822_STR_NONE);
+	    break;
+	case TOK822_COMMENT:
+	case TOK822_ATOM:
+	case TOK822_QSTRING:
+	    vstring_strcat(vp, vstring_str(tp->vstr));
+	    break;
+	case TOK822_DOMLIT:
+	    VSTRING_ADDCH(vp, '[');
+	    vstring_strcat(vp, vstring_str(tp->vstr));
+	    VSTRING_ADDCH(vp, ']');
+	    break;
+	case TOK822_STARTGRP:
+	    VSTRING_ADDCH(vp, ':');
+	    break;
+	default:
+	    if (tp->type >= TOK822_MINTOK)
+		msg_panic("tok822_internalize: unknown operator %d", tp->type);
+	    VSTRING_ADDCH(vp, tp->type);
+	}
+	if (tok822_append_space(tp))
+	    VSTRING_ADDCH(vp, ' ');
+    }
+    if (flags & TOK822_STR_TERM)
+	VSTRING_TERMINATE(vp);
+    return (vp);
+}
+
+/* strip_address - strip non-address text from address expression */
+
+static void strip_address(VSTRING *vp, ssize_t start, TOK822 *addr)
+{
+    VSTRING *tmp;
+
+    /*
+     * Emit plain <address>. Discard any comments or phrases.
+     */
+    VSTRING_TERMINATE(vp);
+    msg_warn("stripping too many comments from address: %.100s...",
+	     printable(vstring_str(vp) + start, '?'));
+    vstring_truncate(vp, start);
+    VSTRING_ADDCH(vp, '<');
+    if (addr) {
+	tmp = vstring_alloc(100);
+	tok822_internalize(tmp, addr, TOK822_STR_TERM);
+	quote_822_local_flags(vp, vstring_str(tmp),
+			      QUOTE_FLAG_8BITCLEAN | QUOTE_FLAG_APPEND);
+	vstring_free(tmp);
+    }
+    VSTRING_ADDCH(vp, '>');
+}
+
+/* tok822_externalize - token tree to string, external form */
+
+VSTRING *tok822_externalize(VSTRING *vp, TOK822 *tree, int flags)
+{
+    VSTRING *tmp;
+    TOK822 *tp;
+    ssize_t start;
+    TOK822 *addr;
+    ssize_t addr_len;
+
+    /*
+     * Guard against a Sendmail buffer overflow (CERT advisory CA-2003-07).
+     * The problem was that Sendmail could store too much non-address text
+     * (comments, phrases, etc.) into a static 256-byte buffer.
+     * 
+     * When the buffer fills up, fixed Sendmail versions remove comments etc.
+     * and reduce the information to just <$g>, which expands to <address>.
+     * No change is made when an address expression (text separated by
+     * commas) contains no address. This fix reportedly also protects
+     * Sendmail systems that are still vulnerable to this problem.
+     * 
+     * Postfix takes the same approach, grudgingly. To avoid unnecessary damage,
+     * Postfix removes comments etc. only when the amount of non-address text
+     * in an address expression (text separated by commas) exceeds 250 bytes.
+     * 
+     * With Sendmail, the address part of an address expression is the
+     * right-most <> instance in that expression. If an address expression
+     * contains no <>, then Postfix guarantees that it contains at most one
+     * non-comment string; that string is the address part of the address
+     * expression, so there is no ambiguity.
+     * 
+     * Finally, we note that stress testing shows that other code in Sendmail
+     * 8.12.8 bluntly truncates ``text <address>'' to 256 bytes even when
+     * this means chopping the <address> somewhere in the middle. This is a
+     * loss of control that we're not entirely comfortable with. However,
+     * unbalanced quotes and dangling backslash do not seem to influence the
+     * way that Sendmail parses headers, so this is not an urgent problem.
+     */
+#define MAX_NONADDR_LENGTH 250
+
+#define RESET_NONADDR_LENGTH { \
+	start = VSTRING_LEN(vp); \
+	addr = 0; \
+	addr_len = 0; \
+    }
+
+#define ENFORCE_NONADDR_LENGTH do { \
+	if (addr && VSTRING_LEN(vp) - addr_len > start + MAX_NONADDR_LENGTH) \
+	    strip_address(vp, start, addr->head); \
+    } while(0)
+
+    if (flags & TOK822_STR_WIPE)
+	VSTRING_RESET(vp);
+
+    if (flags & TOK822_STR_TRNC)
+	RESET_NONADDR_LENGTH;
+
+    for (tp = tree; tp; tp = tp->next) {
+	switch (tp->type) {
+	case ',':
+	    if (flags & TOK822_STR_TRNC)
+		ENFORCE_NONADDR_LENGTH;
+	    VSTRING_ADDCH(vp, tp->type);
+	    VSTRING_ADDCH(vp, (flags & TOK822_STR_LINE) ? '\n' : ' ');
+	    if (flags & TOK822_STR_TRNC)
+		RESET_NONADDR_LENGTH;
+	    continue;
+
+	    /*
+	     * XXX In order to correctly externalize an address, it is not
+	     * sufficient to quote individual atoms. There are higher-level
+	     * rules that say when an address localpart needs to be quoted.
+	     * We wing it with the quote_822_local() routine, which ignores
+	     * the issue of atoms in the domain part that would need quoting.
+	     */
+	case TOK822_ADDR:
+	    addr = tp;
+	    tmp = vstring_alloc(100);
+	    tok822_internalize(tmp, tp->head, TOK822_STR_TERM);
+	    addr_len = VSTRING_LEN(vp);
+	    quote_822_local_flags(vp, vstring_str(tmp),
+				  QUOTE_FLAG_8BITCLEAN | QUOTE_FLAG_APPEND);
+	    addr_len = VSTRING_LEN(vp) - addr_len;
+	    vstring_free(tmp);
+	    break;
+	case TOK822_ATOM:
+	case TOK822_COMMENT:
+	    vstring_strcat(vp, vstring_str(tp->vstr));
+	    break;
+	case TOK822_QSTRING:
+	    VSTRING_ADDCH(vp, '"');
+	    tok822_copy_quoted(vp, vstring_str(tp->vstr), "\"\\\r\n");
+	    VSTRING_ADDCH(vp, '"');
+	    break;
+	case TOK822_DOMLIT:
+	    VSTRING_ADDCH(vp, '[');
+	    tok822_copy_quoted(vp, vstring_str(tp->vstr), "\\\r\n");
+	    VSTRING_ADDCH(vp, ']');
+	    break;
+	case TOK822_STARTGRP:
+	    VSTRING_ADDCH(vp, ':');
+	    break;
+	case '<':
+	    if (tp->next && tp->next->type == '>') {
+		addr = tp;
+		addr_len = 0;
+	    }
+	    VSTRING_ADDCH(vp, '<');
+	    break;
+	default:
+	    if (tp->type >= TOK822_MINTOK)
+		msg_panic("tok822_externalize: unknown operator %d", tp->type);
+	    VSTRING_ADDCH(vp, tp->type);
+	}
+	if (tok822_append_space(tp))
+	    VSTRING_ADDCH(vp, ' ');
+    }
+    if (flags & TOK822_STR_TRNC)
+	ENFORCE_NONADDR_LENGTH;
+
+    if (flags & TOK822_STR_TERM)
+	VSTRING_TERMINATE(vp);
+    return (vp);
+}
+
+/* tok822_copy_quoted - copy a string while quoting */
+
+static void tok822_copy_quoted(VSTRING *vp, char *str, char *quote_set)
+{
+    int     ch;
+
+    while ((ch = *(unsigned char *) str++) != 0) {
+	if (strchr(quote_set, ch))
+	    VSTRING_ADDCH(vp, '\\');
+	VSTRING_ADDCH(vp, ch);
+    }
+}
+
+/* tok822_append_space - see if space is needed after this token */
+
+static int tok822_append_space(TOK822 *tp)
+{
+    TOK822 *next;
+
+    if (tp == 0 || (next = tp->next) == 0 || tp->owner != 0)
+	return (0);
+    if (tp->type == ',' || tp->type == TOK822_STARTGRP || next->type == '<')
+	return (1);
+
+#define NON_OPERATOR(x) \
+    (x->type == TOK822_ATOM || x->type == TOK822_QSTRING \
+     || x->type == TOK822_COMMENT || x->type == TOK822_DOMLIT \
+     || x->type == TOK822_ADDR)
+
+    return (NON_OPERATOR(tp) && NON_OPERATOR(next));
+}
+
+/* tok822_scan_limit - tokenize string */
+
+TOK822 *tok822_scan_limit(const char *str, TOK822 **tailp, int tok_count_limit)
+{
+    TOK822 *head = 0;
+    TOK822 *tail = 0;
+    TOK822 *tp;
+    int     ch;
+    int     tok_count = 0;
+
+    /*
+     * XXX 2822 new feature: Section 4.1 allows "." to appear in a phrase (to
+     * allow for forms such as: Johnny B. Goode <johhny@domain.org>. I cannot
+     * handle that at the tokenizer level - it is not context sensitive. And
+     * to fix this at the parser level requires radical changes to preserve
+     * white space as part of the token stream. Thanks a lot, people.
+     */
+    while ((ch = *(unsigned char *) str++) != 0) {
+	if (IS_SPACE_TAB_CR_LF(ch))
+	    continue;
+	if (ch == '(') {
+	    tp = tok822_alloc(TOK822_COMMENT, (char *) 0);
+	    str = tok822_comment(tp, str);
+	} else if (ch == '[') {
+	    tp = tok822_alloc(TOK822_DOMLIT, (char *) 0);
+	    COLLECT_SKIP_LAST(tp, str, ch, ch != ']');
+	} else if (ch == '"') {
+	    tp = tok822_alloc(TOK822_QSTRING, (char *) 0);
+	    COLLECT_SKIP_LAST(tp, str, ch, ch != '"');
+	} else if (ch != '\\' && strchr(tok822_opchar, ch)) {
+	    tp = tok822_alloc(ch, (char *) 0);
+	} else {
+	    tp = tok822_alloc(TOK822_ATOM, (char *) 0);
+	    str -= 1;				/* \ may be first */
+	    COLLECT(tp, str, ch, !IS_SPACE_TAB_CR_LF(ch) && !strchr(tok822_opchar, ch));
+	    tok822_quote_atom(tp);
+	}
+	if (head == 0) {
+	    head = tail = tp;
+	    while (tail->next)
+		tail = tail->next;
+	} else {
+	    tail = tok822_append(tail, tp);
+	}
+	if (tok_count_limit > 0 && ++tok_count >= tok_count_limit)
+	    break;
+    }
+    if (tailp)
+	*tailp = tail;
+    return (head);
+}
+
+/* tok822_parse_limit - translate external string to token tree */
+
+TOK822 *tok822_parse_limit(const char *str, int tok_count_limit)
+{
+    TOK822 *head;
+    TOK822 *tail;
+    TOK822 *right;
+    TOK822 *first_token;
+    TOK822 *last_token;
+    TOK822 *tp;
+    int     state;
+
+    /*
+     * First, tokenize the string, from left to right. We are not allowed to
+     * throw away any information that we do not understand. With a flat
+     * token list that contains all tokens, we can always convert back to
+     * string form.
+     */
+    if ((first_token = tok822_scan_limit(str, &last_token, tok_count_limit)) == 0)
+	return (0);
+
+    /*
+     * For convenience, sandwich the token list between two sentinel tokens.
+     */
+#define GLUE(left,rite) { left->next = rite; rite->prev = left; }
+
+    head = tok822_alloc(0, (char *) 0);
+    GLUE(head, first_token);
+    tail = tok822_alloc(0, (char *) 0);
+    GLUE(last_token, tail);
+
+    /*
+     * Next step is to transform the token list into a parse tree. This is
+     * done most conveniently from right to left. If there is something that
+     * we do not understand, just leave it alone, don't throw it away. The
+     * address information that we're looking for sits in-between the current
+     * node (tp) and the one called right. Add missing commas on the fly.
+     */
+    state = DO_WORD;
+    right = tail;
+    tp = tail->prev;
+    while (tp->type) {
+	if (tp->type == TOK822_COMMENT) {	/* move comment to the side */
+	    MOVE_COMMENT_AND_CONTINUE(tp, right);
+	} else if (tp->type == ';') {		/* rh side of named group */
+	    right = tok822_group(TOK822_ADDR, tp, right, ADD_COMMA);
+	    state = DO_GROUP | DO_WORD;
+	} else if (tp->type == ':' && (state & DO_GROUP) != 0) {
+	    tp->type = TOK822_STARTGRP;
+	    (void) tok822_group(TOK822_ADDR, tp, right, NO_MISSING_COMMA);
+	    SKIP(tp, tp->type != ',');
+	    right = tp;
+	    continue;
+	} else if (tp->type == '>') {		/* rh side of <route> */
+	    right = tok822_group(TOK822_ADDR, tp, right, ADD_COMMA);
+	    SKIP_MOVE_COMMENT(tp, tp->type != '<', right);
+	    (void) tok822_group(TOK822_ADDR, tp, right, NO_MISSING_COMMA);
+	    SKIP(tp, tp->type > 0xff || strchr(">;,:", tp->type) == 0);
+	    right = tp;
+	    state |= DO_WORD;
+	    continue;
+	} else if (tp->type == TOK822_ATOM || tp->type == TOK822_QSTRING
+		   || tp->type == TOK822_DOMLIT) {
+	    if ((state & DO_WORD) == 0)
+		right = tok822_group(TOK822_ADDR, tp, right, ADD_COMMA)->next;
+	    state &= ~DO_WORD;
+	} else if (tp->type == ',') {
+	    right = tok822_group(TOK822_ADDR, tp, right, NO_MISSING_COMMA);
+	    state |= DO_WORD;
+	} else {
+	    state |= DO_WORD;
+	}
+	tp = tp->prev;
+    }
+    (void) tok822_group(TOK822_ADDR, tp, right, NO_MISSING_COMMA);
+
+    /*
+     * Discard the sentinel tokens on the left and right extremes. Properly
+     * terminate the resulting list.
+     */
+    tp = (head->next != tail ? head->next : 0);
+    tok822_cut_before(head->next);
+    tok822_free(head);
+    tok822_cut_before(tail);
+    tok822_free(tail);
+    return (tp);
+}
+
+/* tok822_quote_atom - see if an atom needs quoting when externalized */
+
+static void tok822_quote_atom(TOK822 *tp)
+{
+    char   *cp;
+    int     ch;
+
+    /*
+     * RFC 822 expects 7-bit data. Rather than quoting every 8-bit character
+     * (and still passing it on as 8-bit data) we leave 8-bit data alone.
+     */
+    for (cp = vstring_str(tp->vstr); (ch = *(unsigned char *) cp) != 0; cp++) {
+	if ( /* !ISASCII(ch) || */ ch == ' '
+	    || ISCNTRL(ch) || strchr(tok822_opchar, ch)) {
+	    tp->type = TOK822_QSTRING;
+	    break;
+	}
+    }
+}
+
+/* tok822_comment - tokenize comment */
+
+static const char *tok822_comment(TOK822 *tp, const char *str)
+{
+    int     level = 1;
+    int     ch;
+
+    /*
+     * XXX We cheat by storing comments in their external form. Otherwise it
+     * would be a royal pain to preserve \ before (. That would require a
+     * recursive parser; the easy to implement stack-based recursion would be
+     * too expensive.
+     */
+    VSTRING_ADDCH(tp->vstr, '(');
+
+    while ((ch = *(unsigned char *) str) != 0) {
+	VSTRING_ADDCH(tp->vstr, ch);
+	str++;
+	if (ch == '(') {			/* comments can nest! */
+	    level++;
+	} else if (ch == ')') {
+	    if (--level == 0)
+		break;
+	} else if (ch == '\\') {
+	    if ((ch = *(unsigned char *) str) == 0)
+		break;
+	    VSTRING_ADDCH(tp->vstr, ch);
+	    str++;
+	}
+    }
+    VSTRING_TERMINATE(tp->vstr);
+    return (str);
+}
+
+/* tok822_group - cluster a group of tokens */
+
+static TOK822 *tok822_group(int group_type, TOK822 *left, TOK822 *right, int sync_type)
+{
+    TOK822 *group;
+    TOK822 *sync;
+    TOK822 *first;
+
+    /*
+     * Cluster the tokens between left and right under their own parse tree
+     * node. Optionally insert a resync token.
+     */
+    if (left != right && (first = left->next) != right) {
+	tok822_cut_before(right);
+	tok822_cut_before(first);
+	group = tok822_alloc(group_type, (char *) 0);
+	tok822_sub_append(group, first);
+	tok822_append(left, group);
+	tok822_append(group, right);
+	if (sync_type) {
+	    sync = tok822_alloc(sync_type, (char *) 0);
+	    tok822_append(left, sync);
+	}
+    }
+    return (left);
+}
+
+/* tok822_scan_addr - convert external address string to address token */
+
+TOK822 *tok822_scan_addr(const char *addr)
+{
+    TOK822 *tree = tok822_alloc(TOK822_ADDR, (char *) 0);
+
+    tree->head = tok822_scan(addr, &tree->tail);
+    return (tree);
+}
+
+#ifdef TEST
+
+#include <unistd.h>
+#include <vstream.h>
+#include <readlline.h>
+
+/* tok822_print - display token */
+
+static void tok822_print(TOK822 *list, int indent)
+{
+    TOK822 *tp;
+
+    for (tp = list; tp; tp = tp->next) {
+	if (tp->type < TOK822_MINTOK) {
+	    vstream_printf("%*s %s \"%c\"\n", indent, "", "OP", tp->type);
+	} else if (tp->type == TOK822_ADDR) {
+	    vstream_printf("%*s %s\n", indent, "", "address");
+	    tok822_print(tp->head, indent + 2);
+	} else if (tp->type == TOK822_STARTGRP) {
+	    vstream_printf("%*s %s\n", indent, "", "group \":\"");
+	} else {
+	    vstream_printf("%*s %s \"%s\"\n", indent, "",
+			   tp->type == TOK822_COMMENT ? "comment" :
+			   tp->type == TOK822_ATOM ? "atom" :
+			   tp->type == TOK822_QSTRING ? "quoted string" :
+			   tp->type == TOK822_DOMLIT ? "domain literal" :
+			   tp->type == TOK822_ADDR ? "address" :
+			   "unknown\n", vstring_str(tp->vstr));
+	}
+    }
+}
+
+int     main(int unused_argc, char **unused_argv)
+{
+    VSTRING *vp = vstring_alloc(100);
+    TOK822 *list;
+    VSTRING *buf = vstring_alloc(100);
+
+#define TEST_TOKEN_LIMIT 20
+
+    while (readlline(buf, VSTREAM_IN, (int *) 0)) {
+	while (VSTRING_LEN(buf) > 0 && vstring_end(buf)[-1] == '\n') {
+	    vstring_end(buf)[-1] = 0;
+	    vstring_truncate(buf, VSTRING_LEN(buf) - 1);
+	}
+	if (!isatty(vstream_fileno(VSTREAM_IN)))
+	    vstream_printf(">>>%s<<<\n\n", vstring_str(buf));
+	list = tok822_parse_limit(vstring_str(buf), TEST_TOKEN_LIMIT);
+	vstream_printf("Parse tree:\n");
+	tok822_print(list, 0);
+	vstream_printf("\n");
+
+	vstream_printf("Internalized:\n%s\n\n",
+		vstring_str(tok822_internalize(vp, list, TOK822_STR_DEFL)));
+	vstream_fflush(VSTREAM_OUT);
+	vstream_printf("Externalized, no newlines inserted:\n%s\n\n",
+		       vstring_str(tok822_externalize(vp, list,
+				       TOK822_STR_DEFL | TOK822_STR_TRNC)));
+	vstream_fflush(VSTREAM_OUT);
+	vstream_printf("Externalized, newlines inserted:\n%s\n\n",
+		       vstring_str(tok822_externalize(vp, list,
+		     TOK822_STR_DEFL | TOK822_STR_LINE | TOK822_STR_TRNC)));
+	vstream_fflush(VSTREAM_OUT);
+	tok822_free_tree(list);
+    }
+    vstring_free(vp);
+    vstring_free(buf);
+    return (0);
+}
+
+#endif