NetBSD-5.0.2/usr.bin/mail/head.c
/* $NetBSD: head.c,v 1.21 2007/10/23 14:58:44 christos Exp $ */
/*
* Copyright (c) 1980, 1993
* The Regents of the University of California. 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. 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 BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)head.c 8.2 (Berkeley) 4/20/95";
#else
__RCSID("$NetBSD: head.c,v 1.21 2007/10/23 14:58:44 christos Exp $");
#endif
#endif /* not lint */
#include "rcv.h"
#include "extern.h"
/*
* Mail -- a mail program
*
* Routines for processing and detecting headlines.
*/
/*
* Match the given string (cp) against the given template (tp).
* Return 1 if they match, 0 if they don't
*/
static int
cmatch(const char *cp, char *tp)
{
while (*cp && *tp)
switch (*tp++) {
case 'a':
if (!islower((unsigned char)*cp++))
return 0;
break;
case 'A':
if (!isupper((unsigned char)*cp++))
return 0;
break;
case ' ':
if (*cp++ != ' ')
return 0;
break;
case '0':
if (!isdigit((unsigned char)*cp++))
return 0;
break;
case 'O':
if (*cp != ' ' && !isdigit((unsigned char)*cp))
return 0;
cp++;
break;
case ':':
if (*cp++ != ':')
return 0;
break;
case 'N':
if (*cp++ != '\n')
return 0;
break;
}
if (*cp || *tp)
return 0;
return 1;
}
/*
* Test to see if the passed string is a ctime(3) generated
* date string as documented in the manual. The template
* below is used as the criterion of correctness.
* Also, we check for a possible trailing time zone using
* the tmztype template.
*/
/*
* 'A' An upper case char
* 'a' A lower case char
* ' ' A space
* '0' A digit
* 'O' An optional digit or space
* ':' A colon
* 'N' A new line
*/
static char ctype[] = "Aaa Aaa O0 00:00:00 0000";
static char SysV_ctype[] = "Aaa Aaa O0 00:00 0000";
static char tmztype[] = "Aaa Aaa O0 00:00:00 AAA 0000";
static char SysV_tmztype[] = "Aaa Aaa O0 00:00 AAA 0000";
static int
isdate(const char date[])
{
return cmatch(date, ctype) ||
cmatch(date, tmztype) ||
cmatch(date, SysV_tmztype) || cmatch(date, SysV_ctype);
}
static void
fail(const char linebuf[], const char reason[])
{
#ifndef FMT_PROG
if (debug)
(void)fprintf(stderr, "\"%s\"\nnot a header because %s\n",
linebuf, reason);
#endif
}
/*
* Collect a liberal (space, tab delimited) word into the word buffer
* passed. Also, return a pointer to the next word following that,
* or NULL if none follow.
*/
static const char *
nextword(const char *wp, char *wbuf)
{
if (wp == NULL) {
*wbuf = 0;
return NULL;
}
while (*wp && !is_WSP(*wp)) {
*wbuf++ = *wp;
if (*wp++ == '"') {
while (*wp && *wp != '"')
*wbuf++ = *wp++;
if (*wp == '"')
*wbuf++ = *wp++;
}
}
*wbuf = '\0';
wp = skip_WSP(wp);
if (*wp == '\0')
return NULL;
return wp;
}
/*
* Copy the string on the left into the string on the right
* and bump the right (reference) string pointer by the length.
* Thus, dynamically allocate space in the right string, copying
* the left string into it.
*/
static char *
copyin(const char *src, char **space)
{
char *cp;
char *begin;
begin = cp = *space;
while ((*cp++ = *src++) != '\0')
continue;
*space = cp;
return begin;
}
/*
* Split a headline into its useful components.
* Copy the line into dynamic string space, then set
* pointers into the copied line in the passed headline
* structure. Actually, it scans.
*
* XXX - line[], pbuf[], and word[] must be LINESIZE in length or
* overflow can occur in nextword() or copyin().
*/
PUBLIC void
parse(const char line[], struct headline *hl, char pbuf[])
{
const char *cp;
char *sp;
char word[LINESIZE];
hl->l_from = NULL;
hl->l_tty = NULL;
hl->l_date = NULL;
cp = line;
sp = pbuf;
/*
* Skip over "From" first.
*/
cp = nextword(cp, word);
cp = nextword(cp, word);
if (*word)
hl->l_from = copyin(word, &sp);
if (cp != NULL && cp[0] == 't' && cp[1] == 't' && cp[2] == 'y') {
cp = nextword(cp, word);
hl->l_tty = copyin(word, &sp);
}
if (cp != NULL)
hl->l_date = copyin(cp, &sp);
}
/*
* See if the passed line buffer is a mail header.
* Return true if yes. Note the extreme pains to
* accomodate all funny formats.
*/
PUBLIC int
ishead(const char linebuf[])
{
const char *cp;
struct headline hl;
char parbuf[LINESIZE];
cp = linebuf;
if (*cp++ != 'F' || *cp++ != 'r' || *cp++ != 'o' || *cp++ != 'm' ||
*cp++ != ' ')
return 0;
parse(linebuf, &hl, parbuf);
if (hl.l_from == NULL || hl.l_date == NULL) {
fail(linebuf, "No from or date field");
return 0;
}
if (!isdate(hl.l_date)) {
fail(linebuf, "Date field not legal date");
return 0;
}
/*
* I guess we got it!
*/
return 1;
}