usr.bin/mail/head.c

   1 /*
   2  * Copyright (c) 1980, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#)head.c   8.2 (Berkeley) 4/20/95
  34  * $FreeBSD: src/usr.bin/mail/head.c,v 1.1.1.1.14.5 2003/06/17 04:25:07 mikeh Exp $
  35  * $DragonFly: src/usr.bin/mail/head.c,v 1.5 2004/09/08 03:01:11 joerg Exp $
  36  */
  37
  38 #include "rcv.h"
  39 #include "extern.h"
  40
  41 /*
  42  * Mail -- a mail program
  43  *
  44  * Routines for processing and detecting headlines.
  45  */
  46
  47 /*
  48  * See if the passed line buffer is a mail header.
  49  * Return true if yes.  Note the extreme pains to
  50  * accomodate all funny formats.
  51  */
  52 int
  53 ishead(char *linebuf)
  54 {
  55         struct headline hl;
  56         char parbuf[BUFSIZ];
  57
  58         if (strncmp(linebuf, "From ", 5) != 0)
  59                 return (0);
  60         parse(linebuf, &hl, parbuf);
  61         if (hl.l_date == NULL) {
  62                 fail(linebuf, "No date field");
  63                 return (0);
  64         }
  65         if (!isdate(hl.l_date)) {
  66                 fail(linebuf, "Date field not legal date");
  67                 return (0);
  68         }
  69         /*
  70          * I guess we got it!
  71          */
  72         return (1);
  73 }
  74
  75 /*ARGSUSED*/
  76 void
  77 fail(const char *linebuf, const char *reason)
  78 {
  79         /*
  80         if (value("debug") == NULL)
  81                 return;
  82         fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason);
  83         */
  84 }
  85
  86 /*
  87  * Split a headline into its useful components.
  88  * Copy the line into dynamic string space, then set
  89  * pointers into the copied line in the passed headline
  90  * structure.  Actually, it scans.
  91  */
  92 void
  93 parse(char *line, struct headline *hl, char *pbuf)
  94 {
  95         char *cp, *sp;
  96         char word[LINESIZE];
  97
  98         hl->l_from = NULL;
  99         hl->l_tty = NULL;
 100         hl->l_date = NULL;
 101         cp = line;
 102         sp = pbuf;
 103         /*
 104          * Skip over "From" first.
 105          */
 106         cp = nextword(cp, word);
 107         /*
 108          * Check for missing return-path.
 109          */
 110         if (isdate(cp)) {
 111                 hl->l_date = copyin(cp, &sp);
 112                 return;
 113         }
 114         cp = nextword(cp, word);
 115         if (strlen(word) > 0)
 116                 hl->l_from = copyin(word, &sp);
 117         if (cp != NULL && strncmp(cp, "tty", 3) == 0) {
 118                 cp = nextword(cp, word);
 119                 hl->l_tty = copyin(word, &sp);
 120         }
 121         if (cp != NULL)
 122                 hl->l_date = copyin(cp, &sp);
 123 }
 124
 125 /*
 126  * Copy the string on the left into the string on the right
 127  * and bump the right (reference) string pointer by the length.
 128  * Thus, dynamically allocate space in the right string, copying
 129  * the left string into it.
 130  */
 131 char *
 132 copyin(char *src, char **space)
 133 {
 134         char *cp, *top;
 135
 136         top = cp = *space;
 137         while ((*cp++ = *src++) != '\0')
 138                 ;
 139         *space = cp;
 140         return (top);
 141 }
 142
 143 /*
 144  * Test to see if the passed string is a ctime(3) generated
 145  * date string as documented in the manual.  The template
 146  * below is used as the criterion of correctness.
 147  * Also, we check for a possible trailing time zone using
 148  * the tmztype template.
 149  *
 150  * If the mail file is created by Sys V (Solaris), there are
 151  * no seconds in the time. If the mail is created by another
 152  * program such as imapd, it might have timezone as
 153  * <-|+>nnnn (-0800 for instance) at the end.
 154  */
 155
 156 /*
 157  * 'A'  An upper case char
 158  * 'a'  A lower case char
 159  * ' '  A space
 160  * '0'  A digit
 161  * 'O'  A digit or space
 162  * 'p'  A punctuation char
 163  * 'P'  A punctuation char or space
 164  * ':'  A colon
 165  * 'N'  A new line
 166  */
 167
 168 static char *date_formats[] = {
 169         "Aaa Aaa O0 00:00:00 0000",        /* Mon Jan 01 23:59:59 2001 */
 170         "Aaa Aaa O0 00:00:00 AAA 0000",    /* Mon Jan 01 23:59:59 PST 2001 */
 171         "Aaa Aaa O0 00:00:00 0000 p0000",  /* Mon Jan 01 23:59:59 2001 -0800 */
 172         "Aaa Aaa O0 00:00 0000",           /* Mon Jan 01 23:59 2001 */
 173         "Aaa Aaa O0 00:00 AAA 0000",       /* Mon Jan 01 23:59 PST 2001 */
 174         "Aaa Aaa O0 00:00 0000 p0000",     /* Mon Jan 01 23:59 2001 -0800 */
 175         NULL
 176 };
 177
 178 int
 179 isdate(char *date)
 180 {
 181         int i;
 182
 183         for(i = 0; date_formats[i] != NULL; i++) {
 184                 if (cmatch(date, date_formats[i]))
 185                         return (1);
 186         }
 187         return (0);
 188 }
 189
 190 /*
 191  * Match the given string (cp) against the given template (tp).
 192  * Return 1 if they match, 0 if they don't
 193  */
 194 int
 195 cmatch(char *cp, char *tp)
 196 {
 197
 198         while (*cp != '\0' && *tp != '\0')
 199                 switch (*tp++) {
 200                 case 'a':
 201                         if (!islower((unsigned char)*cp++))
 202                                 return (0);
 203                         break;
 204                 case 'A':
 205                         if (!isupper((unsigned char)*cp++))
 206                                 return (0);
 207                         break;
 208                 case ' ':
 209                         if (*cp++ != ' ')
 210                                 return (0);
 211                         break;
 212                 case '0':
 213                         if (!isdigit((unsigned char)*cp++))
 214                                 return (0);
 215                         break;
 216                 case 'O':
 217                         if (*cp != ' ' && !isdigit((unsigned char)*cp))
 218                                 return (0);
 219                         cp++;
 220                         break;
 221                 case 'p':
 222                         if (!ispunct((unsigned char)*cp++))
 223                                 return (0);
 224                         break;
 225                 case 'P':
 226                         if (*cp != ' ' && !ispunct((unsigned char)*cp))
 227                                 return (0);
 228                         cp++;
 229                         break;
 230                 case ':':
 231                         if (*cp++ != ':')
 232                                 return (0);
 233                         break;
 234                 case 'N':
 235                         if (*cp++ != '\n')
 236                                 return (0);
 237                         break;
 238                 }
 239         if (*cp != '\0' || *tp != '\0')
 240                 return (0);
 241         return (1);
 242 }
 243
 244 /*
 245  * Collect a liberal (space, tab delimited) word into the word buffer
 246  * passed.  Also, return a pointer to the next word following that,
 247  * or NULL if none follow.
 248  */
 249 char *
 250 nextword(char *wp, char *wbuf)
 251 {
 252         int c;
 253
 254         if (wp == NULL) {
 255                 *wbuf = '\0';
 256                 return (NULL);
 257         }
 258         while ((c = *wp++) != '\0' && c != ' ' && c != '\t') {
 259                 *wbuf++ = c;
 260                 if (c == '"') {
 261                         while ((c = *wp++) != '\0' && c != '"')
 262                                 *wbuf++ = c;
 263                         if (c == '"')
 264                                 *wbuf++ = c;
 265                         else
 266                                 wp--;
 267                 }
 268         }
 269         *wbuf = '\0';
 270         for (; c == ' ' || c == '\t'; c = *wp++)
 271                 ;
 272         if (c == '\0')
 273                 return (NULL);
 274         return (wp - 1);
 275 }