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