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
  34 #ifndef lint
  35 #if 0
  36 static char sccsid[] = "@(#)head.c      8.2 (Berkeley) 4/20/95";
  37 #endif
  38 #endif /* not lint */
  39 #include <sys/cdefs.h>
  40 __FBSDID("$FreeBSD$");
  41
  42 #include "rcv.h"
  43 #include "extern.h"
  44
  45 /*
  46  * Mail -- a mail program
  47  *
  48  * Routines for processing and detecting headlines.
  49  */
  50
  51 /*
  52  * See if the passed line buffer is a mail header.
  53  * Return true if yes.  Note the extreme pains to
  54  * accomodate all funny formats.
  55  */
  56 int
  57 ishead(linebuf)
  58         char linebuf[];
  59 {
  60         struct headline hl;
  61         char parbuf[BUFSIZ];
  62
  63         if (strncmp(linebuf, "From ", 5) != 0)
  64                 return (0);
  65         parse(linebuf, &hl, parbuf);
  66         if (hl.l_date == NULL) {
  67                 fail(linebuf, "No date field");
  68                 return (0);
  69         }
  70         if (!isdate(hl.l_date)) {
  71                 fail(linebuf, "Date field not legal date");
  72                 return (0);
  73         }
  74         /*
  75          * I guess we got it!
  76          */
  77         return (1);
  78 }
  79
  80 /*ARGSUSED*/
  81 void
  82 fail(linebuf, reason)
  83         const char *linebuf, *reason;
  84 {
  85
  86         /*
  87         if (value("debug") == NULL)
  88                 return;
  89         fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason);
  90         */
  91 }
  92
  93 /*
  94  * Split a headline into its useful components.
  95  * Copy the line into dynamic string space, then set
  96  * pointers into the copied line in the passed headline
  97  * structure.  Actually, it scans.
  98  */
  99 void
 100 parse(line, hl, pbuf)
 101         char line[], pbuf[];
 102         struct headline *hl;
 103 {
 104         char *cp, *sp;
 105         char word[LINESIZE];
 106
 107         hl->l_from = NULL;
 108         hl->l_tty = NULL;
 109         hl->l_date = NULL;
 110         cp = line;
 111         sp = pbuf;
 112         /*
 113          * Skip over "From" first.
 114          */
 115         cp = nextword(cp, word);
 116         /*
 117          * Check for missing return-path.
 118          */
 119         if (isdate(cp)) {
 120                 hl->l_date = copyin(cp, &sp);
 121                 return;
 122         }
 123         cp = nextword(cp, word);
 124         if (strlen(word) > 0)
 125                 hl->l_from = copyin(word, &sp);
 126         if (cp != NULL && strncmp(cp, "tty", 3) == 0) {
 127                 cp = nextword(cp, word);
 128                 hl->l_tty = copyin(word, &sp);
 129         }
 130         if (cp != NULL)
 131                 hl->l_date = copyin(cp, &sp);
 132 }
 133
 134 /*
 135  * Copy the string on the left into the string on the right
 136  * and bump the right (reference) string pointer by the length.
 137  * Thus, dynamically allocate space in the right string, copying
 138  * the left string into it.
 139  */
 140 char *
 141 copyin(src, space)
 142         char *src;
 143         char **space;
 144 {
 145         char *cp, *top;
 146
 147         top = cp = *space;
 148         while ((*cp++ = *src++) != '\0')
 149                 ;
 150         *space = cp;
 151         return (top);
 152 }
 153
 154 /*
 155  * Test to see if the passed string is a ctime(3) generated
 156  * date string as documented in the manual.  The template
 157  * below is used as the criterion of correctness.
 158  * Also, we check for a possible trailing time zone using
 159  * the tmztype template.
 160  *
 161  * If the mail file is created by Sys V (Solaris), there are
 162  * no seconds in the time. If the mail is created by another
 163  * program such as imapd, it might have timezone as
 164  * <-|+>nnnn (-0800 for instance) at the end.
 165  */
 166
 167 /*
 168  * 'A'  An upper case char
 169  * 'a'  A lower case char
 170  * ' '  A space
 171  * '0'  A digit
 172  * 'O'  A digit or space
 173  * 'p'  A punctuation char
 174  * 'P'  A punctuation char or space
 175  * ':'  A colon
 176  * 'N'  A new line
 177  */
 178
 179 static char *date_formats[] = {
 180         "Aaa Aaa O0 00:00:00 0000",        /* Mon Jan 01 23:59:59 2001 */
 181         "Aaa Aaa O0 00:00:00 AAA 0000",    /* Mon Jan 01 23:59:59 PST 2001 */
 182         "Aaa Aaa O0 00:00:00 0000 p0000",  /* Mon Jan 01 23:59:59 2001 -0800 */
 183         "Aaa Aaa O0 00:00 0000",           /* Mon Jan 01 23:59 2001 */
 184         "Aaa Aaa O0 00:00 AAA 0000",       /* Mon Jan 01 23:59 PST 2001 */
 185         "Aaa Aaa O0 00:00 0000 p0000",     /* Mon Jan 01 23:59 2001 -0800 */
 186         NULL
 187 };
 188
 189 int
 190 isdate(date)
 191         char date[];
 192 {
 193         int i;
 194
 195         for(i = 0; date_formats[i] != NULL; i++) {
 196                 if (cmatch(date, date_formats[i]))
 197                         return (1);
 198         }
 199         return (0);
 200 }
 201
 202 /*
 203  * Match the given string (cp) against the given template (tp).
 204  * Return 1 if they match, 0 if they don't
 205  */
 206 int
 207 cmatch(cp, tp)
 208         char *cp, *tp;
 209 {
 210
 211         while (*cp != '\0' && *tp != '\0')
 212                 switch (*tp++) {
 213                 case 'a':
 214                         if (!islower((unsigned char)*cp++))
 215                                 return (0);
 216                         break;
 217                 case 'A':
 218                         if (!isupper((unsigned char)*cp++))
 219                                 return (0);
 220                         break;
 221                 case ' ':
 222                         if (*cp++ != ' ')
 223                                 return (0);
 224                         break;
 225                 case '0':
 226                         if (!isdigit((unsigned char)*cp++))
 227                                 return (0);
 228                         break;
 229                 case 'O':
 230                         if (*cp != ' ' && !isdigit((unsigned char)*cp))
 231                                 return (0);
 232                         cp++;
 233                         break;
 234                 case 'p':
 235                         if (!ispunct((unsigned char)*cp++))
 236                                 return (0);
 237                         break;
 238                 case 'P':
 239                         if (*cp != ' ' && !ispunct((unsigned char)*cp))
 240                                 return (0);
 241                         cp++;
 242                         break;
 243                 case ':':
 244                         if (*cp++ != ':')
 245                                 return (0);
 246                         break;
 247                 case 'N':
 248                         if (*cp++ != '\n')
 249                                 return (0);
 250                         break;
 251                 }
 252         if (*cp != '\0' || *tp != '\0')
 253                 return (0);
 254         return (1);
 255 }
 256
 257 /*
 258  * Collect a liberal (space, tab delimited) word into the word buffer
 259  * passed.  Also, return a pointer to the next word following that,
 260  * or NULL if none follow.
 261  */
 262 char *
 263 nextword(wp, wbuf)
 264         char *wp, *wbuf;
 265 {
 266         int c;
 267
 268         if (wp == NULL) {
 269                 *wbuf = '\0';
 270                 return (NULL);
 271         }
 272         while ((c = *wp++) != '\0' && c != ' ' && c != '\t') {
 273                 *wbuf++ = c;
 274                 if (c == '"') {
 275                         while ((c = *wp++) != '\0' && c != '"')
 276                                 *wbuf++ = c;
 277                         if (c == '"')
 278                                 *wbuf++ = c;
 279                         else
 280                                 wp--;
 281                 }
 282         }
 283         *wbuf = '\0';
 284         for (; c == ' ' || c == '\t'; c = *wp++)
 285                 ;
 286         if (c == '\0')
 287                 return (NULL);
 288         return (wp - 1);
 289 }