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