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 #ifndef lint 33 #if 0 34 static char sccsid[] = "@(#)head.c 8.2 (Berkeley) 4/20/95"; 35 #endif 36 #endif /* not lint */ 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "rcv.h" 41 #include "extern.h" 42 43 /* 44 * Mail -- a mail program 45 * 46 * Routines for processing and detecting headlines. 47 */ 48 49 /* 50 * See if the passed line buffer is a mail header. 51 * Return true if yes. Note the extreme pains to 52 * accommodate all funny formats. 53 */ 54 int 55 ishead(char linebuf[]) 56 { 57 struct headline hl; 58 char parbuf[BUFSIZ]; 59 60 if (strncmp(linebuf, "From ", 5) != 0) 61 return (0); 62 parse(linebuf, &hl, parbuf); 63 if (hl.l_date == NULL) { 64 fail(linebuf, "No date field"); 65 return (0); 66 } 67 if (!isdate(hl.l_date)) { 68 fail(linebuf, "Date field not legal date"); 69 return (0); 70 } 71 /* 72 * I guess we got it! 73 */ 74 return (1); 75 } 76 77 void 78 fail(const char *linebuf __unused, const char *reason __unused) 79 { 80 81 /* 82 if (value("debug") == NULL) 83 return; 84 fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason); 85 */ 86 } 87 88 /* 89 * Split a headline into its useful components. 90 * Copy the line into dynamic string space, then set 91 * pointers into the copied line in the passed headline 92 * structure. Actually, it scans. 93 */ 94 void 95 parse(char line[], struct headline *hl, char pbuf[]) 96 { 97 char *cp, *sp; 98 char word[LINESIZE]; 99 100 hl->l_from = NULL; 101 hl->l_tty = NULL; 102 hl->l_date = NULL; 103 cp = line; 104 sp = pbuf; 105 /* 106 * Skip over "From" first. 107 */ 108 cp = nextword(cp, word); 109 /* 110 * Check for missing return-path. 111 */ 112 if (isdate(cp)) { 113 hl->l_date = copyin(cp, &sp); 114 return; 115 } 116 cp = nextword(cp, word); 117 if (strlen(word) > 0) 118 hl->l_from = copyin(word, &sp); 119 if (cp != NULL && strncmp(cp, "tty", 3) == 0) { 120 cp = nextword(cp, word); 121 hl->l_tty = copyin(word, &sp); 122 } 123 if (cp != NULL) 124 hl->l_date = copyin(cp, &sp); 125 } 126 127 /* 128 * Copy the string on the left into the string on the right 129 * and bump the right (reference) string pointer by the length. 130 * Thus, dynamically allocate space in the right string, copying 131 * the left string into it. 132 */ 133 char * 134 copyin(char *src, char **space) 135 { 136 char *cp, *top; 137 138 top = cp = *space; 139 while ((*cp++ = *src++) != '\0') 140 ; 141 *space = cp; 142 return (top); 143 } 144 145 /* 146 * Test to see if the passed string is a ctime(3) generated 147 * date string as documented in the manual. The template 148 * below is used as the criterion of correctness. 149 * Also, we check for a possible trailing time zone using 150 * the tmztype template. 151 * 152 * If the mail file is created by Sys V (Solaris), there are 153 * no seconds in the time. If the mail is created by another 154 * program such as imapd, it might have timezone as 155 * <-|+>nnnn (-0800 for instance) at the end. 156 */ 157 158 /* 159 * 'A' An upper case char 160 * 'a' A lower case char 161 * ' ' A space 162 * '0' A digit 163 * 'O' A digit or space 164 * 'p' A punctuation char 165 * 'P' A punctuation char or space 166 * ':' A colon 167 * 'N' A new line 168 */ 169 170 static char *date_formats[] = { 171 "Aaa Aaa O0 00:00:00 0000", /* Mon Jan 01 23:59:59 2001 */ 172 "Aaa Aaa O0 00:00:00 AAA 0000", /* Mon Jan 01 23:59:59 PST 2001 */ 173 "Aaa Aaa O0 00:00:00 0000 p0000", /* Mon Jan 01 23:59:59 2001 -0800 */ 174 "Aaa Aaa O0 00:00 0000", /* Mon Jan 01 23:59 2001 */ 175 "Aaa Aaa O0 00:00 AAA 0000", /* Mon Jan 01 23:59 PST 2001 */ 176 "Aaa Aaa O0 00:00 0000 p0000", /* Mon Jan 01 23:59 2001 -0800 */ 177 NULL 178 }; 179 180 int 181 isdate(char date[]) 182 { 183 int i; 184 185 for(i = 0; date_formats[i] != NULL; i++) { 186 if (cmatch(date, date_formats[i])) 187 return (1); 188 } 189 return (0); 190 } 191 192 /* 193 * Match the given string (cp) against the given template (tp). 194 * Return 1 if they match, 0 if they don't 195 */ 196 int 197 cmatch(char *cp, char *tp) 198 { 199 200 while (*cp != '\0' && *tp != '\0') 201 switch (*tp++) { 202 case 'a': 203 if (!islower((unsigned char)*cp++)) 204 return (0); 205 break; 206 case 'A': 207 if (!isupper((unsigned char)*cp++)) 208 return (0); 209 break; 210 case ' ': 211 if (*cp++ != ' ') 212 return (0); 213 break; 214 case '0': 215 if (!isdigit((unsigned char)*cp++)) 216 return (0); 217 break; 218 case 'O': 219 if (*cp != ' ' && !isdigit((unsigned char)*cp)) 220 return (0); 221 cp++; 222 break; 223 case 'p': 224 if (!ispunct((unsigned char)*cp++)) 225 return (0); 226 break; 227 case 'P': 228 if (*cp != ' ' && !ispunct((unsigned char)*cp)) 229 return (0); 230 cp++; 231 break; 232 case ':': 233 if (*cp++ != ':') 234 return (0); 235 break; 236 case 'N': 237 if (*cp++ != '\n') 238 return (0); 239 break; 240 } 241 if (*cp != '\0' || *tp != '\0') 242 return (0); 243 return (1); 244 } 245 246 /* 247 * Collect a liberal (space, tab delimited) word into the word buffer 248 * passed. Also, return a pointer to the next word following that, 249 * or NULL if none follow. 250 */ 251 char * 252 nextword(char *wp, char *wbuf) 253 { 254 int c; 255 256 if (wp == NULL) { 257 *wbuf = '\0'; 258 return (NULL); 259 } 260 while ((c = *wp++) != '\0' && c != ' ' && c != '\t') { 261 *wbuf++ = c; 262 if (c == '"') { 263 while ((c = *wp++) != '\0' && c != '"') 264 *wbuf++ = c; 265 if (c == '"') 266 *wbuf++ = c; 267 else 268 wp--; 269 } 270 } 271 *wbuf = '\0'; 272 for (; c == ' ' || c == '\t'; c = *wp++) 273 ; 274 if (c == '\0') 275 return (NULL); 276 return (wp - 1); 277 } 278