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 #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 * accommodate 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 void 76 fail(const char *linebuf __unused, const char *reason __unused) 77 { 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 } 276