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