1 /* $NetBSD: head.c,v 1.22 2012/12/01 11:41:50 mbalmer Exp $ */ 2 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 <sys/cdefs.h> 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)head.c 8.2 (Berkeley) 4/20/95"; 36 #else 37 __RCSID("$NetBSD: head.c,v 1.22 2012/12/01 11:41:50 mbalmer Exp $"); 38 #endif 39 #endif /* not lint */ 40 41 #include "rcv.h" 42 #include "extern.h" 43 44 /* 45 * Mail -- a mail program 46 * 47 * Routines for processing and detecting headlines. 48 */ 49 50 /* 51 * Match the given string (cp) against the given template (tp). 52 * Return 1 if they match, 0 if they don't 53 */ 54 static int 55 cmatch(const char *cp, char *tp) 56 { 57 58 while (*cp && *tp) 59 switch (*tp++) { 60 case 'a': 61 if (!islower((unsigned char)*cp++)) 62 return 0; 63 break; 64 case 'A': 65 if (!isupper((unsigned char)*cp++)) 66 return 0; 67 break; 68 case ' ': 69 if (*cp++ != ' ') 70 return 0; 71 break; 72 case '0': 73 if (!isdigit((unsigned char)*cp++)) 74 return 0; 75 break; 76 case 'O': 77 if (*cp != ' ' && !isdigit((unsigned char)*cp)) 78 return 0; 79 cp++; 80 break; 81 case ':': 82 if (*cp++ != ':') 83 return 0; 84 break; 85 case 'N': 86 if (*cp++ != '\n') 87 return 0; 88 break; 89 } 90 if (*cp || *tp) 91 return 0; 92 return 1; 93 } 94 95 /* 96 * Test to see if the passed string is a ctime(3) generated 97 * date string as documented in the manual. The template 98 * below is used as the criterion of correctness. 99 * Also, we check for a possible trailing time zone using 100 * the tmztype template. 101 */ 102 103 /* 104 * 'A' An upper case char 105 * 'a' A lower case char 106 * ' ' A space 107 * '0' A digit 108 * 'O' An optional digit or space 109 * ':' A colon 110 * 'N' A new line 111 */ 112 static char ctype[] = "Aaa Aaa O0 00:00:00 0000"; 113 static char SysV_ctype[] = "Aaa Aaa O0 00:00 0000"; 114 static char tmztype[] = "Aaa Aaa O0 00:00:00 AAA 0000"; 115 static char SysV_tmztype[] = "Aaa Aaa O0 00:00 AAA 0000"; 116 117 static int 118 isdate(const char date[]) 119 { 120 121 return cmatch(date, ctype) || 122 cmatch(date, tmztype) || 123 cmatch(date, SysV_tmztype) || cmatch(date, SysV_ctype); 124 } 125 126 static void 127 fail(const char linebuf[], const char reason[]) 128 { 129 #ifndef FMT_PROG 130 if (debug) 131 (void)fprintf(stderr, "\"%s\"\nnot a header because %s\n", 132 linebuf, reason); 133 #endif 134 } 135 136 /* 137 * Collect a liberal (space, tab delimited) word into the word buffer 138 * passed. Also, return a pointer to the next word following that, 139 * or NULL if none follow. 140 */ 141 static const char * 142 nextword(const char *wp, char *wbuf) 143 { 144 if (wp == NULL) { 145 *wbuf = 0; 146 return NULL; 147 } 148 while (*wp && !is_WSP(*wp)) { 149 *wbuf++ = *wp; 150 if (*wp++ == '"') { 151 while (*wp && *wp != '"') 152 *wbuf++ = *wp++; 153 if (*wp == '"') 154 *wbuf++ = *wp++; 155 } 156 } 157 *wbuf = '\0'; 158 wp = skip_WSP(wp); 159 if (*wp == '\0') 160 return NULL; 161 return wp; 162 } 163 164 /* 165 * Copy the string on the left into the string on the right 166 * and bump the right (reference) string pointer by the length. 167 * Thus, dynamically allocate space in the right string, copying 168 * the left string into it. 169 */ 170 static char * 171 copyin(const char *src, char **space) 172 { 173 char *cp; 174 char *begin; 175 176 begin = cp = *space; 177 while ((*cp++ = *src++) != '\0') 178 continue; 179 *space = cp; 180 return begin; 181 } 182 183 /* 184 * Split a headline into its useful components. 185 * Copy the line into dynamic string space, then set 186 * pointers into the copied line in the passed headline 187 * structure. Actually, it scans. 188 * 189 * XXX - line[], pbuf[], and word[] must be LINESIZE in length or 190 * overflow can occur in nextword() or copyin(). 191 */ 192 PUBLIC void 193 parse(const char line[], struct headline *hl, char pbuf[]) 194 { 195 const char *cp; 196 char *sp; 197 char word[LINESIZE]; 198 199 hl->l_from = NULL; 200 hl->l_tty = NULL; 201 hl->l_date = NULL; 202 cp = line; 203 sp = pbuf; 204 /* 205 * Skip over "From" first. 206 */ 207 cp = nextword(cp, word); 208 cp = nextword(cp, word); 209 if (*word) 210 hl->l_from = copyin(word, &sp); 211 if (cp != NULL && cp[0] == 't' && cp[1] == 't' && cp[2] == 'y') { 212 cp = nextword(cp, word); 213 hl->l_tty = copyin(word, &sp); 214 } 215 if (cp != NULL) 216 hl->l_date = copyin(cp, &sp); 217 } 218 219 /* 220 * See if the passed line buffer is a mail header. 221 * Return true if yes. Note the extreme pains to 222 * accommodate all funny formats. 223 */ 224 PUBLIC int 225 ishead(const char linebuf[]) 226 { 227 const char *cp; 228 struct headline hl; 229 char parbuf[LINESIZE]; 230 231 cp = linebuf; 232 if (*cp++ != 'F' || *cp++ != 'r' || *cp++ != 'o' || *cp++ != 'm' || 233 *cp++ != ' ') 234 return 0; 235 parse(linebuf, &hl, parbuf); 236 if (hl.l_from == NULL || hl.l_date == NULL) { 237 fail(linebuf, "No from or date field"); 238 return 0; 239 } 240 if (!isdate(hl.l_date)) { 241 fail(linebuf, "Date field not legal date"); 242 return 0; 243 } 244 /* 245 * I guess we got it! 246 */ 247 return 1; 248 } 249