/* $NetBSD: head.c,v 1.24 2013/01/16 15:21:42 christos Exp $ */ /* * Copyright (c) 1980, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <sys/cdefs.h> #ifndef lint #if 0 static char sccsid[] = "@(#)head.c 8.2 (Berkeley) 4/20/95"; #else __RCSID("$NetBSD: head.c,v 1.24 2013/01/16 15:21:42 christos Exp $"); #endif #endif /* not lint */ #include "rcv.h" #include "extern.h" /* * Mail -- a mail program * * Routines for processing and detecting headlines. */ /* * Match the given string (cp) against the given template (tp). * Return 1 if they match, 0 if they don't */ static int cmatch(const char *cp, const char *tp) { while (*cp && *tp) switch (*tp++) { case 'a': if (!islower((unsigned char)*cp++)) return 0; break; case 'A': if (!isupper((unsigned char)*cp++)) return 0; break; case ' ': if (*cp++ != ' ') return 0; break; case '0': if (!isdigit((unsigned char)*cp++)) return 0; break; case 'O': if (*cp != ' ' && !isdigit((unsigned char)*cp)) return 0; cp++; break; case ':': if (*cp++ != ':') return 0; break; case 'N': if (*cp++ != '\n') return 0; break; case '+': if (*cp != '+' && *cp != '-') return 0; cp++; break; } if (*cp || *tp) return 0; return 1; } /* * Test to see if the passed string is a ctime(3) generated * date string as documented in the manual. The template * below is used as the criterion of correctness. * Also, we check for a possible trailing time zone using * the tmztype template. */ /* * 'A' An upper case char * 'a' A lower case char * ' ' A space * '0' A digit * 'O' An optional digit or space * ':' A colon * 'N' A new line * '+' A plus or minus sign */ static struct cmatch_data { size_t tlen; char const *tdata; } const cmatch_data[] = { #define TSZ(a) (sizeof(a) - 1), a { TSZ("Aaa Aaa O0 00:00:00 0000") }, /* BSD ctype */ { TSZ("Aaa Aaa O0 00:00 0000") }, /* SysV ctype */ { TSZ("Aaa Aaa O0 00:00:00 AAA 0000") }, /* BSD tmztype */ { TSZ("Aaa Aaa O0 00:00 AAA 0000") }, /* SysV tmztype */ /* * RFC 822-alike From_ lines do not conform to RFC 4155, but seem to * be used in the wild by UW-imap (MBX format plus) */ { TSZ("Aaa Aaa O0 00:00:00 0000 +0000") }, /* RFC822, UT offset */ /* * RFC 822 with zone spec: * 1. military, * 2. UT, * 3. north america time zone strings * note that 1. is strictly speaking not correct as some letters are * not used */ { TSZ("Aaa Aaa O0 00:00:00 0000 A") }, { TSZ("Aaa Aaa O0 00:00:00 0000 AA") }, { TSZ("Aaa Aaa O0 00:00:00 0000 AAA") }, { 0, NULL }, }; static int isdate(const char date[]) { static size_t cmatch_minlen = 0; struct cmatch_data const *cmdp; size_t dl = strlen(date); if (cmatch_minlen == 0) for (cmdp = cmatch_data; cmdp->tdata != NULL; ++cmdp) cmatch_minlen = MIN(cmatch_minlen, cmdp->tlen); if (dl < cmatch_minlen) return 0; for (cmdp = cmatch_data; cmdp->tdata != NULL; ++cmdp) if (dl == cmdp->tlen && cmatch(date, cmdp->tdata)) return 1; return 0; } static void fail(const char linebuf[], const char reason[]) { #ifndef FMT_PROG if (debug) (void)fprintf(stderr, "\"%s\"\nnot a header because %s\n", linebuf, reason); #endif } /* * Collect a liberal (space, tab delimited) word into the word buffer * passed. Also, return a pointer to the next word following that, * or NULL if none follow. */ static const char * nextword(const char *wp, char *wbuf) { if (wp == NULL) { *wbuf = 0; return NULL; } while (*wp && !is_WSP(*wp)) { *wbuf++ = *wp; if (*wp++ == '"') { while (*wp && *wp != '"') *wbuf++ = *wp++; if (*wp == '"') *wbuf++ = *wp++; } } *wbuf = '\0'; wp = skip_WSP(wp); if (*wp == '\0') return NULL; return wp; } /* * Copy the string on the left into the string on the right * and bump the right (reference) string pointer by the length. * Thus, dynamically allocate space in the right string, copying * the left string into it. */ static char * copyin(const char *src, char **space) { char *cp; char *begin; begin = cp = *space; while ((*cp++ = *src++) != '\0') continue; *space = cp; return begin; } /* * Split a headline into its useful components. * Copy the line into dynamic string space, then set * pointers into the copied line in the passed headline * structure. Actually, it scans. * * XXX - line[], pbuf[], and word[] must be LINESIZE in length or * overflow can occur in nextword() or copyin(). */ PUBLIC void parse(const char line[], struct headline *hl, char pbuf[]) { const char *cp; char *sp; char word[LINESIZE]; hl->l_from = NULL; hl->l_tty = NULL; hl->l_date = NULL; cp = line; sp = pbuf; /* * Skip over "From" first. */ cp = nextword(cp, word); cp = nextword(cp, word); if (*word) hl->l_from = copyin(word, &sp); if (cp != NULL && cp[0] == 't' && cp[1] == 't' && cp[2] == 'y') { cp = nextword(cp, word); hl->l_tty = copyin(word, &sp); } if (cp != NULL) hl->l_date = copyin(cp, &sp); } /* * See if the passed line buffer is a mail header. * Return true if yes. Note the extreme pains to * accommodate all funny formats. */ PUBLIC int ishead(const char linebuf[]) { const char *cp; struct headline hl; char parbuf[LINESIZE]; cp = linebuf; if (*cp++ != 'F' || *cp++ != 'r' || *cp++ != 'o' || *cp++ != 'm' || *cp++ != ' ') return 0; parse(linebuf, &hl, parbuf); if (hl.l_from == NULL || hl.l_date == NULL) { fail(linebuf, "No from or date field"); return 0; } if (!isdate(hl.l_date)) { fail(linebuf, "Date field not legal date"); return 0; } /* * I guess we got it! */ return 1; }
