/* * rfc822.c -- code for slicing and dicing RFC822 mail headers * * Copyright 1997 by Eric S. Raymond * For license terms, see the file COPYING in this directory. */ #include #include #include #if defined(STDC_HEADERS) #include #endif #include "fetchmail.h" #define HEADER_END(p) ((p)[0] == '\n' && ((p)[1] != ' ' && (p)[1] != '\t')) #ifdef TESTMAIN static int verbose; char *program_name = "rfc822"; #endif /* TESTMAIN */ char *reply_hack(buf, host) /* hack message headers so replies will work properly */ char *buf; /* header to be hacked */ const char *host; /* server hostname */ { char *from, *cp, last_nws = '\0', *parens_from = NULL; int parendepth, state, has_bare_name_part, has_host_part; int addresscount = 1; if (strncasecmp("From: ", buf, 6) && strncasecmp("To: ", buf, 4) && strncasecmp("Reply-To: ", buf, 10) && strncasecmp("Return-Path: ", buf, 13) && strncasecmp("Cc: ", buf, 4) && strncasecmp("Bcc: ", buf, 5) && strncasecmp("Resent-From: ", buf, 13) && strncasecmp("Resent-To: ", buf, 11) && strncasecmp("Resent-Cc: ", buf, 11) && strncasecmp("Resent-Bcc: ", buf, 12) && strncasecmp("Apparently-From:", buf, 16) && strncasecmp("Apparently-To:", buf, 14) && strncasecmp("Sender:", buf, 7) && strncasecmp("Resent-Sender:", buf, 14) ) { return(buf); } #ifndef TESTMAIN if (outlevel >= O_DEBUG) error_build(0, 0, "About to rewrite %s", buf); #else /* make room to hack the address; buf must be malloced */ for (cp = buf; *cp; cp++) if (*cp == ',' || isspace(*cp)) addresscount++; buf = (char *)xrealloc(buf, strlen(buf) + addresscount * strlen(host) + 1); #endif /* TESTMAIN */ /* * This is going to foo up on some ill-formed addresses. * Note that we don't rewrite the fake address <> in order to * avoid screwing up bounce suppression with a null Return-Path. */ parendepth = state = 0; has_host_part = has_bare_name_part = FALSE; for (from = buf; *from; from++) { #ifdef TESTMAIN if (verbose) { printf("state %d: %s", state, buf); printf("%*s^\n", from - buf + 10, " "); } #endif /* TESTMAIN */ if (state != 2) if (*from == '(') ++parendepth; else if (*from == ')') --parendepth; if (!parendepth && !has_host_part) switch (state) { case 0: /* before header colon */ if (*from == ':') state = 1; break; case 1: /* we've seen the colon, we're looking for addresses */ if (!isspace(*from)) last_nws = *from; if (*from == '<') state = 3; else if (*from == '@') has_host_part = TRUE; else if (*from == '"') state = 2; /* * Not expanding on last non-WS == ';' deals with groupnames, * an obscure misfeature described in sections * 6.1, 6.2.6, and A.1.5 of the RFC822 standard. */ else if ((*from == ',' || HEADER_END(from)) && has_bare_name_part && !has_host_part && last_nws != ';') { int hostlen; char *p; p = from; if (parens_from) from = parens_from; while (isspace(*from) || (*from == ',')) --from; from++; hostlen = strlen(host); for (cp = from + strlen(from); cp >= from; --cp) cp[hostlen+1] = *cp; *from++ = '@'; memcpy(from, host, hostlen); from = p + hostlen + 1; has_host_part = TRUE; } else if (from[1] == '(' && has_bare_name_part && !has_host_part && last_nws != ';' && last_nws != ')') { parens_from = from; } else if (!isspace(*from)) has_bare_name_part = TRUE; break; case 2: /* we're in a string */ if (*from == '"') state = 1; break; case 3: /* we're in a <>-enclosed address */ if (*from == '@') has_host_part = TRUE; else if (*from == '>' && from[-1] != '<') { state = 1; if (!has_host_part) { int hostlen; hostlen = strlen(host); for (cp = from + strlen(from); cp >= from; --cp) cp[hostlen+1] = *cp; *from++ = '@'; memcpy(from, host, hostlen); from += hostlen; has_host_part = TRUE; } } break; } /* * If we passed a comma, reset everything. */ if (from[-1] == ',' && !parendepth) { has_host_part = has_bare_name_part = FALSE; parens_from = NULL; } } #ifndef TESTMAIN if (outlevel >= O_DEBUG) error_complete(0, 0, "Rewritten version is %s", buf); #endif /* TESTMAIN */ return(buf); } char *nxtaddr(hdr) /* parse addresses in succession out of a specified RFC822 header */ const char *hdr; /* header to be parsed, NUL to continue previous hdr */ { static char *tp, address[POPBUFSIZE+1]; static const char *hp; static int state, oldstate; #ifdef TESTMAIN static const char *orighdr; #endif /* TESTMAIN */ int parendepth = 0; #define START_HDR 0 /* before header colon */ #define SKIP_JUNK 1 /* skip whitespace, \n, and junk */ #define BARE_ADDRESS 2 /* collecting address without delimiters */ #define INSIDE_DQUOTE 3 /* inside double quotes */ #define INSIDE_PARENS 4 /* inside parentheses */ #define INSIDE_BRACKETS 5 /* inside bracketed address */ #define ENDIT_ALL 6 /* after last address */ if (hdr) { hp = hdr; state = START_HDR; #ifdef TESTMAIN orighdr = hdr; #endif /* TESTMAIN */ tp = address; } for (; *hp; hp++) { #ifdef TESTMAIN if (verbose) { printf("state %d: %s", state, orighdr); printf("%*s^\n", hp - orighdr + 10, " "); } #endif /* TESTMAIN */ if (state == ENDIT_ALL) /* after last address */ return(NULL); else if (HEADER_END(hp)) { state = ENDIT_ALL; if (tp > address) { while (isspace(*--tp)) continue; *++tp = '\0'; } return(tp > address ? (tp = address) : (char *)NULL); } else if (*hp == '\\') /* handle RFC822 escaping */ { if (state != INSIDE_PARENS) { *tp++ = *hp++; /* take the escape */ *tp++ = *hp; /* take following char */ } } else switch (state) { case START_HDR: /* before header colon */ if (*hp == ':') state = SKIP_JUNK; break; case SKIP_JUNK: /* looking for address start */ if (*hp == '"') /* quoted string */ { oldstate = SKIP_JUNK; state = INSIDE_DQUOTE; *tp++ = *hp; } else if (*hp == '(') /* address comment -- ignore */ { parendepth = 1; oldstate = SKIP_JUNK; state = INSIDE_PARENS; } else if (*hp == '<') /* begin
*/ { state = INSIDE_BRACKETS; tp = address; } else if (*hp != ',' && !isspace(*hp)) { --hp; state = BARE_ADDRESS; } break; case BARE_ADDRESS: /* collecting address without delimiters */ if (*hp == ',') /* end of address */ { if (tp > address) { *tp++ = '\0'; state = SKIP_JUNK; return(tp = address); } } else if (*hp == '(') /* beginning of comment */ { parendepth = 1; oldstate = BARE_ADDRESS; state = INSIDE_PARENS; } else if (*hp == '<') /* beginning of real address */ { state = INSIDE_BRACKETS; tp = address; } else if (!isspace(*hp)) /* just take it, ignoring whitespace */ *tp++ = *hp; break; case INSIDE_DQUOTE: /* we're in a quoted string, copy verbatim */ if (*hp != '"') *tp++ = *hp; else { *tp++ = *hp; state = oldstate; } break; case INSIDE_PARENS: /* we're in a parenthesized comment, ignore */ if (*hp == '(') ++parendepth; else if (*hp == ')') --parendepth; if (parendepth == 0) state = oldstate; break; case INSIDE_BRACKETS: /* possible <>-enclosed address */ if (*hp == '>') /* end of address */ { *tp++ = '\0'; state = SKIP_JUNK; ++hp; return(tp = address); } else if (*hp == '<') /* nested <> */ tp = address; else if (*hp == '"') /* quoted address */ { *tp++ = *hp; oldstate = INSIDE_BRACKETS; state = INSIDE_DQUOTE; } else /* just copy address */ *tp++ = *hp; break; } } return(NULL); } #ifdef TESTMAIN static void parsebuf(char *longbuf, int reply) { char *cp; if (reply) { reply_hack(longbuf, "HOSTNAME.NET"); printf("Rewritten buffer: %s", longbuf); } else if ((cp = nxtaddr(longbuf)) != (char *)NULL) do { printf("\t-> \"%s\"\n", cp); } while ((cp = nxtaddr((char *)NULL)) != (char *)NULL); } main(int argc, char *argv[]) { char buf[MSGBUFSIZE], longbuf[BUFSIZ]; int ch, reply; verbose = reply = FALSE; while ((ch = getopt(argc, argv, "rv")) != EOF) switch(ch) { case 'r': reply = TRUE; break; case 'v': verbose = TRUE; break; } while (fgets(buf, sizeof(buf)-1, stdin)) { if (buf[0] == ' ' || buf[0] == '\t') strcat(longbuf, buf); else if (!strncasecmp("From: ", buf, 6) || !strncasecmp("To: ", buf, 4) || !strncasecmp("Reply-", buf, 6) || !strncasecmp("Cc: ", buf, 4) || !strncasecmp("Bcc: ", buf, 5)) strcpy(longbuf, buf); else if (longbuf[0]) { if (verbose) fputs(longbuf, stdout); parsebuf(longbuf, reply); longbuf[0] = '\0'; } } if (longbuf[0]) { if (verbose) fputs(longbuf, stdout); parsebuf(longbuf, reply); } } #endif /* TESTMAIN */ /* rfc822.c end */