| 1 |
/* Mixmaster version 3 -- (C) 1999 Anonymizer Inc.
|
| 2 |
|
| 3 |
Mixmaster may be redistributed and modified under certain conditions.
|
| 4 |
This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF
|
| 5 |
ANY KIND, either express or implied. See the file COPYRIGHT for
|
| 6 |
details.
|
| 7 |
|
| 8 |
Process remailer messages
|
| 9 |
$Id: rem.c,v 1.7 2001/12/15 05:10:52 rabbi Exp $ */
|
| 10 |
|
| 11 |
|
| 12 |
#include "mix3.h"
|
| 13 |
#include <stdlib.h>
|
| 14 |
#include <string.h>
|
| 15 |
#include <time.h>
|
| 16 |
#include <ctype.h>
|
| 17 |
#include <sys/types.h>
|
| 18 |
#include <sys/stat.h>
|
| 19 |
#ifdef POSIX
|
| 20 |
#include <unistd.h>
|
| 21 |
#else
|
| 22 |
#include <io.h>
|
| 23 |
#endif
|
| 24 |
#ifndef _MSC
|
| 25 |
#include <dirent.h>
|
| 26 |
#endif
|
| 27 |
#include <assert.h>
|
| 28 |
|
| 29 |
int blockrequest(BUFFER *message);
|
| 30 |
|
| 31 |
#define REQUESTHELP 100
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| 32 |
#define REQUESTSTATS 101
|
| 33 |
#define REQUESTKEY 200
|
| 34 |
#define REQUESTCONF 201
|
| 35 |
#define REQUESTOPKEY 202
|
| 36 |
#define BLOCKREQUEST 666
|
| 37 |
#define DISABLED 99
|
| 38 |
|
| 39 |
#define CPUNKMSG 1
|
| 40 |
#define MIXMSG 2
|
| 41 |
|
| 42 |
int mix_decrypt(BUFFER *message)
|
| 43 |
{
|
| 44 |
int type = 0;
|
| 45 |
BUFFER *field, *content;
|
| 46 |
BUFFER *to, *subject, *replyto, *reply;
|
| 47 |
FILE *f;
|
| 48 |
BUFFER *block;
|
| 49 |
int err = 0;
|
| 50 |
int quoted_printable = 0; /* is this message quoted printable encoded */
|
| 51 |
|
| 52 |
mix_init(NULL);
|
| 53 |
field = buf_new();
|
| 54 |
content = buf_new();
|
| 55 |
to = buf_new();
|
| 56 |
replyto = buf_new();
|
| 57 |
reply = buf_new();
|
| 58 |
block = buf_new();
|
| 59 |
subject = buf_new();
|
| 60 |
buf_sets(subject, "Subject: Re: your mail");
|
| 61 |
|
| 62 |
buf_rewind(message);
|
| 63 |
|
| 64 |
f = mix_openfile(SOURCEBLOCK, "r");
|
| 65 |
if (f != NULL) {
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| 66 |
buf_read(block, f);
|
| 67 |
fclose(f);
|
| 68 |
}
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| 69 |
for (;;) {
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| 70 |
err = buf_getheader(message, field, content);
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| 71 |
if (err == 1) {
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| 72 |
/* "::" marks for additional header lines */
|
| 73 |
while (buf_lookahead(message, field) == 1)
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| 74 |
buf_getheader(message, field, content);
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| 75 |
if (isline(field, HDRMARK))
|
| 76 |
continue;
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| 77 |
else
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| 78 |
goto hdrend;
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| 79 |
}
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| 80 |
if (err == -1)
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| 81 |
goto hdrend;
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| 82 |
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| 83 |
if ((bufieq(field, "from") || bufieq(field, "sender") || bufieq(field,"received")) &&
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| 84 |
doblock(content, block, 1) != 0)
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goto end;
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| 86 |
|
| 87 |
if (bufieq(field, "to"))
|
| 88 |
buf_cat(to, content);
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| 89 |
else if (bufieq(field, "from") && replyto->length == 0)
|
| 90 |
/* reply to From address if no Reply-To header present */
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| 91 |
buf_set(replyto, content);
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| 92 |
else if (bufieq(field, "reply-to"))
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| 93 |
buf_set(replyto, content);
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| 94 |
else if (MIX && bufieq(field, "remailer-type") &&
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| 95 |
bufileft(content, "mixmaster"))
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| 96 |
type = MIXMSG;
|
| 97 |
else if (bufieq(field, "subject")) {
|
| 98 |
if (bufieq(content, "help") || bufieq(content, "remailer-help"))
|
| 99 |
type = REQUESTHELP;
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| 100 |
else if (bufieq(content, "remailer-stats"))
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| 101 |
type = REQUESTSTATS;
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| 102 |
else if (bufieq(content, "remailer-key"))
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| 103 |
type = REQUESTKEY;
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| 104 |
else if (bufieq(content, "remailer-adminkey"))
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| 105 |
type = REQUESTOPKEY;
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| 106 |
else if (bufieq(content, "remailer-conf"))
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| 107 |
type = REQUESTCONF;
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| 108 |
else if (bufileft(content, "destination-block"))
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| 109 |
type = BLOCKREQUEST;
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| 110 |
else {
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| 111 |
buf_sets(subject, "Subject: ");
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| 112 |
if (!bufileft(content, "re:"))
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| 113 |
buf_appends(subject, "Re: ");
|
| 114 |
buf_cat(subject, content);
|
| 115 |
}
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| 116 |
} else if (bufieq(field, "test-to") || bufieq(field, "encrypted") ||
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| 117 |
bufieq(field, "anon-to") ||
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| 118 |
bufieq(field, "request-remailing-to") ||
|
| 119 |
bufieq(field, "remail-to") || bufieq(field, "anon-post-to") ||
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bufieq(field, "post-to") || bufieq(field, "anon-send-to") ||
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| 121 |
bufieq(field, "send-to") || bufieq(field, "remix-to"))
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type = CPUNKMSG;
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| 123 |
else if (bufieq(field, "content-transfer-encoding")
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| 124 |
&& bufieq(content, "quoted-printable")) {
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| 125 |
quoted_printable = 1;
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}
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| 127 |
|
| 128 |
}
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| 129 |
hdrend:
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| 130 |
if (quoted_printable)
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| 131 |
qp_decode_message(message);
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| 133 |
if (type > 0 && REMAIL == 0)
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type = DISABLED;
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| 135 |
switch (type) {
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case REQUESTHELP:
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if (sendinfofile(HELPFILE, NULL, replyto, NULL) == -1)
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errlog(WARNING, "No help file available.\n");
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break;
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case REQUESTKEY:
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err = key(reply);
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| 142 |
if (err == 0)
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err = sendmail(reply, REMAILERNAME, replyto);
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| 144 |
break;
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| 145 |
case REQUESTOPKEY:
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err = adminkey(reply);
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| 147 |
if (err == 0)
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| 148 |
err = sendmail(reply, REMAILERNAME, replyto);
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break;
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| 150 |
case REQUESTSTATS:
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err = stats(reply);
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if (err == 0)
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err = sendmail(reply, REMAILERNAME, replyto);
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break;
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case REQUESTCONF:
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err = conf(reply);
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| 157 |
if (err == 0)
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err = sendmail(reply, REMAILERNAME, replyto);
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break;
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| 160 |
case CPUNKMSG:
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err = t1_decrypt(message);
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| 162 |
if (err != 0) {
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| 163 |
errlog(LOG, "Invalid type 1 message from %b\n", replyto);
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sendinfofile(USAGEFILE, USAGELOG, replyto, NULL);
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logmail(err == -2 ? MAILUSAGE : MAILERROR, message);
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}
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break;
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case MIXMSG:
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err = t2_decrypt(message);
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if (err == -1) {
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errlog(LOG, "Invalid type 2 message from %b\n", replyto);
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sendinfofile(USAGEFILE, USAGELOG, replyto, NULL);
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logmail(MAILERROR, message);
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}
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| 175 |
break;
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| 176 |
case BLOCKREQUEST:
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blockrequest(message);
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| 178 |
logmail(MAILBLOCK, message);
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break;
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| 180 |
case DISABLED:
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errlog(ERRORMSG, "Remailer is disabled.\n");
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| 182 |
buf_sets(reply, "Subject: remailer error\n\nThe remailer is disabled.\n");
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sendmail(reply, REMAILERNAME, replyto);
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| 184 |
logmail(MAILERROR, message);
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| 185 |
break;
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| 186 |
default:
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| 187 |
if (strifind
|
| 188 |
(replyto->data, "mailer-daemon")) {
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| 189 |
errlog(LOG, "Bounce mail from %b\n", replyto);
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| 190 |
logmail(MAILBOUNCE, message);
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| 191 |
} else if (bufifind(to, REMAILERADDR) && blockrequest(message))
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logmail(MAILBLOCK, message);
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| 193 |
else if (!AUTOREPLY)
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logmail(MAILBOX, message);
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else if (bufifind(to, REMAILERADDR)) {
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errlog(LOG, "Non-remailer message from %b\n", replyto);
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sendinfofile(USAGEFILE, USAGELOG, replyto, NULL);
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logmail(MAILUSAGE, message);
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} else if (bufifind(to, COMPLAINTS)) {
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errlog(WARNING, "Abuse complaint from %b\n", replyto);
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| 201 |
sendinfofile(ABUSEFILE, NULL, replyto, subject);
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| 202 |
logmail(MAILABUSE, message);
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} else if (ANONADDR[0] && bufifind(to, ANONADDR)) {
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errlog(LOG, "Reply to anonymous message from %b\n", replyto);
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sendinfofile(REPLYFILE, NULL, replyto, subject);
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logmail(MAILANON, message);
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} else {
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| 208 |
errlog(DEBUGINFO, "Mail from %b\n", replyto);
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| 209 |
logmail(MAILBOX, message);
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}
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err = 1;
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| 212 |
}
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end:
|
| 214 |
buf_free(field);
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| 215 |
buf_free(content);
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| 216 |
buf_free(to);
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| 217 |
buf_free(replyto);
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| 218 |
buf_free(reply);
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| 219 |
buf_free(block);
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| 220 |
buf_free(subject);
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| 221 |
return (err);
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}
|
| 223 |
|
| 224 |
int t2_decrypt(BUFFER *in)
|
| 225 |
{
|
| 226 |
int err = 0;
|
| 227 |
BUFFER *msg;
|
| 228 |
|
| 229 |
msg = buf_new();
|
| 230 |
do {
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| 231 |
err = mix_dearmor(in, msg);
|
| 232 |
if (err != -1) {
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| 233 |
if (v3_magic(msg->data))
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| 234 |
err = mix3_decrypt(msg);
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| 235 |
else
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| 236 |
err = mix2_decrypt(msg);
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| 237 |
}
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| 238 |
}
|
| 239 |
while (in->ptr + 1000 < in->length); /* accept several packets in one message */
|
| 240 |
|
| 241 |
buf_free(msg);
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| 242 |
return (err);
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| 243 |
}
|
| 244 |
|
| 245 |
int mix_pool(BUFFER *msg, int type, long latent)
|
| 246 |
{
|
| 247 |
char path[PATHMAX], pathtmp[PATHMAX];
|
| 248 |
FILE *f;
|
| 249 |
int err = -1;
|
| 250 |
|
| 251 |
f = pool_new(latent > 0 ? "lat" : "msg", pathtmp, path);
|
| 252 |
if (f != NULL) {
|
| 253 |
if (latent > 0)
|
| 254 |
fprintf(f, "%d %ld\n", type, latent + time(NULL));
|
| 255 |
else
|
| 256 |
fprintf(f, "%d 0\n", type);
|
| 257 |
err = buf_write(msg, f);
|
| 258 |
fclose(f);
|
| 259 |
}
|
| 260 |
if (err == 0) {
|
| 261 |
rename(pathtmp, path);
|
| 262 |
errlog(DEBUGINFO, "Added message to pool.\n");
|
| 263 |
}
|
| 264 |
return (err);
|
| 265 |
}
|
| 266 |
|
| 267 |
int pool_packetfile(char *fname, BUFFER *mid, int packetnum)
|
| 268 |
/* create a filename */
|
| 269 |
{
|
| 270 |
#ifdef SHORTNAMES
|
| 271 |
sprintf(fname, "%s%cp%02x%02x%02x%01x.%02x", POOLDIR, DIRSEP,
|
| 272 |
mid->data[0], mid->data[1], mid->data[2], mid->data[3] & 15,
|
| 273 |
packetnum);
|
| 274 |
#else
|
| 275 |
sprintf(fname, "%s%cp%02x%02x%02x%02x%02x%02x%01x", POOLDIR, DIRSEP,
|
| 276 |
packetnum, mid->data[0], mid->data[1], mid->data[2], mid->data[3],
|
| 277 |
mid->data[4], mid->data[5] & 15);
|
| 278 |
#endif
|
| 279 |
return (0);
|
| 280 |
}
|
| 281 |
|
| 282 |
void pool_packetexp(void)
|
| 283 |
{
|
| 284 |
DIR *d;
|
| 285 |
struct dirent *e;
|
| 286 |
struct stat sb;
|
| 287 |
|
| 288 |
d = opendir(POOLDIR);
|
| 289 |
if (d != NULL)
|
| 290 |
for (;;) {
|
| 291 |
e = readdir(d);
|
| 292 |
if (e == NULL)
|
| 293 |
break;
|
| 294 |
if (e->d_name[0] == 'p') {
|
| 295 |
if (stat(e->d_name, &sb) == 0 &&
|
| 296 |
time(NULL) - sb.st_mtime > PACKETEXP) {
|
| 297 |
errlog(NOTICE, "Expiring partial message %s.\n",
|
| 298 |
e->d_name);
|
| 299 |
unlink(e->d_name);
|
| 300 |
}
|
| 301 |
}
|
| 302 |
}
|
| 303 |
closedir(d);
|
| 304 |
}
|
| 305 |
|
| 306 |
void logmail(char *mailbox, BUFFER *message)
|
| 307 |
{
|
| 308 |
time_t t;
|
| 309 |
struct tm *tc;
|
| 310 |
char line[LINELEN];
|
| 311 |
|
| 312 |
/* mailbox is "|program", "user@host", "stdout" or "filename" */
|
| 313 |
buf_rewind(message);
|
| 314 |
if (mailbox[0] == '\0') /* default action */
|
| 315 |
mailbox = MAILBOX;
|
| 316 |
if (strieq(mailbox, "stdout"))
|
| 317 |
buf_write(message, stdout);
|
| 318 |
else if (mailbox[0] == '|') {
|
| 319 |
FILE *p;
|
| 320 |
|
| 321 |
errlog(DEBUGINFO, "Piping message to %s.", mailbox + 1);
|
| 322 |
p = openpipe(mailbox + 1);
|
| 323 |
if (p != NULL) {
|
| 324 |
buf_write(message, p);
|
| 325 |
closepipe(p);
|
| 326 |
}
|
| 327 |
} else if (strchr(mailbox, '@')) {
|
| 328 |
BUFFER *field, *content;
|
| 329 |
|
| 330 |
field = buf_new();
|
| 331 |
content = buf_new();
|
| 332 |
while (buf_getheader(message, field, content) == 0)
|
| 333 |
if (bufieq(field, "x-loop") && bufifind(content, REMAILERADDR)) {
|
| 334 |
errlog(WARNING, "Loop detected! Message not sent to %s.\n", mailbox);
|
| 335 |
goto isloop;
|
| 336 |
}
|
| 337 |
buf_sets(content, mailbox);
|
| 338 |
sendmail(message, NULL, content);
|
| 339 |
isloop:
|
| 340 |
buf_free(field);
|
| 341 |
buf_free(content);
|
| 342 |
} else {
|
| 343 |
FILE *mbox;
|
| 344 |
|
| 345 |
mbox = mix_openfile(mailbox, "a");
|
| 346 |
if (mbox == NULL) {
|
| 347 |
errlog(ERRORMSG, "Can't write to mail folder %s\n", mailbox);
|
| 348 |
return;
|
| 349 |
}
|
| 350 |
lock(mbox);
|
| 351 |
if (!bufileft(message, "From ")) {
|
| 352 |
t = time(NULL);
|
| 353 |
tc = localtime(&t);
|
| 354 |
strftime(line, LINELEN, "From Mixmaster %a %b %d %H:%M:%S %Y\n", tc);
|
| 355 |
fprintf(mbox, line);
|
| 356 |
}
|
| 357 |
buf_write(message, mbox);
|
| 358 |
fprintf(mbox, "\n");
|
| 359 |
unlock(mbox);
|
| 360 |
fclose(mbox);
|
| 361 |
}
|
| 362 |
}
|
| 363 |
|
| 364 |
int blockrequest(BUFFER *message)
|
| 365 |
{
|
| 366 |
int request = 0, domain;
|
| 367 |
BUFFER *from, *line, *field, *content, *addr;
|
| 368 |
FILE *f;
|
| 369 |
char *destblklst = (char *)malloc( strlen(DESTBLOCK)+1 );
|
| 370 |
char *destblk;
|
| 371 |
|
| 372 |
from = buf_new();
|
| 373 |
line = buf_new();
|
| 374 |
field = buf_new();
|
| 375 |
content = buf_new();
|
| 376 |
addr = buf_new();
|
| 377 |
|
| 378 |
buf_rewind(message);
|
| 379 |
while (buf_getheader(message, field, content) == 0)
|
| 380 |
if (bufieq(field, "from"))
|
| 381 |
buf_set(from, content);
|
| 382 |
else if (bufieq(field, "subject"))
|
| 383 |
buf_cat(message, content);
|
| 384 |
/* Append the subject to the message body so destination block requests
|
| 385 |
in the subject line work too (we process the body a few lines down) */
|
| 386 |
while (buf_getline(message, line) != -1)
|
| 387 |
if (bufifind(line, "destination-block")) {
|
| 388 |
buf_clear(addr);
|
| 389 |
request = 1;
|
| 390 |
{
|
| 391 |
int c = 0;
|
| 392 |
|
| 393 |
while (!strileft(line->data + line->ptr, "block"))
|
| 394 |
line->ptr++;
|
| 395 |
while (c != ' ' && c != -1)
|
| 396 |
c = tolower(buf_getc(line));
|
| 397 |
while (c == ' ')
|
| 398 |
c = buf_getc(line);
|
| 399 |
if (c != -1)
|
| 400 |
do {
|
| 401 |
buf_appendc(addr, c);
|
| 402 |
c = buf_getc(line);
|
| 403 |
} while (c > ' ');
|
| 404 |
}
|
| 405 |
if (addr->length == 0)
|
| 406 |
rfc822_addr (addr, from);
|
| 407 |
if (addr->length == 0) {
|
| 408 |
return (2);
|
| 409 |
};
|
| 410 |
if (! buffind(addr, "@"))
|
| 411 |
{
|
| 412 |
errlog(LOG, "Ignoring blocking request for %b from %b "
|
| 413 |
"(no @ sign in address).\n", addr, from);
|
| 414 |
return (2);
|
| 415 |
};
|
| 416 |
if (bufieq(addr, REMAILERADDR)) {
|
| 417 |
errlog(LOG, "Ignoring blocking request for %b from %b.\n", addr, from);
|
| 418 |
return (2);
|
| 419 |
}
|
| 420 |
if (bufleft(addr, "/")) {
|
| 421 |
errlog(LOG, "Ignoring blocking request: %b from %b is a regex.\n",
|
| 422 |
addr, from);
|
| 423 |
return (2);
|
| 424 |
}
|
| 425 |
if (buf_ieq(addr, from))
|
| 426 |
errlog(NOTICE, "Blocking request for %b\n", addr);
|
| 427 |
else
|
| 428 |
errlog(NOTICE, "Blocking request for %b from %b\n", addr, from);
|
| 429 |
if (AUTOBLOCK) {
|
| 430 |
domain = 0;
|
| 431 |
if (addr->data[0] == '@') {
|
| 432 |
domain = 1;
|
| 433 |
buf_sets(line, "postmaster");
|
| 434 |
buf_cat(line, addr);
|
| 435 |
buf_move(addr, line);
|
| 436 |
}
|
| 437 |
buf_clear(line);
|
| 438 |
rfc822_addr(addr, line);
|
| 439 |
if (strchr(line->data, '@') && strchr(strchr(line->data, '@'), '.')) {
|
| 440 |
strcpy( destblklst, DESTBLOCK );
|
| 441 |
destblk = strtok( destblklst, " " );
|
| 442 |
f = mix_openfile( destblk, "a" );
|
| 443 |
free( destblklst );
|
| 444 |
if (f != NULL) {
|
| 445 |
lock(f);
|
| 446 |
sendinfofile(BLOCKFILE, NULL, line, NULL);
|
| 447 |
if (line->length) {
|
| 448 |
if (domain)
|
| 449 |
fprintf(f, "%s", line->data + sizeof("postmaster") - 1);
|
| 450 |
else
|
| 451 |
fprintf(f, "%s", line->data);
|
| 452 |
} else
|
| 453 |
errlog(NOTICE, "%b already blocked.\n", addr);
|
| 454 |
unlock(f);
|
| 455 |
fclose(f);
|
| 456 |
} else
|
| 457 |
errlog(ERRORMSG, "Can't write to %s.\n", DESTBLOCK);
|
| 458 |
} else
|
| 459 |
errlog(WARNING, "Invalid address not added to %s: %b\n", DESTBLOCK,
|
| 460 |
addr);
|
| 461 |
}
|
| 462 |
}
|
| 463 |
return (request);
|
| 464 |
}
|
| 465 |
|
| 466 |
|
| 467 |
int idexp(void)
|
| 468 |
{
|
| 469 |
FILE *f;
|
| 470 |
BUFFER *b;
|
| 471 |
long now, then;
|
| 472 |
char line[LINELEN];
|
| 473 |
LOCK *i;
|
| 474 |
|
| 475 |
if (IDEXP == 0)
|
| 476 |
return (0);
|
| 477 |
|
| 478 |
b = buf_new();
|
| 479 |
f = mix_openfile(IDLOG, "r");
|
| 480 |
if (f == NULL)
|
| 481 |
return (-1);
|
| 482 |
i = lockfile(IDLOG);
|
| 483 |
now = time(NULL);
|
| 484 |
fgets(line, sizeof(line), f); /* replace first line */
|
| 485 |
while (fgets(line, sizeof(line), f) != NULL) {
|
| 486 |
sscanf(line, "%*s %ld", &then);
|
| 487 |
if (now - then < IDEXP)
|
| 488 |
buf_appends(b, line);
|
| 489 |
}
|
| 490 |
fclose(f);
|
| 491 |
f = mix_openfile(IDLOG, "w");
|
| 492 |
if (f != NULL) {
|
| 493 |
fprintf(f, "expired %ld\n", now - IDEXP);
|
| 494 |
buf_write(b, f);
|
| 495 |
fclose(f);
|
| 496 |
}
|
| 497 |
unlockfile(i);
|
| 498 |
return (0);
|
| 499 |
}
|