Mix/Src/rem.c

/* Mixmaster version 3  --  (C) 1999 Anonymizer Inc.

   Mixmaster may be redistributed and modified under certain conditions.
   This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF
   ANY KIND, either express or implied. See the file COPYRIGHT for
   details.

   Process remailer messages
   $Id: rem.c,v 1.1 2001/10/31 08:19:53 rabbi Exp $ */


#include "mix3.h"
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef POSIX
#include <unistd.h>
#else
#include <io.h>
#endif
#ifndef _MSC
#include <dirent.h>
#endif
#include <assert.h>

int blockrequest(BUFFER *message);

#define REQUESTHELP  100
#define REQUESTSTATS 101
#define REQUESTKEY   200
#define REQUESTCONF  201
#define REQUESTOPKEY 202
#define BLOCKREQUEST 666
#define DISABLED      99

#define CPUNKMSG 1
#define MIXMSG 2

int mix_decrypt(BUFFER *message)
{
  int type = 0;
  BUFFER *field, *content;
  BUFFER *to, *subject, *replyto, *reply;
  FILE *f;
  BUFFER *block;
  int err = 0;

  mix_init(NULL);
  field = buf_new();
  content = buf_new();
  to = buf_new();
  replyto = buf_new();
  reply = buf_new();
  block = buf_new();
  subject = buf_new();
  buf_sets(subject, "Subject: Re: your mail");

  buf_rewind(message);

  f = mix_openfile(SOURCEBLOCK, "r");
  if (f != NULL) {
    buf_read(block, f);
    fclose(f);
  }
  for (;;) {
    err = buf_getheader(message, field, content);
    if (err == 1) {
      /* "::" marks for additional header lines */
      while (buf_lookahead(message, field) == 1)
        buf_getheader(message, field, content);
      if (isline(field, HDRMARK))
        continue;
      else
        goto hdrend;
    }
    if (err == -1)
      goto hdrend;

    if ((bufieq(field, "from") || bufieq(field, "sender") || bufieq(field,"received")) &&
       doblock(content, block, 1) != 0)
      goto end;

    if (bufieq(field, "to"))
      buf_cat(to, content);
    else if (bufieq(field, "from") && replyto->length == 0)
      /* reply to From address if no Reply-To header present */
      buf_set(replyto, content);
    else if (bufieq(field, "reply-to"))
      buf_set(replyto, content);
    else if (MIX && bufieq(field, "remailer-type") &&
             bufileft(content, "mixmaster"))
      type = MIXMSG;
    else if (bufieq(field, "subject")) {
      if (bufieq(content, "help") || bufieq(content, "remailer-help"))
        type = REQUESTHELP;
      else if (bufieq(content, "remailer-stats"))
        type = REQUESTSTATS;
      else if (bufieq(content, "remailer-key"))
        type = REQUESTKEY;
      else if (bufieq(content, "remailer-adminkey"))
        type = REQUESTOPKEY;
      else if (bufieq(content, "remailer-conf"))
        type = REQUESTCONF;
      else if (bufileft(content, "destination-block"))
        type = BLOCKREQUEST;
      else {
        buf_sets(subject, "Subject: ");
        if (!bufileft(content, "re:"))
          buf_appends(subject, "Re: ");
        buf_cat(subject, content);
      }
    } else if (bufieq(field, "test-to") || bufieq(field, "encrypted") ||
               bufieq(field, "anon-to") ||
               bufieq(field, "request-remailing-to") ||
               bufieq(field, "remail-to") || bufieq(field, "anon-post-to") ||
               bufieq(field, "post-to") || bufieq(field, "anon-send-to") ||
               bufieq(field, "send-to") || bufieq(field, "remix-to"))
      type = CPUNKMSG;
  }
hdrend:
  if (type > 0 && REMAIL == 0)
    type = DISABLED;
  switch (type) {
  case REQUESTHELP:
    if (sendinfofile(HELPFILE, NULL, replyto, NULL) == -1)
      errlog(WARNING, "No help file available.\n");
    break;
  case REQUESTKEY:
    err = key(reply);
    if (err == 0)
      err = sendmail(reply, REMAILERNAME, replyto);
    break;
  case REQUESTOPKEY:
    err = adminkey(reply);
    if (err == 0)
      err = sendmail(reply, REMAILERNAME, replyto);
    break;
  case REQUESTSTATS:
    err = stats(reply);
    if (err == 0)
      err = sendmail(reply, REMAILERNAME, replyto);
    break;
  case REQUESTCONF:
    err = conf(reply);
    if (err == 0)
      err = sendmail(reply, REMAILERNAME, replyto);
    break;
  case CPUNKMSG:
    err = t1_decrypt(message);
    if (err != 0) {
      errlog(LOG, "Invalid type 1 message from %b\n", replyto);
      sendinfofile(USAGEFILE, USAGELOG, replyto, NULL);
      logmail(err == -2 ? MAILUSAGE : MAILERROR, message);
    }
    break;
  case MIXMSG:
    err = t2_decrypt(message);
    if (err == -1) {
      errlog(LOG, "Invalid type 2 message from %b\n", replyto);
      sendinfofile(USAGEFILE, USAGELOG, replyto, NULL);
      logmail(MAILERROR, message);
    }
    break;
  case BLOCKREQUEST:
    blockrequest(message);
    logmail(MAILBLOCK, message);
    break;
  case DISABLED:
    errlog(ERRORMSG, "Remailer is disabled.\n");
    buf_sets(reply, "Subject: remailer error\n\nThe remailer is disabled.\n");
    sendmail(reply, REMAILERNAME, replyto);
    logmail(MAILERROR, message);
    break;
  default:
    if (strifind
        (replyto->data, "mailer-daemon")) {
      errlog(LOG, "Bounce mail from %b\n", replyto);
      logmail(MAILBOUNCE, message);
    } else if (bufifind(to, REMAILERADDR) && blockrequest(message))
      logmail(MAILBLOCK, message);
    else if (!AUTOREPLY)
      logmail(MAILBOX, message);
    else if (bufifind(to, REMAILERADDR)) {
      errlog(LOG, "Non-remailer message from %b\n", replyto);
      sendinfofile(USAGEFILE, USAGELOG, replyto, NULL);
      logmail(MAILUSAGE, message);
    } else if (bufifind(to, COMPLAINTS)) {
      errlog(WARNING, "Abuse complaint from %b\n", replyto);
      sendinfofile(ABUSEFILE, NULL, replyto, subject);
      logmail(MAILABUSE, message);
    } else if (ANONADDR[0] && bufifind(to, ANONADDR)) {
      errlog(LOG, "Reply to anonymous message from %b\n", replyto);
      sendinfofile(REPLYFILE, NULL, replyto, subject);
      logmail(MAILANON, message);
    } else {
      errlog(DEBUGINFO, "Mail from %b\n", replyto);
      logmail(MAILBOX, message);
    }
    err = 1;
  }
end:
  buf_free(field);
  buf_free(content);
  buf_free(to);
  buf_free(replyto);
  buf_free(reply);
  buf_free(block);
  buf_free(subject);
  return (err);
}

int t2_decrypt(BUFFER *in)
{
  int err = 0;
  BUFFER *msg;

  msg = buf_new();
  do {
    err = mix_dearmor(in, msg);
    if (err != -1) {
      if (v3_magic(msg->data))
        err = mix3_decrypt(msg);
      else
        err = mix2_decrypt(msg);
    }
  }
  while (in->ptr + 1000 < in->length);  /* accept several packets in one message */

  buf_free(msg);
  return (err);
}

int mix_pool(BUFFER *msg, int type, long latent)
{
  char path[PATHMAX], pathtmp[PATHMAX];
  FILE *f;
  int err = -1;

  f = pool_new(latent > 0 ? "lat" : "msg", pathtmp, path);
  if (f != NULL) {
    if (latent > 0)
      fprintf(f, "%d %ld\n", type, latent + time(NULL));
    else
      fprintf(f, "%d 0\n", type);
    err = buf_write(msg, f);
    fclose(f);
  }
  if (err == 0) {
    rename(pathtmp, path);
    errlog(DEBUGINFO, "Added message to pool.\n");
  }
  return (err);
}

int pool_packetfile(char *fname, BUFFER *mid, int packetnum)
     /* create a filename */
{
#ifdef SHORTNAMES
  sprintf(fname, "%s/p%02x%02x%02x%01x.%02x", POOLDIR,
          mid->data[0], mid->data[1], mid->data[2], mid->data[3] & 15,
          packetnum);
#else
  sprintf(fname, "%s/p%02x%02x%02x%02x%02x%02x%01x", POOLDIR,
          packetnum, mid->data[0], mid->data[1], mid->data[2], mid->data[3],
          mid->data[4], mid->data[5] & 15);
#endif
  return (0);
}

void pool_packetexp(void)
{
  DIR *d;
  struct dirent *e;
  struct stat sb;

  d = opendir(POOLDIR);
  if (d != NULL)
    for (;;) {
      e = readdir(d);
      if (e == NULL)
        break;
      if (e->d_name[0] == 'p') {
        if (stat(e->d_name, &sb) == 0 &&
            time(NULL) - sb.st_mtime > PACKETEXP) {
          errlog(NOTICE, "Expiring partial message %s.\n",
                 e->d_name);
          unlink(e->d_name);
        }
      }
    }
  closedir(d);
}

void logmail(char *mailbox, BUFFER *message)
{
  /* mailbox is "|program", "user@host", "stdout" or "filename" */
  buf_rewind(message);
  if (mailbox[0] == '\0')       /* default action */
    mailbox = MAILBOX;
  if (strieq(mailbox, "stdout"))
    buf_write(message, stdout);
  else if (mailbox[0] == '|') {
    FILE *p;

    errlog(DEBUGINFO, "Piping message to %s.", mailbox + 1);
    p = openpipe(mailbox + 1);
    if (p != NULL) {
      buf_write(message, p);
      closepipe(p);
    }
  } else if (strchr(mailbox, '@')) {
    BUFFER *field, *content;

    field = buf_new();
    content = buf_new();
    while (buf_getheader(message, field, content) == 0)
      if (bufieq(field, "x-loop") && bufifind(content, REMAILERADDR)) {
        errlog(WARNING, "Loop detected! Message not sent to %s.\n", mailbox);
        goto isloop;
      }
    buf_sets(content, mailbox);
    sendmail(message, NULL, content);
  isloop:
    buf_free(field);
    buf_free(content);
  } else {
    FILE *mbox;

    mbox = mix_openfile(mailbox, "a");
    if (mbox == NULL) {
      errlog(ERRORMSG, "Can't write to mail folder %s\n", mailbox);
      return;
    }
    lock(mbox);
    if (!bufileft(message, "From "))
      fprintf(mbox, "From Mixmaster Wed Jan 01 00:00:00 1970\n");
    buf_write(message, mbox);
    fprintf(mbox, "\n");
    unlock(mbox);
    fclose(mbox);
  }
}

int blockrequest(BUFFER *message)
{
  int request = 0, domain;
  BUFFER *from, *line, *field, *content, *addr;
  FILE *f;
  char *destblklst = (char *)malloc( strlen(DESTBLOCK)+1 );
  char *destblk;

  from = buf_new();
  line = buf_new();
  field = buf_new();
  content = buf_new();
  addr = buf_new();

  buf_rewind(message);
  while (buf_getheader(message, field, content) == 0)
    if (bufieq(field, "from"))
      buf_set(from, content);
    else if (bufieq(field, "subject"))
      buf_cat(message, content);
  while (buf_getline(message, line) != -1)
    if (bufifind(line, "destination-block")) {
      buf_clear(addr);
      request = 1;
      if (buffind(line, "@")) {
        int c = 0;

        while (!strileft(line->data + line->ptr, "block"))
          line->ptr++;
        while (c != ' ')
          c = tolower(buf_getc(line));
        while (c == ' ')
          c = buf_getc(line);
        do {
          buf_appendc(addr, c);
          c = buf_getc(line);
        } while (c > ' ');
      } else
        buf_set(addr, from);
      if (bufieq(addr, REMAILERADDR)) {
        errlog(LOG, "Ignoring blocking request for %b from %b.\n", addr, from);
        return (2);
      }
      if (buf_ieq(addr, from))
        errlog(NOTICE, "Blocking request for %b\n", addr);
      else
        errlog(NOTICE, "Blocking request for %b from %b\n", addr, from);
      if (AUTOBLOCK) {
        domain = 0;
        if (addr->data[0] == '@') {
          domain = 1;
          buf_sets(line, "postmaster");
          buf_cat(line, addr);
          buf_move(addr, line);
        }
        buf_clear(line);
        rfc822_addr(addr, line);
        if (strchr(line->data, '@') && strchr(strchr(line->data, '@'), '.')) {
          strcpy( destblklst, DESTBLOCK );
          destblk = strtok( destblklst, " " );
          f = mix_openfile( destblk, "a" );
          free( destblklst );
          if (f != NULL) {
            lock(f);
            sendinfofile(BLOCKFILE, NULL, line, NULL);
            if (line->length) {
              if (domain)
                fprintf(f, "%s", line->data + sizeof("postmaster") - 1);
              else
                fprintf(f, "%s", line->data);
            } else
              errlog(NOTICE, "%b already blocked.\n", addr);
            unlock(f);
            fclose(f);
          } else
            errlog(ERRORMSG, "Can't write to %s.\n", DESTBLOCK);
        } else
          errlog(WARNING, "Invalid address not added to %s: %b\n", DESTBLOCK,
                 addr);
      }
    }
  return (request);
}


int idexp(void)
{
  FILE *f;
  BUFFER *b;
  long now, then;
  char line[LINELEN];
  LOCK *i;

  if (IDEXP == 0)
    return (0);

  b = buf_new();
  f = mix_openfile(IDLOG, "r");
  if (f == NULL)
    return (-1);
  i = lockfile(IDLOG);
  now = time(NULL);
  fgets(line, sizeof(line), f); /* replace first line */
  while (fgets(line, sizeof(line), f) != NULL) {
    sscanf(line, "%*s %ld", &then);
    if (now - then < IDEXP)
      buf_appends(b, line);
  }
  fclose(f);
  f = mix_openfile(IDLOG, "w");
  if (f != NULL) {
    fprintf(f, "expired %ld\n", now - IDEXP);
    buf_write(b, f);
    fclose(f);
  }
  unlockfile(i);
  return (0);
}
1	rabbi	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 1.1 2001/10/31 08:19:53 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
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
51			mix_init(NULL);
52			field = buf_new();
53			content = buf_new();
54			to = buf_new();
55			replyto = buf_new();
56			reply = buf_new();
57			block = buf_new();
58			subject = buf_new();
59			buf_sets(subject, "Subject: Re: your mail");
60
61			buf_rewind(message);
62
63			f = mix_openfile(SOURCEBLOCK, "r");
64			if (f != NULL) {
65			buf_read(block, f);
66			fclose(f);
67			}
68			for (;;) {
69			err = buf_getheader(message, field, content);
70			if (err == 1) {
71			/* "::" marks for additional header lines */
72			while (buf_lookahead(message, field) == 1)
73			buf_getheader(message, field, content);
74			if (isline(field, HDRMARK))
75			continue;
76			else
77			goto hdrend;
78			}
79			if (err == -1)
80			goto hdrend;
81
82			if ((bufieq(field, "from") \|\| bufieq(field, "sender") \|\| bufieq(field,"received")) &&
83			doblock(content, block, 1) != 0)
84			goto end;
85
86			if (bufieq(field, "to"))
87			buf_cat(to, content);
88			else if (bufieq(field, "from") && replyto->length == 0)
89			/* reply to From address if no Reply-To header present */
90			buf_set(replyto, content);
91			else if (bufieq(field, "reply-to"))
92			buf_set(replyto, content);
93			else if (MIX && bufieq(field, "remailer-type") &&
94			bufileft(content, "mixmaster"))
95			type = MIXMSG;
96			else if (bufieq(field, "subject")) {
97			if (bufieq(content, "help") \|\| bufieq(content, "remailer-help"))
98			type = REQUESTHELP;
99			else if (bufieq(content, "remailer-stats"))
100			type = REQUESTSTATS;
101			else if (bufieq(content, "remailer-key"))
102			type = REQUESTKEY;
103			else if (bufieq(content, "remailer-adminkey"))
104			type = REQUESTOPKEY;
105			else if (bufieq(content, "remailer-conf"))
106			type = REQUESTCONF;
107			else if (bufileft(content, "destination-block"))
108			type = BLOCKREQUEST;
109			else {
110			buf_sets(subject, "Subject: ");
111			if (!bufileft(content, "re:"))
112			buf_appends(subject, "Re: ");
113			buf_cat(subject, content);
114			}
115			} else if (bufieq(field, "test-to") \|\| bufieq(field, "encrypted") \|\|
116			bufieq(field, "anon-to") \|\|
117			bufieq(field, "request-remailing-to") \|\|
118			bufieq(field, "remail-to") \|\| bufieq(field, "anon-post-to") \|\|
119			bufieq(field, "post-to") \|\| bufieq(field, "anon-send-to") \|\|
120			bufieq(field, "send-to") \|\| bufieq(field, "remix-to"))
121			type = CPUNKMSG;
122			}
123			hdrend:
124			if (type > 0 && REMAIL == 0)
125			type = DISABLED;
126			switch (type) {
127			case REQUESTHELP:
128			if (sendinfofile(HELPFILE, NULL, replyto, NULL) == -1)
129			errlog(WARNING, "No help file available.\n");
130			break;
131			case REQUESTKEY:
132			err = key(reply);
133			if (err == 0)
134			err = sendmail(reply, REMAILERNAME, replyto);
135			break;
136			case REQUESTOPKEY:
137			err = adminkey(reply);
138			if (err == 0)
139			err = sendmail(reply, REMAILERNAME, replyto);
140			break;
141			case REQUESTSTATS:
142			err = stats(reply);
143			if (err == 0)
144			err = sendmail(reply, REMAILERNAME, replyto);
145			break;
146			case REQUESTCONF:
147			err = conf(reply);
148			if (err == 0)
149			err = sendmail(reply, REMAILERNAME, replyto);
150			break;
151			case CPUNKMSG:
152			err = t1_decrypt(message);
153			if (err != 0) {
154			errlog(LOG, "Invalid type 1 message from %b\n", replyto);
155			sendinfofile(USAGEFILE, USAGELOG, replyto, NULL);
156			logmail(err == -2 ? MAILUSAGE : MAILERROR, message);
157			}
158			break;
159			case MIXMSG:
160			err = t2_decrypt(message);
161			if (err == -1) {
162			errlog(LOG, "Invalid type 2 message from %b\n", replyto);
163			sendinfofile(USAGEFILE, USAGELOG, replyto, NULL);
164			logmail(MAILERROR, message);
165			}
166			break;
167			case BLOCKREQUEST:
168			blockrequest(message);
169			logmail(MAILBLOCK, message);
170			break;
171			case DISABLED:
172			errlog(ERRORMSG, "Remailer is disabled.\n");
173			buf_sets(reply, "Subject: remailer error\n\nThe remailer is disabled.\n");
174			sendmail(reply, REMAILERNAME, replyto);
175			logmail(MAILERROR, message);
176			break;
177			default:
178			if (strifind
179			(replyto->data, "mailer-daemon")) {
180			errlog(LOG, "Bounce mail from %b\n", replyto);
181			logmail(MAILBOUNCE, message);
182			} else if (bufifind(to, REMAILERADDR) && blockrequest(message))
183			logmail(MAILBLOCK, message);
184			else if (!AUTOREPLY)
185			logmail(MAILBOX, message);
186			else if (bufifind(to, REMAILERADDR)) {
187			errlog(LOG, "Non-remailer message from %b\n", replyto);
188			sendinfofile(USAGEFILE, USAGELOG, replyto, NULL);
189			logmail(MAILUSAGE, message);
190			} else if (bufifind(to, COMPLAINTS)) {
191			errlog(WARNING, "Abuse complaint from %b\n", replyto);
192			sendinfofile(ABUSEFILE, NULL, replyto, subject);
193			logmail(MAILABUSE, message);
194			} else if (ANONADDR[0] && bufifind(to, ANONADDR)) {
195			errlog(LOG, "Reply to anonymous message from %b\n", replyto);
196			sendinfofile(REPLYFILE, NULL, replyto, subject);
197			logmail(MAILANON, message);
198			} else {
199			errlog(DEBUGINFO, "Mail from %b\n", replyto);
200			logmail(MAILBOX, message);
201			}
202			err = 1;
203			}
204			end:
205			buf_free(field);
206			buf_free(content);
207			buf_free(to);
208			buf_free(replyto);
209			buf_free(reply);
210			buf_free(block);
211			buf_free(subject);
212			return (err);
213			}
214
215			int t2_decrypt(BUFFER *in)
216			{
217			int err = 0;
218			BUFFER *msg;
219
220			msg = buf_new();
221			do {
222			err = mix_dearmor(in, msg);
223			if (err != -1) {
224			if (v3_magic(msg->data))
225			err = mix3_decrypt(msg);
226			else
227			err = mix2_decrypt(msg);
228			}
229			}
230			while (in->ptr + 1000 < in->length); /* accept several packets in one message */
231
232			buf_free(msg);
233			return (err);
234			}
235
236			int mix_pool(BUFFER *msg, int type, long latent)
237			{
238			char path[PATHMAX], pathtmp[PATHMAX];
239			FILE *f;
240			int err = -1;
241
242			f = pool_new(latent > 0 ? "lat" : "msg", pathtmp, path);
243			if (f != NULL) {
244			if (latent > 0)
245			fprintf(f, "%d %ld\n", type, latent + time(NULL));
246			else
247			fprintf(f, "%d 0\n", type);
248			err = buf_write(msg, f);
249			fclose(f);
250			}
251			if (err == 0) {
252			rename(pathtmp, path);
253			errlog(DEBUGINFO, "Added message to pool.\n");
254			}
255			return (err);
256			}
257
258			int pool_packetfile(char fname, BUFFER mid, int packetnum)
259			/* create a filename */
260			{
261			#ifdef SHORTNAMES
262			sprintf(fname, "%s/p%02x%02x%02x%01x.%02x", POOLDIR,
263			mid->data[0], mid->data[1], mid->data[2], mid->data[3] & 15,
264			packetnum);
265			#else
266			sprintf(fname, "%s/p%02x%02x%02x%02x%02x%02x%01x", POOLDIR,
267			packetnum, mid->data[0], mid->data[1], mid->data[2], mid->data[3],
268			mid->data[4], mid->data[5] & 15);
269			#endif
270			return (0);
271			}
272
273			void pool_packetexp(void)
274			{
275			DIR *d;
276			struct dirent *e;
277			struct stat sb;
278
279			d = opendir(POOLDIR);
280			if (d != NULL)
281			for (;;) {
282			e = readdir(d);
283			if (e == NULL)
284			break;
285			if (e->d_name[0] == 'p') {
286			if (stat(e->d_name, &sb) == 0 &&
287			time(NULL) - sb.st_mtime > PACKETEXP) {
288			errlog(NOTICE, "Expiring partial message %s.\n",
289			e->d_name);
290			unlink(e->d_name);
291			}
292			}
293			}
294			closedir(d);
295			}
296
297			void logmail(char mailbox, BUFFER message)
298			{
299			/* mailbox is "\|program", "user@host", "stdout" or "filename" */
300			buf_rewind(message);
301			if (mailbox[0] == '\0') /* default action */
302			mailbox = MAILBOX;
303			if (strieq(mailbox, "stdout"))
304			buf_write(message, stdout);
305			else if (mailbox[0] == '\|') {
306			FILE *p;
307
308			errlog(DEBUGINFO, "Piping message to %s.", mailbox + 1);
309			p = openpipe(mailbox + 1);
310			if (p != NULL) {
311			buf_write(message, p);
312			closepipe(p);
313			}
314			} else if (strchr(mailbox, '@')) {
315			BUFFER field, content;
316
317			field = buf_new();
318			content = buf_new();
319			while (buf_getheader(message, field, content) == 0)
320			if (bufieq(field, "x-loop") && bufifind(content, REMAILERADDR)) {
321			errlog(WARNING, "Loop detected! Message not sent to %s.\n", mailbox);
322			goto isloop;
323			}
324			buf_sets(content, mailbox);
325			sendmail(message, NULL, content);
326			isloop:
327			buf_free(field);
328			buf_free(content);
329			} else {
330			FILE *mbox;
331
332			mbox = mix_openfile(mailbox, "a");
333			if (mbox == NULL) {
334			errlog(ERRORMSG, "Can't write to mail folder %s\n", mailbox);
335			return;
336			}
337			lock(mbox);
338			if (!bufileft(message, "From "))
339			fprintf(mbox, "From Mixmaster Wed Jan 01 00:00:00 1970\n");
340			buf_write(message, mbox);
341			fprintf(mbox, "\n");
342			unlock(mbox);
343			fclose(mbox);
344			}
345			}
346
347			int blockrequest(BUFFER *message)
348			{
349			int request = 0, domain;
350			BUFFER from, line, field, content, *addr;
351			FILE *f;
352			char destblklst = (char )malloc( strlen(DESTBLOCK)+1 );
353			char *destblk;
354
355			from = buf_new();
356			line = buf_new();
357			field = buf_new();
358			content = buf_new();
359			addr = buf_new();
360
361			buf_rewind(message);
362			while (buf_getheader(message, field, content) == 0)
363			if (bufieq(field, "from"))
364			buf_set(from, content);
365			else if (bufieq(field, "subject"))
366			buf_cat(message, content);
367			while (buf_getline(message, line) != -1)
368			if (bufifind(line, "destination-block")) {
369			buf_clear(addr);
370			request = 1;
371			if (buffind(line, "@")) {
372			int c = 0;
373
374			while (!strileft(line->data + line->ptr, "block"))
375			line->ptr++;
376			while (c != ' ')
377			c = tolower(buf_getc(line));
378			while (c == ' ')
379			c = buf_getc(line);
380			do {
381			buf_appendc(addr, c);
382			c = buf_getc(line);
383			} while (c > ' ');
384			} else
385			buf_set(addr, from);
386			if (bufieq(addr, REMAILERADDR)) {
387			errlog(LOG, "Ignoring blocking request for %b from %b.\n", addr, from);
388			return (2);
389			}
390			if (buf_ieq(addr, from))
391			errlog(NOTICE, "Blocking request for %b\n", addr);
392			else
393			errlog(NOTICE, "Blocking request for %b from %b\n", addr, from);
394			if (AUTOBLOCK) {
395			domain = 0;
396			if (addr->data[0] == '@') {
397			domain = 1;
398			buf_sets(line, "postmaster");
399			buf_cat(line, addr);
400			buf_move(addr, line);
401			}
402			buf_clear(line);
403			rfc822_addr(addr, line);
404			if (strchr(line->data, '@') && strchr(strchr(line->data, '@'), '.')) {
405			strcpy( destblklst, DESTBLOCK );
406			destblk = strtok( destblklst, " " );
407			f = mix_openfile( destblk, "a" );
408			free( destblklst );
409			if (f != NULL) {
410			lock(f);
411			sendinfofile(BLOCKFILE, NULL, line, NULL);
412			if (line->length) {
413			if (domain)
414			fprintf(f, "%s", line->data + sizeof("postmaster") - 1);
415			else
416			fprintf(f, "%s", line->data);
417			} else
418			errlog(NOTICE, "%b already blocked.\n", addr);
419			unlock(f);
420			fclose(f);
421			} else
422			errlog(ERRORMSG, "Can't write to %s.\n", DESTBLOCK);
423			} else
424			errlog(WARNING, "Invalid address not added to %s: %b\n", DESTBLOCK,
425			addr);
426			}
427			}
428			return (request);
429			}
430
431
432			int idexp(void)
433			{
434			FILE *f;
435			BUFFER *b;
436			long now, then;
437			char line[LINELEN];
438			LOCK *i;
439
440			if (IDEXP == 0)
441			return (0);
442
443			b = buf_new();
444			f = mix_openfile(IDLOG, "r");
445			if (f == NULL)
446			return (-1);
447			i = lockfile(IDLOG);
448			now = time(NULL);
449			fgets(line, sizeof(line), f); /* replace first line */
450			while (fgets(line, sizeof(line), f) != NULL) {
451			sscanf(line, "%*s %ld", &then);
452			if (now - then < IDEXP)
453			buf_appends(b, line);
454			}
455			fclose(f);
456			f = mix_openfile(IDLOG, "w");
457			if (f != NULL) {
458			fprintf(f, "expired %ld\n", now - IDEXP);
459			buf_write(b, f);
460			fclose(f);
461			}
462			unlockfile(i);
463			return (0);
464			}