Adding upstream version 4.94.2.upstream/4.94.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 646 insertions, 0 deletions

diff --git a/src/spam.c b/src/spam.c
new file mode 100644
index 0000000..2fffa14
--- /dev/null
+++ b/src/spam.c
@@ -0,0 +1,646 @@
+/*************************************************
+*     Exim - an Internet mail transport agent    *
+*************************************************/
+
+/* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2003 - 2015
+ * License: GPL
+ * Copyright (c) The Exim Maintainers 2016 - 2020
+ */
+
+/* Code for calling spamassassin's spamd. Called from acl.c. */
+
+#include "exim.h"
+#ifdef WITH_CONTENT_SCAN
+#include "spam.h"
+
+uschar spam_score_buffer[16];
+uschar spam_score_int_buffer[16];
+uschar spam_bar_buffer[128];
+uschar spam_action_buffer[32];
+uschar spam_report_buffer[32600];
+uschar * prev_user_name = NULL;
+int spam_ok = 0;
+int spam_rc = 0;
+uschar *prev_spamd_address_work = NULL;
+
+static const uschar * loglabel = US"spam acl condition:";
+
+
+static int
+spamd_param_init(spamd_address_container *spamd)
+{
+/* default spamd server weight, time and priority value */
+spamd->is_rspamd = FALSE;
+spamd->is_failed = FALSE;
+spamd->weight = SPAMD_WEIGHT;
+spamd->timeout = SPAMD_TIMEOUT;
+spamd->retry = 0;
+spamd->priority = 1;
+return 0;
+}
+
+
+static int
+spamd_param(const uschar * param, spamd_address_container * spamd)
+{
+static int timesinceday = -1;
+const uschar * s;
+const uschar * name;
+
+/*XXX more clever parsing could discard embedded spaces? */
+
+if (sscanf(CCS param, "pri=%u", &spamd->priority))
+  return 0; /* OK */
+
+if (sscanf(CCS param, "weight=%u", &spamd->weight))
+  {
+  if (spamd->weight == 0) /* this server disabled: skip it */
+    return 1;
+  return 0; /* OK */
+  }
+
+if (Ustrncmp(param, "time=", 5) == 0)
+  {
+  unsigned int start_h = 0, start_m = 0, start_s = 0;
+  unsigned int end_h = 24, end_m = 0, end_s = 0;
+  unsigned int time_start, time_end;
+  const uschar * end_string;
+
+  name = US"time";
+  s = param+5;
+  if ((end_string = Ustrchr(s, '-')))
+    {
+    end_string++;
+    if (  sscanf(CS end_string, "%u.%u.%u", &end_h,   &end_m,   &end_s)   == 0
+       || sscanf(CS s,          "%u.%u.%u", &start_h, &start_m, &start_s) == 0
+       )
+      goto badval;
+    }
+  else
+    goto badval;
+
+  if (timesinceday < 0)
+    {
+    time_t now = time(NULL);
+    struct tm *tmp = localtime(&now);
+    timesinceday = tmp->tm_hour*3600 + tmp->tm_min*60 + tmp->tm_sec;
+    }
+
+  time_start = start_h*3600 + start_m*60 + start_s;
+  time_end = end_h*3600 + end_m*60 + end_s;
+
+  if (timesinceday < time_start || timesinceday >= time_end)
+    return 1; /* skip spamd server */
+
+  return 0; /* OK */
+  }
+
+if (Ustrcmp(param, "variant=rspamd") == 0)
+  {
+  spamd->is_rspamd = TRUE;
+  return 0;
+  }
+
+if (Ustrncmp(param, "tmo=", 4) == 0)
+  {
+  int sec = readconf_readtime((s = param+4), '\0', FALSE);
+  name = US"timeout";
+  if (sec < 0)
+    goto badval;
+  spamd->timeout = sec;
+  return 0;
+  }
+
+if (Ustrncmp(param, "retry=", 6) == 0)
+  {
+  int sec = readconf_readtime((s = param+6), '\0', FALSE);
+  name = US"retry";
+  if (sec < 0)
+    goto badval;
+  spamd->retry = sec;
+  return 0;
+  }
+
+log_write(0, LOG_MAIN, "%s warning - invalid spamd parameter: '%s'",
+  loglabel, param);
+return -1; /* syntax error */
+
+badval:
+  log_write(0, LOG_MAIN,
+    "%s warning - invalid spamd %s value: '%s'", loglabel, name, s);
+  return -1; /* syntax error */
+}
+
+
+static int
+spamd_get_server(spamd_address_container ** spamds, int num_servers)
+{
+unsigned int i;
+spamd_address_container * sd;
+long weights;
+unsigned pri;
+static BOOL srandomed = FALSE;
+
+/* speedup, if we have only 1 server */
+if (num_servers == 1)
+  return (spamds[0]->is_failed ? -1 : 0);
+
+/* init ranmod */
+if (!srandomed)
+  {
+  struct timeval tv;
+  gettimeofday(&tv, NULL);
+  srandom((unsigned int)(tv.tv_usec/1000));
+  srandomed = TRUE;
+  }
+
+/* scan for highest pri */
+for (pri = 0, i = 0; i < num_servers; i++)
+  {
+  sd = spamds[i];
+  if (!sd->is_failed && sd->priority > pri) pri = sd->priority;
+  }
+
+/* get sum of weights */
+for (weights = 0, i = 0; i < num_servers; i++)
+  {
+  sd = spamds[i];
+  if (!sd->is_failed && sd->priority == pri) weights += sd->weight;
+  }
+if (weights == 0)	/* all servers failed */
+  return -1;
+
+for (long rnd = random() % weights, i = 0; i < num_servers; i++)
+  {
+  sd = spamds[i];
+  if (!sd->is_failed && sd->priority == pri)
+    if ((rnd -= sd->weight) < 0)
+      return i;
+  }
+
+log_write(0, LOG_MAIN|LOG_PANIC,
+  "%s unknown error (memory/cpu corruption?)", loglabel);
+return -1;
+}
+
+
+int
+spam(const uschar **listptr)
+{
+int sep = 0;
+const uschar *list = *listptr;
+uschar *user_name;
+unsigned long mbox_size;
+FILE *mbox_file;
+client_conn_ctx spamd_cctx = {.sock = -1};
+uschar spamd_buffer[32600];
+int i, j, offset, result;
+uschar spamd_version[8];
+uschar spamd_short_result[8];
+uschar spamd_score_char;
+double spamd_threshold, spamd_score, spamd_reject_score;
+int spamd_report_offset;
+uschar *p,*q;
+int override = 0;
+time_t start;
+size_t read, wrote;
+#ifndef NO_POLL_H
+struct pollfd pollfd;
+#else                               /* Patch posted by Erik ? for OS X */
+struct timeval select_tv;         /* and applied by PH */
+fd_set select_fd;
+#endif
+uschar *spamd_address_work;
+spamd_address_container * sd;
+
+/* stop compiler warning */
+result = 0;
+
+/* find the username from the option list */
+if (!(user_name = string_nextinlist(&list, &sep, NULL, 0)))
+  {
+  /* no username given, this means no scanning should be done */
+  return FAIL;
+  }
+
+/* if username is "0" or "false", do not scan */
+if ( (Ustrcmp(user_name,"0") == 0) ||
+     (strcmpic(user_name,US"false") == 0) )
+  return FAIL;
+
+/* if there is an additional option, check if it is "true" */
+if (strcmpic(list,US"true") == 0)
+  /* in that case, always return true later */
+  override = 1;
+
+/* expand spamd_address if needed */
+if (*spamd_address == '$')
+  {
+  spamd_address_work = expand_string(spamd_address);
+  if (spamd_address_work == NULL)
+    {
+    log_write(0, LOG_MAIN|LOG_PANIC,
+      "%s spamd_address starts with $, but expansion failed: %s",
+      loglabel, expand_string_message);
+    return DEFER;
+    }
+  }
+else
+  spamd_address_work = spamd_address;
+
+DEBUG(D_acl) debug_printf_indent("spamd: addrlist '%s'\n", spamd_address_work);
+
+/* check if previous spamd_address was expanded and has changed. dump cached results if so */
+if (  spam_ok
+   && prev_spamd_address_work != NULL
+   && Ustrcmp(prev_spamd_address_work, spamd_address_work) != 0
+   )
+  spam_ok = 0;
+
+/* if we scanned for this username last time, just return */
+if (spam_ok && Ustrcmp(prev_user_name, user_name) == 0)
+  return override ? OK : spam_rc;
+
+/* make sure the eml mbox file is spooled up */
+
+if (!(mbox_file = spool_mbox(&mbox_size, NULL, NULL)))
+  {								/* error while spooling */
+  log_write(0, LOG_MAIN|LOG_PANIC,
+	 "%s error while creating mbox spool file", loglabel);
+  return DEFER;
+  }
+
+start = time(NULL);
+
+  {
+  int num_servers = 0;
+  int current_server;
+  uschar * address;
+  const uschar * spamd_address_list_ptr = spamd_address_work;
+  spamd_address_container * spamd_address_vector[32];
+
+  /* Check how many spamd servers we have
+     and register their addresses */
+  sep = 0;				/* default colon-sep */
+  while ((address = string_nextinlist(&spamd_address_list_ptr, &sep, NULL, 0)))
+    {
+    const uschar * sublist;
+    int sublist_sep = -(int)' ';	/* default space-sep */
+    unsigned args;
+    uschar * s;
+
+    DEBUG(D_acl) debug_printf_indent("spamd: addr entry '%s'\n", address);
+    sd = store_get(sizeof(spamd_address_container), FALSE);
+
+    for (sublist = address, args = 0, spamd_param_init(sd);
+	 (s = string_nextinlist(&sublist, &sublist_sep, NULL, 0));
+	 args++
+	 )
+      {
+	DEBUG(D_acl) debug_printf_indent("spamd:  addr parm '%s'\n", s);
+	switch (args)
+	{
+	case 0:   sd->hostspec = s;
+		  if (*s == '/') args++;	/* local; no port */
+		  break;
+	case 1:   sd->hostspec = string_sprintf("%s %s", sd->hostspec, s);
+		  break;
+	default:  spamd_param(s, sd);
+		  break;
+	}
+      }
+    if (args < 2)
+      {
+      log_write(0, LOG_MAIN,
+	"%s warning - invalid spamd address: '%s'", loglabel, address);
+      continue;
+      }
+
+    spamd_address_vector[num_servers] = sd;
+    if (++num_servers > 31)
+      break;
+    }
+
+  /* check if we have at least one server */
+  if (!num_servers)
+    {
+    log_write(0, LOG_MAIN|LOG_PANIC,
+       "%s no useable spamd server addresses in spamd_address configuration option.",
+       loglabel);
+    goto defer;
+    }
+
+  current_server = spamd_get_server(spamd_address_vector, num_servers);
+  sd = spamd_address_vector[current_server];
+  for(;;)
+    {
+    uschar * errstr;
+
+    DEBUG(D_acl) debug_printf_indent("spamd: trying server %s\n", sd->hostspec);
+
+    for (;;)
+      {
+      /*XXX could potentially use TFO early-data here */
+      if (  (spamd_cctx.sock = ip_streamsocket(sd->hostspec, &errstr, 5, NULL)) >= 0
+         || sd->retry <= 0
+	 )
+	break;
+      DEBUG(D_acl) debug_printf_indent("spamd: server %s: retry conn\n", sd->hostspec);
+      while (sd->retry > 0) sd->retry = sleep(sd->retry);
+      }
+    if (spamd_cctx.sock >= 0)
+      break;
+
+    log_write(0, LOG_MAIN, "%s spamd: %s", loglabel, errstr);
+    sd->is_failed = TRUE;
+
+    current_server = spamd_get_server(spamd_address_vector, num_servers);
+    if (current_server < 0)
+      {
+      log_write(0, LOG_MAIN|LOG_PANIC, "%s all spamd servers failed", loglabel);
+      goto defer;
+      }
+    sd = spamd_address_vector[current_server];
+    }
+  }
+
+(void)fcntl(spamd_cctx.sock, F_SETFL, O_NONBLOCK);
+/* now we are connected to spamd on spamd_cctx.sock */
+if (sd->is_rspamd)
+  {
+  gstring * req_str;
+  const uschar * s;
+
+  req_str = string_append(NULL, 8,
+    "CHECK RSPAMC/1.3\r\nContent-length: ", string_sprintf("%lu\r\n", mbox_size),
+    "Queue-Id: ", message_id,
+    "\r\nFrom: <", sender_address,
+    ">\r\nRecipient-Number: ", string_sprintf("%d\r\n", recipients_count));
+
+  for (int i = 0; i < recipients_count; i++)
+    req_str = string_append(req_str, 3,
+      "Rcpt: <", recipients_list[i].address, ">\r\n");
+  if ((s = expand_string(US"$sender_helo_name")) && *s)
+    req_str = string_append(req_str, 3, "Helo: ", s, "\r\n");
+  if ((s = expand_string(US"$sender_host_name")) && *s)
+    req_str = string_append(req_str, 3, "Hostname: ", s, "\r\n");
+  if (sender_host_address)
+    req_str = string_append(req_str, 3, "IP: ", sender_host_address, "\r\n");
+  if ((s = expand_string(US"$authenticated_id")) && *s)
+    req_str = string_append(req_str, 3, "User: ", s, "\r\n");
+  req_str = string_catn(req_str, US"\r\n", 2);
+  wrote = send(spamd_cctx.sock, req_str->s, req_str->ptr, 0);
+  }
+else
+  {				/* spamassassin variant */
+  int n;
+  uschar * s = string_sprintf(
+	  "REPORT SPAMC/1.2\r\nUser: %s\r\nContent-length: %ld\r\n\r\n%n",
+	  user_name, mbox_size, &n);
+  /* send our request */
+  wrote = send(spamd_cctx.sock, s, n, 0);
+  }
+
+if (wrote == -1)
+  {
+  (void)close(spamd_cctx.sock);
+  log_write(0, LOG_MAIN|LOG_PANIC,
+       "%s spamd %s send failed: %s", loglabel, callout_address, strerror(errno));
+  goto defer;
+  }
+
+/* now send the file */
+/* spamd sometimes accepts connections but doesn't read data off
+ * the connection.  We make the file descriptor non-blocking so
+ * that the write will only write sufficient data without blocking
+ * and we poll the descriptor to make sure that we can write without
+ * blocking.  Short writes are gracefully handled and if the whole
+ * transaction takes too long it is aborted.
+ * Note: poll() is not supported in OSX 10.2 and is reported to be
+ *       broken in more recent versions (up to 10.4).
+ */
+#ifndef NO_POLL_H
+pollfd.fd = spamd_cctx.sock;
+pollfd.events = POLLOUT;
+#endif
+(void)fcntl(spamd_cctx.sock, F_SETFL, O_NONBLOCK);
+do
+  {
+  read = fread(spamd_buffer,1,sizeof(spamd_buffer),mbox_file);
+  if (read > 0)
+    {
+    offset = 0;
+again:
+#ifndef NO_POLL_H
+    result = poll(&pollfd, 1, 1000);
+
+/* Patch posted by Erik ? for OS X and applied by PH */
+#else
+    select_tv.tv_sec = 1;
+    select_tv.tv_usec = 0;
+    FD_ZERO(&select_fd);
+    FD_SET(spamd_cctx.sock, &select_fd);
+    result = select(spamd_cctx.sock+1, NULL, &select_fd, NULL, &select_tv);
+#endif
+/* End Erik's patch */
+
+    if (result == -1 && errno == EINTR)
+      goto again;
+    else if (result < 1)
+      {
+      if (result == -1)
+	log_write(0, LOG_MAIN|LOG_PANIC,
+	  "%s %s on spamd %s socket", loglabel, callout_address, strerror(errno));
+      else
+	{
+	if (time(NULL) - start < sd->timeout)
+	  goto again;
+	log_write(0, LOG_MAIN|LOG_PANIC,
+	  "%s timed out writing spamd %s, socket", loglabel, callout_address);
+	}
+      (void)close(spamd_cctx.sock);
+      goto defer;
+      }
+
+    wrote = send(spamd_cctx.sock,spamd_buffer + offset,read - offset,0);
+    if (wrote == -1)
+      {
+      log_write(0, LOG_MAIN|LOG_PANIC,
+	  "%s %s on spamd %s socket", loglabel, callout_address, strerror(errno));
+      (void)close(spamd_cctx.sock);
+      goto defer;
+      }
+    if (offset + wrote != read)
+      {
+      offset += wrote;
+      goto again;
+      }
+    }
+  }
+while (!feof(mbox_file) && !ferror(mbox_file));
+
+if (ferror(mbox_file))
+  {
+  log_write(0, LOG_MAIN|LOG_PANIC,
+    "%s error reading spool file: %s", loglabel, strerror(errno));
+  (void)close(spamd_cctx.sock);
+  goto defer;
+  }
+
+(void)fclose(mbox_file);
+
+/* we're done sending, close socket for writing */
+if (!sd->is_rspamd)
+  shutdown(spamd_cctx.sock,SHUT_WR);
+
+/* read spamd response using what's left of the timeout.  */
+memset(spamd_buffer, 0, sizeof(spamd_buffer));
+offset = 0;
+while ((i = ip_recv(&spamd_cctx,
+		   spamd_buffer + offset,
+		   sizeof(spamd_buffer) - offset - 1,
+		   sd->timeout + start)) > 0)
+  offset += i;
+spamd_buffer[offset] = '\0';	/* guard byte */
+
+/* error handling */
+if (i <= 0 && errno != 0)
+  {
+  log_write(0, LOG_MAIN|LOG_PANIC,
+       "%s error reading from spamd %s, socket: %s", loglabel, callout_address, strerror(errno));
+  (void)close(spamd_cctx.sock);
+  return DEFER;
+  }
+
+/* reading done */
+(void)close(spamd_cctx.sock);
+
+if (sd->is_rspamd)
+  {				/* rspamd variant of reply */
+  int r;
+  if (  (r = sscanf(CS spamd_buffer,
+	  "RSPAMD/%7s 0 EX_OK\r\nMetric: default; %7s %lf / %lf / %lf\r\n%n",
+	  spamd_version, spamd_short_result, &spamd_score, &spamd_threshold,
+	  &spamd_reject_score, &spamd_report_offset)) != 5
+     || spamd_report_offset >= offset		/* verify within buffer */
+     )
+    {
+    log_write(0, LOG_MAIN|LOG_PANIC,
+	      "%s cannot parse spamd %s, output: %d", loglabel, callout_address, r);
+    return DEFER;
+    }
+  /* now parse action */
+  p = &spamd_buffer[spamd_report_offset];
+
+  if (Ustrncmp(p, "Action: ", sizeof("Action: ") - 1) == 0)
+    {
+    p += sizeof("Action: ") - 1;
+    q = &spam_action_buffer[0];
+    while (*p && *p != '\r' && (q - spam_action_buffer) < sizeof(spam_action_buffer) - 1)
+      *q++ = *p++;
+    *q = '\0';
+    }
+  }
+else
+  {				/* spamassassin */
+  /* dig in the spamd output and put the report in a multiline header,
+  if requested */
+  if (sscanf(CS spamd_buffer,
+       "SPAMD/%7s 0 EX_OK\r\nContent-length: %*u\r\n\r\n%lf/%lf\r\n%n",
+       spamd_version,&spamd_score,&spamd_threshold,&spamd_report_offset) != 3)
+    {
+      /* try to fall back to pre-2.50 spamd output */
+      if (sscanf(CS spamd_buffer,
+	   "SPAMD/%7s 0 EX_OK\r\nSpam: %*s ; %lf / %lf\r\n\r\n%n",
+	   spamd_version,&spamd_score,&spamd_threshold,&spamd_report_offset) != 3)
+	{
+	log_write(0, LOG_MAIN|LOG_PANIC,
+		  "%s cannot parse spamd %s output", loglabel, callout_address);
+	return DEFER;
+	}
+    }
+
+  Ustrcpy(spam_action_buffer,
+    spamd_score >= spamd_threshold ? US"reject" : US"no action");
+  }
+
+/* Create report. Since this is a multiline string,
+we must hack it into shape first */
+p = &spamd_buffer[spamd_report_offset];
+q = spam_report_buffer;
+while (*p != '\0')
+  {
+  /* skip \r */
+  if (*p == '\r')
+    {
+    p++;
+    continue;
+    }
+  *q++ = *p;
+  if (*p++ == '\n')
+    {
+    /* add an extra space after the newline to ensure
+    that it is treated as a header continuation line */
+    *q++ = ' ';
+    }
+  }
+/* NULL-terminate */
+*q-- = '\0';
+/* cut off trailing leftovers */
+while (*q <= ' ')
+  *q-- = '\0';
+
+spam_report = spam_report_buffer;
+spam_action = spam_action_buffer;
+
+/* create spam bar */
+spamd_score_char = spamd_score > 0 ? '+' : '-';
+j = abs((int)(spamd_score));
+i = 0;
+if (j != 0)
+  while ((i < j) && (i <= MAX_SPAM_BAR_CHARS))
+     spam_bar_buffer[i++] = spamd_score_char;
+else
+  {
+  spam_bar_buffer[0] = '/';
+  i = 1;
+  }
+spam_bar_buffer[i] = '\0';
+spam_bar = spam_bar_buffer;
+
+/* create "float" spam score */
+(void)string_format(spam_score_buffer, sizeof(spam_score_buffer),
+	"%.1f", spamd_score);
+spam_score = spam_score_buffer;
+
+/* create "int" spam score */
+j = (int)((spamd_score + 0.001)*10);
+(void)string_format(spam_score_int_buffer, sizeof(spam_score_int_buffer),
+	"%d", j);
+spam_score_int = spam_score_int_buffer;
+
+/* compare threshold against score */
+spam_rc = spamd_score >= spamd_threshold
+  ? OK	/* spam as determined by user's threshold */
+  : FAIL;	/* not spam */
+
+/* remember expanded spamd_address if needed */
+if (spamd_address_work != spamd_address)
+  prev_spamd_address_work = string_copy(spamd_address_work);
+
+/* remember user name and "been here" for it */
+prev_user_name = user_name;
+spam_ok = 1;
+
+return override
+  ? OK		/* always return OK, no matter what the score */
+  : spam_rc;
+
+defer:
+  (void)fclose(mbox_file);
+  return DEFER;
+}
+
+#endif
+/* vi: aw ai sw=2
+*/