Adding upstream version 4.96.upstream/4.96upstream

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

1 files changed, 874 insertions, 0 deletions

diff --git a/src/moan.c b/src/moan.c
new file mode 100644
index 0000000..4f2550d
--- /dev/null
+++ b/src/moan.c
@@ -0,0 +1,874 @@
+/*************************************************
+*     Exim - an Internet mail transport agent    *
+*************************************************/
+
+/* Copyright (c) The Exim Maintainers 2020 - 2022 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* See the file NOTICE for conditions of use and distribution. */
+
+/* Functions for sending messages to sender or to mailmaster. */
+
+
+#include "exim.h"
+
+
+
+/*************************************************
+*            Write From: line for DSN            *
+*************************************************/
+
+/* This function is called to write the From: line in automatically generated
+messages - bounces, warnings, etc. It expands a configuration item in order to
+get the text. If the expansion fails, a panic is logged and the default value
+for the option is used.
+
+Argument:   the FILE to write to
+Returns:    nothing
+*/
+
+void
+moan_write_from(FILE *f)
+{
+uschar * s = expand_string(dsn_from);
+if (!s)
+  {
+  log_write(0, LOG_MAIN|LOG_PANIC,
+    "Failed to expand dsn_from (using default): %s", expand_string_message);
+  s = expand_string(US DEFAULT_DSN_FROM);
+  }
+fprintf(f, "From: %s\n", s);
+}
+
+
+
+/*************************************************
+*            Write References: line for DSN      *
+*************************************************/
+
+/* Generate a References: header if there is in the header_list
+at least one of Message-ID:, References:, or In-Reply-To: (see RFC 2822).
+
+Arguments:  f		the FILE to write to
+	    message_id	optional already-found message-id, or NULL
+
+Returns:    nothing
+*/
+
+void
+moan_write_references(FILE * fp, uschar * message_id)
+{
+header_line * h;
+
+if (!message_id)
+  for (h = header_list; h; h = h->next)
+    if (h->type == htype_id)
+      {
+      message_id = Ustrchr(h->text, ':') + 1;
+      Uskip_whitespace(&message_id);
+      }
+
+for (h = header_list; h; h = h->next)
+  if (h->type != htype_old && strncmpic(US"References:", h->text, 11) == 0)
+    break;
+
+if (!h)
+  for (h = header_list; h; h = h->next)
+    if (h->type != htype_old && strncmpic(US"In-Reply-To:", h->text, 12) == 0)
+      break;
+
+/* We limit the total length of references.  Although there is no fixed
+limit, some systems do not like headers growing beyond recognition.
+Keep the first message ID for the thread root and the last few for
+the position inside the thread, up to a maximum of 12 altogether. */
+
+if (h || message_id)
+  {
+  fprintf(fp, "References:");
+  if (h)
+    {
+    const uschar * s;
+    uschar * id, * error;
+    uschar * referenced_ids[12];
+    int reference_count = 0;
+
+    s = Ustrchr(h->text, ':') + 1;
+    f.parse_allow_group = FALSE;
+    while (*s && (s = parse_message_id(s, &id, &error)))
+      if (reference_count == nelem(referenced_ids))
+        {
+        memmove(referenced_ids + 1, referenced_ids + 2,
+           sizeof(referenced_ids) - 2*sizeof(uschar *));
+        referenced_ids[reference_count - 1] = id;
+        }
+      else
+	referenced_ids[reference_count++] = id;
+
+    for (int i = 0; i < reference_count; ++i)
+      fprintf(fp, " %s", referenced_ids[i]);
+    }
+
+  /* The message id will have a newline on the end of it. */
+
+  if (message_id) fprintf(fp, " %s", message_id);
+  else fprintf(fp, "\n");
+  }
+}
+
+
+
+/*************************************************
+*              Send error message                *
+*************************************************/
+
+/* This function sends an error message by opening a pipe to a new process
+running Exim, and writing a message to it using the "-t" option. This is not
+used for delivery failures, which have their own code for handing failed
+addresses.
+
+Arguments:
+  recipient      addressee for the message
+  ident          identifies the type of error
+  eblock         chain of error_blocks containing data about the error
+  headers        the message's headers
+  message_file   FILE containing the body of the message
+  firstline      contains first line of file, if it was read to check for
+                   "From ", but it turned out not to be
+
+Returns:         TRUE if message successfully sent
+*/
+
+BOOL
+moan_send_message(uschar *recipient, int ident, error_block *eblock,
+  header_line *headers, FILE *message_file, uschar *firstline)
+{
+int written = 0;
+int fd;
+int status;
+int count = 0;
+int size_limit = bounce_return_size_limit;
+FILE * fp;
+int pid;
+
+#ifdef SUPPORT_DMARC
+uschar * s, * s2;
+
+/* For DMARC if there is a specific sender set, expand the variable for the
+header From: and grab the address from that for the envelope FROM. */
+
+if (  ident == ERRMESS_DMARC_FORENSIC
+   && dmarc_forensic_sender
+   && (s = expand_string(dmarc_forensic_sender))
+   && *s
+   && (s2 = expand_string(string_sprintf("${address:%s}", s)))
+   && *s2
+   )
+  pid = child_open_exim2(&fd, s2, bounce_sender_authentication,
+		US"moan_send_message");
+else
+  {
+  s = NULL;
+  pid = child_open_exim(&fd, US"moan_send_message");
+  }
+
+#else
+pid = child_open_exim(&fd, US"moan_send_message");
+#endif
+
+if (pid < 0)
+  {
+  DEBUG(D_any) debug_printf("Failed to create child to send message: %s\n",
+    strerror(errno));
+  return FALSE;
+  }
+else DEBUG(D_any) debug_printf("Child process %d for sending message\n", pid);
+
+/* Creation of child succeeded */
+
+fp = fdopen(fd, "wb");
+if (errors_reply_to) fprintf(fp, "Reply-To: %s\n", errors_reply_to);
+fprintf(fp, "Auto-Submitted: auto-replied\n");
+
+#ifdef SUPPORT_DMARC
+if (s)
+  fprintf(fp, "From: %s\n", s);
+else
+#endif
+  moan_write_from(fp);
+
+fprintf(fp, "To: %s\n", recipient);
+moan_write_references(fp, NULL);
+
+switch(ident)
+  {
+  case ERRMESS_BADARGADDRESS:
+    fprintf(fp,
+      "Subject: Mail failure - malformed recipient address\n\n");
+    fprintf(fp,
+      "A message that you sent contained a recipient address that was incorrectly\n"
+      "constructed:\n\n");
+    fprintf(fp, "  %s  %s\n", eblock->text1, eblock->text2);
+    count = Ustrlen(eblock->text1);
+    if (count > 0 && eblock->text1[count-1] == '.')
+      fprintf(fp,
+	"\nRecipient addresses must not end with a '.' character.\n");
+    fprintf(fp,
+      "\nThe message has not been delivered to any recipients.\n");
+    break;
+
+  case ERRMESS_BADNOADDRESS:
+  case ERRMESS_BADADDRESS:
+    fprintf(fp,
+      "Subject: Mail failure - malformed recipient address\n\n");
+    fprintf(fp,
+      "A message that you sent contained one or more recipient addresses that were\n"
+      "incorrectly constructed:\n\n");
+
+    while (eblock)
+      {
+      fprintf(fp, "  %s: %s\n", eblock->text1, eblock->text2);
+      count++;
+      eblock = eblock->next;
+      }
+
+    fprintf(fp, (count == 1)? "\nThis address has been ignored. " :
+      "\nThese addresses have been ignored. ");
+
+    fprintf(fp, (ident == ERRMESS_BADADDRESS)?
+      "The other addresses in the message were\n"
+      "syntactically valid and have been passed on for an attempt at delivery.\n" :
+
+      "There were no other addresses in your\n"
+      "message, and so no attempt at delivery was possible.\n");
+    break;
+
+  case ERRMESS_IGADDRESS:
+    fprintf(fp, "Subject: Mail failure - no recipient addresses\n\n");
+    fprintf(fp,
+      "A message that you sent using the -t command line option contained no\n"
+      "addresses that were not also on the command line, and were therefore\n"
+      "suppressed. This left no recipient addresses, and so no delivery could\n"
+      "be attempted.\n");
+    break;
+
+  case ERRMESS_NOADDRESS:
+    fprintf(fp, "Subject: Mail failure - no recipient addresses\n\n");
+    fprintf(fp,
+      "A message that you sent contained no recipient addresses, and therefore no\n"
+      "delivery could be attempted.\n");
+    break;
+
+  case ERRMESS_IOERR:
+    fprintf(fp, "Subject: Mail failure - system failure\n\n");
+    fprintf(fp,
+      "A system failure was encountered while processing a message that you sent,\n"
+      "so it has not been possible to deliver it. The error was:\n\n%s\n",
+      eblock->text1);
+    break;
+
+  case ERRMESS_VLONGHEADER:
+    fprintf(fp, "Subject: Mail failure - overlong header section\n\n");
+    fprintf(fp,
+      "A message that you sent contained a header section that was excessively\n"
+      "long and could not be handled by the mail transmission software. The\n"
+      "message has not been delivered to any recipients.\n");
+    break;
+
+  case ERRMESS_VLONGHDRLINE:
+    fprintf(fp, "Subject: Mail failure - overlong header line\n\n");
+    fprintf(fp,
+      "A message that you sent contained a header line that was excessively\n"
+      "long and could not be handled by the mail transmission software. The\n"
+      "message has not been delivered to any recipients.\n");
+    break;
+
+  case ERRMESS_TOOBIG:
+    fprintf(fp, "Subject: Mail failure - message too big\n\n");
+    fprintf(fp,
+      "A message that you sent was longer than the maximum size allowed on this\n"
+      "system. It was not delivered to any recipients.\n");
+    break;
+
+  case ERRMESS_TOOMANYRECIP:
+    fprintf(fp, "Subject: Mail failure - too many recipients\n\n");
+    fprintf(fp,
+      "A message that you sent contained more recipients than allowed on this\n"
+      "system. It was not delivered to any recipients.\n");
+    break;
+
+  case ERRMESS_LOCAL_SCAN:
+  case ERRMESS_LOCAL_ACL:
+    fprintf(fp, "Subject: Mail failure - rejected by local scanning code\n\n");
+    fprintf(fp,
+      "A message that you sent was rejected by the local scanning code that\n"
+      "checks incoming messages on this system.");
+      if (eblock->text1)
+	fprintf(fp, " The following error was given:\n\n  %s", eblock->text1);
+  fprintf(fp, "\n");
+  break;
+
+#ifdef SUPPORT_DMARC
+  case ERRMESS_DMARC_FORENSIC:
+    bounce_return_message = TRUE;
+    bounce_return_body    = FALSE;
+    fprintf(fp, "Subject: DMARC Forensic Report for %s from IP %s\n\n",
+	  eblock ? eblock->text2 : US"Unknown",
+          sender_host_address);
+    fprintf(fp,
+      "A message claiming to be from you has failed the published DMARC\n"
+      "policy for your domain.\n\n");
+    while (eblock)
+      {
+      fprintf(fp, "  %s: %s\n", eblock->text1, eblock->text2);
+      count++;
+      eblock = eblock->next;
+      }
+  break;
+#endif
+
+  default:
+    fprintf(fp, "Subject: Mail failure\n\n");
+    fprintf(fp,
+      "A message that you sent has caused the error routine to be entered with\n"
+      "an unknown error number (%d).\n", ident);
+    break;
+  }
+
+/* Now, if configured, copy the message; first the headers and then the rest of
+the input if available, up to the configured limit, if the option for including
+message bodies in bounces is set. */
+
+if (bounce_return_message)
+  {
+  if (bounce_return_body)
+    {
+    fprintf(fp, "\n"
+      "------ This is a copy of your message, including all the headers.");
+    if (size_limit == 0 || size_limit > thismessage_size_limit)
+      size_limit = thismessage_size_limit;
+    if (size_limit > 0 && size_limit < message_size)
+      {
+      int x = size_limit;
+      uschar *k = US"";
+      if ((x & 1023) == 0)
+        {
+        k = US"K";
+        x >>= 10;
+        }
+      fprintf(fp, "\n"
+        "------ No more than %d%s characters of the body are included.\n\n",
+          x, k);
+      }
+    else fprintf(fp, " ------\n\n");
+    }
+  else
+    {
+    fprintf(fp, "\n"
+      "------ This is a copy of the headers that were received before the "
+      "error\n       was detected.\n\n");
+    }
+
+  /* If the error occurred before the Received: header was created, its text
+  field will still be NULL; just omit such a header line. */
+
+  while (headers)
+    {
+    if (headers->text != NULL) fprintf(fp, "%s", CS headers->text);
+    headers = headers->next;
+    }
+
+  if (ident != ERRMESS_VLONGHEADER && ident != ERRMESS_VLONGHDRLINE)
+    fputc('\n', fp);
+
+  /* After early detection of an error, the message file may be STDIN,
+  in which case we might have to terminate on a line containing just "."
+  as well as on EOF. We may already have the first line in memory. */
+
+  if (bounce_return_body && message_file)
+    {
+    BOOL enddot = f.dot_ends && message_file == stdin;
+    uschar * buf = store_get(bounce_return_linesize_limit+2, GET_TAINTED);
+
+    if (firstline) fprintf(fp, "%s", CS firstline);
+
+    while (fgets(CS buf, bounce_return_linesize_limit+2, message_file))
+      {
+      int len;
+
+      if (enddot && *buf == '.' && buf[1] == '\n')
+	{
+	fputc('.', fp);
+	break;
+	}
+
+      len = Ustrlen(buf);
+      if (buf[len-1] != '\n')
+	{	/* eat rest of partial line */
+	int ch;
+	while ((ch = fgetc(message_file)) != EOF && ch != '\n') ;
+	}
+
+      if (size_limit > 0 && len > size_limit - written)
+	{
+	buf[size_limit - written] = '\0';
+	fputs(CS buf, fp);
+	break;
+	}
+
+      fputs(CS buf, fp);
+      }
+    }
+#ifdef SUPPORT_DMARC
+  /* Overkill, but use exact test in case future code gets inserted */
+  else if (bounce_return_body && message_file == NULL)
+    {
+    /*XXX limit line length here? */
+    /* This doesn't print newlines, disable until can parse and fix
+     * output to be legible.  */
+    fprintf(fp, "%s", expand_string(US"$message_body"));
+    }
+#endif
+  }
+/* Close the file, which should send an EOF to the child process
+that is receiving the message. Wait for it to finish, without a timeout. */
+
+(void)fclose(fp);
+status = child_close(pid, 0);  /* Waits for child to close */
+if (status != 0)
+  {
+  uschar *msg = US"Child mail process returned status";
+  if (status == -257)
+    log_write(0, LOG_MAIN, "%s %d: errno=%d: %s", msg, status, errno,
+      strerror(errno));
+  else
+    log_write(0, LOG_MAIN, "%s %d", msg, status);
+  return FALSE;
+  }
+
+return TRUE;
+}
+
+
+
+/*************************************************
+*          Send message to sender                *
+*************************************************/
+
+/* This function is called when errors are detected during the receipt of a
+message. Delivery failures are handled separately in deliver.c.
+
+If there is a valid sender_address, and the failing message is not a local
+error message, then this function calls moan_send_message to send a message to
+that person. If the sender's address is null, then an error has occurred with a
+message that was generated by a mailer daemon. All we can do is to write
+information to log files. The same action is taken if local_error_message is
+set - this can happen for non null-senders in certain configurations where exim
+doesn't run setuid root.
+
+Arguments:
+  ident         identifies the particular error
+  eblock        chain of error_blocks containing data about the error
+  headers       message's headers (chain)
+  message_file  a FILE where the body of the message can be read
+  check_sender  if TRUE, read the first line of the file for a possible
+                  "From " sender (if a trusted caller)
+
+Returns:        FALSE if there is no sender_address to send to;
+                else the return from moan_send_message()
+*/
+
+BOOL
+moan_to_sender(int ident, error_block *eblock, header_line *headers,
+  FILE *message_file, BOOL check_sender)
+{
+uschar *firstline = NULL;
+uschar *msg = US"Error while reading message with no usable sender address";
+
+if (message_reference)
+  msg = string_sprintf("%s (R=%s)", msg, message_reference);
+
+/* Find the sender from a From line if permitted and possible */
+
+if (check_sender && message_file && f.trusted_caller &&
+    Ufgets(big_buffer, BIG_BUFFER_SIZE, message_file) != NULL)
+  {
+  uschar *new_sender = NULL;
+  if (regex_match_and_setup(regex_From, big_buffer, 0, -1))
+    new_sender = expand_string(uucp_from_sender);
+  if (new_sender) sender_address = new_sender;
+    else firstline = big_buffer;
+  }
+
+/* If viable sender address, send a message */
+
+if (sender_address && sender_address[0] && !f.local_error_message)
+  return moan_send_message(sender_address, ident, eblock, headers,
+    message_file, firstline);
+
+/* Otherwise, we can only log */
+
+switch(ident)
+  {
+  case ERRMESS_BADARGADDRESS:
+  case ERRMESS_BADNOADDRESS:
+  case ERRMESS_BADADDRESS:
+  log_write(0, LOG_MAIN, "%s: at least one malformed recipient address: "
+    "%s - %s", msg, eblock->text1, eblock->text2);
+  break;
+
+  case ERRMESS_IGADDRESS:
+  case ERRMESS_NOADDRESS:
+  log_write(0, LOG_MAIN, "%s: no recipient addresses", msg);
+  break;
+
+  /* This error has already been logged. */
+  case ERRMESS_IOERR:
+  break;
+
+  case ERRMESS_VLONGHEADER:
+  log_write(0, LOG_MAIN, "%s: excessively long message header section read "
+    "(more than %d characters)", msg, header_maxsize);
+  break;
+
+  case ERRMESS_VLONGHDRLINE:
+  log_write(0, LOG_MAIN, "%s: excessively long message header line read "
+    "(more than %d characters)", msg, header_line_maxsize);
+  break;
+
+  case ERRMESS_TOOBIG:
+  log_write(0, LOG_MAIN, "%s: message too big (limit set to %d)", msg,
+    thismessage_size_limit);
+  break;
+
+  case ERRMESS_TOOMANYRECIP:
+  log_write(0, LOG_MAIN, "%s: too many recipients (max set to %d)", msg,
+    recipients_max);
+  break;
+
+  case ERRMESS_LOCAL_SCAN:
+  log_write(0, LOG_MAIN, "%s: rejected by local_scan: %s", msg, eblock->text1);
+  break;
+
+  case ERRMESS_LOCAL_ACL:
+  log_write(0, LOG_MAIN, "%s: rejected by non-SMTP ACL: %s", msg, eblock->text1);
+  break;
+
+  default:
+  log_write(0, LOG_MAIN|LOG_PANIC, "%s: unknown error number %d", msg,
+    ident);
+  break;
+  }
+
+return FALSE;
+}
+
+
+
+/*************************************************
+*            Send message to someone             *
+*************************************************/
+
+/* This is called when exim is configured to tell someone (often the
+mailmaster) about some incident.
+
+Arguments:
+  who           address to send mail to
+  addr          chain of deferred addresses whose details are to be included
+  subject       subject text for the message
+  format        a printf() format for the body of the message
+  ...           arguments for the format
+
+Returns:        nothing
+*/
+
+void
+moan_tell_someone(uschar *who, address_item *addr,
+  const uschar *subject, const char *format, ...)
+{
+FILE *f;
+va_list ap;
+int fd;
+int pid = child_open_exim(&fd, US"moan_tell_someone");
+
+if (pid < 0)
+  {
+  DEBUG(D_any) debug_printf("Failed to create child to send message: %s\n",
+    strerror(errno));
+  return;
+  }
+
+f = fdopen(fd, "wb");
+fprintf(f, "Auto-Submitted: auto-replied\n");
+moan_write_from(f);
+fprintf(f, "To: %s\n", who);
+moan_write_references(f, NULL);
+fprintf(f, "Subject: %s\n\n", subject);
+va_start(ap, format);
+vfprintf(f, format, ap);
+va_end(ap);
+
+if (addr)
+  {
+  fprintf(f, "\nThe following address(es) have yet to be delivered:\n");
+  for (; addr; addr = addr->next)
+    {
+    uschar * parent = addr->parent ? addr->parent->address : NULL;
+    fprintf(f, "  %s", addr->address);
+    if (parent) fprintf(f, " <%s>", parent);
+    if (addr->basic_errno > 0) fprintf(f, ": %s", strerror(addr->basic_errno));
+    if (addr->message) fprintf(f, ": %s", addr->message);
+    fprintf(f, "\n");
+    }
+  }
+
+(void)fclose(f);
+child_close(pid, 0);  /* Waits for child to close; no timeout */
+}
+
+
+
+/*************************************************
+*            Handle SMTP batch error             *
+*************************************************/
+
+/* This is called when something goes wrong in batched (-bS) SMTP input.
+Information is written to stdout and/or stderr, and Exim exits with a non-zero
+completion code. BSMTP is almost always called by some other program, so it is
+up to that program to interpret the return code and do something with the error
+information, and also to preserve the batch input file for human analysis.
+
+Formerly, Exim used to attempt to continue after some errors, but this strategy
+has been abandoned as it can lead to loss of messages.
+
+Arguments:
+  cmd_buffer   the command causing the error, or NULL
+  format       a printf() format
+  ...          arguments for the format
+
+Returns:       does not return; exits from the program
+               exit code = 1 if some messages were accepted
+               exit code = 2 if no messages were accepted
+*/
+
+void
+moan_smtp_batch(uschar *cmd_buffer, const char *format, ...)
+{
+va_list ap;
+int yield = (receive_messagecount > 0)? 1 : 2;
+
+DEBUG(D_any) debug_printf("Handling error in batched SMTP input\n");
+
+/* On stdout, write stuff that a program could parse fairly easily. */
+
+va_start(ap, format);
+vfprintf(stdout, format, ap);
+va_end(ap);
+
+fprintf(stdout, "\nTransaction started in line %d\n",
+  bsmtp_transaction_linecount);
+fprintf(stdout,   "Error detected in line %d\n", receive_linecount);
+if (cmd_buffer != NULL) fprintf(stdout, "%s\n", cmd_buffer);
+
+/* On stderr, write stuff for human consumption */
+
+fprintf(stderr,
+  "An error was detected while processing a file of BSMTP input.\n"
+  "The error message was:\n\n  ");
+
+va_start(ap, format);
+vfprintf(stderr, format, ap);
+va_end(ap);
+
+fprintf(stderr,
+  "\n\nThe SMTP transaction started in line %d.\n"
+      "The error was detected in line %d.\n",
+  bsmtp_transaction_linecount, receive_linecount);
+
+if (cmd_buffer != NULL)
+  {
+  fprintf(stderr, "The SMTP command at fault was:\n\n   %s\n\n",
+    cmd_buffer);
+  }
+
+fprintf(stderr, "%d previous message%s successfully processed.\n",
+  receive_messagecount, (receive_messagecount == 1)? " was" : "s were");
+
+fprintf(stderr, "The rest of the batch was abandoned.\n");
+
+exim_exit(yield);
+}
+
+
+
+
+/*************************************************
+*         Check for error copies                 *
+*************************************************/
+
+/* This function is passed the recipient of an error message, and must check
+the error_copies string to see whether there is an additional recipient list to
+which errors for this recipient must be bcc'd. The incoming recipient is always
+fully qualified.
+
+Argument:   recipient address
+Returns:    additional recipient list or NULL
+*/
+
+uschar *
+moan_check_errorcopy(uschar *recipient)
+{
+uschar *item, *localpart, *domain;
+const uschar *listptr = errors_copy;
+uschar *yield = NULL;
+int sep = 0;
+int llen;
+
+if (errors_copy == NULL) return NULL;
+
+/* Set up pointer to the local part and domain, and compute the
+length of the local part. */
+
+localpart = recipient;
+domain = Ustrrchr(recipient, '@');
+if (domain == NULL) return NULL;  /* should not occur, but avoid crash */
+llen = domain++ - recipient;
+
+/* Scan through the configured items */
+
+while ((item = string_nextinlist(&listptr, &sep, NULL, 0)))
+  {
+  const uschar *newaddress = item;
+  const uschar *pattern = string_dequote(&newaddress);
+
+  /* If no new address found, just skip this item. */
+
+  while (isspace(*newaddress)) newaddress++;
+  if (*newaddress == 0) continue;
+
+  /* We now have an item to match as an address in item, and the additional
+  address in newaddress. If the pattern matches, expand the new address string
+  and return it. During expansion, make local part and domain available for
+  insertion. This requires a copy to be made; we can't just temporarily
+  terminate it, as the whole address is required for $0. */
+
+  if (match_address_list(recipient, TRUE, TRUE, &pattern, NULL, 0, UCHAR_MAX+1,
+        NULL) == OK)
+    {
+    deliver_localpart = string_copyn(localpart, llen);
+    deliver_domain = domain;
+    yield = expand_string_copy(newaddress);
+    deliver_domain = deliver_localpart = NULL;
+    if (yield == NULL)
+      log_write(0, LOG_MAIN|LOG_PANIC, "Failed to expand %s when processing "
+        "errors_copy: %s", newaddress, expand_string_message);
+    break;
+    }
+  }
+
+DEBUG(D_any) debug_printf("errors_copy check returned %s\n",
+  (yield == NULL)? US"NULL" : yield);
+
+expand_nmax = -1;
+return yield;
+}
+
+
+
+/************************************************
+*        Handle skipped syntax errors           *
+************************************************/
+
+/* This function is called by the redirect router when it has skipped over one
+or more syntax errors in the list of addresses. If there is an address to mail
+to, send a message, and always write the information to the log. In the case of
+a filter file, a "syntax error" might actually be something else, such as the
+inability to open a log file. Thus, the wording of the error message is
+general.
+
+Arguments:
+  rname             the router name
+  eblock            chain of error blocks
+  syntax_errors_to  address to send mail to, or NULL
+  some              TRUE if some addresses were generated; FALSE if none were
+  custom            custom message text
+
+Returns:            FALSE if string expansion failed; TRUE otherwise
+*/
+
+BOOL
+moan_skipped_syntax_errors(uschar *rname, error_block *eblock,
+  uschar *syntax_errors_to, BOOL some, uschar *custom)
+{
+int pid, fd;
+uschar *s, *t;
+FILE *f;
+
+for (error_block * e = eblock; e; e = e->next)
+  if (e->text2 != NULL)
+    log_write(0, LOG_MAIN, "%s router: skipped error: %s in \"%s\"",
+      rname, e->text1, e->text2);
+  else
+    log_write(0, LOG_MAIN, "%s router: skipped error: %s", rname,
+      e->text1);
+
+if (!syntax_errors_to) return TRUE;
+
+if (!(s = expand_string(syntax_errors_to)))
+  {
+  log_write(0, LOG_MAIN, "%s router failed to expand %s: %s", rname,
+    syntax_errors_to, expand_string_message);
+  return FALSE;
+  }
+
+/* If we can't create a process to send the message, just forget about
+it. */
+
+pid = child_open_exim(&fd, US"moan_skipped_syntax_errors");
+
+if (pid < 0)
+  {
+  DEBUG(D_any) debug_printf("Failed to create child to send message: %s\n",
+    strerror(errno));
+  return TRUE;
+  }
+
+f = fdopen(fd, "wb");
+fprintf(f, "Auto-Submitted: auto-replied\n");
+moan_write_from(f);
+fprintf(f, "To: %s\n", s);
+fprintf(f, "Subject: error(s) in forwarding or filtering\n\n");
+moan_write_references(f, NULL);
+
+if (custom)
+  {
+  if (!(t = expand_string(custom)))
+    {
+    log_write(0, LOG_MAIN, "%s router failed to expand %s: %s", rname,
+      custom, expand_string_message);
+    return FALSE;
+    }
+  fprintf(f, "%s\n\n", t);
+  }
+
+fprintf(f, "The %s router encountered the following error(s):\n\n",
+  rname);
+
+for (error_block * e = eblock; e; e = e->next)
+  {
+  fprintf(f, "  %s", e->text1);
+  if (e->text2 != NULL)
+    fprintf(f, " in the address\n  \"%s\"", e->text2);
+  fprintf(f, "\n\n");
+  }
+
+if (some)
+  fprintf(f, "Other addresses were processed normally.\n");
+else
+  fprintf(f, "No valid addresses were generated.\n");
+
+(void)fclose(f);
+child_close(pid, 0);  /* Waits for child to close; no timeout */
+
+return TRUE;
+}
+
+/* End of moan.c */