Tighter guard for POLLRDHUP
[exim.git] / src / src / acl.c
index e8a0657f2f6787fa4719b1392fcabd7fd7b715aa..5a5abaebf1ba59e47079f0e61acee11f0388dcd4 100644 (file)
@@ -2,7 +2,7 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2014 */
+/* Copyright (c) University of Cambridge 1995 - 2015 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* Code for handling Access Control Lists (ACLs) */
@@ -181,17 +181,17 @@ that follows! */
 
 enum {
   CONTROL_AUTH_UNADVERTISED,
-  #ifdef EXPERIMENTAL_BRIGHTMAIL
+#ifdef EXPERIMENTAL_BRIGHTMAIL
   CONTROL_BMI_RUN,
-  #endif
+#endif
   CONTROL_DEBUG,
-  #ifndef DISABLE_DKIM
+#ifndef DISABLE_DKIM
   CONTROL_DKIM_VERIFY,
-  #endif
-  #ifdef EXPERIMENTAL_DMARC
+#endif
+#ifdef EXPERIMENTAL_DMARC
   CONTROL_DMARC_VERIFY,
   CONTROL_DMARC_FORENSIC,
-  #endif
+#endif
   CONTROL_DSCP,
   CONTROL_ERROR,
   CONTROL_CASEFUL_LOCAL_PART,
@@ -203,11 +203,14 @@ enum {
   CONTROL_QUEUE_ONLY,
   CONTROL_SUBMISSION,
   CONTROL_SUPPRESS_LOCAL_FIXUPS,
-  #ifdef WITH_CONTENT_SCAN
+#ifdef WITH_CONTENT_SCAN
   CONTROL_NO_MBOX_UNSPOOL,
-  #endif
+#endif
   CONTROL_FAKEDEFER,
   CONTROL_FAKEREJECT,
+#ifdef EXPERIMENTAL_INTERNATIONAL
+  CONTROL_UTF8_DOWNCONVERT,
+#endif
   CONTROL_NO_MULTILINE,
   CONTROL_NO_PIPELINING,
   CONTROL_NO_DELAY_FLUSH,
@@ -221,17 +224,17 @@ and should be tidied up. */
 
 static uschar *controls[] = {
   US"allow_auth_unadvertised",
-  #ifdef EXPERIMENTAL_BRIGHTMAIL
+#ifdef EXPERIMENTAL_BRIGHTMAIL
   US"bmi_run",
-  #endif
+#endif
   US"debug",
-  #ifndef DISABLE_DKIM
+#ifndef DISABLE_DKIM
   US"dkim_disable_verify",
-  #endif
-  #ifdef EXPERIMENTAL_DMARC
+#endif
+#ifdef EXPERIMENTAL_DMARC
   US"dmarc_disable_verify",
   US"dmarc_enable_forensic",
-  #endif
+#endif
   US"dscp",
   US"error",
   US"caseful_local_part",
@@ -243,11 +246,14 @@ static uschar *controls[] = {
   US"queue_only",
   US"submission",
   US"suppress_local_fixups",
-  #ifdef WITH_CONTENT_SCAN
+#ifdef WITH_CONTENT_SCAN
   US"no_mbox_unspool",
-  #endif
+#endif
   US"fakedefer",
   US"fakereject",
+#ifdef EXPERIMENTAL_INTERNATIONAL
+  US"utf8_downconvert",
+#endif
   US"no_multiline_responses",
   US"no_pipelining",
   US"no_delay_flush",
@@ -491,7 +497,7 @@ static unsigned int cond_forbids[] = {
 
   (unsigned int)
   ~((1<<ACL_WHERE_RCPT)                             /* local_parts */
-  #ifdef EXPERIMENTAL_PRDR
+  #ifndef DISABLE_PRDR
     |(1<<ACL_WHERE_PRDR)
   #endif
     ),
@@ -600,26 +606,26 @@ static unsigned int control_forbids[] = {
   (unsigned int)
   ~((1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)),   /* allow_auth_unadvertised */
 
-  #ifdef EXPERIMENTAL_BRIGHTMAIL
+#ifdef EXPERIMENTAL_BRIGHTMAIL
   0,                                               /* bmi_run */
-  #endif
+#endif
 
   0,                                               /* debug */
 
-  #ifndef DISABLE_DKIM
+#ifndef DISABLE_DKIM
   (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)|      /* dkim_disable_verify */
-  #ifndef DISABLE_PRDR
+ifndef DISABLE_PRDR
     (1<<ACL_WHERE_PRDR)|
-  #endif
+endif
     (1<<ACL_WHERE_NOTSMTP_START),
-  #endif
+#endif
 
-  #ifdef EXPERIMENTAL_DMARC
+#ifdef EXPERIMENTAL_DMARC
   (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)|      /* dmarc_disable_verify */
     (1<<ACL_WHERE_NOTSMTP_START),
   (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)|      /* dmarc_enable_forensic */
     (1<<ACL_WHERE_NOTSMTP_START),
-  #endif
+#endif
 
   (1<<ACL_WHERE_NOTSMTP)|
     (1<<ACL_WHERE_NOTSMTP_START)|
@@ -663,30 +669,34 @@ static unsigned int control_forbids[] = {
     (1<<ACL_WHERE_PREDATA)|
     (1<<ACL_WHERE_NOTSMTP_START)),
 
-  #ifdef WITH_CONTENT_SCAN
+#ifdef WITH_CONTENT_SCAN
   (unsigned int)
   ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)|       /* no_mbox_unspool */
     (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
     // (1<<ACL_WHERE_PRDR)|    /* Not allow one user to freeze for all */
     (1<<ACL_WHERE_MIME)),
-  #endif
+#endif
 
   (unsigned int)
   ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)|       /* fakedefer */
     (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
-  #ifndef DISABLE_PRDR
+#ifndef DISABLE_PRDR
     (1<<ACL_WHERE_PRDR)|
-  #endif
+#endif
     (1<<ACL_WHERE_MIME)),
 
   (unsigned int)
   ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)|       /* fakereject */
     (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
-  #ifndef DISABLE_PRDR
+#ifndef DISABLE_PRDR
     (1<<ACL_WHERE_PRDR)|
-  #endif
+#endif
     (1<<ACL_WHERE_MIME)),
 
+#ifdef EXPERIMENTAL_INTERNATIONAL
+  0,                                               /* utf8_downconvert */
+#endif
+
   (1<<ACL_WHERE_NOTSMTP)|                          /* no_multiline */
     (1<<ACL_WHERE_NOTSMTP_START),
 
@@ -709,37 +719,40 @@ typedef struct control_def {
 } control_def;
 
 static control_def controls_list[] = {
-  { US"allow_auth_unadvertised", CONTROL_AUTH_UNADVERTISED, FALSE },
+  { US"allow_auth_unadvertised", CONTROL_AUTH_UNADVERTISED,     FALSE },
 #ifdef EXPERIMENTAL_BRIGHTMAIL
-  { US"bmi_run",                 CONTROL_BMI_RUN, FALSE },
+  { US"bmi_run",                 CONTROL_BMI_RUN,               FALSE },
 #endif
-  { US"debug",                   CONTROL_DEBUG, TRUE },
+  { US"debug",                   CONTROL_DEBUG,                 TRUE },
 #ifndef DISABLE_DKIM
-  { US"dkim_disable_verify",     CONTROL_DKIM_VERIFY, FALSE },
+  { US"dkim_disable_verify",     CONTROL_DKIM_VERIFY,           FALSE },
 #endif
 #ifdef EXPERIMENTAL_DMARC
-  { US"dmarc_disable_verify",    CONTROL_DMARC_VERIFY, FALSE },
-  { US"dmarc_enable_forensic",   CONTROL_DMARC_FORENSIC, FALSE },
+  { US"dmarc_disable_verify",    CONTROL_DMARC_VERIFY,          FALSE },
+  { US"dmarc_enable_forensic",   CONTROL_DMARC_FORENSIC,        FALSE },
 #endif
-  { US"dscp",                    CONTROL_DSCP, TRUE },
-  { US"caseful_local_part",      CONTROL_CASEFUL_LOCAL_PART, FALSE },
-  { US"caselower_local_part",    CONTROL_CASELOWER_LOCAL_PART, FALSE },
-  { US"enforce_sync",            CONTROL_ENFORCE_SYNC, FALSE },
-  { US"freeze",                  CONTROL_FREEZE, TRUE },
-  { US"no_callout_flush",        CONTROL_NO_CALLOUT_FLUSH, FALSE },
-  { US"no_delay_flush",          CONTROL_NO_DELAY_FLUSH, FALSE },
-  { US"no_enforce_sync",         CONTROL_NO_ENFORCE_SYNC, FALSE },
-  { US"no_multiline_responses",  CONTROL_NO_MULTILINE, FALSE },
-  { US"no_pipelining",           CONTROL_NO_PIPELINING, FALSE },
-  { US"queue_only",              CONTROL_QUEUE_ONLY, FALSE },
+  { US"dscp",                    CONTROL_DSCP,                  TRUE },
+  { US"caseful_local_part",      CONTROL_CASEFUL_LOCAL_PART,    FALSE },
+  { US"caselower_local_part",    CONTROL_CASELOWER_LOCAL_PART,  FALSE },
+  { US"enforce_sync",            CONTROL_ENFORCE_SYNC,          FALSE },
+  { US"freeze",                  CONTROL_FREEZE,                TRUE },
+  { US"no_callout_flush",        CONTROL_NO_CALLOUT_FLUSH,      FALSE },
+  { US"no_delay_flush",          CONTROL_NO_DELAY_FLUSH,        FALSE },
+  { US"no_enforce_sync",         CONTROL_NO_ENFORCE_SYNC,       FALSE },
+  { US"no_multiline_responses",  CONTROL_NO_MULTILINE,          FALSE },
+  { US"no_pipelining",           CONTROL_NO_PIPELINING,         FALSE },
+  { US"queue_only",              CONTROL_QUEUE_ONLY,            FALSE },
 #ifdef WITH_CONTENT_SCAN
-  { US"no_mbox_unspool",         CONTROL_NO_MBOX_UNSPOOL, FALSE },
+  { US"no_mbox_unspool",         CONTROL_NO_MBOX_UNSPOOL,       FALSE },
 #endif
-  { US"fakedefer",               CONTROL_FAKEDEFER, TRUE },
-  { US"fakereject",              CONTROL_FAKEREJECT, TRUE },
-  { US"submission",              CONTROL_SUBMISSION, TRUE },
+  { US"fakedefer",               CONTROL_FAKEDEFER,             TRUE },
+  { US"fakereject",              CONTROL_FAKEREJECT,            TRUE },
+  { US"submission",              CONTROL_SUBMISSION,            TRUE },
   { US"suppress_local_fixups",   CONTROL_SUPPRESS_LOCAL_FIXUPS, FALSE },
-  { US"cutthrough_delivery",     CONTROL_CUTTHROUGH_DELIVERY, FALSE }
+  { US"cutthrough_delivery",     CONTROL_CUTTHROUGH_DELIVERY,   FALSE },
+#ifdef EXPERIMENTAL_INTERNATIONAL
+  { US"utf8_downconvert",        CONTROL_UTF8_DOWNCONVERT,      TRUE }
+#endif
   };
 
 /* Support data structures for Client SMTP Authorization. acl_verify_csa()
@@ -802,7 +815,7 @@ static uschar *ratelimit_option_string[] = {
 
 /* Enable recursion between acl_check_internal() and acl_check_condition() */
 
-static int acl_check_wargs(int, address_item *, uschar *, int, uschar **,
+static int acl_check_wargs(int, address_item *, const uschar *, int, uschar **,
     uschar **);
 
 
@@ -1049,9 +1062,9 @@ Returns:    nothing
 */
 
 static void
-setup_header(uschar *hstring)
+setup_header(const uschar *hstring)
 {
-uschar *p, *q;
+const uschar *p, *q;
 int hlen = Ustrlen(hstring);
 
 /* Ignore any leading newlines */
@@ -1059,14 +1072,24 @@ while (*hstring == '\n') hstring++, hlen--;
 
 /* An empty string does nothing; ensure exactly one final newline. */
 if (hlen <= 0) return;
-if (hstring[--hlen] != '\n') hstring = string_sprintf("%s\n", hstring);
-else while(hstring[--hlen] == '\n') hstring[hlen+1] = '\0';
+if (hstring[--hlen] != '\n')
+  q = string_sprintf("%s\n", hstring);
+else if (hstring[hlen-1] == '\n')
+  {
+  uschar * s = string_copy(hstring);
+  while(s[--hlen] == '\n')
+    s[hlen+1] = '\0';
+  q = s;
+  }
+else
+  q = hstring;
 
 /* Loop for multiple header lines, taking care about continuations */
 
-for (p = q = hstring; *p != 0; )
+for (p = q; *p != 0; )
   {
-  uschar *s;
+  const uschar *s;
+  uschar * hdr;
   int newtype = htype_add_bot;
   header_line **hptr = &acl_added_headers;
 
@@ -1114,14 +1137,14 @@ for (p = q = hstring; *p != 0; )
     if (*s == ':' || !isgraph(*s)) break;
     }
 
-  s = string_sprintf("%s%.*s", (*s == ':')? "" : "X-ACL-Warn: ", (int) (q - p), p);
-  hlen = Ustrlen(s);
+  hdr = string_sprintf("%s%.*s", (*s == ':')? "" : "X-ACL-Warn: ", (int) (q - p), p);
+  hlen = Ustrlen(hdr);
 
   /* See if this line has already been added */
 
   while (*hptr != NULL)
     {
-    if (Ustrncmp((*hptr)->text, s, hlen) == 0) break;
+    if (Ustrncmp((*hptr)->text, hdr, hlen) == 0) break;
     hptr = &((*hptr)->next);
     }
 
@@ -1130,7 +1153,7 @@ for (p = q = hstring; *p != 0; )
   if (*hptr == NULL)
     {
     header_line *h = store_get(sizeof(header_line));
-    h->text = s;
+    h->text = hdr;
     h->next = NULL;
     h->type = newtype;
     h->slen = hlen;
@@ -1197,15 +1220,12 @@ Returns:    nothing
 */
 
 static void
-setup_remove_header(uschar *hnames)
+setup_remove_header(const uschar *hnames)
 {
 if (*hnames != 0)
-  {
-  if (acl_removed_headers == NULL)
-    acl_removed_headers = hnames;
-  else
-    acl_removed_headers = string_sprintf("%s : %s", acl_removed_headers, hnames);
-  }
+  acl_removed_headers = acl_removed_headers
+    ? string_sprintf("%s : %s", acl_removed_headers, hnames)
+    : string_copy(hnames);
 }
 
 
@@ -1389,9 +1409,6 @@ for (rr = dns_next_rr(dnsa, dnss, reset);
   if (rr->type != T_A
     #if HAVE_IPV6
       && rr->type != T_AAAA
-      #ifdef SUPPORT_A6
-        && rr->type != T_A6
-      #endif
     #endif
   ) continue;
 
@@ -1444,10 +1461,11 @@ Returns:    CSA_UNKNOWN    no valid CSA record found
 */
 
 static int
-acl_verify_csa(uschar *domain)
+acl_verify_csa(const uschar *domain)
 {
 tree_node *t;
-uschar *found, *p;
+const uschar *found;
+uschar *p;
 int priority, weight, port;
 dns_answer dnsa;
 dns_scan dnss;
@@ -1470,7 +1488,7 @@ containing a keyword and a colon before the actual IP address. */
 
 if (domain[0] == '[')
   {
-  uschar *start = Ustrchr(domain, ':');
+  const uschar *start = Ustrchr(domain, ':');
   if (start == NULL) start = domain;
   domain = string_copyn(start + 1, Ustrlen(start) - 2);
   }
@@ -1550,7 +1568,7 @@ for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
   assertion: legitimate SMTP clients are all explicitly authorized with CSA
   SRV records of their own. */
 
-  if (found != domain)
+  if (Ustrcmp(found, domain) != 0)
     {
     if (port & 1)
       return t->data.val = CSA_FAIL_EXPLICIT;
@@ -1610,24 +1628,20 @@ else
   type = T_A;
 
 
-#if HAVE_IPV6 && defined(SUPPORT_A6)
-DNS_LOOKUP_AGAIN:
-#endif
-
 lookup_dnssec_authenticated = NULL;
 switch (dns_lookup(&dnsa, target, type, NULL))
   {
   /* If something bad happened (most commonly DNS_AGAIN), defer. */
 
   default:
-  return t->data.val = CSA_DEFER_ADDR;
+    return t->data.val = CSA_DEFER_ADDR;
 
   /* If the query succeeded, scan the addresses and return the result. */
 
   case DNS_SUCCEED:
-  rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target);
-  if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
-  /* else fall through */
+    rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target);
+    if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
+    /* else fall through */
 
   /* If the target has no IP addresses, the client cannot have an authorized
   IP address. However, if the target site uses A6 records (not AAAA records)
@@ -1635,12 +1649,7 @@ switch (dns_lookup(&dnsa, target, type, NULL))
 
   case DNS_NOMATCH:
   case DNS_NODATA:
-
-  #if HAVE_IPV6 && defined(SUPPORT_A6)
-  if (type == T_AAAA) { type = T_A6; goto DNS_LOOKUP_AGAIN; }
-  #endif
-
-  return t->data.val = CSA_FAIL_NOADDR;
+    return t->data.val = CSA_FAIL_NOADDR;
   }
 }
 
@@ -1662,7 +1671,7 @@ typedef struct {
   unsigned alt_opt_sep;                /* >0 Non-/ option separator (custom parser) */
   } verify_type_t;
 static verify_type_t verify_type_list[] = {
-    { US"reverse_host_lookup", VERIFY_REV_HOST_LKUP,   ~0,     TRUE, 0 },
+    { US"reverse_host_lookup", VERIFY_REV_HOST_LKUP,   ~0,     FALSE, 0 },
     { US"certificate",         VERIFY_CERT,            ~0,     TRUE, 0 },
     { US"helo",                        VERIFY_HELO,            ~0,     TRUE, 0 },
     { US"csa",                 VERIFY_CSA,             ~0,     FALSE, 0 },
@@ -1726,7 +1735,7 @@ Returns:       OK        verification condition succeeded
 */
 
 static int
-acl_verify(int where, address_item *addr, uschar *arg,
+acl_verify(int where, address_item *addr, const uschar *arg,
   uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
 {
 int sep = '/';
@@ -1750,7 +1759,7 @@ an error if options are given for items that don't expect them.
 */
 
 uschar *slash = Ustrchr(arg, '/');
-uschar *list = arg;
+const uschar *list = arg;
 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
 verify_type_t * vp;
 
@@ -1783,7 +1792,11 @@ switch(vp->value)
   {
   case VERIFY_REV_HOST_LKUP:
     if (sender_host_address == NULL) return OK;
-    return acl_verify_reverse(user_msgptr, log_msgptr);
+    if ((rc = acl_verify_reverse(user_msgptr, log_msgptr)) == DEFER)
+      while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
+       if (strcmpic(ss, US"defer_ok") == 0)
+         return OK;
+    return rc;
 
   case VERIFY_CERT:
     /* TLS certificate verification is done at STARTTLS time; here we just
@@ -1911,12 +1924,13 @@ while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
       while (isspace(*ss)) ss++;
       if (*ss++ == '=')
         {
+       const uschar * sublist = ss;
         int optsep = ',';
         uschar *opt;
         uschar buffer[256];
-        while (isspace(*ss)) ss++;
+        while (isspace(*sublist)) sublist++;
 
-        while ((opt = string_nextinlist(&ss, &optsep, buffer, sizeof(buffer)))
+        while ((opt = string_nextinlist(&sublist, &optsep, buffer, sizeof(buffer)))
               != NULL)
           {
          callout_opt_t * op;
@@ -2078,6 +2092,13 @@ else if (verify_sender_address != NULL)
     uschar *save_address_data = deliver_address_data;
 
     sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
+#ifdef EXPERIMENTAL_INTERNATIONAL
+    if ((sender_vaddr->prop.utf8_msg = message_smtputf8))
+      {
+      sender_vaddr->prop.utf8_downcvt =       message_utf8_downconvert == 1;
+      sender_vaddr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
+      }
+#endif
     if (no_details) setflag(sender_vaddr, af_sverify_told);
     if (verify_sender_address[0] != 0)
       {
@@ -2134,7 +2155,7 @@ else if (verify_sender_address != NULL)
 
   /* Put the sender address_data value into $sender_address_data */
 
-  sender_address_data = sender_vaddr->p.address_data;
+  sender_address_data = sender_vaddr->prop.address_data;
   }
 
 /* A recipient address just gets a straightforward verify; again we must handle
@@ -2164,7 +2185,7 @@ else
   if (testflag((&addr2), af_pass_message)) acl_temp_details = TRUE;
 
   /* Make $address_data visible */
-  deliver_address_data = addr2.p.address_data;
+  deliver_address_data = addr2.prop.address_data;
   }
 
 /* We have a result from the relevant test. Handle defer overrides first. */
@@ -2183,13 +2204,9 @@ sender_verified_failed to the address item that actually failed. */
 if (rc != OK && verify_sender_address != NULL)
   {
   if (rc != DEFER)
-    {
     *log_msgptr = *user_msgptr = US"Sender verify failed";
-    }
   else if (*basic_errno != ERRNO_CALLOUTDEFER)
-    {
     *log_msgptr = *user_msgptr = US"Could not complete sender verify";
-    }
   else
     {
     *log_msgptr = US"Could not complete sender verify callout";
@@ -2239,7 +2256,7 @@ Returns:      CONTROL_xxx value
 */
 
 static int
-decode_control(uschar *arg, uschar **pptr, int where, uschar **log_msgptr)
+decode_control(const uschar *arg, const uschar **pptr, int where, uschar **log_msgptr)
 {
 int len;
 control_def *d;
@@ -2324,7 +2341,7 @@ Returns:       OK        - Sender's rate is above limit
 */
 
 static int
-acl_ratelimit(uschar *arg, int where, uschar **log_msgptr)
+acl_ratelimit(const uschar *arg, int where, uschar **log_msgptr)
 {
 double limit, period, count;
 uschar *ss;
@@ -2352,7 +2369,10 @@ rate measurement as opposed to rate limiting. */
 
 sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0);
 if (sender_rate_limit == NULL)
+  {
   limit = -1.0;
+  ss = NULL;   /* compiler quietening */
+  }
 else
   {
   limit = Ustrtod(sender_rate_limit, &ss);
@@ -2850,7 +2870,7 @@ Returns:       OK        - Completed.
 */
 
 static int
-acl_udpsend(uschar *arg, uschar **log_msgptr)
+acl_udpsend(const uschar *arg, uschar **log_msgptr)
 {
 int sep = 0;
 uschar *hostname;
@@ -2976,15 +2996,14 @@ uschar *user_message = NULL;
 uschar *log_message = NULL;
 uschar *debug_tag = NULL;
 uschar *debug_opts = NULL;
-uschar *p = NULL;
 int rc = OK;
 #ifdef WITH_CONTENT_SCAN
-int sep = '/';
+int sep = -'/';
 #endif
 
 for (; cb != NULL; cb = cb->next)
   {
-  uschar *arg;
+  const uschar *arg;
   int control_type;
 
   /* The message and log_message items set up messages to be used in
@@ -3123,267 +3142,315 @@ for (; cb != NULL; cb = cb->next)
     break;
 
     case ACLC_CONTROL:
-    control_type = decode_control(arg, &p, where, log_msgptr);
-
-    /* Check if this control makes sense at this time */
-
-    if ((control_forbids[control_type] & (1 << where)) != 0)
       {
-      *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
-        controls[control_type], acl_wherenames[where]);
-      return ERROR;
-      }
+      const uschar *p = NULL;
+      control_type = decode_control(arg, &p, where, log_msgptr);
 
-    switch(control_type)
-      {
-      case CONTROL_AUTH_UNADVERTISED:
-      allow_auth_unadvertised = TRUE;
-      break;
+      /* Check if this control makes sense at this time */
 
-      #ifdef EXPERIMENTAL_BRIGHTMAIL
-      case CONTROL_BMI_RUN:
-      bmi_run = 1;
-      break;
-      #endif
-
-      #ifndef DISABLE_DKIM
-      case CONTROL_DKIM_VERIFY:
-      dkim_disable_verify = TRUE;
-      #ifdef EXPERIMENTAL_DMARC
-      /* Since DKIM was blocked, skip DMARC too */
-      dmarc_disable_verify = TRUE;
-      dmarc_enable_forensic = FALSE;
-      #endif
-      break;
-      #endif
+      if ((control_forbids[control_type] & (1 << where)) != 0)
+       {
+       *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
+         controls[control_type], acl_wherenames[where]);
+       return ERROR;
+       }
 
-      #ifdef EXPERIMENTAL_DMARC
-      case CONTROL_DMARC_VERIFY:
-      dmarc_disable_verify = TRUE;
-      break;
+      switch(control_type)
+       {
+       case CONTROL_AUTH_UNADVERTISED:
+       allow_auth_unadvertised = TRUE;
+       break;
 
-      case CONTROL_DMARC_FORENSIC:
-      dmarc_enable_forensic = TRUE;
-      break;
-      #endif
+       #ifdef EXPERIMENTAL_BRIGHTMAIL
+       case CONTROL_BMI_RUN:
+       bmi_run = 1;
+       break;
+       #endif
+
+       #ifndef DISABLE_DKIM
+       case CONTROL_DKIM_VERIFY:
+       dkim_disable_verify = TRUE;
+       #ifdef EXPERIMENTAL_DMARC
+       /* Since DKIM was blocked, skip DMARC too */
+       dmarc_disable_verify = TRUE;
+       dmarc_enable_forensic = FALSE;
+       #endif
+       break;
+       #endif
 
-      case CONTROL_DSCP:
-      if (*p == '/')
-        {
-        int fd, af, level, optname, value;
-        /* If we are acting on stdin, the setsockopt may fail if stdin is not
-        a socket; we can accept that, we'll just debug-log failures anyway. */
-        fd = fileno(smtp_in);
-        af = ip_get_address_family(fd);
-        if (af < 0)
-          {
-          HDEBUG(D_acl)
-            debug_printf("smtp input is probably not a socket [%s], not setting DSCP\n",
-                strerror(errno));
-          break;
-          }
-        if (dscp_lookup(p+1, af, &level, &optname, &value))
-          {
-          if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
-            {
-            HDEBUG(D_acl) debug_printf("failed to set input DSCP[%s]: %s\n",
-                p+1, strerror(errno));
-            }
-          else
-            {
-            HDEBUG(D_acl) debug_printf("set input DSCP to \"%s\"\n", p+1);
-            }
-          }
-        else
-          {
-          *log_msgptr = string_sprintf("unrecognised DSCP value in \"control=%s\"", arg);
-          return ERROR;
-          }
-        }
-      else
-        {
-        *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
-        return ERROR;
-        }
-      break;
+       #ifdef EXPERIMENTAL_DMARC
+       case CONTROL_DMARC_VERIFY:
+       dmarc_disable_verify = TRUE;
+       break;
 
-      case CONTROL_ERROR:
-      return ERROR;
+       case CONTROL_DMARC_FORENSIC:
+       dmarc_enable_forensic = TRUE;
+       break;
+       #endif
+
+       case CONTROL_DSCP:
+       if (*p == '/')
+         {
+         int fd, af, level, optname, value;
+         /* If we are acting on stdin, the setsockopt may fail if stdin is not
+         a socket; we can accept that, we'll just debug-log failures anyway. */
+         fd = fileno(smtp_in);
+         af = ip_get_address_family(fd);
+         if (af < 0)
+           {
+           HDEBUG(D_acl)
+             debug_printf("smtp input is probably not a socket [%s], not setting DSCP\n",
+                 strerror(errno));
+           break;
+           }
+         if (dscp_lookup(p+1, af, &level, &optname, &value))
+           {
+           if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
+             {
+             HDEBUG(D_acl) debug_printf("failed to set input DSCP[%s]: %s\n",
+                 p+1, strerror(errno));
+             }
+           else
+             {
+             HDEBUG(D_acl) debug_printf("set input DSCP to \"%s\"\n", p+1);
+             }
+           }
+         else
+           {
+           *log_msgptr = string_sprintf("unrecognised DSCP value in \"control=%s\"", arg);
+           return ERROR;
+           }
+         }
+       else
+         {
+         *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
+         return ERROR;
+         }
+       break;
 
-      case CONTROL_CASEFUL_LOCAL_PART:
-      deliver_localpart = addr->cc_local_part;
-      break;
+       case CONTROL_ERROR:
+       return ERROR;
 
-      case CONTROL_CASELOWER_LOCAL_PART:
-      deliver_localpart = addr->lc_local_part;
-      break;
+       case CONTROL_CASEFUL_LOCAL_PART:
+       deliver_localpart = addr->cc_local_part;
+       break;
 
-      case CONTROL_ENFORCE_SYNC:
-      smtp_enforce_sync = TRUE;
-      break;
+       case CONTROL_CASELOWER_LOCAL_PART:
+       deliver_localpart = addr->lc_local_part;
+       break;
 
-      case CONTROL_NO_ENFORCE_SYNC:
-      smtp_enforce_sync = FALSE;
-      break;
+       case CONTROL_ENFORCE_SYNC:
+       smtp_enforce_sync = TRUE;
+       break;
 
-      #ifdef WITH_CONTENT_SCAN
-      case CONTROL_NO_MBOX_UNSPOOL:
-      no_mbox_unspool = TRUE;
-      break;
-      #endif
+       case CONTROL_NO_ENFORCE_SYNC:
+       smtp_enforce_sync = FALSE;
+       break;
 
-      case CONTROL_NO_MULTILINE:
-      no_multiline_responses = TRUE;
-      break;
+       #ifdef WITH_CONTENT_SCAN
+       case CONTROL_NO_MBOX_UNSPOOL:
+       no_mbox_unspool = TRUE;
+       break;
+       #endif
 
-      case CONTROL_NO_PIPELINING:
-      pipelining_enable = FALSE;
-      break;
+       case CONTROL_NO_MULTILINE:
+       no_multiline_responses = TRUE;
+       break;
 
-      case CONTROL_NO_DELAY_FLUSH:
-      disable_delay_flush = TRUE;
-      break;
+       case CONTROL_NO_PIPELINING:
+       pipelining_enable = FALSE;
+       break;
 
-      case CONTROL_NO_CALLOUT_FLUSH:
-      disable_callout_flush = TRUE;
-      break;
+       case CONTROL_NO_DELAY_FLUSH:
+       disable_delay_flush = TRUE;
+       break;
 
-      case CONTROL_FAKEREJECT:
-      cancel_cutthrough_connection("fakereject");
-      case CONTROL_FAKEDEFER:
-      fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
-      if (*p == '/')
-        {
-        uschar *pp = p + 1;
-        while (*pp != 0) pp++;
-        fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
-        p = pp;
-        }
-       else
-        {
-        /* Explicitly reset to default string */
-        fake_response_text = US"Your message has been rejected but is being kept for evaluation.\nIf it was a legitimate message, it may still be delivered to the target recipient(s).";
-        }
-      break;
+       case CONTROL_NO_CALLOUT_FLUSH:
+       disable_callout_flush = TRUE;
+       break;
 
-      case CONTROL_FREEZE:
-      deliver_freeze = TRUE;
-      deliver_frozen_at = time(NULL);
-      freeze_tell = freeze_tell_config;       /* Reset to configured value */
-      if (Ustrncmp(p, "/no_tell", 8) == 0)
-        {
-        p += 8;
-        freeze_tell = NULL;
-        }
-      if (*p != 0)
-        {
-        *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
-        return ERROR;
-        }
-      cancel_cutthrough_connection("item frozen");
-      break;
+       case CONTROL_FAKEREJECT:
+       cancel_cutthrough_connection("fakereject");
+       case CONTROL_FAKEDEFER:
+       fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
+       if (*p == '/')
+         {
+         const uschar *pp = p + 1;
+         while (*pp != 0) pp++;
+         fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
+         p = pp;
+         }
+        else
+         {
+         /* Explicitly reset to default string */
+         fake_response_text = US"Your message has been rejected but is being kept for evaluation.\nIf it was a legitimate message, it may still be delivered to the target recipient(s).";
+         }
+       break;
 
-      case CONTROL_QUEUE_ONLY:
-      queue_only_policy = TRUE;
-      cancel_cutthrough_connection("queueing forced");
-      break;
+       case CONTROL_FREEZE:
+       deliver_freeze = TRUE;
+       deliver_frozen_at = time(NULL);
+       freeze_tell = freeze_tell_config;       /* Reset to configured value */
+       if (Ustrncmp(p, "/no_tell", 8) == 0)
+         {
+         p += 8;
+         freeze_tell = NULL;
+         }
+       if (*p != 0)
+         {
+         *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
+         return ERROR;
+         }
+       cancel_cutthrough_connection("item frozen");
+       break;
 
-      case CONTROL_SUBMISSION:
-      originator_name = US"";
-      submission_mode = TRUE;
-      while (*p == '/')
-        {
-        if (Ustrncmp(p, "/sender_retain", 14) == 0)
-          {
-          p += 14;
-          active_local_sender_retain = TRUE;
-          active_local_from_check = FALSE;
-          }
-        else if (Ustrncmp(p, "/domain=", 8) == 0)
-          {
-          uschar *pp = p + 8;
-          while (*pp != 0 && *pp != '/') pp++;
-          submission_domain = string_copyn(p+8, pp-p-8);
-          p = pp;
-          }
-        /* The name= option must be last, because it swallows the rest of
-        the string. */
-        else if (Ustrncmp(p, "/name=", 6) == 0)
-          {
-          uschar *pp = p + 6;
-          while (*pp != 0) pp++;
-          submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
-            big_buffer, big_buffer_size));
-          p = pp;
-          }
-        else break;
-        }
-      if (*p != 0)
-        {
-        *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
-        return ERROR;
-        }
-      break;
+       case CONTROL_QUEUE_ONLY:
+       queue_only_policy = TRUE;
+       cancel_cutthrough_connection("queueing forced");
+       break;
 
-      case CONTROL_DEBUG:
-      while (*p == '/')
-        {
-        if (Ustrncmp(p, "/tag=", 5) == 0)
-          {
-          uschar *pp = p + 5;
-          while (*pp != '\0' && *pp != '/') pp++;
-          debug_tag = string_copyn(p+5, pp-p-5);
-          p = pp;
-          }
-        else if (Ustrncmp(p, "/opts=", 6) == 0)
-          {
-          uschar *pp = p + 6;
-          while (*pp != '\0' && *pp != '/') pp++;
-          debug_opts = string_copyn(p+6, pp-p-6);
-          p = pp;
-          }
-        }
-        debug_logging_activate(debug_tag, debug_opts);
-      break;
+       case CONTROL_SUBMISSION:
+       originator_name = US"";
+       submission_mode = TRUE;
+       while (*p == '/')
+         {
+         if (Ustrncmp(p, "/sender_retain", 14) == 0)
+           {
+           p += 14;
+           active_local_sender_retain = TRUE;
+           active_local_from_check = FALSE;
+           }
+         else if (Ustrncmp(p, "/domain=", 8) == 0)
+           {
+           const uschar *pp = p + 8;
+           while (*pp != 0 && *pp != '/') pp++;
+           submission_domain = string_copyn(p+8, pp-p-8);
+           p = pp;
+           }
+         /* The name= option must be last, because it swallows the rest of
+         the string. */
+         else if (Ustrncmp(p, "/name=", 6) == 0)
+           {
+           const uschar *pp = p + 6;
+           while (*pp != 0) pp++;
+           submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
+             big_buffer, big_buffer_size));
+           p = pp;
+           }
+         else break;
+         }
+       if (*p != 0)
+         {
+         *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
+         return ERROR;
+         }
+       break;
 
-      case CONTROL_SUPPRESS_LOCAL_FIXUPS:
-      suppress_local_fixups = TRUE;
-      break;
+       case CONTROL_DEBUG:
+       while (*p == '/')
+         {
+         if (Ustrncmp(p, "/tag=", 5) == 0)
+           {
+           const uschar *pp = p + 5;
+           while (*pp != '\0' && *pp != '/') pp++;
+           debug_tag = string_copyn(p+5, pp-p-5);
+           p = pp;
+           }
+         else if (Ustrncmp(p, "/opts=", 6) == 0)
+           {
+           const uschar *pp = p + 6;
+           while (*pp != '\0' && *pp != '/') pp++;
+           debug_opts = string_copyn(p+6, pp-p-6);
+           p = pp;
+           }
+         }
+         debug_logging_activate(debug_tag, debug_opts);
+       break;
 
-      case CONTROL_CUTTHROUGH_DELIVERY:
-      if (deliver_freeze)
-        *log_msgptr = US"frozen";
-      else if (queue_only_policy)
-        *log_msgptr = US"queue-only";
-      else if (fake_response == FAIL)
-        *log_msgptr = US"fakereject";
-      else
-       {
-       cutthrough_delivery = TRUE;
+       case CONTROL_SUPPRESS_LOCAL_FIXUPS:
+       suppress_local_fixups = TRUE;
        break;
+
+       case CONTROL_CUTTHROUGH_DELIVERY:
+       if (prdr_requested)
+         /* Too hard to think about for now.  We might in future cutthrough
+         the case where both sides handle prdr and this-node prdr acl
+         is "accept" */
+         *log_msgptr = string_sprintf("PRDR on %s reception\n", arg);
+       else
+         {
+         if (deliver_freeze)
+           *log_msgptr = US"frozen";
+         else if (queue_only_policy)
+           *log_msgptr = US"queue-only";
+         else if (fake_response == FAIL)
+           *log_msgptr = US"fakereject";
+         else
+           {
+           if (rcpt_count == 1) cutthrough.delivery = TRUE;
+           break;
+           }
+         *log_msgptr = string_sprintf("\"control=%s\" on %s item",
+                                       arg, *log_msgptr);
+         }
+       return ERROR;
+
+    #ifdef EXPERIMENTAL_INTERNATIONAL
+       case CONTROL_UTF8_DOWNCONVERT:
+       if (*p == '/')
+         {
+         if (p[1] == '1')
+           {
+           message_utf8_downconvert = 1;
+           addr->prop.utf8_downcvt = TRUE;
+           addr->prop.utf8_downcvt_maybe = FALSE;
+           p += 2;
+           break;
+           }
+         if (p[1] == '0')
+           {
+           message_utf8_downconvert = 0;
+           addr->prop.utf8_downcvt = FALSE;
+           addr->prop.utf8_downcvt_maybe = FALSE;
+           p += 2;
+           break;
+           }
+         if (p[1] == '-' && p[2] == '1')
+           {
+           message_utf8_downconvert = -1;
+           addr->prop.utf8_downcvt = FALSE;
+           addr->prop.utf8_downcvt_maybe = TRUE;
+           p += 3;
+           break;
+           }
+         *log_msgptr = US"bad option value for control=utf8_downconvert";
+         }
+       else
+         {
+         message_utf8_downconvert = 1;
+         addr->prop.utf8_downcvt = TRUE;
+         addr->prop.utf8_downcvt_maybe = FALSE;
+         break;
+         }
+       return ERROR;
+    #endif
+
        }
-      *log_msgptr = string_sprintf("\"control=%s\" on %s item",
-                                   arg, *log_msgptr);
-      return ERROR;
+      break;
       }
-    break;
 
     #ifdef EXPERIMENTAL_DCC
     case ACLC_DCC:
       {
       /* Seperate the regular expression and any optional parameters. */
-      uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
+      const uschar * list = arg;
+      uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
       /* Run the dcc backend. */
       rc = dcc_process(&ss);
       /* Modify return code based upon the existance of options. */
-      while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
-            != NULL) {
+      while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
         if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
-          {
-          /* FAIL so that the message is passed to the next ACL */
-          rc = FAIL;
-          }
-        }
+          rc = FAIL;   /* FAIL so that the message is passed to the next ACL */
       }
     break;
     #endif
@@ -3413,6 +3480,34 @@ for (; cb != NULL; cb = cb->next)
             debug_printf("delay skipped in -bh checking mode\n");
           }
 
+       /* NOTE 1: Remember that we may be
+        dealing with stdin/stdout here, in addition to TCP/IP connections.
+        Also, delays may be specified for non-SMTP input, where smtp_out and
+        smtp_in will be NULL. Whatever is done must work in all cases.
+
+        NOTE 2: The added feature of flushing the output before a delay must
+        apply only to SMTP input. Hence the test for smtp_out being non-NULL.
+        */
+
+        else
+          {
+          if (smtp_out != NULL && !disable_delay_flush)
+           mac_smtp_fflush();
+
+#if !defined(NO_POLL_H) && defined (POLLRDHUP)
+           {
+           struct pollfd p;
+           nfds_t n = 0;
+           if (smtp_out)
+             {
+             p.fd = fileno(smtp_out);
+             p.events = POLLRDHUP;
+             n = 1;
+             }
+           if (poll(&p, n, delay*1000) > 0)
+             HDEBUG(D_acl) debug_printf("delay cancelled by peer close\n");
+           }
+#else
         /* It appears to be impossible to detect that a TCP/IP connection has
         gone away without reading from it. This means that we cannot shorten
         the delay below if the client goes away, because we cannot discover
@@ -3422,20 +3517,10 @@ for (; cb != NULL; cb = cb->next)
         Exim process is not held up unnecessarily. However, it seems that we
         can't. The poll() function does not do the right thing, and in any case
         it is not always available.
-
-        NOTE 1: If ever this state of affairs changes, remember that we may be
-        dealing with stdin/stdout here, in addition to TCP/IP connections.
-        Also, delays may be specified for non-SMTP input, where smtp_out and
-        smtp_in will be NULL. Whatever is done must work in all cases.
-
-        NOTE 2: The added feature of flushing the output before a delay must
-        apply only to SMTP input. Hence the test for smtp_out being non-NULL.
         */
 
-        else
-          {
-          if (smtp_out != NULL && !disable_delay_flush) mac_smtp_fflush();
           while (delay > 0) delay = sleep(delay);
+#endif
           }
         }
       }
@@ -3480,7 +3565,7 @@ for (; cb != NULL; cb = cb->next)
 
     case ACLC_DOMAINS:
     rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
-      addr->domain_cache, MCL_DOMAIN, TRUE, &deliver_domain_data);
+      addr->domain_cache, MCL_DOMAIN, TRUE, CUSS &deliver_domain_data);
     break;
 
     /* The value in tls_cipher is the full cipher name, for example,
@@ -3513,24 +3598,25 @@ for (; cb != NULL; cb = cb->next)
 
     case ACLC_HOSTS:
     rc = verify_check_this_host(&arg, sender_host_cache, NULL,
-      (sender_host_address == NULL)? US"" : sender_host_address, &host_data);
-    if (host_data != NULL) host_data = string_copy_malloc(host_data);
+      (sender_host_address == NULL)? US"" : sender_host_address,
+      CUSS &host_data);
+    if (rc == DEFER) *log_msgptr = search_error_message;
+    if (host_data) host_data = string_copy_malloc(host_data);
     break;
 
     case ACLC_LOCAL_PARTS:
     rc = match_isinlist(addr->cc_local_part, &arg, 0,
       &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
-      &deliver_localpart_data);
+      CUSS &deliver_localpart_data);
     break;
 
     case ACLC_LOG_REJECT_TARGET:
       {
       int logbits = 0;
       int sep = 0;
-      uschar *s = arg;
+      const uschar *s = arg;
       uschar *ss;
-      while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size))
-              != NULL)
+      while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size)))
         {
         if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN;
         else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC;
@@ -3549,7 +3635,7 @@ for (; cb != NULL; cb = cb->next)
     case ACLC_LOGWRITE:
       {
       int logbits = 0;
-      uschar *s = arg;
+      const uschar *s = arg;
       if (*s == ':')
         {
         s++;
@@ -3580,21 +3666,29 @@ for (; cb != NULL; cb = cb->next)
     break;
 
     #ifdef WITH_CONTENT_SCAN
-    case ACLC_MALWARE:
+    case ACLC_MALWARE:                 /* Run the malware backend. */
       {
       /* Separate the regular expression and any optional parameters. */
-      uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
-      /* Run the malware backend. */
-      rc = malware(&ss);
-      /* Modify return code based upon the existance of options. */
-      while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
-            != NULL) {
-        if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
-          {
-          /* FAIL so that the message is passed to the next ACL */
-          rc = FAIL;
-          }
-        }
+      const uschar * list = arg;
+      uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
+      uschar *opt;
+      BOOL defer_ok = FALSE;
+      int timeout = 0;
+
+      while ((opt = string_nextinlist(&list, &sep, NULL, 0)))
+        if (strcmpic(opt, US"defer_ok") == 0)
+         defer_ok = TRUE;
+       else if (  strncmpic(opt, US"tmo=", 4) == 0
+               && (timeout = readconf_readtime(opt+4, '\0', FALSE)) < 0
+               )
+         {
+         *log_msgptr = string_sprintf("bad timeout value in '%s'", opt);
+         return ERROR;
+         }
+
+      rc = malware(ss, timeout);
+      if (rc == DEFER && defer_ok)
+       rc = FAIL;      /* FAIL so that the message is passed to the next ACL */
       }
     break;
 
@@ -3608,8 +3702,8 @@ for (; cb != NULL; cb = cb->next)
     break;
 
     case ACLC_RECIPIENTS:
-    rc = match_address_list(addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
-      &recipient_data);
+    rc = match_address_list((const uschar *)addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
+      CUSS &recipient_data);
     break;
 
     #ifdef WITH_CONTENT_SCAN
@@ -3633,8 +3727,8 @@ for (; cb != NULL; cb = cb->next)
     break;
 
     case ACLC_SENDERS:
-    rc = match_address_list(sender_address, TRUE, TRUE, &arg,
-      sender_address_cache, -1, 0, &sender_data);
+    rc = match_address_list((const uschar *)sender_address, TRUE, TRUE, &arg,
+      sender_address_cache, -1, 0, CUSS &sender_data);
     break;
 
     /* Connection variables must persist forever */
@@ -3652,11 +3746,12 @@ for (; cb != NULL; cb = cb->next)
     case ACLC_SPAM:
       {
       /* Seperate the regular expression and any optional parameters. */
-      uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
+      const uschar * list = arg;
+      uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
       /* Run the spam backend. */
-      rc = spam(&ss);
+      rc = spam(CUSS &ss);
       /* Modify return code based upon the existance of options. */
-      while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
+      while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
             != NULL) {
         if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
           {
@@ -4052,19 +4147,12 @@ while (acl != NULL)
   int cond;
   int basic_errno = 0;
   BOOL endpass_seen = FALSE;
+  BOOL acl_quit_check = level == 0
+    && (where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT);
 
   *log_msgptr = *user_msgptr = NULL;
   acl_temp_details = FALSE;
 
-  if ((where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT) &&
-      acl->verb != ACL_ACCEPT &&
-      acl->verb != ACL_WARN)
-    {
-    *log_msgptr = string_sprintf("\"%s\" is not allowed in a QUIT or not-QUIT ACL",
-      verbs[acl->verb]);
-    return ERROR;
-    }
-
   HDEBUG(D_acl) debug_printf("processing \"%s\"\n", verbs[acl->verb]);
 
   /* Clear out any search error message from a previous check before testing
@@ -4129,7 +4217,11 @@ while (acl != NULL)
   switch(acl->verb)
     {
     case ACL_ACCEPT:
-    if (cond == OK || cond == DISCARD) return cond;
+    if (cond == OK || cond == DISCARD)
+      {
+      HDEBUG(D_acl) debug_printf("end of %s: ACCEPT\n", acl_name);
+      return cond;
+      }
     if (endpass_seen)
       {
       HDEBUG(D_acl) debug_printf("accept: endpass encountered - denying access\n");
@@ -4140,17 +4232,29 @@ while (acl != NULL)
     case ACL_DEFER:
     if (cond == OK)
       {
+      HDEBUG(D_acl) debug_printf("end of %s: DEFER\n", acl_name);
+      if (acl_quit_check) goto badquit;
       acl_temp_details = TRUE;
       return DEFER;
       }
     break;
 
     case ACL_DENY:
-    if (cond == OK) return FAIL;
+    if (cond == OK)
+      {
+      HDEBUG(D_acl) debug_printf("end of %s: DENY\n", acl_name);
+      if (acl_quit_check) goto badquit;
+      return FAIL;
+      }
     break;
 
     case ACL_DISCARD:
-    if (cond == OK || cond == DISCARD) return DISCARD;
+    if (cond == OK || cond == DISCARD)
+      {
+      HDEBUG(D_acl) debug_printf("end of %s: DISCARD\n", acl_name);
+      if (acl_quit_check) goto badquit;
+      return DISCARD;
+      }
     if (endpass_seen)
       {
       HDEBUG(D_acl) debug_printf("discard: endpass encountered - denying access\n");
@@ -4159,11 +4263,21 @@ while (acl != NULL)
     break;
 
     case ACL_DROP:
-    if (cond == OK) return FAIL_DROP;
+    if (cond == OK)
+      {
+      HDEBUG(D_acl) debug_printf("end of %s: DROP\n", acl_name);
+      if (acl_quit_check) goto badquit;
+      return FAIL_DROP;
+      }
     break;
 
     case ACL_REQUIRE:
-    if (cond != OK) return cond;
+    if (cond != OK)
+      {
+      HDEBUG(D_acl) debug_printf("end of %s: not OK\n", acl_name);
+      if (acl_quit_check) goto badquit;
+      return cond;
+      }
     break;
 
     case ACL_WARN:
@@ -4192,6 +4306,11 @@ while (acl != NULL)
 
 HDEBUG(D_acl) debug_printf("end of %s: implicit DENY\n", acl_name);
 return FAIL;
+
+badquit:
+  *log_msgptr = string_sprintf("QUIT or not-QUIT teplevel ACL may not fail "
+    "('%s' verb used incorrectly)", verbs[acl->verb]);
+  return ERROR;
 }
 
 
@@ -4201,7 +4320,7 @@ return FAIL;
 the name of an ACL followed optionally by up to 9 space-separated arguments.
 The name and args are separately expanded.  Args go into $acl_arg globals. */
 static int
-acl_check_wargs(int where, address_item *addr, uschar *s, int level,
+acl_check_wargs(int where, address_item *addr, const uschar *s, int level,
   uschar **user_msgptr, uschar **log_msgptr)
 {
 uschar * tmp;
@@ -4320,9 +4439,9 @@ ratelimiters_cmd = NULL;
 log_reject_target = LOG_MAIN|LOG_REJECT;
 
 #ifndef DISABLE_PRDR
-if (where == ACL_WHERE_RCPT || where == ACL_WHERE_PRDR )
+if (where == ACL_WHERE_RCPT || where == ACL_WHERE_PRDR)
 #else
-if (where == ACL_WHERE_RCPT )
+if (where == ACL_WHERE_RCPT)
 #endif
   {
   adb = address_defaults;
@@ -4333,6 +4452,13 @@ if (where == ACL_WHERE_RCPT )
     *log_msgptr = US"defer in percent_hack_domains check";
     return DEFER;
     }
+#ifdef EXPERIMENTAL_INTERNATIONAL
+  if ((addr->prop.utf8_msg = message_smtputf8))
+    {
+    addr->prop.utf8_downcvt =       message_utf8_downconvert == 1;
+    addr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
+    }
+#endif
   deliver_domain = addr->domain;
   deliver_localpart = addr->local_part;
   }
@@ -4366,9 +4492,7 @@ case ACL_WHERE_RCPT:
 #ifndef DISABLE_PRDR
 case ACL_WHERE_PRDR:
 #endif
-  if( rcpt_count > 1 )
-    cancel_cutthrough_connection("more than one recipient");
-  else if (rc == OK  &&  cutthrough_delivery  &&  cutthrough_fd < 0)
+  if (rc == OK  &&  cutthrough.delivery  && rcpt_count > cutthrough.nrcpt)
     open_cutthrough_connection(addr);
   break;