Expand max_rcpt option on smtp transport. Bug 2946

6 files changed, 30 insertions, 12 deletions

diff --git a/src/src/deliver.c b/src/src/deliver.c
index c5e00eaef..ca31df587 100644
--- a/src/src/deliver.c
+++ b/src/src/deliver.c
@@ -4290,10 +4290,14 @@ So look out for the place it gets used.
     }
 
   /* Get the maximum it can handle in one envelope, with zero meaning
-  unlimited, which is forced for the MUA wrapper case. */
-
-  address_count_max = tp->max_addresses;
-  if (address_count_max == 0 || mua_wrapper) address_count_max = 999999;
+  unlimited, which is forced for the MUA wrapper case and if the
+  value could vary depending on the messages.
+  For those, we only split (below) by (tpt,dest,erraddr,hdrs) and rely on the
+  transport splitting further by max_rcp.  So we potentially lose some
+  parallellism. */
+
+  address_count_max = mua_wrapper || Ustrchr(tp->max_addresses, '$')
+    ? UNLIMITED_ADDRS : expand_max_rcpt(tp->max_addresses);
 
 
   /************************************************************************/
diff --git a/src/src/functions.h b/src/src/functions.h
index 3ca346c04..1817144ea 100644
--- a/src/src/functions.h
+++ b/src/src/functions.h
@@ -1307,6 +1307,14 @@ debug_printf("cmdlog: '%s'\n", client_cmd_log ? client_cmd_log->s : US"(unset)")
 
 
 
+static inline int
+expand_max_rcpt(const uschar * str_max_rcpt)
+{
+const uschar * s = expand_cstring(str_max_rcpt);
+int res;
+return !s || !*s || (res = Uatoi(s)) == 0 ? UNLIMITED_ADDRS : res;
+}
+
 # endif	/* !COMPILE_UTILITY */
 
 /******************************************************************************/
@@ -1314,6 +1322,6 @@ debug_printf("cmdlog: '%s'\n", client_cmd_log ? client_cmd_log->s : US"(unset)")
 
 #endif  /* _FUNCTIONS_H_ */
 
-/* vi: aw
+/* vi: aw ai sw=2
 */
 /* End of functions.h */
diff --git a/src/src/globals.c b/src/src/globals.c
index e5b72592f..efe34902a 100644
--- a/src/src/globals.c
+++ b/src/src/globals.c
@@ -1592,7 +1592,7 @@ transport_instance  transport_defaults = {
     /* All non-mentioned elements zero/NULL/FALSE */
     .batch_max =		1,
     .multi_domain =		TRUE,
-    .max_addresses =		100,
+    .max_addresses =		US"100",
     .connection_max_messages =	500,
     .uid =			(uid_t)(-1),
     .gid =			(gid_t)(-1),
diff --git a/src/src/macros.h b/src/src/macros.h
index a631877a1..585067fc9 100644
--- a/src/src/macros.h
+++ b/src/src/macros.h
@@ -1136,4 +1136,8 @@ typedef unsigned mcs_flags;
 #else
 # define EXIM_NOFOLLOW 0
 #endif
+
+/* A big number for (effectively) unlimited envelope addresses */
+#define UNLIMITED_ADDRS		999999
+
 /* End of macros.h */
diff --git a/src/src/structs.h b/src/src/structs.h
index e1d93a943..eae66e88d 100644
--- a/src/src/structs.h
+++ b/src/src/structs.h
@@ -183,7 +183,7 @@ typedef struct transport_instance {
   uschar *expand_multi_domain;    /* )                                  */
   BOOL    multi_domain;           /* )                                  */
   BOOL    overrides_hosts;        /* ) Used only for remote transports  */
-  int     max_addresses;          /* )                                  */
+  uschar *max_addresses;          /* )                                  */
   int     connection_max_messages;/* )                                  */
                                   /**************************************/
   BOOL    deliver_as_creator;     /* Used only by pipe at present */
diff --git a/src/src/transports/smtp.c b/src/src/transports/smtp.c
index ed5f83b3e..c5951832b 100644
--- a/src/src/transports/smtp.c
+++ b/src/src/transports/smtp.c
@@ -114,7 +114,7 @@ optionlist smtp_transport_options[] = {
   { "interface",            opt_stringptr, LOFF(interface) },
   { "keepalive",            opt_bool,	   LOFF(keepalive) },
   { "lmtp_ignore_quota",    opt_bool,	   LOFF(lmtp_ignore_quota) },
-  { "max_rcpt",             opt_int | opt_public,
+  { "max_rcpt",             opt_stringptr | opt_public,
       OPT_OFF(transport_instance, max_addresses) },
   { "message_linelength_limit", opt_int,   LOFF(message_linelength_limit) },
   { "multi_domain",         opt_expand_bool | opt_public,
@@ -2121,8 +2121,9 @@ sx->dane_required =
   verify_check_given_host(CUSS &ob->hosts_require_dane, sx->conn_args.host) == OK;
 #endif
 
-if ((sx->max_mail = sx->conn_args.tblock->connection_max_messages) == 0) sx->max_mail = 999999;
-if ((sx->max_rcpt = sx->conn_args.tblock->max_addresses) == 0)           sx->max_rcpt = 999999;
+if ((sx->max_mail = sx->conn_args.tblock->connection_max_messages) == 0)
+  sx->max_mail = UNLIMITED_ADDRS;
+sx->max_rcpt = expand_max_rcpt(sx->conn_args.tblock->max_addresses);
 sx->igquotstr = US"";
 if (!sx->helo_data) sx->helo_data = ob->helo_data;
 
@@ -2819,8 +2820,9 @@ if (tls_out.active.sock >= 0)
 #ifdef EXPERIMMENTAL_ESMTP_LIMITS
   /* As we are about to send another EHLO, forget any LIMITS received so far. */
   sx->peer_limit_mail = sx->peer_limit_rcpt = sx->peer_limit_rcptdom = 0;
-  if ((sx->max_mail = sx->conn_args.tblock->connection_max_message) == 0) sx->max_mail = 999999;
-  if ((sx->max_rcpt = sx->conn_args.tblock->max_addresses) == 0)          sx->max_rcpt = 999999;
+  if ((sx->max_mail = sx->conn_args.tblock->connection_max_message) == 0)
+    sx->max_mail = UNLIMITED_ADDRS;
+  sx->max_rcpt = expand_max_rcpt(sx->conn_args.tblock->max_addresses);
   sx->single_rcpt_domain = FALSE;
 #endif