CVE-2020-28012: Missing close-on-exec flag for privileged pipe

[exim.git] / doc / doc-txt / experimental-spec.txt

diff --git a/doc/doc-txt/experimental-spec.txt b/doc/doc-txt/experimental-spec.txt
index 5193f1729118f490311654d66a7fed87dc03a473..3beab4b9c9e86d5192a0f3c995e03272d23c68a6 100644 (file)
--- a/doc/doc-txt/experimental-spec.txt
+++ b/doc/doc-txt/experimental-spec.txt
@@ -292,10 +292,11 @@ These four steps are explained in more details below.
 
 
 
 
 
 

-SRS (Sender Rewriting Scheme) Support
+SRS (Sender Rewriting Scheme) Support (using libsrs_alt)

 --------------------------------------------------------------
 --------------------------------------------------------------

+See also below, for an alternative native support implementation.

 
 

-Exiscan  currently  includes SRS  support  via Miles  Wilton's
+Exim  currently  includes SRS  support  via Miles  Wilton's

 libsrs_alt library. The current version of the supported
 library is 0.5, there are reports of 1.0 working.
 
 libsrs_alt library. The current version of the supported
 library is 0.5, there are reports of 1.0 working.
 


@@ -343,6 +344,76 @@ For configuration information see https://github.com/Exim/exim/wiki/SRS .
 
 
 
 
 
 

+SRS (Sender Rewriting Scheme) Support (native)
+--------------------------------------------------------------
+This is less full-featured than the libsrs_alt version above.
+
+The Exim build needs to be done with this in Local/Makefile:
+EXPERIMENTAL_SRS_NATIVE=yes
+
+The following are provided:
+- an expansion item "srs_encode"
+  This takes three arguments:
+  - a site SRS secret
+  - the return_path
+  - the pre-forwarding domain
+
+- an expansion condition "inbound_srs"
+  This takes two arguments: the local_part to check, and a site SRS secret.
+  If the secret is zero-length, only the pattern of the local_part is checked.
+  The $srs_recipient variable is set as a side-effect.
+
+- an expansion variable $srs_recipient
+  This gets the original return_path encoded in the SRS'd local_part
+
+- predefined macros _HAVE_SRS and _HAVE_NATIVE_SRS
+
+Sample usage:
+
+  #macro
+  SRS_SECRET = <pick something unique for your site for this>
+  
+  #routers
+
+  outbound:
+    driver =    dnslookup
+    # if outbound, and forwarding has been done, use an alternate transport
+    domains =   ! +my_domains
+    transport = ${if eq {$local_part@$domain} \
+                        {$original_local_part@$original_domain} \
+                     {remote_smtp} {remote_forwarded_smtp}}
+  
+  inbound_srs:
+    driver =    redirect
+    senders =   :
+    domains =   +my_domains
+    # detect inbound bounces which are SRS'd, and decode them
+    condition = ${if inbound_srs {$local_part} {SRS_SECRET}}
+    data =      $srs_recipient
+  
+  inbound_srs_failure:
+    driver =    redirect
+    senders =   :
+    domains =   +my_domains
+    # detect inbound bounces which look SRS'd but are invalid
+    condition = ${if inbound_srs {$local_part} {}}
+    allow_fail
+    data =      :fail: Invalid SRS recipient address
+
+  #... further routers here
+
+  
+  # transport; should look like the non-forward outbound
+  # one, plus the max_rcpt and return_path options
+  remote_forwarded_smtp:
+    driver =              smtp
+    # modify the envelope from, for mails that we forward
+    max_rcpt =            1
+    return_path =         ${srs_encode {SRS_SECRET} {$return_path} {$original_domain}}
+
+
+
+

 DCC Support
 --------------------------------------------------------------
 Distributed Checksum Clearinghouse; http://www.rhyolite.com/dcc/
 DCC Support
 --------------------------------------------------------------
 Distributed Checksum Clearinghouse; http://www.rhyolite.com/dcc/


@@ -737,6 +808,59 @@ Issues:
    hosts_require_ocsp will fail
 
 
    hosts_require_ocsp will fail
 
 

+
+Dovecot authenticator via inet socket
+------------------------------------
+If Dovecot is configured similar to :-
+
+service auth {
+...
+#SASL
+  inet_listener {
+    name = exim
+    port = 12345
+  }
+...
+}
+
+then an Exim authenticator can be configured :-
+
+  dovecot-plain:
+    driver =           dovecot
+    public_name =      PLAIN
+    server_socket =    dovecot_server_name 12345
+    server_tls =       true
+    server_set_id =    $auth1
+
+If the server_socket does not start with a / it is taken as a hostname (or IP);
+and a whitespace-separated port number must be given.
+
+
+
+Twophase queue run fast ramp
+----------------------------
+To include this feature, add to Local/Makefile:
+  EXPERIMENTAL_QUEUE_RAMP=yes
+
+If the (added for this feature) main-section option "queue_fast_ramp" (boolean)
+is set, and a two-phase ("-qq") queue run finds, during the first phase, a
+suitably large number of message routed for a given host - then (subject to
+the usual queue-runner resource limits) delivery for that host is initiated
+immediately, overlapping with the remainder of the first phase.
+
+This is incompatible with queue_run_in_order.
+
+The result should be a faster startup of deliveries when a large queue is
+present and reasonable numbers of messages are routed to common hosts; this
+could be a smarthost case, or delivery onto the Internet where a large proportion
+of recipients hapen to be on a Gorilla-sized provider.
+
+As usual, the presence of a configuration option is associated with a
+predefined macro, making it possible to write portable configurations.
+For this one, the macro is _OPT_MAIN_QUEUE_FAST_RAMP.
+
+
+

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