Adding upstream version 3.4.23.upstream/3.4.23upstream

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

1 files changed, 165 insertions, 0 deletions

diff --git a/src/global/scache.h b/src/global/scache.h
new file mode 100644
index 0000000..a46362a
--- /dev/null
+++ b/src/global/scache.h
@@ -0,0 +1,165 @@
+#ifndef _SCACHE_H_INCLUDED_
+#define _SCACHE_H_INCLUDED_
+
+/*++
+/* NAME
+/*	scache 3h
+/* SUMMARY
+/*	generic session cache API
+/* SYNOPSIS
+/*	#include <scache.h>
+/* DESCRIPTION
+/* .nf
+
+ /*
+  * Utility library.
+  */
+#include <vstring.h>
+
+typedef struct SCACHE SCACHE;
+typedef struct SCACHE_SIZE SCACHE_SIZE;
+
+ /*
+  * In order to cache a session, we specify:
+  * 
+  * - TTL for this session.
+  * 
+  * - File descriptor.
+  * 
+  * - Transport name and physical endpoint. The transport name must be included,
+  * because fall-back destinations can be transport-dependent, and routing
+  * for a given destination may be context dependent.
+  * 
+  * In the case of SMTP, the physical endpoint is the numerical IP address and
+  * TCP port.
+  * 
+  * - Application-specific endpoint properties.
+  * 
+  * In the case of SMTP, the properties specify the ESMTP features advertised by
+  * the server.
+  * 
+  * Note: with message delivery transports that have only one endpoint per
+  * logical destination, the above is the only information that needs to be
+  * maintained in a connection cache.
+  */
+typedef void (*SCACHE_SAVE_ENDP_FN) (SCACHE *, int, const char *, const char *, int);
+typedef int (*SCACHE_FIND_ENDP_FN) (SCACHE *, const char *, VSTRING *);
+
+ /*
+  * The following information is stored in order to make a binding from
+  * logical destination to physical destination. One logical destination can
+  * have multiple physical destinations (and one physical destination can
+  * have multiple sessions).
+  * 
+  * - TTL for this binding.
+  * 
+  * - Transport name and logical destination.
+  * 
+  * In the case of SMTP: the next-hop (NOT: fall-back) destination domain and
+  * destination network port. It is not useful to create a link for an
+  * address literal (but it is not harmful either: it just wastes a few
+  * bits). This information specifies the destination domain in [] if no MX
+  * lookup is done.
+  * 
+  * - Application-specific properties.
+  * 
+  * In case the of SMTP, the properties specify a) whether a physical endpoint
+  * is best mx host with respect to a logical or fall-back destination (this
+  * information is needed by the loop detection code in smtp_proto.c).
+  * 
+  * - Transport name and physical endpoint (see above).
+  * 
+  * Note 1: there is no need to store the binding's MX preference or equivalent
+  * with respect to the logical destination; a client should store only the
+  * first successful session for a given delivery request (otherwise the
+  * client would keep talking to a less preferred server after the cached
+  * connection for a more preferred server expires). After a failed delivery,
+  * the client should not attempt to cache follow-up sessions with less
+  * preferred endpoints under the same logical destination.
+  * 
+  * Note 2: logical to physical bindings exist independently from cached
+  * sessions. The two types of information have independent TTLs; creation
+  * and destruction proceed independently. Thus, a logical to physical
+  * binding can refer to an endpoint for which all cached connections are
+  * occupied or expired.
+  */
+typedef void (*SCACHE_SAVE_DEST_FN) (SCACHE *, int, const char *, const char *, const char *);
+typedef int (*SCACHE_FIND_DEST_FN) (SCACHE *, const char *, VSTRING *, VSTRING *);
+
+ /*
+  * Session cache statistics. These are the actual numbers at a specific
+  * point in time.
+  */
+struct SCACHE_SIZE {
+    int     dest_count;			/* Nr of destination names */
+    int     endp_count;			/* Nr of endpoint addresses */
+    int     sess_count;			/* Nr of cached sessions */
+};
+
+ /*
+  * Generic session cache object. Actual session cache objects are derived
+  * types with some additional, cache dependent, private information.
+  */
+struct SCACHE {
+    SCACHE_SAVE_ENDP_FN save_endp;
+    SCACHE_FIND_ENDP_FN find_endp;
+    SCACHE_SAVE_DEST_FN save_dest;
+    SCACHE_FIND_DEST_FN find_dest;
+    void    (*size) (struct SCACHE *, SCACHE_SIZE *);
+    void    (*free) (struct SCACHE *);
+};
+
+extern SCACHE *scache_single_create(void);
+extern SCACHE *scache_clnt_create(const char *, int, int, int);
+extern SCACHE *scache_multi_create(void);
+
+#define scache_save_endp(scache, ttl, endp_label, endp_prop, fd) \
+    (scache)->save_endp((scache), (ttl), (endp_label), (endp_prop), (fd))
+#define scache_find_endp(scache, endp_label, endp_prop) \
+    (scache)->find_endp((scache), (endp_label), (endp_prop))
+#define scache_save_dest(scache, ttl, dest_label, dest_prop, endp_label) \
+    (scache)->save_dest((scache), (ttl), (dest_label), (dest_prop), (endp_label))
+#define scache_find_dest(scache, dest_label, dest_prop, endp_prop) \
+    (scache)->find_dest((scache), (dest_label), (dest_prop), (endp_prop))
+#define scache_size(scache, stats) (scache)->size((scache), (stats))
+#define scache_free(scache) (scache)->free(scache)
+
+ /*
+  * Cache types.
+  */
+#define SCACHE_TYPE_SINGLE	1	/* single-instance cache */
+#define SCACHE_TYPE_CLIENT	2	/* session cache client */
+#define SCACHE_TYPE_MULTI	3	/* multi-instance cache */
+
+ /*
+  * Client-server protocol.
+  */
+#define SCACHE_REQ_FIND_ENDP	"find_endp"
+#define SCACHE_REQ_SAVE_ENDP	"save_endp"
+#define SCACHE_REQ_FIND_DEST	"find_dest"
+#define SCACHE_REQ_SAVE_DEST	"save_dest"
+
+ /*
+  * Session cache server status codes.
+  */
+#define SCACHE_STAT_OK		0	/* request completed successfully */
+#define SCACHE_STAT_BAD		1	/* malformed request */
+#define SCACHE_STAT_FAIL	2	/* request completed unsuccessfully */
+
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*
+/*	Wietse Venema
+/*	Google, Inc.
+/*	111 8th Avenue
+/*	New York, NY 10011, USA
+/*--*/
+
+#endif