1 files changed, 81 insertions, 0 deletions
diff --git a/tcpd/tlscache.h b/tcpd/tlscache.h
new file mode 100644
index 0000000..5789ca1
--- /dev/null
+++ b/tcpd/tlscache.h
@@ -0,0 +1,81 @@
+/*
+** Copyright 2002 Double Precision, Inc.
+** See COPYING for distribution information.
+*/
+
+#ifndef tlscache_h
+#define tlscache_h
+
+#include	"config.h"
+
+#include	<sys/types.h>
+#include	<unistd.h>
+
+
+/*
+** This module implements a cache for SSL sessions, however the interface
+** is generic enough to accomodate caching of any kind of small object.
+** The cache is a disk file, that contains a circular cache (when the
+** end of the file is reached, we wrap around and begin adding new cached
+** object to the beginning of the file, overwriting the oldest one).
+**
+** Well, that's the general idea, but technically it's the other way around.
+** The cache begins at the end of the file, and grows towards the beginning
+** of the file, then wraps around to the end of the file again.  The cache
+** is searched by reading the file starting with wherever the current add
+** position is, then wrapping around if necessary.  Hence, the cache file
+** is searched starting with the most recently added object; which is the
+** expected usage pattern.
+**
+** File locking is used to implement concurrency.
+*/
+
+struct CACHE {
+	int fd;
+	char *filename;
+};
+
+/*
+** Open a cache file.  If it doesn't exist, create one with the indicated
+** size (in bytes).
+*/
+
+struct CACHE *tls_cache_open(const char *filename,
+			     off_t req_size);	/* In bytes */
+
+/*
+** Close and deallocate the CACHE object.
+*/
+void tls_cache_close(struct CACHE *p);
+
+/*
+** Cache a new object, val, vallen bytes long.
+*/
+
+int tls_cache_add(struct CACHE *p, const char *val, size_t vallen);
+
+/*
+** Read the cache file.  walk_func is a callback function that's repeatedly
+** called for each cached object.  walk_func should return 0 to continue
+** with the next cached object; a positive value to stop reading the cache
+** (object found); a negative value to stopr eading the cache and remove it
+** (if it's corrupted, for some reason).  walk_func receives 'arg', a
+** transparent pointer.
+**
+** tls_cache_walk returns 0 when all cached objects were read, or the non-0
+** return value from the callback function.  tls_cache_walk will return -1
+** if it itself encounters an error.
+**
+** The callback function may modify rec, and set *doupdate to non-zero in
+** order to update the cached record (the return code is still processed in
+** the normal way).  The updated record will be saved if the callback function
+** terminate with 0 or a positive return code.
+*/
+
+int tls_cache_walk(struct CACHE *p,
+		   int (*walk_func)(void *rec, size_t recsize,
+				    int *doupdate, void *arg),
+		   void *arg);
+
+
+#endif