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/*++
/* NAME
/* scache 3
/* SUMMARY
/* generic session cache API
/* SYNOPSIS
/* #include <scache.h>
/* DESCRIPTION
/* typedef struct {
/* .in +4
/* int dest_count;
/* int endp_count;
/* int sess_count;
/* .in -4
/* } SCACHE_SIZE;
/*
/* unsigned scache_size(scache, size)
/* SCACHE *scache;
/* SCACHE_SIZE *size;
/*
/* void scache_free(scache)
/* SCACHE *scache;
/*
/* void scache_save_endp(scache, endp_ttl, endp_label, endp_prop, fd)
/* SCACHE *scache;
/* int endp_ttl;
/* const char *endp_label;
/* const char *endp_prop;
/* int fd;
/*
/* int scache_find_endp(scache, endp_label, endp_prop)
/* SCACHE *scache;
/* const char *endp_label;
/* VSTRING *endp_prop;
/*
/* void scache_save_dest(scache, dest_ttl, dest_label,
/* dest_prop, endp_label)
/* SCACHE *scache;
/* int dest_ttl;
/* const char *dest_label;
/* const char *dest_prop;
/* const char *endp_label;
/*
/* int scache_find_dest(dest_label, dest_prop, endp_prop)
/* SCACHE *scache;
/* const char *dest_label;
/* VSTRING *dest_prop;
/* VSTRING *endp_prop;
/* DESCRIPTION
/* This module implements a generic session cache interface.
/* Specific cache types are described in scache_single(3),
/* scache_clnt(3) and scache_multi(3). These documents also
/* describe now to instantiate a specific session cache type.
/*
/* The code maintains two types of association: a) physical
/* endpoint to file descriptor, and b) logical endpoint
/* to physical endpoint. Physical endpoints are stored and
/* looked up under their low-level session details such as
/* numerical addresses, while logical endpoints are stored
/* and looked up by the domain name that humans use. One logical
/* endpoint can refer to multiple physical endpoints, one
/* physical endpoint may be referenced by multiple logical
/* endpoints, and one physical endpoint may have multiple
/* sessions.
/*
/* scache_size() returns the number of logical destination
/* names, physical endpoint addresses, and cached sessions.
/*
/* scache_free() destroys the specified session cache.
/*
/* scache_save_endp() stores an open session under the specified
/* physical endpoint name.
/*
/* scache_find_endp() looks up a saved session under the
/* specified physical endpoint name.
/*
/* scache_save_dest() associates the specified physical endpoint
/* with the specified logical endpoint name.
/*
/* scache_find_dest() looks up a saved session under the
/* specified physical endpoint name.
/*
/* Arguments:
/* .IP endp_ttl
/* How long the session should be cached. When information
/* expires it is purged automatically.
/* .IP endp_label
/* The transport name and the physical endpoint name under
/* which the session is stored and looked up.
/*
/* In the case of SMTP, the physical endpoint includes the numerical
/* IP address, address family information, and the numerical TCP port.
/* .IP endp_prop
/* Application-specific data with endpoint attributes. It is up to
/* the application to passivate (flatten) and re-activate this content
/* upon storage and retrieval, respectively.
/* .sp
/* In the case of SMTP, the endpoint attributes specify the
/* server hostname, IP address, numerical TCP port, as well
/* as ESMTP features advertised by the server, and when information
/* expires. All this in some application-specific format that is easy
/* to unravel when re-activating a cached session.
/* .IP dest_ttl
/* How long the destination-to-endpoint binding should be
/* cached. When information expires it is purged automatically.
/* .IP dest_label
/* The transport name and the logical destination under which the
/* destination-to-endpoint binding is stored and looked up.
/*
/* In the case of SMTP, the logical destination is the DNS
/* host or domain name with or without [], plus the numerical TCP port.
/* .IP dest_prop
/* Application-specific attributes that describe features of
/* this logical to physical binding. It is up to the application
/* to passivate (flatten) and re-activate this content.
/* upon storage and retrieval, respectively
/* .sp
/* In case the of an SMTP logical destination to physical
/* endpoint binding, the attributes specify the logical
/* destination name, numerical port, whether the physical
/* endpoint is best mx host with respect to a logical or
/* fall-back destination, and when information expires.
/* .IP fd
/* File descriptor with session to be cached.
/* DIAGNOSTICS
/* scache_find_endp() and scache_find_dest() return -1 when
/* the lookup fails, and a file descriptor upon success.
/*
/* Other diagnostics: fatal error: memory allocation problem;
/* panic: internal consistency failure.
/* SEE ALSO
/* scache_single(3), single-session, in-memory cache
/* scache_clnt(3), session cache client
/* scache_multi(3), multi-session, in-memory cache
/* 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
/*--*/
/* System library. */
#include <sys_defs.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
/* Utility library. */
#include <msg.h>
#include <vstream.h>
#include <vstring.h>
#include <vstring_vstream.h>
#include <argv.h>
#include <events.h>
/* Global library. */
#include <scache.h>
#ifdef TEST
/*
* Driver program for cache regression tests. Although all variants are
* relatively simple to verify by hand for single session storage, more
* sophisticated instrumentation is needed to demonstrate that the
* multi-session cache manager properly handles collisions in the time
* domain and in all the name space domains.
*/
static SCACHE *scache;
static VSTRING *endp_prop;
static VSTRING *dest_prop;
static int verbose_level = 3;
/*
* Cache mode lookup table. We don't do the client-server variant because
* that drags in a ton of configuration junk; the client-server protocol is
* relatively easy to verify manually.
*/
struct cache_type {
char *mode;
SCACHE *(*create) (void);
};
static struct cache_type cache_types[] = {
"single", scache_single_create,
"multi", scache_multi_create,
0,
};
#define STR(x) vstring_str(x)
/* cache_type - select session cache type */
static void cache_type(ARGV *argv)
{
struct cache_type *cp;
if (argv->argc != 2) {
msg_error("usage: %s mode", argv->argv[0]);
return;
}
if (scache != 0)
scache_free(scache);
for (cp = cache_types; cp->mode != 0; cp++) {
if (strcmp(cp->mode, argv->argv[1]) == 0) {
scache = cp->create();
return;
}
}
msg_error("unknown cache type: %s", argv->argv[1]);
}
/* handle_events - handle events while time advances */
static void handle_events(ARGV *argv)
{
int delay;
time_t before;
time_t after;
if (argv->argc != 2 || (delay = atoi(argv->argv[1])) <= 0) {
msg_error("usage: %s time", argv->argv[0]);
return;
}
before = event_time();
event_drain(delay);
after = event_time();
if (after < before + delay)
sleep(before + delay - after);
}
/* save_endp - save endpoint->session binding */
static void save_endp(ARGV *argv)
{
int ttl;
int fd;
if (argv->argc != 5
|| (ttl = atoi(argv->argv[1])) <= 0
|| (fd = atoi(argv->argv[4])) <= 0) {
msg_error("usage: save_endp ttl endpoint endp_props fd");
return;
}
if (DUP2(0, fd) < 0)
msg_fatal("dup2(0, %d): %m", fd);
scache_save_endp(scache, ttl, argv->argv[2], argv->argv[3], fd);
}
/* find_endp - find endpoint->session binding */
static void find_endp(ARGV *argv)
{
int fd;
if (argv->argc != 2) {
msg_error("usage: find_endp endpoint");
return;
}
if ((fd = scache_find_endp(scache, argv->argv[1], endp_prop)) >= 0)
close(fd);
}
/* save_dest - save destination->endpoint binding */
static void save_dest(ARGV *argv)
{
int ttl;
if (argv->argc != 5 || (ttl = atoi(argv->argv[1])) <= 0) {
msg_error("usage: save_dest ttl destination dest_props endpoint");
return;
}
scache_save_dest(scache, ttl, argv->argv[2], argv->argv[3], argv->argv[4]);
}
/* find_dest - find destination->endpoint->session binding */
static void find_dest(ARGV *argv)
{
int fd;
if (argv->argc != 2) {
msg_error("usage: find_dest destination");
return;
}
if ((fd = scache_find_dest(scache, argv->argv[1], dest_prop, endp_prop)) >= 0)
close(fd);
}
/* verbose - adjust noise level during cache manipulation */
static void verbose(ARGV *argv)
{
int level;
if (argv->argc != 2 || (level = atoi(argv->argv[1])) < 0) {
msg_error("usage: verbose level");
return;
}
verbose_level = level;
}
/*
* The command lookup table.
*/
struct action {
char *command;
void (*action) (ARGV *);
int flags;
};
#define FLAG_NEED_CACHE (1<<0)
static void help(ARGV *);
static struct action actions[] = {
"cache_type", cache_type, 0,
"save_endp", save_endp, FLAG_NEED_CACHE,
"find_endp", find_endp, FLAG_NEED_CACHE,
"save_dest", save_dest, FLAG_NEED_CACHE,
"find_dest", find_dest, FLAG_NEED_CACHE,
"sleep", handle_events, 0,
"verbose", verbose, 0,
"?", help, 0,
0,
};
/* help - list commands */
static void help(ARGV *argv)
{
struct action *ap;
vstream_printf("commands:");
for (ap = actions; ap->command != 0; ap++)
vstream_printf(" %s", ap->command);
vstream_printf("\n");
vstream_fflush(VSTREAM_OUT);
}
/* get_buffer - prompt for input or log input */
static int get_buffer(VSTRING *buf, VSTREAM *fp, int interactive)
{
int status;
if (interactive) {
vstream_printf("> ");
vstream_fflush(VSTREAM_OUT);
}
if ((status = vstring_get_nonl(buf, fp)) != VSTREAM_EOF) {
if (!interactive) {
vstream_printf(">>> %s\n", STR(buf));
vstream_fflush(VSTREAM_OUT);
}
}
return (status);
}
/* at last, the main program */
int main(int unused_argc, char **unused_argv)
{
VSTRING *buf = vstring_alloc(1);
ARGV *argv;
struct action *ap;
int interactive = isatty(0);
endp_prop = vstring_alloc(1);
dest_prop = vstring_alloc(1);
vstream_fileno(VSTREAM_ERR) = 1;
while (get_buffer(buf, VSTREAM_IN, interactive) != VSTREAM_EOF) {
argv = argv_split(STR(buf), CHARS_SPACE);
if (argv->argc > 0 && argv->argv[0][0] != '#') {
msg_verbose = verbose_level;
for (ap = actions; ap->command != 0; ap++) {
if (strcmp(ap->command, argv->argv[0]) == 0) {
if ((ap->flags & FLAG_NEED_CACHE) != 0 && scache == 0)
msg_error("no session cache");
else
ap->action(argv);
break;
}
}
msg_verbose = 0;
if (ap->command == 0)
msg_error("bad command: %s", argv->argv[0]);
}
argv_free(argv);
}
scache_free(scache);
vstring_free(endp_prop);
vstring_free(dest_prop);
vstring_free(buf);
exit(0);
}
#endif