1 files changed, 300 insertions, 0 deletions

diff --git a/src/util/attr_clnt.c b/src/util/attr_clnt.c
new file mode 100644
index 0000000..d944be5
--- /dev/null
+++ b/src/util/attr_clnt.c
@@ -0,0 +1,300 @@
+/*++
+/* NAME
+/*	attr_clnt 3
+/* SUMMARY
+/*	attribute query-reply client
+/* SYNOPSIS
+/*	#include <attr_clnt.h>
+/*
+/*	typedef int (*ATTR_CLNT_PRINT_FN) (VSTREAM *, int, va_list);
+/*	typedef int (*ATTR_CLNT_SCAN_FN) (VSTREAM *, int, va_list);
+/*	typedef int (*ATTR_CLNT_HANDSHAKE_FN) (VSTREAM *);
+/*
+/*	ATTR_CLNT *attr_clnt_create(server, timeout, max_idle, max_ttl)
+/*	const char *server;
+/*	int	timeout;
+/*	int	max_idle;
+/*	int	max_ttl;
+/*
+/*	int	attr_clnt_request(client,
+/*			send_flags, send_type, send_name, ..., ATTR_TYPE_END,
+/*			recv_flags, recv_type, recv_name, ..., ATTR_TYPE_END)
+/*	ATTR_CLNT *client;
+/*	int	send_flags;
+/*	int	send_type;
+/*	const char *send_name;
+/*	int	recv_flags;
+/*	int	recv_type;
+/*	const char *recv_name;
+/*
+/*	void	attr_clnt_free(client)
+/*	ATTR_CLNT *client;
+/*
+/*	void	attr_clnt_control(client, name, value, ... ATTR_CLNT_CTL_END)
+/*	ATTR_CLNT *client;
+/*	int	name;
+/* DESCRIPTION
+/*	This module implements a client for a simple attribute-based
+/*	protocol. The default protocol is described in attr_scan_plain(3).
+/*
+/*	attr_clnt_create() creates a client handle. See auto_clnt(3) for
+/*	a description of the arguments.
+/*
+/*	attr_clnt_request() sends the specified request attributes and
+/*	receives a reply. The reply argument specifies a name-value table.
+/*	The other arguments are as described in attr_print_plain(3). The
+/*	result is the number of attributes received or -1 in case of trouble.
+/*
+/*	attr_clnt_free() destroys a client handle and closes its connection.
+/*
+/*	attr_clnt_control() allows the user to fine tune the behavior of
+/*	the specified client. The arguments are a list of (name, value)
+/*	terminated with ATTR_CLNT_CTL_END.
+/*	The following lists the names and the types of the corresponding
+/*	value arguments.
+/* .IP "ATTR_CLNT_CTL_PROTO(ATTR_CLNT_PRINT_FN, ATTR_CLNT_SCAN_FN)"
+/*	Specifies alternatives for the attr_plain_print() and
+/*	attr_plain_scan() functions.
+/* .IP "ATTR_CLNT_CTL_REQ_LIMIT(int)"
+/*	The maximal number of requests per connection (default: 0,
+/*	i.e. no limit).  To enable the limit, specify a value greater
+/*	than zero.
+/* .IP "ATTR_CLNT_CTL_TRY_LIMIT(int)"
+/*	The maximal number of attempts to send a request before
+/*	giving up (default: 2). To disable the limit, specify a
+/*	value equal to zero.
+/* .IP "ATTR_CLNT_CTL_TRY_DELAY(int)"
+/*	The time in seconds between attempts to send a request
+/*	(default: 1).  Specify a value greater than zero.
+/* .IP "ATTR_CLNT_CTL_HANDSHAKE(VSTREAM *)"
+/*      A pointer to function that will be called at the start of a
+/*      new connection, and that returns 0 in case of success.
+/* DIAGNOSTICS
+/*	Warnings: communication failure.
+/* SEE ALSO
+/*	auto_clnt(3), client endpoint management
+/*	attr_scan_plain(3), attribute protocol
+/*	attr_print_plain(3), attribute protocol
+/* 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
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <unistd.h>
+#include <errno.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+#include <vstream.h>
+#include <htable.h>
+#include <attr.h>
+#include <iostuff.h>
+#include <compat_va_copy.h>
+#include <auto_clnt.h>
+#include <attr_clnt.h>
+
+/* Application-specific. */
+
+struct ATTR_CLNT {
+    AUTO_CLNT *auto_clnt;
+    /* Remaining properties are set with attr_clnt_control(). */
+    ATTR_CLNT_PRINT_FN print;
+    ATTR_CLNT_SCAN_FN scan;
+    int     req_limit;
+    int     req_count;
+    int     try_limit;
+    int     try_delay;
+};
+
+#define ATTR_CLNT_DEF_REQ_LIMIT	(0)	/* default per-session request limit */
+#define ATTR_CLNT_DEF_TRY_LIMIT	(2)	/* default request (re)try limit */
+#define ATTR_CLNT_DEF_TRY_DELAY	(1)	/* default request (re)try delay */
+
+/* attr_clnt_free - destroy attribute client */
+
+void    attr_clnt_free(ATTR_CLNT *client)
+{
+    auto_clnt_free(client->auto_clnt);
+    myfree((void *) client);
+}
+
+/* attr_clnt_create - create attribute client */
+
+ATTR_CLNT *attr_clnt_create(const char *service, int timeout,
+			            int max_idle, int max_ttl)
+{
+    ATTR_CLNT *client;
+
+    client = (ATTR_CLNT *) mymalloc(sizeof(*client));
+    client->auto_clnt = auto_clnt_create(service, timeout, max_idle, max_ttl);
+    client->scan = attr_vscan_plain;
+    client->print = attr_vprint_plain;
+    client->req_limit = ATTR_CLNT_DEF_REQ_LIMIT;
+    client->req_count = 0;
+    client->try_limit = ATTR_CLNT_DEF_TRY_LIMIT;
+    client->try_delay = ATTR_CLNT_DEF_TRY_DELAY;
+    return (client);
+}
+
+/* attr_clnt_request - send query, receive reply */
+
+int     attr_clnt_request(ATTR_CLNT *client, int send_flags,...)
+{
+    const char *myname = "attr_clnt_request";
+    VSTREAM *stream;
+    int     count = 0;
+    va_list saved_ap;
+    va_list ap;
+    int     type;
+    int     recv_flags;
+    int     err;
+    int     ret;
+
+    /*
+     * XXX If the stream is readable before we send anything, then assume the
+     * remote end disconnected.
+     * 
+     * XXX For some reason we can't simply call the scan routine after the print
+     * routine, that messes up the argument list.
+     */
+#define SKIP_ARG(ap, type) { \
+	(void) va_arg(ap, char *); \
+	(void) va_arg(ap, type); \
+    }
+#define SKIP_ARG2(ap, t1, t2) { \
+	SKIP_ARG(ap, t1); \
+	(void) va_arg(ap, t2); \
+    }
+
+    /* Finalize argument lists before returning. */
+    va_start(saved_ap, send_flags);
+    for (;;) {
+	errno = 0;
+	if ((stream = auto_clnt_access(client->auto_clnt)) != 0
+	    && readable(vstream_fileno(stream)) == 0) {
+	    errno = 0;
+	    VA_COPY(ap, saved_ap);
+	    err = (client->print(stream, send_flags, ap) != 0
+		   || vstream_fflush(stream) != 0);
+	    va_end(ap);
+	    if (err == 0) {
+		VA_COPY(ap, saved_ap);
+		while ((type = va_arg(ap, int)) != ATTR_TYPE_END) {
+		    switch (type) {
+		    case ATTR_TYPE_STR:
+			SKIP_ARG(ap, char *);
+			break;
+		    case ATTR_TYPE_DATA:
+			SKIP_ARG2(ap, ssize_t, char *);
+			break;
+		    case ATTR_TYPE_INT:
+			SKIP_ARG(ap, int);
+			break;
+		    case ATTR_TYPE_LONG:
+			SKIP_ARG(ap, long);
+			break;
+		    case ATTR_TYPE_HASH:
+			(void) va_arg(ap, HTABLE *);
+			break;
+		    default:
+			msg_panic("%s: unexpected attribute type %d",
+				  myname, type);
+		    }
+		}
+		recv_flags = va_arg(ap, int);
+		ret = client->scan(stream, recv_flags, ap);
+		va_end(ap);
+		/* Finalize argument lists before returning. */
+		if (ret > 0) {
+		    if (client->req_limit > 0
+			&& (client->req_count += 1) >= client->req_limit) {
+			auto_clnt_recover(client->auto_clnt);
+			client->req_count = 0;
+		    }
+		    break;
+		}
+	    }
+	}
+	if ((++count >= client->try_limit && client->try_limit > 0)
+	    || msg_verbose
+	    || (errno && errno != EPIPE && errno != ENOENT && errno != ECONNRESET))
+	    msg_warn("problem talking to server %s: %m",
+		     auto_clnt_name(client->auto_clnt));
+	/* Finalize argument lists before returning. */
+	if (count >= client->try_limit && client->try_limit > 0) {
+	    ret = -1;
+	    break;
+	}
+	sleep(client->try_delay);
+	auto_clnt_recover(client->auto_clnt);
+	client->req_count = 0;
+    }
+    /* Finalize argument lists before returning. */
+    va_end(saved_ap);
+    return (ret);
+}
+
+/* attr_clnt_control - fine control */
+
+void    attr_clnt_control(ATTR_CLNT *client, int name,...)
+{
+    const char *myname = "attr_clnt_control";
+    va_list ap;
+
+    for (va_start(ap, name); name != ATTR_CLNT_CTL_END; name = va_arg(ap, int)) {
+	switch (name) {
+	case ATTR_CLNT_CTL_PROTO:
+	    client->print = va_arg(ap, ATTR_CLNT_PRINT_FN);
+	    client->scan = va_arg(ap, ATTR_CLNT_SCAN_FN);
+	    break;
+	case ATTR_CLNT_CTL_HANDSHAKE:
+	    auto_clnt_control(client->auto_clnt,
+			      AUTO_CLNT_CTL_HANDSHAKE,
+			      va_arg(ap, ATTR_CLNT_HANDSHAKE_FN),
+			      AUTO_CLNT_CTL_END);
+	    break;
+	case ATTR_CLNT_CTL_REQ_LIMIT:
+	    client->req_limit = va_arg(ap, int);
+	    if (client->req_limit < 0)
+		msg_panic("%s: bad request limit: %d",
+			  myname, client->req_limit);
+	    if (msg_verbose)
+		msg_info("%s: new request limit %d",
+			 myname, client->req_limit);
+	    break;
+	case ATTR_CLNT_CTL_TRY_LIMIT:
+	    client->try_limit = va_arg(ap, int);
+	    if (client->try_limit < 0)
+		msg_panic("%s: bad retry limit: %d", myname, client->try_limit);
+	    if (msg_verbose)
+		msg_info("%s: new retry limit %d", myname, client->try_limit);
+	    break;
+	case ATTR_CLNT_CTL_TRY_DELAY:
+	    client->try_delay = va_arg(ap, int);
+	    if (client->try_delay <= 0)
+		msg_panic("%s: bad retry delay: %d", myname, client->try_delay);
+	    if (msg_verbose)
+		msg_info("%s: new retry delay %d", myname, client->try_delay);
+	    break;
+	default:
+	    msg_panic("%s: bad name %d", myname, name);
+	}
+    }
+    va_end(ap);
+}