First preview release.

ocx_stdio.c

@@ -0,0 +1,172 @@
+/*-
+ * Copyright (c) 2014 Poul-Henning Kamp
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * Operational Context STDIO
+ * =========================
+ *
+ *	"The most effective debugging tool is still careful thought,
+ *	 coupled with judiciously placed print statements."
+ *		-- Brian Kernighan, "Unix for Beginners" (1979)
+ *
+ * The problem with print statements is where they end up.  For instance
+ * in a server with a CLI interface, you want the print statements to go
+ * to the CLI session which called the code.
+ *
+ * An "Operational Context" is a back-pointer to where the print statement
+ * should end up.
+ *
+ * We operate with three "channels", DIAG, TRACE and DEBUG.
+ *
+ * DIAG is mandatory output, error messages, diagnostics etc.
+ *	This should always end up where the action was initiated.
+ *
+ * DEBUG is optional output which may be supressed.
+ *	This should go where DIAG goes, unless specifically redirected
+ *	by the operator.
+ *
+ * TRACE is data collection, statistics etc.
+ *	In general this goes nowhere unless configured to end up
+ *	somewhere.
+ *
+ * About this implementation:
+ *
+ * This is a very naiive implementation spitting things out to stdout/stderr,
+ * knowing that we are a single threaded program.
+ *
+ * XXX: Pull in sbufs to do it right.
+ */
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+
+#include "ntimed.h"
+
+static FILE *tracefile;
+
+static FILE *
+getdst(enum ocx_chan chan)
+{
+	if (chan == OCX_DIAG)
+		return (stderr);
+	if (chan == OCX_TRACE)
+		return (tracefile);
+	if (chan == OCX_DEBUG)
+		return (stdout);
+	WRONG("Wrong ocx_chan");
+	return (NULL);
+}
+
+static void __match_proto__()
+putv(struct ocx *ocx, enum ocx_chan chan, const char *fmt, va_list ap)
+{
+	FILE *dst = getdst(chan);
+	va_list ap2;
+
+	va_copy(ap2, ap);
+	AZ(ocx);
+	if (dst != NULL)
+		(void)vfprintf(dst, fmt, ap);
+	if (chan == OCX_DIAG)
+		vsyslog(LOG_ERR, fmt, ap2);
+}
+
+/**********************************************************************
+ * XXX: take strftime format string to chop tracefiles in time.
+ */
+
+void
+ArgTracefile(const char *fn)
+{
+
+	if (tracefile != NULL && tracefile != stdout) {
+		AZ(fclose(tracefile));
+		tracefile = NULL;
+	}
+
+	if (fn == NULL)
+		return;
+
+	if (!strcmp(fn, "-")) {
+		tracefile = stdout;
+		return;
+	}
+
+	tracefile = fopen(fn, "w");
+	if (tracefile == NULL)
+		Fail(NULL, 1, "Could not open '%s' for writing", fn);
+	setbuf(tracefile, NULL);
+}
+
+/**********************************************************************
+ * XXX: The stuff below is generic and really ought to be in ocx.c on
+ * XXX: its own.
+ */
+
+void
+Put(struct ocx *ocx, enum ocx_chan chan, const char *fmt, ...)
+{
+	va_list ap;
+
+	AZ(ocx);
+	va_start(ap, fmt);
+	putv(ocx, chan, fmt, ap);
+	va_end(ap);
+}
+
+void
+PutHex(struct ocx *ocx, enum ocx_chan chan, const void *ptr, ssize_t len)
+{
+	const uint8_t *p = ptr;
+	const char *s = "";
+
+	AN(ptr);
+	assert(len >= 0);
+
+	while(len--) {
+		Put(ocx, chan, "%s%02x", s, *p++);
+		s = " ";
+	}
+}
+
+void
+Fail(struct ocx *ocx, int err, const char *fmt, ...)
+{
+	va_list ap;
+
+	if (err)
+		err = errno;
+	Put(ocx, OCX_DIAG, "Failure: ");
+	va_start(ap, fmt);
+	putv(ocx, OCX_DIAG, fmt, ap);
+	va_end(ap);
+	Put(ocx, OCX_DIAG, "\n");
+	if (err)
+		Put(ocx, OCX_DIAG, "errno = %d (%s)\n", err, strerror(err));
+	exit(1);
+}