From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Mon, 23 Mar 2020 16:29:16 +0000 (+0200)
Subject: lib-test: Add fuzzing framework
X-Git-Tag: 2.3.14.rc1~181
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=48114f39d81a690e3f18e69a3a658fc75d5f3b88;p=thirdparty%2Fdovecot%2Fcore.git

lib-test: Add fuzzing framework
---

diff --git a/src/lib-test/Makefile.am b/src/lib-test/Makefile.am
index 6c472fcbf1..ce7417d642 100644
--- a/src/lib-test/Makefile.am
+++ b/src/lib-test/Makefile.am
@@ -5,12 +5,14 @@ AM_CPPFLAGS = \
 	-I$(top_srcdir)/src/lib-charset
 
 libtest_la_SOURCES = \
+	fuzzer.c \
 	test-common.c \
 	test-istream.c \
 	test-ostream.c \
 	test-subprocess.c
 
 headers = \
+	fuzzer.h \
 	test-common.h \
 	test-subprocess.h
 
diff --git a/src/lib-test/fuzzer.c b/src/lib-test/fuzzer.c
new file mode 100644
index 0000000000..52790177cf
--- /dev/null
+++ b/src/lib-test/fuzzer.c
@@ -0,0 +1,79 @@
+/* Copyright (c) 2020 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "lib-signals.h"
+#include "net.h"
+#include "istream.h"
+#include "ostream.h"
+#include "iostream-pump.h"
+#include "fuzzer.h"
+
+#include <sys/socket.h>
+#include <unistd.h>
+
+void fuzzer_init(struct fuzzer_context *fuzz_ctx)
+{
+	i_zero(fuzz_ctx);
+	if (!lib_is_initialized()) {
+		lib_init();
+		lib_signals_init();
+		lib_signals_ignore(SIGPIPE, TRUE);
+	}
+	fuzz_ctx->fd = -1;
+}
+
+void fuzzer_deinit(struct fuzzer_context *fuzz_ctx)
+{
+	iostream_pump_destroy(&fuzz_ctx->pump);
+	/* ensure fd gets closed, we don't care
+	   if this fails. */
+	if (fuzz_ctx->fd > -1)
+		(void)close(fuzz_ctx->fd);
+	io_loop_destroy(&fuzz_ctx->ioloop);
+}
+
+static void pump_finished(enum iostream_pump_status status ATTR_UNUSED,
+			  struct fuzzer_context *fuzz_ctx)
+{
+	struct istream *input = iostream_pump_get_input(fuzz_ctx->pump);
+	struct ostream *output = iostream_pump_get_output(fuzz_ctx->pump);
+
+	switch (status) {
+	case IOSTREAM_PUMP_STATUS_INPUT_EOF:
+		break;
+	case IOSTREAM_PUMP_STATUS_INPUT_ERROR:
+		i_error("read(%s) failed: %s", i_stream_get_name(input),
+			i_stream_get_error(input));
+		break;
+	case IOSTREAM_PUMP_STATUS_OUTPUT_ERROR:
+		i_error("write(%s) failed: %s", o_stream_get_name(output),
+			o_stream_get_error(output));
+		break;
+	};
+
+	if (shutdown(o_stream_get_fd(output), SHUT_RDWR) < 0)
+		i_fatal("shutdown() failed: %m");
+	iostream_pump_destroy(&fuzz_ctx->pump);
+}
+
+int fuzzer_io_as_fd(struct fuzzer_context *fuzz_ctx,
+		   const uint8_t *data, size_t size)
+{
+	int sfd[2];
+
+	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sfd) < 0)
+		i_fatal("socketpair() failed: %m");
+	net_set_nonblock(sfd[0], TRUE);
+	net_set_nonblock(sfd[1], TRUE);
+
+	struct istream *input = i_stream_create_from_data(data, size);
+	struct ostream *output = o_stream_create_fd_autoclose(&sfd[0], IO_BLOCK_SIZE);
+	fuzz_ctx->pump = iostream_pump_create(input, output);
+	fuzz_ctx->fd = sfd[1];
+	iostream_pump_set_completion_callback(fuzz_ctx->pump, pump_finished,
+					      fuzz_ctx);
+	i_stream_unref(&input);
+	o_stream_unref(&output);
+	iostream_pump_start(fuzz_ctx->pump);
+	return sfd[1];
+}
diff --git a/src/lib-test/fuzzer.h b/src/lib-test/fuzzer.h
new file mode 100644
index 0000000000..85d83c4d5e
--- /dev/null
+++ b/src/lib-test/fuzzer.h
@@ -0,0 +1,37 @@
+#ifndef FUZZER_H
+#define FUZZER_H
+
+struct iostream_pump;
+struct ioloop;
+
+struct fuzzer_context {
+	int fd;
+	struct iostream_pump *pump;
+	struct ioloop *ioloop;
+};
+
+#define FUZZ_BEGIN_DATA(data_arg, size_arg) \
+	int LLVMFuzzerTestOneInput(data_arg, size_arg); \
+	int LLVMFuzzerTestOneInput(data_arg, size_arg) { \
+		struct fuzzer_context fuzz_ctx; \
+		fuzzer_init(&fuzz_ctx); T_BEGIN {
+
+#define FUZZ_BEGIN_STR(str_arg) \
+	FUZZ_BEGIN_DATA(const uint8_t *_param_data, size_t _param_size) \
+	str_arg = t_strndup(_param_data, _param_size);
+
+#define FUZZ_BEGIN_FD \
+	FUZZ_BEGIN_DATA(const uint8_t *_param_data, size_t _param_size) \
+	fuzz_ctx.ioloop = io_loop_create(); \
+	(void)fuzzer_io_as_fd(&fuzz_ctx, _param_data, _param_size);
+
+#define FUZZ_END \
+	} T_END; fuzzer_deinit(&fuzz_ctx); return 0; }
+
+void fuzzer_init(struct fuzzer_context *fuzz_ctx);
+void fuzzer_deinit(struct fuzzer_context *fuzz_ctx);
+
+int fuzzer_io_as_fd(struct fuzzer_context *fuzz_ctx,
+		    const uint8_t *data, size_t size);
+
+#endif