[PATCH mdnsd 07/10] tests: add dns_handle_packet_file tool

[Petr Štetiar]

So it can read packets from file, which is handy when using for example
AFL or hongfuzz fuzzers.

Signed-off-by: Petr Štetiar <ynezz at true.cz>
---
 tests/CMakeLists.txt           | 10 ++++++
 tests/dns_handle_packet_file.c | 64 ++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+)
 create mode 100644 tests/dns_handle_packet_file.c

diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 02b121c7b8ec..99c248281eb1 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -1,3 +1,13 @@
 IF(CMAKE_C_COMPILER_ID STREQUAL "Clang")
   ADD_SUBDIRECTORY(fuzz)
+
+  ADD_EXECUTABLE(dhpf-san dns_handle_packet_file.c)
+  TARGET_INCLUDE_DIRECTORIES(dhpf-san PRIVATE ${PROJECT_SOURCE_DIR})
+  TARGET_COMPILE_OPTIONS(dhpf-san PRIVATE -g -fno-omit-frame-pointer -fsanitize=undefined,address,leak -fno-sanitize-recover=all)
+  TARGET_LINK_OPTIONS(dhpf-san PRIVATE -fsanitize=undefined,address,leak)
+  TARGET_LINK_LIBRARIES(dhpf-san umdns-lib-san)
 ENDIF()
+
+ADD_EXECUTABLE(dhpf dns_handle_packet_file.c)
+TARGET_INCLUDE_DIRECTORIES(dhpf PRIVATE ${PROJECT_SOURCE_DIR})
+TARGET_LINK_LIBRARIES(dhpf umdns-lib)
diff --git a/tests/dns_handle_packet_file.c b/tests/dns_handle_packet_file.c
new file mode 100644
index 000000000000..cbcea08b9751
--- /dev/null
+++ b/tests/dns_handle_packet_file.c
@@ -0,0 +1,64 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "dns.h"
+#include "cache.c"
+#include "interface.h"
+
+int cfg_proto = 0;
+int cfg_no_subnet = 0;
+
+static void fuzz_dns_handle_packet(uint8_t *input, size_t size)
+{
+	struct sockaddr from;
+	struct interface iface;
+	struct cache_service *s, *t;
+
+	memset(&from, 0, sizeof(from));
+	memset(&iface, 0, sizeof(iface));
+
+	cache_init();
+	dns_handle_packet(&iface, &from, 1922, input, size);
+
+	avl_for_each_element_safe(&services, s, avl, t)
+		cache_service_free(s);
+}
+
+int main(int argc, char *argv[])
+{
+	size_t len = 0;
+	FILE *fd = NULL;
+	uint8_t *buf = NULL;
+
+	if (argc != 2) {
+		fprintf(stderr, "Usage: %s <packet.bin>\n", argv[0]);
+		return -1;
+	}
+
+	fd = fopen(argv[1], "r");
+	if (!fd) {
+		perror("unable to open input file\n");
+		return -1;
+	}
+
+	buf = calloc(1, MDNS_BUF_LEN+1);
+	if (!buf)
+		return -1;
+
+	len = fread(buf, 1, MDNS_BUF_LEN, fd);
+
+	fuzz_dns_handle_packet(buf, len);
+
+	fclose(fd);
+	free(buf);
+}