tools/fuzz: add AFL stub program for libefl fuzzer

And hook it up into build system.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>

.gitignore

@@ -146,6 +146,7 @@ tools/flask/utils/flask-loadpolicy
 tools/flask/utils/flask-setenforce
 tools/flask/utils/flask-set-bool
 tools/flask/utils/flask-label-pci
+tools/fuzz/libelf/afl-libelf-fuzzer
 tools/fuzz/x86_instruction_emulator/x86_emulate*
 tools/fuzz/x86_instruction_emulator/afl-x86-insn-emulator-fuzzer
 tools/helpers/_paths.h

tools/fuzz/libelf/Makefile

@@ -19,6 +19,8 @@ libelf.a: $(ELF_LIB_OBJS)
 .PHONY: libelf-fuzzer-all
 libelf-fuzzer-all: libelf.a libelf-fuzzer.o
 
+afl-libelf-fuzzer: afl-libelf-fuzzer.o libelf-fuzzer.o $(ELF_LIB_OBJS)
+
 # Common targets
 .PHONY: all
 all: libelf-fuzzer-all
@@ -28,7 +30,10 @@ distclean: clean
 
 .PHONY: clean
 clean:
-	rm -f *.o *.a
+	rm -f *.o *.a *-libelf-fuzzer
 
 .PHONY: install
 install: all
+
+.PHONY: afl
+afl: afl-libelf-fuzzer

tools/fuzz/libelf/afl-libelf-fuzzer.c

@@ -0,0 +1,57 @@
+#include <assert.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+extern int LLVMFuzzerTestOneInput(const uint8_t *data_p, size_t size);
+
+#define INPUT_SIZE  4096
+static uint8_t input[INPUT_SIZE];
+
+int main(int argc, char **argv)
+{
+    size_t size;
+    FILE *fp;
+
+    if ( argc != 2 )
+    {
+        printf("Expecting only one argument\n");
+        exit(-1);
+    }
+
+    fp = fopen(argv[1], "rb");
+    if ( fp == NULL )
+    {
+        perror("fopen");
+        exit(-1);
+    }
+
+    size = fread(input, 1, INPUT_SIZE, fp);
+
+    if ( ferror(fp) )
+    {
+        perror("fread");
+        exit(-1);
+    }
+
+    if ( !feof(fp) )
+    {
+        printf("Input too large\n");
+        exit(-1);
+    }
+
+    fclose(fp);
+
+    LLVMFuzzerTestOneInput(input, size);
+
+    return 0;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */