src: arch: Add x86 arch

Author: shaymargolis

shellblocks/src/arch/utils.h

@@ -3,6 +3,8 @@
 
 #if defined(__mips__)
 #include "mips/utils.h"
+#elif defined(__i386__) || defined(__x86_64__)
+#include "x86/utils.h"
 #elif defined(__arm__)
 #include "arm/utils.h"
 #endif

shellblocks/src/arch/x86/utils.h

@@ -0,0 +1,14 @@
+#ifndef SHELLCODE_BLOCKS_ARCH_I386_UTILS_H
+#define SHELLCODE_BLOCKS_ARCH_I386_UTILS_H
+
+#define NOP_OPCODE (0x90909090)
+
+#define GET_REL_ADDRESS(OUTPUT, LABEL)                         \
+    __asm__ volatile (                                         \
+        "call " GET_REL_LABEL(LABEL) "\n\t"                    \
+        GET_REL_LABEL(LABEL) ": pop %0\n\t"                    \
+        "add $(" #LABEL " - " GET_REL_LABEL(LABEL) "), %0\n\t" \
+        : "=r" (OUTPUT) : :                                    \
+    )
+
+#endif // !SHELLCODE_BLOCKS_ARCH_I386_UTILS_H