Import release 0.07

[secnet.git] / unaligned.h

diff --git a/unaligned.h b/unaligned.h
new file mode 100644 (file)
index 0000000..45b0d3c
--- /dev/null
+++ b/unaligned.h
@@ -0,0 +1,42 @@
+#ifndef unaligned_h
+#define unaligned_h
+
+/* Parts of the secnet key-exchange protocol require access to
+   unaligned big-endian quantities in buffers. These macros provide
+   convenient access, even on architectures that don't support unaligned
+   accesses. */
+
+#define put_uint32(a,v) do { (a)[0]=(v)>>24; (a)[1]=((v)&0xff0000)>>16; \
+(a)[2]=((v)&0xff00)>>8; (a)[3]=(v)&0xff; } while(0)
+
+#define put_uint16(a,v) do {(a)[0]=((v)&0xff00)>>8; (a)[1]=(v)&0xff;} while(0)
+
+#define get_uint32(a) (((a)[0]<<24)|((a)[1]<<16)|((a)[2])<<8|(a)[3])
+
+#define get_uint16(a) (((a)[0]<<8)|(a)[1])
+
+#define buf_append_uint32(buf,v) do { uint8_t *c=buf_append((buf),4); \
+    put_uint32(c,(v)); } while(0)
+
+#define buf_append_uint16(buf,v) do { uint8_t *c=buf_append((buf),2); \
+       put_uint16(c,(v)); } while(0)
+
+#define buf_prepend_uint32(buf,v) do { uint8_t *c=buf_prepend((buf),4); \
+           put_uint32(c,(v)); } while(0)
+
+#define buf_prepend_uint16(buf,v) do { uint8_t *c=buf_prepend((buf),2); \
+               put_uint16(c,(v)); } while(0)
+
+#define buf_unappend_uint32(buf) ({uint8_t *c=buf_unappend((buf),4); \
+                   get_uint32(c);})
+
+#define buf_unappend_uint16(buf) ({uint8_t *c=buf_unappend((buf),2); \
+                       get_uint16(c);})
+
+#define buf_unprepend_uint32(buf) ({uint8_t *c=buf_unprepend((buf),4); \
+                       get_uint32(c);})
+
+#define buf_unprepend_uint16(buf) ({uint8_t *c=buf_unprepend((buf),2); \
+                       get_uint16(c);})
+
+#endif /* unaligned_h */