diff --git a/adsbus/Makefile b/adsbus/Makefile
index 06545bd..635b9ce 100644
--- a/adsbus/Makefile
+++ b/adsbus/Makefile
@@ -3,9 +3,9 @@ CFLAGS ?= -Wall -Werror -O4 -g --std=gnu11 --pedantic-errors -fPIE -pie -fstack-
 LDFLAGS ?= $(CFLAGS) -Wl,-z,relro -Wl,-z,now
 LIBS ?= -ljansson
 
-OBJ_NETWORK = receive.o send.o incoming.o outgoing.o
+OBJ_NETWORK = incoming.o outgoing.o receive.o send.o
 OBJ_PROTOCOL = airspy_adsb.o beast.o json.o raw.o stats.o
-OBJ_UTIL = rand.o uuid.o wakeup.o opts.o hex.o common.o
+OBJ_UTIL = buf.o hex.o opts.o rand.o uuid.o wakeup.o common.o
 
 all: adsbus
 
diff --git a/adsbus/airspy_adsb.c b/adsbus/airspy_adsb.c
index 46885bf..31e2365 100644
--- a/adsbus/airspy_adsb.c
+++ b/adsbus/airspy_adsb.c
@@ -3,6 +3,7 @@
 #include <string.h>
 
 #include "common.h"
+#include "buf.h"
 #include "hex.h"
 #include "receive.h"
 #include "uuid.h"
diff --git a/adsbus/beast.c b/adsbus/beast.c
index 6b318c4..6f97c90 100644
--- a/adsbus/beast.c
+++ b/adsbus/beast.c
@@ -4,7 +4,9 @@
 #include <stdint.h>
 
 #include "common.h"
+#include "buf.h"
 #include "receive.h"
+
 #include "beast.h"
 
 struct __attribute__((packed)) beast_common_overlay {
diff --git a/adsbus/buf.c b/adsbus/buf.c
new file mode 100644
index 0000000..41fd330
--- /dev/null
+++ b/adsbus/buf.c
@@ -0,0 +1,37 @@
+#include <assert.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "buf.h"
+
+void buf_init(struct buf *buf) {
+	buf->start = 0;
+	buf->length = 0;
+}
+
+ssize_t buf_fill(struct buf *buf, int fd) {
+	if (buf->start + buf->length == BUF_LEN_MAX) {
+		assert(buf->start > 0);
+		memmove(buf->buf, buf_at(buf, 0), buf->length);
+		buf->start = 0;
+	}
+
+	size_t space = BUF_LEN_MAX - buf->length - buf->start;
+	ssize_t in = read(fd, buf_at(buf, buf->length), space);
+	if (in <= 0) {
+		return in;
+	}
+	buf->length += in;
+	return in;
+}
+
+void buf_consume(struct buf *buf, size_t length) {
+	assert(buf->length >= length);
+
+	buf->length -= length;
+	if (buf->length) {
+		buf->start += length;
+	} else {
+		buf->start = 0;
+	}
+}
diff --git a/adsbus/buf.h b/adsbus/buf.h
new file mode 100644
index 0000000..bb967c7
--- /dev/null
+++ b/adsbus/buf.h
@@ -0,0 +1,21 @@
+#pragma once
+
+#include <stddef.h>
+
+#define BUF_LEN_MAX 256
+struct buf {
+	char buf[BUF_LEN_MAX];
+	size_t start;
+	size_t length;
+};
+#define BUF_INIT { \
+	.start = 0, \
+	.length = 0, \
+}
+
+#define buf_chr(buff, at) ((buff)->buf[(buff)->start + (at)])
+#define buf_at(buff, at) (&buf_chr(buff, at))
+
+void buf_init(struct buf *);
+ssize_t buf_fill(struct buf *, int);
+void buf_consume(struct buf *, size_t);
diff --git a/adsbus/common.c b/adsbus/common.c
index 5a29105..000ec21 100644
--- a/adsbus/common.c
+++ b/adsbus/common.c
@@ -85,39 +85,6 @@ void peer_loop() {
 }
 
 
-void buf_init(struct buf *buf) {
-	buf->start = 0;
-	buf->length = 0;
-}
-
-ssize_t buf_fill(struct buf *buf, int fd) {
-	if (buf->start + buf->length == BUF_LEN_MAX) {
-		assert(buf->start > 0);
-		memmove(buf->buf, buf_at(buf, 0), buf->length);
-		buf->start = 0;
-	}
-
-	size_t space = BUF_LEN_MAX - buf->length - buf->start;
-	ssize_t in = read(fd, buf_at(buf, buf->length), space);
-	if (in <= 0) {
-		return in;
-	}
-	buf->length += in;
-	return in;
-}
-
-void buf_consume(struct buf *buf, size_t length) {
-	assert(buf->length >= length);
-
-	buf->length -= length;
-	if (buf->length) {
-		buf->start += length;
-	} else {
-		buf->start = 0;
-	}
-}
-
-
 char *packet_type_names[] = {
 	"Mode-S short",
 	"Mode-S long",
diff --git a/adsbus/common.h b/adsbus/common.h
index f761531..3976bf2 100644
--- a/adsbus/common.h
+++ b/adsbus/common.h
@@ -19,27 +19,6 @@ void peer_epoll_del(struct peer *);
 void peer_loop();
 
 
-//////// buf
-
-#define BUF_LEN_MAX 256
-struct buf {
-	char buf[BUF_LEN_MAX];
-	size_t start;
-	size_t length;
-};
-#define BUF_INIT { \
-	.start = 0, \
-	.length = 0, \
-}
-
-#define buf_chr(buff, at) ((buff)->buf[(buff)->start + (at)])
-#define buf_at(buff, at) (&buf_chr(buff, at))
-
-void buf_init(struct buf *);
-ssize_t buf_fill(struct buf *, int);
-void buf_consume(struct buf *, size_t);
-
-
 //////// packet
 
 #define DATA_LEN_MAX 14
diff --git a/adsbus/json.c b/adsbus/json.c
index 13a3623..3aa5160 100644
--- a/adsbus/json.c
+++ b/adsbus/json.c
@@ -4,6 +4,7 @@
 #include <jansson.h>
 
 #include "hex.h"
+#include "buf.h"
 #include "rand.h"
 #include "receive.h"
 #include "send.h"
diff --git a/adsbus/json.h b/adsbus/json.h
index bc324a6..b15600a 100644
--- a/adsbus/json.h
+++ b/adsbus/json.h
@@ -1,5 +1,7 @@
 #pragma once
 
+struct buf;
+
 void json_init();
 void json_serialize(struct packet *, struct buf *);
 
diff --git a/adsbus/rand.c b/adsbus/rand.c
index c6a79e1..1bba340 100644
--- a/adsbus/rand.c
+++ b/adsbus/rand.c
@@ -7,7 +7,7 @@
 #include <unistd.h>
 #include <string.h>
 
-#include "common.h"
+#include "buf.h"
 
 #include "rand.h"
 
diff --git a/adsbus/raw.c b/adsbus/raw.c
index c735cd2..ed4c036 100644
--- a/adsbus/raw.c
+++ b/adsbus/raw.c
@@ -3,6 +3,7 @@
 #include <string.h>
 
 #include "common.h"
+#include "buf.h"
 #include "hex.h"
 #include "uuid.h"
 
diff --git a/adsbus/receive.c b/adsbus/receive.c
index 3ccbb0c..b361902 100644
--- a/adsbus/receive.c
+++ b/adsbus/receive.c
@@ -6,10 +6,9 @@
 
 #include "airspy_adsb.h"
 #include "beast.h"
+#include "buf.h"
 #include "raw.h"
-
 #include "send.h"
-
 #include "uuid.h"
 
 #include "receive.h"
diff --git a/adsbus/send.c b/adsbus/send.c
index 08163be..41a6e70 100644
--- a/adsbus/send.c
+++ b/adsbus/send.c
@@ -10,10 +10,10 @@
 
 #include "airspy_adsb.h"
 #include "beast.h"
+#include "buf.h"
 #include "json.h"
 #include "raw.h"
 #include "stats.h"
-
 #include "uuid.h"
 
 #include "send.h"
diff --git a/adsbus/stats.c b/adsbus/stats.c
index 723705f..306de43 100644
--- a/adsbus/stats.c
+++ b/adsbus/stats.c
@@ -3,7 +3,9 @@
 #include <jansson.h>
 
 #include "common.h"
+#include "buf.h"
 #include "json.h"
+
 #include "stats.h"
 
 static struct stats_state {