diff --git a/nhrpd/zbuf.h b/nhrpd/zbuf.h
new file mode 100644
index 0000000..73d7073
--- /dev/null
+++ b/nhrpd/zbuf.h
@@ -0,0 +1,189 @@
+/* Stream/packet buffer API
+ * Copyright (c) 2014-2015 Timo Teräs
+ *
+ * This file is free software: you may copy, redistribute and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef ZBUF_H
+#define ZBUF_H
+
+#include <stdint.h>
+#include <string.h>
+#include <endian.h>
+#include <sys/types.h>
+
+#include "zassert.h"
+#include "list.h"
+
+struct zbuf {
+	struct list_head queue_list;
+	unsigned allocated : 1;
+	unsigned error : 1;
+	uint8_t *buf, *end;
+	uint8_t *head, *tail;
+};
+
+struct zbuf_queue {
+	struct list_head queue_head;
+};
+
+struct zbuf *zbuf_alloc(size_t size);
+void zbuf_init(struct zbuf *zb, void *buf, size_t len, size_t datalen);
+void zbuf_free(struct zbuf *zb);
+
+static inline size_t zbuf_size(struct zbuf *zb)
+{
+	return zb->end - zb->buf;
+}
+
+static inline size_t zbuf_used(struct zbuf *zb)
+{
+	return zb->tail - zb->head;
+}
+
+static inline size_t zbuf_tailroom(struct zbuf *zb)
+{
+	return zb->end - zb->tail;
+}
+
+static inline size_t zbuf_headroom(struct zbuf *zb)
+{
+	return zb->head - zb->buf;
+}
+
+void zbuf_reset(struct zbuf *zb);
+void zbuf_reset_head(struct zbuf *zb, void *ptr);
+ssize_t zbuf_read(struct zbuf *zb, int fd, size_t maxlen);
+ssize_t zbuf_write(struct zbuf *zb, int fd);
+ssize_t zbuf_recv(struct zbuf *zb, int fd);
+ssize_t zbuf_send(struct zbuf *zb, int fd);
+
+static inline void zbuf_set_rerror(struct zbuf *zb)
+{
+	zb->error = 1;
+	zb->head = zb->tail;
+}
+
+static inline void zbuf_set_werror(struct zbuf *zb)
+{
+	zb->error = 1;
+	zb->tail = zb->end;
+}
+
+static inline void *__zbuf_pull(struct zbuf *zb, size_t size, int error)
+{
+	void *head = zb->head;
+	if (size > zbuf_used(zb)) {
+		if (error) zbuf_set_rerror(zb);
+		return NULL;
+	}
+	zb->head += size;
+	return head;
+}
+
+#define zbuf_pull(zb, type) ((type *)__zbuf_pull(zb, sizeof(type), 1))
+#define zbuf_pulln(zb, sz) ((void *)__zbuf_pull(zb, sz, 1))
+#define zbuf_may_pull(zb, type) ((type *)__zbuf_pull(zb, sizeof(type), 0))
+#define zbuf_may_pulln(zb, sz) ((void *)__zbuf_pull(zb, sz, 0))
+
+void *zbuf_may_pull_until(struct zbuf *zb, const char *sep, struct zbuf *msg);
+
+static inline void zbuf_get(struct zbuf *zb, void *dst, size_t len)
+{
+	void *src = zbuf_pulln(zb, len);
+	if (src) memcpy(dst, src, len);
+}
+
+static inline uint8_t zbuf_get8(struct zbuf *zb)
+{
+	uint8_t *src = zbuf_pull(zb, uint8_t);
+	if (src) return *src;
+	return 0;
+}
+
+static inline uint32_t zbuf_get32(struct zbuf *zb)
+{
+	struct unaligned32 {
+		uint32_t value;
+	} __attribute__((packed));
+
+	struct unaligned32 *v = zbuf_pull(zb, struct unaligned32);
+	if (v) return v->value;
+	return 0;
+}
+
+static inline uint16_t zbuf_get_be16(struct zbuf *zb)
+{
+	struct unaligned16 {
+		uint16_t value;
+	} __attribute__((packed));
+
+	struct unaligned16 *v = zbuf_pull(zb, struct unaligned16);
+	if (v) return be16toh(v->value);
+	return 0;
+}
+
+static inline uint32_t zbuf_get_be32(struct zbuf *zb)
+{
+	return be32toh(zbuf_get32(zb));
+}
+
+static inline void *__zbuf_push(struct zbuf *zb, size_t size, int error)
+{
+	void *tail = zb->tail;
+	if (size > zbuf_tailroom(zb)) {
+		if (error) zbuf_set_werror(zb);
+		return NULL;
+	}
+	zb->tail += size;
+	return tail;
+}
+
+#define zbuf_push(zb, type) ((type *)__zbuf_push(zb, sizeof(type), 1))
+#define zbuf_pushn(zb, sz) ((void *)__zbuf_push(zb, sz, 1))
+#define zbuf_may_push(zb, type) ((type *)__zbuf_may_push(zb, sizeof(type), 0))
+#define zbuf_may_pushn(zb, sz) ((void *)__zbuf_push(zb, sz, 0))
+
+static inline void zbuf_put(struct zbuf *zb, const void *src, size_t len)
+{
+	void *dst = zbuf_pushn(zb, len);
+	if (dst) memcpy(dst, src, len);
+}
+
+static inline void zbuf_put8(struct zbuf *zb, uint8_t val)
+{
+	uint8_t *dst = zbuf_push(zb, uint8_t);
+	if (dst) *dst = val;
+}
+
+static inline void zbuf_put_be16(struct zbuf *zb, uint16_t val)
+{
+	struct unaligned16 {
+		uint16_t value;
+	} __attribute__((packed));
+
+	struct unaligned16 *v = zbuf_push(zb, struct unaligned16);
+	if (v) v->value = htobe16(val);
+}
+
+static inline void zbuf_put_be32(struct zbuf *zb, uint32_t val)
+{
+	struct unaligned32 {
+		uint32_t value;
+	} __attribute__((packed));
+
+	struct unaligned32 *v = zbuf_push(zb, struct unaligned32);
+	if (v) v->value = htobe32(val);
+}
+
+void zbuf_copy(struct zbuf *zb, struct zbuf *src, size_t len);
+
+void zbufq_init(struct zbuf_queue *);
+void zbufq_reset(struct zbuf_queue *);
+void zbufq_queue(struct zbuf_queue *, struct zbuf *);
+int zbufq_write(struct zbuf_queue *, int);
+
+#endif