--- /dev/null
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+#ifndef __LWIP_PBUF_H__
+#define __LWIP_PBUF_H__
+
+#include "lwip/opt.h"
+#include "lwip/err.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define PBUF_TRANSPORT_HLEN 20
+#define PBUF_IP_HLEN 20
+
+typedef enum {
+ PBUF_TRANSPORT,
+ PBUF_IP,
+ PBUF_LINK,
+ PBUF_RAW
+} pbuf_layer;
+
+typedef enum {
+ PBUF_RAM, /* pbuf data is stored in RAM */
+ PBUF_ROM, /* pbuf data is stored in ROM */
+ PBUF_REF, /* pbuf comes from the pbuf pool */
+ PBUF_POOL /* pbuf payload refers to RAM */
+} pbuf_type;
+
+
+/** indicates this packet's data should be immediately passed to the application */
+#define PBUF_FLAG_PUSH 0x01U
+
+struct pbuf {
+ /** next pbuf in singly linked pbuf chain */
+ struct pbuf *next;
+
+ /** pointer to the actual data in the buffer */
+ void *payload;
+
+ /**
+ * total length of this buffer and all next buffers in chain
+ * belonging to the same packet.
+ *
+ * For non-queue packet chains this is the invariant:
+ * p->tot_len == p->len + (p->next? p->next->tot_len: 0)
+ */
+ u16_t tot_len;
+
+ /** length of this buffer */
+ u16_t len;
+
+ /** pbuf_type as u8_t instead of enum to save space */
+ u8_t /*pbuf_type*/ type;
+
+ /** misc flags */
+ u8_t flags;
+
+ /**
+ * the reference count always equals the number of pointers
+ * that refer to this pbuf. This can be pointers from an application,
+ * the stack itself, or pbuf->next pointers from a chain.
+ */
+ u16_t ref;
+
+};
+
+/* Initializes the pbuf module. This call is empty for now, but may not be in future. */
+#define pbuf_init()
+
+struct pbuf *pbuf_alloc(pbuf_layer l, u16_t size, pbuf_type type);
+void pbuf_realloc(struct pbuf *p, u16_t size);
+u8_t pbuf_header(struct pbuf *p, s16_t header_size);
+void pbuf_ref(struct pbuf *p);
+void pbuf_ref_chain(struct pbuf *p);
+u8_t pbuf_free(struct pbuf *p);
+u8_t pbuf_clen(struct pbuf *p);
+void pbuf_cat(struct pbuf *head, struct pbuf *tail);
+void pbuf_chain(struct pbuf *head, struct pbuf *tail);
+struct pbuf *pbuf_dechain(struct pbuf *p);
+err_t pbuf_copy(struct pbuf *p_to, struct pbuf *p_from);
+u16_t pbuf_copy_partial(struct pbuf *p, void *dataptr, u16_t len, u16_t offset);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __LWIP_PBUF_H__ */
