pbuf.h

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/*
 * 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_HDR_PBUF_H
#define LWIP_HDR_PBUF_H

#include "lwip/opt.h"
#include "lwip/err.h"

#ifdef __cplusplus
extern "C" {
#endif

#ifndef LWIP_SUPPORT_CUSTOM_PBUF
#define LWIP_SUPPORT_CUSTOM_PBUF ((IP_FRAG && !IP_FRAG_USES_STATIC_BUF && !LWIP_NETIF_TX_SINGLE_PBUF) || (LWIP_IPV6 && LWIP_IPV6_FRAG))
#endif

/* @todo: We need a mechanism to prevent wasting memory in every pbuf
   (TCP vs. UDP, IPv4 vs. IPv6: UDP/IPv4 packets may waste up to 28 bytes) */

#define PBUF_TRANSPORT_HLEN 20
#if LWIP_IPV6
#define PBUF_IP_HLEN        40
#else
#define PBUF_IP_HLEN        20
#endif

typedef enum {
  PBUF_TRANSPORT,
  PBUF_IP,
  PBUF_LINK,
  PBUF_RAW_TX,
  PBUF_RAW
} pbuf_layer;

typedef enum {
  PBUF_RAM,
  PBUF_ROM,
  PBUF_REF,
  PBUF_POOL
} pbuf_type;


#define PBUF_FLAG_PUSH      0x01U

#define PBUF_FLAG_IS_CUSTOM 0x02U

#define PBUF_FLAG_MCASTLOOP 0x04U

#define PBUF_FLAG_LLBCAST   0x08U

#define PBUF_FLAG_LLMCAST   0x10U

#define PBUF_FLAG_TCP_FIN   0x20U

struct pbuf {
  struct pbuf *next;

  void *payload;

  u16_t tot_len;

  u16_t len;

  u8_t /*pbuf_type*/ type;

  u8_t flags;

  u16_t ref;
};


struct pbuf_rom {
  struct pbuf *next;

  const void *payload;
};

#if LWIP_SUPPORT_CUSTOM_PBUF

typedef void (*pbuf_free_custom_fn)(struct pbuf *p);

struct pbuf_custom {
  struct pbuf pbuf;
  pbuf_free_custom_fn custom_free_function;
};
#endif /* LWIP_SUPPORT_CUSTOM_PBUF */

#if LWIP_TCP && TCP_QUEUE_OOSEQ

#ifndef PBUF_POOL_FREE_OOSEQ
#define PBUF_POOL_FREE_OOSEQ 1
#endif /* PBUF_POOL_FREE_OOSEQ */
#if NO_SYS && PBUF_POOL_FREE_OOSEQ
extern volatile u8_t pbuf_free_ooseq_pending;
void pbuf_free_ooseq(void);
#define PBUF_CHECK_FREE_OOSEQ() do { if(pbuf_free_ooseq_pending) { \
  /* pbuf_alloc() reported PBUF_POOL to be empty -> try to free some \
     ooseq queued pbufs now */ \
  pbuf_free_ooseq(); }}while(0)
#endif /* NO_SYS && PBUF_POOL_FREE_OOSEQ*/
#endif /* LWIP_TCP && TCP_QUEUE_OOSEQ */

/* 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 length, pbuf_type type);
#if LWIP_SUPPORT_CUSTOM_PBUF
struct pbuf *pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type,
                                 struct pbuf_custom *p, void *payload_mem,
                                 u16_t payload_mem_len);
#endif /* LWIP_SUPPORT_CUSTOM_PBUF */
void pbuf_realloc(struct pbuf *p, u16_t size);
u8_t pbuf_header(struct pbuf *p, s16_t header_size);
u8_t pbuf_header_force(struct pbuf *p, s16_t header_size);
void pbuf_ref(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);
err_t pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len);
err_t pbuf_take_at(struct pbuf *buf, const void *dataptr, u16_t len, u16_t offset);
struct pbuf *pbuf_skip(struct pbuf* in, u16_t in_offset, u16_t* out_offset);
struct pbuf *pbuf_coalesce(struct pbuf *p, pbuf_layer layer);
#if LWIP_CHECKSUM_ON_COPY
err_t pbuf_fill_chksum(struct pbuf *p, u16_t start_offset, const void *dataptr,
                       u16_t len, u16_t *chksum);
#endif /* LWIP_CHECKSUM_ON_COPY */
#if LWIP_TCP && TCP_QUEUE_OOSEQ && LWIP_WND_SCALE
void pbuf_split_64k(struct pbuf *p, struct pbuf **rest);
#endif /* LWIP_TCP && TCP_QUEUE_OOSEQ && LWIP_WND_SCALE */

u8_t pbuf_get_at(struct pbuf* p, u16_t offset);
void pbuf_put_at(struct pbuf* p, u16_t offset, u8_t data);
u16_t pbuf_memcmp(struct pbuf* p, u16_t offset, const void* s2, u16_t n);
u16_t pbuf_memfind(struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset);
u16_t pbuf_strstr(struct pbuf* p, const char* substr);

#ifdef __cplusplus
}
#endif

#endif /* LWIP_HDR_PBUF_H */