2 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
5 * Redistribution and use in source and binary forms, with or without modification,
6 * are permitted provided that the following conditions are met:
8 * 1. Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
19 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
21 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
24 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
27 * This file is part of the lwIP TCP/IP stack.
29 * Author: Adam Dunkels <adam@sics.se>
33 #ifndef __LWIP_PBUF_H__
34 #define __LWIP_PBUF_H__
43 /** Currently, the pbuf_custom code is only needed for one specific configuration
45 #define LWIP_SUPPORT_CUSTOM_PBUF (IP_FRAG && !IP_FRAG_USES_STATIC_BUF && !LWIP_NETIF_TX_SINGLE_PBUF)
47 /* @todo: We need a mechanism to prevent wasting memory in every pbuf
48 (TCP vs. UDP, IPv4 vs. IPv6: UDP/IPv4 packets may waste up to 28 bytes) */
50 #define PBUF_TRANSPORT_HLEN 20
52 #define PBUF_IP_HLEN 40
54 #define PBUF_IP_HLEN 20
65 PBUF_RAM, /* pbuf data is stored in RAM */
66 PBUF_ROM, /* pbuf data is stored in ROM */
67 PBUF_REF, /* pbuf comes from the pbuf pool */
68 PBUF_POOL /* pbuf payload refers to RAM */
72 /** indicates this packet's data should be immediately passed to the application */
73 #define PBUF_FLAG_PUSH 0x01U
74 /** indicates this is a custom pbuf: pbuf_free and pbuf_header handle such a
76 #define PBUF_FLAG_IS_CUSTOM 0x02U
77 /** indicates this pbuf is UDP multicast to be looped back */
78 #define PBUF_FLAG_MCASTLOOP 0x04U
79 /** indicates this pbuf was received as link-level broadcast */
80 #define PBUF_FLAG_LLBCAST 0x08U
81 /** indicates this pbuf was received as link-level multicast */
82 #define PBUF_FLAG_LLMCAST 0x10U
85 /** next pbuf in singly linked pbuf chain */
88 /** pointer to the actual data in the buffer */
92 * total length of this buffer and all next buffers in chain
93 * belonging to the same packet.
95 * For non-queue packet chains this is the invariant:
96 * p->tot_len == p->len + (p->next? p->next->tot_len: 0)
100 /** length of this buffer */
103 /** pbuf_type as u8_t instead of enum to save space */
104 u8_t /*pbuf_type*/ type;
110 * the reference count always equals the number of pointers
111 * that refer to this pbuf. This can be pointers from an application,
112 * the stack itself, or pbuf->next pointers from a chain.
117 #if LWIP_SUPPORT_CUSTOM_PBUF
118 /** Prototype for a function to free a custom pbuf */
119 typedef void (*pbuf_free_custom_fn)(struct pbuf *p);
121 /** A custom pbuf: like a pbuf, but following a function pointer to free it. */
123 /** The actual pbuf */
125 /** This function is called when pbuf_free deallocates this pbuf(_custom) */
126 pbuf_free_custom_fn custom_free_function;
128 #endif /* LWIP_SUPPORT_CUSTOM_PBUF */
130 #if LWIP_TCP && TCP_QUEUE_OOSEQ
131 /** Define this to 0 to prevent freeing ooseq pbufs when the PBUF_POOL is empty */
132 #ifndef PBUF_POOL_FREE_OOSEQ
133 #define PBUF_POOL_FREE_OOSEQ 1
134 #endif /* PBUF_POOL_FREE_OOSEQ */
135 #if NO_SYS && PBUF_POOL_FREE_OOSEQ
136 extern volatile u8_t pbuf_free_ooseq_pending;
137 void pbuf_free_ooseq();
138 /** When not using sys_check_timeouts(), call PBUF_CHECK_FREE_OOSEQ()
139 at regular intervals from main level to check if ooseq pbufs need to be
141 #define PBUF_CHECK_FREE_OOSEQ() do { if(pbuf_free_ooseq_pending) { \
142 /* pbuf_alloc() reported PBUF_POOL to be empty -> try to free some \
143 ooseq queued pbufs now */ \
144 pbuf_free_ooseq(); }}while(0)
145 #endif /* NO_SYS && PBUF_POOL_FREE_OOSEQ*/
146 #endif /* LWIP_TCP && TCP_QUEUE_OOSEQ */
148 /* Initializes the pbuf module. This call is empty for now, but may not be in future. */
151 struct pbuf *pbuf_alloc(pbuf_layer l, u16_t length, pbuf_type type);
152 #if LWIP_SUPPORT_CUSTOM_PBUF
153 struct pbuf *pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type,
154 struct pbuf_custom *p, void *payload_mem,
155 u16_t payload_mem_len);
156 #endif /* LWIP_SUPPORT_CUSTOM_PBUF */
157 void pbuf_realloc(struct pbuf *p, u16_t size);
158 u8_t pbuf_header(struct pbuf *p, s16_t header_size);
159 void pbuf_ref(struct pbuf *p);
160 u8_t pbuf_free(struct pbuf *p);
161 u8_t pbuf_clen(struct pbuf *p);
162 void pbuf_cat(struct pbuf *head, struct pbuf *tail);
163 void pbuf_chain(struct pbuf *head, struct pbuf *tail);
164 struct pbuf *pbuf_dechain(struct pbuf *p);
165 err_t pbuf_copy(struct pbuf *p_to, struct pbuf *p_from);
166 u16_t pbuf_copy_partial(struct pbuf *p, void *dataptr, u16_t len, u16_t offset);
167 err_t pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len);
168 struct pbuf *pbuf_coalesce(struct pbuf *p, pbuf_layer layer);
169 #if LWIP_CHECKSUM_ON_COPY
170 err_t pbuf_fill_chksum(struct pbuf *p, u16_t start_offset, const void *dataptr,
171 u16_t len, u16_t *chksum);
172 #endif /* LWIP_CHECKSUM_ON_COPY */
174 u8_t pbuf_get_at(struct pbuf* p, u16_t offset);
175 u16_t pbuf_memcmp(struct pbuf* p, u16_t offset, const void* s2, u16_t n);
176 u16_t pbuf_memfind(struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset);
177 u16_t pbuf_strstr(struct pbuf* p, const char* substr);
183 #endif /* __LWIP_PBUF_H__ */