1 /* 2 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without modification, 6 * are permitted provided that the following conditions are met: 7 * 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. 15 * 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 25 * OF SUCH DAMAGE. 26 * 27 * This file is part of the lwIP TCP/IP stack. 28 * 29 * Author: Adam Dunkels <adam@sics.se> 30 * 31 */ 32 33 #ifndef __LWIP_PBUF_H__ 34 #define __LWIP_PBUF_H__ 35 36 #include "lwip/opt.h" 37 #include "lwip/err.h" 38 39 #ifdef __cplusplus 40 extern "C" { 41 #endif 42 43 /** Currently, the pbuf_custom code is only needed for one specific configuration 44 * of IP_FRAG */ 45 #define LWIP_SUPPORT_CUSTOM_PBUF (IP_FRAG && !IP_FRAG_USES_STATIC_BUF && !LWIP_NETIF_TX_SINGLE_PBUF) 46 47 #define PBUF_TRANSPORT_HLEN 20 48 #define PBUF_IP_HLEN 20 49 50 typedef enum { 51 PBUF_TRANSPORT, 52 PBUF_IP, 53 PBUF_LINK, 54 PBUF_RAW 55 } pbuf_layer; 56 57 typedef enum { 58 PBUF_RAM, /* pbuf data is stored in RAM */ 59 PBUF_ROM, /* pbuf data is stored in ROM */ 60 PBUF_REF, /* pbuf comes from the pbuf pool */ 61 PBUF_POOL /* pbuf payload refers to RAM */ 62 } pbuf_type; 63 64 65 /** indicates this packet's data should be immediately passed to the application */ 66 #define PBUF_FLAG_PUSH 0x01U 67 /** indicates this is a custom pbuf: pbuf_free and pbuf_header handle such a 68 a pbuf differently */ 69 #define PBUF_FLAG_IS_CUSTOM 0x02U 70 /** indicates this pbuf is UDP multicast to be looped back */ 71 #define PBUF_FLAG_MCASTLOOP 0x04U 72 73 struct pbuf { 74 /** next pbuf in singly linked pbuf chain */ 75 struct pbuf *next; 76 77 /** pointer to the actual data in the buffer */ 78 void *payload; 79 80 /** 81 * total length of this buffer and all next buffers in chain 82 * belonging to the same packet. 83 * 84 * For non-queue packet chains this is the invariant: 85 * p->tot_len == p->len + (p->next? p->next->tot_len: 0) 86 */ 87 u16_t tot_len; 88 89 /** length of this buffer */ 90 u16_t len; 91 92 /** pbuf_type as u8_t instead of enum to save space */ 93 u8_t /*pbuf_type*/ type; 94 95 /** misc flags */ 96 u8_t flags; 97 98 /** 99 * the reference count always equals the number of pointers 100 * that refer to this pbuf. This can be pointers from an application, 101 * the stack itself, or pbuf->next pointers from a chain. 102 */ 103 u16_t ref; 104 }; 105 106 #if LWIP_SUPPORT_CUSTOM_PBUF 107 /** Prototype for a function to free a custom pbuf */ 108 typedef void (*pbuf_free_custom_fn)(struct pbuf *p); 109 110 /** A custom pbuf: like a pbuf, but following a function pointer to free it. */ 111 struct pbuf_custom { 112 /** The actual pbuf */ 113 struct pbuf pbuf; 114 /** This function is called when pbuf_free deallocates this pbuf(_custom) */ 115 pbuf_free_custom_fn custom_free_function; 116 }; 117 #endif /* LWIP_SUPPORT_CUSTOM_PBUF */ 118 119 /* Initializes the pbuf module. This call is empty for now, but may not be in future. */ 120 #define pbuf_init() 121 122 struct pbuf *pbuf_alloc(pbuf_layer l, u16_t length, pbuf_type type); 123 #if LWIP_SUPPORT_CUSTOM_PBUF 124 struct pbuf *pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type, 125 struct pbuf_custom *p, void *payload_mem, 126 u16_t payload_mem_len); 127 #endif /* LWIP_SUPPORT_CUSTOM_PBUF */ 128 void pbuf_realloc(struct pbuf *p, u16_t size); 129 u8_t pbuf_header(struct pbuf *p, s16_t header_size); 130 void pbuf_ref(struct pbuf *p); 131 u8_t pbuf_free(struct pbuf *p); 132 u8_t pbuf_clen(struct pbuf *p); 133 void pbuf_cat(struct pbuf *head, struct pbuf *tail); 134 void pbuf_chain(struct pbuf *head, struct pbuf *tail); 135 struct pbuf *pbuf_dechain(struct pbuf *p); 136 err_t pbuf_copy(struct pbuf *p_to, struct pbuf *p_from); 137 u16_t pbuf_copy_partial(struct pbuf *p, void *dataptr, u16_t len, u16_t offset); 138 err_t pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len); 139 struct pbuf *pbuf_coalesce(struct pbuf *p, pbuf_layer layer); 140 #if LWIP_CHECKSUM_ON_COPY 141 err_t pbuf_fill_chksum(struct pbuf *p, u16_t start_offset, const void *dataptr, 142 u16_t len, u16_t *chksum); 143 #endif /* LWIP_CHECKSUM_ON_COPY */ 144 145 u8_t pbuf_get_at(struct pbuf* p, u16_t offset); 146 u16_t pbuf_memcmp(struct pbuf* p, u16_t offset, const void* s2, u16_t n); 147 u16_t pbuf_memfind(struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset); 148 u16_t pbuf_strstr(struct pbuf* p, const char* substr); 149 150 #ifdef __cplusplus 151 } 152 #endif 153 154 #endif /* __LWIP_PBUF_H__ */ 155