[164] | 1 | /**
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| 2 | * @file
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| 3 | * Packet buffer management
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| 4 | *
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| 5 | * Packets are built from the pbuf data structure. It supports dynamic
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| 6 | * memory allocation for packet contents or can reference externally
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| 7 | * managed packet contents both in RAM and ROM. Quick allocation for
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| 8 | * incoming packets is provided through pools with fixed sized pbufs.
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| 9 | *
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| 10 | * A packet may span over multiple pbufs, chained as a singly linked
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| 11 | * list. This is called a "pbuf chain".
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| 12 | *
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| 13 | * Multiple packets may be queued, also using this singly linked list.
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| 14 | * This is called a "packet queue".
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| 15 | *
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| 16 | * So, a packet queue consists of one or more pbuf chains, each of
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| 17 | * which consist of one or more pbufs. CURRENTLY, PACKET QUEUES ARE
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| 18 | * NOT SUPPORTED!!! Use helper structs to queue multiple packets.
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| 19 | *
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| 20 | * The differences between a pbuf chain and a packet queue are very
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| 21 | * precise but subtle.
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| 22 | *
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| 23 | * The last pbuf of a packet has a ->tot_len field that equals the
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| 24 | * ->len field. It can be found by traversing the list. If the last
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| 25 | * pbuf of a packet has a ->next field other than NULL, more packets
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| 26 | * are on the queue.
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| 27 | *
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| 28 | * Therefore, looping through a pbuf of a single packet, has an
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| 29 | * loop end condition (tot_len == p->len), NOT (next == NULL).
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| 30 | */
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| 31 |
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| 32 | /*
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| 33 | * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
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| 34 | * All rights reserved.
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| 35 | *
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| 36 | * Redistribution and use in source and binary forms, with or without modification,
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| 37 | * are permitted provided that the following conditions are met:
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| 38 | *
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| 39 | * 1. Redistributions of source code must retain the above copyright notice,
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| 40 | * this list of conditions and the following disclaimer.
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| 41 | * 2. Redistributions in binary form must reproduce the above copyright notice,
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| 42 | * this list of conditions and the following disclaimer in the documentation
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| 43 | * and/or other materials provided with the distribution.
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| 44 | * 3. The name of the author may not be used to endorse or promote products
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| 45 | * derived from this software without specific prior written permission.
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| 46 | *
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| 47 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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| 48 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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| 49 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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| 50 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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| 51 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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| 52 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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| 53 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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| 54 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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| 55 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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| 56 | * OF SUCH DAMAGE.
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| 57 | *
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| 58 | * This file is part of the lwIP TCP/IP stack.
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| 59 | *
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| 60 | * Author: Adam Dunkels <adam@sics.se>
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| 61 | *
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| 62 | */
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| 63 |
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| 64 | #include "lwip/opt.h"
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| 65 |
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| 66 | #include "lwip/stats.h"
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| 67 | #include "lwip/def.h"
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| 68 | #include "lwip/mem.h"
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| 69 | #include "lwip/memp.h"
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| 70 | #include "lwip/pbuf.h"
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| 71 | #include "lwip/sys.h"
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| 72 | #include "arch/perf.h"
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| 73 | #if LWIP_TCP && TCP_QUEUE_OOSEQ
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| 74 | #include "lwip/tcp_impl.h"
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| 75 | #endif
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| 76 | #if LWIP_CHECKSUM_ON_COPY
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| 77 | #include "lwip/inet_chksum.h"
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| 78 | #endif
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| 79 |
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| 80 | #include <string.h>
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| 81 |
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| 82 | #define SIZEOF_STRUCT_PBUF LWIP_MEM_ALIGN_SIZE(sizeof(struct pbuf))
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| 83 | /* Since the pool is created in memp, PBUF_POOL_BUFSIZE will be automatically
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| 84 | aligned there. Therefore, PBUF_POOL_BUFSIZE_ALIGNED can be used here. */
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| 85 | #define PBUF_POOL_BUFSIZE_ALIGNED LWIP_MEM_ALIGN_SIZE(PBUF_POOL_BUFSIZE)
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| 86 |
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| 87 | #if !LWIP_TCP || !TCP_QUEUE_OOSEQ || !PBUF_POOL_FREE_OOSEQ
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| 88 | #define PBUF_POOL_IS_EMPTY()
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| 89 | #else /* !LWIP_TCP || !TCP_QUEUE_OOSEQ || !PBUF_POOL_FREE_OOSEQ */
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| 90 |
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| 91 | #if !NO_SYS
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| 92 | #ifndef PBUF_POOL_FREE_OOSEQ_QUEUE_CALL
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| 93 | #include "lwip/tcpip.h"
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| 94 | #define PBUF_POOL_FREE_OOSEQ_QUEUE_CALL() do { \
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| 95 | if(tcpip_callback_with_block(pbuf_free_ooseq_callback, NULL, 0) != ERR_OK) { \
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| 96 | SYS_ARCH_PROTECT(old_level); \
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| 97 | pbuf_free_ooseq_pending = 0; \
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| 98 | SYS_ARCH_UNPROTECT(old_level); \
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| 99 | } } while(0)
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| 100 | #endif /* PBUF_POOL_FREE_OOSEQ_QUEUE_CALL */
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| 101 | #endif /* !NO_SYS */
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| 102 |
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| 103 | volatile u8_t pbuf_free_ooseq_pending;
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| 104 | #define PBUF_POOL_IS_EMPTY() pbuf_pool_is_empty()
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| 105 |
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| 106 | /**
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| 107 | * Attempt to reclaim some memory from queued out-of-sequence TCP segments
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| 108 | * if we run out of pool pbufs. It's better to give priority to new packets
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| 109 | * if we're running out.
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| 110 | *
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| 111 | * This must be done in the correct thread context therefore this function
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| 112 | * can only be used with NO_SYS=0 and through tcpip_callback.
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| 113 | */
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| 114 | #if !NO_SYS
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| 115 | static
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| 116 | #endif /* !NO_SYS */
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| 117 | void
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| 118 | pbuf_free_ooseq(void)
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| 119 | {
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| 120 | struct tcp_pcb* pcb;
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| 121 | SYS_ARCH_DECL_PROTECT(old_level);
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| 122 |
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| 123 | SYS_ARCH_PROTECT(old_level);
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| 124 | pbuf_free_ooseq_pending = 0;
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| 125 | SYS_ARCH_UNPROTECT(old_level);
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| 126 |
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| 127 | for (pcb = tcp_active_pcbs; NULL != pcb; pcb = pcb->next) {
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| 128 | if (NULL != pcb->ooseq) {
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| 129 | /** Free the ooseq pbufs of one PCB only */
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| 130 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free_ooseq: freeing out-of-sequence pbufs\n"));
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| 131 | tcp_segs_free(pcb->ooseq);
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| 132 | pcb->ooseq = NULL;
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| 133 | return;
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| 134 | }
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| 135 | }
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| 136 | }
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| 137 |
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| 138 | #if !NO_SYS
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| 139 | /**
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| 140 | * Just a callback function for tcpip_timeout() that calls pbuf_free_ooseq().
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| 141 | */
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| 142 | static void
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| 143 | pbuf_free_ooseq_callback(void *arg)
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| 144 | {
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| 145 | LWIP_UNUSED_ARG(arg);
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| 146 | pbuf_free_ooseq();
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| 147 | }
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| 148 | #endif /* !NO_SYS */
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| 149 |
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| 150 | /** Queue a call to pbuf_free_ooseq if not already queued. */
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| 151 | static void
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| 152 | pbuf_pool_is_empty(void)
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| 153 | {
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| 154 | #ifndef PBUF_POOL_FREE_OOSEQ_QUEUE_CALL
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| 155 | SYS_ARCH_DECL_PROTECT(old_level);
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| 156 | SYS_ARCH_PROTECT(old_level);
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| 157 | pbuf_free_ooseq_pending = 1;
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| 158 | SYS_ARCH_UNPROTECT(old_level);
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| 159 | #else /* PBUF_POOL_FREE_OOSEQ_QUEUE_CALL */
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| 160 | u8_t queued;
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| 161 | SYS_ARCH_DECL_PROTECT(old_level);
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| 162 | SYS_ARCH_PROTECT(old_level);
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| 163 | queued = pbuf_free_ooseq_pending;
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| 164 | pbuf_free_ooseq_pending = 1;
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| 165 | SYS_ARCH_UNPROTECT(old_level);
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| 166 |
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| 167 | if(!queued) {
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| 168 | /* queue a call to pbuf_free_ooseq if not already queued */
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| 169 | PBUF_POOL_FREE_OOSEQ_QUEUE_CALL();
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| 170 | }
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| 171 | #endif /* PBUF_POOL_FREE_OOSEQ_QUEUE_CALL */
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| 172 | }
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| 173 | #endif /* !LWIP_TCP || !TCP_QUEUE_OOSEQ || !PBUF_POOL_FREE_OOSEQ */
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| 174 |
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| 175 | /**
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| 176 | * Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
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| 177 | *
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| 178 | * The actual memory allocated for the pbuf is determined by the
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| 179 | * layer at which the pbuf is allocated and the requested size
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| 180 | * (from the size parameter).
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| 181 | *
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| 182 | * @param layer flag to define header size
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| 183 | * @param length size of the pbuf's payload
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| 184 | * @param type this parameter decides how and where the pbuf
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| 185 | * should be allocated as follows:
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| 186 | *
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| 187 | * - PBUF_RAM: buffer memory for pbuf is allocated as one large
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| 188 | * chunk. This includes protocol headers as well.
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| 189 | * - PBUF_ROM: no buffer memory is allocated for the pbuf, even for
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| 190 | * protocol headers. Additional headers must be prepended
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| 191 | * by allocating another pbuf and chain in to the front of
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| 192 | * the ROM pbuf. It is assumed that the memory used is really
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| 193 | * similar to ROM in that it is immutable and will not be
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| 194 | * changed. Memory which is dynamic should generally not
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| 195 | * be attached to PBUF_ROM pbufs. Use PBUF_REF instead.
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| 196 | * - PBUF_REF: no buffer memory is allocated for the pbuf, even for
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| 197 | * protocol headers. It is assumed that the pbuf is only
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| 198 | * being used in a single thread. If the pbuf gets queued,
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| 199 | * then pbuf_take should be called to copy the buffer.
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| 200 | * - PBUF_POOL: the pbuf is allocated as a pbuf chain, with pbufs from
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| 201 | * the pbuf pool that is allocated during pbuf_init().
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| 202 | *
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| 203 | * @return the allocated pbuf. If multiple pbufs where allocated, this
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| 204 | * is the first pbuf of a pbuf chain.
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| 205 | */
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| 206 | struct pbuf *
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| 207 | pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
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| 208 | {
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| 209 | struct pbuf *p, *q, *r;
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| 210 | u16_t offset;
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| 211 | s32_t rem_len; /* remaining length */
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| 212 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F")\n", length));
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| 213 |
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| 214 | /* determine header offset */
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| 215 | switch (layer) {
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| 216 | case PBUF_TRANSPORT:
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| 217 | /* add room for transport (often TCP) layer header */
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| 218 | offset = PBUF_LINK_HLEN + PBUF_IP_HLEN + PBUF_TRANSPORT_HLEN;
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| 219 | break;
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| 220 | case PBUF_IP:
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| 221 | /* add room for IP layer header */
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| 222 | offset = PBUF_LINK_HLEN + PBUF_IP_HLEN;
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| 223 | break;
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| 224 | case PBUF_LINK:
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| 225 | /* add room for link layer header */
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| 226 | offset = PBUF_LINK_HLEN;
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| 227 | break;
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| 228 | case PBUF_RAW:
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| 229 | offset = 0;
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| 230 | break;
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| 231 | default:
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| 232 | LWIP_ASSERT("pbuf_alloc: bad pbuf layer", 0);
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| 233 | return NULL;
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| 234 | }
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| 235 |
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| 236 | switch (type) {
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| 237 | case PBUF_POOL:
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| 238 | /* allocate head of pbuf chain into p */
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| 239 | p = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
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| 240 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc: allocated pbuf %p\n", (void *)p));
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| 241 | if (p == NULL) {
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| 242 | PBUF_POOL_IS_EMPTY();
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| 243 | return NULL;
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| 244 | }
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| 245 | p->type = type;
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| 246 | p->next = NULL;
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| 247 |
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| 248 | /* make the payload pointer point 'offset' bytes into pbuf data memory */
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| 249 | p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + (SIZEOF_STRUCT_PBUF + offset)));
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| 250 | LWIP_ASSERT("pbuf_alloc: pbuf p->payload properly aligned",
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| 251 | ((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
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| 252 | /* the total length of the pbuf chain is the requested size */
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| 253 | p->tot_len = length;
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| 254 | /* set the length of the first pbuf in the chain */
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| 255 | p->len = LWIP_MIN(length, PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset));
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| 256 | LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
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| 257 | ((u8_t*)p->payload + p->len <=
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| 258 | (u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
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| 259 | LWIP_ASSERT("PBUF_POOL_BUFSIZE must be bigger than MEM_ALIGNMENT",
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| 260 | (PBUF_POOL_BUFSIZE_ALIGNED - LWIP_MEM_ALIGN_SIZE(offset)) > 0 );
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| 261 | /* set reference count (needed here in case we fail) */
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| 262 | p->ref = 1;
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| 263 |
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| 264 | /* now allocate the tail of the pbuf chain */
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| 265 |
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| 266 | /* remember first pbuf for linkage in next iteration */
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| 267 | r = p;
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| 268 | /* remaining length to be allocated */
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| 269 | rem_len = length - p->len;
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| 270 | /* any remaining pbufs to be allocated? */
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| 271 | while (rem_len > 0) {
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| 272 | q = (struct pbuf *)memp_malloc(MEMP_PBUF_POOL);
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| 273 | if (q == NULL) {
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| 274 | PBUF_POOL_IS_EMPTY();
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| 275 | /* free chain so far allocated */
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| 276 | pbuf_free(p);
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| 277 | /* bail out unsuccesfully */
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| 278 | return NULL;
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| 279 | }
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| 280 | q->type = type;
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| 281 | q->flags = 0;
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| 282 | q->next = NULL;
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| 283 | /* make previous pbuf point to this pbuf */
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| 284 | r->next = q;
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| 285 | /* set total length of this pbuf and next in chain */
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| 286 | LWIP_ASSERT("rem_len < max_u16_t", rem_len < 0xffff);
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| 287 | q->tot_len = (u16_t)rem_len;
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| 288 | /* this pbuf length is pool size, unless smaller sized tail */
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| 289 | q->len = LWIP_MIN((u16_t)rem_len, PBUF_POOL_BUFSIZE_ALIGNED);
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| 290 | q->payload = (void *)((u8_t *)q + SIZEOF_STRUCT_PBUF);
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| 291 | LWIP_ASSERT("pbuf_alloc: pbuf q->payload properly aligned",
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| 292 | ((mem_ptr_t)q->payload % MEM_ALIGNMENT) == 0);
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| 293 | LWIP_ASSERT("check p->payload + p->len does not overflow pbuf",
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| 294 | ((u8_t*)p->payload + p->len <=
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| 295 | (u8_t*)p + SIZEOF_STRUCT_PBUF + PBUF_POOL_BUFSIZE_ALIGNED));
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| 296 | q->ref = 1;
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| 297 | /* calculate remaining length to be allocated */
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| 298 | rem_len -= q->len;
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| 299 | /* remember this pbuf for linkage in next iteration */
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| 300 | r = q;
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| 301 | }
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| 302 | /* end of chain */
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| 303 | /*r->next = NULL;*/
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| 304 |
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| 305 | break;
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| 306 | case PBUF_RAM:
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| 307 | /* If pbuf is to be allocated in RAM, allocate memory for it. */
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| 308 | p = (struct pbuf*)mem_malloc(LWIP_MEM_ALIGN_SIZE(SIZEOF_STRUCT_PBUF + offset) + LWIP_MEM_ALIGN_SIZE(length));
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| 309 | if (p == NULL) {
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| 310 | return NULL;
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| 311 | }
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| 312 | /* Set up internal structure of the pbuf. */
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| 313 | p->payload = LWIP_MEM_ALIGN((void *)((u8_t *)p + SIZEOF_STRUCT_PBUF + offset));
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| 314 | p->len = p->tot_len = length;
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| 315 | p->next = NULL;
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| 316 | p->type = type;
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| 317 |
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| 318 | LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
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| 319 | ((mem_ptr_t)p->payload % MEM_ALIGNMENT) == 0);
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| 320 | break;
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| 321 | /* pbuf references existing (non-volatile static constant) ROM payload? */
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| 322 | case PBUF_ROM:
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| 323 | /* pbuf references existing (externally allocated) RAM payload? */
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| 324 | case PBUF_REF:
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| 325 | /* only allocate memory for the pbuf structure */
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| 326 | p = (struct pbuf *)memp_malloc(MEMP_PBUF);
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| 327 | if (p == NULL) {
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| 328 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
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| 329 | ("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_%s.\n",
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| 330 | (type == PBUF_ROM) ? "ROM" : "REF"));
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| 331 | return NULL;
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| 332 | }
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| 333 | /* caller must set this field properly, afterwards */
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| 334 | p->payload = NULL;
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| 335 | p->len = p->tot_len = length;
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| 336 | p->next = NULL;
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| 337 | p->type = type;
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| 338 | break;
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| 339 | default:
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| 340 | LWIP_ASSERT("pbuf_alloc: erroneous type", 0);
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| 341 | return NULL;
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| 342 | }
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| 343 | /* set reference count */
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| 344 | p->ref = 1;
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| 345 | /* set flags */
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| 346 | p->flags = 0;
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| 347 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloc(length=%"U16_F") == %p\n", length, (void *)p));
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| 348 | return p;
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| 349 | }
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| 350 |
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| 351 | #if LWIP_SUPPORT_CUSTOM_PBUF
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| 352 | /** Initialize a custom pbuf (already allocated).
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| 353 | *
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| 354 | * @param layer flag to define header size
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| 355 | * @param length size of the pbuf's payload
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| 356 | * @param type type of the pbuf (only used to treat the pbuf accordingly, as
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| 357 | * this function allocates no memory)
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| 358 | * @param p pointer to the custom pbuf to initialize (already allocated)
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| 359 | * @param payload_mem pointer to the buffer that is used for payload and headers,
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| 360 | * must be at least big enough to hold 'length' plus the header size,
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| 361 | * may be NULL if set later.
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| 362 | * ATTENTION: The caller is responsible for correct alignment of this buffer!!
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| 363 | * @param payload_mem_len the size of the 'payload_mem' buffer, must be at least
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| 364 | * big enough to hold 'length' plus the header size
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| 365 | */
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| 366 | struct pbuf*
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| 367 | pbuf_alloced_custom(pbuf_layer l, u16_t length, pbuf_type type, struct pbuf_custom *p,
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| 368 | void *payload_mem, u16_t payload_mem_len)
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| 369 | {
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| 370 | u16_t offset;
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| 371 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_alloced_custom(length=%"U16_F")\n", length));
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| 372 |
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| 373 | /* determine header offset */
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| 374 | switch (l) {
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| 375 | case PBUF_TRANSPORT:
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| 376 | /* add room for transport (often TCP) layer header */
|
---|
| 377 | offset = PBUF_LINK_HLEN + PBUF_IP_HLEN + PBUF_TRANSPORT_HLEN;
|
---|
| 378 | break;
|
---|
| 379 | case PBUF_IP:
|
---|
| 380 | /* add room for IP layer header */
|
---|
| 381 | offset = PBUF_LINK_HLEN + PBUF_IP_HLEN;
|
---|
| 382 | break;
|
---|
| 383 | case PBUF_LINK:
|
---|
| 384 | /* add room for link layer header */
|
---|
| 385 | offset = PBUF_LINK_HLEN;
|
---|
| 386 | break;
|
---|
| 387 | case PBUF_RAW:
|
---|
| 388 | offset = 0;
|
---|
| 389 | break;
|
---|
| 390 | default:
|
---|
| 391 | LWIP_ASSERT("pbuf_alloced_custom: bad pbuf layer", 0);
|
---|
| 392 | return NULL;
|
---|
| 393 | }
|
---|
| 394 |
|
---|
| 395 | if (LWIP_MEM_ALIGN_SIZE(offset) + length > payload_mem_len) {
|
---|
| 396 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_WARNING, ("pbuf_alloced_custom(length=%"U16_F") buffer too short\n", length));
|
---|
| 397 | return NULL;
|
---|
| 398 | }
|
---|
| 399 |
|
---|
| 400 | p->pbuf.next = NULL;
|
---|
| 401 | if (payload_mem != NULL) {
|
---|
| 402 | p->pbuf.payload = (u8_t *)payload_mem + LWIP_MEM_ALIGN_SIZE(offset);
|
---|
| 403 | } else {
|
---|
| 404 | p->pbuf.payload = NULL;
|
---|
| 405 | }
|
---|
| 406 | p->pbuf.flags = PBUF_FLAG_IS_CUSTOM;
|
---|
| 407 | p->pbuf.len = p->pbuf.tot_len = length;
|
---|
| 408 | p->pbuf.type = type;
|
---|
| 409 | p->pbuf.ref = 1;
|
---|
| 410 | return &p->pbuf;
|
---|
| 411 | }
|
---|
| 412 | #endif /* LWIP_SUPPORT_CUSTOM_PBUF */
|
---|
| 413 |
|
---|
| 414 | /**
|
---|
| 415 | * Shrink a pbuf chain to a desired length.
|
---|
| 416 | *
|
---|
| 417 | * @param p pbuf to shrink.
|
---|
| 418 | * @param new_len desired new length of pbuf chain
|
---|
| 419 | *
|
---|
| 420 | * Depending on the desired length, the first few pbufs in a chain might
|
---|
| 421 | * be skipped and left unchanged. The new last pbuf in the chain will be
|
---|
| 422 | * resized, and any remaining pbufs will be freed.
|
---|
| 423 | *
|
---|
| 424 | * @note If the pbuf is ROM/REF, only the ->tot_len and ->len fields are adjusted.
|
---|
| 425 | * @note May not be called on a packet queue.
|
---|
| 426 | *
|
---|
| 427 | * @note Despite its name, pbuf_realloc cannot grow the size of a pbuf (chain).
|
---|
| 428 | */
|
---|
| 429 | void
|
---|
| 430 | pbuf_realloc(struct pbuf *p, u16_t new_len)
|
---|
| 431 | {
|
---|
| 432 | struct pbuf *q;
|
---|
| 433 | u16_t rem_len; /* remaining length */
|
---|
| 434 | s32_t grow;
|
---|
| 435 |
|
---|
| 436 | LWIP_ASSERT("pbuf_realloc: p != NULL", p != NULL);
|
---|
| 437 | LWIP_ASSERT("pbuf_realloc: sane p->type", p->type == PBUF_POOL ||
|
---|
| 438 | p->type == PBUF_ROM ||
|
---|
| 439 | p->type == PBUF_RAM ||
|
---|
| 440 | p->type == PBUF_REF);
|
---|
| 441 |
|
---|
| 442 | /* desired length larger than current length? */
|
---|
| 443 | if (new_len >= p->tot_len) {
|
---|
| 444 | /* enlarging not yet supported */
|
---|
| 445 | return;
|
---|
| 446 | }
|
---|
| 447 |
|
---|
| 448 | /* the pbuf chain grows by (new_len - p->tot_len) bytes
|
---|
| 449 | * (which may be negative in case of shrinking) */
|
---|
| 450 | grow = new_len - p->tot_len;
|
---|
| 451 |
|
---|
| 452 | /* first, step over any pbufs that should remain in the chain */
|
---|
| 453 | rem_len = new_len;
|
---|
| 454 | q = p;
|
---|
| 455 | /* should this pbuf be kept? */
|
---|
| 456 | while (rem_len > q->len) {
|
---|
| 457 | /* decrease remaining length by pbuf length */
|
---|
| 458 | rem_len -= q->len;
|
---|
| 459 | /* decrease total length indicator */
|
---|
| 460 | LWIP_ASSERT("grow < max_u16_t", grow < 0xffff);
|
---|
| 461 | q->tot_len += (u16_t)grow;
|
---|
| 462 | /* proceed to next pbuf in chain */
|
---|
| 463 | q = q->next;
|
---|
| 464 | LWIP_ASSERT("pbuf_realloc: q != NULL", q != NULL);
|
---|
| 465 | }
|
---|
| 466 | /* we have now reached the new last pbuf (in q) */
|
---|
| 467 | /* rem_len == desired length for pbuf q */
|
---|
| 468 |
|
---|
| 469 | /* shrink allocated memory for PBUF_RAM */
|
---|
| 470 | /* (other types merely adjust their length fields */
|
---|
| 471 | if ((q->type == PBUF_RAM) && (rem_len != q->len)) {
|
---|
| 472 | /* reallocate and adjust the length of the pbuf that will be split */
|
---|
| 473 | q = (struct pbuf *)mem_trim(q, (u16_t)((u8_t *)q->payload - (u8_t *)q) + rem_len);
|
---|
| 474 | LWIP_ASSERT("mem_trim returned q == NULL", q != NULL);
|
---|
| 475 | }
|
---|
| 476 | /* adjust length fields for new last pbuf */
|
---|
| 477 | q->len = rem_len;
|
---|
| 478 | q->tot_len = q->len;
|
---|
| 479 |
|
---|
| 480 | /* any remaining pbufs in chain? */
|
---|
| 481 | if (q->next != NULL) {
|
---|
| 482 | /* free remaining pbufs in chain */
|
---|
| 483 | pbuf_free(q->next);
|
---|
| 484 | }
|
---|
| 485 | /* q is last packet in chain */
|
---|
| 486 | q->next = NULL;
|
---|
| 487 |
|
---|
| 488 | }
|
---|
| 489 |
|
---|
| 490 | /**
|
---|
| 491 | * Adjusts the payload pointer to hide or reveal headers in the payload.
|
---|
| 492 | *
|
---|
| 493 | * Adjusts the ->payload pointer so that space for a header
|
---|
| 494 | * (dis)appears in the pbuf payload.
|
---|
| 495 | *
|
---|
| 496 | * The ->payload, ->tot_len and ->len fields are adjusted.
|
---|
| 497 | *
|
---|
| 498 | * @param p pbuf to change the header size.
|
---|
| 499 | * @param header_size_increment Number of bytes to increment header size which
|
---|
| 500 | * increases the size of the pbuf. New space is on the front.
|
---|
| 501 | * (Using a negative value decreases the header size.)
|
---|
| 502 | * If hdr_size_inc is 0, this function does nothing and returns succesful.
|
---|
| 503 | *
|
---|
| 504 | * PBUF_ROM and PBUF_REF type buffers cannot have their sizes increased, so
|
---|
| 505 | * the call will fail. A check is made that the increase in header size does
|
---|
| 506 | * not move the payload pointer in front of the start of the buffer.
|
---|
| 507 | * @return non-zero on failure, zero on success.
|
---|
| 508 | *
|
---|
| 509 | */
|
---|
| 510 | u8_t
|
---|
| 511 | pbuf_header(struct pbuf *p, s16_t header_size_increment)
|
---|
| 512 | {
|
---|
| 513 | u16_t type;
|
---|
| 514 | void *payload;
|
---|
| 515 | u16_t increment_magnitude;
|
---|
| 516 |
|
---|
| 517 | LWIP_ASSERT("p != NULL", p != NULL);
|
---|
| 518 | if ((header_size_increment == 0) || (p == NULL)) {
|
---|
| 519 | return 0;
|
---|
| 520 | }
|
---|
| 521 |
|
---|
| 522 | if (header_size_increment < 0){
|
---|
| 523 | increment_magnitude = -header_size_increment;
|
---|
| 524 | /* Check that we aren't going to move off the end of the pbuf */
|
---|
| 525 | LWIP_ERROR("increment_magnitude <= p->len", (increment_magnitude <= p->len), return 1;);
|
---|
| 526 | } else {
|
---|
| 527 | increment_magnitude = header_size_increment;
|
---|
| 528 | #if 0
|
---|
| 529 | /* Can't assert these as some callers speculatively call
|
---|
| 530 | pbuf_header() to see if it's OK. Will return 1 below instead. */
|
---|
| 531 | /* Check that we've got the correct type of pbuf to work with */
|
---|
| 532 | LWIP_ASSERT("p->type == PBUF_RAM || p->type == PBUF_POOL",
|
---|
| 533 | p->type == PBUF_RAM || p->type == PBUF_POOL);
|
---|
| 534 | /* Check that we aren't going to move off the beginning of the pbuf */
|
---|
| 535 | LWIP_ASSERT("p->payload - increment_magnitude >= p + SIZEOF_STRUCT_PBUF",
|
---|
| 536 | (u8_t *)p->payload - increment_magnitude >= (u8_t *)p + SIZEOF_STRUCT_PBUF);
|
---|
| 537 | #endif
|
---|
| 538 | }
|
---|
| 539 |
|
---|
| 540 | type = p->type;
|
---|
| 541 | /* remember current payload pointer */
|
---|
| 542 | payload = p->payload;
|
---|
| 543 |
|
---|
| 544 | /* pbuf types containing payloads? */
|
---|
| 545 | if (type == PBUF_RAM || type == PBUF_POOL) {
|
---|
| 546 | /* set new payload pointer */
|
---|
| 547 | p->payload = (u8_t *)p->payload - header_size_increment;
|
---|
| 548 | /* boundary check fails? */
|
---|
| 549 | if ((u8_t *)p->payload < (u8_t *)p + SIZEOF_STRUCT_PBUF) {
|
---|
| 550 | LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
|
---|
| 551 | ("pbuf_header: failed as %p < %p (not enough space for new header size)\n",
|
---|
| 552 | (void *)p->payload, (void *)(p + 1)));
|
---|
| 553 | /* restore old payload pointer */
|
---|
| 554 | p->payload = payload;
|
---|
| 555 | /* bail out unsuccesfully */
|
---|
| 556 | return 1;
|
---|
| 557 | }
|
---|
| 558 | /* pbuf types refering to external payloads? */
|
---|
| 559 | } else if (type == PBUF_REF || type == PBUF_ROM) {
|
---|
| 560 | /* hide a header in the payload? */
|
---|
| 561 | if ((header_size_increment < 0) && (increment_magnitude <= p->len)) {
|
---|
| 562 | /* increase payload pointer */
|
---|
| 563 | p->payload = (u8_t *)p->payload - header_size_increment;
|
---|
| 564 | } else {
|
---|
| 565 | /* cannot expand payload to front (yet!)
|
---|
| 566 | * bail out unsuccesfully */
|
---|
| 567 | return 1;
|
---|
| 568 | }
|
---|
| 569 | } else {
|
---|
| 570 | /* Unknown type */
|
---|
| 571 | LWIP_ASSERT("bad pbuf type", 0);
|
---|
| 572 | return 1;
|
---|
| 573 | }
|
---|
| 574 | /* modify pbuf length fields */
|
---|
| 575 | p->len += header_size_increment;
|
---|
| 576 | p->tot_len += header_size_increment;
|
---|
| 577 |
|
---|
| 578 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_header: old %p new %p (%"S16_F")\n",
|
---|
| 579 | (void *)payload, (void *)p->payload, header_size_increment));
|
---|
| 580 |
|
---|
| 581 | return 0;
|
---|
| 582 | }
|
---|
| 583 |
|
---|
| 584 | /**
|
---|
| 585 | * Dereference a pbuf chain or queue and deallocate any no-longer-used
|
---|
| 586 | * pbufs at the head of this chain or queue.
|
---|
| 587 | *
|
---|
| 588 | * Decrements the pbuf reference count. If it reaches zero, the pbuf is
|
---|
| 589 | * deallocated.
|
---|
| 590 | *
|
---|
| 591 | * For a pbuf chain, this is repeated for each pbuf in the chain,
|
---|
| 592 | * up to the first pbuf which has a non-zero reference count after
|
---|
| 593 | * decrementing. So, when all reference counts are one, the whole
|
---|
| 594 | * chain is free'd.
|
---|
| 595 | *
|
---|
| 596 | * @param p The pbuf (chain) to be dereferenced.
|
---|
| 597 | *
|
---|
| 598 | * @return the number of pbufs that were de-allocated
|
---|
| 599 | * from the head of the chain.
|
---|
| 600 | *
|
---|
| 601 | * @note MUST NOT be called on a packet queue (Not verified to work yet).
|
---|
| 602 | * @note the reference counter of a pbuf equals the number of pointers
|
---|
| 603 | * that refer to the pbuf (or into the pbuf).
|
---|
| 604 | *
|
---|
| 605 | * @internal examples:
|
---|
| 606 | *
|
---|
| 607 | * Assuming existing chains a->b->c with the following reference
|
---|
| 608 | * counts, calling pbuf_free(a) results in:
|
---|
| 609 | *
|
---|
| 610 | * 1->2->3 becomes ...1->3
|
---|
| 611 | * 3->3->3 becomes 2->3->3
|
---|
| 612 | * 1->1->2 becomes ......1
|
---|
| 613 | * 2->1->1 becomes 1->1->1
|
---|
| 614 | * 1->1->1 becomes .......
|
---|
| 615 | *
|
---|
| 616 | */
|
---|
| 617 | u8_t
|
---|
| 618 | pbuf_free(struct pbuf *p)
|
---|
| 619 | {
|
---|
| 620 | u16_t type;
|
---|
| 621 | struct pbuf *q;
|
---|
| 622 | u8_t count;
|
---|
| 623 |
|
---|
| 624 | if (p == NULL) {
|
---|
| 625 | LWIP_ASSERT("p != NULL", p != NULL);
|
---|
| 626 | /* if assertions are disabled, proceed with debug output */
|
---|
| 627 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
|
---|
| 628 | ("pbuf_free(p == NULL) was called.\n"));
|
---|
| 629 | return 0;
|
---|
| 630 | }
|
---|
| 631 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free(%p)\n", (void *)p));
|
---|
| 632 |
|
---|
| 633 | PERF_START;
|
---|
| 634 |
|
---|
| 635 | LWIP_ASSERT("pbuf_free: sane type",
|
---|
| 636 | p->type == PBUF_RAM || p->type == PBUF_ROM ||
|
---|
| 637 | p->type == PBUF_REF || p->type == PBUF_POOL);
|
---|
| 638 |
|
---|
| 639 | count = 0;
|
---|
| 640 | /* de-allocate all consecutive pbufs from the head of the chain that
|
---|
| 641 | * obtain a zero reference count after decrementing*/
|
---|
| 642 | while (p != NULL) {
|
---|
| 643 | u16_t ref;
|
---|
| 644 | SYS_ARCH_DECL_PROTECT(old_level);
|
---|
| 645 | /* Since decrementing ref cannot be guaranteed to be a single machine operation
|
---|
| 646 | * we must protect it. We put the new ref into a local variable to prevent
|
---|
| 647 | * further protection. */
|
---|
| 648 | SYS_ARCH_PROTECT(old_level);
|
---|
| 649 | /* all pbufs in a chain are referenced at least once */
|
---|
| 650 | LWIP_ASSERT("pbuf_free: p->ref > 0", p->ref > 0);
|
---|
| 651 | /* decrease reference count (number of pointers to pbuf) */
|
---|
| 652 | ref = --(p->ref);
|
---|
| 653 | SYS_ARCH_UNPROTECT(old_level);
|
---|
| 654 | /* this pbuf is no longer referenced to? */
|
---|
| 655 | if (ref == 0) {
|
---|
| 656 | /* remember next pbuf in chain for next iteration */
|
---|
| 657 | q = p->next;
|
---|
| 658 | LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free: deallocating %p\n", (void *)p));
|
---|
| 659 | type = p->type;
|
---|
| 660 | #if LWIP_SUPPORT_CUSTOM_PBUF
|
---|
| 661 | /* is this a custom pbuf? */
|
---|
| 662 | if ((p->flags & PBUF_FLAG_IS_CUSTOM) != 0) {
|
---|
| 663 | struct pbuf_custom *pc = (struct pbuf_custom*)p;
|
---|
| 664 | LWIP_ASSERT("pc->custom_free_function != NULL", pc->custom_free_function != NULL);
|
---|
| 665 | pc->custom_free_function(p);
|
---|
| 666 | } else
|
---|
| 667 | #endif /* LWIP_SUPPORT_CUSTOM_PBUF */
|
---|
| 668 | {
|
---|
| 669 | /* is this a pbuf from the pool? */
|
---|
| 670 | if (type == PBUF_POOL) {
|
---|
| 671 | memp_free(MEMP_PBUF_POOL, p);
|
---|
| 672 | /* is this a ROM or RAM referencing pbuf? */
|
---|
| 673 | } else if (type == PBUF_ROM || type == PBUF_REF) {
|
---|
| 674 | memp_free(MEMP_PBUF, p);
|
---|
| 675 | /* type == PBUF_RAM */
|
---|
| 676 | } else {
|
---|
| 677 | mem_free(p);
|
---|
| 678 | }
|
---|
| 679 | }
|
---|
| 680 | count++;
|
---|
| 681 | /* proceed to next pbuf */
|
---|
| 682 | p = q;
|
---|
| 683 | /* p->ref > 0, this pbuf is still referenced to */
|
---|
| 684 | /* (and so the remaining pbufs in chain as well) */
|
---|
| 685 | } else {
|
---|
| 686 | LWIP_DEBUGF( PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_free: %p has ref %"U16_F", ending here.\n", (void *)p, ref));
|
---|
| 687 | /* stop walking through the chain */
|
---|
| 688 | p = NULL;
|
---|
| 689 | }
|
---|
| 690 | }
|
---|
| 691 | PERF_STOP("pbuf_free");
|
---|
| 692 | /* return number of de-allocated pbufs */
|
---|
| 693 | return count;
|
---|
| 694 | }
|
---|
| 695 |
|
---|
| 696 | /**
|
---|
| 697 | * Count number of pbufs in a chain
|
---|
| 698 | *
|
---|
| 699 | * @param p first pbuf of chain
|
---|
| 700 | * @return the number of pbufs in a chain
|
---|
| 701 | */
|
---|
| 702 |
|
---|
| 703 | u8_t
|
---|
| 704 | pbuf_clen(struct pbuf *p)
|
---|
| 705 | {
|
---|
| 706 | u8_t len;
|
---|
| 707 |
|
---|
| 708 | len = 0;
|
---|
| 709 | while (p != NULL) {
|
---|
| 710 | ++len;
|
---|
| 711 | p = p->next;
|
---|
| 712 | }
|
---|
| 713 | return len;
|
---|
| 714 | }
|
---|
| 715 |
|
---|
| 716 | /**
|
---|
| 717 | * Increment the reference count of the pbuf.
|
---|
| 718 | *
|
---|
| 719 | * @param p pbuf to increase reference counter of
|
---|
| 720 | *
|
---|
| 721 | */
|
---|
| 722 | void
|
---|
| 723 | pbuf_ref(struct pbuf *p)
|
---|
| 724 | {
|
---|
| 725 | SYS_ARCH_DECL_PROTECT(old_level);
|
---|
| 726 | /* pbuf given? */
|
---|
| 727 | if (p != NULL) {
|
---|
| 728 | SYS_ARCH_PROTECT(old_level);
|
---|
| 729 | ++(p->ref);
|
---|
| 730 | SYS_ARCH_UNPROTECT(old_level);
|
---|
| 731 | }
|
---|
| 732 | }
|
---|
| 733 |
|
---|
| 734 | /**
|
---|
| 735 | * Concatenate two pbufs (each may be a pbuf chain) and take over
|
---|
| 736 | * the caller's reference of the tail pbuf.
|
---|
| 737 | *
|
---|
| 738 | * @note The caller MAY NOT reference the tail pbuf afterwards.
|
---|
| 739 | * Use pbuf_chain() for that purpose.
|
---|
| 740 | *
|
---|
| 741 | * @see pbuf_chain()
|
---|
| 742 | */
|
---|
| 743 |
|
---|
| 744 | void
|
---|
| 745 | pbuf_cat(struct pbuf *h, struct pbuf *t)
|
---|
| 746 | {
|
---|
| 747 | struct pbuf *p;
|
---|
| 748 |
|
---|
| 749 | LWIP_ERROR("(h != NULL) && (t != NULL) (programmer violates API)",
|
---|
| 750 | ((h != NULL) && (t != NULL)), return;);
|
---|
| 751 |
|
---|
| 752 | /* proceed to last pbuf of chain */
|
---|
| 753 | for (p = h; p->next != NULL; p = p->next) {
|
---|
| 754 | /* add total length of second chain to all totals of first chain */
|
---|
| 755 | p->tot_len += t->tot_len;
|
---|
| 756 | }
|
---|
| 757 | /* { p is last pbuf of first h chain, p->next == NULL } */
|
---|
| 758 | LWIP_ASSERT("p->tot_len == p->len (of last pbuf in chain)", p->tot_len == p->len);
|
---|
| 759 | LWIP_ASSERT("p->next == NULL", p->next == NULL);
|
---|
| 760 | /* add total length of second chain to last pbuf total of first chain */
|
---|
| 761 | p->tot_len += t->tot_len;
|
---|
| 762 | /* chain last pbuf of head (p) with first of tail (t) */
|
---|
| 763 | p->next = t;
|
---|
| 764 | /* p->next now references t, but the caller will drop its reference to t,
|
---|
| 765 | * so netto there is no change to the reference count of t.
|
---|
| 766 | */
|
---|
| 767 | }
|
---|
| 768 |
|
---|
| 769 | /**
|
---|
| 770 | * Chain two pbufs (or pbuf chains) together.
|
---|
| 771 | *
|
---|
| 772 | * The caller MUST call pbuf_free(t) once it has stopped
|
---|
| 773 | * using it. Use pbuf_cat() instead if you no longer use t.
|
---|
| 774 | *
|
---|
| 775 | * @param h head pbuf (chain)
|
---|
| 776 | * @param t tail pbuf (chain)
|
---|
| 777 | * @note The pbufs MUST belong to the same packet.
|
---|
| 778 | * @note MAY NOT be called on a packet queue.
|
---|
| 779 | *
|
---|
| 780 | * The ->tot_len fields of all pbufs of the head chain are adjusted.
|
---|
| 781 | * The ->next field of the last pbuf of the head chain is adjusted.
|
---|
| 782 | * The ->ref field of the first pbuf of the tail chain is adjusted.
|
---|
| 783 | *
|
---|
| 784 | */
|
---|
| 785 | void
|
---|
| 786 | pbuf_chain(struct pbuf *h, struct pbuf *t)
|
---|
| 787 | {
|
---|
| 788 | pbuf_cat(h, t);
|
---|
| 789 | /* t is now referenced by h */
|
---|
| 790 | pbuf_ref(t);
|
---|
| 791 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_chain: %p references %p\n", (void *)h, (void *)t));
|
---|
| 792 | }
|
---|
| 793 |
|
---|
| 794 | /**
|
---|
| 795 | * Dechains the first pbuf from its succeeding pbufs in the chain.
|
---|
| 796 | *
|
---|
| 797 | * Makes p->tot_len field equal to p->len.
|
---|
| 798 | * @param p pbuf to dechain
|
---|
| 799 | * @return remainder of the pbuf chain, or NULL if it was de-allocated.
|
---|
| 800 | * @note May not be called on a packet queue.
|
---|
| 801 | */
|
---|
| 802 | struct pbuf *
|
---|
| 803 | pbuf_dechain(struct pbuf *p)
|
---|
| 804 | {
|
---|
| 805 | struct pbuf *q;
|
---|
| 806 | u8_t tail_gone = 1;
|
---|
| 807 | /* tail */
|
---|
| 808 | q = p->next;
|
---|
| 809 | /* pbuf has successor in chain? */
|
---|
| 810 | if (q != NULL) {
|
---|
| 811 | /* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
|
---|
| 812 | LWIP_ASSERT("p->tot_len == p->len + q->tot_len", q->tot_len == p->tot_len - p->len);
|
---|
| 813 | /* enforce invariant if assertion is disabled */
|
---|
| 814 | q->tot_len = p->tot_len - p->len;
|
---|
| 815 | /* decouple pbuf from remainder */
|
---|
| 816 | p->next = NULL;
|
---|
| 817 | /* total length of pbuf p is its own length only */
|
---|
| 818 | p->tot_len = p->len;
|
---|
| 819 | /* q is no longer referenced by p, free it */
|
---|
| 820 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_dechain: unreferencing %p\n", (void *)q));
|
---|
| 821 | tail_gone = pbuf_free(q);
|
---|
| 822 | if (tail_gone > 0) {
|
---|
| 823 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE,
|
---|
| 824 | ("pbuf_dechain: deallocated %p (as it is no longer referenced)\n", (void *)q));
|
---|
| 825 | }
|
---|
| 826 | /* return remaining tail or NULL if deallocated */
|
---|
| 827 | }
|
---|
| 828 | /* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
|
---|
| 829 | LWIP_ASSERT("p->tot_len == p->len", p->tot_len == p->len);
|
---|
| 830 | return ((tail_gone > 0) ? NULL : q);
|
---|
| 831 | }
|
---|
| 832 |
|
---|
| 833 | /**
|
---|
| 834 | *
|
---|
| 835 | * Create PBUF_RAM copies of pbufs.
|
---|
| 836 | *
|
---|
| 837 | * Used to queue packets on behalf of the lwIP stack, such as
|
---|
| 838 | * ARP based queueing.
|
---|
| 839 | *
|
---|
| 840 | * @note You MUST explicitly use p = pbuf_take(p);
|
---|
| 841 | *
|
---|
| 842 | * @note Only one packet is copied, no packet queue!
|
---|
| 843 | *
|
---|
| 844 | * @param p_to pbuf destination of the copy
|
---|
| 845 | * @param p_from pbuf source of the copy
|
---|
| 846 | *
|
---|
| 847 | * @return ERR_OK if pbuf was copied
|
---|
| 848 | * ERR_ARG if one of the pbufs is NULL or p_to is not big
|
---|
| 849 | * enough to hold p_from
|
---|
| 850 | */
|
---|
| 851 | err_t
|
---|
| 852 | pbuf_copy(struct pbuf *p_to, struct pbuf *p_from)
|
---|
| 853 | {
|
---|
| 854 | u16_t offset_to=0, offset_from=0, len;
|
---|
| 855 |
|
---|
| 856 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy(%p, %p)\n",
|
---|
| 857 | (void*)p_to, (void*)p_from));
|
---|
| 858 |
|
---|
| 859 | /* is the target big enough to hold the source? */
|
---|
| 860 | LWIP_ERROR("pbuf_copy: target not big enough to hold source", ((p_to != NULL) &&
|
---|
| 861 | (p_from != NULL) && (p_to->tot_len >= p_from->tot_len)), return ERR_ARG;);
|
---|
| 862 |
|
---|
| 863 | /* iterate through pbuf chain */
|
---|
| 864 | do
|
---|
| 865 | {
|
---|
| 866 | /* copy one part of the original chain */
|
---|
| 867 | if ((p_to->len - offset_to) >= (p_from->len - offset_from)) {
|
---|
| 868 | /* complete current p_from fits into current p_to */
|
---|
| 869 | len = p_from->len - offset_from;
|
---|
| 870 | } else {
|
---|
| 871 | /* current p_from does not fit into current p_to */
|
---|
| 872 | len = p_to->len - offset_to;
|
---|
| 873 | }
|
---|
| 874 | MEMCPY((u8_t*)p_to->payload + offset_to, (u8_t*)p_from->payload + offset_from, len);
|
---|
| 875 | offset_to += len;
|
---|
| 876 | offset_from += len;
|
---|
| 877 | LWIP_ASSERT("offset_to <= p_to->len", offset_to <= p_to->len);
|
---|
| 878 | LWIP_ASSERT("offset_from <= p_from->len", offset_from <= p_from->len);
|
---|
| 879 | if (offset_from >= p_from->len) {
|
---|
| 880 | /* on to next p_from (if any) */
|
---|
| 881 | offset_from = 0;
|
---|
| 882 | p_from = p_from->next;
|
---|
| 883 | }
|
---|
| 884 | if (offset_to == p_to->len) {
|
---|
| 885 | /* on to next p_to (if any) */
|
---|
| 886 | offset_to = 0;
|
---|
| 887 | p_to = p_to->next;
|
---|
| 888 | LWIP_ERROR("p_to != NULL", (p_to != NULL) || (p_from == NULL) , return ERR_ARG;);
|
---|
| 889 | }
|
---|
| 890 |
|
---|
| 891 | if((p_from != NULL) && (p_from->len == p_from->tot_len)) {
|
---|
| 892 | /* don't copy more than one packet! */
|
---|
| 893 | LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
|
---|
| 894 | (p_from->next == NULL), return ERR_VAL;);
|
---|
| 895 | }
|
---|
| 896 | if((p_to != NULL) && (p_to->len == p_to->tot_len)) {
|
---|
| 897 | /* don't copy more than one packet! */
|
---|
| 898 | LWIP_ERROR("pbuf_copy() does not allow packet queues!\n",
|
---|
| 899 | (p_to->next == NULL), return ERR_VAL;);
|
---|
| 900 | }
|
---|
| 901 | } while (p_from);
|
---|
| 902 | LWIP_DEBUGF(PBUF_DEBUG | LWIP_DBG_TRACE, ("pbuf_copy: end of chain reached.\n"));
|
---|
| 903 | return ERR_OK;
|
---|
| 904 | }
|
---|
| 905 |
|
---|
| 906 | /**
|
---|
| 907 | * Copy (part of) the contents of a packet buffer
|
---|
| 908 | * to an application supplied buffer.
|
---|
| 909 | *
|
---|
| 910 | * @param buf the pbuf from which to copy data
|
---|
| 911 | * @param dataptr the application supplied buffer
|
---|
| 912 | * @param len length of data to copy (dataptr must be big enough). No more
|
---|
| 913 | * than buf->tot_len will be copied, irrespective of len
|
---|
| 914 | * @param offset offset into the packet buffer from where to begin copying len bytes
|
---|
| 915 | * @return the number of bytes copied, or 0 on failure
|
---|
| 916 | */
|
---|
| 917 | u16_t
|
---|
| 918 | pbuf_copy_partial(struct pbuf *buf, void *dataptr, u16_t len, u16_t offset)
|
---|
| 919 | {
|
---|
| 920 | struct pbuf *p;
|
---|
| 921 | u16_t left;
|
---|
| 922 | u16_t buf_copy_len;
|
---|
| 923 | u16_t copied_total = 0;
|
---|
| 924 |
|
---|
| 925 | LWIP_ERROR("pbuf_copy_partial: invalid buf", (buf != NULL), return 0;);
|
---|
| 926 | LWIP_ERROR("pbuf_copy_partial: invalid dataptr", (dataptr != NULL), return 0;);
|
---|
| 927 |
|
---|
| 928 | left = 0;
|
---|
| 929 |
|
---|
| 930 | if((buf == NULL) || (dataptr == NULL)) {
|
---|
| 931 | return 0;
|
---|
| 932 | }
|
---|
| 933 |
|
---|
| 934 | /* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
|
---|
| 935 | for(p = buf; len != 0 && p != NULL; p = p->next) {
|
---|
| 936 | if ((offset != 0) && (offset >= p->len)) {
|
---|
| 937 | /* don't copy from this buffer -> on to the next */
|
---|
| 938 | offset -= p->len;
|
---|
| 939 | } else {
|
---|
| 940 | /* copy from this buffer. maybe only partially. */
|
---|
| 941 | buf_copy_len = p->len - offset;
|
---|
| 942 | if (buf_copy_len > len)
|
---|
| 943 | buf_copy_len = len;
|
---|
| 944 | /* copy the necessary parts of the buffer */
|
---|
| 945 | MEMCPY(&((char*)dataptr)[left], &((char*)p->payload)[offset], buf_copy_len);
|
---|
| 946 | copied_total += buf_copy_len;
|
---|
| 947 | left += buf_copy_len;
|
---|
| 948 | len -= buf_copy_len;
|
---|
| 949 | offset = 0;
|
---|
| 950 | }
|
---|
| 951 | }
|
---|
| 952 | return copied_total;
|
---|
| 953 | }
|
---|
| 954 |
|
---|
| 955 | /**
|
---|
| 956 | * Copy application supplied data into a pbuf.
|
---|
| 957 | * This function can only be used to copy the equivalent of buf->tot_len data.
|
---|
| 958 | *
|
---|
| 959 | * @param buf pbuf to fill with data
|
---|
| 960 | * @param dataptr application supplied data buffer
|
---|
| 961 | * @param len length of the application supplied data buffer
|
---|
| 962 | *
|
---|
| 963 | * @return ERR_OK if successful, ERR_MEM if the pbuf is not big enough
|
---|
| 964 | */
|
---|
| 965 | err_t
|
---|
| 966 | pbuf_take(struct pbuf *buf, const void *dataptr, u16_t len)
|
---|
| 967 | {
|
---|
| 968 | struct pbuf *p;
|
---|
| 969 | u16_t buf_copy_len;
|
---|
| 970 | u16_t total_copy_len = len;
|
---|
| 971 | u16_t copied_total = 0;
|
---|
| 972 |
|
---|
| 973 | LWIP_ERROR("pbuf_take: invalid buf", (buf != NULL), return 0;);
|
---|
| 974 | LWIP_ERROR("pbuf_take: invalid dataptr", (dataptr != NULL), return 0;);
|
---|
| 975 |
|
---|
| 976 | if ((buf == NULL) || (dataptr == NULL) || (buf->tot_len < len)) {
|
---|
| 977 | return ERR_ARG;
|
---|
| 978 | }
|
---|
| 979 |
|
---|
| 980 | /* Note some systems use byte copy if dataptr or one of the pbuf payload pointers are unaligned. */
|
---|
| 981 | for(p = buf; total_copy_len != 0; p = p->next) {
|
---|
| 982 | LWIP_ASSERT("pbuf_take: invalid pbuf", p != NULL);
|
---|
| 983 | buf_copy_len = total_copy_len;
|
---|
| 984 | if (buf_copy_len > p->len) {
|
---|
| 985 | /* this pbuf cannot hold all remaining data */
|
---|
| 986 | buf_copy_len = p->len;
|
---|
| 987 | }
|
---|
| 988 | /* copy the necessary parts of the buffer */
|
---|
| 989 | MEMCPY(p->payload, &((char*)dataptr)[copied_total], buf_copy_len);
|
---|
| 990 | total_copy_len -= buf_copy_len;
|
---|
| 991 | copied_total += buf_copy_len;
|
---|
| 992 | }
|
---|
| 993 | LWIP_ASSERT("did not copy all data", total_copy_len == 0 && copied_total == len);
|
---|
| 994 | return ERR_OK;
|
---|
| 995 | }
|
---|
| 996 |
|
---|
| 997 | /**
|
---|
| 998 | * Creates a single pbuf out of a queue of pbufs.
|
---|
| 999 | *
|
---|
| 1000 | * @remark: Either the source pbuf 'p' is freed by this function or the original
|
---|
| 1001 | * pbuf 'p' is returned, therefore the caller has to check the result!
|
---|
| 1002 | *
|
---|
| 1003 | * @param p the source pbuf
|
---|
| 1004 | * @param layer pbuf_layer of the new pbuf
|
---|
| 1005 | *
|
---|
| 1006 | * @return a new, single pbuf (p->next is NULL)
|
---|
| 1007 | * or the old pbuf if allocation fails
|
---|
| 1008 | */
|
---|
| 1009 | struct pbuf*
|
---|
| 1010 | pbuf_coalesce(struct pbuf *p, pbuf_layer layer)
|
---|
| 1011 | {
|
---|
| 1012 | struct pbuf *q;
|
---|
| 1013 | err_t err;
|
---|
| 1014 | if (p->next == NULL) {
|
---|
| 1015 | return p;
|
---|
| 1016 | }
|
---|
| 1017 | q = pbuf_alloc(layer, p->tot_len, PBUF_RAM);
|
---|
| 1018 | if (q == NULL) {
|
---|
| 1019 | /* @todo: what do we do now? */
|
---|
| 1020 | return p;
|
---|
| 1021 | }
|
---|
| 1022 | err = pbuf_copy(q, p);
|
---|
| 1023 | LWIP_ASSERT("pbuf_copy failed", err == ERR_OK);
|
---|
| 1024 | pbuf_free(p);
|
---|
| 1025 | return q;
|
---|
| 1026 | }
|
---|
| 1027 |
|
---|
| 1028 | #if LWIP_CHECKSUM_ON_COPY
|
---|
| 1029 | /**
|
---|
| 1030 | * Copies data into a single pbuf (*not* into a pbuf queue!) and updates
|
---|
| 1031 | * the checksum while copying
|
---|
| 1032 | *
|
---|
| 1033 | * @param p the pbuf to copy data into
|
---|
| 1034 | * @param start_offset offset of p->payload where to copy the data to
|
---|
| 1035 | * @param dataptr data to copy into the pbuf
|
---|
| 1036 | * @param len length of data to copy into the pbuf
|
---|
| 1037 | * @param chksum pointer to the checksum which is updated
|
---|
| 1038 | * @return ERR_OK if successful, another error if the data does not fit
|
---|
| 1039 | * within the (first) pbuf (no pbuf queues!)
|
---|
| 1040 | */
|
---|
| 1041 | err_t
|
---|
| 1042 | pbuf_fill_chksum(struct pbuf *p, u16_t start_offset, const void *dataptr,
|
---|
| 1043 | u16_t len, u16_t *chksum)
|
---|
| 1044 | {
|
---|
| 1045 | u32_t acc;
|
---|
| 1046 | u16_t copy_chksum;
|
---|
| 1047 | char *dst_ptr;
|
---|
| 1048 | LWIP_ASSERT("p != NULL", p != NULL);
|
---|
| 1049 | LWIP_ASSERT("dataptr != NULL", dataptr != NULL);
|
---|
| 1050 | LWIP_ASSERT("chksum != NULL", chksum != NULL);
|
---|
| 1051 | LWIP_ASSERT("len != 0", len != 0);
|
---|
| 1052 |
|
---|
| 1053 | if ((start_offset >= p->len) || (start_offset + len > p->len)) {
|
---|
| 1054 | return ERR_ARG;
|
---|
| 1055 | }
|
---|
| 1056 |
|
---|
| 1057 | dst_ptr = ((char*)p->payload) + start_offset;
|
---|
| 1058 | copy_chksum = LWIP_CHKSUM_COPY(dst_ptr, dataptr, len);
|
---|
| 1059 | if ((start_offset & 1) != 0) {
|
---|
| 1060 | copy_chksum = SWAP_BYTES_IN_WORD(copy_chksum);
|
---|
| 1061 | }
|
---|
| 1062 | acc = *chksum;
|
---|
| 1063 | acc += copy_chksum;
|
---|
| 1064 | *chksum = FOLD_U32T(acc);
|
---|
| 1065 | return ERR_OK;
|
---|
| 1066 | }
|
---|
| 1067 | #endif /* LWIP_CHECKSUM_ON_COPY */
|
---|
| 1068 |
|
---|
| 1069 | /** Get one byte from the specified position in a pbuf
|
---|
| 1070 | * WARNING: returns zero for offset >= p->tot_len
|
---|
| 1071 | *
|
---|
| 1072 | * @param p pbuf to parse
|
---|
| 1073 | * @param offset offset into p of the byte to return
|
---|
| 1074 | * @return byte at an offset into p OR ZERO IF 'offset' >= p->tot_len
|
---|
| 1075 | */
|
---|
| 1076 | u8_t
|
---|
| 1077 | pbuf_get_at(struct pbuf* p, u16_t offset)
|
---|
| 1078 | {
|
---|
| 1079 | u16_t copy_from = offset;
|
---|
| 1080 | struct pbuf* q = p;
|
---|
| 1081 |
|
---|
| 1082 | /* get the correct pbuf */
|
---|
| 1083 | while ((q != NULL) && (q->len <= copy_from)) {
|
---|
| 1084 | copy_from -= q->len;
|
---|
| 1085 | q = q->next;
|
---|
| 1086 | }
|
---|
| 1087 | /* return requested data if pbuf is OK */
|
---|
| 1088 | if ((q != NULL) && (q->len > copy_from)) {
|
---|
| 1089 | return ((u8_t*)q->payload)[copy_from];
|
---|
| 1090 | }
|
---|
| 1091 | return 0;
|
---|
| 1092 | }
|
---|
| 1093 |
|
---|
| 1094 | /** Compare pbuf contents at specified offset with memory s2, both of length n
|
---|
| 1095 | *
|
---|
| 1096 | * @param p pbuf to compare
|
---|
| 1097 | * @param offset offset into p at wich to start comparing
|
---|
| 1098 | * @param s2 buffer to compare
|
---|
| 1099 | * @param n length of buffer to compare
|
---|
| 1100 | * @return zero if equal, nonzero otherwise
|
---|
| 1101 | * (0xffff if p is too short, diffoffset+1 otherwise)
|
---|
| 1102 | */
|
---|
| 1103 | u16_t
|
---|
| 1104 | pbuf_memcmp(struct pbuf* p, u16_t offset, const void* s2, u16_t n)
|
---|
| 1105 | {
|
---|
| 1106 | u16_t start = offset;
|
---|
| 1107 | struct pbuf* q = p;
|
---|
| 1108 |
|
---|
| 1109 | /* get the correct pbuf */
|
---|
| 1110 | while ((q != NULL) && (q->len <= start)) {
|
---|
| 1111 | start -= q->len;
|
---|
| 1112 | q = q->next;
|
---|
| 1113 | }
|
---|
| 1114 | /* return requested data if pbuf is OK */
|
---|
| 1115 | if ((q != NULL) && (q->len > start)) {
|
---|
| 1116 | u16_t i;
|
---|
| 1117 | for(i = 0; i < n; i++) {
|
---|
| 1118 | u8_t a = pbuf_get_at(q, start + i);
|
---|
| 1119 | u8_t b = ((u8_t*)s2)[i];
|
---|
| 1120 | if (a != b) {
|
---|
| 1121 | return i+1;
|
---|
| 1122 | }
|
---|
| 1123 | }
|
---|
| 1124 | return 0;
|
---|
| 1125 | }
|
---|
| 1126 | return 0xffff;
|
---|
| 1127 | }
|
---|
| 1128 |
|
---|
| 1129 | /** Find occurrence of mem (with length mem_len) in pbuf p, starting at offset
|
---|
| 1130 | * start_offset.
|
---|
| 1131 | *
|
---|
| 1132 | * @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as
|
---|
| 1133 | * return value 'not found'
|
---|
| 1134 | * @param mem search for the contents of this buffer
|
---|
| 1135 | * @param mem_len length of 'mem'
|
---|
| 1136 | * @param start_offset offset into p at which to start searching
|
---|
| 1137 | * @return 0xFFFF if substr was not found in p or the index where it was found
|
---|
| 1138 | */
|
---|
| 1139 | u16_t
|
---|
| 1140 | pbuf_memfind(struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset)
|
---|
| 1141 | {
|
---|
| 1142 | u16_t i;
|
---|
| 1143 | u16_t max = p->tot_len - mem_len;
|
---|
| 1144 | if (p->tot_len >= mem_len + start_offset) {
|
---|
| 1145 | for(i = start_offset; i <= max; ) {
|
---|
| 1146 | u16_t plus = pbuf_memcmp(p, i, mem, mem_len);
|
---|
| 1147 | if (plus == 0) {
|
---|
| 1148 | return i;
|
---|
| 1149 | } else {
|
---|
| 1150 | i += plus;
|
---|
| 1151 | }
|
---|
| 1152 | }
|
---|
| 1153 | }
|
---|
| 1154 | return 0xFFFF;
|
---|
| 1155 | }
|
---|
| 1156 |
|
---|
| 1157 | /** Find occurrence of substr with length substr_len in pbuf p, start at offset
|
---|
| 1158 | * start_offset
|
---|
| 1159 | * WARNING: in contrast to strstr(), this one does not stop at the first \0 in
|
---|
| 1160 | * the pbuf/source string!
|
---|
| 1161 | *
|
---|
| 1162 | * @param p pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as
|
---|
| 1163 | * return value 'not found'
|
---|
| 1164 | * @param substr string to search for in p, maximum length is 0xFFFE
|
---|
| 1165 | * @return 0xFFFF if substr was not found in p or the index where it was found
|
---|
| 1166 | */
|
---|
| 1167 | u16_t
|
---|
| 1168 | pbuf_strstr(struct pbuf* p, const char* substr)
|
---|
| 1169 | {
|
---|
| 1170 | size_t substr_len;
|
---|
| 1171 | if ((substr == NULL) || (substr[0] == 0) || (p->tot_len == 0xFFFF)) {
|
---|
| 1172 | return 0xFFFF;
|
---|
| 1173 | }
|
---|
| 1174 | substr_len = strlen(substr);
|
---|
| 1175 | if (substr_len >= 0xFFFF) {
|
---|
| 1176 | return 0xFFFF;
|
---|
| 1177 | }
|
---|
| 1178 | return pbuf_memfind(p, substr, (u16_t)substr_len, 0);
|
---|
| 1179 | }
|
---|