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Diffstat (limited to 'lwip/src/include/lwip/pbuf.h')
| -rw-r--r-- | lwip/src/include/lwip/pbuf.h | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/lwip/src/include/lwip/pbuf.h b/lwip/src/include/lwip/pbuf.h new file mode 100644 index 0000000..82902a4 --- /dev/null +++ b/lwip/src/include/lwip/pbuf.h @@ -0,0 +1,322 @@ +/** + * @file + * pbuf API + */ + +/* + * 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 + +/** LWIP_SUPPORT_CUSTOM_PBUF==1: Custom pbufs behave much like their pbuf type + * but they are allocated by external code (initialised by calling + * pbuf_alloced_custom()) and when pbuf_free gives up their last reference, they + * are freed by calling pbuf_custom->custom_free_function(). + * Currently, the pbuf_custom code is only needed for one specific configuration + * of IP_FRAG, unless required by external driver/application code. */ +#ifndef LWIP_SUPPORT_CUSTOM_PBUF +#define LWIP_SUPPORT_CUSTOM_PBUF ((IP_FRAG && !LWIP_NETIF_TX_SINGLE_PBUF) || (LWIP_IPV6 && LWIP_IPV6_FRAG)) +#endif + +/** @ingroup pbuf + * PBUF_NEEDS_COPY(p): return a boolean value indicating whether the given + * pbuf needs to be copied in order to be kept around beyond the current call + * stack without risking being corrupted. The default setting provides safety: + * it will make a copy iof any pbuf chain that does not consist entirely of + * PBUF_ROM type pbufs. For setups with zero-copy support, it may be redefined + * to evaluate to true in all cases, for example. However, doing so also has an + * effect on the application side: any buffers that are *not* copied must also + * *not* be reused by the application after passing them to lwIP. For example, + * when setting PBUF_NEEDS_COPY to (0), after using udp_send() with a PBUF_RAM + * pbuf, the application must free the pbuf immediately, rather than reusing it + * for other purposes. For more background information on this, see tasks #6735 + * and #7896, and bugs #11400 and #49914. */ +#ifndef PBUF_NEEDS_COPY +#define PBUF_NEEDS_COPY(p) ((p)->type_internal & PBUF_TYPE_FLAG_DATA_VOLATILE) +#endif /* PBUF_NEEDS_COPY */ + +/* @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 + +/** + * @ingroup pbuf + * Enumeration of pbuf layers + */ +typedef enum { + /** Includes spare room for transport layer header, e.g. UDP header. + * Use this if you intend to pass the pbuf to functions like udp_send(). + */ + PBUF_TRANSPORT = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN + PBUF_IP_HLEN + PBUF_TRANSPORT_HLEN, + /** Includes spare room for IP header. + * Use this if you intend to pass the pbuf to functions like raw_send(). + */ + PBUF_IP = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN + PBUF_IP_HLEN, + /** Includes spare room for link layer header (ethernet header). + * Use this if you intend to pass the pbuf to functions like ethernet_output(). + * @see PBUF_LINK_HLEN + */ + PBUF_LINK = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN, + /** Includes spare room for additional encapsulation header before ethernet + * headers (e.g. 802.11). + * Use this if you intend to pass the pbuf to functions like netif->linkoutput(). + * @see PBUF_LINK_ENCAPSULATION_HLEN + */ + PBUF_RAW_TX = PBUF_LINK_ENCAPSULATION_HLEN, + /** Use this for input packets in a netif driver when calling netif->input() + * in the most common case - ethernet-layer netif driver. */ + PBUF_RAW = 0 +} pbuf_layer; + + +/* Base flags for pbuf_type definitions: */ + +/** Indicates that the payload directly follows the struct pbuf. + * This makes @ref pbuf_header work in both directions. */ +#define PBUF_TYPE_FLAG_STRUCT_DATA_CONTIGUOUS 0x80 +/** Indicates the data stored in this pbuf can change. If this pbuf needs + * to be queued, it must be copied/duplicated. */ +#define PBUF_TYPE_FLAG_DATA_VOLATILE 0x40 +/** 4 bits are reserved for 16 allocation sources (e.g. heap, pool1, pool2, etc) + * Internally, we use: 0=heap, 1=MEMP_PBUF, 2=MEMP_PBUF_POOL -> 13 types free*/ +#define PBUF_TYPE_ALLOC_SRC_MASK 0x0F +/** Indicates this pbuf is used for RX (if not set, indicates use for TX). + * This information can be used to keep some spare RX buffers e.g. for + * receiving TCP ACKs to unblock a connection) */ +#define PBUF_ALLOC_FLAG_RX 0x0100 +/** Indicates the application needs the pbuf payload to be in one piece */ +#define PBUF_ALLOC_FLAG_DATA_CONTIGUOUS 0x0200 + +#define PBUF_TYPE_ALLOC_SRC_MASK_STD_HEAP 0x00 +#define PBUF_TYPE_ALLOC_SRC_MASK_STD_MEMP_PBUF 0x01 +#define PBUF_TYPE_ALLOC_SRC_MASK_STD_MEMP_PBUF_POOL 0x02 +/** First pbuf allocation type for applications */ +#define PBUF_TYPE_ALLOC_SRC_MASK_APP_MIN 0x03 +/** Last pbuf allocation type for applications */ +#define PBUF_TYPE_ALLOC_SRC_MASK_APP_MAX PBUF_TYPE_ALLOC_SRC_MASK + +/** + * @ingroup pbuf + * Enumeration of pbuf types + */ +typedef enum { + /** pbuf data is stored in RAM, used for TX mostly, struct pbuf and its payload + are allocated in one piece of contiguous memory (so the first payload byte + can be calculated from struct pbuf). + pbuf_alloc() allocates PBUF_RAM pbufs as unchained pbufs (although that might + change in future versions). + This should be used for all OUTGOING packets (TX).*/ + PBUF_RAM = (PBUF_ALLOC_FLAG_DATA_CONTIGUOUS | PBUF_TYPE_FLAG_STRUCT_DATA_CONTIGUOUS | PBUF_TYPE_ALLOC_SRC_MASK_STD_HEAP), + /** pbuf data is stored in ROM, i.e. struct pbuf and its payload are located in + totally different memory areas. Since it points to ROM, payload does not + have to be copied when queued for transmission. */ + PBUF_ROM = PBUF_TYPE_ALLOC_SRC_MASK_STD_MEMP_PBUF, + /** pbuf comes from the pbuf pool. Much like PBUF_ROM but payload might change + so it has to be duplicated when queued before transmitting, depending on + who has a 'ref' to it. */ + PBUF_REF = (PBUF_TYPE_FLAG_DATA_VOLATILE | PBUF_TYPE_ALLOC_SRC_MASK_STD_MEMP_PBUF), + /** pbuf payload refers to RAM. This one comes from a pool and should be used + for RX. Payload can be chained (scatter-gather RX) but like PBUF_RAM, struct + pbuf and its payload are allocated in one piece of contiguous memory (so + the first payload byte can be calculated from struct pbuf). + Don't use this for TX, if the pool becomes empty e.g. because of TCP queuing, + you are unable to receive TCP acks! */ + PBUF_POOL = (PBUF_ALLOC_FLAG_RX | PBUF_TYPE_FLAG_STRUCT_DATA_CONTIGUOUS | PBUF_TYPE_ALLOC_SRC_MASK_STD_MEMP_PBUF_POOL) +} pbuf_type; + + +/** indicates this packet's data should be immediately passed to the application */ +#define PBUF_FLAG_PUSH 0x01U +/** indicates this is a custom pbuf: pbuf_free calls pbuf_custom->custom_free_function() + when the last reference is released (plus custom PBUF_RAM cannot be trimmed) */ +#define PBUF_FLAG_IS_CUSTOM 0x02U +/** indicates this pbuf is UDP multicast to be looped back */ +#define PBUF_FLAG_MCASTLOOP 0x04U +/** indicates this pbuf was received as link-level broadcast */ +#define PBUF_FLAG_LLBCAST 0x08U +/** indicates this pbuf was received as link-level multicast */ +#define PBUF_FLAG_LLMCAST 0x10U +/** indicates this pbuf includes a TCP FIN flag */ +#define PBUF_FLAG_TCP_FIN 0x20U + +/** Main packet buffer struct */ +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; + + /** a bit field indicating pbuf type and allocation sources + (see PBUF_TYPE_FLAG_*, PBUF_ALLOC_FLAG_* and PBUF_TYPE_ALLOC_SRC_MASK) + */ + u8_t type_internal; + + /** 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. + */ + LWIP_PBUF_REF_T ref; + + /** For incoming packets, this contains the input netif's index */ + u8_t if_idx; +}; + + +/** Helper struct for const-correctness only. + * The only meaning of this one is to provide a const payload pointer + * for PBUF_ROM type. + */ +struct pbuf_rom { + /** next pbuf in singly linked pbuf chain */ + struct pbuf *next; + + /** pointer to the actual data in the buffer */ + const void *payload; +}; + +#if LWIP_SUPPORT_CUSTOM_PBUF +/** Prototype for a function to free a custom pbuf */ +typedef void (*pbuf_free_custom_fn)(struct pbuf *p); + +/** A custom pbuf: like a pbuf, but following a function pointer to free it. */ +struct pbuf_custom { + /** The actual pbuf */ + struct pbuf pbuf; + /** This function is called when pbuf_free deallocates this pbuf(_custom) */ + pbuf_free_custom_fn custom_free_function; +}; +#endif /* LWIP_SUPPORT_CUSTOM_PBUF */ + +/** Define this to 0 to prevent freeing ooseq pbufs when the PBUF_POOL is empty */ +#ifndef PBUF_POOL_FREE_OOSEQ +#define PBUF_POOL_FREE_OOSEQ 1 +#endif /* PBUF_POOL_FREE_OOSEQ */ +#if LWIP_TCP && TCP_QUEUE_OOSEQ && NO_SYS && PBUF_POOL_FREE_OOSEQ +extern volatile u8_t pbuf_free_ooseq_pending; +void pbuf_free_ooseq(void); +/** When not using sys_check_timeouts(), call PBUF_CHECK_FREE_OOSEQ() + at regular intervals from main level to check if ooseq pbufs need to be + freed! */ +#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) +#else /* LWIP_TCP && TCP_QUEUE_OOSEQ && NO_SYS && PBUF_POOL_FREE_OOSEQ */ + /* Otherwise declare an empty PBUF_CHECK_FREE_OOSEQ */ + #define PBUF_CHECK_FREE_OOSEQ() +#endif /* LWIP_TCP && TCP_QUEUE_OOSEQ && NO_SYS && PBUF_POOL_FREE_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); +struct pbuf *pbuf_alloc_reference(void *payload, 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); +#define pbuf_get_allocsrc(p) ((p)->type_internal & PBUF_TYPE_ALLOC_SRC_MASK) +#define pbuf_match_allocsrc(p, type) (pbuf_get_allocsrc(p) == ((type) & PBUF_TYPE_ALLOC_SRC_MASK)) +#define pbuf_match_type(p, type) pbuf_match_allocsrc(p, type) +u8_t pbuf_header(struct pbuf *p, s16_t header_size); +u8_t pbuf_header_force(struct pbuf *p, s16_t header_size); +u8_t pbuf_add_header(struct pbuf *p, size_t header_size_increment); +u8_t pbuf_add_header_force(struct pbuf *p, size_t header_size_increment); +u8_t pbuf_remove_header(struct pbuf *p, size_t header_size); +struct pbuf *pbuf_free_header(struct pbuf *q, u16_t size); +void pbuf_ref(struct pbuf *p); +u8_t pbuf_free(struct pbuf *p); +u16_t pbuf_clen(const 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, const struct pbuf *p_from); +u16_t pbuf_copy_partial(const struct pbuf *p, void *dataptr, u16_t len, u16_t offset); +void *pbuf_get_contiguous(const struct pbuf *p, void *buffer, size_t bufsize, 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); +struct pbuf *pbuf_clone(pbuf_layer l, pbuf_type type, struct pbuf *p); +#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(const struct pbuf* p, u16_t offset); +int pbuf_try_get_at(const struct pbuf* p, u16_t offset); +void pbuf_put_at(struct pbuf* p, u16_t offset, u8_t data); +u16_t pbuf_memcmp(const struct pbuf* p, u16_t offset, const void* s2, u16_t n); +u16_t pbuf_memfind(const struct pbuf* p, const void* mem, u16_t mem_len, u16_t start_offset); +u16_t pbuf_strstr(const struct pbuf* p, const char* substr); + +#ifdef __cplusplus +} +#endif + +#endif /* LWIP_HDR_PBUF_H */ |