ref: 0.13.0
src/libs/mynewt-nimble/porting/nimble/include/os/os_mbuf.h
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/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ /** * @addtogroup OSKernel * @{ * @defgroup OSMbuf Chained Memory Buffers * @{ */ #ifndef _OS_MBUF_H #define _OS_MBUF_H #include "os/os.h" #ifdef __cplusplus extern "C" { #endif /** * A mbuf pool from which to allocate mbufs. This contains a pointer to the os * mempool to allocate mbufs out of, the total number of elements in the pool, * and the amount of "user" data in a non-packet header mbuf. The total pool * size, in bytes, should be: * os_mbuf_count * (omp_databuf_len + sizeof(struct os_mbuf)) */ struct os_mbuf_pool { /** * Total length of the databuf in each mbuf. This is the size of the * mempool block, minus the mbuf header */ uint16_t omp_databuf_len; /** * The memory pool which to allocate mbufs out of */ struct os_mempool *omp_pool; STAILQ_ENTRY(os_mbuf_pool) omp_next; }; /** * A packet header structure that preceeds the mbuf packet headers. */ struct os_mbuf_pkthdr { /** * Overall length of the packet. */ uint16_t omp_len; /** * Flags */ uint16_t omp_flags; STAILQ_ENTRY(os_mbuf_pkthdr) omp_next; }; /** * Chained memory buffer. */ struct os_mbuf { /** * Current pointer to data in the structure */ uint8_t *om_data; /** * Flags associated with this buffer, see OS_MBUF_F_* defintions */ uint8_t om_flags; /** * Length of packet header */ uint8_t om_pkthdr_len; /** * Length of data in this buffer */ uint16_t om_len; /** * The mbuf pool this mbuf was allocated out of */ struct os_mbuf_pool *om_omp; SLIST_ENTRY(os_mbuf) om_next; /** * Pointer to the beginning of the data, after this buffer */ uint8_t om_databuf[0]; }; /** * Structure representing a queue of mbufs. */ struct os_mqueue { STAILQ_HEAD(, os_mbuf_pkthdr) mq_head; /** Event to post when new buffers are available on the queue. */ struct ble_npl_event mq_ev; }; /* * Given a flag number, provide the mask for it * * @param __n The number of the flag in the mask */ #define OS_MBUF_F_MASK(__n) (1 << (__n)) /* * Checks whether a given mbuf is a packet header mbuf * * @param __om The mbuf to check */ #define OS_MBUF_IS_PKTHDR(__om) \ ((__om)->om_pkthdr_len >= sizeof (struct os_mbuf_pkthdr)) /** Get a packet header pointer given an mbuf pointer */ #define OS_MBUF_PKTHDR(__om) ((struct os_mbuf_pkthdr *) \ ((uint8_t *)&(__om)->om_data + sizeof(struct os_mbuf))) /** Given a mbuf packet header pointer, return a pointer to the mbuf */ #define OS_MBUF_PKTHDR_TO_MBUF(__hdr) \ (struct os_mbuf *)((uint8_t *)(__hdr) - sizeof(struct os_mbuf)) /** * Gets the length of an entire mbuf chain. The specified mbuf must have a * packet header. */ #define OS_MBUF_PKTLEN(__om) (OS_MBUF_PKTHDR(__om)->omp_len) /** * Access the data of a mbuf, and cast it to type * * @param __om The mbuf to access, and cast * @param __type The type to cast it to */ #define OS_MBUF_DATA(__om, __type) \ (__type) ((__om)->om_data) /** * Access the "user header" in the head of an mbuf chain. * * @param om Pointer to the head of an mbuf chain. */ #define OS_MBUF_USRHDR(om) \ (void *)((uint8_t *)om + sizeof (struct os_mbuf) + \ sizeof (struct os_mbuf_pkthdr)) /** * Retrieves the length of the user header in an mbuf. * * @param om Pointer to the mbuf to query. */ #define OS_MBUF_USRHDR_LEN(om) \ ((om)->om_pkthdr_len - sizeof (struct os_mbuf_pkthdr)) /** @cond INTERNAL_HIDDEN */ /* * Called by OS_MBUF_LEADINGSPACE() macro */ static inline uint16_t _os_mbuf_leadingspace(struct os_mbuf *om) { uint16_t startoff; uint16_t leadingspace; startoff = 0; if (OS_MBUF_IS_PKTHDR(om)) { startoff = om->om_pkthdr_len; } leadingspace = (uint16_t) (OS_MBUF_DATA(om, uint8_t *) - ((uint8_t *) &om->om_databuf[0] + startoff)); return (leadingspace); } /** @endcond */ /** * Returns the leading space (space at the beginning) of the mbuf. * Works on both packet header, and regular mbufs, as it accounts * for the additional space allocated to the packet header. * * @param __omp Is the mbuf pool (which contains packet header length.) * @param __om Is the mbuf in that pool to get the leadingspace for * * @return Amount of leading space available in the mbuf */ #define OS_MBUF_LEADINGSPACE(__om) _os_mbuf_leadingspace(__om) /** @cond INTERNAL_HIDDEN */ /* Called by OS_MBUF_TRAILINGSPACE() macro. */ static inline uint16_t _os_mbuf_trailingspace(struct os_mbuf *om) { struct os_mbuf_pool *omp; omp = om->om_omp; return (&om->om_databuf[0] + omp->omp_databuf_len) - (om->om_data + om->om_len); } /** @endcond */ /** * Returns the trailing space (space at the end) of the mbuf. * Works on both packet header and regular mbufs. * * @param __omp The mbuf pool for this mbuf * @param __om Is the mbuf in that pool to get trailing space for * * @return The amount of trailing space available in the mbuf */ #define OS_MBUF_TRAILINGSPACE(__om) _os_mbuf_trailingspace(__om) /** * Initializes an mqueue. An mqueue is a queue of mbufs that ties to a * particular task's event queue. Mqueues form a helper API around a common * paradigm: wait on an event queue until at least one packet is available, * then process a queue of packets. * * When mbufs are available on the queue, an event OS_EVENT_T_MQUEUE_DATA * will be posted to the task's mbuf queue. * * @param mq The mqueue to initialize * @param ev_cb The callback to associate with the mqeueue * event. Typically, this callback pulls each * packet off the mqueue and processes them. * @param arg The argument to associate with the mqueue event. * * @return 0 on success, non-zero on failure. */ int os_mqueue_init(struct os_mqueue *mq, ble_npl_event_fn *ev_cb, void *arg); /** * Remove and return a single mbuf from the mbuf queue. Does not block. * * @param mq The mbuf queue to pull an element off of. * * @return The next mbuf in the queue, or NULL if queue has no mbufs. */ struct os_mbuf *os_mqueue_get(struct os_mqueue *); /** * Adds a packet (i.e. packet header mbuf) to an mqueue. The event associated * with the mqueue gets posted to the specified eventq. * * @param mq The mbuf queue to append the mbuf to. * @param evq The event queue to post an event to. * @param m The mbuf to append to the mbuf queue. * * @return 0 on success, non-zero on failure. */ int os_mqueue_put(struct os_mqueue *, struct ble_npl_eventq *, struct os_mbuf *); /** * MSYS is a system level mbuf registry. Allows the system to share * packet buffers amongst the various networking stacks that can be running * simultaeneously. * * Mbuf pools are created in the system initialization code, and then when * a mbuf is allocated out of msys, it will try and find the best fit based * upon estimated mbuf size. * * os_msys_register() registers a mbuf pool with MSYS, and allows MSYS to * allocate mbufs out of it. * * @param new_pool The pool to register with MSYS * * @return 0 on success, non-zero on failure */ int os_msys_register(struct os_mbuf_pool *); /** * Allocate a mbuf from msys. Based upon the data size requested, * os_msys_get() will choose the mbuf pool that has the best fit. * * @param dsize The estimated size of the data being stored in the mbuf * @param leadingspace The amount of leadingspace to allocate in the mbuf * * @return A freshly allocated mbuf on success, NULL on failure. */ struct os_mbuf *os_msys_get(uint16_t dsize, uint16_t leadingspace); /** * De-registers all mbuf pools from msys. */ void os_msys_reset(void); /** * Allocate a packet header structure from the MSYS pool. See * os_msys_register() for a description of MSYS. * * @param dsize The estimated size of the data being stored in the mbuf * @param user_hdr_len The length to allocate for the packet header structure * * @return A freshly allocated mbuf on success, NULL on failure. */ struct os_mbuf *os_msys_get_pkthdr(uint16_t dsize, uint16_t user_hdr_len); /** * Count the number of blocks in all the mbuf pools that are allocated. * * @return total number of blocks allocated in Msys */ int os_msys_count(void); /** * Return the number of free blocks in Msys * * @return Number of free blocks available in Msys */ int os_msys_num_free(void); /** * Initialize a pool of mbufs. * * @param omp The mbuf pool to initialize * @param mp The memory pool that will hold this mbuf pool * @param buf_len The length of the buffer itself. * @param nbufs The number of buffers in the pool * * @return 0 on success, error code on failure. */ int os_mbuf_pool_init(struct os_mbuf_pool *, struct os_mempool *mp, uint16_t, uint16_t); /** * Get an mbuf from the mbuf pool. The mbuf is allocated, and initialized * prior to being returned. * * @param omp The mbuf pool to return the packet from * @param leadingspace The amount of leadingspace to put before the data * section by default. * * @return An initialized mbuf on success, and NULL on failure. */ struct os_mbuf *os_mbuf_get(struct os_mbuf_pool *omp, uint16_t); /** * Allocate a new packet header mbuf out of the os_mbuf_pool. * * @param omp The mbuf pool to allocate out of * @param user_pkthdr_len The packet header length to reserve for the caller. * * @return A freshly allocated mbuf on success, NULL on failure. */ struct os_mbuf *os_mbuf_get_pkthdr(struct os_mbuf_pool *omp, uint8_t pkthdr_len); /** * Duplicate a chain of mbufs. Return the start of the duplicated chain. * * @param omp The mbuf pool to duplicate out of * @param om The mbuf chain to duplicate * * @return A pointer to the new chain of mbufs */ struct os_mbuf *os_mbuf_dup(struct os_mbuf *m); /** * Locates the specified absolute offset within an mbuf chain. The offset * can be one past than the total length of the chain, but no greater. * * @param om The start of the mbuf chain to seek within. * @param off The absolute address to find. * @param out_off On success, this points to the relative offset * within the returned mbuf. * * @return The mbuf containing the specified offset on * success. * NULL if the specified offset is out of bounds. */ struct os_mbuf *os_mbuf_off(const struct os_mbuf *om, int off, uint16_t *out_off); /* * Copy data from an mbuf chain starting "off" bytes from the beginning, * continuing for "len" bytes, into the indicated buffer. * * @param m The mbuf chain to copy from * @param off The offset into the mbuf chain to begin copying from * @param len The length of the data to copy * @param dst The destination buffer to copy into * * @return 0 on success; * -1 if the mbuf does not contain enough data. */ int os_mbuf_copydata(const struct os_mbuf *m, int off, int len, void *dst); /** * Append data onto a mbuf * * @param om The mbuf to append the data onto * @param data The data to append onto the mbuf * @param len The length of the data to append * * @return 0 on success, and an error code on failure */ int os_mbuf_append(struct os_mbuf *m, const void *, uint16_t); /** * Reads data from one mbuf and appends it to another. On error, the specified * data range may be partially appended. Neither mbuf is required to contain * an mbuf packet header. * * @param dst The mbuf to append to. * @param src The mbuf to copy data from. * @param src_off The absolute offset within the source mbuf * chain to read from. * @param len The number of bytes to append. * * @return 0 on success; * OS_EINVAL if the specified range extends beyond * the end of the source mbuf chain. */ int os_mbuf_appendfrom(struct os_mbuf *dst, const struct os_mbuf *src, uint16_t src_off, uint16_t len); /** * Release a mbuf back to the pool * * @param omp The Mbuf pool to release back to * @param om The Mbuf to release back to the pool * * @return 0 on success, -1 on failure */ int os_mbuf_free(struct os_mbuf *mb); /** * Free a chain of mbufs * * @param omp The mbuf pool to free the chain of mbufs into * @param om The starting mbuf of the chain to free back into the pool * * @return 0 on success, -1 on failure */ int os_mbuf_free_chain(struct os_mbuf *om); /** * Adjust the length of a mbuf, trimming either from the head or the tail * of the mbuf. * * @param mp The mbuf chain to adjust * @param req_len The length to trim from the mbuf. If positive, trims * from the head of the mbuf, if negative, trims from the * tail of the mbuf. */ void os_mbuf_adj(struct os_mbuf *mp, int req_len); /** * Performs a memory compare of the specified region of an mbuf chain against a * flat buffer. * * @param om The start of the mbuf chain to compare. * @param off The offset within the mbuf chain to start the * comparison. * @param data The flat buffer to compare. * @param len The length of the flat buffer. * * @return 0 if both memory regions are identical; * A memcmp return code if there is a mismatch; * INT_MAX if the mbuf is too short. */ int os_mbuf_cmpf(const struct os_mbuf *om, int off, const void *data, int len); /** * Compares the contents of two mbuf chains. The ranges of the two chains to * be compared are specified via the two offset parameters and the len * parameter. Neither mbuf chain is required to contain a packet header. * * @param om1 The first mbuf chain to compare. * @param offset1 The absolute offset within om1 at which to * start the comparison. * @param om2 The second mbuf chain to compare. * @param offset2 The absolute offset within om2 at which to * start the comparison. * @param len The number of bytes to compare. * * @return 0 if both mbuf segments are identical; * A memcmp() return code if the segment contents * differ; * INT_MAX if a specified range extends beyond the * end of its corresponding mbuf chain. */ int os_mbuf_cmpm(const struct os_mbuf *om1, uint16_t offset1, const struct os_mbuf *om2, uint16_t offset2, uint16_t len); /** * Increases the length of an mbuf chain by adding data to the front. If there * is insufficient room in the leading mbuf, additional mbufs are allocated and * prepended as necessary. If this function fails to allocate an mbuf, the * entire chain is freed. * * The specified mbuf chain does not need to contain a packet header. * * @param omp The mbuf pool to allocate from. * @param om The head of the mbuf chain. * @param len The number of bytes to prepend. * * @return The new head of the chain on success; * NULL on failure. */ struct os_mbuf *os_mbuf_prepend(struct os_mbuf *om, int len); /** * Prepends a chunk of empty data to the specified mbuf chain and ensures the * chunk is contiguous. If either operation fails, the specified mbuf chain is * freed and NULL is returned. * * @param om The mbuf chain to prepend to. * @param len The number of bytes to prepend and pullup. * * @return The modified mbuf on success; * NULL on failure (and the mbuf chain is freed). */ struct os_mbuf *os_mbuf_prepend_pullup(struct os_mbuf *om, uint16_t len); /** * Copies the contents of a flat buffer into an mbuf chain, starting at the * specified destination offset. If the mbuf is too small for the source data, * it is extended as necessary. If the destination mbuf contains a packet * header, the header length is updated. * * @param omp The mbuf pool to allocate from. * @param om The mbuf chain to copy into. * @param off The offset within the chain to copy to. * @param src The source buffer to copy from. * @param len The number of bytes to copy. * * @return 0 on success; nonzero on failure. */ int os_mbuf_copyinto(struct os_mbuf *om, int off, const void *src, int len); /** * Attaches a second mbuf chain onto the end of the first. If the first chain * contains a packet header, the header's length is updated. If the second * chain has a packet header, its header is cleared. * * @param first The mbuf chain being attached to. * @param second The mbuf chain that gets attached. */ void os_mbuf_concat(struct os_mbuf *first, struct os_mbuf *second); /** * Increases the length of an mbuf chain by the specified amount. If there is * not sufficient room in the last buffer, a new buffer is allocated and * appended to the chain. It is an error to request more data than can fit in * a single buffer. * * @param omp * @param om The head of the chain to extend. * @param len The number of bytes to extend by. * * @return A pointer to the new data on success; * NULL on failure. */ void *os_mbuf_extend(struct os_mbuf *om, uint16_t len); /** * Rearrange a mbuf chain so that len bytes are contiguous, * and in the data area of an mbuf (so that OS_MBUF_DATA() will * work on a structure of size len.) Returns the resulting * mbuf chain on success, free's it and returns NULL on failure. * * If there is room, it will add up to "max_protohdr - len" * extra bytes to the contiguous region, in an attempt to avoid being * called next time. * * @param omp The mbuf pool to take the mbufs out of * @param om The mbuf chain to make contiguous * @param len The number of bytes in the chain to make contiguous * * @return The contiguous mbuf chain on success, NULL on failure. */ struct os_mbuf *os_mbuf_pullup(struct os_mbuf *om, uint16_t len); /** * Removes and frees empty mbufs from the front of a chain. If the chain * contains a packet header, it is preserved. * * @param om The mbuf chain to trim. * * @return The head of the trimmed mbuf chain. */ struct os_mbuf *os_mbuf_trim_front(struct os_mbuf *om); /** * Creates a single chained mbuf from m1 and m2 utilizing all * the available buffer space in all mbufs in the resulting * chain. In other words, ensures there is no leading space in * any mbuf in the resulting chain and trailing space only in * the last mbuf in the chain. Mbufs from either chain may be * freed if not needed. No mbufs are allocated. Note that mbufs * from m2 are added to the end of m1. If m1 has a packet * header, it is retained and length updated. If m2 has a packet * header it is discarded. If m1 is NULL, NULL is returned and * m2 is left untouched. * * @param m1 Pointer to first mbuf chain to pack * @param m2 Pointer to second mbuf chain to pack * * @return struct os_mbuf* Pointer to resulting mbuf chain */ struct os_mbuf *os_mbuf_pack_chains(struct os_mbuf *m1, struct os_mbuf *m2); #ifdef __cplusplus } #endif #endif /* _OS_MBUF_H */ /** * @} OSMbuf * @} OSKernel */ |