/* * Copyright (c) 2015 Cisco and/or its affiliates. * Licensed 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. */ /* * buffer.h: VLIB buffers * * Copyright (c) 2008 Eliot Dresselhaus * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #ifndef included_vlib_buffer_h #define included_vlib_buffer_h #include #include #include #include #include #include /* for vlib_error_t */ #include /* for __PRE_DATA_SIZE */ #define VLIB_BUFFER_DATA_SIZE (2048) #define VLIB_BUFFER_PRE_DATA_SIZE __PRE_DATA_SIZE /* Minimum buffer chain segment size. Does not apply to last buffer in chain. Dataplane code can safely asume that specified amount of data is not split into 2 chained buffers */ #define VLIB_BUFFER_MIN_CHAIN_SEG_SIZE (128) /* Amount of head buffer data copied to each replica head buffer */ #define VLIB_BUFFER_CLONE_HEAD_SIZE (256) typedef u8 vlib_buffer_free_list_index_t; /** \file vlib buffer structure definition and a few select access methods. This structure and the buffer allocation mechanism should perhaps live in vnet, but it would take a lot of typing to make it so. */ /** * Buffer Flags */ #define foreach_vlib_buffer_flag \ _( 0, IS_TRACED, 0) \ _( 1, NEXT_PRESENT, 0) \ _( 2, TOTAL_LENGTH_VALID, 0) \ _( 3, EXT_HDR_VALID, "ext-hdr-valid") /* NOTE: only buffer generic flags should be defined here, please consider using user flags. i.e. src/vnet/buffer.h */ enum { #define _(bit, name, v) VLIB_BUFFER_##name = (1 << (bit)), foreach_vlib_buffer_flag #undef _ }; enum { #define _(bit, name, v) VLIB_BUFFER_LOG2_##name = (bit), foreach_vlib_buffer_flag #undef _ }; /* User defined buffer flags. */ #define LOG2_VLIB_BUFFER_FLAG_USER(n) (32 - (n)) #define VLIB_BUFFER_FLAG_USER(n) (1 << LOG2_VLIB_BUFFER_FLAG_USER(n)) #define VLIB_BUFFER_FLAGS_ALL (0x0f) /* VLIB buffer representation. */ typedef struct { CLIB_CACHE_LINE_ALIGN_MARK (cacheline0); /* Offset within data[] that we are currently processing. If negative current header points into predata area. */ i16 current_data; /**< signed offset in data[], pre_data[] that we are currently processing. If negative current header points into predata area. */ u16 current_length; /**< Nbytes between current data and the end of this buffer. */ u32 flags; /**< buffer flags:
VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index,
VLIB_BUFFER_IS_TRACED: trace this buffer.
VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer.
VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says
VLIB_BUFFER_EXT_HDR_VALID: buffer contains valid external buffer manager header, set to avoid adding it to a flow report
VLIB_BUFFER_FLAG_USER(n): user-defined bit N */ u32 flow_id; /**< Generic flow identifier */ u32 next_buffer; /**< Next buffer for this linked-list of buffers. Only valid if VLIB_BUFFER_NEXT_PRESENT flag is set. */ u32 current_config_index; /**< Used by feature subgraph arcs to visit enabled feature nodes */ vlib_error_t error; /**< Error code for buffers to be enqueued to error handler. */ u8 n_add_refs; /**< Number of additional references to this buffer. */ u8 buffer_pool_index; /**< index of buffer pool this buffer belongs. */ u32 opaque[10]; /**< Opaque data used by sub-graphs for their own purposes. See .../vnet/vnet/buffer.h */ STRUCT_MARK (template_end); /**< part of buffer metadata which is initialized on alloc ends here. It may be different than cacheline on systems with buffer cacheline size */ /***** end of first cache line */ CLIB_CACHE_LINE_ALIGN_MARK (cacheline1); u32 trace_index; /**< Specifies index into trace buffer if VLIB_PACKET_IS_TRACED flag is set. */ u32 recycle_count; /**< Used by L2 path recycle code */ u32 total_length_not_including_first_buffer; /**< Only valid for first buffer in chain. Current length plus total length given here give total number of bytes in buffer chain. */ u8 align_pad[4]; /**< available */ u32 opaque2[12]; /**< More opaque data, see ../vnet/vnet/buffer.h */ /***** end of second cache line */ CLIB_CACHE_LINE_ALIGN_MARK (cacheline2); u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE]; /**< Space for inserting data before buffer start. Packet rewrite string will be rewritten backwards and may extend back before buffer->data[0]. Must come directly before packet data. */ u8 data[0]; /**< Packet data. Hardware DMA here */ } vlib_buffer_t; /* Must be a multiple of 64B. */ #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE) /** \brief Prefetch buffer metadata. The first 64 bytes of buffer contains most header information @param b - (vlib_buffer_t *) pointer to the buffer @param type - LOAD, STORE. In most cases, STORE is the right answer */ #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type) #define vlib_prefetch_buffer_data(b,type) \ CLIB_PREFETCH (vlib_buffer_get_current(b), CLIB_CACHE_LINE_BYTES, type) always_inline void vlib_buffer_struct_is_sane (vlib_buffer_t * b) { ASSERT (sizeof (b[0]) % 64 == 0); /* Rewrite data must be before and contiguous with packet data. */ ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data); } always_inline uword vlib_buffer_get_va (vlib_buffer_t * b) { return pointer_to_uword (b->data); } /** \brief Get pointer to current data to process @param b - (vlib_buffer_t *) pointer to the buffer @return - (void *) (b->data + b->current_data) */ always_inline void * vlib_buffer_get_current (vlib_buffer_t * b) { /* Check bounds. */ ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE); return b->data + b->current_data; } always_inline uword vlib_buffer_get_current_va (vlib_buffer_t * b) { return vlib_buffer_get_va (b) + b->current_data; } /** \brief Advance current data pointer by the supplied (signed!) amount @param b - (vlib_buffer_t *) pointer to the buffer @param l - (word) signed increment */ always_inline void vlib_buffer_advance (vlib_buffer_t * b, word l) { ASSERT (b->current_length >= l); b->current_data += l; b->current_length -= l; ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0 || b->current_length >= VLIB_BUFFER_MIN_CHAIN_SEG_SIZE); } /** \brief Check if there is enough space in buffer to advance @param b - (vlib_buffer_t *) pointer to the buffer @param l - (word) size to check @return - 0 if there is less space than 'l' in buffer */ always_inline u8 vlib_buffer_has_space (vlib_buffer_t * b, word l) { return b->current_length >= l; } /** \brief Reset current header & length to state they were in when packet was received. @param b - (vlib_buffer_t *) pointer to the buffer */ always_inline void vlib_buffer_reset (vlib_buffer_t * b) { b->current_length += clib_max (b->current_data, 0); b->current_data = 0; } /** \brief Get pointer to buffer's opaque data array @param b - (vlib_buffer_t *) pointer to the buffer @return - (void *) b->opaque */ always_inline void * vlib_get_buffer_opaque (vlib_buffer_t * b) { return (void *) b->opaque; } /** \brief Get pointer to buffer's opaque2 data array @param b - (vlib_buffer_t *) pointer to the buffer @return - (void *) b->opaque2 */ always_inline void * vlib_get_buffer_opaque2 (vlib_buffer_t * b) { return (void *) b->opaque2; } /** \brief Get pointer to the end of buffer's data * @param b pointer to the buffer * @return pointer to tail of packet's data */ always_inline u8 * vlib_buffer_get_tail (vlib_buffer_t * b) { return b->data + b->current_data + b->current_length; } /** \brief Append uninitialized data to buffer * @param b pointer to the buffer * @param size number of uninitialized bytes * @return pointer to beginning of uninitialized data */ always_inline void * vlib_buffer_put_uninit (vlib_buffer_t * b, u16 size) { void *p = vlib_buffer_get_tail (b); /* XXX make sure there's enough space */ b->current_length += size; return p; } /** \brief Prepend uninitialized data to buffer * @param b pointer to the buffer * @param size number of uninitialized bytes * @return pointer to beginning of uninitialized data */ always_inline void * vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size) { ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size); b->current_data -= size; b->current_length += size; return vlib_buffer_get_current (b); } /** \brief Make head room, typically for packet headers * @param b pointer to the buffer * @param size number of head room bytes * @return pointer to start of buffer (current data) */ always_inline void * vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size) { ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size); b->current_data += size; return vlib_buffer_get_current (b); } /** \brief Retrieve bytes from buffer head * @param b pointer to the buffer * @param size number of bytes to pull * @return pointer to start of buffer (current data) */ always_inline void * vlib_buffer_pull (vlib_buffer_t * b, u8 size) { if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size) return 0; void *data = vlib_buffer_get_current (b); vlib_buffer_advance (b, size); return data; } /* Forward declaration. */ struct vlib_main_t; typedef struct vlib_buffer_free_list_t { /* Template buffer used to initialize first 16 bytes of buffers allocated on this free list. */ vlib_buffer_t buffer_init_template; /* Our index into vlib_main_t's buffer_free_list_pool. */ vlib_buffer_free_list_index_t index; /* Number of data bytes for buffers in this free list. */ u32 n_data_bytes; /* Number of buffers to allocate when we need to allocate new buffers */ u32 min_n_buffers_each_alloc; /* Total number of buffers allocated from this free list. */ u32 n_alloc; /* Vector of free buffers. Each element is a byte offset into I/O heap. */ u32 *buffers; /* index of buffer pool used to get / put buffers */ u8 buffer_pool_index; /* Free list name. */ u8 *name; /* Callback functions to initialize newly allocated buffers. If null buffers are zeroed. */ void (*buffer_init_function) (struct vlib_main_t * vm, struct vlib_buffer_free_list_t * fl, u32 * buffers, u32 n_buffers); uword buffer_init_function_opaque; } __attribute__ ((aligned (16))) vlib_buffer_free_list_t; typedef uword (vlib_buffer_fill_free_list_cb_t) (struct vlib_main_t * vm, vlib_buffer_free_list_t * fl, uword min_free_buffers); typedef void (vlib_buffer_free_cb_t) (struct vlib_main_t * vm, u32 * buffers, u32 n_buffers); typedef void (vlib_buffer_free_no_next_cb_t) (struct vlib_main_t * vm, u32 * buffers, u32 n_buffers); typedef struct { vlib_buffer_fill_free_list_cb_t *vlib_buffer_fill_free_list_cb; vlib_buffer_free_cb_t *vlib_buffer_free_cb; vlib_buffer_free_no_next_cb_t *vlib_buffer_free_no_next_cb; } vlib_buffer_callbacks_t; extern vlib_buffer_callbacks_t *vlib_buffer_callbacks; typedef struct { CLIB_CACHE_LINE_ALIGN_MARK (cacheline0); uword start; uword size; uword log2_page_size; u32 physmem_map_index; u32 buffer_size; u32 *buffers; clib_spinlock_t lock; } vlib_buffer_pool_t; typedef struct { CLIB_CACHE_LINE_ALIGN_MARK (cacheline0); /* Virtual memory address and size of buffer memory, used for calculating buffer index */ uword buffer_mem_start; uword buffer_mem_size; vlib_buffer_pool_t *buffer_pools; /* Buffer free callback, for subversive activities */ u32 (*buffer_free_callback) (struct vlib_main_t * vm, u32 * buffers, u32 n_buffers, u32 follow_buffer_next); #define VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX (0) #define VLIB_BUFFER_DEFAULT_FREE_LIST_BYTES VLIB_BUFFER_DATA_SIZE /* Hash table mapping buffer size (rounded to next unit of sizeof (vlib_buffer_t)) to free list index. */ uword *free_list_by_size; /* Hash table mapping buffer index into number 0 => allocated but free, 1 => allocated and not-free. If buffer index is not in hash table then this buffer has never been allocated. */ uword *buffer_known_hash; clib_spinlock_t buffer_known_hash_lockp; /* Callbacks */ vlib_buffer_callbacks_t cb; int callbacks_registered; } vlib_buffer_main_t; u8 vlib_buffer_register_physmem_map (struct vlib_main_t *vm, u32 physmem_map_index); clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm); void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp); /* */ /** \brief Compile time buffer trajectory tracing option Turn this on if you run into "bad monkey" contexts, and you want to know exactly which nodes they've visited... See vlib/main.c... */ #define VLIB_BUFFER_TRACE_TRAJECTORY 0 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0 extern void (*vlib_buffer_trace_trajectory_cb) (vlib_buffer_t * b, u32 index); extern void (*vlib_buffer_trace_trajectory_init_cb) (vlib_buffer_t * b); extern void vlib_buffer_trace_trajectory_init (vlib_buffer_t * b); #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) \ vlib_buffer_trace_trajectory_init (b); #else #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */ #endif /* included_vlib_buffer_h */ #define VLIB_BUFFER_REGISTER_CALLBACKS(x,...) \ __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks; \ static void __vlib_add_buffer_callbacks_t_##x (void) \ __attribute__((__constructor__)) ; \ static void __vlib_add_buffer_callbacks_t_##x (void) \ { \ if (vlib_buffer_callbacks) \ clib_panic ("vlib buffer callbacks already registered"); \ vlib_buffer_callbacks = &__##x##_buffer_callbacks; \ } \ static void __vlib_rm_buffer_callbacks_t_##x (void) \ __attribute__((__destructor__)) ; \ static void __vlib_rm_buffer_callbacks_t_##x (void) \ { vlib_buffer_callbacks = 0; } \ __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */