/* * 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_PRE_DATA_SIZE __PRE_DATA_SIZE #define VLIB_BUFFER_DEFAULT_DATA_SIZE (2048) /* 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) /** \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, "next-present") \ _( 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 union { struct { CLIB_CACHE_LINE_ALIGN_MARK (cacheline0); /** signed offset in data[], pre_data[] that we are currently * processing. If negative current header points into predata area. */ i16 current_data; /** Nbytes between current data and the end of this buffer. */ u16 current_length; /** 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 flags; /** Generic flow identifier */ u32 flow_id; /** Reference count for this buffer. */ volatile u8 ref_count; /** index of buffer pool this buffer belongs. */ u8 buffer_pool_index; /** Error code for buffers to be enqueued to error handler. */ vlib_error_t error; /** Next buffer for this linked-list of buffers. Only valid if * VLIB_BUFFER_NEXT_PRESENT flag is set. */ u32 next_buffer; /** The following fields can be in a union because once a packet enters * the punt path, it is no longer on a feature arc */ union { /** Used by feature subgraph arcs to visit enabled feature nodes */ u32 current_config_index; /* the reason the packet once punted */ u32 punt_reason; }; /** Opaque data used by sub-graphs for their own purposes. */ u32 opaque[10]; /** part of buffer metadata which is initialized on alloc ends here. */ STRUCT_MARK (template_end); /** start of 2nd cache line */ CLIB_CACHE_LINE_ALIGN_MARK (cacheline1); /** Specifies trace buffer handle if VLIB_PACKET_IS_TRACED flag is * set. */ u32 trace_handle; /** Only valid for first buffer in chain. Current length plus total length * given here give total number of bytes in buffer chain. */ u32 total_length_not_including_first_buffer; /**< More opaque data, see ../vnet/vnet/buffer.h */ u32 opaque2[14]; /** start of third cache line */ CLIB_CACHE_LINE_ALIGN_MARK (cacheline2); /** 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 pre_data[VLIB_BUFFER_PRE_DATA_SIZE]; /** Packet data */ u8 data[0]; }; #ifdef CLIB_HAVE_VEC128 u8x16 as_u8x16[4]; #endif #ifdef CLIB_HAVE_VEC256 u8x32 as_u8x32[2]; #endif #ifdef CLIB_HAVE_VEC512 u8x64 as_u8x64[1]; #endif } vlib_buffer_t; #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 Construct a trace handle from thread and pool index * @param thread Thread id * @param pool_index Pool index * @return trace handle */ always_inline u32 vlib_buffer_make_trace_handle (u32 thread, u32 pool_index) { u32 rv; ASSERT (thread < 0xff); ASSERT (pool_index < 0x00FFFFFF); rv = (thread << 24) | (pool_index & 0x00FFFFFF); return rv; } /** \brief Extract the thread id from a trace handle * @param trace_handle the trace handle * @return the thread id */ always_inline u32 vlib_buffer_get_trace_thread (vlib_buffer_t * b) { u32 trace_handle = b->trace_handle; return trace_handle >> 24; } /** \brief Extract the trace (pool) index from a trace handle * @param trace_handle the trace handle * @return the trace index */ always_inline u32 vlib_buffer_get_trace_index (vlib_buffer_t * b) { u32 trace_handle = b->trace_handle; return trace_handle & 0x00FFFFFF; } /** \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 { CLIB_CACHE_LINE_ALIGN_MARK (cacheline0); u32 *cached_buffers; u32 n_alloc; } vlib_buffer_pool_thread_t; typedef struct { CLIB_CACHE_LINE_ALIGN_MARK (cacheline0); uword start; uword size; uword log2_page_size; u8 index; u32 numa_node; u32 physmem_map_index; u32 data_size; u32 n_buffers; u32 *buffers; u8 *name; clib_spinlock_t lock; /* per-thread data */ vlib_buffer_pool_thread_t *threads; /* buffer metadata template */ vlib_buffer_t buffer_template; } vlib_buffer_pool_t; #define VLIB_BUFFER_MAX_NUMA_NODES 32 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; /* 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; u8 default_buffer_pool_index_for_numa[VLIB_BUFFER_MAX_NUMA_NODES]; /* config */ u32 buffers_per_numa; u16 ext_hdr_size; u32 default_data_size; /* logging */ vlib_log_class_t log_default; } vlib_buffer_main_t; clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm); /* */ /** \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 */ extern u16 __vlib_buffer_external_hdr_size; #define VLIB_BUFFER_SET_EXT_HDR_SIZE(x) \ static void __clib_constructor \ vnet_buffer_set_ext_hdr_size() \ { \ if (__vlib_buffer_external_hdr_size) \ clib_error ("buffer external header space already set"); \ __vlib_buffer_external_hdr_size = CLIB_CACHE_LINE_ROUND (x); \ } #endif /* included_vlib_buffer_h */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */