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Diffstat (limited to 'src/vlib/buffer.h')
| -rw-r--r-- | src/vlib/buffer.h | 540 |
1 files changed, 540 insertions, 0 deletions
diff --git a/src/vlib/buffer.h b/src/vlib/buffer.h new file mode 100644 index 00000000..e47dbc6d --- /dev/null +++ b/src/vlib/buffer.h @@ -0,0 +1,540 @@ +/* + * 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 <vppinfra/types.h> +#include <vppinfra/cache.h> +#include <vppinfra/serialize.h> +#include <vppinfra/vector.h> +#include <vppinfra/lock.h> +#include <vlib/error.h> /* for vlib_error_t */ + +#include <vlib/config.h> /* for __PRE_DATA_SIZE */ +#define VLIB_BUFFER_DATA_SIZE (2048) +#define VLIB_BUFFER_PRE_DATA_SIZE __PRE_DATA_SIZE + +/** \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. +*/ + +/* VLIB buffer representation. */ +typedef struct +{ + CLIB_CACHE_LINE_ALIGN_MARK (cacheline0); + STRUCT_MARK (template_start); + /* 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: + <br> VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index, + <br> VLIB_BUFFER_IS_TRACED: trace this buffer. + <br> VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer. + <br> VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says + <br> VLIB_BUFFER_REPL_FAIL: packet replication failure + <br> VLIB_BUFFER_RECYCLE: as it says + <br> VLIB_BUFFER_FLOW_REPORT: buffer is a flow report, + <br> VLIB_BUFFER_EXT_HDR_VALID: buffer contains valid external buffer manager header, + set to avoid adding it to a flow report + <br> VLIB_BUFFER_FLAG_USER(n): user-defined bit N + */ + +/* any change to the following line requres update of + * vlib_buffer_get_free_list_index(...) and + * vlib_buffer_set_free_list_index(...) functions */ +#define VLIB_BUFFER_FREE_LIST_INDEX_MASK ((1 << 5) - 1) + +#define VLIB_BUFFER_IS_TRACED (1 << 5) +#define VLIB_BUFFER_LOG2_NEXT_PRESENT (6) +#define VLIB_BUFFER_NEXT_PRESENT (1 << VLIB_BUFFER_LOG2_NEXT_PRESENT) +#define VLIB_BUFFER_IS_RECYCLED (1 << 7) +#define VLIB_BUFFER_TOTAL_LENGTH_VALID (1 << 8) +#define VLIB_BUFFER_REPL_FAIL (1 << 9) +#define VLIB_BUFFER_RECYCLE (1 << 10) +#define VLIB_BUFFER_FLOW_REPORT (1 << 11) +#define VLIB_BUFFER_EXT_HDR_VALID (1 << 12) + + /* 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)) + + STRUCT_MARK (template_end); + + u32 next_buffer; /**< Next buffer for this linked-list of buffers. + Only valid if VLIB_BUFFER_NEXT_PRESENT flag is set. + */ + + vlib_error_t error; /**< Error code for buffers to be enqueued + to error handler. + */ + u32 current_config_index; /**< Used by feature subgraph arcs to + visit enabled feature nodes + */ + + u8 feature_arc_index; /**< Used to identify feature arcs by intermediate + feature node + */ + + u8 n_add_refs; /**< Number of additional references to this buffer. */ + + u8 dont_waste_me[2]; /**< Available space in the (precious) + first 32 octets of buffer metadata + Before allocating any of it, discussion required! + */ + + u32 opaque[10]; /**< Opaque data used by sub-graphs for their own purposes. + See .../vnet/vnet/buffer.h + */ + 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. + */ + u32 opaque2[13]; /**< More opaque data, currently unused */ + + /***** 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) + +always_inline vlib_buffer_t * +vlib_buffer_next_contiguous (vlib_buffer_t * b, u32 buffer_bytes) +{ + return (void *) (b + 1) + buffer_bytes; +} + +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); +} + +/** \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; +} + +/** \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; +} + +/** \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, u8 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. */ + u32 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 + from physmem heap. */ + u32 min_n_buffers_each_physmem_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; + + /* global vector of free buffers, used only on main thread. + Bufers are returned to global buffers only in case when number of + buffers on free buffers list grows about threshold */ + u32 *global_buffers; + clib_spinlock_t global_buffers_lock; + + /* Memory chunks allocated for this free list + recorded here so they can be freed when free list + is deleted. */ + void **buffer_memory_allocated; + + /* 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); + + /* Callback function to announce that buffers have been + added to the freelist */ + void (*buffers_added_to_freelist_function) + (struct vlib_main_t * vm, struct vlib_buffer_free_list_t * fl); + + uword buffer_init_function_opaque; +} __attribute__ ((aligned (16))) vlib_buffer_free_list_t; + +typedef struct +{ + u32 (*vlib_buffer_alloc_cb) (struct vlib_main_t * vm, u32 * buffers, + u32 n_buffers); + u32 (*vlib_buffer_alloc_from_free_list_cb) (struct vlib_main_t * vm, + u32 * buffers, u32 n_buffers, + u32 free_list_index); + void (*vlib_buffer_free_cb) (struct vlib_main_t * vm, u32 * buffers, + u32 n_buffers); + void (*vlib_buffer_free_no_next_cb) (struct vlib_main_t * vm, u32 * buffers, + u32 n_buffers); + void (*vlib_packet_template_init_cb) (struct vlib_main_t * vm, void *t, + void *packet_data, + uword n_packet_data_bytes, + uword + min_n_buffers_each_physmem_alloc, + u8 * name); + void (*vlib_buffer_delete_free_list_cb) (struct vlib_main_t * vm, + u32 free_list_index); +} vlib_buffer_callbacks_t; + +extern vlib_buffer_callbacks_t *vlib_buffer_callbacks; + +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_physmem_region_index_t physmem_region; + + /* Buffer free callback, for subversive activities */ + u32 (*buffer_free_callback) (struct vlib_main_t * vm, + u32 * buffers, + u32 n_buffers, u32 follow_buffer_next); + /* Pool of buffer free lists. + Multiple free lists exist for packet generator which uses + separate free lists for each packet stream --- so as to avoid + initializing static data for each packet generated. */ + vlib_buffer_free_list_t *buffer_free_list_pool; +#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; + + /* List of free-lists needing Blue Light Special announcements */ + vlib_buffer_free_list_t **announce_list; + + /* Callbacks */ + vlib_buffer_callbacks_t cb; + int callbacks_registered; +} vlib_buffer_main_t; + +void vlib_buffer_add_mem_range (struct vlib_main_t *vm, uword start, + uword size); +clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm); + +typedef struct +{ + struct vlib_main_t *vlib_main; + + u32 first_buffer, last_buffer; + + union + { + struct + { + /* Total accumulated bytes in chain starting with first_buffer. */ + u32 n_total_data_bytes; + + /* Max number of bytes to accumulate in chain starting with first_buffer. + As this limit is reached buffers are enqueued to next node. */ + u32 max_n_data_bytes_per_chain; + + /* Next node to enqueue buffers to relative to current process node. */ + u32 next_index; + + /* Free list to use to allocate new buffers. */ + u32 free_list_index; + } tx; + + struct + { + /* CLIB fifo of buffer indices waiting to be unserialized. */ + u32 *buffer_fifo; + + /* Event type used to signal that RX buffers have been added to fifo. */ + uword ready_one_time_event; + } rx; + }; +} vlib_serialize_buffer_main_t; + +void serialize_open_vlib_buffer (serialize_main_t * m, struct vlib_main_t *vm, + vlib_serialize_buffer_main_t * sm); +void unserialize_open_vlib_buffer (serialize_main_t * m, + struct vlib_main_t *vm, + vlib_serialize_buffer_main_t * sm); + +u32 serialize_close_vlib_buffer (serialize_main_t * m); +void unserialize_close_vlib_buffer (serialize_main_t * m); +void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp); + +always_inline u32 +serialize_vlib_buffer_n_bytes (serialize_main_t * m) +{ + serialize_stream_t *s = &m->stream; + vlib_serialize_buffer_main_t *sm + = uword_to_pointer (m->stream.data_function_opaque, + vlib_serialize_buffer_main_t *); + return sm->tx.n_total_data_bytes + s->current_buffer_index + + vec_len (s->overflow_buffer); +} + +/* + */ + +/** \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 +#define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) (b)->pre_data[0]=0 +#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; \ +} \ +__VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |