X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=src%2Fvlib%2Fbuffer_funcs.h;h=77964fde82121676325fb6c52384f14d0f794b38;hb=e09a2337b82d2dcb5b7379a9581477af291d1a75;hp=58abdb18841773750237a3bc15e83a334924137b;hpb=2b65f9ca04847b6e37861983183f5093b601fbb2;p=vpp.git diff --git a/src/vlib/buffer_funcs.h b/src/vlib/buffer_funcs.h index 58abdb18841..77964fde821 100644 --- a/src/vlib/buffer_funcs.h +++ b/src/vlib/buffer_funcs.h @@ -51,6 +51,32 @@ vlib buffer access methods. */ +typedef void (vlib_buffer_enqueue_to_next_fn_t) (vlib_main_t *vm, + vlib_node_runtime_t *node, + u32 *buffers, u16 *nexts, + uword count); +typedef void (vlib_buffer_enqueue_to_single_next_fn_t) ( + vlib_main_t *vm, vlib_node_runtime_t *node, u32 *ers, u16 next_index, + u32 count); + +typedef u32 (vlib_buffer_enqueue_to_thread_fn_t) ( + vlib_main_t *vm, vlib_node_runtime_t *node, u32 frame_queue_index, + u32 *buffer_indices, u16 *thread_indices, u32 n_packets, + int drop_on_congestion); + +typedef u32 (vlib_frame_queue_dequeue_fn_t) (vlib_main_t *vm, + vlib_frame_queue_main_t *fqm); + +typedef struct +{ + vlib_buffer_enqueue_to_next_fn_t *buffer_enqueue_to_next_fn; + vlib_buffer_enqueue_to_single_next_fn_t *buffer_enqueue_to_single_next_fn; + vlib_buffer_enqueue_to_thread_fn_t *buffer_enqueue_to_thread_fn; + vlib_frame_queue_dequeue_fn_t *frame_queue_dequeue_fn; +} vlib_buffer_func_main_t; + +extern vlib_buffer_func_main_t vlib_buffer_func_main; + always_inline void vlib_buffer_validate (vlib_main_t * vm, vlib_buffer_t * b) { @@ -101,42 +127,42 @@ vlib_buffer_get_default_data_size (vlib_main_t * vm) static_always_inline void vlib_buffer_copy_indices (u32 * dst, u32 * src, u32 n_indices) { -#if defined(CLIB_HAVE_VEC512) - while (n_indices >= 16) + clib_memcpy_u32 (dst, src, n_indices); +} + +always_inline void +vlib_buffer_copy_indices_from_ring (u32 * dst, u32 * ring, u32 start, + u32 ring_size, u32 n_buffers) +{ + ASSERT (n_buffers <= ring_size); + + if (PREDICT_TRUE (start + n_buffers <= ring_size)) { - u32x16_store_unaligned (u32x16_load_unaligned (src), dst); - dst += 16; - src += 16; - n_indices -= 16; + vlib_buffer_copy_indices (dst, ring + start, n_buffers); } -#endif - -#if defined(CLIB_HAVE_VEC256) - while (n_indices >= 8) + else { - u32x8_store_unaligned (u32x8_load_unaligned (src), dst); - dst += 8; - src += 8; - n_indices -= 8; + u32 n = ring_size - start; + vlib_buffer_copy_indices (dst, ring + start, n); + vlib_buffer_copy_indices (dst + n, ring, n_buffers - n); } -#endif +} -#if defined(CLIB_HAVE_VEC128) - while (n_indices >= 4) +always_inline void +vlib_buffer_copy_indices_to_ring (u32 * ring, u32 * src, u32 start, + u32 ring_size, u32 n_buffers) +{ + ASSERT (n_buffers <= ring_size); + + if (PREDICT_TRUE (start + n_buffers <= ring_size)) { - u32x4_store_unaligned (u32x4_load_unaligned (src), dst); - dst += 4; - src += 4; - n_indices -= 4; + vlib_buffer_copy_indices (ring + start, src, n_buffers); } -#endif - - while (n_indices) + else { - dst[0] = src[0]; - dst += 1; - src += 1; - n_indices -= 1; + u32 n = ring_size - start; + vlib_buffer_copy_indices (ring + start, src, n); + vlib_buffer_copy_indices (ring, src + n, n_buffers - n); } } @@ -179,37 +205,78 @@ vlib_get_buffers_with_offset (vlib_main_t * vm, u32 * bi, void **b, int count, i32 offset) { uword buffer_mem_start = vm->buffer_main->buffer_mem_start; -#ifdef CLIB_HAVE_VEC256 - u64x4 off = u64x4_splat (buffer_mem_start + offset); +#ifdef CLIB_HAVE_VEC512 + u64x8 of8 = u64x8_splat (buffer_mem_start + offset); + u64x4 off = u64x8_extract_lo (of8); /* if count is not const, compiler will not unroll while loop se we maintain two-in-parallel variant */ + while (count >= 32) + { + u64x8 b0 = u64x8_from_u32x8 (u32x8_load_unaligned (bi)); + u64x8 b1 = u64x8_from_u32x8 (u32x8_load_unaligned (bi + 8)); + u64x8 b2 = u64x8_from_u32x8 (u32x8_load_unaligned (bi + 16)); + u64x8 b3 = u64x8_from_u32x8 (u32x8_load_unaligned (bi + 24)); + /* shift and add to get vlib_buffer_t pointer */ + u64x8_store_unaligned ((b0 << CLIB_LOG2_CACHE_LINE_BYTES) + of8, b); + u64x8_store_unaligned ((b1 << CLIB_LOG2_CACHE_LINE_BYTES) + of8, b + 8); + u64x8_store_unaligned ((b2 << CLIB_LOG2_CACHE_LINE_BYTES) + of8, b + 16); + u64x8_store_unaligned ((b3 << CLIB_LOG2_CACHE_LINE_BYTES) + of8, b + 24); + b += 32; + bi += 32; + count -= 32; + } while (count >= 8) { - u64x4 b0 = u32x4_extend_to_u64x4 (u32x4_load_unaligned (bi)); - u64x4 b1 = u32x4_extend_to_u64x4 (u32x4_load_unaligned (bi + 4)); + u64x8 b0 = u64x8_from_u32x8 (u32x8_load_unaligned (bi)); /* shift and add to get vlib_buffer_t pointer */ - u64x4_store_unaligned ((b0 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b); - u64x4_store_unaligned ((b1 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b + 4); + u64x8_store_unaligned ((b0 << CLIB_LOG2_CACHE_LINE_BYTES) + of8, b); b += 8; bi += 8; count -= 8; } +#elif defined CLIB_HAVE_VEC256 + u64x4 off = u64x4_splat (buffer_mem_start + offset); + /* if count is not const, compiler will not unroll while loop + se we maintain two-in-parallel variant */ + while (count >= 32) + { + u64x4 b0 = u64x4_from_u32x4 (u32x4_load_unaligned (bi)); + u64x4 b1 = u64x4_from_u32x4 (u32x4_load_unaligned (bi + 4)); + u64x4 b2 = u64x4_from_u32x4 (u32x4_load_unaligned (bi + 8)); + u64x4 b3 = u64x4_from_u32x4 (u32x4_load_unaligned (bi + 12)); + u64x4 b4 = u64x4_from_u32x4 (u32x4_load_unaligned (bi + 16)); + u64x4 b5 = u64x4_from_u32x4 (u32x4_load_unaligned (bi + 20)); + u64x4 b6 = u64x4_from_u32x4 (u32x4_load_unaligned (bi + 24)); + u64x4 b7 = u64x4_from_u32x4 (u32x4_load_unaligned (bi + 28)); + /* shift and add to get vlib_buffer_t pointer */ + u64x4_store_unaligned ((b0 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b); + u64x4_store_unaligned ((b1 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b + 4); + u64x4_store_unaligned ((b2 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b + 8); + u64x4_store_unaligned ((b3 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b + 12); + u64x4_store_unaligned ((b4 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b + 16); + u64x4_store_unaligned ((b5 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b + 20); + u64x4_store_unaligned ((b6 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b + 24); + u64x4_store_unaligned ((b7 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b + 28); + b += 32; + bi += 32; + count -= 32; + } #endif while (count >= 4) { #ifdef CLIB_HAVE_VEC256 - u64x4 b0 = u32x4_extend_to_u64x4 (u32x4_load_unaligned (bi)); + u64x4 b0 = u64x4_from_u32x4 (u32x4_load_unaligned (bi)); /* shift and add to get vlib_buffer_t pointer */ u64x4_store_unaligned ((b0 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b); #elif defined (CLIB_HAVE_VEC128) u64x2 off = u64x2_splat (buffer_mem_start + offset); u32x4 bi4 = u32x4_load_unaligned (bi); - u64x2 b0 = u32x4_extend_to_u64x2 ((u32x4) bi4); + u64x2 b0 = u64x2_from_u32x4 ((u32x4) bi4); #if defined (__aarch64__) - u64x2 b1 = u32x4_extend_to_u64x2_high ((u32x4) bi4); + u64x2 b1 = u64x2_from_u32x4_high ((u32x4) bi4); #else bi4 = u32x4_shuffle (bi4, 2, 3, 0, 1); - u64x2 b1 = u32x4_extend_to_u64x2 ((u32x4) bi4); + u64x2 b1 = u64x2_from_u32x4 ((u32x4) bi4); #endif u64x2_store_unaligned ((b0 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b); u64x2_store_unaligned ((b1 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b + 2); @@ -488,7 +555,7 @@ vlib_get_buffer_pool (vlib_main_t * vm, u8 buffer_pool_index) return vec_elt_at_index (bm->buffer_pools, buffer_pool_index); } -static_always_inline uword +static_always_inline __clib_warn_unused_result uword vlib_buffer_pool_get (vlib_main_t * vm, u8 buffer_pool_index, u32 * buffers, u32 n_buffers) { @@ -526,7 +593,7 @@ vlib_buffer_pool_get (vlib_main_t * vm, u8 buffer_pool_index, u32 * buffers, less than the number requested or zero */ -always_inline u32 +always_inline __clib_warn_unused_result u32 vlib_buffer_alloc_from_pool (vlib_main_t * vm, u32 * buffers, u32 n_buffers, u8 buffer_pool_index) { @@ -535,6 +602,17 @@ vlib_buffer_alloc_from_pool (vlib_main_t * vm, u32 * buffers, u32 n_buffers, vlib_buffer_pool_thread_t *bpt; u32 *src, *dst, len, n_left; + /* If buffer allocation fault injection is configured */ + if (VLIB_BUFFER_ALLOC_FAULT_INJECTOR > 0) + { + u32 vlib_buffer_alloc_may_fail (vlib_main_t *, u32); + + /* See how many buffers we're willing to allocate */ + n_buffers = vlib_buffer_alloc_may_fail (vm, n_buffers); + if (n_buffers == 0) + return (n_buffers); + } + bp = vec_elt_at_index (bm->buffer_pools, buffer_pool_index); bpt = vec_elt_at_index (bp->threads, vm->thread_index); @@ -548,11 +626,7 @@ vlib_buffer_alloc_from_pool (vlib_main_t * vm, u32 * buffers, u32 n_buffers, src = bpt->cached_buffers + len - n_buffers; vlib_buffer_copy_indices (dst, src, n_buffers); bpt->n_cached -= n_buffers; - - if (CLIB_DEBUG > 0) - vlib_buffer_validate_alloc_free (vm, buffers, n_buffers, - VLIB_BUFFER_KNOWN_FREE); - return n_buffers; + goto done; } /* alloc bigger than cache - take buffers directly from main pool */ @@ -560,11 +634,7 @@ vlib_buffer_alloc_from_pool (vlib_main_t * vm, u32 * buffers, u32 n_buffers, { n_buffers = vlib_buffer_pool_get (vm, buffer_pool_index, buffers, n_buffers); - - if (CLIB_DEBUG > 0) - vlib_buffer_validate_alloc_free (vm, buffers, n_buffers, - VLIB_BUFFER_KNOWN_FREE); - return n_buffers; + goto done; } /* take everything available in the cache */ @@ -592,11 +662,13 @@ vlib_buffer_alloc_from_pool (vlib_main_t * vm, u32 * buffers, u32 n_buffers, n_buffers -= n_left; +done: /* Verify that buffers are known free. */ if (CLIB_DEBUG > 0) vlib_buffer_validate_alloc_free (vm, buffers, n_buffers, VLIB_BUFFER_KNOWN_FREE); - + if (PREDICT_FALSE (bm->alloc_callback_fn != 0)) + bm->alloc_callback_fn (vm, buffer_pool_index, buffers, n_buffers); return n_buffers; } @@ -609,7 +681,7 @@ vlib_buffer_alloc_from_pool (vlib_main_t * vm, u32 * buffers, u32 n_buffers, @return - (u32) number of buffers actually allocated, may be less than the number requested or zero */ -always_inline u32 +always_inline __clib_warn_unused_result u32 vlib_buffer_alloc_on_numa (vlib_main_t * vm, u32 * buffers, u32 n_buffers, u32 numa_node) { @@ -626,7 +698,7 @@ vlib_buffer_alloc_on_numa (vlib_main_t * vm, u32 * buffers, u32 n_buffers, less than the number requested or zero */ -always_inline u32 +always_inline __clib_warn_unused_result u32 vlib_buffer_alloc (vlib_main_t * vm, u32 * buffers, u32 n_buffers) { return vlib_buffer_alloc_on_numa (vm, buffers, n_buffers, vm->numa_node); @@ -642,7 +714,7 @@ vlib_buffer_alloc (vlib_main_t * vm, u32 * buffers, u32 n_buffers) @return - (u32) number of buffers actually allocated, may be less than the number requested or zero */ -always_inline u32 +always_inline __clib_warn_unused_result u32 vlib_buffer_alloc_to_ring (vlib_main_t * vm, u32 * ring, u32 start, u32 ring_size, u32 n_buffers) { @@ -671,7 +743,7 @@ vlib_buffer_alloc_to_ring (vlib_main_t * vm, u32 * ring, u32 start, @return - (u32) number of buffers actually allocated, may be less than the number requested or zero */ -always_inline u32 +always_inline __clib_warn_unused_result u32 vlib_buffer_alloc_to_ring_from_pool (vlib_main_t * vm, u32 * ring, u32 start, u32 ring_size, u32 n_buffers, u8 buffer_pool_index) @@ -698,6 +770,7 @@ static_always_inline void vlib_buffer_pool_put (vlib_main_t * vm, u8 buffer_pool_index, u32 * buffers, u32 n_buffers) { + vlib_buffer_main_t *bm = vm->buffer_main; vlib_buffer_pool_t *bp = vlib_get_buffer_pool (vm, buffer_pool_index); vlib_buffer_pool_thread_t *bpt = vec_elt_at_index (bp->threads, vm->thread_index); @@ -706,6 +779,8 @@ vlib_buffer_pool_put (vlib_main_t * vm, u8 buffer_pool_index, if (CLIB_DEBUG > 0) vlib_buffer_validate_alloc_free (vm, buffers, n_buffers, VLIB_BUFFER_KNOWN_ALLOCATED); + if (PREDICT_FALSE (bm->free_callback_fn != 0)) + bm->free_callback_fn (vm, buffer_pool_index, buffers, n_buffers); n_cached = bpt->n_cached; n_empty = VLIB_BUFFER_POOL_PER_THREAD_CACHE_SZ - n_cached; @@ -739,28 +814,42 @@ vlib_buffer_free_inline (vlib_main_t * vm, u32 * buffers, u32 n_buffers, vlib_buffer_t bt = { }; #if defined(CLIB_HAVE_VEC128) vlib_buffer_t bpi_mask = {.buffer_pool_index = ~0 }; - vlib_buffer_t bpi_vec = {.buffer_pool_index = ~0 }; + vlib_buffer_t bpi_vec = {}; vlib_buffer_t flags_refs_mask = { .flags = VLIB_BUFFER_NEXT_PRESENT, .ref_count = ~1 }; #endif + if (PREDICT_FALSE (n_buffers == 0)) + return; + + vlib_buffer_t *b = vlib_get_buffer (vm, buffers[0]); + buffer_pool_index = b->buffer_pool_index; + bp = vlib_get_buffer_pool (vm, buffer_pool_index); + vlib_buffer_copy_template (&bt, &bp->buffer_template); +#if defined(CLIB_HAVE_VEC128) + bpi_vec.buffer_pool_index = buffer_pool_index; +#endif + while (n_buffers) { vlib_buffer_t *b[8]; u32 bi, sum = 0, flags, next; - if (n_buffers < 12) + if (n_buffers < 4) goto one_by_one; vlib_get_buffers (vm, buffers, b, 4); - vlib_get_buffers (vm, buffers + 8, b + 4, 4); - vlib_prefetch_buffer_header (b[4], LOAD); - vlib_prefetch_buffer_header (b[5], LOAD); - vlib_prefetch_buffer_header (b[6], LOAD); - vlib_prefetch_buffer_header (b[7], LOAD); + if (n_buffers >= 12) + { + vlib_get_buffers (vm, buffers + 8, b + 4, 4); + vlib_prefetch_buffer_header (b[4], LOAD); + vlib_prefetch_buffer_header (b[5], LOAD); + vlib_prefetch_buffer_header (b[6], LOAD); + vlib_prefetch_buffer_header (b[7], LOAD); + } #if defined(CLIB_HAVE_VEC128) u8x16 p0, p1, p2, p3, r; @@ -1172,11 +1261,11 @@ vlib_buffer_clone_256 (vlib_main_t * vm, u32 src_buffer, u32 * buffers, d->next_buffer = src_buffer; } vlib_buffer_advance (s, head_end_offset); - s->ref_count = n_buffers; + s->ref_count = n_buffers ? n_buffers : s->ref_count; while (s->flags & VLIB_BUFFER_NEXT_PRESENT) { s = vlib_get_buffer (vm, s->next_buffer); - s->ref_count = n_buffers; + s->ref_count = n_buffers ? n_buffers : s->ref_count; } return n_buffers; @@ -1376,139 +1465,148 @@ vlib_buffer_space_left_at_end (vlib_main_t * vm, vlib_buffer_t * b) ((u8 *) vlib_buffer_get_current (b) + b->current_length); } +#define VLIB_BUFFER_LINEARIZE_MAX 64 + always_inline u32 vlib_buffer_chain_linearize (vlib_main_t * vm, vlib_buffer_t * b) { - vlib_buffer_t *db = b, *sb, *first = b; - int is_cloned = 0; - u32 bytes_left = 0, data_size; - u16 src_left, dst_left, n_buffers = 1; - u8 *dp, *sp; - u32 to_free = 0; + vlib_buffer_t *dst_b; + u32 n_buffers = 1, to_free = 0; + u16 rem_len, dst_len, data_size, src_len = 0; + u8 *dst, *src = 0; if (PREDICT_TRUE ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0)) return 1; + ASSERT (1 == b->ref_count); + if (PREDICT_FALSE (1 != b->ref_count)) + return 0; + data_size = vlib_buffer_get_default_data_size (vm); + rem_len = vlib_buffer_length_in_chain (vm, b) - b->current_length; - dst_left = vlib_buffer_space_left_at_end (vm, b); + dst_b = b; + dst = vlib_buffer_get_tail (dst_b); + dst_len = vlib_buffer_space_left_at_end (vm, dst_b); - while (b->flags & VLIB_BUFFER_NEXT_PRESENT) - { - b = vlib_get_buffer (vm, b->next_buffer); - if (b->ref_count > 1) - is_cloned = 1; - bytes_left += b->current_length; - n_buffers++; - } + b->total_length_not_including_first_buffer -= dst_len; - /* if buffer is cloned, create completely new chain - unless everything fits - * into one buffer */ - if (is_cloned && bytes_left >= dst_left) + while (rem_len > 0) { - u32 len = 0; - u32 space_needed = bytes_left - dst_left; - u32 tail; - - if (vlib_buffer_alloc (vm, &tail, 1) == 0) - return 0; - - ++n_buffers; - len += data_size; - b = vlib_get_buffer (vm, tail); + u16 copy_len; - while (len < space_needed) + while (0 == src_len) { - u32 bi; - if (vlib_buffer_alloc (vm, &bi, 1) == 0) - { - vlib_buffer_free_one (vm, tail); - return 0; - } - b->flags = VLIB_BUFFER_NEXT_PRESENT; - b->next_buffer = bi; - b = vlib_get_buffer (vm, bi); - len += data_size; - n_buffers++; + ASSERT (b->flags & VLIB_BUFFER_NEXT_PRESENT); + if (PREDICT_FALSE (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))) + break; /* malformed chained buffer */ + + b = vlib_get_buffer (vm, b->next_buffer); + src = vlib_buffer_get_current (b); + src_len = b->current_length; } - sb = vlib_get_buffer (vm, first->next_buffer); - to_free = first->next_buffer; - first->next_buffer = tail; - } - else - sb = vlib_get_buffer (vm, first->next_buffer); - src_left = sb->current_length; - sp = vlib_buffer_get_current (sb); - dp = vlib_buffer_get_tail (db); + if (0 == dst_len) + { + ASSERT (dst_b->flags & VLIB_BUFFER_NEXT_PRESENT); + if (PREDICT_FALSE (!(dst_b->flags & VLIB_BUFFER_NEXT_PRESENT))) + break; /* malformed chained buffer */ - while (bytes_left) - { - u16 bytes_to_copy; + vlib_buffer_t *next_dst_b = vlib_get_buffer (vm, dst_b->next_buffer); - if (dst_left == 0) - { - db->current_length = dp - (u8 *) vlib_buffer_get_current (db); - ASSERT (db->flags & VLIB_BUFFER_NEXT_PRESENT); - db = vlib_get_buffer (vm, db->next_buffer); - dst_left = data_size; - if (db->current_data > 0) + if (PREDICT_TRUE (1 == next_dst_b->ref_count)) { - db->current_data = 0; + /* normal case: buffer is not cloned, just use it */ + dst_b = next_dst_b; } else { - dst_left += -db->current_data; + /* cloned buffer, build a new dest chain from there */ + vlib_buffer_t *bufs[VLIB_BUFFER_LINEARIZE_MAX]; + u32 bis[VLIB_BUFFER_LINEARIZE_MAX + 1]; + const int n = (rem_len + data_size - 1) / data_size; + int n_alloc; + int i; + + ASSERT (n <= VLIB_BUFFER_LINEARIZE_MAX); + if (PREDICT_FALSE (n > VLIB_BUFFER_LINEARIZE_MAX)) + return 0; + + n_alloc = vlib_buffer_alloc (vm, bis, n); + if (PREDICT_FALSE (n_alloc != n)) + { + vlib_buffer_free (vm, bis, n_alloc); + return 0; + } + + vlib_get_buffers (vm, bis, bufs, n); + + for (i = 0; i < n - 1; i++) + { + bufs[i]->flags |= VLIB_BUFFER_NEXT_PRESENT; + bufs[i]->next_buffer = bis[i + 1]; + } + + to_free = dst_b->next_buffer; + dst_b->next_buffer = bis[0]; + dst_b = bufs[0]; } - dp = vlib_buffer_get_current (db); - } - while (src_left == 0) - { - ASSERT (sb->flags & VLIB_BUFFER_NEXT_PRESENT); - sb = vlib_get_buffer (vm, sb->next_buffer); - src_left = sb->current_length; - sp = vlib_buffer_get_current (sb); + n_buffers++; + + dst_b->current_data = clib_min (0, dst_b->current_data); + dst_b->current_length = 0; + + dst = dst_b->data + dst_b->current_data; + dst_len = data_size - dst_b->current_data; } - bytes_to_copy = clib_min (dst_left, src_left); + copy_len = clib_min (src_len, dst_len); - if (dp != sp) + if (PREDICT_TRUE (src == dst)) { - if (sb == db) - bytes_to_copy = clib_min (bytes_to_copy, sp - dp); - - clib_memcpy_fast (dp, sp, bytes_to_copy); + /* nothing to do */ + } + else if (src + copy_len > dst && dst + copy_len > src) + { + /* src and dst overlap */ + ASSERT (b == dst_b); + memmove (dst, src, copy_len); + } + else + { + clib_memcpy_fast (dst, src, copy_len); } - src_left -= bytes_to_copy; - dst_left -= bytes_to_copy; - dp += bytes_to_copy; - sp += bytes_to_copy; - bytes_left -= bytes_to_copy; + dst_b->current_length += copy_len; + + dst += copy_len; + src += copy_len; + dst_len -= copy_len; + src_len -= copy_len; + rem_len -= copy_len; } - if (db != first) - db->current_data = 0; - db->current_length = dp - (u8 *) vlib_buffer_get_current (db); - if (is_cloned && to_free) + /* in case of a malformed chain buffer, we'll exit early from the loop. */ + ASSERT (0 == rem_len); + b->total_length_not_including_first_buffer -= rem_len; + + if (to_free) vlib_buffer_free_one (vm, to_free); - else + + if (dst_b->flags & VLIB_BUFFER_NEXT_PRESENT) { - if (db->flags & VLIB_BUFFER_NEXT_PRESENT) - vlib_buffer_free_one (vm, db->next_buffer); - db->flags &= ~VLIB_BUFFER_NEXT_PRESENT; - b = first; - n_buffers = 1; - while (b->flags & VLIB_BUFFER_NEXT_PRESENT) + /* the resulting chain is smaller than the original, cut it there */ + dst_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT; + vlib_buffer_free_one (vm, dst_b->next_buffer); + if (1 == n_buffers) { - b = vlib_get_buffer (vm, b->next_buffer); - ++n_buffers; + /* no longer a chained buffer */ + dst_b->flags &= ~VLIB_BUFFER_TOTAL_LENGTH_VALID; + dst_b->total_length_not_including_first_buffer = 0; } } - first->flags &= ~VLIB_BUFFER_TOTAL_LENGTH_VALID; - return n_buffers; }