From 49433adb9145bfd3a9cbaa99b01c6c14aeda71a4 Mon Sep 17 00:00:00 2001 From: Dave Barach Date: Wed, 8 Aug 2018 17:59:03 -0400 Subject: Thread-safe ARP / ND throttling Change-Id: I810d834c407bd404d5f0544cdec0674f0bb92d31 Signed-off-by: Dave Barach Signed-off-by: Dave Barach --- src/vnet/ip/ip6_neighbor.c | 59 +++++++++++++++++----------------------------- 1 file changed, 21 insertions(+), 38 deletions(-) (limited to 'src/vnet/ip/ip6_neighbor.c') diff --git a/src/vnet/ip/ip6_neighbor.c b/src/vnet/ip/ip6_neighbor.c index 6227ed6dfb0..fff81749ea2 100644 --- a/src/vnet/ip/ip6_neighbor.c +++ b/src/vnet/ip/ip6_neighbor.c @@ -3165,10 +3165,9 @@ ip6_discover_neighbor_inline (vlib_main_t * vm, ip_lookup_main_t *lm = &im->lookup_main; u32 *from, *to_next_drop; uword n_left_from, n_left_to_next_drop; - static f64 time_last_seed_change = -1e100; - static u32 hash_seeds[3]; - static uword hash_bitmap[256 / BITS (uword)]; f64 time_now; + u64 seed; + u32 thread_index = vm->thread_index; int bogus_length; ip6_neighbor_main_t *nm = &ip6_neighbor_main; @@ -3176,20 +3175,15 @@ ip6_discover_neighbor_inline (vlib_main_t * vm, ip6_forward_next_trace (vm, node, frame, VLIB_TX); time_now = vlib_time_now (vm); - if (time_now - time_last_seed_change > 1e-3) + if (time_now - im->nd_throttle_last_seed_change_time[thread_index] > 1e-3) { - uword i; - u32 *r = clib_random_buffer_get_data (&vm->random_buffer, - sizeof (hash_seeds)); - for (i = 0; i < ARRAY_LEN (hash_seeds); i++) - hash_seeds[i] = r[i]; + (void) random_u64 (&im->nd_throttle_seeds[thread_index]); + memset (im->nd_throttle_bitmaps[thread_index], 0, + ND_THROTTLE_BITS / BITS (u8)); - /* Mark all hash keys as been not-seen before. */ - for (i = 0; i < ARRAY_LEN (hash_bitmap); i++) - hash_bitmap[i] = 0; - - time_last_seed_change = time_now; + im->nd_throttle_last_seed_change_time[thread_index] = time_now; } + seed = im->nd_throttle_seeds[thread_index]; from = vlib_frame_vector_args (frame); n_left_from = frame->n_vectors; @@ -3203,8 +3197,9 @@ ip6_discover_neighbor_inline (vlib_main_t * vm, { vlib_buffer_t *p0; ip6_header_t *ip0; - u32 pi0, adj_index0, a0, b0, c0, m0, sw_if_index0, drop0; - uword bm0; + u32 pi0, adj_index0, w0, sw_if_index0, drop0; + u64 r0; + uword m0; ip_adjacency_t *adj0; vnet_hw_interface_t *hw_if0; ip6_radv_t *radv_info; @@ -3228,33 +3223,21 @@ ip6_discover_neighbor_inline (vlib_main_t * vm, adj0->sub_type.nbr.next_hop.ip6.as_u64[1]; } - a0 = hash_seeds[0]; - b0 = hash_seeds[1]; - c0 = hash_seeds[2]; - sw_if_index0 = adj0->rewrite_header.sw_if_index; vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0; - a0 ^= sw_if_index0; - b0 ^= ip0->dst_address.as_u32[0]; - c0 ^= ip0->dst_address.as_u32[1]; - - hash_v3_mix32 (a0, b0, c0); - - b0 ^= ip0->dst_address.as_u32[2]; - c0 ^= ip0->dst_address.as_u32[3]; - - hash_v3_finalize32 (a0, b0, c0); - - c0 &= BITS (hash_bitmap) - 1; - c0 = c0 / BITS (uword); - m0 = (uword) 1 << (c0 % BITS (uword)); + /* Compute the ND throttle bitmap hash */ + r0 = ip0->dst_address.as_u64[0] ^ ip0->dst_address.as_u64[1] ^ seed; - bm0 = hash_bitmap[c0]; - drop0 = (bm0 & m0) != 0; + /* Find the word and bit */ + r0 &= ND_THROTTLE_BITS - 1; + w0 = r0 / BITS (uword); + m0 = (uword) 1 << (r0 % BITS (uword)); - /* Mark it as seen. */ - hash_bitmap[c0] = bm0 | m0; + /* If the bit is set, drop the ND request */ + drop0 = (im->nd_throttle_bitmaps[thread_index][w0] & m0) != 0; + /* (unconditionally) mark the bit "inuse" */ + im->nd_throttle_bitmaps[thread_index][w0] |= m0; from += 1; n_left_from -= 1; -- cgit 1.2.3-korg