From 49433adb9145bfd3a9cbaa99b01c6c14aeda71a4 Mon Sep 17 00:00:00 2001 From: Dave Barach Date: Wed, 8 Aug 2018 17:59:03 -0400 Subject: [PATCH] Thread-safe ARP / ND throttling Change-Id: I810d834c407bd404d5f0544cdec0674f0bb92d31 Signed-off-by: Dave Barach Signed-off-by: Dave Barach --- src/vnet/ip/ip4.h | 8 +++++++ src/vnet/ip/ip4_forward.c | 55 ++++++++++++++++-------------------------- src/vnet/ip/ip4_input.c | 22 +++++++++++++++++ src/vnet/ip/ip6.h | 8 +++++++ src/vnet/ip/ip6_input.c | 26 ++++++++++++++++++-- src/vnet/ip/ip6_neighbor.c | 59 +++++++++++++++++----------------------------- 6 files changed, 103 insertions(+), 75 deletions(-) diff --git a/src/vnet/ip/ip4.h b/src/vnet/ip/ip4.h index fcef559010c..e3cbe27dd89 100644 --- a/src/vnet/ip/ip4.h +++ b/src/vnet/ip/ip4.h @@ -154,8 +154,16 @@ typedef struct ip4_main_t /** The memory heap for the mtries */ void *mtrie_mheap; + + /** ARP throttling */ + uword **arp_throttle_bitmaps; + u32 *arp_throttle_seeds; + f64 *arp_throttle_last_seed_change_time; + } ip4_main_t; +#define ARP_THROTTLE_BITS (512) + /** Global ip4 main structure. */ extern ip4_main_t ip4_main; diff --git a/src/vnet/ip/ip4_forward.c b/src/vnet/ip/ip4_forward.c index 8d4aead051e..11bcf3a9435 100644 --- a/src/vnet/ip/ip4_forward.c +++ b/src/vnet/ip/ip4_forward.c @@ -1722,29 +1722,23 @@ ip4_arp_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, next_index; - static f64 time_last_seed_change = -1e100; - static u32 hash_seeds[3]; - static uword hash_bitmap[256 / BITS (uword)]; + u32 thread_index = vm->thread_index; + u32 seed; f64 time_now; if (node->flags & VLIB_NODE_FLAG_TRACE) ip4_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->arp_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]; - - /* Mark all hash keys as been no-seen before. */ - for (i = 0; i < ARRAY_LEN (hash_bitmap); i++) - hash_bitmap[i] = 0; + (void) random_u32 (&im->arp_throttle_seeds[thread_index]); + memset (im->arp_throttle_bitmaps[thread_index], 0, + ARP_THROTTLE_BITS / BITS (u8)); - time_last_seed_change = time_now; + im->arp_throttle_last_seed_change_time[thread_index] = time_now; } + seed = im->arp_throttle_seeds[thread_index]; from = vlib_frame_vector_args (frame); n_left_from = frame->n_vectors; @@ -1759,11 +1753,11 @@ ip4_arp_inline (vlib_main_t * vm, while (n_left_from > 0 && n_left_to_next_drop > 0) { - u32 pi0, adj_index0, a0, b0, c0, m0, sw_if_index0, drop0; + u32 pi0, adj_index0, r0, w0, sw_if_index0, drop0; + uword m0; ip_adjacency_t *adj0; vlib_buffer_t *p0; ip4_header_t *ip0; - uword bm0; pi0 = from[0]; @@ -1773,39 +1767,30 @@ ip4_arp_inline (vlib_main_t * vm, adj0 = adj_get (adj_index0); ip0 = vlib_buffer_get_current (p0); - 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; - if (is_glean) + if (PREDICT_TRUE (is_glean)) { /* * this is the Glean case, so we are ARPing for the * packet's destination */ - a0 ^= ip0->dst_address.data_u32; + r0 = ip0->dst_address.data_u32; } else { - a0 ^= adj0->sub_type.nbr.next_hop.ip4.data_u32; + r0 = adj0->sub_type.nbr.next_hop.ip4.data_u32; } - b0 ^= sw_if_index0; - - hash_v3_mix32 (a0, b0, c0); - hash_v3_finalize32 (a0, b0, c0); - - c0 &= BITS (hash_bitmap) - 1; - m0 = (uword) 1 << (c0 % BITS (uword)); - c0 = c0 / BITS (uword); - bm0 = hash_bitmap[c0]; - drop0 = (bm0 & m0) != 0; + r0 ^= seed; + /* Select bit number */ + r0 &= ARP_THROTTLE_BITS - 1; + w0 = r0 / BITS (uword); + m0 = (uword) 1 << (r0 % BITS (uword)); - /* Mark it as seen. */ - hash_bitmap[c0] = bm0 | m0; + drop0 = (im->arp_throttle_bitmaps[thread_index][w0] & m0) != 0; + im->arp_throttle_bitmaps[thread_index][w0] |= m0; from += 1; n_left_from -= 1; diff --git a/src/vnet/ip/ip4_input.c b/src/vnet/ip/ip4_input.c index 971445c7cd0..d11d558eb93 100644 --- a/src/vnet/ip/ip4_input.c +++ b/src/vnet/ip/ip4_input.c @@ -383,6 +383,28 @@ ip4_init (vlib_main_t * vm) } VLIB_INIT_FUNCTION (ip4_init); + +static clib_error_t * +ip4_main_loop_enter (vlib_main_t * vm) +{ + ip4_main_t *im = &ip4_main; + vlib_thread_main_t *tm = &vlib_thread_main; + u32 n_vlib_mains = tm->n_vlib_mains; + int i; + + + vec_validate (im->arp_throttle_bitmaps, n_vlib_mains); + vec_validate (im->arp_throttle_seeds, n_vlib_mains); + vec_validate (im->arp_throttle_last_seed_change_time, n_vlib_mains); + + for (i = 0; i < n_vlib_mains; i++) + vec_validate (im->arp_throttle_bitmaps[i], + (ARP_THROTTLE_BITS / BITS (uword)) - 1); + return 0; +} + +VLIB_MAIN_LOOP_ENTER_FUNCTION (ip4_main_loop_enter); + #endif /* diff --git a/src/vnet/ip/ip6.h b/src/vnet/ip/ip6.h index 8b1516cf353..a6feec5685e 100644 --- a/src/vnet/ip/ip6.h +++ b/src/vnet/ip/ip6.h @@ -219,8 +219,16 @@ typedef struct ip6_main_t /* HBH processing enabled? */ u8 hbh_enabled; + + /** ND throttling */ + uword **nd_throttle_bitmaps; + u64 *nd_throttle_seeds; + f64 *nd_throttle_last_seed_change_time; + } ip6_main_t; +#define ND_THROTTLE_BITS 512 + /* Global ip6 main structure. */ extern ip6_main_t ip6_main; diff --git a/src/vnet/ip/ip6_input.c b/src/vnet/ip/ip6_input.c index 6a7669db297..977d2703d19 100644 --- a/src/vnet/ip/ip6_input.c +++ b/src/vnet/ip/ip6_input.c @@ -246,8 +246,10 @@ VLIB_REGISTER_NODE (ip6_input_node) = { }; /* *INDENT-ON* */ -VLIB_NODE_FUNCTION_MULTIARCH (ip6_input_node, ip6_input) - static clib_error_t *ip6_init (vlib_main_t * vm) +VLIB_NODE_FUNCTION_MULTIARCH (ip6_input_node, ip6_input); + +static clib_error_t * +ip6_init (vlib_main_t * vm) { ethernet_register_input_type (vm, ETHERNET_TYPE_IP6, ip6_input_node.index); ppp_register_input_protocol (vm, PPP_PROTOCOL_ip6, ip6_input_node.index); @@ -270,6 +272,26 @@ VLIB_NODE_FUNCTION_MULTIARCH (ip6_input_node, ip6_input) VLIB_INIT_FUNCTION (ip6_init); +static clib_error_t * +ip6_main_loop_enter (vlib_main_t * vm) +{ + ip6_main_t *im = &ip6_main; + vlib_thread_main_t *tm = &vlib_thread_main; + u32 n_vlib_mains = tm->n_vlib_mains; + int i; + + vec_validate (im->nd_throttle_bitmaps, n_vlib_mains); + vec_validate (im->nd_throttle_seeds, n_vlib_mains); + vec_validate (im->nd_throttle_last_seed_change_time, n_vlib_mains); + + for (i = 0; i < n_vlib_mains; i++) + vec_validate (im->nd_throttle_bitmaps[i], + (ND_THROTTLE_BITS / BITS (uword)) - 1); + return 0; +} + +VLIB_MAIN_LOOP_ENTER_FUNCTION (ip6_main_loop_enter); + /* * fd.io coding-style-patch-verification: ON * 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; -- 2.16.6