diff options
Diffstat (limited to 'src/vnet/ip/ip4_reassembly.c')
| -rw-r--r-- | src/vnet/ip/ip4_reassembly.c | 1277 |
1 files changed, 1277 insertions, 0 deletions
diff --git a/src/vnet/ip/ip4_reassembly.c b/src/vnet/ip/ip4_reassembly.c new file mode 100644 index 00000000000..6b8d66532fa --- /dev/null +++ b/src/vnet/ip/ip4_reassembly.c @@ -0,0 +1,1277 @@ +/* + * Copyright (c) 2017 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. + */ + +/** + * @file + * @brief IPv4 Reassembly. + * + * This file contains the source code for IPv4 reassembly. + */ + +#include <vppinfra/vec.h> +#include <vnet/vnet.h> +#include <vnet/ip/ip.h> +#include <vppinfra/bihash_24_8.h> +#include <vnet/ip/ip4_reassembly.h> + +#define MSEC_PER_SEC 1000 +#define IP4_REASS_TIMEOUT_DEFAULT_MS 100 +#define IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS 10000 // 10 seconds default +#define IP4_REASS_MAX_REASSEMBLIES_DEAFULT 1024 +#define IP4_REASS_HT_LOAD_FACTOR (0.75) + +#define IP4_REASS_DEBUG_BUFFERS 0 +#if IP4_REASS_DEBUG_BUFFERS +#define IP4_REASS_DEBUG_BUFFER(bi, what) \ + do \ + { \ + u32 _bi = bi; \ + printf (#what "buffer %u", _bi); \ + vlib_buffer_t *_b = vlib_get_buffer (vm, _bi); \ + while (_b->flags & VLIB_BUFFER_NEXT_PRESENT) \ + { \ + _bi = _b->next_buffer; \ + printf ("[%u]", _bi); \ + _b = vlib_get_buffer (vm, _bi); \ + } \ + printf ("\n"); \ + fflush (stdout); \ + } \ + while (0) +#else +#define IP4_REASS_DEBUG_BUFFER(...) +#endif + +static vlib_node_registration_t ip4_reass_node; + +typedef struct +{ + union + { + struct + { + // align by making this 4 octets even though its a 2 octets field + u32 xx_id; + ip4_address_t src; + ip4_address_t dst; + // align by making this 4 octets even though its a 2 octets field + u32 frag_id; + // align by making this 4 octets even though its a 1 octet field + u32 proto; + u32 unused; + }; + u64 as_u64[3]; + }; +} ip4_reass_key_t; + +always_inline u32 +ip4_reass_buffer_get_data_offset_no_check (vlib_buffer_t * b) +{ + vnet_buffer_opaque_t *vnb = vnet_buffer (b); + return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first; +} + +always_inline u32 +ip4_reass_buffer_get_data_offset (vlib_buffer_t * b) +{ + vnet_buffer_opaque_t *vnb = vnet_buffer (b); + ASSERT (vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first); + return ip4_reass_buffer_get_data_offset_no_check (b); +} + +always_inline u16 +ip4_reass_buffer_get_data_len_no_check (vlib_buffer_t * b) +{ + vnet_buffer_opaque_t *vnb = vnet_buffer (b); + return clib_min (vnb->ip.reass.range_last, vnb->ip.reass.fragment_last) - + (vnb->ip.reass.fragment_first + ip4_reass_buffer_get_data_offset (b)) + 1; +} + +always_inline u16 +ip4_reass_buffer_get_data_len (vlib_buffer_t * b) +{ + vnet_buffer_opaque_t *vnb = vnet_buffer (b); + ASSERT (vnb->ip.reass.range_last > vnb->ip.reass.fragment_first); + return ip4_reass_buffer_get_data_len_no_check (b); +} + +typedef struct +{ + // hash table key + ip4_reass_key_t key; + f64 first_heard; + // time when last packet was received + f64 last_heard; + // internal id of this reassembly + u32 id; + // buffer index of first buffer in this reassembly context + u32 first_bi; + // last octet of packet, ~0 until fragment without more_fragments arrives + u32 last_packet_octet; + // length of data collected so far + u32 data_len; + // trace operation counter + u32 trace_op_counter; +} ip4_reass_t; + +typedef struct +{ + // IPv4 config + u32 timeout_ms; + f64 timeout; + u32 expire_walk_interval_ms; + u32 max_reass_n; + + // IPv4 runtime + ip4_reass_t *pool; + clib_bihash_24_8_t hash; + u32 reass_n; + u32 id_counter; + u32 buffers_n; + + // convenience + vlib_main_t *vlib_main; + vnet_main_t *vnet_main; + + // node index of ip4-drop node + u32 ip4_drop_idx; + u32 ip4_reass_expire_node_idx; + +} ip4_reass_main_t; + +ip4_reass_main_t ip4_reass_main; + +typedef enum +{ + IP4_REASSEMBLY_NEXT_INPUT, + IP4_REASSEMBLY_NEXT_DROP, + IP4_REASSEMBLY_N_NEXT, +} ip4_reass_next_t; + +typedef enum +{ + RANGE_NEW, + RANGE_SHRINK, + RANGE_DISCARD, + RANGE_OVERLAP, + FINALIZE, +} ip4_reass_trace_operation_e; + +typedef struct +{ + u16 range_first; + u16 range_last; + u32 range_bi; + i32 data_offset; + u32 data_len; + u32 first_bi; +} ip4_reass_range_trace_t; + +typedef struct +{ + ip4_reass_trace_operation_e action; + u32 pool_index; + u32 reass_id; + ip4_reass_range_trace_t trace_range; + u32 size_diff; + u32 op_id; + u32 fragment_first; + u32 fragment_last; + u32 total_data_len; +} ip4_reass_trace_t; + +void +ip4_reass_trace_details (vlib_main_t * vm, u32 bi, + ip4_reass_range_trace_t * trace) +{ + vlib_buffer_t *b = vlib_get_buffer (vm, bi); + vnet_buffer_opaque_t *vnb = vnet_buffer (b); + trace->range_first = vnb->ip.reass.range_first; + trace->range_last = vnb->ip.reass.range_last; + trace->data_offset = ip4_reass_buffer_get_data_offset_no_check (b); + trace->data_len = ip4_reass_buffer_get_data_len_no_check (b); + trace->range_bi = bi; +} + +u8 * +format_ip4_reass_range_trace (u8 * s, va_list * args) +{ + ip4_reass_range_trace_t *trace = va_arg (*args, ip4_reass_range_trace_t *); + s = format (s, "range: [%u, %u], off %d, len %u, bi %u", trace->range_first, + trace->range_last, trace->data_offset, trace->data_len, + trace->range_bi); + return s; +} + +u8 * +format_ip4_reass_trace (u8 * s, va_list * args) +{ + CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); + CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); + ip4_reass_trace_t *t = va_arg (*args, ip4_reass_trace_t *); + s = format (s, "reass id: %u, op id: %u ", t->reass_id, t->op_id); + u32 indent = format_get_indent (s); + s = format (s, "first bi: %u, data len: %u, ip/fragment[%u, %u]", + t->trace_range.first_bi, t->total_data_len, t->fragment_first, + t->fragment_last); + switch (t->action) + { + case RANGE_SHRINK: + s = format (s, "\n%Ushrink %U by %u", format_white_space, indent, + format_ip4_reass_range_trace, &t->trace_range, + t->size_diff); + break; + case RANGE_DISCARD: + s = format (s, "\n%Udiscard %U", format_white_space, indent, + format_ip4_reass_range_trace, &t->trace_range); + break; + case RANGE_NEW: + s = format (s, "\n%Unew %U", format_white_space, indent, + format_ip4_reass_range_trace, &t->trace_range); + break; + case RANGE_OVERLAP: + s = format (s, "\n%Uoverlapping/ignored %U", format_white_space, indent, + format_ip4_reass_range_trace, &t->trace_range); + break; + case FINALIZE: + s = format (s, "\n%Ufinalize reassembly", format_white_space, indent); + break; + } + return s; +} + +void +ip4_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node, + ip4_reass_main_t * rm, ip4_reass_t * reass, u32 bi, + ip4_reass_trace_operation_e action, u32 size_diff) +{ + vlib_buffer_t *b = vlib_get_buffer (vm, bi); + vnet_buffer_opaque_t *vnb = vnet_buffer (b); + ip4_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0])); + t->pool_index = reass - rm->pool; + t->reass_id = reass->id; + t->action = action; + ip4_reass_trace_details (vm, bi, &t->trace_range); + t->size_diff = size_diff; + t->op_id = reass->trace_op_counter; + ++reass->trace_op_counter; + t->fragment_first = vnb->ip.reass.fragment_first; + t->fragment_last = vnb->ip.reass.fragment_last; + t->trace_range.first_bi = reass->first_bi; + t->total_data_len = reass->data_len; +#if 0 + static u8 *s = NULL; + s = format (s, "%U", format_ip4_reass_trace, NULL, NULL, t); + printf ("%.*s\n", vec_len (s), s); + fflush (stdout); + vec_reset_length (s); +#endif +} + +void +ip4_reass_free (ip4_reass_main_t * rm, ip4_reass_t * reass) +{ + clib_bihash_kv_24_8_t kv; + kv.key[0] = reass->key.as_u64[0]; + kv.key[1] = reass->key.as_u64[1]; + kv.key[2] = reass->key.as_u64[2]; + clib_bihash_add_del_24_8 (&rm->hash, &kv, 0); + pool_put (rm->pool, reass); + --rm->reass_n; +} + +static void +ip4_reass_on_timeout (vlib_main_t * vm, ip4_reass_main_t * rm, + ip4_reass_t * reass, u32 ** vec_drop_timeout) +{ + u32 range_bi = reass->first_bi; + vlib_buffer_t *range_b; + vnet_buffer_opaque_t *range_vnb; + while (~0 != range_bi) + { + range_b = vlib_get_buffer (vm, range_bi); + range_vnb = vnet_buffer (range_b); + u32 bi = range_bi; + while (~0 != bi) + { + vec_add1 (*vec_drop_timeout, bi); + vlib_buffer_t *b = vlib_get_buffer (vm, bi); + if (b->flags & VLIB_BUFFER_NEXT_PRESENT) + { + bi = b->next_buffer; + b->flags &= ~VLIB_BUFFER_NEXT_PRESENT; + } + else + { + bi = ~0; + } + } + range_bi = range_vnb->ip.reass.next_range_bi; + } +} + +ip4_reass_t * +ip4_reass_find_or_create (vlib_main_t * vm, ip4_reass_main_t * rm, + ip4_reass_key_t * k, u32 ** vec_drop_timeout) +{ + ip4_reass_t *reass = NULL; + f64 now = vlib_time_now (rm->vlib_main); + clib_bihash_kv_24_8_t kv, value; + kv.key[0] = k->as_u64[0]; + kv.key[1] = k->as_u64[1]; + kv.key[2] = k->as_u64[2]; + + if (!clib_bihash_search_24_8 (&rm->hash, &kv, &value)) + { + reass = pool_elt_at_index (rm->pool, value.value); + if (now > reass->last_heard + rm->timeout) + { + ip4_reass_on_timeout (vm, rm, reass, vec_drop_timeout); + ip4_reass_free (rm, reass); + reass = NULL; + } + } + + if (reass) + { + reass->last_heard = now; + return reass; + } + + if (rm->reass_n >= rm->max_reass_n) + { + reass = NULL; + return reass; + } + else + { + pool_get (rm->pool, reass); + memset (reass, 0, sizeof (*reass)); + reass->id = rm->id_counter; + ++rm->id_counter; + reass->first_bi = ~0; + reass->last_packet_octet = ~0; + reass->data_len = 0; + ++rm->reass_n; + } + + reass->key.as_u64[0] = kv.key[0] = k->as_u64[0]; + reass->key.as_u64[1] = kv.key[1] = k->as_u64[1]; + reass->key.as_u64[2] = kv.key[2] = k->as_u64[2]; + kv.value = reass - rm->pool; + reass->last_heard = now; + + if (clib_bihash_add_del_24_8 (&rm->hash, &kv, 1)) + { + ip4_reass_free (rm, reass); + reass = NULL; + } + + return reass; +} + +void +ip4_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node, + ip4_reass_main_t * rm, ip4_reass_t * reass, u32 * bi0, + u32 * next0, vlib_error_t * error0, u32 next_input, + u32 ** vec_drop_compress, u32 ** vec_drop_overlap) +{ + ASSERT (~0 != reass->first_bi); + vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi); + vlib_buffer_t *last_b = NULL; + u32 sub_chain_bi = reass->first_bi; + u32 total_length = 0; + u32 buf_cnt = 0; + u32 dropped_cnt = 0; + do + { + u32 tmp_bi = sub_chain_bi; + vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi); + ip4_header_t *ip = vlib_buffer_get_current (tmp); + u32 data_len = ip4_reass_buffer_get_data_len (tmp); + u32 trim_front = + ip4_header_bytes (ip) + ip4_reass_buffer_get_data_offset (tmp); + u32 trim_end = + vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len; + if (tmp_bi == reass->first_bi) + { + /* first buffer - keep ip4 header */ + ASSERT (0 == ip4_reass_buffer_get_data_offset (tmp)); + trim_front = 0; + trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len - + ip4_header_bytes (ip); + } + u32 keep_data = + vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end; + while (1) + { + ++buf_cnt; + if (trim_front) + { + if (trim_front > tmp->current_length) + { + /* drop whole buffer */ + vec_add1 (*vec_drop_compress, tmp_bi); + ++dropped_cnt; + trim_front -= tmp->current_length; + ASSERT (tmp->flags & VLIB_BUFFER_NEXT_PRESENT); + tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT; + tmp_bi = tmp->next_buffer; + tmp = vlib_get_buffer (vm, tmp_bi); + continue; + } + else + { + vlib_buffer_advance (tmp, trim_front); + trim_front = 0; + } + } + if (keep_data) + { + if (last_b) + { + last_b->flags |= VLIB_BUFFER_NEXT_PRESENT; + last_b->next_buffer = tmp_bi; + } + last_b = tmp; + if (keep_data <= tmp->current_length) + { + tmp->current_length = keep_data; + keep_data = 0; + } + else + { + keep_data -= tmp->current_length; + ASSERT (tmp->flags & VLIB_BUFFER_NEXT_PRESENT); + } + total_length += tmp->current_length; + } + else + { + vec_add1 (*vec_drop_overlap, tmp_bi); + ASSERT (reass->first_bi != tmp_bi); + ++dropped_cnt; + } + if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT) + { + tmp_bi = tmp->next_buffer; + tmp = vlib_get_buffer (vm, tmp->next_buffer); + } + else + { + break; + } + } + sub_chain_bi = + vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip. + reass.next_range_bi; + } + while (~0 != sub_chain_bi); + last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT; + ASSERT (rm->buffers_n >= (buf_cnt - dropped_cnt)); + rm->buffers_n -= buf_cnt - dropped_cnt; + ASSERT (total_length >= first_b->current_length); + total_length -= first_b->current_length; + first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID; + first_b->total_length_not_including_first_buffer = total_length; + ip4_header_t *ip = vlib_buffer_get_current (first_b); + ip->flags_and_fragment_offset = 0; + ip->length = clib_host_to_net_u16 (first_b->current_length + total_length); + ip->checksum = ip4_header_checksum (ip); + vlib_buffer_chain_compress (vm, first_b, vec_drop_compress); + if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED)) + { + ip4_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0); +#if 0 + // following code does a hexdump of packet fragments to stdout ... + do + { + u32 bi = reass->first_bi; + u8 *s = NULL; + while (~0 != bi) + { + vlib_buffer_t *b = vlib_get_buffer (vm, bi); + s = format (s, "%u: %U\n", bi, format_hexdump, + vlib_buffer_get_current (b), b->current_length); + if (b->flags & VLIB_BUFFER_NEXT_PRESENT) + { + bi = b->next_buffer; + } + else + { + break; + } + } + printf ("%.*s\n", vec_len (s), s); + fflush (stdout); + vec_free (s); + } + while (0); +#endif + } + *bi0 = reass->first_bi; + *next0 = next_input; + *error0 = IP4_ERROR_NONE; + ip4_reass_free (rm, reass); + reass = NULL; +} + +static u32 +ip4_reass_get_buffer_chain_length (vlib_main_t * vm, vlib_buffer_t * b) +{ + u32 len = 0; + while (b) + { + ++len; + if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT)) + { + b = vlib_get_buffer (vm, b->next_buffer); + } + else + { + break; + } + } + return len; +} + +static void +ip4_reass_insert_range_in_chain (vlib_main_t * vm, + ip4_reass_main_t * rm, + ip4_reass_t * reass, + u32 prev_range_bi, u32 new_next_bi) +{ + + vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi); + vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b); + if (~0 != prev_range_bi) + { + vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi); + vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b); + new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi; + prev_vnb->ip.reass.next_range_bi = new_next_bi; + } + else + { + if (~0 != reass->first_bi) + { + new_next_vnb->ip.reass.next_range_bi = reass->first_bi; + } + reass->first_bi = new_next_bi; + } + reass->data_len += ip4_reass_buffer_get_data_len (new_next_b); + rm->buffers_n += ip4_reass_get_buffer_chain_length (vm, new_next_b); +} + +static void +ip4_reass_remove_range_from_chain (vlib_main_t * vm, + vlib_node_runtime_t * node, + ip4_reass_main_t * rm, + u32 ** vec_drop_overlap, + ip4_reass_t * reass, u32 prev_range_bi, + u32 discard_bi) +{ + vlib_buffer_t *discard_b = vlib_get_buffer (vm, discard_bi); + vnet_buffer_opaque_t *discard_vnb = vnet_buffer (discard_b); + if (~0 != prev_range_bi) + { + vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi); + vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b); + ASSERT (prev_vnb->ip.reass.next_range_bi == discard_bi); + prev_vnb->ip.reass.next_range_bi = discard_vnb->ip.reass.next_range_bi; + } + else + { + reass->first_bi = discard_vnb->ip.reass.next_range_bi; + } + reass->data_len -= ip4_reass_buffer_get_data_len (discard_b); + while (1) + { + vec_add1 (*vec_drop_overlap, discard_bi); + if (PREDICT_FALSE (discard_b->flags & VLIB_BUFFER_IS_TRACED)) + { + ip4_reass_add_trace (vm, node, rm, reass, discard_bi, RANGE_DISCARD, + 0); + } + if (discard_b->flags & VLIB_BUFFER_NEXT_PRESENT) + { + discard_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT; + discard_bi = discard_b->next_buffer; + discard_b = vlib_get_buffer (vm, discard_bi); + } + else + { + break; + } + } +} + +void +ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node, + ip4_reass_main_t * rm, ip4_reass_t * reass, u32 * bi0, + u32 * next0, vlib_error_t * error0, + u32 ** vec_drop_overlap, u32 ** vec_drop_compress, + u32 next_input, u32 next_drop) +{ + int consumed = 0; + vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0); + ip4_header_t *fip = vlib_buffer_get_current (fb); + ASSERT (fb->current_length >= sizeof (*fip)); + vnet_buffer_opaque_t *fvnb = vnet_buffer (fb); + u32 fragment_first = fvnb->ip.reass.fragment_first = + ip4_get_fragment_offset_bytes (fip); + u32 fragment_length = + clib_net_to_host_u16 (fip->length) - ip4_header_bytes (fip); + u32 fragment_last = fvnb->ip.reass.fragment_last = + fragment_first + fragment_length - 1; + int more_fragments = ip4_get_fragment_more (fip); + u32 candidate_range_bi = reass->first_bi; + u32 prev_range_bi = ~0; + fvnb->ip.reass.range_first = fragment_first; + fvnb->ip.reass.range_last = fragment_last; + fvnb->ip.reass.next_range_bi = ~0; + if (!more_fragments) + { + reass->last_packet_octet = fragment_last; + } + if (~0 == reass->first_bi) + { + // starting a new reassembly + ip4_reass_insert_range_in_chain (vm, rm, reass, prev_range_bi, *bi0); + if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED)) + { + ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0); + } + *bi0 = ~0; + fvnb->ip.reass.estimated_mtu = clib_net_to_host_u16 (fip->length); + return; + } + fvnb->ip.reass.estimated_mtu = clib_min (clib_net_to_host_u16 (fip->length), + fvnb->ip.reass.estimated_mtu); + while (~0 != candidate_range_bi) + { + vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi); + vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b); + if (fragment_first > candidate_vnb->ip.reass.range_last) + { + // this fragments starts after candidate range + prev_range_bi = candidate_range_bi; + candidate_range_bi = candidate_vnb->ip.reass.next_range_bi; + if (candidate_vnb->ip.reass.range_last < fragment_last && + ~0 == candidate_range_bi) + { + // special case - this fragment falls beyond all known ranges + ip4_reass_insert_range_in_chain (vm, rm, reass, prev_range_bi, + *bi0); + consumed = 1; + break; + } + continue; + } + if (fragment_last < candidate_vnb->ip.reass.range_first) + { + // this fragment ends before candidate range without any overlap + ip4_reass_insert_range_in_chain (vm, rm, reass, prev_range_bi, + *bi0); + consumed = 1; + } + else + { + if (fragment_first >= candidate_vnb->ip.reass.range_first && + fragment_last <= candidate_vnb->ip.reass.range_last) + { + // this fragment is a (sub)part of existing range, ignore it + if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED)) + { + ip4_reass_add_trace (vm, node, rm, reass, *bi0, + RANGE_OVERLAP, 0); + } + break; + } + int discard_candidate = 0; + if (fragment_first < candidate_vnb->ip.reass.range_first) + { + u32 overlap = + fragment_last - candidate_vnb->ip.reass.range_first + 1; + if (overlap < ip4_reass_buffer_get_data_len (candidate_b)) + { + candidate_vnb->ip.reass.range_first += overlap; + ASSERT (reass->data_len >= overlap); + reass->data_len -= overlap; + if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED)) + { + ip4_reass_add_trace (vm, node, rm, reass, + candidate_range_bi, RANGE_SHRINK, + overlap); + } + ip4_reass_insert_range_in_chain (vm, rm, reass, + prev_range_bi, *bi0); + consumed = 1; + } + else + { + discard_candidate = 1; + } + } + else if (fragment_last > candidate_vnb->ip.reass.range_last) + { + u32 overlap = + candidate_vnb->ip.reass.range_last - fragment_first + 1; + if (overlap < ip4_reass_buffer_get_data_len (candidate_b)) + { + fvnb->ip.reass.range_first += overlap; + if (~0 != candidate_vnb->ip.reass.next_range_bi) + { + prev_range_bi = candidate_range_bi; + candidate_range_bi = + candidate_vnb->ip.reass.next_range_bi; + continue; + } + else + { + // special case - last range discarded + ip4_reass_insert_range_in_chain (vm, rm, reass, + candidate_range_bi, + *bi0); + consumed = 1; + } + } + else + { + discard_candidate = 1; + } + } + else + { + discard_candidate = 1; + } + if (discard_candidate) + { + u32 next_range_bi = candidate_vnb->ip.reass.next_range_bi; + // discard candidate range, probe next range + ip4_reass_remove_range_from_chain (vm, node, rm, + vec_drop_overlap, reass, + prev_range_bi, + candidate_range_bi); + if (~0 != next_range_bi) + { + candidate_range_bi = next_range_bi; + continue; + } + else + { + // special case - last range discarded + ip4_reass_insert_range_in_chain (vm, rm, reass, + prev_range_bi, *bi0); + consumed = 1; + } + } + } + break; + } + if (consumed) + { + if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED)) + { + ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0); + } + } + if (~0 != reass->last_packet_octet && + reass->data_len == reass->last_packet_octet + 1) + { + ip4_reass_finalize (vm, node, rm, reass, bi0, next0, error0, next_input, + vec_drop_compress, vec_drop_overlap); + } + else + { + if (consumed) + { + *bi0 = ~0; + } + else + { + *next0 = next_drop; + *error0 = IP4_ERROR_REASS_DUPLICATE_FRAGMENT; + } + } +} + +always_inline uword +ip4_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node, + vlib_frame_t * frame) +{ + u32 *from = vlib_frame_vector_args (frame); + u32 n_left_from, n_left_to_next, *to_next, next_index; + ip4_reass_main_t *rm = &ip4_reass_main; + + n_left_from = frame->n_vectors; + next_index = node->cached_next_index; + static u32 *vec_drop_timeout = NULL; // indexes of buffers which timed out + static u32 *vec_drop_overlap = NULL; // indexes of buffers which were discarded due to overlap + static u32 *vec_drop_compress = NULL; // indexes of buffers dicarded due to buffer compression + while (n_left_from > 0 || vec_len (vec_drop_timeout) > 0 || + vec_len (vec_drop_overlap) > 0) + { + vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); + + while (vec_len (vec_drop_timeout) > 0 && n_left_to_next > 0) + { + u32 bi = vec_pop (vec_drop_timeout); + vlib_buffer_t *b = vlib_get_buffer (vm, bi); + b->error = node->errors[IP4_ERROR_REASS_TIMEOUT]; + to_next[0] = bi; + to_next += 1; + n_left_to_next -= 1; + vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, + n_left_to_next, bi, + IP4_REASSEMBLY_NEXT_DROP); + IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout); + ASSERT (rm->buffers_n > 0); + --rm->buffers_n; + } + + while (vec_len (vec_drop_overlap) > 0 && n_left_to_next > 0) + { + u32 bi = vec_pop (vec_drop_overlap); + vlib_buffer_t *b = vlib_get_buffer (vm, bi); + b->error = node->errors[IP4_ERROR_REASS_DUPLICATE_FRAGMENT]; + to_next[0] = bi; + to_next += 1; + n_left_to_next -= 1; + vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, + n_left_to_next, bi, + IP4_REASSEMBLY_NEXT_DROP); + IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_duplicate_fragment); + ASSERT (rm->buffers_n > 0); + --rm->buffers_n; + } + + while (vec_len (vec_drop_compress) > 0 && n_left_to_next > 0) + { + u32 bi = vec_pop (vec_drop_compress); + vlib_buffer_t *b = vlib_get_buffer (vm, bi); + b->error = node->errors[IP4_ERROR_NONE]; + to_next[0] = bi; + to_next += 1; + n_left_to_next -= 1; + vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, + n_left_to_next, bi, + IP4_REASSEMBLY_NEXT_DROP); + IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_compress); + ASSERT (rm->buffers_n > 0); + --rm->buffers_n; + } + + while (n_left_from > 0 && n_left_to_next > 0) + { + u32 bi0; + vlib_buffer_t *b0; + u32 next0; //, error0; + + bi0 = from[0]; + b0 = vlib_get_buffer (vm, bi0); + + ip4_header_t *ip0 = vlib_buffer_get_current (b0); + ip4_reass_key_t k; + k.src.as_u32 = ip0->src_address.as_u32; + k.dst.as_u32 = ip0->dst_address.as_u32; + k.xx_id = vnet_buffer (b0)->sw_if_index[VLIB_RX]; + k.frag_id = ip0->fragment_id; + k.proto = ip0->protocol; + k.unused = 0; + ip4_reass_t *reass = + ip4_reass_find_or_create (vm, rm, &k, &vec_drop_timeout); + + u32 error0 = IP4_ERROR_NONE; + if (reass) + { + ip4_reass_update (vm, node, rm, reass, &bi0, &next0, &error0, + &vec_drop_overlap, &vec_drop_compress, + IP4_REASSEMBLY_NEXT_INPUT, + IP4_REASSEMBLY_NEXT_DROP); + } + else + { + next0 = IP4_REASSEMBLY_NEXT_DROP; + error0 = IP4_ERROR_REASS_LIMIT_REACHED; + } + + b0->error = node->errors[error0]; + + if (bi0 != ~0) + { + to_next[0] = bi0; + to_next += 1; + n_left_to_next -= 1; + vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, + n_left_to_next, bi0, next0); + IP4_REASS_DEBUG_BUFFER (bi0, enqueue_next); + } + + from += 1; + n_left_from -= 1; + } + + vlib_put_next_frame (vm, node, next_index, n_left_to_next); + } + + return frame->n_vectors; +} + +static char *ip4_reassembly_error_strings[] = { +#define _(sym, string) string, + foreach_ip4_error +#undef _ +}; + +/* *INDENT-OFF* */ +VLIB_REGISTER_NODE (ip4_reass_node, static) = { + .function = ip4_reassembly, + .name = "ip4-reassembly", + .vector_size = sizeof (u32), + .format_trace = format_ip4_reass_trace, + .n_errors = ARRAY_LEN (ip4_reassembly_error_strings), + .error_strings = ip4_reassembly_error_strings, + .n_next_nodes = IP4_REASSEMBLY_N_NEXT, + .next_nodes = + { + [IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input", + [IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop", + }, +}; +/* *INDENT-ON* */ + +VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node, ip4_reassembly) + static u32 ip4_reass_get_nbuckets () +{ + ip4_reass_main_t *rm = &ip4_reass_main; + u32 nbuckets; + u8 i; + + nbuckets = (u32) (rm->max_reass_n / IP4_REASS_HT_LOAD_FACTOR); + + for (i = 0; i < 31; i++) + if ((1 << i) >= nbuckets) + break; + nbuckets = 1 << i; + + return nbuckets; +} + +typedef enum +{ + IP4_EVENT_CONFIG_CHANGED = 1, +} ip4_reass_event_t; + +typedef struct +{ + int failure; + clib_bihash_24_8_t *new_hash; +} ip4_rehash_cb_ctx; + +void +ip4_rehash_cb (clib_bihash_kv_24_8_t * kv, void *_ctx) +{ + ip4_rehash_cb_ctx *ctx = _ctx; + if (clib_bihash_add_del_24_8 (ctx->new_hash, kv, 1)) + { + ctx->failure = 1; + } +} + +vnet_api_error_t +ip4_reass_set (u32 timeout_ms, u32 max_reassemblies, + u32 expire_walk_interval_ms) +{ + u32 old_nbuckets = ip4_reass_get_nbuckets (); + ip4_reass_main.timeout_ms = timeout_ms; + ip4_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC; + ip4_reass_main.max_reass_n = max_reassemblies; + ip4_reass_main.expire_walk_interval_ms = expire_walk_interval_ms; + vlib_process_signal_event (ip4_reass_main.vlib_main, + ip4_reass_main.ip4_reass_expire_node_idx, + IP4_EVENT_CONFIG_CHANGED, 0); + u32 new_nbuckets = ip4_reass_get_nbuckets (); + if (ip4_reass_main.max_reass_n > 0 && new_nbuckets > 1 && + new_nbuckets != old_nbuckets) + { + clib_bihash_24_8_t new_hash; + memset (&new_hash, 0, sizeof (new_hash)); + ip4_rehash_cb_ctx ctx; + ctx.failure = 0; + ctx.new_hash = &new_hash; + clib_bihash_init_24_8 (&new_hash, "ip4-reass", new_nbuckets, + new_nbuckets * 1024); + clib_bihash_foreach_key_value_pair_24_8 (&ip4_reass_main.hash, + ip4_rehash_cb, &ctx); + if (ctx.failure) + { + clib_bihash_free_24_8 (&new_hash); + return -1; + } + else + { + clib_bihash_free_24_8 (&ip4_reass_main.hash); + clib_memcpy (&ip4_reass_main.hash, &new_hash, + sizeof (ip4_reass_main.hash)); + } + } + return 0; +} + +vnet_api_error_t +ip4_reass_get (u32 * timeout_ms, u32 * max_reassemblies, + u32 * expire_walk_interval_ms) +{ + *timeout_ms = ip4_reass_main.timeout_ms; + *max_reassemblies = ip4_reass_main.max_reass_n; + *expire_walk_interval_ms = ip4_reass_main.expire_walk_interval_ms; + return 0; +} + +clib_error_t * +ip4_reass_init_function (vlib_main_t * vm) +{ + ip4_reass_main_t *rm = &ip4_reass_main; + clib_error_t *error = 0; + u32 nbuckets; + + rm->vlib_main = vm; + rm->vnet_main = vnet_get_main (); + + rm->reass_n = 0; + pool_alloc (rm->pool, rm->max_reass_n); + ip4_reass_set (IP4_REASS_TIMEOUT_DEFAULT_MS, + IP4_REASS_MAX_REASSEMBLIES_DEAFULT, + IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS); + + nbuckets = ip4_reass_get_nbuckets (); + clib_bihash_init_24_8 (&rm->hash, "ip4-reass", nbuckets, nbuckets * 1024); + + vlib_node_t *node = vlib_get_node_by_name (vm, (u8 *) "ip4-drop"); + ASSERT (node); + rm->ip4_drop_idx = node->index; + node = vlib_get_node_by_name (vm, (u8 *) "ip4-reassembly-expire-walk"); + ASSERT (node); + rm->ip4_reass_expire_node_idx = node->index; + return error; +} + +VLIB_INIT_FUNCTION (ip4_reass_init_function); + +static uword +ip4_reass_walk_expired (vlib_main_t * vm, + vlib_node_runtime_t * node, vlib_frame_t * f) +{ + ip4_reass_main_t *rm = &ip4_reass_main; + uword event_type, *event_data = 0; + + while (true) + { + vlib_process_wait_for_event_or_clock (vm, + (f64) rm->expire_walk_interval_ms + / (f64) MSEC_PER_SEC); + event_type = vlib_process_get_events (vm, &event_data); + + switch (event_type) + { + case ~0: /* no events => timeout */ + /* nothing to do here */ + break; + case IP4_EVENT_CONFIG_CHANGED: + break; + default: + clib_warning ("BUG: event type 0x%wx", event_type); + break; + } + f64 now = vlib_time_now (vm); + + ip4_reass_t *reass; + u32 *vec_drop_timeout = NULL; + int *pool_indexes_to_free = NULL; + + int index; + /* *INDENT-OFF* */ + pool_foreach_index (index, rm->pool, ({ + reass = pool_elt_at_index (rm->pool, index); + if (now > reass->last_heard + rm->timeout) + { + vec_add1 (pool_indexes_to_free, index); + } + })); + /* *INDENT-ON* */ + int *i; + /* *INDENT-OFF* */ + vec_foreach (i, pool_indexes_to_free) + { + ip4_reass_t *reass = pool_elt_at_index (rm->pool, i[0]); + ip4_reass_on_timeout (vm, rm, reass, &vec_drop_timeout); + ip4_reass_free (rm, reass); + } + /* *INDENT-ON* */ + + while (vec_len (vec_drop_timeout) > 0) + { + vlib_frame_t *f = vlib_get_frame_to_node (vm, rm->ip4_drop_idx); + u32 *to_next = vlib_frame_vector_args (f); + u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors; + u32 n_trace = 0; + while (vec_len (vec_drop_timeout) > 0 && n_left_to_next > 0) + { + u32 bi = vec_pop (vec_drop_timeout); + vlib_buffer_t *b = vlib_get_buffer (vm, bi); + if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED)) + { + if (pool_is_free_index (vm->trace_main.trace_buffer_pool, + b->trace_index)) + { + /* the trace is gone, don't trace this buffer anymore */ + b->flags &= ~VLIB_BUFFER_IS_TRACED; + } + else + { + ++n_trace; + } + } + b->error = node->errors[IP4_ERROR_REASS_TIMEOUT]; + to_next[0] = bi; + ++f->n_vectors; + to_next += 1; + n_left_to_next -= 1; + IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout_walk); + ASSERT (rm->buffers_n > 0); + --rm->buffers_n; + } + if (PREDICT_FALSE (n_trace > 0)) + { + f->flags |= VLIB_FRAME_TRACE; + } + vlib_put_frame_to_node (vm, rm->ip4_drop_idx, f); + } + + vec_free (pool_indexes_to_free); + vec_free (vec_drop_timeout); + if (event_data) + { + _vec_len (event_data) = 0; + } + } + + return 0; +} + +static vlib_node_registration_t ip4_reass_expire_node; + +/* *INDENT-OFF* */ +VLIB_REGISTER_NODE (ip4_reass_expire_node, static) = { + .function = ip4_reass_walk_expired, + .type = VLIB_NODE_TYPE_PROCESS, + .name = "ip4-reassembly-expire-walk", + .format_trace = format_ip4_reass_trace, + .n_errors = ARRAY_LEN (ip4_reassembly_error_strings), + .error_strings = ip4_reassembly_error_strings, + +}; +/* *INDENT-ON* */ + +static u8 * +format_ip4_reass_key (u8 * s, va_list * args) +{ + ip4_reass_key_t *key = va_arg (*args, ip4_reass_key_t *); + s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u", + key->xx_id, format_ip4_address, &key->src, format_ip4_address, + &key->dst, clib_net_to_host_u16 (key->frag_id), key->proto); + return s; +} + +static u8 * +format_ip4_reass (u8 * s, va_list * args) +{ + vlib_main_t *vm = va_arg (*args, vlib_main_t *); + ip4_reass_t *reass = va_arg (*args, ip4_reass_t *); + + s = format (s, "ID: %u, key: %U\n first_bi: %u, data_len: %u, " + "last_packet_octet: %u, trace_op_counter: %u\n", + reass->id, format_ip4_reass_key, &reass->key, reass->first_bi, + reass->data_len, reass->last_packet_octet, + reass->trace_op_counter); + u32 bi = reass->first_bi; + u32 counter = 0; + while (~0 != bi) + { + vlib_buffer_t *b = vlib_get_buffer (vm, bi); + vnet_buffer_opaque_t *vnb = vnet_buffer (b); + s = format (s, " #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, " + "fragment[%u, %u]\n", + counter, vnb->ip.reass.range_first, + vnb->ip.reass.range_last, bi, + ip4_reass_buffer_get_data_offset_no_check (b), + ip4_reass_buffer_get_data_len_no_check (b), + vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last); + if (b->flags & VLIB_BUFFER_NEXT_PRESENT) + { + bi = b->next_buffer; + } + else + { + bi = ~0; + } + } + return s; +} + +static clib_error_t * +show_ip4_reass (vlib_main_t * vm, unformat_input_t * input, + CLIB_UNUSED (vlib_cli_command_t * lmd)) +{ + ip4_reass_main_t *rm = &ip4_reass_main; + + vlib_cli_output (vm, "---------------------"); + vlib_cli_output (vm, "IP4 reassembly status"); + vlib_cli_output (vm, "---------------------"); + if (unformat (input, "details")) + { + ip4_reass_t *reass; + /* *INDENT-OFF* */ + pool_foreach (reass, rm->pool, { + vlib_cli_output (vm, "%U", format_ip4_reass, vm, reass); + }); + /* *INDENT-ON* */ + } + vlib_cli_output (vm, "---------------------"); + vlib_cli_output (vm, "Current IP4 reassemblies count: %lu\n", rm->reass_n); + vlib_cli_output (vm, + "Maximum configured concurrent IP4 reassemblies: %lu\n", + (long unsigned) rm->max_reass_n); + vlib_cli_output (vm, "Buffers in use: %lu\n", + (long unsigned) rm->buffers_n); + return 0; +} + +/* *INDENT-OFF* */ +VLIB_CLI_COMMAND (show_ip4_reassembly_cmd, static) = { + .path = "show ip4-reassembly", + .short_help = "show ip4-reassembly [details]", + .function = show_ip4_reass, +}; +/* *INDENT-ON* */ + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |