/* * 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_16_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_DEFAULT 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 typedef enum { IP4_REASS_RC_OK, IP4_REASS_RC_INTERNAL_ERROR, IP4_REASS_RC_NO_BUF, } ip4_reass_rc_t; typedef struct { union { struct { u32 xx_id; ip4_address_t src; ip4_address_t dst; u16 frag_id; u8 proto; u8 unused; }; u64 as_u64[2]; }; } ip4_reass_key_t; typedef union { struct { u32 reass_index; u32 thread_index; }; u64 as_u64; } ip4_reass_val_t; typedef union { struct { ip4_reass_key_t k; ip4_reass_val_t v; }; clib_bihash_kv_16_8_t kv; } ip4_reass_kv_t; always_inline u32 ip4_reass_buffer_get_data_offset (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 u16 ip4_reass_buffer_get_data_len (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; } typedef struct { // hash table key ip4_reass_key_t key; // time when last packet was received f64 last_heard; // internal id of this reassembly u64 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; // next index - used by non-feature node u8 next_index; // minimum fragment length for this reassembly - used to estimate MTU u16 min_fragment_length; } ip4_reass_t; typedef struct { ip4_reass_t *pool; u32 reass_n; u32 id_counter; clib_spinlock_t lock; } ip4_reass_per_thread_t; typedef struct { // IPv4 config u32 timeout_ms; f64 timeout; u32 expire_walk_interval_ms; u32 max_reass_n; // IPv4 runtime clib_bihash_16_8_t hash; // per-thread data ip4_reass_per_thread_t *per_thread_data; // 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; /** Worker handoff */ u32 fq_index; u32 fq_feature_index; } ip4_reass_main_t; ip4_reass_main_t ip4_reass_main; typedef enum { IP4_REASSEMBLY_NEXT_INPUT, IP4_REASSEMBLY_NEXT_DROP, IP4_REASSEMBLY_NEXT_HANDOFF, 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 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; static 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 (b); trace->data_len = ip4_reass_buffer_get_data_len (b); trace->range_bi = bi; } static 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; } static 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); if (pool_is_free_index (vm->trace_main.trace_buffer_pool, b->trace_index)) { // this buffer's trace is gone b->flags &= ~VLIB_BUFFER_IS_TRACED; return; } ip4_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0])); 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 } always_inline void ip4_reass_free (ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt, ip4_reass_t * reass) { clib_bihash_kv_16_8_t kv; kv.key[0] = reass->key.as_u64[0]; kv.key[1] = reass->key.as_u64[1]; clib_bihash_add_del_16_8 (&rm->hash, &kv, 0); pool_put (rt->pool, reass); --rt->reass_n; } always_inline void ip4_reass_on_timeout (vlib_main_t * vm, ip4_reass_main_t * rm, ip4_reass_t * reass) { u32 range_bi = reass->first_bi; vlib_buffer_t *range_b; vnet_buffer_opaque_t *range_vnb; u32 *to_free = NULL; 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 (to_free, 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; } vlib_buffer_free (vm, to_free, vec_len (to_free)); vec_free (to_free); } ip4_reass_t * ip4_reass_find_or_create (vlib_main_t * vm, ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt, ip4_reass_kv_t * kv, u8 * do_handoff) { ip4_reass_t *reass = NULL; f64 now = vlib_time_now (rm->vlib_main); if (!clib_bihash_search_16_8 (&rm->hash, (clib_bihash_kv_16_8_t *) kv, (clib_bihash_kv_16_8_t *) kv)) { if (vm->thread_index != kv->v.thread_index) { *do_handoff = 1; return NULL; } reass = pool_elt_at_index (rt->pool, kv->v.reass_index); if (now > reass->last_heard + rm->timeout) { ip4_reass_on_timeout (vm, rm, reass); ip4_reass_free (rm, rt, reass); reass = NULL; } } if (reass) { reass->last_heard = now; return reass; } if (rt->reass_n >= rm->max_reass_n) { reass = NULL; return reass; } else { pool_get (rt->pool, reass); clib_memset (reass, 0, sizeof (*reass)); reass->id = ((u64) vm->thread_index * 1000000000) + rt->id_counter; ++rt->id_counter; reass->first_bi = ~0; reass->last_packet_octet = ~0; reass->data_len = 0; ++rt->reass_n; } reass->key.as_u64[0] = ((clib_bihash_kv_16_8_t *) kv)->key[0]; reass->key.as_u64[1] = ((clib_bihash_kv_16_8_t *) kv)->key[1]; kv->v.reass_index = (reass - rt->pool); kv->v.thread_index = vm->thread_index; reass->last_heard = now; if (clib_bihash_add_del_16_8 (&rm->hash, (clib_bihash_kv_16_8_t *) kv, 1)) { ip4_reass_free (rm, rt, reass); reass = NULL; } return reass; } always_inline ip4_reass_rc_t ip4_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node, ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt, ip4_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0, bool is_feature) { 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; 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); vnet_buffer_opaque_t *vnb = vnet_buffer (tmp); if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) && !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first)) { return IP4_REASS_RC_INTERNAL_ERROR; } 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 */ if (0 != ip4_reass_buffer_get_data_offset (tmp)) { return IP4_REASS_RC_INTERNAL_ERROR; } trim_front = 0; trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len - ip4_header_bytes (ip); if (!(vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0)) { return IP4_REASS_RC_INTERNAL_ERROR; } } 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 */ vlib_buffer_free_one (vm, tmp_bi); trim_front -= tmp->current_length; if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT)) { return IP4_REASS_RC_INTERNAL_ERROR; } 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; if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT)) { return IP4_REASS_RC_INTERNAL_ERROR; } } total_length += tmp->current_length; } else { vlib_buffer_free_one (vm, tmp_bi); if (reass->first_bi == tmp_bi) { return IP4_REASS_RC_INTERNAL_ERROR; } } 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); if (!last_b) { return IP4_REASS_RC_INTERNAL_ERROR; } last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT; if (total_length < first_b->current_length) { return IP4_REASS_RC_INTERNAL_ERROR; } 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); if (!vlib_buffer_chain_linearize (vm, first_b)) { return IP4_REASS_RC_NO_BUF; } 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; if (is_feature) { *next0 = IP4_REASSEMBLY_NEXT_INPUT; } else { *next0 = reass->next_index; } vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length; *error0 = IP4_ERROR_NONE; ip4_reass_free (rm, rt, reass); reass = NULL; return IP4_REASS_RC_OK; } always_inline ip4_reass_rc_t ip4_reass_insert_range_in_chain (vlib_main_t * vm, ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt, 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; } vnet_buffer_opaque_t *vnb = vnet_buffer (new_next_b); if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) && !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first)) { return IP4_REASS_RC_INTERNAL_ERROR; } reass->data_len += ip4_reass_buffer_get_data_len (new_next_b); return IP4_REASS_RC_OK; } always_inline ip4_reass_rc_t ip4_reass_remove_range_from_chain (vlib_main_t * vm, vlib_node_runtime_t * node, ip4_reass_main_t * rm, 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); if (!(prev_vnb->ip.reass.next_range_bi == discard_bi)) { return IP4_REASS_RC_INTERNAL_ERROR; } 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; } vnet_buffer_opaque_t *vnb = vnet_buffer (discard_b); if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) && !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first)) { return IP4_REASS_RC_INTERNAL_ERROR; } reass->data_len -= ip4_reass_buffer_get_data_len (discard_b); while (1) { vlib_buffer_free_one (vm, 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; } } return IP4_REASS_RC_OK; } always_inline ip4_reass_rc_t ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node, ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt, ip4_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0, bool is_feature) { ip4_reass_rc_t rc = IP4_REASS_RC_OK; int consumed = 0; vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0); ip4_header_t *fip = vlib_buffer_get_current (fb); vnet_buffer_opaque_t *fvnb = vnet_buffer (fb); reass->next_index = fvnb->ip.reass.next_index; // store next_index before it's overwritten const u32 fragment_first = ip4_get_fragment_offset_bytes (fip); const u32 fragment_length = clib_net_to_host_u16 (fip->length) - ip4_header_bytes (fip); const u32 fragment_last = fragment_first + fragment_length - 1; fvnb->ip.reass.fragment_first = fragment_first; fvnb->ip.reass.fragment_last = fragment_last; 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 rc = ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi, *bi0); if (IP4_REASS_RC_OK != rc) { return rc; } if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED)) { ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0); } *bi0 = ~0; reass->min_fragment_length = clib_net_to_host_u16 (fip->length); return IP4_REASS_RC_OK; } reass->min_fragment_length = 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 rc = ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi, *bi0); if (IP4_REASS_RC_OK != rc) { return rc; } consumed = 1; break; } continue; } if (fragment_last < candidate_vnb->ip.reass.range_first) { // this fragment ends before candidate range without any overlap rc = ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi, *bi0); if (IP4_REASS_RC_OK != rc) { return rc; } 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; if (reass->data_len < overlap) { return IP4_REASS_RC_INTERNAL_ERROR; } 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); } rc = ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi, *bi0); if (IP4_REASS_RC_OK != rc) { return rc; } 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 rc = ip4_reass_insert_range_in_chain (vm, rm, rt, reass, candidate_range_bi, *bi0); if (IP4_REASS_RC_OK != rc) { return rc; } 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 rc = ip4_reass_remove_range_from_chain (vm, node, rm, reass, prev_range_bi, candidate_range_bi); if (IP4_REASS_RC_OK != rc) { return rc; } if (~0 != next_range_bi) { candidate_range_bi = next_range_bi; continue; } else { // special case - last range discarded rc = ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi, *bi0); if (IP4_REASS_RC_OK != rc) { return rc; } 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) { return ip4_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0, is_feature); } else { if (consumed) { *bi0 = ~0; } else { *next0 = IP4_REASSEMBLY_NEXT_DROP; *error0 = IP4_ERROR_REASS_DUPLICATE_FRAGMENT; } } return rc; } always_inline uword ip4_reassembly_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame, bool is_feature) { 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; ip4_reass_per_thread_t *rt = &rm->per_thread_data[vm->thread_index]; clib_spinlock_lock (&rt->lock); n_left_from = frame->n_vectors; next_index = node->cached_next_index; while (n_left_from > 0) { vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); while (n_left_from > 0 && n_left_to_next > 0) { u32 bi0; vlib_buffer_t *b0; u32 next0; u32 error0 = IP4_ERROR_NONE; bi0 = from[0]; b0 = vlib_get_buffer (vm, bi0); ip4_header_t *ip0 = vlib_buffer_get_current (b0); if (!ip4_get_fragment_more (ip0) && !ip4_get_fragment_offset (ip0)) { // this is a whole packet - no fragmentation if (is_feature) { next0 = IP4_REASSEMBLY_NEXT_INPUT; } else { next0 = vnet_buffer (b0)->ip.reass.next_index; } } else { const u32 fragment_first = ip4_get_fragment_offset_bytes (ip0); const u32 fragment_length = clib_net_to_host_u16 (ip0->length) - ip4_header_bytes (ip0); const u32 fragment_last = fragment_first + fragment_length - 1; if (fragment_first > fragment_last || fragment_first + fragment_length > UINT16_MAX - 20 || (fragment_length < 8 && ip4_get_fragment_more (ip0))) // 8 is minimum frag length per RFC 791 { next0 = IP4_REASSEMBLY_NEXT_DROP; error0 = IP4_ERROR_REASS_MALFORMED_PACKET; } else { ip4_reass_kv_t kv; u8 do_handoff = 0; kv.k.as_u64[0] = (u64) vec_elt (ip4_main.fib_index_by_sw_if_index, vnet_buffer (b0)->sw_if_index[VLIB_RX]) | (u64) ip0->src_address.as_u32 << 32; kv.k.as_u64[1] = (u64) ip0->dst_address.as_u32 | (u64) ip0->fragment_id << 32 | (u64) ip0->protocol << 48; ip4_reass_t *reass = ip4_reass_find_or_create (vm, rm, rt, &kv, &do_handoff); if (PREDICT_FALSE (do_handoff)) { next0 = IP4_REASSEMBLY_NEXT_HANDOFF; if (is_feature) vnet_buffer (b0)->ip. reass.owner_feature_thread_index = kv.v.thread_index; else vnet_buffer (b0)->ip.reass.owner_thread_index = kv.v.thread_index; } else if (reass) { switch (ip4_reass_update (vm, node, rm, rt, reass, &bi0, &next0, &error0, is_feature)) { case IP4_REASS_RC_OK: /* nothing to do here */ break; case IP4_REASS_RC_NO_BUF: /* fallthrough */ case IP4_REASS_RC_INTERNAL_ERROR: /* drop everything and start with a clean slate */ ip4_reass_on_timeout (vm, rm, reass); ip4_reass_free (rm, rt, reass); goto next_packet; break; } } 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; if (is_feature && IP4_ERROR_NONE == error0) { b0 = vlib_get_buffer (vm, bi0); vnet_feature_next (&next0, b0); } vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, n_left_to_next, bi0, next0); IP4_REASS_DEBUG_BUFFER (bi0, enqueue_next); } next_packet: from += 1; n_left_from -= 1; } vlib_put_next_frame (vm, node, next_index, n_left_to_next); } clib_spinlock_unlock (&rt->lock); return frame->n_vectors; } static char *ip4_reassembly_error_strings[] = { #define _(sym, string) string, foreach_ip4_error #undef _ }; static uword ip4_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { return ip4_reassembly_inline (vm, node, frame, false /* is_feature */ ); } /* *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", [IP4_REASSEMBLY_NEXT_HANDOFF] = "ip4-reassembly-handoff", }, }; /* *INDENT-ON* */ VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node, ip4_reassembly); static uword ip4_reassembly_feature (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { return ip4_reassembly_inline (vm, node, frame, true /* is_feature */ ); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (ip4_reass_node_feature, static) = { .function = ip4_reassembly_feature, .name = "ip4-reassembly-feature", .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", [IP4_REASSEMBLY_NEXT_HANDOFF] = "ip4-reass-feature-hoff", }, }; /* *INDENT-ON* */ VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node_feature, ip4_reassembly_feature); /* *INDENT-OFF* */ VNET_FEATURE_INIT (ip4_reassembly_feature, static) = { .arc_name = "ip4-unicast", .node_name = "ip4-reassembly-feature", .runs_before = VNET_FEATURES ("ip4-lookup"), .runs_after = 0, }; /* *INDENT-ON* */ always_inline 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_16_8_t *new_hash; } ip4_rehash_cb_ctx; static void ip4_rehash_cb (clib_bihash_kv_16_8_t * kv, void *_ctx) { ip4_rehash_cb_ctx *ctx = _ctx; if (clib_bihash_add_del_16_8 (ctx->new_hash, kv, 1)) { ctx->failure = 1; } } static void ip4_reass_set_params (u32 timeout_ms, u32 max_reassemblies, u32 expire_walk_interval_ms) { 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; } 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_set_params (timeout_ms, max_reassemblies, 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 > old_nbuckets) { clib_bihash_16_8_t new_hash; clib_memset (&new_hash, 0, sizeof (new_hash)); ip4_rehash_cb_ctx ctx; ctx.failure = 0; ctx.new_hash = &new_hash; clib_bihash_init_16_8 (&new_hash, "ip4-reass", new_nbuckets, new_nbuckets * 1024); clib_bihash_foreach_key_value_pair_16_8 (&ip4_reass_main.hash, ip4_rehash_cb, &ctx); if (ctx.failure) { clib_bihash_free_16_8 (&new_hash); return -1; } else { clib_bihash_free_16_8 (&ip4_reass_main.hash); clib_memcpy_fast (&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; } static 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; vlib_node_t *node; rm->vlib_main = vm; rm->vnet_main = vnet_get_main (); vec_validate (rm->per_thread_data, vlib_num_workers ()); ip4_reass_per_thread_t *rt; vec_foreach (rt, rm->per_thread_data) { clib_spinlock_init (&rt->lock); pool_alloc (rt->pool, rm->max_reass_n); } node = vlib_get_node_by_name (vm, (u8 *) "ip4-reassembly-expire-walk"); ASSERT (node); rm->ip4_reass_expire_node_idx = node->index; ip4_reass_set_params (IP4_REASS_TIMEOUT_DEFAULT_MS, IP4_REASS_MAX_REASSEMBLIES_DEFAULT, IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS); nbuckets = ip4_reass_get_nbuckets (); clib_bihash_init_16_8 (&rm->hash, "ip4-reass", nbuckets, nbuckets * 1024); node = vlib_get_node_by_name (vm, (u8 *) "ip4-drop"); ASSERT (node); rm->ip4_drop_idx = node->index; rm->fq_index = vlib_frame_queue_main_init (ip4_reass_node.index, 0); rm->fq_feature_index = vlib_frame_queue_main_init (ip4_reass_node_feature.index, 0); 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; int *pool_indexes_to_free = NULL; uword thread_index = 0; int index; const uword nthreads = vlib_num_workers () + 1; for (thread_index = 0; thread_index < nthreads; ++thread_index) { ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index]; clib_spinlock_lock (&rt->lock); vec_reset_length (pool_indexes_to_free); /* *INDENT-OFF* */ pool_foreach_index (index, rt->pool, ({ reass = pool_elt_at_index (rt->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 (rt->pool, i[0]); ip4_reass_on_timeout (vm, rm, reass); ip4_reass_free (rm, rt, reass); } /* *INDENT-ON* */ clib_spinlock_unlock (&rt->lock); } vec_free (pool_indexes_to_free); if (event_data) { _vec_len (event_data) = 0; } } return 0; } /* *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: %lu, 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 (b), ip4_reass_buffer_get_data_len (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, "---------------------"); bool details = false; if (unformat (input, "details")) { details = true; } u32 sum_reass_n = 0; ip4_reass_t *reass; uword thread_index; const uword nthreads = vlib_num_workers () + 1; for (thread_index = 0; thread_index < nthreads; ++thread_index) { ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index]; clib_spinlock_lock (&rt->lock); if (details) { /* *INDENT-OFF* */ pool_foreach (reass, rt->pool, { vlib_cli_output (vm, "%U", format_ip4_reass, vm, reass); }); /* *INDENT-ON* */ } sum_reass_n += rt->reass_n; clib_spinlock_unlock (&rt->lock); } vlib_cli_output (vm, "---------------------"); vlib_cli_output (vm, "Current IP4 reassemblies count: %lu\n", (long unsigned) sum_reass_n); vlib_cli_output (vm, "Maximum configured concurrent IP4 reassemblies per worker-thread: %lu\n", (long unsigned) rm->max_reass_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* */ vnet_api_error_t ip4_reass_enable_disable (u32 sw_if_index, u8 enable_disable) { return vnet_feature_enable_disable ("ip4-unicast", "ip4-reassembly-feature", sw_if_index, enable_disable, 0, 0); } #define foreach_ip4_reassembly_handoff_error \ _(CONGESTION_DROP, "congestion drop") typedef enum { #define _(sym,str) IP4_REASSEMBLY_HANDOFF_ERROR_##sym, foreach_ip4_reassembly_handoff_error #undef _ IP4_REASSEMBLY_HANDOFF_N_ERROR, } ip4_reassembly_handoff_error_t; static char *ip4_reassembly_handoff_error_strings[] = { #define _(sym,string) string, foreach_ip4_reassembly_handoff_error #undef _ }; typedef struct { u32 next_worker_index; } ip4_reassembly_handoff_trace_t; static u8 * format_ip4_reassembly_handoff_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_reassembly_handoff_trace_t *t = va_arg (*args, ip4_reassembly_handoff_trace_t *); s = format (s, "ip4-reassembly-handoff: next-worker %d", t->next_worker_index); return s; } always_inline uword ip4_reassembly_handoff_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame, bool is_feature) { ip4_reass_main_t *rm = &ip4_reass_main; vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b; u32 n_enq, n_left_from, *from; u16 thread_indices[VLIB_FRAME_SIZE], *ti; u32 fq_index; from = vlib_frame_vector_args (frame); n_left_from = frame->n_vectors; vlib_get_buffers (vm, from, bufs, n_left_from); b = bufs; ti = thread_indices; fq_index = (is_feature) ? rm->fq_feature_index : rm->fq_index; while (n_left_from > 0) { ti[0] = (is_feature) ? vnet_buffer (b[0])->ip. reass.owner_feature_thread_index : vnet_buffer (b[0])->ip. reass.owner_thread_index; if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) && (b[0]->flags & VLIB_BUFFER_IS_TRACED))) { ip4_reassembly_handoff_trace_t *t = vlib_add_trace (vm, node, b[0], sizeof (*t)); t->next_worker_index = ti[0]; } n_left_from -= 1; ti += 1; b += 1; } n_enq = vlib_buffer_enqueue_to_thread (vm, fq_index, from, thread_indices, frame->n_vectors, 1); if (n_enq < frame->n_vectors) vlib_node_increment_counter (vm, node->node_index, IP4_REASSEMBLY_HANDOFF_ERROR_CONGESTION_DROP, frame->n_vectors - n_enq); return frame->n_vectors; } VLIB_NODE_FN (ip4_reassembly_handoff_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { return ip4_reassembly_handoff_node_inline (vm, node, frame, false /* is_feature */ ); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (ip4_reassembly_handoff_node) = { .name = "ip4-reassembly-handoff", .vector_size = sizeof (u32), .n_errors = ARRAY_LEN(ip4_reassembly_handoff_error_strings), .error_strings = ip4_reassembly_handoff_error_strings, .format_trace = format_ip4_reassembly_handoff_trace, .n_next_nodes = 1, .next_nodes = { [0] = "error-drop", }, }; /* *INDENT-ON* */ /* *INDENT-OFF* */ VLIB_NODE_FN (ip4_reassembly_feature_handoff_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { return ip4_reassembly_handoff_node_inline (vm, node, frame, true /* is_feature */ ); } /* *INDENT-ON* */ /* *INDENT-OFF* */ VLIB_REGISTER_NODE (ip4_reassembly_feature_handoff_node) = { .name = "ip4-reass-feature-hoff", .vector_size = sizeof (u32), .n_errors = ARRAY_LEN(ip4_reassembly_handoff_error_strings), .error_strings = ip4_reassembly_handoff_error_strings, .format_trace = format_ip4_reassembly_handoff_trace, .n_next_nodes = 1, .next_nodes = { [0] = "error-drop", }, }; /* *INDENT-ON* */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */