diff options
Diffstat (limited to 'vpp/plugins/acl-plugin/acl/l2sess_node.c')
| -rw-r--r-- | vpp/plugins/acl-plugin/acl/l2sess_node.c | 763 |
1 files changed, 763 insertions, 0 deletions
diff --git a/vpp/plugins/acl-plugin/acl/l2sess_node.c b/vpp/plugins/acl-plugin/acl/l2sess_node.c new file mode 100644 index 00000000..689d216d --- /dev/null +++ b/vpp/plugins/acl-plugin/acl/l2sess_node.c @@ -0,0 +1,763 @@ +/* + * Copyright (c) 2016 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. + */ +#include <netinet/in.h> +#include <vlib/vlib.h> +#include <vnet/vnet.h> +#include <vnet/pg/pg.h> +#include <vppinfra/error.h> +#include <acl/l2sess.h> +#include <vnet/l2/l2_classify.h> + + +typedef struct +{ + u32 next_index; + u32 sw_if_index; + u32 trace_flags; + u32 session_tables[2]; + u32 session_nexts[2]; + u8 l4_proto; +} l2sess_trace_t; + +/* packet trace format function */ + +#define _(node_name, node_var, is_out, is_ip6, is_track) \ +static u8 * format_## node_var ##_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 *); \ + l2sess_trace_t * t = va_arg (*args, l2sess_trace_t *); \ + \ + s = format (s, node_name ": sw_if_index %d, next index %d trace_flags %08x L4 proto %d\n" \ + " tables [ %d, %d ] nexts [ %d, %d ]", \ + t->sw_if_index, t->next_index, t->trace_flags, t->l4_proto, \ + t->session_tables[0], t->session_tables[1], \ + t->session_nexts[0], t->session_nexts[1]); \ + return s; \ +} +foreach_l2sess_node +#undef _ +#define foreach_l2sess_error \ +_(SWAPPED, "Mac swap packets processed") + typedef enum +{ +#define _(sym,str) L2SESS_ERROR_##sym, + foreach_l2sess_error +#undef _ + L2SESS_N_ERROR, +} l2sess_error_t; + +static char *l2sess_error_strings[] = { +#define _(sym,string) string, + foreach_l2sess_error +#undef _ +}; + +typedef enum +{ + L2SESS_NEXT_DROP, + L2SESS_N_NEXT, +} l2sess_next_t; + +u8 +l2sess_get_l4_proto (vlib_buffer_t * b0, int node_is_ip6) +{ + u8 proto; + int proto_offset; + if (node_is_ip6) + { + proto_offset = 20; + } + else + { + proto_offset = 23; + } + proto = *((u8 *) vlib_buffer_get_current (b0) + proto_offset); + return proto; +} + + +u8 +l2sess_get_tcp_flags (vlib_buffer_t * b0, int node_is_ip6) +{ + u8 flags; + int flags_offset; + if (node_is_ip6) + { + flags_offset = 14 + 40 + 13; /* FIXME: no extension headers assumed */ + } + else + { + flags_offset = 14 + 20 + 13; + } + flags = *((u8 *) vlib_buffer_get_current (b0) + flags_offset); + return flags; +} + +static inline int +l4_tcp_or_udp (u8 proto) +{ + return ((proto == 6) || (proto == 17)); +} + +void +l2sess_get_session_tables (l2sess_main_t * sm, u32 sw_if_index, + int node_is_out, int node_is_ip6, u8 l4_proto, + u32 * session_tables) +{ +/* + * Based on the direction, l3 and l4 protocol, fill a u32[2] array: + * [0] is index for the "direct match" path, [1] is for "mirrored match". + * Store the indices of the tables to add the session to in session_tables[] + */ + l2_output_classify_main_t *l2om = &l2_output_classify_main; + l2_input_classify_main_t *l2im = &l2_input_classify_main; + + u32 output_table_index; + u32 input_table_index; + + if (!l4_tcp_or_udp (l4_proto)) + { + return; + } + + if (node_is_ip6) + { + vec_validate_init_empty (l2im-> + classify_table_index_by_sw_if_index + [L2_INPUT_CLASSIFY_TABLE_IP6], sw_if_index, + ~0); + input_table_index = + l2im-> + classify_table_index_by_sw_if_index[L2_INPUT_CLASSIFY_TABLE_IP6] + [sw_if_index]; + vec_validate_init_empty (l2om-> + classify_table_index_by_sw_if_index + [L2_OUTPUT_CLASSIFY_TABLE_IP6], sw_if_index, + ~0); + output_table_index = + l2om-> + classify_table_index_by_sw_if_index[L2_OUTPUT_CLASSIFY_TABLE_IP6] + [sw_if_index]; + } + else + { + vec_validate_init_empty (l2im-> + classify_table_index_by_sw_if_index + [L2_INPUT_CLASSIFY_TABLE_IP4], sw_if_index, + ~0); + input_table_index = + l2im-> + classify_table_index_by_sw_if_index[L2_INPUT_CLASSIFY_TABLE_IP4] + [sw_if_index]; + vec_validate_init_empty (l2om-> + classify_table_index_by_sw_if_index + [L2_OUTPUT_CLASSIFY_TABLE_IP4], sw_if_index, + ~0); + output_table_index = + l2om-> + classify_table_index_by_sw_if_index[L2_OUTPUT_CLASSIFY_TABLE_IP4] + [sw_if_index]; + } + + if (node_is_out) + { + session_tables[0] = output_table_index; + session_tables[1] = input_table_index; + } + else + { + session_tables[0] = input_table_index; + session_tables[1] = output_table_index; + } +} + +void +l2sess_get_session_nexts (l2sess_main_t * sm, u32 sw_if_index, + int node_is_out, int node_is_ip6, u8 l4_proto, + u32 * session_nexts) +{ +/* + * Based on the direction, l3 and l4 protocol, fill a u32[2] array: + * [0] is the index for the "direct match" path, [1] is for "mirrored match". + * Store the match_next_index in session_nexts[] for a new session entry which is being added to session tables. + */ + u32 input_node_index; + u32 output_node_index; + + if (!l4_tcp_or_udp (l4_proto)) + { + return; + } + + input_node_index = + sm->next_slot_track_node_by_is_ip6_is_out[node_is_ip6][0]; + output_node_index = + sm->next_slot_track_node_by_is_ip6_is_out[node_is_ip6][1]; + + if (node_is_out) + { + session_nexts[0] = output_node_index; + session_nexts[1] = input_node_index; + } + else + { + session_nexts[0] = input_node_index; + session_nexts[1] = output_node_index; + } +} + + +static inline void +swap_bytes (vlib_buffer_t * b0, int off_a, int off_b, int nbytes) +{ + u8 tmp; + u8 *pa = vlib_buffer_get_current (b0) + off_a; + u8 *pb = vlib_buffer_get_current (b0) + off_b; + while (nbytes--) + { + tmp = *pa; + *pa++ = *pb; + *pb++ = tmp; + } +} + +/* + * This quite pro[bv]ably is a terrible idea performance wise. Moreso doing it twice. + * Would having a long (ish) chunk of memory work better for this ? + * We will see when we get to the performance of this. + */ +void +l2sess_flip_l3l4_fields (vlib_buffer_t * b0, int node_is_ip6, u8 l4_proto) +{ + if (!l4_tcp_or_udp (l4_proto)) + { + return; + } + if (node_is_ip6) + { + swap_bytes (b0, 22, 38, 16); /* L3 */ + swap_bytes (b0, 54, 56, 2); /* L4 (when no EH!) */ + } + else + { + swap_bytes (b0, 26, 30, 4); /* L3 */ + swap_bytes (b0, 34, 36, 2); /* L4 */ + } +} + +void +l2sess_add_session (vlib_buffer_t * b0, int node_is_out, int node_is_ip6, + u32 session_table, u32 session_match_next, + u32 opaque_index) +{ + vnet_classify_main_t *cm = &vnet_classify_main; + u32 action = 0; + u32 metadata = 0; + +#ifdef DEBUG_SESSIONS + printf ("Adding session to table %d with next %d\n", session_table, + session_match_next); +#endif + vnet_classify_add_del_session (cm, session_table, + vlib_buffer_get_current (b0), + session_match_next, opaque_index, 0, action, + metadata, 1); +} + + + +static void * +get_ptr_to_offset (vlib_buffer_t * b0, int offset) +{ + u8 *p = vlib_buffer_get_current (b0) + offset; + return p; +} + + +/* + * FIXME: Hardcoded offsets are ugly, although if casting to structs one + * would need to take care about alignment.. So let's for now be naive and simple. + */ + +void +session_store_ip4_l3l4_info (vlib_buffer_t * b0, l2s_session_t * sess, + int node_is_out) +{ + clib_memcpy (&sess->side[1 - node_is_out].addr.ip4, + get_ptr_to_offset (b0, 26), 4); + clib_memcpy (&sess->side[node_is_out].addr.ip4, get_ptr_to_offset (b0, 30), + 4); + sess->side[1 - node_is_out].port = + ntohs (*(u16 *) get_ptr_to_offset (b0, 34)); + sess->side[node_is_out].port = ntohs (*(u16 *) get_ptr_to_offset (b0, 36)); +} + +void +session_store_ip6_l3l4_info (vlib_buffer_t * b0, l2s_session_t * sess, + int node_is_out) +{ + clib_memcpy (&sess->side[1 - node_is_out].addr.ip6, + get_ptr_to_offset (b0, 22), 16); + clib_memcpy (&sess->side[node_is_out].addr.ip4, get_ptr_to_offset (b0, 38), + 16); + sess->side[1 - node_is_out].port = + ntohs (*(u16 *) get_ptr_to_offset (b0, 54)); + sess->side[node_is_out].port = ntohs (*(u16 *) get_ptr_to_offset (b0, 56)); +} + +static void +build_match_from_session (l2sess_main_t * sm, u8 * match, + l2s_session_t * sess, int is_out) +{ + if (sess->is_ip6) + { + match[20] = sess->l4_proto; + clib_memcpy (&match[22], &sess->side[1 - is_out].addr.ip6, 16); + clib_memcpy (&match[38], &sess->side[is_out].addr.ip4, 16); + *(u16 *) & match[54] = htons (sess->side[1 - is_out].port); + *(u16 *) & match[56] = htons (sess->side[is_out].port); + } + else + { + match[23] = sess->l4_proto; + clib_memcpy (&match[26], &sess->side[1 - is_out].addr.ip6, 4); + clib_memcpy (&match[30], &sess->side[is_out].addr.ip4, 4); + *(u16 *) & match[34] = htons (sess->side[1 - is_out].port); + *(u16 *) & match[36] = htons (sess->side[is_out].port); + } +} + +static void +delete_session (l2sess_main_t * sm, u32 sw_if_index, u32 session_index) +{ + vnet_classify_main_t *cm = &vnet_classify_main; + u8 match[5 * 16]; /* For building the mock of the packet to delete the classifier session */ + u32 session_tables[2] = { ~0, ~0 }; + l2s_session_t *sess = sm->sessions + session_index; + if (pool_is_free (sm->sessions, sess)) + { + sm->counter_attempted_delete_free_session++; + return; + } + l2sess_get_session_tables (sm, sw_if_index, 0, sess->is_ip6, sess->l4_proto, + session_tables); + if (session_tables[1] != ~0) + { + build_match_from_session (sm, match, sess, 1); + vnet_classify_add_del_session (cm, session_tables[1], match, 0, 0, 0, 0, + 0, 0); + } + if (session_tables[1] != ~0) + { + build_match_from_session (sm, match, sess, 1); + vnet_classify_add_del_session (cm, session_tables[1], match, 0, 0, 0, 0, + 0, 0); + } + pool_put (sm->sessions, sess); +} + +static void +udp_session_account_buffer (vlib_buffer_t * b0, l2s_session_t * s, + int which_side, u64 now) +{ + l2s_session_side_t *ss = &s->side[which_side]; + ss->active_time = now; + ss->n_packets++; + ss->n_bytes += b0->current_data + b0->current_length; +} + +static inline u64 +udp_session_get_timeout (l2sess_main_t * sm, l2s_session_t * sess, u64 now) +{ + return (sm->udp_session_idle_timeout); +} + +static void +tcp_session_account_buffer (vlib_buffer_t * b0, l2s_session_t * s, + int which_side, u64 now) +{ + l2s_session_side_t *ss = &s->side[which_side]; + ss->active_time = now; + ss->n_packets++; + ss->n_bytes += b0->current_data + b0->current_length; + /* Very very lightweight TCP state tracking: just record which flags were seen */ + s->tcp_flags_seen |= + l2sess_get_tcp_flags (b0, s->is_ip6) << (8 * which_side); +} + +/* + * Since we are tracking for the purposes of timing the sessions out, + * we mostly care about two states: established (maximize the idle timeouts) + * and transient (halfopen/halfclosed/reset) - we need to have a reasonably short timeout to + * quickly get rid of sessions but not short enough to violate the TCP specs. + */ + +static inline u64 +tcp_session_get_timeout (l2sess_main_t * sm, l2s_session_t * sess, u64 now) +{ + /* seen both SYNs and ACKs but not FINs means we are in establshed state */ + u16 masked_flags = + sess->tcp_flags_seen & ((TCP_FLAGS_RSTFINACKSYN << 8) + + TCP_FLAGS_RSTFINACKSYN); + if (((TCP_FLAGS_ACKSYN << 8) + TCP_FLAGS_ACKSYN) == masked_flags) + { + return (sm->tcp_session_idle_timeout); + } + else + { + return (sm->tcp_session_transient_timeout); + } +} + +static inline u64 +session_get_timeout (l2sess_main_t * sm, l2s_session_t * sess, u64 now) +{ + u64 timeout; + + switch (sess->l4_proto) + { + case 6: + timeout = tcp_session_get_timeout (sm, sess, now); + break; + case 17: + timeout = udp_session_get_timeout (sm, sess, now); + break; + default: + timeout = 0; + } + + return timeout; +} + +static inline u64 +get_session_last_active_time(l2s_session_t * sess) +{ + u64 last_active = + sess->side[0].active_time > + sess->side[1].active_time ? sess->side[0].active_time : sess->side[1]. + active_time; + return last_active; +} + +static int +session_is_alive (l2sess_main_t * sm, l2s_session_t * sess, u64 now, u64 *last_active_cache) +{ + u64 last_active = get_session_last_active_time(sess); + u64 timeout = session_get_timeout (sm, sess, now); + int is_alive = ((now - last_active) < timeout); + if (last_active_cache) + *last_active_cache = last_active; + return is_alive; +} + +static void +check_idle_sessions (l2sess_main_t * sm, u32 sw_if_index, u64 now) +{ + sm->timer_wheel_next_expiring_time = 0; + sm->data_from_advancing_timing_wheel + = + timing_wheel_advance (&sm->timing_wheel, now, + sm->data_from_advancing_timing_wheel, + &sm->timer_wheel_next_expiring_time); +#ifdef DEBUG_SESSIONS_VERBOSE + { + clib_time_t *ct = &sm->vlib_main->clib_time; + f64 ctime; + ctime = now * ct->seconds_per_clock; + clib_warning ("Now : %U", format_time_interval, "h:m:s:u", ctime); + ctime = sm->timer_wheel_next_expiring_time * ct->seconds_per_clock; + clib_warning ("Next expire: %U", format_time_interval, "h:m:s:u", ctime); + clib_warning ("Expired items: %d", + (int) vec_len (sm->data_from_advancing_timing_wheel)); + } +#endif + + sm->timer_wheel_next_expiring_time = now + sm->timer_wheel_tick; + if (PREDICT_FALSE ( 0 == sm->data_from_advancing_timing_wheel )) { + return; + } + + if (PREDICT_FALSE (_vec_len (sm->data_from_advancing_timing_wheel) > 0)) + { + uword i; + for (i = 0; i < _vec_len (sm->data_from_advancing_timing_wheel); i++) + { + u32 session_index = sm->data_from_advancing_timing_wheel[i]; + if (!pool_is_free_index (sm->sessions, session_index)) + { + l2s_session_t *sess = sm->sessions + session_index; + u64 last_active; + if (session_is_alive (sm, sess, now, &last_active)) + { +#ifdef DEBUG_SESSIONS + clib_warning ("Restarting timer for session %d", (int) session_index); +#endif + /* Pretend we did this in the past, at last_active moment */ + timing_wheel_insert (&sm->timing_wheel, + last_active + session_get_timeout (sm, sess, + last_active), + session_index); + } + else + { +#ifdef DEBUG_SESSIONS + clib_warning ("Deleting session %d", (int) session_index); +#endif + delete_session (sm, sw_if_index, session_index); + } + } + } + _vec_len (sm->data_from_advancing_timing_wheel) = 0; + } +} + +static uword +l2sess_node_fn (vlib_main_t * vm, + vlib_node_runtime_t * node, vlib_frame_t * frame, + int node_is_out, int node_is_ip6, int node_is_track, + u32 *feat_next_node_index) +{ + u32 n_left_from, *from, *to_next; + l2sess_next_t next_index; + u32 pkts_swapped = 0; + u32 feature_bitmap0; + u32 trace_flags0; + + l2sess_main_t *sm = &l2sess_main; + + from = vlib_frame_vector_args (frame); + n_left_from = frame->n_vectors; + next_index = node->cached_next_index; + + while (n_left_from > 0) + { + u32 n_left_to_next; + + vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); + + /* Only a single loop for now for simplicity */ + + while (n_left_from > 0 && n_left_to_next > 0) + { + u32 bi0; + vlib_buffer_t *b0; + u32 next0 = L2SESS_NEXT_DROP; + u32 sw_if_index0; + //ethernet_header_t *en0; + + /* speculatively enqueue b0 to the current next frame */ + bi0 = from[0]; + to_next[0] = bi0; + from += 1; + to_next += 1; + n_left_from -= 1; + n_left_to_next -= 1; + + b0 = vlib_get_buffer (vm, bi0); + //en0 = vlib_buffer_get_current (b0); + +/* + * node_is_out : 1 = is output, 0 = is input + * node_is_ip6 : 1 = is ip6, 0 = is ip4 + * node_is_track : 1 = is a state tracking node, 0 - is a session addition node + * + * The below code adjust the behavior according to these parameters. + */ + { + u32 session_tables[2] = { ~0, ~0 }; + u32 session_nexts[2] = { ~0, ~0 }; + u8 l4_proto; + u64 now = clib_cpu_time_now (); + + trace_flags0 = 0; + if (node_is_out) + { + sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX]; + } + else + { + sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX]; + } + /* potentially also remove the nodes here */ + feature_bitmap0 = vnet_buffer (b0)->l2.feature_bitmap; + + if (node_is_track) + { + u32 sess_index = vnet_buffer (b0)->l2_classify.opaque_index; + l2s_session_t *sess = sm->sessions + sess_index; + l4_proto = sess->l4_proto; + + if (session_is_alive (sm, sess, now, 0)) + { + if (6 == l4_proto) + { + tcp_session_account_buffer (b0, sess, node_is_out, + now); + } + else + { + udp_session_account_buffer (b0, sess, node_is_out, + now); + } + } + else + { + timing_wheel_delete (&sm->timing_wheel, sess_index); + delete_session (sm, sw_if_index0, sess_index); + /* FIXME: drop the packet that hit the obsolete node, for now. We really ought to recycle it. */ + next0 = 0; + } + } + else + { + /* + * "-add" node: take l2opaque which arrived to us, and deduce + * the tables out of that. ~0 means the topmost classifier table + * applied for this AF on the RX(for input)/TX(for output)) sw_if_index. + * Also add the mirrored session to the paired table. + */ + l2s_session_t *sess; + u32 sess_index; + + l4_proto = l2sess_get_l4_proto (b0, node_is_ip6); + + pool_get (sm->sessions, sess); + sess_index = sess - sm->sessions; + sess->create_time = now; + sess->side[node_is_out].active_time = now; + sess->side[1 - node_is_out].active_time = now; + sess->l4_proto = l4_proto; + sess->is_ip6 = node_is_ip6; + if (node_is_ip6) + { + session_store_ip6_l3l4_info (b0, sess, node_is_out); + } + else + { + session_store_ip4_l3l4_info (b0, sess, node_is_out); + } + + l2sess_get_session_tables (sm, sw_if_index0, node_is_out, + node_is_ip6, l4_proto, + session_tables); + l2sess_get_session_nexts (sm, sw_if_index0, node_is_out, + node_is_ip6, l4_proto, + session_nexts); + l2sess_flip_l3l4_fields (b0, node_is_ip6, l4_proto); + if (session_tables[1] != ~0) + { + l2sess_add_session (b0, node_is_out, node_is_ip6, + session_tables[1], session_nexts[1], + sess_index); + } + l2sess_flip_l3l4_fields (b0, node_is_ip6, l4_proto); + if (session_tables[0] != ~0) + { + l2sess_add_session (b0, node_is_out, node_is_ip6, + session_tables[0], session_nexts[0], + sess_index); + } + if (6 == sess->l4_proto) + { + tcp_session_account_buffer (b0, sess, node_is_out, now); + } + else + { + udp_session_account_buffer (b0, sess, node_is_out, now); + } + timing_wheel_insert (&sm->timing_wheel, + now + session_get_timeout (sm, sess, + now), + sess_index); + } + + if (now >= sm->timer_wheel_next_expiring_time) + { + check_idle_sessions (sm, sw_if_index0, now); + } + + next0 = feat_bitmap_get_next_node_index (feat_next_node_index, + feature_bitmap0); + + if (next0 >= node->n_next_nodes) + { + trace_flags0 |= 1; + } + + if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) + && (b0->flags & VLIB_BUFFER_IS_TRACED))) + { + l2sess_trace_t *t = + vlib_add_trace (vm, node, b0, sizeof (*t)); + t->sw_if_index = sw_if_index0; + t->next_index = next0; + t->trace_flags = trace_flags0; + t->l4_proto = l4_proto; + t->session_tables[0] = session_tables[0]; + t->session_tables[1] = session_tables[1]; + t->session_nexts[0] = session_nexts[0]; + t->session_nexts[1] = session_nexts[1]; + } + + } + pkts_swapped += 1; + if (next0 >= node->n_next_nodes) + { + next0 = 0; + } + + /* verify speculative enqueue, maybe switch current next frame */ + vlib_validate_buffer_enqueue_x1 (vm, node, next_index, + to_next, n_left_to_next, + bi0, next0); + } + + vlib_put_next_frame (vm, node, next_index, n_left_to_next); + } + vlib_node_increment_counter (vm, node->node_index, + L2SESS_ERROR_SWAPPED, pkts_swapped); + return frame->n_vectors; +} + + +#define _(node_name, node_var, is_out, is_ip6, is_track) \ +static uword \ +node_var ## node_fn (vlib_main_t * vm, \ + vlib_node_runtime_t * node, \ + vlib_frame_t * frame) \ +{ \ + l2sess_main_t *sm = &l2sess_main; \ + return l2sess_node_fn(vm, node, frame, \ + is_out, is_ip6, is_track, \ + sm->node_var ## _feat_next_node_index); \ +} \ +VLIB_REGISTER_NODE (node_var) = { \ + .function = node_var ## node_fn, \ + .name = node_name, \ + .vector_size = sizeof (u32), \ + .format_trace = format_ ## node_var ## _trace, \ + .type = VLIB_NODE_TYPE_INTERNAL, \ + \ + .n_errors = ARRAY_LEN(l2sess_error_strings), \ + .error_strings = l2sess_error_strings, \ + \ + .n_next_nodes = L2SESS_N_NEXT, \ + .next_nodes = { \ + [L2SESS_NEXT_DROP] = "error-drop", \ + }, \ +}; +foreach_l2sess_node +#undef _ |