| /* |
| * 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 <vppinfra/sparse_vec.h> |
| #include <vnet/tcp/tcp_packet.h> |
| #include <vnet/tcp/tcp.h> |
| #include <vnet/session/session.h> |
| #include <math.h> |
| |
| static char *tcp_error_strings[] = { |
| #define tcp_error(n,s) s, |
| #include <vnet/tcp/tcp_error.def> |
| #undef tcp_error |
| }; |
| |
| /* All TCP nodes have the same outgoing arcs */ |
| #define foreach_tcp_state_next \ |
| _ (DROP, "error-drop") \ |
| _ (TCP4_OUTPUT, "tcp4-output") \ |
| _ (TCP6_OUTPUT, "tcp6-output") |
| |
| typedef enum _tcp_established_next |
| { |
| #define _(s,n) TCP_ESTABLISHED_NEXT_##s, |
| foreach_tcp_state_next |
| #undef _ |
| TCP_ESTABLISHED_N_NEXT, |
| } tcp_established_next_t; |
| |
| typedef enum _tcp_rcv_process_next |
| { |
| #define _(s,n) TCP_RCV_PROCESS_NEXT_##s, |
| foreach_tcp_state_next |
| #undef _ |
| TCP_RCV_PROCESS_N_NEXT, |
| } tcp_rcv_process_next_t; |
| |
| typedef enum _tcp_syn_sent_next |
| { |
| #define _(s,n) TCP_SYN_SENT_NEXT_##s, |
| foreach_tcp_state_next |
| #undef _ |
| TCP_SYN_SENT_N_NEXT, |
| } tcp_syn_sent_next_t; |
| |
| typedef enum _tcp_listen_next |
| { |
| #define _(s,n) TCP_LISTEN_NEXT_##s, |
| foreach_tcp_state_next |
| #undef _ |
| TCP_LISTEN_N_NEXT, |
| } tcp_listen_next_t; |
| |
| /* Generic, state independent indices */ |
| typedef enum _tcp_state_next |
| { |
| #define _(s,n) TCP_NEXT_##s, |
| foreach_tcp_state_next |
| #undef _ |
| TCP_STATE_N_NEXT, |
| } tcp_state_next_t; |
| |
| #define tcp_next_output(is_ip4) (is_ip4 ? TCP_NEXT_TCP4_OUTPUT \ |
| : TCP_NEXT_TCP6_OUTPUT) |
| |
| vlib_node_registration_t tcp4_established_node; |
| vlib_node_registration_t tcp6_established_node; |
| |
| /** |
| * Validate segment sequence number. As per RFC793: |
| * |
| * Segment Receive Test |
| * Length Window |
| * ------- ------- ------------------------------------------- |
| * 0 0 SEG.SEQ = RCV.NXT |
| * 0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND |
| * >0 0 not acceptable |
| * >0 >0 RCV.NXT =< SEG.SEQ < RCV.NXT+RCV.WND |
| * or RCV.NXT =< SEG.SEQ+SEG.LEN-1 < RCV.NXT+RCV.WND |
| * |
| * This ultimately consists in checking if segment falls within the window. |
| * The one important difference compared to RFC793 is that we use rcv_las, |
| * or the rcv_nxt at last ack sent instead of rcv_nxt since that's the |
| * peer's reference when computing our receive window. |
| * |
| * This: |
| * seq_leq (end_seq, tc->rcv_las + tc->rcv_wnd) && seq_geq (seq, tc->rcv_las) |
| * however, is too strict when we have retransmits. Instead we just check that |
| * the seq is not beyond the right edge and that the end of the segment is not |
| * less than the left edge. |
| * |
| * N.B. rcv_nxt and rcv_wnd are both updated in this node if acks are sent, so |
| * use rcv_nxt in the right edge window test instead of rcv_las. |
| * |
| */ |
| always_inline u8 |
| tcp_segment_in_rcv_wnd (tcp_connection_t * tc, u32 seq, u32 end_seq) |
| { |
| return (seq_geq (end_seq, tc->rcv_las) |
| && seq_leq (seq, tc->rcv_nxt + tc->rcv_wnd)); |
| } |
| |
| void |
| tcp_options_parse (tcp_header_t * th, tcp_options_t * to) |
| { |
| const u8 *data; |
| u8 opt_len, opts_len, kind; |
| int j; |
| sack_block_t b; |
| |
| opts_len = (tcp_doff (th) << 2) - sizeof (tcp_header_t); |
| data = (const u8 *) (th + 1); |
| |
| /* Zero out all flags but those set in SYN */ |
| to->flags &= (TCP_OPTS_FLAG_SACK_PERMITTED | TCP_OPTS_FLAG_WSCALE); |
| |
| for (; opts_len > 0; opts_len -= opt_len, data += opt_len) |
| { |
| kind = data[0]; |
| |
| /* Get options length */ |
| if (kind == TCP_OPTION_EOL) |
| break; |
| else if (kind == TCP_OPTION_NOOP) |
| opt_len = 1; |
| else |
| { |
| /* broken options */ |
| if (opts_len < 2) |
| break; |
| opt_len = data[1]; |
| |
| /* weird option length */ |
| if (opt_len < 2 || opt_len > opts_len) |
| break; |
| } |
| |
| /* Parse options */ |
| switch (kind) |
| { |
| case TCP_OPTION_MSS: |
| if ((opt_len == TCP_OPTION_LEN_MSS) && tcp_syn (th)) |
| { |
| to->flags |= TCP_OPTS_FLAG_MSS; |
| to->mss = clib_net_to_host_u16 (*(u16 *) (data + 2)); |
| } |
| break; |
| case TCP_OPTION_WINDOW_SCALE: |
| if ((opt_len == TCP_OPTION_LEN_WINDOW_SCALE) && tcp_syn (th)) |
| { |
| to->flags |= TCP_OPTS_FLAG_WSCALE; |
| to->wscale = data[2]; |
| if (to->wscale > TCP_MAX_WND_SCALE) |
| { |
| clib_warning ("Illegal window scaling value: %d", |
| to->wscale); |
| to->wscale = TCP_MAX_WND_SCALE; |
| } |
| } |
| break; |
| case TCP_OPTION_TIMESTAMP: |
| if (opt_len == TCP_OPTION_LEN_TIMESTAMP) |
| { |
| to->flags |= TCP_OPTS_FLAG_TSTAMP; |
| to->tsval = clib_net_to_host_u32 (*(u32 *) (data + 2)); |
| to->tsecr = clib_net_to_host_u32 (*(u32 *) (data + 6)); |
| } |
| break; |
| case TCP_OPTION_SACK_PERMITTED: |
| if (opt_len == TCP_OPTION_LEN_SACK_PERMITTED && tcp_syn (th)) |
| to->flags |= TCP_OPTS_FLAG_SACK_PERMITTED; |
| break; |
| case TCP_OPTION_SACK_BLOCK: |
| /* If SACK permitted was not advertised or a SYN, break */ |
| if ((to->flags & TCP_OPTS_FLAG_SACK_PERMITTED) == 0 || tcp_syn (th)) |
| break; |
| |
| /* If too short or not correctly formatted, break */ |
| if (opt_len < 10 || ((opt_len - 2) % TCP_OPTION_LEN_SACK_BLOCK)) |
| break; |
| |
| to->flags |= TCP_OPTS_FLAG_SACK; |
| to->n_sack_blocks = (opt_len - 2) / TCP_OPTION_LEN_SACK_BLOCK; |
| vec_reset_length (to->sacks); |
| for (j = 0; j < to->n_sack_blocks; j++) |
| { |
| b.start = clib_net_to_host_u32 (*(u32 *) (data + 2 + 4 * j)); |
| b.end = clib_net_to_host_u32 (*(u32 *) (data + 6 + 4 * j)); |
| vec_add1 (to->sacks, b); |
| } |
| break; |
| default: |
| /* Nothing to see here */ |
| continue; |
| } |
| } |
| } |
| |
| always_inline int |
| tcp_segment_check_paws (tcp_connection_t * tc) |
| { |
| /* XXX normally test for timestamp should be lt instead of leq, but for |
| * local testing this is not enough */ |
| return tcp_opts_tstamp (&tc->opt) && tc->tsval_recent |
| && timestamp_lt (tc->opt.tsval, tc->tsval_recent); |
| } |
| |
| /** |
| * Validate incoming segment as per RFC793 p. 69 and RFC1323 p. 19 |
| * |
| * It first verifies if segment has a wrapped sequence number (PAWS) and then |
| * does the processing associated to the first four steps (ignoring security |
| * and precedence): sequence number, rst bit and syn bit checks. |
| * |
| * @return 0 if segments passes validation. |
| */ |
| static int |
| tcp_segment_validate (vlib_main_t * vm, tcp_connection_t * tc0, |
| vlib_buffer_t * b0, tcp_header_t * th0, u32 * next0) |
| { |
| u8 paws_failed; |
| |
| if (PREDICT_FALSE (!tcp_ack (th0) && !tcp_rst (th0) && !tcp_syn (th0))) |
| return -1; |
| |
| tcp_options_parse (th0, &tc0->opt); |
| |
| /* RFC1323: Check against wrapped sequence numbers (PAWS). If we have |
| * timestamp to echo and it's less than tsval_recent, drop segment |
| * but still send an ACK in order to retain TCP's mechanism for detecting |
| * and recovering from half-open connections */ |
| paws_failed = tcp_segment_check_paws (tc0); |
| if (paws_failed) |
| { |
| clib_warning ("paws failed"); |
| |
| /* If it just so happens that a segment updates tsval_recent for a |
| * segment over 24 days old, invalidate tsval_recent. */ |
| if (timestamp_lt (tc0->tsval_recent_age + TCP_PAWS_IDLE, |
| tcp_time_now ())) |
| { |
| /* Age isn't reset until we get a valid tsval (bsd inspired) */ |
| tc0->tsval_recent = 0; |
| } |
| else |
| { |
| /* Drop after ack if not rst */ |
| if (!tcp_rst (th0)) |
| { |
| tcp_make_ack (tc0, b0); |
| *next0 = tcp_next_output (tc0->c_is_ip4); |
| TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0); |
| return -1; |
| } |
| } |
| } |
| |
| /* 1st: check sequence number */ |
| if (!tcp_segment_in_rcv_wnd (tc0, vnet_buffer (b0)->tcp.seq_number, |
| vnet_buffer (b0)->tcp.seq_end)) |
| { |
| /* If our window is 0 and the packet is in sequence, let it pass |
| * through for ack processing. It should be dropped later.*/ |
| if (tc0->rcv_wnd == 0 |
| && tc0->rcv_nxt == vnet_buffer (b0)->tcp.seq_number) |
| { |
| /* TODO Should segment be tagged? */ |
| } |
| else |
| { |
| /* If not RST, send dup ack */ |
| if (!tcp_rst (th0)) |
| { |
| tcp_make_ack (tc0, b0); |
| *next0 = tcp_next_output (tc0->c_is_ip4); |
| TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc0); |
| } |
| return -1; |
| } |
| } |
| |
| /* 2nd: check the RST bit */ |
| if (tcp_rst (th0)) |
| { |
| tcp_connection_reset (tc0); |
| return -1; |
| } |
| |
| /* 3rd: check security and precedence (skip) */ |
| |
| /* 4th: check the SYN bit */ |
| if (tcp_syn (th0)) |
| { |
| tcp_send_reset (b0, tc0->c_is_ip4); |
| return -1; |
| } |
| |
| /* If PAWS passed and segment in window, save timestamp */ |
| if (!paws_failed) |
| { |
| tc0->tsval_recent = tc0->opt.tsval; |
| tc0->tsval_recent_age = tcp_time_now (); |
| } |
| |
| return 0; |
| } |
| |
| always_inline int |
| tcp_rcv_ack_is_acceptable (tcp_connection_t * tc0, vlib_buffer_t * tb0) |
| { |
| /* SND.UNA =< SEG.ACK =< SND.NXT */ |
| return (seq_leq (tc0->snd_una, vnet_buffer (tb0)->tcp.ack_number) |
| && seq_leq (vnet_buffer (tb0)->tcp.ack_number, tc0->snd_nxt)); |
| } |
| |
| /** |
| * Compute smoothed RTT as per VJ's '88 SIGCOMM and RFC6298 |
| * |
| * Note that although the original article, srtt and rttvar are scaled |
| * to minimize round-off errors, here we don't. Instead, we rely on |
| * better precision time measurements. |
| * |
| * TODO support us rtt resolution |
| */ |
| static void |
| tcp_estimate_rtt (tcp_connection_t * tc, u32 mrtt) |
| { |
| int err; |
| |
| if (tc->srtt != 0) |
| { |
| err = mrtt - tc->srtt; |
| tc->srtt += err >> 3; |
| |
| /* XXX Drop in RTT results in RTTVAR increase and bigger RTO. |
| * The increase should be bound */ |
| tc->rttvar += ((int) clib_abs (err) - (int) tc->rttvar) >> 2; |
| } |
| else |
| { |
| /* First measurement. */ |
| tc->srtt = mrtt; |
| tc->rttvar = mrtt >> 1; |
| } |
| } |
| |
| /** Update RTT estimate and RTO timer |
| * |
| * Measure RTT: We have two sources of RTT measurements: TSOPT and ACK |
| * timing. Middle boxes are known to fiddle with TCP options so we |
| * should give higher priority to ACK timing. |
| * |
| * return 1 if valid rtt 0 otherwise |
| */ |
| static int |
| tcp_update_rtt (tcp_connection_t * tc, u32 ack) |
| { |
| u32 mrtt = 0; |
| |
| /* Karn's rule, part 1. Don't use retransmitted segments to estimate |
| * RTT because they're ambiguous. */ |
| if (tc->rtt_seq && seq_gt (ack, tc->rtt_seq) && !tc->rto_boff) |
| { |
| mrtt = tcp_time_now () - tc->rtt_ts; |
| } |
| |
| /* As per RFC7323 TSecr can be used for RTTM only if the segment advances |
| * snd_una, i.e., the left side of the send window: |
| * seq_lt (tc->snd_una, ack). Note: last condition could be dropped, we don't |
| * try to update rtt for dupacks */ |
| else if (tcp_opts_tstamp (&tc->opt) && tc->opt.tsecr && tc->bytes_acked) |
| { |
| mrtt = tcp_time_now () - tc->opt.tsecr; |
| } |
| |
| /* Ignore dubious measurements */ |
| if (mrtt == 0 || mrtt > TCP_RTT_MAX) |
| return 0; |
| |
| tcp_estimate_rtt (tc, mrtt); |
| |
| tc->rto = clib_min (tc->srtt + (tc->rttvar << 2), TCP_RTO_MAX); |
| |
| /* Allow measuring of RTT and make sure boff is 0 */ |
| tc->rtt_seq = 0; |
| tc->rto_boff = 0; |
| |
| return 1; |
| } |
| |
| /** |
| * Dequeue bytes that have been acked and while at it update RTT estimates. |
| */ |
| static void |
| tcp_dequeue_acked (tcp_connection_t * tc, u32 ack) |
| { |
| /* Dequeue the newly ACKed bytes */ |
| stream_session_dequeue_drop (&tc->connection, tc->bytes_acked); |
| |
| /* Update rtt and rto */ |
| tcp_update_rtt (tc, ack); |
| } |
| |
| /** |
| * Check if dupack as per RFC5681 Sec. 2 |
| * |
| * This works only if called before updating snd_wnd. |
| * */ |
| always_inline u8 |
| tcp_ack_is_dupack (tcp_connection_t * tc, vlib_buffer_t * b, u32 new_snd_wnd) |
| { |
| return ((vnet_buffer (b)->tcp.ack_number == tc->snd_una) |
| && seq_gt (tc->snd_una_max, tc->snd_una) |
| && (vnet_buffer (b)->tcp.seq_end == vnet_buffer (b)->tcp.seq_number) |
| && (new_snd_wnd == tc->snd_wnd)); |
| } |
| |
| void |
| scoreboard_remove_hole (sack_scoreboard_t * sb, sack_scoreboard_hole_t * hole) |
| { |
| sack_scoreboard_hole_t *next, *prev; |
| |
| if (hole->next != TCP_INVALID_SACK_HOLE_INDEX) |
| { |
| next = pool_elt_at_index (sb->holes, hole->next); |
| next->prev = hole->prev; |
| } |
| |
| if (hole->prev != TCP_INVALID_SACK_HOLE_INDEX) |
| { |
| prev = pool_elt_at_index (sb->holes, hole->prev); |
| prev->next = hole->next; |
| } |
| else |
| { |
| sb->head = hole->next; |
| } |
| |
| pool_put (sb->holes, hole); |
| } |
| |
| sack_scoreboard_hole_t * |
| scoreboard_insert_hole (sack_scoreboard_t * sb, u32 prev_index, |
| u32 start, u32 end) |
| { |
| sack_scoreboard_hole_t *hole, *next, *prev; |
| u32 hole_index; |
| |
| pool_get (sb->holes, hole); |
| memset (hole, 0, sizeof (*hole)); |
| |
| hole->start = start; |
| hole->end = end; |
| hole_index = hole - sb->holes; |
| |
| prev = scoreboard_get_hole (sb, prev_index); |
| if (prev) |
| { |
| hole->prev = prev - sb->holes; |
| hole->next = prev->next; |
| |
| if ((next = scoreboard_next_hole (sb, hole))) |
| next->prev = hole_index; |
| |
| prev->next = hole_index; |
| } |
| else |
| { |
| sb->head = hole_index; |
| hole->prev = TCP_INVALID_SACK_HOLE_INDEX; |
| hole->next = TCP_INVALID_SACK_HOLE_INDEX; |
| } |
| |
| return hole; |
| } |
| |
| void |
| tcp_rcv_sacks (tcp_connection_t * tc, u32 ack) |
| { |
| sack_scoreboard_t *sb = &tc->sack_sb; |
| sack_block_t *blk, tmp; |
| sack_scoreboard_hole_t *hole, *next_hole, *last_hole, *new_hole; |
| u32 blk_index = 0, old_sacked_bytes, hole_index; |
| int i, j; |
| |
| sb->last_sacked_bytes = 0; |
| sb->snd_una_adv = 0; |
| old_sacked_bytes = sb->sacked_bytes; |
| |
| if (!tcp_opts_sack (&tc->opt) && sb->head == TCP_INVALID_SACK_HOLE_INDEX) |
| return; |
| |
| /* Remove invalid blocks */ |
| blk = tc->opt.sacks; |
| while (blk < vec_end (tc->opt.sacks)) |
| { |
| if (seq_lt (blk->start, blk->end) |
| && seq_gt (blk->start, tc->snd_una) |
| && seq_gt (blk->start, ack) && seq_leq (blk->end, tc->snd_nxt)) |
| { |
| blk++; |
| continue; |
| } |
| vec_del1 (tc->opt.sacks, blk - tc->opt.sacks); |
| } |
| |
| /* Add block for cumulative ack */ |
| if (seq_gt (ack, tc->snd_una)) |
| { |
| tmp.start = tc->snd_una; |
| tmp.end = ack; |
| vec_add1 (tc->opt.sacks, tmp); |
| } |
| |
| if (vec_len (tc->opt.sacks) == 0) |
| return; |
| |
| /* Make sure blocks are ordered */ |
| for (i = 0; i < vec_len (tc->opt.sacks); i++) |
| for (j = i + 1; j < vec_len (tc->opt.sacks); j++) |
| if (seq_lt (tc->opt.sacks[j].start, tc->opt.sacks[i].start)) |
| { |
| tmp = tc->opt.sacks[i]; |
| tc->opt.sacks[i] = tc->opt.sacks[j]; |
| tc->opt.sacks[j] = tmp; |
| } |
| |
| if (sb->head == TCP_INVALID_SACK_HOLE_INDEX) |
| { |
| /* If no holes, insert the first that covers all outstanding bytes */ |
| last_hole = scoreboard_insert_hole (sb, TCP_INVALID_SACK_HOLE_INDEX, |
| tc->snd_una, tc->snd_una_max); |
| sb->tail = scoreboard_hole_index (sb, last_hole); |
| } |
| else |
| { |
| /* If we have holes but snd_una_max is beyond the last hole, update |
| * last hole end */ |
| tmp = tc->opt.sacks[vec_len (tc->opt.sacks) - 1]; |
| last_hole = scoreboard_last_hole (sb); |
| if (seq_gt (tc->snd_una_max, sb->max_byte_sacked) |
| && seq_gt (tc->snd_una_max, last_hole->end)) |
| last_hole->end = tc->snd_una_max; |
| } |
| |
| /* Walk the holes with the SACK blocks */ |
| hole = pool_elt_at_index (sb->holes, sb->head); |
| while (hole && blk_index < vec_len (tc->opt.sacks)) |
| { |
| blk = &tc->opt.sacks[blk_index]; |
| |
| if (seq_leq (blk->start, hole->start)) |
| { |
| /* Block covers hole. Remove hole */ |
| if (seq_geq (blk->end, hole->end)) |
| { |
| next_hole = scoreboard_next_hole (sb, hole); |
| |
| /* Byte accounting */ |
| if (seq_leq (hole->end, ack)) |
| { |
| /* Bytes lost because snd_wnd left edge advances */ |
| if (next_hole && seq_leq (next_hole->start, ack)) |
| sb->sacked_bytes -= next_hole->start - hole->end; |
| else |
| sb->sacked_bytes -= ack - hole->end; |
| } |
| else |
| { |
| sb->sacked_bytes += scoreboard_hole_bytes (hole); |
| } |
| |
| /* snd_una needs to be advanced */ |
| if (seq_geq (ack, hole->end)) |
| { |
| if (next_hole && seq_lt (ack, next_hole->start)) |
| sb->snd_una_adv = next_hole->start - ack; |
| else |
| sb->snd_una_adv = sb->max_byte_sacked - ack; |
| |
| /* all these can be delivered */ |
| sb->sacked_bytes -= sb->snd_una_adv; |
| } |
| |
| /* About to remove last hole */ |
| if (hole == last_hole) |
| { |
| sb->tail = hole->prev; |
| last_hole = scoreboard_last_hole (sb); |
| /* keep track of max byte sacked in case the last hole |
| * is acked */ |
| if (seq_gt (hole->end, sb->max_byte_sacked)) |
| sb->max_byte_sacked = hole->end; |
| } |
| scoreboard_remove_hole (sb, hole); |
| hole = next_hole; |
| } |
| /* Partial 'head' overlap */ |
| else |
| { |
| if (seq_gt (blk->end, hole->start)) |
| { |
| sb->sacked_bytes += blk->end - hole->start; |
| hole->start = blk->end; |
| } |
| blk_index++; |
| } |
| } |
| else |
| { |
| /* Hole must be split */ |
| if (seq_lt (blk->end, hole->end)) |
| { |
| sb->sacked_bytes += blk->end - blk->start; |
| hole_index = scoreboard_hole_index (sb, hole); |
| new_hole = scoreboard_insert_hole (sb, hole_index, blk->end, |
| hole->end); |
| |
| /* Pool might've moved */ |
| hole = scoreboard_get_hole (sb, hole_index); |
| hole->end = blk->start; |
| |
| /* New or split of tail */ |
| if ((last_hole->end == new_hole->end) |
| || seq_lt (last_hole->end, new_hole->start)) |
| { |
| last_hole = new_hole; |
| sb->tail = scoreboard_hole_index (sb, new_hole); |
| } |
| |
| blk_index++; |
| hole = scoreboard_next_hole (sb, hole); |
| } |
| else |
| { |
| sb->sacked_bytes += hole->end - blk->start; |
| hole->end = blk->start; |
| hole = scoreboard_next_hole (sb, hole); |
| } |
| } |
| } |
| |
| sb->last_sacked_bytes = sb->sacked_bytes + sb->snd_una_adv |
| - old_sacked_bytes; |
| } |
| |
| /** Update snd_wnd |
| * |
| * If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set |
| * SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK */ |
| static void |
| tcp_update_snd_wnd (tcp_connection_t * tc, u32 seq, u32 ack, u32 snd_wnd) |
| { |
| if (seq_lt (tc->snd_wl1, seq) |
| || (tc->snd_wl1 == seq && seq_leq (tc->snd_wl2, ack))) |
| { |
| tc->snd_wnd = snd_wnd; |
| tc->snd_wl1 = seq; |
| tc->snd_wl2 = ack; |
| TCP_EVT_DBG (TCP_EVT_SND_WND, tc); |
| |
| /* Set probe timer if we just got 0 wnd */ |
| if (tc->snd_wnd < tc->snd_mss |
| && !tcp_timer_is_active (tc, TCP_TIMER_PERSIST)) |
| tcp_persist_timer_set (tc); |
| else |
| tcp_persist_timer_reset (tc); |
| } |
| } |
| |
| void |
| tcp_cc_congestion (tcp_connection_t * tc) |
| { |
| tc->snd_congestion = tc->snd_nxt; |
| tc->cc_algo->congestion (tc); |
| TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 4); |
| } |
| |
| void |
| tcp_cc_recover (tcp_connection_t * tc) |
| { |
| /* TODO: check if time to recover was small. It might be that RTO popped |
| * too soon. |
| */ |
| |
| tc->cc_algo->recovered (tc); |
| |
| tc->rtx_bytes = 0; |
| tc->rcv_dupacks = 0; |
| tc->snd_nxt = tc->snd_una; |
| |
| tc->cc_algo->rcv_ack (tc); |
| tc->tsecr_last_ack = tc->opt.tsecr; |
| |
| tcp_cong_recovery_off (tc); |
| |
| TCP_EVT_DBG (TCP_EVT_CC_EVT, tc, 3); |
| } |
| |
| static void |
| tcp_cc_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b) |
| { |
| u8 partial_ack; |
| |
| if (tcp_in_cong_recovery (tc)) |
| { |
| partial_ack = seq_lt (tc->snd_una, tc->snd_congestion); |
| if (!partial_ack) |
| { |
| /* Clear retransmitted bytes. */ |
| tcp_cc_recover (tc); |
| } |
| else |
| { |
| TCP_EVT_DBG (TCP_EVT_CC_PACK, tc); |
| |
| /* Clear retransmitted bytes. XXX should we clear all? */ |
| tc->rtx_bytes = 0; |
| tc->cc_algo->rcv_cong_ack (tc, TCP_CC_PARTIALACK); |
| |
| /* In case snd_nxt is still in the past and output tries to |
| * shove some new bytes */ |
| tc->snd_nxt = tc->snd_una_max; |
| |
| /* XXX need proper RFC6675 support */ |
| if (tc->sack_sb.last_sacked_bytes && !tcp_in_recovery (tc)) |
| { |
| tcp_fast_retransmit (tc); |
| } |
| else |
| { |
| /* Retransmit first unacked segment */ |
| tcp_retransmit_first_unacked (tc); |
| } |
| } |
| } |
| else |
| { |
| tc->cc_algo->rcv_ack (tc); |
| tc->tsecr_last_ack = tc->opt.tsecr; |
| tc->rcv_dupacks = 0; |
| } |
| } |
| |
| static void |
| tcp_cc_rcv_dupack (tcp_connection_t * tc, u32 ack) |
| { |
| // ASSERT (seq_geq(tc->snd_una, ack)); |
| |
| tc->rcv_dupacks++; |
| if (tc->rcv_dupacks == TCP_DUPACK_THRESHOLD) |
| { |
| /* RFC6582 NewReno heuristic to avoid multiple fast retransmits */ |
| if (tc->opt.tsecr != tc->tsecr_last_ack) |
| { |
| tc->rcv_dupacks = 0; |
| return; |
| } |
| |
| tcp_fastrecovery_on (tc); |
| |
| /* Handle congestion and dupack */ |
| tcp_cc_congestion (tc); |
| tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK); |
| |
| tcp_fast_retransmit (tc); |
| |
| /* Post retransmit update cwnd to ssthresh and account for the |
| * three segments that have left the network and should've been |
| * buffered at the receiver */ |
| tc->cwnd = tc->ssthresh + TCP_DUPACK_THRESHOLD * tc->snd_mss; |
| } |
| else if (tc->rcv_dupacks > TCP_DUPACK_THRESHOLD) |
| { |
| ASSERT (tcp_in_fastrecovery (tc)); |
| |
| tc->cc_algo->rcv_cong_ack (tc, TCP_CC_DUPACK); |
| } |
| } |
| |
| void |
| tcp_cc_init (tcp_connection_t * tc) |
| { |
| tc->cc_algo = tcp_cc_algo_get (TCP_CC_NEWRENO); |
| tc->cc_algo->init (tc); |
| } |
| |
| static int |
| tcp_rcv_ack (tcp_connection_t * tc, vlib_buffer_t * b, |
| tcp_header_t * th, u32 * next, u32 * error) |
| { |
| u32 new_snd_wnd; |
| |
| /* If the ACK acks something not yet sent (SEG.ACK > SND.NXT) */ |
| if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_nxt)) |
| { |
| /* If we have outstanding data and this is within the window, accept it, |
| * probably retransmit has timed out. Otherwise ACK segment and then |
| * drop it */ |
| if (seq_gt (vnet_buffer (b)->tcp.ack_number, tc->snd_una_max)) |
| { |
| tcp_make_ack (tc, b); |
| *next = tcp_next_output (tc->c_is_ip4); |
| *error = TCP_ERROR_ACK_INVALID; |
| TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 0, |
| vnet_buffer (b)->tcp.ack_number); |
| return -1; |
| } |
| |
| TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 2, |
| vnet_buffer (b)->tcp.ack_number); |
| |
| tc->snd_nxt = vnet_buffer (b)->tcp.ack_number; |
| *error = TCP_ERROR_ACK_FUTURE; |
| } |
| |
| /* If old ACK, probably it's an old dupack */ |
| if (seq_lt (vnet_buffer (b)->tcp.ack_number, tc->snd_una)) |
| { |
| *error = TCP_ERROR_ACK_OLD; |
| TCP_EVT_DBG (TCP_EVT_ACK_RCV_ERR, tc, 1, |
| vnet_buffer (b)->tcp.ack_number); |
| if (tcp_in_fastrecovery (tc) && tc->rcv_dupacks == TCP_DUPACK_THRESHOLD) |
| { |
| TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc); |
| tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number); |
| } |
| return -1; |
| } |
| |
| if (tcp_opts_sack_permitted (&tc->opt)) |
| tcp_rcv_sacks (tc, vnet_buffer (b)->tcp.ack_number); |
| |
| new_snd_wnd = clib_net_to_host_u16 (th->window) << tc->snd_wscale; |
| |
| if (tcp_ack_is_dupack (tc, b, new_snd_wnd)) |
| { |
| TCP_EVT_DBG (TCP_EVT_DUPACK_RCVD, tc, 1); |
| tcp_cc_rcv_dupack (tc, vnet_buffer (b)->tcp.ack_number); |
| *error = TCP_ERROR_ACK_DUP; |
| return -1; |
| } |
| |
| /* |
| * Valid ACK |
| */ |
| |
| tc->bytes_acked = vnet_buffer (b)->tcp.ack_number - tc->snd_una; |
| tc->snd_una = vnet_buffer (b)->tcp.ack_number + tc->sack_sb.snd_una_adv; |
| |
| /* Dequeue ACKed data and update RTT */ |
| tcp_dequeue_acked (tc, vnet_buffer (b)->tcp.ack_number); |
| tcp_update_snd_wnd (tc, vnet_buffer (b)->tcp.seq_number, |
| vnet_buffer (b)->tcp.ack_number, new_snd_wnd); |
| |
| /* If some of our sent bytes have been acked, update cc and retransmit |
| * timer. */ |
| if (tc->bytes_acked) |
| { |
| TCP_EVT_DBG (TCP_EVT_ACK_RCVD, tc); |
| |
| /* Updates congestion control (slow start/congestion avoidance) */ |
| tcp_cc_rcv_ack (tc, b); |
| |
| /* If everything has been acked, stop retransmit timer |
| * otherwise update */ |
| if (tc->snd_una == tc->snd_una_max) |
| tcp_retransmit_timer_reset (tc); |
| else |
| tcp_retransmit_timer_update (tc); |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * Build SACK list as per RFC2018. |
| * |
| * Makes sure the first block contains the segment that generated the current |
| * ACK and the following ones are the ones most recently reported in SACK |
| * blocks. |
| * |
| * @param tc TCP connection for which the SACK list is updated |
| * @param start Start sequence number of the newest SACK block |
| * @param end End sequence of the newest SACK block |
| */ |
| static void |
| tcp_update_sack_list (tcp_connection_t * tc, u32 start, u32 end) |
| { |
| sack_block_t *new_list = 0, block; |
| int i; |
| |
| /* If the first segment is ooo add it to the list. Last write might've moved |
| * rcv_nxt over the first segment. */ |
| if (seq_lt (tc->rcv_nxt, start)) |
| { |
| block.start = start; |
| block.end = end; |
| vec_add1 (new_list, block); |
| } |
| |
| /* Find the blocks still worth keeping. */ |
| for (i = 0; i < vec_len (tc->snd_sacks); i++) |
| { |
| /* Discard if: |
| * 1) rcv_nxt advanced beyond current block OR |
| * 2) Segment overlapped by the first segment, i.e., it has been merged |
| * into it.*/ |
| if (seq_leq (tc->snd_sacks[i].start, tc->rcv_nxt) |
| || seq_leq (tc->snd_sacks[i].start, end)) |
| continue; |
| |
| /* Save to new SACK list. */ |
| vec_add1 (new_list, tc->snd_sacks[i]); |
| } |
| |
| ASSERT (vec_len (new_list) < TCP_MAX_SACK_BLOCKS); |
| |
| /* Replace old vector with new one */ |
| vec_free (tc->snd_sacks); |
| tc->snd_sacks = new_list; |
| } |
| |
| /** Enqueue data for delivery to application */ |
| always_inline int |
| tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b, |
| u16 data_len) |
| { |
| int written; |
| |
| /* Pure ACK. Update rcv_nxt and be done. */ |
| if (PREDICT_FALSE (data_len == 0)) |
| { |
| tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end; |
| return TCP_ERROR_PURE_ACK; |
| } |
| |
| written = stream_session_enqueue_data (&tc->connection, |
| vlib_buffer_get_current (b), |
| data_len, 1 /* queue event */ ); |
| |
| TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written); |
| |
| /* Update rcv_nxt */ |
| if (PREDICT_TRUE (written == data_len)) |
| { |
| tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end; |
| } |
| /* If more data written than expected, account for out-of-order bytes. */ |
| else if (written > data_len) |
| { |
| tc->rcv_nxt = vnet_buffer (b)->tcp.seq_end + written - data_len; |
| |
| /* Send ACK confirming the update */ |
| tc->flags |= TCP_CONN_SNDACK; |
| } |
| else if (written > 0) |
| { |
| /* We've written something but FIFO is probably full now */ |
| tc->rcv_nxt += written; |
| |
| /* Depending on how fast the app is, all remaining buffers in burst will |
| * not be enqueued. Inform peer */ |
| tc->flags |= TCP_CONN_SNDACK; |
| |
| return TCP_ERROR_PARTIALLY_ENQUEUED; |
| } |
| else |
| { |
| tc->flags |= TCP_CONN_SNDACK; |
| return TCP_ERROR_FIFO_FULL; |
| } |
| |
| /* Update SACK list if need be */ |
| if (tcp_opts_sack_permitted (&tc->opt)) |
| { |
| /* Remove SACK blocks that have been delivered */ |
| tcp_update_sack_list (tc, tc->rcv_nxt, tc->rcv_nxt); |
| } |
| |
| return TCP_ERROR_ENQUEUED; |
| } |
| |
| /** Enqueue out-of-order data */ |
| always_inline int |
| tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b, |
| u16 data_len) |
| { |
| stream_session_t *s0; |
| u32 offset, seq; |
| int rv; |
| |
| /* Pure ACK. Do nothing */ |
| if (PREDICT_FALSE (data_len == 0)) |
| { |
| return TCP_ERROR_PURE_ACK; |
| } |
| |
| s0 = stream_session_get (tc->c_s_index, tc->c_thread_index); |
| seq = vnet_buffer (b)->tcp.seq_number; |
| offset = seq - tc->rcv_nxt; |
| |
| rv = svm_fifo_enqueue_with_offset (s0->server_rx_fifo, s0->pid, offset, |
| data_len, vlib_buffer_get_current (b)); |
| |
| /* Nothing written */ |
| if (rv) |
| { |
| TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, 0); |
| return TCP_ERROR_FIFO_FULL; |
| } |
| |
| TCP_EVT_DBG (TCP_EVT_INPUT, tc, 1, data_len, data_len); |
| |
| /* Update SACK list if in use */ |
| if (tcp_opts_sack_permitted (&tc->opt)) |
| { |
| ooo_segment_t *newest; |
| u32 start, end; |
| |
| /* Get the newest segment from the fifo */ |
| newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo); |
| start = tc->rcv_nxt + ooo_segment_offset (s0->server_rx_fifo, newest); |
| end = tc->rcv_nxt + ooo_segment_end_offset (s0->server_rx_fifo, newest); |
| |
| tcp_update_sack_list (tc, start, end); |
| } |
| |
| return TCP_ERROR_ENQUEUED; |
| } |
| |
| /** |
| * Check if ACK could be delayed. If ack can be delayed, it should return |
| * true for a full frame. If we're always acking return 0. |
| */ |
| always_inline int |
| tcp_can_delack (tcp_connection_t * tc) |
| { |
| /* Send ack if ... */ |
| if (TCP_ALWAYS_ACK |
| /* just sent a rcv wnd 0 */ |
| || (tc->flags & TCP_CONN_SENT_RCV_WND0) != 0 |
| /* constrained to send ack */ |
| || (tc->flags & TCP_CONN_SNDACK) != 0 |
| /* we're almost out of tx wnd */ |
| || tcp_available_snd_space (tc) < 2 * tc->snd_mss) |
| return 0; |
| |
| return 1; |
| } |
| |
| static int |
| tcp_segment_rcv (tcp_main_t * tm, tcp_connection_t * tc, vlib_buffer_t * b, |
| u16 n_data_bytes, u32 * next0) |
| { |
| u32 error = 0; |
| |
| /* Handle out-of-order data */ |
| if (PREDICT_FALSE (vnet_buffer (b)->tcp.seq_number != tc->rcv_nxt)) |
| { |
| /* Old sequence numbers allowed through because they overlapped |
| * the rx window */ |
| if (seq_lt (vnet_buffer (b)->tcp.seq_number, tc->rcv_nxt)) |
| { |
| error = TCP_ERROR_SEGMENT_OLD; |
| *next0 = TCP_NEXT_DROP; |
| goto done; |
| } |
| |
| error = tcp_session_enqueue_ooo (tc, b, n_data_bytes); |
| |
| /* N.B. Should not filter burst of dupacks. Two issues 1) dupacks open |
| * cwnd on remote peer when congested 2) acks leaving should have the |
| * latest rcv_wnd since the burst may eaten up all of it, so only the |
| * old ones could be filtered. |
| */ |
| |
| /* RFC2581: Send DUPACK for fast retransmit */ |
| tcp_make_ack (tc, b); |
| *next0 = tcp_next_output (tc->c_is_ip4); |
| |
| /* Mark as DUPACK. We may filter these in output if |
| * the burst fills the holes. */ |
| if (n_data_bytes) |
| vnet_buffer (b)->tcp.flags = TCP_BUF_FLAG_DUPACK; |
| |
| TCP_EVT_DBG (TCP_EVT_DUPACK_SENT, tc); |
| goto done; |
| } |
| |
| /* In order data, enqueue. Fifo figures out by itself if any out-of-order |
| * segments can be enqueued after fifo tail offset changes. */ |
| error = tcp_session_enqueue_data (tc, b, n_data_bytes); |
| |
| if (n_data_bytes == 0) |
| { |
| *next0 = TCP_NEXT_DROP; |
| goto done; |
| } |
| |
| /* Check if ACK can be delayed */ |
| if (tcp_can_delack (tc)) |
| { |
| if (!tcp_timer_is_active (tc, TCP_TIMER_DELACK)) |
| tcp_timer_set (tc, TCP_TIMER_DELACK, TCP_DELACK_TIME); |
| goto done; |
| } |
| |
| *next0 = tcp_next_output (tc->c_is_ip4); |
| tcp_make_ack (tc, b); |
| |
| done: |
| return error; |
| } |
| |
| typedef struct |
| { |
| tcp_header_t tcp_header; |
| tcp_connection_t tcp_connection; |
| } tcp_rx_trace_t; |
| |
| u8 * |
| format_tcp_rx_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 *); |
| tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *); |
| uword indent = format_get_indent (s); |
| |
| s = format (s, "%U\n%U%U", |
| format_tcp_header, &t->tcp_header, 128, |
| format_white_space, indent, |
| format_tcp_connection_verbose, &t->tcp_connection); |
| |
| return s; |
| } |
| |
| u8 * |
| format_tcp_rx_trace_short (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 *); |
| tcp_rx_trace_t *t = va_arg (*args, tcp_rx_trace_t *); |
| |
| s = format (s, "%d -> %d (%U)", |
| clib_net_to_host_u16 (t->tcp_header.src_port), |
| clib_net_to_host_u16 (t->tcp_header.dst_port), format_tcp_state, |
| &t->tcp_connection.state); |
| |
| return s; |
| } |
| |
| always_inline void |
| tcp_established_inc_counter (vlib_main_t * vm, u8 is_ip4, u8 evt, u8 val) |
| { |
| if (PREDICT_TRUE (!val)) |
| return; |
| |
| if (is_ip4) |
| vlib_node_increment_counter (vm, tcp4_established_node.index, evt, val); |
| else |
| vlib_node_increment_counter (vm, tcp6_established_node.index, evt, val); |
| } |
| |
| always_inline uword |
| tcp46_established_inline (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame, int is_ip4) |
| { |
| u32 n_left_from, next_index, *from, *to_next; |
| u32 my_thread_index = vm->thread_index, errors = 0; |
| tcp_main_t *tm = vnet_get_tcp_main (); |
| |
| from = vlib_frame_vector_args (from_frame); |
| n_left_from = 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); |
| |
| while (n_left_from > 0 && n_left_to_next > 0) |
| { |
| u32 bi0; |
| vlib_buffer_t *b0; |
| tcp_rx_trace_t *t0; |
| tcp_header_t *th0 = 0; |
| tcp_connection_t *tc0; |
| ip4_header_t *ip40; |
| ip6_header_t *ip60; |
| u32 n_advance_bytes0, n_data_bytes0; |
| u32 next0 = TCP_ESTABLISHED_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED; |
| |
| 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); |
| tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index, |
| my_thread_index); |
| |
| if (PREDICT_FALSE (tc0 == 0)) |
| { |
| error0 = TCP_ERROR_INVALID_CONNECTION; |
| goto done; |
| } |
| |
| /* Checksum computed by ipx_local no need to compute again */ |
| |
| if (is_ip4) |
| { |
| ip40 = vlib_buffer_get_current (b0); |
| th0 = ip4_next_header (ip40); |
| n_advance_bytes0 = (ip4_header_bytes (ip40) |
| + tcp_header_bytes (th0)); |
| n_data_bytes0 = clib_net_to_host_u16 (ip40->length) |
| - n_advance_bytes0; |
| } |
| else |
| { |
| ip60 = vlib_buffer_get_current (b0); |
| th0 = ip6_next_header (ip60); |
| n_advance_bytes0 = tcp_header_bytes (th0); |
| n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length) |
| - n_advance_bytes0; |
| n_advance_bytes0 += sizeof (ip60[0]); |
| } |
| |
| /* SYNs, FINs and data consume sequence numbers */ |
| vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number |
| + tcp_is_syn (th0) + tcp_is_fin (th0) + n_data_bytes0; |
| |
| /* TODO header prediction fast path */ |
| |
| /* 1-4: check SEQ, RST, SYN */ |
| if (PREDICT_FALSE (tcp_segment_validate (vm, tc0, b0, th0, &next0))) |
| { |
| error0 = TCP_ERROR_SEGMENT_INVALID; |
| TCP_EVT_DBG (TCP_EVT_SEG_INVALID, tc0, |
| vnet_buffer (b0)->tcp.seq_number, |
| vnet_buffer (b0)->tcp.seq_end); |
| goto done; |
| } |
| |
| /* 5: check the ACK field */ |
| if (tcp_rcv_ack (tc0, b0, th0, &next0, &error0)) |
| { |
| goto done; |
| } |
| |
| /* 6: check the URG bit TODO */ |
| |
| /* 7: process the segment text */ |
| |
| vlib_buffer_advance (b0, n_advance_bytes0); |
| error0 = tcp_segment_rcv (tm, tc0, b0, n_data_bytes0, &next0); |
| |
| /* 8: check the FIN bit */ |
| if (tcp_fin (th0)) |
| { |
| /* Enter CLOSE-WAIT and notify session. Don't send ACK, instead |
| * wait for session to call close. To avoid lingering |
| * in CLOSE-WAIT, set timer (reuse WAITCLOSE). */ |
| tc0->state = TCP_STATE_CLOSE_WAIT; |
| TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0); |
| stream_session_disconnect_notify (&tc0->connection); |
| tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME); |
| } |
| |
| done: |
| b0->error = node->errors[error0]; |
| if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED)) |
| { |
| t0 = vlib_add_trace (vm, node, b0, sizeof (*t0)); |
| clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header)); |
| clib_memcpy (&t0->tcp_connection, tc0, |
| sizeof (t0->tcp_connection)); |
| } |
| |
| 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); |
| } |
| |
| errors = session_manager_flush_enqueue_events (my_thread_index); |
| tcp_established_inc_counter (vm, is_ip4, TCP_ERROR_EVENT_FIFO_FULL, errors); |
| |
| return from_frame->n_vectors; |
| } |
| |
| static uword |
| tcp4_established (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame) |
| { |
| return tcp46_established_inline (vm, node, from_frame, 1 /* is_ip4 */ ); |
| } |
| |
| static uword |
| tcp6_established (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame) |
| { |
| return tcp46_established_inline (vm, node, from_frame, 0 /* is_ip4 */ ); |
| } |
| |
| /* *INDENT-OFF* */ |
| VLIB_REGISTER_NODE (tcp4_established_node) = |
| { |
| .function = tcp4_established, |
| .name = "tcp4-established", |
| /* Takes a vector of packets. */ |
| .vector_size = sizeof (u32), |
| .n_errors = TCP_N_ERROR, |
| .error_strings = tcp_error_strings, |
| .n_next_nodes = TCP_ESTABLISHED_N_NEXT, |
| .next_nodes = |
| { |
| #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n, |
| foreach_tcp_state_next |
| #undef _ |
| }, |
| .format_trace = format_tcp_rx_trace_short, |
| }; |
| /* *INDENT-ON* */ |
| |
| VLIB_NODE_FUNCTION_MULTIARCH (tcp4_established_node, tcp4_established); |
| |
| /* *INDENT-OFF* */ |
| VLIB_REGISTER_NODE (tcp6_established_node) = |
| { |
| .function = tcp6_established, |
| .name = "tcp6-established", |
| /* Takes a vector of packets. */ |
| .vector_size = sizeof (u32), |
| .n_errors = TCP_N_ERROR, |
| .error_strings = tcp_error_strings, |
| .n_next_nodes = TCP_ESTABLISHED_N_NEXT, |
| .next_nodes = |
| { |
| #define _(s,n) [TCP_ESTABLISHED_NEXT_##s] = n, |
| foreach_tcp_state_next |
| #undef _ |
| }, |
| .format_trace = format_tcp_rx_trace_short, |
| }; |
| /* *INDENT-ON* */ |
| |
| |
| VLIB_NODE_FUNCTION_MULTIARCH (tcp6_established_node, tcp6_established); |
| |
| vlib_node_registration_t tcp4_syn_sent_node; |
| vlib_node_registration_t tcp6_syn_sent_node; |
| |
| always_inline uword |
| tcp46_syn_sent_inline (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame, int is_ip4) |
| { |
| tcp_main_t *tm = vnet_get_tcp_main (); |
| u32 n_left_from, next_index, *from, *to_next; |
| u32 my_thread_index = vm->thread_index, errors = 0; |
| u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP; |
| |
| from = vlib_frame_vector_args (from_frame); |
| n_left_from = 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); |
| |
| while (n_left_from > 0 && n_left_to_next > 0) |
| { |
| u32 bi0, ack0, seq0; |
| vlib_buffer_t *b0; |
| tcp_rx_trace_t *t0; |
| tcp_header_t *tcp0 = 0; |
| tcp_connection_t *tc0; |
| ip4_header_t *ip40; |
| ip6_header_t *ip60; |
| u32 n_advance_bytes0, n_data_bytes0; |
| tcp_connection_t *new_tc0; |
| u32 next0 = TCP_SYN_SENT_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED; |
| |
| 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); |
| tc0 = |
| tcp_half_open_connection_get (vnet_buffer (b0)-> |
| tcp.connection_index); |
| |
| ack0 = vnet_buffer (b0)->tcp.ack_number; |
| seq0 = vnet_buffer (b0)->tcp.seq_number; |
| |
| /* Checksum computed by ipx_local no need to compute again */ |
| |
| if (is_ip4) |
| { |
| ip40 = vlib_buffer_get_current (b0); |
| tcp0 = ip4_next_header (ip40); |
| n_advance_bytes0 = (ip4_header_bytes (ip40) |
| + tcp_header_bytes (tcp0)); |
| n_data_bytes0 = clib_net_to_host_u16 (ip40->length) |
| - n_advance_bytes0; |
| } |
| else |
| { |
| ip60 = vlib_buffer_get_current (b0); |
| tcp0 = ip6_next_header (ip60); |
| n_advance_bytes0 = tcp_header_bytes (tcp0); |
| n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length) |
| - n_advance_bytes0; |
| n_advance_bytes0 += sizeof (ip60[0]); |
| } |
| |
| if (PREDICT_FALSE |
| (!tcp_ack (tcp0) && !tcp_rst (tcp0) && !tcp_syn (tcp0))) |
| goto drop; |
| |
| /* SYNs, FINs and data consume sequence numbers */ |
| vnet_buffer (b0)->tcp.seq_end = seq0 + tcp_is_syn (tcp0) |
| + tcp_is_fin (tcp0) + n_data_bytes0; |
| |
| /* |
| * 1. check the ACK bit |
| */ |
| |
| /* |
| * If the ACK bit is set |
| * If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send a reset (unless |
| * the RST bit is set, if so drop the segment and return) |
| * <SEQ=SEG.ACK><CTL=RST> |
| * and discard the segment. Return. |
| * If SND.UNA =< SEG.ACK =< SND.NXT then the ACK is acceptable. |
| */ |
| if (tcp_ack (tcp0)) |
| { |
| if (ack0 <= tc0->iss || ack0 > tc0->snd_nxt) |
| { |
| if (!tcp_rst (tcp0)) |
| tcp_send_reset (b0, is_ip4); |
| |
| goto drop; |
| } |
| |
| /* Make sure ACK is valid */ |
| if (tc0->snd_una > ack0) |
| goto drop; |
| } |
| |
| /* |
| * 2. check the RST bit |
| */ |
| |
| if (tcp_rst (tcp0)) |
| { |
| /* If ACK is acceptable, signal client that peer is not |
| * willing to accept connection and drop connection*/ |
| if (tcp_ack (tcp0)) |
| { |
| stream_session_connect_notify (&tc0->connection, sst, |
| 1 /* fail */ ); |
| tcp_connection_cleanup (tc0); |
| } |
| goto drop; |
| } |
| |
| /* |
| * 3. check the security and precedence (skipped) |
| */ |
| |
| /* |
| * 4. check the SYN bit |
| */ |
| |
| /* No SYN flag. Drop. */ |
| if (!tcp_syn (tcp0)) |
| goto drop; |
| |
| /* Stop connection establishment and retransmit timers */ |
| tcp_timer_reset (tc0, TCP_TIMER_ESTABLISH); |
| tcp_timer_reset (tc0, TCP_TIMER_RETRANSMIT_SYN); |
| |
| /* Valid SYN or SYN-ACK. Move connection from half-open pool to |
| * current thread pool. */ |
| pool_get (tm->connections[my_thread_index], new_tc0); |
| clib_memcpy (new_tc0, tc0, sizeof (*new_tc0)); |
| |
| new_tc0->c_thread_index = my_thread_index; |
| |
| /* Cleanup half-open connection XXX lock */ |
| pool_put (tm->half_open_connections, tc0); |
| |
| new_tc0->rcv_nxt = vnet_buffer (b0)->tcp.seq_end; |
| new_tc0->irs = seq0; |
| |
| /* Parse options */ |
| tcp_options_parse (tcp0, &new_tc0->opt); |
| |
| if (tcp_opts_tstamp (&new_tc0->opt)) |
| { |
| new_tc0->tsval_recent = new_tc0->opt.tsval; |
| new_tc0->tsval_recent_age = tcp_time_now (); |
| } |
| |
| if (tcp_opts_wscale (&new_tc0->opt)) |
| new_tc0->snd_wscale = new_tc0->opt.wscale; |
| |
| /* No scaling */ |
| new_tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window); |
| new_tc0->snd_wl1 = seq0; |
| new_tc0->snd_wl2 = ack0; |
| |
| tcp_connection_init_vars (new_tc0); |
| |
| /* SYN-ACK: See if we can switch to ESTABLISHED state */ |
| if (tcp_ack (tcp0)) |
| { |
| /* Our SYN is ACKed: we have iss < ack = snd_una */ |
| |
| /* TODO Dequeue acknowledged segments if we support Fast Open */ |
| new_tc0->snd_una = ack0; |
| new_tc0->state = TCP_STATE_ESTABLISHED; |
| |
| /* Make sure las is initialized for the wnd computation */ |
| new_tc0->rcv_las = new_tc0->rcv_nxt; |
| |
| /* Notify app that we have connection */ |
| stream_session_connect_notify (&new_tc0->connection, sst, 0); |
| |
| /* Make sure after data segment processing ACK is sent */ |
| new_tc0->flags |= TCP_CONN_SNDACK; |
| } |
| /* SYN: Simultaneous open. Change state to SYN-RCVD and send SYN-ACK */ |
| else |
| { |
| new_tc0->state = TCP_STATE_SYN_RCVD; |
| |
| /* Notify app that we have connection */ |
| stream_session_connect_notify (&new_tc0->connection, sst, 0); |
| |
| tcp_make_synack (new_tc0, b0); |
| next0 = tcp_next_output (is_ip4); |
| |
| goto drop; |
| } |
| |
| /* Read data, if any */ |
| if (n_data_bytes0) |
| { |
| error0 = |
| tcp_segment_rcv (tm, new_tc0, b0, n_data_bytes0, &next0); |
| if (error0 == TCP_ERROR_PURE_ACK) |
| error0 = TCP_ERROR_SYN_ACKS_RCVD; |
| } |
| else |
| { |
| tcp_make_ack (new_tc0, b0); |
| next0 = tcp_next_output (new_tc0->c_is_ip4); |
| } |
| |
| drop: |
| |
| b0->error = error0 ? node->errors[error0] : 0; |
| if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED)) |
| { |
| t0 = vlib_add_trace (vm, node, b0, sizeof (*t0)); |
| clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header)); |
| clib_memcpy (&t0->tcp_connection, tc0, |
| sizeof (t0->tcp_connection)); |
| } |
| |
| 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); |
| } |
| |
| errors = session_manager_flush_enqueue_events (my_thread_index); |
| if (errors) |
| { |
| if (is_ip4) |
| vlib_node_increment_counter (vm, tcp4_established_node.index, |
| TCP_ERROR_EVENT_FIFO_FULL, errors); |
| else |
| vlib_node_increment_counter (vm, tcp6_established_node.index, |
| TCP_ERROR_EVENT_FIFO_FULL, errors); |
| } |
| |
| return from_frame->n_vectors; |
| } |
| |
| static uword |
| tcp4_syn_sent (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame) |
| { |
| return tcp46_syn_sent_inline (vm, node, from_frame, 1 /* is_ip4 */ ); |
| } |
| |
| static uword |
| tcp6_syn_sent_rcv (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame) |
| { |
| return tcp46_syn_sent_inline (vm, node, from_frame, 0 /* is_ip4 */ ); |
| } |
| |
| /* *INDENT-OFF* */ |
| VLIB_REGISTER_NODE (tcp4_syn_sent_node) = |
| { |
| .function = tcp4_syn_sent, |
| .name = "tcp4-syn-sent", |
| /* Takes a vector of packets. */ |
| .vector_size = sizeof (u32), |
| .n_errors = TCP_N_ERROR, |
| .error_strings = tcp_error_strings, |
| .n_next_nodes = TCP_SYN_SENT_N_NEXT, |
| .next_nodes = |
| { |
| #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n, |
| foreach_tcp_state_next |
| #undef _ |
| }, |
| .format_trace = format_tcp_rx_trace_short, |
| }; |
| /* *INDENT-ON* */ |
| |
| VLIB_NODE_FUNCTION_MULTIARCH (tcp4_syn_sent_node, tcp4_syn_sent); |
| |
| /* *INDENT-OFF* */ |
| VLIB_REGISTER_NODE (tcp6_syn_sent_node) = |
| { |
| .function = tcp6_syn_sent_rcv, |
| .name = "tcp6-syn-sent", |
| /* Takes a vector of packets. */ |
| .vector_size = sizeof (u32), |
| .n_errors = TCP_N_ERROR, |
| .error_strings = tcp_error_strings, |
| .n_next_nodes = TCP_SYN_SENT_N_NEXT, |
| .next_nodes = |
| { |
| #define _(s,n) [TCP_SYN_SENT_NEXT_##s] = n, |
| foreach_tcp_state_next |
| #undef _ |
| }, |
| .format_trace = format_tcp_rx_trace_short, |
| }; |
| /* *INDENT-ON* */ |
| |
| VLIB_NODE_FUNCTION_MULTIARCH (tcp6_syn_sent_node, tcp6_syn_sent_rcv); |
| /** |
| * Handles reception for all states except LISTEN, SYN-SENT and ESTABLISHED |
| * as per RFC793 p. 64 |
| */ |
| always_inline uword |
| tcp46_rcv_process_inline (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame, int is_ip4) |
| { |
| tcp_main_t *tm = vnet_get_tcp_main (); |
| u32 n_left_from, next_index, *from, *to_next; |
| u32 my_thread_index = vm->thread_index, errors = 0; |
| |
| from = vlib_frame_vector_args (from_frame); |
| n_left_from = 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); |
| |
| while (n_left_from > 0 && n_left_to_next > 0) |
| { |
| u32 bi0; |
| vlib_buffer_t *b0; |
| tcp_rx_trace_t *t0; |
| tcp_header_t *tcp0 = 0; |
| tcp_connection_t *tc0; |
| ip4_header_t *ip40; |
| ip6_header_t *ip60; |
| u32 n_advance_bytes0, n_data_bytes0; |
| u32 next0 = TCP_RCV_PROCESS_NEXT_DROP, error0 = TCP_ERROR_ENQUEUED; |
| |
| 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); |
| tc0 = tcp_connection_get (vnet_buffer (b0)->tcp.connection_index, |
| my_thread_index); |
| if (PREDICT_FALSE (tc0 == 0)) |
| { |
| error0 = TCP_ERROR_INVALID_CONNECTION; |
| goto drop; |
| } |
| |
| /* Checksum computed by ipx_local no need to compute again */ |
| |
| if (is_ip4) |
| { |
| ip40 = vlib_buffer_get_current (b0); |
| tcp0 = ip4_next_header (ip40); |
| n_advance_bytes0 = (ip4_header_bytes (ip40) |
| + tcp_header_bytes (tcp0)); |
| n_data_bytes0 = clib_net_to_host_u16 (ip40->length) |
| - n_advance_bytes0; |
| } |
| else |
| { |
| ip60 = vlib_buffer_get_current (b0); |
| tcp0 = ip6_next_header (ip60); |
| n_advance_bytes0 = tcp_header_bytes (tcp0); |
| n_data_bytes0 = clib_net_to_host_u16 (ip60->payload_length) |
| - n_advance_bytes0; |
| n_advance_bytes0 += sizeof (ip60[0]); |
| } |
| |
| /* SYNs, FINs and data consume sequence numbers */ |
| vnet_buffer (b0)->tcp.seq_end = vnet_buffer (b0)->tcp.seq_number |
| + tcp_is_syn (tcp0) + tcp_is_fin (tcp0) + n_data_bytes0; |
| |
| /* |
| * Special treatment for CLOSED |
| */ |
| switch (tc0->state) |
| { |
| case TCP_STATE_CLOSED: |
| goto drop; |
| break; |
| } |
| |
| /* |
| * For all other states (except LISTEN) |
| */ |
| |
| /* 1-4: check SEQ, RST, SYN */ |
| if (PREDICT_FALSE |
| (tcp_segment_validate (vm, tc0, b0, tcp0, &next0))) |
| { |
| error0 = TCP_ERROR_SEGMENT_INVALID; |
| goto drop; |
| } |
| |
| /* 5: check the ACK field */ |
| switch (tc0->state) |
| { |
| case TCP_STATE_SYN_RCVD: |
| /* |
| * If the segment acknowledgment is not acceptable, form a |
| * reset segment, |
| * <SEQ=SEG.ACK><CTL=RST> |
| * and send it. |
| */ |
| if (!tcp_rcv_ack_is_acceptable (tc0, b0)) |
| { |
| tcp_send_reset (b0, is_ip4); |
| goto drop; |
| } |
| /* Switch state to ESTABLISHED */ |
| tc0->state = TCP_STATE_ESTABLISHED; |
| |
| /* Initialize session variables */ |
| tc0->snd_una = vnet_buffer (b0)->tcp.ack_number; |
| tc0->snd_wnd = clib_net_to_host_u16 (tcp0->window) |
| << tc0->opt.wscale; |
| tc0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number; |
| tc0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number; |
| |
| /* Shoulder tap the server */ |
| stream_session_accept_notify (&tc0->connection); |
| |
| /* Reset SYN-ACK retransmit timer */ |
| tcp_retransmit_timer_reset (tc0); |
| break; |
| case TCP_STATE_ESTABLISHED: |
| /* We can get packets in established state here because they |
| * were enqueued before state change */ |
| if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0)) |
| goto drop; |
| |
| break; |
| case TCP_STATE_FIN_WAIT_1: |
| /* In addition to the processing for the ESTABLISHED state, if |
| * our FIN is now acknowledged then enter FIN-WAIT-2 and |
| * continue processing in that state. */ |
| if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0)) |
| goto drop; |
| |
| /* If FIN is ACKed */ |
| if (tc0->snd_una == tc0->snd_una_max) |
| { |
| tc0->state = TCP_STATE_FIN_WAIT_2; |
| /* Stop all timers, 2MSL will be set lower */ |
| tcp_connection_timers_reset (tc0); |
| } |
| break; |
| case TCP_STATE_FIN_WAIT_2: |
| /* In addition to the processing for the ESTABLISHED state, if |
| * the retransmission queue is empty, the user's CLOSE can be |
| * acknowledged ("ok") but do not delete the TCB. */ |
| if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0)) |
| goto drop; |
| /* check if rtx queue is empty and ack CLOSE TODO */ |
| break; |
| case TCP_STATE_CLOSE_WAIT: |
| /* Do the same processing as for the ESTABLISHED state. */ |
| if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0)) |
| goto drop; |
| break; |
| case TCP_STATE_CLOSING: |
| /* In addition to the processing for the ESTABLISHED state, if |
| * the ACK acknowledges our FIN then enter the TIME-WAIT state, |
| * otherwise ignore the segment. */ |
| if (tcp_rcv_ack (tc0, b0, tcp0, &next0, &error0)) |
| goto drop; |
| |
| /* XXX test that send queue empty */ |
| tc0->state = TCP_STATE_TIME_WAIT; |
| goto drop; |
| |
| break; |
| case TCP_STATE_LAST_ACK: |
| /* The only thing that can arrive in this state is an |
| * acknowledgment of our FIN. If our FIN is now acknowledged, |
| * delete the TCB, enter the CLOSED state, and return. */ |
| |
| if (!tcp_rcv_ack_is_acceptable (tc0, b0)) |
| goto drop; |
| |
| tc0->state = TCP_STATE_CLOSED; |
| |
| /* Don't delete the connection/session yet. Instead, wait a |
| * reasonable amount of time until the pipes are cleared. In |
| * particular, this makes sure that we won't have dead sessions |
| * when processing events on the tx path */ |
| tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_CLEANUP_TIME); |
| |
| /* Stop retransmit */ |
| tcp_retransmit_timer_reset (tc0); |
| |
| goto drop; |
| |
| break; |
| case TCP_STATE_TIME_WAIT: |
| /* The only thing that can arrive in this state is a |
| * retransmission of the remote FIN. Acknowledge it, and restart |
| * the 2 MSL timeout. */ |
| |
| /* TODO */ |
| goto drop; |
| break; |
| default: |
| ASSERT (0); |
| } |
| |
| /* 6: check the URG bit TODO */ |
| |
| /* 7: process the segment text */ |
| switch (tc0->state) |
| { |
| case TCP_STATE_ESTABLISHED: |
| case TCP_STATE_FIN_WAIT_1: |
| case TCP_STATE_FIN_WAIT_2: |
| vlib_buffer_advance (b0, n_advance_bytes0); |
| error0 = tcp_segment_rcv (tm, tc0, b0, n_data_bytes0, &next0); |
| break; |
| case TCP_STATE_CLOSE_WAIT: |
| case TCP_STATE_CLOSING: |
| case TCP_STATE_LAST_ACK: |
| case TCP_STATE_TIME_WAIT: |
| /* This should not occur, since a FIN has been received from the |
| * remote side. Ignore the segment text. */ |
| break; |
| } |
| |
| /* 8: check the FIN bit */ |
| if (!tcp_fin (tcp0)) |
| goto drop; |
| |
| switch (tc0->state) |
| { |
| case TCP_STATE_ESTABLISHED: |
| case TCP_STATE_SYN_RCVD: |
| /* Send FIN-ACK notify app and enter CLOSE-WAIT */ |
| tcp_connection_timers_reset (tc0); |
| tcp_make_fin (tc0, b0); |
| next0 = tcp_next_output (tc0->c_is_ip4); |
| stream_session_disconnect_notify (&tc0->connection); |
| tc0->state = TCP_STATE_CLOSE_WAIT; |
| break; |
| case TCP_STATE_CLOSE_WAIT: |
| case TCP_STATE_CLOSING: |
| case TCP_STATE_LAST_ACK: |
| /* move along .. */ |
| break; |
| case TCP_STATE_FIN_WAIT_1: |
| tc0->state = TCP_STATE_TIME_WAIT; |
| tcp_connection_timers_reset (tc0); |
| tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME); |
| break; |
| case TCP_STATE_FIN_WAIT_2: |
| /* Got FIN, send ACK! */ |
| tc0->state = TCP_STATE_TIME_WAIT; |
| tcp_timer_set (tc0, TCP_TIMER_WAITCLOSE, TCP_CLOSEWAIT_TIME); |
| tcp_make_ack (tc0, b0); |
| next0 = tcp_next_output (is_ip4); |
| break; |
| case TCP_STATE_TIME_WAIT: |
| /* Remain in the TIME-WAIT state. Restart the 2 MSL time-wait |
| * timeout. |
| */ |
| tcp_timer_update (tc0, TCP_TIMER_WAITCLOSE, TCP_2MSL_TIME); |
| break; |
| } |
| TCP_EVT_DBG (TCP_EVT_FIN_RCVD, tc0); |
| |
| b0->error = error0 ? node->errors[error0] : 0; |
| |
| drop: |
| if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED)) |
| { |
| t0 = vlib_add_trace (vm, node, b0, sizeof (*t0)); |
| clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header)); |
| clib_memcpy (&t0->tcp_connection, tc0, |
| sizeof (t0->tcp_connection)); |
| } |
| |
| 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); |
| } |
| |
| errors = session_manager_flush_enqueue_events (my_thread_index); |
| if (errors) |
| { |
| if (is_ip4) |
| vlib_node_increment_counter (vm, tcp4_established_node.index, |
| TCP_ERROR_EVENT_FIFO_FULL, errors); |
| else |
| vlib_node_increment_counter (vm, tcp6_established_node.index, |
| TCP_ERROR_EVENT_FIFO_FULL, errors); |
| } |
| |
| return from_frame->n_vectors; |
| } |
| |
| static uword |
| tcp4_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame) |
| { |
| return tcp46_rcv_process_inline (vm, node, from_frame, 1 /* is_ip4 */ ); |
| } |
| |
| static uword |
| tcp6_rcv_process (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame) |
| { |
| return tcp46_rcv_process_inline (vm, node, from_frame, 0 /* is_ip4 */ ); |
| } |
| |
| /* *INDENT-OFF* */ |
| VLIB_REGISTER_NODE (tcp4_rcv_process_node) = |
| { |
| .function = tcp4_rcv_process, |
| .name = "tcp4-rcv-process", |
| /* Takes a vector of packets. */ |
| .vector_size = sizeof (u32), |
| .n_errors = TCP_N_ERROR, |
| .error_strings = tcp_error_strings, |
| .n_next_nodes = TCP_RCV_PROCESS_N_NEXT, |
| .next_nodes = |
| { |
| #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n, |
| foreach_tcp_state_next |
| #undef _ |
| }, |
| .format_trace = format_tcp_rx_trace_short, |
| }; |
| /* *INDENT-ON* */ |
| |
| VLIB_NODE_FUNCTION_MULTIARCH (tcp4_rcv_process_node, tcp4_rcv_process); |
| |
| /* *INDENT-OFF* */ |
| VLIB_REGISTER_NODE (tcp6_rcv_process_node) = |
| { |
| .function = tcp6_rcv_process, |
| .name = "tcp6-rcv-process", |
| /* Takes a vector of packets. */ |
| .vector_size = sizeof (u32), |
| .n_errors = TCP_N_ERROR, |
| .error_strings = tcp_error_strings, |
| .n_next_nodes = TCP_RCV_PROCESS_N_NEXT, |
| .next_nodes = |
| { |
| #define _(s,n) [TCP_RCV_PROCESS_NEXT_##s] = n, |
| foreach_tcp_state_next |
| #undef _ |
| }, |
| .format_trace = format_tcp_rx_trace_short, |
| }; |
| /* *INDENT-ON* */ |
| |
| VLIB_NODE_FUNCTION_MULTIARCH (tcp6_rcv_process_node, tcp6_rcv_process); |
| |
| vlib_node_registration_t tcp4_listen_node; |
| vlib_node_registration_t tcp6_listen_node; |
| |
| /** |
| * LISTEN state processing as per RFC 793 p. 65 |
| */ |
| always_inline uword |
| tcp46_listen_inline (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame, int is_ip4) |
| { |
| u32 n_left_from, next_index, *from, *to_next; |
| u32 my_thread_index = vm->thread_index; |
| tcp_main_t *tm = vnet_get_tcp_main (); |
| u8 sst = is_ip4 ? SESSION_TYPE_IP4_TCP : SESSION_TYPE_IP6_TCP; |
| |
| from = vlib_frame_vector_args (from_frame); |
| n_left_from = 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); |
| |
| while (n_left_from > 0 && n_left_to_next > 0) |
| { |
| u32 bi0; |
| vlib_buffer_t *b0; |
| tcp_rx_trace_t *t0; |
| tcp_header_t *th0 = 0; |
| tcp_connection_t *lc0; |
| ip4_header_t *ip40; |
| ip6_header_t *ip60; |
| tcp_connection_t *child0; |
| u32 error0 = TCP_ERROR_SYNS_RCVD, next0 = TCP_LISTEN_NEXT_DROP; |
| |
| 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); |
| lc0 = tcp_listener_get (vnet_buffer (b0)->tcp.connection_index); |
| |
| if (is_ip4) |
| { |
| ip40 = vlib_buffer_get_current (b0); |
| th0 = ip4_next_header (ip40); |
| } |
| else |
| { |
| ip60 = vlib_buffer_get_current (b0); |
| th0 = ip6_next_header (ip60); |
| } |
| |
| /* Create child session. For syn-flood protection use filter */ |
| |
| /* 1. first check for an RST */ |
| if (tcp_rst (th0)) |
| goto drop; |
| |
| /* 2. second check for an ACK */ |
| if (tcp_ack (th0)) |
| { |
| tcp_send_reset (b0, is_ip4); |
| goto drop; |
| } |
| |
| /* 3. check for a SYN (did that already) */ |
| |
| /* Create child session and send SYN-ACK */ |
| pool_get (tm->connections[my_thread_index], child0); |
| memset (child0, 0, sizeof (*child0)); |
| |
| child0->c_c_index = child0 - tm->connections[my_thread_index]; |
| child0->c_lcl_port = lc0->c_lcl_port; |
| child0->c_rmt_port = th0->src_port; |
| child0->c_is_ip4 = is_ip4; |
| child0->c_thread_index = my_thread_index; |
| |
| if (is_ip4) |
| { |
| child0->c_lcl_ip4.as_u32 = ip40->dst_address.as_u32; |
| child0->c_rmt_ip4.as_u32 = ip40->src_address.as_u32; |
| } |
| else |
| { |
| clib_memcpy (&child0->c_lcl_ip6, &ip60->dst_address, |
| sizeof (ip6_address_t)); |
| clib_memcpy (&child0->c_rmt_ip6, &ip60->src_address, |
| sizeof (ip6_address_t)); |
| } |
| |
| if (stream_session_accept (&child0->connection, lc0->c_s_index, sst, |
| 0 /* notify */ )) |
| { |
| error0 = TCP_ERROR_CREATE_SESSION_FAIL; |
| goto drop; |
| } |
| |
| tcp_options_parse (th0, &child0->opt); |
| |
| child0->irs = vnet_buffer (b0)->tcp.seq_number; |
| child0->rcv_nxt = vnet_buffer (b0)->tcp.seq_number + 1; |
| child0->rcv_las = child0->rcv_nxt; |
| child0->state = TCP_STATE_SYN_RCVD; |
| |
| /* RFC1323: TSval timestamps sent on {SYN} and {SYN,ACK} |
| * segments are used to initialize PAWS. */ |
| if (tcp_opts_tstamp (&child0->opt)) |
| { |
| child0->tsval_recent = child0->opt.tsval; |
| child0->tsval_recent_age = tcp_time_now (); |
| } |
| |
| if (tcp_opts_wscale (&child0->opt)) |
| child0->snd_wscale = child0->opt.wscale; |
| |
| /* No scaling */ |
| child0->snd_wnd = clib_net_to_host_u16 (th0->window); |
| child0->snd_wl1 = vnet_buffer (b0)->tcp.seq_number; |
| child0->snd_wl2 = vnet_buffer (b0)->tcp.ack_number; |
| |
| tcp_connection_init_vars (child0); |
| |
| TCP_EVT_DBG (TCP_EVT_SYN_RCVD, child0); |
| |
| /* Reuse buffer to make syn-ack and send */ |
| tcp_make_synack (child0, b0); |
| next0 = tcp_next_output (is_ip4); |
| |
| drop: |
| if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED)) |
| { |
| t0 = vlib_add_trace (vm, node, b0, sizeof (*t0)); |
| clib_memcpy (&t0->tcp_header, th0, sizeof (t0->tcp_header)); |
| clib_memcpy (&t0->tcp_connection, lc0, |
| sizeof (t0->tcp_connection)); |
| } |
| |
| b0->error = node->errors[error0]; |
| |
| 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); |
| } |
| return from_frame->n_vectors; |
| } |
| |
| static uword |
| tcp4_listen (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame) |
| { |
| return tcp46_listen_inline (vm, node, from_frame, 1 /* is_ip4 */ ); |
| } |
| |
| static uword |
| tcp6_listen (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame) |
| { |
| return tcp46_listen_inline (vm, node, from_frame, 0 /* is_ip4 */ ); |
| } |
| |
| /* *INDENT-OFF* */ |
| VLIB_REGISTER_NODE (tcp4_listen_node) = |
| { |
| .function = tcp4_listen, |
| .name = "tcp4-listen", |
| /* Takes a vector of packets. */ |
| .vector_size = sizeof (u32), |
| .n_errors = TCP_N_ERROR, |
| .error_strings = tcp_error_strings, |
| .n_next_nodes = TCP_LISTEN_N_NEXT, |
| .next_nodes = |
| { |
| #define _(s,n) [TCP_LISTEN_NEXT_##s] = n, |
| foreach_tcp_state_next |
| #undef _ |
| }, |
| .format_trace = format_tcp_rx_trace_short, |
| }; |
| /* *INDENT-ON* */ |
| |
| VLIB_NODE_FUNCTION_MULTIARCH (tcp4_listen_node, tcp4_listen); |
| |
| /* *INDENT-OFF* */ |
| VLIB_REGISTER_NODE (tcp6_listen_node) = |
| { |
| .function = tcp6_listen, |
| .name = "tcp6-listen", |
| /* Takes a vector of packets. */ |
| .vector_size = sizeof (u32), |
| .n_errors = TCP_N_ERROR, |
| .error_strings = tcp_error_strings, |
| .n_next_nodes = TCP_LISTEN_N_NEXT, |
| .next_nodes = |
| { |
| #define _(s,n) [TCP_LISTEN_NEXT_##s] = n, |
| foreach_tcp_state_next |
| #undef _ |
| }, |
| .format_trace = format_tcp_rx_trace_short, |
| }; |
| /* *INDENT-ON* */ |
| |
| VLIB_NODE_FUNCTION_MULTIARCH (tcp6_listen_node, tcp6_listen); |
| |
| vlib_node_registration_t tcp4_input_node; |
| vlib_node_registration_t tcp6_input_node; |
| |
| typedef enum _tcp_input_next |
| { |
| TCP_INPUT_NEXT_DROP, |
| TCP_INPUT_NEXT_LISTEN, |
| TCP_INPUT_NEXT_RCV_PROCESS, |
| TCP_INPUT_NEXT_SYN_SENT, |
| TCP_INPUT_NEXT_ESTABLISHED, |
| TCP_INPUT_NEXT_RESET, |
| TCP_INPUT_N_NEXT |
| } tcp_input_next_t; |
| |
| #define foreach_tcp4_input_next \ |
| _ (DROP, "error-drop") \ |
| _ (LISTEN, "tcp4-listen") \ |
| _ (RCV_PROCESS, "tcp4-rcv-process") \ |
| _ (SYN_SENT, "tcp4-syn-sent") \ |
| _ (ESTABLISHED, "tcp4-established") \ |
| _ (RESET, "tcp4-reset") |
| |
| #define foreach_tcp6_input_next \ |
| _ (DROP, "error-drop") \ |
| _ (LISTEN, "tcp6-listen") \ |
| _ (RCV_PROCESS, "tcp6-rcv-process") \ |
| _ (SYN_SENT, "tcp6-syn-sent") \ |
| _ (ESTABLISHED, "tcp6-established") \ |
| _ (RESET, "tcp6-reset") |
| |
| #define filter_flags (TCP_FLAG_SYN|TCP_FLAG_ACK|TCP_FLAG_RST|TCP_FLAG_FIN) |
| |
| always_inline uword |
| tcp46_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame, int is_ip4) |
| { |
| u32 n_left_from, next_index, *from, *to_next; |
| u32 my_thread_index = vm->thread_index; |
| tcp_main_t *tm = vnet_get_tcp_main (); |
| |
| from = vlib_frame_vector_args (from_frame); |
| n_left_from = 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); |
| |
| while (n_left_from > 0 && n_left_to_next > 0) |
| { |
| u32 bi0; |
| vlib_buffer_t *b0; |
| tcp_rx_trace_t *t0; |
| tcp_header_t *tcp0 = 0; |
| tcp_connection_t *tc0; |
| ip4_header_t *ip40; |
| ip6_header_t *ip60; |
| u32 error0 = TCP_ERROR_NO_LISTENER, next0 = TCP_INPUT_NEXT_DROP; |
| u8 flags0; |
| |
| 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); |
| vnet_buffer (b0)->tcp.flags = 0; |
| |
| if (is_ip4) |
| { |
| ip40 = vlib_buffer_get_current (b0); |
| tcp0 = ip4_next_header (ip40); |
| |
| /* lookup session */ |
| tc0 = |
| (tcp_connection_t *) |
| stream_session_lookup_transport4 (&ip40->dst_address, |
| &ip40->src_address, |
| tcp0->dst_port, |
| tcp0->src_port, |
| SESSION_TYPE_IP4_TCP, |
| my_thread_index); |
| } |
| else |
| { |
| ip60 = vlib_buffer_get_current (b0); |
| tcp0 = ip6_next_header (ip60); |
| tc0 = |
| (tcp_connection_t *) |
| stream_session_lookup_transport6 (&ip60->src_address, |
| &ip60->dst_address, |
| tcp0->src_port, |
| tcp0->dst_port, |
| SESSION_TYPE_IP6_TCP, |
| my_thread_index); |
| } |
| |
| /* Session exists */ |
| if (PREDICT_TRUE (0 != tc0)) |
| { |
| /* Save connection index */ |
| vnet_buffer (b0)->tcp.connection_index = tc0->c_c_index; |
| vnet_buffer (b0)->tcp.seq_number = |
| clib_net_to_host_u32 (tcp0->seq_number); |
| vnet_buffer (b0)->tcp.ack_number = |
| clib_net_to_host_u32 (tcp0->ack_number); |
| |
| flags0 = tcp0->flags & filter_flags; |
| next0 = tm->dispatch_table[tc0->state][flags0].next; |
| error0 = tm->dispatch_table[tc0->state][flags0].error; |
| |
| if (PREDICT_FALSE (error0 == TCP_ERROR_DISPATCH)) |
| { |
| /* Overload tcp flags to store state */ |
| vnet_buffer (b0)->tcp.flags = tc0->state; |
| } |
| } |
| else |
| { |
| /* Send reset */ |
| next0 = TCP_INPUT_NEXT_RESET; |
| error0 = TCP_ERROR_NO_LISTENER; |
| } |
| |
| b0->error = error0 ? node->errors[error0] : 0; |
| |
| if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED)) |
| { |
| t0 = vlib_add_trace (vm, node, b0, sizeof (*t0)); |
| clib_memcpy (&t0->tcp_header, tcp0, sizeof (t0->tcp_header)); |
| clib_memcpy (&t0->tcp_connection, tc0, |
| sizeof (t0->tcp_connection)); |
| } |
| |
| 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); |
| } |
| |
| return from_frame->n_vectors; |
| } |
| |
| static uword |
| tcp4_input (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame) |
| { |
| return tcp46_input_inline (vm, node, from_frame, 1 /* is_ip4 */ ); |
| } |
| |
| static uword |
| tcp6_input (vlib_main_t * vm, vlib_node_runtime_t * node, |
| vlib_frame_t * from_frame) |
| { |
| return tcp46_input_inline (vm, node, from_frame, 0 /* is_ip4 */ ); |
| } |
| |
| /* *INDENT-OFF* */ |
| VLIB_REGISTER_NODE (tcp4_input_node) = |
| { |
| .function = tcp4_input, |
| .name = "tcp4-input", |
| /* Takes a vector of packets. */ |
| .vector_size = sizeof (u32), |
| .n_errors = TCP_N_ERROR, |
| .error_strings = tcp_error_strings, |
| .n_next_nodes = TCP_INPUT_N_NEXT, |
| .next_nodes = |
| { |
| #define _(s,n) [TCP_INPUT_NEXT_##s] = n, |
| foreach_tcp4_input_next |
| #undef _ |
| }, |
| .format_buffer = format_tcp_header, |
| .format_trace = format_tcp_rx_trace, |
| }; |
| /* *INDENT-ON* */ |
| |
| VLIB_NODE_FUNCTION_MULTIARCH (tcp4_input_node, tcp4_input); |
| |
| /* *INDENT-OFF* */ |
| VLIB_REGISTER_NODE (tcp6_input_node) = |
| { |
| .function = tcp6_input, |
| .name = "tcp6-input", |
| /* Takes a vector of packets. */ |
| .vector_size = sizeof (u32), |
| .n_errors = TCP_N_ERROR, |
| .error_strings = tcp_error_strings, |
| .n_next_nodes = TCP_INPUT_N_NEXT, |
| .next_nodes = |
| { |
| #define _(s,n) [TCP_INPUT_NEXT_##s] = n, |
| foreach_tcp6_input_next |
| #undef _ |
| }, |
| .format_buffer = format_tcp_header, |
| .format_trace = format_tcp_rx_trace, |
| }; |
| /* *INDENT-ON* */ |
| |
| VLIB_NODE_FUNCTION_MULTIARCH (tcp6_input_node, tcp6_input); |
| |
| static void |
| tcp_dispatch_table_init (tcp_main_t * tm) |
| { |
| int i, j; |
| for (i = 0; i < ARRAY_LEN (tm->dispatch_table); i++) |
| for (j = 0; j < ARRAY_LEN (tm->dispatch_table[i]); j++) |
| { |
| tm->dispatch_table[i][j].next = TCP_INPUT_NEXT_DROP; |
| tm->dispatch_table[i][j].error = TCP_ERROR_DISPATCH; |
| } |
| |
| #define _(t,f,n,e) \ |
| do { \ |
| tm->dispatch_table[TCP_STATE_##t][f].next = (n); \ |
| tm->dispatch_table[TCP_STATE_##t][f].error = (e); \ |
| } while (0) |
| |
| /* SYNs for new connections -> tcp-listen. */ |
| _(LISTEN, TCP_FLAG_SYN, TCP_INPUT_NEXT_LISTEN, TCP_ERROR_NONE); |
| /* ACK for for a SYN-ACK -> tcp-rcv-process. */ |
| _(SYN_RCVD, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); |
| /* SYN-ACK for a SYN */ |
| _(SYN_SENT, TCP_FLAG_SYN | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, |
| TCP_ERROR_NONE); |
| _(SYN_SENT, TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE); |
| _(SYN_SENT, TCP_FLAG_RST, TCP_INPUT_NEXT_SYN_SENT, TCP_ERROR_NONE); |
| _(SYN_SENT, TCP_FLAG_RST | TCP_FLAG_ACK, TCP_INPUT_NEXT_SYN_SENT, |
| TCP_ERROR_NONE); |
| /* ACK for for established connection -> tcp-established. */ |
| _(ESTABLISHED, TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); |
| /* FIN for for established connection -> tcp-established. */ |
| _(ESTABLISHED, TCP_FLAG_FIN, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); |
| _(ESTABLISHED, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_ESTABLISHED, |
| TCP_ERROR_NONE); |
| _(ESTABLISHED, TCP_FLAG_RST, TCP_INPUT_NEXT_ESTABLISHED, TCP_ERROR_NONE); |
| /* ACK or FIN-ACK to our FIN */ |
| _(FIN_WAIT_1, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); |
| _(FIN_WAIT_1, TCP_FLAG_ACK | TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, |
| TCP_ERROR_NONE); |
| /* FIN in reply to our FIN from the other side */ |
| _(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); |
| /* FIN confirming that the peer (app) has closed */ |
| _(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); |
| _(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, |
| TCP_ERROR_NONE); |
| _(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE); |
| #undef _ |
| } |
| |
| clib_error_t * |
| tcp_input_init (vlib_main_t * vm) |
| { |
| clib_error_t *error = 0; |
| tcp_main_t *tm = vnet_get_tcp_main (); |
| |
| if ((error = vlib_call_init_function (vm, tcp_init))) |
| return error; |
| |
| /* Initialize dispatch table. */ |
| tcp_dispatch_table_init (tm); |
| |
| return error; |
| } |
| |
| VLIB_INIT_FUNCTION (tcp_input_init); |
| |
| /* |
| * fd.io coding-style-patch-verification: ON |
| * |
| * Local Variables: |
| * eval: (c-set-style "gnu") |
| * End: |
| */ |