| /* RxRPC packet reception |
| * |
| * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved. |
| * Written by David Howells (dhowells@redhat.com) |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/module.h> |
| #include <linux/net.h> |
| #include <linux/skbuff.h> |
| #include <linux/errqueue.h> |
| #include <linux/udp.h> |
| #include <linux/in.h> |
| #include <linux/in6.h> |
| #include <linux/icmp.h> |
| #include <linux/gfp.h> |
| #include <net/sock.h> |
| #include <net/af_rxrpc.h> |
| #include <net/ip.h> |
| #include <net/udp.h> |
| #include <net/net_namespace.h> |
| #include "ar-internal.h" |
| |
| static void rxrpc_proto_abort(const char *why, |
| struct rxrpc_call *call, rxrpc_seq_t seq) |
| { |
| if (rxrpc_abort_call(why, call, seq, RX_PROTOCOL_ERROR, EBADMSG)) { |
| set_bit(RXRPC_CALL_EV_ABORT, &call->events); |
| rxrpc_queue_call(call); |
| } |
| } |
| |
| /* |
| * Do TCP-style congestion management [RFC 5681]. |
| */ |
| static void rxrpc_congestion_management(struct rxrpc_call *call, |
| struct sk_buff *skb, |
| struct rxrpc_ack_summary *summary, |
| rxrpc_serial_t acked_serial) |
| { |
| enum rxrpc_congest_change change = rxrpc_cong_no_change; |
| unsigned int cumulative_acks = call->cong_cumul_acks; |
| unsigned int cwnd = call->cong_cwnd; |
| bool resend = false; |
| |
| summary->flight_size = |
| (call->tx_top - call->tx_hard_ack) - summary->nr_acks; |
| |
| if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) { |
| summary->retrans_timeo = true; |
| call->cong_ssthresh = max_t(unsigned int, |
| summary->flight_size / 2, 2); |
| cwnd = 1; |
| if (cwnd >= call->cong_ssthresh && |
| call->cong_mode == RXRPC_CALL_SLOW_START) { |
| call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; |
| call->cong_tstamp = skb->tstamp; |
| cumulative_acks = 0; |
| } |
| } |
| |
| cumulative_acks += summary->nr_new_acks; |
| cumulative_acks += summary->nr_rot_new_acks; |
| if (cumulative_acks > 255) |
| cumulative_acks = 255; |
| |
| summary->mode = call->cong_mode; |
| summary->cwnd = call->cong_cwnd; |
| summary->ssthresh = call->cong_ssthresh; |
| summary->cumulative_acks = cumulative_acks; |
| summary->dup_acks = call->cong_dup_acks; |
| |
| switch (call->cong_mode) { |
| case RXRPC_CALL_SLOW_START: |
| if (summary->nr_nacks > 0) |
| goto packet_loss_detected; |
| if (summary->cumulative_acks > 0) |
| cwnd += 1; |
| if (cwnd >= call->cong_ssthresh) { |
| call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; |
| call->cong_tstamp = skb->tstamp; |
| } |
| goto out; |
| |
| case RXRPC_CALL_CONGEST_AVOIDANCE: |
| if (summary->nr_nacks > 0) |
| goto packet_loss_detected; |
| |
| /* We analyse the number of packets that get ACK'd per RTT |
| * period and increase the window if we managed to fill it. |
| */ |
| if (call->peer->rtt_usage == 0) |
| goto out; |
| if (ktime_before(skb->tstamp, |
| ktime_add_ns(call->cong_tstamp, |
| call->peer->rtt))) |
| goto out_no_clear_ca; |
| change = rxrpc_cong_rtt_window_end; |
| call->cong_tstamp = skb->tstamp; |
| if (cumulative_acks >= cwnd) |
| cwnd++; |
| goto out; |
| |
| case RXRPC_CALL_PACKET_LOSS: |
| if (summary->nr_nacks == 0) |
| goto resume_normality; |
| |
| if (summary->new_low_nack) { |
| change = rxrpc_cong_new_low_nack; |
| call->cong_dup_acks = 1; |
| if (call->cong_extra > 1) |
| call->cong_extra = 1; |
| goto send_extra_data; |
| } |
| |
| call->cong_dup_acks++; |
| if (call->cong_dup_acks < 3) |
| goto send_extra_data; |
| |
| change = rxrpc_cong_begin_retransmission; |
| call->cong_mode = RXRPC_CALL_FAST_RETRANSMIT; |
| call->cong_ssthresh = max_t(unsigned int, |
| summary->flight_size / 2, 2); |
| cwnd = call->cong_ssthresh + 3; |
| call->cong_extra = 0; |
| call->cong_dup_acks = 0; |
| resend = true; |
| goto out; |
| |
| case RXRPC_CALL_FAST_RETRANSMIT: |
| if (!summary->new_low_nack) { |
| if (summary->nr_new_acks == 0) |
| cwnd += 1; |
| call->cong_dup_acks++; |
| if (call->cong_dup_acks == 2) { |
| change = rxrpc_cong_retransmit_again; |
| call->cong_dup_acks = 0; |
| resend = true; |
| } |
| } else { |
| change = rxrpc_cong_progress; |
| cwnd = call->cong_ssthresh; |
| if (summary->nr_nacks == 0) |
| goto resume_normality; |
| } |
| goto out; |
| |
| default: |
| BUG(); |
| goto out; |
| } |
| |
| resume_normality: |
| change = rxrpc_cong_cleared_nacks; |
| call->cong_dup_acks = 0; |
| call->cong_extra = 0; |
| call->cong_tstamp = skb->tstamp; |
| if (cwnd < call->cong_ssthresh) |
| call->cong_mode = RXRPC_CALL_SLOW_START; |
| else |
| call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; |
| out: |
| cumulative_acks = 0; |
| out_no_clear_ca: |
| if (cwnd >= RXRPC_RXTX_BUFF_SIZE - 1) |
| cwnd = RXRPC_RXTX_BUFF_SIZE - 1; |
| call->cong_cwnd = cwnd; |
| call->cong_cumul_acks = cumulative_acks; |
| trace_rxrpc_congest(call, summary, acked_serial, change); |
| if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events)) |
| rxrpc_queue_call(call); |
| return; |
| |
| packet_loss_detected: |
| change = rxrpc_cong_saw_nack; |
| call->cong_mode = RXRPC_CALL_PACKET_LOSS; |
| call->cong_dup_acks = 0; |
| goto send_extra_data; |
| |
| send_extra_data: |
| /* Send some previously unsent DATA if we have some to advance the ACK |
| * state. |
| */ |
| if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & |
| RXRPC_TX_ANNO_LAST || |
| summary->nr_acks != call->tx_top - call->tx_hard_ack) { |
| call->cong_extra++; |
| wake_up(&call->waitq); |
| } |
| goto out_no_clear_ca; |
| } |
| |
| /* |
| * Ping the other end to fill our RTT cache and to retrieve the rwind |
| * and MTU parameters. |
| */ |
| static void rxrpc_send_ping(struct rxrpc_call *call, struct sk_buff *skb, |
| int skew) |
| { |
| struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| ktime_t now = skb->tstamp; |
| |
| if (call->peer->rtt_usage < 3 || |
| ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), now)) |
| rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial, |
| true, true, |
| rxrpc_propose_ack_ping_for_params); |
| } |
| |
| /* |
| * Apply a hard ACK by advancing the Tx window. |
| */ |
| static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to, |
| struct rxrpc_ack_summary *summary) |
| { |
| struct sk_buff *skb, *list = NULL; |
| bool rot_last = false; |
| int ix; |
| u8 annotation; |
| |
| if (call->acks_lowest_nak == call->tx_hard_ack) { |
| call->acks_lowest_nak = to; |
| } else if (before_eq(call->acks_lowest_nak, to)) { |
| summary->new_low_nack = true; |
| call->acks_lowest_nak = to; |
| } |
| |
| spin_lock(&call->lock); |
| |
| while (before(call->tx_hard_ack, to)) { |
| call->tx_hard_ack++; |
| ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK; |
| skb = call->rxtx_buffer[ix]; |
| annotation = call->rxtx_annotations[ix]; |
| rxrpc_see_skb(skb, rxrpc_skb_tx_rotated); |
| call->rxtx_buffer[ix] = NULL; |
| call->rxtx_annotations[ix] = 0; |
| skb->next = list; |
| list = skb; |
| |
| if (annotation & RXRPC_TX_ANNO_LAST) { |
| set_bit(RXRPC_CALL_TX_LAST, &call->flags); |
| rot_last = true; |
| } |
| if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK) |
| summary->nr_rot_new_acks++; |
| } |
| |
| spin_unlock(&call->lock); |
| |
| trace_rxrpc_transmit(call, (rot_last ? |
| rxrpc_transmit_rotate_last : |
| rxrpc_transmit_rotate)); |
| wake_up(&call->waitq); |
| |
| while (list) { |
| skb = list; |
| list = skb->next; |
| skb->next = NULL; |
| rxrpc_free_skb(skb, rxrpc_skb_tx_freed); |
| } |
| |
| return rot_last; |
| } |
| |
| /* |
| * End the transmission phase of a call. |
| * |
| * This occurs when we get an ACKALL packet, the first DATA packet of a reply, |
| * or a final ACK packet. |
| */ |
| static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun, |
| const char *abort_why) |
| { |
| |
| ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags)); |
| |
| write_lock(&call->state_lock); |
| |
| switch (call->state) { |
| case RXRPC_CALL_CLIENT_SEND_REQUEST: |
| case RXRPC_CALL_CLIENT_AWAIT_REPLY: |
| if (reply_begun) |
| call->state = RXRPC_CALL_CLIENT_RECV_REPLY; |
| else |
| call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY; |
| break; |
| |
| case RXRPC_CALL_SERVER_AWAIT_ACK: |
| __rxrpc_call_completed(call); |
| rxrpc_notify_socket(call); |
| break; |
| |
| default: |
| goto bad_state; |
| } |
| |
| write_unlock(&call->state_lock); |
| if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY) { |
| rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, 0, 0, false, true, |
| rxrpc_propose_ack_client_tx_end); |
| trace_rxrpc_transmit(call, rxrpc_transmit_await_reply); |
| } else { |
| trace_rxrpc_transmit(call, rxrpc_transmit_end); |
| } |
| _leave(" = ok"); |
| return true; |
| |
| bad_state: |
| write_unlock(&call->state_lock); |
| kdebug("end_tx %s", rxrpc_call_states[call->state]); |
| rxrpc_proto_abort(abort_why, call, call->tx_top); |
| return false; |
| } |
| |
| /* |
| * Begin the reply reception phase of a call. |
| */ |
| static bool rxrpc_receiving_reply(struct rxrpc_call *call) |
| { |
| struct rxrpc_ack_summary summary = { 0 }; |
| rxrpc_seq_t top = READ_ONCE(call->tx_top); |
| |
| if (call->ackr_reason) { |
| spin_lock_bh(&call->lock); |
| call->ackr_reason = 0; |
| call->resend_at = call->expire_at; |
| call->ack_at = call->expire_at; |
| spin_unlock_bh(&call->lock); |
| rxrpc_set_timer(call, rxrpc_timer_init_for_reply, |
| ktime_get_real()); |
| } |
| |
| if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) { |
| if (!rxrpc_rotate_tx_window(call, top, &summary)) { |
| rxrpc_proto_abort("TXL", call, top); |
| return false; |
| } |
| } |
| if (!rxrpc_end_tx_phase(call, true, "ETD")) |
| return false; |
| call->tx_phase = false; |
| return true; |
| } |
| |
| /* |
| * Scan a jumbo packet to validate its structure and to work out how many |
| * subpackets it contains. |
| * |
| * A jumbo packet is a collection of consecutive packets glued together with |
| * little headers between that indicate how to change the initial header for |
| * each subpacket. |
| * |
| * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but |
| * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any |
| * size. |
| */ |
| static bool rxrpc_validate_jumbo(struct sk_buff *skb) |
| { |
| struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| unsigned int offset = sizeof(struct rxrpc_wire_header); |
| unsigned int len = skb->len; |
| int nr_jumbo = 1; |
| u8 flags = sp->hdr.flags; |
| |
| do { |
| nr_jumbo++; |
| if (len - offset < RXRPC_JUMBO_SUBPKTLEN) |
| goto protocol_error; |
| if (flags & RXRPC_LAST_PACKET) |
| goto protocol_error; |
| offset += RXRPC_JUMBO_DATALEN; |
| if (skb_copy_bits(skb, offset, &flags, 1) < 0) |
| goto protocol_error; |
| offset += sizeof(struct rxrpc_jumbo_header); |
| } while (flags & RXRPC_JUMBO_PACKET); |
| |
| sp->nr_jumbo = nr_jumbo; |
| return true; |
| |
| protocol_error: |
| return false; |
| } |
| |
| /* |
| * Handle reception of a duplicate packet. |
| * |
| * We have to take care to avoid an attack here whereby we're given a series of |
| * jumbograms, each with a sequence number one before the preceding one and |
| * filled up to maximum UDP size. If they never send us the first packet in |
| * the sequence, they can cause us to have to hold on to around 2MiB of kernel |
| * space until the call times out. |
| * |
| * We limit the space usage by only accepting three duplicate jumbo packets per |
| * call. After that, we tell the other side we're no longer accepting jumbos |
| * (that information is encoded in the ACK packet). |
| */ |
| static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq, |
| u8 annotation, bool *_jumbo_bad) |
| { |
| /* Discard normal packets that are duplicates. */ |
| if (annotation == 0) |
| return; |
| |
| /* Skip jumbo subpackets that are duplicates. When we've had three or |
| * more partially duplicate jumbo packets, we refuse to take any more |
| * jumbos for this call. |
| */ |
| if (!*_jumbo_bad) { |
| call->nr_jumbo_bad++; |
| *_jumbo_bad = true; |
| } |
| } |
| |
| /* |
| * Process a DATA packet, adding the packet to the Rx ring. |
| */ |
| static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb, |
| u16 skew) |
| { |
| struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| unsigned int offset = sizeof(struct rxrpc_wire_header); |
| unsigned int ix; |
| rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0; |
| rxrpc_seq_t seq = sp->hdr.seq, hard_ack; |
| bool immediate_ack = false, jumbo_bad = false, queued; |
| u16 len; |
| u8 ack = 0, flags, annotation = 0; |
| |
| _enter("{%u,%u},{%u,%u}", |
| call->rx_hard_ack, call->rx_top, skb->len, seq); |
| |
| _proto("Rx DATA %%%u { #%u f=%02x }", |
| sp->hdr.serial, seq, sp->hdr.flags); |
| |
| if (call->state >= RXRPC_CALL_COMPLETE) |
| return; |
| |
| /* Received data implicitly ACKs all of the request packets we sent |
| * when we're acting as a client. |
| */ |
| if ((call->state == RXRPC_CALL_CLIENT_SEND_REQUEST || |
| call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY) && |
| !rxrpc_receiving_reply(call)) |
| return; |
| |
| call->ackr_prev_seq = seq; |
| |
| hard_ack = READ_ONCE(call->rx_hard_ack); |
| if (after(seq, hard_ack + call->rx_winsize)) { |
| ack = RXRPC_ACK_EXCEEDS_WINDOW; |
| ack_serial = serial; |
| goto ack; |
| } |
| |
| flags = sp->hdr.flags; |
| if (flags & RXRPC_JUMBO_PACKET) { |
| if (call->nr_jumbo_bad > 3) { |
| ack = RXRPC_ACK_NOSPACE; |
| ack_serial = serial; |
| goto ack; |
| } |
| annotation = 1; |
| } |
| |
| next_subpacket: |
| queued = false; |
| ix = seq & RXRPC_RXTX_BUFF_MASK; |
| len = skb->len; |
| if (flags & RXRPC_JUMBO_PACKET) |
| len = RXRPC_JUMBO_DATALEN; |
| |
| if (flags & RXRPC_LAST_PACKET) { |
| if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && |
| seq != call->rx_top) |
| return rxrpc_proto_abort("LSN", call, seq); |
| } else { |
| if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && |
| after_eq(seq, call->rx_top)) |
| return rxrpc_proto_abort("LSA", call, seq); |
| } |
| |
| if (before_eq(seq, hard_ack)) { |
| ack = RXRPC_ACK_DUPLICATE; |
| ack_serial = serial; |
| goto skip; |
| } |
| |
| if (flags & RXRPC_REQUEST_ACK && !ack) { |
| ack = RXRPC_ACK_REQUESTED; |
| ack_serial = serial; |
| } |
| |
| if (call->rxtx_buffer[ix]) { |
| rxrpc_input_dup_data(call, seq, annotation, &jumbo_bad); |
| if (ack != RXRPC_ACK_DUPLICATE) { |
| ack = RXRPC_ACK_DUPLICATE; |
| ack_serial = serial; |
| } |
| immediate_ack = true; |
| goto skip; |
| } |
| |
| /* Queue the packet. We use a couple of memory barriers here as need |
| * to make sure that rx_top is perceived to be set after the buffer |
| * pointer and that the buffer pointer is set after the annotation and |
| * the skb data. |
| * |
| * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window() |
| * and also rxrpc_fill_out_ack(). |
| */ |
| rxrpc_get_skb(skb, rxrpc_skb_rx_got); |
| call->rxtx_annotations[ix] = annotation; |
| smp_wmb(); |
| call->rxtx_buffer[ix] = skb; |
| if (after(seq, call->rx_top)) { |
| smp_store_release(&call->rx_top, seq); |
| } else if (before(seq, call->rx_top)) { |
| /* Send an immediate ACK if we fill in a hole */ |
| if (!ack) { |
| ack = RXRPC_ACK_DELAY; |
| ack_serial = serial; |
| } |
| immediate_ack = true; |
| } |
| if (flags & RXRPC_LAST_PACKET) { |
| set_bit(RXRPC_CALL_RX_LAST, &call->flags); |
| trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq); |
| } else { |
| trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq); |
| } |
| queued = true; |
| |
| if (after_eq(seq, call->rx_expect_next)) { |
| if (after(seq, call->rx_expect_next)) { |
| _net("OOS %u > %u", seq, call->rx_expect_next); |
| ack = RXRPC_ACK_OUT_OF_SEQUENCE; |
| ack_serial = serial; |
| } |
| call->rx_expect_next = seq + 1; |
| } |
| |
| skip: |
| offset += len; |
| if (flags & RXRPC_JUMBO_PACKET) { |
| if (skb_copy_bits(skb, offset, &flags, 1) < 0) |
| return rxrpc_proto_abort("XJF", call, seq); |
| offset += sizeof(struct rxrpc_jumbo_header); |
| seq++; |
| serial++; |
| annotation++; |
| if (flags & RXRPC_JUMBO_PACKET) |
| annotation |= RXRPC_RX_ANNO_JLAST; |
| if (after(seq, hard_ack + call->rx_winsize)) { |
| ack = RXRPC_ACK_EXCEEDS_WINDOW; |
| ack_serial = serial; |
| if (!jumbo_bad) { |
| call->nr_jumbo_bad++; |
| jumbo_bad = true; |
| } |
| goto ack; |
| } |
| |
| _proto("Rx DATA Jumbo %%%u", serial); |
| goto next_subpacket; |
| } |
| |
| if (queued && flags & RXRPC_LAST_PACKET && !ack) { |
| ack = RXRPC_ACK_DELAY; |
| ack_serial = serial; |
| } |
| |
| ack: |
| if (ack) |
| rxrpc_propose_ACK(call, ack, skew, ack_serial, |
| immediate_ack, true, |
| rxrpc_propose_ack_input_data); |
| |
| rxrpc_notify_socket(call); |
| _leave(" [queued]"); |
| } |
| |
| /* |
| * Process a requested ACK. |
| */ |
| static void rxrpc_input_requested_ack(struct rxrpc_call *call, |
| ktime_t resp_time, |
| rxrpc_serial_t orig_serial, |
| rxrpc_serial_t ack_serial) |
| { |
| struct rxrpc_skb_priv *sp; |
| struct sk_buff *skb; |
| ktime_t sent_at; |
| int ix; |
| |
| for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) { |
| skb = call->rxtx_buffer[ix]; |
| if (!skb) |
| continue; |
| |
| sp = rxrpc_skb(skb); |
| if (sp->hdr.serial != orig_serial) |
| continue; |
| smp_rmb(); |
| sent_at = skb->tstamp; |
| goto found; |
| } |
| return; |
| |
| found: |
| rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack, |
| orig_serial, ack_serial, sent_at, resp_time); |
| } |
| |
| /* |
| * Process a ping response. |
| */ |
| static void rxrpc_input_ping_response(struct rxrpc_call *call, |
| ktime_t resp_time, |
| rxrpc_serial_t orig_serial, |
| rxrpc_serial_t ack_serial) |
| { |
| rxrpc_serial_t ping_serial; |
| ktime_t ping_time; |
| |
| ping_time = call->ping_time; |
| smp_rmb(); |
| ping_serial = call->ping_serial; |
| |
| if (!test_bit(RXRPC_CALL_PINGING, &call->flags) || |
| before(orig_serial, ping_serial)) |
| return; |
| clear_bit(RXRPC_CALL_PINGING, &call->flags); |
| if (after(orig_serial, ping_serial)) |
| return; |
| |
| rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response, |
| orig_serial, ack_serial, ping_time, resp_time); |
| } |
| |
| /* |
| * Process the extra information that may be appended to an ACK packet |
| */ |
| static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb, |
| struct rxrpc_ackinfo *ackinfo) |
| { |
| struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| struct rxrpc_peer *peer; |
| unsigned int mtu; |
| bool wake = false; |
| u32 rwind = ntohl(ackinfo->rwind); |
| |
| _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }", |
| sp->hdr.serial, |
| ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU), |
| rwind, ntohl(ackinfo->jumbo_max)); |
| |
| if (call->tx_winsize != rwind) { |
| if (rwind > RXRPC_RXTX_BUFF_SIZE - 1) |
| rwind = RXRPC_RXTX_BUFF_SIZE - 1; |
| if (rwind > call->tx_winsize) |
| wake = true; |
| call->tx_winsize = rwind; |
| } |
| |
| if (call->cong_ssthresh > rwind) |
| call->cong_ssthresh = rwind; |
| |
| mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU)); |
| |
| peer = call->peer; |
| if (mtu < peer->maxdata) { |
| spin_lock_bh(&peer->lock); |
| peer->maxdata = mtu; |
| peer->mtu = mtu + peer->hdrsize; |
| spin_unlock_bh(&peer->lock); |
| _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata); |
| } |
| |
| if (wake) |
| wake_up(&call->waitq); |
| } |
| |
| /* |
| * Process individual soft ACKs. |
| * |
| * Each ACK in the array corresponds to one packet and can be either an ACK or |
| * a NAK. If we get find an explicitly NAK'd packet we resend immediately; |
| * packets that lie beyond the end of the ACK list are scheduled for resend by |
| * the timer on the basis that the peer might just not have processed them at |
| * the time the ACK was sent. |
| */ |
| static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks, |
| rxrpc_seq_t seq, int nr_acks, |
| struct rxrpc_ack_summary *summary) |
| { |
| int ix; |
| u8 annotation, anno_type; |
| |
| for (; nr_acks > 0; nr_acks--, seq++) { |
| ix = seq & RXRPC_RXTX_BUFF_MASK; |
| annotation = call->rxtx_annotations[ix]; |
| anno_type = annotation & RXRPC_TX_ANNO_MASK; |
| annotation &= ~RXRPC_TX_ANNO_MASK; |
| switch (*acks++) { |
| case RXRPC_ACK_TYPE_ACK: |
| summary->nr_acks++; |
| if (anno_type == RXRPC_TX_ANNO_ACK) |
| continue; |
| summary->nr_new_acks++; |
| call->rxtx_annotations[ix] = |
| RXRPC_TX_ANNO_ACK | annotation; |
| break; |
| case RXRPC_ACK_TYPE_NACK: |
| if (!summary->nr_nacks && |
| call->acks_lowest_nak != seq) { |
| call->acks_lowest_nak = seq; |
| summary->new_low_nack = true; |
| } |
| summary->nr_nacks++; |
| if (anno_type == RXRPC_TX_ANNO_NAK) |
| continue; |
| summary->nr_new_nacks++; |
| if (anno_type == RXRPC_TX_ANNO_RETRANS) |
| continue; |
| call->rxtx_annotations[ix] = |
| RXRPC_TX_ANNO_NAK | annotation; |
| break; |
| default: |
| return rxrpc_proto_abort("SFT", call, 0); |
| } |
| } |
| } |
| |
| /* |
| * Process an ACK packet. |
| * |
| * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet |
| * in the ACK array. Anything before that is hard-ACK'd and may be discarded. |
| * |
| * A hard-ACK means that a packet has been processed and may be discarded; a |
| * soft-ACK means that the packet may be discarded and retransmission |
| * requested. A phase is complete when all packets are hard-ACK'd. |
| */ |
| static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb, |
| u16 skew) |
| { |
| struct rxrpc_ack_summary summary = { 0 }; |
| struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| union { |
| struct rxrpc_ackpacket ack; |
| struct rxrpc_ackinfo info; |
| u8 acks[RXRPC_MAXACKS]; |
| } buf; |
| rxrpc_serial_t acked_serial; |
| rxrpc_seq_t first_soft_ack, hard_ack; |
| int nr_acks, offset, ioffset; |
| |
| _enter(""); |
| |
| offset = sizeof(struct rxrpc_wire_header); |
| if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) { |
| _debug("extraction failure"); |
| return rxrpc_proto_abort("XAK", call, 0); |
| } |
| offset += sizeof(buf.ack); |
| |
| acked_serial = ntohl(buf.ack.serial); |
| first_soft_ack = ntohl(buf.ack.firstPacket); |
| hard_ack = first_soft_ack - 1; |
| nr_acks = buf.ack.nAcks; |
| summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ? |
| buf.ack.reason : RXRPC_ACK__INVALID); |
| |
| trace_rxrpc_rx_ack(call, first_soft_ack, summary.ack_reason, nr_acks); |
| |
| _proto("Rx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }", |
| sp->hdr.serial, |
| ntohs(buf.ack.maxSkew), |
| first_soft_ack, |
| ntohl(buf.ack.previousPacket), |
| acked_serial, |
| rxrpc_ack_names[summary.ack_reason], |
| buf.ack.nAcks); |
| |
| if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE) |
| rxrpc_input_ping_response(call, skb->tstamp, acked_serial, |
| sp->hdr.serial); |
| if (buf.ack.reason == RXRPC_ACK_REQUESTED) |
| rxrpc_input_requested_ack(call, skb->tstamp, acked_serial, |
| sp->hdr.serial); |
| |
| if (buf.ack.reason == RXRPC_ACK_PING) { |
| _proto("Rx ACK %%%u PING Request", sp->hdr.serial); |
| rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE, |
| skew, sp->hdr.serial, true, true, |
| rxrpc_propose_ack_respond_to_ping); |
| } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) { |
| rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, |
| skew, sp->hdr.serial, true, true, |
| rxrpc_propose_ack_respond_to_ack); |
| } |
| |
| /* Discard any out-of-order or duplicate ACKs. */ |
| if (before_eq(sp->hdr.serial, call->acks_latest)) { |
| _debug("discard ACK %d <= %d", |
| sp->hdr.serial, call->acks_latest); |
| return; |
| } |
| call->acks_latest_ts = skb->tstamp; |
| call->acks_latest = sp->hdr.serial; |
| |
| /* Parse rwind and mtu sizes if provided. */ |
| ioffset = offset + nr_acks + 3; |
| if (skb->len >= ioffset + sizeof(buf.info)) { |
| if (skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0) |
| return rxrpc_proto_abort("XAI", call, 0); |
| rxrpc_input_ackinfo(call, skb, &buf.info); |
| } |
| |
| if (first_soft_ack == 0) |
| return rxrpc_proto_abort("AK0", call, 0); |
| |
| /* Ignore ACKs unless we are or have just been transmitting. */ |
| switch (call->state) { |
| case RXRPC_CALL_CLIENT_SEND_REQUEST: |
| case RXRPC_CALL_CLIENT_AWAIT_REPLY: |
| case RXRPC_CALL_SERVER_SEND_REPLY: |
| case RXRPC_CALL_SERVER_AWAIT_ACK: |
| break; |
| default: |
| return; |
| } |
| |
| if (before(hard_ack, call->tx_hard_ack) || |
| after(hard_ack, call->tx_top)) |
| return rxrpc_proto_abort("AKW", call, 0); |
| if (nr_acks > call->tx_top - hard_ack) |
| return rxrpc_proto_abort("AKN", call, 0); |
| |
| if (after(hard_ack, call->tx_hard_ack)) { |
| if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) { |
| rxrpc_end_tx_phase(call, false, "ETA"); |
| return; |
| } |
| } |
| |
| if (nr_acks > 0) { |
| if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) |
| return rxrpc_proto_abort("XSA", call, 0); |
| rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks, |
| &summary); |
| } |
| |
| if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & |
| RXRPC_TX_ANNO_LAST && |
| summary.nr_acks == call->tx_top - hard_ack && |
| rxrpc_is_client_call(call)) |
| rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial, |
| false, true, |
| rxrpc_propose_ack_ping_for_lost_reply); |
| |
| return rxrpc_congestion_management(call, skb, &summary, acked_serial); |
| } |
| |
| /* |
| * Process an ACKALL packet. |
| */ |
| static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb) |
| { |
| struct rxrpc_ack_summary summary = { 0 }; |
| struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| |
| _proto("Rx ACKALL %%%u", sp->hdr.serial); |
| |
| if (rxrpc_rotate_tx_window(call, call->tx_top, &summary)) |
| rxrpc_end_tx_phase(call, false, "ETL"); |
| } |
| |
| /* |
| * Process an ABORT packet. |
| */ |
| static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb) |
| { |
| struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| __be32 wtmp; |
| u32 abort_code = RX_CALL_DEAD; |
| |
| _enter(""); |
| |
| if (skb->len >= 4 && |
| skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), |
| &wtmp, sizeof(wtmp)) >= 0) |
| abort_code = ntohl(wtmp); |
| |
| _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code); |
| |
| if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, |
| abort_code, ECONNABORTED)) |
| rxrpc_notify_socket(call); |
| } |
| |
| /* |
| * Process an incoming call packet. |
| */ |
| static void rxrpc_input_call_packet(struct rxrpc_call *call, |
| struct sk_buff *skb, u16 skew) |
| { |
| struct rxrpc_skb_priv *sp = rxrpc_skb(skb); |
| |
| _enter("%p,%p", call, skb); |
| |
| switch (sp->hdr.type) { |
| case RXRPC_PACKET_TYPE_DATA: |
| rxrpc_input_data(call, skb, skew); |
| break; |
| |
| case RXRPC_PACKET_TYPE_ACK: |
| rxrpc_input_ack(call, skb, skew); |
| break; |
| |
| case RXRPC_PACKET_TYPE_BUSY: |
| _proto("Rx BUSY %%%u", sp->hdr.serial); |
| |
| /* Just ignore BUSY packets from the server; the retry and |
| * lifespan timers will take care of business. BUSY packets |
| * from the client don't make sense. |
| */ |
| break; |
| |
| case RXRPC_PACKET_TYPE_ABORT: |
| rxrpc_input_abort(call, skb); |
| break; |
| |
| case RXRPC_PACKET_TYPE_ACKALL: |
| rxrpc_input_ackall(call, skb); |
| break; |
| |
| default: |
| _proto("Rx %s %%%u", rxrpc_pkts[sp->hdr.type], sp->hdr.serial); |
| break; |
| } |
| |
| _leave(""); |
| } |
| |
| /* |
| * Handle a new call on a channel implicitly completing the preceding call on |
| * that channel. |
| * |
| * TODO: If callNumber > call_id + 1, renegotiate security. |
| */ |
| static void rxrpc_input_implicit_end_call(struct rxrpc_connection *conn, |
| struct rxrpc_call *call) |
| { |
| switch (call->state) { |
| case RXRPC_CALL_SERVER_AWAIT_ACK: |
| rxrpc_call_completed(call); |
| break; |
| case RXRPC_CALL_COMPLETE: |
| break; |
| default: |
| if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, ESHUTDOWN)) { |
| set_bit(RXRPC_CALL_EV_ABORT, &call->events); |
| rxrpc_queue_call(call); |
| } |
| break; |
| } |
| |
| __rxrpc_disconnect_call(conn, call); |
| rxrpc_notify_socket(call); |
| } |
| |
| /* |
| * post connection-level events to the connection |
| * - this includes challenges, responses, some aborts and call terminal packet |
| * retransmission. |
| */ |
| static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn, |
| struct sk_buff *skb) |
| { |
| _enter("%p,%p", conn, skb); |
| |
| skb_queue_tail(&conn->rx_queue, skb); |
| rxrpc_queue_conn(conn); |
| } |
| |
| /* |
| * post endpoint-level events to the local endpoint |
| * - this includes debug and version messages |
| */ |
| static void rxrpc_post_packet_to_local(struct rxrpc_local *local, |
| struct sk_buff *skb) |
| { |
| _enter("%p,%p", local, skb); |
| |
| skb_queue_tail(&local->event_queue, skb); |
| rxrpc_queue_local(local); |
| } |
| |
| /* |
| * put a packet up for transport-level abort |
| */ |
| static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb) |
| { |
| CHECK_SLAB_OKAY(&local->usage); |
| |
| skb_queue_tail(&local->reject_queue, skb); |
| rxrpc_queue_local(local); |
| } |
| |
| /* |
| * Extract the wire header from a packet and translate the byte order. |
| */ |
| static noinline |
| int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb) |
| { |
| struct rxrpc_wire_header whdr; |
| |
| /* dig out the RxRPC connection details */ |
| if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) |
| return -EBADMSG; |
| |
| memset(sp, 0, sizeof(*sp)); |
| sp->hdr.epoch = ntohl(whdr.epoch); |
| sp->hdr.cid = ntohl(whdr.cid); |
| sp->hdr.callNumber = ntohl(whdr.callNumber); |
| sp->hdr.seq = ntohl(whdr.seq); |
| sp->hdr.serial = ntohl(whdr.serial); |
| sp->hdr.flags = whdr.flags; |
| sp->hdr.type = whdr.type; |
| sp->hdr.userStatus = whdr.userStatus; |
| sp->hdr.securityIndex = whdr.securityIndex; |
| sp->hdr._rsvd = ntohs(whdr._rsvd); |
| sp->hdr.serviceId = ntohs(whdr.serviceId); |
| return 0; |
| } |
| |
| /* |
| * handle data received on the local endpoint |
| * - may be called in interrupt context |
| * |
| * The socket is locked by the caller and this prevents the socket from being |
| * shut down and the local endpoint from going away, thus sk_user_data will not |
| * be cleared until this function returns. |
| */ |
| void rxrpc_data_ready(struct sock *udp_sk) |
| { |
| struct rxrpc_connection *conn; |
| struct rxrpc_channel *chan; |
| struct rxrpc_call *call; |
| struct rxrpc_skb_priv *sp; |
| struct rxrpc_local *local = udp_sk->sk_user_data; |
| struct sk_buff *skb; |
| unsigned int channel; |
| int ret, skew; |
| |
| _enter("%p", udp_sk); |
| |
| ASSERT(!irqs_disabled()); |
| |
| skb = skb_recv_datagram(udp_sk, 0, 1, &ret); |
| if (!skb) { |
| if (ret == -EAGAIN) |
| return; |
| _debug("UDP socket error %d", ret); |
| return; |
| } |
| |
| rxrpc_new_skb(skb, rxrpc_skb_rx_received); |
| |
| _net("recv skb %p", skb); |
| |
| /* we'll probably need to checksum it (didn't call sock_recvmsg) */ |
| if (skb_checksum_complete(skb)) { |
| rxrpc_free_skb(skb, rxrpc_skb_rx_freed); |
| __UDP_INC_STATS(&init_net, UDP_MIB_INERRORS, 0); |
| _leave(" [CSUM failed]"); |
| return; |
| } |
| |
| __UDP_INC_STATS(&init_net, UDP_MIB_INDATAGRAMS, 0); |
| |
| /* The socket buffer we have is owned by UDP, with UDP's data all over |
| * it, but we really want our own data there. |
| */ |
| skb_orphan(skb); |
| sp = rxrpc_skb(skb); |
| |
| /* dig out the RxRPC connection details */ |
| if (rxrpc_extract_header(sp, skb) < 0) |
| goto bad_message; |
| |
| if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) { |
| static int lose; |
| if ((lose++ & 7) == 7) { |
| trace_rxrpc_rx_lose(sp); |
| rxrpc_lose_skb(skb, rxrpc_skb_rx_lost); |
| return; |
| } |
| } |
| |
| trace_rxrpc_rx_packet(sp); |
| |
| _net("Rx RxRPC %s ep=%x call=%x:%x", |
| sp->hdr.flags & RXRPC_CLIENT_INITIATED ? "ToServer" : "ToClient", |
| sp->hdr.epoch, sp->hdr.cid, sp->hdr.callNumber); |
| |
| if (sp->hdr.type >= RXRPC_N_PACKET_TYPES || |
| !((RXRPC_SUPPORTED_PACKET_TYPES >> sp->hdr.type) & 1)) { |
| _proto("Rx Bad Packet Type %u", sp->hdr.type); |
| goto bad_message; |
| } |
| |
| switch (sp->hdr.type) { |
| case RXRPC_PACKET_TYPE_VERSION: |
| rxrpc_post_packet_to_local(local, skb); |
| goto out; |
| |
| case RXRPC_PACKET_TYPE_BUSY: |
| if (sp->hdr.flags & RXRPC_CLIENT_INITIATED) |
| goto discard; |
| |
| case RXRPC_PACKET_TYPE_DATA: |
| if (sp->hdr.callNumber == 0) |
| goto bad_message; |
| if (sp->hdr.flags & RXRPC_JUMBO_PACKET && |
| !rxrpc_validate_jumbo(skb)) |
| goto bad_message; |
| break; |
| } |
| |
| rcu_read_lock(); |
| |
| conn = rxrpc_find_connection_rcu(local, skb); |
| if (conn) { |
| if (sp->hdr.securityIndex != conn->security_ix) |
| goto wrong_security; |
| |
| if (sp->hdr.callNumber == 0) { |
| /* Connection-level packet */ |
| _debug("CONN %p {%d}", conn, conn->debug_id); |
| rxrpc_post_packet_to_conn(conn, skb); |
| goto out_unlock; |
| } |
| |
| /* Note the serial number skew here */ |
| skew = (int)sp->hdr.serial - (int)conn->hi_serial; |
| if (skew >= 0) { |
| if (skew > 0) |
| conn->hi_serial = sp->hdr.serial; |
| } else { |
| skew = -skew; |
| skew = min(skew, 65535); |
| } |
| |
| /* Call-bound packets are routed by connection channel. */ |
| channel = sp->hdr.cid & RXRPC_CHANNELMASK; |
| chan = &conn->channels[channel]; |
| |
| /* Ignore really old calls */ |
| if (sp->hdr.callNumber < chan->last_call) |
| goto discard_unlock; |
| |
| if (sp->hdr.callNumber == chan->last_call) { |
| if (chan->call || |
| sp->hdr.type == RXRPC_PACKET_TYPE_ABORT) |
| goto discard_unlock; |
| |
| /* For the previous service call, if completed |
| * successfully, we discard all further packets. |
| */ |
| if (rxrpc_conn_is_service(conn) && |
| chan->last_type == RXRPC_PACKET_TYPE_ACK) |
| goto discard_unlock; |
| |
| /* But otherwise we need to retransmit the final packet |
| * from data cached in the connection record. |
| */ |
| rxrpc_post_packet_to_conn(conn, skb); |
| goto out_unlock; |
| } |
| |
| call = rcu_dereference(chan->call); |
| |
| if (sp->hdr.callNumber > chan->call_id) { |
| if (!(sp->hdr.flags & RXRPC_CLIENT_INITIATED)) { |
| rcu_read_unlock(); |
| goto reject_packet; |
| } |
| if (call) |
| rxrpc_input_implicit_end_call(conn, call); |
| call = NULL; |
| } |
| } else { |
| skew = 0; |
| call = NULL; |
| } |
| |
| if (!call || atomic_read(&call->usage) == 0) { |
| if (!(sp->hdr.type & RXRPC_CLIENT_INITIATED) || |
| sp->hdr.callNumber == 0 || |
| sp->hdr.type != RXRPC_PACKET_TYPE_DATA) |
| goto bad_message_unlock; |
| if (sp->hdr.seq != 1) |
| goto discard_unlock; |
| call = rxrpc_new_incoming_call(local, conn, skb); |
| if (!call) { |
| rcu_read_unlock(); |
| goto reject_packet; |
| } |
| rxrpc_send_ping(call, skb, skew); |
| } |
| |
| rxrpc_input_call_packet(call, skb, skew); |
| goto discard_unlock; |
| |
| discard_unlock: |
| rcu_read_unlock(); |
| discard: |
| rxrpc_free_skb(skb, rxrpc_skb_rx_freed); |
| out: |
| trace_rxrpc_rx_done(0, 0); |
| return; |
| |
| out_unlock: |
| rcu_read_unlock(); |
| goto out; |
| |
| wrong_security: |
| rcu_read_unlock(); |
| trace_rxrpc_abort("SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, |
| RXKADINCONSISTENCY, EBADMSG); |
| skb->priority = RXKADINCONSISTENCY; |
| goto post_abort; |
| |
| bad_message_unlock: |
| rcu_read_unlock(); |
| bad_message: |
| trace_rxrpc_abort("BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, |
| RX_PROTOCOL_ERROR, EBADMSG); |
| skb->priority = RX_PROTOCOL_ERROR; |
| post_abort: |
| skb->mark = RXRPC_SKB_MARK_LOCAL_ABORT; |
| reject_packet: |
| trace_rxrpc_rx_done(skb->mark, skb->priority); |
| rxrpc_reject_packet(local, skb); |
| _leave(" [badmsg]"); |
| } |