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835 lines
18 KiB
835 lines
18 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* shdlc Link Layer Control |
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* |
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* Copyright (C) 2012 Intel Corporation. All rights reserved. |
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*/ |
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|
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#define pr_fmt(fmt) "shdlc: %s: " fmt, __func__ |
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|
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#include <linux/types.h> |
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#include <linux/sched.h> |
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#include <linux/wait.h> |
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#include <linux/slab.h> |
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#include <linux/skbuff.h> |
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|
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#include "llc.h" |
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|
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enum shdlc_state { |
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SHDLC_DISCONNECTED = 0, |
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SHDLC_CONNECTING = 1, |
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SHDLC_NEGOTIATING = 2, |
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SHDLC_HALF_CONNECTED = 3, |
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SHDLC_CONNECTED = 4 |
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}; |
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|
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struct llc_shdlc { |
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struct nfc_hci_dev *hdev; |
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xmit_to_drv_t xmit_to_drv; |
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rcv_to_hci_t rcv_to_hci; |
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|
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struct mutex state_mutex; |
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enum shdlc_state state; |
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int hard_fault; |
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|
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wait_queue_head_t *connect_wq; |
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int connect_tries; |
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int connect_result; |
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struct timer_list connect_timer;/* aka T3 in spec 10.6.1 */ |
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|
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u8 w; /* window size */ |
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bool srej_support; |
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|
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struct timer_list t1_timer; /* send ack timeout */ |
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bool t1_active; |
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|
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struct timer_list t2_timer; /* guard/retransmit timeout */ |
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bool t2_active; |
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|
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int ns; /* next seq num for send */ |
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int nr; /* next expected seq num for receive */ |
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int dnr; /* oldest sent unacked seq num */ |
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|
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struct sk_buff_head rcv_q; |
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|
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struct sk_buff_head send_q; |
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bool rnr; /* other side is not ready to receive */ |
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|
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struct sk_buff_head ack_pending_q; |
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|
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struct work_struct sm_work; |
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|
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int tx_headroom; |
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int tx_tailroom; |
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|
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llc_failure_t llc_failure; |
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}; |
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|
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#define SHDLC_LLC_HEAD_ROOM 2 |
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|
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#define SHDLC_MAX_WINDOW 4 |
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#define SHDLC_SREJ_SUPPORT false |
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|
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#define SHDLC_CONTROL_HEAD_MASK 0xe0 |
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#define SHDLC_CONTROL_HEAD_I 0x80 |
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#define SHDLC_CONTROL_HEAD_I2 0xa0 |
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#define SHDLC_CONTROL_HEAD_S 0xc0 |
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#define SHDLC_CONTROL_HEAD_U 0xe0 |
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|
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#define SHDLC_CONTROL_NS_MASK 0x38 |
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#define SHDLC_CONTROL_NR_MASK 0x07 |
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#define SHDLC_CONTROL_TYPE_MASK 0x18 |
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|
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#define SHDLC_CONTROL_M_MASK 0x1f |
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|
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enum sframe_type { |
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S_FRAME_RR = 0x00, |
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S_FRAME_REJ = 0x01, |
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S_FRAME_RNR = 0x02, |
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S_FRAME_SREJ = 0x03 |
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}; |
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|
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enum uframe_modifier { |
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U_FRAME_UA = 0x06, |
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U_FRAME_RSET = 0x19 |
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}; |
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|
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#define SHDLC_CONNECT_VALUE_MS 5 |
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#define SHDLC_T1_VALUE_MS(w) ((5 * w) / 4) |
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#define SHDLC_T2_VALUE_MS 300 |
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|
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#define SHDLC_DUMP_SKB(info, skb) \ |
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do { \ |
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pr_debug("%s:\n", info); \ |
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print_hex_dump(KERN_DEBUG, "shdlc: ", DUMP_PREFIX_OFFSET, \ |
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16, 1, skb->data, skb->len, 0); \ |
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} while (0) |
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|
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/* checks x < y <= z modulo 8 */ |
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static bool llc_shdlc_x_lt_y_lteq_z(int x, int y, int z) |
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{ |
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if (x < z) |
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return ((x < y) && (y <= z)) ? true : false; |
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else |
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return ((y > x) || (y <= z)) ? true : false; |
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} |
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|
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/* checks x <= y < z modulo 8 */ |
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static bool llc_shdlc_x_lteq_y_lt_z(int x, int y, int z) |
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{ |
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if (x <= z) |
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return ((x <= y) && (y < z)) ? true : false; |
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else /* x > z -> z+8 > x */ |
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return ((y >= x) || (y < z)) ? true : false; |
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} |
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|
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static struct sk_buff *llc_shdlc_alloc_skb(struct llc_shdlc *shdlc, |
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int payload_len) |
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{ |
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struct sk_buff *skb; |
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|
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skb = alloc_skb(shdlc->tx_headroom + SHDLC_LLC_HEAD_ROOM + |
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shdlc->tx_tailroom + payload_len, GFP_KERNEL); |
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if (skb) |
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skb_reserve(skb, shdlc->tx_headroom + SHDLC_LLC_HEAD_ROOM); |
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|
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return skb; |
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} |
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|
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/* immediately sends an S frame. */ |
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static int llc_shdlc_send_s_frame(struct llc_shdlc *shdlc, |
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enum sframe_type sframe_type, int nr) |
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{ |
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int r; |
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struct sk_buff *skb; |
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|
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pr_debug("sframe_type=%d nr=%d\n", sframe_type, nr); |
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|
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skb = llc_shdlc_alloc_skb(shdlc, 0); |
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if (skb == NULL) |
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return -ENOMEM; |
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|
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*(u8 *)skb_push(skb, 1) = SHDLC_CONTROL_HEAD_S | (sframe_type << 3) | nr; |
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|
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r = shdlc->xmit_to_drv(shdlc->hdev, skb); |
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|
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kfree_skb(skb); |
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|
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return r; |
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} |
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|
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/* immediately sends an U frame. skb may contain optional payload */ |
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static int llc_shdlc_send_u_frame(struct llc_shdlc *shdlc, |
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struct sk_buff *skb, |
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enum uframe_modifier uframe_modifier) |
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{ |
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int r; |
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|
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pr_debug("uframe_modifier=%d\n", uframe_modifier); |
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|
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*(u8 *)skb_push(skb, 1) = SHDLC_CONTROL_HEAD_U | uframe_modifier; |
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r = shdlc->xmit_to_drv(shdlc->hdev, skb); |
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|
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kfree_skb(skb); |
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|
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return r; |
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} |
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|
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/* |
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* Free ack_pending frames until y_nr - 1, and reset t2 according to |
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* the remaining oldest ack_pending frame sent time |
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*/ |
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static void llc_shdlc_reset_t2(struct llc_shdlc *shdlc, int y_nr) |
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{ |
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struct sk_buff *skb; |
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int dnr = shdlc->dnr; /* MUST initially be < y_nr */ |
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pr_debug("release ack pending up to frame %d excluded\n", y_nr); |
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while (dnr != y_nr) { |
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pr_debug("release ack pending frame %d\n", dnr); |
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skb = skb_dequeue(&shdlc->ack_pending_q); |
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kfree_skb(skb); |
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dnr = (dnr + 1) % 8; |
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} |
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if (skb_queue_empty(&shdlc->ack_pending_q)) { |
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if (shdlc->t2_active) { |
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del_timer_sync(&shdlc->t2_timer); |
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shdlc->t2_active = false; |
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|
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pr_debug |
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("All sent frames acked. Stopped T2(retransmit)\n"); |
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} |
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} else { |
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skb = skb_peek(&shdlc->ack_pending_q); |
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|
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mod_timer(&shdlc->t2_timer, *(unsigned long *)skb->cb + |
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msecs_to_jiffies(SHDLC_T2_VALUE_MS)); |
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shdlc->t2_active = true; |
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|
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pr_debug |
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("Start T2(retransmit) for remaining unacked sent frames\n"); |
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} |
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} |
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|
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/* |
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* Receive validated frames from lower layer. skb contains HCI payload only. |
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* Handle according to algorithm at spec:10.8.2 |
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*/ |
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static void llc_shdlc_rcv_i_frame(struct llc_shdlc *shdlc, |
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struct sk_buff *skb, int ns, int nr) |
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{ |
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int x_ns = ns; |
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int y_nr = nr; |
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pr_debug("recvd I-frame %d, remote waiting frame %d\n", ns, nr); |
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if (shdlc->state != SHDLC_CONNECTED) |
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goto exit; |
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if (x_ns != shdlc->nr) { |
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llc_shdlc_send_s_frame(shdlc, S_FRAME_REJ, shdlc->nr); |
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goto exit; |
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} |
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|
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if (!shdlc->t1_active) { |
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shdlc->t1_active = true; |
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mod_timer(&shdlc->t1_timer, jiffies + |
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msecs_to_jiffies(SHDLC_T1_VALUE_MS(shdlc->w))); |
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pr_debug("(re)Start T1(send ack)\n"); |
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} |
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if (skb->len) { |
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shdlc->rcv_to_hci(shdlc->hdev, skb); |
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skb = NULL; |
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} |
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shdlc->nr = (shdlc->nr + 1) % 8; |
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|
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if (llc_shdlc_x_lt_y_lteq_z(shdlc->dnr, y_nr, shdlc->ns)) { |
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llc_shdlc_reset_t2(shdlc, y_nr); |
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shdlc->dnr = y_nr; |
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} |
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exit: |
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kfree_skb(skb); |
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} |
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static void llc_shdlc_rcv_ack(struct llc_shdlc *shdlc, int y_nr) |
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{ |
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pr_debug("remote acked up to frame %d excluded\n", y_nr); |
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|
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if (llc_shdlc_x_lt_y_lteq_z(shdlc->dnr, y_nr, shdlc->ns)) { |
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llc_shdlc_reset_t2(shdlc, y_nr); |
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shdlc->dnr = y_nr; |
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} |
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} |
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static void llc_shdlc_requeue_ack_pending(struct llc_shdlc *shdlc) |
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{ |
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struct sk_buff *skb; |
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pr_debug("ns reset to %d\n", shdlc->dnr); |
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while ((skb = skb_dequeue_tail(&shdlc->ack_pending_q))) { |
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skb_pull(skb, 1); /* remove control field */ |
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skb_queue_head(&shdlc->send_q, skb); |
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} |
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shdlc->ns = shdlc->dnr; |
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} |
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static void llc_shdlc_rcv_rej(struct llc_shdlc *shdlc, int y_nr) |
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{ |
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struct sk_buff *skb; |
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pr_debug("remote asks retransmission from frame %d\n", y_nr); |
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if (llc_shdlc_x_lteq_y_lt_z(shdlc->dnr, y_nr, shdlc->ns)) { |
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if (shdlc->t2_active) { |
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del_timer_sync(&shdlc->t2_timer); |
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shdlc->t2_active = false; |
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pr_debug("Stopped T2(retransmit)\n"); |
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} |
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if (shdlc->dnr != y_nr) { |
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while ((shdlc->dnr = ((shdlc->dnr + 1) % 8)) != y_nr) { |
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skb = skb_dequeue(&shdlc->ack_pending_q); |
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kfree_skb(skb); |
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} |
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} |
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llc_shdlc_requeue_ack_pending(shdlc); |
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} |
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} |
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/* See spec RR:10.8.3 REJ:10.8.4 */ |
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static void llc_shdlc_rcv_s_frame(struct llc_shdlc *shdlc, |
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enum sframe_type s_frame_type, int nr) |
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{ |
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struct sk_buff *skb; |
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if (shdlc->state != SHDLC_CONNECTED) |
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return; |
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switch (s_frame_type) { |
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case S_FRAME_RR: |
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llc_shdlc_rcv_ack(shdlc, nr); |
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if (shdlc->rnr == true) { /* see SHDLC 10.7.7 */ |
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shdlc->rnr = false; |
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if (shdlc->send_q.qlen == 0) { |
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skb = llc_shdlc_alloc_skb(shdlc, 0); |
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if (skb) |
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skb_queue_tail(&shdlc->send_q, skb); |
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} |
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} |
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break; |
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case S_FRAME_REJ: |
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llc_shdlc_rcv_rej(shdlc, nr); |
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break; |
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case S_FRAME_RNR: |
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llc_shdlc_rcv_ack(shdlc, nr); |
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shdlc->rnr = true; |
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break; |
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default: |
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break; |
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} |
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} |
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|
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static void llc_shdlc_connect_complete(struct llc_shdlc *shdlc, int r) |
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{ |
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pr_debug("result=%d\n", r); |
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|
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del_timer_sync(&shdlc->connect_timer); |
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|
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if (r == 0) { |
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shdlc->ns = 0; |
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shdlc->nr = 0; |
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shdlc->dnr = 0; |
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|
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shdlc->state = SHDLC_HALF_CONNECTED; |
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} else { |
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shdlc->state = SHDLC_DISCONNECTED; |
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} |
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shdlc->connect_result = r; |
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wake_up(shdlc->connect_wq); |
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} |
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static int llc_shdlc_connect_initiate(struct llc_shdlc *shdlc) |
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{ |
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struct sk_buff *skb; |
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|
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pr_debug("\n"); |
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skb = llc_shdlc_alloc_skb(shdlc, 2); |
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if (skb == NULL) |
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return -ENOMEM; |
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skb_put_u8(skb, SHDLC_MAX_WINDOW); |
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skb_put_u8(skb, SHDLC_SREJ_SUPPORT ? 1 : 0); |
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return llc_shdlc_send_u_frame(shdlc, skb, U_FRAME_RSET); |
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} |
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|
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static int llc_shdlc_connect_send_ua(struct llc_shdlc *shdlc) |
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{ |
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struct sk_buff *skb; |
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|
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pr_debug("\n"); |
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|
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skb = llc_shdlc_alloc_skb(shdlc, 0); |
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if (skb == NULL) |
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return -ENOMEM; |
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|
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return llc_shdlc_send_u_frame(shdlc, skb, U_FRAME_UA); |
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} |
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static void llc_shdlc_rcv_u_frame(struct llc_shdlc *shdlc, |
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struct sk_buff *skb, |
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enum uframe_modifier u_frame_modifier) |
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{ |
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u8 w = SHDLC_MAX_WINDOW; |
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bool srej_support = SHDLC_SREJ_SUPPORT; |
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int r; |
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|
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pr_debug("u_frame_modifier=%d\n", u_frame_modifier); |
|
|
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switch (u_frame_modifier) { |
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case U_FRAME_RSET: |
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switch (shdlc->state) { |
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case SHDLC_NEGOTIATING: |
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case SHDLC_CONNECTING: |
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/* |
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* We sent RSET, but chip wants to negotiate or we |
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* got RSET before we managed to send out our. |
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*/ |
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if (skb->len > 0) |
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w = skb->data[0]; |
|
|
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if (skb->len > 1) |
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srej_support = skb->data[1] & 0x01 ? true : |
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false; |
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|
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if ((w <= SHDLC_MAX_WINDOW) && |
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(SHDLC_SREJ_SUPPORT || (srej_support == false))) { |
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shdlc->w = w; |
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shdlc->srej_support = srej_support; |
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r = llc_shdlc_connect_send_ua(shdlc); |
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llc_shdlc_connect_complete(shdlc, r); |
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} |
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break; |
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case SHDLC_HALF_CONNECTED: |
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/* |
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* Chip resent RSET due to its timeout - Ignote it |
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* as we already sent UA. |
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*/ |
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break; |
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case SHDLC_CONNECTED: |
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/* |
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* Chip wants to reset link. This is unexpected and |
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* unsupported. |
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*/ |
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shdlc->hard_fault = -ECONNRESET; |
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break; |
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default: |
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break; |
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} |
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break; |
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case U_FRAME_UA: |
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if ((shdlc->state == SHDLC_CONNECTING && |
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shdlc->connect_tries > 0) || |
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(shdlc->state == SHDLC_NEGOTIATING)) { |
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llc_shdlc_connect_complete(shdlc, 0); |
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shdlc->state = SHDLC_CONNECTED; |
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} |
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break; |
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default: |
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break; |
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} |
|
|
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kfree_skb(skb); |
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} |
|
|
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static void llc_shdlc_handle_rcv_queue(struct llc_shdlc *shdlc) |
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{ |
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struct sk_buff *skb; |
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u8 control; |
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int nr; |
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int ns; |
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enum sframe_type s_frame_type; |
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enum uframe_modifier u_frame_modifier; |
|
|
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if (shdlc->rcv_q.qlen) |
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pr_debug("rcvQlen=%d\n", shdlc->rcv_q.qlen); |
|
|
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while ((skb = skb_dequeue(&shdlc->rcv_q)) != NULL) { |
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control = skb->data[0]; |
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skb_pull(skb, 1); |
|
switch (control & SHDLC_CONTROL_HEAD_MASK) { |
|
case SHDLC_CONTROL_HEAD_I: |
|
case SHDLC_CONTROL_HEAD_I2: |
|
if (shdlc->state == SHDLC_HALF_CONNECTED) |
|
shdlc->state = SHDLC_CONNECTED; |
|
|
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ns = (control & SHDLC_CONTROL_NS_MASK) >> 3; |
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nr = control & SHDLC_CONTROL_NR_MASK; |
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llc_shdlc_rcv_i_frame(shdlc, skb, ns, nr); |
|
break; |
|
case SHDLC_CONTROL_HEAD_S: |
|
if (shdlc->state == SHDLC_HALF_CONNECTED) |
|
shdlc->state = SHDLC_CONNECTED; |
|
|
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s_frame_type = (control & SHDLC_CONTROL_TYPE_MASK) >> 3; |
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nr = control & SHDLC_CONTROL_NR_MASK; |
|
llc_shdlc_rcv_s_frame(shdlc, s_frame_type, nr); |
|
kfree_skb(skb); |
|
break; |
|
case SHDLC_CONTROL_HEAD_U: |
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u_frame_modifier = control & SHDLC_CONTROL_M_MASK; |
|
llc_shdlc_rcv_u_frame(shdlc, skb, u_frame_modifier); |
|
break; |
|
default: |
|
pr_err("UNKNOWN Control=%d\n", control); |
|
kfree_skb(skb); |
|
break; |
|
} |
|
} |
|
} |
|
|
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static int llc_shdlc_w_used(int ns, int dnr) |
|
{ |
|
int unack_count; |
|
|
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if (dnr <= ns) |
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unack_count = ns - dnr; |
|
else |
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unack_count = 8 - dnr + ns; |
|
|
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return unack_count; |
|
} |
|
|
|
/* Send frames according to algorithm at spec:10.8.1 */ |
|
static void llc_shdlc_handle_send_queue(struct llc_shdlc *shdlc) |
|
{ |
|
struct sk_buff *skb; |
|
int r; |
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unsigned long time_sent; |
|
|
|
if (shdlc->send_q.qlen) |
|
pr_debug |
|
("sendQlen=%d ns=%d dnr=%d rnr=%s w_room=%d unackQlen=%d\n", |
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shdlc->send_q.qlen, shdlc->ns, shdlc->dnr, |
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shdlc->rnr == false ? "false" : "true", |
|
shdlc->w - llc_shdlc_w_used(shdlc->ns, shdlc->dnr), |
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shdlc->ack_pending_q.qlen); |
|
|
|
while (shdlc->send_q.qlen && shdlc->ack_pending_q.qlen < shdlc->w && |
|
(shdlc->rnr == false)) { |
|
|
|
if (shdlc->t1_active) { |
|
del_timer_sync(&shdlc->t1_timer); |
|
shdlc->t1_active = false; |
|
pr_debug("Stopped T1(send ack)\n"); |
|
} |
|
|
|
skb = skb_dequeue(&shdlc->send_q); |
|
|
|
*(u8 *)skb_push(skb, 1) = SHDLC_CONTROL_HEAD_I | (shdlc->ns << 3) | |
|
shdlc->nr; |
|
|
|
pr_debug("Sending I-Frame %d, waiting to rcv %d\n", shdlc->ns, |
|
shdlc->nr); |
|
SHDLC_DUMP_SKB("shdlc frame written", skb); |
|
|
|
r = shdlc->xmit_to_drv(shdlc->hdev, skb); |
|
if (r < 0) { |
|
shdlc->hard_fault = r; |
|
break; |
|
} |
|
|
|
shdlc->ns = (shdlc->ns + 1) % 8; |
|
|
|
time_sent = jiffies; |
|
*(unsigned long *)skb->cb = time_sent; |
|
|
|
skb_queue_tail(&shdlc->ack_pending_q, skb); |
|
|
|
if (shdlc->t2_active == false) { |
|
shdlc->t2_active = true; |
|
mod_timer(&shdlc->t2_timer, time_sent + |
|
msecs_to_jiffies(SHDLC_T2_VALUE_MS)); |
|
pr_debug("Started T2 (retransmit)\n"); |
|
} |
|
} |
|
} |
|
|
|
static void llc_shdlc_connect_timeout(struct timer_list *t) |
|
{ |
|
struct llc_shdlc *shdlc = from_timer(shdlc, t, connect_timer); |
|
|
|
pr_debug("\n"); |
|
|
|
schedule_work(&shdlc->sm_work); |
|
} |
|
|
|
static void llc_shdlc_t1_timeout(struct timer_list *t) |
|
{ |
|
struct llc_shdlc *shdlc = from_timer(shdlc, t, t1_timer); |
|
|
|
pr_debug("SoftIRQ: need to send ack\n"); |
|
|
|
schedule_work(&shdlc->sm_work); |
|
} |
|
|
|
static void llc_shdlc_t2_timeout(struct timer_list *t) |
|
{ |
|
struct llc_shdlc *shdlc = from_timer(shdlc, t, t2_timer); |
|
|
|
pr_debug("SoftIRQ: need to retransmit\n"); |
|
|
|
schedule_work(&shdlc->sm_work); |
|
} |
|
|
|
static void llc_shdlc_sm_work(struct work_struct *work) |
|
{ |
|
struct llc_shdlc *shdlc = container_of(work, struct llc_shdlc, sm_work); |
|
int r; |
|
|
|
pr_debug("\n"); |
|
|
|
mutex_lock(&shdlc->state_mutex); |
|
|
|
switch (shdlc->state) { |
|
case SHDLC_DISCONNECTED: |
|
skb_queue_purge(&shdlc->rcv_q); |
|
skb_queue_purge(&shdlc->send_q); |
|
skb_queue_purge(&shdlc->ack_pending_q); |
|
break; |
|
case SHDLC_CONNECTING: |
|
if (shdlc->hard_fault) { |
|
llc_shdlc_connect_complete(shdlc, shdlc->hard_fault); |
|
break; |
|
} |
|
|
|
if (shdlc->connect_tries++ < 5) |
|
r = llc_shdlc_connect_initiate(shdlc); |
|
else |
|
r = -ETIME; |
|
if (r < 0) { |
|
llc_shdlc_connect_complete(shdlc, r); |
|
} else { |
|
mod_timer(&shdlc->connect_timer, jiffies + |
|
msecs_to_jiffies(SHDLC_CONNECT_VALUE_MS)); |
|
|
|
shdlc->state = SHDLC_NEGOTIATING; |
|
} |
|
break; |
|
case SHDLC_NEGOTIATING: |
|
if (timer_pending(&shdlc->connect_timer) == 0) { |
|
shdlc->state = SHDLC_CONNECTING; |
|
schedule_work(&shdlc->sm_work); |
|
} |
|
|
|
llc_shdlc_handle_rcv_queue(shdlc); |
|
|
|
if (shdlc->hard_fault) { |
|
llc_shdlc_connect_complete(shdlc, shdlc->hard_fault); |
|
break; |
|
} |
|
break; |
|
case SHDLC_HALF_CONNECTED: |
|
case SHDLC_CONNECTED: |
|
llc_shdlc_handle_rcv_queue(shdlc); |
|
llc_shdlc_handle_send_queue(shdlc); |
|
|
|
if (shdlc->t1_active && timer_pending(&shdlc->t1_timer) == 0) { |
|
pr_debug |
|
("Handle T1(send ack) elapsed (T1 now inactive)\n"); |
|
|
|
shdlc->t1_active = false; |
|
r = llc_shdlc_send_s_frame(shdlc, S_FRAME_RR, |
|
shdlc->nr); |
|
if (r < 0) |
|
shdlc->hard_fault = r; |
|
} |
|
|
|
if (shdlc->t2_active && timer_pending(&shdlc->t2_timer) == 0) { |
|
pr_debug |
|
("Handle T2(retransmit) elapsed (T2 inactive)\n"); |
|
|
|
shdlc->t2_active = false; |
|
|
|
llc_shdlc_requeue_ack_pending(shdlc); |
|
llc_shdlc_handle_send_queue(shdlc); |
|
} |
|
|
|
if (shdlc->hard_fault) |
|
shdlc->llc_failure(shdlc->hdev, shdlc->hard_fault); |
|
break; |
|
default: |
|
break; |
|
} |
|
mutex_unlock(&shdlc->state_mutex); |
|
} |
|
|
|
/* |
|
* Called from syscall context to establish shdlc link. Sleeps until |
|
* link is ready or failure. |
|
*/ |
|
static int llc_shdlc_connect(struct llc_shdlc *shdlc) |
|
{ |
|
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(connect_wq); |
|
|
|
pr_debug("\n"); |
|
|
|
mutex_lock(&shdlc->state_mutex); |
|
|
|
shdlc->state = SHDLC_CONNECTING; |
|
shdlc->connect_wq = &connect_wq; |
|
shdlc->connect_tries = 0; |
|
shdlc->connect_result = 1; |
|
|
|
mutex_unlock(&shdlc->state_mutex); |
|
|
|
schedule_work(&shdlc->sm_work); |
|
|
|
wait_event(connect_wq, shdlc->connect_result != 1); |
|
|
|
return shdlc->connect_result; |
|
} |
|
|
|
static void llc_shdlc_disconnect(struct llc_shdlc *shdlc) |
|
{ |
|
pr_debug("\n"); |
|
|
|
mutex_lock(&shdlc->state_mutex); |
|
|
|
shdlc->state = SHDLC_DISCONNECTED; |
|
|
|
mutex_unlock(&shdlc->state_mutex); |
|
|
|
schedule_work(&shdlc->sm_work); |
|
} |
|
|
|
/* |
|
* Receive an incoming shdlc frame. Frame has already been crc-validated. |
|
* skb contains only LLC header and payload. |
|
* If skb == NULL, it is a notification that the link below is dead. |
|
*/ |
|
static void llc_shdlc_recv_frame(struct llc_shdlc *shdlc, struct sk_buff *skb) |
|
{ |
|
if (skb == NULL) { |
|
pr_err("NULL Frame -> link is dead\n"); |
|
shdlc->hard_fault = -EREMOTEIO; |
|
} else { |
|
SHDLC_DUMP_SKB("incoming frame", skb); |
|
skb_queue_tail(&shdlc->rcv_q, skb); |
|
} |
|
|
|
schedule_work(&shdlc->sm_work); |
|
} |
|
|
|
static void *llc_shdlc_init(struct nfc_hci_dev *hdev, xmit_to_drv_t xmit_to_drv, |
|
rcv_to_hci_t rcv_to_hci, int tx_headroom, |
|
int tx_tailroom, int *rx_headroom, int *rx_tailroom, |
|
llc_failure_t llc_failure) |
|
{ |
|
struct llc_shdlc *shdlc; |
|
|
|
*rx_headroom = SHDLC_LLC_HEAD_ROOM; |
|
*rx_tailroom = 0; |
|
|
|
shdlc = kzalloc(sizeof(struct llc_shdlc), GFP_KERNEL); |
|
if (shdlc == NULL) |
|
return NULL; |
|
|
|
mutex_init(&shdlc->state_mutex); |
|
shdlc->state = SHDLC_DISCONNECTED; |
|
|
|
timer_setup(&shdlc->connect_timer, llc_shdlc_connect_timeout, 0); |
|
timer_setup(&shdlc->t1_timer, llc_shdlc_t1_timeout, 0); |
|
timer_setup(&shdlc->t2_timer, llc_shdlc_t2_timeout, 0); |
|
|
|
shdlc->w = SHDLC_MAX_WINDOW; |
|
shdlc->srej_support = SHDLC_SREJ_SUPPORT; |
|
|
|
skb_queue_head_init(&shdlc->rcv_q); |
|
skb_queue_head_init(&shdlc->send_q); |
|
skb_queue_head_init(&shdlc->ack_pending_q); |
|
|
|
INIT_WORK(&shdlc->sm_work, llc_shdlc_sm_work); |
|
|
|
shdlc->hdev = hdev; |
|
shdlc->xmit_to_drv = xmit_to_drv; |
|
shdlc->rcv_to_hci = rcv_to_hci; |
|
shdlc->tx_headroom = tx_headroom; |
|
shdlc->tx_tailroom = tx_tailroom; |
|
shdlc->llc_failure = llc_failure; |
|
|
|
return shdlc; |
|
} |
|
|
|
static void llc_shdlc_deinit(struct nfc_llc *llc) |
|
{ |
|
struct llc_shdlc *shdlc = nfc_llc_get_data(llc); |
|
|
|
skb_queue_purge(&shdlc->rcv_q); |
|
skb_queue_purge(&shdlc->send_q); |
|
skb_queue_purge(&shdlc->ack_pending_q); |
|
|
|
kfree(shdlc); |
|
} |
|
|
|
static int llc_shdlc_start(struct nfc_llc *llc) |
|
{ |
|
struct llc_shdlc *shdlc = nfc_llc_get_data(llc); |
|
|
|
return llc_shdlc_connect(shdlc); |
|
} |
|
|
|
static int llc_shdlc_stop(struct nfc_llc *llc) |
|
{ |
|
struct llc_shdlc *shdlc = nfc_llc_get_data(llc); |
|
|
|
llc_shdlc_disconnect(shdlc); |
|
|
|
return 0; |
|
} |
|
|
|
static void llc_shdlc_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb) |
|
{ |
|
struct llc_shdlc *shdlc = nfc_llc_get_data(llc); |
|
|
|
llc_shdlc_recv_frame(shdlc, skb); |
|
} |
|
|
|
static int llc_shdlc_xmit_from_hci(struct nfc_llc *llc, struct sk_buff *skb) |
|
{ |
|
struct llc_shdlc *shdlc = nfc_llc_get_data(llc); |
|
|
|
skb_queue_tail(&shdlc->send_q, skb); |
|
|
|
schedule_work(&shdlc->sm_work); |
|
|
|
return 0; |
|
} |
|
|
|
static struct nfc_llc_ops llc_shdlc_ops = { |
|
.init = llc_shdlc_init, |
|
.deinit = llc_shdlc_deinit, |
|
.start = llc_shdlc_start, |
|
.stop = llc_shdlc_stop, |
|
.rcv_from_drv = llc_shdlc_rcv_from_drv, |
|
.xmit_from_hci = llc_shdlc_xmit_from_hci, |
|
}; |
|
|
|
int nfc_llc_shdlc_register(void) |
|
{ |
|
return nfc_llc_register(LLC_SHDLC_NAME, &llc_shdlc_ops); |
|
}
|
|
|