Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  *	LAPB release 002
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *	This code REQUIRES 2.1.15 or higher/ NET3.038
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  *	History
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  *	LAPB 001	Jonathan Naylor	Started Coding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  *	LAPB 002	Jonathan Naylor	New timer architecture.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/socket.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/in.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <linux/timer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include <linux/sockios.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #include <linux/net.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) #include <linux/inet.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #include <linux/skbuff.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) #include <net/sock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #include <linux/fcntl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) #include <linux/interrupt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) #include <net/lapb.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34)  *  This procedure is passed a buffer descriptor for an iframe. It builds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35)  *  the rest of the control part of the frame and then writes it out.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) static void lapb_send_iframe(struct lapb_cb *lapb, struct sk_buff *skb, int poll_bit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	unsigned char *frame;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	if (!skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	if (lapb->mode & LAPB_EXTENDED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 		frame = skb_push(skb, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 		frame[0] = LAPB_I;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 		frame[0] |= lapb->vs << 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 		frame[1] = poll_bit ? LAPB_EPF : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 		frame[1] |= lapb->vr << 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 		frame = skb_push(skb, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 		*frame = LAPB_I;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 		*frame |= poll_bit ? LAPB_SPF : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 		*frame |= lapb->vr << 5;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 		*frame |= lapb->vs << 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	lapb_dbg(1, "(%p) S%d TX I(%d) S%d R%d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 		 lapb->dev, lapb->state, poll_bit, lapb->vs, lapb->vr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	lapb_transmit_buffer(lapb, skb, LAPB_COMMAND);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) void lapb_kick(struct lapb_cb *lapb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	struct sk_buff *skb, *skbn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	unsigned short modulus, start, end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	start = !skb_peek(&lapb->ack_queue) ? lapb->va : lapb->vs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	end   = (lapb->va + lapb->window) % modulus;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	if (!(lapb->condition & LAPB_PEER_RX_BUSY_CONDITION) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	    start != end && skb_peek(&lapb->write_queue)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 		lapb->vs = start;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 		 * Dequeue the frame and copy it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		skb = skb_dequeue(&lapb->write_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 		do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 			skbn = skb_copy(skb, GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 			if (!skbn) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 				skb_queue_head(&lapb->write_queue, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 				break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 			if (skb->sk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 				skb_set_owner_w(skbn, skb->sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 			/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 			 * Transmit the frame copy.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 			 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 			lapb_send_iframe(lapb, skbn, LAPB_POLLOFF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 			lapb->vs = (lapb->vs + 1) % modulus;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 			/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 			 * Requeue the original data frame.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 			 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 			skb_queue_tail(&lapb->ack_queue, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		} while (lapb->vs != end && (skb = skb_dequeue(&lapb->write_queue)) != NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 		lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 		if (!lapb_t1timer_running(lapb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 			lapb_start_t1timer(lapb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) void lapb_transmit_buffer(struct lapb_cb *lapb, struct sk_buff *skb, int type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	unsigned char *ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	ptr = skb_push(skb, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	if (lapb->mode & LAPB_MLP) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 		if (lapb->mode & LAPB_DCE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 			if (type == LAPB_COMMAND)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 				*ptr = LAPB_ADDR_C;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 			if (type == LAPB_RESPONSE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 				*ptr = LAPB_ADDR_D;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 			if (type == LAPB_COMMAND)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 				*ptr = LAPB_ADDR_D;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 			if (type == LAPB_RESPONSE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 				*ptr = LAPB_ADDR_C;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 		if (lapb->mode & LAPB_DCE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 			if (type == LAPB_COMMAND)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 				*ptr = LAPB_ADDR_A;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 			if (type == LAPB_RESPONSE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 				*ptr = LAPB_ADDR_B;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 			if (type == LAPB_COMMAND)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 				*ptr = LAPB_ADDR_B;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 			if (type == LAPB_RESPONSE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 				*ptr = LAPB_ADDR_A;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	lapb_dbg(2, "(%p) S%d TX %3ph\n", lapb->dev, lapb->state, skb->data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	if (!lapb_data_transmit(lapb, skb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 		kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) void lapb_establish_data_link(struct lapb_cb *lapb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	lapb->condition = 0x00;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	lapb->n2count   = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	if (lapb->mode & LAPB_EXTENDED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 		lapb_dbg(1, "(%p) S%d TX SABME(1)\n", lapb->dev, lapb->state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 		lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 		lapb_dbg(1, "(%p) S%d TX SABM(1)\n", lapb->dev, lapb->state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 		lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	lapb_start_t1timer(lapb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	lapb_stop_t2timer(lapb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) void lapb_enquiry_response(struct lapb_cb *lapb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	lapb_dbg(1, "(%p) S%d TX RR(1) R%d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		 lapb->dev, lapb->state, lapb->vr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	lapb_send_control(lapb, LAPB_RR, LAPB_POLLON, LAPB_RESPONSE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) void lapb_timeout_response(struct lapb_cb *lapb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	lapb_dbg(1, "(%p) S%d TX RR(0) R%d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		 lapb->dev, lapb->state, lapb->vr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	lapb_send_control(lapb, LAPB_RR, LAPB_POLLOFF, LAPB_RESPONSE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) void lapb_check_iframes_acked(struct lapb_cb *lapb, unsigned short nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	if (lapb->vs == nr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 		lapb_frames_acked(lapb, nr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 		lapb_stop_t1timer(lapb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 		lapb->n2count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 	} else if (lapb->va != nr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 		lapb_frames_acked(lapb, nr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 		lapb_start_t1timer(lapb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) void lapb_check_need_response(struct lapb_cb *lapb, int type, int pf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	if (type == LAPB_COMMAND && pf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 		lapb_enquiry_response(lapb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) }