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)  *	X.25 Packet Layer release 002
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *	This is ALPHA test software. This code may break your machine,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *	randomly fail to work with new releases, misbehave and/or generally
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  *	screw up. It might even work.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  *	This code REQUIRES 2.1.15 or higher
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  *	History
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12)  *	X.25 001	Jonathan Naylor	  Started coding.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13)  *	X.25 002	Jonathan Naylor	  Centralised disconnection processing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14)  *	mar/20/00	Daniela Squassoni Disabling/enabling of facilities
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15)  *					  negotiation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16)  *	jun/24/01	Arnaldo C. Melo	  use skb_queue_purge, cleanups
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17)  *	apr/04/15	Shaun Pereira		Fast select with no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18)  *						restriction on response.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #define pr_fmt(fmt) "X25: " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) #include <linux/skbuff.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #include <net/sock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #include <net/tcp_states.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) #include <net/x25.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32)  *	This routine purges all of the queues of frames.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) void x25_clear_queues(struct sock *sk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	struct x25_sock *x25 = x25_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	skb_queue_purge(&sk->sk_write_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	skb_queue_purge(&x25->ack_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	skb_queue_purge(&x25->interrupt_in_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	skb_queue_purge(&x25->interrupt_out_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	skb_queue_purge(&x25->fragment_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47)  * This routine purges the input queue of those frames that have been
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48)  * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49)  * SDL diagram.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) void x25_frames_acked(struct sock *sk, unsigned short nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	struct sk_buff *skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	struct x25_sock *x25 = x25_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	int modulus = x25->neighbour->extended ? X25_EMODULUS : X25_SMODULUS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	 * Remove all the ack-ed frames from the ack queue.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	if (x25->va != nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 		while (skb_peek(&x25->ack_queue) && x25->va != nr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 			skb = skb_dequeue(&x25->ack_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 			kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 			x25->va = (x25->va + 1) % modulus;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) void x25_requeue_frames(struct sock *sk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	struct sk_buff *skb, *skb_prev = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	 * Requeue all the un-ack-ed frames on the output queue to be picked
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	 * up by x25_kick. This arrangement handles the possibility of an empty
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	 * output queue.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	while ((skb = skb_dequeue(&x25_sk(sk)->ack_queue)) != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 		if (!skb_prev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 			skb_queue_head(&sk->sk_write_queue, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 		else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 			skb_append(skb_prev, skb, &sk->sk_write_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		skb_prev = skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87)  *	Validate that the value of nr is between va and vs. Return true or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88)  *	false for testing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) int x25_validate_nr(struct sock *sk, unsigned short nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	struct x25_sock *x25 = x25_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	unsigned short vc = x25->va;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	int modulus = x25->neighbour->extended ? X25_EMODULUS : X25_SMODULUS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	while (vc != x25->vs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 		if (nr == vc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 			return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 		vc = (vc + 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) 	return nr == x25->vs ? 1 : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)  *  This routine is called when the packet layer internally generates a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)  *  control frame.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) void x25_write_internal(struct sock *sk, int frametype)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	struct x25_sock *x25 = x25_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	struct sk_buff *skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	unsigned char  *dptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	unsigned char  facilities[X25_MAX_FAC_LEN];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	unsigned char  addresses[1 + X25_ADDR_LEN];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	unsigned char  lci1, lci2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 	 *	Default safe frame size.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	int len = X25_MAX_L2_LEN + X25_EXT_MIN_LEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	 *	Adjust frame size.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	switch (frametype) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	case X25_CALL_REQUEST:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 		len += 1 + X25_ADDR_LEN + X25_MAX_FAC_LEN + X25_MAX_CUD_LEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	case X25_CALL_ACCEPTED: /* fast sel with no restr on resp */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 		if (x25->facilities.reverse & 0x80) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 			len += 1 + X25_MAX_FAC_LEN + X25_MAX_CUD_LEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 			len += 1 + X25_MAX_FAC_LEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	case X25_CLEAR_REQUEST:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	case X25_RESET_REQUEST:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 		len += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	case X25_RR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	case X25_RNR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	case X25_REJ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	case X25_CLEAR_CONFIRMATION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	case X25_INTERRUPT_CONFIRMATION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	case X25_RESET_CONFIRMATION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 		pr_err("invalid frame type %02X\n", frametype);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	 *	Space for Ethernet and 802.2 LLC headers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	skb_reserve(skb, X25_MAX_L2_LEN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	 *	Make space for the GFI and LCI, and fill them in.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	dptr = skb_put(skb, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	lci1 = (x25->lci >> 8) & 0x0F;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	lci2 = (x25->lci >> 0) & 0xFF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	if (x25->neighbour->extended) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 		*dptr++ = lci1 | X25_GFI_EXTSEQ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 		*dptr++ = lci2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 		*dptr++ = lci1 | X25_GFI_STDSEQ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		*dptr++ = lci2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	 *	Now fill in the frame type specific information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	switch (frametype) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 		case X25_CALL_REQUEST:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 			dptr    = skb_put(skb, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 			*dptr++ = X25_CALL_REQUEST;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 			len     = x25_addr_aton(addresses, &x25->dest_addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 						&x25->source_addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 			skb_put_data(skb, addresses, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 			len     = x25_create_facilities(facilities,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 					&x25->facilities,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 					&x25->dte_facilities,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 					x25->neighbour->global_facil_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 			skb_put_data(skb, facilities, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 			skb_put_data(skb, x25->calluserdata.cuddata,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 				     x25->calluserdata.cudlength);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 			x25->calluserdata.cudlength = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 		case X25_CALL_ACCEPTED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 			dptr    = skb_put(skb, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 			*dptr++ = X25_CALL_ACCEPTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 			*dptr++ = 0x00;		/* Address lengths */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 			len     = x25_create_facilities(facilities,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 							&x25->facilities,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 							&x25->dte_facilities,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 							x25->vc_facil_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 			skb_put_data(skb, facilities, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 			/* fast select with no restriction on response
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 				allows call user data. Userland must
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 				ensure it is ours and not theirs */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 			if(x25->facilities.reverse & 0x80) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 				skb_put_data(skb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 					     x25->calluserdata.cuddata,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 					     x25->calluserdata.cudlength);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 			x25->calluserdata.cudlength = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 		case X25_CLEAR_REQUEST:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 			dptr    = skb_put(skb, 3);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 			*dptr++ = frametype;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 			*dptr++ = x25->causediag.cause;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 			*dptr++ = x25->causediag.diagnostic;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 		case X25_RESET_REQUEST:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 			dptr    = skb_put(skb, 3);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 			*dptr++ = frametype;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 			*dptr++ = 0x00;		/* XXX */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 			*dptr++ = 0x00;		/* XXX */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 		case X25_RR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 		case X25_RNR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 		case X25_REJ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 			if (x25->neighbour->extended) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 				dptr     = skb_put(skb, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 				*dptr++  = frametype;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 				*dptr++  = (x25->vr << 1) & 0xFE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 			} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 				dptr     = skb_put(skb, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 				*dptr    = frametype;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 				*dptr++ |= (x25->vr << 5) & 0xE0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 		case X25_CLEAR_CONFIRMATION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 		case X25_INTERRUPT_CONFIRMATION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 		case X25_RESET_CONFIRMATION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 			dptr  = skb_put(skb, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 			*dptr = frametype;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 	x25_transmit_link(skb, x25->neighbour);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258)  *	Unpick the contents of the passed X.25 Packet Layer frame.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) int x25_decode(struct sock *sk, struct sk_buff *skb, int *ns, int *nr, int *q,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 	       int *d, int *m)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 	struct x25_sock *x25 = x25_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 	unsigned char *frame;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 		return X25_ILLEGAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 	frame = skb->data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	*ns = *nr = *q = *d = *m = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 	switch (frame[2]) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 	case X25_CALL_REQUEST:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 	case X25_CALL_ACCEPTED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 	case X25_CLEAR_REQUEST:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	case X25_CLEAR_CONFIRMATION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 	case X25_INTERRUPT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 	case X25_INTERRUPT_CONFIRMATION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 	case X25_RESET_REQUEST:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 	case X25_RESET_CONFIRMATION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	case X25_RESTART_REQUEST:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 	case X25_RESTART_CONFIRMATION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 	case X25_REGISTRATION_REQUEST:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 	case X25_REGISTRATION_CONFIRMATION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 	case X25_DIAGNOSTIC:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 		return frame[2];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 	if (x25->neighbour->extended) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 		if (frame[2] == X25_RR  ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 		    frame[2] == X25_RNR ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 		    frame[2] == X25_REJ) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 			if (!pskb_may_pull(skb, X25_EXT_MIN_LEN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 				return X25_ILLEGAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 			frame = skb->data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 			*nr = (frame[3] >> 1) & 0x7F;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 			return frame[2];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 		if ((frame[2] & 0x1F) == X25_RR  ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 		    (frame[2] & 0x1F) == X25_RNR ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 		    (frame[2] & 0x1F) == X25_REJ) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 			*nr = (frame[2] >> 5) & 0x07;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 			return frame[2] & 0x1F;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 	if (x25->neighbour->extended) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 		if ((frame[2] & 0x01) == X25_DATA) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 			if (!pskb_may_pull(skb, X25_EXT_MIN_LEN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 				return X25_ILLEGAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 			frame = skb->data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) 			*q  = (frame[0] & X25_Q_BIT) == X25_Q_BIT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 			*d  = (frame[0] & X25_D_BIT) == X25_D_BIT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) 			*m  = (frame[3] & X25_EXT_M_BIT) == X25_EXT_M_BIT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 			*nr = (frame[3] >> 1) & 0x7F;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 			*ns = (frame[2] >> 1) & 0x7F;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 			return X25_DATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 		if ((frame[2] & 0x01) == X25_DATA) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) 			*q  = (frame[0] & X25_Q_BIT) == X25_Q_BIT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 			*d  = (frame[0] & X25_D_BIT) == X25_D_BIT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) 			*m  = (frame[2] & X25_STD_M_BIT) == X25_STD_M_BIT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 			*nr = (frame[2] >> 5) & 0x07;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 			*ns = (frame[2] >> 1) & 0x07;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) 			return X25_DATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 	pr_debug("invalid PLP frame %3ph\n", frame);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 	return X25_ILLEGAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) void x25_disconnect(struct sock *sk, int reason, unsigned char cause,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 		    unsigned char diagnostic)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 	struct x25_sock *x25 = x25_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 	x25_clear_queues(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 	x25_stop_timer(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 	x25->lci   = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 	x25->state = X25_STATE_0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 	x25->causediag.cause      = cause;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 	x25->causediag.diagnostic = diagnostic;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) 	sk->sk_state     = TCP_CLOSE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) 	sk->sk_err       = reason;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 	sk->sk_shutdown |= SEND_SHUTDOWN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 	if (!sock_flag(sk, SOCK_DEAD)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) 		sk->sk_state_change(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) 		sock_set_flag(sk, SOCK_DEAD);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) 	if (x25->neighbour) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) 		read_lock_bh(&x25_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) 		x25_neigh_put(x25->neighbour);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) 		x25->neighbour = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) 		read_unlock_bh(&x25_list_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369)  * Clear an own-rx-busy condition and tell the peer about this, provided
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370)  * that there is a significant amount of free receive buffer space available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) void x25_check_rbuf(struct sock *sk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) 	struct x25_sock *x25 = x25_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) 	if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf >> 1) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) 	    (x25->condition & X25_COND_OWN_RX_BUSY)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) 		x25->condition &= ~X25_COND_OWN_RX_BUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) 		x25->condition &= ~X25_COND_ACK_PENDING;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) 		x25->vl         = x25->vr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) 		x25_write_internal(sk, X25_RR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) 		x25_stop_timer(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) }