cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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nr_subr.c (5993B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *
      4 * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
      5 */
      6#include <linux/errno.h>
      7#include <linux/types.h>
      8#include <linux/socket.h>
      9#include <linux/in.h>
     10#include <linux/kernel.h>
     11#include <linux/timer.h>
     12#include <linux/string.h>
     13#include <linux/sockios.h>
     14#include <linux/net.h>
     15#include <linux/slab.h>
     16#include <net/ax25.h>
     17#include <linux/inet.h>
     18#include <linux/netdevice.h>
     19#include <linux/skbuff.h>
     20#include <net/sock.h>
     21#include <net/tcp_states.h>
     22#include <linux/uaccess.h>
     23#include <linux/fcntl.h>
     24#include <linux/mm.h>
     25#include <linux/interrupt.h>
     26#include <net/netrom.h>
     27
     28/*
     29 *	This routine purges all of the queues of frames.
     30 */
     31void nr_clear_queues(struct sock *sk)
     32{
     33	struct nr_sock *nr = nr_sk(sk);
     34
     35	skb_queue_purge(&sk->sk_write_queue);
     36	skb_queue_purge(&nr->ack_queue);
     37	skb_queue_purge(&nr->reseq_queue);
     38	skb_queue_purge(&nr->frag_queue);
     39}
     40
     41/*
     42 * This routine purges the input queue of those frames that have been
     43 * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
     44 * SDL diagram.
     45 */
     46void nr_frames_acked(struct sock *sk, unsigned short nr)
     47{
     48	struct nr_sock *nrom = nr_sk(sk);
     49	struct sk_buff *skb;
     50
     51	/*
     52	 * Remove all the ack-ed frames from the ack queue.
     53	 */
     54	if (nrom->va != nr) {
     55		while (skb_peek(&nrom->ack_queue) != NULL && nrom->va != nr) {
     56			skb = skb_dequeue(&nrom->ack_queue);
     57			kfree_skb(skb);
     58			nrom->va = (nrom->va + 1) % NR_MODULUS;
     59		}
     60	}
     61}
     62
     63/*
     64 * Requeue all the un-ack-ed frames on the output queue to be picked
     65 * up by nr_kick called from the timer. This arrangement handles the
     66 * possibility of an empty output queue.
     67 */
     68void nr_requeue_frames(struct sock *sk)
     69{
     70	struct sk_buff *skb, *skb_prev = NULL;
     71
     72	while ((skb = skb_dequeue(&nr_sk(sk)->ack_queue)) != NULL) {
     73		if (skb_prev == NULL)
     74			skb_queue_head(&sk->sk_write_queue, skb);
     75		else
     76			skb_append(skb_prev, skb, &sk->sk_write_queue);
     77		skb_prev = skb;
     78	}
     79}
     80
     81/*
     82 *	Validate that the value of nr is between va and vs. Return true or
     83 *	false for testing.
     84 */
     85int nr_validate_nr(struct sock *sk, unsigned short nr)
     86{
     87	struct nr_sock *nrom = nr_sk(sk);
     88	unsigned short vc = nrom->va;
     89
     90	while (vc != nrom->vs) {
     91		if (nr == vc) return 1;
     92		vc = (vc + 1) % NR_MODULUS;
     93	}
     94
     95	return nr == nrom->vs;
     96}
     97
     98/*
     99 *	Check that ns is within the receive window.
    100 */
    101int nr_in_rx_window(struct sock *sk, unsigned short ns)
    102{
    103	struct nr_sock *nr = nr_sk(sk);
    104	unsigned short vc = nr->vr;
    105	unsigned short vt = (nr->vl + nr->window) % NR_MODULUS;
    106
    107	while (vc != vt) {
    108		if (ns == vc) return 1;
    109		vc = (vc + 1) % NR_MODULUS;
    110	}
    111
    112	return 0;
    113}
    114
    115/*
    116 *  This routine is called when the HDLC layer internally generates a
    117 *  control frame.
    118 */
    119void nr_write_internal(struct sock *sk, int frametype)
    120{
    121	struct nr_sock *nr = nr_sk(sk);
    122	struct sk_buff *skb;
    123	unsigned char  *dptr;
    124	int len, timeout;
    125
    126	len = NR_NETWORK_LEN + NR_TRANSPORT_LEN;
    127
    128	switch (frametype & 0x0F) {
    129	case NR_CONNREQ:
    130		len += 17;
    131		break;
    132	case NR_CONNACK:
    133		len += (nr->bpqext) ? 2 : 1;
    134		break;
    135	case NR_DISCREQ:
    136	case NR_DISCACK:
    137	case NR_INFOACK:
    138		break;
    139	default:
    140		printk(KERN_ERR "NET/ROM: nr_write_internal - invalid frame type %d\n", frametype);
    141		return;
    142	}
    143
    144	if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
    145		return;
    146
    147	/*
    148	 *	Space for AX.25 and NET/ROM network header
    149	 */
    150	skb_reserve(skb, NR_NETWORK_LEN);
    151
    152	dptr = skb_put(skb, skb_tailroom(skb));
    153
    154	switch (frametype & 0x0F) {
    155	case NR_CONNREQ:
    156		timeout  = nr->t1 / HZ;
    157		*dptr++  = nr->my_index;
    158		*dptr++  = nr->my_id;
    159		*dptr++  = 0;
    160		*dptr++  = 0;
    161		*dptr++  = frametype;
    162		*dptr++  = nr->window;
    163		memcpy(dptr, &nr->user_addr, AX25_ADDR_LEN);
    164		dptr[6] &= ~AX25_CBIT;
    165		dptr[6] &= ~AX25_EBIT;
    166		dptr[6] |= AX25_SSSID_SPARE;
    167		dptr    += AX25_ADDR_LEN;
    168		memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN);
    169		dptr[6] &= ~AX25_CBIT;
    170		dptr[6] &= ~AX25_EBIT;
    171		dptr[6] |= AX25_SSSID_SPARE;
    172		dptr    += AX25_ADDR_LEN;
    173		*dptr++  = timeout % 256;
    174		*dptr++  = timeout / 256;
    175		break;
    176
    177	case NR_CONNACK:
    178		*dptr++ = nr->your_index;
    179		*dptr++ = nr->your_id;
    180		*dptr++ = nr->my_index;
    181		*dptr++ = nr->my_id;
    182		*dptr++ = frametype;
    183		*dptr++ = nr->window;
    184		if (nr->bpqext) *dptr++ = sysctl_netrom_network_ttl_initialiser;
    185		break;
    186
    187	case NR_DISCREQ:
    188	case NR_DISCACK:
    189		*dptr++ = nr->your_index;
    190		*dptr++ = nr->your_id;
    191		*dptr++ = 0;
    192		*dptr++ = 0;
    193		*dptr++ = frametype;
    194		break;
    195
    196	case NR_INFOACK:
    197		*dptr++ = nr->your_index;
    198		*dptr++ = nr->your_id;
    199		*dptr++ = 0;
    200		*dptr++ = nr->vr;
    201		*dptr++ = frametype;
    202		break;
    203	}
    204
    205	nr_transmit_buffer(sk, skb);
    206}
    207
    208/*
    209 * This routine is called to send an error reply.
    210 */
    211void __nr_transmit_reply(struct sk_buff *skb, int mine, unsigned char cmdflags)
    212{
    213	struct sk_buff *skbn;
    214	unsigned char *dptr;
    215	int len;
    216
    217	len = NR_NETWORK_LEN + NR_TRANSPORT_LEN + 1;
    218
    219	if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL)
    220		return;
    221
    222	skb_reserve(skbn, 0);
    223
    224	dptr = skb_put(skbn, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
    225
    226	skb_copy_from_linear_data_offset(skb, 7, dptr, AX25_ADDR_LEN);
    227	dptr[6] &= ~AX25_CBIT;
    228	dptr[6] &= ~AX25_EBIT;
    229	dptr[6] |= AX25_SSSID_SPARE;
    230	dptr += AX25_ADDR_LEN;
    231
    232	skb_copy_from_linear_data(skb, dptr, AX25_ADDR_LEN);
    233	dptr[6] &= ~AX25_CBIT;
    234	dptr[6] |= AX25_EBIT;
    235	dptr[6] |= AX25_SSSID_SPARE;
    236	dptr += AX25_ADDR_LEN;
    237
    238	*dptr++ = sysctl_netrom_network_ttl_initialiser;
    239
    240	if (mine) {
    241		*dptr++ = 0;
    242		*dptr++ = 0;
    243		*dptr++ = skb->data[15];
    244		*dptr++ = skb->data[16];
    245	} else {
    246		*dptr++ = skb->data[15];
    247		*dptr++ = skb->data[16];
    248		*dptr++ = 0;
    249		*dptr++ = 0;
    250	}
    251
    252	*dptr++ = cmdflags;
    253	*dptr++ = 0;
    254
    255	if (!nr_route_frame(skbn, NULL))
    256		kfree_skb(skbn);
    257}
    258
    259void nr_disconnect(struct sock *sk, int reason)
    260{
    261	nr_stop_t1timer(sk);
    262	nr_stop_t2timer(sk);
    263	nr_stop_t4timer(sk);
    264	nr_stop_idletimer(sk);
    265
    266	nr_clear_queues(sk);
    267
    268	nr_sk(sk)->state = NR_STATE_0;
    269
    270	sk->sk_state     = TCP_CLOSE;
    271	sk->sk_err       = reason;
    272	sk->sk_shutdown |= SEND_SHUTDOWN;
    273
    274	if (!sock_flag(sk, SOCK_DEAD)) {
    275		sk->sk_state_change(sk);
    276		sock_set_flag(sk, SOCK_DEAD);
    277	}
    278}