rose_subr.c
上传用户:jlfgdled
上传日期:2013-04-10
资源大小:33168k
文件大小:13k
- /*
- * ROSE release 003
- *
- * This code REQUIRES 2.1.15 or higher/ NET3.038
- *
- * This module:
- * This module is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- *
- * History
- * ROSE 001 Jonathan(G4KLX) Cloned from nr_subr.c
- * ROSE 002 Jonathan(G4KLX) Centralised disconnect processing.
- * ROSE 003 Jonathan(G4KLX) Added use count to neighbours.
- */
- #include <linux/errno.h>
- #include <linux/types.h>
- #include <linux/socket.h>
- #include <linux/in.h>
- #include <linux/kernel.h>
- #include <linux/sched.h>
- #include <linux/timer.h>
- #include <linux/string.h>
- #include <linux/sockios.h>
- #include <linux/net.h>
- #include <net/ax25.h>
- #include <linux/inet.h>
- #include <linux/netdevice.h>
- #include <linux/skbuff.h>
- #include <net/sock.h>
- #include <asm/segment.h>
- #include <asm/system.h>
- #include <linux/fcntl.h>
- #include <linux/mm.h>
- #include <linux/interrupt.h>
- #include <net/rose.h>
- /*
- * This routine purges all of the queues of frames.
- */
- void rose_clear_queues(struct sock *sk)
- {
- skb_queue_purge(&sk->write_queue);
- skb_queue_purge(&sk->protinfo.rose->ack_queue);
- }
- /*
- * This routine purges the input queue of those frames that have been
- * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
- * SDL diagram.
- */
- void rose_frames_acked(struct sock *sk, unsigned short nr)
- {
- struct sk_buff *skb;
- /*
- * Remove all the ack-ed frames from the ack queue.
- */
- if (sk->protinfo.rose->va != nr) {
- while (skb_peek(&sk->protinfo.rose->ack_queue) != NULL && sk->protinfo.rose->va != nr) {
- skb = skb_dequeue(&sk->protinfo.rose->ack_queue);
- kfree_skb(skb);
- sk->protinfo.rose->va = (sk->protinfo.rose->va + 1) % ROSE_MODULUS;
- }
- }
- }
- void rose_requeue_frames(struct sock *sk)
- {
- struct sk_buff *skb, *skb_prev = NULL;
- /*
- * Requeue all the un-ack-ed frames on the output queue to be picked
- * up by rose_kick. This arrangement handles the possibility of an
- * empty output queue.
- */
- while ((skb = skb_dequeue(&sk->protinfo.rose->ack_queue)) != NULL) {
- if (skb_prev == NULL)
- skb_queue_head(&sk->write_queue, skb);
- else
- skb_append(skb_prev, skb);
- skb_prev = skb;
- }
- }
- /*
- * Validate that the value of nr is between va and vs. Return true or
- * false for testing.
- */
- int rose_validate_nr(struct sock *sk, unsigned short nr)
- {
- unsigned short vc = sk->protinfo.rose->va;
- while (vc != sk->protinfo.rose->vs) {
- if (nr == vc) return 1;
- vc = (vc + 1) % ROSE_MODULUS;
- }
- if (nr == sk->protinfo.rose->vs) return 1;
- return 0;
- }
- /*
- * This routine is called when the packet layer internally generates a
- * control frame.
- */
- void rose_write_internal(struct sock *sk, int frametype)
- {
- struct sk_buff *skb;
- unsigned char *dptr;
- unsigned char lci1, lci2;
- char buffer[100];
- int len, faclen = 0;
- int ax25_header_len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1;
- len = ax25_header_len + ROSE_MIN_LEN;
-
- switch (frametype) {
- case ROSE_CALL_REQUEST:
- len += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
- faclen = rose_create_facilities(buffer, sk->protinfo.rose);
- len += faclen;
- break;
- case ROSE_CALL_ACCEPTED:
- case ROSE_RESET_REQUEST:
- len += 2;
- break;
- case ROSE_CLEAR_REQUEST:
- len += 3;
- /* facilities */
- faclen = 3 + 2 + AX25_ADDR_LEN + 3 + ROSE_ADDR_LEN;
- dptr = buffer;
- *dptr++ = faclen-1; /* Facilities length */
- *dptr++ = 0;
- *dptr++ = FAC_NATIONAL;
- *dptr++ = FAC_NATIONAL_FAIL_CALL;
- *dptr++ = AX25_ADDR_LEN;
- memcpy(dptr, &rose_callsign, AX25_ADDR_LEN);
- dptr += AX25_ADDR_LEN;
- *dptr++ = FAC_NATIONAL_FAIL_ADD;
- *dptr++ = ROSE_ADDR_LEN + 1;
- *dptr++ = ROSE_ADDR_LEN * 2;
- memcpy(dptr, &sk->protinfo.rose->source_addr, ROSE_ADDR_LEN);
- len += faclen;
- break;
- }
- if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
- return;
- /*
- * Space for AX.25 header and PID.
- */
- skb_reserve(skb, ax25_header_len);
-
- dptr = skb_put(skb, len - ax25_header_len);
- lci1 = (sk->protinfo.rose->lci >> 8) & 0x0F;
- lci2 = (sk->protinfo.rose->lci >> 0) & 0xFF;
- switch (frametype) {
- case ROSE_CALL_REQUEST:
- *dptr++ = ROSE_GFI | lci1;
- *dptr++ = lci2;
- *dptr++ = frametype;
- *dptr++ = 0xAA;
- memcpy(dptr, &sk->protinfo.rose->dest_addr, ROSE_ADDR_LEN);
- dptr += ROSE_ADDR_LEN;
- memcpy(dptr, &sk->protinfo.rose->source_addr, ROSE_ADDR_LEN);
- dptr += ROSE_ADDR_LEN;
- memcpy(dptr, buffer, faclen);
- dptr += faclen;
- break;
- case ROSE_CALL_ACCEPTED:
- *dptr++ = ROSE_GFI | lci1;
- *dptr++ = lci2;
- *dptr++ = frametype;
- *dptr++ = 0x00; /* Address length */
- *dptr++ = 0; /* Facilities length */
- break;
- case ROSE_CLEAR_REQUEST:
- *dptr++ = ROSE_GFI | lci1;
- *dptr++ = lci2;
- *dptr++ = frametype;
- *dptr++ = sk->protinfo.rose->cause;
- *dptr++ = sk->protinfo.rose->diagnostic;
- *dptr++ = 0x00; /* Address length */
- memcpy(dptr, buffer, faclen);
- dptr += faclen;
- break;
- case ROSE_RESET_REQUEST:
- *dptr++ = ROSE_GFI | lci1;
- *dptr++ = lci2;
- *dptr++ = frametype;
- *dptr++ = ROSE_DTE_ORIGINATED;
- *dptr++ = 0;
- break;
- case ROSE_RR:
- case ROSE_RNR:
- *dptr++ = ROSE_GFI | lci1;
- *dptr++ = lci2;
- *dptr = frametype;
- *dptr++ |= (sk->protinfo.rose->vr << 5) & 0xE0;
- break;
- case ROSE_CLEAR_CONFIRMATION:
- case ROSE_RESET_CONFIRMATION:
- *dptr++ = ROSE_GFI | lci1;
- *dptr++ = lci2;
- *dptr++ = frametype;
- break;
- default:
- printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02Xn", frametype);
- kfree_skb(skb);
- return;
- }
- rose_transmit_link(skb, sk->protinfo.rose->neighbour);
- }
- int rose_decode(struct sk_buff *skb, int *ns, int *nr, int *q, int *d, int *m)
- {
- unsigned char *frame;
- frame = skb->data;
- *ns = *nr = *q = *d = *m = 0;
- switch (frame[2]) {
- case ROSE_CALL_REQUEST:
- case ROSE_CALL_ACCEPTED:
- case ROSE_CLEAR_REQUEST:
- case ROSE_CLEAR_CONFIRMATION:
- case ROSE_RESET_REQUEST:
- case ROSE_RESET_CONFIRMATION:
- return frame[2];
- default:
- break;
- }
- if ((frame[2] & 0x1F) == ROSE_RR ||
- (frame[2] & 0x1F) == ROSE_RNR) {
- *nr = (frame[2] >> 5) & 0x07;
- return frame[2] & 0x1F;
- }
- if ((frame[2] & 0x01) == ROSE_DATA) {
- *q = (frame[0] & ROSE_Q_BIT) == ROSE_Q_BIT;
- *d = (frame[0] & ROSE_D_BIT) == ROSE_D_BIT;
- *m = (frame[2] & ROSE_M_BIT) == ROSE_M_BIT;
- *nr = (frame[2] >> 5) & 0x07;
- *ns = (frame[2] >> 1) & 0x07;
- return ROSE_DATA;
- }
- return ROSE_ILLEGAL;
- }
- static int rose_parse_national(unsigned char *p, struct rose_facilities_struct *facilities, int len)
- {
- unsigned char *pt;
- unsigned char l, lg, n = 0;
- int fac_national_digis_received = 0;
- do {
- switch (*p & 0xC0) {
- case 0x00:
- p += 2;
- n += 2;
- len -= 2;
- break;
- case 0x40:
- if (*p == FAC_NATIONAL_RAND)
- facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF);
- p += 3;
- n += 3;
- len -= 3;
- break;
- case 0x80:
- p += 4;
- n += 4;
- len -= 4;
- break;
- case 0xC0:
- l = p[1];
- if (*p == FAC_NATIONAL_DEST_DIGI) {
- if (!fac_national_digis_received) {
- memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN);
- facilities->source_ndigis = 1;
- }
- }
- else if (*p == FAC_NATIONAL_SRC_DIGI) {
- if (!fac_national_digis_received) {
- memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN);
- facilities->dest_ndigis = 1;
- }
- }
- else if (*p == FAC_NATIONAL_FAIL_CALL) {
- memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN);
- }
- else if (*p == FAC_NATIONAL_FAIL_ADD) {
- memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN);
- }
- else if (*p == FAC_NATIONAL_DIGIS) {
- fac_national_digis_received = 1;
- facilities->source_ndigis = 0;
- facilities->dest_ndigis = 0;
- for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
- if (pt[6] & AX25_HBIT)
- memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
- else
- memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
- }
- }
- p += l + 2;
- n += l + 2;
- len -= l + 2;
- break;
- }
- } while (*p != 0x00 && len > 0);
- return n;
- }
- static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len)
- {
- unsigned char l, n = 0;
- char callsign[11];
- do {
- switch (*p & 0xC0) {
- case 0x00:
- p += 2;
- n += 2;
- len -= 2;
- break;
- case 0x40:
- p += 3;
- n += 3;
- len -= 3;
- break;
- case 0x80:
- p += 4;
- n += 4;
- len -= 4;
- break;
- case 0xC0:
- l = p[1];
- if (*p == FAC_CCITT_DEST_NSAP) {
- memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
- memcpy(callsign, p + 12, l - 10);
- callsign[l - 10] = '';
- facilities->source_call = *asc2ax(callsign);
- }
- if (*p == FAC_CCITT_SRC_NSAP) {
- memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN);
- memcpy(callsign, p + 12, l - 10);
- callsign[l - 10] = '';
- facilities->dest_call = *asc2ax(callsign);
- }
- p += l + 2;
- n += l + 2;
- len -= l + 2;
- break;
- }
- } while (*p != 0x00 && len > 0);
- return n;
- }
- int rose_parse_facilities(unsigned char *p, struct rose_facilities_struct *facilities)
- {
- int facilities_len, len;
- facilities_len = *p++;
- if (facilities_len == 0)
- return 0;
- while (facilities_len > 0) {
- if (*p == 0x00) {
- facilities_len--;
- p++;
- switch (*p) {
- case FAC_NATIONAL: /* National */
- len = rose_parse_national(p + 1, facilities, facilities_len - 1);
- facilities_len -= len + 1;
- p += len + 1;
- break;
- case FAC_CCITT: /* CCITT */
- len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
- facilities_len -= len + 1;
- p += len + 1;
- break;
- default:
- printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02Xn", *p);
- facilities_len--;
- p++;
- break;
- }
- }
- else break; /* Error in facilities format */
- }
- return 1;
- }
- int rose_create_facilities(unsigned char *buffer, rose_cb *rose)
- {
- unsigned char *p = buffer + 1;
- char *callsign;
- int len, nb;
- /* National Facilities */
- if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) {
- *p++ = 0x00;
- *p++ = FAC_NATIONAL;
- if (rose->rand != 0) {
- *p++ = FAC_NATIONAL_RAND;
- *p++ = (rose->rand >> 8) & 0xFF;
- *p++ = (rose->rand >> 0) & 0xFF;
- }
- /* Sent before older facilities */
- if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) {
- int maxdigi = 0;
- *p++ = FAC_NATIONAL_DIGIS;
- *p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis);
- for (nb = 0 ; nb < rose->source_ndigis ; nb++) {
- if (++maxdigi >= ROSE_MAX_DIGIS)
- break;
- memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN);
- p[6] |= AX25_HBIT;
- p += AX25_ADDR_LEN;
- }
- for (nb = 0 ; nb < rose->dest_ndigis ; nb++) {
- if (++maxdigi >= ROSE_MAX_DIGIS)
- break;
- memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN);
- p[6] &= ~AX25_HBIT;
- p += AX25_ADDR_LEN;
- }
- }
- /* For compatibility */
- if (rose->source_ndigis > 0) {
- *p++ = FAC_NATIONAL_SRC_DIGI;
- *p++ = AX25_ADDR_LEN;
- memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN);
- p += AX25_ADDR_LEN;
- }
- /* For compatibility */
- if (rose->dest_ndigis > 0) {
- *p++ = FAC_NATIONAL_DEST_DIGI;
- *p++ = AX25_ADDR_LEN;
- memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN);
- p += AX25_ADDR_LEN;
- }
- }
- *p++ = 0x00;
- *p++ = FAC_CCITT;
- *p++ = FAC_CCITT_DEST_NSAP;
- callsign = ax2asc(&rose->dest_call);
- *p++ = strlen(callsign) + 10;
- *p++ = (strlen(callsign) + 9) * 2; /* ??? */
- *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
- *p++ = ROSE_ADDR_LEN * 2;
- memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN);
- p += ROSE_ADDR_LEN;
- memcpy(p, callsign, strlen(callsign));
- p += strlen(callsign);
- *p++ = FAC_CCITT_SRC_NSAP;
- callsign = ax2asc(&rose->source_call);
- *p++ = strlen(callsign) + 10;
- *p++ = (strlen(callsign) + 9) * 2; /* ??? */
- *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
- *p++ = ROSE_ADDR_LEN * 2;
- memcpy(p, &rose->source_addr, ROSE_ADDR_LEN);
- p += ROSE_ADDR_LEN;
- memcpy(p, callsign, strlen(callsign));
- p += strlen(callsign);
- len = p - buffer;
- buffer[0] = len - 1;
- return len;
- }
- void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic)
- {
- rose_stop_timer(sk);
- rose_stop_idletimer(sk);
- rose_clear_queues(sk);
- sk->protinfo.rose->lci = 0;
- sk->protinfo.rose->state = ROSE_STATE_0;
- if (cause != -1)
- sk->protinfo.rose->cause = cause;
- if (diagnostic != -1)
- sk->protinfo.rose->diagnostic = diagnostic;
- sk->state = TCP_CLOSE;
- sk->err = reason;
- sk->shutdown |= SEND_SHUTDOWN;
- if (!sk->dead)
- sk->state_change(sk);
- sk->dead = 1;
- }