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root/net/rose/rose_subr.c

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DEFINITIONS

This source file includes following definitions.
  1. rose_clear_queues
  2. rose_frames_acked
  3. rose_requeue_frames
  4. rose_validate_nr
  5. rose_write_internal
  6. rose_decode
  7. rose_parse_national
  8. rose_parse_ccitt
  9. rose_parse_facilities
  10. rose_create_facilities
  11. rose_disconnect

/*
 * This program 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.
 *
 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
 */
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.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 <net/tcp_states.h>
#include <asm/system.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <net/rose.h>

static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose);

/*
 *      This routine purges all of the queues of frames.
 */
void rose_clear_queues(struct sock *sk)
{
        skb_queue_purge(&sk->sk_write_queue);
        skb_queue_purge(&rose_sk(sk)->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;
        struct rose_sock *rose = rose_sk(sk);

        /*
         * Remove all the ack-ed frames from the ack queue.
         */
        if (rose->va != nr) {
                while (skb_peek(&rose->ack_queue) != NULL && rose->va != nr) {
                        skb = skb_dequeue(&rose->ack_queue);
                        kfree_skb(skb);
                        rose->va = (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(&rose_sk(sk)->ack_queue)) != NULL) {
                if (skb_prev == NULL)
                        skb_queue_head(&sk->sk_write_queue, skb);
                else
                        skb_append(skb_prev, skb, &sk->sk_write_queue);
                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)
{
        struct rose_sock *rose = rose_sk(sk);
        unsigned short vc = rose->va;

        while (vc != rose->vs) {
                if (nr == vc) return 1;
                vc = (vc + 1) % ROSE_MODULUS;
        }

        return nr == rose->vs;
}

/*
 *  This routine is called when the packet layer internally generates a
 *  control frame.
 */
void rose_write_internal(struct sock *sk, int frametype)
{
        struct rose_sock *rose = rose_sk(sk);
        struct sk_buff *skb;
        unsigned char  *dptr;
        unsigned char  lci1, lci2;
        char buffer[100];
        int len, faclen = 0;

        len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;

        switch (frametype) {
        case ROSE_CALL_REQUEST:
                len   += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
                faclen = rose_create_facilities(buffer, rose);
                len   += faclen;
                break;
        case ROSE_CALL_ACCEPTED:
        case ROSE_CLEAR_REQUEST:
        case ROSE_RESET_REQUEST:
                len   += 2;
                break;
        }

        if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
                return;

        /*
         *      Space for AX.25 header and PID.
         */
        skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1);

        dptr = skb_put(skb, skb_tailroom(skb));

        lci1 = (rose->lci >> 8) & 0x0F;
        lci2 = (rose->lci >> 0) & 0xFF;

        switch (frametype) {
        case ROSE_CALL_REQUEST:
                *dptr++ = ROSE_GFI | lci1;
                *dptr++ = lci2;
                *dptr++ = frametype;
                *dptr++ = 0xAA;
                memcpy(dptr, &rose->dest_addr,  ROSE_ADDR_LEN);
                dptr   += ROSE_ADDR_LEN;
                memcpy(dptr, &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++ = rose->cause;
                *dptr++ = rose->diagnostic;
                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++ |= (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 %02X\n", frametype);
                kfree_skb(skb);
                return;
        }

        rose_transmit_link(skb, 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] = '\0';
                                asc2ax(&facilities->source_call, 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] = '\0';
                                asc2ax(&facilities->dest_call, 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 %02X\n", *p);
                                facilities_len--;
                                p++;
                                break;
                        }
                } else
                        break;  /* Error in facilities format */
        }

        return 1;
}

static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose)
{
        unsigned char *p = buffer + 1;
        char *callsign;
        char buf[11];
        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(buf, &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(buf, &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)
{
        struct rose_sock *rose = rose_sk(sk);

        rose_stop_timer(sk);
        rose_stop_idletimer(sk);

        rose_clear_queues(sk);

        rose->lci   = 0;
        rose->state = ROSE_STATE_0;

        if (cause != -1)
                rose->cause = cause;

        if (diagnostic != -1)
                rose->diagnostic = diagnostic;

        sk->sk_state     = TCP_CLOSE;
        sk->sk_err       = reason;
        sk->sk_shutdown |= SEND_SHUTDOWN;

        if (!sock_flag(sk, SOCK_DEAD)) {
                sk->sk_state_change(sk);
                sock_set_flag(sk, SOCK_DEAD);
        }
}

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