diff options
Diffstat (limited to 'net/ax25/ax25_subr.c')
| -rw-r--r-- | net/ax25/ax25_subr.c | 388 |
1 files changed, 144 insertions, 244 deletions
diff --git a/net/ax25/ax25_subr.c b/net/ax25/ax25_subr.c index 669789646..f8700bd8f 100644 --- a/net/ax25/ax25_subr.c +++ b/net/ax25/ax25_subr.c @@ -1,223 +1,77 @@ /* - * AX.25 release 037 + * ax25_subr.c: Subroutines for NEW-AX.25 state machine * - * This code REQUIRES 2.1.15 or higher/ NET3.038 + * Authors: Jens David (DG1KJD), Matthias Welwarsky (DG2FEF), Jonathan (G4KL + * Alan Cox (GW4PTS), Joerg (DL1BKE), et al * - * 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. + * Comment: Most of this code is based on the SDL diagrams published in the + * ARRL Computer Networking Conference papers. The diagrams have mi + * in them, but are mostly correct. Before you modify the code coul + * read the SDL diagrams as the code is not obvious and probably ve + * easy to break; * - * Most of this code is based on the SDL diagrams published in the 7th - * ARRL Computer Networking Conference papers. The diagrams have mistakes - * in them, but are mostly correct. Before you modify the code could you - * read the SDL diagrams as the code is not obvious and probably very - * easy to break; + * Changelog: * - * History - * AX.25 029 Alan(GW4PTS) Switched to KA9Q constant names. Removed - * old BSD code. - * AX.25 030 Jonathan(G4KLX) Added support for extended AX.25. - * Added fragmentation support. - * Darryl(G7LED) Added function ax25_requeue_frames() to split - * it up from ax25_frames_acked(). - * AX.25 031 Joerg(DL1BKE) DAMA needs KISS Fullduplex ON/OFF. - * Thus we have ax25_kiss_cmd() now... ;-) - * Dave Brown(N2RJT) - * Killed a silly bug in the DAMA code. - * Joerg(DL1BKE) Found the real bug in ax25.h, sri. - * AX.25 032 Joerg(DL1BKE) Added ax25_queue_length to count the number of - * enqueued buffers of a socket.. - * AX.25 035 Frederic(F1OAT) Support for pseudo-digipeating. - * AX.25 037 Jonathan(G4KLX) New timer architecture. + * License: 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. */ -#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/uaccess.h> -#include <asm/system.h> -#include <linux/fcntl.h> +#include <linux/tcp.h> #include <linux/mm.h> -#include <linux/interrupt.h> +#include <net/sock.h> +#include <net/ax25.h> +#include <net/ax25dev.h> + +#include "ax25_ddi.h" +#include "ax25_in.h" +#include "ax25_subr.h" +#include "ax25_core.h" +#include "ax25_vj.h" +#include "ax25_timer.h" /* * This routine purges all the queues of frames. */ void ax25_clear_queues(ax25_cb *ax25) { - struct sk_buff *skb; - - while ((skb = skb_dequeue(&ax25->write_queue)) != NULL) - kfree_skb(skb); + int i; - while ((skb = skb_dequeue(&ax25->ack_queue)) != NULL) - kfree_skb(skb); + skb_queue_purge(&ax25->frag_queue); + skb_queue_purge(&ax25->rcv_queue); + skb_queue_purge(&ax25->write_queue); + skb_queue_purge(&ax25->ack_queue); - while ((skb = skb_dequeue(&ax25->reseq_queue)) != NULL) - kfree_skb(skb); + for (i = 0; i <= AX25_SEQMASK; i++) { + struct sk_buff *skb; - while ((skb = skb_dequeue(&ax25->frag_queue)) != NULL) - kfree_skb(skb); -} - -/* - * 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 ax25_frames_acked(ax25_cb *ax25, unsigned short nr) -{ - struct sk_buff *skb; - - /* - * Remove all the ack-ed frames from the ack queue. - */ - if (ax25->va != nr) { - while (skb_peek(&ax25->ack_queue) != NULL && ax25->va != nr) { - skb = skb_dequeue(&ax25->ack_queue); + if ((skb = ax25->reseq[i].skb) != NULL) { + ax25->reseq[i].skb = NULL; + ax25->reseq[i].csum = 0; kfree_skb(skb); - ax25->va = (ax25->va + 1) % ax25->modulus; } } } -void ax25_requeue_frames(ax25_cb *ax25) -{ - struct sk_buff *skb, *skb_prev = NULL; - - /* - * Requeue all the un-ack-ed frames on the output queue to be picked - * up by ax25_kick called from the timer. This arrangement handles the - * possibility of an empty output queue. - */ - while ((skb = skb_dequeue(&ax25->ack_queue)) != NULL) { - if (skb_prev == NULL) - skb_queue_head(&ax25->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. + * this is new */ -int ax25_validate_nr(ax25_cb *ax25, unsigned short nr) +void ax25_tx_command(ax25_cb *ax25, int frametype, int poll_bit) { - unsigned short vc = ax25->va; - - while (vc != ax25->vs) { - if (nr == vc) return 1; - vc = (vc + 1) % ax25->modulus; - } - - if (nr == ax25->vs) return 1; - - return 0; + if (poll_bit) + frametype |= 0x100; + ax25->tx_cmd = frametype; + ax25_kick(ax25); } -/* - * This routine is the centralised routine for parsing the control - * information for the different frame formats. - */ -int ax25_decode(ax25_cb *ax25, struct sk_buff *skb, int *ns, int *nr, int *pf) +void ax25_tx_response(ax25_cb *ax25, int frametype, int poll_bit) { - unsigned char *frame; - int frametype = AX25_ILLEGAL; - - frame = skb->data; - *ns = *nr = *pf = 0; - - if (ax25->modulus == AX25_MODULUS) { - if ((frame[0] & AX25_S) == 0) { - frametype = AX25_I; /* I frame - carries NR/NS/PF */ - *ns = (frame[0] >> 1) & 0x07; - *nr = (frame[0] >> 5) & 0x07; - *pf = frame[0] & AX25_PF; - } else if ((frame[0] & AX25_U) == 1) { /* S frame - take out PF/NR */ - frametype = frame[0] & 0x0F; - *nr = (frame[0] >> 5) & 0x07; - *pf = frame[0] & AX25_PF; - } else if ((frame[0] & AX25_U) == 3) { /* U frame - take out PF */ - frametype = frame[0] & ~AX25_PF; - *pf = frame[0] & AX25_PF; - } - skb_pull(skb, 1); - } else { - if ((frame[0] & AX25_S) == 0) { - frametype = AX25_I; /* I frame - carries NR/NS/PF */ - *ns = (frame[0] >> 1) & 0x7F; - *nr = (frame[1] >> 1) & 0x7F; - *pf = frame[1] & AX25_EPF; - skb_pull(skb, 2); - } else if ((frame[0] & AX25_U) == 1) { /* S frame - take out PF/NR */ - frametype = frame[0] & 0x0F; - *nr = (frame[1] >> 1) & 0x7F; - *pf = frame[1] & AX25_EPF; - skb_pull(skb, 2); - } else if ((frame[0] & AX25_U) == 3) { /* U frame - take out PF */ - frametype = frame[0] & ~AX25_PF; - *pf = frame[0] & AX25_PF; - skb_pull(skb, 1); - } - } - - return frametype; -} - -/* - * This routine is called when the HDLC layer internally generates a - * command or response for the remote machine ( eg. RR, UA etc. ). - * Only supervisory or unnumbered frames are processed. - */ -void ax25_send_control(ax25_cb *ax25, int frametype, int poll_bit, int type) -{ - struct sk_buff *skb; - unsigned char *dptr; - - if ((skb = alloc_skb(AX25_BPQ_HEADER_LEN + ax25_addr_size(ax25->digipeat) + 2, GFP_ATOMIC)) == NULL) - return; - - skb_reserve(skb, AX25_BPQ_HEADER_LEN + ax25_addr_size(ax25->digipeat)); - - skb->nh.raw = skb->data; - - /* Assume a response - address structure for DTE */ - if (ax25->modulus == AX25_MODULUS) { - dptr = skb_put(skb, 1); - *dptr = frametype; - *dptr |= (poll_bit) ? AX25_PF : 0; - if ((frametype & AX25_U) == AX25_S) /* S frames carry NR */ - *dptr |= (ax25->vr << 5); - } else { - if ((frametype & AX25_U) == AX25_U) { - dptr = skb_put(skb, 1); - *dptr = frametype; - *dptr |= (poll_bit) ? AX25_PF : 0; - } else { - dptr = skb_put(skb, 2); - dptr[0] = frametype; - dptr[1] = (ax25->vr << 1); - dptr[1] |= (poll_bit) ? AX25_EPF : 0; - } - } - - ax25_transmit_buffer(ax25, skb, type); + if (poll_bit) + frametype |= 0x100; + ax25->tx_rsp = frametype; + ax25_kick(ax25); } /* @@ -225,44 +79,39 @@ void ax25_send_control(ax25_cb *ax25, int frametype, int poll_bit, int type) * * Note: src here is the sender, thus it's the target of the DM */ -void ax25_return_dm(struct net_device *dev, ax25_address *src, ax25_address *dest, ax25_digi *digi) +void ax25_return_dm(struct net_device *dev, ax25_pktinfo *pkt) { struct sk_buff *skb; - char *dptr; - ax25_digi retdigi; + unsigned char *dptr; + int sizeof_addr; + ax25_addr_t addr; - if (dev == NULL) - return; + sizeof_addr = ax25_sizeof_addr(&pkt->addr); - if ((skb = alloc_skb(AX25_BPQ_HEADER_LEN + ax25_addr_size(digi) + 1, GFP_ATOMIC)) == NULL) + if ((skb = alloc_skb(AX25_BPQ_HEADER_LEN + sizeof_addr + 1, GFP_ATOMIC)) == NULL) return; /* Next SABM will get DM'd */ - skb_reserve(skb, AX25_BPQ_HEADER_LEN + ax25_addr_size(digi)); - skb->nh.raw = skb->data; - - ax25_digi_invert(digi, &retdigi); - - dptr = skb_put(skb, 1); + skb_reserve(skb, AX25_BPQ_HEADER_LEN + sizeof_addr); + ax25_invert_addr(&pkt->addr, &addr); - *dptr = AX25_DM | AX25_PF; + *skb_put(skb, 1) = AX25_DM|AX25_PF; /* * Do the address ourselves */ - dptr = skb_push(skb, ax25_addr_size(digi)); - dptr += ax25_addr_build(dptr, dest, src, &retdigi, AX25_RESPONSE, AX25_MODULUS); - - skb->dev = dev; - - ax25_queue_xmit(skb); + skb->nh.raw = skb->data; + dptr = skb_push(skb, sizeof_addr); + dptr += ax25_build_addr(dptr, &addr, AX25_RESPONSE, AX25_SEQMASK); + ax25_send_unproto(skb, dev); } /* * Exponential backoff for AX.25 */ -void ax25_calculate_t1(ax25_cb *ax25) +unsigned short ax25_calculate_t1(ax25_cb *ax25) { - int n, t = 2; + int n; + int t = 1; switch (ax25->backoff) { case 0: @@ -273,52 +122,103 @@ void ax25_calculate_t1(ax25_cb *ax25) break; case 2: - for (n = 0; n < ax25->n2count; n++) - t *= 2; - if (t > 8) t = 8; + t <<= (ax25->n2count < 8 ? ax25->n2count : 8); break; } - ax25->t1 = t * ax25->rtt; -} + n = (t * ax25->rtt); -/* - * Calculate the Round Trip Time - */ -void ax25_calculate_rtt(ax25_cb *ax25) -{ - if (ax25->backoff == 0) - return; + if (n > AX25_T1CLAMPHI) + return AX25_T1CLAMPHI; - if (ax25_t1timer_running(ax25) && ax25->n2count == 0) - ax25->rtt = (9 * ax25->rtt + ax25->t1 - ax25_display_timer(&ax25->t1timer)) / 10; + if (n < AX25_T1CLAMPLO) + return AX25_T1CLAMPLO; - if (ax25->rtt < AX25_T1CLAMPLO) - ax25->rtt = AX25_T1CLAMPLO; + return n; +} - if (ax25->rtt > AX25_T1CLAMPHI) - ax25->rtt = AX25_T1CLAMPHI; +void ax25_close_socket(struct sock *sk, int reason) +{ + sk->err = reason; + sk->shutdown = SHUTDOWN_MASK; + sk->state = TCP_CLOSE; + sk->state_change(sk); + sk->dead = 1; } void ax25_disconnect(ax25_cb *ax25, int reason) { ax25_clear_queues(ax25); + ax25_link_failed(ax25, reason); + write_lock(&ax25->timer_lock); + ax25->wrt_timer = 0; + ax25->ack_timer = 0; + ax25->idletimer = 0; + ax25->vs = 0; + ax25->va = 0; + ax25->vr = 0; + ax25->vl = 0; + ax25->killtimer = 90 * AX25_SLOWHZ; + ax25->state = AX25_STATE_0; + write_unlock(&ax25->timer_lock); + if (ax25->peer && ax25->peer->state > AX25_STATE_2) + ax25_set_cond(ax25->peer, AX25_COND_RELEASE); + if (ax25->slcomp) { + axhc_free(ax25->slcomp); + ax25->slcomp = NULL; + } +} - ax25_stop_t1timer(ax25); - ax25_stop_t2timer(ax25); - ax25_stop_t3timer(ax25); - ax25_stop_idletimer(ax25); +void ax25_nr_error_recovery(ax25_cb *ax25) +{ + if (ax25->peer != NULL) + ax25->peer->condition |= AX25_COND_RELEASE; - ax25->state = AX25_STATE_0; + ax25_clear_queues(ax25); + ax25_start_t1(ax25); + ax25->state = AX25_STATE_2; + ax25_tx_command(ax25, AX25_DISC, AX25_POLLON); +} - ax25_link_failed(ax25, reason); +void ax25_establish_data_link(ax25_cb *ax25) +{ + ax25->timer_lock= RW_LOCK_UNLOCKED; + ax25->state = AX25_STATE_1; + ax25->n2count = 0; + ax25->ack_timer = 0; + ax25->vs = 0; + ax25->va = 0; + ax25->vr = 0; + ax25->vl = 0; + ax25_set_cond(ax25, AX25_COND_SETUP); + ax25_start_t1(ax25); + + if (ax25->seqmask == AX25_SEQMASK) + ax25_tx_command(ax25, AX25_SABM, AX25_POLLON); + else + ax25_tx_command(ax25, AX25_SABME, AX25_POLLON); - if (ax25->sk != NULL) { - ax25->sk->state = TCP_CLOSE; - ax25->sk->err = reason; - ax25->sk->shutdown |= SEND_SHUTDOWN; - if (!ax25->sk->dead) - ax25->sk->state_change(ax25->sk); - ax25->sk->dead = 1; - } +} + +void ax25_transmit_enquiry(ax25_cb *ax25) +{ + int ft = (ax25->condition & AX25_COND_OWN_RX_BUSY) ? AX25_RNR:AX25_RR; + ax25_tx_command(ax25, ft, AX25_POLLON); + ax25_start_t1(ax25); + ax25_clr_cond(ax25, AX25_COND_ACK_PENDING); + if (DAMA_STATE(ax25) & DAMA_SLAVE) AX25_PTR(ax25->device)->dama_polled = 1; +} + +void ax25_enquiry_response(ax25_cb *ax25) +{ + int ft = (ax25->condition & AX25_COND_OWN_RX_BUSY) ? AX25_RNR:AX25_RR; + ax25_tx_response(ax25, ft, AX25_POLLON); + ax25_clr_cond(ax25, AX25_COND_ACK_PENDING); +} + +void ax25_timeout_response(ax25_cb *ax25) +{ + int ft = (ax25->condition & AX25_COND_OWN_RX_BUSY) ? AX25_RNR:AX25_RR; + ax25_tx_response(ax25, ft, AX25_POLLOFF); + ax25_clr_cond(ax25, AX25_COND_ACK_PENDING); } |