diff options
Diffstat (limited to 'net/ax25/ax25_out.c')
-rw-r--r-- | net/ax25/ax25_out.c | 356 |
1 files changed, 45 insertions, 311 deletions
diff --git a/net/ax25/ax25_out.c b/net/ax25/ax25_out.c index 231c170e7..a222ad1e8 100644 --- a/net/ax25/ax25_out.c +++ b/net/ax25/ax25_out.c @@ -1,129 +1,74 @@ /* - * AX.25 release 037 + * ax25_out.c: Subroutines for outgoing packets * - * 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 028a Jonathan(G4KLX) New state machine based on SDL diagrams. - * AX.25 029 Alan(GW4PTS) Switched to KA9Q constant names. - * Jonathan(G4KLX) Only poll when window is full. - * AX.25 030 Jonathan(G4KLX) Added fragmentation to ax25_output. - * Added support for extended AX.25. - * AX.25 031 Joerg(DL1BKE) Added DAMA support - * Joerg(DL1BKE) Modified fragmenter to fragment vanilla - * AX.25 I-Frames. Added PACLEN parameter. - * Joerg(DL1BKE) Fixed a problem with buffer allocation - * for fragments. - * AX.25 037 Jonathan(G4KLX) New timer architecture. - * Joerg(DL1BKE) Fixed DAMA Slave mode: will work - * on non-DAMA interfaces like AX25L2V2 - * again (this behaviour is _required_). - * Joerg(DL1BKE) ax25_check_iframes_acked() returns a - * value now (for DAMA n2count handling) + * 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/config.h> -#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 <linux/netfilter.h> +#include <net/ax25.h> +#include <net/ax25dev.h> #include <net/sock.h> -#include <asm/uaccess.h> -#include <asm/system.h> -#include <linux/fcntl.h> -#include <linux/mm.h> -#include <linux/interrupt.h> -ax25_cb *ax25_send_frame(struct sk_buff *skb, int paclen, ax25_address *src, ax25_address *dest, ax25_digi *digi, struct net_device *dev) +#include "ax25_core.h" +#include "ax25_route.h" +#include "ax25_vj.h" +#include "ax25_ddi.h" +#include "ax25_subr.h" + +/* ---------------------------------------------------------------------*/ +/* + * send an iframe on a connection, maybe establish the connection first. + */ +ax25_cb *ax25_send_frame(struct sk_buff *skb, int paclen, ax25_addr_t *addr, struct net_device *dev) { - ax25_dev *ax25_dev; ax25_cb *ax25; - /* - * Take the default packet length for the device if zero is - * specified. - */ - if (paclen == 0) { - if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) - return NULL; - - paclen = ax25_dev->values[AX25_VALUES_PACLEN]; - } + if (paclen == 0) + paclen = ax25_dev_get_value(dev, AX25_VALUES_PACLEN); /* * Look for an existing connection. */ - if ((ax25 = ax25_find_cb(src, dest, digi, dev)) != NULL) { + if ((ax25 = ax25_find_cb(addr, dev)) != NULL) { + /* reuse a just disconnected control block */ + if (ax25->state == AX25_STATE_0 || ax25->state == AX25_STATE_2) { + if (ax25->slcomp) { + axhc_free(ax25->slcomp); + ax25->slcomp = NULL; + } + ax25->slcomp_enable = ax25_rt_mode_get(&addr->dest) == 'C'; + ax25_establish_data_link(ax25); + } ax25_output(ax25, paclen, skb); return ax25; /* It already existed */ } - if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) - return NULL; - if ((ax25 = ax25_create_cb()) == NULL) return NULL; - ax25_fillin_cb(ax25, ax25_dev); + ax25_fillin_cb(ax25, dev); - ax25->source_addr = *src; - ax25->dest_addr = *dest; - - if (digi != NULL) { - if ((ax25->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) { - ax25_free_cb(ax25); - return NULL; - } - memcpy(ax25->digipeat, digi, sizeof(ax25_digi)); - } - - switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) { - case AX25_PROTO_STD_SIMPLEX: - case AX25_PROTO_STD_DUPLEX: - ax25_std_establish_data_link(ax25); - break; - -#ifdef CONFIG_AX25_DAMA_SLAVE - case AX25_PROTO_DAMA_SLAVE: - if (ax25_dev->dama.slave) - ax25_ds_establish_data_link(ax25); - else - ax25_std_establish_data_link(ax25); - break; -#endif - } - - ax25_insert_socket(ax25); - - ax25->state = AX25_STATE_1; - - ax25_start_heartbeat(ax25); + ax25->addr = *addr; + ax25->slcomp_enable = ax25_rt_mode_get(&addr->dest) == 'C'; + ax25_establish_data_link(ax25); + ax25_insert_cb(ax25); ax25_output(ax25, paclen, skb); - return ax25; /* We had to create it */ } @@ -138,7 +83,6 @@ void ax25_output(ax25_cb *ax25, int paclen, struct sk_buff *skb) struct sk_buff *skbn; unsigned char *p; int frontlen, len, fragno, ka9qfrag, first = 1; - long flags; if ((skb->len - 1) > paclen) { if (*skb->data == AX25_P_TEXT) { @@ -155,11 +99,7 @@ void ax25_output(ax25_cb *ax25, int paclen, struct sk_buff *skb) frontlen = skb_headroom(skb); /* Address space + CTRL */ while (skb->len > 0) { - save_flags(flags); - cli(); - if ((skbn = alloc_skb(paclen + 2 + frontlen, GFP_ATOMIC)) == NULL) { - restore_flags(flags); printk(KERN_CRIT "AX.25: ax25_output - out of memory\n"); return; } @@ -167,13 +107,11 @@ void ax25_output(ax25_cb *ax25, int paclen, struct sk_buff *skb) if (skb->sk != NULL) skb_set_owner_w(skbn, skb->sk); - restore_flags(flags); - len = (paclen > skb->len) ? skb->len : paclen; if (ka9qfrag == 1) { skb_reserve(skbn, frontlen + 2); - skbn->nh.raw = skbn->data + (skb->nh.raw - skb->data); + memcpy(skb_put(skbn, len), skb->data, len); p = skb_push(skbn, 2); @@ -186,7 +124,6 @@ void ax25_output(ax25_cb *ax25, int paclen, struct sk_buff *skb) } } else { skb_reserve(skbn, frontlen + 1); - skbn->nh.raw = skbn->data + (skb->nh.raw - skb->data); memcpy(skb_put(skbn, len), skb->data, len); p = skb_push(skbn, 1); *p = AX25_P_TEXT; @@ -201,209 +138,6 @@ void ax25_output(ax25_cb *ax25, int paclen, struct sk_buff *skb) skb_queue_tail(&ax25->write_queue, skb); /* Throw it on the queue */ } - switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) { - case AX25_PROTO_STD_SIMPLEX: - case AX25_PROTO_STD_DUPLEX: - ax25_kick(ax25); - break; - -#ifdef CONFIG_AX25_DAMA_SLAVE - /* - * A DAMA slave is _required_ to work as normal AX.25L2V2 - * if no DAMA master is available. - */ - case AX25_PROTO_DAMA_SLAVE: - if (!ax25->ax25_dev->dama.slave) ax25_kick(ax25); - break; -#endif - } -} - -/* - * This procedure is passed a buffer descriptor for an iframe. It builds - * the rest of the control part of the frame and then writes it out. - */ -static void ax25_send_iframe(ax25_cb *ax25, struct sk_buff *skb, int poll_bit) -{ - unsigned char *frame; - - if (skb == NULL) - return; - - skb->nh.raw = skb->data; - - if (ax25->modulus == AX25_MODULUS) { - frame = skb_push(skb, 1); - - *frame = AX25_I; - *frame |= (poll_bit) ? AX25_PF : 0; - *frame |= (ax25->vr << 5); - *frame |= (ax25->vs << 1); - } else { - frame = skb_push(skb, 2); - - frame[0] = AX25_I; - frame[0] |= (ax25->vs << 1); - frame[1] = (poll_bit) ? AX25_EPF : 0; - frame[1] |= (ax25->vr << 1); - } - - ax25_start_idletimer(ax25); - - ax25_transmit_buffer(ax25, skb, AX25_COMMAND); -} - -void ax25_kick(ax25_cb *ax25) -{ - struct sk_buff *skb, *skbn; - int last = 1; - unsigned short start, end, next; - - if (ax25->state != AX25_STATE_3 && ax25->state != AX25_STATE_4) - return; - - if (ax25->condition & AX25_COND_PEER_RX_BUSY) - return; - - if (skb_peek(&ax25->write_queue) == NULL) - return; - - start = (skb_peek(&ax25->ack_queue) == NULL) ? ax25->va : ax25->vs; - end = (ax25->va + ax25->window) % ax25->modulus; - - if (start == end) - return; - - ax25->vs = start; - - /* - * Transmit data until either we're out of data to send or - * the window is full. Send a poll on the final I frame if - * the window is filled. - */ - - /* - * Dequeue the frame and copy it. - */ - skb = skb_dequeue(&ax25->write_queue); - - do { - if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) { - skb_queue_head(&ax25->write_queue, skb); - break; - } - - if (skb->sk != NULL) - skb_set_owner_w(skbn, skb->sk); - - next = (ax25->vs + 1) % ax25->modulus; - last = (next == end); - - /* - * Transmit the frame copy. - * bke 960114: do not set the Poll bit on the last frame - * in DAMA mode. - */ - switch (ax25->ax25_dev->values[AX25_VALUES_PROTOCOL]) { - case AX25_PROTO_STD_SIMPLEX: - case AX25_PROTO_STD_DUPLEX: - ax25_send_iframe(ax25, skbn, (last) ? AX25_POLLON : AX25_POLLOFF); - break; - -#ifdef CONFIG_AX25_DAMA_SLAVE - case AX25_PROTO_DAMA_SLAVE: - ax25_send_iframe(ax25, skbn, AX25_POLLOFF); - break; -#endif - } - - ax25->vs = next; - - /* - * Requeue the original data frame. - */ - skb_queue_tail(&ax25->ack_queue, skb); - - } while (!last && (skb = skb_dequeue(&ax25->write_queue)) != NULL); - - ax25->condition &= ~AX25_COND_ACK_PENDING; - - if (!ax25_t1timer_running(ax25)) { - ax25_stop_t3timer(ax25); - ax25_calculate_t1(ax25); - ax25_start_t1timer(ax25); - } -} - -void ax25_transmit_buffer(ax25_cb *ax25, struct sk_buff *skb, int type) -{ - struct sk_buff *skbn; - unsigned char *ptr; - int headroom; - - if (ax25->ax25_dev == NULL) { - ax25_disconnect(ax25, ENETUNREACH); - return; - } - - headroom = ax25_addr_size(ax25->digipeat); - - if (skb_headroom(skb) < headroom) { - if ((skbn = skb_realloc_headroom(skb, headroom)) == NULL) { - printk(KERN_CRIT "AX.25: ax25_transmit_buffer - out of memory\n"); - kfree_skb(skb); - return; - } - - if (skb->sk != NULL) - skb_set_owner_w(skbn, skb->sk); - - kfree_skb(skb); - skb = skbn; - } - - ptr = skb_push(skb, headroom); - - ax25_addr_build(ptr, &ax25->source_addr, &ax25->dest_addr, ax25->digipeat, type, ax25->modulus); - - skb->dev = ax25->ax25_dev->dev; - - ax25_queue_xmit(skb); -} - -/* - * A small shim to dev_queue_xmit to add the KISS control byte, and do - * any packet forwarding in operation. - */ -void ax25_queue_xmit(struct sk_buff *skb) -{ - unsigned char *ptr; - - skb->protocol = htons(ETH_P_AX25); - skb->dev = ax25_fwd_dev(skb->dev); - - ptr = skb_push(skb, 1); - *ptr = 0x00; /* KISS */ - - dev_queue_xmit(skb); -} - -int ax25_check_iframes_acked(ax25_cb *ax25, unsigned short nr) -{ - if (ax25->vs == nr) { - ax25_frames_acked(ax25, nr); - ax25_calculate_rtt(ax25); - ax25_stop_t1timer(ax25); - ax25_start_t3timer(ax25); - return 1; - } else { - if (ax25->va != nr) { - ax25_frames_acked(ax25, nr); - ax25_calculate_t1(ax25); - ax25_start_t1timer(ax25); - return 1; - } - } - return 0; + ax25_kick(ax25); } |