linux/net/ax25/ax25_out.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* Copyright (C) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
* Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
*/
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/spinlock.h>
#include <linux/net.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/uaccess.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
static DEFINE_SPINLOCK(ax25_frag_lock);
ax25_cb *ax25_send_frame(struct sk_buff *skb, int paclen, const ax25_address *src, ax25_address *dest, ax25_digi *digi, 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];
}
/*
* Look for an existing connection.
*/
if ((ax25 = ax25_find_cb(src, dest, digi, dev)) != NULL) {
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->source_addr = *src;
ax25->dest_addr = *dest;
if (digi != NULL) {
ax25->digipeat = kmemdup(digi, sizeof(*digi), GFP_ATOMIC);
if (ax25->digipeat == NULL) {
ax25_cb_put(ax25);
return NULL;
}
}
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
}
/*
* There is one ref for the state machine; a caller needs
* one more to put it back, just like with the existing one.
*/
ax25_cb_hold(ax25);
ax25_cb_add(ax25);
ax25->state = AX25_STATE_1;
ax25_start_heartbeat(ax25);
ax25_output(ax25, paclen, skb);
return ax25; /* We had to create it */
}
EXPORT_SYMBOL(ax25_send_frame);
/*
* All outgoing AX.25 I frames pass via this routine. Therefore this is
* where the fragmentation of frames takes place. If fragment is set to
* zero then we are not allowed to do fragmentation, even if the frame
* is too large.
*/
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;
if (paclen < 16) {
WARN_ON_ONCE(1);
kfree_skb(skb);
return;
}
if ((skb->len - 1) > paclen) {
if (*skb->data == AX25_P_TEXT) {
skb_pull(skb, 1); /* skip PID */
ka9qfrag = 0;
} else {
paclen -= 2; /* Allow for fragment control info */
ka9qfrag = 1;
}
fragno = skb->len / paclen;
if (skb->len % paclen == 0) fragno--;
frontlen = skb_headroom(skb); /* Address space + CTRL */
while (skb->len > 0) {
spin_lock_bh(&ax25_frag_lock);
if ((skbn = alloc_skb(paclen + 2 + frontlen, GFP_ATOMIC)) == NULL) {
spin_unlock_bh(&ax25_frag_lock);
printk(KERN_CRIT "AX.25: ax25_output - out of memory\n");
return;
}
if (skb->sk != NULL)
skb_set_owner_w(skbn, skb->sk);
spin_unlock_bh(&ax25_frag_lock);
len = (paclen > skb->len) ? skb->len : paclen;
if (ka9qfrag == 1) {
skb_reserve(skbn, frontlen + 2);
skb_set_network_header(skbn,
skb_network_offset(skb));
skb_copy_from_linear_data(skb, skb_put(skbn, len), len);
p = skb_push(skbn, 2);
*p++ = AX25_P_SEGMENT;
*p = fragno--;
if (first) {
*p |= AX25_SEG_FIRST;
first = 0;
}
} else {
skb_reserve(skbn, frontlen + 1);
skb_set_network_header(skbn,
skb_network_offset(skb));
skb_copy_from_linear_data(skb, skb_put(skbn, len), len);
p = skb_push(skbn, 1);
*p = AX25_P_TEXT;
}
skb_pull(skb, len);
skb_queue_tail(&ax25->write_queue, skbn); /* Throw it on the queue */
}
kfree_skb(skb);
} else {
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_reset_network_header(skb);
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;
/*
* 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.
* Check for race with ax25_clear_queues().
*/
skb = skb_dequeue(&ax25->write_queue);
if (!skb)
return;
ax25->vs = start;
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)
{
unsigned char *ptr;
int headroom;
if (ax25->ax25_dev == NULL) {
ax25_disconnect(ax25, ENETUNREACH);
return;
}
headroom = ax25_addr_size(ax25->digipeat);
if (unlikely(skb_headroom(skb) < headroom)) {
skb = skb_expand_head(skb, headroom);
if (!skb) {
printk(KERN_CRIT "AX.25: ax25_transmit_buffer - out of memory\n");
return;
}
}
ptr = skb_push(skb, headroom);
ax25_addr_build(ptr, &ax25->source_addr, &ax25->dest_addr, ax25->digipeat, type, ax25->modulus);
ax25_queue_xmit(skb, ax25->ax25_dev->dev);
}
/*
* 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, struct net_device *dev)
{
unsigned char *ptr;
skb->protocol = ax25_type_trans(skb, ax25_fwd_dev(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;
}