-/* write.c
- * Linux CAN-bus device driver.
- * Written by Arnaud Westenberg email:arnaud@wanadoo.nl
- * Rewritten for new CAN queues by Pavel Pisa - OCERA team member
- * email:pisa@cmp.felk.cvut.cz
- * This software is released under the GPL-License.
- * Version lincan-0.2 9 Jul 2003
- */
+/**************************************************************************/
+/* File: write.c - systemcall to send messages through driver FIFOs */
+/* */
+/* LinCAN - (Not only) Linux CAN bus driver */
+/* Copyright (C) 2002-2009 DCE FEE CTU Prague <http://dce.felk.cvut.cz> */
+/* Copyright (C) 2002-2009 Pavel Pisa <pisa@cmp.felk.cvut.cz> */
+/* Funded by OCERA and FRESCOR IST projects */
+/* Based on CAN driver code by Arnaud Westenberg <arnaud@wanadoo.nl> */
+/* */
+/* LinCAN is free software; you can redistribute it and/or modify it */
+/* under terms of the GNU General Public License as published by the */
+/* Free Software Foundation; either version 2, or (at your option) any */
+/* later version. LinCAN is distributed in the hope that it will be */
+/* useful, but WITHOUT ANY WARRANTY; without even the implied warranty */
+/* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU */
+/* General Public License for more details. You should have received a */
+/* copy of the GNU General Public License along with LinCAN; see file */
+/* COPYING. If not, write to the Free Software Foundation, 675 Mass Ave, */
+/* Cambridge, MA 02139, USA. */
+/* */
+/* To allow use of LinCAN in the compact embedded systems firmware */
+/* and RT-executives (RTEMS for example), main authors agree with next */
+/* special exception: */
+/* */
+/* Including LinCAN header files in a file, instantiating LinCAN generics */
+/* or templates, or linking other files with LinCAN objects to produce */
+/* an application image/executable, does not by itself cause the */
+/* resulting application image/executable to be covered by */
+/* the GNU General Public License. */
+/* This exception does not however invalidate any other reasons */
+/* why the executable file might be covered by the GNU Public License. */
+/* Publication of enhanced or derived LinCAN files is required although. */
+/**************************************************************************/
#include "../include/can.h"
#include "../include/can_sysdep.h"
#include "../include/main.h"
+#include "../include/write.h"
ssize_t can_write(struct file *file, const char *buffer, size_t length, loff_t *offset)
{
struct canque_ends_t *qends;
struct canque_edge_t *qedge;
struct canque_slot_t *slot;
- int ret = 0;
- int bytes_to_copy = 0;
+ int ret;
+ unsigned bytes_to_copy;
if(!canuser || (canuser->magic != CAN_USER_MAGIC)){
- CANMSG("can_close: bad canuser magic\n");
+ CANMSG("can_write: bad canuser magic\n");
return -ENODEV;
}
DEBUGMSG("this will always return 0 !\n");
return 0;
}
- if (length > 8 * sizeof(struct canmsg_t)) {
+ if (length > INT_MAX) {
CANMSG("Trying to write more than is supported.\n");
return -1;
}
CANMSG("The number of bytes requested to be written is not a multiple of\n");
CANMSG("'sizeof(struct canmsg_t)', currently this is not allowed.\n");
return -1;
- }
+ }
/* Initialize hardware pointers */
obj = canuser->msgobj;
/* Prepare first message */
- copy_from_user(&msg_buff, buffer, sizeof(struct canmsg_t));
- /* Automatic selection of extended format if "extended" set and ID>2047 */
- if (extended) if (msg_buff.id & ~0x7ffl ) msg_buff.flags |= MSG_EXT;
+ ret = copy_from_user(&msg_buff, buffer, sizeof(struct canmsg_t));
+ if(ret) return -EFAULT;
+
+ /* Automatic selection of extended format if ID>2047 */
+ if (msg_buff.id & ~0x7ffl & MSG_ID_MASK ) msg_buff.flags |= MSG_EXT;
+ /* has been dependent on "extended" option */
/* If the output buffer is full, return immediately in case O_NONBLOCK
* has been specified or loop until space becomes available.
*/
- if ((ret=canque_get_inslot4id(qends, &qedge, &slot,
+ if ((ret=canque_get_inslot4id(qends, &qedge, &slot,
0, msg_buff.id, 0))<0){
DEBUGMSG("Buffer is full\n");
if(ret < -1)
if (file->f_flags & O_NONBLOCK)
return -EAGAIN;
- ret=canque_get_inslot4id_wait_kern(qends, &qedge, &slot,
+ ret=canque_get_inslot4id_wait_kern(qends, &qedge, &slot,
0, msg_buff.id, 0);
if(ret<0) {
if (signal_pending(current))
buffer += sizeof(struct canmsg_t);
bytes_to_copy = length-sizeof(struct canmsg_t);
- /*
+ /*
* Try to send more messages
*/
- while (bytes_to_copy > 0) {
+ while (bytes_to_copy >= sizeof(struct canmsg_t)) {
+ bytes_to_copy -= sizeof(struct canmsg_t);
/* Prepare first message */
- copy_from_user(&msg_buff, buffer, sizeof(struct canmsg_t));
- /* Automatic selection of extended format if "extended" set and ID>2047 */
- if (extended) if (msg_buff.id & ~0x7ffl ) msg_buff.flags |= MSG_EXT;
+ ret = copy_from_user(&msg_buff, buffer, sizeof(struct canmsg_t));
+ if(ret) return -EFAULT;
+
+ /* Automatic selection of extended format if ID>2047 */
+ if (msg_buff.id & ~0x7ffl & MSG_ID_MASK ) msg_buff.flags |= MSG_EXT;
+ /* has been dependent on "extended" option */
+
/* Get slot */
- if(canque_get_inslot4id(qends, &qedge, &slot,
+ if(canque_get_inslot4id(qends, &qedge, &slot,
0, msg_buff.id, 0) < 0) break;
slot->msg=msg_buff;
canque_put_inslot(qends, qedge, slot);
buffer += sizeof(struct canmsg_t);
- bytes_to_copy -= sizeof(struct canmsg_t);
}
if(file->f_flags & O_SYNC) {
canque_sync_wait_kern(qends, qedge);
}
return length-bytes_to_copy;
-}
+}