ubuntu-linux-kernel/arch/um/drivers/slip_common.c

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2024-04-01 15:06:58 +00:00
// SPDX-License-Identifier: GPL-2.0
#include <string.h>
#include "slip_common.h"
#include <net_user.h>
int slip_proto_read(int fd, void *buf, int len, struct slip_proto *slip)
{
int i, n, size, start;
if(slip->more > 0){
i = 0;
while(i < slip->more){
size = slip_unesc(slip->ibuf[i++], slip->ibuf,
&slip->pos, &slip->esc);
if(size){
memcpy(buf, slip->ibuf, size);
memmove(slip->ibuf, &slip->ibuf[i],
slip->more - i);
slip->more = slip->more - i;
return size;
}
}
slip->more = 0;
}
n = net_read(fd, &slip->ibuf[slip->pos],
sizeof(slip->ibuf) - slip->pos);
if(n <= 0)
return n;
start = slip->pos;
for(i = 0; i < n; i++){
size = slip_unesc(slip->ibuf[start + i], slip->ibuf,&slip->pos,
&slip->esc);
if(size){
memcpy(buf, slip->ibuf, size);
memmove(slip->ibuf, &slip->ibuf[start+i+1],
n - (i + 1));
slip->more = n - (i + 1);
return size;
}
}
return 0;
}
int slip_proto_write(int fd, void *buf, int len, struct slip_proto *slip)
{
int actual, n;
actual = slip_esc(buf, slip->obuf, len);
n = net_write(fd, slip->obuf, actual);
if(n < 0)
return n;
else return len;
}