LXR linux/arch/um/drivers/slip

   1#include <string.h>
   2#include "slip_common.h"
   3#include <net_user.h>
   4
   5int slip_proto_read(int fd, void *buf, int len, struct slip_proto *slip)
   6{
   7        int i, n, size, start;
   8
   9        if(slip->more > 0){
  10                i = 0;
  11                while(i < slip->more){
  12                        size = slip_unesc(slip->ibuf[i++], slip->ibuf,
  13                                          &slip->pos, &slip->esc);
  14                        if(size){
  15                                memcpy(buf, slip->ibuf, size);
  16                                memmove(slip->ibuf, &slip->ibuf[i],
  17                                        slip->more - i);
  18                                slip->more = slip->more - i;
  19                                return size;
  20                        }
  21                }
  22                slip->more = 0;
  23        }
  24
  25        n = net_read(fd, &slip->ibuf[slip->pos],
  26                     sizeof(slip->ibuf) - slip->pos);
  27        if(n <= 0)
  28                return n;
  29
  30        start = slip->pos;
  31        for(i = 0; i < n; i++){
  32                size = slip_unesc(slip->ibuf[start + i], slip->ibuf,&slip->pos,
  33                                  &slip->esc);
  34                if(size){
  35                        memcpy(buf, slip->ibuf, size);
  36                        memmove(slip->ibuf, &slip->ibuf[start+i+1],
  37                                n - (i + 1));
  38                        slip->more = n - (i + 1);
  39                        return size;
  40                }
  41        }
  42        return 0;
  43}
  44
  45int slip_proto_write(int fd, void *buf, int len, struct slip_proto *slip)
  46{
  47        int actual, n;
  48
  49        actual = slip_esc(buf, slip->obuf, len);
  50        n = net_write(fd, slip->obuf, actual);
  51        if(n < 0)
  52                return n;
  53        else return len;
  54}
  55