arch/um/drivers/slip_common.c

   1 #include <string.h>
   2 #include "slip_common.h"
   3 #include "net_user.h"
   4
   5 int 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
  45 int 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 }