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#include <u.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <assert.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <msg.h> /* ../include/msg.h */
/* NOTE: msg_flatten and msg_init need to remain in sync.
* Preferably the msg_flatten and msg_init functions of different
* versions should still be able to talk to one another, i.e. the
* message protocol on the wire should stay the same.
off bytes value
0 2 0xfeed (cookie)
2 2 message type
4 4 total message length (len)
8 2 message id
10 2 window id
12 4 r.p0
16 4 r.p1
20 2 flag
22 len-22 null-terminated utf string
*/
enum {
HEADERSIZE = 22,
COOKIE = 0xfeed,
DEBUG=0
};
static ushort get2(uchar*);
static ulong get4(uchar*);
static void put2(uchar*, ushort);
static void put4(uchar*, ulong);
void
msg_fill(Msg*m, Mtype t, Id w, Range r, ushort flag, char*s) {
m->t = t;
m->w = w;
m->r = r;
m->flag = flag;
m->s = s;
}
/* Return number of bytes which would be needed to
* flatten 'm'
*/
int
msg_size(Msg *m)
{
assert(m);
return HEADERSIZE + 1 + (m->s? strlen(m->s) : 0);
}
/* Flatten 'm' into 'buf', which has at least msg_size(m) bytes of space.
*/
void
msg_flatten
(Msg*m, uchar*buf)
{
if(DEBUG) {
printf("flattening ");
msg_print(m);
}
put2(buf, COOKIE);
put2(buf+2, m->t);
put4(buf+4, msg_size(m));
put2(buf+8, m->m);
put2(buf+10, m->w);
put4(buf+12, m->r.p0);
put4(buf+16, m->r.p1);
put2(buf+20, m->flag);
strcpy(buf+22, m->s?m->s:"");
}
/* Fill in the fields of 'm', using 'buf', which has 'size' bytes.
* PRE: at least msg_bufsize() bytes in 'buf'
*
* POST: m's fields are filled in. m.s points to a null-terminated
* string WITHIN BUF. We return 0.
* If there was some internal inconsistency, we return -1, and
* the contents of 'm' are undefined.
*
* WARNING: We may point to a string inside 'buf', rather than
* copying it. This means you should not free 'buf' until you've
* finished with 'm'.
*/
int
msg_init (Msg*m, uchar*buf)
{
ulong len;
len = get4(buf+4);
if (get2(buf)!=COOKIE || len<HEADERSIZE) {
return -1;
}
m->t = get2(buf+2);
m->m = get2(buf+8);
m->w = get2(buf+10);
m->r.p0 = get4(buf+12);
m->r.p1 = get4(buf+16);
m->flag = get2(buf+20);
m->s = buf+22;
buf[len-1]='\0'; /* ENSURE m->s is null-terminated */
if(DEBUG) {
printf("initialized ");
msg_print(m);
}
return 0;
}
/* Return number of bytes needed for the complete message,
* of which the beginning is in the buffer. There must be
* at least 8 bytes in the buffer already, or we get garbage.
*/
ulong
msg_bufsize (uchar*buf)
{
return get4(buf+4);
}
void
msg_print(Msg *m)
{
printf("(");
switch(m->t) {
case WRerror : printf("(WRerror"); break;
case WMlist : printf("WMlist"); break;
case WRlist : printf("WRlist"); break;
case WMnew : printf("WMnew"); break;
case WRnew : printf("WRnew"); break;
case WMattach : printf("WMattach"); break;
case WRattach : printf("WRattach"); break;
case WMsetname : printf("WMsetname"); break;
case WMgetname : printf("WMgetname"); break;
case WRsetname : printf("WRsetname"); break;
case WRgetname : printf("WRgetname"); break;
case WMsettools : printf("WMsettools"); break;
case WMgettools : printf("WMgettools"); break;
case WRsettools : printf("WRsettools"); break;
case WRgettools : printf("WRgettools"); break;
case WMread : printf("WMread"); break;
case WRread : printf("WRread"); break;
case WMreplace : printf("WMreplace"); break;
case WRreplace : printf("WRreplace"); break;
case WMexec : printf("WMexec"); break;
case WRexec : printf("WRexec"); break;
case WMgoto : printf("WMgoto"); break;
case WRgoto : printf("WRgoto"); break;
case WMfencepost : printf("WMfencepost"); break;
case WEexec : printf("WEexec"); break;
case WEreplace : printf("WEreplace"); break;
case WEgoto : printf("WEgoto"); break;
case WEdestroy : printf("WEdestroy"); break;
case WEfencepost : printf("WEfencepost"); break;
default : printf("Unknown"); break;
}
printf(", %d", m->m);
printf(", %d", m->w);
printf(", %d", m->flag);
printf(", (%lu,%lu)", m->r.p0, m->r.p1);
printf(", [%s]) ", m->s?m->s:"");
}
static ushort
get2(uchar*p)
{
return (p[0]<<8) + p[1];
}
static ulong
get4(uchar*p)
{
return (p[0]<<24) + (p[1]<<16) + (p[2]<<8) + p[3];
}
static void
put2(uchar*p, ushort n)
{
p[0] = (n>>8)&0xff;
p[1] = n &0xff;
}
static void
put4(uchar*p, ulong n)
{
p[0] = (n>>24)&0xff;
p[1] = (n>>16)&0xff;
p[2] = (n>>8)&0xff;
p[3] = (n)&0xff;
}
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