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#include <u.h>
#include <libc.h>
#include <fcall.h>
#include <fs.h>
#include "plumb.h"
static Fsys *fsplumb;
static int pfd = -1;
static Fid *pfid;
int
plumbopen(char *name, int omode)
{
if(fsplumb == nil)
fsplumb = nsmount("plumb", "");
if(fsplumb == nil)
return -1;
/*
* It's important that when we send something,
* we find out whether it was a valid plumb write.
* (If it isn't, the client might fall back to some
* other mechanism or indicate to the user what happened.)
* We can't use a pipe for this, so we have to use the
* fid interface. But we need to return a fd.
* Return a fd for /dev/null so that we return a unique
* file descriptor. In plumbsend we'll look for pfd
* and use the recorded fid instead.
*/
if((omode&3) == OWRITE){
if(pfd != -1){
werrstr("already have plumb send open");
return -1;
}
pfd = open("/dev/null", OWRITE);
if(pfd < 0)
return -1;
pfid = fsopen(fsplumb, name, omode);
if(pfid == nil){
close(pfd);
pfd = -1;
return -1;
}
return pfd;
}
return fsopenfd(fsplumb, name, omode);
}
Fid*
plumbopenfid(char *name, int mode)
{
if(fsplumb == nil)
fsplumb = nsmount("plumb", "");
if(fsplumb == nil)
return nil;
return fsopen(fsplumb, name, mode);
}
int
plumbsendtofid(Fid *fid, Plumbmsg *m)
{
char *buf;
int n;
if(fid == nil){
werrstr("invalid fid");
return -1;
}
buf = plumbpack(m, &n);
if(buf == nil)
return -1;
n = fswrite(fid, buf, n);
free(buf);
return n;
}
int
plumbsend(int fd, Plumbmsg *m)
{
if(fd == -1){
werrstr("invalid fd");
return -1;
}
if(fd != pfd){
werrstr("fd is not the plumber");
return -1;
}
return plumbsendtofid(pfid, m);
}
Plumbmsg*
plumbrecv(int fd)
{
char *buf;
Plumbmsg *m;
int n, more;
buf = malloc(8192);
if(buf == nil)
return nil;
n = read(fd, buf, 8192);
m = nil;
if(n > 0){
m = plumbunpackpartial(buf, n, &more);
if(m==nil && more>0){
/* we now know how many more bytes to read for complete message */
buf = realloc(buf, n+more);
if(buf == nil)
return nil;
if(readn(fd, buf+n, more) == more)
m = plumbunpackpartial(buf, n+more, nil);
}
}
free(buf);
return m;
}
Plumbmsg*
plumbrecvfid(Fid *fid)
{
char *buf;
Plumbmsg *m;
int n, more;
buf = malloc(8192);
if(buf == nil)
return nil;
n = fsread(fid, buf, 8192);
m = nil;
if(n > 0){
m = plumbunpackpartial(buf, n, &more);
if(m==nil && more>0){
/* we now know how many more bytes to read for complete message */
buf = realloc(buf, n+more);
if(buf == nil)
return nil;
if(fsreadn(fid, buf+n, more) == more)
m = plumbunpackpartial(buf, n+more, nil);
}
}
free(buf);
return m;
}
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