/*
* The port_close_fd() function dissociates a file descriptor from a port
* and removes all allocated resources.
* close(2) detects in the uf_entry_t structure that the fd is associated
* with a port (at least one port).
* The fd can be associated with several ports.
*/
void
port_close_pfd(portfd_t *pfd)
{
port_t *pp;
port_fdcache_t *pcp;
/*
* the portfd_t passed in should be for this proc.
*/
ASSERT(curproc->p_pid == PFTOD(pfd)->pd_portev->portkev_pid);
pp = PFTOD(pfd)->pd_portev->portkev_port;
pcp = pp->port_queue.portq_pcp;
mutex_enter(&pcp->pc_lock);
(void) port_remove_fd_object(pfd, pp, pcp);
mutex_exit(&pcp->pc_lock);
}
/*
* The port_dissociate_fd() function dissociates the delivered file
* descriptor from the event port and removes already fired events.
* If a fd is shared between processes, all involved processes will get
* the same rights related to re-association of the fd with the port and
* retrieve of events from that fd.
* The process which associated the fd with a port for the first time
* becomes also the owner of the association. Only the owner of the
* association is allowed to dissociate the fd from the port.
*/
int
port_dissociate_fd(port_t *pp, uintptr_t object)
{
int fd;
port_fdcache_t *pcp;
portfd_t *pfd;
file_t *fp;
if (object > (uintptr_t)INT_MAX)
return (EBADFD);
fd = object;
pcp = pp->port_queue.portq_pcp;
mutex_enter(&pcp->pc_lock);
if (pcp->pc_hash == NULL) {
/* no file descriptor cache available */
mutex_exit(&pcp->pc_lock);
return (0);
}
if ((fp = getf(fd)) == NULL) {
mutex_exit(&pcp->pc_lock);
return (EBADFD);
}
pfd = port_cache_lookup_fp(pcp, fd, fp);
if (pfd == NULL) {
releasef(fd);
mutex_exit(&pcp->pc_lock);
return (0);
}
/* only association owner is allowed to remove the association */
if (curproc->p_pid != PFTOD(pfd)->pd_portev->portkev_pid) {
releasef(fd);
mutex_exit(&pcp->pc_lock);
return (EACCES);
}
/* remove port from the file descriptor interested list */
delfd_port(fd, pfd);
releasef(fd);
/* remove polldat & port event structure */
port_remove_fd_object(pfd, pp, pcp);
mutex_exit(&pcp->pc_lock);
return (0);
}
/*
* The port_remove_portfd() function dissociates the port from the fd
* and vive versa.
*/
static void
port_remove_portfd(polldat_t *pdp, port_fdcache_t *pcp)
{
port_t *pp;
file_t *fp;
ASSERT(MUTEX_HELD(&pcp->pc_lock));
pp = pdp->pd_portev->portkev_port;
fp = getf(pdp->pd_fd);
/*
* If we did not get the fp for pd_fd but its portfd_t
* still exist in the cache, it means the pd_fd is being
* closed by some other thread which will also free the portfd_t.
*/
if (fp != NULL) {
delfd_port(pdp->pd_fd, PDTOF(pdp));
releasef(pdp->pd_fd);
port_remove_fd_object(PDTOF(pdp), pp, pcp);
}
}
