/*
* fds_select_check
*
* given an fd_set that has been passed to select, as well as a list of
* fds that are being monitored, figure out which ones have an event and
* use the callback provided to deal with the event.
*/
static void fds_select_check(fd_set *fdset, dlist_t *fds, int *count)
{
scamper_fd_poll_t *fdp;
dlist_node_t *node;
/* stop now if there is nothing to check */
if(fdset == NULL || *count == 0)
{
return;
}
/* nodes in this list should not be removed while this function is called */
dlist_lock(fds);
/* loop through */
node = dlist_head_node(fds);
while(node != NULL && *count > 0)
{
fdp = (scamper_fd_poll_t *)dlist_node_item(node);
node = dlist_node_next(node);
if(FD_ISSET(fdp->fdn->fd, fdset))
{
fdp->cb(fdp->fdn->fd, fdp->param);
(*count)--;
}
}
/* can modify the list now */
dlist_unlock(fds);
return;
}
/*
* fds_select_assemble
*
* given a list of scamper_fd_poll_t structures held in a list, compose an
* fd_set for them to pass to select.
*/
static fd_set *fds_select_assemble(dlist_t *fds, fd_set *fdset, int *nfds)
{
scamper_fd_poll_t *fdp;
dlist_node_t *node;
int count = 0;
FD_ZERO(fdset);
node = dlist_head_node(fds);
while(node != NULL)
{
/* file descriptor associated with the node */
fdp = (scamper_fd_poll_t *)dlist_node_item(node);
/* get the next node incase this node is subsequently removed */
node = dlist_node_next(node);
/* if there is nothing using this fdn any longer, then stop polling it */
if(fdp->fdn->refcnt == 0 && fdp->fdn->rc0 == NULL)
{
fd_refcnt_0(fdp->fdn);
continue;
}
/* if the inactive flag is set, then skip over this file descriptor */
if((fdp->flags & SCAMPER_FD_POLL_FLAG_INACTIVE) != 0)
{
dlist_node_eject(fds, fdp->node);
fdp->list = NULL;
continue;
}
/* monitor this file descriptor */
FD_SET(fdp->fdn->fd, fdset);
count++;
/* update the maxfd seen if appropriate */
if(*nfds < fdp->fdn->fd)
{
*nfds = fdp->fdn->fd;
}
}
/*
* if there are no fds in the set to monitor, then return a null pointer
* to pass to select
*/
if(count == 0)
{
return NULL;
}
return fdset;
}
static rtsock_pair_t *rtsock_pair_get(uint16_t seq)
{
rtsock_pair_t *pair;
dlist_node_t *node;
for(node=dlist_head_node(pairs); node != NULL; node=dlist_node_next(node))
{
pair = dlist_node_item(node);
if(pair->seq != seq)
continue;
dlist_node_pop(pairs, node);
pair->node = NULL;
return pair;
}
return NULL;
}
static void sniff_check(scamper_dl_rec_t *dl)
{
scamper_task_sig_t *sig;
s2t_t *s2t;
dlist_node_t *n;
scamper_addr_t src;
uint16_t id;
if(dlist_count(sniff) <= 0)
return;
if(SCAMPER_DL_IS_ICMP_ECHO_REPLY(dl))
id = dl->dl_icmp_id;
else if(SCAMPER_DL_IS_ICMP_Q_ICMP_ECHO(dl))
id = dl->dl_icmp_icmp_id;
else
return;
if(SCAMPER_DL_IS_IPV4(dl))
src.type = SCAMPER_ADDR_TYPE_IPV4;
else if(SCAMPER_DL_IS_IPV6(dl))
src.type = SCAMPER_ADDR_TYPE_IPV6;
else
return;
src.addr = dl->dl_ip_dst;
for(n = dlist_head_node(sniff); n != NULL; n = dlist_node_next(n))
{
s2t = dlist_node_item(n); sig = s2t->sig;
if(sig->sig_sniff_icmp_id != id)
continue;
if(scamper_addr_cmp(sig->sig_sniff_src, &src) != 0)
continue;
if(s2t->task->funcs->handle_dl != NULL)
s2t->task->funcs->handle_dl(s2t->task, dl);
}
return;
}
static int fds_poll(struct timeval *tv)
{
scamper_fd_t *fd;
dlist_node_t *n;
int timeout;
int rc, count = 0, in = 0, out = 0;
size_t size;
n = dlist_head_node(fd_list);
while(n != NULL)
{
fd = dlist_node_item(n);
n = dlist_node_next(n);
/* if there is nothing using this fdn any longer, then stop polling it */
if(fd->refcnt == 0 && fd->rc0 == NULL)
{
fd_refcnt_0(fd);
continue;
}
/* don't poll an inactive fd */
if((fd->read.flags & SCAMPER_FD_POLL_FLAG_INACTIVE) != 0 &&
(fd->write.flags & SCAMPER_FD_POLL_FLAG_INACTIVE) != 0)
continue;
if(count + 1 > poll_fdc)
{
size = (count+1) * sizeof(struct pollfd);
if(realloc_wrap((void **)&poll_fds, size) != 0)
{
printerror(errno,strerror,__func__,"could not realloc poll_fds");
return -1;
}
poll_fdc = count + 1;
}
poll_fds[count].fd = fd->fd;
poll_fds[count].events = 0;
poll_fds[count].revents = 0;
if((fd->read.flags & SCAMPER_FD_POLL_FLAG_INACTIVE) == 0)
{
poll_fds[count].events |= POLLIN;
in++;
}
if((fd->write.flags & SCAMPER_FD_POLL_FLAG_INACTIVE) == 0)
{
poll_fds[count].events |= POLLOUT;
out++;
}
count++;
}
if(tv != NULL)
{
timeout = (tv->tv_sec * 1000) + (tv->tv_usec / 1000);
if(timeout == 0 && tv->tv_usec != 0)
timeout++;
}
else
{
timeout = -1;
}
if((rc = poll(poll_fds, count, timeout)) < 0)
{
printerror(errno, strerror, __func__, "could not poll");
return -1;
}
if(rc > 0)
{
if(in != 0)
fds_poll_check(POLLIN, rc < in ? rc : in, count);
if(out != 0)
fds_poll_check(POLLOUT, rc < out ? rc : out, count);
}
return 0;
}