/**************************************************************************
write wrapper function -vasc
**************************************************************************/
static int write_socket_data(struct connection *pc,
struct socket_packet_buffer *buf, int limit)
{
int start, nput, nblock;
if (is_server() && pc->server.is_closing) {
return 0;
}
for (start=0; buf->ndata-start>limit;) {
fd_set writefs, exceptfs;
struct timeval tv;
FC_FD_ZERO(&writefs);
FC_FD_ZERO(&exceptfs);
FD_SET(pc->sock, &writefs);
FD_SET(pc->sock, &exceptfs);
tv.tv_sec = 0; tv.tv_usec = 0;
if (fc_select(pc->sock+1, NULL, &writefs, &exceptfs, &tv) <= 0) {
if (errno != EINTR) {
break;
} else {
/* EINTR can happen sometimes, especially when compiling with -pg.
* Generally we just want to run select again. */
continue;
}
}
if (FD_ISSET(pc->sock, &exceptfs)) {
connection_close(pc, _("network exception"));
return -1;
}
if (FD_ISSET(pc->sock, &writefs)) {
nblock=MIN(buf->ndata-start, MAX_LEN_PACKET);
log_debug("trying to write %d limit=%d", nblock, limit);
if((nput=fc_writesocket(pc->sock,
(const char *)buf->data+start, nblock)) == -1) {
#ifdef NONBLOCKING_SOCKETS
if (errno == EWOULDBLOCK || errno == EAGAIN) {
break;
}
#endif
connection_close(pc, _("lagging connection"));
return -1;
}
start += nput;
}
}
if (start > 0) {
buf->ndata -= start;
memmove(buf->data, buf->data+start, buf->ndata);
pc->last_write = timer_renew(pc->last_write, TIMER_USER, TIMER_ACTIVE);
timer_start(pc->last_write);
}
return 0;
}
/****************************************************************************
A wrapper around read_socket_data() which also handles the case the
socket becomes writeable and there is still data which should be sent
to the server.
Returns:
-1 : an error occurred - you should close the socket
-2 : the connection was closed
>0 : number of bytes read
=0 : no data read, would block
****************************************************************************/
static int read_from_connection(struct connection *pc, bool block)
{
for (;;) {
fd_set readfs, writefs, exceptfs;
int socket_fd = pc->sock;
bool have_data_for_server = (pc->used && pc->send_buffer
&& 0 < pc->send_buffer->ndata);
int n;
struct timeval tv;
tv.tv_sec = 0;
tv.tv_usec = 0;
FC_FD_ZERO(&readfs);
FD_SET(socket_fd, &readfs);
FC_FD_ZERO(&exceptfs);
FD_SET(socket_fd, &exceptfs);
if (have_data_for_server) {
FC_FD_ZERO(&writefs);
FD_SET(socket_fd, &writefs);
n = fc_select(socket_fd + 1, &readfs, &writefs, &exceptfs,
block ? NULL : &tv);
} else {
n = fc_select(socket_fd + 1, &readfs, NULL, &exceptfs,
block ? NULL : &tv);
}
/* the socket is neither readable, writeable nor got an
* exception */
if (n == 0) {
return 0;
}
if (n == -1) {
if (errno == EINTR) {
/* EINTR can happen sometimes, especially when compiling with -pg.
* Generally we just want to run select again. */
log_debug("select() returned EINTR");
continue;
}
log_error("select() return=%d errno=%d (%s)",
n, errno, fc_strerror(fc_get_errno()));
return -1;
}
if (FD_ISSET(socket_fd, &exceptfs)) {
return -1;
}
if (have_data_for_server && FD_ISSET(socket_fd, &writefs)) {
flush_connection_send_buffer_all(pc);
}
if (FD_ISSET(socket_fd, &readfs)) {
return read_socket_data(socket_fd, pc->buffer);
}
}
}