/* Stolen from Unix Network Programming by Stevens, Fenner, Rudoff p89 */
ssize_t tcp_read(int file_descriptor, void *vptr, size_t n, const struct timeval * ptv)
{
size_t nleft;
ssize_t nread;
char *ptr;
//printf("NetRead attempt %d bytes Time:(%ld,%ld)\n",(int)n,ptv->tv_sec,ptv->tv_usec ) ;
ptr = vptr;
nleft = n;
while (nleft > 0) {
int rc;
fd_set readset;
struct timeval tv = { ptv->tv_sec, ptv->tv_usec, };
/* Initialize readset */
FD_ZERO(&readset);
FD_SET(file_descriptor, &readset);
/* Read if it doesn't timeout first */
rc = select(file_descriptor + 1, &readset, NULL, NULL, &tv);
if (rc > 0) {
/* Is there something to read? */
if (FD_ISSET(file_descriptor, &readset) == 0) {
return -EIO; /* error */
}
//update_max_delay(pn);
if ((nread = read(file_descriptor, ptr, nleft)) < 0) {
if (errno == EINTR) {
errno = 0; // clear errno. We never use it anyway.
nread = 0; /* and call read() again */
} else {
ERROR_DATA("Network data read error\n");
return (-1);
}
} else if (nread == 0) {
break; /* EOF */
}
//Debug_Bytes( "NETREAD",ptr, nread ) ;
nleft -= nread;
ptr += nread;
} else if (rc < 0) { /* select error */
if (errno == EINTR) {
/* select() was interrupted, try again */
continue;
}
ERROR_DATA("Selection error (network)\n");
return -EINTR;
} else { /* timed out */
LEVEL_CONNECT("TIMEOUT after %d bytes\n", n - nleft);
return -EAGAIN;
}
}
return (n - nleft); /* return >= 0 */
}
/* return < 0 if failure */
ZERO_OR_ERROR tcp_read(FILE_DESCRIPTOR_OR_ERROR file_descriptor, BYTE * buffer, size_t requested_size, const struct timeval * ptv, size_t * chars_in)
{
size_t to_be_read = requested_size ;
if ( FILE_DESCRIPTOR_NOT_VALID( file_descriptor ) ) {
return -EBADF ;
}
LEVEL_DEBUG("attempt %d bytes Time: "TVformat,(int)requested_size, TVvar(ptv) ) ;
*chars_in = 0 ;
while (to_be_read > 0) {
int select_result;
fd_set readset;
struct timeval tv ;
/* Initialize readset */
FD_ZERO(&readset);
FD_SET(file_descriptor, &readset);
/* Read if it doesn't timeout first */
timercpy( &tv, ptv ) ;
select_result = select(file_descriptor + 1, &readset, NULL, NULL, &tv);
if (select_result > 0) {
ssize_t read_result;
/* Is there something to read? */
if (FD_ISSET(file_descriptor, &readset) == 0) {
LEVEL_DEBUG("tcp_error -- nothing avialable to read");
return -EBADF ; /* error */
}
errno = 0 ;
read_result = read(file_descriptor, &buffer[*chars_in], to_be_read) ;
if ( read_result < 0 ) {
if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK) {
read_result = 0; /* and call read() again */
} else {
LEVEL_DATA("Network data read error errno=%d %s", errno, strerror(errno));
STAT_ADD1(NET_read_errors);
return -EBADF ;
}
} else if (read_result == 0) {
break; /* EOF */
}
TrafficInFD("NETREAD", &buffer[*chars_in], read_result, file_descriptor ) ;
to_be_read -= read_result;
*chars_in += read_result ;
} else if (select_result < 0) { /* select error */
if (errno == EINTR) {
/* select() was interrupted, try again */
continue;
}
ERROR_DATA("Select error");
return -EBADF;
} else { /* timed out */
LEVEL_CONNECT("TIMEOUT after %d bytes", requested_size - to_be_read);
return -EAGAIN;
}
}
LEVEL_DEBUG("read: %d - %d = %d",(int)requested_size, (int) to_be_read, (int) (requested_size-to_be_read) ) ;
return 0;
}
