/** List of open files */
static LIST_HEAD ( posix_files );
-/** Minimum file descriptor that will ever be allocated */
-#define POSIX_FD_MIN ( 1 )
-
-/** Maximum file descriptor that will ever be allocated */
-#define POSIX_FD_MAX ( 255 )
-
/**
* Free open file
*
return rc;
}
+/**
+ * Check file descriptors for readiness
+ *
+ * @v readfds File descriptors to check
+ * @v wait Wait until data is ready
+ * @ret nready Number of ready file descriptors
+ */
+int select ( fd_set *readfds, int wait ) {
+ struct posix_file *file;
+ int fd;
+
+ do {
+ for ( fd = POSIX_FD_MIN ; fd <= POSIX_FD_MAX ; fd++ ) {
+ if ( ! FD_ISSET ( fd, readfds ) )
+ continue;
+ file = posix_fd_to_file ( fd );
+ if ( ! file )
+ return -EBADF;
+ if ( ( list_empty ( &file->data ) ) &&
+ ( file->rc != -EINPROGRESS ) )
+ continue;
+ /* Data is available or status has changed */
+ FD_ZERO ( readfds );
+ FD_SET ( fd, readfds );
+ return 1;
+ }
+ step();
+ } while ( wait );
+
+ return 0;
+}
+
/**
* Read data from file
*
* @v offset Starting offset within data buffer
* @v len Maximum length to read
* @ret len Actual length read, or negative error number
+ *
+ * This call is non-blocking; if no data is available to read then
+ * -EWOULDBLOCK will be returned.
*/
ssize_t read_user ( int fd, userptr_t buffer, off_t offset, size_t max_len ) {
struct posix_file *file;
struct io_buffer *iobuf;
- size_t frag_len;
- ssize_t len = 0;
+ size_t len;
/* Identify file */
file = posix_fd_to_file ( fd );
if ( ! file )
return -EBADF;
- while ( 1 ) {
- /* Try to fetch more data if none available */
- if ( list_empty ( &file->data ) )
- step();
- /* Dequeue at most one received I/O buffer into user buffer */
- list_for_each_entry ( iobuf, &file->data, list ) {
- frag_len = iob_len ( iobuf );
- if ( frag_len > max_len )
- frag_len = max_len;
- copy_to_user ( buffer, offset, iobuf->data,
- frag_len );
- iob_pull ( iobuf, frag_len );
- if ( ! iob_len ( iobuf ) ) {
- list_del ( &iobuf-> list );
- free_iob ( iobuf );
- }
- file->pos += frag_len;
- len += frag_len;
- offset += frag_len;
- max_len -= frag_len;
- break;
+ /* Try to fetch more data if none available */
+ if ( list_empty ( &file->data ) )
+ step();
+
+ /* Dequeue at most one received I/O buffer into user buffer */
+ list_for_each_entry ( iobuf, &file->data, list ) {
+ len = iob_len ( iobuf );
+ if ( len > max_len )
+ len = max_len;
+ copy_to_user ( buffer, offset, iobuf->data, len );
+ iob_pull ( iobuf, len );
+ if ( ! iob_len ( iobuf ) ) {
+ list_del ( &iobuf->list );
+ free_iob ( iobuf );
}
- /* If buffer is full, return */
- if ( ! max_len )
- return len;
- /* If file has completed, return */
- if ( file->rc != -EINPROGRESS )
- return ( file->rc ? file->rc : len );
+ file->pos += len;
+ return len;
}
+
+ /* If file has completed, return (after returning all data) */
+ if ( file->rc != -EINPROGRESS )
+ return file->rc;
+
+ /* No data ready and file still in progress; return -WOULDBLOCK */
+ return -EWOULDBLOCK;
}
/**
#include <stdint.h>
#include <gpxe/uaccess.h>
+/** Minimum file descriptor that will ever be allocated */
+#define POSIX_FD_MIN ( 1 )
+
+/** Maximum file descriptor that will ever be allocated */
+#define POSIX_FD_MAX ( 31 )
+
+/** File descriptor set as used for select() */
+typedef uint32_t fd_set;
+
extern int open ( const char *uri_string );
extern ssize_t read_user ( int fd, userptr_t buffer,
off_t offset, size_t len );
+extern int select ( fd_set *readfds, int wait );
extern ssize_t fsize ( int fd );
extern int close ( int fd );
+/**
+ * Zero a file descriptor set
+ *
+ * @v set File descriptor set
+ */
+static inline __attribute__ (( always_inline )) void
+FD_ZERO ( fd_set *set ) {
+ *set = 0;
+}
+
+/**
+ * Set a bit within a file descriptor set
+ *
+ * @v fd File descriptor
+ * @v set File descriptor set
+ */
+static inline __attribute__ (( always_inline )) void
+FD_SET ( int fd, fd_set *set ) {
+ *set |= ( 1 << fd );
+}
+
+/**
+ * Clear a bit within a file descriptor set
+ *
+ * @v fd File descriptor
+ * @v set File descriptor set
+ */
+static inline __attribute__ (( always_inline )) void
+FD_CLR ( int fd, fd_set *set ) {
+ *set &= ~( 1 << fd );
+}
+
+/**
+ * Test a bit within a file descriptor set
+ *
+ * @v fd File descriptor
+ * @v set File descriptor set
+ * @ret is_set Corresponding bit is set
+ */
+static inline __attribute__ (( always_inline )) int
+FD_ISSET ( int fd, fd_set *set ) {
+ return ( *set & ( 1 << fd ) );
+}
+
/**
* Read data from file
*
( ( filename[0] == '/' ) ? "" : "/" ), filename );
}
+/**
+ * Read as much as possible from file
+ *
+ * @v fd File descriptor
+ * @v buffer Data buffer
+ * @v max_len Maximum length to read
+ * @ret len Actual length read, or negative error
+ */
+static ssize_t pxe_tftp_read_all ( int fd, userptr_t buffer,
+ size_t max_len ) {
+ fd_set fdset;
+ off_t offset = 0;
+ int ready;
+ ssize_t len;
+
+ do {
+ FD_ZERO ( &fdset );
+ FD_SET ( fd, &fdset );
+ ready = select ( &fdset, 1 );
+ if ( ready < 0 )
+ return ready;
+ len = read_user ( fd, buffer, offset, max_len );
+ if ( len < 0 )
+ return len;
+ offset += len;
+ max_len -= len;
+ } while ( max_len && len );
+
+ return offset;
+}
+
/**
* TFTP OPEN
*
buffer = real_to_user ( tftp_read->Buffer.segment,
tftp_read->Buffer.offset );
- len = read_user ( pxe_single_fd, buffer, 0, pxe_single_blksize );
+ len = pxe_tftp_read_all ( pxe_single_fd, buffer, pxe_single_blksize );
if ( len < 0 ) {
tftp_read->Status = PXENV_STATUS ( len );
return PXENV_EXIT_FAILURE;
}
+
tftp_read->BufferSize = len;
tftp_read->PacketNumber = ++pxe_single_blkidx;
char uri_string[PXE_URI_LEN];
int fd;
userptr_t buffer;
- size_t max_len;
- ssize_t frag_len;
- size_t len = 0;
- int rc = -ENOBUFS;
+ ssize_t len;
+ int rc = 0;
DBG ( "PXENV_TFTP_READ_FILE" );
/* Read file */
buffer = phys_to_user ( tftp_read_file->Buffer );
- max_len = tftp_read_file->BufferSize;
- while ( max_len ) {
- frag_len = read_user ( fd, buffer, len, max_len );
- if ( frag_len <= 0 ) {
- rc = frag_len;
- break;
- }
- len += frag_len;
- max_len -= frag_len;
- }
+ len = pxe_tftp_read_all ( fd, buffer, tftp_read_file->BufferSize );
+ if ( len < 0 )
+ rc = len;
close ( fd );
tftp_read_file->BufferSize = len;
http://git.etherboot.org / people / sha0 / gpxe.git / commitdiff