diff options
| -rw-r--r-- | src/core/download.c | 172 | ||||
| -rw-r--r-- | src/include/gpxe/download.h | 59 |
2 files changed, 231 insertions, 0 deletions
diff --git a/src/core/download.c b/src/core/download.c new file mode 100644 index 000000000..f748d0233 --- /dev/null +++ b/src/core/download.c @@ -0,0 +1,172 @@ +/* + * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +/** + * @file + * + * Download protocols + * + */ + +#include <stdint.h> +#include <stdlib.h> +#include <errno.h> +#include <gpxe/umalloc.h> +#include <gpxe/ebuffer.h> +#include <gpxe/download.h> + +/** Registered download protocols */ +static struct download_protocol download_protocols[0] + __table_start ( struct download_protocol, download_protocols ); +static struct download_protocol download_protocols_end[0] + __table_end ( struct download_protocol, download_protocols ); + +/** + * Identify download protocol + * + * @v name Download protocol name + * @ret protocol Download protocol, or NULL + */ +static struct download_protocol * find_protocol ( const char *name ) { + struct download_protocol *protocol; + + for ( protocol = download_protocols; protocol < download_protocols_end; + protocol++ ) { + if ( strcmp ( name, protocol->name ) == 0 ) + return protocol; + } + return NULL; +} + +/** Free download resources */ +static void download_reap ( struct async *async ) { + struct download *download = + container_of ( async, struct download, async ); + + free ( download ); +} + +/** + * Handle download termination + * + * @v async Download asynchronous operation + * @v signal SIGCHLD + */ +static void download_sigchld ( struct async *async, + enum signal signal __unused ) { + struct download *download = + container_of ( async, struct download, async ); + int rc; + + /* Reap child */ + async_wait ( async, &rc, 1 ); + + /* Clean up */ + if ( rc == 0 ) { + /* Transfer ownership of buffer to parent */ + *(download->data) = download->buffer.addr; + *(download->len) = download->buffer.fill; + } else { + /* Discard the buffer */ + ufree ( download->buffer.addr ); + } + free_uri ( download->uri ); + download->uri = NULL; + + /* Terminate ourselves */ + async_done ( async, rc ); +} + +/** Download asynchronous operations */ +static struct async_operations download_async_operations = { + .reap = download_reap, + .signal = { + [SIGCHLD] = download_sigchld, + }, +}; + +/** + * Start download + * + * @v uri_string URI as a string (e.g. "http://www.nowhere.com/vmlinuz") + * @v parent Parent asynchronous operation + * @ret data Loaded file + * @ret len Length of loaded file + * @ret rc Return status code + * + * Starts download of a file to a user buffer. The user buffer is + * allocated with umalloc(). The parent asynchronous operation will + * be notified via SIGCHLD when the download completes. If the + * download completes successfully, the @c data and @c len fields will + * have been filled in, and the parent takes ownership of the buffer, + * which must eventually be freed with ufree(). + * + * The uri_string does not need to remain persistent for the duration + * of the download; the parent may discard it as soon as + * start_download returns. + */ +int start_download ( const char *uri_string, struct async *parent, + userptr_t *data, size_t *len ) { + struct download *download; + int rc; + + /* Allocate and populate download structure */ + download = malloc ( sizeof ( *download ) ); + if ( ! download ) + return -ENOMEM; + memset ( download, 0, sizeof ( *download ) ); + download->data = data; + download->len = len; + async_init ( &download->async, &download_async_operations, parent ); + + /* Parse the URI */ + download->uri = parse_uri ( uri_string ); + if ( ! download->uri ) { + rc = -ENOMEM; + goto err; + } + + /* Allocate an expandable buffer to hold the file */ + if ( ( rc = ebuffer_alloc ( &download->buffer, 0 ) ) != 0 ) + goto err; + + /* Identify the download protocol */ + download->protocol = find_protocol ( download->uri->scheme ); + if ( ! download->protocol ) { + DBG ( "No such protocol \"%s\"\n", download->uri->scheme ); + rc = -ENOTSUP; + goto err; + } + + /* Start the actual download */ + if ( ( rc = download->protocol->start_download ( download->uri, + &download->buffer, &download->async ) ) != 0 ) { + DBG ( "Could not start \"%s\" download: %s\n", + download->uri->scheme, strerror ( rc ) ); + goto err; + } + + return 0; + + err: + async_uninit ( &download->async ); + ufree ( download->buffer.addr ); + free_uri ( download->uri ); + free ( download ); + return rc; +} diff --git a/src/include/gpxe/download.h b/src/include/gpxe/download.h new file mode 100644 index 000000000..cb58b7adc --- /dev/null +++ b/src/include/gpxe/download.h @@ -0,0 +1,59 @@ +#ifndef _GPXE_DOWNLOAD_H +#define _GPXE_DOWNLOAD_H + +/** @file + * + * Download protocols + * + */ + +#include <stdint.h> +#include <gpxe/uaccess.h> +#include <gpxe/async.h> +#include <gpxe/buffer.h> +#include <gpxe/uri.h> +#include <gpxe/tables.h> + +/** A download protocol */ +struct download_protocol { + /** Protocol name (e.g. "http") */ + const char *name; + /** Start a download via this protocol + * + * @v uri Uniform Resource Identifier + * @v buffer Buffer into which to download file + * @v parent Parent asynchronous operation + * @ret rc Return status code + * + * The @c uri and @c buffer will remain persistent for the + * duration of the asynchronous operation. + */ + int ( * start_download ) ( struct uri *uri, struct buffer *buffer, + struct async *parent ); +}; + +/** Register a download protocol */ +#define __download_protocol __table ( struct download_protocol, \ + download_protocols, 01 ) + +/** A download in progress */ +struct download { + /** User buffer allocated for the download */ + userptr_t *data; + /** Size of the download */ + size_t *len; + + /** URI being downloaded */ + struct uri *uri; + /** Expandable buffer for this download */ + struct buffer buffer; + /** Download protocol */ + struct download_protocol *protocol; + /** Asynchronous operation for this download */ + struct async async; +}; + +extern int start_download ( const char *uri_string, struct async *parent, + userptr_t *data, size_t *len ); + +#endif /* _GPXE_DOWNLOAD_H */ |