datauri.c File Reference

Data URIs. More...

#include <string.h>
#include <strings.h>
#include <errno.h>
#include <ipxe/base64.h>
#include <ipxe/blob.h>
#include <ipxe/open.h>
#include <ipxe/datauri.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
	FILE_SECBOOT (PERMITTED)
int	datauri_parse (struct uri *uri, void *buf)
	Parse data URI.
static int	datauri_open (struct interface *xfer, struct uri *uri)
	Open data URI.

Variables
struct uri_opener data_uri_opener	__uri_opener
	Data URI opener.

Detailed Description

Data URIs.

The "data" URI scheme is defined in RFC 2397. In the interest of reducing code size, we support only a practical subset of the specification. Media types will be ignored (and must not contain a literal comma character). Base64 encoding is supported.

URI encoding will already have been stripped by the URI parser. Special characters may therefore be used in the URI string (e.g. "hello%20world"). However, URI-encoded NUL bytes (%00) will not work as expected, since they will be interpreted as terminating the URI string. If NUL bytes are required, then Base64 encoding must be used instead.

Definition in file datauri.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

FILE_SECBOOT()

FILE_SECBOOT

(

PERMITTED

)

datauri_parse()

int datauri_parse	(	struct uri *	uri,
		void *	buf )

Parse data URI.

Parameters

uri	Data URI
buf	Buffer to fill in

Return values

len	Length of data, or negative error

The buffer length must be at least the size reported by datauri_max_len().

Definition at line 62 of file datauri.c.

                                                 {
        static const char b64marker[7] = ";base64";
        const char *comma;
        const char *encoded;
        size_t prefix_len;
        int len;
        int rc;
 
        /* Sanity check */
        if ( ! uri->opaque ) {
                DBGC ( uri, "DATA %p has no opaque part\n", uri );
                return -EINVAL;
        }
 
        /* Locate encoded string */
        comma = strchr ( uri->opaque, ',' );
        if ( ! comma ) {
                DBGC ( uri, "DATA %p has no comma separator\n", uri );
                return -EINVAL;
        }
        prefix_len = ( comma - uri->opaque );
        encoded = ( comma + 1 );
        len = strlen ( encoded );
 
        /* Decode string */
        if ( ( prefix_len >= sizeof ( b64marker ) ) &&
             ( strncasecmp ( ( comma - sizeof ( b64marker ) ), b64marker,
                             sizeof ( b64marker ) ) == 0 ) ) {
 
                /* Decode Base64 string */
                len = base64_decode ( encoded, buf, len );
                if ( len < 0 ) {
                        rc = len;
                        DBGC ( uri, "DATA %p could not decode Base64: %s\n",
                               uri, strerror ( rc ) );
                        return rc;
                }
 
        } else {
 
                /* Copy raw string */
                strcpy ( buf, encoded );
        }
 
        DBGC ( uri, "DATA %p decoded \"%s\":\n", uri, uri->opaque );
        DBGC_HDA ( uri, 0, buf, len );
        return len;
}

References base64_decode(), DBGC, DBGC_HDA, EINVAL, len, uri::opaque, rc, strchr(), strcpy(), strerror(), strlen(), and strncasecmp().

Referenced by datauri_fail_okx(), datauri_okx(), and datauri_open().

datauri_open()

int datauri_open ( struct interface * xfer, struct uri * uri )

static

Open data URI.

Parameters

xfer	Data transfer interface
uri	URI

Return values

rc	Return status code

Definition at line 118 of file datauri.c.

                                                                    {
        void *data;
        int len;
        int rc;
 
        /* Allocate space for parsed data */
        data = malloc ( datauri_max_len ( uri ) );
        if ( ! data ) {
                rc = -ENOMEM;
                goto err_alloc;
        }
 
        /* Parse data */
        len = datauri_parse ( uri, data );
        if ( len < 0 )  {
                rc = len;
                goto err_parse;
        }
 
        /* Open downloadable blob */
        if ( ( rc = blob_open ( xfer, data, len ) ) != 0 )
                goto err_open;
 
 err_open:
 err_parse:
        free ( data );
 err_alloc:
        return rc;
}

References blob_open(), data, datauri_max_len(), datauri_parse(), ENOMEM, free, len, malloc(), and rc.

Variable Documentation

__uri_opener

struct uri_opener data_uri_opener __uri_opener

Initial value:

                = {
        .scheme = "data",
        .open = datauri_open,
}

Data URI opener.

Definition at line 149 of file datauri.c.

                                               {
        .scheme = "data",
        .open = datauri_open,
};