Re: [PATCH v6 09/14] efi_loader: net: add support to send http requests and parse http headers

On 28.11.24 15:44, Adriano Cordova wrote:

Add network-stack agnostic way to send an http request and parse http headers from efi drivers. This uses wget as a backend and communicates with it via efi_wget_info.

The function efi_net_do_request allocates a buffer on behalf of an efi application using efi_alloc and passes it to wget to receive the data. If the method is GET and the buffer is too small, it re-allocates the buffer based on the last received Content-Length header and tries again. If the method is HEAD it just issues one request. So issuing a HEAD request (to update Content-Length) and then a GET request is preferred but not required.

The function efi_net_parse_headers parses a raw buffer containing an http header into an array of EFI specific 'http_header' structs.

Signed-off-by: Adriano Cordova adrianox@gmail.com

Reviewed-by: Heinrich Schuchardt xypron.glpk@gmx.de

---

(no changes since v4)

Changes in v4:

• Remove void* casts
• Add documentation

Changes in v3:

• Add a struct wget_http_info efi_wget_info for efi_net to pass to wget when issuing wget requests, instead of using the old wget_info (see v2 of the series 'wget: Expose wget to applications').
• Let a pointer to the http status code be passed to efi_net_do_request for it to fill it for the client after a request. include/efi_loader.h | 13 ++++ lib/efi_loader/efi_net.c | 155 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 168 insertions(+)

diff --git a/include/efi_loader.h b/include/efi_loader.h index 0da0248db4..b6f865ca76 100644 --- a/include/efi_loader.h +++ b/include/efi_loader.h @@ -16,6 +16,7 @@ #include <image.h> #include <pe.h> #include <linux/list.h> +#include <linux/sizes.h> #include <linux/oid_registry.h>

struct blk_desc; @@ -136,6 +137,18 @@ void efi_net_get_addr(struct efi_ipv4_address *ip, void efi_net_set_addr(struct efi_ipv4_address *ip, struct efi_ipv4_address *mask, struct efi_ipv4_address *gw); +efi_status_t efi_net_do_request(u8 *url, enum efi_http_method method, void **buffer,

• 		u32 *status_code, ulong *file_size, char *headers_buffer);
  

+#define MAX_HTTP_HEADERS_SIZE SZ_64K +#define MAX_HTTP_HEADERS 100 +#define MAX_HTTP_HEADER_NAME 128 +#define MAX_HTTP_HEADER_VALUE 512 +struct http_header {

• uchar name[MAX_HTTP_HEADER_NAME];
• uchar value[MAX_HTTP_HEADER_VALUE];

+};

+void efi_net_parse_headers(ulong *num_headers, struct http_header *headers); #else static inline void efi_net_get_dp(struct efi_device_path **dp) { } static inline void efi_net_get_addr(struct efi_ipv4_address *ip, diff --git a/lib/efi_loader/efi_net.c b/lib/efi_loader/efi_net.c index e8af2e3d95..368f62c5b2 100644 --- a/lib/efi_loader/efi_net.c +++ b/lib/efi_loader/efi_net.c @@ -17,6 +17,7 @@

#include <efi_loader.h> #include <dm.h> +#include <linux/sizes.h> #include <malloc.h> #include <vsprintf.h> #include <net.h> @@ -40,6 +41,12 @@ static struct efi_net_obj *netobj; */ static struct efi_device_path *net_dp;

+static struct wget_http_info efi_wget_info = {

• .set_bootdev = false,
• .check_buffer_size = true,

+};

• /*
  • The notification function of this event is called in every timer cycle
  • to check if a new network packet has been received.

@@ -1175,3 +1182,151 @@ void efi_net_set_addr(struct efi_ipv4_address *ip, memcpy(&net_netmask, mask, sizeof(*mask)); #endif }

+/**

• • efi_net_set_buffer() - allocate a buffer of min 64K
• • @buffer: allocated buffer
• • @size: desired buffer size
• • Return: status code
• */

+static efi_status_t efi_net_set_buffer(void **buffer, size_t size) +{

• efi_status_t ret = EFI_SUCCESS;
• if (size < SZ_64K)

• size = SZ_64K;
  

• efi_free_pool(*buffer);
• *buffer = efi_alloc(size);
• if (!*buffer)

• ret = EFI_OUT_OF_RESOURCES;
  

• efi_wget_info.buffer_size = (ulong)size;
• return ret;

+}

+/**

• • efi_net_parse_headers() - parse HTTP headers
• • Parses the raw buffer efi_wget_info.headers into an array headers
• • of efi structs http_headers. The array should be at least
• • MAX_HTTP_HEADERS long.
• • @num_headers: number of headers
• • @headers: caller provided array of struct http_headers
• */

+void efi_net_parse_headers(ulong *num_headers, struct http_header *headers) +{

• if (!num_headers || !headers)

• return;
  

• // Populate info with http headers.
• *num_headers = 0;
• const uchar *line_start = efi_wget_info.headers;
• const uchar *line_end;
• ulong count;
• struct http_header *current_header;
• const uchar *separator;
• size_t name_length, value_length;
• // Skip the first line (request or status line)
• line_end = strstr(line_start, "\r\n");
• if (line_end)

• line_start = line_end + 2;
  

• while ((line_end = strstr(line_start, "\r\n")) != NULL) {

• count = *num_headers;
  

• if (line_start == line_end || count >= MAX_HTTP_HEADERS)
  

• 	break;
  

• current_header = headers + count;
  

• separator = strchr(line_start, ':');
  

• if (separator) {
  

• 	name_length = separator - line_start;
  

• 	++separator;
  

• 	while (*separator == ' ')
  

• 		++separator;
  

• 	value_length = line_end - separator;
  

• 	if (name_length < MAX_HTTP_HEADER_NAME &&
  

• 	    value_length < MAX_HTTP_HEADER_VALUE) {
  

• 		strncpy(current_header->name, line_start, name_length);
  

• 		current_header->name[name_length] = '\0';
  

• 		strncpy(current_header->value, separator, value_length);
  

• 		current_header->value[value_length] = '\0';
  

• 		(*num_headers)++;
  

• 	}
  

• }
  

• line_start = line_end + 2;
  

• }

+}

+/**

• • efi_net_do_request() - issue an HTTP request using wget
• • @url: url
• • @method: HTTP method
• • @buffer: data buffer
• • @status_code: HTTP status code
• • @file_size: file size in bytes
• • @headers_buffer: headers buffer
• • Return: status code
• */

+efi_status_t efi_net_do_request(u8 *url, enum efi_http_method method, void **buffer,

• 		u32 *status_code, ulong *file_size, char *headers_buffer)
  

+{

• efi_status_t ret = EFI_SUCCESS;
• int wget_ret;
• static bool last_head;
• if (!buffer || !file_size)

• return EFI_ABORTED;
  

• efi_wget_info.method = (enum wget_http_method)method;
• efi_wget_info.headers = headers_buffer;
• switch (method) {
• case HTTP_METHOD_GET:

• ret = efi_net_set_buffer(buffer, last_head ? (size_t)efi_wget_info.hdr_cont_len : 0);
  

• if (ret != EFI_SUCCESS)
  

• 	goto out;
  

• wget_ret = wget_request((ulong)*buffer, url, &efi_wget_info);
  

• if ((ulong)efi_wget_info.hdr_cont_len > efi_wget_info.buffer_size) {
  

• 	// Try again with updated buffer size
  

• 	ret = efi_net_set_buffer(buffer, (size_t)efi_wget_info.hdr_cont_len);
  

• 	if (ret != EFI_SUCCESS)
  

• 		goto out;
  

• 	if (wget_request((ulong)*buffer, url, &efi_wget_info)) {
  

• 		efi_free_pool(*buffer);
  

• 		ret = EFI_DEVICE_ERROR;
  

• 		goto out;
  

• 	}
  

• } else if (wget_ret) {
  

• 	efi_free_pool(*buffer);
  

• 	ret = EFI_DEVICE_ERROR;
  

• 	goto out;
  

• }
  

• // Pass the actual number of received bytes to the application
  

• *file_size = efi_wget_info.file_size;
  

• *status_code = efi_wget_info.status_code;
  

• last_head = false;
  

• break;
  

• case HTTP_METHOD_HEAD:

• ret = efi_net_set_buffer(buffer, 0);
  

• if (ret != EFI_SUCCESS)
  

• 	goto out;
  

• wget_request((ulong)*buffer, url, &efi_wget_info);
  

• *file_size = 0;
  

• *status_code = efi_wget_info.status_code;
  

• last_head = true;
  

• break;
  

• default:

• ret = EFI_UNSUPPORTED;
  

• break;
  

• }

+out:

• return ret;

+}