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 ---
(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; +}