From d8e330b95368ce43da47e114eb1d699eedb18e57 Mon Sep 17 00:00:00 2001 From: Matthew Garrett Date: Fri, 12 Oct 2012 20:13:46 -0400 Subject: [PATCH] Add draft version of Neil's netboot code --- Makefile | 4 +- netboot.c | 365 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ netboot.h | 9 ++ shim.c | 30 ++++- 4 files changed, 400 insertions(+), 8 deletions(-) create mode 100644 netboot.c create mode 100644 netboot.h diff --git a/Makefile b/Makefile index bea0ebd..37c5d9d 100644 --- a/Makefile +++ b/Makefile @@ -29,8 +29,8 @@ LDFLAGS = -nostdlib -znocombreloc -T $(EFI_LDS) -shared -Bsymbolic -L$(EFI_PATH VERSION = 0.1 TARGET = shim.efi MokManager.efi -OBJS = shim.o cert.o -SOURCES = shim.c shim.h signature.h PeImage.h +OBJS = shim.o netboot.o cert.o +SOURCES = shim.c shim.h netboot.c signature.h PeImage.h MOK_OBJS = MokManager.o MOK_SOURCES = MokManager.c shim.h diff --git a/netboot.c b/netboot.c new file mode 100644 index 0000000..cc43b72 --- /dev/null +++ b/netboot.c @@ -0,0 +1,365 @@ +/* + * netboot - trivial UEFI first-stage bootloader netboot support + * + * Copyright 2012 Red Hat, Inc + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Significant portions of this code are derived from Tianocore + * (http://tianocore.sf.net) and are Copyright 2009-2012 Intel + * Corporation. + */ + +#include +#include +#include +#include "shim.h" +#include "netboot.h" + + +static inline unsigned short int __swap16(unsigned short int x) +{ + __asm__("xchgb %b0,%h0" + : "=q" (x) + : "0" (x)); + return x; +} + +#define ntohs(x) __swap16(x) +#define htons(x) ntohs(x) + +static EFI_PXE_BASE_CODE *pxe; +static EFI_IP_ADDRESS tftp_addr; +static char *full_path; + + +/* + * Not in the EFI header set yet, so I have to declare it here + */ +typedef struct { + UINT32 MessageType:8; + UINT32 TransactionId:24; + UINT8 DhcpOptions[1024]; +} EFI_PXE_BASE_CODE_DHCPV6_PACKET; + +typedef struct { + UINT16 OpCode; + UINT16 Length; + UINT8 Data[1]; +} EFI_DHCP6_PACKET_OPTION; + +/* + * usingNetboot + * Returns TRUE if we identify a protocol that is enabled and Providing us with + * the needed information to fetch a grubx64.efi image + */ +BOOLEAN findNetboot(EFI_HANDLE image_handle) +{ + UINTN bs = sizeof(EFI_HANDLE); + EFI_GUID pxe_base_code_protocol = EFI_PXE_BASE_CODE_PROTOCOL; + EFI_HANDLE *hbuf; + BOOLEAN rc = FALSE; + void *buffer = AllocatePool(bs); + UINTN errcnt = 0; + UINTN i; + EFI_STATUS status; + + if (!buffer) + return FALSE; + +try_again: + status = uefi_call_wrapper(BS->LocateHandle,5, ByProtocol, + &pxe_base_code_protocol, NULL, &bs, + buffer); + + if (status == EFI_BUFFER_TOO_SMALL) { + errcnt++; + FreePool(buffer); + if (errcnt > 1) + return FALSE; + buffer = AllocatePool(bs); + if (!buffer) + return FALSE; + goto try_again; + } + + /* + * We have a list of pxe supporting protocols, lets see if any are + * active + */ + hbuf = buffer; + pxe = NULL; + for (i=0; i < (bs / sizeof(EFI_HANDLE)); i++) { + status = uefi_call_wrapper(BS->OpenProtocol, 6, hbuf[i], + &pxe_base_code_protocol, + &pxe, image_handle, NULL, + EFI_OPEN_PROTOCOL_GET_PROTOCOL); + + if (status != EFI_SUCCESS) { + pxe = NULL; + continue; + } + + if (!pxe || !pxe->Mode) { + pxe = NULL; + continue; + } + + if (pxe->Mode->Started && pxe->Mode->DhcpAckReceived) { + /* + * We've located a pxe protocol handle thats been + * started and has received an ACK, meaning its + * something we'll be able to get tftp server info + * out of + */ + rc = TRUE; + break; + } + + } + + FreePool(buffer); + return rc; +} + +static char *get_v6_bootfile_url(EFI_PXE_BASE_CODE_DHCPV6_PACKET *pkt) +{ + void *optr; + EFI_DHCP6_PACKET_OPTION *option; + char *url; + UINT32 urllen; + + optr = pkt->DhcpOptions; + + for(;;) { + option = (EFI_DHCP6_PACKET_OPTION *)optr; + + if (ntohs(option->OpCode) == 0) + return NULL; + + if (ntohs(option->OpCode) == 59) { + /* This is the bootfile url option */ + urllen = ntohs(option->Length); + url = AllocatePool(urllen+2); + if (!url) + return NULL; + memset(url, 0, urllen+2); + memcpy(url, option->Data, urllen); + return url; + } + optr += 4 + ntohs(option->Length); + } + + return NULL; +} + +static UINT16 str2ns(UINT8 *str) +{ + UINT16 ret = 0; + UINT8 v; + for(;*str;str++) { + if ('0' <= *str && *str <= '9') + v = *str - '0'; + else if ('A' <= *str && *str <= 'F') + v = *str - 'A' + 10; + else if ('a' <= *str && *str <= 'f') + v = *str - 'a' + 10; + else + v = 0; + ret = (ret << 4) + v; + } + return htons(ret); +} + +static UINT8 *str2ip6(char *str) +{ + UINT8 i, j, p; + size_t len; + UINT8 *a, *b, t; + static UINT16 ip[8]; + + for(i=0; i < 8; i++) { + ip[i] = 0; + } + len = strlen((UINT8 *)str); + a = b = (UINT8 *)str; + for(i=p=0; i < len; i++, b++) { + if (*b != ':') + continue; + *b = '\0'; + ip[p++] = str2ns(a); + *b = ':'; + a = b + 1; + if ( *(b+1) == ':' ) + break; + } + a = b = (UINT8 *)(str + len); + for(j=len, p=7; j > i; j--, a--) { + if (*a != ':') + continue; + t = *b; + *b = '\0'; + ip[p--] = str2ns(a+1); + *b = t; + b = a; + } + return (UINT8 *)ip; +} + +static BOOLEAN extract_tftp_info(char *url) +{ + char *start, *end; + char ip6str[128]; + char *template = "/grubx64.efi"; + + if (strncmp((UINT8 *)url, (UINT8 *)"tftp://", 7)) { + Print(L"URLS MUST START WITH tftp://\n"); + return FALSE; + } + start = url + 7; + if (*start != '[') { + Print(L"TFTP SERVER MUST BE ENCLOSED IN [..]\n"); + return FALSE; + } + + start++; + end = start; + while ((*end != '\0') && (*end != ']')) { + end++; + } + if (end == '\0') { + Print(L"TFTP SERVER MUST BE ENCLOSED IN [..]\n"); + return FALSE; + } + *end = '\0'; + memset(ip6str, 0, 128); + memcpy(ip6str, start, strlen((UINT8 *)start)); + *end = ']'; + end++; + memcpy(&tftp_addr.v6, str2ip6(ip6str), 16); + full_path = AllocatePool(strlen((UINT8 *)end)+strlen((UINT8 *)template)+1); + if (!full_path) + return FALSE; + memset(full_path, 0, strlen((UINT8 *)end)+strlen((UINT8 *)template)); + memcpy(full_path, end, strlen((UINT8 *)end)); + end = strrchr(full_path, '/'); + if (!end) + end = full_path; + memcpy(end, template, strlen((UINT8 *)template)); + + return TRUE; +} + +static EFI_STATUS parseDhcp6() +{ + EFI_PXE_BASE_CODE_DHCPV6_PACKET *packet = (EFI_PXE_BASE_CODE_DHCPV6_PACKET *)&pxe->Mode->DhcpAck.Raw; + char *bootfile_url; + + + bootfile_url = get_v6_bootfile_url(packet); + if (extract_tftp_info(bootfile_url) == FALSE) + return EFI_NOT_FOUND; + if (!bootfile_url) + return EFI_NOT_FOUND; + return EFI_SUCCESS; +} + +static EFI_STATUS parseDhcp4() +{ + char *template = "/grubx64.efi"; + char *tmp = AllocatePool(16); + + + if (!tmp) + return EFI_OUT_OF_RESOURCES; + + + memcpy(&tftp_addr.v4, pxe->Mode->DhcpAck.Dhcpv4.BootpSiAddr, 4); + + memcpy(tmp, template, 12); + tmp[13] = '\0'; + full_path = tmp; + + /* Note we don't capture the filename option here because we know its shim.efi + * We instead assume the filename at the end of the path is going to be grubx64.efi + */ + return EFI_SUCCESS; +} + +EFI_STATUS parseNetbootinfo(EFI_HANDLE image_handle) +{ + + EFI_STATUS rc; + + if (!pxe) + return EFI_NOT_READY; + + memset((UINT8 *)&tftp_addr, 0, sizeof(tftp_addr)); + + /* + * If we've discovered an active pxe protocol figure out + * if its ipv4 or ipv6 + */ + if (pxe->Mode->UsingIpv6){ + rc = parseDhcp6(); + } else + rc = parseDhcp4(); + return rc; +} + +EFI_STATUS FetchNetbootimage(EFI_HANDLE image_handle, VOID **buffer, UINTN *bufsiz) +{ + EFI_STATUS rc; + EFI_PXE_BASE_CODE_TFTP_OPCODE read = EFI_PXE_BASE_CODE_TFTP_READ_FILE; + BOOLEAN overwrite = FALSE; + BOOLEAN nobuffer = FALSE; + UINTN blksz = 512; + + Print(L"Fetching Netboot Image\n"); + if (*buffer == NULL) { + *buffer = AllocatePool(4096 * 1024); + if (!*buffer) + return EFI_OUT_OF_RESOURCES; + *bufsiz = 4096 * 1024; + } + +try_again: + rc = uefi_call_wrapper(pxe->Mtftp, 10, pxe, read, *buffer, overwrite, + &bufsiz, &blksz, &tftp_addr, full_path, NULL, nobuffer); + + if (rc == EFI_BUFFER_TOO_SMALL) { + /* try again, doubling buf size */ + *bufsiz *= 2; + FreePool(*buffer); + *buffer = AllocatePool(*bufsiz); + if (!*buffer) + return EFI_OUT_OF_RESOURCES; + goto try_again; + } + + return rc; + +} diff --git a/netboot.h b/netboot.h new file mode 100644 index 0000000..2cdb421 --- /dev/null +++ b/netboot.h @@ -0,0 +1,9 @@ +#ifndef _NETBOOT_H_ +#define _NETBOOT_H_ + +extern BOOLEAN findNetboot(EFI_HANDLE image_handle); + +extern EFI_STATUS parseNetbootinfo(EFI_HANDLE image_handle); + +extern EFI_STATUS FetchNetbootimage(EFI_HANDLE image_handle, VOID **buffer, UINTN *bufsiz); +#endif diff --git a/shim.c b/shim.c index 4eab87a..c87579a 100644 --- a/shim.c +++ b/shim.c @@ -39,6 +39,7 @@ #include "PeImage.h" #include "shim.h" #include "signature.h" +#include "netboot.h" #define SECOND_STAGE L"\\grub.efi" #define MOK_MANAGER L"\\MokManager.efi" @@ -680,7 +681,6 @@ static EFI_STATUS read_header(void *data, unsigned int datasize, Print(L"Empty security header\n"); return EFI_INVALID_PARAMETER; } - return EFI_SUCCESS; } @@ -942,7 +942,9 @@ EFI_STATUS start_image(EFI_HANDLE image_handle, CHAR16 *ImagePath) EFI_STATUS efi_status; EFI_LOADED_IMAGE *li, li_bak; EFI_DEVICE_PATH *path; - CHAR16 *PathName; + CHAR16 *PathName = NULL; + void *sourcebuffer = NULL; + UINTN sourcesize = 0; void *data = NULL; int datasize; @@ -961,11 +963,27 @@ EFI_STATUS start_image(EFI_HANDLE image_handle, CHAR16 *ImagePath) goto done; } - efi_status = load_image(li, &data, &datasize, PathName); + if (findNetboot(image_handle)) { + efi_status = parseNetbootinfo(image_handle); + if (efi_status != EFI_SUCCESS) { + Print(L"Netboot parsing failed: %d\n", efi_status); + return EFI_PROTOCOL_ERROR; + } + efi_status = FetchNetbootimage(image_handle, &sourcebuffer, + &sourcesize); + if (efi_status != EFI_SUCCESS) { + Print(L"Unable to fetch TFTP image\n"); + return efi_status; + } + data = sourcebuffer; + datasize = sourcesize; + } else { + efi_status = load_image(li, &data, &datasize, PathName); - if (efi_status != EFI_SUCCESS) { - Print(L"Failed to load image\n"); - goto done; + if (efi_status != EFI_SUCCESS) { + Print(L"Failed to load image\n"); + goto done; + } } CopyMem(&li_bak, li, sizeof(li_bak));