efi-boot-shim/netboot.c
2012-10-12 20:14:14 -04:00

366 lines
8.6 KiB
C

/*
* netboot - trivial UEFI first-stage bootloader netboot support
*
* Copyright 2012 Red Hat, Inc <mjg@redhat.com>
*
* 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 <efi.h>
#include <efilib.h>
#include <string.h>
#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;
}