grub/fs/i386/pc/pxe.c
Vladimir 'phcoder' Serbinenko 1b8cb8573b intwrap grub_pxe_scan
2010-04-04 15:49:06 +02:00

635 lines
15 KiB
C

/* pxe.c - Driver to provide access to the pxe filesystem */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2008,2009 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/dl.h>
#include <grub/fs.h>
#include <grub/mm.h>
#include <grub/disk.h>
#include <grub/file.h>
#include <grub/misc.h>
#include <grub/bufio.h>
#include <grub/env.h>
#include <grub/machine/pxe.h>
#include <grub/machine/int.h>
#include <grub/machine/memory.h>
#define SEGMENT(x) ((x) >> 4)
#define OFFSET(x) ((x) & 0xF)
#define SEGOFS(x) ((SEGMENT(x) << 16) + OFFSET(x))
#define LINEAR(x) (void *) (((x >> 16) <<4) + (x & 0xFFFF))
struct grub_pxe_disk_data
{
grub_uint32_t server_ip;
grub_uint32_t gateway_ip;
};
struct grub_pxenv *grub_pxe_pxenv;
static grub_uint32_t grub_pxe_your_ip;
static grub_uint32_t grub_pxe_default_server_ip;
static grub_uint32_t grub_pxe_default_gateway_ip;
static unsigned grub_pxe_blksize = GRUB_PXE_MIN_BLKSIZE;
static grub_file_t curr_file = 0;
struct grub_pxe_data
{
grub_uint32_t packet_number;
grub_uint32_t block_size;
char filename[0];
};
static grub_uint32_t pxe_rm_entry = 0;
static struct grub_pxenv *
grub_pxe_scan (void)
{
struct grub_bios_int_registers regs;
struct grub_pxenv *ret;
void *pxe;
regs.flags = GRUB_CPU_INT_FLAGS_DEFAULT;
regs.ebx = 0;
regs.ecx = 0;
regs.eax = 0x5650;
grub_bios_interrupt (0x1a, &regs);
if ((regs.eax & 0xffff) != 0x564e)
return NULL;
ret = (struct grub_pxenv *) ((regs.es << 4) + (regs.ebx & 0xffff));
if (grub_memcmp (ret->signature, GRUB_PXE_SIGNATURE, sizeof (ret->signature))
!= 0)
return NULL;
if (ret->version < 0x201)
return NULL;
pxe = (void *) ((((ret->pxe_ptr & 0xffff0000) >> 16) << 4)
+ (ret->pxe_ptr & 0xffff));
if (!pxe)
return NULL;
/* !PXE */
if (*(grub_uint32_t *) pxe != 0x45585021)
return NULL;
pxe_rm_entry = ret->rm_entry;
return ret;
}
static int
grub_pxe_iterate (int (*hook) (const char *name))
{
if (hook ("pxe"))
return 1;
return 0;
}
static grub_err_t
parse_ip (const char *val, grub_uint32_t *ip, const char **rest)
{
grub_uint32_t newip = 0;
unsigned long t;
int i;
const char *ptr = val;
for (i = 0; i < 4; i++)
{
t = grub_strtoul (ptr, (char **) &ptr, 0);
if (grub_errno)
return grub_errno;
if (t & ~0xff)
return grub_error (GRUB_ERR_OUT_OF_RANGE, "Invalid IP.");
newip >>= 8;
newip |= (t << 24);
if (i != 3 && *ptr != '.')
return grub_error (GRUB_ERR_OUT_OF_RANGE, "Invalid IP.");
ptr++;
}
*ip = newip;
if (rest)
*rest = ptr - 1;
return 0;
}
static grub_err_t
grub_pxe_open (const char *name, grub_disk_t disk)
{
struct grub_pxe_disk_data *data;
if (grub_strcmp (name, "pxe") != 0
&& grub_strncmp (name, "pxe:", sizeof ("pxe:") - 1) != 0)
return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "not a pxe disk");
data = grub_malloc (sizeof (*data));
if (!data)
return grub_errno;
if (grub_strncmp (name, "pxe:", sizeof ("pxe:") - 1) == 0)
{
const char *ptr;
grub_err_t err;
ptr = name + sizeof ("pxe:") - 1;
err = parse_ip (ptr, &(data->server_ip), &ptr);
if (err)
return err;
if (*ptr == ':')
{
err = parse_ip (ptr + 1, &(data->server_ip), 0);
if (err)
return err;
}
else
data->gateway_ip = grub_pxe_default_gateway_ip;
}
else
{
data->server_ip = grub_pxe_default_server_ip;
data->gateway_ip = grub_pxe_default_gateway_ip;
}
disk->total_sectors = 0;
disk->id = (unsigned long) data;
disk->has_partitions = 0;
disk->data = data;
return GRUB_ERR_NONE;
}
static void
grub_pxe_close (grub_disk_t disk)
{
grub_free (disk->data);
}
static grub_err_t
grub_pxe_read (grub_disk_t disk __attribute((unused)),
grub_disk_addr_t sector __attribute((unused)),
grub_size_t size __attribute((unused)),
char *buf __attribute((unused)))
{
return GRUB_ERR_OUT_OF_RANGE;
}
static grub_err_t
grub_pxe_write (grub_disk_t disk __attribute((unused)),
grub_disk_addr_t sector __attribute((unused)),
grub_size_t size __attribute((unused)),
const char *buf __attribute((unused)))
{
return GRUB_ERR_OUT_OF_RANGE;
}
static struct grub_disk_dev grub_pxe_dev =
{
.name = "pxe",
.id = GRUB_DISK_DEVICE_PXE_ID,
.iterate = grub_pxe_iterate,
.open = grub_pxe_open,
.close = grub_pxe_close,
.read = grub_pxe_read,
.write = grub_pxe_write,
.next = 0
};
static grub_err_t
grub_pxefs_dir (grub_device_t device,
const char *path __attribute__ ((unused)),
int (*hook) (const char *filename,
const struct grub_dirhook_info *info)
__attribute__ ((unused)))
{
if (device->disk->dev->id != GRUB_DISK_DEVICE_PXE_ID)
return grub_error (GRUB_ERR_IO, "not a pxe disk");
return GRUB_ERR_NONE;
}
static grub_err_t
grub_pxefs_open (struct grub_file *file, const char *name)
{
union
{
struct grub_pxenv_tftp_get_fsize c1;
struct grub_pxenv_tftp_open c2;
} c;
struct grub_pxe_data *data;
struct grub_pxe_disk_data *disk_data = file->device->disk->data;
grub_file_t file_int, bufio;
if (file->device->disk->dev->id != GRUB_DISK_DEVICE_PXE_ID)
return grub_error (GRUB_ERR_IO, "not a pxe disk");
if (curr_file != 0)
{
grub_pxe_call (GRUB_PXENV_TFTP_CLOSE, &c.c2, pxe_rm_entry);
curr_file = 0;
}
c.c1.server_ip = disk_data->server_ip;
c.c1.gateway_ip = disk_data->gateway_ip;
grub_strcpy ((char *)&c.c1.filename[0], name);
grub_pxe_call (GRUB_PXENV_TFTP_GET_FSIZE, &c.c1, pxe_rm_entry);
if (c.c1.status)
return grub_error (GRUB_ERR_FILE_NOT_FOUND, "file not found");
file->size = c.c1.file_size;
c.c2.tftp_port = grub_cpu_to_be16 (GRUB_PXE_TFTP_PORT);
c.c2.packet_size = grub_pxe_blksize;
grub_pxe_call (GRUB_PXENV_TFTP_OPEN, &c.c2, pxe_rm_entry);
if (c.c2.status)
return grub_error (GRUB_ERR_BAD_FS, "open fails");
data = grub_zalloc (sizeof (struct grub_pxe_data) + grub_strlen (name) + 1);
if (! data)
return grub_errno;
data->block_size = c.c2.packet_size;
grub_strcpy (data->filename, name);
file_int = grub_malloc (sizeof (*file_int));
if (! file_int)
{
grub_free (data);
return grub_errno;
}
file->data = data;
grub_memcpy (file_int, file, sizeof (struct grub_file));
curr_file = file_int;
bufio = grub_bufio_open (file_int, data->block_size);
if (! bufio)
{
grub_free (file_int);
grub_free (data);
return grub_errno;
}
grub_memcpy (file, bufio, sizeof (struct grub_file));
return GRUB_ERR_NONE;
}
static grub_ssize_t
grub_pxefs_read (grub_file_t file, char *buf, grub_size_t len)
{
struct grub_pxenv_tftp_read c;
struct grub_pxe_data *data;
struct grub_pxe_disk_data *disk_data = file->device->disk->data;
grub_uint32_t pn, r;
data = file->data;
pn = grub_divmod64 (file->offset, data->block_size, &r);
if (r)
{
grub_error (GRUB_ERR_BAD_FS,
"read access must be aligned to packet size");
return -1;
}
if ((curr_file != file) || (data->packet_number > pn))
{
struct grub_pxenv_tftp_open o;
if (curr_file != 0)
grub_pxe_call (GRUB_PXENV_TFTP_CLOSE, &o, pxe_rm_entry);
o.server_ip = disk_data->server_ip;
o.gateway_ip = disk_data->gateway_ip;
grub_strcpy ((char *)&o.filename[0], data->filename);
o.tftp_port = grub_cpu_to_be16 (GRUB_PXE_TFTP_PORT);
o.packet_size = grub_pxe_blksize;
grub_pxe_call (GRUB_PXENV_TFTP_OPEN, &o, pxe_rm_entry);
if (o.status)
{
grub_error (GRUB_ERR_BAD_FS, "open fails");
return -1;
}
data->block_size = o.packet_size;
data->packet_number = 0;
curr_file = file;
}
c.buffer = SEGOFS (GRUB_MEMORY_MACHINE_SCRATCH_ADDR);
while (pn >= data->packet_number)
{
c.buffer_size = data->block_size;
grub_pxe_call (GRUB_PXENV_TFTP_READ, &c, pxe_rm_entry);
if (c.status)
{
grub_error (GRUB_ERR_BAD_FS, "read fails");
return -1;
}
data->packet_number++;
}
grub_memcpy (buf, (char *) GRUB_MEMORY_MACHINE_SCRATCH_ADDR, len);
return len;
}
static grub_err_t
grub_pxefs_close (grub_file_t file)
{
struct grub_pxenv_tftp_close c;
if (curr_file == file)
{
grub_pxe_call (GRUB_PXENV_TFTP_CLOSE, &c, pxe_rm_entry);
curr_file = 0;
}
grub_free (file->data);
return GRUB_ERR_NONE;
}
static grub_err_t
grub_pxefs_label (grub_device_t device __attribute ((unused)),
char **label __attribute ((unused)))
{
*label = 0;
return GRUB_ERR_NONE;
}
static struct grub_fs grub_pxefs_fs =
{
.name = "pxefs",
.dir = grub_pxefs_dir,
.open = grub_pxefs_open,
.read = grub_pxefs_read,
.close = grub_pxefs_close,
.label = grub_pxefs_label,
.next = 0
};
static char *
grub_env_write_readonly (struct grub_env_var *var __attribute__ ((unused)),
const char *val __attribute__ ((unused)))
{
return NULL;
}
static void
set_mac_env (grub_uint8_t *mac_addr, grub_size_t mac_len)
{
char buf[(sizeof ("XX:") - 1) * mac_len + 1];
char *ptr = buf;
unsigned i;
for (i = 0; i < mac_len; i++)
{
grub_snprintf (ptr, sizeof (buf) - (ptr - buf),
"%02x:", mac_addr[i] & 0xff);
ptr += (sizeof ("XX:") - 1);
}
if (mac_len)
*(ptr - 1) = 0;
else
buf[0] = 0;
grub_env_set ("net_pxe_mac", buf);
/* XXX: Is it possible to change MAC in PXE? */
grub_register_variable_hook ("net_pxe_mac", 0, grub_env_write_readonly);
}
static void
set_env_limn_ro (const char *varname, char *value, grub_size_t len)
{
char c;
c = value[len];
value[len] = 0;
grub_env_set (varname, value);
value[len] = c;
grub_register_variable_hook (varname, 0, grub_env_write_readonly);
}
static void
parse_dhcp_vendor (void *vend, int limit)
{
grub_uint8_t *ptr, *ptr0;
ptr = ptr0 = vend;
if (grub_be_to_cpu32 (*(grub_uint32_t *) ptr) != 0x63825363)
return;
ptr = ptr + sizeof (grub_uint32_t);
while (ptr - ptr0 < limit)
{
grub_uint8_t tagtype;
grub_uint8_t taglength;
tagtype = *ptr++;
/* Pad tag. */
if (tagtype == 0)
continue;
/* End tag. */
if (tagtype == 0xff)
return;
taglength = *ptr++;
switch (tagtype)
{
case 12:
set_env_limn_ro ("net_pxe_hostname", (char *) ptr, taglength);
break;
case 15:
set_env_limn_ro ("net_pxe_domain", (char *) ptr, taglength);
break;
case 17:
set_env_limn_ro ("net_pxe_rootpath", (char *) ptr, taglength);
break;
case 18:
set_env_limn_ro ("net_pxe_extensionspath", (char *) ptr, taglength);
break;
/* If you need any other options please contact GRUB
developpement team. */
}
ptr += taglength;
}
}
static void
grub_pxe_detect (void)
{
struct grub_pxenv *pxenv;
struct grub_pxenv_get_cached_info ci;
struct grub_pxenv_boot_player *bp;
pxenv = grub_pxe_scan ();
if (! pxenv)
return;
ci.packet_type = GRUB_PXENV_PACKET_TYPE_DHCP_ACK;
ci.buffer = 0;
ci.buffer_size = 0;
grub_pxe_call (GRUB_PXENV_GET_CACHED_INFO, &ci, pxe_rm_entry);
if (ci.status)
return;
bp = LINEAR (ci.buffer);
grub_pxe_your_ip = bp->your_ip;
grub_pxe_default_server_ip = bp->server_ip;
grub_pxe_default_gateway_ip = bp->gateway_ip;
set_mac_env (bp->mac_addr, bp->hw_len < sizeof (bp->mac_addr) ? bp->hw_len
: sizeof (bp->mac_addr));
set_env_limn_ro ("net_pxe_boot_file", (char *) bp->boot_file,
sizeof (bp->boot_file));
set_env_limn_ro ("net_pxe_dhcp_server_name", (char *) bp->server_name,
sizeof (bp->server_name));
parse_dhcp_vendor (&bp->vendor, sizeof (bp->vendor));
grub_pxe_pxenv = pxenv;
}
void
grub_pxe_unload (void)
{
if (grub_pxe_pxenv)
{
grub_fs_unregister (&grub_pxefs_fs);
grub_disk_dev_unregister (&grub_pxe_dev);
grub_pxe_pxenv = 0;
}
}
static void
set_ip_env (char *varname, grub_uint32_t ip)
{
char buf[sizeof ("XXX.XXX.XXX.XXX")];
grub_snprintf (buf, sizeof (buf), "%d.%d.%d.%d", (ip & 0xff),
(ip >> 8) & 0xff, (ip >> 16) & 0xff, (ip >> 24) & 0xff);
grub_env_set (varname, buf);
}
static char *
write_ip_env (grub_uint32_t *ip, const char *val)
{
char *buf;
grub_err_t err;
grub_uint32_t newip;
err = parse_ip (val, &newip, 0);
if (err)
return 0;
/* Normalize the IP. */
buf = grub_xasprintf ("%d.%d.%d.%d", (newip & 0xff), (newip >> 8) & 0xff,
(newip >> 16) & 0xff, (newip >> 24) & 0xff);
if (!buf)
return 0;
*ip = newip;
return buf;
}
static char *
grub_env_write_pxe_default_server (struct grub_env_var *var
__attribute__ ((unused)),
const char *val)
{
return write_ip_env (&grub_pxe_default_server_ip, val);
}
static char *
grub_env_write_pxe_default_gateway (struct grub_env_var *var
__attribute__ ((unused)),
const char *val)
{
return write_ip_env (&grub_pxe_default_gateway_ip, val);
}
static char *
grub_env_write_pxe_blocksize (struct grub_env_var *var __attribute__ ((unused)),
const char *val)
{
unsigned size;
char *buf;
size = grub_strtoul (val, 0, 0);
if (grub_errno)
return 0;
if (size < GRUB_PXE_MIN_BLKSIZE)
size = GRUB_PXE_MIN_BLKSIZE;
else if (size > GRUB_PXE_MAX_BLKSIZE)
size = GRUB_PXE_MAX_BLKSIZE;
buf = grub_xasprintf ("%d", size);
if (!buf)
return 0;
grub_pxe_blksize = size;
return buf;
}
GRUB_MOD_INIT(pxe)
{
grub_pxe_detect ();
if (grub_pxe_pxenv)
{
char *buf;
buf = grub_xasprintf ("%d", grub_pxe_blksize);
if (buf)
grub_env_set ("pxe_blksize", buf);
grub_free (buf);
set_ip_env ("pxe_default_server", grub_pxe_default_server_ip);
set_ip_env ("pxe_default_gateway", grub_pxe_default_gateway_ip);
set_ip_env ("net_pxe_ip", grub_pxe_your_ip);
grub_register_variable_hook ("pxe_default_server", 0,
grub_env_write_pxe_default_server);
grub_register_variable_hook ("pxe_default_gateway", 0,
grub_env_write_pxe_default_gateway);
/* XXX: Is it possible to change IP in PXE? */
grub_register_variable_hook ("net_pxe_ip", 0,
grub_env_write_readonly);
grub_register_variable_hook ("pxe_blksize", 0,
grub_env_write_pxe_blocksize);
grub_disk_dev_register (&grub_pxe_dev);
grub_fs_register (&grub_pxefs_fs);
}
}
GRUB_MOD_FINI(pxe)
{
grub_pxe_unload ();
}