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grub/grub-core/net/bootp.c
Vladimir Serbinenko 17b4355943 * grub-core/net/bootp.c (grub_cmd_dhcpopt): Use snprintf where it 
was intended.
2013-12-21 13:35:28 +01:00

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/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2010,2011 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/net.h>
#include <grub/env.h>
#include <grub/i18n.h>
#include <grub/command.h>
#include <grub/net/ip.h>
#include <grub/net/netbuff.h>
#include <grub/net/udp.h>
#include <grub/datetime.h>
static char *
grub_env_write_readonly (struct grub_env_var *var __attribute__ ((unused)),
const char *val __attribute__ ((unused)))
{
return NULL;
}
static void
set_env_limn_ro (const char *intername, const char *suffix,
const char *value, grub_size_t len)
{
char *varname, *varvalue;
char *ptr;
varname = grub_xasprintf ("net_%s_%s", intername, suffix);
if (!varname)
return;
for (ptr = varname; *ptr; ptr++)
if (*ptr == ':')
*ptr = '_';
varvalue = grub_malloc (len + 1);
if (!varvalue)
{
grub_free (varname);
return;
}
grub_memcpy (varvalue, value, len);
varvalue[len] = 0;
grub_env_set (varname, varvalue);
grub_register_variable_hook (varname, 0, grub_env_write_readonly);
grub_env_export (varname);
grub_free (varname);
grub_free (varvalue);
}
static void
parse_dhcp_vendor (const char *name, const void *vend, int limit, int *mask)
{
const grub_uint8_t *ptr, *ptr0;
ptr = ptr0 = vend;
if (ptr[0] != GRUB_NET_BOOTP_RFC1048_MAGIC_0
|| ptr[1] != GRUB_NET_BOOTP_RFC1048_MAGIC_1
|| ptr[2] != GRUB_NET_BOOTP_RFC1048_MAGIC_2
|| ptr[3] != GRUB_NET_BOOTP_RFC1048_MAGIC_3)
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 == GRUB_NET_BOOTP_PAD)
continue;
/* End tag. */
if (tagtype == GRUB_NET_BOOTP_END)
return;
taglength = *ptr++;
switch (tagtype)
{
case GRUB_NET_BOOTP_NETMASK:
if (taglength == 4)
{
int i;
for (i = 0; i < 32; i++)
if (!(ptr[i / 8] & (1 << (7 - (i % 8)))))
break;
*mask = i;
}
break;
case GRUB_NET_BOOTP_ROUTER:
if (taglength == 4)
{
grub_net_network_level_netaddress_t target;
grub_net_network_level_address_t gw;
char *rname;
target.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
target.ipv4.base = 0;
target.ipv4.masksize = 0;
gw.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
grub_memcpy (&gw.ipv4, ptr, sizeof (gw.ipv4));
rname = grub_xasprintf ("%s:default", name);
if (rname)
grub_net_add_route_gw (rname, target, gw);
grub_free (rname);
}
break;
case GRUB_NET_BOOTP_DNS:
{
int i;
for (i = 0; i < taglength / 4; i++)
{
struct grub_net_network_level_address s;
s.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
s.ipv4 = grub_get_unaligned32 (ptr);
s.option = DNS_OPTION_PREFER_IPV4;
grub_net_add_dns_server (&s);
ptr += 4;
}
}
continue;
case GRUB_NET_BOOTP_HOSTNAME:
set_env_limn_ro (name, "hostname", (const char *) ptr, taglength);
break;
case GRUB_NET_BOOTP_DOMAIN:
set_env_limn_ro (name, "domain", (const char *) ptr, taglength);
break;
case GRUB_NET_BOOTP_ROOT_PATH:
set_env_limn_ro (name, "rootpath", (const char *) ptr, taglength);
break;
case GRUB_NET_BOOTP_EXTENSIONS_PATH:
set_env_limn_ro (name, "extensionspath", (const char *) ptr, taglength);
break;
/* If you need any other options please contact GRUB
development team. */
}
ptr += taglength;
}
}
#define OFFSET_OF(x, y) ((grub_size_t)((grub_uint8_t *)((y)->x) - (grub_uint8_t *)(y)))
struct grub_net_network_level_interface *
grub_net_configure_by_dhcp_ack (const char *name,
struct grub_net_card *card,
grub_net_interface_flags_t flags,
const struct grub_net_bootp_packet *bp,
grub_size_t size,
int is_def, char **device, char **path)
{
grub_net_network_level_address_t addr;
grub_net_link_level_address_t hwaddr;
struct grub_net_network_level_interface *inter;
int mask = -1;
addr.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
addr.ipv4 = bp->your_ip;
if (device)
*device = 0;
if (path)
*path = 0;
grub_memcpy (hwaddr.mac, bp->mac_addr,
bp->hw_len < sizeof (hwaddr.mac) ? bp->hw_len
: sizeof (hwaddr.mac));
hwaddr.type = GRUB_NET_LINK_LEVEL_PROTOCOL_ETHERNET;
inter = grub_net_add_addr (name, card, &addr, &hwaddr, flags);
if (bp->gateway_ip)
{
grub_net_network_level_netaddress_t target;
grub_net_network_level_address_t gw;
char *rname;
target.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
target.ipv4.base = bp->server_ip;
target.ipv4.masksize = 32;
gw.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
gw.ipv4 = bp->gateway_ip;
rname = grub_xasprintf ("%s:gw", name);
if (rname)
grub_net_add_route_gw (rname, target, gw);
grub_free (rname);
target.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
target.ipv4.base = bp->gateway_ip;
target.ipv4.masksize = 32;
grub_net_add_route (name, target, inter);
}
if (size > OFFSET_OF (boot_file, bp))
set_env_limn_ro (name, "boot_file", (char *) bp->boot_file,
sizeof (bp->boot_file));
if (is_def)
grub_net_default_server = 0;
if (is_def && !grub_net_default_server && bp->server_ip)
{
grub_net_default_server = grub_xasprintf ("%d.%d.%d.%d",
((grub_uint8_t *) &bp->server_ip)[0],
((grub_uint8_t *) &bp->server_ip)[1],
((grub_uint8_t *) &bp->server_ip)[2],
((grub_uint8_t *) &bp->server_ip)[3]);
grub_print_error ();
}
if (is_def)
{
grub_env_set ("net_default_interface", name);
grub_env_export ("net_default_interface");
}
if (device && !*device && bp->server_ip)
{
*device = grub_xasprintf ("tftp,%d.%d.%d.%d",
((grub_uint8_t *) &bp->server_ip)[0],
((grub_uint8_t *) &bp->server_ip)[1],
((grub_uint8_t *) &bp->server_ip)[2],
((grub_uint8_t *) &bp->server_ip)[3]);
grub_print_error ();
}
if (size > OFFSET_OF (server_name, bp)
&& bp->server_name[0])
{
set_env_limn_ro (name, "dhcp_server_name", (char *) bp->server_name,
sizeof (bp->server_name));
if (is_def && !grub_net_default_server)
{
grub_net_default_server = grub_strdup (bp->server_name);
grub_print_error ();
}
if (device && !*device)
{
*device = grub_xasprintf ("tftp,%s", bp->server_name);
grub_print_error ();
}
}
if (size > OFFSET_OF (boot_file, bp) && path)
{
*path = grub_strndup (bp->boot_file, sizeof (bp->boot_file));
grub_print_error ();
if (*path)
{
char *slash;
slash = grub_strrchr (*path, '/');
if (slash)
*slash = 0;
else
**path = 0;
}
}
if (size > OFFSET_OF (vendor, bp))
parse_dhcp_vendor (name, &bp->vendor, size - OFFSET_OF (vendor, bp), &mask);
grub_net_add_ipv4_local (inter, mask);
inter->dhcp_ack = grub_malloc (size);
if (inter->dhcp_ack)
{
grub_memcpy (inter->dhcp_ack, bp, size);
inter->dhcp_acklen = size;
}
else
grub_errno = GRUB_ERR_NONE;
return inter;
}
void
grub_net_process_dhcp (struct grub_net_buff *nb,
struct grub_net_card *card)
{
char *name;
struct grub_net_network_level_interface *inf;
name = grub_xasprintf ("%s:dhcp", card->name);
if (!name)
{
grub_print_error ();
return;
}
grub_net_configure_by_dhcp_ack (name, card,
0, (const struct grub_net_bootp_packet *) nb->data,
(nb->tail - nb->data), 0, 0, 0);
grub_free (name);
if (grub_errno)
grub_print_error ();
else
{
FOR_NET_NETWORK_LEVEL_INTERFACES(inf)
if (grub_memcmp (inf->name, card->name, grub_strlen (card->name)) == 0
&& grub_memcmp (inf->name + grub_strlen (card->name),
":dhcp_tmp", sizeof (":dhcp_tmp") - 1) == 0)
{
grub_net_network_level_interface_unregister (inf);
break;
}
}
}
static char
hexdigit (grub_uint8_t val)
{
if (val < 10)
return val + '0';
return val + 'a' - 10;
}
static grub_err_t
grub_cmd_dhcpopt (struct grub_command *cmd __attribute__ ((unused)),
int argc, char **args)
{
struct grub_net_network_level_interface *inter;
int num;
grub_uint8_t *ptr;
grub_uint8_t taglength;
if (argc < 4)
return grub_error (GRUB_ERR_BAD_ARGUMENT,
N_("four arguments expected"));
FOR_NET_NETWORK_LEVEL_INTERFACES (inter)
if (grub_strcmp (inter->name, args[1]) == 0)
break;
if (!inter)
return grub_error (GRUB_ERR_BAD_ARGUMENT,
N_("unrecognised network interface `%s'"), args[1]);
if (!inter->dhcp_ack)
return grub_error (GRUB_ERR_IO, N_("no DHCP info found"));
if (inter->dhcp_acklen <= OFFSET_OF (vendor, inter->dhcp_ack))
return grub_error (GRUB_ERR_IO, N_("no DHCP options found"));
num = grub_strtoul (args[2], 0, 0);
if (grub_errno)
return grub_errno;
ptr = inter->dhcp_ack->vendor;
if (ptr[0] != GRUB_NET_BOOTP_RFC1048_MAGIC_0
|| ptr[1] != GRUB_NET_BOOTP_RFC1048_MAGIC_1
|| ptr[2] != GRUB_NET_BOOTP_RFC1048_MAGIC_2
|| ptr[3] != GRUB_NET_BOOTP_RFC1048_MAGIC_3)
return grub_error (GRUB_ERR_IO, N_("no DHCP options found"));
ptr = ptr + sizeof (grub_uint32_t);
while (1)
{
grub_uint8_t tagtype;
if (ptr >= ((grub_uint8_t *) inter->dhcp_ack) + inter->dhcp_acklen)
return grub_error (GRUB_ERR_IO, N_("no DHCP option %d found"), num);
tagtype = *ptr++;
/* Pad tag. */
if (tagtype == 0)
continue;
/* End tag. */
if (tagtype == 0xff)
return grub_error (GRUB_ERR_IO, N_("no DHCP option %d found"), num);
taglength = *ptr++;
if (tagtype == num)
break;
ptr += taglength;
}
if (grub_strcmp (args[3], "string") == 0)
{
char *val = grub_malloc (taglength + 1);
if (!val)
return grub_errno;
grub_memcpy (val, ptr, taglength);
val[taglength] = 0;
if (args[0][0] == '-' && args[0][1] == 0)
grub_printf ("%s\n", val);
else
return grub_env_set (args[0], val);
return GRUB_ERR_NONE;
}
if (grub_strcmp (args[3], "number") == 0)
{
grub_uint64_t val = 0;
int i;
for (i = 0; i < taglength; i++)
val = (val << 8) | ptr[i];
if (args[0][0] == '-' && args[0][1] == 0)
grub_printf ("%llu\n", (unsigned long long) val);
else
{
char valn[64];
grub_snprintf (valn, sizeof (valn), "%lld\n", (unsigned long long) val);
return grub_env_set (args[0], valn);
}
return GRUB_ERR_NONE;
}
if (grub_strcmp (args[3], "hex") == 0)
{
char *val = grub_malloc (2 * taglength + 1);
int i;
if (!val)
return grub_errno;
for (i = 0; i < taglength; i++)
{
val[2 * i] = hexdigit (ptr[i] >> 4);
val[2 * i + 1] = hexdigit (ptr[i] & 0xf);
}
val[2 * taglength] = 0;
if (args[0][0] == '-' && args[0][1] == 0)
grub_printf ("%s\n", val);
else
return grub_env_set (args[0], val);
return GRUB_ERR_NONE;
}
return grub_error (GRUB_ERR_BAD_ARGUMENT,
N_("unrecognised DHCP option format specification `%s'"),
args[3]);
}
/* FIXME: allow to specify mac address. */
static grub_err_t
grub_cmd_bootp (struct grub_command *cmd __attribute__ ((unused)),
int argc, char **args)
{
struct grub_net_card *card;
struct grub_net_network_level_interface *ifaces;
grub_size_t ncards = 0;
unsigned j = 0;
int interval;
grub_err_t err;
FOR_NET_CARDS (card)
{
if (argc > 0 && grub_strcmp (card->name, args[0]) != 0)
continue;
ncards++;
}
if (ncards == 0)
return grub_error (GRUB_ERR_NET_NO_CARD, N_("no network card found"));
ifaces = grub_zalloc (ncards * sizeof (ifaces[0]));
if (!ifaces)
return grub_errno;
j = 0;
FOR_NET_CARDS (card)
{
if (argc > 0 && grub_strcmp (card->name, args[0]) != 0)
continue;
ifaces[j].card = card;
ifaces[j].next = &ifaces[j+1];
if (j)
ifaces[j].prev = &ifaces[j-1].next;
ifaces[j].name = grub_xasprintf ("%s:dhcp_tmp", card->name);
card->num_ifaces++;
if (!ifaces[j].name)
{
unsigned i;
for (i = 0; i < j; i++)
grub_free (ifaces[i].name);
grub_free (ifaces);
return grub_errno;
}
ifaces[j].address.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_DHCP_RECV;
grub_memcpy (&ifaces[j].hwaddress, &card->default_address,
sizeof (ifaces[j].hwaddress));
j++;
}
ifaces[ncards - 1].next = grub_net_network_level_interfaces;
if (grub_net_network_level_interfaces)
grub_net_network_level_interfaces->prev = & ifaces[ncards - 1].next;
grub_net_network_level_interfaces = &ifaces[0];
ifaces[0].prev = &grub_net_network_level_interfaces;
for (interval = 200; interval < 10000; interval *= 2)
{
int done = 0;
for (j = 0; j < ncards; j++)
{
struct grub_net_bootp_packet *pack;
struct grub_datetime date;
grub_int32_t t = 0;
struct grub_net_buff *nb;
struct udphdr *udph;
grub_net_network_level_address_t target;
grub_net_link_level_address_t ll_target;
if (!ifaces[j].prev)
continue;
nb = grub_netbuff_alloc (sizeof (*pack) + 64 + 128);
if (!nb)
{
grub_netbuff_free (nb);
return grub_errno;
}
err = grub_netbuff_reserve (nb, sizeof (*pack) + 64 + 128);
if (err)
{
grub_netbuff_free (nb);
return err;
}
err = grub_netbuff_push (nb, sizeof (*pack) + 64);
if (err)
{
grub_netbuff_free (nb);
return err;
}
pack = (void *) nb->data;
done = 1;
grub_memset (pack, 0, sizeof (*pack) + 64);
pack->opcode = 1;
pack->hw_type = 1;
pack->hw_len = 6;
err = grub_get_datetime (&date);
if (err || !grub_datetime2unixtime (&date, &t))
{
grub_errno = GRUB_ERR_NONE;
t = 0;
}
pack->ident = grub_cpu_to_be32 (t);
pack->seconds = grub_cpu_to_be16 (t);
grub_memcpy (&pack->mac_addr, &ifaces[j].hwaddress.mac, 6);
grub_netbuff_push (nb, sizeof (*udph));
udph = (struct udphdr *) nb->data;
udph->src = grub_cpu_to_be16 (68);
udph->dst = grub_cpu_to_be16 (67);
udph->chksum = 0;
udph->len = grub_cpu_to_be16 (nb->tail - nb->data);
target.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
target.ipv4 = 0xffffffff;
err = grub_net_link_layer_resolve (&ifaces[j], &target, &ll_target);
if (err)
return err;
udph->chksum = grub_net_ip_transport_checksum (nb, GRUB_NET_IP_UDP,
&ifaces[j].address,
&target);
err = grub_net_send_ip_packet (&ifaces[j], &target, &ll_target, nb,
GRUB_NET_IP_UDP);
grub_netbuff_free (nb);
if (err)
return err;
}
if (!done)
break;
grub_net_poll_cards (interval, 0);
}
err = GRUB_ERR_NONE;
for (j = 0; j < ncards; j++)
{
grub_free (ifaces[j].name);
if (!ifaces[j].prev)
continue;
grub_error_push ();
grub_net_network_level_interface_unregister (&ifaces[j]);
err = grub_error (GRUB_ERR_FILE_NOT_FOUND,
N_("couldn't autoconfigure %s"),
ifaces[j].card->name);
}
grub_free (ifaces);
return err;
}
static grub_command_t cmd_getdhcp, cmd_bootp;
void
grub_bootp_init (void)
{
cmd_bootp = grub_register_command ("net_bootp", grub_cmd_bootp,
N_("[CARD]"),
N_("perform a bootp autoconfiguration"));
cmd_getdhcp = grub_register_command ("net_get_dhcp_option", grub_cmd_dhcpopt,
N_("VAR INTERFACE NUMBER DESCRIPTION"),
N_("retrieve DHCP option and save it into VAR. If VAR is - then print the value."));
}
void
grub_bootp_fini (void)
{
grub_unregister_command (cmd_getdhcp);
grub_unregister_command (cmd_bootp);
}
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