grub/grub-core/net/icmp6.c
Josef Bacik eb9f401fc1 net: fix ipv6 routing
ipv6 routing in grub2 is broken, we cannot talk to anything outside our local
network or anything that doesn't route in our global namespace.  This patch
fixes this by doing a couple of things

1) Read the router information off of the router advertisement.  If we have a
router lifetime we need to take the source address and create a route from it.

2) Changes the routing stuff slightly to allow you to specify a gateway _and_ an
interface.  Since the router advertisements come in on the link local address we
need to associate it with the global address on the card.  So when we are
processing the router advertisement, either use the SLAAC interface we create
and add the route to that interface, or loop through the global addresses we
currently have on our interface and associate it with one of those addresses.
We need to have a special case here for the default route so that it gets used,
we do this by setting the masksize to 0 to mean it encompasses all networks.
The routing code will automatically select the best route so if there is a
closer match we will use that.

With this patch I can now talk to ipv6 addresses outside of my local network.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
2016-02-25 22:38:52 +03:00

679 lines
18 KiB
C

/*
* 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/net/ip.h>
#include <grub/net/netbuff.h>
struct icmp_header
{
grub_uint8_t type;
grub_uint8_t code;
grub_uint16_t checksum;
} GRUB_PACKED;
struct ping_header
{
grub_uint16_t id;
grub_uint16_t seq;
} GRUB_PACKED;
struct router_adv
{
grub_uint8_t ttl;
grub_uint8_t flags;
grub_uint16_t router_lifetime;
grub_uint32_t reachable_time;
grub_uint32_t retrans_timer;
grub_uint8_t options[0];
} GRUB_PACKED;
struct option_header
{
grub_uint8_t type;
grub_uint8_t len;
} GRUB_PACKED;
struct prefix_option
{
struct option_header header;
grub_uint8_t prefixlen;
grub_uint8_t flags;
grub_uint32_t valid_lifetime;
grub_uint32_t preferred_lifetime;
grub_uint32_t reserved;
grub_uint64_t prefix[2];
} GRUB_PACKED;
struct neighbour_solicit
{
grub_uint32_t reserved;
grub_uint64_t target[2];
} GRUB_PACKED;
struct neighbour_advertise
{
grub_uint32_t flags;
grub_uint64_t target[2];
} GRUB_PACKED;
struct router_solicit
{
grub_uint32_t reserved;
} GRUB_PACKED;
enum
{
FLAG_SLAAC = 0x40
};
enum
{
ICMP6_ECHO = 128,
ICMP6_ECHO_REPLY = 129,
ICMP6_ROUTER_SOLICIT = 133,
ICMP6_ROUTER_ADVERTISE = 134,
ICMP6_NEIGHBOUR_SOLICIT = 135,
ICMP6_NEIGHBOUR_ADVERTISE = 136,
};
enum
{
OPTION_SOURCE_LINK_LAYER_ADDRESS = 1,
OPTION_TARGET_LINK_LAYER_ADDRESS = 2,
OPTION_PREFIX = 3
};
enum
{
FLAG_SOLICITED = (1 << 30),
FLAG_OVERRIDE = (1 << 29)
};
grub_err_t
grub_net_recv_icmp6_packet (struct grub_net_buff *nb,
struct grub_net_card *card,
struct grub_net_network_level_interface *inf,
const grub_net_link_level_address_t *ll_src,
const grub_net_network_level_address_t *source,
const grub_net_network_level_address_t *dest,
grub_uint8_t ttl)
{
struct icmp_header *icmph;
struct grub_net_network_level_interface *orig_inf = inf;
grub_err_t err;
grub_uint16_t checksum;
icmph = (struct icmp_header *) nb->data;
if (nb->tail - nb->data < (grub_ssize_t) sizeof (*icmph))
{
grub_netbuff_free (nb);
return GRUB_ERR_NONE;
}
checksum = icmph->checksum;
icmph->checksum = 0;
if (checksum != grub_net_ip_transport_checksum (nb,
GRUB_NET_IP_ICMPV6,
source,
dest))
{
grub_dprintf ("net", "invalid ICMPv6 checksum: %04x instead of %04x\n",
checksum,
grub_net_ip_transport_checksum (nb,
GRUB_NET_IP_ICMPV6,
source,
dest));
icmph->checksum = checksum;
grub_netbuff_free (nb);
return GRUB_ERR_NONE;
}
icmph->checksum = checksum;
err = grub_netbuff_pull (nb, sizeof (*icmph));
if (err)
{
grub_netbuff_free (nb);
return err;
}
grub_dprintf ("net", "ICMPv6 message: %02x, %02x\n",
icmph->type, icmph->code);
switch (icmph->type)
{
case ICMP6_ECHO:
/* Don't accept multicast pings. */
if (!inf)
break;
{
struct grub_net_buff *nb_reply;
struct icmp_header *icmphr;
if (icmph->code)
break;
nb_reply = grub_netbuff_alloc (nb->tail - nb->data + 512);
if (!nb_reply)
{
grub_netbuff_free (nb);
return grub_errno;
}
err = grub_netbuff_reserve (nb_reply, nb->tail - nb->data + 512);
if (err)
goto ping_fail;
err = grub_netbuff_push (nb_reply, nb->tail - nb->data);
if (err)
goto ping_fail;
grub_memcpy (nb_reply->data, nb->data, nb->tail - nb->data);
err = grub_netbuff_push (nb_reply, sizeof (*icmphr));
if (err)
goto ping_fail;
icmphr = (struct icmp_header *) nb_reply->data;
icmphr->type = ICMP6_ECHO_REPLY;
icmphr->code = 0;
icmphr->checksum = 0;
icmphr->checksum = grub_net_ip_transport_checksum (nb_reply,
GRUB_NET_IP_ICMPV6,
&inf->address,
source);
err = grub_net_send_ip_packet (inf, source, ll_src, nb_reply,
GRUB_NET_IP_ICMPV6);
ping_fail:
grub_netbuff_free (nb);
grub_netbuff_free (nb_reply);
return err;
}
case ICMP6_NEIGHBOUR_SOLICIT:
{
struct neighbour_solicit *nbh;
struct grub_net_buff *nb_reply;
struct option_header *ohdr;
struct neighbour_advertise *adv;
struct icmp_header *icmphr;
grub_uint8_t *ptr;
if (icmph->code)
break;
if (ttl != 0xff)
break;
nbh = (struct neighbour_solicit *) nb->data;
err = grub_netbuff_pull (nb, sizeof (*nbh));
if (err)
{
grub_netbuff_free (nb);
return err;
}
for (ptr = (grub_uint8_t *) nb->data; ptr < nb->tail;
ptr += ohdr->len * 8)
{
ohdr = (struct option_header *) ptr;
if (ohdr->len == 0 || ptr + 8 * ohdr->len > nb->tail)
{
grub_netbuff_free (nb);
return GRUB_ERR_NONE;
}
if (ohdr->type == OPTION_SOURCE_LINK_LAYER_ADDRESS
&& ohdr->len == 1)
{
grub_net_link_level_address_t ll_address;
ll_address.type = GRUB_NET_LINK_LEVEL_PROTOCOL_ETHERNET;
grub_memcpy (ll_address.mac, ohdr + 1, sizeof (ll_address.mac));
grub_net_link_layer_add_address (card, source, &ll_address, 0);
}
}
FOR_NET_NETWORK_LEVEL_INTERFACES (inf)
{
if (inf->card == card
&& inf->address.type == GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6
&& grub_memcmp (&inf->address.ipv6, &nbh->target, 16) == 0)
break;
}
if (!inf)
break;
nb_reply = grub_netbuff_alloc (sizeof (struct neighbour_advertise)
+ sizeof (struct option_header)
+ 6
+ sizeof (struct icmp_header)
+ GRUB_NET_OUR_IPV6_HEADER_SIZE
+ GRUB_NET_MAX_LINK_HEADER_SIZE);
if (!nb_reply)
{
grub_netbuff_free (nb);
return grub_errno;
}
err = grub_netbuff_reserve (nb_reply,
sizeof (struct neighbour_advertise)
+ sizeof (struct option_header)
+ 6
+ sizeof (struct icmp_header)
+ GRUB_NET_OUR_IPV6_HEADER_SIZE
+ GRUB_NET_MAX_LINK_HEADER_SIZE);
if (err)
goto ndp_fail;
err = grub_netbuff_push (nb_reply, 6);
if (err)
goto ndp_fail;
grub_memcpy (nb_reply->data, inf->hwaddress.mac, 6);
err = grub_netbuff_push (nb_reply, sizeof (*ohdr));
if (err)
goto ndp_fail;
ohdr = (struct option_header *) nb_reply->data;
ohdr->type = OPTION_TARGET_LINK_LAYER_ADDRESS;
ohdr->len = 1;
err = grub_netbuff_push (nb_reply, sizeof (*adv));
if (err)
goto ndp_fail;
adv = (struct neighbour_advertise *) nb_reply->data;
adv->flags = grub_cpu_to_be32_compile_time (FLAG_SOLICITED
| FLAG_OVERRIDE);
grub_memcpy (&adv->target, &nbh->target, 16);
err = grub_netbuff_push (nb_reply, sizeof (*icmphr));
if (err)
goto ndp_fail;
icmphr = (struct icmp_header *) nb_reply->data;
icmphr->type = ICMP6_NEIGHBOUR_ADVERTISE;
icmphr->code = 0;
icmphr->checksum = 0;
icmphr->checksum = grub_net_ip_transport_checksum (nb_reply,
GRUB_NET_IP_ICMPV6,
&inf->address,
source);
err = grub_net_send_ip_packet (inf, source, ll_src, nb_reply,
GRUB_NET_IP_ICMPV6);
ndp_fail:
grub_netbuff_free (nb);
grub_netbuff_free (nb_reply);
return err;
}
case ICMP6_NEIGHBOUR_ADVERTISE:
{
struct neighbour_advertise *nbh;
grub_uint8_t *ptr;
struct option_header *ohdr;
if (icmph->code)
break;
if (ttl != 0xff)
break;
nbh = (struct neighbour_advertise *) nb->data;
err = grub_netbuff_pull (nb, sizeof (*nbh));
if (err)
{
grub_netbuff_free (nb);
return err;
}
for (ptr = (grub_uint8_t *) nb->data; ptr < nb->tail;
ptr += ohdr->len * 8)
{
ohdr = (struct option_header *) ptr;
if (ohdr->len == 0 || ptr + 8 * ohdr->len > nb->tail)
{
grub_netbuff_free (nb);
return GRUB_ERR_NONE;
}
if (ohdr->type == OPTION_TARGET_LINK_LAYER_ADDRESS
&& ohdr->len == 1)
{
grub_net_link_level_address_t ll_address;
ll_address.type = GRUB_NET_LINK_LEVEL_PROTOCOL_ETHERNET;
grub_memcpy (ll_address.mac, ohdr + 1, sizeof (ll_address.mac));
grub_net_link_layer_add_address (card, source, &ll_address, 0);
}
}
break;
}
case ICMP6_ROUTER_ADVERTISE:
{
grub_uint8_t *ptr;
struct option_header *ohdr;
struct router_adv *radv;
struct grub_net_network_level_interface *route_inf = NULL;
int default_route = 0;
if (icmph->code)
break;
radv = (struct router_adv *)nb->data;
err = grub_netbuff_pull (nb, sizeof (struct router_adv));
if (err)
{
grub_netbuff_free (nb);
return err;
}
if (grub_be_to_cpu16 (radv->router_lifetime) > 0)
{
struct grub_net_route *route;
FOR_NET_ROUTES (route)
{
if (!grub_memcmp (&route->gw, source, sizeof (route->gw)))
break;
}
if (route == NULL)
default_route = 1;
}
for (ptr = (grub_uint8_t *) nb->data; ptr < nb->tail;
ptr += ohdr->len * 8)
{
ohdr = (struct option_header *) ptr;
if (ohdr->len == 0 || ptr + 8 * ohdr->len > nb->tail)
{
grub_netbuff_free (nb);
return GRUB_ERR_NONE;
}
if (ohdr->type == OPTION_SOURCE_LINK_LAYER_ADDRESS
&& ohdr->len == 1)
{
grub_net_link_level_address_t ll_address;
ll_address.type = GRUB_NET_LINK_LEVEL_PROTOCOL_ETHERNET;
grub_memcpy (ll_address.mac, ohdr + 1, sizeof (ll_address.mac));
grub_net_link_layer_add_address (card, source, &ll_address, 0);
}
if (ohdr->type == OPTION_PREFIX && ohdr->len == 4)
{
struct prefix_option *opt = (struct prefix_option *) ptr;
struct grub_net_slaac_mac_list *slaac;
if (!(opt->flags & FLAG_SLAAC)
|| (grub_be_to_cpu64 (opt->prefix[0]) >> 48) == 0xfe80
|| (grub_be_to_cpu32 (opt->preferred_lifetime)
> grub_be_to_cpu32 (opt->valid_lifetime))
|| opt->prefixlen != 64)
{
grub_dprintf ("net", "discarded prefix: %d, %d, %d, %d\n",
!(opt->flags & FLAG_SLAAC),
(grub_be_to_cpu64 (opt->prefix[0]) >> 48) == 0xfe80,
(grub_be_to_cpu32 (opt->preferred_lifetime)
> grub_be_to_cpu32 (opt->valid_lifetime)),
opt->prefixlen != 64);
continue;
}
for (slaac = card->slaac_list; slaac; slaac = slaac->next)
{
grub_net_network_level_address_t addr;
grub_net_network_level_netaddress_t netaddr;
if (slaac->address.type
!= GRUB_NET_LINK_LEVEL_PROTOCOL_ETHERNET)
continue;
addr.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6;
addr.ipv6[0] = opt->prefix[0];
addr.ipv6[1] = grub_net_ipv6_get_id (&slaac->address);
netaddr.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6;
netaddr.ipv6.base[0] = opt->prefix[0];
netaddr.ipv6.base[1] = 0;
netaddr.ipv6.masksize = 64;
FOR_NET_NETWORK_LEVEL_INTERFACES (inf)
{
if (inf->card == card
&& grub_net_addr_cmp (&inf->address, &addr) == 0)
break;
}
/* Update lease time if needed here once we have
lease times. */
if (inf)
{
if (!route_inf)
route_inf = inf;
continue;
}
grub_dprintf ("net", "creating slaac\n");
{
char *name;
name = grub_xasprintf ("%s:%d",
slaac->name, slaac->slaac_counter++);
if (!name)
{
grub_errno = GRUB_ERR_NONE;
continue;
}
inf = grub_net_add_addr (name,
card, &addr,
&slaac->address, 0);
if (!route_inf)
route_inf = inf;
grub_net_add_route (name, netaddr, inf);
grub_free (name);
}
}
}
}
if (default_route)
{
char *name;
grub_net_network_level_netaddress_t netaddr;
name = grub_xasprintf ("%s:ra:default6", card->name);
if (!name)
{
grub_errno = GRUB_ERR_NONE;
goto next;
}
/* Default routes take alll of the traffic, so make the mask huge */
netaddr.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6;
netaddr.ipv6.masksize = 0;
netaddr.ipv6.base[0] = 0;
netaddr.ipv6.base[1] = 0;
/* May not have gotten slaac info, find a global address on this
card. */
if (route_inf == NULL)
{
FOR_NET_NETWORK_LEVEL_INTERFACES (inf)
{
if (inf->card == card && inf != orig_inf
&& inf->address.type == GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6
&& grub_net_hwaddr_cmp(&inf->hwaddress,
&orig_inf->hwaddress) == 0)
{
route_inf = inf;
break;
}
}
}
if (route_inf != NULL)
grub_net_add_route_gw (name, netaddr, *source, route_inf);
grub_free (name);
}
next:
if (ptr != nb->tail)
break;
}
};
grub_netbuff_free (nb);
return GRUB_ERR_NONE;
}
grub_err_t
grub_net_icmp6_send_request (struct grub_net_network_level_interface *inf,
const grub_net_network_level_address_t *proto_addr)
{
struct grub_net_buff *nb;
grub_err_t err = GRUB_ERR_NONE;
int i;
struct option_header *ohdr;
struct neighbour_solicit *sol;
struct icmp_header *icmphr;
grub_net_network_level_address_t multicast;
grub_net_link_level_address_t ll_multicast;
grub_uint8_t *nbd;
multicast.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6;
multicast.ipv6[0] = grub_be_to_cpu64_compile_time (0xff02ULL << 48);
multicast.ipv6[1] = (grub_be_to_cpu64_compile_time (0x01ff000000ULL)
| (proto_addr->ipv6[1]
& grub_be_to_cpu64_compile_time (0xffffff)));
err = grub_net_link_layer_resolve (inf, &multicast, &ll_multicast);
if (err)
return err;
nb = grub_netbuff_alloc (sizeof (struct neighbour_solicit)
+ sizeof (struct option_header)
+ 6
+ sizeof (struct icmp_header)
+ GRUB_NET_OUR_IPV6_HEADER_SIZE
+ GRUB_NET_MAX_LINK_HEADER_SIZE);
if (!nb)
return grub_errno;
err = grub_netbuff_reserve (nb,
sizeof (struct neighbour_solicit)
+ sizeof (struct option_header)
+ 6
+ sizeof (struct icmp_header)
+ GRUB_NET_OUR_IPV6_HEADER_SIZE
+ GRUB_NET_MAX_LINK_HEADER_SIZE);
err = grub_netbuff_push (nb, 6);
if (err)
goto fail;
grub_memcpy (nb->data, inf->hwaddress.mac, 6);
err = grub_netbuff_push (nb, sizeof (*ohdr));
if (err)
goto fail;
ohdr = (struct option_header *) nb->data;
ohdr->type = OPTION_SOURCE_LINK_LAYER_ADDRESS;
ohdr->len = 1;
err = grub_netbuff_push (nb, sizeof (*sol));
if (err)
goto fail;
sol = (struct neighbour_solicit *) nb->data;
sol->reserved = 0;
grub_memcpy (&sol->target, &proto_addr->ipv6, 16);
err = grub_netbuff_push (nb, sizeof (*icmphr));
if (err)
goto fail;
icmphr = (struct icmp_header *) nb->data;
icmphr->type = ICMP6_NEIGHBOUR_SOLICIT;
icmphr->code = 0;
icmphr->checksum = 0;
icmphr->checksum = grub_net_ip_transport_checksum (nb,
GRUB_NET_IP_ICMPV6,
&inf->address,
&multicast);
nbd = nb->data;
err = grub_net_send_ip_packet (inf, &multicast, &ll_multicast, nb,
GRUB_NET_IP_ICMPV6);
if (err)
goto fail;
for (i = 0; i < GRUB_NET_TRIES; i++)
{
if (grub_net_link_layer_resolve_check (inf, proto_addr))
break;
grub_net_poll_cards (GRUB_NET_INTERVAL + (i * GRUB_NET_INTERVAL_ADDITION),
0);
if (grub_net_link_layer_resolve_check (inf, proto_addr))
break;
nb->data = nbd;
err = grub_net_send_ip_packet (inf, &multicast, &ll_multicast, nb,
GRUB_NET_IP_ICMPV6);
if (err)
break;
}
fail:
grub_netbuff_free (nb);
return err;
}
grub_err_t
grub_net_icmp6_send_router_solicit (struct grub_net_network_level_interface *inf)
{
struct grub_net_buff *nb;
grub_err_t err = GRUB_ERR_NONE;
grub_net_network_level_address_t multicast;
grub_net_link_level_address_t ll_multicast;
struct option_header *ohdr;
struct router_solicit *sol;
struct icmp_header *icmphr;
multicast.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6;
multicast.ipv6[0] = grub_cpu_to_be64_compile_time (0xff02ULL << 48);
multicast.ipv6[1] = grub_cpu_to_be64_compile_time (0x02ULL);
err = grub_net_link_layer_resolve (inf, &multicast, &ll_multicast);
if (err)
return err;
nb = grub_netbuff_alloc (sizeof (struct router_solicit)
+ sizeof (struct option_header)
+ 6
+ sizeof (struct icmp_header)
+ GRUB_NET_OUR_IPV6_HEADER_SIZE
+ GRUB_NET_MAX_LINK_HEADER_SIZE);
if (!nb)
return grub_errno;
err = grub_netbuff_reserve (nb,
sizeof (struct router_solicit)
+ sizeof (struct option_header)
+ 6
+ sizeof (struct icmp_header)
+ GRUB_NET_OUR_IPV6_HEADER_SIZE
+ GRUB_NET_MAX_LINK_HEADER_SIZE);
if (err)
goto fail;
err = grub_netbuff_push (nb, 6);
if (err)
goto fail;
grub_memcpy (nb->data, inf->hwaddress.mac, 6);
err = grub_netbuff_push (nb, sizeof (*ohdr));
if (err)
goto fail;
ohdr = (struct option_header *) nb->data;
ohdr->type = OPTION_SOURCE_LINK_LAYER_ADDRESS;
ohdr->len = 1;
err = grub_netbuff_push (nb, sizeof (*sol));
if (err)
goto fail;
sol = (struct router_solicit *) nb->data;
sol->reserved = 0;
err = grub_netbuff_push (nb, sizeof (*icmphr));
if (err)
goto fail;
icmphr = (struct icmp_header *) nb->data;
icmphr->type = ICMP6_ROUTER_SOLICIT;
icmphr->code = 0;
icmphr->checksum = 0;
icmphr->checksum = grub_net_ip_transport_checksum (nb,
GRUB_NET_IP_ICMPV6,
&inf->address,
&multicast);
err = grub_net_send_ip_packet (inf, &multicast, &ll_multicast, nb,
GRUB_NET_IP_ICMPV6);
fail:
grub_netbuff_free (nb);
return err;
}