grub_net_add_addr may fail with OOM and we use returned interface
later without any checks.

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>

From RFC1542:

   The 'giaddr' field is rather poorly named.  It exists to facilitate
   the transfer of BOOTREQUEST messages from a client, through BOOTP
   relay agents, to servers on different networks than the client.
   Similarly, it facilitates the delivery of BOOTREPLY messages from the
   servers, through BOOTP relay agents, back to the client.  In no case
   does it represent a general IP router to be used by the client.  A
   BOOTP client MUST set the 'giaddr' field to zero (0.0.0.0) in all
   BOOTREQUEST messages it generates.

   A BOOTP client MUST NOT interpret the 'giaddr' field of a BOOTREPLY
   message to be the IP address of an IP router.  A BOOTP client SHOULD
   completely ignore the contents of the 'giaddr' field in BOOTREPLY
   messages.

Leave code ifdef'd out for the time being in case we see regression.

Suggested by: Rink Springer <rink@rink.nu>
Closes: 43396

This tries to catch all cases where grub_cpu_to_XXX was used for constant
expressions (including sizeof).

* grub-core/net/bootp.c: Remove set_env_limn_ro.
* grub-core/net/net.c: Add grub_env_set_net_property.
* include/grub/net.h: Likewise.

	was intended.

	(parse_dhcp_vendor): Likewise.

Adding multiple questions on a single DNS query is not supportted by
most DNS servers. This patch issues two separate DNS queries
sequentially for ipv4 and then for ipv6.

Fixes: https://savannah.gnu.org/bugs/?39710

 * grub-core/net/bootp.c (parse_dhcp_vendor): Add DNS option.
 * grub-core/net/dns.c (grub_dns_qtype_id): New enum.
 * (grub_net_dns_lookup): Now using separated dns packages.
 * (grub_cmd_nslookup): Add error condition.
 * (grub_cmd_list_dns): Print DNS option.
 * (grub_cmd_add_dns): Add four parameters: --only-ipv4,
 * --only-ipv6, --prefer-ipv4, and --prefer-ipv6.
 * include/grub/net.h (grub_dns_option_t): New enum.
 * (grub_net_network_level_address): option added.
Also-by: Paulo Flabiano Smorigo <pfsmorigo@br.ibm.com>
Signed-off-by: Paulo Flabiano Smorigo <pfsmorigo@br.ibm.com>

	* grub-core/net/bootp.c: Likewise.
	* grub-core/net/dns.c: Likewise.
	* grub-core/net/icmp6.c: Likewise.
	* grub-core/net/net.c: Likewise.

	* grub-core/net/net.c: Likewise.

	present.
	* include/grub/err.h (grub_err_t): New enum value GRUB_ERR_NET_NO_CARD.

	the direct route for server/gateway.

	IP address to server name since we may not hame the DNS.

	* grub-core/net/bootp.c (parse_dhcp_vendor): Parse mask.
	(grub_net_configure_by_dhcp_ack): Use mask and grub_net_add_ipv4_local.
	* grub-core/net/net.c (grub_net_add_addr): Split creating local route
	into ...
	(grub_net_add_ipv4_local): ... this.
	(grub_cmd_addaddr): Use grub_net_add_ipv4_local.
	* include/grub/net.h (GRUB_NET_BOOTP_NETMASK): New enum value.
	(grub_net_add_ipv4_local): New proto.

	* include/grub/net.h (grub_net_poll_cards): New argument stop_condition.
	All users updated.
	* grub-core/net/arp.c (have_pending): New var.
	(pending_req): Likewise.
	(grub_net_arp_send_request): Fill pending_req and use have_pending as
	stop indicator.
	(grub_net_arp_receive): Set have_pending.
	* grub-core/net/dns.c (recv_data): New field stop.
	(recv_hook): Set stop.
	(grub_net_dns_lookup): Init stop and use as stop condition.
	* grub-core/net/http.c (http_establish): Use headers_recv as stop
	condition.
	* grub-core/net/net.c (grub_net_poll_cards): New argument
	stop_condition. Stop when it goes true.
	* grub-core/net/tcp.c (grub_net_tcp_open): Use `established' as stop
	indicator.
	* grub-core/net/tftp.c (tftp_open): Use `have_oack' as stop indicator.

	'_' in variable names.
	* grub-core/net/net.c (grub_net_network_level_interface_register):
	Likewise.

	warning.

	on it.

	* grub-core/commands/cacheinfo.c: Likewise.
	* grub-core/commands/cmp.c: Likewise.
	* grub-core/commands/efi/loadbios.c: Likewise.
	* grub-core/commands/gptsync.c: Likewise.
	* grub-core/commands/ieee1275/suspend.c: Likewise.
	* grub-core/commands/legacycfg.c: Likewise.
	* grub-core/commands/memrw.c: Likewise.
	* grub-core/commands/minicmd.c: Likewise.
	* grub-core/commands/parttool.c: Likewise.
	* grub-core/commands/time.c: Likewise.
	* grub-core/commands/videoinfo.c: Likewise.
	* grub-core/disk/geli.c: Likewise.
	* grub-core/disk/i386/pc/biosdisk.c: Likewise.
	* grub-core/disk/luks.c: Likewise.
	* grub-core/disk/lvm.c: Likewise.
	* grub-core/font/font_cmd.c: Likewise.
	* grub-core/fs/zfs/zfscrypt.c: Likewise.
	* grub-core/fs/zfs/zfsinfo.c: Likewise.
	* grub-core/gfxmenu/view.c: Likewise.
	* grub-core/kern/emu/hostdisk.c: Likewise.
	* grub-core/kern/emu/main.c: Likewise.
	* grub-core/kern/emu/misc.c: Likewise.
	* grub-core/kern/emu/mm.c: Likewise.
	* grub-core/kern/mips/arc/init.c: Likewise.
	* grub-core/kern/mips/loongson/init.c: Likewise.
	* grub-core/kern/partition.c: Likewise.
	* grub-core/lib/i386/halt.c: Likewise.
	* grub-core/lib/mips/arc/reboot.c: Likewise.
	* grub-core/lib/mips/loongson/reboot.c: Likewise.
	* grub-core/loader/i386/pc/chainloader.c: Likewise.
	* grub-core/loader/i386/xnu.c: Likewise.
	* grub-core/loader/multiboot.c: Likewise.
	* grub-core/net/bootp.c: Likewise.
	* grub-core/net/net.c: Likewise.
	* grub-core/normal/term.c: Likewise.
	* grub-core/partmap/bsdlabel.c: Likewise.
	* grub-core/parttool/msdospart.c: Likewise.
	* grub-core/term/gfxterm.c: Likewise.
	* grub-core/term/terminfo.c: Likewise.
	* grub-core/video/i386/pc/vbe.c: Likewise.
	* util/grub-menulst2cfg.c: Likewise.
	* util/grub-mkdevicemap.c: Likewise.
	* util/grub-mklayout.c: Likewise.
	* util/grub-mkrelpath.c: Likewise.
	* util/grub-script-check.c: Likewise.
	* util/ieee1275/grub-ofpathname.c: Likewise.
	* util/resolve.c: Likewise.