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issue separate DNS queries for ipv4 and ipv6

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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>
This commit is contained in:
Gustavo Luiz Duarte 2013-11-05 17:30:20 -02:00 committed by Paulo Flabiano Smorigo
parent 339eacce1b
commit 9e236169e9
No known key found for this signature in database
GPG key ID: 7EAF9619EF7C9B1C
4 changed files with 125 additions and 39 deletions
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21
ChangeLog
View file

@ -1,3 +1,24 @@
2013-11-05 Gustavo Luiz Duarte <gustavold@linux.vnet.ibm.com>
2013-11-05 Paulo Flabiano Smorigo <pfsmorigo@br.ibm.com>
Issue separate DNS queries for ipv4 and ipv6
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.
2013-11-05 Vladimir Testov <vladimir.testov@rosalab.ru>
* grub-core/video/fb/video_fb.c: Merge two blit functions

1
grub-core/net/bootp.c
View file

@ -123,6 +123,7 @@ parse_dhcp_vendor (const char *name, void *vend, int limit, int *mask)
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;
}

133
grub-core/net/dns.c
View file

@ -34,6 +34,12 @@ struct dns_cache_element
#define DNS_CACHE_SIZE 1021
#define DNS_HASH_BASE 423
typedef enum grub_dns_qtype_id
{
GRUB_DNS_QTYPE_A = 1,
GRUB_DNS_QTYPE_AAAA = 28
} grub_dns_qtype_id_t;
static struct dns_cache_element dns_cache[DNS_CACHE_SIZE];
static struct grub_net_network_level_address *dns_servers;
static grub_size_t dns_nservers, dns_servers_alloc;
@ -426,6 +432,7 @@ grub_net_dns_lookup (const char *name,
const char *iptr;
struct dns_header *head;
static grub_uint16_t id = 1;
grub_uint8_t *qtypeptr;
grub_err_t err = GRUB_ERR_NONE;
struct recv_data data = {naddresses, addresses, cache,
grub_cpu_to_be16 (id++), 0, 0, name, 0};
@ -478,8 +485,7 @@ grub_net_dns_lookup (const char *name,
+ GRUB_NET_MAX_LINK_HEADER_SIZE
+ GRUB_NET_UDP_HEADER_SIZE
+ sizeof (struct dns_header)
+ grub_strlen (name) + 2 + 4
+ 2 + 4);
+ grub_strlen (name) + 2 + 4);
if (!nb)
{
grub_free (sockets);
@ -490,7 +496,7 @@ grub_net_dns_lookup (const char *name,
+ GRUB_NET_MAX_LINK_HEADER_SIZE
+ GRUB_NET_UDP_HEADER_SIZE);
grub_netbuff_put (nb, sizeof (struct dns_header)
+ grub_strlen (name) + 2 + 4 + 2 + 4);
+ grub_strlen (name) + 2 + 4);
head = (struct dns_header *) nb->data;
optr = (grub_uint8_t *) (head + 1);
for (iptr = name; *iptr; )
@ -516,20 +522,9 @@ grub_net_dns_lookup (const char *name,
}
*optr++ = 0;
/* Type: A. */
/* Type. */
*optr++ = 0;
*optr++ = 1;
/* Class. */
*optr++ = 0;
*optr++ = 1;
/* Compressed name. */
*optr++ = 0xc0;
*optr++ = 0x0c;
/* Type: AAAA. */
*optr++ = 0;
*optr++ = 28;
qtypeptr = optr++;
/* Class. */
*optr++ = 0;
@ -538,7 +533,7 @@ grub_net_dns_lookup (const char *name,
head->id = data.id;
head->flags = FLAGS_RD;
head->ra_z_r_code = 0;
head->qdcount = grub_cpu_to_be16_compile_time (2);
head->qdcount = grub_cpu_to_be16_compile_time (1);
head->ancount = grub_cpu_to_be16_compile_time (0);
head->nscount = grub_cpu_to_be16_compile_time (0);
head->arcount = grub_cpu_to_be16_compile_time (0);
@ -572,18 +567,33 @@ grub_net_dns_lookup (const char *name,
goto out;
for (j = 0; j < send_servers; j++)
{
grub_err_t err2;
if (!sockets[j])
continue;
nb->data = nbd;
err2 = grub_net_send_udp_packet (sockets[j], nb);
if (err2)
{
grub_errno = GRUB_ERR_NONE;
err = err2;
}
if (*data.naddresses)
goto out;
grub_err_t err2;
if (!sockets[j])
continue;
nb->data = nbd;
grub_size_t t = 0;
do
{
if (servers[j].option == DNS_OPTION_IPV4 ||
((servers[j].option == DNS_OPTION_PREFER_IPV4) && (t++ == 0)) ||
((servers[j].option == DNS_OPTION_PREFER_IPV6) && (t++ == 1)))
*qtypeptr = GRUB_DNS_QTYPE_A;
else
*qtypeptr = GRUB_DNS_QTYPE_AAAA;
grub_dprintf ("dns", "QTYPE: %u QNAME: %s\n", *qtypeptr, name);
err2 = grub_net_send_udp_packet (sockets[j], nb);
if (err2)
{
grub_errno = GRUB_ERR_NONE;
err = err2;
}
if (*data.naddresses)
goto out;
}
while (t == 1);
}
grub_net_poll_cards (200, &data.stop);
}
@ -615,22 +625,28 @@ grub_cmd_nslookup (struct grub_command *cmd __attribute__ ((unused)),
int argc, char **args)
{
grub_err_t err;
grub_size_t naddresses, i;
struct grub_net_network_level_address cmd_server;
struct grub_net_network_level_address *servers;
grub_size_t nservers, i, naddresses = 0;
struct grub_net_network_level_address *addresses = 0;
if (argc != 2 && argc != 1)
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("two arguments expected"));
if (argc == 2)
{
struct grub_net_network_level_address server;
err = grub_net_resolve_address (args[1], &server);
err = grub_net_resolve_address (args[1], &cmd_server);
if (err)
return err;
err = grub_net_dns_lookup (args[0], &server, 1, &naddresses,
&addresses, 0);
servers = &cmd_server;
nservers = 1;
}
else
err = grub_net_dns_lookup (args[0], dns_servers, dns_nservers, &naddresses,
&addresses, 0);
{
servers = dns_servers;
nservers = dns_nservers;
}
grub_net_dns_lookup (args[0], servers, nservers, &naddresses,
&addresses, 0);
for (i = 0; i < naddresses; i++)
{
@ -639,7 +655,9 @@ grub_cmd_nslookup (struct grub_command *cmd __attribute__ ((unused)),
grub_printf ("%s\n", buf);
}
grub_free (addresses);
return GRUB_ERR_NONE;
if (naddresses)
return GRUB_ERR_NONE;
return grub_error (GRUB_ERR_NET_NO_DOMAIN, N_("no DNS record found"));
}
static grub_err_t
@ -648,11 +666,32 @@ grub_cmd_list_dns (struct grub_command *cmd __attribute__ ((unused)),
char **args __attribute__ ((unused)))
{
grub_size_t i;
const char *strtype = "";
for (i = 0; i < dns_nservers; i++)
{
switch (dns_servers[i].option)
{
case DNS_OPTION_IPV4:
strtype = "only ipv4";
break;
case DNS_OPTION_IPV6:
strtype = "only ipv6";
break;
case DNS_OPTION_PREFER_IPV4:
strtype = "prefer ipv4";
break;
case DNS_OPTION_PREFER_IPV6:
strtype = "prefer ipv6";
break;
}
char buf[GRUB_NET_MAX_STR_ADDR_LEN];
grub_net_addr_to_str (&dns_servers[i], buf);
grub_printf ("%s\n", buf);
grub_printf ("%s (%s)\n", buf, strtype);
}
return GRUB_ERR_NONE;
}
@ -664,8 +703,24 @@ grub_cmd_add_dns (struct grub_command *cmd __attribute__ ((unused)),
grub_err_t err;
struct grub_net_network_level_address server;
if (argc != 1)
if ((argc < 1) || (argc > 2))
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("one argument expected"));
else if (argc == 1)
server.option = DNS_OPTION_PREFER_IPV4;
else
{
if (grub_strcmp (args[1], "--only-ipv4") == 0)
server.option = DNS_OPTION_IPV4;
else if (grub_strcmp (args[1], "--only-ipv6") == 0)
server.option = DNS_OPTION_IPV6;
else if (grub_strcmp (args[1], "--prefer-ipv4") == 0)
server.option = DNS_OPTION_PREFER_IPV4;
else if (grub_strcmp (args[1], "--prefer-ipv6") == 0)
server.option = DNS_OPTION_PREFER_IPV6;
else
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("invalid argument"));
}
err = grub_net_resolve_address (args[0], &server);
if (err)
return err;

9
include/grub/net.h
View file

@ -156,6 +156,14 @@ typedef enum grub_network_level_protocol_id
GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6
} grub_network_level_protocol_id_t;
typedef enum
{
DNS_OPTION_IPV4,
DNS_OPTION_IPV6,
DNS_OPTION_PREFER_IPV4,
DNS_OPTION_PREFER_IPV6
} grub_dns_option_t;
typedef struct grub_net_network_level_address
{
grub_network_level_protocol_id_t type;
@ -164,6 +172,7 @@ typedef struct grub_net_network_level_address
grub_uint32_t ipv4;
grub_uint64_t ipv6[2];
};
grub_dns_option_t option;
} grub_net_network_level_address_t;
typedef struct grub_net_network_level_netaddress