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support cname

This commit is contained in:
Vladimir 'phcoder' Serbinenko 2011-12-16 13:43:31 +01:00
parent 34feab6f21
commit 3729fcfc1a
1 changed files with 133 additions and 34 deletions
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167
grub-core/net/dns.c
View File

@ -66,21 +66,33 @@ struct recv_data
int cache;
grub_uint16_t id;
int dns_err;
const char *name;
char *name;
};
static int
check_name (const grub_uint8_t *name_at, const grub_uint8_t *head,
const grub_uint8_t *tail, const char *check_with)
check_name_real (const grub_uint8_t *name_at, const grub_uint8_t *head,
const grub_uint8_t *tail, const char *check_with,
int *length, char *set)
{
const char *readable_ptr = check_with;
const grub_uint8_t *ptr;
char *optr = set;
int bytes_processed = 0;
if (length)
*length = 0;
for (ptr = name_at; ptr < tail && bytes_processed < tail - head + 2; )
{
/* End marker. */
if (!*ptr)
return (*readable_ptr == 0);
{
if (length && *length)
(*length)--;
if (optr && optr != set)
optr--;
if (optr)
*optr = 0;
return !readable_ptr || (*readable_ptr == 0);
}
if (*ptr & 0xc0)
{
bytes_processed += 2;
@ -89,22 +101,66 @@ check_name (const grub_uint8_t *name_at, const grub_uint8_t *head,
ptr = head + (((ptr[0] & 0x3f) << 8) | ptr[1]);
continue;
}
if (grub_memcmp (ptr + 1, readable_ptr, *ptr) != 0)
if (readable_ptr && grub_memcmp (ptr + 1, readable_ptr, *ptr) != 0)
return 0;
if (grub_memchr (ptr + 1, 0, *ptr)
|| grub_memchr (ptr + 1, '.', *ptr))
return 0;
if (readable_ptr[*ptr] != '.' && readable_ptr[*ptr] != 0)
if (readable_ptr)
readable_ptr += *ptr;
if (readable_ptr && *readable_ptr != '.' && *readable_ptr != 0)
return 0;
bytes_processed += *ptr + 1;
readable_ptr += *ptr;
if (*readable_ptr)
if (length)
*length += *ptr + 1;
if (optr)
{
grub_memcpy (optr, ptr + 1, *ptr);
optr += *ptr;
}
if (optr)
*optr++ = '.';
if (readable_ptr && *readable_ptr)
readable_ptr++;
ptr += *ptr + 1;
}
return 0;
}
static int
check_name (const grub_uint8_t *name_at, const grub_uint8_t *head,
const grub_uint8_t *tail, const char *check_with)
{
return check_name_real (name_at, head, tail, check_with, NULL, NULL);
}
static char *
get_name (const grub_uint8_t *name_at, const grub_uint8_t *head,
const grub_uint8_t *tail)
{
int length;
char *ret;
if (!check_name_real (name_at, head, tail, NULL, &length, NULL))
return NULL;
ret = grub_malloc (length + 1);
if (!ret)
return NULL;
if (!check_name_real (name_at, head, tail, NULL, NULL, ret))
{
grub_free (ret);
return NULL;
}
return ret;
}
enum
{
DNS_CLASS_A = 1,
DNS_CLASS_CNAME = 5,
DNS_CLASS_AAAA = 28
};
static grub_err_t
recv_hook (grub_net_udp_socket_t sock __attribute__ ((unused)),
struct grub_net_buff *nb,
@ -113,7 +169,9 @@ recv_hook (grub_net_udp_socket_t sock __attribute__ ((unused)),
struct dns_header *head;
struct recv_data *data = data_;
int i, j;
grub_uint8_t *ptr;
grub_uint8_t *ptr, *reparse_ptr;
int redirect_cnt = 0;
char *redirect_save = NULL;
head = (struct dns_header *) nb->data;
ptr = (grub_uint8_t *) (head + 1);
@ -161,10 +219,12 @@ recv_hook (grub_net_udp_socket_t sock __attribute__ ((unused)),
grub_netbuff_free (nb);
return GRUB_ERR_NONE;
}
for (i = 0; i < grub_cpu_to_be16 (head->ancount); i++)
reparse_ptr = ptr;
reparse:
for (i = 0, ptr = reparse_ptr; i < grub_cpu_to_be16 (head->ancount); i++)
{
int ignored = 0;
int is_ipv6 = 0;
grub_uint8_t class;
grub_uint32_t ttl = 0;
grub_uint16_t length;
if (ptr >= nb->tail)
@ -188,11 +248,7 @@ recv_hook (grub_net_udp_socket_t sock __attribute__ ((unused)),
}
if (*ptr++ != 0)
ignored = 1;
if (*ptr != 1 && *ptr != 28)
ignored = 1;
if (*ptr == 28)
is_ipv6 = 1;
ptr++;
class = *ptr++;
if (*ptr++ != 0)
ignored = 1;
if (*ptr++ != 1)
@ -211,25 +267,56 @@ recv_hook (grub_net_udp_socket_t sock __attribute__ ((unused)),
grub_netbuff_free (nb);
return GRUB_ERR_NONE;
}
if (!ignored && !is_ipv6 && length == 4)
{
(*data->addresses)[*data->naddresses].type
= GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
grub_memcpy (&(*data->addresses)[*data->naddresses].ipv4,
ptr, 4);
(*data->naddresses)++;
}
if (!ignored && is_ipv6 && length == 16)
{
(*data->addresses)[*data->naddresses].type
= GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6;
grub_memcpy (&(*data->addresses)[*data->naddresses].ipv6,
if (!ignored)
switch (class)
{
case DNS_CLASS_A:
if (length != 4)
break;
(*data->addresses)[*data->naddresses].type
= GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
grub_memcpy (&(*data->addresses)[*data->naddresses].ipv4,
ptr, 4);
(*data->naddresses)++;
break;
case DNS_CLASS_AAAA:
if (length != 16)
break;
(*data->addresses)[*data->naddresses].type
= GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6;
grub_memcpy (&(*data->addresses)[*data->naddresses].ipv6,
ptr, 16);
(*data->naddresses)++;
(*data->naddresses)++;
break;
case DNS_CLASS_CNAME:
if (!(redirect_cnt & (redirect_cnt - 1)))
{
grub_free (redirect_save);
redirect_save = data->name;
}
else
grub_free (data->name);
redirect_cnt++;
data->name = get_name (ptr, nb->data, nb->tail);
if (!data->name)
{
data->dns_err = 1;
grub_errno = 0;
return GRUB_ERR_NONE;
}
grub_dprintf ("dns", "CNAME %s\n", data->name);
if (grub_strcmp (redirect_save, data->name) == 0)
{
data->dns_err = 1;
grub_free (redirect_save);
return GRUB_ERR_NONE;
}
goto reparse;
}
ptr += length;
}
grub_netbuff_free (nb);
grub_free (redirect_save);
return GRUB_ERR_NONE;
}
@ -251,10 +338,14 @@ grub_net_dns_lookup (const char *name,
static grub_uint16_t id = 1;
grub_err_t err = GRUB_ERR_NONE;
struct recv_data data = {naddresses, addresses, cache,
grub_cpu_to_be16 (id++), 0, name};
grub_cpu_to_be16 (id++), 0, 0};
grub_uint8_t *nbd;
int have_server = 0;
data.name = grub_strdup (name);
if (!data.name)
return grub_errno;
*naddresses = 0;
/* if (cache && cache_lookup (name, servers, n_servers, addresses))
return GRUB_ERR_NONE;*/
@ -266,7 +357,10 @@ grub_net_dns_lookup (const char *name,
+ grub_strlen (name) + 2 + 4
+ 2 + 4);
if (!nb)
return grub_errno;
{
grub_free (data.name);
return grub_errno;
}
grub_netbuff_reserve (nb, GRUB_NET_OUR_MAX_IP_HEADER_SIZE
+ GRUB_NET_MAX_LINK_HEADER_SIZE
+ GRUB_NET_UDP_HEADER_SIZE);
@ -281,8 +375,11 @@ grub_net_dns_lookup (const char *name,
if (!dot)
dot = iptr + grub_strlen (iptr);
if ((dot - iptr) >= 64)
return grub_error (GRUB_ERR_BAD_ARGUMENT,
"domain component is too long");
{
grub_free (data.name);
return grub_error (GRUB_ERR_BAD_ARGUMENT,
"domain component is too long");
}
*optr = (dot - iptr);
optr++;
grub_memcpy (optr, iptr, dot - iptr);
@ -365,9 +462,11 @@ grub_net_dns_lookup (const char *name,
grub_net_poll_cards (200);
}
out:
grub_free (data.name);
grub_netbuff_free (nb);
for (j = 0; j < send_servers; j++)
grub_net_udp_close (sockets[j]);
if (*data.naddresses)
return GRUB_ERR_NONE;
if (data.dns_err)