support cname
This commit is contained in:
Vladimir 'phcoder' Serbinenko
parent
34feab6f21
commit
3729fcfc1a
1 changed files with 133 additions and 34 deletions
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@ -66,21 +66,33 @@ struct recv_data
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int cache;
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grub_uint16_t id;
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int dns_err;
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const char *name;
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char *name;
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};
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static int
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check_name (const grub_uint8_t *name_at, const grub_uint8_t *head,
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const grub_uint8_t *tail, const char *check_with)
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check_name_real (const grub_uint8_t *name_at, const grub_uint8_t *head,
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const grub_uint8_t *tail, const char *check_with,
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int *length, char *set)
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{
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const char *readable_ptr = check_with;
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const grub_uint8_t *ptr;
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char *optr = set;
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int bytes_processed = 0;
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if (length)
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*length = 0;
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for (ptr = name_at; ptr < tail && bytes_processed < tail - head + 2; )
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{
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/* End marker. */
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if (!*ptr)
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return (*readable_ptr == 0);
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{
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if (length && *length)
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(*length)--;
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if (optr && optr != set)
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optr--;
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if (optr)
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*optr = 0;
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return !readable_ptr || (*readable_ptr == 0);
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}
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if (*ptr & 0xc0)
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{
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bytes_processed += 2;
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@ -89,22 +101,66 @@ check_name (const grub_uint8_t *name_at, const grub_uint8_t *head,
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ptr = head + (((ptr[0] & 0x3f) << 8) | ptr[1]);
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continue;
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}
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if (grub_memcmp (ptr + 1, readable_ptr, *ptr) != 0)
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if (readable_ptr && grub_memcmp (ptr + 1, readable_ptr, *ptr) != 0)
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return 0;
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if (grub_memchr (ptr + 1, 0, *ptr)
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|| grub_memchr (ptr + 1, '.', *ptr))
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return 0;
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if (readable_ptr[*ptr] != '.' && readable_ptr[*ptr] != 0)
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if (readable_ptr)
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readable_ptr += *ptr;
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if (readable_ptr && *readable_ptr != '.' && *readable_ptr != 0)
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return 0;
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bytes_processed += *ptr + 1;
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readable_ptr += *ptr;
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if (*readable_ptr)
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if (length)
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*length += *ptr + 1;
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if (optr)
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{
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grub_memcpy (optr, ptr + 1, *ptr);
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optr += *ptr;
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}
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if (optr)
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*optr++ = '.';
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if (readable_ptr && *readable_ptr)
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readable_ptr++;
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ptr += *ptr + 1;
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}
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return 0;
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}
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static int
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check_name (const grub_uint8_t *name_at, const grub_uint8_t *head,
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const grub_uint8_t *tail, const char *check_with)
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{
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return check_name_real (name_at, head, tail, check_with, NULL, NULL);
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}
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static char *
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get_name (const grub_uint8_t *name_at, const grub_uint8_t *head,
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const grub_uint8_t *tail)
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{
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int length;
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char *ret;
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if (!check_name_real (name_at, head, tail, NULL, &length, NULL))
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return NULL;
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ret = grub_malloc (length + 1);
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if (!ret)
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return NULL;
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if (!check_name_real (name_at, head, tail, NULL, NULL, ret))
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{
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grub_free (ret);
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return NULL;
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}
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return ret;
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}
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enum
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{
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DNS_CLASS_A = 1,
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DNS_CLASS_CNAME = 5,
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DNS_CLASS_AAAA = 28
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};
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static grub_err_t
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recv_hook (grub_net_udp_socket_t sock __attribute__ ((unused)),
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struct grub_net_buff *nb,
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@ -113,7 +169,9 @@ recv_hook (grub_net_udp_socket_t sock __attribute__ ((unused)),
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struct dns_header *head;
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struct recv_data *data = data_;
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int i, j;
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grub_uint8_t *ptr;
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grub_uint8_t *ptr, *reparse_ptr;
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int redirect_cnt = 0;
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char *redirect_save = NULL;
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head = (struct dns_header *) nb->data;
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ptr = (grub_uint8_t *) (head + 1);
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@ -161,10 +219,12 @@ recv_hook (grub_net_udp_socket_t sock __attribute__ ((unused)),
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grub_netbuff_free (nb);
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return GRUB_ERR_NONE;
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}
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for (i = 0; i < grub_cpu_to_be16 (head->ancount); i++)
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reparse_ptr = ptr;
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reparse:
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for (i = 0, ptr = reparse_ptr; i < grub_cpu_to_be16 (head->ancount); i++)
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{
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int ignored = 0;
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int is_ipv6 = 0;
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grub_uint8_t class;
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grub_uint32_t ttl = 0;
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grub_uint16_t length;
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if (ptr >= nb->tail)
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@ -188,11 +248,7 @@ recv_hook (grub_net_udp_socket_t sock __attribute__ ((unused)),
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}
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if (*ptr++ != 0)
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ignored = 1;
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if (*ptr != 1 && *ptr != 28)
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ignored = 1;
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if (*ptr == 28)
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is_ipv6 = 1;
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ptr++;
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class = *ptr++;
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if (*ptr++ != 0)
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ignored = 1;
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if (*ptr++ != 1)
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@ -211,25 +267,56 @@ recv_hook (grub_net_udp_socket_t sock __attribute__ ((unused)),
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grub_netbuff_free (nb);
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return GRUB_ERR_NONE;
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}
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if (!ignored && !is_ipv6 && length == 4)
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{
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(*data->addresses)[*data->naddresses].type
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= GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
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grub_memcpy (&(*data->addresses)[*data->naddresses].ipv4,
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ptr, 4);
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(*data->naddresses)++;
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}
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if (!ignored && is_ipv6 && length == 16)
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{
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(*data->addresses)[*data->naddresses].type
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= GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6;
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grub_memcpy (&(*data->addresses)[*data->naddresses].ipv6,
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if (!ignored)
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switch (class)
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{
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case DNS_CLASS_A:
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if (length != 4)
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break;
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(*data->addresses)[*data->naddresses].type
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= GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
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grub_memcpy (&(*data->addresses)[*data->naddresses].ipv4,
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ptr, 4);
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(*data->naddresses)++;
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break;
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case DNS_CLASS_AAAA:
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if (length != 16)
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break;
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(*data->addresses)[*data->naddresses].type
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= GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6;
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grub_memcpy (&(*data->addresses)[*data->naddresses].ipv6,
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ptr, 16);
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(*data->naddresses)++;
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(*data->naddresses)++;
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break;
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case DNS_CLASS_CNAME:
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if (!(redirect_cnt & (redirect_cnt - 1)))
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{
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grub_free (redirect_save);
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redirect_save = data->name;
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}
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else
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grub_free (data->name);
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redirect_cnt++;
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data->name = get_name (ptr, nb->data, nb->tail);
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if (!data->name)
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{
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data->dns_err = 1;
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grub_errno = 0;
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return GRUB_ERR_NONE;
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}
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grub_dprintf ("dns", "CNAME %s\n", data->name);
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if (grub_strcmp (redirect_save, data->name) == 0)
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{
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data->dns_err = 1;
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grub_free (redirect_save);
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return GRUB_ERR_NONE;
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}
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goto reparse;
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}
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ptr += length;
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}
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grub_netbuff_free (nb);
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grub_free (redirect_save);
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return GRUB_ERR_NONE;
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}
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@ -251,10 +338,14 @@ grub_net_dns_lookup (const char *name,
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static grub_uint16_t id = 1;
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grub_err_t err = GRUB_ERR_NONE;
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struct recv_data data = {naddresses, addresses, cache,
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grub_cpu_to_be16 (id++), 0, name};
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grub_cpu_to_be16 (id++), 0, 0};
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grub_uint8_t *nbd;
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int have_server = 0;
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data.name = grub_strdup (name);
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if (!data.name)
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return grub_errno;
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*naddresses = 0;
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/* if (cache && cache_lookup (name, servers, n_servers, addresses))
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return GRUB_ERR_NONE;*/
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@ -266,7 +357,10 @@ grub_net_dns_lookup (const char *name,
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+ grub_strlen (name) + 2 + 4
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+ 2 + 4);
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if (!nb)
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return grub_errno;
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{
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grub_free (data.name);
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return grub_errno;
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}
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grub_netbuff_reserve (nb, GRUB_NET_OUR_MAX_IP_HEADER_SIZE
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+ GRUB_NET_MAX_LINK_HEADER_SIZE
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+ GRUB_NET_UDP_HEADER_SIZE);
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@ -281,8 +375,11 @@ grub_net_dns_lookup (const char *name,
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if (!dot)
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dot = iptr + grub_strlen (iptr);
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if ((dot - iptr) >= 64)
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return grub_error (GRUB_ERR_BAD_ARGUMENT,
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"domain component is too long");
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{
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grub_free (data.name);
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return grub_error (GRUB_ERR_BAD_ARGUMENT,
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"domain component is too long");
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}
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*optr = (dot - iptr);
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optr++;
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grub_memcpy (optr, iptr, dot - iptr);
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@ -365,9 +462,11 @@ grub_net_dns_lookup (const char *name,
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grub_net_poll_cards (200);
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}
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out:
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grub_free (data.name);
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grub_netbuff_free (nb);
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for (j = 0; j < send_servers; j++)
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grub_net_udp_close (sockets[j]);
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if (*data.naddresses)
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return GRUB_ERR_NONE;
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if (data.dns_err)
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