net/dhcp: Refactor DHCP packet transmission into separate function
In contrast to BOOTP, DHCP uses a 4-way handshake, so requires to send packets more often. Refactor the generation and sending of the BOOTREQUEST packet into a separate function, so that future code can more easily reuse this. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Andrei Borzenkov
Vincent Batts
parent
6c0969eed5
commit
f8da4f6154
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@ -49,6 +49,8 @@ enum
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GRUB_DHCP_OPT_OVERLOAD_SNAME = 2,
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};
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#define GRUB_BOOTP_MAX_OPTIONS_SIZE 64
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static const void *
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find_dhcp_option (const struct grub_net_bootp_packet *bp, grub_size_t size,
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grub_uint8_t opt_code, grub_uint8_t *opt_len)
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@ -340,6 +342,112 @@ grub_net_configure_by_dhcp_ack (const char *name,
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return inter;
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}
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static grub_err_t
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send_dhcp_packet (struct grub_net_network_level_interface *iface)
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{
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grub_err_t err;
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struct grub_net_bootp_packet *pack;
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struct grub_datetime date;
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grub_int32_t t = 0;
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struct grub_net_buff *nb;
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struct udphdr *udph;
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grub_net_network_level_address_t target;
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grub_net_link_level_address_t ll_target;
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grub_uint8_t *offset;
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nb = grub_netbuff_alloc (sizeof (*pack) + sizeof(dhcp_option_header)
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+ sizeof(grub_userclass)
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+ sizeof(grub_dhcpdiscover)
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+ sizeof(grub_dhcptime)
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+ GRUB_BOOTP_MAX_OPTIONS_SIZE + 128);
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if (!nb)
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return grub_errno;
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err = grub_netbuff_reserve (nb, sizeof (*pack) + sizeof(dhcp_option_header)
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+ sizeof(grub_userclass)
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+ sizeof(grub_dhcpdiscover)
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+ sizeof(grub_dhcptime)
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+ GRUB_BOOTP_MAX_OPTIONS_SIZE + 128);
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if (err)
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goto out;
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err = grub_netbuff_push (nb, sizeof(dhcp_option_header)
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+ sizeof(grub_userclass)
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+ sizeof(grub_dhcpdiscover)
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+ sizeof(grub_dhcptime)
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+ GRUB_BOOTP_MAX_OPTIONS_SIZE);
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if (err)
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goto out;
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grub_memset (nb->data, 0, sizeof(dhcp_option_header)
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+ sizeof(grub_userclass)
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+ sizeof(grub_dhcpdiscover)
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+ sizeof(grub_dhcptime)
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+ GRUB_BOOTP_MAX_OPTIONS_SIZE);
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err = grub_netbuff_push (nb, sizeof (*pack));
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if (err)
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goto out;
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pack = (void *) nb->data;
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grub_memset (pack, 0, sizeof (*pack));
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pack->opcode = 1;
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pack->hw_type = 1;
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pack->hw_len = 6;
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err = grub_get_datetime (&date);
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if (err || !grub_datetime2unixtime (&date, &t))
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{
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grub_errno = GRUB_ERR_NONE;
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t = 0;
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}
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pack->seconds = grub_cpu_to_be16 (t);
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pack->ident = grub_cpu_to_be32 (t);
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grub_memcpy (&pack->mac_addr, &iface->hwaddress.mac, 6);
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offset = (grub_uint8_t *)&pack->vendor;
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grub_memcpy (offset, dhcp_option_header, sizeof(dhcp_option_header));
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offset += sizeof(dhcp_option_header);
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grub_memcpy (offset, grub_dhcpdiscover, sizeof(grub_dhcpdiscover));
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offset += sizeof(grub_dhcpdiscover);
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grub_memcpy (offset, grub_userclass, sizeof(grub_userclass));
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offset += sizeof(grub_userclass);
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grub_memcpy (offset, grub_dhcptime, sizeof(grub_dhcptime));
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/* insert Client System Architecture (option 93) */
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offset += sizeof(grub_dhcptime);
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offset[0] = 93;
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offset[1] = 2;
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offset[2] = (GRUB_NET_BOOTP_ARCH >> 8);
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offset[3] = (GRUB_NET_BOOTP_ARCH & 0xFF);
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/* option terminator */
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offset[4] = 255;
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grub_netbuff_push (nb, sizeof (*udph));
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udph = (struct udphdr *) nb->data;
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udph->src = grub_cpu_to_be16_compile_time (68);
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udph->dst = grub_cpu_to_be16_compile_time (67);
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udph->chksum = 0;
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udph->len = grub_cpu_to_be16 (nb->tail - nb->data);
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target.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
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target.ipv4 = 0xffffffff;
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err = grub_net_link_layer_resolve (iface, &target, &ll_target);
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if (err)
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goto out;
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udph->chksum = grub_net_ip_transport_checksum (nb, GRUB_NET_IP_UDP,
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&iface->address,
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&target);
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err = grub_net_send_ip_packet (iface, &target, &ll_target, nb,
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GRUB_NET_IP_UDP);
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out:
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grub_netbuff_free (nb);
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return err;
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}
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void
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grub_net_process_dhcp (struct grub_net_buff *nb,
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struct grub_net_card *card)
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@ -496,6 +604,7 @@ grub_cmd_bootp (struct grub_command *cmd __attribute__ ((unused)),
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unsigned j = 0;
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int interval;
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grub_err_t err;
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unsigned i;
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FOR_NET_CARDS (card)
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{
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@ -524,7 +633,6 @@ grub_cmd_bootp (struct grub_command *cmd __attribute__ ((unused)),
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card->num_ifaces++;
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if (!ifaces[j].name)
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{
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unsigned i;
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for (i = 0; i < j; i++)
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grub_free (ifaces[i].name);
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grub_free (ifaces);
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@ -542,100 +650,21 @@ grub_cmd_bootp (struct grub_command *cmd __attribute__ ((unused)),
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ifaces[0].prev = &grub_net_network_level_interfaces;
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for (interval = 200; interval < 10000; interval *= 2)
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{
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int done = 0;
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int need_poll = 0;
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for (j = 0; j < ncards; j++)
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{
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struct grub_net_bootp_packet *pack;
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struct grub_datetime date;
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grub_int32_t t = 0;
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struct grub_net_buff *nb;
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struct udphdr *udph;
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grub_net_network_level_address_t target;
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grub_net_link_level_address_t ll_target;
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grub_uint8_t *offset;
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if (!ifaces[j].prev)
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continue;
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nb = grub_netbuff_alloc (sizeof (*pack) + sizeof(dhcp_option_header)
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+ sizeof(grub_userclass)
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+ sizeof(grub_dhcpdiscover)
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+ sizeof(grub_dhcptime) + 64 + 128);
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if (!nb)
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{
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grub_netbuff_free (nb);
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return grub_errno;
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}
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err = grub_netbuff_reserve (nb, sizeof (*pack) + 64 + 128);
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err = send_dhcp_packet (&ifaces[j]);
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if (err)
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{
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grub_netbuff_free (nb);
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return err;
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grub_print_error ();
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continue;
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}
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err = grub_netbuff_push (nb, sizeof (*pack) + 64);
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if (err)
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{
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grub_netbuff_free (nb);
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return err;
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}
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pack = (void *) nb->data;
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done = 1;
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grub_memset (pack, 0, sizeof (*pack) + 64);
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pack->opcode = 1;
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pack->hw_type = 1;
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pack->hw_len = 6;
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err = grub_get_datetime (&date);
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if (err || !grub_datetime2unixtime (&date, &t))
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{
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grub_errno = GRUB_ERR_NONE;
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t = 0;
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}
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pack->ident = grub_cpu_to_be32 (t);
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pack->seconds = grub_cpu_to_be16 (t);
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grub_memcpy (&pack->mac_addr, &ifaces[j].hwaddress.mac, 6);
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offset = (grub_uint8_t *)&pack->vendor;
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grub_memcpy (offset, dhcp_option_header, sizeof(dhcp_option_header));
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offset += sizeof(dhcp_option_header);
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grub_memcpy (offset, grub_dhcpdiscover, sizeof(grub_dhcpdiscover));
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offset += sizeof(grub_dhcpdiscover);
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grub_memcpy (offset, grub_userclass, sizeof(grub_userclass));
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offset += sizeof(grub_userclass);
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grub_memcpy (offset, grub_dhcptime, sizeof(grub_dhcptime));
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/* insert Client System Architecture (option 93) */
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offset += sizeof(grub_dhcptime);
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offset[0] = 93;
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offset[1] = 2;
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offset[2] = (GRUB_NET_BOOTP_ARCH >> 8);
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offset[3] = (GRUB_NET_BOOTP_ARCH & 0xFF);
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/* option terminator */
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offset[4] = 255;
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grub_netbuff_push (nb, sizeof (*udph));
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udph = (struct udphdr *) nb->data;
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udph->src = grub_cpu_to_be16_compile_time (68);
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udph->dst = grub_cpu_to_be16_compile_time (67);
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udph->chksum = 0;
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udph->len = grub_cpu_to_be16 (nb->tail - nb->data);
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target.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4;
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target.ipv4 = 0xffffffff;
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err = grub_net_link_layer_resolve (&ifaces[j], &target, &ll_target);
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if (err)
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return err;
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udph->chksum = grub_net_ip_transport_checksum (nb, GRUB_NET_IP_UDP,
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&ifaces[j].address,
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&target);
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err = grub_net_send_ip_packet (&ifaces[j], &target, &ll_target, nb,
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GRUB_NET_IP_UDP);
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grub_netbuff_free (nb);
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if (err)
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return err;
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need_poll = 1;
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}
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if (!done)
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if (!need_poll)
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break;
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grub_net_poll_cards (interval, 0);
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}
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