diff options
Diffstat (limited to 'grub-core/net/ethernet.c')
| -rw-r--r-- | grub-core/net/ethernet.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/grub-core/net/ethernet.c b/grub-core/net/ethernet.c new file mode 100644 index 0000000..4d7ceed --- /dev/null +++ b/grub-core/net/ethernet.c @@ -0,0 +1,171 @@ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2010,2011 Free Software Foundation, Inc. + * + * GRUB is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * GRUB is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GRUB. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <grub/misc.h> +#include <grub/mm.h> +#include <grub/env.h> +#include <grub/net/ethernet.h> +#include <grub/net/ip.h> +#include <grub/net/arp.h> +#include <grub/net/netbuff.h> +#include <grub/net.h> +#include <grub/time.h> +#include <grub/net/arp.h> + +#define LLCADDRMASK 0x7f + +struct etherhdr +{ + grub_uint8_t dst[6]; + grub_uint8_t src[6]; + grub_uint16_t type; +} GRUB_PACKED; + +struct llchdr +{ + grub_uint8_t dsap; + grub_uint8_t ssap; + grub_uint8_t ctrl; +} GRUB_PACKED; + +struct snaphdr +{ + grub_uint8_t oui[3]; + grub_uint16_t type; +} GRUB_PACKED; + +grub_err_t +send_ethernet_packet (struct grub_net_network_level_interface *inf, + struct grub_net_buff *nb, + grub_net_link_level_address_t target_addr, + grub_net_ethertype_t ethertype) +{ + struct etherhdr *eth; + grub_err_t err; + grub_uint8_t etherhdr_size; + grub_uint16_t vlantag_id = VLANTAG_IDENTIFIER; + + etherhdr_size = sizeof (*eth); + COMPILE_TIME_ASSERT (sizeof (*eth) + 4 < GRUB_NET_MAX_LINK_HEADER_SIZE); + + /* Increase ethernet header in case of vlantag */ + if (inf->vlantag != 0) + etherhdr_size += 4; + + err = grub_netbuff_push (nb, etherhdr_size); + if (err) + return err; + eth = (struct etherhdr *) nb->data; + grub_memcpy (eth->dst, target_addr.mac, 6); + grub_memcpy (eth->src, inf->hwaddress.mac, 6); + + eth->type = grub_cpu_to_be16 (ethertype); + if (!inf->card->opened) + { + err = GRUB_ERR_NONE; + if (inf->card->driver->open) + err = inf->card->driver->open (inf->card); + if (err) + return err; + inf->card->opened = 1; + } + + /* Check and add a vlan-tag if needed. */ + if (inf->vlantag != 0) + { + /* Move eth type to the right */ + grub_memcpy ((char *) nb->data + etherhdr_size - 2, + (char *) nb->data + etherhdr_size - 6, 2); + + /* Add the tag in the middle */ + grub_memcpy ((char *) nb->data + etherhdr_size - 6, &vlantag_id, 2); + grub_memcpy ((char *) nb->data + etherhdr_size - 4, (char *) &(inf->vlantag), 2); + } + + return inf->card->driver->send (inf->card, nb); +} + +grub_err_t +grub_net_recv_ethernet_packet (struct grub_net_buff *nb, + struct grub_net_card *card) +{ + struct etherhdr *eth; + struct llchdr *llch; + struct snaphdr *snaph; + grub_net_ethertype_t type; + grub_net_link_level_address_t hwaddress; + grub_net_link_level_address_t src_hwaddress; + grub_err_t err; + grub_uint8_t etherhdr_size = sizeof (*eth); + grub_uint16_t vlantag = 0; + + + /* Check if a vlan-tag is present. If so, the ethernet header is 4 bytes */ + /* longer than the original one. The vlantag id is extracted and the header */ + /* is reseted to the original size. */ + if (grub_get_unaligned16 (nb->data + etherhdr_size - 2) == VLANTAG_IDENTIFIER) + { + vlantag = grub_get_unaligned16 (nb->data + etherhdr_size); + etherhdr_size += 4; + /* Move eth type to the original position */ + grub_memcpy((char *) nb->data + etherhdr_size - 6, + (char *) nb->data + etherhdr_size - 2, 2); + } + + eth = (struct etherhdr *) nb->data; + type = grub_be_to_cpu16 (eth->type); + err = grub_netbuff_pull (nb, etherhdr_size); + if (err) + return err; + + if (type <= 1500) + { + llch = (struct llchdr *) nb->data; + type = llch->dsap & LLCADDRMASK; + + if (llch->dsap == 0xaa && llch->ssap == 0xaa && llch->ctrl == 0x3) + { + err = grub_netbuff_pull (nb, sizeof (*llch)); + if (err) + return err; + snaph = (struct snaphdr *) nb->data; + type = snaph->type; + } + } + + hwaddress.type = GRUB_NET_LINK_LEVEL_PROTOCOL_ETHERNET; + grub_memcpy (hwaddress.mac, eth->dst, sizeof (hwaddress.mac)); + src_hwaddress.type = GRUB_NET_LINK_LEVEL_PROTOCOL_ETHERNET; + grub_memcpy (src_hwaddress.mac, eth->src, sizeof (src_hwaddress.mac)); + + switch (type) + { + /* ARP packet. */ + case GRUB_NET_ETHERTYPE_ARP: + grub_net_arp_receive (nb, card, &vlantag); + grub_netbuff_free (nb); + return GRUB_ERR_NONE; + /* IP packet. */ + case GRUB_NET_ETHERTYPE_IP: + case GRUB_NET_ETHERTYPE_IP6: + return grub_net_recv_ip_packets (nb, card, &hwaddress, &src_hwaddress, + &vlantag); + } + grub_netbuff_free (nb); + return GRUB_ERR_NONE; +} |