From: Chad Kimes Date: Wed, 2 Mar 2022 19:21:22 +0000 (-0500) Subject: net/ethernet: Fix VLAN networking on little-endian systems X-Git-Tag: grub-2.12-rc1~470 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c216df4036b67e27defafd65543c075274709b37;p=thirdparty%2Fgrub.git net/ethernet: Fix VLAN networking on little-endian systems VLAN configuration seems to have never worked on little-endian systems. This is likely because VLANTAG_IDENTIFIER is not byte-swapped before copying into the net buffer, nor is inf->vlantag. We can resolve this by using grub_cpu_to_be16{_compile_time}() and its inverse when copying VLAN info to/from the net buffer. Signed-off-by: Chad Kimes Reviewed-by: Daniel Kiper --- diff --git a/grub-core/net/ethernet.c b/grub-core/net/ethernet.c index 4d7ceed6f..a9906338c 100644 --- a/grub-core/net/ethernet.c +++ b/grub-core/net/ethernet.c @@ -58,7 +58,7 @@ send_ethernet_packet (struct grub_net_network_level_interface *inf, struct etherhdr *eth; grub_err_t err; grub_uint8_t etherhdr_size; - grub_uint16_t vlantag_id = VLANTAG_IDENTIFIER; + grub_uint16_t vlantag_id = grub_cpu_to_be16_compile_time (VLANTAG_IDENTIFIER); etherhdr_size = sizeof (*eth); COMPILE_TIME_ASSERT (sizeof (*eth) + 4 < GRUB_NET_MAX_LINK_HEADER_SIZE); @@ -93,8 +93,9 @@ send_ethernet_packet (struct grub_net_network_level_interface *inf, (char *) nb->data + etherhdr_size - 6, 2); /* Add the tag in the middle */ + grub_uint16_t vlan = grub_cpu_to_be16 (inf->vlantag); grub_memcpy ((char *) nb->data + etherhdr_size - 6, &vlantag_id, 2); - grub_memcpy ((char *) nb->data + etherhdr_size - 4, (char *) &(inf->vlantag), 2); + grub_memcpy ((char *) nb->data + etherhdr_size - 4, &vlan, 2); } return inf->card->driver->send (inf->card, nb); @@ -118,9 +119,9 @@ grub_net_recv_ethernet_packet (struct grub_net_buff *nb, /* 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) + if (grub_get_unaligned16 (nb->data + etherhdr_size - 2) == grub_cpu_to_be16_compile_time (VLANTAG_IDENTIFIER)) { - vlantag = grub_get_unaligned16 (nb->data + etherhdr_size); + vlantag = grub_be_to_cpu16 (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,