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net/dns.c: Fix endian conversion for big-endian in dns command 

net/dns.c used endian conversion macros wrongly (shorts in reply
were put swapped into CPU, and then ntohs() was used to swap it
back, which broke on big-endian).

Fix this by using the correct linux conversion macro for reading
a unaligned short in network byte order: get_unaligned_be16()
Thanks to Mike Frysinger pointing at the best macro to use.

Tested on big and little endian qemu boards (mips and versatile)

Signed-off-by: Bernhard Kaindl <bernhard.kaindl@thalesgroup.com>
Cc: Pieter Voorthuijsen <pieter.voorthuijsen@prodrive.nl>
Cc: Robin Getz <rgetz@blackfin.uclinux.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
This commit is contained in:
Bernhard Kaindl 2011-10-15 23:59:22 +00:00 committed by Wolfgang Denk
parent f5ca20c6b6
commit 6dc809f407
1 changed files with 8 additions and 12 deletions
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20
net/dns.c
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@ -25,6 +25,7 @@
#include <common.h>
#include <command.h>
#include <net.h>
#include <asm/unaligned.h>
#include "dns.h"
@ -109,7 +110,6 @@ DnsHandler(uchar *pkt, unsigned dest, IPaddr_t sip, unsigned src, unsigned len)
int found, stop, dlen;
char IPStr[22];
IPaddr_t IPAddress;
short tmp;
debug("%s\n", __func__);
@ -120,14 +120,14 @@ DnsHandler(uchar *pkt, unsigned dest, IPaddr_t sip, unsigned src, unsigned len)
debug("0x%p - 0x%.2x 0x%.2x 0x%.2x 0x%.2x\n",
pkt+i, pkt[i], pkt[i+1], pkt[i+2], pkt[i+3]);
/* We sent 1 query. We want to see more that 1 answer. */
/* We sent one query. We want to have a single answer: */
header = (struct header *) pkt;
if (ntohs(header->nqueries) != 1)
return;
/* Received 0 answers */
if (header->nanswers == 0) {
puts("DNS server returned no answers\n");
puts("DNS: host not found\n");
NetState = NETLOOP_SUCCESS;
return;
}
@ -139,9 +139,8 @@ DnsHandler(uchar *pkt, unsigned dest, IPaddr_t sip, unsigned src, unsigned len)
continue;
/* We sent query class 1, query type 1 */
tmp = p[1] | (p[2] << 8);
if (&p[5] > e || ntohs(tmp) != DNS_A_RECORD) {
puts("DNS response was not A record\n");
if (&p[5] > e || get_unaligned_be16(p+1) != DNS_A_RECORD) {
puts("DNS: response was not an A record\n");
NetState = NETLOOP_SUCCESS;
return;
}
@ -160,14 +159,12 @@ DnsHandler(uchar *pkt, unsigned dest, IPaddr_t sip, unsigned src, unsigned len)
}
debug("Name (Offset in header): %d\n", p[1]);
tmp = p[2] | (p[3] << 8);
type = ntohs(tmp);
type = get_unaligned_be16(p+2);
debug("type = %d\n", type);
if (type == DNS_CNAME_RECORD) {
/* CNAME answer. shift to the next section */
debug("Found canonical name\n");
tmp = p[10] | (p[11] << 8);
dlen = ntohs(tmp);
dlen = get_unaligned_be16(p+10);
debug("dlen = %d\n", dlen);
p += 12 + dlen;
} else if (type == DNS_A_RECORD) {
@ -181,8 +178,7 @@ DnsHandler(uchar *pkt, unsigned dest, IPaddr_t sip, unsigned src, unsigned len)
if (found && &p[12] < e) {
tmp = p[10] | (p[11] << 8);
dlen = ntohs(tmp);
dlen = get_unaligned_be16(p+10);
p += 12;
memcpy(&IPAddress, p, 4);