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>
diff --git a/net/dns.c b/net/dns.c
index b51d1bd..7a3f1f9 100644
--- a/net/dns.c
+++ b/net/dns.c
@@ -25,6 +25,7 @@
#include <common.h>
#include <command.h>
#include <net.h>
+#include <asm/unaligned.h>
#include "dns.h"
@@ -109,7 +110,6 @@
int found, stop, dlen;
char IPStr[22];
IPaddr_t IPAddress;
- short tmp;
debug("%s\n", __func__);
@@ -120,14 +120,14 @@
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 @@
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 @@
}
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 @@
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);