net: avoid address-of-packed-member error
sandbox_defconfig does not compile using GCC 9.2.1:
net/net.c: In function ‘net_process_received_packet’:
net/net.c:1288:23: error: taking address of packed member of ‘struct
ip_udp_hdr’ may result in an unaligned pointer value
[-Werror=address-of-packed-member]
1288 | sumptr = (ushort *)&(ip->udp_src);
| ^~~~~~~~~~~~~~
Avoid the error by using a u8 pointer instead of an u16 pointer and
in-lining ntohs().
Simplify the checksumming of the last message byte.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/net/net.c b/net/net.c
index 5114364..5199d67 100644
--- a/net/net.c
+++ b/net/net.c
@@ -1271,7 +1271,7 @@
#ifdef CONFIG_UDP_CHECKSUM
if (ip->udp_xsum != 0) {
ulong xsum;
- ushort *sumptr;
+ u8 *sumptr;
ushort sumlen;
xsum = ip->ip_p;
@@ -1282,22 +1282,16 @@
xsum += (ntohl(ip->ip_dst.s_addr) >> 0) & 0x0000ffff;
sumlen = ntohs(ip->udp_len);
- sumptr = (ushort *)&(ip->udp_src);
+ sumptr = (u8 *)&ip->udp_src;
while (sumlen > 1) {
- ushort sumdata;
-
- sumdata = *sumptr++;
- xsum += ntohs(sumdata);
+ /* inlined ntohs() to avoid alignment errors */
+ xsum += (sumptr[0] << 8) + sumptr[1];
+ sumptr += 2;
sumlen -= 2;
}
- if (sumlen > 0) {
- ushort sumdata;
-
- sumdata = *(unsigned char *)sumptr;
- sumdata = (sumdata << 8) & 0xff00;
- xsum += sumdata;
- }
+ if (sumlen > 0)
+ xsum += (sumptr[0] << 8) + sumptr[0];
while ((xsum >> 16) != 0) {
xsum = (xsum & 0x0000ffff) +
((xsum >> 16) & 0x0000ffff);