net: qualcomm: rmnet: Fix incorrect UL checksum offload logic

The udp_ip4_ind bit is set only for IPv4 UDP non-fragmented packets
so that the hardware can flip the checksum to 0xFFFF if the computed
checksum is 0 per RFC768.

However, this bit had to be set for IPv6 UDP non fragmented packets
as well per hardware requirements. Otherwise, IPv6 UDP packets
with computed checksum as 0 were transmitted by hardware and were
dropped in the network.

In addition to setting this bit for IPv6 UDP, the field is also
appropriately renamed to udp_ind as part of this change.

Fixes: 5eb5f8608ef1 ("net: qualcomm: rmnet: Add support for TX checksum offload")
Cc: Sean Tranchetti <stranche@codeaurora.org>
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
index 60189923737a79f0735ffec15b96c3c110b579d6..21d38167f96180718fdcda68ed2433d73271b1bf 100644 (file)
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c
@@ -206,9 +206,9 @@ rmnet_map_ipv4_ul_csum_header(void *iphdr,
        ul_header->csum_insert_offset = skb->csum_offset;
        ul_header->csum_enabled = 1;
        if (ip4h->protocol == IPPROTO_UDP)
-               ul_header->udp_ip4_ind = 1;
+               ul_header->udp_ind = 1;
        else
-               ul_header->udp_ip4_ind = 0;
+               ul_header->udp_ind = 0;
 
        /* Changing remaining fields to network order */
        hdr++;
@@ -239,6 +239,7 @@ rmnet_map_ipv6_ul_csum_header(void *ip6hdr,
                              struct rmnet_map_ul_csum_header *ul_header,
                              struct sk_buff *skb)
 {
+       struct ipv6hdr *ip6h = (struct ipv6hdr *)ip6hdr;
        __be16 *hdr = (__be16 *)ul_header, offset;
 
        offset = htons((__force u16)(skb_transport_header(skb) -
@@ -246,7 +247,11 @@ rmnet_map_ipv6_ul_csum_header(void *ip6hdr,
        ul_header->csum_start_offset = offset;
        ul_header->csum_insert_offset = skb->csum_offset;
        ul_header->csum_enabled = 1;
-       ul_header->udp_ip4_ind = 0;
+
+       if (ip6h->nexthdr == IPPROTO_UDP)
+               ul_header->udp_ind = 1;
+       else
+               ul_header->udp_ind = 0;
 
        /* Changing remaining fields to network order */
        hdr++;
@@ -419,7 +424,7 @@ sw_csum:
        ul_header->csum_start_offset = 0;
        ul_header->csum_insert_offset = 0;
        ul_header->csum_enabled = 0;
-       ul_header->udp_ip4_ind = 0;
+       ul_header->udp_ind = 0;
 
        priv->stats.csum_sw++;
 }

diff --git a/include/linux/if_rmnet.h b/include/linux/if_rmnet.h
index b4f5403383fc9be106fad4cde572909df920c00c..9661416a9bb473da8bb329477b548a22fce4eaae 100644 (file)
--- a/include/linux/if_rmnet.h
+++ b/include/linux/if_rmnet.h
@@ -41,11 +41,11 @@ struct rmnet_map_ul_csum_header {
        __be16 csum_start_offset;
 #if defined(__LITTLE_ENDIAN_BITFIELD)
        u16 csum_insert_offset:14;
-       u16 udp_ip4_ind:1;
+       u16 udp_ind:1;
        u16 csum_enabled:1;
 #elif defined (__BIG_ENDIAN_BITFIELD)
        u16 csum_enabled:1;
-       u16 udp_ip4_ind:1;
+       u16 udp_ind:1;
        u16 csum_insert_offset:14;
 #else
 #error "Please fix <asm/byteorder.h>"