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authorSubash Abhinov Kasiviswanathan <subashab@codeaurora.org>2018-01-07 21:36:37 +0300
committerDavid S. Miller <davem@davemloft.net>2018-01-08 21:58:49 +0300
commitbbd21b247cb596a426a1df0ad7658f141f558f86 (patch)
tree9aefd55eb3c584b12bd910bfc2a8f813206d01a7 /drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
parentc597897b08cb56e6a8b240245c074d43d1fde735 (diff)
downloadlinux-bbd21b247cb596a426a1df0ad7658f141f558f86.tar.xz
net: qualcomm: rmnet: Add support for RX checksum offload
When using the MAPv4 packet format, receive checksum offload can be enabled in hardware. The checksum computation over pseudo header is not offloaded but the rest of the checksum computation over the payload is offloaded. This applies only for TCP / UDP packets which are not fragmented. rmnet validates the TCP/UDP checksum for the packet using the checksum from the checksum trailer added to the packet by hardware. The validation performed is as following - 1. Perform 1's complement over the checksum value from the trailer 2. Compute 1's complement checksum over IPv4 / IPv6 header and subtracts it from the value from step 1 3. Computes 1's complement checksum over IPv4 / IPv6 pseudo header and adds it to the value from step 2 4. Subtracts the checksum value from the TCP / UDP header from the value from step 3. 5. Compares the value from step 4 to the checksum value from the TCP / UDP header. 6. If the comparison in step 5 succeeds, CHECKSUM_UNNECESSARY is set and the packet is passed on to network stack. If there is a failure, then the packet is passed on as such without modifying the ip_summed field. The checksum field is also checked for UDP checksum 0 as per RFC 768 and for unexpected TCP checksum of 0. If checksum offload is disabled when using MAPv4 packet format in receive path, the packet is queued as is to network stack without the validations above. Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c')
-rw-r--r--drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
index 8f8c4f205166..340945857d23 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c
@@ -66,8 +66,8 @@ __rmnet_map_ingress_handler(struct sk_buff *skb,
struct rmnet_port *port)
{
struct rmnet_endpoint *ep;
+ u16 len, pad;
u8 mux_id;
- u16 len;
if (RMNET_MAP_GET_CD_BIT(skb)) {
if (port->data_format & RMNET_INGRESS_FORMAT_MAP_COMMANDS)
@@ -77,7 +77,8 @@ __rmnet_map_ingress_handler(struct sk_buff *skb,
}
mux_id = RMNET_MAP_GET_MUX_ID(skb);
- len = RMNET_MAP_GET_LENGTH(skb) - RMNET_MAP_GET_PAD(skb);
+ pad = RMNET_MAP_GET_PAD(skb);
+ len = RMNET_MAP_GET_LENGTH(skb) - pad;
if (mux_id >= RMNET_MAX_LOGICAL_EP)
goto free_skb;
@@ -90,8 +91,14 @@ __rmnet_map_ingress_handler(struct sk_buff *skb,
/* Subtract MAP header */
skb_pull(skb, sizeof(struct rmnet_map_header));
- skb_trim(skb, len);
rmnet_set_skb_proto(skb);
+
+ if (port->data_format & RMNET_INGRESS_FORMAT_MAP_CKSUMV4) {
+ if (!rmnet_map_checksum_downlink_packet(skb, len + pad))
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ }
+
+ skb_trim(skb, len);
rmnet_deliver_skb(skb);
return;
@@ -115,7 +122,7 @@ rmnet_map_ingress_handler(struct sk_buff *skb,
}
if (port->data_format & RMNET_INGRESS_FORMAT_DEAGGREGATION) {
- while ((skbn = rmnet_map_deaggregate(skb)) != NULL)
+ while ((skbn = rmnet_map_deaggregate(skb, port)) != NULL)
__rmnet_map_ingress_handler(skbn, port);
consume_skb(skb);