From dba003067a43a9699bef0c4bdbe320ece5a109b8 Mon Sep 17 00:00:00 2001 From: Davide Caratti Date: Thu, 18 May 2017 15:44:40 +0200 Subject: [PATCH] net: use skb->csum_not_inet to identify packets needing crc32c skb->csum_not_inet carries the indication on which algorithm is needed to compute checksum on skb in the transmit path, when skb->ip_summed is equal to CHECKSUM_PARTIAL. If skb carries a SCTP packet and crc32c hasn't been yet written in L4 header, skb->csum_not_inet is assigned to 1; otherwise, assume Internet Checksum is needed and thus set skb->csum_not_inet to 0. Suggested-by: Tom Herbert Signed-off-by: Davide Caratti Acked-by: Tom Herbert Signed-off-by: David S. Miller --- include/linux/skbuff.h | 16 +++++++++------- net/core/dev.c | 1 + net/sched/act_csum.c | 1 + net/sctp/offload.c | 1 + net/sctp/output.c | 1 + 5 files changed, 13 insertions(+), 7 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index c38f890..a43d208 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -189,12 +189,13 @@ * * NETIF_F_SCTP_CRC - This feature indicates that a device is capable of * offloading the SCTP CRC in a packet. To perform this offload the stack - * will set ip_summed to CHECKSUM_PARTIAL and set csum_start and csum_offset - * accordingly. Note the there is no indication in the skbuff that the - * CHECKSUM_PARTIAL refers to an SCTP checksum, a driver that supports - * both IP checksum offload and SCTP CRC offload must verify which offload - * is configured for a packet presumably by inspecting packet headers; in - * case, skb_crc32c_csum_help is provided to compute CRC on SCTP packets. + * will set set csum_start and csum_offset accordingly, set ip_summed to + * CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication in + * the skbuff that the CHECKSUM_PARTIAL refers to CRC32c. + * A driver that supports both IP checksum offload and SCTP CRC32c offload + * must verify which offload is configured for a packet by testing the + * value of skb->csum_not_inet; skb_crc32c_csum_help is provided to resolve + * CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1. * * NETIF_F_FCOE_CRC - This feature indicates that a device is capable of * offloading the FCOE CRC in a packet. To perform this offload the stack @@ -557,6 +558,7 @@ typedef unsigned char *sk_buff_data_t; * @wifi_acked_valid: wifi_acked was set * @wifi_acked: whether frame was acked on wifi or not * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS + * @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL * @dst_pending_confirm: need to confirm neighbour * @napi_id: id of the NAPI struct this skb came from * @secmark: security marking @@ -685,7 +687,7 @@ struct sk_buff { __u8 csum_valid:1; __u8 csum_complete_sw:1; __u8 csum_level:2; - __u8 __csum_bad_unused:1; /* one bit hole */ + __u8 csum_not_inet:1; __u8 dst_pending_confirm:1; #ifdef CONFIG_IPV6_NDISC_NODETYPE diff --git a/net/core/dev.c b/net/core/dev.c index f0281ff..71107d1 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2649,6 +2649,7 @@ int skb_crc32c_csum_help(struct sk_buff *skb) crc32c_csum_stub)); *(__le32 *)(skb->data + offset) = crc32c_csum; skb->ip_summed = CHECKSUM_NONE; + skb->csum_not_inet = 0; out: return ret; } diff --git a/net/sched/act_csum.c b/net/sched/act_csum.c index ab6fdbd..3317a2f 100644 --- a/net/sched/act_csum.c +++ b/net/sched/act_csum.c @@ -350,6 +350,7 @@ static int tcf_csum_sctp(struct sk_buff *skb, unsigned int ihl, sctph->checksum = sctp_compute_cksum(skb, skb_network_offset(skb) + ihl); skb->ip_summed = CHECKSUM_NONE; + skb->csum_not_inet = 0; return 1; } diff --git a/net/sctp/offload.c b/net/sctp/offload.c index b671984..275925b 100644 --- a/net/sctp/offload.c +++ b/net/sctp/offload.c @@ -35,6 +35,7 @@ static __le32 sctp_gso_make_checksum(struct sk_buff *skb) { skb->ip_summed = CHECKSUM_NONE; + skb->csum_not_inet = 0; return sctp_compute_cksum(skb, skb_transport_offset(skb)); } diff --git a/net/sctp/output.c b/net/sctp/output.c index 1409a87..e2edf2e 100644 --- a/net/sctp/output.c +++ b/net/sctp/output.c @@ -538,6 +538,7 @@ merge: } else { chksum: head->ip_summed = CHECKSUM_PARTIAL; + head->csum_not_inet = 1; head->csum_start = skb_transport_header(head) - head->head; head->csum_offset = offsetof(struct sctphdr, checksum); } -- 2.7.4