From: Davide Caratti <dcaratti@redhat.com>
To: David Laight <David.Laight@ACULAB.COM>,
Tom Herbert <tom@herbertland.com>
Cc: "David S . Miller" <davem@davemloft.net>,
Linux Kernel Network Developers <netdev@vger.kernel.org>,
"linux-sctp @ vger . kernel . org" <linux-sctp@vger.kernel.org>,
Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Subject: [PATCH RFC net-next v2 2/4] net: introduce skb_sctp_csum_help
Date: Tue, 28 Feb 2017 11:32:46 +0100 [thread overview]
Message-ID: <139092e2e728bd3fba48f32d5e10b1bf47be86d6.1488199633.git.dcaratti@redhat.com> (raw)
In-Reply-To: <1488202783.2713.67.camel@redhat.com>
In-Reply-To: <56fcd0848eae2b0693797e09500892659323546c.1488199633.git.dcaratti@redhat.com>
skb_sctp_csum_help is like skb_checksum_help, but it is designed for
checksumming SCTP packets using crc32c (see RFC3309), provided that
sctp.ko has been loaded before. In case sctp.ko is not loaded, invoking
skb_sctp_csum_help on a skb results in the following printout:
sk_buff: attempt to compute crc32c without sctp.ko
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
---
include/linux/netdevice.h | 1 +
include/linux/skbuff.h | 3 ++-
net/core/dev.c | 40 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 43 insertions(+), 1 deletion(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index f40f0ab..8c34735 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3918,6 +3918,7 @@ void netdev_rss_key_fill(void *buffer, size_t len);
int dev_get_nest_level(struct net_device *dev);
int skb_checksum_help(struct sk_buff *skb);
+int skb_sctp_csum_help(struct sk_buff *skb);
struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
netdev_features_t features, bool tx_path);
struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index cab9a32..0671131 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -192,7 +192,8 @@
* 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.
+ * is configured for a packet presumably by inspecting packet headers; in
+ * case, skb_sctp_csum_help is provided to compute CRC on SCTP packets.
*
* 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
diff --git a/net/core/dev.c b/net/core/dev.c
index 05d19c6..b9fb843 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -140,6 +140,7 @@
#include <linux/hrtimer.h>
#include <linux/netfilter_ingress.h>
#include <linux/crash_dump.h>
+#include <linux/sctp.h>
#include "net-sysfs.h"
@@ -2578,6 +2579,45 @@ int skb_checksum_help(struct sk_buff *skb)
}
EXPORT_SYMBOL(skb_checksum_help);
+int skb_sctp_csum_help(struct sk_buff *skb)
+{
+ __le32 crc32c_csum;
+ int ret = 0, offset;
+
+ if (skb->ip_summed != CHECKSUM_PARTIAL)
+ goto out;
+
+ if (unlikely(skb_is_gso(skb)))
+ goto out;
+
+ /* Before computing a checksum, we should make sure no frag could
+ * be modified by an external entity : checksum could be wrong.
+ */
+ if (unlikely(skb_has_shared_frag(skb))) {
+ ret = __skb_linearize(skb);
+ if (ret)
+ goto out;
+ }
+
+ offset = skb_checksum_start_offset(skb);
+ crc32c_csum = cpu_to_le32(~__skb_checksum(skb, offset,
+ skb->len - offset, ~(__u32)0,
+ sctp_csum_stub));
+ offset += offsetof(struct sctphdr, checksum);
+ BUG_ON(offset >= skb_headlen(skb));
+
+ if (skb_cloned(skb) &&
+ !skb_clone_writable(skb, offset + sizeof(__le32))) {
+ ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
+ if (ret)
+ goto out;
+ }
+ *(__le32 *)(skb->data + offset) = crc32c_csum;
+ skb->ip_summed = CHECKSUM_NONE;
+out:
+ return ret;
+}
+
__be16 skb_network_protocol(struct sk_buff *skb, int *depth)
{
__be16 type = skb->protocol;
--
2.7.4
next prev parent reply other threads:[~2017-02-28 10:35 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-23 16:52 [RFC PATCH net-next 0/5] net: improve support for SCTP checksums Davide Caratti
2017-01-23 16:52 ` [RFC PATCH net-next 1/5] skbuff: add stub to help computing crc32c on SCTP packets Davide Caratti
2017-01-23 16:52 ` [RFC PATCH net-next 2/5] net: split skb_checksum_help Davide Caratti
2017-01-23 20:59 ` Tom Herbert
2017-01-24 16:35 ` David Laight
2017-02-02 15:07 ` Davide Caratti
2017-02-02 16:55 ` David Laight
2017-02-02 18:08 ` Tom Herbert
2017-02-27 13:39 ` Davide Caratti
2017-02-27 15:11 ` Tom Herbert
2017-02-28 10:31 ` Davide Caratti
2017-02-28 10:32 ` [PATCH RFC net-next v2 1/4] skbuff: add stub to help computing crc32c on SCTP packets Davide Caratti
2017-02-28 10:32 ` Davide Caratti [this message]
2017-02-28 10:32 ` [PATCH RFC net-next v2 3/4] net: more accurate checksumming in validate_xmit_skb Davide Caratti
2017-02-28 19:50 ` Tom Herbert
2017-02-28 10:32 ` [PATCH RFC net-next v2 4/4] Documentation: update notes on checksum offloading Davide Caratti
2017-02-28 22:46 ` [PATCH RFC net-next v2 1/4] skbuff: add stub to help computing crc32c on SCTP packets Alexander Duyck
2017-03-01 3:17 ` Tom Herbert
2017-03-01 10:53 ` David Laight
2017-03-06 21:51 ` Davide Caratti
2017-03-07 18:06 ` Alexander Duyck
2017-03-18 13:17 ` Davide Caratti
2017-03-18 22:35 ` Tom Herbert
2017-04-07 14:16 ` [PATCH RFC net-next v3 0/7] improve CRC32c in the forwarding path Davide Caratti
2017-04-07 14:16 ` [PATCH RFC net-next v3 1/7] skbuff: add stub to help computing crc32c on SCTP packets Davide Caratti
2017-04-07 14:16 ` [PATCH RFC net-next v3 2/7] net: introduce skb_crc32c_csum_help Davide Caratti
2017-04-07 14:16 ` [PATCH RFC net-next v3 3/7] sk_buff: remove support for csum_bad in sk_buff Davide Caratti
2017-04-07 14:16 ` [PATCH RFC net-next v3 4/7] net: use skb->csum_algo to identify packets needing crc32c Davide Caratti
2017-04-07 15:43 ` Tom Herbert
2017-04-07 17:29 ` Davide Caratti
2017-04-07 18:11 ` Tom Herbert
2017-04-13 10:36 ` Davide Caratti
2017-04-20 13:38 ` [PATCH RFC net-next v4 0/7] net: improve support for SCTP checksums Davide Caratti
2017-04-20 13:38 ` [PATCH RFC net-next v4 1/7] skbuff: add stub to help computing crc32c on SCTP packets Davide Caratti
2017-04-20 13:38 ` [PATCH RFC net-next v4 2/7] net: introduce skb_crc32c_csum_help Davide Caratti
2017-04-27 12:29 ` Marcelo Ricardo Leitner
2017-04-20 13:38 ` [PATCH RFC net-next v4 3/7] sk_buff: remove support for csum_bad in sk_buff Davide Caratti
2017-04-27 1:34 ` [sk_buff] 95510aef27: BUG:Bad_page_state_in_process kernel test robot
2017-04-29 20:21 ` [PATCH RFC net-next v4 3/7] sk_buff: remove support for csum_bad in sk_buff Tom Herbert
2017-04-20 13:38 ` [PATCH RFC net-next v4 4/7] net: use skb->csum_not_inet to identify packets needing crc32c Davide Caratti
2017-04-29 20:18 ` Tom Herbert
2017-04-20 13:38 ` [PATCH RFC net-next v4 5/7] net: more accurate checksumming in validate_xmit_skb() Davide Caratti
2017-04-20 13:38 ` [PATCH RFC net-next v4 6/7] openvswitch: more accurate checksumming in queue_userspace_packet() Davide Caratti
2017-04-20 13:38 ` [PATCH RFC net-next v4 7/7] sk_buff.h: improve description of CHECKSUM_{COMPLETE,UNNECESSARY} Davide Caratti
2017-04-29 20:20 ` Tom Herbert
2017-04-27 12:41 ` [PATCH RFC net-next v4 0/7] net: improve support for SCTP checksums Marcelo Ricardo Leitner
2017-04-07 14:16 ` [PATCH RFC net-next v3 5/7] net: more accurate checksumming in validate_xmit_skb() Davide Caratti
2017-04-07 14:16 ` [PATCH RFC net-next v3 6/7] openvswitch: more accurate checksumming in queue_userspace_packet() Davide Caratti
2017-04-07 14:16 ` [PATCH RFC net-next v3 7/7] sk_buff.h: improve description of CHECKSUM_{COMPLETE,UNNECESSARY} Davide Caratti
2017-01-23 16:52 ` [RFC PATCH net-next 3/5] net: introduce skb_sctp_csum_help Davide Caratti
2017-01-23 16:52 ` [RFC PATCH net-next 4/5] net: more accurate checksumming in validate_xmit_skb Davide Caratti
2017-01-23 16:52 ` [RFC PATCH net-next 5/5] Documentation: add description of skb_sctp_csum_help Davide Caratti
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