sctp_compute_checksum requires crc32c symbol (provided by libcrc32c), so
it can't be used in net core. Like it has been done previously with other
symbols (e.g. ipv6_dst_lookup), introduce a stub struct skb_checksum_ops
to allow computation of crc32c checksum in net core after sctp.ko (and thus
libcrc32c) has been loaded.
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
Signed-off-by: Davide Caratti <dcaratti@xxxxxxxxxx>
---
include/linux/skbuff.h | 2 ++
net/core/skbuff.c | 24 ++++++++++++++++++++++++
net/sctp/offload.c | 7 +++++++
3 files changed, 33 insertions(+)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index c776abd..8e9dd82 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3126,6 +3126,8 @@ struct skb_checksum_ops {
__wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len);
};
+extern const struct skb_checksum_ops *crc32c_csum_stub __read_mostly;
+
__wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
__wsum csum, const struct skb_checksum_ops *ops);
__wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 9f78109..1a142aa 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2242,6 +2242,30 @@ __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset,
}
EXPORT_SYMBOL(skb_copy_and_csum_bits);
+static __wsum warn_crc32c_csum_update(const void *buff, int len, __wsum sum)
+{
+ net_warn_ratelimited(
+ "%s: attempt to compute crc32c without libcrc32c.ko\n",
+ __func__);
+ return 0;
+}
+
+static __wsum warn_crc32c_csum_combine(__wsum csum, __wsum csum2,
+ int offset, int len)
+{
+ net_warn_ratelimited(
+ "%s: attempt to compute crc32c without libcrc32c.ko\n",
+ __func__);
+ return 0;
+}
+
+const struct skb_checksum_ops *crc32c_csum_stub __read_mostly =
+ &(struct skb_checksum_ops) {
+ .update = warn_crc32c_csum_update,
+ .combine = warn_crc32c_csum_combine,
+};
+EXPORT_SYMBOL(crc32c_csum_stub);
+
/**
* skb_zerocopy_headlen - Calculate headroom needed for skb_zerocopy()
* @from: source buffer
diff --git a/net/sctp/offload.c b/net/sctp/offload.c
index 4f5a2b5..378f462 100644
--- a/net/sctp/offload.c
+++ b/net/sctp/offload.c
@@ -98,6 +98,12 @@ static const struct net_offload sctp6_offload = {
},
};
+static const struct skb_checksum_ops *crc32c_csum_ops __read_mostly =
+ &(struct skb_checksum_ops) {
+ .update = sctp_csum_update,
+ .combine = sctp_csum_combine,
+};
+
int __init sctp_offload_init(void)
{
int ret;
@@ -110,6 +116,7 @@ int __init sctp_offload_init(void)
if (ret)
goto ipv4;
+ crc32c_csum_stub = crc32c_csum_ops;
return ret;
ipv4:
--
2.7.4
--
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