From mboxrd@z Thu Jan 1 00:00:00 1970 From: Davide Caratti Subject: [PATCH RFC net-next v3 1/7] skbuff: add stub to help computing crc32c on SCTP packets Date: Fri, 7 Apr 2017 16:16:04 +0200 Message-ID: <5fe8cde0648e74c3d2a897c1992ae06088cea527.1491562390.git.dcaratti@redhat.com> References: Cc: Linux Kernel Network Developers , linux-sctp@vger.kernel.org To: Tom Herbert , Alexander Duyck , David Laight , "David S . Miller" , Marcelo Ricardo Leitner Return-path: Received: from mx1.redhat.com ([209.132.183.28]:50358 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933475AbdDGOQ2 (ORCPT ); Fri, 7 Apr 2017 10:16:28 -0400 In-Reply-To: In-Reply-To: References: Sender: netdev-owner@vger.kernel.org List-ID: 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 Signed-off-by: Davide Caratti --- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Davide Caratti Date: Fri, 07 Apr 2017 14:16:04 +0000 Subject: [PATCH RFC net-next v3 1/7] skbuff: add stub to help computing crc32c on SCTP packets Message-Id: <5fe8cde0648e74c3d2a897c1992ae06088cea527.1491562390.git.dcaratti@redhat.com> List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tom Herbert , Alexander Duyck , David Laight , "David S . Miller" , Marcelo Ricardo Leitner Cc: Linux Kernel Network Developers , linux-sctp@vger.kernel.org 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 Signed-off-by: Davide Caratti --- 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