* [PATCH stable] ipvs: sctp: fix checksumming on snat and dnat handlers [not found] <cover.1361451476.git.dborkman@redhat.com> @ 2013-02-21 13:05 ` Daniel Borkmann 2013-02-21 15:14 ` Neil Horman 0 siblings, 1 reply; 3+ messages in thread From: Daniel Borkmann @ 2013-02-21 13:05 UTC (permalink / raw) To: netfilter-devel, lvs-devel, linux-sctp Cc: Julian Anastasov, Simon Horman, Pablo Neira Ayuso In our test lab, we have a simple SCTP client connecting to a SCTP server via an IPVS load balancer. On some machines, load balancing works, but on others the initial handshake just fails, thus no SCTP connection whatsoever can be established! We observed that the SCTP INIT-ACK handshake reply from the IPVS machine to the client had a correct IP checksum, but corrupt SCTP checksum when forwarded, thus on the client-side the packet was dropped and an intial handshake retriggered until all attempts run into the void. To fix this issue, this patch i) adds a missing CHECKSUM_UNNECESSARY after the full checksum (re-)calculation (as done in IPVS TCP and UDP code as well), and ii) calculates the checksum in little-endian format (as fixed with the SCTP code in commit 4458f04c: sctp: Clean up sctp checksumming code). Stable backport of upstream commit 4b47bc9a. Cc: Julian Anastasov <ja@ssi.bg> Cc: Simon Horman <horms@verge.net.au> Cc: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> --- net/netfilter/ipvs/ip_vs_proto_sctp.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/net/netfilter/ipvs/ip_vs_proto_sctp.c b/net/netfilter/ipvs/ip_vs_proto_sctp.c index 9f3fb75..94bb367 100644 --- a/net/netfilter/ipvs/ip_vs_proto_sctp.c +++ b/net/netfilter/ipvs/ip_vs_proto_sctp.c @@ -70,7 +70,7 @@ sctp_snat_handler(struct sk_buff *skb, sctp_sctphdr_t *sctph; unsigned int sctphoff; struct sk_buff *iter; - __be32 crc32; + __u32 crc32; #ifdef CONFIG_IP_VS_IPV6 if (cp->af == AF_INET6) @@ -101,8 +101,9 @@ sctp_snat_handler(struct sk_buff *skb, skb_walk_frags(skb, iter) crc32 = sctp_update_cksum((u8 *) iter->data, skb_headlen(iter), crc32); - crc32 = sctp_end_cksum(crc32); - sctph->checksum = crc32; + sctph->checksum = sctp_end_cksum(crc32); + + skb->ip_summed = CHECKSUM_UNNECESSARY; return 1; } @@ -114,7 +115,7 @@ sctp_dnat_handler(struct sk_buff *skb, sctp_sctphdr_t *sctph; unsigned int sctphoff; struct sk_buff *iter; - __be32 crc32; + __u32 crc32; #ifdef CONFIG_IP_VS_IPV6 if (cp->af == AF_INET6) @@ -145,8 +146,9 @@ sctp_dnat_handler(struct sk_buff *skb, skb_walk_frags(skb, iter) crc32 = sctp_update_cksum((u8 *) iter->data, skb_headlen(iter), crc32); - crc32 = sctp_end_cksum(crc32); - sctph->checksum = crc32; + sctph->checksum = sctp_end_cksum(crc32); + + skb->ip_summed = CHECKSUM_UNNECESSARY; return 1; } -- 1.7.11.7 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH stable] ipvs: sctp: fix checksumming on snat and dnat handlers 2013-02-21 13:05 ` [PATCH stable] ipvs: sctp: fix checksumming on snat and dnat handlers Daniel Borkmann @ 2013-02-21 15:14 ` Neil Horman 2013-02-25 15:40 ` Pablo Neira Ayuso 0 siblings, 1 reply; 3+ messages in thread From: Neil Horman @ 2013-02-21 15:14 UTC (permalink / raw) To: Daniel Borkmann Cc: netfilter-devel, lvs-devel, linux-sctp, Julian Anastasov, Simon Horman, Pablo Neira Ayuso On Thu, Feb 21, 2013 at 02:05:39PM +0100, Daniel Borkmann wrote: > In our test lab, we have a simple SCTP client connecting to a SCTP > server via an IPVS load balancer. On some machines, load balancing > works, but on others the initial handshake just fails, thus no > SCTP connection whatsoever can be established! > > We observed that the SCTP INIT-ACK handshake reply from the IPVS > machine to the client had a correct IP checksum, but corrupt SCTP > checksum when forwarded, thus on the client-side the packet was > dropped and an intial handshake retriggered until all attempts > run into the void. > > To fix this issue, this patch i) adds a missing CHECKSUM_UNNECESSARY > after the full checksum (re-)calculation (as done in IPVS TCP and UDP > code as well), and ii) calculates the checksum in little-endian format > (as fixed with the SCTP code in commit 4458f04c: sctp: Clean up sctp > checksumming code). Stable backport of upstream commit 4b47bc9a. > > Cc: Julian Anastasov <ja@ssi.bg> > Cc: Simon Horman <horms@verge.net.au> > Cc: Pablo Neira Ayuso <pablo@netfilter.org> > Signed-off-by: Daniel Borkmann <dborkman@redhat.com> > --- > net/netfilter/ipvs/ip_vs_proto_sctp.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/net/netfilter/ipvs/ip_vs_proto_sctp.c b/net/netfilter/ipvs/ip_vs_proto_sctp.c > index 9f3fb75..94bb367 100644 > --- a/net/netfilter/ipvs/ip_vs_proto_sctp.c > +++ b/net/netfilter/ipvs/ip_vs_proto_sctp.c > @@ -70,7 +70,7 @@ sctp_snat_handler(struct sk_buff *skb, > sctp_sctphdr_t *sctph; > unsigned int sctphoff; > struct sk_buff *iter; > - __be32 crc32; > + __u32 crc32; > > #ifdef CONFIG_IP_VS_IPV6 > if (cp->af == AF_INET6) > @@ -101,8 +101,9 @@ sctp_snat_handler(struct sk_buff *skb, > skb_walk_frags(skb, iter) > crc32 = sctp_update_cksum((u8 *) iter->data, skb_headlen(iter), > crc32); > - crc32 = sctp_end_cksum(crc32); > - sctph->checksum = crc32; > + sctph->checksum = sctp_end_cksum(crc32); > + > + skb->ip_summed = CHECKSUM_UNNECESSARY; > > return 1; > } > @@ -114,7 +115,7 @@ sctp_dnat_handler(struct sk_buff *skb, > sctp_sctphdr_t *sctph; > unsigned int sctphoff; > struct sk_buff *iter; > - __be32 crc32; > + __u32 crc32; > > #ifdef CONFIG_IP_VS_IPV6 > if (cp->af == AF_INET6) > @@ -145,8 +146,9 @@ sctp_dnat_handler(struct sk_buff *skb, > skb_walk_frags(skb, iter) > crc32 = sctp_update_cksum((u8 *) iter->data, skb_headlen(iter), > crc32); > - crc32 = sctp_end_cksum(crc32); > - sctph->checksum = crc32; > + sctph->checksum = sctp_end_cksum(crc32); > + > + skb->ip_summed = CHECKSUM_UNNECESSARY; > > return 1; > } > -- > 1.7.11.7 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Acked-by: Neil Horman <nhorman@tuxdriver.com> ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH stable] ipvs: sctp: fix checksumming on snat and dnat handlers 2013-02-21 15:14 ` Neil Horman @ 2013-02-25 15:40 ` Pablo Neira Ayuso 0 siblings, 0 replies; 3+ messages in thread From: Pablo Neira Ayuso @ 2013-02-25 15:40 UTC (permalink / raw) To: Neil Horman Cc: Daniel Borkmann, netfilter-devel, lvs-devel, linux-sctp, Julian Anastasov, Simon Horman On Thu, Feb 21, 2013 at 10:14:51AM -0500, Neil Horman wrote: > On Thu, Feb 21, 2013 at 02:05:39PM +0100, Daniel Borkmann wrote: > > In our test lab, we have a simple SCTP client connecting to a SCTP > > server via an IPVS load balancer. On some machines, load balancing > > works, but on others the initial handshake just fails, thus no > > SCTP connection whatsoever can be established! > > > > We observed that the SCTP INIT-ACK handshake reply from the IPVS > > machine to the client had a correct IP checksum, but corrupt SCTP > > checksum when forwarded, thus on the client-side the packet was > > dropped and an intial handshake retriggered until all attempts > > run into the void. > > > > To fix this issue, this patch i) adds a missing CHECKSUM_UNNECESSARY > > after the full checksum (re-)calculation (as done in IPVS TCP and UDP > > code as well), and ii) calculates the checksum in little-endian format > > (as fixed with the SCTP code in commit 4458f04c: sctp: Clean up sctp > > checksumming code). Stable backport of upstream commit 4b47bc9a. > > > > Cc: Julian Anastasov <ja@ssi.bg> > > Cc: Simon Horman <horms@verge.net.au> > > Cc: Pablo Neira Ayuso <pablo@netfilter.org> > > Signed-off-by: Daniel Borkmann <dborkman@redhat.com> [...] > Acked-by: Neil Horman <nhorman@tuxdriver.com> Enqueued to -stable. Thanks. ^ permalink raw reply [flat|nested] 3+ messages in thread
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2013-02-21 13:05 ` [PATCH stable] ipvs: sctp: fix checksumming on snat and dnat handlers Daniel Borkmann
2013-02-21 15:14 ` Neil Horman
2013-02-25 15:40 ` Pablo Neira Ayuso
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