diff options
| author | Julian Anastasov <ja@ssi.bg> | 2026-07-30 21:35:06 +0300 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2026-07-31 15:58:30 +0200 |
| commit | 99609cb0aa789c8d071050ce8579989551882cc6 (patch) | |
| tree | 69cfeec3bb84e869106da19ac5f7853191d0e21b /include | |
| parent | 646922a0379496154e8c8faca4f8e2fd9100cacc (diff) | |
ipvs: return the csum validation for forward hook
Sashiko notes that playing games with the skb dst and rt
flags instead of providing hooknum is not a good idea
when validating the checksums.
Also, skipping checksum validation for FORWARD packets
risk silent data corruption, even if the only user is
the FTP-CMD packets coming from the real server.
Sashiko also noticed that by using common checksum
helper in the previous commit we actually fixed old bug
where the TCP/UDP checksum for IPv6 on CHECKSUM_COMPLETE
was not validated correctly.
Fixes: e876b75b9020 ("ipvs: fix the checksum validations")
Link: https://sashiko.dev/#/patchset/20260722211420.153933-1-pablo%40netfilter.org
Link: https://sashiko.dev/#/patchset/20260727185024.67534-1-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260728202520.59179-1-ja%40ssi.bg
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/ip_vs.h | 19 |
1 files changed, 5 insertions, 14 deletions
diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h index 1235f1934e94..d2813eb795be 100644 --- a/include/net/ip_vs.h +++ b/include/net/ip_vs.h @@ -25,9 +25,7 @@ #include <linux/netfilter.h> /* for union nf_inet_addr */ #include <linux/ip.h> #include <linux/ipv6.h> /* for struct ipv6hdr */ -#include <net/route.h> #include <net/ipv6.h> -#include <net/ip6_fib.h> #if IS_ENABLED(CONFIG_NF_CONNTRACK) #include <net/netfilter/nf_conntrack.h> #endif @@ -2095,30 +2093,23 @@ static inline __wsum ip_vs_check_diff2(__be16 old, __be16 new, __wsum oldsum) return csum_partial(diff, sizeof(diff), oldsum); } -static inline bool ip_vs_checksum_needed(struct sk_buff *skb, int af) +static inline bool ip_vs_checksum_needed(struct sk_buff *skb) { /* Checksum unnecessary or already validated? */ if (skb_csum_unnecessary(skb)) return false; - /* LOCAL_OUT ? */ - if (!skb->dev || skb->dev->flags & IFF_LOOPBACK) + /* Locally generated ? */ + if (!skb->dev) return false; - /* !LOCAL_IN (FORWARD) ? */ - if (af == AF_INET6) { - if (!(dst_rt6_info(skb_dst(skb))->rt6i_flags & RTF_LOCAL)) - return false; - } else { - if (!(skb_rtable(skb)->rt_flags & RTCF_LOCAL)) - return false; - } return true; } static inline bool ip_vs_checksum_common_check(struct sk_buff *skb, int offset, int proto, int af) { - if (!ip_vs_checksum_needed(skb, af)) + if (!ip_vs_checksum_needed(skb)) return true; + /* Validate csum even for FORWARD */ return !nf_checksum(skb, NF_INET_LOCAL_IN, offset, proto, af); } |