diff options
| author | Alin Nastac <alin.nastac@gmail.com> | 2019-02-13 09:14:53 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2019-02-13 10:03:53 +0100 |
| commit | 7fc38225363dd8f19e667ad7c77b63bc4a5c065d (patch) | |
| tree | e0a67965b1a12cb5d3aac2f0720cbae18e84c111 /net | |
| parent | netfilter: conntrack: fix cloned unconfirmed skb->_nfct race in __nf_conntrac... (diff) | |
| download | linux-7fc38225363dd8f19e667ad7c77b63bc4a5c065d.tar.xz linux-7fc38225363dd8f19e667ad7c77b63bc4a5c065d.zip | |
netfilter: reject: skip csum verification for protocols that don't support it
Some protocols have other means to verify the payload integrity
(AH, ESP, SCTP) while others are incompatible with nf_ip(6)_checksum
implementation because checksum is either optional or might be
partial (UDPLITE, DCCP, GRE). Because nf_ip(6)_checksum was used
to validate the packets, ip(6)tables REJECT rules were not capable
to generate ICMP(v6) errors for the protocols mentioned above.
This commit also fixes the incorrect pseudo-header protocol used
for IPv4 packets that carry other transport protocols than TCP or
UDP (pseudo-header used protocol 0 iso the proper value).
Signed-off-by: Alin Nastac <alin.nastac@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/bridge/netfilter/nft_reject_bridge.c | 10 | ||||
| -rw-r--r-- | net/ipv4/netfilter/nf_reject_ipv4.c | 9 | ||||
| -rw-r--r-- | net/ipv6/netfilter/nf_reject_ipv6.c | 3 |
3 files changed, 10 insertions, 12 deletions
diff --git a/net/bridge/netfilter/nft_reject_bridge.c b/net/bridge/netfilter/nft_reject_bridge.c index 419e8edf23ba..1b1856744c80 100644 --- a/net/bridge/netfilter/nft_reject_bridge.c +++ b/net/bridge/netfilter/nft_reject_bridge.c @@ -125,13 +125,10 @@ static void nft_reject_br_send_v4_unreach(struct net *net, if (pskb_trim_rcsum(oldskb, ntohs(ip_hdr(oldskb)->tot_len))) return; - if (ip_hdr(oldskb)->protocol == IPPROTO_TCP || - ip_hdr(oldskb)->protocol == IPPROTO_UDP) - proto = ip_hdr(oldskb)->protocol; - else - proto = 0; + proto = ip_hdr(oldskb)->protocol; if (!skb_csum_unnecessary(oldskb) && + nf_reject_verify_csum(proto) && nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), proto)) return; @@ -234,6 +231,9 @@ static bool reject6_br_csum_ok(struct sk_buff *skb, int hook) if (thoff < 0 || thoff >= skb->len || (fo & htons(~0x7)) != 0) return false; + if (!nf_reject_verify_csum(proto)) + return true; + return nf_ip6_checksum(skb, hook, thoff, proto) == 0; } diff --git a/net/ipv4/netfilter/nf_reject_ipv4.c b/net/ipv4/netfilter/nf_reject_ipv4.c index aa8304c618b8..7dc3c324b911 100644 --- a/net/ipv4/netfilter/nf_reject_ipv4.c +++ b/net/ipv4/netfilter/nf_reject_ipv4.c @@ -173,21 +173,16 @@ EXPORT_SYMBOL_GPL(nf_send_reset); void nf_send_unreach(struct sk_buff *skb_in, int code, int hook) { struct iphdr *iph = ip_hdr(skb_in); - u8 proto; + u8 proto = iph->protocol; if (iph->frag_off & htons(IP_OFFSET)) return; - if (skb_csum_unnecessary(skb_in)) { + if (skb_csum_unnecessary(skb_in) || !nf_reject_verify_csum(proto)) { icmp_send(skb_in, ICMP_DEST_UNREACH, code, 0); return; } - if (iph->protocol == IPPROTO_TCP || iph->protocol == IPPROTO_UDP) - proto = iph->protocol; - else - proto = 0; - if (nf_ip_checksum(skb_in, hook, ip_hdrlen(skb_in), proto) == 0) icmp_send(skb_in, ICMP_DEST_UNREACH, code, 0); } diff --git a/net/ipv6/netfilter/nf_reject_ipv6.c b/net/ipv6/netfilter/nf_reject_ipv6.c index b9c8a763c863..02e9228641e0 100644 --- a/net/ipv6/netfilter/nf_reject_ipv6.c +++ b/net/ipv6/netfilter/nf_reject_ipv6.c @@ -233,6 +233,9 @@ static bool reject6_csum_ok(struct sk_buff *skb, int hook) if (thoff < 0 || thoff >= skb->len || (fo & htons(~0x7)) != 0) return false; + if (!nf_reject_verify_csum(proto)) + return true; + return nf_ip6_checksum(skb, hook, thoff, proto) == 0; } |