path: root/net/ipv4
diff options
authorAlin Nastac <alin.nastac@gmail.com>2019-02-13 09:14:53 +0100
committerPablo Neira Ayuso <pablo@netfilter.org>2019-02-13 10:03:53 +0100
commit7fc38225363dd8f19e667ad7c77b63bc4a5c065d (patch)
treee0a67965b1a12cb5d3aac2f0720cbae18e84c111 /net/ipv4
parentnetfilter: conntrack: fix cloned unconfirmed skb->_nfct race in __nf_conntrack_confirm (diff)
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/ipv4')
1 files changed, 2 insertions, 7 deletions
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))
- 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);
- 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);