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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 /include/net/netfilter/nf_reject.h
parent13f5251fd17088170c18844534682d9cab5ff5aa (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 'include/net/netfilter/nf_reject.h')
-rw-r--r--include/net/netfilter/nf_reject.h27
1 files changed, 27 insertions, 0 deletions
diff --git a/include/net/netfilter/nf_reject.h b/include/net/netfilter/nf_reject.h
new file mode 100644
index 000000000000..221f877f29d1
--- /dev/null
+++ b/include/net/netfilter/nf_reject.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _NF_REJECT_H
+#define _NF_REJECT_H
+
+static inline bool nf_reject_verify_csum(__u8 proto)
+{
+ /* Skip protocols that don't use 16-bit one's complement checksum
+ * of the entire payload.
+ */
+ switch (proto) {
+ /* Protocols with other integrity checks. */
+ case IPPROTO_AH:
+ case IPPROTO_ESP:
+ case IPPROTO_SCTP:
+
+ /* Protocols with partial checksums. */
+ case IPPROTO_UDPLITE:
+ case IPPROTO_DCCP:
+
+ /* Protocols with optional checksums. */
+ case IPPROTO_GRE:
+ return false;
+ }
+ return true;
+}
+
+#endif /* _NF_REJECT_H */