ppp makes my head hurt. so does mpls. when do we need to dissect it?
---------- Forwarded message ---------
From: Marcin Szycik <marcin.szy...@linux.intel.com>
Date: Wed, Jun 29, 2022 at 8:01 AM
Subject: [RFC PATCH net-next v3 1/4] flow_dissector: Add PPPoE dissectors
To: <net...@vger.kernel.org>
Cc: <anthony.l.ngu...@intel.com>, <da...@davemloft.net>,
<xiyou.wangc...@gmail.com>, <jesse.brandeb...@intel.com>,
<gustavo...@kernel.org>, <baowen.zh...@corigine.com>,
<boris.sukholi...@broadcom.com>, <eduma...@google.com>,
<k...@kernel.org>, <j...@mojatatu.com>, <j...@resnulli.us>,
<k...@linutronix.de>, <pa...@netfilter.org>, <pab...@redhat.com>,
<pa...@nvidia.com>, <simon.hor...@corigine.com>,
<komachi.yosh...@gmail.com>, <zhangkai...@126.com>,
<intel-wired-...@lists.osuosl.org>,
<michal.swiatkow...@linux.intel.com>, <wojciech.dre...@intel.com>,
<alexandr.loba...@intel.com>, <gna...@redhat.com>,
<mostr...@earthlink.net>, <pau...@samba.org>
From: Wojciech Drewek <wojciech.dre...@intel.com>
Allow to dissect PPPoE specific fields which are:
- session ID (16 bits)
- ppp protocol (16 bits)
The goal is to make the following TC command possible:
# tc filter add dev ens6f0 ingress prio 1 protocol ppp_ses \
flower \
pppoe_sid 12 \
ppp_proto ip \
action drop
Note that only PPPoE Session is supported.
Signed-off-by: Wojciech Drewek <wojciech.dre...@intel.com>
---
v3: revert byte order changes in is_ppp_proto_supported from previous
version, add kernel-doc for is_ppp_proto_supported
v2: use ntohs instead of htons in is_ppp_proto_supported
include/net/flow_dissector.h | 11 ++++++++
net/core/flow_dissector.c | 55 ++++++++++++++++++++++++++++++++----
2 files changed, 60 insertions(+), 6 deletions(-)
diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
index a4c6057c7097..8ff40c7c3f1c 100644
--- a/include/net/flow_dissector.h
+++ b/include/net/flow_dissector.h
@@ -261,6 +261,16 @@ struct flow_dissector_key_num_of_vlans {
u8 num_of_vlans;
};
+/**
+ * struct flow_dissector_key_pppoe:
+ * @session_id: pppoe session id
+ * @ppp_proto: ppp protocol
+ */
+struct flow_dissector_key_pppoe {
+ u16 session_id;
+ __be16 ppp_proto;
+};
+
enum flow_dissector_key_id {
FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
@@ -291,6 +301,7 @@ enum flow_dissector_key_id {
FLOW_DISSECTOR_KEY_CT, /* struct flow_dissector_key_ct */
FLOW_DISSECTOR_KEY_HASH, /* struct flow_dissector_key_hash */
FLOW_DISSECTOR_KEY_NUM_OF_VLANS, /* struct
flow_dissector_key_num_of_vlans */
+ FLOW_DISSECTOR_KEY_PPPOE, /* struct flow_dissector_key_pppoe */
FLOW_DISSECTOR_KEY_MAX,
};
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 6aee04f75e3e..42393af477a2 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -895,6 +895,39 @@ bool bpf_flow_dissect(struct bpf_prog *prog,
struct bpf_flow_dissector *ctx,
return result == BPF_OK;
}
+/**
+ * is_ppp_proto_supported - checks if inner PPP protocol should be dissected
+ * @proto: protocol type (PPP proto field)
+ */
+static bool is_ppp_proto_supported(__be16 proto)
+{
+ switch (proto) {
+ case htons(PPP_AT):
+ case htons(PPP_IPX):
+ case htons(PPP_VJC_COMP):
+ case htons(PPP_VJC_UNCOMP):
+ case htons(PPP_MP):
+ case htons(PPP_COMPFRAG):
+ case htons(PPP_COMP):
+ case htons(PPP_MPLS_UC):
+ case htons(PPP_MPLS_MC):
+ case htons(PPP_IPCP):
+ case htons(PPP_ATCP):
+ case htons(PPP_IPXCP):
+ case htons(PPP_IPV6CP):
+ case htons(PPP_CCPFRAG):
+ case htons(PPP_MPLSCP):
+ case htons(PPP_LCP):
+ case htons(PPP_PAP):
+ case htons(PPP_LQR):
+ case htons(PPP_CHAP):
+ case htons(PPP_CBCP):
+ return true;
+ default:
+ return false;
+ }
+}
+
/**
* __skb_flow_dissect - extract the flow_keys struct and return it
* @net: associated network namespace, derived from @skb if NULL
@@ -1221,19 +1254,29 @@ bool __skb_flow_dissect(const struct net *net,
}
nhoff += PPPOE_SES_HLEN;
- switch (hdr->proto) {
- case htons(PPP_IP):
+ if (hdr->proto == htons(PPP_IP)) {
proto = htons(ETH_P_IP);
fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
- break;
- case htons(PPP_IPV6):
+ } else if (hdr->proto == htons(PPP_IPV6)) {
proto = htons(ETH_P_IPV6);
fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
- break;
- default:
+ } else if (is_ppp_proto_supported(hdr->proto)) {
+ fdret = FLOW_DISSECT_RET_OUT_GOOD;
+ } else {
fdret = FLOW_DISSECT_RET_OUT_BAD;
break;
}
+
+ if (dissector_uses_key(flow_dissector,
+ FLOW_DISSECTOR_KEY_PPPOE)) {
+ struct flow_dissector_key_pppoe *key_pppoe;
+
+ key_pppoe = skb_flow_dissector_target(flow_dissector,
+
FLOW_DISSECTOR_KEY_PPPOE,
+ target_container);
+ key_pppoe->session_id = ntohs(hdr->hdr.sid);
+ key_pppoe->ppp_proto = hdr->proto;
+ }
break;
}
case htons(ETH_P_TIPC): {
--
2.35.1
--
FQ World Domination pending: https://blog.cerowrt.org/post/state_of_fq_codel/
Dave Täht CEO, TekLibre, LLC
_______________________________________________
Cake mailing list
Cake@lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/cake
