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