diff --git a/include/linux/ppp_defs.h b/include/linux/ppp_defs.h index 9d2b388fae1a..b7e57fdbd413 100644 --- a/include/linux/ppp_defs.h +++ b/include/linux/ppp_defs.h @@ -11,4 +11,18 @@ #include #define PPP_FCS(fcs, c) crc_ccitt_byte(fcs, c) + +/** + * ppp_proto_is_valid - checks if PPP protocol is valid + * @proto: PPP protocol + * + * Assumes proto is not compressed. + * Protocol is valid if the value is odd and the least significant bit of the + * most significant octet is 0 (see RFC 1661, section 2). + */ +static inline bool ppp_proto_is_valid(u16 proto) +{ + return !!((proto & 0x0101) == 0x0001); +} + #endif /* _PPP_DEFS_H_ */ diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h index 0f9544a9bb9e..6c74812d64b2 100644 --- a/include/net/flow_dissector.h +++ b/include/net/flow_dissector.h @@ -277,6 +277,18 @@ 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 + * @type: pppoe eth type + */ +struct flow_dissector_key_pppoe { + __be16 session_id; + __be16 ppp_proto; + __be16 type; +}; + enum flow_dissector_key_id { FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */ FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */ @@ -307,6 +319,7 @@ 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..237d396b6e41 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -895,6 +895,11 @@ bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx, return result == BPF_OK; } +static bool is_pppoe_ses_hdr_valid(struct pppoe_hdr hdr) +{ + return hdr.ver == 1 && hdr.type == 1 && hdr.code == 0; +} + /** * __skb_flow_dissect - extract the flow_keys struct and return it * @net: associated network namespace, derived from @skb if NULL @@ -1214,26 +1219,60 @@ proto_again: struct pppoe_hdr hdr; __be16 proto; } *hdr, _hdr; + u16 ppp_proto; + hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); if (!hdr) { fdret = FLOW_DISSECT_RET_OUT_BAD; break; } - nhoff += PPPOE_SES_HLEN; - switch (hdr->proto) { - case htons(PPP_IP): - proto = htons(ETH_P_IP); - fdret = FLOW_DISSECT_RET_PROTO_AGAIN; - break; - case htons(PPP_IPV6): - proto = htons(ETH_P_IPV6); - fdret = FLOW_DISSECT_RET_PROTO_AGAIN; - break; - default: + if (!is_pppoe_ses_hdr_valid(hdr->hdr)) { fdret = FLOW_DISSECT_RET_OUT_BAD; break; } + + /* least significant bit of the most significant octet + * indicates if protocol field was compressed + */ + ppp_proto = ntohs(hdr->proto); + if (ppp_proto & 0x0100) { + ppp_proto = ppp_proto >> 8; + nhoff += PPPOE_SES_HLEN - 1; + } else { + nhoff += PPPOE_SES_HLEN; + } + + if (ppp_proto == PPP_IP) { + proto = htons(ETH_P_IP); + fdret = FLOW_DISSECT_RET_PROTO_AGAIN; + } else if (ppp_proto == PPP_IPV6) { + proto = htons(ETH_P_IPV6); + fdret = FLOW_DISSECT_RET_PROTO_AGAIN; + } else if (ppp_proto == PPP_MPLS_UC) { + proto = htons(ETH_P_MPLS_UC); + fdret = FLOW_DISSECT_RET_PROTO_AGAIN; + } else if (ppp_proto == PPP_MPLS_MC) { + proto = htons(ETH_P_MPLS_MC); + fdret = FLOW_DISSECT_RET_PROTO_AGAIN; + } else if (ppp_proto_is_valid(ppp_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 = hdr->hdr.sid; + key_pppoe->ppp_proto = htons(ppp_proto); + key_pppoe->type = htons(ETH_P_PPP_SES); + } break; } case htons(ETH_P_TIPC): {