[PATCH v5 1/1] rps: Inspect PPTP encapsulated by GRE to get flow hash
From: <hidden>
Date: 2016-08-09 00:38:30
From: Gao Feng <redacted>
The PPTP is encapsulated by GRE header with that GRE_VERSION bits
must contain one. But current GRE RPS needs the GRE_VERSION must be
zero. So RPS does not work for PPTP traffic.
In my test environment, there are four MIPS cores, and all traffic
are passed through by PPTP. As a result, only one core is 100% busy
while other three cores are very idle. After this patch, the usage
of four cores are balanced well.
Signed-off-by: Gao Feng <redacted>
---
v5: 1) Make fix header of gre_full_hdr as uname struct;
2) Create macro GRE_PPTP_KEY_MASK;
v4: 1) Define struct gre_full_hdr, and use sizeof its member directly;
2) Move version and routing check ahead;
3) Only PPTP in GRE check the ack flag;
v3: 1) Move struct pptp_gre_header defination into new file pptp.h
2) Use sizeof GRE and PPTP type instead of literal value;
3) Remove strict flag check for PPTP to robust;
4) Consolidate the codes again;
v2: Update according to Tom and Philp's advice.
1) Consolidate the codes with GRE version 0 path;
2) Use PPP_PROTOCOL to get ppp protol;
3) Set the FLOW_DIS_ENCAPSULATION flag;
v1: Intial Patch
drivers/net/ppp/pptp.c | 36 +------------
include/net/gre.h | 13 ++++-
include/net/pptp.h | 40 +++++++++++++++
include/uapi/linux/if_tunnel.h | 7 ++-
net/core/flow_dissector.c | 113 ++++++++++++++++++++++++++++-------------
5 files changed, 138 insertions(+), 71 deletions(-)
create mode 100644 include/net/pptp.h
diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index ae0905e..3e68dbc 100644
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c@@ -37,6 +37,7 @@ #include <net/icmp.h> #include <net/route.h> #include <net/gre.h> +#include <net/pptp.h> #include <linux/uaccess.h>
@@ -53,41 +54,6 @@ static struct proto pptp_sk_proto __read_mostly; static const struct ppp_channel_ops pptp_chan_ops; static const struct proto_ops pptp_ops; -#define PPP_LCP_ECHOREQ 0x09 -#define PPP_LCP_ECHOREP 0x0A -#define SC_RCV_BITS (SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP) - -#define MISSING_WINDOW 20 -#define WRAPPED(curseq, lastseq)\ - ((((curseq) & 0xffffff00) == 0) &&\ - (((lastseq) & 0xffffff00) == 0xffffff00)) - -#define PPTP_GRE_PROTO 0x880B -#define PPTP_GRE_VER 0x1 - -#define PPTP_GRE_FLAG_C 0x80 -#define PPTP_GRE_FLAG_R 0x40 -#define PPTP_GRE_FLAG_K 0x20 -#define PPTP_GRE_FLAG_S 0x10 -#define PPTP_GRE_FLAG_A 0x80 - -#define PPTP_GRE_IS_C(f) ((f)&PPTP_GRE_FLAG_C) -#define PPTP_GRE_IS_R(f) ((f)&PPTP_GRE_FLAG_R) -#define PPTP_GRE_IS_K(f) ((f)&PPTP_GRE_FLAG_K) -#define PPTP_GRE_IS_S(f) ((f)&PPTP_GRE_FLAG_S) -#define PPTP_GRE_IS_A(f) ((f)&PPTP_GRE_FLAG_A) - -#define PPTP_HEADER_OVERHEAD (2+sizeof(struct pptp_gre_header)) -struct pptp_gre_header { - u8 flags; - u8 ver; - __be16 protocol; - __be16 payload_len; - __be16 call_id; - __be32 seq; - __be32 ack; -} __packed; - static struct pppox_sock *lookup_chan(u16 call_id, __be32 s_addr) { struct pppox_sock *sock;
diff --git a/include/net/gre.h b/include/net/gre.h
index 7a54a31..6347f16 100644
--- a/include/net/gre.h
+++ b/include/net/gre.h@@ -7,9 +7,20 @@ struct gre_base_hdr { __be16 flags; __be16 protocol; -}; +} __packed; #define GRE_HEADER_SECTION 4 +struct gre_full_hdr { + struct { + __be16 flags; + __be16 protocols; + }; + __be16 csum; + __be16 reserved1; + __be32 key; + __be32 seq; +} __packed; + #define GREPROTO_CISCO 0 #define GREPROTO_PPTP 1 #define GREPROTO_MAX 2
diff --git a/include/net/pptp.h b/include/net/pptp.h
new file mode 100644
index 0000000..301d3e2
--- /dev/null
+++ b/include/net/pptp.h@@ -0,0 +1,40 @@ +#ifndef _NET_PPTP_H +#define _NET_PPTP_H + +#define PPP_LCP_ECHOREQ 0x09 +#define PPP_LCP_ECHOREP 0x0A +#define SC_RCV_BITS (SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP) + +#define MISSING_WINDOW 20 +#define WRAPPED(curseq, lastseq)\ + ((((curseq) & 0xffffff00) == 0) &&\ + (((lastseq) & 0xffffff00) == 0xffffff00)) + +#define PPTP_GRE_PROTO 0x880B +#define PPTP_GRE_VER 0x1 + +#define PPTP_GRE_FLAG_C 0x80 +#define PPTP_GRE_FLAG_R 0x40 +#define PPTP_GRE_FLAG_K 0x20 +#define PPTP_GRE_FLAG_S 0x10 +#define PPTP_GRE_FLAG_A 0x80 + +#define PPTP_GRE_IS_C(f) ((f)&PPTP_GRE_FLAG_C) +#define PPTP_GRE_IS_R(f) ((f)&PPTP_GRE_FLAG_R) +#define PPTP_GRE_IS_K(f) ((f)&PPTP_GRE_FLAG_K) +#define PPTP_GRE_IS_S(f) ((f)&PPTP_GRE_FLAG_S) +#define PPTP_GRE_IS_A(f) ((f)&PPTP_GRE_FLAG_A) + +#define PPTP_HEADER_OVERHEAD (2+sizeof(struct pptp_gre_header)) +struct pptp_gre_header { + u8 flags; + u8 ver; + __be16 protocol; + __be16 payload_len; + __be16 call_id; + __be32 seq; + __be32 ack; +} __packed; + + +#endif
diff --git a/include/uapi/linux/if_tunnel.h b/include/uapi/linux/if_tunnel.h
index 1046f55..0c11918 100644
--- a/include/uapi/linux/if_tunnel.h
+++ b/include/uapi/linux/if_tunnel.h@@ -24,9 +24,14 @@ #define GRE_SEQ __cpu_to_be16(0x1000) #define GRE_STRICT __cpu_to_be16(0x0800) #define GRE_REC __cpu_to_be16(0x0700) -#define GRE_FLAGS __cpu_to_be16(0x00F8) +#define GRE_ACK __cpu_to_be16(0x0080) +#define GRE_FLAGS __cpu_to_be16(0x0078) #define GRE_VERSION __cpu_to_be16(0x0007) +#define GRE_VERSION_1 __cpu_to_be16(0x0001) +#define GRE_PROTO_PPP __cpu_to_be16(0x880b) +#define GRE_PPTP_KEY_MASK htonl(0xffff) + struct ip_tunnel_parm { char name[IFNAMSIZ]; int link;
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 61ad43f..91028ae 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c@@ -6,6 +6,8 @@ #include <linux/if_vlan.h> #include <net/ip.h> #include <net/ipv6.h> +#include <net/gre.h> +#include <net/pptp.h> #include <linux/igmp.h> #include <linux/icmp.h> #include <linux/sctp.h>
@@ -338,32 +340,42 @@ mpls: ip_proto_again: switch (ip_proto) { case IPPROTO_GRE: { - struct gre_hdr { - __be16 flags; - __be16 proto; - } *hdr, _hdr; + struct gre_base_hdr *hdr, _hdr; + u16 gre_ver; + int offset = 0; hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); if (!hdr) goto out_bad; - /* - * Only look inside GRE if version zero and no - * routing - */ - if (hdr->flags & (GRE_VERSION | GRE_ROUTING)) + + /* Only look inside GRE without routing */ + if (hdr->flags & GRE_ROUTING) break; - proto = hdr->proto; - nhoff += 4; + /* Only look inside GRE for version 0 and 1 */ + gre_ver = ntohs(hdr->flags & GRE_VERSION); + if (gre_ver > 1) + break; + + proto = hdr->protocol; + if (gre_ver) { + /* Version1 must be PPTP, and check the flags */ + if (!(proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY))) + break; + } + + offset += sizeof(struct gre_base_hdr); + if (hdr->flags & GRE_CSUM) - nhoff += 4; + offset += sizeof(((struct gre_full_hdr *)0)->csum) + + sizeof(((struct gre_full_hdr *)0)->reserved1); + if (hdr->flags & GRE_KEY) { const __be32 *keyid; __be32 _keyid; - keyid = __skb_header_pointer(skb, nhoff, sizeof(_keyid), + keyid = __skb_header_pointer(skb, nhoff + offset, sizeof(_keyid), data, hlen, &_keyid); - if (!keyid) goto out_bad;
@@ -372,32 +384,65 @@ ip_proto_again: key_keyid = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_GRE_KEYID, target_container); - key_keyid->keyid = *keyid; + if (gre_ver == 0) + key_keyid->keyid = *keyid; + else + key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK; } - nhoff += 4; + offset += sizeof(((struct gre_full_hdr *)0)->key); } + if (hdr->flags & GRE_SEQ) - nhoff += 4; - if (proto == htons(ETH_P_TEB)) { - const struct ethhdr *eth; - struct ethhdr _eth; - - eth = __skb_header_pointer(skb, nhoff, - sizeof(_eth), - data, hlen, &_eth); - if (!eth) + offset += sizeof(((struct pptp_gre_header *)0)->seq); + + if (gre_ver == 0) { + if (proto == htons(ETH_P_TEB)) { + const struct ethhdr *eth; + struct ethhdr _eth; + + eth = __skb_header_pointer(skb, nhoff + offset, + sizeof(_eth), + data, hlen, &_eth); + if (!eth) + goto out_bad; + proto = eth->h_proto; + offset += sizeof(*eth); + + /* Cap headers that we access via pointers at the + * end of the Ethernet header as our maximum alignment + * at that point is only 2 bytes. + */ + if (NET_IP_ALIGN) + hlen = (nhoff + offset); + } + } else { /* version 1, must be PPTP */ + u8 _ppp_hdr[PPP_HDRLEN]; + u8 *ppp_hdr; + + if (hdr->flags & GRE_ACK) + offset += sizeof(((struct pptp_gre_header *)0)->ack); + + ppp_hdr = skb_header_pointer(skb, nhoff + offset, + sizeof(_ppp_hdr), _ppp_hdr); + if (!ppp_hdr) goto out_bad; - proto = eth->h_proto; - nhoff += sizeof(*eth); - - /* Cap headers that we access via pointers at the - * end of the Ethernet header as our maximum alignment - * at that point is only 2 bytes. - */ - if (NET_IP_ALIGN) - hlen = nhoff; + + switch (PPP_PROTOCOL(ppp_hdr)) { + case PPP_IP: + proto = htons(ETH_P_IP); + break; + case PPP_IPV6: + proto = htons(ETH_P_IPV6); + break; + default: + /* Could probably catch some more like MPLS */ + break; + } + + offset += PPP_HDRLEN; } + nhoff += offset; key_control->flags |= FLOW_DIS_ENCAPSULATION; if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) goto out_good;
--
1.9.1