From 03459345bc00da70a35fa39bcfcf13d779097074 Mon Sep 17 00:00:00 2001 From: Gao Feng Date: Sat, 13 Aug 2016 00:30:48 +0800 Subject: [PATCH] pptp: Refactor the struct and macros of PPTP codes 1. Use struct gre_base_hdr directly in pptp_gre_header instead of duplicated members; 2. Use existing macros like GRE_KEY, GRE_SEQ, and so on instead of duplicated macros defined by PPTP; 3. Add new macros like GRE_IS_ACK/SEQ and so on instead of PPTP_GRE_IS_A/S and so on; Signed-off-by: Gao Feng Reviewed-by: Philip Prindeville Signed-off-by: David S. Miller --- drivers/net/ppp/pptp.c | 28 +++++++++++++--------------- include/net/pptp.h | 19 +------------------ include/uapi/linux/if_tunnel.h | 12 ++++++++++-- 3 files changed, 24 insertions(+), 35 deletions(-) diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c index 3e68dbc..1951b10 100644 --- a/drivers/net/ppp/pptp.c +++ b/drivers/net/ppp/pptp.c @@ -206,16 +206,14 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb) skb_push(skb, header_len); hdr = (struct pptp_gre_header *)(skb->data); - hdr->flags = PPTP_GRE_FLAG_K; - hdr->ver = PPTP_GRE_VER; - hdr->protocol = htons(PPTP_GRE_PROTO); - hdr->call_id = htons(opt->dst_addr.call_id); + hdr->gre_hd.flags = GRE_KEY | GRE_VERSION_1 | GRE_SEQ; + hdr->gre_hd.protocol = GRE_PROTO_PPP; + hdr->call_id = htons(opt->dst_addr.call_id); - hdr->flags |= PPTP_GRE_FLAG_S; - hdr->seq = htonl(++opt->seq_sent); + hdr->seq = htonl(++opt->seq_sent); if (opt->ack_sent != seq_recv) { /* send ack with this message */ - hdr->ver |= PPTP_GRE_FLAG_A; + hdr->gre_hd.flags |= GRE_ACK; hdr->ack = htonl(seq_recv); opt->ack_sent = seq_recv; } @@ -278,7 +276,7 @@ static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb) headersize = sizeof(*header); /* test if acknowledgement present */ - if (PPTP_GRE_IS_A(header->ver)) { + if (GRE_IS_ACK(header->gre_hd.flags)) { __u32 ack; if (!pskb_may_pull(skb, headersize)) @@ -286,7 +284,7 @@ static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb) header = (struct pptp_gre_header *)(skb->data); /* ack in different place if S = 0 */ - ack = PPTP_GRE_IS_S(header->flags) ? header->ack : header->seq; + ack = GRE_IS_SEQ(header->gre_hd.flags) ? header->ack : header->seq; ack = ntohl(ack); @@ -299,7 +297,7 @@ static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb) headersize -= sizeof(header->ack); } /* test if payload present */ - if (!PPTP_GRE_IS_S(header->flags)) + if (!GRE_IS_SEQ(header->gre_hd.flags)) goto drop; payload_len = ntohs(header->payload_len); @@ -360,11 +358,11 @@ static int pptp_rcv(struct sk_buff *skb) header = (struct pptp_gre_header *)skb->data; - if (ntohs(header->protocol) != PPTP_GRE_PROTO || /* PPTP-GRE protocol for PPTP */ - PPTP_GRE_IS_C(header->flags) || /* flag C should be clear */ - PPTP_GRE_IS_R(header->flags) || /* flag R should be clear */ - !PPTP_GRE_IS_K(header->flags) || /* flag K should be set */ - (header->flags&0xF) != 0) /* routing and recursion ctrl = 0 */ + if (header->gre_hd.protocol != GRE_PROTO_PPP || /* PPTP-GRE protocol for PPTP */ + GRE_IS_CSUM(header->gre_hd.flags) || /* flag CSUM should be clear */ + GRE_IS_ROUTING(header->gre_hd.flags) || /* flag ROUTING should be clear */ + !GRE_IS_KEY(header->gre_hd.flags) || /* flag KEY should be set */ + (header->gre_hd.flags & GRE_FLAGS)) /* flag Recursion Ctrl should be clear */ /* if invalid, discard this packet */ goto drop; diff --git a/include/net/pptp.h b/include/net/pptp.h index 301d3e2..92e9f1f 100644 --- a/include/net/pptp.h +++ b/include/net/pptp.h @@ -10,26 +10,9 @@ ((((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; + struct gre_base_hdr gre_hd; __be16 payload_len; __be16 call_id; __be32 seq; diff --git a/include/uapi/linux/if_tunnel.h b/include/uapi/linux/if_tunnel.h index 60dbb20..361b9f0 100644 --- a/include/uapi/linux/if_tunnel.h +++ b/include/uapi/linux/if_tunnel.h @@ -28,8 +28,16 @@ #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_IS_CSUM(f) ((f) & GRE_CSUM) +#define GRE_IS_ROUTING(f) ((f) & GRE_ROUTING) +#define GRE_IS_KEY(f) ((f) & GRE_KEY) +#define GRE_IS_SEQ(f) ((f) & GRE_SEQ) +#define GRE_IS_STRICT(f) ((f) & GRE_STRICT) +#define GRE_IS_REC(f) ((f) & GRE_REC) +#define GRE_IS_ACK(f) ((f) & GRE_ACK) + +#define GRE_VERSION_1 __cpu_to_be16(0x0001) +#define GRE_PROTO_PPP __cpu_to_be16(0x880b) #define GRE_PPTP_KEY_MASK __cpu_to_be32(0xffff) struct ip_tunnel_parm { -- 2.7.4