Commit 03459345 authored by Gao Feng's avatar Gao Feng Committed by David S. Miller
Browse files

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: default avatarGao Feng <fgao@ikuai8.com>
Reviewed-by: default avatarPhilip Prindeville <philipp@redfish-solutions.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cfad65c7

drivers/net/ppp/pptp.c

+13 −15
Original line number Diff line number Diff line
@@ -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->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);

	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;

include/net/pptp.h

+1 −18
Original line number Diff line number Diff line
@@ -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;

include/uapi/linux/if_tunnel.h

+10 −2
Original line number Diff line number Diff line
@@ -28,6 +28,14 @@ 
#define GRE_FLAGS	__cpu_to_be16(0x0078)

#define GRE_VERSION	__cpu_to_be16(0x0007)



#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)

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