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 <fgao@ikuai8.com>
Reviewed-by: Philip Prindeville <philipp@redfish-solutions.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index 3e68dbc0af7f04edd3dadd0a93e993c5c1256f12..1951b1085cb8943d85af68a26d0e22dc35ce3a16 100644 (file)
--- 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 301d3e2ba1f9af8aabd9590825a71b8854835c27..92e9f1fe262844ad6f226c11333211df02954388 100644 (file)
--- 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 60dbb200de607a84596ff116bc449a61f81869d8..361b9f0f20d7a0161e9a600b13ccf5309391c4f9 100644 (file)
--- 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 {