[PATCH 4.4 10/29] l2tp: Refactor the codes with existing macros instead of literal number

From: Greg Kroah-Hartman
Date: Sat Apr 11 2020 - 08:10:39 EST


From: Gao Feng <fgao@xxxxxxxxxx>

commit 54c151d9ed1321e6e623c80ffe42cd2eb1571744 upstream.

Use PPP_ALLSTATIONS, PPP_UI, and SEND_SHUTDOWN instead of 0xff,
0x03, and 2 separately.

Signed-off-by: Gao Feng <fgao@xxxxxxxxxx>
Acked-by: Guillaume Nault <g.nault@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/l2tp/l2tp_ppp.c | 20 +++++++++-----------
1 file changed, 9 insertions(+), 11 deletions(-)

--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -177,7 +177,7 @@ static int pppol2tp_recv_payload_hook(st
if (!pskb_may_pull(skb, 2))
return 1;

- if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03))
+ if ((skb->data[0] == PPP_ALLSTATIONS) && (skb->data[1] == PPP_UI))
skb_pull(skb, 2);

return 0;
@@ -297,7 +297,6 @@ static void pppol2tp_session_sock_put(st
static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m,
size_t total_len)
{
- static const unsigned char ppph[2] = { 0xff, 0x03 };
struct sock *sk = sock->sk;
struct sk_buff *skb;
int error;
@@ -327,7 +326,7 @@ static int pppol2tp_sendmsg(struct socke
error = -ENOMEM;
skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
uhlen + session->hdr_len +
- sizeof(ppph) + total_len,
+ 2 + total_len, /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
0, GFP_KERNEL);
if (!skb)
goto error_put_sess_tun;
@@ -340,8 +339,8 @@ static int pppol2tp_sendmsg(struct socke
skb_reserve(skb, uhlen);

/* Add PPP header */
- skb->data[0] = ppph[0];
- skb->data[1] = ppph[1];
+ skb->data[0] = PPP_ALLSTATIONS;
+ skb->data[1] = PPP_UI;
skb_put(skb, 2);

/* Copy user data into skb */
@@ -384,7 +383,6 @@ error:
*/
static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
{
- static const u8 ppph[2] = { 0xff, 0x03 };
struct sock *sk = (struct sock *) chan->private;
struct sock *sk_tun;
struct l2tp_session *session;
@@ -413,14 +411,14 @@ static int pppol2tp_xmit(struct ppp_chan
sizeof(struct iphdr) + /* IP header */
uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */
session->hdr_len + /* L2TP header */
- sizeof(ppph); /* PPP header */
+ 2; /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
if (skb_cow_head(skb, headroom))
goto abort_put_sess_tun;

/* Setup PPP header */
- __skb_push(skb, sizeof(ppph));
- skb->data[0] = ppph[0];
- skb->data[1] = ppph[1];
+ __skb_push(skb, 2);
+ skb->data[0] = PPP_ALLSTATIONS;
+ skb->data[1] = PPP_UI;

local_bh_disable();
l2tp_xmit_skb(session, skb, session->hdr_len);
@@ -455,7 +453,7 @@ static void pppol2tp_session_close(struc
BUG_ON(session->magic != L2TP_SESSION_MAGIC);

if (sock) {
- inet_shutdown(sock, 2);
+ inet_shutdown(sock, SEND_SHUTDOWN);
/* Don't let the session go away before our socket does */
l2tp_session_inc_refcount(session);
}