Skip to content

Commit

Permalink
l2tp: avoid using ->tunnel_sock for getting session's parent tunnel
Browse files Browse the repository at this point in the history 
Sessions don't need to use l2tp_sock_to_tunnel(xxx->tunnel_sock) for
accessing their parent tunnel. They have the .tunnel field in the
l2tp_session structure for that. Furthermore, in all these cases, the
session is registered, so we're guaranteed that .tunnel isn't NULL and
that the session properly holds a reference on the tunnel.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
  • Loading branch information
Guillaume Nault authored and David S. Miller committed Nov 11, 2017
1 parent 8fdfd65 commit 7198c77
Showing 1 changed file with 12 additions and 54 deletions.
66 changes: 12 additions & 54 deletions net/l2tp/l2tp_ppp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -295,7 +295,6 @@ static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m,
int error;
struct l2tp_session *session;
struct l2tp_tunnel *tunnel;
struct pppol2tp_session *ps;
int uhlen;

error = -ENOTCONN;
Expand All @@ -308,10 +307,7 @@ static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m,
if (session == NULL)
goto error;

ps = l2tp_session_priv(session);
tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
if (tunnel == NULL)
goto error_put_sess;
tunnel = session->tunnel;

uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;

Expand All @@ -322,7 +318,7 @@ static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m,
2 + total_len, /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
0, GFP_KERNEL);
if (!skb)
goto error_put_sess_tun;
goto error_put_sess;

/* Reserve space for headers. */
skb_reserve(skb, NET_SKB_PAD);
Expand All @@ -340,20 +336,17 @@ static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m,
error = memcpy_from_msg(skb_put(skb, total_len), m, total_len);
if (error < 0) {
kfree_skb(skb);
goto error_put_sess_tun;
goto error_put_sess;
}

local_bh_disable();
l2tp_xmit_skb(session, skb, session->hdr_len);
local_bh_enable();

sock_put(ps->tunnel_sock);
sock_put(sk);

return total_len;

error_put_sess_tun:
sock_put(ps->tunnel_sock);
error_put_sess:
sock_put(sk);
error:
Expand All @@ -377,10 +370,8 @@ static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m,
static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
{
struct sock *sk = (struct sock *) chan->private;
struct sock *sk_tun;
struct l2tp_session *session;
struct l2tp_tunnel *tunnel;
struct pppol2tp_session *ps;
int uhlen, headroom;

if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
Expand All @@ -391,13 +382,7 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
if (session == NULL)
goto abort;

ps = l2tp_session_priv(session);
sk_tun = ps->tunnel_sock;
if (sk_tun == NULL)
goto abort_put_sess;
tunnel = l2tp_sock_to_tunnel(sk_tun);
if (tunnel == NULL)
goto abort_put_sess;
tunnel = session->tunnel;

uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
headroom = NET_SKB_PAD +
Expand All @@ -406,7 +391,7 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
session->hdr_len + /* L2TP header */
2; /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
if (skb_cow_head(skb, headroom))
goto abort_put_sess_tun;
goto abort_put_sess;

/* Setup PPP header */
__skb_push(skb, 2);
Expand All @@ -417,12 +402,10 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
l2tp_xmit_skb(session, skb, session->hdr_len);
local_bh_enable();

sock_put(sk_tun);
sock_put(sk);

return 1;

abort_put_sess_tun:
sock_put(sk_tun);
abort_put_sess:
sock_put(sk);
abort:
Expand Down Expand Up @@ -919,9 +902,7 @@ static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
goto end;

pls = l2tp_session_priv(session);
tunnel = l2tp_sock_to_tunnel(pls->tunnel_sock);
if (tunnel == NULL)
goto end_put_sess;
tunnel = session->tunnel;

inet = inet_sk(tunnel->sock);
if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
Expand Down Expand Up @@ -1001,8 +982,6 @@ static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
*usockaddr_len = len;
error = 0;

sock_put(pls->tunnel_sock);
end_put_sess:
sock_put(sk);
end:
return error;
Expand Down Expand Up @@ -1241,7 +1220,6 @@ static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
struct sock *sk = sock->sk;
struct l2tp_session *session;
struct l2tp_tunnel *tunnel;
struct pppol2tp_session *ps;
int err;

if (!sk)
Expand All @@ -1265,16 +1243,10 @@ static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
/* Special case: if session's session_id is zero, treat ioctl as a
* tunnel ioctl
*/
ps = l2tp_session_priv(session);
if ((session->session_id == 0) &&
(session->peer_session_id == 0)) {
err = -EBADF;
tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
if (tunnel == NULL)
goto end_put_sess;

tunnel = session->tunnel;
err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
sock_put(ps->tunnel_sock);
goto end_put_sess;
}

Expand Down Expand Up @@ -1400,7 +1372,6 @@ static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
struct sock *sk = sock->sk;
struct l2tp_session *session;
struct l2tp_tunnel *tunnel;
struct pppol2tp_session *ps;
int val;
int err;

Expand All @@ -1425,20 +1396,14 @@ static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,

/* Special case: if session_id == 0x0000, treat as operation on tunnel
*/
ps = l2tp_session_priv(session);
if ((session->session_id == 0) &&
(session->peer_session_id == 0)) {
err = -EBADF;
tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
if (tunnel == NULL)
goto end_put_sess;

tunnel = session->tunnel;
err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
sock_put(ps->tunnel_sock);
} else
} else {
err = pppol2tp_session_setsockopt(sk, session, optname, val);
}

end_put_sess:
sock_put(sk);
end:
return err;
Expand Down Expand Up @@ -1526,7 +1491,6 @@ static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
struct l2tp_tunnel *tunnel;
int val, len;
int err;
struct pppol2tp_session *ps;

if (level != SOL_PPPOL2TP)
return -EINVAL;
Expand All @@ -1550,16 +1514,10 @@ static int pppol2tp_getsockopt(struct socket *sock, int level, int optname,
goto end;

/* Special case: if session_id == 0x0000, treat as operation on tunnel */
ps = l2tp_session_priv(session);
if ((session->session_id == 0) &&
(session->peer_session_id == 0)) {
err = -EBADF;
tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock);
if (tunnel == NULL)
goto end_put_sess;

tunnel = session->tunnel;
err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
sock_put(ps->tunnel_sock);
if (err)
goto end_put_sess;
} else {
Expand Down

0 comments on commit 7198c77

Please sign in to comment.