From 7198c77aa05560c257ee377ec1f4796812121580 Mon Sep 17 00:00:00 2001 From: Guillaume Nault Date: Sat, 11 Nov 2017 06:06:31 +0900 Subject: [PATCH] l2tp: avoid using ->tunnel_sock for getting session's parent tunnel 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 Signed-off-by: David S. Miller --- net/l2tp/l2tp_ppp.c | 66 ++++++++++------------------------------------------- 1 file changed, 12 insertions(+), 54 deletions(-) diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index 5f5c78b..88b4cb1 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -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; @@ -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; @@ -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); @@ -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: @@ -377,10 +370,8 @@ error: 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)) @@ -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 + @@ -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); @@ -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: @@ -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)) { @@ -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; @@ -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) @@ -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; } @@ -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; @@ -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; @@ -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; @@ -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 { -- 2.7.4