From bb5016eac1656506df1a9d6057ce5bec342afbef Mon Sep 17 00:00:00 2001 From: Guillaume Nault Date: Thu, 6 Mar 2014 11:14:30 +0100 Subject: [PATCH] l2tp: fix manual sequencing (de)activation in L2TPv2 Commit e0d4435f "l2tp: Update PPP-over-L2TP driver to work over L2TPv3" broke the PPPOL2TP_SO_SENDSEQ setsockopt. The L2TP header length was previously computed by pppol2tp_l2t_header_len() before each call to l2tp_xmit_skb(). Now that header length is retrieved from the hdr_len session field, this field must be updated every time the L2TP header format is modified, or l2tp_xmit_skb() won't push the right amount of data for the L2TP header. This patch uses l2tp_session_set_header_len() to adjust hdr_len every time sequencing is (de)activated from userspace (either by the PPPOL2TP_SO_SENDSEQ setsockopt or the L2TP_ATTR_SEND_SEQ netlink attribute). Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller --- net/l2tp/l2tp_core.c | 4 ++-- net/l2tp/l2tp_core.h | 1 + net/l2tp/l2tp_netlink.c | 4 +++- net/l2tp/l2tp_ppp.c | 1 + 4 files changed, 7 insertions(+), 3 deletions(-) diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 735d0f6..85d9d94 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -112,7 +112,6 @@ struct l2tp_net { spinlock_t l2tp_session_hlist_lock; }; -static void l2tp_session_set_header_len(struct l2tp_session *session, int version); static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); static inline struct l2tp_tunnel *l2tp_tunnel(struct sock *sk) @@ -1863,7 +1862,7 @@ EXPORT_SYMBOL_GPL(l2tp_session_delete); /* We come here whenever a session's send_seq, cookie_len or * l2specific_len parameters are set. */ -static void l2tp_session_set_header_len(struct l2tp_session *session, int version) +void l2tp_session_set_header_len(struct l2tp_session *session, int version) { if (version == L2TP_HDR_VER_2) { session->hdr_len = 6; @@ -1876,6 +1875,7 @@ static void l2tp_session_set_header_len(struct l2tp_session *session, int versio } } +EXPORT_SYMBOL_GPL(l2tp_session_set_header_len); struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunnel, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) { diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h index 1f01ba3..3f93ccd 100644 --- a/net/l2tp/l2tp_core.h +++ b/net/l2tp/l2tp_core.h @@ -263,6 +263,7 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, int length, int (*payload_hook)(struct sk_buff *skb)); int l2tp_session_queue_purge(struct l2tp_session *session); int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb); +void l2tp_session_set_header_len(struct l2tp_session *session, int version); int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len); diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c index 4cfd722..bd7387a 100644 --- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -578,8 +578,10 @@ static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *inf if (info->attrs[L2TP_ATTR_RECV_SEQ]) session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]); - if (info->attrs[L2TP_ATTR_SEND_SEQ]) + if (info->attrs[L2TP_ATTR_SEND_SEQ]) { session->send_seq = nla_get_u8(info->attrs[L2TP_ATTR_SEND_SEQ]); + l2tp_session_set_header_len(session, session->tunnel->version); + } if (info->attrs[L2TP_ATTR_LNS_MODE]) session->lns_mode = nla_get_u8(info->attrs[L2TP_ATTR_LNS_MODE]); diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index be5fadf..6bfeaa7 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -1312,6 +1312,7 @@ static int pppol2tp_session_setsockopt(struct sock *sk, po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ : PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; } + l2tp_session_set_header_len(session, session->tunnel->version); l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set send_seq=%d\n", session->name, session->send_seq); -- 2.7.4