From 863def15b9755d9016df4d93addf3127f1dc67f4 Mon Sep 17 00:00:00 2001 From: James Chapman Date: Wed, 3 Jan 2018 22:48:04 +0000 Subject: l2tp: revert "l2tp: add peer_offset parameter" Revert commit f15bc54eeecd ("l2tp: add peer_offset parameter"). This is removed because it is adding another configurable offset and configurable offsets are being removed. Signed-off-by: James Chapman Signed-off-by: David S. Miller --- net/l2tp/l2tp_core.c | 3 +-- net/l2tp/l2tp_core.h | 13 +++---------- net/l2tp/l2tp_debugfs.c | 8 +++----- net/l2tp/l2tp_netlink.c | 21 +-------------------- 4 files changed, 8 insertions(+), 37 deletions(-) (limited to 'net') diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 6ff64717da1e..115918ad8eca 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -792,7 +792,7 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, ptr += 2 + offset; } } else - ptr += session->peer_offset; + ptr += session->offset; offset = ptr - optr; if (!pskb_may_pull(skb, offset)) @@ -1785,7 +1785,6 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn session->lns_mode = cfg->lns_mode; session->reorder_timeout = cfg->reorder_timeout; session->offset = cfg->offset; - session->peer_offset = cfg->peer_offset; session->l2specific_type = cfg->l2specific_type; session->l2specific_len = cfg->l2specific_len; session->cookie_len = cfg->cookie_len; diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h index c6fe7cc42a05..9534e16965cc 100644 --- a/net/l2tp/l2tp_core.h +++ b/net/l2tp/l2tp_core.h @@ -59,8 +59,7 @@ struct l2tp_session_cfg { int debug; /* bitmask of debug message * categories */ u16 vlan_id; /* VLAN pseudowire only */ - u16 offset; /* offset to tx payload */ - u16 peer_offset; /* offset to rx payload */ + u16 offset; /* offset to payload */ u16 l2specific_len; /* Layer 2 specific length */ u16 l2specific_type; /* Layer 2 specific type */ u8 cookie[8]; /* optional cookie */ @@ -87,14 +86,8 @@ struct l2tp_session { int cookie_len; u8 peer_cookie[8]; int peer_cookie_len; - u16 offset; /* offset from end of L2TP - * header to beginning of - * tx data - */ - u16 peer_offset; /* offset from end of L2TP - * header to beginning of - * rx data - */ + u16 offset; /* offset from end of L2TP header + to beginning of data */ u16 l2specific_len; u16 l2specific_type; u16 hdr_len; diff --git a/net/l2tp/l2tp_debugfs.c b/net/l2tp/l2tp_debugfs.c index 4cc30b38aba4..eb69411bcb47 100644 --- a/net/l2tp/l2tp_debugfs.c +++ b/net/l2tp/l2tp_debugfs.c @@ -180,9 +180,8 @@ static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v) session->lns_mode ? "LNS" : "LAC", session->debug, jiffies_to_msecs(session->reorder_timeout)); - seq_printf(m, " offset %hu peer_offset %hu l2specific %hu/%hu\n", - session->offset, session->peer_offset, - session->l2specific_type, session->l2specific_len); + seq_printf(m, " offset %hu l2specific %hu/%hu\n", + session->offset, session->l2specific_type, session->l2specific_len); if (session->cookie_len) { seq_printf(m, " cookie %02x%02x%02x%02x", session->cookie[0], session->cookie[1], @@ -229,8 +228,7 @@ static int l2tp_dfs_seq_show(struct seq_file *m, void *v) seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); seq_puts(m, " SESSION ID, peer ID, PWTYPE\n"); seq_puts(m, " refcnt cnt\n"); - seq_puts(m, " offset OFFSET peer_offset OFFSET"); - seq_puts(m, " l2specific TYPE/LEN\n"); + seq_puts(m, " offset OFFSET l2specific TYPE/LEN\n"); seq_puts(m, " [ cookie ]\n"); seq_puts(m, " [ peer cookie ]\n"); seq_puts(m, " config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n"); diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c index d7d4d7a7a54d..7e9c50125556 100644 --- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -547,25 +547,9 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf } if (tunnel->version > 2) { - if (info->attrs[L2TP_ATTR_PEER_OFFSET]) { - struct nlattr *peer_offset; - - peer_offset = info->attrs[L2TP_ATTR_PEER_OFFSET]; - cfg.peer_offset = nla_get_u16(peer_offset); - } - - if (info->attrs[L2TP_ATTR_OFFSET]) { + if (info->attrs[L2TP_ATTR_OFFSET]) cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]); - /* in order to maintain compatibility with older - * versions where offset was used for both tx and - * rx side, update rx side with offset if peer_offset - * is not provided by userspace - */ - if (!info->attrs[L2TP_ATTR_PEER_OFFSET]) - cfg.peer_offset = cfg.offset; - } - if (info->attrs[L2TP_ATTR_DATA_SEQ]) cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]); @@ -779,8 +763,6 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int fl nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) || (session->offset && nla_put_u16(skb, L2TP_ATTR_OFFSET, session->offset)) || - (session->peer_offset && - nla_put_u16(skb, L2TP_ATTR_PEER_OFFSET, session->peer_offset)) || (session->cookie_len && nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len, &session->cookie[0])) || @@ -921,7 +903,6 @@ static const struct nla_policy l2tp_nl_policy[L2TP_ATTR_MAX + 1] = { [L2TP_ATTR_PW_TYPE] = { .type = NLA_U16, }, [L2TP_ATTR_ENCAP_TYPE] = { .type = NLA_U16, }, [L2TP_ATTR_OFFSET] = { .type = NLA_U16, }, - [L2TP_ATTR_PEER_OFFSET] = { .type = NLA_U16, }, [L2TP_ATTR_DATA_SEQ] = { .type = NLA_U8, }, [L2TP_ATTR_L2SPEC_TYPE] = { .type = NLA_U8, }, [L2TP_ATTR_L2SPEC_LEN] = { .type = NLA_U8, }, -- cgit v1.2.3-59-g8ed1b From de3b58bc359a861d5132300f53f95e83f71954b3 Mon Sep 17 00:00:00 2001 From: James Chapman Date: Wed, 3 Jan 2018 22:48:05 +0000 Subject: l2tp: revert "l2tp: fix missing print session offset info" Revert commit 820da5357572 ("l2tp: fix missing print session offset info"). The peer_offset parameter is removed. Signed-off-by: James Chapman Signed-off-by: David S. Miller --- net/l2tp/l2tp_netlink.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'net') diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c index 7e9c50125556..a1f24fb2be98 100644 --- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -761,8 +761,6 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int fl if ((session->ifname[0] && nla_put_string(skb, L2TP_ATTR_IFNAME, session->ifname)) || - (session->offset && - nla_put_u16(skb, L2TP_ATTR_OFFSET, session->offset)) || (session->cookie_len && nla_put(skb, L2TP_ATTR_COOKIE, session->cookie_len, &session->cookie[0])) || -- cgit v1.2.3-59-g8ed1b From 900631ee6a2651dc4fbaecb8ef9fa5f1e3378853 Mon Sep 17 00:00:00 2001 From: James Chapman Date: Wed, 3 Jan 2018 22:48:06 +0000 Subject: l2tp: remove configurable payload offset If L2TP_ATTR_OFFSET is set to a non-zero value in L2TPv3 tunnels, it results in L2TPv3 packets being transmitted which might not be compliant with the L2TPv3 RFC. This patch has l2tp ignore the offset setting and send all packets with no offset. In more detail: L2TPv2 supports a variable offset from the L2TPv2 header to the payload. The offset value is indicated by an optional field in the L2TP header. Our L2TP implementation already detects the presence of the optional offset and skips that many bytes when handling data received packets. All transmitted packets are always transmitted with no offset. L2TPv3 has no optional offset field in the L2TPv3 packet header. Instead, L2TPv3 defines optional fields in a "Layer-2 Specific Sublayer". At the time when the original L2TP code was written, there was talk at IETF of offset being implemented in a new Layer-2 Specific Sublayer. A L2TP_ATTR_OFFSET netlink attribute was added so that this offset could be configured and the intention was to allow it to be also used to set the tx offset for L2TPv2. However, no L2TPv3 offset was ever specified and the L2TP_ATTR_OFFSET parameter was forgotten about. Setting L2TP_ATTR_OFFSET results in L2TPv3 packets being transmitted with the specified number of bytes padding between L2TPv3 header and payload. This is not compliant with L2TPv3 RFC3931. This change removes the configurable offset altogether while retaining L2TP_ATTR_OFFSET for backwards compatibility. Any L2TP_ATTR_OFFSET value is ignored. Signed-off-by: James Chapman Signed-off-by: David S. Miller --- net/l2tp/l2tp_core.c | 14 ++++---------- net/l2tp/l2tp_core.h | 3 --- net/l2tp/l2tp_debugfs.c | 4 ++-- net/l2tp/l2tp_netlink.c | 3 --- 4 files changed, 6 insertions(+), 18 deletions(-) (limited to 'net') diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 115918ad8eca..786cd7f6a5e8 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -780,10 +780,8 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, } } - /* Session data offset is handled differently for L2TPv2 and - * L2TPv3. For L2TPv2, there is an optional 16-bit value in - * the header. For L2TPv3, the offset is negotiated using AVPs - * in the session setup control protocol. + /* Session data offset is defined only for L2TPv2 and is + * indicated by an optional 16-bit value in the header. */ if (tunnel->version == L2TP_HDR_VER_2) { /* If offset bit set, skip it. */ @@ -791,8 +789,7 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, offset = ntohs(*(__be16 *)ptr); ptr += 2 + offset; } - } else - ptr += session->offset; + } offset = ptr - optr; if (!pskb_may_pull(skb, offset)) @@ -1068,8 +1065,6 @@ static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) } bufp += session->l2specific_len; } - if (session->offset) - bufp += session->offset; return bufp - optr; } @@ -1734,7 +1729,7 @@ void l2tp_session_set_header_len(struct l2tp_session *session, int version) if (session->send_seq) session->hdr_len += 4; } else { - session->hdr_len = 4 + session->cookie_len + session->l2specific_len + session->offset; + session->hdr_len = 4 + session->cookie_len + session->l2specific_len; if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) session->hdr_len += 4; } @@ -1784,7 +1779,6 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn session->recv_seq = cfg->recv_seq; session->lns_mode = cfg->lns_mode; session->reorder_timeout = cfg->reorder_timeout; - session->offset = cfg->offset; session->l2specific_type = cfg->l2specific_type; session->l2specific_len = cfg->l2specific_len; session->cookie_len = cfg->cookie_len; diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h index 9534e16965cc..c2e9bbd79b35 100644 --- a/net/l2tp/l2tp_core.h +++ b/net/l2tp/l2tp_core.h @@ -59,7 +59,6 @@ struct l2tp_session_cfg { int debug; /* bitmask of debug message * categories */ u16 vlan_id; /* VLAN pseudowire only */ - u16 offset; /* offset to payload */ u16 l2specific_len; /* Layer 2 specific length */ u16 l2specific_type; /* Layer 2 specific type */ u8 cookie[8]; /* optional cookie */ @@ -86,8 +85,6 @@ struct l2tp_session { int cookie_len; u8 peer_cookie[8]; int peer_cookie_len; - u16 offset; /* offset from end of L2TP header - to beginning of data */ u16 l2specific_len; u16 l2specific_type; u16 hdr_len; diff --git a/net/l2tp/l2tp_debugfs.c b/net/l2tp/l2tp_debugfs.c index eb69411bcb47..2c30587d1a14 100644 --- a/net/l2tp/l2tp_debugfs.c +++ b/net/l2tp/l2tp_debugfs.c @@ -180,8 +180,8 @@ static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v) session->lns_mode ? "LNS" : "LAC", session->debug, jiffies_to_msecs(session->reorder_timeout)); - seq_printf(m, " offset %hu l2specific %hu/%hu\n", - session->offset, session->l2specific_type, session->l2specific_len); + seq_printf(m, " offset 0 l2specific %hu/%hu\n", + session->l2specific_type, session->l2specific_len); if (session->cookie_len) { seq_printf(m, " cookie %02x%02x%02x%02x", session->cookie[0], session->cookie[1], diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c index a1f24fb2be98..e1ca29f79821 100644 --- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -547,9 +547,6 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf } if (tunnel->version > 2) { - if (info->attrs[L2TP_ATTR_OFFSET]) - cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]); - if (info->attrs[L2TP_ATTR_DATA_SEQ]) cfg.data_seq = nla_get_u8(info->attrs[L2TP_ATTR_DATA_SEQ]); -- cgit v1.2.3-59-g8ed1b