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authorLorenzo Bianconi <lorenzo.bianconi@redhat.com>2017-12-22 15:10:18 +0100
committerDavid S. Miller <davem@davemloft.net>2017-12-27 12:11:51 -0500
commitf15bc54eeecd86dfba3885aab839cd1f45172a38 (patch)
treeb0ce5e53ca229d324ba653f64b9cc4ac34dd8e4b
parent820da5357572715c6235ba3b3daa2d5b43a1198f (diff)
l2tp: add peer_offset parameter
Introduce peer_offset parameter in order to add the capability to specify two different values for payload offset on tx/rx side. If just offset is provided by userspace use it for rx side as well in order to maintain compatibility with older l2tp versions Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/uapi/linux/l2tp.h1
-rw-r--r--net/l2tp/l2tp_core.c3
-rw-r--r--net/l2tp/l2tp_core.h13
-rw-r--r--net/l2tp/l2tp_debugfs.c8
-rw-r--r--net/l2tp/l2tp_netlink.c21
5 files changed, 38 insertions, 8 deletions
diff --git a/include/uapi/linux/l2tp.h b/include/uapi/linux/l2tp.h
index d84ce5c1c9aa..d6fee55dbded 100644
--- a/include/uapi/linux/l2tp.h
+++ b/include/uapi/linux/l2tp.h
@@ -127,6 +127,7 @@ enum {
L2TP_ATTR_UDP_ZERO_CSUM6_TX, /* flag */
L2TP_ATTR_UDP_ZERO_CSUM6_RX, /* flag */
L2TP_ATTR_PAD,
+ L2TP_ATTR_PEER_OFFSET, /* u16 */
__L2TP_ATTR_MAX,
};
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 115918ad8eca..6ff64717da1e 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->offset;
+ ptr += session->peer_offset;
offset = ptr - optr;
if (!pskb_may_pull(skb, offset))
@@ -1785,6 +1785,7 @@ 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 9534e16965cc..c6fe7cc42a05 100644
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h
@@ -59,7 +59,8 @@ struct l2tp_session_cfg {
int debug; /* bitmask of debug message
* categories */
u16 vlan_id; /* VLAN pseudowire only */
- u16 offset; /* offset to payload */
+ u16 offset; /* offset to tx payload */
+ u16 peer_offset; /* offset to rx payload */
u16 l2specific_len; /* Layer 2 specific length */
u16 l2specific_type; /* Layer 2 specific type */
u8 cookie[8]; /* optional cookie */
@@ -86,8 +87,14 @@ 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 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 l2specific_len;
u16 l2specific_type;
u16 hdr_len;
diff --git a/net/l2tp/l2tp_debugfs.c b/net/l2tp/l2tp_debugfs.c
index eb69411bcb47..4cc30b38aba4 100644
--- a/net/l2tp/l2tp_debugfs.c
+++ b/net/l2tp/l2tp_debugfs.c
@@ -180,8 +180,9 @@ 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 %hu peer_offset %hu l2specific %hu/%hu\n",
+ session->offset, session->peer_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],
@@ -228,7 +229,8 @@ 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 l2specific TYPE/LEN\n");
+ seq_puts(m, " offset OFFSET peer_offset OFFSET");
+ seq_puts(m, " 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 7e9c50125556..d7d4d7a7a54d 100644
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -547,9 +547,25 @@ 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])
+ 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]) {
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]);
@@ -763,6 +779,8 @@ 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])) ||
@@ -903,6 +921,7 @@ 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, },