Merge tag 'sh-pfc-for-v5.1-tag2' of git://git.kernel.org/pub/scm/linux/kernel/git...

[mirror_ubuntu-focal-kernel.git] / net / l2tp / l2tp_core.h

diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
index 9c9afe94d389bb6fd0440e053043cb01fcd85528..b2ce90260c35f6d0cdd70241a28f54cedf580ea3 100644 (file)
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h
@@ -301,6 +301,26 @@ static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
 }
 #endif
 
+static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session *session, struct sk_buff *skb,
+                                              unsigned char **ptr, unsigned char **optr)
+{
+       int opt_len = session->peer_cookie_len + l2tp_get_l2specific_len(session);
+
+       if (opt_len > 0) {
+               int off = *ptr - *optr;
+
+               if (!pskb_may_pull(skb, off + opt_len))
+                       return -1;
+
+               if (skb->data != *optr) {
+                       *optr = skb->data;
+                       *ptr = skb->data + off;
+               }
+       }
+
+       return 0;
+}
+
 #define l2tp_printk(ptr, type, func, fmt, ...)                         \
 do {                                                                   \
        if (((ptr)->debug) & (type))                                    \