From: Simon Farnsworth Date: Sun, 1 Mar 2015 10:54:39 +0000 Subject: [PATCH] pppoe: Use workqueue to die properly when a PADT is received When a PADT frame is received, the socket may not be in a good state to close down the PPP interface. The current implementation handles this by simply blocking all further PPP traffic, and hoping that the lack of traffic will trigger the user to investigate. Use schedule_work to get to a process context from which we clear down the PPP interface, in a fashion analogous to hangup on a TTY-based PPP interface. This causes pppd to disconnect immediately, and allows tools to take immediate corrective action. Note that pppd's rp_pppoe.so plugin has code in it to disable the session when it disconnects; however, as a consequence of this patch, the session is already disabled before rp_pppoe.so is asked to disable the session. The result is a harmless error message: Failed to disconnect PPPoE socket: 114 Operation already in progress This message is safe to ignore, as long as the error is 114 Operation already in progress; in that specific case, it means that the PPPoE session has already been disabled before pppd tried to disable it. Signed-off-by: Simon Farnsworth Tested-by: Dan Williams Tested-by: Christoph Schulz Signed-off-by: David S. Miller --- --- a/drivers/net/ppp/pppoe.c +++ b/drivers/net/ppp/pppoe.c @@ -454,6 +454,18 @@ out: return NET_RX_DROP; } +static void pppoe_unbind_sock_work(struct work_struct *work) +{ + struct pppox_sock *po = container_of(work, struct pppox_sock, + proto.pppoe.padt_work); + struct sock *sk = sk_pppox(po); + + lock_sock(sk); + pppox_unbind_sock(sk); + release_sock(sk); + sock_put(sk); +} + /************************************************************************ * * Receive a PPPoE Discovery frame. @@ -499,7 +511,8 @@ static int pppoe_disc_rcv(struct sk_buff } bh_unlock_sock(sk); - sock_put(sk); + if (!schedule_work(&po->proto.pppoe.padt_work)) + sock_put(sk); } abort: @@ -612,6 +625,8 @@ static int pppoe_connect(struct socket * lock_sock(sk); + INIT_WORK(&po->proto.pppoe.padt_work, pppoe_unbind_sock_work); + error = -EINVAL; if (sp->sa_protocol != PX_PROTO_OE) goto end; --- a/include/linux/if_pppox.h +++ b/include/linux/if_pppox.h @@ -19,6 +19,7 @@ #include #include #include +#include #include static inline struct pppoe_hdr *pppoe_hdr(const struct sk_buff *skb) @@ -32,6 +33,7 @@ struct pppoe_opt { struct pppoe_addr pa; /* what this socket is bound to*/ struct sockaddr_pppox relay; /* what socket data will be relayed to (PPPoE relaying) */ + struct work_struct padt_work;/* Work item for handling PADT */ }; struct pptp_opt {