From 6482f554e2b9cbe733d63124765104f29cf0c9ad Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?R=C3=A9mi=20Denis-Courmont?= Date: Wed, 15 Sep 2010 12:19:53 +0000 Subject: [PATCH] Phonet: remove dangling pipe if an endpoint is closed early MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Closing a pipe endpoint is not normally allowed by the Phonet pipe, other than as a side after-effect of removing the pipe between two endpoints. But there is no way to prevent Linux userspace processes from being killed or suffering from bugs, so this can still happen. We might as well forcefully close Phonet pipe endpoints then. The cellular modem supports only a few existing pipes at a time. So we really should not leak them. This change instructs the modem to destroy the pipe if either of the pipe's endpoint (Linux socket) is closed too early. Signed-off-by: Rémi Denis-Courmont Signed-off-by: David S. Miller --- include/net/phonet/pep.h | 5 +++++ net/phonet/pep.c | 27 ++++++++++++++++++++++++++- 2 files changed, 31 insertions(+), 1 deletion(-) diff --git a/include/net/phonet/pep.h b/include/net/phonet/pep.h index 35672b1cf44a..37f23dc05de8 100644 --- a/include/net/phonet/pep.h +++ b/include/net/phonet/pep.h @@ -77,6 +77,11 @@ static inline struct pnpipehdr *pnp_hdr(struct sk_buff *skb) #define MAX_PNPIPE_HEADER (MAX_PHONET_HEADER + 4) enum { + PNS_PIPE_CREATE_REQ = 0x00, + PNS_PIPE_CREATE_RESP, + PNS_PIPE_REMOVE_REQ, + PNS_PIPE_REMOVE_RESP, + PNS_PIPE_DATA = 0x20, PNS_PIPE_ALIGNED_DATA, diff --git a/net/phonet/pep.c b/net/phonet/pep.c index 04e34196c9de..d0e7eb24c8b9 100644 --- a/net/phonet/pep.c +++ b/net/phonet/pep.c @@ -620,6 +620,28 @@ static int pep_do_rcv(struct sock *sk, struct sk_buff *skb) return err; } +static int pipe_do_remove(struct sock *sk) +{ + struct pep_sock *pn = pep_sk(sk); + struct pnpipehdr *ph; + struct sk_buff *skb; + + skb = alloc_skb(MAX_PNPIPE_HEADER, GFP_KERNEL); + if (!skb) + return -ENOMEM; + + skb_reserve(skb, MAX_PNPIPE_HEADER); + __skb_push(skb, sizeof(*ph)); + skb_reset_transport_header(skb); + ph = pnp_hdr(skb); + ph->utid = 0; + ph->message_id = PNS_PIPE_REMOVE_REQ; + ph->pipe_handle = pn->pipe_handle; + ph->data[0] = PAD; + + return pn_skb_send(sk, skb, &pipe_srv); +} + /* associated socket ceases to exist */ static void pep_sock_close(struct sock *sk, long timeout) { @@ -638,7 +660,10 @@ static void pep_sock_close(struct sock *sk, long timeout) sk_for_each_safe(sknode, p, n, &pn->ackq) sk_del_node_init(sknode); sk->sk_state = TCP_CLOSE; - } + } else if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED)) + /* Forcefully remove dangling Phonet pipe */ + pipe_do_remove(sk); + ifindex = pn->ifindex; pn->ifindex = 0; release_sock(sk);