From 77db1980565626471a980f0d2d17299e4bd5e7a5 Mon Sep 17 00:00:00 2001 From: Marcel Holtmann Date: Mon, 14 Jul 2008 20:13:45 +0200 Subject: [PATCH] [Bluetooth] Enforce security for outgoing RFCOMM connections Recent tests with various Bluetooth headsets have shown that some of them don't enforce authentication and encryption when connecting. All of them leave it up to the host stack to enforce it. Non of them should allow unencrypted connections, but that is how it is. So in case the link mode settings require authentication and/or encryption it will now also be enforced on outgoing RFCOMM connections. Previously this was only done for incoming connections. This support has a small drawback from a protocol level point of view since the host stack can't really tell with 100% certainty if a remote side is already authenticated or not. So if both sides are configured to enforce authentication it will be requested twice. Most Bluetooth chips are caching this information and thus no extra authentication procedure has to be triggered over-the-air, but it can happen. Signed-off-by: Marcel Holtmann --- include/net/bluetooth/rfcomm.h | 1 + net/bluetooth/rfcomm/core.c | 77 ++++++++++++++++++++-------------- net/bluetooth/rfcomm/sock.c | 8 ++-- 3 files changed, 52 insertions(+), 34 deletions(-) diff --git a/include/net/bluetooth/rfcomm.h b/include/net/bluetooth/rfcomm.h index 98ec7a320689..8c54ff37ad4f 100644 --- a/include/net/bluetooth/rfcomm.h +++ b/include/net/bluetooth/rfcomm.h @@ -181,6 +181,7 @@ struct rfcomm_dlc { u8 priority; u8 v24_sig; u8 mscex; + u8 out; u32 link_mode; diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c index 0c2c93735e93..1f92f9ab4959 100644 --- a/net/bluetooth/rfcomm/core.c +++ b/net/bluetooth/rfcomm/core.c @@ -53,7 +53,7 @@ #define BT_DBG(D...) #endif -#define VERSION "1.8" +#define VERSION "1.9" static int disable_cfc = 0; static int channel_mtu = -1; @@ -230,6 +230,21 @@ static int rfcomm_l2sock_create(struct socket **sock) return err; } +static inline int rfcomm_check_link_mode(struct rfcomm_dlc *d) +{ + struct sock *sk = d->session->sock->sk; + + if (d->link_mode & (RFCOMM_LM_ENCRYPT | RFCOMM_LM_SECURE)) { + if (!hci_conn_encrypt(l2cap_pi(sk)->conn->hcon)) + return 1; + } else if (d->link_mode & RFCOMM_LM_AUTH) { + if (!hci_conn_auth(l2cap_pi(sk)->conn->hcon)) + return 1; + } + + return 0; +} + /* ---- RFCOMM DLCs ---- */ static void rfcomm_dlc_timeout(unsigned long arg) { @@ -371,15 +386,23 @@ static int __rfcomm_dlc_open(struct rfcomm_dlc *d, bdaddr_t *src, bdaddr_t *dst, d->addr = __addr(s->initiator, dlci); d->priority = 7; - d->state = BT_CONFIG; + d->state = BT_CONFIG; rfcomm_dlc_link(s, d); + d->out = 1; + d->mtu = s->mtu; d->cfc = (s->cfc == RFCOMM_CFC_UNKNOWN) ? 0 : s->cfc; - if (s->state == BT_CONNECTED) - rfcomm_send_pn(s, 1, d); + if (s->state == BT_CONNECTED) { + if (rfcomm_check_link_mode(d)) + set_bit(RFCOMM_AUTH_PENDING, &d->flags); + else + rfcomm_send_pn(s, 1, d); + } + rfcomm_dlc_set_timer(d, RFCOMM_CONN_TIMEOUT); + return 0; } @@ -1146,21 +1169,6 @@ static int rfcomm_recv_disc(struct rfcomm_session *s, u8 dlci) return 0; } -static inline int rfcomm_check_link_mode(struct rfcomm_dlc *d) -{ - struct sock *sk = d->session->sock->sk; - - if (d->link_mode & (RFCOMM_LM_ENCRYPT | RFCOMM_LM_SECURE)) { - if (!hci_conn_encrypt(l2cap_pi(sk)->conn->hcon)) - return 1; - } else if (d->link_mode & RFCOMM_LM_AUTH) { - if (!hci_conn_auth(l2cap_pi(sk)->conn->hcon)) - return 1; - } - - return 0; -} - static void rfcomm_dlc_accept(struct rfcomm_dlc *d) { struct sock *sk = d->session->sock->sk; @@ -1205,10 +1213,8 @@ static int rfcomm_recv_sabm(struct rfcomm_session *s, u8 dlci) if (rfcomm_check_link_mode(d)) { set_bit(RFCOMM_AUTH_PENDING, &d->flags); rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT); - return 0; - } - - rfcomm_dlc_accept(d); + } else + rfcomm_dlc_accept(d); } return 0; } @@ -1223,10 +1229,8 @@ static int rfcomm_recv_sabm(struct rfcomm_session *s, u8 dlci) if (rfcomm_check_link_mode(d)) { set_bit(RFCOMM_AUTH_PENDING, &d->flags); rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT); - return 0; - } - - rfcomm_dlc_accept(d); + } else + rfcomm_dlc_accept(d); } else { rfcomm_send_dm(s, dlci); } @@ -1636,7 +1640,11 @@ static void rfcomm_process_connect(struct rfcomm_session *s) d = list_entry(p, struct rfcomm_dlc, list); if (d->state == BT_CONFIG) { d->mtu = s->mtu; - rfcomm_send_pn(s, 1, d); + if (rfcomm_check_link_mode(d)) { + set_bit(RFCOMM_AUTH_PENDING, &d->flags); + rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT); + } else + rfcomm_send_pn(s, 1, d); } } } @@ -1709,7 +1717,11 @@ static inline void rfcomm_process_dlcs(struct rfcomm_session *s) if (test_and_clear_bit(RFCOMM_AUTH_ACCEPT, &d->flags)) { rfcomm_dlc_clear_timer(d); - rfcomm_dlc_accept(d); + if (d->out) { + rfcomm_send_pn(s, 1, d); + rfcomm_dlc_set_timer(d, RFCOMM_CONN_TIMEOUT); + } else + rfcomm_dlc_accept(d); if (d->link_mode & RFCOMM_LM_SECURE) { struct sock *sk = s->sock->sk; hci_conn_change_link_key(l2cap_pi(sk)->conn->hcon); @@ -1717,7 +1729,10 @@ static inline void rfcomm_process_dlcs(struct rfcomm_session *s) continue; } else if (test_and_clear_bit(RFCOMM_AUTH_REJECT, &d->flags)) { rfcomm_dlc_clear_timer(d); - rfcomm_send_dm(s, d->dlci); + if (!d->out) + rfcomm_send_dm(s, d->dlci); + else + d->state = BT_CLOSED; __rfcomm_dlc_close(d, ECONNREFUSED); continue; } @@ -1726,7 +1741,7 @@ static inline void rfcomm_process_dlcs(struct rfcomm_session *s) continue; if ((d->state == BT_CONNECTED || d->state == BT_DISCONN) && - d->mscex == RFCOMM_MSCEX_OK) + d->mscex == RFCOMM_MSCEX_OK) rfcomm_process_tx(d); } } diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c index 5083adcbfae5..cacb1ab51f99 100644 --- a/net/bluetooth/rfcomm/sock.c +++ b/net/bluetooth/rfcomm/sock.c @@ -309,13 +309,13 @@ static struct sock *rfcomm_sock_alloc(struct net *net, struct socket *sock, int sk->sk_destruct = rfcomm_sock_destruct; sk->sk_sndtimeo = RFCOMM_CONN_TIMEOUT; - sk->sk_sndbuf = RFCOMM_MAX_CREDITS * RFCOMM_DEFAULT_MTU * 10; - sk->sk_rcvbuf = RFCOMM_MAX_CREDITS * RFCOMM_DEFAULT_MTU * 10; + sk->sk_sndbuf = RFCOMM_MAX_CREDITS * RFCOMM_DEFAULT_MTU * 10; + sk->sk_rcvbuf = RFCOMM_MAX_CREDITS * RFCOMM_DEFAULT_MTU * 10; sock_reset_flag(sk, SOCK_ZAPPED); sk->sk_protocol = proto; - sk->sk_state = BT_OPEN; + sk->sk_state = BT_OPEN; bt_sock_link(&rfcomm_sk_list, sk); @@ -413,6 +413,8 @@ static int rfcomm_sock_connect(struct socket *sock, struct sockaddr *addr, int a bacpy(&bt_sk(sk)->dst, &sa->rc_bdaddr); rfcomm_pi(sk)->channel = sa->rc_channel; + d->link_mode = rfcomm_pi(sk)->link_mode; + err = rfcomm_dlc_open(d, &bt_sk(sk)->src, &sa->rc_bdaddr, sa->rc_channel); if (!err) err = bt_sock_wait_state(sk, BT_CONNECTED, -- 2.20.1