From 09572fca7223bcf32c9f0d5e100d8381a81d55f4 Mon Sep 17 00:00:00 2001 From: Luiz Augusto von Dentz Date: Thu, 16 Sep 2021 13:10:46 -0700 Subject: [PATCH] Bluetooth: hci_sock: Add support for BT_{SND,RCV}BUF This adds support for BT_{SND,RCV}BUF so userspace can set MTU based on the channel usage. Fixes: https://github.com/bluez/bluez/issues/201 Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Marcel Holtmann --- net/bluetooth/hci_sock.c | 102 ++++++++++++++++++++++++++++++++++----- 1 file changed, 91 insertions(+), 11 deletions(-) diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c index 55b0d177375b..99de17922bda 100644 --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -57,6 +57,7 @@ struct hci_pinfo { unsigned long flags; __u32 cookie; char comm[TASK_COMM_LEN]; + __u16 mtu; }; static struct hci_dev *hci_hdev_from_sock(struct sock *sk) @@ -1374,6 +1375,10 @@ static int hci_sock_bind(struct socket *sock, struct sockaddr *addr, break; } + /* Default MTU to HCI_MAX_FRAME_SIZE if not set */ + if (!hci_pi(sk)->mtu) + hci_pi(sk)->mtu = HCI_MAX_FRAME_SIZE; + sk->sk_state = BT_BOUND; done: @@ -1719,7 +1724,7 @@ static int hci_sock_sendmsg(struct socket *sock, struct msghdr *msg, if (flags & ~(MSG_DONTWAIT | MSG_NOSIGNAL | MSG_ERRQUEUE | MSG_CMSG_COMPAT)) return -EINVAL; - if (len < 4 || len > HCI_MAX_FRAME_SIZE) + if (len < 4 || len > hci_pi(sk)->mtu) return -EINVAL; buf = kmalloc(len, GFP_KERNEL); @@ -1849,8 +1854,8 @@ static int hci_sock_sendmsg(struct socket *sock, struct msghdr *msg, goto done; } -static int hci_sock_setsockopt(struct socket *sock, int level, int optname, - sockptr_t optval, unsigned int len) +static int hci_sock_setsockopt_old(struct socket *sock, int level, int optname, + sockptr_t optval, unsigned int len) { struct hci_ufilter uf = { .opcode = 0 }; struct sock *sk = sock->sk; @@ -1858,9 +1863,6 @@ static int hci_sock_setsockopt(struct socket *sock, int level, int optname, BT_DBG("sk %p, opt %d", sk, optname); - if (level != SOL_HCI) - return -ENOPROTOOPT; - lock_sock(sk); if (hci_pi(sk)->channel != HCI_CHANNEL_RAW) { @@ -1935,8 +1937,56 @@ static int hci_sock_setsockopt(struct socket *sock, int level, int optname, return err; } -static int hci_sock_getsockopt(struct socket *sock, int level, int optname, - char __user *optval, int __user *optlen) +static int hci_sock_setsockopt(struct socket *sock, int level, int optname, + sockptr_t optval, unsigned int len) +{ + struct sock *sk = sock->sk; + int err = 0, opt = 0; + + BT_DBG("sk %p, opt %d", sk, optname); + + if (level == SOL_HCI) + return hci_sock_setsockopt_old(sock, level, optname, optval, + len); + + if (level != SOL_BLUETOOTH) + return -ENOPROTOOPT; + + lock_sock(sk); + + switch (optname) { + case BT_SNDMTU: + case BT_RCVMTU: + switch (hci_pi(sk)->channel) { + /* Don't allow changing MTU for channels that are meant for HCI + * traffic only. + */ + case HCI_CHANNEL_RAW: + case HCI_CHANNEL_USER: + err = -ENOPROTOOPT; + goto done; + } + + if (copy_from_sockptr(&opt, optval, sizeof(u16))) { + err = -EFAULT; + break; + } + + hci_pi(sk)->mtu = opt; + break; + + default: + err = -ENOPROTOOPT; + break; + } + +done: + release_sock(sk); + return err; +} + +static int hci_sock_getsockopt_old(struct socket *sock, int level, int optname, + char __user *optval, int __user *optlen) { struct hci_ufilter uf; struct sock *sk = sock->sk; @@ -1944,9 +1994,6 @@ static int hci_sock_getsockopt(struct socket *sock, int level, int optname, BT_DBG("sk %p, opt %d", sk, optname); - if (level != SOL_HCI) - return -ENOPROTOOPT; - if (get_user(len, optlen)) return -EFAULT; @@ -2004,6 +2051,39 @@ static int hci_sock_getsockopt(struct socket *sock, int level, int optname, return err; } +static int hci_sock_getsockopt(struct socket *sock, int level, int optname, + char __user *optval, int __user *optlen) +{ + struct sock *sk = sock->sk; + int err = 0; + + BT_DBG("sk %p, opt %d", sk, optname); + + if (level == SOL_HCI) + return hci_sock_getsockopt_old(sock, level, optname, optval, + optlen); + + if (level != SOL_BLUETOOTH) + return -ENOPROTOOPT; + + lock_sock(sk); + + switch (optname) { + case BT_SNDMTU: + case BT_RCVMTU: + if (put_user(hci_pi(sk)->mtu, (u16 __user *)optval)) + err = -EFAULT; + break; + + default: + err = -ENOPROTOOPT; + break; + } + + release_sock(sk); + return err; +} + static const struct proto_ops hci_sock_ops = { .family = PF_BLUETOOTH, .owner = THIS_MODULE,