by Jian-Hong Pan

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Jian-Hong Pan <[email protected]> 於 2019年1月7日週一下午10:47寫道：
>
> Andreas Färber <[email protected]> 於 2018年12月29日週六下午3:27寫道：
> >
> > Hi Jian-Hong,
> >
> > Am 16.12.18 um 11:18 schrieb Jian-Hong Pan:
> > > This patch adds a new address/protocol family for LoRaWAN network.
> > > It also implements the the functions and maps to Datagram socket for
> > > LoRaWAN unconfirmed data messages.
> > >
> > > Signed-off-by: Jian-Hong Pan <[email protected]>
> > [...]
> > > include/linux/lora/lorawan_netdev.h | 52 +++
> > > net/lorawan/Kconfig | 10 +
> > > net/lorawan/Makefile | 2 +
> > > net/lorawan/socket.c | 686 ++++++++++++++++++++++++++++
> > > 4 files changed, 750 insertions(+)
> > > create mode 100644 include/linux/lora/lorawan_netdev.h
> > > create mode 100644 net/lorawan/Kconfig
> > > create mode 100644 net/lorawan/Makefile
> > > create mode 100644 net/lorawan/socket.c
> >
> > I'm not 100% happy with this yet, but to decouple it from the soft-MAC
> > discussion (patches 2-6/6) and to allow reuse by Ben, I've staged it in
> > linux-lora.git.
> >
> > We can clean it up with incremental patches there (and squash later).
> >
> > >
> > > diff --git a/include/linux/lora/lorawan_netdev.h b/include/linux/lora/lorawan_netdev.h
> > > new file mode 100644
> > > index 000000000000..5bffb5164f95
> > > --- /dev/null
> > > +++ b/include/linux/lora/lorawan_netdev.h
> > > @@ -0,0 +1,52 @@
> > > +/* SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause */
> >
> > Is there any practical reason you dual-license your code? My LoRa code
> > is only GPL - should I reconsider that?
>
> I use dual-license due to the event "[Ksummit-discuss] [CORE TOPIC]
> GPL defense issues"
> https://lists.linuxfoundation.org/pipermail/ksummit-discuss/2016-August/003580.html
>
> > > +/*-
> >
> > I assume the dash is a typo?
> >
> > > + * LoRaWAN stack related definitions
> > > + *
> > > + * Copyright (c) 2018 Jian-Hong, Pan <[email protected]>
> > > + *
> >
> > Leftover white line from old license header?
> >
> > > + */
> > > +
> > > +#ifndef __LORAWAN_NET_DEVICE_H__
> > > +#define __LORAWAN_NET_DEVICE_H__
> > > +
> > > +enum {
> > > + LRW_ADDR_APPEUI,
> > > + LRW_ADDR_DEVEUI,
> > > + LRW_ADDR_DEVADDR,
> > > +};
> > > +
> > > +struct lrw_addr_in {
> > > + int addr_type;
> > > + union {
> > > + u64 app_eui;
> > > + u64 dev_eui;
> >
> > In my RFC and in linux-lora.git I have a lora_eui typedef - any reason
> > you're not using it here?
>
> lora_eui is defined as a type of u8 array with 8 bytes in
> include/linux/lora/dev.h
> typedef u8 lora_eui[8];
> It is not a basic nor simple data type.
>
> 1. There is the endian issue. LoRaWAN uses little endian for
> transmission. If u64 data type is used, we can call functions like
> cpu_to_le64 and le64_to_cpu to deal the endian jobs directly.
> 2. We can compare the EUIs with relational operators directly if the
> EUI is not a type of array.
>
> > > + u32 devaddr;
> > > + };
> > > +};
> > > +
> > > +struct sockaddr_lorawan {
> > > + sa_family_t family; /* AF_LORAWAN */
> > > + struct lrw_addr_in addr_in;
> > > +};
> > > +
> > > +/**
> > > + * lrw_mac_cb - This structure holds the control buffer (cb) of sk_buff
> > > + *
> > > + * @devaddr: the LoRaWAN device address of this LoRaWAN hardware
> > > + */
> > > +struct lrw_mac_cb {
> > > + u32 devaddr;
> > > +};
> > > +
> > > +/**
> > > + * lrw_get_mac_cb - Get the LoRaWAN MAC control buffer of the sk_buff
> > > + * @skb: the exchanging sk_buff
> > > + *
> > > + * Return: the pointer of LoRaWAN MAC control buffer
> > > + */
> > > +static inline struct lrw_mac_cb *lrw_get_mac_cb(struct sk_buff *skb)
> > > +{
> > > + return (struct lrw_mac_cb *)skb->cb;
> > > +}
> >
> > For LoRa I have a separate lora/skb.h - suggest to split this off into
> > its own header consistently.
>
> Sounds good.
> Do you prefer separate them into lora/skb.h or lora/lorawan_skb.h?
>
> > > +
> > > +#endif
> > > diff --git a/net/lorawan/Kconfig b/net/lorawan/Kconfig
> > > new file mode 100644
> > > index 000000000000..bf6c9b77573b
> > > --- /dev/null
> > > +++ b/net/lorawan/Kconfig
> > > @@ -0,0 +1,10 @@
> > > +config LORAWAN
> > > + tristate "LoRaWAN Network support"
> >
> > The N in LoRaWAN is already for Network. :)
> >
> > > + help
> > > + LoRaWAN defines low data rate, low power and long range wireless
> > > + wide area networks. It was designed to organize networks of automation
> > > + devices, such as sensors, switches and actuators. It can operate
> > > + multiple kilometers wide.
> >
> > The missing information here to distinguish it from LoRa would be that
> > it's a client/server technology centered around gateways. In particular
> > gateways that anyone can run, distinguishing it from (Sigfox or) NB-IoT.
> >
> > > +
> > > + Say Y here to compile LoRaWAN support into the kernel or say M to
> > > + compile it as a module.
> > > diff --git a/net/lorawan/Makefile b/net/lorawan/Makefile
> > > new file mode 100644
> > > index 000000000000..8c923ca6541a
> > > --- /dev/null
> > > +++ b/net/lorawan/Makefile
> > > @@ -0,0 +1,2 @@
> > > +obj-$(CONFIG_LORAWAN) += lorawan.o
> > > +lorawan-objs := socket.o
> >
> > Both Kconfig and Makefile are not integrated into net/ here. That
> > happens only in 6/6.
> >
> > > diff --git a/net/lorawan/socket.c b/net/lorawan/socket.c
> > > new file mode 100644
> > > index 000000000000..7ef106b877ca
> > > --- /dev/null
> > > +++ b/net/lorawan/socket.c
> > > @@ -0,0 +1,686 @@
> > > +// SPDX-License-Identifier: GPL-2.0-or-later OR BSD-3-Clause
> > > +/*-
> >
> > ?
> >
> > > + * LoRaWAN stack related definitions
> > > + *
> > > + * Copyright (c) 2018 Jian-Hong, Pan <[email protected]>
> > > + *
> >
> > ?
> >
> > > + */
> > > +
> > > +#define LORAWAN_MODULE_NAME "lorawan"
> > > +
> > > +#define pr_fmt(fmt) LORAWAN_MODULE_NAME ": " fmt
> > > +
> > > +#include <linux/init.h>
> > > +#include <linux/module.h>
> > > +#include <linux/list.h>
> > > +#include <linux/net.h>
> > > +#include <linux/if_arp.h>
> > > +#include <linux/termios.h> /* For TIOCOUTQ/INQ */
> > > +#include <net/sock.h>
> > > +#include <linux/lora/lorawan_netdev.h>
> >
> > Please sort headers alphabetically.
> >
> > > +
> > > +/**
> > > + * dgram_sock - This structure holds the states of Datagram socket
> > > + *
> > > + * @sk: network layer representation of the socket
> > > + * sk must be the first member of dgram_sock
> >
> > Might that sentence be more useful as inline comment below?
> >
> > > + * @src_devaddr: the LoRaWAN device address for this connection
> > > + * @bound: this socket is bound or not
> > > + * @connected: this socket is connected to the destination or not
> > > + * @want_ack: this socket needs to ack for the connection or not
> >
> > Doesn't exist below?
> >
> > > + */
> > > +struct dgram_sock {
> > > + struct sock sk;
> > > + u32 src_devaddr;
> > > +
> > > + u8 bound:1;
> > > + u8 connected:1;
> > > +};
> > > +
> > > +static HLIST_HEAD(dgram_head);
> > > +static DEFINE_RWLOCK(dgram_lock);
> > > +
> > > +static struct dgram_sock *
> > > +dgram_sk(const struct sock *sk)
> > > +{
> > > + return container_of(sk, struct dgram_sock, sk);
> > > +}
> > > +
> > > +static struct net_device *
> > > +lrw_get_dev_by_addr(struct net *net, u32 devaddr)
> > > +{
> > > + __be32 be_addr = cpu_to_be32(devaddr);
> > > + struct net_device *ndev = NULL;
> > > +
> > > + rcu_read_lock();
> > > + ndev = dev_getbyhwaddr_rcu(net, ARPHRD_LORAWAN, (char *)&be_addr);
> > > + if (ndev)
> > > + dev_hold(ndev);
> > > + rcu_read_unlock();
> > > +
> > > + return ndev;
> > > +}
> > > +
> > > +static int
> > > +dgram_init(struct sock *sk)
> > > +{
> > > + return 0;
> > > +}
> > > +
> > > +static void
> > > +dgram_close(struct sock *sk, long timeout)
> > > +{
> > > + sk_common_release(sk);
> > > +}
> > > +
> > > +static int
> > > +dgram_bind(struct sock *sk, struct sockaddr *uaddr, int len)
> > > +{
> > > + struct sockaddr_lorawan *addr = (struct sockaddr_lorawan *)uaddr;
> > > + struct dgram_sock *ro = dgram_sk(sk);
> > > + struct net_device *ndev;
> > > + int ret;
> > > +
> > > + lock_sock(sk);
> > > + ro->bound = 0;
> > > +
> > > + ret = -EINVAL;
> > > + if (len < sizeof(*addr))
> > > + goto dgram_bind_end;
> > > +
> > > + if (addr->family != AF_LORAWAN)
> > > + goto dgram_bind_end;
> > > +
> > > + if (addr->addr_in.addr_type != LRW_ADDR_DEVADDR)
> > > + goto dgram_bind_end;
> > > +
> > > + pr_debug("%s: bind address %X\n", __func__, addr->addr_in.devaddr);
> > > + ndev = lrw_get_dev_by_addr(sock_net(sk), addr->addr_in.devaddr);
> > > + if (!ndev) {
> > > + ret = -ENODEV;
> > > + goto dgram_bind_end;
> > > + }
> > > + netdev_dbg(ndev, "%s: get ndev\n", __func__);
> > > +
> > > + if (ndev->type != ARPHRD_LORAWAN) {
> > > + ret = -ENODEV;
> > > + goto dgram_bind_end;
> >
> > This is leaking ndev.
> >
> > > + }
> > > +
> > > + ro->src_devaddr = addr->addr_in.devaddr;
> > > + ro->bound = 1;
> > > + ret = 0;
> > > + dev_put(ndev);
> > > + pr_debug("%s: bound address %X\n", __func__, ro->src_devaddr);
> > > +
> > > +dgram_bind_end:
> > > + release_sock(sk);
> > > + return ret;
> > > +}
> > > +
> > > +static int
> > > +lrw_dev_hard_header(struct sk_buff *skb, struct net_device *ndev,
> > > + const u32 src_devaddr, size_t len)
> > > +{
> > > + /* TODO: Prepare the LoRaWAN sending header here */
> >
> > I wonder, is your idea that you would always write headers here but have
> > me ignore them in hard-MAC drivers by accessing data and not head?
> >
> > I.e., does this dgram (and a later seqpacket) implementation give us not
> > just the buffer to pass to hard-MAC or soft-MAC but actually LoRa, too,
> > so that maclorawan needs to further post-processing of header/checksum?
>
> I put lrw_dev_hard_header function here for the header processing nnd
> thought it might be called in the future originally. However, as you
> mentioned, we already have soft and hard-MAC and this abstraction
> layer only pass the buffer. So, it can be removed now.
>
> > > + return 0;
> > > +}
> > > +
> > > +static int
> > > +dgram_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
> > > +{
> > > + struct dgram_sock *ro = dgram_sk(sk);
> > > + struct net_device *ndev;
> > > + struct sk_buff *skb;
> > > + size_t hlen;
> > > + size_t tlen;
> > > + int ret;
> > > +
> > > + pr_debug("%s: going to send %zu bytes", __func__, size);
> >
> > \n
> >
> > > + if (msg->msg_flags & MSG_OOB) {
> > > + pr_debug("msg->msg_flags = 0x%x\n", msg->msg_flags);
> > > + return -EOPNOTSUPP;
> > > + }
> > > +
> > > + pr_debug("%s: check msg_name\n", __func__);
> > > + if (!ro->connected && !msg->msg_name)
> > > + return -EDESTADDRREQ;
> > > + else if (ro->connected && msg->msg_name)
> > > + return -EISCONN;
> > > +
> > > + pr_debug("%s: check bound\n", __func__);
> > > + if (!ro->bound)
> > > + ndev = dev_getfirstbyhwtype(sock_net(sk), ARPHRD_LORAWAN);
> > > + else
> > > + ndev = lrw_get_dev_by_addr(sock_net(sk), ro->src_devaddr);
> > > +
> > > + if (!ndev) {
> > > + pr_debug("no dev\n");
> > > + ret = -ENXIO;
> > > + goto dgram_sendmsg_end;
> > > + }
> > > +
> > > + if (size > ndev->mtu) {
> > > + netdev_dbg(ndev, "size = %zu, mtu = %u\n", size, ndev->mtu);
> > > + ret = -EMSGSIZE;
> > > + goto dgram_sendmsg_end;
> >
> > Leaks at least ndev from lrw_get_dev_by_addr.
> >
> > > + }
> > > +
> > > + netdev_dbg(ndev, "%s: create skb\n", __func__);
> > > + hlen = LL_RESERVED_SPACE(ndev);
> > > + tlen = ndev->needed_tailroom;
> > > + skb = sock_alloc_send_skb(sk, hlen + tlen + size,
> > > + msg->msg_flags & MSG_DONTWAIT,
> > > + &ret);
> > > +
> > > + if (!skb)
> > > + goto dgram_sendmsg_no_skb;
> > > +
> > > + skb_reserve(skb, hlen);
> > > + skb_reset_network_header(skb);
> > > +
> > > + ret = lrw_dev_hard_header(skb, ndev, 0, size);
> > > + if (ret < 0)
> > > + goto dgram_sendmsg_no_skb;
> > > +
> > > + ret = memcpy_from_msg(skb_put(skb, size), msg, size);
> > > + if (ret > 0)
> > > + goto dgram_sendmsg_err_skb;
> > > +
> > > + skb->dev = ndev;
> > > + skb->protocol = htons(ETH_P_LORAWAN);
> > > +
> > > + netdev_dbg(ndev, "%s: push skb to xmit queue\n", __func__);
> > > + ret = dev_queue_xmit(skb);
> > > + if (ret > 0)
> > > + ret = net_xmit_errno(ret);
> > > + netdev_dbg(ndev, "%s: pushed skb to xmit queue with ret=%d\n",
> > > + __func__, ret);
> > > + dev_put(ndev);
> > > +
> > > + return ret ?: size;
> > > +
> > > +dgram_sendmsg_err_skb:
> > > + kfree_skb(skb);
> > > +dgram_sendmsg_no_skb:
> > > + dev_put(ndev);
> > > +
> > > +dgram_sendmsg_end:
> > > + return ret;
> > > +}
> > > +
> > > +static int
> > > +dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
> > > + int noblock, int flags, int *addr_len)
> > > +{
> > > + DECLARE_SOCKADDR(struct sockaddr_lorawan *, saddr, msg->msg_name);
> > > + struct sk_buff *skb;
> > > + size_t copied = 0;
> > > + int err;
> > > +
> > > + skb = skb_recv_datagram(sk, flags, noblock, &err);
> > > + if (!skb)
> > > + goto dgram_recvmsg_end;
> > > +
> > > + copied = skb->len;
> > > + if (len < copied) {
> > > + msg->msg_flags |= MSG_TRUNC;
> > > + copied = len;
> > > + }
> > > +
> > > + err = skb_copy_datagram_msg(skb, 0, msg, copied);
> > > + if (err)
> > > + goto dgram_recvmsg_done;
> > > +
> > > + sock_recv_ts_and_drops(msg, sk, skb);
> > > + if (saddr) {
> > > + memset(saddr, 0, sizeof(*saddr));
> > > + saddr->family = AF_LORAWAN;
> > > + saddr->addr_in.devaddr = lrw_get_mac_cb(skb)->devaddr;
> > > + *addr_len = sizeof(*saddr);
> > > + }
> > > +
> > > + if (flags & MSG_TRUNC)
> > > + copied = skb->len;
> > > +
> > > +dgram_recvmsg_done:
> > > + skb_free_datagram(sk, skb);
> > > +
> > > +dgram_recvmsg_end:
> > > + if (err)
> > > + return err;
> > > + return copied;
> > > +}
> > > +
> > > +static int
> > > +dgram_hash(struct sock *sk)
> > > +{
> > > + pr_debug("%s\n", __func__);
> > > + write_lock_bh(&dgram_lock);
> > > + sk_add_node(sk, &dgram_head);
> > > + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
> > > + write_unlock_bh(&dgram_lock);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static void
> > > +dgram_unhash(struct sock *sk)
> > > +{
> > > + pr_debug("%s\n", __func__);
> > > + write_lock_bh(&dgram_lock);
> > > + if (sk_del_node_init(sk))
> > > + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
> > > + write_unlock_bh(&dgram_lock);
> > > +}
> > > +
> > > +static int
> > > +dgram_connect(struct sock *sk, struct sockaddr *uaddr, int len)
> > > +{
> > > + struct dgram_sock *ro = dgram_sk(sk);
> > > +
> > > + /* Nodes of LoRaWAN send data to a gateway only, then data is received
> > > + * and transferred to servers with the gateway's policy.
> > > + * So, the destination address is not used by nodes.
> > > + */
> > > + lock_sock(sk);
> > > + ro->connected = 1;
> > > + release_sock(sk);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int
> > > +dgram_disconnect(struct sock *sk, int flags)
> > > +{
> > > + struct dgram_sock *ro = dgram_sk(sk);
> > > +
> > > + lock_sock(sk);
> > > + ro->connected = 0;
> > > + release_sock(sk);
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int
> > > +dgram_ioctl(struct sock *sk, int cmd, unsigned long arg)
> > > +{
> > > + struct net_device *ndev = sk->sk_dst_cache->dev;
> > > + struct sk_buff *skb;
> > > + int amount;
> > > + int err;
> > > +
> > > + netdev_dbg(ndev, "%s: ioctl file (cmd=0x%X)\n", __func__, cmd);
> > > + switch (cmd) {
> > > + case SIOCOUTQ:
> > > + amount = sk_wmem_alloc_get(sk);
> > > + err = put_user(amount, (int __user *)arg);
> > > + break;
> > > + case SIOCINQ:
> > > + amount = 0;
> > > + spin_lock_bh(&sk->sk_receive_queue.lock);
> > > + skb = skb_peek(&sk->sk_receive_queue);
> > > + if (skb) {
> > > + /* We will only return the amount of this packet
> > > + * since that is all that will be read.
> > > + */
> > > + amount = skb->len;
> > > + }
> > > + spin_unlock_bh(&sk->sk_receive_queue.lock);
> > > + err = put_user(amount, (int __user *)arg);
> > > + break;
> > > + default:
> > > + err = -ENOIOCTLCMD;
> > > + }
> > > +
> > > + return err;
> > > +}
> > > +
> > > +static int
> > > +dgram_getsockopt(struct sock *sk, int level, int optname,
> > > + char __user *optval, int __user *optlen)
> > > +{
> > > + int val, len;
> > > +
> > > + if (level != SOL_LORAWAN)
> > > + return -EOPNOTSUPP;
> > > +
> > > + if (get_user(len, optlen))
> > > + return -EFAULT;
> > > +
> > > + len = min_t(unsigned int, len, sizeof(int));
> > > +
> > > + switch (optname) {
> > > + default:
> > > + return -ENOPROTOOPT;
> > > + }
> > > +
> > > + if (put_user(len, optlen))
> > > + return -EFAULT;
> > > +
> > > + if (copy_to_user(optval, &val, len))
> > > + return -EFAULT;
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int
> > > +dgram_setsockopt(struct sock *sk, int level, int optname,
> > > + char __user *optval, unsigned int optlen)
> > > +{
> > > + int val;
> > > + int err;
> > > +
> > > + err = 0;
> > > +
> > > + if (optlen < sizeof(int))
> > > + return -EINVAL;
> > > +
> > > + if (get_user(val, (int __user *)optval))
> > > + return -EFAULT;
> > > +
> > > + lock_sock(sk);
> > > +
> > > + switch (optname) {
> > > + default:
> > > + err = -ENOPROTOOPT;
> > > + break;
> > > + }
> > > +
> > > + release_sock(sk);
> > > +
> > > + return err;
> > > +}
> > > +
> > > +static struct proto lrw_dgram_prot = {
> > > + .name = "LoRaWAN",
> > > + .owner = THIS_MODULE,
> > > + .obj_size = sizeof(struct dgram_sock),
> > > + .init = dgram_init,
> > > + .close = dgram_close,
> > > + .bind = dgram_bind,
> > > + .sendmsg = dgram_sendmsg,
> > > + .recvmsg = dgram_recvmsg,
> > > + .hash = dgram_hash,
> > > + .unhash = dgram_unhash,
> > > + .connect = dgram_connect,
> > > + .disconnect = dgram_disconnect,
> > > + .ioctl = dgram_ioctl,
> > > + .getsockopt = dgram_getsockopt,
> > > + .setsockopt = dgram_setsockopt,
> > > +};
> > > +
> > > +static int
> > > +lrw_sock_release(struct socket *sock)
> > > +{
> > > + struct sock *sk = sock->sk;
> > > +
> > > + if (sk) {
> > > + sock->sk = NULL;
> > > + sk->sk_prot->close(sk, 0);
> > > + }
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +static int
> > > +lrw_sock_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
> > > +{
> > > + struct sockaddr_lorawan *addr = (struct sockaddr_lorawan *)uaddr;
> > > + struct sock *sk = sock->sk;
> > > +
> > > + pr_debug("%s: bind address %X\n", __func__, addr->addr_in.devaddr);
> > > + if (sk->sk_prot->bind)
> > > + return sk->sk_prot->bind(sk, uaddr, addr_len);
> > > +
> > > + return sock_no_bind(sock, uaddr, addr_len);
> > > +}
> > > +
> > > +static int
> > > +lrw_sock_connect(struct socket *sock, struct sockaddr *uaddr,
> > > + int addr_len, int flags)
> > > +{
> > > + struct sock *sk = sock->sk;
> > > +
> > > + if (addr_len < sizeof(uaddr->sa_family))
> > > + return -EINVAL;
> > > +
> > > + return sk->sk_prot->connect(sk, uaddr, addr_len);
> > > +}
> > > +
> > > +static int
> > > +lrw_ndev_ioctl(struct sock *sk, struct ifreq __user *arg, unsigned int cmd)
> > > +{
> > > + struct net_device *ndev;
> > > + struct ifreq ifr;
> > > + int ret;
> > > +
> > > + pr_debug("%s: cmd %ud\n", __func__, cmd);
> > > + ret = -ENOIOCTLCMD;
> > > +
> > > + if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
> > > + return -EFAULT;
> > > +
> > > + ifr.ifr_name[IFNAMSIZ - 1] = 0;
> > > +
> > > + dev_load(sock_net(sk), ifr.ifr_name);
> > > + ndev = dev_get_by_name(sock_net(sk), ifr.ifr_name);
> > > +
> > > + netdev_dbg(ndev, "%s: cmd %ud\n", __func__, cmd);
> > > + if (!ndev)
> > > + return -ENODEV;
> > > +
> > > + if (ndev->type == ARPHRD_LORAWAN && ndev->netdev_ops->ndo_do_ioctl)
> > > + ret = ndev->netdev_ops->ndo_do_ioctl(ndev, &ifr, cmd);
> > > +
> > > + if (!ret && copy_to_user(arg, &ifr, sizeof(struct ifreq)))
> > > + ret = -EFAULT;
> > > + dev_put(ndev);
> > > +
> > > + return ret;
> > > +}
> > > +
> > > +static int
> > > +lrw_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
> > > +{
> > > + struct sock *sk = sock->sk;
> > > +
> > > + pr_debug("%s: cmd %ud\n", __func__, cmd);
> > > + switch (cmd) {
> > > + case SIOCGSTAMP:
> > > + return sock_get_timestamp(sk, (struct timeval __user *)arg);
> > > + case SIOCGSTAMPNS:
> > > + return sock_get_timestampns(sk, (struct timespec __user *)arg);
> > > + case SIOCOUTQ:
> > > + case SIOCINQ:
> > > + if (!sk->sk_prot->ioctl)
> > > + return -ENOIOCTLCMD;
> > > + return sk->sk_prot->ioctl(sk, cmd, arg);
> > > + default:
> > > + return lrw_ndev_ioctl(sk, (struct ifreq __user *)arg, cmd);
> > > + }
> > > +}
> > > +
> > > +static int
> > > +lrw_sock_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
> > > +{
> > > + struct sock *sk = sock->sk;
> > > +
> > > + pr_debug("%s: going to send %zu bytes\n", __func__, len);
> > > + return sk->sk_prot->sendmsg(sk, msg, len);
> > > +}
> > > +
> > > +static const struct proto_ops lrw_dgram_ops = {
> > > + .family = PF_LORAWAN,
> > > + .owner = THIS_MODULE,
> > > + .release = lrw_sock_release,
> > > + .bind = lrw_sock_bind,
> > > + .connect = lrw_sock_connect,
> > > + .socketpair = sock_no_socketpair,
> > > + .accept = sock_no_accept,
> > > + .getname = sock_no_getname,
> > > + .poll = datagram_poll,
> > > + .ioctl = lrw_sock_ioctl,
> > > + .listen = sock_no_listen,
> > > + .shutdown = sock_no_shutdown,
> > > + .setsockopt = sock_common_setsockopt,
> > > + .getsockopt = sock_common_getsockopt,
> > > + .sendmsg = lrw_sock_sendmsg,
> > > + .recvmsg = sock_common_recvmsg,
> > > + .mmap = sock_no_mmap,
> > > + .sendpage = sock_no_sendpage,
> > > +};
> > > +
> > > +static int
> > > +lorawan_creat(struct net *net, struct socket *sock, int protocol, int kern)
> >
> > create
> > Also, why lorawan_ here and lrw_ elsewhere?
> >
> > > +{
> > > + struct sock *sk;
> > > + int ret;
> > > +
> > > + if (!net_eq(net, &init_net))
> > > + return -EAFNOSUPPORT;
> > > +
> > > + if (sock->type != SOCK_DGRAM)
> > > + return -EAFNOSUPPORT;
> > > +
> > > + /* Allocates enough memory for dgram_sock whose first member is sk */
> > > + sk = sk_alloc(net, PF_LORAWAN, GFP_KERNEL, &lrw_dgram_prot, kern);
> > > + if (!sk)
> > > + return -ENOMEM;
> > > +
> > > + sock->ops = &lrw_dgram_ops;
> > > + sock_init_data(sock, sk);
> > > + sk->sk_family = PF_LORAWAN;
> > > + sock_set_flag(sk, SOCK_ZAPPED);
> > > +
> > > + if (sk->sk_prot->hash) {
> > > + ret = sk->sk_prot->hash(sk);
> > > + if (ret) {
> > > + sk_common_release(sk);
> > > + goto lorawan_creat_end;
> > > + }
> > > + }
> > > +
> > > + if (sk->sk_prot->init) {
> > > + ret = sk->sk_prot->init(sk);
> > > + if (ret)
> > > + sk_common_release(sk);
> > > + }
> > > +
> > > +lorawan_creat_end:
> >
> > create
> >
> > > + return ret;
> > > +}
> > > +
> > > +static const struct net_proto_family lorawan_family_ops = {
> > > + .owner = THIS_MODULE,
> > > + .family = PF_LORAWAN,
> > > + .create = lorawan_creat,
> > > +};
> > > +
> > > +static int
> > > +lrw_dgram_deliver(struct net_device *ndev, struct sk_buff *skb)
> > > +{
> > > + struct dgram_sock *ro;
> > > + struct sock *sk;
> > > + bool found;
> > > + int ret;
> > > +
> > > + ret = NET_RX_SUCCESS;
> > > + found = false;
> >
> > In times of C99 you could probably fold that into the declarations.

I have thought this issue many times, but give up and just follow
"Reverse XMAS tree declarations" rule in net subsystem. [1]
David also gave the related review comment. [2]

[1] https://lore.kernel.org/patchwork/patch/732076/
[2] https://lkml.org/lkml/2018/11/5/916

Regards,
Jian-Hong Pan

> > > +
> > > + read_lock(&dgram_lock);
> > > + sk_for_each(sk, &dgram_head) {
> > > + ro = dgram_sk(sk);
> > > + if (cpu_to_be32(ro->src_devaddr) == *(__be32 *)ndev->dev_addr) {
> > > + found = true;
> > > + break;
> > > + }
> > > + }
> > > + read_unlock(&dgram_lock);
> > > +
> > > + if (!found)
> > > + goto lrw_dgram_deliver_err;
> > > +
> > > + skb = skb_share_check(skb, GFP_ATOMIC);
> > > + if (!skb)
> > > + return NET_RX_DROP;
> > > +
> > > + if (sock_queue_rcv_skb(sk, skb) < 0)
> > > + goto lrw_dgram_deliver_err;
> > > +
> > > + return ret;
> > > +
> > > +lrw_dgram_deliver_err:
> > > + kfree_skb(skb);
> > > + ret = NET_RX_DROP;
> > > + return ret;
> > > +}
> > > +
> > > +static int
> > > +lorawan_rcv(struct sk_buff *skb, struct net_device *ndev,
> > > + struct packet_type *pt, struct net_device *orig_ndev)
> > > +{
> > > + if (!netif_running(ndev))
> > > + goto lorawan_rcv_drop;
> > > +
> > > + if (!net_eq(dev_net(ndev), &init_net))
> > > + goto lorawan_rcv_drop;
> > > +
> > > + if (ndev->type != ARPHRD_LORAWAN)
> > > + goto lorawan_rcv_drop;
> > > +
> > > + if (skb->pkt_type != PACKET_OTHERHOST)
> > > + return lrw_dgram_deliver(ndev, skb);
> > > +
> > > +lorawan_rcv_drop:
> > > + kfree_skb(skb);
> > > + return NET_RX_DROP;
> > > +}
> > > +
> > > +static struct packet_type lorawan_packet_type = {
> > > + .type = htons(ETH_P_LORAWAN),
> > > + .func = lorawan_rcv,
> > > +};
> > > +
> > > +static int __init
> > > +lrw_sock_init(void)
> > > +{
> > > + int ret;
> > > +
> > > + pr_info("module inserted\n");
> > > + ret = proto_register(&lrw_dgram_prot, 1);
> > > + if (ret)
> > > + goto lrw_sock_init_end;
> > > +
> > > + /* Tell SOCKET that we are alive */
> >
> > Drop?
> >
> > > + ret = sock_register(&lorawan_family_ops);
> > > + if (ret)
> > > + goto lrw_sock_init_err;
> > > +
> > > + dev_add_pack(&lorawan_packet_type);
> > > + ret = 0;
> > > + goto lrw_sock_init_end;
> > > +
> > > +lrw_sock_init_err:
> > > + proto_unregister(&lrw_dgram_prot);
> > > +
> > > +lrw_sock_init_end:
> > > + return 0;
> >
> > return ret;?
> >
> > > +}
> > > +
> > > +static void __exit
> > > +lrw_sock_exit(void)
> > > +{
> > > + dev_remove_pack(&lorawan_packet_type);
> > > + sock_unregister(PF_LORAWAN);
> > > + proto_unregister(&lrw_dgram_prot);
> > > + pr_info("module removed\n");
> > > +}
> > > +
> > > +module_init(lrw_sock_init);
> > > +module_exit(lrw_sock_exit);
> > > +
> > > +MODULE_AUTHOR("Jian-Hong Pan, <[email protected]>");
> >
> > Drop the comma?
> >
> > > +MODULE_DESCRIPTION("LoRaWAN socket kernel module");
> >
> > Aren't they all kernel modules? :)
> >
> > > +MODULE_LICENSE("Dual BSD/GPL");
> > > +MODULE_ALIAS_NETPROTO(PF_LORAWAN);
>
> Thanks for the reviewing. Preparing the fixing patches now. :)
>
> Jain-Hong Pan