[RFC net-next 04/15] net: Add lora subsystem

Andreas Färber
2018-07-01T11:07:53Z

Implement or stub out PF_LORA net_proto_family and datagram proto_ops.

Signed-off-by: Andreas Färber <afaerber@suse.de>
---
include/linux/lora/skb.h | 29 +++++
net/Kconfig | 1 +
net/Makefile | 1 +
net/lora/Kconfig | 9 ++
net/lora/Makefile | 8 ++
net/lora/af_lora.c | 152 ++++++++++++++++++++++++
net/lora/af_lora.h | 13 +++
net/lora/dgram.c | 293 +++++++++++++++++++++++++++++++++++++++++++++++
8 files changed, 506 insertions(+)
create mode 100644 include/linux/lora/skb.h
create mode 100644 net/lora/Kconfig
create mode 100644 net/lora/Makefile
create mode 100644 net/lora/af_lora.c
create mode 100644 net/lora/af_lora.h
create mode 100644 net/lora/dgram.c

diff --git a/include/linux/lora/skb.h b/include/linux/lora/skb.h
new file mode 100644
index 000000000000..8806741464d0
--- /dev/null
+++ b/include/linux/lora/skb.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * linux/lora/skb.h
+ *
+ * Copyright (c) 2017-2018 Andreas Färber
+ */
+#ifndef _LORA_SKB_H
+#define _LORA_SKB_H
+
+#include <linux/types.h>
+#include <linux/skbuff.h>
+
+struct lora_skb_priv {
+ int ifindex;
+};
+
+static inline struct lora_skb_priv *lora_skb_prv(struct sk_buff *skb)
+{
+ return (struct lora_skb_priv *)(skb->head);
+}
+
+static inline void lora_skb_reserve(struct sk_buff *skb)
+{
+ skb_reserve(skb, sizeof(struct lora_skb_priv));
+}
+
+struct sk_buff *alloc_lora_skb(struct net_device *dev, u8 **data);
+
+#endif /* _LORA_SKB_H */
diff --git a/net/Kconfig b/net/Kconfig
index f738a6f27665..d294ecc50a3b 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -223,6 +223,7 @@ source "net/phonet/Kconfig"
source "net/6lowpan/Kconfig"
source "net/ieee802154/Kconfig"
source "net/mac802154/Kconfig"
+source "net/lora/Kconfig"
source "net/sched/Kconfig"
source "net/dcb/Kconfig"
source "net/dns_resolver/Kconfig"
diff --git a/net/Makefile b/net/Makefile
index bdaf53925acd..e80b84313851 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -62,6 +62,7 @@ endif
obj-$(CONFIG_6LOWPAN) += 6lowpan/
obj-$(CONFIG_IEEE802154) += ieee802154/
obj-$(CONFIG_MAC802154) += mac802154/
+obj-$(CONFIG_LORA) += lora/

ifeq ($(CONFIG_NET),y)
obj-$(CONFIG_SYSCTL) += sysctl_net.o
diff --git a/net/lora/Kconfig b/net/lora/Kconfig
new file mode 100644
index 000000000000..44972ea8769f
--- /dev/null
+++ b/net/lora/Kconfig
@@ -0,0 +1,9 @@
+#
+# LoRa
+#
+
+menuconfig LORA
+ depends on NET
+ tristate "LoRa subsystem support"
+ help
+ LoRa ...
diff --git a/net/lora/Makefile b/net/lora/Makefile
new file mode 100644
index 000000000000..b58675ef7846
--- /dev/null
+++ b/net/lora/Makefile
@@ -0,0 +1,8 @@
+#
+# LoRa
+#
+
+obj-$(CONFIG_LORA) += lora.o
+
+lora-y := af_lora.o
+lora-y += dgram.o
diff --git a/net/lora/af_lora.c b/net/lora/af_lora.c
new file mode 100644
index 000000000000..662482fe4c9b
--- /dev/null
+++ b/net/lora/af_lora.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2017-2018 Andreas Färber
+ */
+
+#include <linux/if_arp.h>
+#include <linux/lora.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/socket.h>
+#include <net/sock.h>
+
+#include "af_lora.h"
+
+int lora_send(struct sk_buff *skb)
+{
+ int ret;
+
+ pr_debug("lora: %s\n", __func__);
+
+ skb->protocol = htons(ETH_P_LORA);
+
+ if (unlikely(skb->len > skb->dev->mtu)) {
+ ret = -EMSGSIZE;
+ goto err_skb;
+ }
+
+ if (unlikely(skb->dev->type != ARPHRD_LORA)) {
+ ret = -EPERM;
+ goto err_skb;
+ }
+
+ if (unlikely(!(skb->dev->flags & IFF_UP))) {
+ ret = -ENETDOWN;
+ goto err_skb;
+ }
+
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+ skb_reset_mac_header(skb);
+ skb_reset_network_header(skb);
+ skb_reset_transport_header(skb);
+
+ if (false) {
+ skb->pkt_type = PACKET_LOOPBACK;
+ } else
+ skb->pkt_type = PACKET_HOST;
+
+ ret = dev_queue_xmit(skb);
+ if (ret > 0)
+ ret = net_xmit_errno(ret);
+ if (ret)
+ return ret;
+
+ return 0;
+
+err_skb:
+ kfree_skb(skb);
+ return ret;
+}
+EXPORT_SYMBOL(lora_send);
+
+static void lora_sock_destruct(struct sock *sk)
+{
+ pr_debug("lora: %s\n", __func__);
+
+ skb_queue_purge(&sk->sk_receive_queue);
+}
+
+static int lora_create(struct net *net, struct socket *sock, int protocol,
+ int kern)
+{
+ struct sock *sk;
+
+ pr_debug("lora: %s\n", __func__);
+
+ sock->state = SS_UNCONNECTED;
+
+ if (protocol < 0 || protocol > LORA_NPROTO)
+ return -EINVAL;
+
+ /*if (!net_eq(net, &init_net))
+ return -EAFNOSUPPORT;*/
+
+ if (sock->type != SOCK_DGRAM)
+ return -ESOCKTNOSUPPORT;
+
+ sock->ops = &dgram_proto_ops;
+
+ sk = sk_alloc(net, PF_LORA, GFP_KERNEL, &dgram_proto, kern);
+ if (!sk)
+ return -ENOMEM;
+
+ sock_init_data(sock, sk);
+ sk->sk_family = PF_LORA;
+ sk->sk_destruct = lora_sock_destruct;
+
+ if (sk->sk_prot->init) {
+ int ret = sk->sk_prot->init(sk);
+ if (ret) {
+ sock_orphan(sk);
+ sock_put(sk);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static const struct net_proto_family lora_net_proto_family = {
+ .family = PF_LORA,
+ .owner = THIS_MODULE,
+ .create = lora_create,
+};
+
+static __init int lora_init(void)
+{
+ int ret;
+
+ pr_debug("lora: init\n");
+
+ ret = proto_register(&dgram_proto, 1);
+ if (ret)
+ goto err_dgram;
+
+ ret = sock_register(&lora_net_proto_family);
+ if (ret)
+ goto err_sock;
+
+ return 0;
+
+err_sock:
+ proto_unregister(&dgram_proto);
+err_dgram:
+ return ret;
+}
+
+static __exit void lora_exit(void)
+{
+ pr_debug("lora: exit\n");
+
+ sock_unregister(PF_LORA);
+ proto_unregister(&dgram_proto);
+}
+
+module_init(lora_init);
+module_exit(lora_exit);
+
+MODULE_DESCRIPTION("LoRa PF_LORA core");
+MODULE_AUTHOR("Andreas Färber <afaerber@suse.de>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NETPROTO(PF_LORA);
diff --git a/net/lora/af_lora.h b/net/lora/af_lora.h
new file mode 100644
index 000000000000..47dd863531b2
--- /dev/null
+++ b/net/lora/af_lora.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2017-2018 Andreas Färber
+ */
+#ifndef AF_LORA_H
+#define AF_LORA_H
+
+extern struct proto dgram_proto;
+extern const struct proto_ops dgram_proto_ops;
+
+int lora_send(struct sk_buff *skb);
+
+#endif /* AF_LORA_H */
diff --git a/net/lora/dgram.c b/net/lora/dgram.c
new file mode 100644
index 000000000000..4d931fd3778a
--- /dev/null
+++ b/net/lora/dgram.c
@@ -0,0 +1,293 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2017-2018 Andreas Färber
+ */
+
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/lora.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/socket.h>
+#include <linux/version.h>
+#include <linux/lora/skb.h>
+#include <net/sock.h>
+
+#include "af_lora.h"
+
+struct dgram_sock {
+ struct sock sk;
+ int ifindex;
+ bool bound;
+ struct notifier_block notifier;
+};
+
+static inline struct dgram_sock *dgram_sk(const struct sock *sk)
+{
+ return (struct dgram_sock *)sk;
+}
+
+static int dgram_bind(struct socket *sock, struct sockaddr *uaddr, int len)
+{
+ struct sockaddr_lora *addr = (struct sockaddr_lora *)uaddr;
+ struct sock *sk = sock->sk;
+ struct dgram_sock *dgram = dgram_sk(sk);
+ int ifindex;
+ int ret = 0;
+ bool notify_enetdown = false;
+
+ pr_debug("lora: %s\n", __func__);
+
+ if (len < sizeof(*addr))
+ return -EINVAL;
+
+ lock_sock(sk);
+
+ if (dgram->bound && addr->lora_ifindex == dgram->ifindex)
+ goto out;
+
+ if (addr->lora_ifindex) {
+ struct net_device *netdev;
+
+ netdev = dev_get_by_index(sock_net(sk), addr->lora_ifindex);
+ if (!netdev) {
+ ret = -ENODEV;
+ goto out;
+ }
+ if (netdev->type != ARPHRD_LORA) {
+ dev_put(netdev);
+ ret = -ENODEV;
+ goto out;
+ }
+ if (!(netdev->flags & IFF_UP))
+ notify_enetdown = true;
+
+ ifindex = netdev->ifindex;
+
+ dev_put(netdev);
+ } else
+ ifindex = 0;
+
+ dgram->ifindex = ifindex;
+ dgram->bound = true;
+
+out:
+ release_sock(sk);
+
+ if (notify_enetdown) {
+ sk->sk_err = ENETDOWN;
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_error_report(sk);
+ }
+
+ return ret;
+}
+
+static int dgram_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
+{
+ struct sock *sk = sock->sk;
+ struct dgram_sock *dgram = dgram_sk(sk);
+ struct sk_buff *skb;
+ struct net_device *netdev;
+ int ifindex;
+ int ret;
+
+ pr_debug("lora: %s\n", __func__);
+
+ if (msg->msg_name) {
+ DECLARE_SOCKADDR(struct sockaddr_lora *, addr, msg->msg_name);
+
+ if (msg->msg_namelen < sizeof(*addr))
+ return -EINVAL;
+
+ if (addr->lora_family != AF_LORA)
+ return -EINVAL;
+
+ ifindex = addr->lora_ifindex;
+ } else
+ ifindex = dgram->ifindex;
+
+ netdev = dev_get_by_index(sock_net(sk), ifindex);
+ if (!netdev)
+ return -ENXIO;
+
+ skb = sock_alloc_send_skb(sk, size + sizeof(struct lora_skb_priv),
+ msg->msg_flags & MSG_DONTWAIT, &ret);
+ if (!skb)
+ goto err_sock_alloc_send_skb;
+
+ lora_skb_reserve(skb);
+ lora_skb_prv(skb)->ifindex = netdev->ifindex;
+
+ ret = memcpy_from_msg(skb_put(skb, size), msg, size);
+ if (ret < 0)
+ goto err_memcpy_from_msg;
+
+ sock_tx_timestamp(sk,
+ sk->sk_tsflags,
+ &skb_shinfo(skb)->tx_flags);
+
+ skb->dev = netdev;
+ skb->sk = sk;
+ skb->priority = sk->sk_priority;
+
+ ret = lora_send(skb);
+
+ dev_put(netdev);
+
+ if (ret)
+ return ret;
+
+ return size;
+
+err_memcpy_from_msg:
+ kfree_skb(skb);
+err_sock_alloc_send_skb:
+ dev_put(netdev);
+ return ret;
+}
+
+static int dgram_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+ pr_debug("lora: %s\n", __func__);
+
+ return -ENOIOCTLCMD;
+}
+
+static int dgram_getname(struct socket *sock, struct sockaddr *uaddr,
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 13, 0)
+ int *len,
+#endif
+ int peer)
+{
+ struct sockaddr_lora *addr = (struct sockaddr_lora *)uaddr;
+ struct sock *sk = sock->sk;
+ struct dgram_sock *dgram = dgram_sk(sk);
+
+ pr_debug("lora: %s\n", __func__);
+
+ if (peer)
+ return -EOPNOTSUPP;
+
+ memset(addr, 0, sizeof(*addr));
+ addr->lora_family = AF_LORA;
+ addr->lora_ifindex = dgram->ifindex;
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 13, 0)
+ return sizeof(*addr);
+#else
+ *len = sizeof(*addr);
+ return 0;
+#endif
+}
+
+static int dgram_release(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct dgram_sock *dgram;
+
+ pr_debug("lora: %s\n", __func__);
+
+ if (!sk)
+ return 0;
+
+ dgram = dgram_sk(sk);
+
+ unregister_netdevice_notifier(&dgram->notifier);
+
+ lock_sock(sk);
+
+ dgram->ifindex = 0;
+ dgram->bound = false;
+
+ sock_orphan(sk);
+ sock->sk = NULL;
+
+ release_sock(sk);
+ sock_put(sk);
+
+ return 0;
+}
+
+const struct proto_ops dgram_proto_ops = {
+ .family = PF_LORA,
+ .release = dgram_release,
+ .bind = dgram_bind,
+ .connect = sock_no_connect,
+ .socketpair = sock_no_socketpair,
+ .accept = sock_no_accept,
+ .getname = dgram_getname,
+ .poll = datagram_poll,
+ .ioctl = dgram_ioctl,
+ .listen = sock_no_listen,
+ .shutdown = sock_no_shutdown,
+ .setsockopt = sock_no_setsockopt,
+ .getsockopt = sock_no_getsockopt,
+ .sendmsg = dgram_sendmsg,
+ .recvmsg = sock_no_recvmsg,
+ .mmap = sock_no_mmap,
+ .sendpage = sock_no_sendpage,
+};
+
+static int dgram_notifier(struct notifier_block *nb, unsigned long msg, void *ptr)
+{
+ struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
+ struct dgram_sock *dgram = container_of(nb, struct dgram_sock, notifier);
+ struct sock *sk = &dgram->sk;
+
+ pr_debug("lora: %s\n", __func__);
+
+ if (!net_eq(dev_net(netdev), sock_net(sk)))
+ return NOTIFY_DONE;
+
+ if (netdev->type != ARPHRD_LORA)
+ return NOTIFY_DONE;
+
+ if (dgram->ifindex != netdev->ifindex)
+ return NOTIFY_DONE;
+
+ switch (msg) {
+ case NETDEV_UNREGISTER:
+ lock_sock(sk);
+
+ dgram->ifindex = 0;
+ dgram->bound = false;
+
+ release_sock(sk);
+
+ sk->sk_err = ENODEV;
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_error_report(sk);
+ break;
+
+ case NETDEV_DOWN:
+ sk->sk_err = ENETDOWN;
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_error_report(sk);
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static int dgram_init(struct sock *sk)
+{
+ struct dgram_sock *dgram = dgram_sk(sk);
+
+ pr_debug("lora: %s\n", __func__);
+
+ dgram->bound = false;
+ dgram->ifindex = 0;
+
+ dgram->notifier.notifier_call = dgram_notifier;
+ register_netdevice_notifier(&dgram->notifier);
+
+ return 0;
+}
+
+struct proto dgram_proto __read_mostly = {
+ .name = "LoRa",
+ .owner = THIS_MODULE,
+ .obj_size = sizeof(struct dgram_sock),
+ .init = dgram_init,
+};
--
2.16.4

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