[PATCH lora-next 09/11] net: lora: introduce lora socket addressing for metadata

[Ben Whitten]

Information such as spreading factor, coding rate and power are on a per
transmission basis so we can encode this information in the lora socket
address.
In future we may have a different format for receive with additional
fields which get populated.

Signed-off-by: Ben Whitten <ben.whit...@lairdtech.com>
---
 include/linux/lora/skb.h  |  9 ++++++++
 include/uapi/linux/lora.h | 14 ++++++++++++
 net/lora/dgram.c          | 45 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 68 insertions(+)

diff --git a/include/linux/lora/skb.h b/include/linux/lora/skb.h
index 8806741464d0..6abeb39b8b7f 100644
--- a/include/linux/lora/skb.h
+++ b/include/linux/lora/skb.h
@@ -12,6 +12,15 @@
 
 struct lora_skb_priv {
        int ifindex;
+
+       u64 freq;
+       u8 sf;
+       u8 cr;
+       u16 bw;
+
+       u8 sync;
+
+       s8 power;
 };
 
 static inline struct lora_skb_priv *lora_skb_prv(struct sk_buff *skb)
diff --git a/include/uapi/linux/lora.h b/include/uapi/linux/lora.h
index 4ff00b9c3c20..4c458ee3ed9a 100644
--- a/include/uapi/linux/lora.h
+++ b/include/uapi/linux/lora.h
@@ -10,6 +10,18 @@
 #include <linux/types.h>
 #include <linux/socket.h>
 
+/* TX addressing definition */
+struct tx_addr {
+       __u64 freq;
+       __u8 sf;
+       __u8 cr;
+       __u16 bw;
+
+       __u8 sync;
+
+       __s8 power;
+};
+
 /* particular protocols of the protocol family PF_LORA */
 #define LORA_PROTO_DATAGRAM    0
 #define LORA_NPROTO            1
@@ -17,7 +29,9 @@
 struct sockaddr_lora {
        __kernel_sa_family_t lora_family;
        int lora_ifindex;
+       __u8 lora_protocol;
        union {
+               struct tx_addr  tx;
        } lora_addr;
 };
 
diff --git a/net/lora/dgram.c b/net/lora/dgram.c
index 4d931fd3778a..1556ad0f8835 100644
--- a/net/lora/dgram.c
+++ b/net/lora/dgram.c
@@ -20,6 +20,15 @@ struct dgram_sock {
        int ifindex;
        bool bound;
        struct notifier_block notifier;
+
+       u64 freq;
+       u8 sf;
+       u8 cr;
+       u16 bw;
+
+       u8 sync;
+
+       s8 power;
 };
 
 static inline struct dgram_sock *dgram_sk(const struct sock *sk)
@@ -69,6 +78,12 @@ static int dgram_bind(struct socket *sock, struct sockaddr 
*uaddr, int len)
                ifindex = 0;
 
        dgram->ifindex = ifindex;
+       dgram->freq = addr->lora_addr.tx.freq;
+       dgram->sf = addr->lora_addr.tx.sf;
+       dgram->cr = addr->lora_addr.tx.cr;
+       dgram->bw = addr->lora_addr.tx.bw;
+       dgram->sync = addr->lora_addr.tx.sync;
+       dgram->power = addr->lora_addr.tx.power;
        dgram->bound = true;
 
 out:
@@ -118,6 +133,12 @@ static int dgram_sendmsg(struct socket *sock, struct 
msghdr *msg, size_t size)
 
        lora_skb_reserve(skb);
        lora_skb_prv(skb)->ifindex = netdev->ifindex;
+       lora_skb_prv(skb)->freq = dgram->freq;
+       lora_skb_prv(skb)->sf = dgram->sf;
+       lora_skb_prv(skb)->cr = dgram->cr;
+       lora_skb_prv(skb)->bw = dgram->bw;
+       lora_skb_prv(skb)->sync = dgram->sync;
+       lora_skb_prv(skb)->power = dgram->power;
 
        ret = memcpy_from_msg(skb_put(skb, size), msg, size);
        if (ret < 0)
@@ -172,6 +193,12 @@ static int dgram_getname(struct socket *sock, struct 
sockaddr *uaddr,
        memset(addr, 0, sizeof(*addr));
        addr->lora_family = AF_LORA;
        addr->lora_ifindex = dgram->ifindex;
+       addr->lora_addr.tx.freq = dgram->freq;
+       addr->lora_addr.tx.sf = dgram->sf;
+       addr->lora_addr.tx.cr = dgram->cr;
+       addr->lora_addr.tx.bw = dgram->bw;
+       addr->lora_addr.tx.sync = dgram->sync;
+       addr->lora_addr.tx.power = dgram->power;
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 13, 0)
        return sizeof(*addr);
@@ -198,6 +225,12 @@ static int dgram_release(struct socket *sock)
        lock_sock(sk);
 
        dgram->ifindex = 0;
+       dgram->freq = 0;
+       dgram->sf = 0;
+       dgram->cr = 0;
+       dgram->bw = 0;
+       dgram->sync = 0;
+       dgram->power = 0;
        dgram->bound = false;
 
        sock_orphan(sk);
@@ -251,6 +284,12 @@ static int dgram_notifier(struct notifier_block *nb, 
unsigned long msg, void *pt
                lock_sock(sk);
 
                dgram->ifindex = 0;
+               dgram->freq = 0;
+               dgram->sf = 0;
+               dgram->cr = 0;
+               dgram->bw = 0;
+               dgram->sync = 0;
+               dgram->power = 0;
                dgram->bound = false;
 
                release_sock(sk);
@@ -277,6 +316,12 @@ static int dgram_init(struct sock *sk)
        pr_debug("lora: %s\n", __func__);
 
        dgram->bound = false;
+       dgram->freq = 0;
+       dgram->sf = 0;
+       dgram->cr = 0;
+       dgram->bw = 0;
+       dgram->sync = 0;
+       dgram->power = 0;
        dgram->ifindex = 0;
 
        dgram->notifier.notifier_call = dgram_notifier;
-- 
2.17.1