Bluetooth: Mesh: Unknown message received by the node

[rhardik]

Describe the bug
I have setup for two devices Node-A (nRF52840 pca10056) and Node-B (nRF52 pca10040).
Node-B sends report continuously at interval of 2550 msec interval to Node-A.
Node-A receives a message with expected value but at the same time it gets one more message with garbage values.
Message length is 5 bytes so it's unsegmented message.

To Reproduce
Steps to reproduce the behavior:

1. Follow zephyr setup guide
2. $ git clone https://github.com/rajputh54/reproduce-zephyr-issues.git
3. $ cd reproduce-zephyr-issues
4. Copy node-a and node-b folders in zephyrproject or zephyr directory
5. Compile node-a and node-b for nRF52 boards and flash the same.
6. Now install nRF mesh app in Android phone.
7. Provison node A and B
8. configure Generic On Off Client (element section)
   • For Node-A, publish to 0xC000 and subscribe to 0xC001
   • For Node B publish to 0xC001 and subscribe to 0xC000
9. Now press button-1 on Node-A device. Node-B will starts sending dummy envi report to Node-A.
   you can see in uart terminal or RTT viewer

Expected behavior
Node-A should get only one call to function envi_report every 2550 msec and print logs
temperature:32 airp:18 humidity:84
but Node-A gets the envi_report function call twice. First time it receives correct value and second call it gives some garbage value for airp and humidity
temperature:32 airp:18 humidity:84 Expected values
temperature:32 airp:3602 humidity:260 Garbage value for airp and humidity.

Impact
annoyance

Screenshots or Console output
Node-B (sender) console output

Node-A (receiver) console output

code snippet
To get full code please have a look at node-a/src/main.c and node-b/src/main.c

////Node-A envi_report function
static void envi_report(struct bt_mesh_model *model,
                struct bt_mesh_msg_ctx *ctx,
                struct net_buf_simple *buf)
{
        s8_t temperature = net_buf_simple_pull_u8(buf);
        u16_t airp = net_buf_simple_pull_le16(buf);
        u16_t humidity = net_buf_simple_pull_le16(buf);

       printk("------------------------\n");
       printk("-->[0x%04x] ", ctx->addr);
       printk("temperature:%hhd airp:%hu humidity:%hu\n", temperature, airp, humidity);
       printk("-------------------------\n");
}

//////Node-B envi report function
static inline void snd_envi_report(void)
{
        int ret;
        u16_t airp = 18, humidity = 84;
        s8_t temperature = die_temperature();
        #if 0
        printk("[<--0x%04x]:timestamp = %u\n", cfg->node_addr, timestamp);
        #endif
        bt_mesh_model_msg_init(mod_pub->msg, OP_ENVI_REPORT);
        net_buf_simple_add_u8(mod_pub->msg, temperature);
        net_buf_simple_add_le16(mod_pub->msg, airp);
        net_buf_simple_add_le16(mod_pub->msg, humidity);
        ret = bt_mesh_model_publish(mod_cli);
        if (ret) {
                printk("\n%s:bt_mesh_model_publish failed, ERR = %d\n", __func__, ret);
                return;
        }
        printk("------------------------\n");
        printk("temperature:%hhd airp:%hu humidity:%hu\n", temperature, airp, humidity);
        printk("-------------------------\n");
}
K_THREAD_DEFINE(envi_tid, 2048, envi_thread, NULL, NULL, NULL, 7, 0, K_NO_WAIT);
static void envi_thread(void)
{
        while (1) {

                if (envi_report_flg) {
                        k_sleep(K_MSEC(2500));
                        snd_envi_report();
                } else {
                        k_thread_suspend(envi_tid);
                }
        }
}

Environment

• OS: Linux
• Toolchain Zephyr SDK
• Commit: b74cad5 (one can try with latest commit)

[LingaoM]

@rajputh54 Can you send different data for every publish message ?
I'm notice that number 18 eq 0b0001 0010 and number 3602 eq 0b1110 0001 0010

[LingaoM]

While I'm found some buffer issure https://github.com/rajputh54/reproduce-zephyr-issues/blob/eb2f049467e778d20885b20561a9d6b48753b163/node-b/src/main.c#L118-L125

As you say above, every publish will occupy five octers (exclude opcode), but you allocated only four octers.

so, i'm guess that opcode OP_ENVI_REPORT --> 2 octers, and temperature --> 1 octer, and only one octer available for var airp (see #24194 (comment)), other value will be undefined.

Next: you should repair pub buffer to 2 + 1 + 2 + 2 octers.

[rhardik]

Thanks a lot for your help !!!
As you suggested, It's working fine after adding enough pub buffer,