Zephyr RTOS: Getting bind error with respect to sockets

[sanjatpanigrahi]

Hi,
I am trying to run a simple socket program, the below are my environment:

i. Intel Agilex 7 FPGA board
ii. Zephyr RTOS

I am able to successfully create a socket but get the below error is generated during the binding process:
(I am printing the error number and the error converted through stderrr())

ErrNo= -1, Error = Not owner

Can anyone please tell me why the binding is throwing an error "Not owner"?

Below are my socket configuration parameters in the pro.conf file:

Sockets

CONFIG_NET_SOCKETS=y
CONFIG_NET_SOCKETS_POSIX_NAMES=y
CONFIG_NET_SOCKETS_POLL_MAX=4
CONFIG_NET_MGMT=y
CONFIG_NET_MGMT_EVENT=y

Networking configuration parameters:
CONFIG_NETWORKING=y
CONFIG_NET_IPV4=y
CONFIG_NET_IPV6=n
CONFIG_NET_TCP=y
CONFIG_NET_UDP=y
CONFIG_NET_ARP=y
CONFIG_SLIP_STATISTICS=n

Best Regards,
Sanjat

[github-actions[bot]]

Hi @sanjatpanigrahi! We appreciate you submitting your first issue for our open-source project. 🌟

Even though I'm a bot, I can assure you that the whole community is genuinely grateful for your time and effort. 🤖💙

[rlubos]

@sanjatpanigrahi I'm not sure if you're checking the error code correctly, -1 suggests that you're only providing the return value from bind() (-1 is returned in case of any error). For the actual error code, you need to check the errno variable after bind() function returns -1.

Also, it'd be good to see some sample code on how are you actually using bind().

[sanjatpanigrahi]

@rlubos I do check the actual error returned from bind(). Below is the code snippet:

#define | EPERM   1
Not owner.

int sockfd, connfd;
unsigned int len;
struct sockaddr_in servaddr, cli;
// socket create and verification
sockfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)

if (sockfd == -1)
die("socket creation failed...");
else
printk("Socket successfully created..\n");

// assign IP, PORT
servaddr.sin_family = AF_INET; // IPv4
servaddr.sin_addr.s_addr = htonl(INADDR_ANY); /* host-to-network endian /
servaddr.sin_port = htons(PORT); / for listening */

bind_status = bind(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
if(bind_status < 0))
printk("Error number = %d, Error status = %s \n", bind_status, strerror(-bind_status));

Few more information:

I am running my application program compiled with Zephyr RTOS below is my command:

cmake -GNinja -DBOARD=intel_socfpga_agilex_socdk ../../samples/server
ninja

I flash the Zephyr RTOS on an Agilex 7 Intel FPGA having an ARM Cortex A53 processor on which first the u-boot runs. Then using ARMDS IDE I flash the "zephyr.elf" which got generated with the above command.

If instead of using Zephyr RTOS, I use Linux on the FPGA and run my program it works. This means, the FPGA board is not broke and the networking works.

I am facing bind error only when I use the Zephyr RTOS to run my application.

[rlubos]

printk("Error number = %d, Error status = %s \n", bind_status, strerror(-bind_status));

Just as I wrote above, bind_status should not be interpreted wiht strerror() as it does not carry the error code. Socket functions in case of error will always return -1, for the actual error code you should check the errno variable (so strerror(errno)) etc.).

As for the board, I'm not familiar with that particular one, but looking at the documentation it seems that the board does not support networking in any form in Zephyr:
https://docs.zephyrproject.org/latest/boards/arm64/intel_socfpga_agilex_socdk/doc/index.html#supported-features
So this is likely the culprit of the bind() failing - if there's no network inerface in the system to work with, bind() will fail.

[sanjatpanigrahi]

phooo... how did I miss it!!!!
Thanks a lot for sharing the webpage.

Does the below:
bind_result = -1, bind_error_number = 125 Error = Address not available

does the above means that the Zephyr RTOS doesn't enables the networking stuffs?
If so, then shouldn't the socket() should also return error?

[rlubos]

does the above means that the Zephyr RTOS doesn't enables the networking stuffs?

Since you don't request any particular address to bind to (INADDR_ANY), this means there isn't any netowrk interface in the system. I. e. the board you use does not define any network device.

If so, then shouldn't the socket() should also return error?

During socket creation, it is not verified whether there are any network interfaces in the system (because at that point socket is not bound to any). But any operation that would require to bind it with particular interface (bind(), send() etc.) would fail.