I’m trying to use RPC calls to perform a NFS mount on a Rocky 8 distro, running in VirtualBox on a Windows host.

I have the following set in my /etc/exports:

/nfstest *(rw,sync,no_root_squash,no_subtree_check)

And I verified I can mount when using mount command:

sudo mount -t nfs 10.0.2.15:/nfstest /mnt/nfs

However, I need to do this programmatically using direct RPC calls.

Here is my code sample:

struct sockaddr_in  server_addr;
struct timeval      timeout;

int mountprog;
int mountvers;
int nfsprog;
int nfsvers;
int mountport = 0;

timeout.tv_sec  = 30;  /* set default timeout to 30.00 seconds */
timeout.tv_usec =  0;

/* Convert NAS IP to binary */
int rc = inet_pton(AF_INET, "10.0.2.15", &server_addr.sin_addr);

server_addr.sin_family = AF_INET;
server_addr.sin_port = 0;

mountprog = MOUNTPROG;
mountvers = MOUNTVERS3;

nfsprog = NFS_PROGRAM;
nfsvers = NFS_V3;

/* Get the NFS remote file handler */
CLIENT *clnt;           /* pointer to client handle */
int sock = RPC_ANYSOCK;
clnt = clntudp_create(&server_addr, mountprog, mountvers,
                             timeout, &sock);
if (clnt != NULL)
{
    clnt->cl_auth = authunix_create_default();

    printf("Successfully created client with clntudp_create()n");

    struct fhstatus mount_res;
    /* directory */
    char *rootpath = "/nfstest";
    dirpath path = rootpath;

    enum clnt_stat retval;

    retval = clnt_call(clnt, MOUNTPROC_MNT, (xdrproc_t)xdr_dirpath, &path, (xdrproc_t)xdr_fhstatus, &mount_res, timeout);

    if (retval != RPC_SUCCESS)
    {
        clnt_perror(clnt, "Mount request failed");
        return -1;
    }

    if (mount_res.fhs_status == 0)
    {
        printf("Mount successful, file  handled obtained: %s n", mount_res.fhstatus_u.fhs_fhandle);
    }
    else
    {
        printf("Mount failed, error code: %dn", mount_res.fhs_status);        
    }
}

clntudp_create() returns a valid client.

clnt_call() returns RPC_SUCCESS.

However, mount_res.fhs_status is set to 13 (EACESS).

Things I’ve tried:

1. Verified firewall is not running

2. Verified exportfs -v returns valid data:

   /nfstest (sync,wdelay,hide,no_subtree_check,sec=sys,rw,secure,no_root_squash,no_all_squash)

3. Ran sudo setenforce 0 to set SELinux to permissive mode

Anything I might be missing here?

The one thing that stands out odd to me is the “hide” flag set when I run exportfs -v. I do not see this “hide” flag in my /etc/exports, so not sure where it’s getting that from, or if that’s the reason for my issues.

I did try adding “nohide” to my /etc/exports, but I still get the errno 13.

Thank you.

EDIT: This is the result of rpcinfo | grep nfs

 100003    3    tcp       0.0.0.0.8.1            nfs        superuser
100003    4    tcp       0.0.0.0.8.1            nfs        superuser
100227    3    tcp       0.0.0.0.8.1            nfs_acl    superuser
100003    3    udp       0.0.0.0.8.1            nfs        superuser
100227    3    udp       0.0.0.0.8.1            nfs_acl    superuser
100003    3    tcp6      ::.8.1                 nfs        superuser
100003    4    tcp6      ::.8.1                 nfs        superuser
100227    3    tcp6      ::.8.1                 nfs_acl    superuser
100003    3    udp6      ::.8.1                 nfs        superuser
100227    3    udp6      ::.8.1                 nfs_acl    superuser

EDIT 2: I was able to get it to work if I ran my C app as “sudo”… so now just have to figure out how to allow nfs mount without sudo.