/*
 * linux/fs/nfsd/nfsctl.c
 *
 * Syscall interface to knfsd.
 *
 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/module.h>

#include <linux/linkage.h>
#include <linux/time.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <linux/net.h>
#include <linux/in.h>
#include <linux/syscalls.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/ctype.h>

#include <linux/nfs.h>
#include <linux/nfsd_idmap.h>
#include <linux/lockd/bind.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/cache.h>
#include <linux/nfsd/xdr.h>
#include <linux/nfsd/syscall.h>

#include <asm/uaccess.h>

/*
 *      We have a single directory with 9 nodes in it.
 */
enum {
        NFSD_Root = 1,
        NFSD_Svc,
        NFSD_Add,
        NFSD_Del,
        NFSD_Export,
        NFSD_Unexport,
        NFSD_Getfd,
        NFSD_Getfs,
        NFSD_List,
        NFSD_Fh,
        NFSD_Threads,
        NFSD_Pool_Threads,
        NFSD_Versions,
        NFSD_Ports,
        NFSD_MaxBlkSize,
        /*
         * The below MUST come last.  Otherwise we leave a hole in nfsd_files[]
         * with !CONFIG_NFSD_V4 and simple_fill_super() goes oops
         */
#ifdef CONFIG_NFSD_V4
        NFSD_Leasetime,
        NFSD_RecoveryDir,
#endif
};

/*
 * write() for these nodes.
 */
static ssize_t write_svc(struct file *file, char *buf, size_t size);
static ssize_t write_add(struct file *file, char *buf, size_t size);
static ssize_t write_del(struct file *file, char *buf, size_t size);
static ssize_t write_export(struct file *file, char *buf, size_t size);
static ssize_t write_unexport(struct file *file, char *buf, size_t size);
static ssize_t write_getfd(struct file *file, char *buf, size_t size);
static ssize_t write_getfs(struct file *file, char *buf, size_t size);
static ssize_t write_filehandle(struct file *file, char *buf, size_t size);
static ssize_t write_threads(struct file *file, char *buf, size_t size);
static ssize_t write_pool_threads(struct file *file, char *buf, size_t size);
static ssize_t write_versions(struct file *file, char *buf, size_t size);
static ssize_t write_ports(struct file *file, char *buf, size_t size);
static ssize_t write_maxblksize(struct file *file, char *buf, size_t size);
#ifdef CONFIG_NFSD_V4
static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
static ssize_t write_recoverydir(struct file *file, char *buf, size_t size);
#endif

static ssize_t (*write_op[])(struct file *, char *, size_t) = {
        [NFSD_Svc] = write_svc,
        [NFSD_Add] = write_add,
        [NFSD_Del] = write_del,
        [NFSD_Export] = write_export,
        [NFSD_Unexport] = write_unexport,
        [NFSD_Getfd] = write_getfd,
        [NFSD_Getfs] = write_getfs,
        [NFSD_Fh] = write_filehandle,
        [NFSD_Threads] = write_threads,
        [NFSD_Pool_Threads] = write_pool_threads,
        [NFSD_Versions] = write_versions,
        [NFSD_Ports] = write_ports,
        [NFSD_MaxBlkSize] = write_maxblksize,
#ifdef CONFIG_NFSD_V4
        [NFSD_Leasetime] = write_leasetime,
        [NFSD_RecoveryDir] = write_recoverydir,
#endif
};

static ssize_t nfsctl_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
{
        ino_t ino =  file->f_path.dentry->d_inode->i_ino;
        char *data;
        ssize_t rv;

        if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
                return -EINVAL;

        data = simple_transaction_get(file, buf, size);
        if (IS_ERR(data))
                return PTR_ERR(data);

        rv =  write_op[ino](file, data, size);
        if (rv >= 0) {
                simple_transaction_set(file, rv);
                rv = size;
        }
        return rv;
}

static ssize_t nfsctl_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
{
        if (! file->private_data) {
                /* An attempt to read a transaction file without writing
                 * causes a 0-byte write so that the file can return
                 * state information
                 */
                ssize_t rv = nfsctl_transaction_write(file, buf, 0, pos);
                if (rv < 0)
                        return rv;
        }
        return simple_transaction_read(file, buf, size, pos);
}

static const struct file_operations transaction_ops = {
        .write          = nfsctl_transaction_write,
        .read           = nfsctl_transaction_read,
        .release        = simple_transaction_release,
};

extern struct seq_operations nfs_exports_op;
static int exports_open(struct inode *inode, struct file *file)
{
        return seq_open(file, &nfs_exports_op);
}

static const struct file_operations exports_operations = {
        .open           = exports_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = seq_release,
};

/*----------------------------------------------------------------------------*/
/*
 * payload - write methods
 * If the method has a response, the response should be put in buf,
 * and the length returned.  Otherwise return 0 or and -error.
 */

static ssize_t write_svc(struct file *file, char *buf, size_t size)
{
        struct nfsctl_svc *data;
        if (size < sizeof(*data))
                return -EINVAL;
        data = (struct nfsctl_svc*) buf;
        return nfsd_svc(data->svc_port, data->svc_nthreads);
}

static ssize_t write_add(struct file *file, char *buf, size_t size)
{
        struct nfsctl_client *data;
        if (size < sizeof(*data))
                return -EINVAL;
        data = (struct nfsctl_client *)buf;
        return exp_addclient(data);
}

static ssize_t write_del(struct file *file, char *buf, size_t size)
{
        struct nfsctl_client *data;
        if (size < sizeof(*data))
                return -EINVAL;
        data = (struct nfsctl_client *)buf;
        return exp_delclient(data);
}

static ssize_t write_export(struct file *file, char *buf, size_t size)
{
        struct nfsctl_export *data;
        if (size < sizeof(*data))
                return -EINVAL;
        data = (struct nfsctl_export*)buf;
        return exp_export(data);
}

static ssize_t write_unexport(struct file *file, char *buf, size_t size)
{
        struct nfsctl_export *data;

        if (size < sizeof(*data))
                return -EINVAL;
        data = (struct nfsctl_export*)buf;
        return exp_unexport(data);
}

static ssize_t write_getfs(struct file *file, char *buf, size_t size)
{
        struct nfsctl_fsparm *data;
        struct sockaddr_in *sin;
        struct auth_domain *clp;
        int err = 0;
        struct knfsd_fh *res;

        if (size < sizeof(*data))
                return -EINVAL;
        data = (struct nfsctl_fsparm*)buf;
        err = -EPROTONOSUPPORT;
        if (data->gd_addr.sa_family != AF_INET)
                goto out;
        sin = (struct sockaddr_in *)&data->gd_addr;
        if (data->gd_maxlen > NFS3_FHSIZE)
                data->gd_maxlen = NFS3_FHSIZE;

        res = (struct knfsd_fh*)buf;

        exp_readlock();
        if (!(clp = auth_unix_lookup(sin->sin_addr)))
                err = -EPERM;
        else {
                err = exp_rootfh(clp, data->gd_path, res, data->gd_maxlen);
                auth_domain_put(clp);
        }
        exp_readunlock();
        if (err == 0)
                err = res->fh_size + offsetof(struct knfsd_fh, fh_base);
 out:
        return err;
}

static ssize_t write_getfd(struct file *file, char *buf, size_t size)
{
        struct nfsctl_fdparm *data;
        struct sockaddr_in *sin;
        struct auth_domain *clp;
        int err = 0;
        struct knfsd_fh fh;
        char *res;

        if (size < sizeof(*data))
                return -EINVAL;
        data = (struct nfsctl_fdparm*)buf;
        err = -EPROTONOSUPPORT;
        if (data->gd_addr.sa_family != AF_INET)
                goto out;
        err = -EINVAL;
        if (data->gd_version < 2 || data->gd_version > NFSSVC_MAXVERS)
                goto out;

        res = buf;
        sin = (struct sockaddr_in *)&data->gd_addr;
        exp_readlock();
        if (!(clp = auth_unix_lookup(sin->sin_addr)))
                err = -EPERM;
        else {
                err = exp_rootfh(clp, data->gd_path, &fh, NFS_FHSIZE);
                auth_domain_put(clp);
        }
        exp_readunlock();

        if (err == 0) {
                memset(res,0, NFS_FHSIZE);
                memcpy(res, &fh.fh_base, fh.fh_size);
                err = NFS_FHSIZE;
        }
 out:
        return err;
}

static ssize_t write_filehandle(struct file *file, char *buf, size_t size)
{
        /* request is:
         *   domain path maxsize
         * response is
         *   filehandle
         *
         * qword quoting is used, so filehandle will be \x....
         */
        char *dname, *path;
        int uninitialized_var(maxsize);
        char *mesg = buf;
        int len;
        struct auth_domain *dom;
        struct knfsd_fh fh;

        if (buf[size-1] != '\n')
                return -EINVAL;
        buf[size-1] = 0;

        dname = mesg;
        len = qword_get(&mesg, dname, size);
        if (len <= 0) return -EINVAL;
        
        path = dname+len+1;
        len = qword_get(&mesg, path, size);
        if (len <= 0) return -EINVAL;

        len = get_int(&mesg, &maxsize);
        if (len)
                return len;

        if (maxsize < NFS_FHSIZE)
                return -EINVAL;
        if (maxsize > NFS3_FHSIZE)
                maxsize = NFS3_FHSIZE;

        if (qword_get(&mesg, mesg, size)>0)
                return -EINVAL;

        /* we have all the words, they are in buf.. */
        dom = unix_domain_find(dname);
        if (!dom)
                return -ENOMEM;

        len = exp_rootfh(dom, path, &fh,  maxsize);
        auth_domain_put(dom);
        if (len)
                return len;
        
        mesg = buf; len = SIMPLE_TRANSACTION_LIMIT;
        qword_addhex(&mesg, &len, (char*)&fh.fh_base, fh.fh_size);
        mesg[-1] = '\n';
        return mesg - buf;      
}

extern int nfsd_nrthreads(void);

static ssize_t write_threads(struct file *file, char *buf, size_t size)
{
        /* if size > 0, look for a number of threads and call nfsd_svc
         * then write out number of threads as reply
         */
        char *mesg = buf;
        int rv;
        if (size > 0) {
                int newthreads;
                rv = get_int(&mesg, &newthreads);
                if (rv)
                        return rv;
                if (newthreads <0)
                        return -EINVAL;
                rv = nfsd_svc(2049, newthreads);
                if (rv)
                        return rv;
        }
        sprintf(buf, "%d\n", nfsd_nrthreads());
        return strlen(buf);
}

extern int nfsd_nrpools(void);
extern int nfsd_get_nrthreads(int n, int *);
extern int nfsd_set_nrthreads(int n, int *);

static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
{
        /* if size > 0, look for an array of number of threads per node
         * and apply them  then write out number of threads per node as reply
         */
        char *mesg = buf;
        int i;
        int rv;
        int len;
        int npools = nfsd_nrpools();
        int *nthreads;

        if (npools == 0) {
                /*
                 * NFS is shut down.  The admin can start it by
                 * writing to the threads file but NOT the pool_threads
                 * file, sorry.  Report zero threads.
                 */
                strcpy(buf, "0\n");
                return strlen(buf);
        }

        nthreads = kcalloc(npools, sizeof(int), GFP_KERNEL);
        if (nthreads == NULL)
                return -ENOMEM;

        if (size > 0) {
                for (i = 0; i < npools; i++) {
                        rv = get_int(&mesg, &nthreads[i]);
                        if (rv == -ENOENT)
                                break;          /* fewer numbers than pools */
                        if (rv)
                                goto out_free;  /* syntax error */
                        rv = -EINVAL;
                        if (nthreads[i] < 0)
                                goto out_free;
                }
                rv = nfsd_set_nrthreads(i, nthreads);
                if (rv)
                        goto out_free;
        }

        rv = nfsd_get_nrthreads(npools, nthreads);
        if (rv)
                goto out_free;

        mesg = buf;
        size = SIMPLE_TRANSACTION_LIMIT;
        for (i = 0; i < npools && size > 0; i++) {
                snprintf(mesg, size, "%d%c", nthreads[i], (i == npools-1 ? '\n' : ' '));
                len = strlen(mesg);
                size -= len;
                mesg += len;
        }

        return (mesg-buf);

out_free:
        kfree(nthreads);
        return rv;
}

static ssize_t write_versions(struct file *file, char *buf, size_t size)
{
        /*
         * Format:
         *   [-/+]vers [-/+]vers ...
         */
        char *mesg = buf;
        char *vers, sign;
        int len, num;
        ssize_t tlen = 0;
        char *sep;

        if (size>0) {
                if (nfsd_serv)
                        /* Cannot change versions without updating
                         * nfsd_serv->sv_xdrsize, and reallocing
                         * rq_argp and rq_resp
                         */
                        return -EBUSY;
                if (buf[size-1] != '\n')
                        return -EINVAL;
                buf[size-1] = 0;

                vers = mesg;
                len = qword_get(&mesg, vers, size);
                if (len <= 0) return -EINVAL;
                do {
                        sign = *vers;
                        if (sign == '+' || sign == '-')
                                num = simple_strtol((vers+1), NULL, 0);
                        else
                                num = simple_strtol(vers, NULL, 0);
                        switch(num) {
                        case 2:
                        case 3:
                        case 4:
                                nfsd_vers(num, sign == '-' ? NFSD_CLEAR : NFSD_SET);
                                break;
                        default:
                                return -EINVAL;
                        }
                        vers += len + 1;
                        tlen += len;
                } while ((len = qword_get(&mesg, vers, size)) > 0);
                /* If all get turned off, turn them back on, as
                 * having no versions is BAD
                 */
                nfsd_reset_versions();
        }
        /* Now write current state into reply buffer */
        len = 0;
        sep = "";
        for (num=2 ; num <= 4 ; num++)
                if (nfsd_vers(num, NFSD_AVAIL)) {
                        len += sprintf(buf+len, "%s%c%d", sep,
                                       nfsd_vers(num, NFSD_TEST)?'+':'-',
                                       num);
                        sep = " ";
                }
        len += sprintf(buf+len, "\n");
        return len;
}

static ssize_t write_ports(struct file *file, char *buf, size_t size)
{
        if (size == 0) {
                int len = 0;
                lock_kernel();
                if (nfsd_serv)
                        len = svc_sock_names(buf, nfsd_serv, NULL);
                unlock_kernel();
                return len;
        }
        /* Either a single 'fd' number is written, in which
         * case it must be for a socket of a supported family/protocol,
         * and we use it as an nfsd socket, or
         * A '-' followed by the 'name' of a socket in which case
         * we close the socket.
         */
        if (isdigit(buf[0])) {
                char *mesg = buf;
                int fd;
                int err;
                err = get_int(&mesg, &fd);
                if (err)
                        return -EINVAL;
                if (fd < 0)
                        return -EINVAL;
                err = nfsd_create_serv();
                if (!err) {
                        int proto = 0;
                        err = svc_addsock(nfsd_serv, fd, buf, &proto);
                        if (err >= 0) {
                                err = lockd_up(proto);
                                if (err < 0)
                                        svc_sock_names(buf+strlen(buf)+1, nfsd_serv, buf);
                        }
                        /* Decrease the count, but don't shutdown the
                         * the service
                         */
                        lock_kernel();
                        nfsd_serv->sv_nrthreads--;
                        unlock_kernel();
                }
                return err < 0 ? err : 0;
        }
        if (buf[0] == '-') {
                char *toclose = kstrdup(buf+1, GFP_KERNEL);
                int len = 0;
                if (!toclose)
                        return -ENOMEM;
                lock_kernel();
                if (nfsd_serv)
                        len = svc_sock_names(buf, nfsd_serv, toclose);
                unlock_kernel();
                if (len >= 0)
                        lockd_down();
                kfree(toclose);
                return len;
        }
        return -EINVAL;
}

int nfsd_max_blksize;

static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
{
        char *mesg = buf;
        if (size > 0) {
                int bsize;
                int rv = get_int(&mesg, &bsize);
                if (rv)
                        return rv;
                /* force bsize into allowed range and
                 * required alignment.
                 */
                if (bsize < 1024)
                        bsize = 1024;
                if (bsize > NFSSVC_MAXBLKSIZE)
                        bsize = NFSSVC_MAXBLKSIZE;
                bsize &= ~(1024-1);
                lock_kernel();
                if (nfsd_serv && nfsd_serv->sv_nrthreads) {
                        unlock_kernel();
                        return -EBUSY;
                }
                nfsd_max_blksize = bsize;
                unlock_kernel();
        }
        return sprintf(buf, "%d\n", nfsd_max_blksize);
}

#ifdef CONFIG_NFSD_V4
extern time_t nfs4_leasetime(void);

static ssize_t write_leasetime(struct file *file, char *buf, size_t size)
{
        /* if size > 10 seconds, call
         * nfs4_reset_lease() then write out the new lease (seconds) as reply
         */
        char *mesg = buf;
        int rv;

        if (size > 0) {
                int lease;
                rv = get_int(&mesg, &lease);
                if (rv)
                        return rv;
                if (lease < 10 || lease > 3600)
                        return -EINVAL;
                nfs4_reset_lease(lease);
        }
        sprintf(buf, "%ld\n", nfs4_lease_time());
        return strlen(buf);
}

static ssize_t write_recoverydir(struct file *file, char *buf, size_t size)
{
        char *mesg = buf;
        char *recdir;
        int len, status;

        if (size > PATH_MAX || buf[size-1] != '\n')
                return -EINVAL;
        buf[size-1] = 0;

        recdir = mesg;
        len = qword_get(&mesg, recdir, size);
        if (len <= 0)
                return -EINVAL;

        status = nfs4_reset_recoverydir(recdir);
        return strlen(buf);
}
#endif

/*----------------------------------------------------------------------------*/
/*
 *      populating the filesystem.
 */

static int nfsd_fill_super(struct super_block * sb, void * data, int silent)
{
        static struct tree_descr nfsd_files[] = {
                [NFSD_Svc] = {".svc", &transaction_ops, S_IWUSR},
                [NFSD_Add] = {".add", &transaction_ops, S_IWUSR},
                [NFSD_Del] = {".del", &transaction_ops, S_IWUSR},
                [NFSD_Export] = {".export", &transaction_ops, S_IWUSR},
                [NFSD_Unexport] = {".unexport", &transaction_ops, S_IWUSR},
                [NFSD_Getfd] = {".getfd", &transaction_ops, S_IWUSR|S_IRUSR},
                [NFSD_Getfs] = {".getfs", &transaction_ops, S_IWUSR|S_IRUSR},
                [NFSD_List] = {"exports", &exports_operations, S_IRUGO},
                [NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR|S_IRUSR},
                [NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR},
                [NFSD_Pool_Threads] = {"pool_threads", &transaction_ops, S_IWUSR|S_IRUSR},
                [NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
                [NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
                [NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
#ifdef CONFIG_NFSD_V4
                [NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
                [NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR},
#endif
                /* last one */ {""}
        };
        return simple_fill_super(sb, 0x6e667364, nfsd_files);
}

static int nfsd_get_sb(struct file_system_type *fs_type,
        int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
        return get_sb_single(fs_type, flags, data, nfsd_fill_super, mnt);
}

static struct file_system_type nfsd_fs_type = {
        .owner          = THIS_MODULE,
        .name           = "nfsd",
        .get_sb         = nfsd_get_sb,
        .kill_sb        = kill_litter_super,
};

static int __init init_nfsd(void)
{
        int retval;
        printk(KERN_INFO "Installing knfsd (copyright (C) 1996 okir@monad.swb.de).\n");

        retval = nfs4_state_init(); /* nfs4 locking state */
        if (retval)
                return retval;
        nfsd_stat_init();       /* Statistics */
        nfsd_cache_init();      /* RPC reply cache */
        nfsd_export_init();     /* Exports table */
        nfsd_lockd_init();      /* lockd->nfsd callbacks */
        nfsd_idmap_init();      /* Name to ID mapping */
        if (proc_mkdir("fs/nfs", NULL)) {
                struct proc_dir_entry *entry;
                entry = create_proc_entry("fs/nfs/exports", 0, NULL);
                if (entry)
                        entry->proc_fops =  &exports_operations;
        }
        retval = register_filesystem(&nfsd_fs_type);
        if (retval) {
                nfsd_export_shutdown();
                nfsd_cache_shutdown();
                remove_proc_entry("fs/nfs/exports", NULL);
                remove_proc_entry("fs/nfs", NULL);
                nfsd_stat_shutdown();
                nfsd_lockd_shutdown();
        }
        return retval;
}

static void __exit exit_nfsd(void)
{
        nfsd_export_shutdown();
        nfsd_cache_shutdown();
        remove_proc_entry("fs/nfs/exports", NULL);
        remove_proc_entry("fs/nfs", NULL);
        nfsd_stat_shutdown();
        nfsd_lockd_shutdown();
        nfsd_idmap_shutdown();
        nfsd4_free_slabs();
        unregister_filesystem(&nfsd_fs_type);
}

MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
MODULE_LICENSE("GPL");
module_init(init_nfsd)
module_exit(exit_nfsd)