/*
 * nfsproc2.c   Process version 2 NFS requests.
 * linux/fs/nfsd/nfs2proc.c
 * 
 * Process version 2 NFS requests.
 *
 * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/linkage.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/locks.h>
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/net.h>
#include <linux/in.h>
#include <linux/version.h>
#include <linux/unistd.h>
#include <linux/slab.h>

#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/cache.h>
#include <linux/nfsd/xdr.h>

typedef struct svc_rqst svc_rqst;
typedef struct svc_buf  svc_buf;

#define NFSDDBG_FACILITY                NFSDDBG_PROC


static void
svcbuf_reserve(struct svc_buf *buf, u32 **ptr, int *len, int nr)
{
        *ptr = buf->buf + nr;
        *len = buf->buflen - buf->len - nr;
}

static int
nfsd_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
{
        return nfs_ok;
}

/*
 * Get a file's attributes
 * N.B. After this call resp->fh needs an fh_put
 */
static int
nfsd_proc_getattr(struct svc_rqst *rqstp, struct nfsd_fhandle  *argp,
                                          struct nfsd_attrstat *resp)
{
        dprintk("nfsd: GETATTR  %s\n", SVCFH_fmt(&argp->fh));

        fh_copy(&resp->fh, &argp->fh);
        return fh_verify(rqstp, &resp->fh, 0, MAY_NOP);
}

/*
 * Set a file's attributes
 * N.B. After this call resp->fh needs an fh_put
 */
static int
nfsd_proc_setattr(struct svc_rqst *rqstp, struct nfsd_sattrargs *argp,
                                          struct nfsd_attrstat  *resp)
{
        dprintk("nfsd: SETATTR  %s, valid=%x, size=%ld\n",
                SVCFH_fmt(&argp->fh),
                argp->attrs.ia_valid, (long) argp->attrs.ia_size);

        fh_copy(&resp->fh, &argp->fh);
        return nfsd_setattr(rqstp, &resp->fh, &argp->attrs,0, (time_t)0);
}

/*
 * Look up a path name component
 * Note: the dentry in the resp->fh may be negative if the file
 * doesn't exist yet.
 * N.B. After this call resp->fh needs an fh_put
 */
static int
nfsd_proc_lookup(struct svc_rqst *rqstp, struct nfsd_diropargs *argp,
                                         struct nfsd_diropres  *resp)
{
        int     nfserr;

        dprintk("nfsd: LOOKUP   %s %.*s\n",
                SVCFH_fmt(&argp->fh), argp->len, argp->name);

        fh_init(&resp->fh, NFS_FHSIZE);
        nfserr = nfsd_lookup(rqstp, &argp->fh, argp->name, argp->len,
                                 &resp->fh);

        fh_put(&argp->fh);
        return nfserr;
}

/*
 * Read a symlink.
 */
static int
nfsd_proc_readlink(struct svc_rqst *rqstp, struct nfsd_fhandle     *argp,
                                           struct nfsd_readlinkres *resp)
{
        u32             *path;
        int             dummy, nfserr;

        dprintk("nfsd: READLINK %s\n", SVCFH_fmt(&argp->fh));

        /* Reserve room for status and path length */
        svcbuf_reserve(&rqstp->rq_resbuf, &path, &dummy, 2);

        /* Read the symlink. */
        resp->len = NFS_MAXPATHLEN;
        nfserr = nfsd_readlink(rqstp, &argp->fh, (char *) path, &resp->len);

        fh_put(&argp->fh);
        return nfserr;
}

/*
 * Read a portion of a file.
 * N.B. After this call resp->fh needs an fh_put
 */
static int
nfsd_proc_read(struct svc_rqst *rqstp, struct nfsd_readargs *argp,
                                       struct nfsd_readres  *resp)
{
        u32 *   buffer;
        int     nfserr, avail;

        dprintk("nfsd: READ    %s %d bytes at %d\n",
                SVCFH_fmt(&argp->fh),
                argp->count, argp->offset);

        /* Obtain buffer pointer for payload. 19 is 1 word for
         * status, 17 words for fattr, and 1 word for the byte count.
         */
        svcbuf_reserve(&rqstp->rq_resbuf, &buffer, &avail, 19);

        if ((avail << 2) < argp->count) {
                printk(KERN_NOTICE
                        "oversized read request from %08x:%d (%d bytes)\n",
                                ntohl(rqstp->rq_addr.sin_addr.s_addr),
                                ntohs(rqstp->rq_addr.sin_port),
                                argp->count);
                argp->count = avail << 2;
        }
        svc_reserve(rqstp, (19<<2) + argp->count + 4);

        resp->count = argp->count;
        nfserr = nfsd_read(rqstp, fh_copy(&resp->fh, &argp->fh),
                                  argp->offset,
                                  (char *) buffer,
                                  &resp->count);

        return nfserr;
}

/*
 * Write data to a file
 * N.B. After this call resp->fh needs an fh_put
 */
static int
nfsd_proc_write(struct svc_rqst *rqstp, struct nfsd_writeargs *argp,
                                        struct nfsd_attrstat  *resp)
{
        int     nfserr;
        int     stable = 1;

        dprintk("nfsd: WRITE    %s %d bytes at %d\n",
                SVCFH_fmt(&argp->fh),
                argp->len, argp->offset);

        nfserr = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh),
                                   argp->offset,
                                   argp->data,
                                   argp->len,
                                   &stable);
        return nfserr;
}

/*
 * CREATE processing is complicated. The keyword here is `overloaded.'
 * The parent directory is kept locked between the check for existence
 * and the actual create() call in compliance with VFS protocols.
 * N.B. After this call _both_ argp->fh and resp->fh need an fh_put
 */
static int
nfsd_proc_create(struct svc_rqst *rqstp, struct nfsd_createargs *argp,
                                         struct nfsd_diropres   *resp)
{
        svc_fh          *dirfhp = &argp->fh;
        svc_fh          *newfhp = &resp->fh;
        struct iattr    *attr = &argp->attrs;
        struct inode    *inode;
        struct dentry   *dchild;
        int             nfserr, type, mode;
        dev_t           rdev = NODEV;

        dprintk("nfsd: CREATE   %s %.*s\n",
                SVCFH_fmt(dirfhp), argp->len, argp->name);

        /* First verify the parent file handle */
        nfserr = fh_verify(rqstp, dirfhp, S_IFDIR, MAY_EXEC);
        if (nfserr)
                goto done; /* must fh_put dirfhp even on error */

        /* Check for MAY_WRITE in nfsd_create if necessary */

        nfserr = nfserr_acces;
        if (!argp->len)
                goto done;
        nfserr = nfserr_exist;
        if (isdotent(argp->name, argp->len))
                goto done;
        fh_lock(dirfhp);
        dchild = lookup_one_len(argp->name, dirfhp->fh_dentry, argp->len);
        if (IS_ERR(dchild)) {
                nfserr = nfserrno(PTR_ERR(dchild));
                goto out_unlock;
        }
        fh_init(newfhp, NFS_FHSIZE);
        nfserr = fh_compose(newfhp, dirfhp->fh_export, dchild, dirfhp);
        if (!nfserr && !dchild->d_inode)
                nfserr = nfserr_noent;
        if (nfserr) {
                if (nfserr != nfserr_noent)
                        goto out_unlock;
                /*
                 * If the new file handle wasn't verified, we can't tell
                 * whether the file exists or not. Time to bail ...
                 */
                nfserr = nfserr_acces;
                if (!newfhp->fh_dentry) {
                        printk(KERN_WARNING 
                                "nfsd_proc_create: file handle not verified\n");
                        goto out_unlock;
                }
        }

        inode = newfhp->fh_dentry->d_inode;

        /* Unfudge the mode bits */
        if (attr->ia_valid & ATTR_MODE) { 
                type = attr->ia_mode & S_IFMT;
                mode = attr->ia_mode & ~S_IFMT;
                if (!type) {
                        /* no type, so if target exists, assume same as that,
                         * else assume a file */
                        if (inode) {
                                type = inode->i_mode & S_IFMT;
                                switch(type) {
                                case S_IFCHR:
                                case S_IFBLK:
                                        /* reserve rdev for later checking */
                                        attr->ia_size = inode->i_rdev;
                                        attr->ia_valid |= ATTR_SIZE;

                                        /* FALLTHROUGH */
                                case S_IFIFO:
                                        /* this is probably a permission check..
                                         * at least IRIX implements perm checking on
                                         *   echo thing > device-special-file-or-pipe
                                         * by doing a CREATE with type==0
                                         */
                                        nfserr = nfsd_permission(newfhp->fh_export,
                                                                 newfhp->fh_dentry,
                                                                 MAY_WRITE|_NFSD_IRIX_BOGOSITY);
                                        if (nfserr && nfserr != nfserr_rofs)
                                                goto out_unlock;
                                }
                        } else
                                type = S_IFREG;
                }
        } else if (inode) {
                type = inode->i_mode & S_IFMT;
                mode = inode->i_mode & ~S_IFMT;
        } else {
                type = S_IFREG;
                mode = 0;       /* ??? */
        }

        attr->ia_valid |= ATTR_MODE;
        attr->ia_mode = mode;

        /* Special treatment for non-regular files according to the
         * gospel of sun micro
         */
        if (type != S_IFREG) {
                int     is_borc = 0;
                u32     size = attr->ia_size;

                rdev = (dev_t) size;
                if (type != S_IFBLK && type != S_IFCHR) {
                        rdev = 0;
                } else if (type == S_IFCHR && !(attr->ia_valid & ATTR_SIZE)) {
                        /* If you think you've seen the worst, grok this. */
                        type = S_IFIFO;
                } else if (size != rdev) {
                        /* dev got truncated because of 16bit Linux dev_t */
                        nfserr = nfserr_inval;
                        goto out_unlock;
                } else {
                        /* Okay, char or block special */
                        is_borc = 1;
                }

                /* we've used the SIZE information, so discard it */
                attr->ia_valid &= ~ATTR_SIZE;

                /* Make sure the type and device matches */
                nfserr = nfserr_exist;
                if (inode && (type != (inode->i_mode & S_IFMT) || 
                    (is_borc && inode->i_rdev != rdev)))
                        goto out_unlock;
        }
        
        nfserr = 0;
        if (!inode) {
                /* File doesn't exist. Create it and set attrs */
                nfserr = nfsd_create(rqstp, dirfhp, argp->name, argp->len,
                                        attr, type, rdev, newfhp);
        } else if (type == S_IFREG) {
                dprintk("nfsd:   existing %s, valid=%x, size=%ld\n",
                        argp->name, attr->ia_valid, (long) attr->ia_size);
                /* File already exists. We ignore all attributes except
                 * size, so that creat() behaves exactly like
                 * open(..., O_CREAT|O_TRUNC|O_WRONLY).
                 */
                attr->ia_valid &= ATTR_SIZE;
                if (attr->ia_valid)
                        nfserr = nfsd_setattr(rqstp, newfhp, attr, 0, (time_t)0);
        }

out_unlock:
        /* We don't really need to unlock, as fh_put does it. */
        fh_unlock(dirfhp);

done:
        fh_put(dirfhp);
        return nfserr;
}

static int
nfsd_proc_remove(struct svc_rqst *rqstp, struct nfsd_diropargs *argp,
                                         void                  *resp)
{
        int     nfserr;

        dprintk("nfsd: REMOVE   %s %.*s\n", SVCFH_fmt(&argp->fh),
                argp->len, argp->name);

        /* Unlink. -SIFDIR means file must not be a directory */
        nfserr = nfsd_unlink(rqstp, &argp->fh, -S_IFDIR, argp->name, argp->len);
        fh_put(&argp->fh);
        return nfserr;
}

static int
nfsd_proc_rename(struct svc_rqst *rqstp, struct nfsd_renameargs *argp,
                                         void                   *resp)
{
        int     nfserr;

        dprintk("nfsd: RENAME   %s %.*s -> \n",
                SVCFH_fmt(&argp->ffh), argp->flen, argp->fname);
        dprintk("nfsd:        ->  %s %.*s\n",
                SVCFH_fmt(&argp->tfh), argp->tlen, argp->tname);

        nfserr = nfsd_rename(rqstp, &argp->ffh, argp->fname, argp->flen,
                                    &argp->tfh, argp->tname, argp->tlen);
        fh_put(&argp->ffh);
        fh_put(&argp->tfh);
        return nfserr;
}

static int
nfsd_proc_link(struct svc_rqst *rqstp, struct nfsd_linkargs *argp,
                                void                        *resp)
{
        int     nfserr;

        dprintk("nfsd: LINK     %s ->\n",
                SVCFH_fmt(&argp->ffh));
        dprintk("nfsd:    %s %.*s\n",
                SVCFH_fmt(&argp->tfh),
                argp->tlen,
                argp->tname);

        nfserr = nfsd_link(rqstp, &argp->tfh, argp->tname, argp->tlen,
                                  &argp->ffh);
        fh_put(&argp->ffh);
        fh_put(&argp->tfh);
        return nfserr;
}

static int
nfsd_proc_symlink(struct svc_rqst *rqstp, struct nfsd_symlinkargs *argp,
                                          void                    *resp)
{
        struct svc_fh   newfh;
        int             nfserr;

        dprintk("nfsd: SYMLINK  %s %.*s -> %.*s\n",
                SVCFH_fmt(&argp->ffh), argp->flen, argp->fname,
                argp->tlen, argp->tname);

        fh_init(&newfh, NFS_FHSIZE);
        /*
         * Create the link, look up new file and set attrs.
         */
        nfserr = nfsd_symlink(rqstp, &argp->ffh, argp->fname, argp->flen,
                                                 argp->tname, argp->tlen,
                                                 &newfh, &argp->attrs);


        fh_put(&argp->ffh);
        fh_put(&newfh);
        return nfserr;
}

/*
 * Make directory. This operation is not idempotent.
 * N.B. After this call resp->fh needs an fh_put
 */
static int
nfsd_proc_mkdir(struct svc_rqst *rqstp, struct nfsd_createargs *argp,
                                        struct nfsd_diropres   *resp)
{
        int     nfserr;

        dprintk("nfsd: MKDIR    %s %.*s\n", SVCFH_fmt(&argp->fh), argp->len, argp->name);

        if (resp->fh.fh_dentry) {
                printk(KERN_WARNING
                        "nfsd_proc_mkdir: response already verified??\n");
        }

        argp->attrs.ia_valid &= ~ATTR_SIZE;
        fh_init(&resp->fh, NFS_FHSIZE);
        nfserr = nfsd_create(rqstp, &argp->fh, argp->name, argp->len,
                                    &argp->attrs, S_IFDIR, 0, &resp->fh);
        fh_put(&argp->fh);
        return nfserr;
}

/*
 * Remove a directory
 */
static int
nfsd_proc_rmdir(struct svc_rqst *rqstp, struct nfsd_diropargs *argp,
                                        void                  *resp)
{
        int     nfserr;

        dprintk("nfsd: RMDIR    %s %.*s\n", SVCFH_fmt(&argp->fh), argp->len, argp->name);

        nfserr = nfsd_unlink(rqstp, &argp->fh, S_IFDIR, argp->name, argp->len);
        fh_put(&argp->fh);
        return nfserr;
}

/*
 * Read a portion of a directory.
 */
static int
nfsd_proc_readdir(struct svc_rqst *rqstp, struct nfsd_readdirargs *argp,
                                          struct nfsd_readdirres  *resp)
{
        u32 *           buffer;
        int             nfserr, count;

        dprintk("nfsd: READDIR  %s %d bytes at %d\n",
                SVCFH_fmt(&argp->fh),           
                argp->count, argp->cookie);

        /* Reserve buffer space for status */
        svcbuf_reserve(&rqstp->rq_resbuf, &buffer, &count, 1);

        /* Shrink to the client read size */
        if (count > (argp->count >> 2))
                count = argp->count >> 2;

        /* Make sure we've room for the NULL ptr & eof flag */
        count -= 2;
        if (count < 0)
                count = 0;

        /* Read directory and encode entries on the fly */
        nfserr = nfsd_readdir(rqstp, &argp->fh, (loff_t) argp->cookie, 
                              nfssvc_encode_entry,
                              buffer, &count, NULL);
        resp->count = count;

        fh_put(&argp->fh);
        return nfserr;
}

/*
 * Get file system info
 */
static int
nfsd_proc_statfs(struct svc_rqst * rqstp, struct nfsd_fhandle   *argp,
                                          struct nfsd_statfsres *resp)
{
        int     nfserr;

        dprintk("nfsd: STATFS   %s\n", SVCFH_fmt(&argp->fh));

        nfserr = nfsd_statfs(rqstp, &argp->fh, &resp->stats);
        fh_put(&argp->fh);
        return nfserr;
}

/*
 * NFSv2 Server procedures.
 * Only the results of non-idempotent operations are cached.
 */
#define nfsd_proc_none          NULL
#define nfssvc_release_none     NULL
struct nfsd_void { int dummy; };

#define PROC(name, argt, rest, relt, cache, respsize)   \
 { (svc_procfunc) nfsd_proc_##name,             \
   (kxdrproc_t) nfssvc_decode_##argt,           \
   (kxdrproc_t) nfssvc_encode_##rest,           \
   (kxdrproc_t) nfssvc_release_##relt,          \
   sizeof(struct nfsd_##argt),                  \
   sizeof(struct nfsd_##rest),                  \
   0,                                           \
   cache,                                       \
   respsize,                                    \
 }

#define ST 1            /* status */
#define FH 8            /* filehandle */
#define AT 18           /* attributes */

struct svc_procedure            nfsd_procedures2[18] = {
  PROC(null,     void,          void,           none,           RC_NOCACHE, ST),
  PROC(getattr,  fhandle,       attrstat,       fhandle,        RC_NOCACHE, ST+AT),
  PROC(setattr,  sattrargs,     attrstat,       fhandle,        RC_REPLBUFF, ST+AT),
  PROC(none,     void,          void,           none,           RC_NOCACHE, ST),
  PROC(lookup,   diropargs,     diropres,       fhandle,        RC_NOCACHE, ST+FH+AT),
  PROC(readlink, fhandle,       readlinkres,    none,           RC_NOCACHE, ST+1+NFS_MAXPATHLEN/4),
  PROC(read,     readargs,      readres,        fhandle,        RC_NOCACHE, ST+AT+1+NFSSVC_MAXBLKSIZE),
  PROC(none,     void,          void,           none,           RC_NOCACHE, ST),
  PROC(write,    writeargs,     attrstat,       fhandle,        RC_REPLBUFF, ST+AT),
  PROC(create,   createargs,    diropres,       fhandle,        RC_REPLBUFF, ST+FH+AT),
  PROC(remove,   diropargs,     void,           none,           RC_REPLSTAT, ST),
  PROC(rename,   renameargs,    void,           none,           RC_REPLSTAT, ST),
  PROC(link,     linkargs,      void,           none,           RC_REPLSTAT, ST),
  PROC(symlink,  symlinkargs,   void,           none,           RC_REPLSTAT, ST),
  PROC(mkdir,    createargs,    diropres,       fhandle,        RC_REPLBUFF, ST+FH+AT),
  PROC(rmdir,    diropargs,     void,           none,           RC_REPLSTAT, ST),
  PROC(readdir,  readdirargs,   readdirres,     none,           RC_REPLBUFF, 0),
  PROC(statfs,   fhandle,       statfsres,      none,           RC_NOCACHE, ST+5),
};


/*
 * Map errnos to NFS errnos.
 */
int
nfserrno (int errno)
{
        static struct {
                int     nfserr;
                int     syserr;
        } nfs_errtbl[] = {
                { nfs_ok, 0 },
                { nfserr_perm, -EPERM },
                { nfserr_noent, -ENOENT },
                { nfserr_io, -EIO },
                { nfserr_nxio, -ENXIO },
                { nfserr_acces, -EACCES },
                { nfserr_exist, -EEXIST },
                { nfserr_xdev, -EXDEV },
                { nfserr_mlink, -EMLINK },
                { nfserr_nodev, -ENODEV },
                { nfserr_notdir, -ENOTDIR },
                { nfserr_isdir, -EISDIR },
                { nfserr_inval, -EINVAL },
                { nfserr_fbig, -EFBIG },
                { nfserr_nospc, -ENOSPC },
                { nfserr_rofs, -EROFS },
                { nfserr_mlink, -EMLINK },
                { nfserr_nametoolong, -ENAMETOOLONG },
                { nfserr_notempty, -ENOTEMPTY },
#ifdef EDQUOT
                { nfserr_dquot, -EDQUOT },
#endif
                { nfserr_stale, -ESTALE },
                { nfserr_dropit, -ENOMEM },
                { -1, -EIO }
        };
        int     i;

        for (i = 0; nfs_errtbl[i].nfserr != -1; i++) {
                if (nfs_errtbl[i].syserr == errno)
                        return nfs_errtbl[i].nfserr;
        }
        printk (KERN_INFO "nfsd: non-standard errno: %d\n", errno);
        return nfserr_io;
}