nfsxdr.c

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/*
 * XDR support for nfsd
 *
 * Copyright (C) 1995, 1996 Olaf Kirch <[email protected]>
 */

#include "xdr.h"
#include "auth.h"

#define NFSDDBG_FACILITY        NFSDDBG_XDR

/*
 * Mapping of S_IF* types to NFS file types
 */
static u32  nfs_ftypes[] = {
    NFNON,  NFCHR,  NFCHR, NFBAD,
    NFDIR,  NFBAD,  NFBLK, NFBAD,
    NFREG,  NFBAD,  NFLNK, NFBAD,
    NFSOCK, NFBAD,  NFLNK, NFBAD,
};


/*
 * XDR functions for basic NFS types
 */
static __be32 *
decode_fh(__be32 *p, struct svc_fh *fhp)
{
    fh_init(fhp, NFS_FHSIZE);
    memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
    fhp->fh_handle.fh_size = NFS_FHSIZE;

    /* FIXME: Look up export pointer here and verify
     * Sun Secure RPC if requested */
    return p + (NFS_FHSIZE >> 2);
}

/* Helper function for NFSv2 ACL code */
__be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
{
    return decode_fh(p, fhp);
}

static __be32 *
encode_fh(__be32 *p, struct svc_fh *fhp)
{
    memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
    return p + (NFS_FHSIZE>> 2);
}

/*
 * Decode a file name and make sure that the path contains
 * no slashes or null bytes.
 */
static __be32 *
decode_filename(__be32 *p, char **namp, unsigned int *lenp)
{
    char        *name;
    unsigned int    i;

    if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
        for (i = 0, name = *namp; i < *lenp; i++, name++) {
            if (*name == '\0' || *name == '/')
                return NULL;
        }
    }

    return p;
}

static __be32 *
decode_pathname(__be32 *p, char **namp, unsigned int *lenp)
{
    char        *name;
    unsigned int    i;

    if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXPATHLEN)) != NULL) {
        for (i = 0, name = *namp; i < *lenp; i++, name++) {
            if (*name == '\0')
                return NULL;
        }
    }

    return p;
}

static __be32 *
decode_sattr(__be32 *p, struct iattr *iap)
{
    u32 tmp, tmp1;

    iap->ia_valid = 0;

    /* Sun client bug compatibility check: some sun clients seem to
     * put 0xffff in the mode field when they mean 0xffffffff.
     * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
     */
    if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
        iap->ia_valid |= ATTR_MODE;
        iap->ia_mode = tmp;
    }
    if ((tmp = ntohl(*p++)) != (u32)-1) {
        iap->ia_valid |= ATTR_UID;
        iap->ia_uid = tmp;
    }
    if ((tmp = ntohl(*p++)) != (u32)-1) {
        iap->ia_valid |= ATTR_GID;
        iap->ia_gid = tmp;
    }
    if ((tmp = ntohl(*p++)) != (u32)-1) {
        iap->ia_valid |= ATTR_SIZE;
        iap->ia_size = tmp;
    }
    tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
    if (tmp != (u32)-1 && tmp1 != (u32)-1) {
        iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
        iap->ia_atime.tv_sec = tmp;
        iap->ia_atime.tv_nsec = tmp1 * 1000; 
    }
    tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
    if (tmp != (u32)-1 && tmp1 != (u32)-1) {
        iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
        iap->ia_mtime.tv_sec = tmp;
        iap->ia_mtime.tv_nsec = tmp1 * 1000; 
        /*
         * Passing the invalid value useconds=1000000 for mtime
         * is a Sun convention for "set both mtime and atime to
         * current server time".  It's needed to make permissions
         * checks for the "touch" program across v2 mounts to
         * Solaris and Irix boxes work correctly. See description of
         * sattr in section 6.1 of "NFS Illustrated" by
         * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
         */
        if (tmp1 == 1000000)
            iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
    }
    return p;
}

static __be32 *
encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
         struct kstat *stat)
{
    struct dentry   *dentry = fhp->fh_dentry;
    int type;
    struct timespec time;
    u32 f;

    type = (stat->mode & S_IFMT);

    *p++ = htonl(nfs_ftypes[type >> 12]);
    *p++ = htonl((u32) stat->mode);
    *p++ = htonl((u32) stat->nlink);
    *p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
    *p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));

    if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
        *p++ = htonl(NFS_MAXPATHLEN);
    } else {
        *p++ = htonl((u32) stat->size);
    }
    *p++ = htonl((u32) stat->blksize);
    if (S_ISCHR(type) || S_ISBLK(type))
        *p++ = htonl(new_encode_dev(stat->rdev));
    else
        *p++ = htonl(0xffffffff);
    *p++ = htonl((u32) stat->blocks);
    switch (fsid_source(fhp)) {
    default:
    case FSIDSOURCE_DEV:
        *p++ = htonl(new_encode_dev(stat->dev));
        break;
    case FSIDSOURCE_FSID:
        *p++ = htonl((u32) fhp->fh_export->ex_fsid);
        break;
    case FSIDSOURCE_UUID:
        f = ((u32*)fhp->fh_export->ex_uuid)[0];
        f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
        f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
        f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
        *p++ = htonl(f);
        break;
    }
    *p++ = htonl((u32) stat->ino);
    *p++ = htonl((u32) stat->atime.tv_sec);
    *p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
    lease_get_mtime(dentry->d_inode, &time); 
    *p++ = htonl((u32) time.tv_sec);
    *p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0); 
    *p++ = htonl((u32) stat->ctime.tv_sec);
    *p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);

    return p;
}

/* Helper function for NFSv2 ACL code */
__be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
{
    struct kstat stat;
    vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry, &stat);
    return encode_fattr(rqstp, p, fhp, &stat);
}

/*
 * XDR decode functions
 */
int
nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
{
    return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
{
    if (!(p = decode_fh(p, &args->fh)))
        return 0;
    return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_sattrargs *args)
{
    p = decode_fh(p, &args->fh);
    if (!p)
        return 0;
    p = decode_sattr(p, &args->attrs);

    return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_diropargs *args)
{
    if (!(p = decode_fh(p, &args->fh))
     || !(p = decode_filename(p, &args->name, &args->len)))
        return 0;

     return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_readargs *args)
{
    unsigned int len;
    int v,pn;
    if (!(p = decode_fh(p, &args->fh)))
        return 0;

    args->offset    = ntohl(*p++);
    len = args->count     = ntohl(*p++);
    p++; /* totalcount - unused */

    if (len > NFSSVC_MAXBLKSIZE_V2)
        len = NFSSVC_MAXBLKSIZE_V2;

    /* set up somewhere to store response.
     * We take pages, put them on reslist and include in iovec
     */
    v=0;
    while (len > 0) {
        pn = rqstp->rq_resused++;
        rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
        rqstp->rq_vec[v].iov_len = len < PAGE_SIZE?len:PAGE_SIZE;
        len -= rqstp->rq_vec[v].iov_len;
        v++;
    }
    args->vlen = v;
    return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_writeargs *args)
{
    unsigned int len, hdr, dlen;
    int v;

    if (!(p = decode_fh(p, &args->fh)))
        return 0;

    p++;                /* beginoffset */
    args->offset = ntohl(*p++); /* offset */
    p++;                /* totalcount */
    len = args->len = ntohl(*p++);
    /*
     * The protocol specifies a maximum of 8192 bytes.
     */
    if (len > NFSSVC_MAXBLKSIZE_V2)
        return 0;

    /*
     * Check to make sure that we got the right number of
     * bytes.
     */
    hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
    dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
        - hdr;

    /*
     * Round the length of the data which was specified up to
     * the next multiple of XDR units and then compare that
     * against the length which was actually received.
     * Note that when RPCSEC/GSS (for example) is used, the
     * data buffer can be padded so dlen might be larger
     * than required.  It must never be smaller.
     */
    if (dlen < XDR_QUADLEN(len)*4)
        return 0;

    rqstp->rq_vec[0].iov_base = (void*)p;
    rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
    v = 0;
    while (len > rqstp->rq_vec[v].iov_len) {
        len -= rqstp->rq_vec[v].iov_len;
        v++;
        rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
        rqstp->rq_vec[v].iov_len = PAGE_SIZE;
    }
    rqstp->rq_vec[v].iov_len = len;
    args->vlen = v + 1;
    return 1;
}

int
nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_createargs *args)
{
    if (   !(p = decode_fh(p, &args->fh))
        || !(p = decode_filename(p, &args->name, &args->len)))
        return 0;
    p = decode_sattr(p, &args->attrs);

    return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_renameargs *args)
{
    if (!(p = decode_fh(p, &args->ffh))
     || !(p = decode_filename(p, &args->fname, &args->flen))
     || !(p = decode_fh(p, &args->tfh))
     || !(p = decode_filename(p, &args->tname, &args->tlen)))
        return 0;

    return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
{
    if (!(p = decode_fh(p, &args->fh)))
        return 0;
    args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);

    return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_linkargs *args)
{
    if (!(p = decode_fh(p, &args->ffh))
     || !(p = decode_fh(p, &args->tfh))
     || !(p = decode_filename(p, &args->tname, &args->tlen)))
        return 0;

    return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_symlinkargs *args)
{
    if (   !(p = decode_fh(p, &args->ffh))
        || !(p = decode_filename(p, &args->fname, &args->flen))
        || !(p = decode_pathname(p, &args->tname, &args->tlen)))
        return 0;
    p = decode_sattr(p, &args->attrs);

    return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_readdirargs *args)
{
    if (!(p = decode_fh(p, &args->fh)))
        return 0;
    args->cookie = ntohl(*p++);
    args->count  = ntohl(*p++);
    if (args->count > PAGE_SIZE)
        args->count = PAGE_SIZE;

    args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);

    return xdr_argsize_check(rqstp, p);
}

/*
 * XDR encode functions
 */
int
nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
{
    return xdr_ressize_check(rqstp, p);
}

int
nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_attrstat *resp)
{
    p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
    return xdr_ressize_check(rqstp, p);
}

int
nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_diropres *resp)
{
    p = encode_fh(p, &resp->fh);
    p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
    return xdr_ressize_check(rqstp, p);
}

int
nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_readlinkres *resp)
{
    *p++ = htonl(resp->len);
    xdr_ressize_check(rqstp, p);
    rqstp->rq_res.page_len = resp->len;
    if (resp->len & 3) {
        /* need to pad the tail */
        rqstp->rq_res.tail[0].iov_base = p;
        *p = 0;
        rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
    }
    return 1;
}

int
nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_readres *resp)
{
    p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
    *p++ = htonl(resp->count);
    xdr_ressize_check(rqstp, p);

    /* now update rqstp->rq_res to reflect data as well */
    rqstp->rq_res.page_len = resp->count;
    if (resp->count & 3) {
        /* need to pad the tail */
        rqstp->rq_res.tail[0].iov_base = p;
        *p = 0;
        rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
    }
    return 1;
}

int
nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_readdirres *resp)
{
    xdr_ressize_check(rqstp, p);
    p = resp->buffer;
    *p++ = 0;           /* no more entries */
    *p++ = htonl((resp->common.err == nfserr_eof));
    rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;

    return 1;
}

int
nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_statfsres *resp)
{
    struct kstatfs  *stat = &resp->stats;

    *p++ = htonl(NFSSVC_MAXBLKSIZE_V2); /* max transfer size */
    *p++ = htonl(stat->f_bsize);
    *p++ = htonl(stat->f_blocks);
    *p++ = htonl(stat->f_bfree);
    *p++ = htonl(stat->f_bavail);
    return xdr_ressize_check(rqstp, p);
}

int
nfssvc_encode_entry(void *ccdv, const char *name,
            int namlen, loff_t offset, u64 ino, unsigned int d_type)
{
    struct readdir_cd *ccd = ccdv;
    struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
    __be32  *p = cd->buffer;
    int buflen, slen;

    /*
    dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
            namlen, name, offset, ino);
     */

    if (offset > ~((u32) 0)) {
        cd->common.err = nfserr_fbig;
        return -EINVAL;
    }
    if (cd->offset)
        *cd->offset = htonl(offset);
    if (namlen > NFS2_MAXNAMLEN)
        namlen = NFS2_MAXNAMLEN;/* truncate filename */

    slen = XDR_QUADLEN(namlen);
    if ((buflen = cd->buflen - slen - 4) < 0) {
        cd->common.err = nfserr_toosmall;
        return -EINVAL;
    }
    if (ino > ~((u32) 0)) {
        cd->common.err = nfserr_fbig;
        return -EINVAL;
    }
    *p++ = xdr_one;             /* mark entry present */
    *p++ = htonl((u32) ino);        /* file id */
    p    = xdr_encode_array(p, name, namlen);/* name length & name */
    cd->offset = p;         /* remember pointer */
    *p++ = htonl(~0U);      /* offset of next entry */

    cd->buflen = buflen;
    cd->buffer = p;
    cd->common.err = nfs_ok;
    return 0;
}

/*
 * XDR release functions
 */
int
nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
                    struct nfsd_fhandle *resp)
{
    fh_put(&resp->fh);
    return 1;
}