svcauth_gss.c

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/*
 * Neil Brown <[email protected]>
 * J. Bruce Fields <[email protected]>
 * Andy Adamson <[email protected]>
 * Dug Song <[email protected]>
 *
 * RPCSEC_GSS server authentication.
 * This implements RPCSEC_GSS as defined in rfc2203 (rpcsec_gss) and rfc2078
 * (gssapi)
 *
 * The RPCSEC_GSS involves three stages:
 *  1/ context creation
 *  2/ data exchange
 *  3/ context destruction
 *
 * Context creation is handled largely by upcalls to user-space.
 *  In particular, GSS_Accept_sec_context is handled by an upcall
 * Data exchange is handled entirely within the kernel
 *  In particular, GSS_GetMIC, GSS_VerifyMIC, GSS_Seal, GSS_Unseal are in-kernel.
 * Context destruction is handled in-kernel
 *  GSS_Delete_sec_context is in-kernel
 *
 * Context creation is initiated by a RPCSEC_GSS_INIT request arriving.
 * The context handle and gss_token are used as a key into the rpcsec_init cache.
 * The content of this cache includes some of the outputs of GSS_Accept_sec_context,
 * being major_status, minor_status, context_handle, reply_token.
 * These are sent back to the client.
 * Sequence window management is handled by the kernel.  The window size if currently
 * a compile time constant.
 *
 * When user-space is happy that a context is established, it places an entry
 * in the rpcsec_context cache. The key for this cache is the context_handle.
 * The content includes:
 *   uid/gidlist - for determining access rights
 *   mechanism type
 *   mechanism specific information, such as a key
 *
 */

#include <linux/slab.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/user_namespace.h>

#include <linux/sunrpc/auth_gss.h>
#include <linux/sunrpc/gss_err.h>
#include <linux/sunrpc/svcauth.h>
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/sunrpc/cache.h>

#include "../netns.h"

#ifdef RPC_DEBUG
# define RPCDBG_FACILITY    RPCDBG_AUTH
#endif

/* The rpcsec_init cache is used for mapping RPCSEC_GSS_{,CONT_}INIT requests
 * into replies.
 *
 * Key is context handle (\x if empty) and gss_token.
 * Content is major_status minor_status (integers) context_handle, reply_token.
 *
 */

static int netobj_equal(struct xdr_netobj *a, struct xdr_netobj *b)
{
    return a->len == b->len && 0 == memcmp(a->data, b->data, a->len);
}

#define RSI_HASHBITS    6
#define RSI_HASHMAX (1<<RSI_HASHBITS)

struct rsi {
    struct cache_head   h;
    struct xdr_netobj   in_handle, in_token;
    struct xdr_netobj   out_handle, out_token;
    int         major_status, minor_status;
};

static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old);
static struct rsi *rsi_lookup(struct cache_detail *cd, struct rsi *item);

static void rsi_free(struct rsi *rsii)
{
    kfree(rsii->in_handle.data);
    kfree(rsii->in_token.data);
    kfree(rsii->out_handle.data);
    kfree(rsii->out_token.data);
}

static void rsi_put(struct kref *ref)
{
    struct rsi *rsii = container_of(ref, struct rsi, h.ref);
    rsi_free(rsii);
    kfree(rsii);
}

static inline int rsi_hash(struct rsi *item)
{
    return hash_mem(item->in_handle.data, item->in_handle.len, RSI_HASHBITS)
         ^ hash_mem(item->in_token.data, item->in_token.len, RSI_HASHBITS);
}

static int rsi_match(struct cache_head *a, struct cache_head *b)
{
    struct rsi *item = container_of(a, struct rsi, h);
    struct rsi *tmp = container_of(b, struct rsi, h);
    return netobj_equal(&item->in_handle, &tmp->in_handle) &&
           netobj_equal(&item->in_token, &tmp->in_token);
}

static int dup_to_netobj(struct xdr_netobj *dst, char *src, int len)
{
    dst->len = len;
    dst->data = (len ? kmemdup(src, len, GFP_KERNEL) : NULL);
    if (len && !dst->data)
        return -ENOMEM;
    return 0;
}

static inline int dup_netobj(struct xdr_netobj *dst, struct xdr_netobj *src)
{
    return dup_to_netobj(dst, src->data, src->len);
}

static void rsi_init(struct cache_head *cnew, struct cache_head *citem)
{
    struct rsi *new = container_of(cnew, struct rsi, h);
    struct rsi *item = container_of(citem, struct rsi, h);

    new->out_handle.data = NULL;
    new->out_handle.len = 0;
    new->out_token.data = NULL;
    new->out_token.len = 0;
    new->in_handle.len = item->in_handle.len;
    item->in_handle.len = 0;
    new->in_token.len = item->in_token.len;
    item->in_token.len = 0;
    new->in_handle.data = item->in_handle.data;
    item->in_handle.data = NULL;
    new->in_token.data = item->in_token.data;
    item->in_token.data = NULL;
}

static void update_rsi(struct cache_head *cnew, struct cache_head *citem)
{
    struct rsi *new = container_of(cnew, struct rsi, h);
    struct rsi *item = container_of(citem, struct rsi, h);

    BUG_ON(new->out_handle.data || new->out_token.data);
    new->out_handle.len = item->out_handle.len;
    item->out_handle.len = 0;
    new->out_token.len = item->out_token.len;
    item->out_token.len = 0;
    new->out_handle.data = item->out_handle.data;
    item->out_handle.data = NULL;
    new->out_token.data = item->out_token.data;
    item->out_token.data = NULL;

    new->major_status = item->major_status;
    new->minor_status = item->minor_status;
}

static struct cache_head *rsi_alloc(void)
{
    struct rsi *rsii = kmalloc(sizeof(*rsii), GFP_KERNEL);
    if (rsii)
        return &rsii->h;
    else
        return NULL;
}

static void rsi_request(struct cache_detail *cd,
               struct cache_head *h,
               char **bpp, int *blen)
{
    struct rsi *rsii = container_of(h, struct rsi, h);

    qword_addhex(bpp, blen, rsii->in_handle.data, rsii->in_handle.len);
    qword_addhex(bpp, blen, rsii->in_token.data, rsii->in_token.len);
    (*bpp)[-1] = '\n';
}

static int rsi_upcall(struct cache_detail *cd, struct cache_head *h)
{
    return sunrpc_cache_pipe_upcall(cd, h, rsi_request);
}


static int rsi_parse(struct cache_detail *cd,
            char *mesg, int mlen)
{
    /* context token expiry major minor context token */
    char *buf = mesg;
    char *ep;
    int len;
    struct rsi rsii, *rsip = NULL;
    time_t expiry;
    int status = -EINVAL;

    memset(&rsii, 0, sizeof(rsii));
    /* handle */
    len = qword_get(&mesg, buf, mlen);
    if (len < 0)
        goto out;
    status = -ENOMEM;
    if (dup_to_netobj(&rsii.in_handle, buf, len))
        goto out;

    /* token */
    len = qword_get(&mesg, buf, mlen);
    status = -EINVAL;
    if (len < 0)
        goto out;
    status = -ENOMEM;
    if (dup_to_netobj(&rsii.in_token, buf, len))
        goto out;

    rsip = rsi_lookup(cd, &rsii);
    if (!rsip)
        goto out;

    rsii.h.flags = 0;
    /* expiry */
    expiry = get_expiry(&mesg);
    status = -EINVAL;
    if (expiry == 0)
        goto out;

    /* major/minor */
    len = qword_get(&mesg, buf, mlen);
    if (len <= 0)
        goto out;
    rsii.major_status = simple_strtoul(buf, &ep, 10);
    if (*ep)
        goto out;
    len = qword_get(&mesg, buf, mlen);
    if (len <= 0)
        goto out;
    rsii.minor_status = simple_strtoul(buf, &ep, 10);
    if (*ep)
        goto out;

    /* out_handle */
    len = qword_get(&mesg, buf, mlen);
    if (len < 0)
        goto out;
    status = -ENOMEM;
    if (dup_to_netobj(&rsii.out_handle, buf, len))
        goto out;

    /* out_token */
    len = qword_get(&mesg, buf, mlen);
    status = -EINVAL;
    if (len < 0)
        goto out;
    status = -ENOMEM;
    if (dup_to_netobj(&rsii.out_token, buf, len))
        goto out;
    rsii.h.expiry_time = expiry;
    rsip = rsi_update(cd, &rsii, rsip);
    status = 0;
out:
    rsi_free(&rsii);
    if (rsip)
        cache_put(&rsip->h, cd);
    else
        status = -ENOMEM;
    return status;
}

static struct cache_detail rsi_cache_template = {
    .owner      = THIS_MODULE,
    .hash_size  = RSI_HASHMAX,
    .name           = "auth.rpcsec.init",
    .cache_put      = rsi_put,
    .cache_upcall   = rsi_upcall,
    .cache_parse    = rsi_parse,
    .match      = rsi_match,
    .init       = rsi_init,
    .update     = update_rsi,
    .alloc      = rsi_alloc,
};

static struct rsi *rsi_lookup(struct cache_detail *cd, struct rsi *item)
{
    struct cache_head *ch;
    int hash = rsi_hash(item);

    ch = sunrpc_cache_lookup(cd, &item->h, hash);
    if (ch)
        return container_of(ch, struct rsi, h);
    else
        return NULL;
}

static struct rsi *rsi_update(struct cache_detail *cd, struct rsi *new, struct rsi *old)
{
    struct cache_head *ch;
    int hash = rsi_hash(new);

    ch = sunrpc_cache_update(cd, &new->h,
                 &old->h, hash);
    if (ch)
        return container_of(ch, struct rsi, h);
    else
        return NULL;
}


/*
 * The rpcsec_context cache is used to store a context that is
 * used in data exchange.
 * The key is a context handle. The content is:
 *  uid, gidlist, mechanism, service-set, mech-specific-data
 */

#define RSC_HASHBITS    10
#define RSC_HASHMAX (1<<RSC_HASHBITS)

#define GSS_SEQ_WIN 128

struct gss_svc_seq_data {
    /* highest seq number seen so far: */
    int         sd_max;
    /* for i such that sd_max-GSS_SEQ_WIN < i <= sd_max, the i-th bit of
     * sd_win is nonzero iff sequence number i has been seen already: */
    unsigned long       sd_win[GSS_SEQ_WIN/BITS_PER_LONG];
    spinlock_t      sd_lock;
};

struct rsc {
    struct cache_head   h;
    struct xdr_netobj   handle;
    struct svc_cred     cred;
    struct gss_svc_seq_data seqdata;
    struct gss_ctx      *mechctx;
};

static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old);
static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item);

static void rsc_free(struct rsc *rsci)
{
    kfree(rsci->handle.data);
    if (rsci->mechctx)
        gss_delete_sec_context(&rsci->mechctx);
    free_svc_cred(&rsci->cred);
}

static void rsc_put(struct kref *ref)
{
    struct rsc *rsci = container_of(ref, struct rsc, h.ref);

    rsc_free(rsci);
    kfree(rsci);
}

static inline int
rsc_hash(struct rsc *rsci)
{
    return hash_mem(rsci->handle.data, rsci->handle.len, RSC_HASHBITS);
}

static int
rsc_match(struct cache_head *a, struct cache_head *b)
{
    struct rsc *new = container_of(a, struct rsc, h);
    struct rsc *tmp = container_of(b, struct rsc, h);

    return netobj_equal(&new->handle, &tmp->handle);
}

static void
rsc_init(struct cache_head *cnew, struct cache_head *ctmp)
{
    struct rsc *new = container_of(cnew, struct rsc, h);
    struct rsc *tmp = container_of(ctmp, struct rsc, h);

    new->handle.len = tmp->handle.len;
    tmp->handle.len = 0;
    new->handle.data = tmp->handle.data;
    tmp->handle.data = NULL;
    new->mechctx = NULL;
    new->cred.cr_group_info = NULL;
    new->cred.cr_principal = NULL;
}

static void
update_rsc(struct cache_head *cnew, struct cache_head *ctmp)
{
    struct rsc *new = container_of(cnew, struct rsc, h);
    struct rsc *tmp = container_of(ctmp, struct rsc, h);

    new->mechctx = tmp->mechctx;
    tmp->mechctx = NULL;
    memset(&new->seqdata, 0, sizeof(new->seqdata));
    spin_lock_init(&new->seqdata.sd_lock);
    new->cred = tmp->cred;
    tmp->cred.cr_group_info = NULL;
    new->cred.cr_principal = tmp->cred.cr_principal;
    tmp->cred.cr_principal = NULL;
}

static struct cache_head *
rsc_alloc(void)
{
    struct rsc *rsci = kmalloc(sizeof(*rsci), GFP_KERNEL);
    if (rsci)
        return &rsci->h;
    else
        return NULL;
}

static int rsc_parse(struct cache_detail *cd,
             char *mesg, int mlen)
{
    /* contexthandle expiry [ uid gid N <n gids> mechname ...mechdata... ] */
    char *buf = mesg;
    int len, rv;
    struct rsc rsci, *rscp = NULL;
    time_t expiry;
    int status = -EINVAL;
    struct gss_api_mech *gm = NULL;

    memset(&rsci, 0, sizeof(rsci));
    /* context handle */
    len = qword_get(&mesg, buf, mlen);
    if (len < 0) goto out;
    status = -ENOMEM;
    if (dup_to_netobj(&rsci.handle, buf, len))
        goto out;

    rsci.h.flags = 0;
    /* expiry */
    expiry = get_expiry(&mesg);
    status = -EINVAL;
    if (expiry == 0)
        goto out;

    rscp = rsc_lookup(cd, &rsci);
    if (!rscp)
        goto out;

    /* uid, or NEGATIVE */
    rv = get_int(&mesg, &rsci.cred.cr_uid);
    if (rv == -EINVAL)
        goto out;
    if (rv == -ENOENT)
        set_bit(CACHE_NEGATIVE, &rsci.h.flags);
    else {
        int N, i;

        /* gid */
        if (get_int(&mesg, &rsci.cred.cr_gid))
            goto out;

        /* number of additional gid's */
        if (get_int(&mesg, &N))
            goto out;
        status = -ENOMEM;
        rsci.cred.cr_group_info = groups_alloc(N);
        if (rsci.cred.cr_group_info == NULL)
            goto out;

        /* gid's */
        status = -EINVAL;
        for (i=0; i<N; i++) {
            gid_t gid;
            kgid_t kgid;
            if (get_int(&mesg, &gid))
                goto out;
            kgid = make_kgid(&init_user_ns, gid);
            if (!gid_valid(kgid))
                goto out;
            GROUP_AT(rsci.cred.cr_group_info, i) = kgid;
        }

        /* mech name */
        len = qword_get(&mesg, buf, mlen);
        if (len < 0)
            goto out;
        gm = gss_mech_get_by_name(buf);
        status = -EOPNOTSUPP;
        if (!gm)
            goto out;

        status = -EINVAL;
        /* mech-specific data: */
        len = qword_get(&mesg, buf, mlen);
        if (len < 0)
            goto out;
        status = gss_import_sec_context(buf, len, gm, &rsci.mechctx, GFP_KERNEL);
        if (status)
            goto out;

        /* get client name */
        len = qword_get(&mesg, buf, mlen);
        if (len > 0) {
            rsci.cred.cr_principal = kstrdup(buf, GFP_KERNEL);
            if (!rsci.cred.cr_principal)
                goto out;
        }

    }
    rsci.h.expiry_time = expiry;
    rscp = rsc_update(cd, &rsci, rscp);
    status = 0;
out:
    gss_mech_put(gm);
    rsc_free(&rsci);
    if (rscp)
        cache_put(&rscp->h, cd);
    else
        status = -ENOMEM;
    return status;
}

static struct cache_detail rsc_cache_template = {
    .owner      = THIS_MODULE,
    .hash_size  = RSC_HASHMAX,
    .name       = "auth.rpcsec.context",
    .cache_put  = rsc_put,
    .cache_parse    = rsc_parse,
    .match      = rsc_match,
    .init       = rsc_init,
    .update     = update_rsc,
    .alloc      = rsc_alloc,
};

static struct rsc *rsc_lookup(struct cache_detail *cd, struct rsc *item)
{
    struct cache_head *ch;
    int hash = rsc_hash(item);

    ch = sunrpc_cache_lookup(cd, &item->h, hash);
    if (ch)
        return container_of(ch, struct rsc, h);
    else
        return NULL;
}

static struct rsc *rsc_update(struct cache_detail *cd, struct rsc *new, struct rsc *old)
{
    struct cache_head *ch;
    int hash = rsc_hash(new);

    ch = sunrpc_cache_update(cd, &new->h,
                 &old->h, hash);
    if (ch)
        return container_of(ch, struct rsc, h);
    else
        return NULL;
}


static struct rsc *
gss_svc_searchbyctx(struct cache_detail *cd, struct xdr_netobj *handle)
{
    struct rsc rsci;
    struct rsc *found;

    memset(&rsci, 0, sizeof(rsci));
    if (dup_to_netobj(&rsci.handle, handle->data, handle->len))
        return NULL;
    found = rsc_lookup(cd, &rsci);
    rsc_free(&rsci);
    if (!found)
        return NULL;
    if (cache_check(cd, &found->h, NULL))
        return NULL;
    return found;
}

/* Implements sequence number algorithm as specified in RFC 2203. */
static int
gss_check_seq_num(struct rsc *rsci, int seq_num)
{
    struct gss_svc_seq_data *sd = &rsci->seqdata;

    spin_lock(&sd->sd_lock);
    if (seq_num > sd->sd_max) {
        if (seq_num >= sd->sd_max + GSS_SEQ_WIN) {
            memset(sd->sd_win,0,sizeof(sd->sd_win));
            sd->sd_max = seq_num;
        } else while (sd->sd_max < seq_num) {
            sd->sd_max++;
            __clear_bit(sd->sd_max % GSS_SEQ_WIN, sd->sd_win);
        }
        __set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win);
        goto ok;
    } else if (seq_num <= sd->sd_max - GSS_SEQ_WIN) {
        goto drop;
    }
    /* sd_max - GSS_SEQ_WIN < seq_num <= sd_max */
    if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win))
        goto drop;
ok:
    spin_unlock(&sd->sd_lock);
    return 1;
drop:
    spin_unlock(&sd->sd_lock);
    return 0;
}

static inline u32 round_up_to_quad(u32 i)
{
    return (i + 3 ) & ~3;
}

static inline int
svc_safe_getnetobj(struct kvec *argv, struct xdr_netobj *o)
{
    int l;

    if (argv->iov_len < 4)
        return -1;
    o->len = svc_getnl(argv);
    l = round_up_to_quad(o->len);
    if (argv->iov_len < l)
        return -1;
    o->data = argv->iov_base;
    argv->iov_base += l;
    argv->iov_len -= l;
    return 0;
}

static inline int
svc_safe_putnetobj(struct kvec *resv, struct xdr_netobj *o)
{
    u8 *p;

    if (resv->iov_len + 4 > PAGE_SIZE)
        return -1;
    svc_putnl(resv, o->len);
    p = resv->iov_base + resv->iov_len;
    resv->iov_len += round_up_to_quad(o->len);
    if (resv->iov_len > PAGE_SIZE)
        return -1;
    memcpy(p, o->data, o->len);
    memset(p + o->len, 0, round_up_to_quad(o->len) - o->len);
    return 0;
}

/*
 * Verify the checksum on the header and return SVC_OK on success.
 * Otherwise, return SVC_DROP (in the case of a bad sequence number)
 * or return SVC_DENIED and indicate error in authp.
 */
static int
gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci,
          __be32 *rpcstart, struct rpc_gss_wire_cred *gc, __be32 *authp)
{
    struct gss_ctx      *ctx_id = rsci->mechctx;
    struct xdr_buf      rpchdr;
    struct xdr_netobj   checksum;
    u32         flavor = 0;
    struct kvec     *argv = &rqstp->rq_arg.head[0];
    struct kvec     iov;

    /* data to compute the checksum over: */
    iov.iov_base = rpcstart;
    iov.iov_len = (u8 *)argv->iov_base - (u8 *)rpcstart;
    xdr_buf_from_iov(&iov, &rpchdr);

    *authp = rpc_autherr_badverf;
    if (argv->iov_len < 4)
        return SVC_DENIED;
    flavor = svc_getnl(argv);
    if (flavor != RPC_AUTH_GSS)
        return SVC_DENIED;
    if (svc_safe_getnetobj(argv, &checksum))
        return SVC_DENIED;

    if (rqstp->rq_deferred) /* skip verification of revisited request */
        return SVC_OK;
    if (gss_verify_mic(ctx_id, &rpchdr, &checksum) != GSS_S_COMPLETE) {
        *authp = rpcsec_gsserr_credproblem;
        return SVC_DENIED;
    }

    if (gc->gc_seq > MAXSEQ) {
        dprintk("RPC:       svcauth_gss: discarding request with "
                "large sequence number %d\n", gc->gc_seq);
        *authp = rpcsec_gsserr_ctxproblem;
        return SVC_DENIED;
    }
    if (!gss_check_seq_num(rsci, gc->gc_seq)) {
        dprintk("RPC:       svcauth_gss: discarding request with "
                "old sequence number %d\n", gc->gc_seq);
        return SVC_DROP;
    }
    return SVC_OK;
}

static int
gss_write_null_verf(struct svc_rqst *rqstp)
{
    __be32     *p;

    svc_putnl(rqstp->rq_res.head, RPC_AUTH_NULL);
    p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
    /* don't really need to check if head->iov_len > PAGE_SIZE ... */
    *p++ = 0;
    if (!xdr_ressize_check(rqstp, p))
        return -1;
    return 0;
}

static int
gss_write_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq)
{
    __be32          xdr_seq;
    u32         maj_stat;
    struct xdr_buf      verf_data;
    struct xdr_netobj   mic;
    __be32          *p;
    struct kvec     iov;

    svc_putnl(rqstp->rq_res.head, RPC_AUTH_GSS);
    xdr_seq = htonl(seq);

    iov.iov_base = &xdr_seq;
    iov.iov_len = sizeof(xdr_seq);
    xdr_buf_from_iov(&iov, &verf_data);
    p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;
    mic.data = (u8 *)(p + 1);
    maj_stat = gss_get_mic(ctx_id, &verf_data, &mic);
    if (maj_stat != GSS_S_COMPLETE)
        return -1;
    *p++ = htonl(mic.len);
    memset((u8 *)p + mic.len, 0, round_up_to_quad(mic.len) - mic.len);
    p += XDR_QUADLEN(mic.len);
    if (!xdr_ressize_check(rqstp, p))
        return -1;
    return 0;
}

struct gss_domain {
    struct auth_domain  h;
    u32         pseudoflavor;
};

static struct auth_domain *
find_gss_auth_domain(struct gss_ctx *ctx, u32 svc)
{
    char *name;

    name = gss_service_to_auth_domain_name(ctx->mech_type, svc);
    if (!name)
        return NULL;
    return auth_domain_find(name);
}

static struct auth_ops svcauthops_gss;

u32 svcauth_gss_flavor(struct auth_domain *dom)
{
    struct gss_domain *gd = container_of(dom, struct gss_domain, h);

    return gd->pseudoflavor;
}

EXPORT_SYMBOL_GPL(svcauth_gss_flavor);

int
svcauth_gss_register_pseudoflavor(u32 pseudoflavor, char * name)
{
    struct gss_domain   *new;
    struct auth_domain  *test;
    int         stat = -ENOMEM;

    new = kmalloc(sizeof(*new), GFP_KERNEL);
    if (!new)
        goto out;
    kref_init(&new->h.ref);
    new->h.name = kstrdup(name, GFP_KERNEL);
    if (!new->h.name)
        goto out_free_dom;
    new->h.flavour = &svcauthops_gss;
    new->pseudoflavor = pseudoflavor;

    stat = 0;
    test = auth_domain_lookup(name, &new->h);
    if (test != &new->h) { /* Duplicate registration */
        auth_domain_put(test);
        kfree(new->h.name);
        goto out_free_dom;
    }
    return 0;

out_free_dom:
    kfree(new);
out:
    return stat;
}

EXPORT_SYMBOL_GPL(svcauth_gss_register_pseudoflavor);

static inline int
read_u32_from_xdr_buf(struct xdr_buf *buf, int base, u32 *obj)
{
    __be32  raw;
    int     status;

    status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
    if (status)
        return status;
    *obj = ntohl(raw);
    return 0;
}

/* It would be nice if this bit of code could be shared with the client.
 * Obstacles:
 *  The client shouldn't malloc(), would have to pass in own memory.
 *  The server uses base of head iovec as read pointer, while the
 *  client uses separate pointer. */
static int
unwrap_integ_data(struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
{
    int stat = -EINVAL;
    u32 integ_len, maj_stat;
    struct xdr_netobj mic;
    struct xdr_buf integ_buf;

    integ_len = svc_getnl(&buf->head[0]);
    if (integ_len & 3)
        return stat;
    if (integ_len > buf->len)
        return stat;
    if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len))
        BUG();
    /* copy out mic... */
    if (read_u32_from_xdr_buf(buf, integ_len, &mic.len))
        BUG();
    if (mic.len > RPC_MAX_AUTH_SIZE)
        return stat;
    mic.data = kmalloc(mic.len, GFP_KERNEL);
    if (!mic.data)
        return stat;
    if (read_bytes_from_xdr_buf(buf, integ_len + 4, mic.data, mic.len))
        goto out;
    maj_stat = gss_verify_mic(ctx, &integ_buf, &mic);
    if (maj_stat != GSS_S_COMPLETE)
        goto out;
    if (svc_getnl(&buf->head[0]) != seq)
        goto out;
    stat = 0;
out:
    kfree(mic.data);
    return stat;
}

static inline int
total_buf_len(struct xdr_buf *buf)
{
    return buf->head[0].iov_len + buf->page_len + buf->tail[0].iov_len;
}

static void
fix_priv_head(struct xdr_buf *buf, int pad)
{
    if (buf->page_len == 0) {
        /* We need to adjust head and buf->len in tandem in this
         * case to make svc_defer() work--it finds the original
         * buffer start using buf->len - buf->head[0].iov_len. */
        buf->head[0].iov_len -= pad;
    }
}

static int
unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gss_ctx *ctx)
{
    u32 priv_len, maj_stat;
    int pad, saved_len, remaining_len, offset;

    rqstp->rq_splice_ok = 0;

    priv_len = svc_getnl(&buf->head[0]);
    if (rqstp->rq_deferred) {
        /* Already decrypted last time through! The sequence number
         * check at out_seq is unnecessary but harmless: */
        goto out_seq;
    }
    /* buf->len is the number of bytes from the original start of the
     * request to the end, where head[0].iov_len is just the bytes
     * not yet read from the head, so these two values are different: */
    remaining_len = total_buf_len(buf);
    if (priv_len > remaining_len)
        return -EINVAL;
    pad = remaining_len - priv_len;
    buf->len -= pad;
    fix_priv_head(buf, pad);

    /* Maybe it would be better to give gss_unwrap a length parameter: */
    saved_len = buf->len;
    buf->len = priv_len;
    maj_stat = gss_unwrap(ctx, 0, buf);
    pad = priv_len - buf->len;
    buf->len = saved_len;
    buf->len -= pad;
    /* The upper layers assume the buffer is aligned on 4-byte boundaries.
     * In the krb5p case, at least, the data ends up offset, so we need to
     * move it around. */
    /* XXX: This is very inefficient.  It would be better to either do
     * this while we encrypt, or maybe in the receive code, if we can peak
     * ahead and work out the service and mechanism there. */
    offset = buf->head[0].iov_len % 4;
    if (offset) {
        buf->buflen = RPCSVC_MAXPAYLOAD;
        xdr_shift_buf(buf, offset);
        fix_priv_head(buf, pad);
    }
    if (maj_stat != GSS_S_COMPLETE)
        return -EINVAL;
out_seq:
    if (svc_getnl(&buf->head[0]) != seq)
        return -EINVAL;
    return 0;
}

struct gss_svc_data {
    /* decoded gss client cred: */
    struct rpc_gss_wire_cred    clcred;
    /* save a pointer to the beginning of the encoded verifier,
     * for use in encryption/checksumming in svcauth_gss_release: */
    __be32              *verf_start;
    struct rsc          *rsci;
};

static int
svcauth_gss_set_client(struct svc_rqst *rqstp)
{
    struct gss_svc_data *svcdata = rqstp->rq_auth_data;
    struct rsc *rsci = svcdata->rsci;
    struct rpc_gss_wire_cred *gc = &svcdata->clcred;
    int stat;

    /*
     * A gss export can be specified either by:
     *  export  *(sec=krb5,rw)
     * or by
     *  export gss/krb5(rw)
     * The latter is deprecated; but for backwards compatibility reasons
     * the nfsd code will still fall back on trying it if the former
     * doesn't work; so we try to make both available to nfsd, below.
     */
    rqstp->rq_gssclient = find_gss_auth_domain(rsci->mechctx, gc->gc_svc);
    if (rqstp->rq_gssclient == NULL)
        return SVC_DENIED;
    stat = svcauth_unix_set_client(rqstp);
    if (stat == SVC_DROP || stat == SVC_CLOSE)
        return stat;
    return SVC_OK;
}

static inline int
gss_write_init_verf(struct cache_detail *cd, struct svc_rqst *rqstp,
        struct xdr_netobj *out_handle, int *major_status)
{
    struct rsc *rsci;
    int        rc;

    if (*major_status != GSS_S_COMPLETE)
        return gss_write_null_verf(rqstp);
    rsci = gss_svc_searchbyctx(cd, out_handle);
    if (rsci == NULL) {
        *major_status = GSS_S_NO_CONTEXT;
        return gss_write_null_verf(rqstp);
    }
    rc = gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN);
    cache_put(&rsci->h, cd);
    return rc;
}

static inline int
gss_read_verf(struct rpc_gss_wire_cred *gc,
          struct kvec *argv, __be32 *authp,
          struct xdr_netobj *in_handle,
          struct xdr_netobj *in_token)
{
    struct xdr_netobj tmpobj;

    /* Read the verifier; should be NULL: */
    *authp = rpc_autherr_badverf;
    if (argv->iov_len < 2 * 4)
        return SVC_DENIED;
    if (svc_getnl(argv) != RPC_AUTH_NULL)
        return SVC_DENIED;
    if (svc_getnl(argv) != 0)
        return SVC_DENIED;
    /* Martial context handle and token for upcall: */
    *authp = rpc_autherr_badcred;
    if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0)
        return SVC_DENIED;
    if (dup_netobj(in_handle, &gc->gc_ctx))
        return SVC_CLOSE;
    *authp = rpc_autherr_badverf;
    if (svc_safe_getnetobj(argv, &tmpobj)) {
        kfree(in_handle->data);
        return SVC_DENIED;
    }
    if (dup_netobj(in_token, &tmpobj)) {
        kfree(in_handle->data);
        return SVC_CLOSE;
    }

    return 0;
}

static inline int
gss_write_resv(struct kvec *resv, size_t size_limit,
           struct xdr_netobj *out_handle, struct xdr_netobj *out_token,
           int major_status, int minor_status)
{
    if (resv->iov_len + 4 > size_limit)
        return -1;
    svc_putnl(resv, RPC_SUCCESS);
    if (svc_safe_putnetobj(resv, out_handle))
        return -1;
    if (resv->iov_len + 3 * 4 > size_limit)
        return -1;
    svc_putnl(resv, major_status);
    svc_putnl(resv, minor_status);
    svc_putnl(resv, GSS_SEQ_WIN);
    if (svc_safe_putnetobj(resv, out_token))
        return -1;
    return 0;
}

/*
 * Having read the cred already and found we're in the context
 * initiation case, read the verifier and initiate (or check the results
 * of) upcalls to userspace for help with context initiation.  If
 * the upcall results are available, write the verifier and result.
 * Otherwise, drop the request pending an answer to the upcall.
 */
static int svcauth_gss_handle_init(struct svc_rqst *rqstp,
            struct rpc_gss_wire_cred *gc, __be32 *authp)
{
    struct kvec *argv = &rqstp->rq_arg.head[0];
    struct kvec *resv = &rqstp->rq_res.head[0];
    struct rsi *rsip, rsikey;
    int ret;
    struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);

    memset(&rsikey, 0, sizeof(rsikey));
    ret = gss_read_verf(gc, argv, authp,
                &rsikey.in_handle, &rsikey.in_token);
    if (ret)
        return ret;

    /* Perform upcall, or find upcall result: */
    rsip = rsi_lookup(sn->rsi_cache, &rsikey);
    rsi_free(&rsikey);
    if (!rsip)
        return SVC_CLOSE;
    if (cache_check(sn->rsi_cache, &rsip->h, &rqstp->rq_chandle) < 0)
        /* No upcall result: */
        return SVC_CLOSE;

    ret = SVC_CLOSE;
    /* Got an answer to the upcall; use it: */
    if (gss_write_init_verf(sn->rsc_cache, rqstp,
                &rsip->out_handle, &rsip->major_status))
        goto out;
    if (gss_write_resv(resv, PAGE_SIZE,
               &rsip->out_handle, &rsip->out_token,
               rsip->major_status, rsip->minor_status))
        goto out;

    ret = SVC_COMPLETE;
out:
    cache_put(&rsip->h, sn->rsi_cache);
    return ret;
}

/*
 * Accept an rpcsec packet.
 * If context establishment, punt to user space
 * If data exchange, verify/decrypt
 * If context destruction, handle here
 * In the context establishment and destruction case we encode
 * response here and return SVC_COMPLETE.
 */
static int
svcauth_gss_accept(struct svc_rqst *rqstp, __be32 *authp)
{
    struct kvec *argv = &rqstp->rq_arg.head[0];
    struct kvec *resv = &rqstp->rq_res.head[0];
    u32     crlen;
    struct gss_svc_data *svcdata = rqstp->rq_auth_data;
    struct rpc_gss_wire_cred *gc;
    struct rsc  *rsci = NULL;
    __be32      *rpcstart;
    __be32      *reject_stat = resv->iov_base + resv->iov_len;
    int     ret;
    struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);

    dprintk("RPC:       svcauth_gss: argv->iov_len = %zd\n",
            argv->iov_len);

    *authp = rpc_autherr_badcred;
    if (!svcdata)
        svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL);
    if (!svcdata)
        goto auth_err;
    rqstp->rq_auth_data = svcdata;
    svcdata->verf_start = NULL;
    svcdata->rsci = NULL;
    gc = &svcdata->clcred;

    /* start of rpc packet is 7 u32's back from here:
     * xid direction rpcversion prog vers proc flavour
     */
    rpcstart = argv->iov_base;
    rpcstart -= 7;

    /* credential is:
     *   version(==1), proc(0,1,2,3), seq, service (1,2,3), handle
     * at least 5 u32s, and is preceded by length, so that makes 6.
     */

    if (argv->iov_len < 5 * 4)
        goto auth_err;
    crlen = svc_getnl(argv);
    if (svc_getnl(argv) != RPC_GSS_VERSION)
        goto auth_err;
    gc->gc_proc = svc_getnl(argv);
    gc->gc_seq = svc_getnl(argv);
    gc->gc_svc = svc_getnl(argv);
    if (svc_safe_getnetobj(argv, &gc->gc_ctx))
        goto auth_err;
    if (crlen != round_up_to_quad(gc->gc_ctx.len) + 5 * 4)
        goto auth_err;

    if ((gc->gc_proc != RPC_GSS_PROC_DATA) && (rqstp->rq_proc != 0))
        goto auth_err;

    *authp = rpc_autherr_badverf;
    switch (gc->gc_proc) {
    case RPC_GSS_PROC_INIT:
    case RPC_GSS_PROC_CONTINUE_INIT:
        return svcauth_gss_handle_init(rqstp, gc, authp);
    case RPC_GSS_PROC_DATA:
    case RPC_GSS_PROC_DESTROY:
        /* Look up the context, and check the verifier: */
        *authp = rpcsec_gsserr_credproblem;
        rsci = gss_svc_searchbyctx(sn->rsc_cache, &gc->gc_ctx);
        if (!rsci)
            goto auth_err;
        switch (gss_verify_header(rqstp, rsci, rpcstart, gc, authp)) {
        case SVC_OK:
            break;
        case SVC_DENIED:
            goto auth_err;
        case SVC_DROP:
            goto drop;
        }
        break;
    default:
        *authp = rpc_autherr_rejectedcred;
        goto auth_err;
    }

    /* now act upon the command: */
    switch (gc->gc_proc) {
    case RPC_GSS_PROC_DESTROY:
        if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
            goto auth_err;
        rsci->h.expiry_time = get_seconds();
        set_bit(CACHE_NEGATIVE, &rsci->h.flags);
        if (resv->iov_len + 4 > PAGE_SIZE)
            goto drop;
        svc_putnl(resv, RPC_SUCCESS);
        goto complete;
    case RPC_GSS_PROC_DATA:
        *authp = rpcsec_gsserr_ctxproblem;
        svcdata->verf_start = resv->iov_base + resv->iov_len;
        if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
            goto auth_err;
        rqstp->rq_cred = rsci->cred;
        get_group_info(rsci->cred.cr_group_info);
        *authp = rpc_autherr_badcred;
        switch (gc->gc_svc) {
        case RPC_GSS_SVC_NONE:
            break;
        case RPC_GSS_SVC_INTEGRITY:
            /* placeholders for length and seq. number: */
            svc_putnl(resv, 0);
            svc_putnl(resv, 0);
            if (unwrap_integ_data(&rqstp->rq_arg,
                    gc->gc_seq, rsci->mechctx))
                goto garbage_args;
            break;
        case RPC_GSS_SVC_PRIVACY:
            /* placeholders for length and seq. number: */
            svc_putnl(resv, 0);
            svc_putnl(resv, 0);
            if (unwrap_priv_data(rqstp, &rqstp->rq_arg,
                    gc->gc_seq, rsci->mechctx))
                goto garbage_args;
            break;
        default:
            goto auth_err;
        }
        svcdata->rsci = rsci;
        cache_get(&rsci->h);
        rqstp->rq_cred.cr_flavor = gss_svc_to_pseudoflavor(
                    rsci->mechctx->mech_type, gc->gc_svc);
        ret = SVC_OK;
        goto out;
    }
garbage_args:
    ret = SVC_GARBAGE;
    goto out;
auth_err:
    /* Restore write pointer to its original value: */
    xdr_ressize_check(rqstp, reject_stat);
    ret = SVC_DENIED;
    goto out;
complete:
    ret = SVC_COMPLETE;
    goto out;
drop:
    ret = SVC_DROP;
out:
    if (rsci)
        cache_put(&rsci->h, sn->rsc_cache);
    return ret;
}

static __be32 *
svcauth_gss_prepare_to_wrap(struct xdr_buf *resbuf, struct gss_svc_data *gsd)
{
    __be32 *p;
    u32 verf_len;

    p = gsd->verf_start;
    gsd->verf_start = NULL;

    /* If the reply stat is nonzero, don't wrap: */
    if (*(p-1) != rpc_success)
        return NULL;
    /* Skip the verifier: */
    p += 1;
    verf_len = ntohl(*p++);
    p += XDR_QUADLEN(verf_len);
    /* move accept_stat to right place: */
    memcpy(p, p + 2, 4);
    /* Also don't wrap if the accept stat is nonzero: */
    if (*p != rpc_success) {
        resbuf->head[0].iov_len -= 2 * 4;
        return NULL;
    }
    p++;
    return p;
}

static inline int
svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
{
    struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
    struct rpc_gss_wire_cred *gc = &gsd->clcred;
    struct xdr_buf *resbuf = &rqstp->rq_res;
    struct xdr_buf integ_buf;
    struct xdr_netobj mic;
    struct kvec *resv;
    __be32 *p;
    int integ_offset, integ_len;
    int stat = -EINVAL;

    p = svcauth_gss_prepare_to_wrap(resbuf, gsd);
    if (p == NULL)
        goto out;
    integ_offset = (u8 *)(p + 1) - (u8 *)resbuf->head[0].iov_base;
    integ_len = resbuf->len - integ_offset;
    BUG_ON(integ_len % 4);
    *p++ = htonl(integ_len);
    *p++ = htonl(gc->gc_seq);
    if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset,
                integ_len))
        BUG();
    if (resbuf->tail[0].iov_base == NULL) {
        if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE)
            goto out_err;
        resbuf->tail[0].iov_base = resbuf->head[0].iov_base
                        + resbuf->head[0].iov_len;
        resbuf->tail[0].iov_len = 0;
        resv = &resbuf->tail[0];
    } else {
        resv = &resbuf->tail[0];
    }
    mic.data = (u8 *)resv->iov_base + resv->iov_len + 4;
    if (gss_get_mic(gsd->rsci->mechctx, &integ_buf, &mic))
        goto out_err;
    svc_putnl(resv, mic.len);
    memset(mic.data + mic.len, 0,
            round_up_to_quad(mic.len) - mic.len);
    resv->iov_len += XDR_QUADLEN(mic.len) << 2;
    /* not strictly required: */
    resbuf->len += XDR_QUADLEN(mic.len) << 2;
    BUG_ON(resv->iov_len > PAGE_SIZE);
out:
    stat = 0;
out_err:
    return stat;
}

static inline int
svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp)
{
    struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
    struct rpc_gss_wire_cred *gc = &gsd->clcred;
    struct xdr_buf *resbuf = &rqstp->rq_res;
    struct page **inpages = NULL;
    __be32 *p, *len;
    int offset;
    int pad;

    p = svcauth_gss_prepare_to_wrap(resbuf, gsd);
    if (p == NULL)
        return 0;
    len = p++;
    offset = (u8 *)p - (u8 *)resbuf->head[0].iov_base;
    *p++ = htonl(gc->gc_seq);
    inpages = resbuf->pages;
    /* XXX: Would be better to write some xdr helper functions for
     * nfs{2,3,4}xdr.c that place the data right, instead of copying: */

    /*
     * If there is currently tail data, make sure there is
     * room for the head, tail, and 2 * RPC_MAX_AUTH_SIZE in
     * the page, and move the current tail data such that
     * there is RPC_MAX_AUTH_SIZE slack space available in
     * both the head and tail.
     */
    if (resbuf->tail[0].iov_base) {
        BUG_ON(resbuf->tail[0].iov_base >= resbuf->head[0].iov_base
                            + PAGE_SIZE);
        BUG_ON(resbuf->tail[0].iov_base < resbuf->head[0].iov_base);
        if (resbuf->tail[0].iov_len + resbuf->head[0].iov_len
                + 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE)
            return -ENOMEM;
        memmove(resbuf->tail[0].iov_base + RPC_MAX_AUTH_SIZE,
            resbuf->tail[0].iov_base,
            resbuf->tail[0].iov_len);
        resbuf->tail[0].iov_base += RPC_MAX_AUTH_SIZE;
    }
    /*
     * If there is no current tail data, make sure there is
     * room for the head data, and 2 * RPC_MAX_AUTH_SIZE in the
     * allotted page, and set up tail information such that there
     * is RPC_MAX_AUTH_SIZE slack space available in both the
     * head and tail.
     */
    if (resbuf->tail[0].iov_base == NULL) {
        if (resbuf->head[0].iov_len + 2*RPC_MAX_AUTH_SIZE > PAGE_SIZE)
            return -ENOMEM;
        resbuf->tail[0].iov_base = resbuf->head[0].iov_base
            + resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE;
        resbuf->tail[0].iov_len = 0;
    }
    if (gss_wrap(gsd->rsci->mechctx, offset, resbuf, inpages))
        return -ENOMEM;
    *len = htonl(resbuf->len - offset);
    pad = 3 - ((resbuf->len - offset - 1)&3);
    p = (__be32 *)(resbuf->tail[0].iov_base + resbuf->tail[0].iov_len);
    memset(p, 0, pad);
    resbuf->tail[0].iov_len += pad;
    resbuf->len += pad;
    return 0;
}

static int
svcauth_gss_release(struct svc_rqst *rqstp)
{
    struct gss_svc_data *gsd = (struct gss_svc_data *)rqstp->rq_auth_data;
    struct rpc_gss_wire_cred *gc = &gsd->clcred;
    struct xdr_buf *resbuf = &rqstp->rq_res;
    int stat = -EINVAL;
    struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net, sunrpc_net_id);

    if (gc->gc_proc != RPC_GSS_PROC_DATA)
        goto out;
    /* Release can be called twice, but we only wrap once. */
    if (gsd->verf_start == NULL)
        goto out;
    /* normally not set till svc_send, but we need it here: */
    /* XXX: what for?  Do we mess it up the moment we call svc_putu32
     * or whatever? */
    resbuf->len = total_buf_len(resbuf);
    switch (gc->gc_svc) {
    case RPC_GSS_SVC_NONE:
        break;
    case RPC_GSS_SVC_INTEGRITY:
        stat = svcauth_gss_wrap_resp_integ(rqstp);
        if (stat)
            goto out_err;
        break;
    case RPC_GSS_SVC_PRIVACY:
        stat = svcauth_gss_wrap_resp_priv(rqstp);
        if (stat)
            goto out_err;
        break;
    /*
     * For any other gc_svc value, svcauth_gss_accept() already set
     * the auth_error appropriately; just fall through:
     */
    }

out:
    stat = 0;
out_err:
    if (rqstp->rq_client)
        auth_domain_put(rqstp->rq_client);
    rqstp->rq_client = NULL;
    if (rqstp->rq_gssclient)
        auth_domain_put(rqstp->rq_gssclient);
    rqstp->rq_gssclient = NULL;
    if (rqstp->rq_cred.cr_group_info)
        put_group_info(rqstp->rq_cred.cr_group_info);
    rqstp->rq_cred.cr_group_info = NULL;
    if (gsd->rsci)
        cache_put(&gsd->rsci->h, sn->rsc_cache);
    gsd->rsci = NULL;

    return stat;
}

static void
svcauth_gss_domain_release(struct auth_domain *dom)
{
    struct gss_domain *gd = container_of(dom, struct gss_domain, h);

    kfree(dom->name);
    kfree(gd);
}

static struct auth_ops svcauthops_gss = {
    .name       = "rpcsec_gss",
    .owner      = THIS_MODULE,
    .flavour    = RPC_AUTH_GSS,
    .accept     = svcauth_gss_accept,
    .release    = svcauth_gss_release,
    .domain_release = svcauth_gss_domain_release,
    .set_client = svcauth_gss_set_client,
};

static int rsi_cache_create_net(struct net *net)
{
    struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
    struct cache_detail *cd;
    int err;

    cd = cache_create_net(&rsi_cache_template, net);
    if (IS_ERR(cd))
        return PTR_ERR(cd);
    err = cache_register_net(cd, net);
    if (err) {
        cache_destroy_net(cd, net);
        return err;
    }
    sn->rsi_cache = cd;
    return 0;
}

static void rsi_cache_destroy_net(struct net *net)
{
    struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
    struct cache_detail *cd = sn->rsi_cache;

    sn->rsi_cache = NULL;
    cache_purge(cd);
    cache_unregister_net(cd, net);
    cache_destroy_net(cd, net);
}

static int rsc_cache_create_net(struct net *net)
{
    struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
    struct cache_detail *cd;
    int err;

    cd = cache_create_net(&rsc_cache_template, net);
    if (IS_ERR(cd))
        return PTR_ERR(cd);
    err = cache_register_net(cd, net);
    if (err) {
        cache_destroy_net(cd, net);
        return err;
    }
    sn->rsc_cache = cd;
    return 0;
}

static void rsc_cache_destroy_net(struct net *net)
{
    struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
    struct cache_detail *cd = sn->rsc_cache;

    sn->rsc_cache = NULL;
    cache_purge(cd);
    cache_unregister_net(cd, net);
    cache_destroy_net(cd, net);
}

int
gss_svc_init_net(struct net *net)
{
    int rv;

    rv = rsc_cache_create_net(net);
    if (rv)
        return rv;
    rv = rsi_cache_create_net(net);
    if (rv)
        goto out1;
    return 0;
out1:
    rsc_cache_destroy_net(net);
    return rv;
}

void
gss_svc_shutdown_net(struct net *net)
{
    rsi_cache_destroy_net(net);
    rsc_cache_destroy_net(net);
}

int
gss_svc_init(void)
{
    return svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss);
}

void
gss_svc_shutdown(void)
{
    svc_auth_unregister(RPC_AUTH_GSS);
}