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linux-zen-desktop/net/sunrpc/auth_gss/svcauth_gss.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Neil Brown <neilb@cse.unsw.edu.au>
* J. Bruce Fields <bfields@umich.edu>
* Andy Adamson <andros@umich.edu>
* Dug Song <dugsong@monkey.org>
*
* 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 <linux/sunrpc/gss_krb5.h>
#include <trace/events/rpcgss.h>
#include "gss_rpc_upcall.h"
/*
* Unfortunately there isn't a maximum checksum size exported via the
* GSS API. Manufacture one based on GSS mechanisms supported by this
* implementation.
*/
#define GSS_MAX_CKSUMSIZE (GSS_KRB5_TOK_HDR_LEN + GSS_KRB5_MAX_CKSUM_LEN)
/*
* This value may be increased in the future to accommodate other
* usage of the scratch buffer.
*/
#define GSS_SCRATCH_SIZE GSS_MAX_CKSUMSIZE
struct gss_svc_data {
/* decoded gss client cred: */
struct rpc_gss_wire_cred clcred;
u32 gsd_databody_offset;
struct rsc *rsci;
/* for temporary results */
__be32 gsd_seq_num;
u8 gsd_scratch[GSS_SCRATCH_SIZE];
};
/* 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;
struct rcu_head rcu_head;
};
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_free_rcu(struct rcu_head *head)
{
struct rsi *rsii = container_of(head, struct rsi, rcu_head);
rsi_free(rsii);
kfree(rsii);
}
static void rsi_put(struct kref *ref)
{
struct rsi *rsii = container_of(ref, struct rsi, h.ref);
call_rcu(&rsii->rcu_head, rsi_free_rcu);
}
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 int rsi_upcall(struct cache_detail *cd, struct cache_head *h)
{
return sunrpc_cache_pipe_upcall_timeout(cd, h);
}
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';
WARN_ONCE(*blen < 0,
"RPCSEC/GSS credential too large - please use gssproxy\n");
}
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;
time64_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 const 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_request = rsi_request,
.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_rcu(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: */
u32 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;
struct rcu_head rcu_head;
};
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_free_rcu(struct rcu_head *head)
{
struct rsc *rsci = container_of(head, struct rsc, rcu_head);
kfree(rsci->handle.data);
kfree(rsci);
}
static void rsc_put(struct kref *ref)
{
struct rsc *rsci = container_of(ref, struct rsc, h.ref);
if (rsci->mechctx)
gss_delete_sec_context(&rsci->mechctx);
free_svc_cred(&rsci->cred);
call_rcu(&rsci->rcu_head, rsc_free_rcu);
}
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;
init_svc_cred(&new->cred);
}
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;
init_svc_cred(&tmp->cred);
}
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_upcall(struct cache_detail *cd, struct cache_head *h)
{
return -EINVAL;
}
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 id;
int len, rv;
struct rsc rsci, *rscp = NULL;
time64_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, &id);
if (rv == -EINVAL)
goto out;
if (rv == -ENOENT)
set_bit(CACHE_NEGATIVE, &rsci.h.flags);
else {
int N, i;
/*
* NOTE: we skip uid_valid()/gid_valid() checks here:
* instead, * -1 id's are later mapped to the
* (export-specific) anonymous id by nfsd_setuser.
*
* (But supplementary gid's get no such special
* treatment so are checked for validity here.)
*/
/* uid */
rsci.cred.cr_uid = make_kuid(current_user_ns(), id);
/* gid */
if (get_int(&mesg, &id))
goto out;
rsci.cred.cr_gid = make_kgid(current_user_ns(), id);
/* number of additional gid's */
if (get_int(&mesg, &N))
goto out;
if (N < 0 || N > NGROUPS_MAX)
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++) {
kgid_t kgid;
if (get_int(&mesg, &id))
goto out;
kgid = make_kgid(current_user_ns(), id);
if (!gid_valid(kgid))
goto out;
rsci.cred.cr_group_info->gid[i] = kgid;
}
groups_sort(rsci.cred.cr_group_info);
/* mech name */
len = qword_get(&mesg, buf, mlen);
if (len < 0)
goto out;
gm = rsci.cred.cr_gss_mech = 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,
NULL, 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) {
status = -ENOMEM;
goto out;
}
}
}
rsci.h.expiry_time = expiry;
rscp = rsc_update(cd, &rsci, rscp);
status = 0;
out:
rsc_free(&rsci);
if (rscp)
cache_put(&rscp->h, cd);
else
status = -ENOMEM;
return status;
}
static const struct cache_detail rsc_cache_template = {
.owner = THIS_MODULE,
.hash_size = RSC_HASHMAX,
.name = "auth.rpcsec.context",
.cache_put = rsc_put,
.cache_upcall = rsc_upcall,
.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_rcu(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;
}
/**
* gss_check_seq_num - GSS sequence number window check
* @rqstp: RPC Call to use when reporting errors
* @rsci: cached GSS context state (updated on return)
* @seq_num: sequence number to check
*
* Implements sequence number algorithm as specified in
* RFC 2203, Section 5.3.3.1. "Context Management".
*
* Return values:
* %true: @rqstp's GSS sequence number is inside the window
* %false: @rqstp's GSS sequence number is outside the window
*/
static bool gss_check_seq_num(const struct svc_rqst *rqstp, struct rsc *rsci,
u32 seq_num)
{
struct gss_svc_seq_data *sd = &rsci->seqdata;
bool result = false;
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 + GSS_SEQ_WIN <= sd->sd_max) {
goto toolow;
}
if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win))
goto alreadyseen;
ok:
result = true;
out:
spin_unlock(&sd->sd_lock);
return result;
toolow:
trace_rpcgss_svc_seqno_low(rqstp, seq_num,
sd->sd_max - GSS_SEQ_WIN,
sd->sd_max);
goto out;
alreadyseen:
trace_rpcgss_svc_seqno_seen(rqstp, seq_num);
goto out;
}
/*
* Decode and verify a Call's verifier field. For RPC_AUTH_GSS Calls,
* the body of this field contains a variable length checksum.
*
* GSS-specific auth_stat values are mandated by RFC 2203 Section
* 5.3.3.3.
*/
static int
svcauth_gss_verify_header(struct svc_rqst *rqstp, struct rsc *rsci,
__be32 *rpcstart, struct rpc_gss_wire_cred *gc)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
struct gss_ctx *ctx_id = rsci->mechctx;
u32 flavor, maj_stat;
struct xdr_buf rpchdr;
struct xdr_netobj checksum;
struct kvec iov;
/*
* Compute the checksum of the incoming Call from the
* XID field to credential field:
*/
iov.iov_base = rpcstart;
iov.iov_len = (u8 *)xdr->p - (u8 *)rpcstart;
xdr_buf_from_iov(&iov, &rpchdr);
/* Call's verf field: */
if (xdr_stream_decode_opaque_auth(xdr, &flavor,
(void **)&checksum.data,
&checksum.len) < 0) {
rqstp->rq_auth_stat = rpc_autherr_badverf;
return SVC_DENIED;
}
if (flavor != RPC_AUTH_GSS) {
rqstp->rq_auth_stat = rpc_autherr_badverf;
return SVC_DENIED;
}
if (rqstp->rq_deferred)
return SVC_OK;
maj_stat = gss_verify_mic(ctx_id, &rpchdr, &checksum);
if (maj_stat != GSS_S_COMPLETE) {
trace_rpcgss_svc_mic(rqstp, maj_stat);
rqstp->rq_auth_stat = rpcsec_gsserr_credproblem;
return SVC_DENIED;
}
if (gc->gc_seq > MAXSEQ) {
trace_rpcgss_svc_seqno_large(rqstp, gc->gc_seq);
rqstp->rq_auth_stat = rpcsec_gsserr_ctxproblem;
return SVC_DENIED;
}
if (!gss_check_seq_num(rqstp, rsci, gc->gc_seq))
return SVC_DROP;
return SVC_OK;
}
/*
* Construct and encode a Reply's verifier field. The verifier's body
* field contains a variable-length checksum of the GSS sequence
* number.
*/
static bool
svcauth_gss_encode_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq)
{
struct gss_svc_data *gsd = rqstp->rq_auth_data;
u32 maj_stat;
struct xdr_buf verf_data;
struct xdr_netobj checksum;
struct kvec iov;
gsd->gsd_seq_num = cpu_to_be32(seq);
iov.iov_base = &gsd->gsd_seq_num;
iov.iov_len = XDR_UNIT;
xdr_buf_from_iov(&iov, &verf_data);
checksum.data = gsd->gsd_scratch;
maj_stat = gss_get_mic(ctx_id, &verf_data, &checksum);
if (maj_stat != GSS_S_COMPLETE)
goto bad_mic;
return xdr_stream_encode_opaque_auth(&rqstp->rq_res_stream, RPC_AUTH_GSS,
checksum.data, checksum.len) > 0;
bad_mic:
trace_rpcgss_svc_get_mic(rqstp, maj_stat);
return false;
}
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);
struct auth_domain *
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;
test = auth_domain_lookup(name, &new->h);
if (test != &new->h) {
pr_warn("svc: duplicate registration of gss pseudo flavour %s.\n",
name);
stat = -EADDRINUSE;
auth_domain_put(test);
goto out_free_name;
}
return test;
out_free_name:
kfree(new->h.name);
out_free_dom:
kfree(new);
out:
return ERR_PTR(stat);
}
EXPORT_SYMBOL_GPL(svcauth_gss_register_pseudoflavor);
/*
* RFC 2203, Section 5.3.2.2
*
* struct rpc_gss_integ_data {
* opaque databody_integ<>;
* opaque checksum<>;
* };
*
* struct rpc_gss_data_t {
* unsigned int seq_num;
* proc_req_arg_t arg;
* };
*/
static noinline_for_stack int
svcauth_gss_unwrap_integ(struct svc_rqst *rqstp, u32 seq, struct gss_ctx *ctx)
{
struct gss_svc_data *gsd = rqstp->rq_auth_data;
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
u32 len, offset, seq_num, maj_stat;
struct xdr_buf *buf = xdr->buf;
struct xdr_buf databody_integ;
struct xdr_netobj checksum;
/* NFS READ normally uses splice to send data in-place. However
* the data in cache can change after the reply's MIC is computed
* but before the RPC reply is sent. To prevent the client from
* rejecting the server-computed MIC in this somewhat rare case,
* do not use splice with the GSS integrity service.
*/
clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
/* Did we already verify the signature on the original pass through? */
if (rqstp->rq_deferred)
return 0;
if (xdr_stream_decode_u32(xdr, &len) < 0)
goto unwrap_failed;
if (len & 3)
goto unwrap_failed;
offset = xdr_stream_pos(xdr);
if (xdr_buf_subsegment(buf, &databody_integ, offset, len))
goto unwrap_failed;
/*
* The xdr_stream now points to the @seq_num field. The next
* XDR data item is the @arg field, which contains the clear
* text RPC program payload. The checksum, which follows the
* @arg field, is located and decoded without updating the
* xdr_stream.
*/
offset += len;
if (xdr_decode_word(buf, offset, &checksum.len))
goto unwrap_failed;
if (checksum.len > sizeof(gsd->gsd_scratch))
goto unwrap_failed;
checksum.data = gsd->gsd_scratch;
if (read_bytes_from_xdr_buf(buf, offset + XDR_UNIT, checksum.data,
checksum.len))
goto unwrap_failed;
maj_stat = gss_verify_mic(ctx, &databody_integ, &checksum);
if (maj_stat != GSS_S_COMPLETE)
goto bad_mic;
/* The received seqno is protected by the checksum. */
if (xdr_stream_decode_u32(xdr, &seq_num) < 0)
goto unwrap_failed;
if (seq_num != seq)
goto bad_seqno;
xdr_truncate_decode(xdr, XDR_UNIT + checksum.len);
return 0;
unwrap_failed:
trace_rpcgss_svc_unwrap_failed(rqstp);
return -EINVAL;
bad_seqno:
trace_rpcgss_svc_seqno_bad(rqstp, seq, seq_num);
return -EINVAL;
bad_mic:
trace_rpcgss_svc_mic(rqstp, maj_stat);
return -EINVAL;
}
/*
* RFC 2203, Section 5.3.2.3
*
* struct rpc_gss_priv_data {
* opaque databody_priv<>
* };
*
* struct rpc_gss_data_t {
* unsigned int seq_num;
* proc_req_arg_t arg;
* };
*/
static noinline_for_stack int
svcauth_gss_unwrap_priv(struct svc_rqst *rqstp, u32 seq, struct gss_ctx *ctx)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
u32 len, maj_stat, seq_num, offset;
struct xdr_buf *buf = xdr->buf;
unsigned int saved_len;
clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
if (xdr_stream_decode_u32(xdr, &len) < 0)
goto unwrap_failed;
if (rqstp->rq_deferred) {
/* Already decrypted last time through! The sequence number
* check at out_seq is unnecessary but harmless: */
goto out_seq;
}
if (len > xdr_stream_remaining(xdr))
goto unwrap_failed;
offset = xdr_stream_pos(xdr);
saved_len = buf->len;
maj_stat = gss_unwrap(ctx, offset, offset + len, buf);
if (maj_stat != GSS_S_COMPLETE)
goto bad_unwrap;
xdr->nwords -= XDR_QUADLEN(saved_len - buf->len);
out_seq:
/* gss_unwrap() decrypted the sequence number. */
if (xdr_stream_decode_u32(xdr, &seq_num) < 0)
goto unwrap_failed;
if (seq_num != seq)
goto bad_seqno;
return 0;
unwrap_failed:
trace_rpcgss_svc_unwrap_failed(rqstp);
return -EINVAL;
bad_seqno:
trace_rpcgss_svc_seqno_bad(rqstp, seq, seq_num);
return -EINVAL;
bad_unwrap:
trace_rpcgss_svc_unwrap(rqstp, maj_stat);
return -EINVAL;
}
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;
rqstp->rq_auth_stat = rpc_autherr_badcred;
/*
* 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;
rqstp->rq_auth_stat = rpc_auth_ok;
return SVC_OK;
}
static bool
svcauth_gss_proc_init_verf(struct cache_detail *cd, struct svc_rqst *rqstp,
struct xdr_netobj *out_handle, int *major_status,
u32 seq_num)
{
struct xdr_stream *xdr = &rqstp->rq_res_stream;
struct rsc *rsci;
bool rc;
if (*major_status != GSS_S_COMPLETE)
goto null_verifier;
rsci = gss_svc_searchbyctx(cd, out_handle);
if (rsci == NULL) {
*major_status = GSS_S_NO_CONTEXT;
goto null_verifier;
}
rc = svcauth_gss_encode_verf(rqstp, rsci->mechctx, seq_num);
cache_put(&rsci->h, cd);
return rc;
null_verifier:
return xdr_stream_encode_opaque_auth(xdr, RPC_AUTH_NULL, NULL, 0) > 0;
}
static void gss_free_in_token_pages(struct gssp_in_token *in_token)
{
u32 inlen;
int i;
i = 0;
inlen = in_token->page_len;
while (inlen) {
if (in_token->pages[i])
put_page(in_token->pages[i]);
inlen -= inlen > PAGE_SIZE ? PAGE_SIZE : inlen;
}
kfree(in_token->pages);
in_token->pages = NULL;
}
static int gss_read_proxy_verf(struct svc_rqst *rqstp,
struct rpc_gss_wire_cred *gc,
struct xdr_netobj *in_handle,
struct gssp_in_token *in_token)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
unsigned int length, pgto_offs, pgfrom_offs;
int pages, i, pgto, pgfrom;
size_t to_offs, from_offs;
u32 inlen;
if (dup_netobj(in_handle, &gc->gc_ctx))
return SVC_CLOSE;
/*
* RFC 2203 Section 5.2.2
*
* struct rpc_gss_init_arg {
* opaque gss_token<>;
* };
*/
if (xdr_stream_decode_u32(xdr, &inlen) < 0)
goto out_denied_free;
if (inlen > xdr_stream_remaining(xdr))
goto out_denied_free;
pages = DIV_ROUND_UP(inlen, PAGE_SIZE);
in_token->pages = kcalloc(pages, sizeof(struct page *), GFP_KERNEL);
if (!in_token->pages)
goto out_denied_free;
in_token->page_base = 0;
in_token->page_len = inlen;
for (i = 0; i < pages; i++) {
in_token->pages[i] = alloc_page(GFP_KERNEL);
if (!in_token->pages[i]) {
gss_free_in_token_pages(in_token);
goto out_denied_free;
}
}
length = min_t(unsigned int, inlen, (char *)xdr->end - (char *)xdr->p);
memcpy(page_address(in_token->pages[0]), xdr->p, length);
inlen -= length;
to_offs = length;
from_offs = rqstp->rq_arg.page_base;
while (inlen) {
pgto = to_offs >> PAGE_SHIFT;
pgfrom = from_offs >> PAGE_SHIFT;
pgto_offs = to_offs & ~PAGE_MASK;
pgfrom_offs = from_offs & ~PAGE_MASK;
length = min_t(unsigned int, inlen,
min_t(unsigned int, PAGE_SIZE - pgto_offs,
PAGE_SIZE - pgfrom_offs));
memcpy(page_address(in_token->pages[pgto]) + pgto_offs,
page_address(rqstp->rq_arg.pages[pgfrom]) + pgfrom_offs,
length);
to_offs += length;
from_offs += length;
inlen -= length;
}
return 0;
out_denied_free:
kfree(in_handle->data);
return SVC_DENIED;
}
/*
* RFC 2203, Section 5.2.3.1.
*
* struct rpc_gss_init_res {
* opaque handle<>;
* unsigned int gss_major;
* unsigned int gss_minor;
* unsigned int seq_window;
* opaque gss_token<>;
* };
*/
static bool
svcxdr_encode_gss_init_res(struct xdr_stream *xdr,
struct xdr_netobj *handle,
struct xdr_netobj *gss_token,
unsigned int major_status,
unsigned int minor_status, u32 seq_num)
{
if (xdr_stream_encode_opaque(xdr, handle->data, handle->len) < 0)
return false;
if (xdr_stream_encode_u32(xdr, major_status) < 0)
return false;
if (xdr_stream_encode_u32(xdr, minor_status) < 0)
return false;
if (xdr_stream_encode_u32(xdr, seq_num) < 0)
return false;
if (xdr_stream_encode_opaque(xdr, gss_token->data, gss_token->len) < 0)
return false;
return true;
}
/*
* 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_legacy_init(struct svc_rqst *rqstp,
struct rpc_gss_wire_cred *gc)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
struct rsi *rsip, rsikey;
__be32 *p;
u32 len;
int ret;
struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id);
memset(&rsikey, 0, sizeof(rsikey));
if (dup_netobj(&rsikey.in_handle, &gc->gc_ctx))
return SVC_CLOSE;
/*
* RFC 2203 Section 5.2.2
*
* struct rpc_gss_init_arg {
* opaque gss_token<>;
* };
*/
if (xdr_stream_decode_u32(xdr, &len) < 0) {
kfree(rsikey.in_handle.data);
return SVC_DENIED;
}
p = xdr_inline_decode(xdr, len);
if (!p) {
kfree(rsikey.in_handle.data);
return SVC_DENIED;
}
rsikey.in_token.data = kmalloc(len, GFP_KERNEL);
if (ZERO_OR_NULL_PTR(rsikey.in_token.data)) {
kfree(rsikey.in_handle.data);
return SVC_CLOSE;
}
memcpy(rsikey.in_token.data, p, len);
rsikey.in_token.len = len;
/* 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;
if (!svcauth_gss_proc_init_verf(sn->rsc_cache, rqstp, &rsip->out_handle,
&rsip->major_status, GSS_SEQ_WIN))
goto out;
if (!svcxdr_set_accept_stat(rqstp))
goto out;
if (!svcxdr_encode_gss_init_res(&rqstp->rq_res_stream, &rsip->out_handle,
&rsip->out_token, rsip->major_status,
rsip->minor_status, GSS_SEQ_WIN))
goto out;
ret = SVC_COMPLETE;
out:
cache_put(&rsip->h, sn->rsi_cache);
return ret;
}
static int gss_proxy_save_rsc(struct cache_detail *cd,
struct gssp_upcall_data *ud,
uint64_t *handle)
{
struct rsc rsci, *rscp = NULL;
static atomic64_t ctxhctr;
long long ctxh;
struct gss_api_mech *gm = NULL;
time64_t expiry;
int status;
memset(&rsci, 0, sizeof(rsci));
/* context handle */
status = -ENOMEM;
/* the handle needs to be just a unique id,
* use a static counter */
ctxh = atomic64_inc_return(&ctxhctr);
/* make a copy for the caller */
*handle = ctxh;
/* make a copy for the rsc cache */
if (dup_to_netobj(&rsci.handle, (char *)handle, sizeof(uint64_t)))
goto out;
rscp = rsc_lookup(cd, &rsci);
if (!rscp)
goto out;
/* creds */
if (!ud->found_creds) {
/* userspace seem buggy, we should always get at least a
* mapping to nobody */
goto out;
} else {
struct timespec64 boot;
/* steal creds */
rsci.cred = ud->creds;
memset(&ud->creds, 0, sizeof(struct svc_cred));
status = -EOPNOTSUPP;
/* get mech handle from OID */
gm = gss_mech_get_by_OID(&ud->mech_oid);
if (!gm)
goto out;
rsci.cred.cr_gss_mech = gm;
status = -EINVAL;
/* mech-specific data: */
status = gss_import_sec_context(ud->out_handle.data,
ud->out_handle.len,
gm, &rsci.mechctx,
&expiry, GFP_KERNEL);
if (status)
goto out;
getboottime64(&boot);
expiry -= boot.tv_sec;
}
rsci.h.expiry_time = expiry;
rscp = rsc_update(cd, &rsci, rscp);
status = 0;
out:
rsc_free(&rsci);
if (rscp)
cache_put(&rscp->h, cd);
else
status = -ENOMEM;
return status;
}
static int svcauth_gss_proxy_init(struct svc_rqst *rqstp,
struct rpc_gss_wire_cred *gc)
{
struct xdr_netobj cli_handle;
struct gssp_upcall_data ud;
uint64_t handle;
int status;
int ret;
struct net *net = SVC_NET(rqstp);
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
memset(&ud, 0, sizeof(ud));
ret = gss_read_proxy_verf(rqstp, gc, &ud.in_handle, &ud.in_token);
if (ret)
return ret;
ret = SVC_CLOSE;
/* Perform synchronous upcall to gss-proxy */
status = gssp_accept_sec_context_upcall(net, &ud);
if (status)
goto out;
trace_rpcgss_svc_accept_upcall(rqstp, ud.major_status, ud.minor_status);
switch (ud.major_status) {
case GSS_S_CONTINUE_NEEDED:
cli_handle = ud.out_handle;
break;
case GSS_S_COMPLETE:
status = gss_proxy_save_rsc(sn->rsc_cache, &ud, &handle);
if (status)
goto out;
cli_handle.data = (u8 *)&handle;
cli_handle.len = sizeof(handle);
break;
default:
goto out;
}
if (!svcauth_gss_proc_init_verf(sn->rsc_cache, rqstp, &cli_handle,
&ud.major_status, GSS_SEQ_WIN))
goto out;
if (!svcxdr_set_accept_stat(rqstp))
goto out;
if (!svcxdr_encode_gss_init_res(&rqstp->rq_res_stream, &cli_handle,
&ud.out_token, ud.major_status,
ud.minor_status, GSS_SEQ_WIN))
goto out;
ret = SVC_COMPLETE;
out:
gss_free_in_token_pages(&ud.in_token);
gssp_free_upcall_data(&ud);
return ret;
}
/*
* Try to set the sn->use_gss_proxy variable to a new value. We only allow
* it to be changed if it's currently undefined (-1). If it's any other value
* then return -EBUSY unless the type wouldn't have changed anyway.
*/
static int set_gss_proxy(struct net *net, int type)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
int ret;
WARN_ON_ONCE(type != 0 && type != 1);
ret = cmpxchg(&sn->use_gss_proxy, -1, type);
if (ret != -1 && ret != type)
return -EBUSY;
return 0;
}
static bool use_gss_proxy(struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
/* If use_gss_proxy is still undefined, then try to disable it */
if (sn->use_gss_proxy == -1)
set_gss_proxy(net, 0);
return sn->use_gss_proxy;
}
static noinline_for_stack int
svcauth_gss_proc_init(struct svc_rqst *rqstp, struct rpc_gss_wire_cred *gc)
{
struct xdr_stream *xdr = &rqstp->rq_arg_stream;
u32 flavor, len;
void *body;
/* Call's verf field: */
if (xdr_stream_decode_opaque_auth(xdr, &flavor, &body, &len) < 0)
return SVC_GARBAGE;
if (flavor != RPC_AUTH_NULL || len != 0) {
rqstp->rq_auth_stat = rpc_autherr_badverf;
return SVC_DENIED;
}
if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0) {
rqstp->rq_auth_stat = rpc_autherr_badcred;
return SVC_DENIED;
}
if (!use_gss_proxy(SVC_NET(rqstp)))
return svcauth_gss_legacy_init(rqstp, gc);
return svcauth_gss_proxy_init(rqstp, gc);
}
#ifdef CONFIG_PROC_FS
static ssize_t write_gssp(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct net *net = pde_data(file_inode(file));
char tbuf[20];
unsigned long i;
int res;
if (*ppos || count > sizeof(tbuf)-1)
return -EINVAL;
if (copy_from_user(tbuf, buf, count))
return -EFAULT;
tbuf[count] = 0;
res = kstrtoul(tbuf, 0, &i);
if (res)
return res;
if (i != 1)
return -EINVAL;
res = set_gssp_clnt(net);
if (res)
return res;
res = set_gss_proxy(net, 1);
if (res)
return res;
return count;
}
static ssize_t read_gssp(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct net *net = pde_data(file_inode(file));
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
unsigned long p = *ppos;
char tbuf[10];
size_t len;
snprintf(tbuf, sizeof(tbuf), "%d\n", sn->use_gss_proxy);
len = strlen(tbuf);
if (p >= len)
return 0;
len -= p;
if (len > count)
len = count;
if (copy_to_user(buf, (void *)(tbuf+p), len))
return -EFAULT;
*ppos += len;
return len;
}
static const struct proc_ops use_gss_proxy_proc_ops = {
.proc_open = nonseekable_open,
.proc_write = write_gssp,
.proc_read = read_gssp,
};
static int create_use_gss_proxy_proc_entry(struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
struct proc_dir_entry **p = &sn->use_gssp_proc;
sn->use_gss_proxy = -1;
*p = proc_create_data("use-gss-proxy", S_IFREG | 0600,
sn->proc_net_rpc,
&use_gss_proxy_proc_ops, net);
if (!*p)
return -ENOMEM;
init_gssp_clnt(sn);
return 0;
}
static void destroy_use_gss_proxy_proc_entry(struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
if (sn->use_gssp_proc) {
remove_proc_entry("use-gss-proxy", sn->proc_net_rpc);
clear_gssp_clnt(sn);
}
}
static ssize_t read_gss_krb5_enctypes(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct rpcsec_gss_oid oid = {
.len = 9,
.data = "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02",
};
struct gss_api_mech *mech;
ssize_t ret;
mech = gss_mech_get_by_OID(&oid);
if (!mech)
return 0;
if (!mech->gm_upcall_enctypes) {
gss_mech_put(mech);
return 0;
}
ret = simple_read_from_buffer(buf, count, ppos,
mech->gm_upcall_enctypes,
strlen(mech->gm_upcall_enctypes));
gss_mech_put(mech);
return ret;
}
static const struct proc_ops gss_krb5_enctypes_proc_ops = {
.proc_open = nonseekable_open,
.proc_read = read_gss_krb5_enctypes,
};
static int create_krb5_enctypes_proc_entry(struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
sn->gss_krb5_enctypes =
proc_create_data("gss_krb5_enctypes", S_IFREG | 0444,
sn->proc_net_rpc, &gss_krb5_enctypes_proc_ops,
net);
return sn->gss_krb5_enctypes ? 0 : -ENOMEM;
}
static void destroy_krb5_enctypes_proc_entry(struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
if (sn->gss_krb5_enctypes)
remove_proc_entry("gss_krb5_enctypes", sn->proc_net_rpc);
}
#else /* CONFIG_PROC_FS */
static int create_use_gss_proxy_proc_entry(struct net *net)
{
return 0;
}
static void destroy_use_gss_proxy_proc_entry(struct net *net) {}
static int create_krb5_enctypes_proc_entry(struct net *net)
{
return 0;
}
static void destroy_krb5_enctypes_proc_entry(struct net *net) {}
#endif /* CONFIG_PROC_FS */
/*
* The Call's credential body should contain a struct rpc_gss_cred_t.
*
* RFC 2203 Section 5
*
* struct rpc_gss_cred_t {
* union switch (unsigned int version) {
* case RPCSEC_GSS_VERS_1:
* struct {
* rpc_gss_proc_t gss_proc;
* unsigned int seq_num;
* rpc_gss_service_t service;
* opaque handle<>;
* } rpc_gss_cred_vers_1_t;
* }
* };
*/
static bool
svcauth_gss_decode_credbody(struct xdr_stream *xdr,
struct rpc_gss_wire_cred *gc,
__be32 **rpcstart)
{
ssize_t handle_len;
u32 body_len;
__be32 *p;
p = xdr_inline_decode(xdr, XDR_UNIT);
if (!p)
return false;
/*
* start of rpc packet is 7 u32's back from here:
* xid direction rpcversion prog vers proc flavour
*/
*rpcstart = p - 7;
body_len = be32_to_cpup(p);
if (body_len > RPC_MAX_AUTH_SIZE)
return false;
/* struct rpc_gss_cred_t */
if (xdr_stream_decode_u32(xdr, &gc->gc_v) < 0)
return false;
if (xdr_stream_decode_u32(xdr, &gc->gc_proc) < 0)
return false;
if (xdr_stream_decode_u32(xdr, &gc->gc_seq) < 0)
return false;
if (xdr_stream_decode_u32(xdr, &gc->gc_svc) < 0)
return false;
handle_len = xdr_stream_decode_opaque_inline(xdr,
(void **)&gc->gc_ctx.data,
body_len);
if (handle_len < 0)
return false;
if (body_len != XDR_UNIT * 5 + xdr_align_size(handle_len))
return false;
gc->gc_ctx.len = handle_len;
return true;
}
/**
* svcauth_gss_accept - Decode and validate incoming RPC_AUTH_GSS credential
* @rqstp: RPC transaction
*
* Return values:
* %SVC_OK: Success
* %SVC_COMPLETE: GSS context lifetime event
* %SVC_DENIED: Credential or verifier is not valid
* %SVC_GARBAGE: Failed to decode credential or verifier
* %SVC_CLOSE: Temporary failure
*
* The rqstp->rq_auth_stat field is also set (see RFCs 2203 and 5531).
*/
static int
svcauth_gss_accept(struct svc_rqst *rqstp)
{
struct gss_svc_data *svcdata = rqstp->rq_auth_data;
__be32 *rpcstart;
struct rpc_gss_wire_cred *gc;
struct rsc *rsci = NULL;
int ret;
struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id);
rqstp->rq_auth_stat = rpc_autherr_badcred;
if (!svcdata)
svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL);
if (!svcdata)
goto auth_err;
rqstp->rq_auth_data = svcdata;
svcdata->gsd_databody_offset = 0;
svcdata->rsci = NULL;
gc = &svcdata->clcred;
if (!svcauth_gss_decode_credbody(&rqstp->rq_arg_stream, gc, &rpcstart))
goto auth_err;
if (gc->gc_v != RPC_GSS_VERSION)
goto auth_err;
switch (gc->gc_proc) {
case RPC_GSS_PROC_INIT:
case RPC_GSS_PROC_CONTINUE_INIT:
if (rqstp->rq_proc != 0)
goto auth_err;
return svcauth_gss_proc_init(rqstp, gc);
case RPC_GSS_PROC_DESTROY:
if (rqstp->rq_proc != 0)
goto auth_err;
fallthrough;
case RPC_GSS_PROC_DATA:
rqstp->rq_auth_stat = rpcsec_gsserr_credproblem;
rsci = gss_svc_searchbyctx(sn->rsc_cache, &gc->gc_ctx);
if (!rsci)
goto auth_err;
switch (svcauth_gss_verify_header(rqstp, rsci, rpcstart, gc)) {
case SVC_OK:
break;
case SVC_DENIED:
goto auth_err;
case SVC_DROP:
goto drop;
}
break;
default:
if (rqstp->rq_proc != 0)
goto auth_err;
rqstp->rq_auth_stat = rpc_autherr_rejectedcred;
goto auth_err;
}
/* now act upon the command: */
switch (gc->gc_proc) {
case RPC_GSS_PROC_DESTROY:
if (!svcauth_gss_encode_verf(rqstp, rsci->mechctx, gc->gc_seq))
goto auth_err;
if (!svcxdr_set_accept_stat(rqstp))
goto auth_err;
/* Delete the entry from the cache_list and call cache_put */
sunrpc_cache_unhash(sn->rsc_cache, &rsci->h);
goto complete;
case RPC_GSS_PROC_DATA:
rqstp->rq_auth_stat = rpcsec_gsserr_ctxproblem;
if (!svcauth_gss_encode_verf(rqstp, rsci->mechctx, gc->gc_seq))
goto auth_err;
if (!svcxdr_set_accept_stat(rqstp))
goto auth_err;
svcdata->gsd_databody_offset = xdr_stream_pos(&rqstp->rq_res_stream);
rqstp->rq_cred = rsci->cred;
get_group_info(rsci->cred.cr_group_info);
rqstp->rq_auth_stat = rpc_autherr_badcred;
switch (gc->gc_svc) {
case RPC_GSS_SVC_NONE:
break;
case RPC_GSS_SVC_INTEGRITY:
/* placeholders for body length and seq. number: */
xdr_reserve_space(&rqstp->rq_res_stream, XDR_UNIT * 2);
if (svcauth_gss_unwrap_integ(rqstp, gc->gc_seq,
rsci->mechctx))
goto garbage_args;
svcxdr_set_auth_slack(rqstp, RPC_MAX_AUTH_SIZE);
break;
case RPC_GSS_SVC_PRIVACY:
/* placeholders for body length and seq. number: */
xdr_reserve_space(&rqstp->rq_res_stream, XDR_UNIT * 2);
if (svcauth_gss_unwrap_priv(rqstp, gc->gc_seq,
rsci->mechctx))
goto garbage_args;
svcxdr_set_auth_slack(rqstp, RPC_MAX_AUTH_SIZE * 2);
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,
GSS_C_QOP_DEFAULT,
gc->gc_svc);
ret = SVC_OK;
trace_rpcgss_svc_authenticate(rqstp, gc);
goto out;
}
garbage_args:
ret = SVC_GARBAGE;
goto out;
auth_err:
xdr_truncate_encode(&rqstp->rq_res_stream, XDR_UNIT * 2);
ret = SVC_DENIED;
goto out;
complete:
ret = SVC_COMPLETE;
goto out;
drop:
ret = SVC_CLOSE;
out:
if (rsci)
cache_put(&rsci->h, sn->rsc_cache);
return ret;
}
static u32
svcauth_gss_prepare_to_wrap(struct svc_rqst *rqstp, struct gss_svc_data *gsd)
{
u32 offset;
/* Release can be called twice, but we only wrap once. */
offset = gsd->gsd_databody_offset;
gsd->gsd_databody_offset = 0;
/* AUTH_ERROR replies are not wrapped. */
if (rqstp->rq_auth_stat != rpc_auth_ok)
return 0;
/* Also don't wrap if the accept_stat is nonzero: */
if (*rqstp->rq_accept_statp != rpc_success)
return 0;
return offset;
}
/*
* RFC 2203, Section 5.3.2.2
*
* struct rpc_gss_integ_data {
* opaque databody_integ<>;
* opaque checksum<>;
* };
*
* struct rpc_gss_data_t {
* unsigned int seq_num;
* proc_req_arg_t arg;
* };
*
* The RPC Reply message has already been XDR-encoded. rq_res_stream
* is now positioned so that the checksum can be written just past
* the RPC Reply message.
*/
static int svcauth_gss_wrap_integ(struct svc_rqst *rqstp)
{
struct gss_svc_data *gsd = rqstp->rq_auth_data;
struct xdr_stream *xdr = &rqstp->rq_res_stream;
struct rpc_gss_wire_cred *gc = &gsd->clcred;
struct xdr_buf *buf = xdr->buf;
struct xdr_buf databody_integ;
struct xdr_netobj checksum;
u32 offset, maj_stat;
offset = svcauth_gss_prepare_to_wrap(rqstp, gsd);
if (!offset)
goto out;
if (xdr_buf_subsegment(buf, &databody_integ, offset + XDR_UNIT,
buf->len - offset - XDR_UNIT))
goto wrap_failed;
/* Buffer space for these has already been reserved in
* svcauth_gss_accept(). */
if (xdr_encode_word(buf, offset, databody_integ.len))
goto wrap_failed;
if (xdr_encode_word(buf, offset + XDR_UNIT, gc->gc_seq))
goto wrap_failed;
checksum.data = gsd->gsd_scratch;
maj_stat = gss_get_mic(gsd->rsci->mechctx, &databody_integ, &checksum);
if (maj_stat != GSS_S_COMPLETE)
goto bad_mic;
if (xdr_stream_encode_opaque(xdr, checksum.data, checksum.len) < 0)
goto wrap_failed;
xdr_commit_encode(xdr);
out:
return 0;
bad_mic:
trace_rpcgss_svc_get_mic(rqstp, maj_stat);
return -EINVAL;
wrap_failed:
trace_rpcgss_svc_wrap_failed(rqstp);
return -EINVAL;
}
/*
* RFC 2203, Section 5.3.2.3
*
* struct rpc_gss_priv_data {
* opaque databody_priv<>
* };
*
* struct rpc_gss_data_t {
* unsigned int seq_num;
* proc_req_arg_t arg;
* };
*
* gss_wrap() expands the size of the RPC message payload in the
* response buffer. The main purpose of svcauth_gss_wrap_priv()
* is to ensure there is adequate space in the response buffer to
* avoid overflow during the wrap.
*/
static int svcauth_gss_wrap_priv(struct svc_rqst *rqstp)
{
struct gss_svc_data *gsd = rqstp->rq_auth_data;
struct rpc_gss_wire_cred *gc = &gsd->clcred;
struct xdr_buf *buf = &rqstp->rq_res;
struct kvec *head = buf->head;
struct kvec *tail = buf->tail;
u32 offset, pad, maj_stat;
__be32 *p;
offset = svcauth_gss_prepare_to_wrap(rqstp, gsd);
if (!offset)
return 0;
/*
* Buffer space for this field has already been reserved
* in svcauth_gss_accept(). Note that the GSS sequence
* number is encrypted along with the RPC reply payload.
*/
if (xdr_encode_word(buf, offset + XDR_UNIT, gc->gc_seq))
goto wrap_failed;
/*
* 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 (tail->iov_base) {
if (tail->iov_base >= head->iov_base + PAGE_SIZE)
goto wrap_failed;
if (tail->iov_base < head->iov_base)
goto wrap_failed;
if (tail->iov_len + head->iov_len
+ 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE)
goto wrap_failed;
memmove(tail->iov_base + RPC_MAX_AUTH_SIZE, tail->iov_base,
tail->iov_len);
tail->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 (!tail->iov_base) {
if (head->iov_len + 2 * RPC_MAX_AUTH_SIZE > PAGE_SIZE)
goto wrap_failed;
tail->iov_base = head->iov_base
+ head->iov_len + RPC_MAX_AUTH_SIZE;
tail->iov_len = 0;
}
maj_stat = gss_wrap(gsd->rsci->mechctx, offset + XDR_UNIT, buf,
buf->pages);
if (maj_stat != GSS_S_COMPLETE)
goto bad_wrap;
/* Wrapping can change the size of databody_priv. */
if (xdr_encode_word(buf, offset, buf->len - offset - XDR_UNIT))
goto wrap_failed;
pad = xdr_pad_size(buf->len - offset - XDR_UNIT);
p = (__be32 *)(tail->iov_base + tail->iov_len);
memset(p, 0, pad);
tail->iov_len += pad;
buf->len += pad;
return 0;
wrap_failed:
trace_rpcgss_svc_wrap_failed(rqstp);
return -EINVAL;
bad_wrap:
trace_rpcgss_svc_wrap(rqstp, maj_stat);
return -ENOMEM;
}
/**
* svcauth_gss_release - Wrap payload and release resources
* @rqstp: RPC transaction context
*
* Return values:
* %0: the Reply is ready to be sent
* %-ENOMEM: failed to allocate memory
* %-EINVAL: encoding error
*
* XXX: These return values do not match the return values documented
* for the auth_ops ->release method in linux/sunrpc/svcauth.h.
*/
static int
svcauth_gss_release(struct svc_rqst *rqstp)
{
struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id);
struct gss_svc_data *gsd = rqstp->rq_auth_data;
struct rpc_gss_wire_cred *gc;
int stat;
if (!gsd)
goto out;
gc = &gsd->clcred;
if (gc->gc_proc != RPC_GSS_PROC_DATA)
goto out;
switch (gc->gc_svc) {
case RPC_GSS_SVC_NONE:
break;
case RPC_GSS_SVC_INTEGRITY:
stat = svcauth_gss_wrap_integ(rqstp);
if (stat)
goto out_err;
break;
case RPC_GSS_SVC_PRIVACY:
stat = svcauth_gss_wrap_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 && gsd->rsci) {
cache_put(&gsd->rsci->h, sn->rsc_cache);
gsd->rsci = NULL;
}
return stat;
}
static void
svcauth_gss_domain_release_rcu(struct rcu_head *head)
{
struct auth_domain *dom = container_of(head, struct auth_domain, rcu_head);
struct gss_domain *gd = container_of(dom, struct gss_domain, h);
kfree(dom->name);
kfree(gd);
}
static void
svcauth_gss_domain_release(struct auth_domain *dom)
{
call_rcu(&dom->rcu_head, svcauth_gss_domain_release_rcu);
}
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;
rv = create_use_gss_proxy_proc_entry(net);
if (rv)
goto out2;
rv = create_krb5_enctypes_proc_entry(net);
if (rv)
goto out3;
return 0;
out3:
destroy_use_gss_proxy_proc_entry(net);
out2:
rsi_cache_destroy_net(net);
out1:
rsc_cache_destroy_net(net);
return rv;
}
void
gss_svc_shutdown_net(struct net *net)
{
destroy_krb5_enctypes_proc_entry(net);
destroy_use_gss_proxy_proc_entry(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);
}
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