/*
* 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/types.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/sunrpc/auth_gss.h>
#include <linux/sunrpc/svcauth.h>
#include <linux/sunrpc/gss_err.h>
#include <linux/sunrpc/svcauth.h>
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/sunrpc/cache.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)
#define RSI_HASHMASK (RSI_HASHMAX-1)
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 cache_head *rsi_table[RSI_HASHMAX];
static struct cache_detail rsi_cache;
static struct rsi *rsi_update(struct rsi *new, struct rsi *old);
static struct rsi *rsi_lookup(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_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(&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;
if (len == 0) {
goto out;
} else {
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(&rsii, rsip);
status = 0;
out:
rsi_free(&rsii);
if (rsip)
cache_put(&rsip->h, &rsi_cache);
else
status = -ENOMEM;
return status;
}
static struct cache_detail rsi_cache = {
.owner = THIS_MODULE,
.hash_size = RSI_HASHMAX,
.hash_table = rsi_table,
.name = "auth.rpcsec.init",
.cache_put = rsi_put,
.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 rsi *item)
{
struct cache_head *ch;
int hash = rsi_hash(item);
ch = sunrpc_cache_lookup(&rsi_cache, &item->h, hash);
if (ch)
return container_of(ch, struct rsi, h);
else
return NULL;
}
static struct rsi *rsi_update(struct rsi *new, struct rsi *old)
{
struct cache_head *ch;
int hash = rsi_hash(new);
ch = sunrpc_cache_update(&rsi_cache, &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 RSC_HASHMASK (RSC_HASHMAX-1)
#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 cache_head *rsc_table[RSC_HASHMAX];
static struct cache_detail rsc_cache;
static struct rsc *rsc_update(struct rsc *new, struct rsc *old);
static struct rsc *rsc_lookup(struct rsc *item);
static void rsc_free(struct rsc *rsci)
{
kfree(rsci->handle.data);
if (rsci->mechctx)
gss_delete_sec_context(&rsci->mechctx);
if (rsci->cred.cr_group_info)
put_group_info(rsci->cred.cr_group_info);
}
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;
}
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;
}
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(&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;
if (get_int(&mesg, &gid))
goto out;
GROUP_AT(rsci.cred.cr_group_info, i) = gid;
}
/* 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);
if (status)
goto out;
}
rsci.h.expiry_time = expiry;
rscp = rsc_update(&rsci, rscp);
status = 0;
out:
gss_mech_put(gm);
rsc_free(&rsci);
if (rscp)
cache_put(&rscp->h, &rsc_cache);
else
status = -ENOMEM;
return status;
}
static struct cache_detail rsc_cache = {
.owner = THIS_MODULE,
.hash_size = RSC_HASHMAX,
.hash_table = rsc_table,
.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 rsc *item)
{
struct cache_head *ch;
int hash = rsc_hash(item);
ch = sunrpc_cache_lookup(&rsc_cache, &item->h, hash);
if (ch)
return container_of(ch, struct rsc, h);
else
return NULL;
}
static struct rsc *rsc_update(struct rsc *new, struct rsc *old)
{
struct cache_head *ch;
int hash = rsc_hash(new);
ch = sunrpc_cache_update(&rsc_cache, &new->h,
&old->h, hash);
if (ch)
return container_of(ch, struct rsc, h);
else
return NULL;
}
static struct rsc *
gss_svc_searchbyctx(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(&rsci);
rsc_free(&rsci);
if (!found)
return NULL;
if (cache_check(&rsc_cache, &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(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;
test = auth_domain_lookup(name, &new->h);
if (test != &new->h) { /* XXX Duplicate registration? */
auth_domain_put(&new->h);
/* dangling ref-count... */
goto out;
}
return 0;
out_free_dom:
kfree(new);
out:
return stat;
}
EXPORT_SYMBOL(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)
return stat;
return SVC_OK;
}
static inline int
gss_write_init_verf(struct svc_rqst *rqstp, struct rsi *rsip)
{
struct rsc *rsci;
int rc;
if (rsip->major_status != GSS_S_COMPLETE)
return gss_write_null_verf(rqstp);
rsci = gss_svc_searchbyctx(&rsip->out_handle);
if (rsci == NULL) {
rsip->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, &rsc_cache);
return rc;
}
/*
* 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 xdr_netobj tmpobj;
struct gss_svc_data *svcdata = rqstp->rq_auth_data;
struct rpc_gss_wire_cred *gc;
struct rsc *rsci = NULL;
struct rsi *rsip, rsikey;
__be32 *rpcstart;
__be32 *reject_stat = resv->iov_base + resv->iov_len;
int ret;
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 preceeded 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;
/*
* We've successfully parsed the credential. Let's check out the
* verifier. An AUTH_NULL verifier is allowed (and required) for
* INIT and CONTINUE_INIT requests. AUTH_RPCSEC_GSS is required for
* PROC_DATA and PROC_DESTROY.
*
* AUTH_NULL verifier is 0 (AUTH_NULL), 0 (length).
* AUTH_RPCSEC_GSS verifier is:
* 6 (AUTH_RPCSEC_GSS), length, checksum.
* checksum is calculated over rpcheader from xid up to here.
*/
*authp = rpc_autherr_badverf;
switch (gc->gc_proc) {
case RPC_GSS_PROC_INIT:
case RPC_GSS_PROC_CONTINUE_INIT:
if (argv->iov_len < 2 * 4)
goto auth_err;
if (svc_getnl(argv) != RPC_AUTH_NULL)
goto auth_err;
if (svc_getnl(argv) != 0)
goto auth_err;
break;
case RPC_GSS_PROC_DATA:
case RPC_GSS_PROC_DESTROY:
*authp = rpcsec_gsserr_credproblem;
rsci = gss_svc_searchbyctx(&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_INIT:
case RPC_GSS_PROC_CONTINUE_INIT:
*authp = rpc_autherr_badcred;
if (gc->gc_proc == RPC_GSS_PROC_INIT && gc->gc_ctx.len != 0)
goto auth_err;
memset(&rsikey, 0, sizeof(rsikey));
if (dup_netobj(&rsikey.in_handle, &gc->gc_ctx))
goto drop;
*authp = rpc_autherr_badverf;
if (svc_safe_getnetobj(argv, &tmpobj)) {
kfree(rsikey.in_handle.data);
goto auth_err;
}
if (dup_netobj(&rsikey.in_token, &tmpobj)) {
kfree(rsikey.in_handle.data);
goto drop;
}
rsip = rsi_lookup(&rsikey);
rsi_free(&rsikey);
if (!rsip) {
goto drop;
}
switch(cache_check(&rsi_cache, &rsip->h, &rqstp->rq_chandle)) {
case -EAGAIN:
case -ETIMEDOUT:
case -ENOENT:
goto drop;
case 0:
if (gss_write_init_verf(rqstp, rsip))
goto drop;
if (resv->iov_len + 4 > PAGE_SIZE)
goto drop;
svc_putnl(resv, RPC_SUCCESS);
if (svc_safe_putnetobj(resv, &rsip->out_handle))
goto drop;
if (resv->iov_len + 3 * 4 > PAGE_SIZE)
goto drop;
svc_putnl(resv, rsip->major_status);
svc_putnl(resv, rsip->minor_status);
svc_putnl(resv, GSS_SEQ_WIN);
if (svc_safe_putnetobj(resv, &rsip->out_token))
goto drop;
}
goto complete;
case RPC_GSS_PROC_DESTROY:
if (gss_write_verf(rqstp, rsci->mechctx, gc->gc_seq))
goto auth_err;
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:
if (unwrap_integ_data(&rqstp->rq_arg,
gc->gc_seq, rsci->mechctx))
goto auth_err;
/* placeholders for length and seq. number: */
svc_putnl(resv, 0);
svc_putnl(resv, 0);
break;
case RPC_GSS_SVC_PRIVACY:
if (unwrap_priv_data(rqstp, &rqstp->rq_arg,
gc->gc_seq, rsci->mechctx))
goto auth_err;
/* placeholders for length and seq. number: */
svc_putnl(resv, 0);
svc_putnl(resv, 0);
break;
default:
goto auth_err;
}
svcdata->rsci = rsci;
cache_get(&rsci->h);
rqstp->rq_flavor = gss_svc_to_pseudoflavor(
rsci->mechctx->mech_type, gc->gc_svc);
ret = SVC_OK;
goto out;
}
auth_err:
/* Restore write pointer to 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, &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 (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 (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;
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;
default:
goto out_err;
}
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, &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,
};
int
gss_svc_init(void)
{
int rv = svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss);
if (rv == 0) {
cache_register(&rsc_cache);
cache_register(&rsi_cache);
}
return rv;
}
void
gss_svc_shutdown(void)
{
if (cache_unregister(&rsc_cache))
printk(KERN_ERR "auth_rpcgss: failed to unregister rsc cache\n");
if (cache_unregister(&rsi_cache))
printk(KERN_ERR "auth_rpcgss: failed to unregister rsi cache\n");
svc_auth_unregister(RPC_AUTH_GSS);
}
