auth_gss.c

h内核

		atomic_inc(&gss_msg->count);
		__gss_unhash_msg(gss_msg);
		spin_unlock(&gss_auth->lock);
		gss_release_msg(gss_msg);
		spin_lock(&gss_auth->lock);
	}
	spin_unlock(&gss_auth->lock);
}

static void
gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
{
	struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
	static unsigned long ratelimit;

	if (msg->errno < 0) {
		dprintk("RPC:      gss_pipe_destroy_msg releasing msg %p\n",
				gss_msg);
		atomic_inc(&gss_msg->count);
		gss_unhash_msg(gss_msg);
		if (msg->errno == -ETIMEDOUT || msg->errno == -EPIPE) {
			unsigned long now = jiffies;
			if (time_after(now, ratelimit)) {
				printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
						    "Please check user daemon is running!\n");
				ratelimit = now + 15*HZ;
			}
		}
		gss_release_msg(gss_msg);
	}
}

/* 
 * NOTE: we have the opportunity to use different 
 * parameters based on the input flavor (which must be a pseudoflavor)
 */
static struct rpc_auth *
gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
{
	struct gss_auth *gss_auth;
	struct rpc_auth * auth;

	dprintk("RPC:      creating GSS authenticator for client %p\n",clnt);

	if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
		goto out_dec;
	gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
	if (!gss_auth->mech) {
		printk(KERN_WARNING "%s: Pseudoflavor %d not found!",
				__FUNCTION__, flavor);
		goto err_free;
	}
	INIT_LIST_HEAD(&gss_auth->upcalls);
	spin_lock_init(&gss_auth->lock);
	auth = &gss_auth->rpc_auth;
	auth->au_cslack = GSS_CRED_SLACK >> 2;
	auth->au_rslack = GSS_VERF_SLACK >> 2;
	auth->au_expire = GSS_CRED_EXPIRE;
	auth->au_ops = &authgss_ops;
	auth->au_flavor = flavor;

	rpcauth_init_credcache(auth);

	snprintf(gss_auth->path, sizeof(gss_auth->path), "%s/%s",
			clnt->cl_pathname,
			gss_auth->mech->gm_name);
	gss_auth->dentry = rpc_mkpipe(gss_auth->path, clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
	if (IS_ERR(gss_auth->dentry))
		goto err_put_mech;

	return auth;
err_put_mech:
	gss_mech_put(gss_auth->mech);
err_free:
	kfree(gss_auth);
out_dec:
	return NULL;
}

static void
gss_destroy(struct rpc_auth *auth)
{
	struct gss_auth *gss_auth;

	dprintk("RPC:      destroying GSS authenticator %p flavor %d\n",
		auth, auth->au_flavor);

	gss_auth = container_of(auth, struct gss_auth, rpc_auth);
	rpc_unlink(gss_auth->path);
	gss_mech_put(gss_auth->mech);

	rpcauth_free_credcache(auth);
}

/* gss_destroy_cred (and gss_destroy_ctx) are used to clean up after failure
 * to create a new cred or context, so they check that things have been
 * allocated before freeing them. */
static void
gss_destroy_ctx(struct gss_cl_ctx *ctx)
{
	dprintk("RPC:      gss_destroy_ctx\n");

	if (ctx->gc_gss_ctx)
		gss_delete_sec_context(&ctx->gc_gss_ctx);

	if (ctx->gc_wire_ctx.len > 0) {
		kfree(ctx->gc_wire_ctx.data);
		ctx->gc_wire_ctx.len = 0;
	}

	kfree(ctx);

}

static void
gss_destroy_cred(struct rpc_cred *rc)
{
	struct gss_cred *cred = (struct gss_cred *)rc;

	dprintk("RPC:      gss_destroy_cred \n");

	if (cred->gc_ctx)
		gss_put_ctx(cred->gc_ctx);
	kfree(cred);
}

static struct rpc_cred *
gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int taskflags)
{
	struct gss_cred	*cred = NULL;

	dprintk("RPC:      gss_create_cred for uid %d, flavor %d\n",
		acred->uid, auth->au_flavor);

	if (!(cred = kmalloc(sizeof(*cred), GFP_KERNEL)))
		goto out_err;

	memset(cred, 0, sizeof(*cred));
	atomic_set(&cred->gc_count, 0);
	cred->gc_uid = acred->uid;
	/*
	 * Note: in order to force a call to call_refresh(), we deliberately
	 * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
	 */
	cred->gc_flags = 0;
	cred->gc_base.cr_ops = &gss_credops;
	cred->gc_flavor = auth->au_flavor;

	return (struct rpc_cred *) cred;

out_err:
	dprintk("RPC:      gss_create_cred failed\n");
	if (cred) gss_destroy_cred((struct rpc_cred *)cred);
	return NULL;
}

static int
gss_match(struct auth_cred *acred, struct rpc_cred *rc, int taskflags)
{
	return (rc->cr_uid == acred->uid);
}

/*
* Marshal credentials.
* Maybe we should keep a cached credential for performance reasons.
*/
static u32 *
gss_marshal(struct rpc_task *task, u32 *p, int ruid)
{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	struct gss_cred	*gss_cred = container_of(cred, struct gss_cred,
						 gc_base);
	struct gss_cl_ctx	*ctx = gss_cred_get_ctx(cred);
	u32		*cred_len;
	struct rpc_rqst *req = task->tk_rqstp;
	u32             maj_stat = 0;
	struct xdr_netobj mic;
	struct kvec	iov;
	struct xdr_buf	verf_buf;
	u32		service;

	dprintk("RPC: %4u gss_marshal\n", task->tk_pid);

	*p++ = htonl(RPC_AUTH_GSS);
	cred_len = p++;

	service = gss_pseudoflavor_to_service(ctx->gc_gss_ctx->mech_type,
						gss_cred->gc_flavor);
	if (service == 0) {
		dprintk("RPC: %4u Bad pseudoflavor %d in gss_marshal\n",
			task->tk_pid, gss_cred->gc_flavor);
		goto out_put_ctx;
	}
	spin_lock(&ctx->gc_seq_lock);
	req->rq_seqno = ctx->gc_seq++;
	spin_unlock(&ctx->gc_seq_lock);

	*p++ = htonl((u32) RPC_GSS_VERSION);
	*p++ = htonl((u32) ctx->gc_proc);
	*p++ = htonl((u32) req->rq_seqno);
	*p++ = htonl((u32) service);
	p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
	*cred_len = htonl((p - (cred_len + 1)) << 2);

	/* We compute the checksum for the verifier over the xdr-encoded bytes
	 * starting with the xid and ending at the end of the credential: */
	iov.iov_base = req->rq_snd_buf.head[0].iov_base;
	if (task->tk_client->cl_xprt->stream)
		/* See clnt.c:call_header() */
		iov.iov_base += 4;
	iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
	xdr_buf_from_iov(&iov, &verf_buf);

	/* set verifier flavor*/
	*p++ = htonl(RPC_AUTH_GSS);

	mic.data = (u8 *)(p + 1);
	maj_stat = gss_get_mic(ctx->gc_gss_ctx,
			       GSS_C_QOP_DEFAULT, 
			       &verf_buf, &mic);
	if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
		cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
	} else if (maj_stat != 0) {
		printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
		goto out_put_ctx;
	}
	p = xdr_encode_opaque(p, NULL, mic.len);
	gss_put_ctx(ctx);
	return p;
out_put_ctx:
	gss_put_ctx(ctx);
	return NULL;
}

/*
* Refresh credentials. XXX - finish
*/
static int
gss_refresh(struct rpc_task *task)
{
	struct rpc_clnt *clnt = task->tk_client;
	struct rpc_cred *cred = task->tk_msg.rpc_cred;

	if (!gss_cred_is_uptodate_ctx(cred))
		return gss_upcall(clnt, task, cred);
	return 0;
}

static u32 *
gss_validate(struct rpc_task *task, u32 *p)
{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	struct gss_cred	*gss_cred = container_of(cred, struct gss_cred,
						gc_base);
	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
	u32		seq, qop_state;
	struct kvec	iov;
	struct xdr_buf	verf_buf;
	struct xdr_netobj mic;
	u32		flav,len;
	u32		service;
	u32		maj_stat;

	dprintk("RPC: %4u gss_validate\n", task->tk_pid);

	flav = ntohl(*p++);
	if ((len = ntohl(*p++)) > RPC_MAX_AUTH_SIZE)
                goto out_bad;
	if (flav != RPC_AUTH_GSS)
		goto out_bad;
	seq = htonl(task->tk_rqstp->rq_seqno);
	iov.iov_base = &seq;
	iov.iov_len = sizeof(seq);
	xdr_buf_from_iov(&iov, &verf_buf);
	mic.data = (u8 *)p;
	mic.len = len;

	maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic, &qop_state);
	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
		cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
	if (maj_stat)
		goto out_bad;
       service = gss_pseudoflavor_to_service(ctx->gc_gss_ctx->mech_type,
					gss_cred->gc_flavor);
       switch (service) {
       case RPC_GSS_SVC_NONE:
	       /* verifier data, flavor, length: */
	       task->tk_auth->au_rslack = XDR_QUADLEN(len) + 2;
	       break;
       case RPC_GSS_SVC_INTEGRITY:
	       /* verifier data, flavor, length, length, sequence number: */
	       task->tk_auth->au_rslack = XDR_QUADLEN(len) + 4;
	       break;
       default:
	       goto out_bad;
       }
	gss_put_ctx(ctx);
	dprintk("RPC: %4u GSS gss_validate: gss_verify_mic succeeded.\n",
			task->tk_pid);
	return p + XDR_QUADLEN(len);
out_bad:
	gss_put_ctx(ctx);
	dprintk("RPC: %4u gss_validate failed.\n", task->tk_pid);
	return NULL;
}

static inline int
gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
		kxdrproc_t encode, struct rpc_rqst *rqstp, u32 *p, void *obj)
{
	struct xdr_buf	*snd_buf = &rqstp->rq_snd_buf;
	struct xdr_buf	integ_buf;
	u32             *integ_len = NULL;
	struct xdr_netobj mic;
	u32		offset, *q;
	struct kvec	*iov;
	u32             maj_stat = 0;
	int		status = -EIO;

	integ_len = p++;
	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
	*p++ = htonl(rqstp->rq_seqno);

	status = encode(rqstp, p, obj);
	if (status)
		return status;

	if (xdr_buf_subsegment(snd_buf, &integ_buf,
				offset, snd_buf->len - offset))
		return status;
	*integ_len = htonl(integ_buf.len);

	/* guess whether we're in the head or the tail: */
	if (snd_buf->page_len || snd_buf->tail[0].iov_len) 
		iov = snd_buf->tail;
	else
		iov = snd_buf->head;
	p = iov->iov_base + iov->iov_len;
	mic.data = (u8 *)(p + 1);

	maj_stat = gss_get_mic(ctx->gc_gss_ctx,
			GSS_C_QOP_DEFAULT, &integ_buf, &mic);
	status = -EIO; /* XXX? */
	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
		cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
	else if (maj_stat)
		return status;
	q = xdr_encode_opaque(p, NULL, mic.len);

	offset = (u8 *)q - (u8 *)p;
	iov->iov_len += offset;
	snd_buf->len += offset;
	return 0;
}

static int
gss_wrap_req(struct rpc_task *task,
	     kxdrproc_t encode, void *rqstp, u32 *p, void *obj)
{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	struct gss_cred	*gss_cred = container_of(cred, struct gss_cred,
			gc_base);
	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
	int             status = -EIO;
	u32		service;

	dprintk("RPC: %4u gss_wrap_req\n", task->tk_pid);
	if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
		/* The spec seems a little ambiguous here, but I think that not
		 * wrapping context destruction requests makes the most sense.
		 */
		status = encode(rqstp, p, obj);
		goto out;
	}
	service = gss_pseudoflavor_to_service(ctx->gc_gss_ctx->mech_type,
						gss_cred->gc_flavor);
	switch (service) {
		case RPC_GSS_SVC_NONE:
			status = encode(rqstp, p, obj);
			goto out;
		case RPC_GSS_SVC_INTEGRITY:
			status = gss_wrap_req_integ(cred, ctx, encode,
								rqstp, p, obj);
			goto out;
		case RPC_GSS_SVC_PRIVACY:
		default:
			goto out;
	}
out:
	gss_put_ctx(ctx);
	dprintk("RPC: %4u gss_wrap_req returning %d\n", task->tk_pid, status);
	return status;
}

static inline int
gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
		struct rpc_rqst *rqstp, u32 **p)
{
	struct xdr_buf	*rcv_buf = &rqstp->rq_rcv_buf;
	struct xdr_buf integ_buf;
	struct xdr_netobj mic;
	u32 data_offset, mic_offset;
	u32 integ_len;
	u32 maj_stat;
	int status = -EIO;

	integ_len = ntohl(*(*p)++);
	if (integ_len & 3)
		return status;
	data_offset = (u8 *)(*p) - (u8 *)rcv_buf->head[0].iov_base;
	mic_offset = integ_len + data_offset;
	if (mic_offset > rcv_buf->len)
		return status;
	if (ntohl(*(*p)++) != rqstp->rq_seqno)
		return status;

	if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset,
				mic_offset - data_offset))
		return status;

	if (xdr_buf_read_netobj(rcv_buf, &mic, mic_offset))
		return status;

	maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf,
			&mic, NULL);
	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
		cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
	if (maj_stat != GSS_S_COMPLETE)
		return status;
	return 0;
}

static int
gss_unwrap_resp(struct rpc_task *task,
		kxdrproc_t decode, void *rqstp, u32 *p, void *obj)
{
	struct rpc_cred *cred = task->tk_msg.rpc_cred;
	struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
			gc_base);
	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
	int             status = -EIO;
	u32		service;

	if (ctx->gc_proc != RPC_GSS_PROC_DATA)
		goto out_decode;
	service = gss_pseudoflavor_to_service(ctx->gc_gss_ctx->mech_type,
						gss_cred->gc_flavor);
	switch (service) {
		case RPC_GSS_SVC_NONE:
			goto out_decode;
		case RPC_GSS_SVC_INTEGRITY:
			status = gss_unwrap_resp_integ(cred, ctx, rqstp, &p);
			if (status)
				goto out;
			break;
		case RPC_GSS_SVC_PRIVACY:
		default:
			goto out;
	}
out_decode:
	status = decode(rqstp, p, obj);
out:
	gss_put_ctx(ctx);
	dprintk("RPC: %4u gss_unwrap_resp returning %d\n", task->tk_pid,
			status);
	return status;
}
  
static struct rpc_authops authgss_ops = {
	.owner		= THIS_MODULE,
	.au_flavor	= RPC_AUTH_GSS,
#ifdef RPC_DEBUG
	.au_name	= "RPCSEC_GSS",
#endif
	.create		= gss_create,
	.destroy	= gss_destroy,
	.crcreate	= gss_create_cred
};

static struct rpc_credops gss_credops = {
	.crdestroy	= gss_destroy_cred,
	.crmatch	= gss_match,
	.crmarshal	= gss_marshal,
	.crrefresh	= gss_refresh,
	.crvalidate	= gss_validate,
	.crwrap_req	= gss_wrap_req,
	.crunwrap_resp	= gss_unwrap_resp,
};

static struct rpc_pipe_ops gss_upcall_ops = {
	.upcall		= gss_pipe_upcall,
	.downcall	= gss_pipe_downcall,
	.destroy_msg	= gss_pipe_destroy_msg,
	.release_pipe	= gss_pipe_release,
};

/*
 * Initialize RPCSEC_GSS module
 */
static int __init init_rpcsec_gss(void)
{
	int err = 0;

	err = rpcauth_register(&authgss_ops);
	if (err)
		goto out;
	err = gss_svc_init();
	if (err)
		goto out_unregister;
	return 0;
out_unregister:
	rpcauth_unregister(&authgss_ops);
out:
	return err;
}

static void __exit exit_rpcsec_gss(void)
{
	gss_svc_shutdown();
	rpcauth_unregister(&authgss_ops);
}

MODULE_LICENSE("GPL");
module_init(init_rpcsec_gss)
module_exit(exit_rpcsec_gss)