svcauth_gss.c

omap3 linux 2.6 用nocc去除了冗余代码

	struct rsc *rsci = svcdata->rsci;
	struct rpc_gss_wire_cred *gc = &svcdata->clcred;

	rqstp->rq_client = find_gss_auth_domain(rsci->mechctx, gc->gc_svc);
	if (rqstp->rq_client == NULL)
		return SVC_DENIED;
	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;
			rqstp->rq_client = NULL;
		}
		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);
		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_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);
}