1 files changed, 448 insertions, 0 deletions
diff --git a/net/sunrpc/auth_gss/gss_mech_switch.c b/net/sunrpc/auth_gss/gss_mech_switch.c
new file mode 100644
index 000000000..fae632da1
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_mech_switch.c
@@ -0,0 +1,448 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ *  linux/net/sunrpc/gss_mech_switch.c
+ *
+ *  Copyright (c) 2001 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  J. Bruce Fields   <bfields@umich.edu>
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/oid_registry.h>
+#include <linux/sunrpc/msg_prot.h>
+#include <linux/sunrpc/gss_asn1.h>
+#include <linux/sunrpc/auth_gss.h>
+#include <linux/sunrpc/svcauth_gss.h>
+#include <linux/sunrpc/gss_err.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/sunrpc/gss_api.h>
+#include <linux/sunrpc/clnt.h>
+#include <trace/events/rpcgss.h>
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY        RPCDBG_AUTH
+#endif
+
+static LIST_HEAD(registered_mechs);
+static DEFINE_SPINLOCK(registered_mechs_lock);
+
+static void
+gss_mech_free(struct gss_api_mech *gm)
+{
+	struct pf_desc *pf;
+	int i;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		pf = &gm->gm_pfs[i];
+		if (pf->domain)
+			auth_domain_put(pf->domain);
+		kfree(pf->auth_domain_name);
+		pf->auth_domain_name = NULL;
+	}
+}
+
+static inline char *
+make_auth_domain_name(char *name)
+{
+	static char	*prefix = "gss/";
+	char		*new;
+
+	new = kmalloc(strlen(name) + strlen(prefix) + 1, GFP_KERNEL);
+	if (new) {
+		strcpy(new, prefix);
+		strcat(new, name);
+	}
+	return new;
+}
+
+static int
+gss_mech_svc_setup(struct gss_api_mech *gm)
+{
+	struct auth_domain *dom;
+	struct pf_desc *pf;
+	int i, status;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		pf = &gm->gm_pfs[i];
+		pf->auth_domain_name = make_auth_domain_name(pf->name);
+		status = -ENOMEM;
+		if (pf->auth_domain_name == NULL)
+			goto out;
+		dom = svcauth_gss_register_pseudoflavor(
+			pf->pseudoflavor, pf->auth_domain_name);
+		if (IS_ERR(dom)) {
+			status = PTR_ERR(dom);
+			goto out;
+		}
+		pf->domain = dom;
+	}
+	return 0;
+out:
+	gss_mech_free(gm);
+	return status;
+}
+
+/**
+ * gss_mech_register - register a GSS mechanism
+ * @gm: GSS mechanism handle
+ *
+ * Returns zero if successful, or a negative errno.
+ */
+int gss_mech_register(struct gss_api_mech *gm)
+{
+	int status;
+
+	status = gss_mech_svc_setup(gm);
+	if (status)
+		return status;
+	spin_lock(&registered_mechs_lock);
+	list_add_rcu(&gm->gm_list, &registered_mechs);
+	spin_unlock(&registered_mechs_lock);
+	dprintk("RPC:       registered gss mechanism %s\n", gm->gm_name);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(gss_mech_register);
+
+/**
+ * gss_mech_unregister - release a GSS mechanism
+ * @gm: GSS mechanism handle
+ *
+ */
+void gss_mech_unregister(struct gss_api_mech *gm)
+{
+	spin_lock(&registered_mechs_lock);
+	list_del_rcu(&gm->gm_list);
+	spin_unlock(&registered_mechs_lock);
+	dprintk("RPC:       unregistered gss mechanism %s\n", gm->gm_name);
+	gss_mech_free(gm);
+}
+EXPORT_SYMBOL_GPL(gss_mech_unregister);
+
+struct gss_api_mech *gss_mech_get(struct gss_api_mech *gm)
+{
+	__module_get(gm->gm_owner);
+	return gm;
+}
+EXPORT_SYMBOL(gss_mech_get);
+
+static struct gss_api_mech *
+_gss_mech_get_by_name(const char *name)
+{
+	struct gss_api_mech	*pos, *gm = NULL;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {
+		if (0 == strcmp(name, pos->gm_name)) {
+			if (try_module_get(pos->gm_owner))
+				gm = pos;
+			break;
+		}
+	}
+	rcu_read_unlock();
+	return gm;
+
+}
+
+struct gss_api_mech * gss_mech_get_by_name(const char *name)
+{
+	struct gss_api_mech *gm = NULL;
+
+	gm = _gss_mech_get_by_name(name);
+	if (!gm) {
+		request_module("rpc-auth-gss-%s", name);
+		gm = _gss_mech_get_by_name(name);
+	}
+	return gm;
+}
+
+struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
+{
+	struct gss_api_mech	*pos, *gm = NULL;
+	char buf[32];
+
+	if (sprint_oid(obj->data, obj->len, buf, sizeof(buf)) < 0)
+		return NULL;
+	request_module("rpc-auth-gss-%s", buf);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {
+		if (obj->len == pos->gm_oid.len) {
+			if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
+				if (try_module_get(pos->gm_owner))
+					gm = pos;
+				break;
+			}
+		}
+	}
+	rcu_read_unlock();
+	if (!gm)
+		trace_rpcgss_oid_to_mech(buf);
+	return gm;
+}
+
+static inline int
+mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
+{
+	int i;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
+			return 1;
+	}
+	return 0;
+}
+
+static struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
+{
+	struct gss_api_mech *gm = NULL, *pos;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {
+		if (!mech_supports_pseudoflavor(pos, pseudoflavor))
+			continue;
+		if (try_module_get(pos->gm_owner))
+			gm = pos;
+		break;
+	}
+	rcu_read_unlock();
+	return gm;
+}
+
+struct gss_api_mech *
+gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
+{
+	struct gss_api_mech *gm;
+
+	gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
+
+	if (!gm) {
+		request_module("rpc-auth-gss-%u", pseudoflavor);
+		gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
+	}
+	return gm;
+}
+
+/**
+ * gss_svc_to_pseudoflavor - map a GSS service number to a pseudoflavor
+ * @gm: GSS mechanism handle
+ * @qop: GSS quality-of-protection value
+ * @service: GSS service value
+ *
+ * Returns a matching security flavor, or RPC_AUTH_MAXFLAVOR if none is found.
+ */
+rpc_authflavor_t gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 qop,
+					 u32 service)
+{
+	int i;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		if (gm->gm_pfs[i].qop == qop &&
+		    gm->gm_pfs[i].service == service) {
+			return gm->gm_pfs[i].pseudoflavor;
+		}
+	}
+	return RPC_AUTH_MAXFLAVOR;
+}
+
+/**
+ * gss_mech_info2flavor - look up a pseudoflavor given a GSS tuple
+ * @info: a GSS mech OID, quality of protection, and service value
+ *
+ * Returns a matching pseudoflavor, or RPC_AUTH_MAXFLAVOR if the tuple is
+ * not supported.
+ */
+rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *info)
+{
+	rpc_authflavor_t pseudoflavor;
+	struct gss_api_mech *gm;
+
+	gm = gss_mech_get_by_OID(&info->oid);
+	if (gm == NULL)
+		return RPC_AUTH_MAXFLAVOR;
+
+	pseudoflavor = gss_svc_to_pseudoflavor(gm, info->qop, info->service);
+
+	gss_mech_put(gm);
+	return pseudoflavor;
+}
+
+/**
+ * gss_mech_flavor2info - look up a GSS tuple for a given pseudoflavor
+ * @pseudoflavor: GSS pseudoflavor to match
+ * @info: rpcsec_gss_info structure to fill in
+ *
+ * Returns zero and fills in "info" if pseudoflavor matches a
+ * supported mechanism.  Otherwise a negative errno is returned.
+ */
+int gss_mech_flavor2info(rpc_authflavor_t pseudoflavor,
+			 struct rpcsec_gss_info *info)
+{
+	struct gss_api_mech *gm;
+	int i;
+
+	gm = gss_mech_get_by_pseudoflavor(pseudoflavor);
+	if (gm == NULL)
+		return -ENOENT;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		if (gm->gm_pfs[i].pseudoflavor == pseudoflavor) {
+			memcpy(info->oid.data, gm->gm_oid.data, gm->gm_oid.len);
+			info->oid.len = gm->gm_oid.len;
+			info->qop = gm->gm_pfs[i].qop;
+			info->service = gm->gm_pfs[i].service;
+			gss_mech_put(gm);
+			return 0;
+		}
+	}
+
+	gss_mech_put(gm);
+	return -ENOENT;
+}
+
+u32
+gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
+{
+	int i;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
+			return gm->gm_pfs[i].service;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(gss_pseudoflavor_to_service);
+
+bool
+gss_pseudoflavor_to_datatouch(struct gss_api_mech *gm, u32 pseudoflavor)
+{
+	int i;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
+			return gm->gm_pfs[i].datatouch;
+	}
+	return false;
+}
+
+char *
+gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
+{
+	int i;
+
+	for (i = 0; i < gm->gm_pf_num; i++) {
+		if (gm->gm_pfs[i].service == service)
+			return gm->gm_pfs[i].auth_domain_name;
+	}
+	return NULL;
+}
+
+void
+gss_mech_put(struct gss_api_mech * gm)
+{
+	if (gm)
+		module_put(gm->gm_owner);
+}
+EXPORT_SYMBOL(gss_mech_put);
+
+/* The mech could probably be determined from the token instead, but it's just
+ * as easy for now to pass it in. */
+int
+gss_import_sec_context(const void *input_token, size_t bufsize,
+		       struct gss_api_mech	*mech,
+		       struct gss_ctx		**ctx_id,
+		       time64_t			*endtime,
+		       gfp_t gfp_mask)
+{
+	if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
+		return -ENOMEM;
+	(*ctx_id)->mech_type = gss_mech_get(mech);
+
+	return mech->gm_ops->gss_import_sec_context(input_token, bufsize,
+						*ctx_id, endtime, gfp_mask);
+}
+
+/* gss_get_mic: compute a mic over message and return mic_token. */
+
+u32
+gss_get_mic(struct gss_ctx	*context_handle,
+	    struct xdr_buf	*message,
+	    struct xdr_netobj	*mic_token)
+{
+	 return context_handle->mech_type->gm_ops
+		->gss_get_mic(context_handle,
+			      message,
+			      mic_token);
+}
+
+/* gss_verify_mic: check whether the provided mic_token verifies message. */
+
+u32
+gss_verify_mic(struct gss_ctx		*context_handle,
+	       struct xdr_buf		*message,
+	       struct xdr_netobj	*mic_token)
+{
+	return context_handle->mech_type->gm_ops
+		->gss_verify_mic(context_handle,
+				 message,
+				 mic_token);
+}
+
+/*
+ * This function is called from both the client and server code.
+ * Each makes guarantees about how much "slack" space is available
+ * for the underlying function in "buf"'s head and tail while
+ * performing the wrap.
+ *
+ * The client and server code allocate RPC_MAX_AUTH_SIZE extra
+ * space in both the head and tail which is available for use by
+ * the wrap function.
+ *
+ * Underlying functions should verify they do not use more than
+ * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
+ * when performing the wrap.
+ */
+u32
+gss_wrap(struct gss_ctx	*ctx_id,
+	 int		offset,
+	 struct xdr_buf	*buf,
+	 struct page	**inpages)
+{
+	return ctx_id->mech_type->gm_ops
+		->gss_wrap(ctx_id, offset, buf, inpages);
+}
+
+u32
+gss_unwrap(struct gss_ctx	*ctx_id,
+	   int			offset,
+	   int			len,
+	   struct xdr_buf	*buf)
+{
+	return ctx_id->mech_type->gm_ops
+		->gss_unwrap(ctx_id, offset, len, buf);
+}
+
+
+/* gss_delete_sec_context: free all resources associated with context_handle.
+ * Note this differs from the RFC 2744-specified prototype in that we don't
+ * bother returning an output token, since it would never be used anyway. */
+
+u32
+gss_delete_sec_context(struct gss_ctx	**context_handle)
+{
+	dprintk("RPC:       gss_delete_sec_context deleting %p\n",
+			*context_handle);
+
+	if (!*context_handle)
+		return GSS_S_NO_CONTEXT;
+	if ((*context_handle)->internal_ctx_id)
+		(*context_handle)->mech_type->gm_ops
+			->gss_delete_sec_context((*context_handle)
+							->internal_ctx_id);
+	gss_mech_put((*context_handle)->mech_type);
+	kfree(*context_handle);
+	*context_handle=NULL;
+	return GSS_S_COMPLETE;
+}