+/*
+ * GSS Proxy upcall module
+ *
+ * Copyright (C) 2012 Simo Sorce <simo@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/sunrpc/svcauth.h>
+#include "gss_rpc_xdr.h"
+
+static bool gssx_check_pointer(struct xdr_stream *xdr)
+{
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, 4);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+ return *p?true:false;
+}
+
+static int gssx_enc_bool(struct xdr_stream *xdr, int v)
+{
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, 4);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+ *p = v ? xdr_one : xdr_zero;
+ return 0;
+}
+
+static int gssx_dec_bool(struct xdr_stream *xdr, u32 *v)
+{
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+ *v = be32_to_cpu(*p);
+ return 0;
+}
+
+static int gssx_enc_buffer(struct xdr_stream *xdr,
+ gssx_buffer *buf)
+{
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, sizeof(u32) + buf->len);
+ if (!p)
+ return -ENOSPC;
+ xdr_encode_opaque(p, buf->data, buf->len);
+ return 0;
+}
+
+static int gssx_enc_in_token(struct xdr_stream *xdr,
+ struct gssp_in_token *in)
+{
+ __be32 *p;
+
+ p = xdr_reserve_space(xdr, 4);
+ if (!p)
+ return -ENOSPC;
+ *p = cpu_to_be32(in->page_len);
+
+ /* all we need to do is to write pages */
+ xdr_write_pages(xdr, in->pages, in->page_base, in->page_len);
+
+ return 0;
+}
+
+
+static int gssx_dec_buffer(struct xdr_stream *xdr,
+ gssx_buffer *buf)
+{
+ u32 length;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+
+ length = be32_to_cpup(p);
+ p = xdr_inline_decode(xdr, length);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+
+ if (buf->len == 0) {
+ /* we intentionally are not interested in this buffer */
+ return 0;
+ }
+ if (length > buf->len)
+ return -ENOSPC;
+
+ if (!buf->data) {
+ buf->data = kmemdup(p, length, GFP_KERNEL);
+ if (!buf->data)
+ return -ENOMEM;
+ } else {
+ memcpy(buf->data, p, length);
+ }
+ buf->len = length;
+ return 0;
+}
+
+static int gssx_enc_option(struct xdr_stream *xdr,
+ struct gssx_option *opt)
+{
+ int err;
+
+ err = gssx_enc_buffer(xdr, &opt->option);
+ if (err)
+ return err;
+ err = gssx_enc_buffer(xdr, &opt->value);
+ return err;
+}
+
+static int gssx_dec_option(struct xdr_stream *xdr,
+ struct gssx_option *opt)
+{
+ int err;
+
+ err = gssx_dec_buffer(xdr, &opt->option);
+ if (err)
+ return err;
+ err = gssx_dec_buffer(xdr, &opt->value);
+ return err;
+}
+
+static int dummy_enc_opt_array(struct xdr_stream *xdr,
+ struct gssx_option_array *oa)
+{
+ __be32 *p;
+
+ if (oa->count != 0)
+ return -EINVAL;
+
+ p = xdr_reserve_space(xdr, 4);
+ if (!p)
+ return -ENOSPC;
+ *p = 0;
+
+ return 0;
+}
+
+static int dummy_dec_opt_array(struct xdr_stream *xdr,
+ struct gssx_option_array *oa)
+{
+ struct gssx_option dummy;
+ u32 count, i;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+ count = be32_to_cpup(p++);
+ memset(&dummy, 0, sizeof(dummy));
+ for (i = 0; i < count; i++) {
+ gssx_dec_option(xdr, &dummy);
+ }
+
+ oa->count = 0;
+ oa->data = NULL;
+ return 0;
+}
+
+static int get_s32(void **p, void *max, s32 *res)
+{
+ void *base = *p;
+ void *next = (void *)((char *)base + sizeof(s32));
+ if (unlikely(next > max || next < base))
+ return -EINVAL;
+ memcpy(res, base, sizeof(s32));
+ *p = next;
+ return 0;
+}
+
+static int gssx_dec_linux_creds(struct xdr_stream *xdr,
+ struct svc_cred *creds)
+{
+ u32 length;
+ __be32 *p;
+ void *q, *end;
+ s32 tmp;
+ int N, i, err;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+
+ length = be32_to_cpup(p);
+
+ /* FIXME: we do not want to use the scratch buffer for this one
+ * may need to use functions that allows us to access an io vector
+ * directly */
+ p = xdr_inline_decode(xdr, length);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+
+ q = p;
+ end = q + length;
+
+ /* uid */
+ err = get_s32(&q, end, &tmp);
+ if (err)
+ return err;
+ creds->cr_uid = tmp;
+
+ /* gid */
+ err = get_s32(&q, end, &tmp);
+ if (err)
+ return err;
+ creds->cr_gid = tmp;
+
+ /* number of additional gid's */
+ err = get_s32(&q, end, &tmp);
+ if (err)
+ return err;
+ N = tmp;
+ creds->cr_group_info = groups_alloc(N);
+ if (creds->cr_group_info == NULL)
+ return -ENOMEM;
+
+ /* gid's */
+ for (i = 0; i < N; i++) {
+ err = get_s32(&q, end, &tmp);
+ if (err) {
+ groups_free(creds->cr_group_info);
+ return err;
+ }
+ GROUP_AT(creds->cr_group_info, i) = tmp;
+ }
+
+ return 0;
+}
+
+static int gssx_dec_option_array(struct xdr_stream *xdr,
+ struct gssx_option_array *oa)
+{
+ struct svc_cred *creds;
+ u32 count, i;
+ __be32 *p;
+ int err;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+ count = be32_to_cpup(p++);
+ if (count != 0) {
+ /* we recognize only 1 currently: CREDS_VALUE */
+ oa->count = 1;
+
+ oa->data = kmalloc(sizeof(struct gssx_option), GFP_KERNEL);
+ if (!oa->data)
+ return -ENOMEM;
+
+ creds = kmalloc(sizeof(struct svc_cred), GFP_KERNEL);
+ if (!creds) {
+ kfree(oa->data);
+ return -ENOMEM;
+ }
+
+ oa->data[0].option.data = CREDS_VALUE;
+ oa->data[0].option.len = sizeof(CREDS_VALUE);
+ oa->data[0].value.data = (void *)creds;
+ oa->data[0].value.len = 0;
+ }
+ for (i = 0; i < count; i++) {
+ gssx_buffer dummy = { 0, NULL };
+ u32 length;
+
+ /* option buffer */
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+
+ length = be32_to_cpup(p);
+ p = xdr_inline_decode(xdr, length);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+
+ if (length == sizeof(CREDS_VALUE) &&
+ memcmp(p, CREDS_VALUE, sizeof(CREDS_VALUE)) == 0) {
+ /* We have creds here. parse them */
+ err = gssx_dec_linux_creds(xdr, creds);
+ if (err)
+ return err;
+ oa->data[0].value.len = 1; /* presence */
+ } else {
+ /* consume uninteresting buffer */
+ err = gssx_dec_buffer(xdr, &dummy);
+ if (err)
+ return err;
+ }
+ }
+ return 0;
+}
+
+static int gssx_dec_status(struct xdr_stream *xdr,
+ struct gssx_status *status)
+{
+ __be32 *p;
+ int err;
+
+ /* status->major_status */
+ p = xdr_inline_decode(xdr, 8);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+ p = xdr_decode_hyper(p, &status->major_status);
+
+ /* status->mech */
+ err = gssx_dec_buffer(xdr, &status->mech);
+ if (err)
+ return err;
+
+ /* status->minor_status */
+ p = xdr_inline_decode(xdr, 8);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+ p = xdr_decode_hyper(p, &status->minor_status);
+
+ /* status->major_status_string */
+ err = gssx_dec_buffer(xdr, &status->major_status_string);
+ if (err)
+ return err;
+
+ /* status->minor_status_string */
+ err = gssx_dec_buffer(xdr, &status->minor_status_string);
+ if (err)
+ return err;
+
+ /* status->server_ctx */
+ err = gssx_dec_buffer(xdr, &status->server_ctx);
+ if (err)
+ return err;
+
+ /* we assume we have no options for now, so simply consume them */
+ /* status->options */
+ err = dummy_dec_opt_array(xdr, &status->options);
+
+ return err;
+}
+
+static int gssx_enc_call_ctx(struct xdr_stream *xdr,
+ struct gssx_call_ctx *ctx)
+{
+ struct gssx_option opt;
+ __be32 *p;
+ int err;
+
+ /* ctx->locale */
+ err = gssx_enc_buffer(xdr, &ctx->locale);
+ if (err)
+ return err;
+
+ /* ctx->server_ctx */
+ err = gssx_enc_buffer(xdr, &ctx->server_ctx);
+ if (err)
+ return err;
+
+ /* we always want to ask for lucid contexts */
+ /* ctx->options */
+ p = xdr_reserve_space(xdr, 4);
+ *p = cpu_to_be32(2);
+
+ /* we want a lucid_v1 context */
+ opt.option.data = LUCID_OPTION;
+ opt.option.len = sizeof(LUCID_OPTION);
+ opt.value.data = LUCID_VALUE;
+ opt.value.len = sizeof(LUCID_VALUE);
+ err = gssx_enc_option(xdr, &opt);
+
+ /* ..and user creds */
+ opt.option.data = CREDS_OPTION;
+ opt.option.len = sizeof(CREDS_OPTION);
+ opt.value.data = CREDS_VALUE;
+ opt.value.len = sizeof(CREDS_VALUE);
+ err = gssx_enc_option(xdr, &opt);
+
+ return err;
+}
+
+static int gssx_dec_name_attr(struct xdr_stream *xdr,
+ struct gssx_name_attr *attr)
+{
+ int err;
+
+ /* attr->attr */
+ err = gssx_dec_buffer(xdr, &attr->attr);
+ if (err)
+ return err;
+
+ /* attr->value */
+ err = gssx_dec_buffer(xdr, &attr->value);
+ if (err)
+ return err;
+
+ /* attr->extensions */
+ err = dummy_dec_opt_array(xdr, &attr->extensions);
+
+ return err;
+}
+
+static int dummy_enc_nameattr_array(struct xdr_stream *xdr,
+ struct gssx_name_attr_array *naa)
+{
+ __be32 *p;
+
+ if (naa->count != 0)
+ return -EINVAL;
+
+ p = xdr_reserve_space(xdr, 4);
+ if (!p)
+ return -ENOSPC;
+ *p = 0;
+
+ return 0;
+}
+
+static int dummy_dec_nameattr_array(struct xdr_stream *xdr,
+ struct gssx_name_attr_array *naa)
+{
+ struct gssx_name_attr dummy;
+ u32 count, i;
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+ count = be32_to_cpup(p++);
+ for (i = 0; i < count; i++) {
+ gssx_dec_name_attr(xdr, &dummy);
+ }
+
+ naa->count = 0;
+ naa->data = NULL;
+ return 0;
+}
+
+static struct xdr_netobj zero_netobj = {};
+
+static struct gssx_name_attr_array zero_name_attr_array = {};
+
+static struct gssx_option_array zero_option_array = {};
+
+static int gssx_enc_name(struct xdr_stream *xdr,
+ struct gssx_name *name)
+{
+ int err;
+
+ /* name->display_name */
+ err = gssx_enc_buffer(xdr, &name->display_name);
+ if (err)
+ return err;
+
+ /* name->name_type */
+ err = gssx_enc_buffer(xdr, &zero_netobj);
+ if (err)
+ return err;
+
+ /* name->exported_name */
+ err = gssx_enc_buffer(xdr, &zero_netobj);
+ if (err)
+ return err;
+
+ /* name->exported_composite_name */
+ err = gssx_enc_buffer(xdr, &zero_netobj);
+ if (err)
+ return err;
+
+ /* leave name_attributes empty for now, will add once we have any
+ * to pass up at all */
+ /* name->name_attributes */
+ err = dummy_enc_nameattr_array(xdr, &zero_name_attr_array);
+ if (err)
+ return err;
+
+ /* leave options empty for now, will add once we have any options
+ * to pass up at all */
+ /* name->extensions */
+ err = dummy_enc_opt_array(xdr, &zero_option_array);
+
+ return err;
+}
+
+static int gssx_dec_name(struct xdr_stream *xdr,
+ struct gssx_name *name)
+{
+ struct xdr_netobj dummy_netobj;
+ struct gssx_name_attr_array dummy_name_attr_array;
+ struct gssx_option_array dummy_option_array;
+ int err;
+
+ /* name->display_name */
+ err = gssx_dec_buffer(xdr, &name->display_name);
+ if (err)
+ return err;
+
+ /* name->name_type */
+ err = gssx_dec_buffer(xdr, &dummy_netobj);
+ if (err)
+ return err;
+
+ /* name->exported_name */
+ err = gssx_dec_buffer(xdr, &dummy_netobj);
+ if (err)
+ return err;
+
+ /* name->exported_composite_name */
+ err = gssx_dec_buffer(xdr, &dummy_netobj);
+ if (err)
+ return err;
+
+ /* we assume we have no attributes for now, so simply consume them */
+ /* name->name_attributes */
+ err = dummy_dec_nameattr_array(xdr, &dummy_name_attr_array);
+ if (err)
+ return err;
+
+ /* we assume we have no options for now, so simply consume them */
+ /* name->extensions */
+ err = dummy_dec_opt_array(xdr, &dummy_option_array);
+
+ return err;
+}
+
+static int dummy_enc_credel_array(struct xdr_stream *xdr,
+ struct gssx_cred_element_array *cea)
+{
+ __be32 *p;
+
+ if (cea->count != 0)
+ return -EINVAL;
+
+ p = xdr_reserve_space(xdr, 4);
+ if (!p)
+ return -ENOSPC;
+ *p = 0;
+
+ return 0;
+}
+
+static int gssx_enc_cred(struct xdr_stream *xdr,
+ struct gssx_cred *cred)
+{
+ int err;
+
+ /* cred->desired_name */
+ err = gssx_enc_name(xdr, &cred->desired_name);
+ if (err)
+ return err;
+
+ /* cred->elements */
+ err = dummy_enc_credel_array(xdr, &cred->elements);
+
+ /* cred->cred_handle_reference */
+ err = gssx_enc_buffer(xdr, &cred->cred_handle_reference);
+ if (err)
+ return err;
+
+ /* cred->needs_release */
+ err = gssx_enc_bool(xdr, cred->needs_release);
+
+ return err;
+}
+
+static int gssx_enc_ctx(struct xdr_stream *xdr,
+ struct gssx_ctx *ctx)
+{
+ __be32 *p;
+ int err;
+
+ /* ctx->exported_context_token */
+ err = gssx_enc_buffer(xdr, &ctx->exported_context_token);
+ if (err)
+ return err;
+
+ /* ctx->state */
+ err = gssx_enc_buffer(xdr, &ctx->state);
+ if (err)
+ return err;
+
+ /* ctx->need_release */
+ err = gssx_enc_bool(xdr, ctx->need_release);
+ if (err)
+ return err;
+
+ /* ctx->mech */
+ err = gssx_enc_buffer(xdr, &ctx->mech);
+ if (err)
+ return err;
+
+ /* ctx->src_name */
+ err = gssx_enc_name(xdr, &ctx->src_name);
+ if (err)
+ return err;
+
+ /* ctx->targ_name */
+ err = gssx_enc_name(xdr, &ctx->targ_name);
+ if (err)
+ return err;
+
+ /* ctx->lifetime */
+ p = xdr_reserve_space(xdr, 8+8);
+ if (!p)
+ return -ENOSPC;
+ p = xdr_encode_hyper(p, ctx->lifetime);
+
+ /* ctx->ctx_flags */
+ p = xdr_encode_hyper(p, ctx->ctx_flags);
+
+ /* ctx->locally_initiated */
+ err = gssx_enc_bool(xdr, ctx->locally_initiated);
+ if (err)
+ return err;
+
+ /* ctx->open */
+ err = gssx_enc_bool(xdr, ctx->open);
+ if (err)
+ return err;
+
+ /* leave options empty for now, will add once we have any options
+ * to pass up at all */
+ /* ctx->options */
+ err = dummy_enc_opt_array(xdr, &ctx->options);
+
+ return err;
+}
+
+static int gssx_dec_ctx(struct xdr_stream *xdr,
+ struct gssx_ctx *ctx)
+{
+ __be32 *p;
+ int err;
+
+ /* ctx->exported_context_token */
+ err = gssx_dec_buffer(xdr, &ctx->exported_context_token);
+ if (err)
+ return err;
+
+ /* ctx->state */
+ err = gssx_dec_buffer(xdr, &ctx->state);
+ if (err)
+ return err;
+
+ /* ctx->need_release */
+ err = gssx_dec_bool(xdr, &ctx->need_release);
+ if (err)
+ return err;
+
+ /* ctx->mech */
+ err = gssx_dec_buffer(xdr, &ctx->mech);
+ if (err)
+ return err;
+
+ /* ctx->src_name */
+ err = gssx_dec_name(xdr, &ctx->src_name);
+ if (err)
+ return err;
+
+ /* ctx->targ_name */
+ err = gssx_dec_name(xdr, &ctx->targ_name);
+ if (err)
+ return err;
+
+ /* ctx->lifetime */
+ p = xdr_inline_decode(xdr, 8+8);
+ if (unlikely(p == NULL))
+ return -ENOSPC;
+ p = xdr_decode_hyper(p, &ctx->lifetime);
+
+ /* ctx->ctx_flags */
+ p = xdr_decode_hyper(p, &ctx->ctx_flags);
+
+ /* ctx->locally_initiated */
+ err = gssx_dec_bool(xdr, &ctx->locally_initiated);
+ if (err)
+ return err;
+
+ /* ctx->open */
+ err = gssx_dec_bool(xdr, &ctx->open);
+ if (err)
+ return err;
+
+ /* we assume we have no options for now, so simply consume them */
+ /* ctx->options */
+ err = dummy_dec_opt_array(xdr, &ctx->options);
+
+ return err;
+}
+
+static int gssx_enc_cb(struct xdr_stream *xdr, struct gssx_cb *cb)
+{
+ __be32 *p;
+ int err;
+
+ /* cb->initiator_addrtype */
+ p = xdr_reserve_space(xdr, 8);
+ if (!p)
+ return -ENOSPC;
+ p = xdr_encode_hyper(p, cb->initiator_addrtype);
+
+ /* cb->initiator_address */
+ err = gssx_enc_buffer(xdr, &cb->initiator_address);
+ if (err)
+ return err;
+
+ /* cb->acceptor_addrtype */
+ p = xdr_reserve_space(xdr, 8);
+ if (!p)
+ return -ENOSPC;
+ p = xdr_encode_hyper(p, cb->acceptor_addrtype);
+
+ /* cb->acceptor_address */
+ err = gssx_enc_buffer(xdr, &cb->acceptor_address);
+ if (err)
+ return err;
+
+ /* cb->application_data */
+ err = gssx_enc_buffer(xdr, &cb->application_data);
+
+ return err;
+}
+
+void gssx_enc_accept_sec_context(struct rpc_rqst *req,
+ struct xdr_stream *xdr,
+ struct gssx_arg_accept_sec_context *arg)
+{
+ int err;
+
+ err = gssx_enc_call_ctx(xdr, &arg->call_ctx);
+ if (err)
+ goto done;
+
+ /* arg->context_handle */
+ if (arg->context_handle) {
+ err = gssx_enc_ctx(xdr, arg->context_handle);
+ if (err)
+ goto done;
+ } else {
+ err = gssx_enc_bool(xdr, 0);
+ }
+
+ /* arg->cred_handle */
+ if (arg->cred_handle) {
+ err = gssx_enc_cred(xdr, arg->cred_handle);
+ if (err)
+ goto done;
+ } else {
+ err = gssx_enc_bool(xdr, 0);
+ }
+
+ /* arg->input_token */
+ err = gssx_enc_in_token(xdr, &arg->input_token);
+ if (err)
+ goto done;
+
+ /* arg->input_cb */
+ if (arg->input_cb) {
+ err = gssx_enc_cb(xdr, arg->input_cb);
+ if (err)
+ goto done;
+ } else {
+ err = gssx_enc_bool(xdr, 0);
+ }
+
+ err = gssx_enc_bool(xdr, arg->ret_deleg_cred);
+ if (err)
+ goto done;
+
+ /* leave options empty for now, will add once we have any options
+ * to pass up at all */
+ /* arg->options */
+ err = dummy_enc_opt_array(xdr, &arg->options);
+
+done:
+ if (err)
+ dprintk("RPC: gssx_enc_accept_sec_context: %d\n", err);
+}
+
+int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp,
+ struct xdr_stream *xdr,
+ struct gssx_res_accept_sec_context *res)
+{
+ int err;
+
+ /* res->status */
+ err = gssx_dec_status(xdr, &res->status);
+ if (err)
+ return err;
+
+ /* res->context_handle */
+ if (gssx_check_pointer(xdr)) {
+ err = gssx_dec_ctx(xdr, res->context_handle);
+ if (err)
+ return err;
+ } else {
+ res->context_handle = NULL;
+ }
+
+ /* res->output_token */
+ if (gssx_check_pointer(xdr)) {
+ err = gssx_dec_buffer(xdr, res->output_token);
+ if (err)
+ return err;
+ } else {
+ res->output_token = NULL;
+ }
+
+ /* res->delegated_cred_handle */
+ if (gssx_check_pointer(xdr)) {
+ /* we do not support upcall servers sending this data. */
+ return -EINVAL;
+ }
+
+ /* res->options */
+ err = gssx_dec_option_array(xdr, &res->options);
+
+ return err;
+}