// SPDX-License-Identifier: GPL-2.0+
/*
* linux/net/sunrpc/gss_rpc_upcall.c
*
* Copyright (C) 2012 Simo Sorce <[email protected]>
*/
#include <linux/types.h>
#include <linux/un.h>
#include <linux/sunrpc/svcauth.h>
#include "gss_rpc_upcall.h"
#define GSSPROXY_SOCK_PATHNAME "/var/run/gssproxy.sock"
#define GSSPROXY_PROGRAM (400112u)
#define GSSPROXY_VERS_1 (1u)
/*
* Encoding/Decoding functions
*/
enum {
GSSX_NULL = 0, /* Unused */
GSSX_INDICATE_MECHS = 1,
GSSX_GET_CALL_CONTEXT = 2,
GSSX_IMPORT_AND_CANON_NAME = 3,
GSSX_EXPORT_CRED = 4,
GSSX_IMPORT_CRED = 5,
GSSX_ACQUIRE_CRED = 6,
GSSX_STORE_CRED = 7,
GSSX_INIT_SEC_CONTEXT = 8,
GSSX_ACCEPT_SEC_CONTEXT = 9,
GSSX_RELEASE_HANDLE = 10,
GSSX_GET_MIC = 11,
GSSX_VERIFY = 12,
GSSX_WRAP = 13,
GSSX_UNWRAP = 14,
GSSX_WRAP_SIZE_LIMIT = 15,
};
#define PROC(proc, name) \
[GSSX_##proc] = { \
.p_proc = GSSX_##proc, \
.p_encode = gssx_enc_##name, \
.p_decode = gssx_dec_##name, \
.p_arglen = GSSX_ARG_##name##_sz, \
.p_replen = GSSX_RES_##name##_sz, \
.p_statidx = GSSX_##proc, \
.p_name = #proc, \
}
static const struct rpc_procinfo gssp_procedures[] = {
PROC(INDICATE_MECHS, indicate_mechs),
PROC(GET_CALL_CONTEXT, get_call_context),
PROC(IMPORT_AND_CANON_NAME, import_and_canon_name),
PROC(EXPORT_CRED, export_cred),
PROC(IMPORT_CRED, import_cred),
PROC(ACQUIRE_CRED, acquire_cred),
PROC(STORE_CRED, store_cred),
PROC(INIT_SEC_CONTEXT, init_sec_context),
PROC(ACCEPT_SEC_CONTEXT, accept_sec_context),
PROC(RELEASE_HANDLE, release_handle),
PROC(GET_MIC, get_mic),
PROC(VERIFY, verify),
PROC(WRAP, wrap),
PROC(UNWRAP, unwrap),
PROC(WRAP_SIZE_LIMIT, wrap_size_limit),
};
/*
* Common transport functions
*/
static const struct rpc_program gssp_program;
static int gssp_rpc_create(struct net *net, struct rpc_clnt **_clnt)
{
static const struct sockaddr_un gssp_localaddr = {
.sun_family = AF_LOCAL,
.sun_path = GSSPROXY_SOCK_PATHNAME,
};
struct rpc_create_args args = {
.net = net,
.protocol = XPRT_TRANSPORT_LOCAL,
.address = (struct sockaddr *)&gssp_localaddr,
.addrsize = sizeof(gssp_localaddr),
.servername = "localhost",
.program = &gssp_program,
.version = GSSPROXY_VERS_1,
.authflavor = RPC_AUTH_NULL,
/*
* Note we want connection to be done in the caller's
* filesystem namespace. We therefore turn off the idle
* timeout, which would result in reconnections being
* done without the correct namespace:
*/
.flags = RPC_CLNT_CREATE_NOPING |
RPC_CLNT_CREATE_CONNECTED |
RPC_CLNT_CREATE_NO_IDLE_TIMEOUT
};
struct rpc_clnt *clnt;
int result = 0;
clnt = rpc_create(&args);
if (IS_ERR(clnt)) {
dprintk("RPC: failed to create AF_LOCAL gssproxy "
"client (errno %ld).\n", PTR_ERR(clnt));
result = PTR_ERR(clnt);
*_clnt = NULL;
goto out;
}
dprintk("RPC: created new gssp local client (gssp_local_clnt: "
"%p)\n", clnt);
*_clnt = clnt;
out:
return result;
}
void init_gssp_clnt(struct sunrpc_net *sn)
{
mutex_init(&sn->gssp_lock);
sn->gssp_clnt = NULL;
}
int set_gssp_clnt(struct net *net)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
struct rpc_clnt *clnt;
int ret;
mutex_lock(&sn->gssp_lock);
ret = gssp_rpc_create(net, &clnt);
if (!ret) {
if (sn->gssp_clnt)
rpc_shutdown_client(sn->gssp_clnt);
sn->gssp_clnt = clnt;
}
mutex_unlock(&sn->gssp_lock);
return ret;
}
void clear_gssp_clnt(struct sunrpc_net *sn)
{
mutex_lock(&sn->gssp_lock);
if (sn->gssp_clnt) {
rpc_shutdown_client(sn->gssp_clnt);
sn->gssp_clnt = NULL;
}
mutex_unlock(&sn->gssp_lock);
}
static struct rpc_clnt *get_gssp_clnt(struct sunrpc_net *sn)
{
struct rpc_clnt *clnt;
mutex_lock(&sn->gssp_lock);
clnt = sn->gssp_clnt;
if (clnt)
refcount_inc(&clnt->cl_count);
mutex_unlock(&sn->gssp_lock);
return clnt;
}
static int gssp_call(struct net *net, struct rpc_message *msg)
{
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
struct rpc_clnt *clnt;
int status;
clnt = get_gssp_clnt(sn);
if (!clnt)
return -EIO;
status = rpc_call_sync(clnt, msg, 0);
if (status < 0) {
dprintk("gssp: rpc_call returned error %d\n", -status);
switch (status) {
case -EPROTONOSUPPORT:
status = -EINVAL;
break;
case -ECONNREFUSED:
case -ETIMEDOUT:
case -ENOTCONN:
status = -EAGAIN;
break;
case -ERESTARTSYS:
if (signalled ())
status = -EINTR;
break;
default:
break;
}
}
rpc_release_client(clnt);
return status;
}
static void gssp_free_receive_pages(struct gssx_arg_accept_sec_context *arg)
{
unsigned int i;
for (i = 0; i < arg->npages && arg->pages[i]; i++)
__free_page(arg->pages[i]);
kfree(arg->pages);
}
static int gssp_alloc_receive_pages(struct gssx_arg_accept_sec_context *arg)
{
unsigned int i;
arg->npages = DIV_ROUND_UP(NGROUPS_MAX * 4, PAGE_SIZE);
arg->pages = kcalloc(arg->npages, sizeof(struct page *), GFP_KERNEL);
if (!arg->pages)
return -ENOMEM;
for (i = 0; i < arg->npages; i++) {
arg->pages[i] = alloc_page(GFP_KERNEL);
if (!arg->pages[i]) {
gssp_free_receive_pages(arg);
return -ENOMEM;
}
}
return 0;
}
static char *gssp_stringify(struct xdr_netobj *netobj)
{
return kmemdup_nul(netobj->data, netobj->len, GFP_KERNEL);
}
static void gssp_hostbased_service(char **principal)
{
char *c;
if (!*principal)
return;
/* terminate and remove realm part */
c = strchr(*principal, '@');
if (c) {
*c = '\0';
/* change service-hostname delimiter */
c = strchr(*principal, '/');
if (c)
*c = '@';
}
if (!c) {
/* not a service principal */
kfree(*principal);
*principal = NULL;
}
}
/*
* Public functions
*/
/* numbers somewhat arbitrary but large enough for current needs */
#define GSSX_MAX_OUT_HANDLE 128
#define GSSX_MAX_SRC_PRINC 256
#define GSSX_KMEMBUF (GSSX_max_output_handle_sz + \
GSSX_max_oid_sz + \
GSSX_max_princ_sz + \
sizeof(struct svc_cred))
int gssp_accept_sec_context_upcall(struct net *net,
struct gssp_upcall_data *data)
{
struct gssx_ctx ctxh = {
.state = data->in_handle
};
struct gssx_arg_accept_sec_context arg = {
.input_token = data->in_token,
};
struct gssx_ctx rctxh = {
/*
* pass in the max length we expect for each of these
* buffers but let the xdr code kmalloc them:
*/
.exported_context_token.len = GSSX_max_output_handle_sz,
.mech.len = GSS_OID_MAX_LEN,
.targ_name.display_name.len = GSSX_max_princ_sz,
.src_name.display_name.len = GSSX_max_princ_sz
};
struct gssx_res_accept_sec_context res = {
.context_handle = &rctxh,
.output_token = &data->out_token
};
struct rpc_message msg = {
.rpc_proc = &gssp_procedures[GSSX_ACCEPT_SEC_CONTEXT],
.rpc_argp = &arg,
.rpc_resp = &res,
.rpc_cred = NULL, /* FIXME ? */
};
struct xdr_netobj client_name = { 0 , NULL };
struct xdr_netobj target_name = { 0, NULL };
int ret;
if (data->in_handle.len != 0)
arg.context_handle = &ctxh;
res.output_token->len = GSSX_max_output_token_sz;
ret = gssp_alloc_receive_pages(&arg);
if (ret)
return ret;
ret = gssp_call(net, &msg);
gssp_free_receive_pages(&arg);
/* we need to fetch all data even in case of error so
* that we can free special strctures is they have been allocated */
data->major_status = res.status.major_status;
data->minor_status = res.status.minor_status;
if (res.context_handle) {
data->out_handle = rctxh.exported_context_token;
data->mech_oid.len = rctxh.mech.len;
if (rctxh.mech.data) {
memcpy(data->mech_oid.data, rctxh.mech.data,
data->mech_oid.len);
kfree(rctxh.mech.data);
}
client_name = rctxh.src_name.display_name;
target_name = rctxh.targ_name.display_name;
}
if (res.options.count == 1) {
gssx_buffer *value = &res.options.data[0].value;
/* Currently we only decode CREDS_VALUE, if we add
* anything else we'll have to loop and match on the
* option name */
if (value->len == 1) {
/* steal group info from struct svc_cred */
data->creds = *(struct svc_cred *)value->data;
data->found_creds = 1;
}
/* whether we use it or not, free data */
kfree(value->data);
}
if (res.options.count != 0) {
kfree(res.options.data);
}
/* convert to GSS_NT_HOSTBASED_SERVICE form and set into creds */
if (data->found_creds) {
if (client_name.data) {
data->creds.cr_raw_principal =
gssp_stringify(&client_name);
data->creds.cr_principal =
gssp_stringify(&client_name);
gssp_hostbased_service(&data->creds.cr_principal);
}
if (target_name.data) {
data->creds.cr_targ_princ =
gssp_stringify(&target_name);
gssp_hostbased_service(&data->creds.cr_targ_princ);
}
}
kfree(client_name.data);
kfree(target_name.data);
return ret;
}
void gssp_free_upcall_data(struct gssp_upcall_data *data)
{
kfree(data->in_handle.data);
kfree(data->out_handle.data);
kfree(data->out_token.data);
free_svc_cred(&data->creds);
}
/*
* Initialization stuff
*/
static unsigned int gssp_version1_counts[ARRAY_SIZE(gssp_procedures)];
static const struct rpc_version gssp_version1 = {
.number = GSSPROXY_VERS_1,
.nrprocs = ARRAY_SIZE(gssp_procedures),
.procs = gssp_procedures,
.counts = gssp_version1_counts,
};
static const struct rpc_version *gssp_version[] = {
NULL,
&gssp_version1,
};
static struct rpc_stat gssp_stats;
static const struct rpc_program gssp_program = {
.name = "gssproxy",
.number = GSSPROXY_PROGRAM,
.nrvers = ARRAY_SIZE(gssp_version),
.version = gssp_version,
.stats = &gssp_stats,
};
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