![J. Bruce Fields](/assets/img/avatar_default.png)
The principal name on a gss cred is used to setup the NFSv4.0 callback, which has to have a client principal name to authenticate to. That code wants the name to be in the form servicetype@hostname. rpc.svcgssd passes down such names (and passes down no principal name at all in the case the principal isn't a service principal). gss-proxy always passes down the principal name, and passes it down in the form servicetype/hostname@REALM. So we've been munging the name gss-proxy passes down into the format the NFSv4.0 callback code expects, or throwing away the name if we can't. Since the introduction of the MACH_CRED enforcement in NFSv4.1, we've also been using the principal name to verify that certain operations are done as the same principal as was used on the original EXCHANGE_ID call. For that application, the original name passed down by gss-proxy is also useful. Lack of that name in some cases was causing some kerberized NFSv4.1 mount failures in an Active Directory environment. This fix only works in the gss-proxy case. The fix for legacy rpc.svcgssd would be more involved, and rpc.svcgssd already has other problems in the AD case. Reported-and-tested-by: James Ralston <ralston@pobox.com> Acked-by: Simo Sorce <simo@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
388 lines
9.5 KiB
C
388 lines
9.5 KiB
C
/*
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* linux/net/sunrpc/gss_rpc_upcall.c
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*
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* Copyright (C) 2012 Simo Sorce <simo@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/types.h>
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#include <linux/un.h>
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#include <linux/sunrpc/svcauth.h>
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#include "gss_rpc_upcall.h"
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#define GSSPROXY_SOCK_PATHNAME "/var/run/gssproxy.sock"
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#define GSSPROXY_PROGRAM (400112u)
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#define GSSPROXY_VERS_1 (1u)
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/*
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* Encoding/Decoding functions
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*/
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enum {
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GSSX_NULL = 0, /* Unused */
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GSSX_INDICATE_MECHS = 1,
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GSSX_GET_CALL_CONTEXT = 2,
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GSSX_IMPORT_AND_CANON_NAME = 3,
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GSSX_EXPORT_CRED = 4,
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GSSX_IMPORT_CRED = 5,
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GSSX_ACQUIRE_CRED = 6,
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GSSX_STORE_CRED = 7,
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GSSX_INIT_SEC_CONTEXT = 8,
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GSSX_ACCEPT_SEC_CONTEXT = 9,
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GSSX_RELEASE_HANDLE = 10,
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GSSX_GET_MIC = 11,
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GSSX_VERIFY = 12,
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GSSX_WRAP = 13,
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GSSX_UNWRAP = 14,
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GSSX_WRAP_SIZE_LIMIT = 15,
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};
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#define PROC(proc, name) \
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[GSSX_##proc] = { \
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.p_proc = GSSX_##proc, \
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.p_encode = (kxdreproc_t)gssx_enc_##name, \
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.p_decode = (kxdrdproc_t)gssx_dec_##name, \
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.p_arglen = GSSX_ARG_##name##_sz, \
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.p_replen = GSSX_RES_##name##_sz, \
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.p_statidx = GSSX_##proc, \
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.p_name = #proc, \
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}
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static struct rpc_procinfo gssp_procedures[] = {
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PROC(INDICATE_MECHS, indicate_mechs),
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PROC(GET_CALL_CONTEXT, get_call_context),
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PROC(IMPORT_AND_CANON_NAME, import_and_canon_name),
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PROC(EXPORT_CRED, export_cred),
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PROC(IMPORT_CRED, import_cred),
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PROC(ACQUIRE_CRED, acquire_cred),
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PROC(STORE_CRED, store_cred),
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PROC(INIT_SEC_CONTEXT, init_sec_context),
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PROC(ACCEPT_SEC_CONTEXT, accept_sec_context),
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PROC(RELEASE_HANDLE, release_handle),
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PROC(GET_MIC, get_mic),
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PROC(VERIFY, verify),
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PROC(WRAP, wrap),
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PROC(UNWRAP, unwrap),
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PROC(WRAP_SIZE_LIMIT, wrap_size_limit),
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};
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/*
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* Common transport functions
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*/
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static const struct rpc_program gssp_program;
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static int gssp_rpc_create(struct net *net, struct rpc_clnt **_clnt)
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{
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static const struct sockaddr_un gssp_localaddr = {
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.sun_family = AF_LOCAL,
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.sun_path = GSSPROXY_SOCK_PATHNAME,
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};
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struct rpc_create_args args = {
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.net = net,
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.protocol = XPRT_TRANSPORT_LOCAL,
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.address = (struct sockaddr *)&gssp_localaddr,
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.addrsize = sizeof(gssp_localaddr),
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.servername = "localhost",
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.program = &gssp_program,
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.version = GSSPROXY_VERS_1,
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.authflavor = RPC_AUTH_NULL,
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/*
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* Note we want connection to be done in the caller's
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* filesystem namespace. We therefore turn off the idle
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* timeout, which would result in reconnections being
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* done without the correct namespace:
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*/
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.flags = RPC_CLNT_CREATE_NOPING |
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RPC_CLNT_CREATE_NO_IDLE_TIMEOUT
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};
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struct rpc_clnt *clnt;
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int result = 0;
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clnt = rpc_create(&args);
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if (IS_ERR(clnt)) {
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dprintk("RPC: failed to create AF_LOCAL gssproxy "
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"client (errno %ld).\n", PTR_ERR(clnt));
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result = PTR_ERR(clnt);
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*_clnt = NULL;
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goto out;
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}
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dprintk("RPC: created new gssp local client (gssp_local_clnt: "
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"%p)\n", clnt);
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*_clnt = clnt;
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out:
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return result;
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}
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void init_gssp_clnt(struct sunrpc_net *sn)
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{
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mutex_init(&sn->gssp_lock);
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sn->gssp_clnt = NULL;
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}
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int set_gssp_clnt(struct net *net)
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{
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struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
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struct rpc_clnt *clnt;
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int ret;
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mutex_lock(&sn->gssp_lock);
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ret = gssp_rpc_create(net, &clnt);
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if (!ret) {
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if (sn->gssp_clnt)
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rpc_shutdown_client(sn->gssp_clnt);
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sn->gssp_clnt = clnt;
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}
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mutex_unlock(&sn->gssp_lock);
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return ret;
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}
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void clear_gssp_clnt(struct sunrpc_net *sn)
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{
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mutex_lock(&sn->gssp_lock);
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if (sn->gssp_clnt) {
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rpc_shutdown_client(sn->gssp_clnt);
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sn->gssp_clnt = NULL;
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}
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mutex_unlock(&sn->gssp_lock);
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}
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static struct rpc_clnt *get_gssp_clnt(struct sunrpc_net *sn)
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{
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struct rpc_clnt *clnt;
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mutex_lock(&sn->gssp_lock);
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clnt = sn->gssp_clnt;
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if (clnt)
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atomic_inc(&clnt->cl_count);
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mutex_unlock(&sn->gssp_lock);
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return clnt;
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}
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static int gssp_call(struct net *net, struct rpc_message *msg)
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{
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struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
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struct rpc_clnt *clnt;
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int status;
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clnt = get_gssp_clnt(sn);
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if (!clnt)
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return -EIO;
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status = rpc_call_sync(clnt, msg, 0);
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if (status < 0) {
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dprintk("gssp: rpc_call returned error %d\n", -status);
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switch (status) {
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case -EPROTONOSUPPORT:
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status = -EINVAL;
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break;
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case -ECONNREFUSED:
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case -ETIMEDOUT:
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case -ENOTCONN:
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status = -EAGAIN;
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break;
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case -ERESTARTSYS:
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if (signalled ())
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status = -EINTR;
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break;
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default:
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break;
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}
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}
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rpc_release_client(clnt);
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return status;
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}
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static void gssp_free_receive_pages(struct gssx_arg_accept_sec_context *arg)
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{
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int i;
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for (i = 0; i < arg->npages && arg->pages[i]; i++)
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__free_page(arg->pages[i]);
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kfree(arg->pages);
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}
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static int gssp_alloc_receive_pages(struct gssx_arg_accept_sec_context *arg)
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{
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arg->npages = DIV_ROUND_UP(NGROUPS_MAX * 4, PAGE_SIZE);
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arg->pages = kzalloc(arg->npages * sizeof(struct page *), GFP_KERNEL);
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/*
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* XXX: actual pages are allocated by xdr layer in
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* xdr_partial_copy_from_skb.
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*/
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if (!arg->pages)
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return -ENOMEM;
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return 0;
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}
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/*
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* Public functions
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*/
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/* numbers somewhat arbitrary but large enough for current needs */
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#define GSSX_MAX_OUT_HANDLE 128
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#define GSSX_MAX_SRC_PRINC 256
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#define GSSX_KMEMBUF (GSSX_max_output_handle_sz + \
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GSSX_max_oid_sz + \
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GSSX_max_princ_sz + \
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sizeof(struct svc_cred))
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int gssp_accept_sec_context_upcall(struct net *net,
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struct gssp_upcall_data *data)
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{
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struct gssx_ctx ctxh = {
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.state = data->in_handle
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};
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struct gssx_arg_accept_sec_context arg = {
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.input_token = data->in_token,
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};
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struct gssx_ctx rctxh = {
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/*
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* pass in the max length we expect for each of these
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* buffers but let the xdr code kmalloc them:
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*/
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.exported_context_token.len = GSSX_max_output_handle_sz,
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.mech.len = GSS_OID_MAX_LEN,
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.src_name.display_name.len = GSSX_max_princ_sz
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};
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struct gssx_res_accept_sec_context res = {
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.context_handle = &rctxh,
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.output_token = &data->out_token
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};
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struct rpc_message msg = {
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.rpc_proc = &gssp_procedures[GSSX_ACCEPT_SEC_CONTEXT],
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.rpc_argp = &arg,
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.rpc_resp = &res,
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.rpc_cred = NULL, /* FIXME ? */
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};
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struct xdr_netobj client_name = { 0 , NULL };
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int ret;
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if (data->in_handle.len != 0)
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arg.context_handle = &ctxh;
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res.output_token->len = GSSX_max_output_token_sz;
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ret = gssp_alloc_receive_pages(&arg);
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if (ret)
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return ret;
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/* use nfs/ for targ_name ? */
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ret = gssp_call(net, &msg);
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gssp_free_receive_pages(&arg);
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/* we need to fetch all data even in case of error so
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* that we can free special strctures is they have been allocated */
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data->major_status = res.status.major_status;
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data->minor_status = res.status.minor_status;
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if (res.context_handle) {
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data->out_handle = rctxh.exported_context_token;
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data->mech_oid.len = rctxh.mech.len;
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if (rctxh.mech.data)
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memcpy(data->mech_oid.data, rctxh.mech.data,
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data->mech_oid.len);
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client_name = rctxh.src_name.display_name;
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}
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if (res.options.count == 1) {
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gssx_buffer *value = &res.options.data[0].value;
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/* Currently we only decode CREDS_VALUE, if we add
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* anything else we'll have to loop and match on the
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* option name */
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if (value->len == 1) {
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/* steal group info from struct svc_cred */
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data->creds = *(struct svc_cred *)value->data;
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data->found_creds = 1;
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}
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/* whether we use it or not, free data */
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kfree(value->data);
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}
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if (res.options.count != 0) {
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kfree(res.options.data);
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}
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/* convert to GSS_NT_HOSTBASED_SERVICE form and set into creds */
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if (data->found_creds && client_name.data != NULL) {
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char *c;
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data->creds.cr_raw_principal = kstrndup(client_name.data,
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client_name.len, GFP_KERNEL);
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data->creds.cr_principal = kstrndup(client_name.data,
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client_name.len, GFP_KERNEL);
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if (data->creds.cr_principal) {
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/* terminate and remove realm part */
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c = strchr(data->creds.cr_principal, '@');
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if (c) {
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*c = '\0';
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/* change service-hostname delimiter */
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c = strchr(data->creds.cr_principal, '/');
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if (c) *c = '@';
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}
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if (!c) {
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/* not a service principal */
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kfree(data->creds.cr_principal);
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data->creds.cr_principal = NULL;
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}
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}
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}
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kfree(client_name.data);
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return ret;
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}
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void gssp_free_upcall_data(struct gssp_upcall_data *data)
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{
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kfree(data->in_handle.data);
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kfree(data->out_handle.data);
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kfree(data->out_token.data);
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free_svc_cred(&data->creds);
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}
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/*
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* Initialization stuff
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*/
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static const struct rpc_version gssp_version1 = {
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.number = GSSPROXY_VERS_1,
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.nrprocs = ARRAY_SIZE(gssp_procedures),
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.procs = gssp_procedures,
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};
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static const struct rpc_version *gssp_version[] = {
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NULL,
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&gssp_version1,
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};
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static struct rpc_stat gssp_stats;
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static const struct rpc_program gssp_program = {
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.name = "gssproxy",
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.number = GSSPROXY_PROGRAM,
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.nrvers = ARRAY_SIZE(gssp_version),
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.version = gssp_version,
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.stats = &gssp_stats,
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};
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