lustre/utils/gss/lgss_keyring.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2011, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  *
  31  * lustre/utils/gss/lgss_keyring.c
  32  *
  33  * user-space upcall to create GSS context, using keyring interface to kernel
  34  *
  35  * Author: Eric Mei <ericm@clusterfs.com>
  36  */
  37
  38 #include <sched.h>
  39 #include <sys/types.h>
  40 #include <sys/stat.h>
  41 #include <unistd.h>
  42 #include <stdlib.h>
  43 #include <stdio.h>
  44 #include <fcntl.h>
  45 #include <inttypes.h>
  46 #include <string.h>
  47 #include <errno.h>
  48 #include <pwd.h>
  49 #include <keyutils.h>
  50 #include <gssapi/gssapi.h>
  51 #include <sys/wait.h>
  52 #include <getopt.h>
  53
  54 #include <libcfs/util/param.h>
  55 #include <libcfs/util/string.h>
  56 #include <uapi/linux/lustre/lgss.h>
  57 #include "lsupport.h"
  58 #include "lgss_utils.h"
  59 #include "lgss_krb5_utils.h"
  60 #include "write_bytes.h"
  61 #include "context.h"
  62
  63 /*
  64  * gss target string of lustre service we are negotiating for
  65  */
  66 static char *g_service = NULL;
  67
  68 /*
  69  * all data about negotiation
  70  */
  71 struct lgss_nego_data {
  72         uint32_t        lnd_established:1;
  73
  74         int             lnd_secid;
  75         uint32_t        lnd_uid;
  76         uint32_t        lnd_lsvc;
  77         char            *lnd_uuid;
  78
  79         gss_OID         lnd_mech;               /* mech OID */
  80         gss_name_t      lnd_svc_name;           /* service name */
  81         unsigned int    lnd_req_flags;          /* request flags */
  82         gss_cred_id_t   lnd_cred;               /* credential */
  83         gss_ctx_id_t    lnd_ctx;                /* session context */
  84         gss_buffer_desc lnd_rmt_ctx;            /* remote handle of context */
  85         gss_buffer_desc lnd_ctx_token;          /* context token for kernel */
  86         uint32_t        lnd_seq_win;            /* sequence window */
  87
  88         int             lnd_rpc_err;
  89         int             lnd_gss_err;
  90 };
  91
  92 /*
  93  * context creation response
  94  */
  95 struct lgss_init_res {
  96         gss_buffer_desc gr_ctx;         /* context handle */
  97         unsigned int    gr_major;       /* major status */
  98         unsigned int    gr_minor;       /* minor status */
  99         unsigned int    gr_win;         /* sequence window */
 100         gss_buffer_desc gr_token;       /* token */
 101 };
 102
 103 struct keyring_upcall_param {
 104         uint32_t        kup_ver;
 105         uint32_t        kup_secid;
 106         uint32_t        kup_uid;
 107         uint32_t        kup_fsuid;
 108         uint32_t        kup_gid;
 109         uint32_t        kup_fsgid;
 110         uint32_t        kup_svc;
 111         uint64_t        kup_nid;
 112         uint64_t        kup_selfnid;
 113         char            kup_svc_type;
 114         char            kup_tgt[64];
 115         char            kup_mech[16];
 116         unsigned int    kup_is_root:1,
 117                         kup_is_mdt:1,
 118                         kup_is_ost:1;
 119         uint32_t        kup_pid;
 120 };
 121
 122 /****************************************
 123  * child process: gss negotiation       *
 124  ****************************************/
 125
 126 static int send_to(int fd, const void *buf, size_t size)
 127 {
 128         ssize_t sz;
 129
 130         sz = write(fd, buf, size);
 131         if (sz == -1) {
 132                 logmsg(LL_ERR, "cannot send to GSS process: %s\n",
 133                        strerror(errno));
 134                 return -errno;
 135         }
 136         if (sz < size) {
 137                 logmsg(LL_ERR, "short write sending to GSS process: %d/%d\n",
 138                        (int)sz, (int)size);
 139                 return -EPROTO;
 140         }
 141
 142         return 0;
 143 }
 144
 145 static int receive_from(int fd, void *buf, size_t size)
 146 {
 147         ssize_t sz;
 148
 149         sz = read(fd, buf, size);
 150         if (sz == -1) {
 151                 logmsg(LL_ERR, "cannot receive from GSS process: %s\n",
 152                        strerror(errno));
 153                 return -errno;
 154         }
 155         if (sz < size) {
 156                 logmsg(LL_ERR, "short read receiving from GSS process: %d/%d\n",
 157                        (int)sz, (int)size);
 158                 return -EPROTO;
 159         }
 160
 161         return 0;
 162 }
 163
 164 static int gss_do_ioctl(struct lgssd_ioctl_param *param)
 165 {
 166         int fd, ret;
 167         glob_t path;
 168         int rc;
 169
 170         rc = cfs_get_param_paths(&path, "sptlrpc/gss/init_channel");
 171         if (rc != 0)
 172                 return rc;
 173
 174         logmsg(LL_TRACE, "to open %s\n", path.gl_pathv[0]);
 175
 176         fd = open(path.gl_pathv[0], O_WRONLY);
 177         if (fd < 0) {
 178                 logmsg(LL_ERR, "can't open %s\n", path.gl_pathv[0]);
 179                 rc = -EACCES;
 180                 goto out_params;
 181         }
 182
 183         logmsg(LL_TRACE, "to down-write\n");
 184
 185         ret = write(fd, param, sizeof(*param));
 186         close(fd);
 187         if (ret != sizeof(*param)) {
 188                 logmsg(LL_ERR, "lustre ioctl err: %s\n", strerror(errno));
 189                 rc = -EACCES;
 190         }
 191
 192 out_params:
 193         cfs_free_param_data(&path);
 194         return rc;
 195 }
 196
 197 static int do_nego_rpc(struct lgss_nego_data *lnd,
 198                        gss_buffer_desc *gss_token,
 199                        struct lgss_init_res *gr,
 200                        int req_fd[2], int reply_fd[2])
 201 {
 202         struct lgssd_ioctl_param param;
 203         struct passwd *pw;
 204         int res;
 205         char outbuf[8192] = { 0 };
 206         unsigned int *p;
 207         int rc = 0;
 208
 209         logmsg(LL_TRACE, "start negotiation rpc\n");
 210
 211         pw = getpwuid(lnd->lnd_uid);
 212         if (!pw) {
 213                 logmsg(LL_ERR, "no uid %u in local user database\n",
 214                        lnd->lnd_uid);
 215                 return -EACCES;
 216         }
 217
 218         param.version = GSSD_INTERFACE_VERSION;
 219         param.secid = lnd->lnd_secid;
 220         param.uuid = lnd->lnd_uuid;
 221         param.lustre_svc = lnd->lnd_lsvc;
 222         param.uid = lnd->lnd_uid;
 223         param.gid = pw->pw_gid;
 224         param.send_token_size = gss_token->length;
 225         param.send_token = (char *) gss_token->value;
 226
 227         if (req_fd[0] == -1 && reply_fd[0] == -1) {
 228                 /* we can do the ioctl directly */
 229                 param.reply_buf_size = sizeof(outbuf);
 230                 param.reply_buf = outbuf;
 231
 232                 rc = gss_do_ioctl(&param);
 233                 if (rc != 0)
 234                         return rc;
 235         } else {
 236                 /* looks like we are running in a container,
 237                  * so we cannot do the ioctl ourselves: delegate to
 238                  * parent process running directly on host */
 239
 240                 /* send ioctl buffer to parent */
 241                 rc = send_to(req_fd[1], &param, sizeof(param));
 242                 if (rc != 0)
 243                         return rc;
 244                 /* send gss token to parent */
 245                 rc = send_to(req_fd[1], gss_token->value, gss_token->length);
 246                 if (rc != 0)
 247                         return rc;
 248
 249                 /* read ioctl status from parent */
 250                 rc = receive_from(reply_fd[0], &param.status,
 251                                   sizeof(param.status));
 252                 if (rc != 0)
 253                         return rc;
 254
 255                 if (param.status == 0) {
 256                         /* read reply buffer from parent */
 257                         rc = receive_from(reply_fd[0], outbuf, sizeof(outbuf));
 258                         if (rc != 0)
 259                                 return rc;
 260                 }
 261         }
 262
 263         logmsg(LL_TRACE, "do_nego_rpc: to parse reply\n");
 264         if (param.status) {
 265                 logmsg(LL_ERR, "status: %ld (%s)\n",
 266                        (long int)param.status, strerror((int)(-param.status)));
 267                 return param.status;
 268         }
 269
 270         p = (unsigned int *)outbuf;
 271         res = *p++;
 272         gr->gr_major = *p++;
 273         gr->gr_minor = *p++;
 274         gr->gr_win = *p++;
 275
 276         gr->gr_ctx.length = *p++;
 277         gr->gr_ctx.value = malloc(gr->gr_ctx.length);
 278         if (gr->gr_ctx.value == NULL)
 279                 return -ENOMEM;
 280         memcpy(gr->gr_ctx.value, p, gr->gr_ctx.length);
 281         p += (((gr->gr_ctx.length + 3) & ~3) / 4);
 282
 283         gr->gr_token.length = *p++;
 284         gr->gr_token.value = malloc(gr->gr_token.length);
 285         if (gr->gr_token.value == NULL) {
 286                 free(gr->gr_ctx.value);
 287                 return -ENOMEM;
 288         }
 289         memcpy(gr->gr_token.value, p, gr->gr_token.length);
 290         p += (((gr->gr_token.length + 3) & ~3) / 4);
 291
 292         logmsg(LL_DEBUG, "do_nego_rpc: receive handle len %zu, token len %zu, "
 293                "res %d\n", gr->gr_ctx.length, gr->gr_token.length, res);
 294
 295         return rc;
 296 }
 297
 298 /* This is used by incomplete GSSAPI implementations that can't use
 299  * gss_init_sec_context and will parse the token themselves (gssnull and sk).
 300  * Callers should have cred->lc_mech_token pointing to a gss_buffer_desc
 301  * token to send to the peer as part of the SEC_CTX_INIT operation.  The return
 302  * RPC's token with be in gr.gr_token which is validated using
 303  * lgss_validate_cred. */
 304 static int lgssc_negotiation_manual(struct lgss_nego_data *lnd,
 305                                     struct lgss_cred *cred,
 306                                     int req_fd[2], int reply_fd[2])
 307 {
 308         struct lgss_init_res gr;
 309         OM_uint32 min_stat;
 310         int rc;
 311
 312         logmsg(LL_TRACE, "starting gss negotation\n");
 313         memset(&gr, 0, sizeof(gr));
 314
 315         lnd->lnd_rpc_err = do_nego_rpc(lnd, &cred->lc_mech_token, &gr,
 316                                        req_fd, reply_fd);
 317         if (lnd->lnd_rpc_err) {
 318                 logmsg(LL_ERR, "negotiation rpc error %d\n", lnd->lnd_rpc_err);
 319                 rc = lnd->lnd_rpc_err;
 320                 goto out_error;
 321         }
 322
 323         if (gr.gr_major == GSS_S_CONTINUE_NEEDED) {
 324                 rc = -EAGAIN;
 325                 goto out_error;
 326
 327         } else if (gr.gr_major != GSS_S_COMPLETE) {
 328                 lnd->lnd_gss_err = gr.gr_major;
 329                 logmsg(LL_ERR, "negotiation gss error %x\n", lnd->lnd_gss_err);
 330                 rc = -ENOTCONN;
 331                 goto out_error;
 332         }
 333
 334         if (gr.gr_ctx.length == 0 || gr.gr_token.length == 0) {
 335                 logmsg(LL_ERR, "zero length context or token received\n");
 336                 rc = -EINVAL;
 337                 goto out_error;
 338         }
 339
 340         rc = lgss_validate_cred(cred, &gr.gr_token, &lnd->lnd_ctx_token);
 341         if (rc) {
 342                 logmsg(LL_ERR, "peer token failed validation\n");
 343                 goto out_error;
 344         }
 345
 346         lnd->lnd_established = 1;
 347         lnd->lnd_seq_win = gr.gr_win;
 348         lnd->lnd_rmt_ctx = gr.gr_ctx;
 349
 350         if (gr.gr_token.length != 0)
 351                 gss_release_buffer(&min_stat, &gr.gr_token);
 352
 353         logmsg(LL_DEBUG, "successfully negotiated a context\n");
 354         return 0;
 355
 356 out_error:
 357         if (gr.gr_ctx.length != 0)
 358                 gss_release_buffer(&min_stat, &gr.gr_ctx);
 359         if (gr.gr_token.length != 0)
 360                 gss_release_buffer(&min_stat, &gr.gr_token);
 361
 362         return rc;
 363 }
 364
 365 /*
 366  * if return error, the lnd_rpc_err or lnd_gss_err is set.
 367  */
 368 static int lgssc_negotiation(struct lgss_nego_data *lnd, int req_fd[2],
 369                              int reply_fd[2])
 370 {
 371         struct lgss_init_res    gr;
 372         gss_buffer_desc        *recv_tokenp, send_token;
 373         OM_uint32               maj_stat, min_stat, ret_flags;
 374
 375         logmsg(LL_TRACE, "start gss negotiation\n");
 376
 377         /* GSS context establishment loop. */
 378         memset(&gr, 0, sizeof(gr));
 379         recv_tokenp = GSS_C_NO_BUFFER;
 380
 381         for (;;) {
 382                 maj_stat = gss_init_sec_context(&min_stat,
 383                                                 lnd->lnd_cred,
 384                                                 &lnd->lnd_ctx,
 385                                                 lnd->lnd_svc_name,
 386                                                 lnd->lnd_mech,
 387                                                 lnd->lnd_req_flags,
 388                                                 0,            /* time req */
 389                                                 NULL,         /* channel */
 390                                                 recv_tokenp,
 391                                                 NULL,         /* used mech */
 392                                                 &send_token,
 393                                                 &ret_flags,
 394                                                 NULL);        /* time rec */
 395
 396                 logmsg_gss(LL_TRACE, lnd->lnd_mech, maj_stat, min_stat,
 397                            "gss_init_sec_context");
 398
 399                 logmsg(LL_TRACE, "send_token:\n");
 400                 log_hexl(LL_TRACE, send_token.value, send_token.length);
 401
 402                 if (recv_tokenp != GSS_C_NO_BUFFER) {
 403                         gss_release_buffer(&min_stat, &gr.gr_token);
 404                         recv_tokenp = GSS_C_NO_BUFFER;
 405                 }
 406
 407                 if (maj_stat != GSS_S_COMPLETE &&
 408                     maj_stat != GSS_S_CONTINUE_NEEDED) {
 409                         lnd->lnd_gss_err = maj_stat;
 410
 411                         logmsg_gss(LL_ERR, lnd->lnd_mech, maj_stat, min_stat,
 412                                    "failed init context");
 413                         break;
 414                 }
 415
 416                 if (send_token.length != 0) {
 417                         memset(&gr, 0, sizeof(gr));
 418
 419                         lnd->lnd_rpc_err = do_nego_rpc(lnd, &send_token, &gr,
 420                                                        req_fd, reply_fd);
 421                         gss_release_buffer(&min_stat, &send_token);
 422
 423                         if (lnd->lnd_rpc_err) {
 424                                 logmsg(LL_ERR, "negotiation rpc error: %d\n",
 425                                        lnd->lnd_rpc_err);
 426                                 return lnd->lnd_rpc_err;
 427                         }
 428
 429                         if (gr.gr_major != GSS_S_COMPLETE &&
 430                             gr.gr_major != GSS_S_CONTINUE_NEEDED) {
 431                                 lnd->lnd_gss_err = gr.gr_major;
 432
 433                                 logmsg(LL_ERR, "negotiation gss error %x\n",
 434                                        lnd->lnd_gss_err);
 435                                 return -ENOTCONN;
 436                         }
 437
 438                         if (gr.gr_ctx.length != 0) {
 439                                 if (lnd->lnd_rmt_ctx.value)
 440                                         gss_release_buffer(&min_stat,
 441                                                            &lnd->lnd_rmt_ctx);
 442                                 lnd->lnd_rmt_ctx = gr.gr_ctx;
 443                         }
 444
 445                         if (gr.gr_token.length != 0) {
 446                                 if (maj_stat != GSS_S_CONTINUE_NEEDED)
 447                                         break;
 448                                 recv_tokenp = &gr.gr_token;
 449                         }
 450                 }
 451
 452                 /* GSS_S_COMPLETE => check gss header verifier,
 453                  * usually checked in gss_validate
 454                  */
 455                 if (maj_stat == GSS_S_COMPLETE) {
 456                         lnd->lnd_established = 1;
 457                         lnd->lnd_seq_win = gr.gr_win;
 458                         break;
 459                 }
 460         }
 461
 462         /* End context negotiation loop. */
 463         if (!lnd->lnd_established) {
 464                 if (gr.gr_token.length != 0)
 465                         gss_release_buffer(&min_stat, &gr.gr_token);
 466
 467                 if (lnd->lnd_gss_err == GSS_S_COMPLETE)
 468                         lnd->lnd_rpc_err = -EACCES;
 469
 470                 logmsg(LL_ERR, "context negotiation failed\n");
 471                 return -1;
 472         }
 473
 474         logmsg(LL_DEBUG, "successfully negotiated a context\n");
 475         return 0;
 476 }
 477
 478 /*
 479  * if return error, the lnd_rpc_err or lnd_gss_err is set.
 480  */
 481 static int lgssc_init_nego_data(struct lgss_nego_data *lnd,
 482                                 struct keyring_upcall_param *kup,
 483                                 enum lgss_mech mech)
 484 {
 485         gss_buffer_desc         sname;
 486         OM_uint32               maj_stat, min_stat;
 487
 488         memset(lnd, 0, sizeof(*lnd));
 489
 490         lnd->lnd_secid = kup->kup_secid;
 491         lnd->lnd_uid = kup->kup_uid;
 492         lnd->lnd_lsvc = kup->kup_svc | mech << LUSTRE_GSS_MECH_SHIFT;
 493         lnd->lnd_uuid = kup->kup_tgt;
 494
 495         lnd->lnd_established = 0;
 496         lnd->lnd_svc_name = GSS_C_NO_NAME;
 497         lnd->lnd_cred = GSS_C_NO_CREDENTIAL;
 498         lnd->lnd_ctx = GSS_C_NO_CONTEXT;
 499         lnd->lnd_rmt_ctx = (gss_buffer_desc) GSS_C_EMPTY_BUFFER;
 500         lnd->lnd_seq_win = 0;
 501
 502         switch (mech) {
 503         case LGSS_MECH_KRB5:
 504                 lnd->lnd_mech = (gss_OID)&krb5oid;
 505                 lnd->lnd_req_flags = GSS_C_MUTUAL_FLAG;
 506                 break;
 507         case LGSS_MECH_NULL:
 508                 lnd->lnd_mech = (gss_OID)&nulloid;
 509                 break;
 510 #ifdef HAVE_OPENSSL_SSK
 511         case LGSS_MECH_SK:
 512                 lnd->lnd_mech = (gss_OID)&skoid;
 513                 lnd->lnd_req_flags = GSS_C_MUTUAL_FLAG;
 514                 break;
 515 #endif
 516         default:
 517                 logmsg(LL_ERR, "invalid mech: %d\n", mech);
 518                 lnd->lnd_rpc_err = -EACCES;
 519                 return -1;
 520         }
 521
 522         sname.value = g_service;
 523         sname.length = strlen(g_service);
 524
 525         maj_stat = gss_import_name(&min_stat, &sname,
 526                                    (gss_OID) GSS_C_NT_HOSTBASED_SERVICE,
 527                                    &lnd->lnd_svc_name);
 528         if (maj_stat != GSS_S_COMPLETE) {
 529                 logmsg_gss(LL_ERR, lnd->lnd_mech, maj_stat, min_stat,
 530                            "can't import svc name");
 531                 lnd->lnd_gss_err = maj_stat;
 532                 return -1;
 533         }
 534
 535         return 0;
 536 }
 537
 538 static void lgssc_fini_nego_data(struct lgss_nego_data *lnd)
 539 {
 540         OM_uint32       maj_stat, min_stat;
 541
 542         if (lnd->lnd_svc_name != GSS_C_NO_NAME) {
 543                 maj_stat = gss_release_name(&min_stat, &lnd->lnd_svc_name);
 544                 if (maj_stat != GSS_S_COMPLETE)
 545                         logmsg_gss(LL_ERR, lnd->lnd_mech, maj_stat, min_stat,
 546                                    "can't release service name");
 547         }
 548
 549         if (lnd->lnd_cred != GSS_C_NO_CREDENTIAL) {
 550                 maj_stat = gss_release_cred(&min_stat, &lnd->lnd_cred);
 551                 if (maj_stat != GSS_S_COMPLETE)
 552                         logmsg_gss(LL_ERR, lnd->lnd_mech, maj_stat, min_stat,
 553                                    "can't release credential");
 554         }
 555 }
 556
 557 static int fork_and_switch_id(int uid, pid_t *child)
 558 {
 559         int status, rc = 0;
 560
 561         *child = fork();
 562         if (*child == -1) {
 563                 logmsg(LL_ERR, "cannot fork child for user %u: %s\n",
 564                        uid, strerror(errno));
 565                 rc = errno;
 566         } else if (*child == 0) {
 567                 /* switch identity */
 568                 rc = switch_identity(uid);
 569                 if (rc)
 570                         rc = errno;
 571         } else {
 572                 if (wait(&status) < 0) {
 573                         rc = errno;
 574                         logmsg(LL_ERR, "child %d failed: %s\n",
 575                                *child, strerror(rc));
 576                 } else {
 577                         rc = WEXITSTATUS(status);
 578                         if (rc)
 579                                 logmsg(LL_ERR, "child %d terminated with %d\n",
 580                                        *child, rc);
 581                 }
 582         }
 583         return rc;
 584 }
 585
 586 static int do_keyctl_update(char *reason, key_serial_t keyid,
 587                             const void *payload, size_t plen)
 588 {
 589         while (keyctl_update(keyid, payload, plen)) {
 590                 if (errno != EAGAIN) {
 591                         logmsg(LL_ERR, "%se key %08x: %s\n",
 592                                reason, keyid, strerror(errno));
 593                         return -1;
 594                 }
 595
 596                 logmsg(LL_WARN, "key %08x: %sing too soon, try again\n",
 597                        keyid, reason);
 598                 sleep(2);
 599         }
 600
 601         logmsg(LL_INFO, "key %08x: %sed\n", keyid, reason);
 602         return 0;
 603 }
 604
 605 static int error_kernel_key(key_serial_t keyid, int rpc_error, int gss_error,
 606                             uid_t uid)
 607 {
 608         key_serial_t inst_keyring = KEY_SPEC_SESSION_KEYRING;
 609         pid_t child = 1;
 610         int seqwin = 0;
 611         char *p, *end;
 612         char buf[32];
 613         int rc;
 614
 615         logmsg(LL_TRACE, "revoking kernel key %08x\n", keyid);
 616
 617         /* Only possessor and uid can update the key. So for a user key that is
 618          * linked to the user keyring, switch uid/gid in a subprocess to not
 619          * change identity in main process.
 620          */
 621         if (uid) {
 622                 rc = fork_and_switch_id(uid, &child);
 623                 if (rc || child)
 624                         goto out;
 625                 inst_keyring = KEY_SPEC_USER_KEYRING;
 626         }
 627
 628         p = buf;
 629         end = buf + sizeof(buf);
 630
 631         WRITE_BYTES(&p, end, seqwin);
 632         WRITE_BYTES(&p, end, rpc_error);
 633         WRITE_BYTES(&p, end, gss_error);
 634
 635         rc = do_keyctl_update("revok", keyid, buf, p - buf);
 636         if (rc)
 637                 goto out;
 638         rc = keyctl_unlink(keyid, inst_keyring);
 639         if (rc)
 640                 logmsg(LL_ERR, "unlink key %08x from %d: %s\n",
 641                        keyid, inst_keyring, strerror(errno));
 642         else
 643                 logmsg(LL_INFO, "key %08x: unlinked from %d\n",
 644                        keyid, inst_keyring);
 645
 646 out:
 647         if (child == 0)
 648                 /* job done for child */
 649                 exit(rc);
 650         return rc;
 651 }
 652
 653 static int update_kernel_key(key_serial_t keyid,
 654                              struct lgss_nego_data *lnd,
 655                              gss_buffer_desc *ctx_token)
 656 {
 657         char *buf = NULL, *p = NULL, *end = NULL;
 658         unsigned int buf_size = 0;
 659         pid_t child = 1;
 660         int uid, rc = 0;
 661
 662         logmsg(LL_TRACE, "updating kernel key %08x\n", keyid);
 663
 664         /* Only possessor and uid can update the key. So for a user key that is
 665          * linked to the user keyring, switch uid/gid in a subprocess to not
 666          * change identity in main process.
 667          */
 668         uid = lnd->lnd_uid;
 669         if (uid) {
 670                 rc = fork_and_switch_id(uid, &child);
 671                 if (rc || child)
 672                         goto out;
 673         }
 674
 675         buf_size = sizeof(lnd->lnd_seq_win) +
 676                 sizeof(lnd->lnd_rmt_ctx.length) + lnd->lnd_rmt_ctx.length +
 677                 sizeof(ctx_token->length) + ctx_token->length;
 678         buf = malloc(buf_size);
 679         if (buf == NULL) {
 680                 logmsg(LL_ERR, "key %08x: can't alloc update buf: size %d\n",
 681                        keyid, buf_size);
 682                 rc = ENOMEM;
 683                 goto out;
 684         }
 685
 686         p = buf;
 687         end = buf + buf_size;
 688         rc = -1;
 689
 690         if (WRITE_BYTES(&p, end, lnd->lnd_seq_win))
 691                 goto out;
 692         if (write_buffer(&p, end, &lnd->lnd_rmt_ctx))
 693                 goto out;
 694         if (write_buffer(&p, end, ctx_token))
 695                 goto out;
 696
 697         rc = do_keyctl_update("updat", keyid, buf, p - buf);
 698
 699 out:
 700         free(buf);
 701         if (child == 0)
 702                 /* job done for child */
 703                 exit(rc);
 704         return rc;
 705 }
 706
 707 static int lgssc_kr_negotiate_krb(key_serial_t keyid, struct lgss_cred *cred,
 708                                   struct keyring_upcall_param *kup,
 709                                   int req_fd[2], int reply_fd[2])
 710 {
 711         struct lgss_nego_data lnd;
 712         OM_uint32 min_stat;
 713         int rc = -1;
 714         bool redo = true;
 715
 716         if (lgss_get_service_str(&g_service, kup->kup_svc, kup->kup_nid)) {
 717                 logmsg(LL_ERR, "key %08x: failed to construct service "
 718                        "string\n", keyid);
 719                 error_kernel_key(keyid, -EACCES, 0, cred->lc_uid);
 720                 goto out_cred;
 721         }
 722
 723         if (lgss_using_cred(cred)) {
 724                 logmsg(LL_ERR, "key %08x: can't using cred\n", keyid);
 725                 error_kernel_key(keyid, -EACCES, 0, cred->lc_uid);
 726                 goto out_cred;
 727         }
 728
 729 retry_nego:
 730         memset(&lnd, 0, sizeof(lnd));
 731         if (lgssc_init_nego_data(&lnd, kup, cred->lc_mech->lmt_mech_n)) {
 732                 logmsg(LL_ERR, "key %08x: failed to initialize "
 733                        "negotiation data\n", keyid);
 734                 error_kernel_key(keyid, lnd.lnd_rpc_err, lnd.lnd_gss_err,
 735                                  cred->lc_uid);
 736                 goto out_cred;
 737         }
 738
 739         rc = lgssc_negotiation(&lnd, req_fd, reply_fd);
 740         if (rc == -EAGAIN || (rc == -ETIMEDOUT && redo)) {
 741                 logmsg(LL_ERR, "Failed negotiation must retry\n");
 742                 redo = false;
 743                 goto retry_nego;
 744         } else if (rc) {
 745                 logmsg(LL_ERR, "key %08x: failed to negotiation\n", keyid);
 746                 error_kernel_key(keyid, lnd.lnd_rpc_err, lnd.lnd_gss_err,
 747                                  cred->lc_uid);
 748                 goto out;
 749         }
 750
 751         rc = serialize_context_for_kernel(&lnd.lnd_ctx, &lnd.lnd_ctx_token,
 752                                           lnd.lnd_mech);
 753         if (rc) {
 754                 logmsg(LL_ERR, "key %08x: failed to export context\n", keyid);
 755                 error_kernel_key(keyid, rc, lnd.lnd_gss_err, cred->lc_uid);
 756                 goto out;
 757         }
 758
 759         rc = update_kernel_key(keyid,  &lnd, &lnd.lnd_ctx_token);
 760         if (rc)
 761                 goto out;
 762
 763         rc = 0;
 764         logmsg(LL_INFO, "key %08x for user %u is updated OK!\n",
 765                keyid, kup->kup_uid);
 766 out:
 767         if (lnd.lnd_ctx_token.length != 0)
 768                 (void)gss_release_buffer(&min_stat, &lnd.lnd_ctx_token);
 769
 770         lgssc_fini_nego_data(&lnd);
 771
 772 out_cred:
 773         lgss_release_cred(cred);
 774         return rc;
 775 }
 776
 777 static int lgssc_kr_negotiate_manual(key_serial_t keyid, struct lgss_cred *cred,
 778                                      struct keyring_upcall_param *kup,
 779                                      int req_fd[2], int reply_fd[2])
 780 {
 781         struct lgss_nego_data lnd;
 782         OM_uint32 min_stat;
 783         int rc;
 784         bool redo = true;
 785
 786         rc = lgss_get_service_str(&g_service, kup->kup_svc, kup->kup_nid);
 787         if (rc) {
 788                 logmsg(LL_ERR, "key %08x: failed to construct service "
 789                        "string\n", keyid);
 790                 error_kernel_key(keyid, -EACCES, 0, 0);
 791                 goto out_cred;
 792         }
 793
 794         rc = lgss_using_cred(cred);
 795         if (rc) {
 796                 logmsg(LL_ERR, "key %08x: can't use cred\n", keyid);
 797                 error_kernel_key(keyid, -EACCES, 0, 0);
 798                 goto out_cred;
 799         }
 800
 801 retry:
 802         memset(&lnd, 0, sizeof(lnd));
 803         rc = lgssc_init_nego_data(&lnd, kup, cred->lc_mech->lmt_mech_n);
 804         if (rc) {
 805                 logmsg(LL_ERR, "key %08x: failed to initialize "
 806                        "negotiation data\n", keyid);
 807                 error_kernel_key(keyid, lnd.lnd_rpc_err, lnd.lnd_gss_err, 0);
 808                 goto out_cred;
 809         }
 810
 811         /*
 812          * Handles the negotiation but then calls lgss_validate to make sure
 813          * the token is valid.  It also populates the lnd_ctx_token for the
 814          * update to the kernel key
 815          */
 816         rc = lgssc_negotiation_manual(&lnd, cred, req_fd, reply_fd);
 817         if (rc == -EAGAIN || (rc == -ETIMEDOUT && redo)) {
 818                 logmsg(LL_ERR, "Failed negotiation must retry\n");
 819                 redo = false;
 820                 goto retry;
 821         } else if (rc) {
 822                 logmsg(LL_ERR, "key %08x: failed to negotiate\n", keyid);
 823                 error_kernel_key(keyid, lnd.lnd_rpc_err, lnd.lnd_gss_err, 0);
 824                 goto out;
 825         }
 826
 827         rc = update_kernel_key(keyid,  &lnd, &lnd.lnd_ctx_token);
 828         if (rc)
 829                 goto out;
 830
 831         logmsg(LL_INFO, "key %08x for user %u is updated OK!\n",
 832                keyid, kup->kup_uid);
 833 out:
 834         if (lnd.lnd_ctx_token.length != 0)
 835                 gss_release_buffer(&min_stat, &lnd.lnd_ctx_token);
 836
 837         lgssc_fini_nego_data(&lnd);
 838
 839 out_cred:
 840         lgss_release_cred(cred);
 841         return rc;
 842 }
 843
 844 /*
 845  * note we inherited assumed authority from parent process
 846  */
 847 static int lgssc_kr_negotiate(key_serial_t keyid, struct lgss_cred *cred,
 848                               struct keyring_upcall_param *kup,
 849                               int req_fd[2], int reply_fd[2])
 850 {
 851         int rc;
 852
 853         logmsg(LL_TRACE, "child start on behalf of key %08x: "
 854                "cred %p, uid %u, svc %u, nid %"PRIx64", uids: %u:%u/%u:%u\n",
 855                keyid, cred, cred->lc_uid, cred->lc_tgt_svc, cred->lc_tgt_nid,
 856                kup->kup_uid, kup->kup_gid, kup->kup_fsuid, kup->kup_fsgid);
 857
 858         switch (cred->lc_mech->lmt_mech_n) {
 859         case LGSS_MECH_NULL:
 860         case LGSS_MECH_SK:
 861                 rc = lgssc_kr_negotiate_manual(keyid, cred, kup,
 862                                                req_fd, reply_fd);
 863                 break;
 864         case LGSS_MECH_KRB5:
 865         default:
 866                 rc = lgssc_kr_negotiate_krb(keyid, cred, kup, req_fd, reply_fd);
 867                 break;
 868         }
 869
 870         return rc;
 871 }
 872
 873 /*
 874  * call out info format: s[:s]...
 875  *  [0]: secid          (uint)
 876  *  [1]: mech_name      (string)
 877  *  [2]: uid            (uint)
 878  *  [3]: gid            (uint)
 879  *  [4]: flags          (string) FMT: r-root; m-mdt; o-ost
 880  *  [5]: svc type       (char)
 881  *  [6]: lustre_svc     (int)
 882  *  [7]: target_nid     (uint64)
 883  *  [8]: target_uuid    (string)
 884  *  [9]: self_nid        (uint64)
 885  *  [10]: pid            (uint)
 886  */
 887 static int parse_callout_info(const char *coinfo,
 888                               struct keyring_upcall_param *uparam)
 889 {
 890         const int       nargs = 11;
 891         char            buf[1024];
 892         char           *string = buf;
 893         int             length, i;
 894         char           *data[nargs];
 895         char           *pos;
 896
 897         length = strlen(coinfo) + 1;
 898         if (length > 1024) {
 899                 logmsg(LL_ERR, "coinfo too long\n");
 900                 return -1;
 901         }
 902         memcpy(buf, coinfo, length);
 903
 904         for (i = 0; i < nargs - 1; i++) {
 905                 pos = strchr(string, ':');
 906                 if (pos == NULL) {
 907                         logmsg(LL_ERR, "short of components\n");
 908                         return -1;
 909                 }
 910
 911                 *pos = '\0';
 912                 data[i] = string;
 913                 string = pos + 1;
 914         }
 915         data[i] = string;
 916
 917         logmsg(LL_TRACE, "components: %s,%s,%s,%s,%s,%c,%s,%s,%s,%s,%s\n",
 918                data[0], data[1], data[2], data[3], data[4], data[5][0],
 919                data[6], data[7], data[8], data[9], data[10]);
 920
 921         uparam->kup_secid = strtol(data[0], NULL, 0);
 922         snprintf(uparam->kup_mech, sizeof(uparam->kup_mech), "%s", data[1]);
 923         uparam->kup_uid = strtol(data[2], NULL, 0);
 924         uparam->kup_gid = strtol(data[3], NULL, 0);
 925         if (strchr(data[4], 'r'))
 926                 uparam->kup_is_root = 1;
 927         if (strchr(data[4], 'm'))
 928                 uparam->kup_is_mdt = 1;
 929         if (strchr(data[4], 'o'))
 930                 uparam->kup_is_ost = 1;
 931         uparam->kup_svc_type = data[5][0];
 932         uparam->kup_svc = strtol(data[6], NULL, 0);
 933         uparam->kup_nid = strtoll(data[7], NULL, 0);
 934         snprintf(uparam->kup_tgt, sizeof(uparam->kup_tgt), "%s", data[8]);
 935         uparam->kup_selfnid = strtoll(data[9], NULL, 0);
 936         uparam->kup_pid = strtol(data[10], NULL, 0);
 937
 938         logmsg(LL_DEBUG, "parse call out info: secid %d, mech %s, ugid %u:%u, "
 939                "is_root %d, is_mdt %d, is_ost %d, svc type %c, svc %d, "
 940                "nid 0x%"PRIx64", tgt %s, self nid 0x%"PRIx64", pid %d\n",
 941                uparam->kup_secid, uparam->kup_mech,
 942                uparam->kup_uid, uparam->kup_gid,
 943                uparam->kup_is_root, uparam->kup_is_mdt, uparam->kup_is_ost,
 944                uparam->kup_svc_type, uparam->kup_svc, uparam->kup_nid,
 945                uparam->kup_tgt, uparam->kup_selfnid, uparam->kup_pid);
 946         return 0;
 947 }
 948
 949 static void set_log_level()
 950 {
 951         unsigned int level;
 952         glob_t path;
 953         FILE *file;
 954
 955         if (cfs_get_param_paths(&path,
 956                                 "sptlrpc/gss/lgss_keyring/debug_level") != 0)
 957                 return;
 958         file = fopen(path.gl_pathv[0], "r");
 959         if (file == NULL) {
 960                 cfs_free_param_data(&path);
 961                 return;
 962         }
 963
 964         if (fscanf(file, "%u", &level) != 1)
 965                 goto out;
 966
 967         if (level >= LL_MAX)
 968                 goto out;
 969
 970         lgss_set_loglevel(level);
 971 out:
 972         cfs_free_param_data(&path);
 973         fclose(file);
 974 }
 975
 976 static int associate_with_ns(char *path)
 977 {
 978         int fd, rc = -1;
 979
 980         fd = open(path, O_RDONLY);
 981         if (fd != -1) {
 982                 rc = setns(fd, 0);
 983                 close(fd);
 984         }
 985
 986         return rc;
 987 }
 988
 989 static int prepare_and_instantiate(struct lgss_cred *cred, key_serial_t keyid,
 990                                    uint32_t uid)
 991 {
 992         key_serial_t inst_keyring;
 993         bool prepared = true;
 994         pid_t child = 1;
 995         int rc = 0;
 996
 997         if (lgss_prepare_cred(cred)) {
 998                 logmsg(LL_ERR, "key %08x: failed to prepare credentials "
 999                        "for user %d\n", keyid, uid);
1000                 /* prepare failed, but still instantiate the key for regular
1001                  * user, so that it can be used to report the error later
1002                  * in the process
1003                  */
1004                 if (cred->lc_root_flags)
1005                         return 1;
1006                 prepared = false;
1007         }
1008
1009         /* Pre initialize the key. Note the keyring linked to is actually of the
1010          * original requesting process, not _this_ upcall process. If it's for
1011          * root user, don't link to any keyrings because we want fully control
1012          * on it, and share it among all root sessions.
1013          * Otherswise link to user keyring, which requires switching uid/gid.
1014          * Do this in a subprocess because other operations need privileges.
1015          */
1016         if (cred->lc_root_flags) {
1017                 inst_keyring = 0;
1018         } else {
1019                 inst_keyring = KEY_SPEC_USER_KEYRING;
1020                 /* fork to not change identity in main process */
1021                 rc = fork_and_switch_id(uid, &child);
1022                 if (rc || child)
1023                         goto out;
1024         }
1025
1026         /* if dealing with a user key, grant user write permission,
1027          * it will be required for key update
1028          */
1029         if (child == 0) {
1030                 key_perm_t perm;
1031
1032                 perm = KEY_POS_VIEW | KEY_POS_WRITE | KEY_POS_SEARCH |
1033                         KEY_POS_LINK | KEY_POS_SETATTR |
1034                         KEY_USR_VIEW | KEY_USR_WRITE;
1035                 if (keyctl_setperm(keyid, perm))
1036                         logmsg(LL_ERR, "setperm %08x on key %08x: %s\n",
1037                                perm, keyid, strerror(errno));
1038         }
1039
1040         rc = keyctl_instantiate(keyid, NULL, 0, inst_keyring);
1041         if (rc) {
1042                 rc = errno;
1043                 logmsg(LL_ERR, "instantiate key %08x in keyring id %d: %s\n",
1044                        keyid, inst_keyring, strerror(rc));
1045         } else {
1046                 logmsg(LL_TRACE,
1047                        "instantiated kernel key %08x in keyring id %d\n",
1048                        keyid, inst_keyring);
1049         }
1050
1051 out:
1052         if (child == 0)
1053                 /* job done for child */
1054                 exit(rc);
1055         return prepared ? rc : 1;
1056 }
1057
1058 /****************************************
1059  * main process                         *
1060  ****************************************/
1061
1062 int main(int argc, char *argv[])
1063 {
1064         struct keyring_upcall_param uparam;
1065         key_serial_t keyid;
1066         key_serial_t sring;
1067         pid_t child;
1068         int req_fd[2] = { -1, -1 };
1069         int reply_fd[2] = { -1, -1 };
1070         struct lgss_mech_type *mech;
1071         struct lgss_cred *cred;
1072         char path[PATH_MAX] = "";
1073         int other_ns = 0;
1074         int rc = 0, opt;
1075         struct stat parent_ns = { .st_ino = 0 };
1076         struct stat caller_ns = { .st_ino = 0 };
1077
1078         static struct option long_opts[] = {
1079                 { .name = "realm", .has_arg = required_argument, .val = 'R'},
1080                 { .name = NULL, } };
1081
1082         set_log_level();
1083
1084         logmsg(LL_TRACE, "start parsing parameters\n");
1085
1086         /* one possible option before upcall parameters: -R REALM */
1087         while ((opt = getopt_long(argc, argv, "R:", long_opts, NULL)) != EOF) {
1088                 switch (opt) {
1089                 case 'R':
1090                         lgss_client_realm = optarg;
1091                         break;
1092                 default:
1093                         logmsg(LL_ERR, "invalid parameter %s\n",
1094                                argv[optind - 1]);
1095                         return 1;
1096                 }
1097         }
1098
1099         if (lgss_client_realm) {
1100                 /* shift args to meet expected upcall parameters */
1101                 argc -= optind - 1;
1102                 argv += optind - 1;
1103         }
1104
1105         /*
1106          * parse & sanity check upcall parameters
1107          * expected to be called with:
1108          * [1]:  operation
1109          * [2]:  key ID
1110          * [3]:  key type
1111          * [4]:  key description
1112          * [5]:  call out info
1113          * [6]:  UID
1114          * [7]:  GID
1115          * [8]:  thread keyring
1116          * [9]:  process keyring
1117          * [10]: session keyring
1118          */
1119         if (argc != 10 + 1) {
1120                 logmsg(LL_ERR, "invalid parameter number %d\n", argc);
1121                 return 1;
1122         }
1123
1124         memset(&uparam, 0, sizeof(uparam));
1125
1126         if (strcmp(argv[1], "create") != 0) {
1127                 logmsg(LL_ERR,
1128                        "invalid OP %s (key %s, desc %s, ugid %s:%s, sring %s, coinfo %s)\n",
1129                        argv[1], argv[2], argv[4], argv[6], argv[7], argv[10],
1130                        argv[5]);
1131                 return 1;
1132         }
1133
1134         if (sscanf(argv[2], "%d", &keyid) != 1) {
1135                 logmsg(LL_ERR,
1136                        "can't extract KeyID: %s (key %s, desc %s, ugid %s:%s, sring %s, coinfo %s)\n",
1137                        argv[2], argv[2], argv[4], argv[6], argv[7], argv[10],
1138                        argv[5]);
1139                 return 1;
1140         }
1141
1142         logmsg(LL_INFO, "key %08x, desc %s, ugid %s:%s, sring %s, coinfo %s\n",
1143                keyid, argv[4], argv[6], argv[7], argv[10], argv[5]);
1144
1145         if (sscanf(argv[6], "%d", &uparam.kup_fsuid) != 1) {
1146                 logmsg(LL_ERR, "can't extract UID: %s\n", argv[6]);
1147                 return 1;
1148         }
1149
1150         if (sscanf(argv[7], "%d", &uparam.kup_fsgid) != 1) {
1151                 logmsg(LL_ERR, "can't extract GID: %s\n", argv[7]);
1152                 return 1;
1153         }
1154
1155         if (sscanf(argv[10], "%d", &sring) != 1) {
1156                 logmsg(LL_ERR, "can't extract session keyring: %s\n", argv[10]);
1157                 return 1;
1158         }
1159
1160         if (parse_callout_info(argv[5], &uparam)) {
1161                 logmsg(LL_ERR, "can't extract callout info: %s\n", argv[5]);
1162                 return 1;
1163         }
1164
1165         logmsg(LL_TRACE, "parsing parameters OK\n");
1166
1167         /*
1168          * prepare a cred
1169          */
1170         mech = lgss_name2mech(uparam.kup_mech);
1171         if (mech == NULL) {
1172                 logmsg(LL_ERR, "key %08x: unsupported mech: %s\n",
1173                        keyid, uparam.kup_mech);
1174                 return 1;
1175         }
1176
1177         if (lgss_mech_initialize(mech)) {
1178                 logmsg(LL_ERR, "key %08x: can't initialize mech %s\n",
1179                        keyid, mech->lmt_name);
1180                 return 1;
1181         }
1182
1183         cred = lgss_create_cred(mech);
1184         if (cred == NULL) {
1185                 logmsg(LL_ERR, "key %08x: can't create a new %s cred\n",
1186                        keyid, mech->lmt_name);
1187                 return 1;
1188         }
1189
1190         cred->lc_uid = uparam.kup_uid;
1191         cred->lc_root_flags |= uparam.kup_is_root ? LGSS_ROOT_CRED_ROOT : 0;
1192         cred->lc_root_flags |= uparam.kup_is_mdt ? LGSS_ROOT_CRED_MDT : 0;
1193         cred->lc_root_flags |= uparam.kup_is_ost ? LGSS_ROOT_CRED_OST : 0;
1194         cred->lc_tgt_nid = uparam.kup_nid;
1195         cred->lc_tgt_svc = uparam.kup_svc;
1196         cred->lc_tgt_uuid = uparam.kup_tgt;
1197         cred->lc_svc_type = uparam.kup_svc_type;
1198         cred->lc_self_nid = uparam.kup_selfnid;
1199
1200         /* Is caller in different namespace? */
1201         /* If passed caller's pid is 0, it means we have to stick
1202          * with current namespace.
1203          */
1204         if (uparam.kup_pid) {
1205                 snprintf(path, sizeof(path), "/proc/%d/ns/mnt", getpid());
1206                 if (stat(path, &parent_ns)) {
1207                         logmsg(LL_DEBUG, "cannot stat %s: %s\n",
1208                                path, strerror(errno));
1209                 } else {
1210                         snprintf(path, sizeof(path), "/proc/%d/ns/mnt",
1211                                  uparam.kup_pid);
1212                         if (stat(path, &caller_ns))
1213                                 logmsg(LL_DEBUG, "cannot stat %s: %s\n",
1214                                        path, strerror(errno));
1215                         else if (caller_ns.st_ino != parent_ns.st_ino)
1216                                 other_ns = 1;
1217                 }
1218         }
1219
1220         /*
1221          * if caller's namespace is different, fork a child and associate it
1222          * with caller's namespace to do credentials preparation
1223          */
1224         if (other_ns) {
1225                 logmsg(LL_TRACE, "caller's namespace is different\n");
1226
1227                 /* use pipes to pass info between child and parent processes */
1228                 if (pipe(req_fd) == -1) {
1229                         logmsg(LL_ERR, "key %08x: pipe failed: %s\n",
1230                                keyid, strerror(errno));
1231                         return 1;
1232                 }
1233                 if (pipe(reply_fd) == -1) {
1234                         logmsg(LL_ERR, "key %08x: pipe failed: %s\n",
1235                                keyid, strerror(errno));
1236                         return 1;
1237                 }
1238
1239                 child = fork();
1240                 if (child == -1) {
1241                         logmsg(LL_ERR, "key %08x: can't create child: %s\n",
1242                                keyid, strerror(errno));
1243                         rc = 1;
1244                         goto out_pipe;
1245                 } else if (child == 0) {
1246                         int rc2;
1247                         /* child process: carry out credentials preparation
1248                          * in caller's namespace */
1249
1250                         close(req_fd[0]); /* close unsed read end */
1251                         req_fd[0] = -1;
1252                         close(reply_fd[1]); /* close unsed write end */
1253                         reply_fd[1] = -1;
1254
1255                         if (associate_with_ns(path) != 0) {
1256                                 logmsg(LL_ERR,
1257                                        "failed to attach to pid %d namespace: "
1258                                        "%s\n", uparam.kup_pid, strerror(errno));
1259                                 rc = 1;
1260                                 goto out_pipe;
1261                         }
1262                         logmsg(LL_TRACE, "working in namespace of pid %d\n",
1263                                uparam.kup_pid);
1264
1265                         rc = prepare_and_instantiate(cred, keyid,
1266                                                      uparam.kup_uid);
1267
1268                         /* send to parent the status of credentials preparation
1269                          * and key instantiation */
1270                         rc2 = send_to(req_fd[1], &rc, sizeof(rc));
1271                         rc = (rc == 0 ? rc2 : rc);
1272                         if (rc != 0)
1273                                 goto out_pipe;
1274
1275                         /* now do real gss negotiation
1276                          * parent main process will not wait for us,
1277                          * as it has to be done in the background */
1278                         rc = lgssc_kr_negotiate(keyid, cred, &uparam,
1279                                                 req_fd, reply_fd);
1280                         goto out_pipe;
1281                 } else {
1282                         int rc2;
1283                         /* parent process: exchange info with child carrying out
1284                          * credentials preparation */
1285
1286                         close(req_fd[1]); /* close unsed write end */
1287                         req_fd[1] = -1;
1288                         close(reply_fd[0]); /* close unsed read end */
1289                         reply_fd[0] = -1;
1290
1291                         /* get status of credentials preparation
1292                          * and key instantiation */
1293                         rc2 = receive_from(req_fd[0], &rc, sizeof(rc));
1294                         if (rc2 != 0 || rc != 0) {
1295                                 logmsg(LL_ERR, "child failed preparing creds: "
1296                                        "%s\n",
1297                                        rc2 != 0 ? strerror(-rc2)
1298                                                 : strerror(rc));
1299                                 goto out_pipe;
1300                         }
1301
1302                         /*
1303                          * fork a child here to participate in gss negotiation,
1304                          * as it has to be done in the background
1305                          */
1306                         child = fork();
1307                         if (child == -1) {
1308                                 logmsg(LL_ERR,
1309                                        "key %08x: can't create child: %s\n",
1310                                        keyid, strerror(errno));
1311                                 rc = 1;
1312                                 goto out_pipe;
1313                         } else if (child == 0) {
1314                                 struct lgssd_ioctl_param param;
1315                                 char outbuf[8192] = { 0 };
1316                                 void *gss_token = NULL;
1317
1318                                 /* get ioctl buffer from child */
1319                                 rc = receive_from(req_fd[0], &param,
1320                                                   sizeof(param));
1321                                 if (rc != 0)
1322                                         goto out_pipe;
1323
1324                                 gss_token = calloc(1, param.send_token_size);
1325                                 if (gss_token == NULL)
1326                                         goto out_pipe;
1327
1328                                 /* get gss token from child */
1329                                 rc = receive_from(req_fd[0], gss_token,
1330                                                   param.send_token_size);
1331                                 if (rc != 0)
1332                                         goto out_token;
1333
1334                                 param.send_token = (char *)gss_token;
1335                                 param.reply_buf_size = sizeof(outbuf);
1336                                 param.reply_buf = outbuf;
1337
1338                                 /* do ioctl in place of child process carrying
1339                                  * out credentials negotiation: as it runs in
1340                                  * a container, it might not be able to
1341                                  * perform ioctl */
1342                                 rc = gss_do_ioctl(&param);
1343                                 if (rc != 0)
1344                                         goto out_token;
1345
1346                                 /* send ioctl status to child */
1347                                 rc = send_to(reply_fd[1], &param.status,
1348                                              sizeof(param.status));
1349                                 if (rc != 0)
1350                                         goto out_token;
1351                                 /* send reply buffer to child */
1352                                 rc = send_to(reply_fd[1], outbuf,
1353                                              sizeof(outbuf));
1354                                 if (rc != 0)
1355                                         goto out_token;
1356
1357 out_token:
1358                                 free(gss_token);
1359                                 goto out_pipe;
1360                         }
1361
1362                         logmsg(LL_TRACE, "forked child %d\n", child);
1363                 }
1364 out_pipe:
1365                 close(req_fd[0]);
1366                 close(req_fd[1]);
1367                 close(reply_fd[0]);
1368                 close(reply_fd[1]);
1369                 lgss_fini(cred);
1370                 return rc;
1371         } else {
1372                 if (uparam.kup_pid)
1373                         logmsg(LL_TRACE, "caller's namespace is the same\n");
1374                 else
1375                         logmsg(LL_TRACE, "stick with current namespace\n");
1376
1377                 /* In case of prepare error, a key will be instantiated
1378                  * all the same. But then we will have to error this key
1379                  * instead of doing normal gss negotiation.
1380                  */
1381                 rc = prepare_and_instantiate(cred, keyid, uparam.kup_uid);
1382
1383                 /*
1384                  * fork a child to do the real gss negotiation
1385                  */
1386                 child = fork();
1387                 if (child == -1) {
1388                         logmsg(LL_ERR, "key %08x: can't create child: %s\n",
1389                                keyid, strerror(errno));
1390                         rc = 1;
1391                         goto out_reg;
1392                 } else if (child == 0) {
1393                         if (rc)
1394                                 rc = error_kernel_key(keyid, -ENOKEY, 0,
1395                                                       cred->lc_uid);
1396                         else
1397                                 rc = lgssc_kr_negotiate(keyid, cred, &uparam,
1398                                                         req_fd, reply_fd);
1399                         goto out_reg;
1400                 } else {
1401                         logmsg(LL_TRACE, "forked child %d\n", child);
1402                         return 0;
1403                 }
1404
1405 out_reg:
1406                 lgss_fini(cred);
1407                 return rc;
1408         }
1409 }