lustre/utils/gss/svcgssd_proc.c

   1 /*
   2  * svc_in_gssd_proc.c
   3  *
   4  * Copyright (c) 2000 The Regents of the University of Michigan.
   5  * All rights reserved.
   6  *
   7  * Copyright (c) 2002 Bruce Fields <bfields@UMICH.EDU>
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its
  19  *    contributors may be used to endorse or promote products derived
  20  *    from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  23  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  25  * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  29  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  30  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  31  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  32  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/stat.h>
  37
  38 #include <inttypes.h>
  39 #include <pwd.h>
  40 #include <stdio.h>
  41 #include <unistd.h>
  42 #include <ctype.h>
  43 #include <string.h>
  44 #include <fcntl.h>
  45 #include <errno.h>
  46 #ifdef HAVE_NETDB_H
  47 # include <netdb.h>
  48 #endif
  49
  50 #include <stdbool.h>
  51 #include <lnet/nidstr.h>
  52
  53 #include "svcgssd.h"
  54 #include "gss_util.h"
  55 #include "err_util.h"
  56 #include "context.h"
  57 #include "cacheio.h"
  58 #include "lsupport.h"
  59 #include "gss_oids.h"
  60 #include "sk_utils.h"
  61 #include <lustre/lustre_idl.h>
  62
  63 #define SVCGSSD_CONTEXT_CHANNEL "/proc/net/rpc/auth.sptlrpc.context/channel"
  64 #define SVCGSSD_INIT_CHANNEL    "/proc/net/rpc/auth.sptlrpc.init/channel"
  65
  66 #define TOKEN_BUF_SIZE          8192
  67
  68 struct svc_cred {
  69         uint32_t cr_remote;
  70         uint32_t cr_usr_root;
  71         uint32_t cr_usr_mds;
  72         uint32_t cr_usr_oss;
  73         uid_t    cr_uid;
  74         uid_t    cr_mapped_uid;
  75         uid_t    cr_gid;
  76 };
  77
  78 struct svc_nego_data {
  79         /* kernel data*/
  80         uint32_t        lustre_svc;
  81         lnet_nid_t      nid;
  82         uint64_t        handle_seq;
  83         char            nm_name[LUSTRE_NODEMAP_NAME_LENGTH + 1];
  84         gss_buffer_desc in_tok;
  85         gss_buffer_desc out_tok;
  86         gss_buffer_desc in_handle;
  87         gss_buffer_desc out_handle;
  88         uint32_t        maj_stat;
  89         uint32_t        min_stat;
  90
  91         /* userspace data */
  92         gss_OID                 mech;
  93         gss_ctx_id_t            ctx;
  94         gss_buffer_desc         ctx_token;
  95 };
  96
  97 static int
  98 do_svc_downcall(gss_buffer_desc *out_handle, struct svc_cred *cred,
  99                 gss_OID mechoid, gss_buffer_desc *context_token)
 100 {
 101         FILE *f;
 102         const char *mechname;
 103         int err;
 104
 105         printerr(2, "doing downcall\n");
 106         mechname = gss_OID_mech_name(mechoid);
 107         if (mechname == NULL)
 108                 goto out_err;
 109         f = fopen(SVCGSSD_CONTEXT_CHANNEL, "w");
 110         if (f == NULL) {
 111                 printerr(0, "WARNING: unable to open downcall channel "
 112                              "%s: %s\n",
 113                              SVCGSSD_CONTEXT_CHANNEL, strerror(errno));
 114                 goto out_err;
 115         }
 116         qword_printhex(f, out_handle->value, out_handle->length);
 117         /* XXX are types OK for the rest of this? */
 118         qword_printint(f, 3600); /* an hour should be sufficient */
 119         qword_printint(f, cred->cr_remote);
 120         qword_printint(f, cred->cr_usr_root);
 121         qword_printint(f, cred->cr_usr_mds);
 122         qword_printint(f, cred->cr_usr_oss);
 123         qword_printint(f, cred->cr_mapped_uid);
 124         qword_printint(f, cred->cr_uid);
 125         qword_printint(f, cred->cr_gid);
 126         qword_print(f, mechname);
 127         qword_printhex(f, context_token->value, context_token->length);
 128         err = qword_eol(f);
 129         fclose(f);
 130         return err;
 131 out_err:
 132         printerr(0, "WARNING: downcall failed\n");
 133         return -1;
 134 }
 135
 136 struct gss_verifier {
 137         u_int32_t       flav;
 138         gss_buffer_desc body;
 139 };
 140
 141 #define RPCSEC_GSS_SEQ_WIN      5
 142
 143 static int
 144 send_response(FILE *f, gss_buffer_desc *in_handle, gss_buffer_desc *in_token,
 145               u_int32_t maj_stat, u_int32_t min_stat,
 146               gss_buffer_desc *out_handle, gss_buffer_desc *out_token)
 147 {
 148         char buf[2 * TOKEN_BUF_SIZE];
 149         char *bp = buf;
 150         int blen = sizeof(buf);
 151         /* XXXARG: */
 152         int g;
 153
 154         printerr(2, "sending reply\n");
 155         qword_addhex(&bp, &blen, in_handle->value, in_handle->length);
 156         qword_addhex(&bp, &blen, in_token->value, in_token->length);
 157         qword_addint(&bp, &blen, 3600); /* an hour should be sufficient */
 158         qword_adduint(&bp, &blen, maj_stat);
 159         qword_adduint(&bp, &blen, min_stat);
 160         qword_addhex(&bp, &blen, out_handle->value, out_handle->length);
 161         qword_addhex(&bp, &blen, out_token->value, out_token->length);
 162         qword_addeol(&bp, &blen);
 163         if (blen <= 0) {
 164                 printerr(0, "WARNING: send_response: message too long\n");
 165                 return -1;
 166         }
 167         g = open(SVCGSSD_INIT_CHANNEL, O_WRONLY);
 168         if (g == -1) {
 169                 printerr(0, "WARNING: open %s failed: %s\n",
 170                                 SVCGSSD_INIT_CHANNEL, strerror(errno));
 171                 return -1;
 172         }
 173         *bp = '\0';
 174         printerr(3, "writing message: %s", buf);
 175         if (write(g, buf, bp - buf) == -1) {
 176                 printerr(0, "WARNING: failed to write message\n");
 177                 close(g);
 178                 return -1;
 179         }
 180         close(g);
 181         return 0;
 182 }
 183
 184 #define rpc_auth_ok                     0
 185 #define rpc_autherr_badcred             1
 186 #define rpc_autherr_rejectedcred        2
 187 #define rpc_autherr_badverf             3
 188 #define rpc_autherr_rejectedverf        4
 189 #define rpc_autherr_tooweak             5
 190 #define rpcsec_gsserr_credproblem       13
 191 #define rpcsec_gsserr_ctxproblem        14
 192
 193 static int
 194 get_ids(gss_name_t client_name, gss_OID mech, struct svc_cred *cred,
 195         lnet_nid_t nid, uint32_t lustre_svc)
 196 {
 197         u_int32_t       maj_stat, min_stat;
 198         gss_buffer_desc name;
 199         char            *sname, *host, *realm;
 200         const int       namebuf_size = 512;
 201         char            namebuf[namebuf_size];
 202         int             res = -1;
 203         gss_OID         name_type = GSS_C_NO_OID;
 204         struct passwd   *pw;
 205
 206         cred->cr_remote = 0;
 207         cred->cr_usr_root = cred->cr_usr_mds = cred->cr_usr_oss = 0;
 208         cred->cr_uid = cred->cr_mapped_uid = cred->cr_gid = -1;
 209
 210         maj_stat = gss_display_name(&min_stat, client_name, &name, &name_type);
 211         if (maj_stat != GSS_S_COMPLETE) {
 212                 pgsserr("get_ids: gss_display_name",
 213                         maj_stat, min_stat, mech);
 214                 return -1;
 215         }
 216         if (name.length >= 0xffff || /* be certain name.length+1 doesn't overflow */
 217             !(sname = calloc(name.length + 1, 1))) {
 218                 printerr(0, "WARNING: get_ids: error allocating %zu bytes "
 219                         "for sname\n", name.length + 1);
 220                 gss_release_buffer(&min_stat, &name);
 221                 return -1;
 222         }
 223         memcpy(sname, name.value, name.length);
 224         sname[name.length] = '\0';
 225         gss_release_buffer(&min_stat, &name);
 226
 227         if (lustre_svc == LUSTRE_GSS_SVC_MDS)
 228                 lookup_mapping(sname, nid, &cred->cr_mapped_uid);
 229         else
 230                 cred->cr_mapped_uid = -1;
 231
 232         realm = strchr(sname, '@');
 233         if (realm) {
 234                 *realm++ = '\0';
 235         } else {
 236                 printerr(0, "ERROR: %s has no realm name\n", sname);
 237                 goto out_free;
 238         }
 239
 240         host = strchr(sname, '/');
 241         if (host)
 242                 *host++ = '\0';
 243
 244         if (strcmp(sname, GSSD_SERVICE_MGS) == 0) {
 245                 printerr(0, "forbid %s as a user name\n", sname);
 246                 goto out_free;
 247         }
 248
 249         /* 1. check host part */
 250         if (host) {
 251                 if (lnet_nid2hostname(nid, namebuf, namebuf_size)) {
 252                         printerr(0, "ERROR: failed to resolve hostname for "
 253                                  "%s/%s@%s from %016llx\n",
 254                                  sname, host, realm, nid);
 255                         goto out_free;
 256                 }
 257
 258                 if (strcasecmp(host, namebuf)) {
 259                         printerr(0, "ERROR: %s/%s@%s claimed hostname doesn't "
 260                                  "match %s, nid %016llx\n", sname, host, realm,
 261                                  namebuf, nid);
 262                         goto out_free;
 263                 }
 264         } else {
 265                 if (!strcmp(sname, GSSD_SERVICE_MDS) ||
 266                     !strcmp(sname, GSSD_SERVICE_OSS)) {
 267                         printerr(0, "ERROR: %s@%s from %016llx doesn't "
 268                                  "bind with hostname\n", sname, realm, nid);
 269                         goto out_free;
 270                 }
 271         }
 272
 273         /* 2. check realm and user */
 274         switch (lustre_svc) {
 275         case LUSTRE_GSS_SVC_MDS:
 276                 if (strcasecmp(mds_local_realm, realm)) {
 277                         cred->cr_remote = 1;
 278
 279                         /* only allow mapped user from remote realm */
 280                         if (cred->cr_mapped_uid == -1) {
 281                                 printerr(0, "ERROR: %s%s%s@%s from %016llx "
 282                                          "is remote but without mapping\n",
 283                                          sname, host ? "/" : "",
 284                                          host ? host : "", realm, nid);
 285                                 break;
 286                         }
 287                 } else {
 288                         if (!strcmp(sname, LUSTRE_ROOT_NAME)) {
 289                                 cred->cr_uid = 0;
 290                                 cred->cr_usr_root = 1;
 291                         } else if (!strcmp(sname, GSSD_SERVICE_MDS)) {
 292                                 cred->cr_uid = 0;
 293                                 cred->cr_usr_mds = 1;
 294                         } else if (!strcmp(sname, GSSD_SERVICE_OSS)) {
 295                                 cred->cr_uid = 0;
 296                                 cred->cr_usr_oss = 1;
 297                         } else {
 298                                 pw = getpwnam(sname);
 299                                 if (pw != NULL) {
 300                                         cred->cr_uid = pw->pw_uid;
 301                                         printerr(2, "%s resolve to uid %u\n",
 302                                                  sname, cred->cr_uid);
 303                                 } else if (cred->cr_mapped_uid != -1) {
 304                                         printerr(2, "user %s from %016llx is "
 305                                                  "mapped to %u\n", sname, nid,
 306                                                  cred->cr_mapped_uid);
 307                                 } else {
 308                                         printerr(0, "ERROR: invalid user, "
 309                                                  "%s/%s@%s from %016llx\n",
 310                                                  sname, host, realm, nid);
 311                                         break;
 312                                 }
 313                         }
 314                 }
 315
 316                 res = 0;
 317                 break;
 318         case LUSTRE_GSS_SVC_MGS:
 319                 if (!strcmp(sname, GSSD_SERVICE_OSS)) {
 320                         cred->cr_uid = 0;
 321                         cred->cr_usr_oss = 1;
 322                 }
 323                 /* fall through */
 324         case LUSTRE_GSS_SVC_OSS:
 325                 if (!strcmp(sname, LUSTRE_ROOT_NAME)) {
 326                         cred->cr_uid = 0;
 327                         cred->cr_usr_root = 1;
 328                 } else if (!strcmp(sname, GSSD_SERVICE_MDS)) {
 329                         cred->cr_uid = 0;
 330                         cred->cr_usr_mds = 1;
 331                 }
 332                 if (cred->cr_uid == -1) {
 333                         printerr(0, "ERROR: svc %d doesn't accept user %s "
 334                                  "from %016llx\n", lustre_svc, sname, nid);
 335                         break;
 336                 }
 337                 res = 0;
 338                 break;
 339         default:
 340                 assert(0);
 341         }
 342
 343 out_free:
 344         if (!res)
 345                 printerr(1, "%s: authenticated %s%s%s@%s from %016llx\n",
 346                          lustre_svc_name[lustre_svc], sname,
 347                          host ? "/" : "", host ? host : "", realm, nid);
 348         free(sname);
 349         return res;
 350 }
 351
 352 typedef struct gss_union_ctx_id_t {
 353         gss_OID         mech_type;
 354         gss_ctx_id_t    internal_ctx_id;
 355 } gss_union_ctx_id_desc, *gss_union_ctx_id_t;
 356
 357 int handle_sk(struct svc_nego_data *snd)
 358 {
 359 #ifdef HAVE_OPENSSL_SSK
 360         struct sk_cred *skc = NULL;
 361         struct svc_cred cred;
 362         gss_buffer_desc bufs[SK_INIT_BUFFERS];
 363         gss_buffer_desc remote_pub_key = GSS_C_EMPTY_BUFFER;
 364         char *target;
 365         uint32_t rc = GSS_S_DEFECTIVE_TOKEN;
 366         uint32_t version;
 367         uint32_t flags;
 368         int i;
 369
 370         printerr(3, "Handling sk request\n");
 371         memset(bufs, 0, sizeof(gss_buffer_desc) * SK_INIT_BUFFERS);
 372
 373         /* See lgss_sk_using_cred() for client side token formation.
 374          * Decoding initiator buffers */
 375         i = sk_decode_netstring(bufs, SK_INIT_BUFFERS, &snd->in_tok);
 376         if (i < SK_INIT_BUFFERS) {
 377                 printerr(0, "Invalid netstring token received from peer\n");
 378                 goto cleanup_buffers;
 379         }
 380
 381         /* Allowing for a larger length first buffer in the future */
 382         if (bufs[SK_INIT_VERSION].length < sizeof(version)) {
 383                 printerr(0, "Invalid version received (wrong size)\n");
 384                 goto cleanup_buffers;
 385         }
 386         memcpy(&version, bufs[SK_INIT_VERSION].value, sizeof(version));
 387         version = be32toh(version);
 388         if (version != SK_MSG_VERSION) {
 389                 printerr(0, "Invalid version received: %d\n", version);
 390                 goto cleanup_buffers;
 391         }
 392
 393         rc = GSS_S_FAILURE;
 394
 395         /* target must be a null terminated string */
 396         i = bufs[SK_INIT_TARGET].length - 1;
 397         target = bufs[SK_INIT_TARGET].value;
 398         if (i >= 0 && target[i] != '\0') {
 399                 printerr(0, "Invalid target from netstring\n");
 400                 goto cleanup_buffers;
 401         }
 402
 403         if (bufs[SK_INIT_FLAGS].length != sizeof(flags)) {
 404                 printerr(0, "Invalid flags from netstring\n");
 405                 goto cleanup_buffers;
 406         }
 407         memcpy(&flags, bufs[SK_INIT_FLAGS].value, sizeof(flags));
 408
 409         skc = sk_create_cred(target, snd->nm_name, be32toh(flags));
 410         if (!skc) {
 411                 printerr(0, "Failed to create sk credentials\n");
 412                 goto cleanup_buffers;
 413         }
 414
 415         /* Verify that the peer has used a prime size greater or equal to
 416          * the size specified in the key file which may contain only zero
 417          * fill but the size specifies the mimimum supported size on
 418          * servers */
 419         if (skc->sc_flags & LGSS_SVC_PRIV &&
 420             bufs[SK_INIT_P].length < skc->sc_p.length) {
 421                 printerr(0, "Peer DHKE prime does not meet the size required "
 422                          "by keyfile: %zd bits\n", skc->sc_p.length * 8);
 423                 goto cleanup_buffers;
 424         }
 425
 426         /* Throw out the p from the server and use the wire data */
 427         free(skc->sc_p.value);
 428         skc->sc_p.value = NULL;
 429         skc->sc_p.length = 0;
 430
 431         /* Take control of all the allocated buffers from decoding */
 432         if (bufs[SK_INIT_RANDOM].length !=
 433             sizeof(skc->sc_kctx.skc_peer_random)) {
 434                 printerr(0, "Invalid size for client random\n");
 435                 goto cleanup_buffers;
 436         }
 437
 438         memcpy(&skc->sc_kctx.skc_peer_random, bufs[SK_INIT_RANDOM].value,
 439                sizeof(skc->sc_kctx.skc_peer_random));
 440         skc->sc_p = bufs[SK_INIT_P];
 441         remote_pub_key = bufs[SK_INIT_PUB_KEY];
 442         skc->sc_nodemap_hash = bufs[SK_INIT_NODEMAP];
 443         skc->sc_hmac = bufs[SK_INIT_HMAC];
 444
 445         /* Verify HMAC from peer.  Ideally this would happen before anything
 446          * else but we don't have enough information to lookup key without the
 447          * token (fsname and cluster_hash) so it's done after. */
 448         rc = sk_verify_hmac(skc, bufs, SK_INIT_BUFFERS - 1, EVP_sha256(),
 449                             &skc->sc_hmac);
 450         if (rc != GSS_S_COMPLETE) {
 451                 printerr(0, "HMAC verification error: 0x%x from peer %s\n",
 452                          rc, libcfs_nid2str((lnet_nid_t)snd->nid));
 453                 goto cleanup_partial;
 454         }
 455
 456         /* Check that the cluster hash matches the hash of nodemap name */
 457         rc = sk_verify_hash(snd->nm_name, EVP_sha256(), &skc->sc_nodemap_hash);
 458         if (rc != GSS_S_COMPLETE) {
 459                 printerr(0, "Cluster hash failed validation: 0x%x\n", rc);
 460                 goto cleanup_partial;
 461         }
 462
 463         rc = sk_gen_params(skc);
 464         if (rc != GSS_S_COMPLETE) {
 465                 printerr(0, "Failed to generate DH params for responder\n");
 466                 goto cleanup_partial;
 467         }
 468         if (sk_compute_dh_key(skc, &remote_pub_key)) {
 469                 printerr(0, "Failed to compute session key from DH params\n");
 470                 goto cleanup_partial;
 471         }
 472
 473         /* Cleanup init buffers we have copied or don't need anymore */
 474         free(bufs[SK_INIT_VERSION].value);
 475         free(bufs[SK_INIT_RANDOM].value);
 476         free(bufs[SK_INIT_TARGET].value);
 477         free(bufs[SK_INIT_FLAGS].value);
 478
 479         /* Server reply contains the servers public key, random,  and HMAC */
 480         version = htobe32(SK_MSG_VERSION);
 481         bufs[SK_RESP_VERSION].value = &version;
 482         bufs[SK_RESP_VERSION].length = sizeof(version);
 483         bufs[SK_RESP_RANDOM].value = &skc->sc_kctx.skc_host_random;
 484         bufs[SK_RESP_RANDOM].length = sizeof(skc->sc_kctx.skc_host_random);
 485         bufs[SK_RESP_PUB_KEY] = skc->sc_pub_key;
 486         if (sk_sign_bufs(&skc->sc_kctx.skc_shared_key, bufs,
 487                          SK_RESP_BUFFERS - 1, EVP_sha256(),
 488                          &skc->sc_hmac)) {
 489                 printerr(0, "Failed to sign parameters\n");
 490                 goto out_err;
 491         }
 492         bufs[SK_RESP_HMAC] = skc->sc_hmac;
 493         if (sk_encode_netstring(bufs, SK_RESP_BUFFERS, &snd->out_tok)) {
 494                 printerr(0, "Failed to encode netstring for token\n");
 495                 goto out_err;
 496         }
 497         printerr(2, "Created netstring of %zd bytes\n", snd->out_tok.length);
 498
 499         if (sk_session_kdf(skc, snd->nid, &snd->in_tok, &snd->out_tok)) {
 500                 printerr(0, "Failed to calulate derviced session key\n");
 501                 goto out_err;
 502         }
 503         if (sk_compute_keys(skc)) {
 504                 printerr(0, "Failed to compute HMAC and encryption keys\n");
 505                 goto out_err;
 506         }
 507         if (sk_serialize_kctx(skc, &snd->ctx_token)) {
 508                 printerr(0, "Failed to serialize context for kernel\n");
 509                 goto out_err;
 510         }
 511
 512         snd->out_handle.length = sizeof(snd->handle_seq);
 513         memcpy(snd->out_handle.value, &snd->handle_seq,
 514                sizeof(snd->handle_seq));
 515         snd->maj_stat = GSS_S_COMPLETE;
 516
 517         /* fix credentials */
 518         memset(&cred, 0, sizeof(cred));
 519         cred.cr_mapped_uid = -1;
 520
 521         if (skc->sc_flags & LGSS_ROOT_CRED_ROOT)
 522                 cred.cr_usr_root = 1;
 523         if (skc->sc_flags & LGSS_ROOT_CRED_MDT)
 524                 cred.cr_usr_mds = 1;
 525         if (skc->sc_flags & LGSS_ROOT_CRED_OST)
 526                 cred.cr_usr_oss = 1;
 527
 528         do_svc_downcall(&snd->out_handle, &cred, snd->mech, &snd->ctx_token);
 529
 530         /* cleanup ctx_token, out_tok is cleaned up in handle_channel_req */
 531         free(remote_pub_key.value);
 532         free(snd->ctx_token.value);
 533         snd->ctx_token.length = 0;
 534
 535         printerr(3, "sk returning success\n");
 536         return 0;
 537
 538 cleanup_buffers:
 539         for (i = 0; i < SK_INIT_BUFFERS; i++)
 540                 free(bufs[i].value);
 541         sk_free_cred(skc);
 542         snd->maj_stat = rc;
 543         return -1;
 544
 545 cleanup_partial:
 546         free(bufs[SK_INIT_VERSION].value);
 547         free(bufs[SK_INIT_RANDOM].value);
 548         free(bufs[SK_INIT_TARGET].value);
 549         free(bufs[SK_INIT_FLAGS].value);
 550         free(remote_pub_key.value);
 551         sk_free_cred(skc);
 552         snd->maj_stat = rc;
 553         return -1;
 554
 555 out_err:
 556         snd->maj_stat = rc;
 557         if (snd->ctx_token.value) {
 558                 free(snd->ctx_token.value);
 559                 snd->ctx_token.value = 0;
 560                 snd->ctx_token.length = 0;
 561         }
 562         free(remote_pub_key.value);
 563         sk_free_cred(skc);
 564         printerr(3, "sk returning failure\n");
 565 #else /* !HAVE_OPENSSL_SSK */
 566         printerr(0, "ERROR: shared key subflavour is not enabled\n");
 567 #endif /* HAVE_OPENSSL_SSK */
 568         return -1;
 569 }
 570
 571 int handle_null(struct svc_nego_data *snd)
 572 {
 573         struct svc_cred cred;
 574         uint64_t tmp;
 575         uint32_t flags;
 576
 577         /* null just uses the same token as the return token and for
 578          * for sending to the kernel.  It is a single uint64_t. */
 579         if (snd->in_tok.length != sizeof(uint64_t)) {
 580                 snd->maj_stat = GSS_S_DEFECTIVE_TOKEN;
 581                 printerr(0, "Invalid token size (%zd) received\n",
 582                          snd->in_tok.length);
 583                 return -1;
 584         }
 585         snd->out_tok.length = snd->in_tok.length;
 586         snd->out_tok.value = malloc(snd->out_tok.length);
 587         if (!snd->out_tok.value) {
 588                 snd->maj_stat = GSS_S_FAILURE;
 589                 printerr(0, "Failed to allocate out_tok\n");
 590                 return -1;
 591         }
 592
 593         snd->ctx_token.length = snd->in_tok.length;
 594         snd->ctx_token.value = malloc(snd->ctx_token.length);
 595         if (!snd->ctx_token.value) {
 596                 snd->maj_stat = GSS_S_FAILURE;
 597                 printerr(0, "Failed to allocate ctx_token\n");
 598                 return -1;
 599         }
 600
 601         snd->out_handle.length = sizeof(snd->handle_seq);
 602         memcpy(snd->out_handle.value, &snd->handle_seq,
 603                sizeof(snd->handle_seq));
 604         snd->maj_stat = GSS_S_COMPLETE;
 605
 606         memcpy(&tmp, snd->in_tok.value, sizeof(tmp));
 607         tmp = be64toh(tmp);
 608         flags = (uint32_t)(tmp & 0x00000000ffffffff);
 609         memset(&cred, 0, sizeof(cred));
 610         cred.cr_mapped_uid = -1;
 611
 612         if (flags & LGSS_ROOT_CRED_ROOT)
 613                 cred.cr_usr_root = 1;
 614         if (flags & LGSS_ROOT_CRED_MDT)
 615                 cred.cr_usr_mds = 1;
 616         if (flags & LGSS_ROOT_CRED_OST)
 617                 cred.cr_usr_oss = 1;
 618
 619         do_svc_downcall(&snd->out_handle, &cred, snd->mech, &snd->ctx_token);
 620
 621         /* cleanup ctx_token, out_tok is cleaned up in handle_channel_req */
 622         free(snd->ctx_token.value);
 623         snd->ctx_token.length = 0;
 624
 625         return 0;
 626 }
 627
 628 static int handle_krb(struct svc_nego_data *snd)
 629 {
 630         u_int32_t               ret_flags;
 631         gss_name_t              client_name;
 632         gss_buffer_desc         ignore_out_tok = {.value = NULL};
 633         gss_OID                 mech = GSS_C_NO_OID;
 634         gss_cred_id_t           svc_cred;
 635         u_int32_t               ignore_min_stat;
 636         struct svc_cred         cred;
 637
 638         svc_cred = gssd_select_svc_cred(snd->lustre_svc);
 639         if (!svc_cred) {
 640                 printerr(0, "no service credential for svc %u\n",
 641                          snd->lustre_svc);
 642                 goto out_err;
 643         }
 644
 645         snd->maj_stat = gss_accept_sec_context(&snd->min_stat, &snd->ctx,
 646                                                svc_cred, &snd->in_tok,
 647                                                GSS_C_NO_CHANNEL_BINDINGS,
 648                                                &client_name, &mech,
 649                                                &snd->out_tok, &ret_flags, NULL,
 650                                                NULL);
 651
 652         if (snd->maj_stat == GSS_S_CONTINUE_NEEDED) {
 653                 printerr(1, "gss_accept_sec_context GSS_S_CONTINUE_NEEDED\n");
 654
 655                 /* Save the context handle for future calls */
 656                 snd->out_handle.length = sizeof(snd->ctx);
 657                 memcpy(snd->out_handle.value, &snd->ctx, sizeof(snd->ctx));
 658                 return 0;
 659         } else if (snd->maj_stat != GSS_S_COMPLETE) {
 660                 printerr(0, "WARNING: gss_accept_sec_context failed\n");
 661                 pgsserr("handle_krb: gss_accept_sec_context",
 662                         snd->maj_stat, snd->min_stat, mech);
 663                 goto out_err;
 664         }
 665
 666         if (get_ids(client_name, mech, &cred, snd->nid, snd->lustre_svc)) {
 667                 /* get_ids() prints error msg */
 668                 snd->maj_stat = GSS_S_BAD_NAME; /* XXX ? */
 669                 gss_release_name(&ignore_min_stat, &client_name);
 670                 goto out_err;
 671         }
 672         gss_release_name(&ignore_min_stat, &client_name);
 673
 674         /* Context complete. Pass handle_seq in out_handle to use
 675          * for context lookup in the kernel. */
 676         snd->out_handle.length = sizeof(snd->handle_seq);
 677         memcpy(snd->out_handle.value, &snd->handle_seq,
 678                sizeof(snd->handle_seq));
 679
 680         /* kernel needs ctx to calculate verifier on null response, so
 681          * must give it context before doing null call: */
 682         if (serialize_context_for_kernel(snd->ctx, &snd->ctx_token, mech)) {
 683                 printerr(0, "WARNING: handle_krb: "
 684                          "serialize_context_for_kernel failed\n");
 685                 snd->maj_stat = GSS_S_FAILURE;
 686                 goto out_err;
 687         }
 688         /* We no longer need the gss context */
 689         gss_delete_sec_context(&ignore_min_stat, &snd->ctx, &ignore_out_tok);
 690         do_svc_downcall(&snd->out_handle, &cred, mech, &snd->ctx_token);
 691
 692         return 0;
 693
 694 out_err:
 695         if (snd->ctx != GSS_C_NO_CONTEXT)
 696                 gss_delete_sec_context(&ignore_min_stat, &snd->ctx,
 697                                        &ignore_out_tok);
 698
 699         return 1;
 700 }
 701
 702 /*
 703  * return -1 only if we detect error during reading from upcall channel,
 704  * all other cases return 0.
 705  */
 706 int handle_channel_request(FILE *f)
 707 {
 708         char                    in_tok_buf[TOKEN_BUF_SIZE];
 709         char                    in_handle_buf[15];
 710         char                    out_handle_buf[15];
 711         gss_buffer_desc         ctx_token      = {.value = NULL},
 712                                 null_token     = {.value = NULL};
 713         uint32_t                lustre_mech;
 714         static char             *lbuf;
 715         static int              lbuflen;
 716         static char             *cp;
 717         int                     get_len;
 718         int                     rc = 1;
 719         u_int32_t               ignore_min_stat;
 720         struct svc_nego_data    snd = {
 721                 .in_tok.value           = in_tok_buf,
 722                 .in_handle.value        = in_handle_buf,
 723                 .out_handle.value       = out_handle_buf,
 724                 .maj_stat               = GSS_S_FAILURE,
 725                 .ctx                    = GSS_C_NO_CONTEXT,
 726         };
 727
 728         printerr(2, "handling request\n");
 729         if (readline(fileno(f), &lbuf, &lbuflen) != 1) {
 730                 printerr(0, "WARNING: failed reading request\n");
 731                 return -1;
 732         }
 733
 734         cp = lbuf;
 735
 736         /* see rsi_request() for the format of data being input here */
 737         qword_get(&cp, (char *)&snd.lustre_svc, sizeof(snd.lustre_svc));
 738
 739         /* lustre_svc is the svc and gss subflavor */
 740         lustre_mech = (snd.lustre_svc & LUSTRE_GSS_MECH_MASK) >>
 741                       LUSTRE_GSS_MECH_SHIFT;
 742         snd.lustre_svc = snd.lustre_svc & LUSTRE_GSS_SVC_MASK;
 743         switch (lustre_mech) {
 744         case LGSS_MECH_KRB5:
 745                 if (!krb_enabled) {
 746                         printerr(1, "WARNING: Request for kerberos but service "
 747                                  "support not enabled\n");
 748                         goto ignore;
 749                 }
 750                 snd.mech = &krb5oid;
 751                 break;
 752         case LGSS_MECH_NULL:
 753                 if (!null_enabled) {
 754                         printerr(1, "WARNING: Request for gssnull but service "
 755                                  "support not enabled\n");
 756                         goto ignore;
 757                 }
 758                 snd.mech = &nulloid;
 759                 break;
 760         case LGSS_MECH_SK:
 761 #ifdef HAVE_OPENSSL_SSK
 762                 if (!sk_enabled) {
 763                         printerr(1, "WARNING: Request for sk but service "
 764                                  "support not enabled\n");
 765                         goto ignore;
 766                 }
 767                 snd.mech = &skoid;
 768 #else
 769                 printerr(1, "ERROR: Request for sk but service "
 770                          "support not enabled\n");
 771 #endif
 772                 break;
 773         default:
 774                 printerr(0, "WARNING: invalid mechanism recevied: %d\n",
 775                          lustre_mech);
 776                 goto out_err;
 777                 break;
 778         }
 779
 780         qword_get(&cp, (char *)&snd.nid, sizeof(snd.nid));
 781         qword_get(&cp, (char *)&snd.handle_seq, sizeof(snd.handle_seq));
 782         qword_get(&cp, snd.nm_name, sizeof(snd.nm_name));
 783         printerr(2, "handling req: svc %u, nid %016llx, idx %"PRIx64" nodemap "
 784                  "%s\n", snd.lustre_svc, snd.nid, snd.handle_seq, snd.nm_name);
 785
 786         get_len = qword_get(&cp, snd.in_handle.value, sizeof(in_handle_buf));
 787         if (get_len < 0) {
 788                 printerr(0, "WARNING: failed parsing request\n");
 789                 goto out_err;
 790         }
 791         snd.in_handle.length = (size_t)get_len;
 792
 793         printerr(3, "in_handle:\n");
 794         print_hexl(3, snd.in_handle.value, snd.in_handle.length);
 795
 796         get_len = qword_get(&cp, snd.in_tok.value, sizeof(in_tok_buf));
 797         if (get_len < 0) {
 798                 printerr(0, "WARNING: failed parsing request\n");
 799                 goto out_err;
 800         }
 801         snd.in_tok.length = (size_t)get_len;
 802
 803         printerr(3, "in_tok:\n");
 804         print_hexl(3, snd.in_tok.value, snd.in_tok.length);
 805
 806         if (snd.in_handle.length != 0) { /* CONTINUE_INIT case */
 807                 if (snd.in_handle.length != sizeof(snd.ctx)) {
 808                         printerr(0, "WARNING: input handle has unexpected "
 809                                  "length %zu\n", snd.in_handle.length);
 810                         goto out_err;
 811                 }
 812                 /* in_handle is the context id stored in the out_handle
 813                  * for the GSS_S_CONTINUE_NEEDED case below.  */
 814                 memcpy(&snd.ctx, snd.in_handle.value, snd.in_handle.length);
 815         }
 816
 817         if (lustre_mech == LGSS_MECH_KRB5)
 818                 rc = handle_krb(&snd);
 819         else if (lustre_mech == LGSS_MECH_SK)
 820                 rc = handle_sk(&snd);
 821         else if (lustre_mech == LGSS_MECH_NULL)
 822                 rc = handle_null(&snd);
 823         else
 824                 printerr(0, "WARNING: Received or request for"
 825                          "subflavor that is not enabled: %d\n", lustre_mech);
 826
 827 out_err:
 828         /* Failures send a null token */
 829         if (rc == 0)
 830                 send_response(f, &snd.in_handle, &snd.in_tok, snd.maj_stat,
 831                               snd.min_stat, &snd.out_handle, &snd.out_tok);
 832         else
 833                 send_response(f, &snd.in_handle, &snd.in_tok, snd.maj_stat,
 834                               snd.min_stat, &null_token, &null_token);
 835
 836         /* cleanup buffers */
 837         if (snd.ctx_token.value != NULL)
 838                 free(ctx_token.value);
 839         if (snd.out_tok.value != NULL)
 840                 gss_release_buffer(&ignore_min_stat, &snd.out_tok);
 841
 842         /* For junk wire data just ignore */
 843 ignore:
 844         return 0;
 845 }