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
  52 #include "svcgssd.h"
  53 #include "gss_util.h"
  54 #include "err_util.h"
  55 #include "context.h"
  56 #include "cacheio.h"
  57 #include "lsupport.h"
  58 #include "gss_oids.h"
  59 #include "sk_utils.h"
  60
  61 #define SVCGSSD_CONTEXT_CHANNEL "/proc/net/rpc/auth.sptlrpc.context/channel"
  62 #define SVCGSSD_INIT_CHANNEL    "/proc/net/rpc/auth.sptlrpc.init/channel"
  63
  64 #define TOKEN_BUF_SIZE          8192
  65
  66 struct svc_cred {
  67         uint32_t cr_remote;
  68         uint32_t cr_usr_root;
  69         uint32_t cr_usr_mds;
  70         uint32_t cr_usr_oss;
  71         uid_t    cr_uid;
  72         uid_t    cr_mapped_uid;
  73         uid_t    cr_gid;
  74 };
  75
  76 struct svc_nego_data {
  77         /* kernel data*/
  78         uint32_t        lustre_svc;
  79         lnet_nid_t      nid;
  80         uint64_t        handle_seq;
  81         char            nm_name[LUSTRE_NODEMAP_NAME_LENGTH + 1];
  82         gss_buffer_desc in_tok;
  83         gss_buffer_desc out_tok;
  84         gss_buffer_desc in_handle;
  85         gss_buffer_desc out_handle;
  86         uint32_t        maj_stat;
  87         uint32_t        min_stat;
  88
  89         /* userspace data */
  90         gss_OID                 mech;
  91         gss_ctx_id_t            ctx;
  92         gss_buffer_desc         ctx_token;
  93 };
  94
  95 static int
  96 do_svc_downcall(gss_buffer_desc *out_handle, struct svc_cred *cred,
  97                 gss_OID mechoid, gss_buffer_desc *context_token)
  98 {
  99         FILE *f;
 100         const char *mechname;
 101         int err;
 102
 103         printerr(2, "doing downcall\n");
 104         mechname = gss_OID_mech_name(mechoid);
 105         if (mechname == NULL)
 106                 goto out_err;
 107         f = fopen(SVCGSSD_CONTEXT_CHANNEL, "w");
 108         if (f == NULL) {
 109                 printerr(0, "WARNING: unable to open downcall channel "
 110                              "%s: %s\n",
 111                              SVCGSSD_CONTEXT_CHANNEL, strerror(errno));
 112                 goto out_err;
 113         }
 114         qword_printhex(f, out_handle->value, out_handle->length);
 115         /* XXX are types OK for the rest of this? */
 116         qword_printint(f, 3600); /* an hour should be sufficient */
 117         qword_printint(f, cred->cr_remote);
 118         qword_printint(f, cred->cr_usr_root);
 119         qword_printint(f, cred->cr_usr_mds);
 120         qword_printint(f, cred->cr_usr_oss);
 121         qword_printint(f, cred->cr_mapped_uid);
 122         qword_printint(f, cred->cr_uid);
 123         qword_printint(f, cred->cr_gid);
 124         qword_print(f, mechname);
 125         qword_printhex(f, context_token->value, context_token->length);
 126         err = qword_eol(f);
 127         fclose(f);
 128         return err;
 129 out_err:
 130         printerr(0, "WARNING: downcall failed\n");
 131         return -1;
 132 }
 133
 134 struct gss_verifier {
 135         u_int32_t       flav;
 136         gss_buffer_desc body;
 137 };
 138
 139 #define RPCSEC_GSS_SEQ_WIN      5
 140
 141 static int
 142 send_response(FILE *f, gss_buffer_desc *in_handle, gss_buffer_desc *in_token,
 143               u_int32_t maj_stat, u_int32_t min_stat,
 144               gss_buffer_desc *out_handle, gss_buffer_desc *out_token)
 145 {
 146         char buf[2 * TOKEN_BUF_SIZE];
 147         char *bp = buf;
 148         int blen = sizeof(buf);
 149         /* XXXARG: */
 150         int g;
 151
 152         printerr(2, "sending reply\n");
 153         qword_addhex(&bp, &blen, in_handle->value, in_handle->length);
 154         qword_addhex(&bp, &blen, in_token->value, in_token->length);
 155         qword_addint(&bp, &blen, 3600); /* an hour should be sufficient */
 156         qword_adduint(&bp, &blen, maj_stat);
 157         qword_adduint(&bp, &blen, min_stat);
 158         qword_addhex(&bp, &blen, out_handle->value, out_handle->length);
 159         qword_addhex(&bp, &blen, out_token->value, out_token->length);
 160         qword_addeol(&bp, &blen);
 161         if (blen <= 0) {
 162                 printerr(0, "WARNING: send_response: message too long\n");
 163                 return -1;
 164         }
 165         g = open(SVCGSSD_INIT_CHANNEL, O_WRONLY);
 166         if (g == -1) {
 167                 printerr(0, "WARNING: open %s failed: %s\n",
 168                                 SVCGSSD_INIT_CHANNEL, strerror(errno));
 169                 return -1;
 170         }
 171         *bp = '\0';
 172         printerr(3, "writing message: %s", buf);
 173         if (write(g, buf, bp - buf) == -1) {
 174                 printerr(0, "WARNING: failed to write message\n");
 175                 close(g);
 176                 return -1;
 177         }
 178         close(g);
 179         return 0;
 180 }
 181
 182 #define rpc_auth_ok                     0
 183 #define rpc_autherr_badcred             1
 184 #define rpc_autherr_rejectedcred        2
 185 #define rpc_autherr_badverf             3
 186 #define rpc_autherr_rejectedverf        4
 187 #define rpc_autherr_tooweak             5
 188 #define rpcsec_gsserr_credproblem       13
 189 #define rpcsec_gsserr_ctxproblem        14
 190
 191 static int
 192 get_ids(gss_name_t client_name, gss_OID mech, struct svc_cred *cred,
 193         lnet_nid_t nid, uint32_t lustre_svc)
 194 {
 195         u_int32_t       maj_stat, min_stat;
 196         gss_buffer_desc name;
 197         char            *sname, *host, *realm;
 198         const int       namebuf_size = 512;
 199         char            namebuf[namebuf_size];
 200         int             res = -1;
 201         gss_OID         name_type = GSS_C_NO_OID;
 202         struct passwd   *pw;
 203
 204         cred->cr_remote = 0;
 205         cred->cr_usr_root = cred->cr_usr_mds = cred->cr_usr_oss = 0;
 206         cred->cr_uid = cred->cr_mapped_uid = cred->cr_gid = -1;
 207
 208         maj_stat = gss_display_name(&min_stat, client_name, &name, &name_type);
 209         if (maj_stat != GSS_S_COMPLETE) {
 210                 pgsserr("get_ids: gss_display_name",
 211                         maj_stat, min_stat, mech);
 212                 return -1;
 213         }
 214         if (name.length >= 0xffff || /* be certain name.length+1 doesn't overflow */
 215             !(sname = calloc(name.length + 1, 1))) {
 216                 printerr(0, "WARNING: get_ids: error allocating %zu bytes "
 217                         "for sname\n", name.length + 1);
 218                 gss_release_buffer(&min_stat, &name);
 219                 return -1;
 220         }
 221         memcpy(sname, name.value, name.length);
 222         sname[name.length] = '\0';
 223         gss_release_buffer(&min_stat, &name);
 224
 225         if (lustre_svc == LUSTRE_GSS_SVC_MDS)
 226                 lookup_mapping(sname, nid, &cred->cr_mapped_uid);
 227         else
 228                 cred->cr_mapped_uid = -1;
 229
 230         realm = strchr(sname, '@');
 231         if (realm) {
 232                 *realm++ = '\0';
 233         } else {
 234                 printerr(0, "ERROR: %s has no realm name\n", sname);
 235                 goto out_free;
 236         }
 237
 238         host = strchr(sname, '/');
 239         if (host)
 240                 *host++ = '\0';
 241
 242         if (strcmp(sname, GSSD_SERVICE_MGS) == 0) {
 243                 printerr(0, "forbid %s as a user name\n", sname);
 244                 goto out_free;
 245         }
 246
 247         /* 1. check host part */
 248         if (host) {
 249                 if (lnet_nid2hostname(nid, namebuf, namebuf_size)) {
 250                         printerr(0, "ERROR: failed to resolve hostname for "
 251                                  "%s/%s@%s from %016llx\n",
 252                                  sname, host, realm, nid);
 253                         goto out_free;
 254                 }
 255
 256                 if (strcasecmp(host, namebuf)) {
 257                         printerr(0, "ERROR: %s/%s@%s claimed hostname doesn't "
 258                                  "match %s, nid %016llx\n", sname, host, realm,
 259                                  namebuf, nid);
 260                         goto out_free;
 261                 }
 262         } else {
 263                 if (!strcmp(sname, GSSD_SERVICE_MDS) ||
 264                     !strcmp(sname, GSSD_SERVICE_OSS)) {
 265                         printerr(0, "ERROR: %s@%s from %016llx doesn't "
 266                                  "bind with hostname\n", sname, realm, nid);
 267                         goto out_free;
 268                 }
 269         }
 270
 271         /* 2. check realm and user */
 272         switch (lustre_svc) {
 273         case LUSTRE_GSS_SVC_MDS:
 274                 if (strcasecmp(mds_local_realm, realm)) {
 275                         cred->cr_remote = 1;
 276
 277                         /* only allow mapped user from remote realm */
 278                         if (cred->cr_mapped_uid == -1) {
 279                                 printerr(0, "ERROR: %s%s%s@%s from %016llx "
 280                                          "is remote but without mapping\n",
 281                                          sname, host ? "/" : "",
 282                                          host ? host : "", realm, nid);
 283                                 break;
 284                         }
 285                 } else {
 286                         if (!strcmp(sname, LUSTRE_ROOT_NAME)) {
 287                                 cred->cr_uid = 0;
 288                                 cred->cr_usr_root = 1;
 289                         } else if (!strcmp(sname, GSSD_SERVICE_MDS)) {
 290                                 cred->cr_uid = 0;
 291                                 cred->cr_usr_mds = 1;
 292                         } else if (!strcmp(sname, GSSD_SERVICE_OSS)) {
 293                                 cred->cr_uid = 0;
 294                                 cred->cr_usr_oss = 1;
 295                         } else {
 296                                 pw = getpwnam(sname);
 297                                 if (pw != NULL) {
 298                                         cred->cr_uid = pw->pw_uid;
 299                                         printerr(2, "%s resolve to uid %u\n",
 300                                                  sname, cred->cr_uid);
 301                                 } else if (cred->cr_mapped_uid != -1) {
 302                                         printerr(2, "user %s from %016llx is "
 303                                                  "mapped to %u\n", sname, nid,
 304                                                  cred->cr_mapped_uid);
 305                                 } else {
 306                                         printerr(0, "ERROR: invalid user, "
 307                                                  "%s/%s@%s from %016llx\n",
 308                                                  sname, host, realm, nid);
 309                                         break;
 310                                 }
 311                         }
 312                 }
 313
 314                 res = 0;
 315                 break;
 316         case LUSTRE_GSS_SVC_MGS:
 317                 if (!strcmp(sname, GSSD_SERVICE_OSS)) {
 318                         cred->cr_uid = 0;
 319                         cred->cr_usr_oss = 1;
 320                 }
 321                 /* fall through */
 322         case LUSTRE_GSS_SVC_OSS:
 323                 if (!strcmp(sname, LUSTRE_ROOT_NAME)) {
 324                         cred->cr_uid = 0;
 325                         cred->cr_usr_root = 1;
 326                 } else if (!strcmp(sname, GSSD_SERVICE_MDS)) {
 327                         cred->cr_uid = 0;
 328                         cred->cr_usr_mds = 1;
 329                 }
 330                 if (cred->cr_uid == -1) {
 331                         printerr(0, "ERROR: svc %d doesn't accept user %s "
 332                                  "from %016llx\n", lustre_svc, sname, nid);
 333                         break;
 334                 }
 335                 res = 0;
 336                 break;
 337         default:
 338                 assert(0);
 339         }
 340
 341 out_free:
 342         if (!res)
 343                 printerr(1, "%s: authenticated %s%s%s@%s from %016llx\n",
 344                          lustre_svc_name[lustre_svc], sname,
 345                          host ? "/" : "", host ? host : "", realm, nid);
 346         free(sname);
 347         return res;
 348 }
 349
 350 typedef struct gss_union_ctx_id_t {
 351         gss_OID         mech_type;
 352         gss_ctx_id_t    internal_ctx_id;
 353 } gss_union_ctx_id_desc, *gss_union_ctx_id_t;
 354
 355 int handle_sk(struct svc_nego_data *snd)
 356 {
 357 #ifdef HAVE_OPENSSL_SSK
 358         struct sk_cred *skc = NULL;
 359         struct svc_cred cred;
 360         gss_buffer_desc bufs[SK_INIT_BUFFERS];
 361         gss_buffer_desc remote_pub_key = GSS_C_EMPTY_BUFFER;
 362         char *target;
 363         uint32_t rc = GSS_S_DEFECTIVE_TOKEN;
 364         uint32_t version;
 365         uint32_t flags;
 366         int i;
 367
 368         printerr(3, "Handling sk request\n");
 369         memset(bufs, 0, sizeof(gss_buffer_desc) * SK_INIT_BUFFERS);
 370
 371         /* See lgss_sk_using_cred() for client side token formation.
 372          * Decoding initiator buffers */
 373         i = sk_decode_netstring(bufs, SK_INIT_BUFFERS, &snd->in_tok);
 374         if (i < SK_INIT_BUFFERS) {
 375                 printerr(0, "Invalid netstring token received from peer\n");
 376                 goto cleanup_buffers;
 377         }
 378
 379         /* Allowing for a larger length first buffer in the future */
 380         if (bufs[SK_INIT_VERSION].length < sizeof(version)) {
 381                 printerr(0, "Invalid version received (wrong size)\n");
 382                 goto cleanup_buffers;
 383         }
 384         memcpy(&version, bufs[SK_INIT_VERSION].value, sizeof(version));
 385         version = be32toh(version);
 386         if (version != SK_MSG_VERSION) {
 387                 printerr(0, "Invalid version received: %d\n", version);
 388                 goto cleanup_buffers;
 389         }
 390
 391         rc = GSS_S_FAILURE;
 392
 393         /* target must be a null terminated string */
 394         i = bufs[SK_INIT_TARGET].length - 1;
 395         target = bufs[SK_INIT_TARGET].value;
 396         if (i >= 0 && target[i] != '\0') {
 397                 printerr(0, "Invalid target from netstring\n");
 398                 goto cleanup_buffers;
 399         }
 400
 401         if (bufs[SK_INIT_FLAGS].length != sizeof(flags)) {
 402                 printerr(0, "Invalid flags from netstring\n");
 403                 goto cleanup_buffers;
 404         }
 405         memcpy(&flags, bufs[SK_INIT_FLAGS].value, sizeof(flags));
 406
 407         skc = sk_create_cred(target, snd->nm_name, be32toh(flags));
 408         if (!skc) {
 409                 printerr(0, "Failed to create sk credentials\n");
 410                 goto cleanup_buffers;
 411         }
 412
 413         /* Verify that the peer has used a prime size greater or equal to
 414          * the size specified in the key file which may contain only zero
 415          * fill but the size specifies the mimimum supported size on
 416          * servers */
 417         if (skc->sc_flags & LGSS_SVC_PRIV &&
 418             bufs[SK_INIT_P].length < skc->sc_p.length) {
 419                 printerr(0, "Peer DHKE prime does not meet the size required "
 420                          "by keyfile: %zd bits\n", skc->sc_p.length * 8);
 421                 goto cleanup_buffers;
 422         }
 423
 424         /* Throw out the p from the server and use the wire data */
 425         free(skc->sc_p.value);
 426         skc->sc_p.value = NULL;
 427         skc->sc_p.length = 0;
 428
 429         /* Take control of all the allocated buffers from decoding */
 430         if (bufs[SK_INIT_RANDOM].length !=
 431             sizeof(skc->sc_kctx.skc_peer_random)) {
 432                 printerr(0, "Invalid size for client random\n");
 433                 goto cleanup_buffers;
 434         }
 435
 436         memcpy(&skc->sc_kctx.skc_peer_random, bufs[SK_INIT_RANDOM].value,
 437                sizeof(skc->sc_kctx.skc_peer_random));
 438         skc->sc_p = bufs[SK_INIT_P];
 439         remote_pub_key = bufs[SK_INIT_PUB_KEY];
 440         skc->sc_nodemap_hash = bufs[SK_INIT_NODEMAP];
 441         skc->sc_hmac = bufs[SK_INIT_HMAC];
 442
 443         /* Verify HMAC from peer.  Ideally this would happen before anything
 444          * else but we don't have enough information to lookup key without the
 445          * token (fsname and cluster_hash) so it's done after. */
 446         rc = sk_verify_hmac(skc, bufs, SK_INIT_BUFFERS - 1, EVP_sha256(),
 447                             &skc->sc_hmac);
 448         if (rc != GSS_S_COMPLETE) {
 449                 printerr(0, "HMAC verification error: 0x%x from peer %s\n",
 450                          rc, libcfs_nid2str((lnet_nid_t)snd->nid));
 451                 goto cleanup_partial;
 452         }
 453
 454         /* Check that the cluster hash matches the hash of nodemap name */
 455         rc = sk_verify_hash(snd->nm_name, EVP_sha256(), &skc->sc_nodemap_hash);
 456         if (rc != GSS_S_COMPLETE) {
 457                 printerr(0, "Cluster hash failed validation: 0x%x\n", rc);
 458                 goto cleanup_partial;
 459         }
 460
 461         rc = sk_gen_params(skc);
 462         if (rc != GSS_S_COMPLETE) {
 463                 printerr(0, "Failed to generate DH params for responder\n");
 464                 goto cleanup_partial;
 465         }
 466         if (sk_compute_dh_key(skc, &remote_pub_key)) {
 467                 printerr(0, "Failed to compute session key from DH params\n");
 468                 goto cleanup_partial;
 469         }
 470
 471         /* Cleanup init buffers we have copied or don't need anymore */
 472         free(bufs[SK_INIT_VERSION].value);
 473         free(bufs[SK_INIT_RANDOM].value);
 474         free(bufs[SK_INIT_TARGET].value);
 475         free(bufs[SK_INIT_FLAGS].value);
 476
 477         /* Server reply contains the servers public key, random,  and HMAC */
 478         version = htobe32(SK_MSG_VERSION);
 479         bufs[SK_RESP_VERSION].value = &version;
 480         bufs[SK_RESP_VERSION].length = sizeof(version);
 481         bufs[SK_RESP_RANDOM].value = &skc->sc_kctx.skc_host_random;
 482         bufs[SK_RESP_RANDOM].length = sizeof(skc->sc_kctx.skc_host_random);
 483         bufs[SK_RESP_PUB_KEY] = skc->sc_pub_key;
 484         if (sk_sign_bufs(&skc->sc_kctx.skc_shared_key, bufs,
 485                          SK_RESP_BUFFERS - 1, EVP_sha256(),
 486                          &skc->sc_hmac)) {
 487                 printerr(0, "Failed to sign parameters\n");
 488                 goto out_err;
 489         }
 490         bufs[SK_RESP_HMAC] = skc->sc_hmac;
 491         if (sk_encode_netstring(bufs, SK_RESP_BUFFERS, &snd->out_tok)) {
 492                 printerr(0, "Failed to encode netstring for token\n");
 493                 goto out_err;
 494         }
 495         printerr(2, "Created netstring of %zd bytes\n", snd->out_tok.length);
 496
 497         if (sk_session_kdf(skc, snd->nid, &snd->in_tok, &snd->out_tok)) {
 498                 printerr(0, "Failed to calulate derviced session key\n");
 499                 goto out_err;
 500         }
 501         if (sk_compute_keys(skc)) {
 502                 printerr(0, "Failed to compute HMAC and encryption keys\n");
 503                 goto out_err;
 504         }
 505         if (sk_serialize_kctx(skc, &snd->ctx_token)) {
 506                 printerr(0, "Failed to serialize context for kernel\n");
 507                 goto out_err;
 508         }
 509
 510         snd->out_handle.length = sizeof(snd->handle_seq);
 511         memcpy(snd->out_handle.value, &snd->handle_seq,
 512                sizeof(snd->handle_seq));
 513         snd->maj_stat = GSS_S_COMPLETE;
 514
 515         /* fix credentials */
 516         memset(&cred, 0, sizeof(cred));
 517         cred.cr_mapped_uid = -1;
 518
 519         if (skc->sc_flags & LGSS_ROOT_CRED_ROOT)
 520                 cred.cr_usr_root = 1;
 521         if (skc->sc_flags & LGSS_ROOT_CRED_MDT)
 522                 cred.cr_usr_mds = 1;
 523         if (skc->sc_flags & LGSS_ROOT_CRED_OST)
 524                 cred.cr_usr_oss = 1;
 525
 526         do_svc_downcall(&snd->out_handle, &cred, snd->mech, &snd->ctx_token);
 527
 528         /* cleanup ctx_token, out_tok is cleaned up in handle_channel_req */
 529         free(remote_pub_key.value);
 530         free(snd->ctx_token.value);
 531         snd->ctx_token.length = 0;
 532
 533         printerr(3, "sk returning success\n");
 534         return 0;
 535
 536 cleanup_buffers:
 537         for (i = 0; i < SK_INIT_BUFFERS; i++)
 538                 free(bufs[i].value);
 539         sk_free_cred(skc);
 540         snd->maj_stat = rc;
 541         return -1;
 542
 543 cleanup_partial:
 544         free(bufs[SK_INIT_VERSION].value);
 545         free(bufs[SK_INIT_RANDOM].value);
 546         free(bufs[SK_INIT_TARGET].value);
 547         free(bufs[SK_INIT_FLAGS].value);
 548         free(remote_pub_key.value);
 549         sk_free_cred(skc);
 550         snd->maj_stat = rc;
 551         return -1;
 552
 553 out_err:
 554         snd->maj_stat = rc;
 555         if (snd->ctx_token.value) {
 556                 free(snd->ctx_token.value);
 557                 snd->ctx_token.value = 0;
 558                 snd->ctx_token.length = 0;
 559         }
 560         free(remote_pub_key.value);
 561         sk_free_cred(skc);
 562         printerr(3, "sk returning failure\n");
 563 #else /* !HAVE_OPENSSL_SSK */
 564         printerr(0, "ERROR: shared key subflavour is not enabled\n");
 565 #endif /* HAVE_OPENSSL_SSK */
 566         return -1;
 567 }
 568
 569 int handle_null(struct svc_nego_data *snd)
 570 {
 571         struct svc_cred cred;
 572         uint64_t tmp;
 573         uint32_t flags;
 574
 575         /* null just uses the same token as the return token and for
 576          * for sending to the kernel.  It is a single uint64_t. */
 577         if (snd->in_tok.length != sizeof(uint64_t)) {
 578                 snd->maj_stat = GSS_S_DEFECTIVE_TOKEN;
 579                 printerr(0, "Invalid token size (%zd) received\n",
 580                          snd->in_tok.length);
 581                 return -1;
 582         }
 583         snd->out_tok.length = snd->in_tok.length;
 584         snd->out_tok.value = malloc(snd->out_tok.length);
 585         if (!snd->out_tok.value) {
 586                 snd->maj_stat = GSS_S_FAILURE;
 587                 printerr(0, "Failed to allocate out_tok\n");
 588                 return -1;
 589         }
 590
 591         snd->ctx_token.length = snd->in_tok.length;
 592         snd->ctx_token.value = malloc(snd->ctx_token.length);
 593         if (!snd->ctx_token.value) {
 594                 snd->maj_stat = GSS_S_FAILURE;
 595                 printerr(0, "Failed to allocate ctx_token\n");
 596                 return -1;
 597         }
 598
 599         snd->out_handle.length = sizeof(snd->handle_seq);
 600         memcpy(snd->out_handle.value, &snd->handle_seq,
 601                sizeof(snd->handle_seq));
 602         snd->maj_stat = GSS_S_COMPLETE;
 603
 604         memcpy(&tmp, snd->in_tok.value, sizeof(tmp));
 605         tmp = be64toh(tmp);
 606         flags = (uint32_t)(tmp & 0x00000000ffffffff);
 607         memset(&cred, 0, sizeof(cred));
 608         cred.cr_mapped_uid = -1;
 609
 610         if (flags & LGSS_ROOT_CRED_ROOT)
 611                 cred.cr_usr_root = 1;
 612         if (flags & LGSS_ROOT_CRED_MDT)
 613                 cred.cr_usr_mds = 1;
 614         if (flags & LGSS_ROOT_CRED_OST)
 615                 cred.cr_usr_oss = 1;
 616
 617         do_svc_downcall(&snd->out_handle, &cred, snd->mech, &snd->ctx_token);
 618
 619         /* cleanup ctx_token, out_tok is cleaned up in handle_channel_req */
 620         free(snd->ctx_token.value);
 621         snd->ctx_token.length = 0;
 622
 623         return 0;
 624 }
 625
 626 static int handle_krb(struct svc_nego_data *snd)
 627 {
 628         u_int32_t               ret_flags;
 629         gss_name_t              client_name;
 630         gss_buffer_desc         ignore_out_tok = {.value = NULL};
 631         gss_OID                 mech = GSS_C_NO_OID;
 632         gss_cred_id_t           svc_cred;
 633         u_int32_t               ignore_min_stat;
 634         struct svc_cred         cred;
 635
 636         svc_cred = gssd_select_svc_cred(snd->lustre_svc);
 637         if (!svc_cred) {
 638                 printerr(0, "no service credential for svc %u\n",
 639                          snd->lustre_svc);
 640                 goto out_err;
 641         }
 642
 643         snd->maj_stat = gss_accept_sec_context(&snd->min_stat, &snd->ctx,
 644                                                svc_cred, &snd->in_tok,
 645                                                GSS_C_NO_CHANNEL_BINDINGS,
 646                                                &client_name, &mech,
 647                                                &snd->out_tok, &ret_flags, NULL,
 648                                                NULL);
 649
 650         if (snd->maj_stat == GSS_S_CONTINUE_NEEDED) {
 651                 printerr(1, "gss_accept_sec_context GSS_S_CONTINUE_NEEDED\n");
 652
 653                 /* Save the context handle for future calls */
 654                 snd->out_handle.length = sizeof(snd->ctx);
 655                 memcpy(snd->out_handle.value, &snd->ctx, sizeof(snd->ctx));
 656                 return 0;
 657         } else if (snd->maj_stat != GSS_S_COMPLETE) {
 658                 printerr(0, "WARNING: gss_accept_sec_context failed\n");
 659                 pgsserr("handle_krb: gss_accept_sec_context",
 660                         snd->maj_stat, snd->min_stat, mech);
 661                 goto out_err;
 662         }
 663
 664         if (get_ids(client_name, mech, &cred, snd->nid, snd->lustre_svc)) {
 665                 /* get_ids() prints error msg */
 666                 snd->maj_stat = GSS_S_BAD_NAME; /* XXX ? */
 667                 gss_release_name(&ignore_min_stat, &client_name);
 668                 goto out_err;
 669         }
 670         gss_release_name(&ignore_min_stat, &client_name);
 671
 672         /* Context complete. Pass handle_seq in out_handle to use
 673          * for context lookup in the kernel. */
 674         snd->out_handle.length = sizeof(snd->handle_seq);
 675         memcpy(snd->out_handle.value, &snd->handle_seq,
 676                sizeof(snd->handle_seq));
 677
 678         /* kernel needs ctx to calculate verifier on null response, so
 679          * must give it context before doing null call: */
 680         if (serialize_context_for_kernel(snd->ctx, &snd->ctx_token, mech)) {
 681                 printerr(0, "WARNING: handle_krb: "
 682                          "serialize_context_for_kernel failed\n");
 683                 snd->maj_stat = GSS_S_FAILURE;
 684                 goto out_err;
 685         }
 686         /* We no longer need the gss context */
 687         gss_delete_sec_context(&ignore_min_stat, &snd->ctx, &ignore_out_tok);
 688         do_svc_downcall(&snd->out_handle, &cred, mech, &snd->ctx_token);
 689
 690         return 0;
 691
 692 out_err:
 693         if (snd->ctx != GSS_C_NO_CONTEXT)
 694                 gss_delete_sec_context(&ignore_min_stat, &snd->ctx,
 695                                        &ignore_out_tok);
 696
 697         return 1;
 698 }
 699
 700 /*
 701  * return -1 only if we detect error during reading from upcall channel,
 702  * all other cases return 0.
 703  */
 704 int handle_channel_request(FILE *f)
 705 {
 706         char                    in_tok_buf[TOKEN_BUF_SIZE];
 707         char                    in_handle_buf[15];
 708         char                    out_handle_buf[15];
 709         gss_buffer_desc         ctx_token      = {.value = NULL},
 710                                 null_token     = {.value = NULL};
 711         uint32_t                lustre_mech;
 712         static char             *lbuf;
 713         static int              lbuflen;
 714         static char             *cp;
 715         int                     get_len;
 716         int                     rc = 1;
 717         u_int32_t               ignore_min_stat;
 718         struct svc_nego_data    snd = {
 719                 .in_tok.value           = in_tok_buf,
 720                 .in_handle.value        = in_handle_buf,
 721                 .out_handle.value       = out_handle_buf,
 722                 .maj_stat               = GSS_S_FAILURE,
 723                 .ctx                    = GSS_C_NO_CONTEXT,
 724         };
 725
 726         printerr(2, "handling request\n");
 727         if (readline(fileno(f), &lbuf, &lbuflen) != 1) {
 728                 printerr(0, "WARNING: failed reading request\n");
 729                 return -1;
 730         }
 731
 732         cp = lbuf;
 733
 734         /* see rsi_request() for the format of data being input here */
 735         qword_get(&cp, (char *)&snd.lustre_svc, sizeof(snd.lustre_svc));
 736
 737         /* lustre_svc is the svc and gss subflavor */
 738         lustre_mech = (snd.lustre_svc & LUSTRE_GSS_MECH_MASK) >>
 739                       LUSTRE_GSS_MECH_SHIFT;
 740         snd.lustre_svc = snd.lustre_svc & LUSTRE_GSS_SVC_MASK;
 741         switch (lustre_mech) {
 742         case LGSS_MECH_KRB5:
 743                 if (!krb_enabled) {
 744                         static time_t next_krb;
 745
 746                         if (time(NULL) > next_krb) {
 747                                 printerr(1, "warning: Request for kerberos but "
 748                                          "service support not enabled\n");
 749                                 next_krb = time(NULL) + 3600;
 750                         }
 751                         goto ignore;
 752                 }
 753                 snd.mech = &krb5oid;
 754                 break;
 755         case LGSS_MECH_NULL:
 756                 if (!null_enabled) {
 757                         static time_t next_null;
 758
 759                         if (time(NULL) > next_null) {
 760                                 printerr(1, "warning: Request for gssnull but "
 761                                          "service support not enabled\n");
 762                                 next_null = time(NULL) + 3600;
 763                         }
 764                         goto ignore;
 765                 }
 766                 snd.mech = &nulloid;
 767                 break;
 768         case LGSS_MECH_SK:
 769                 if (!sk_enabled) {
 770                         static time_t next_ssk;
 771
 772                         if (time(NULL) > next_ssk) {
 773                                 printerr(1, "warning: Request for SSK but "
 774                                          "service support not %s\n",
 775 #ifdef HAVE_OPENSSL_SSK
 776                                          "enabled"
 777 #else
 778                                          "included"
 779 #endif
 780                                         );
 781                                 next_ssk = time(NULL) + 3600;
 782                         }
 783
 784                         goto ignore;
 785                 }
 786                 snd.mech = &skoid;
 787                 break;
 788         default:
 789                 printerr(0, "WARNING: invalid mechanism recevied: %d\n",
 790                          lustre_mech);
 791                 goto out_err;
 792                 break;
 793         }
 794
 795         qword_get(&cp, (char *)&snd.nid, sizeof(snd.nid));
 796         qword_get(&cp, (char *)&snd.handle_seq, sizeof(snd.handle_seq));
 797         qword_get(&cp, snd.nm_name, sizeof(snd.nm_name));
 798         printerr(2, "handling req: svc %u, nid %016llx, idx %"PRIx64" nodemap "
 799                  "%s\n", snd.lustre_svc, snd.nid, snd.handle_seq, snd.nm_name);
 800
 801         get_len = qword_get(&cp, snd.in_handle.value, sizeof(in_handle_buf));
 802         if (get_len < 0) {
 803                 printerr(0, "WARNING: failed parsing request\n");
 804                 goto out_err;
 805         }
 806         snd.in_handle.length = (size_t)get_len;
 807
 808         printerr(3, "in_handle:\n");
 809         print_hexl(3, snd.in_handle.value, snd.in_handle.length);
 810
 811         get_len = qword_get(&cp, snd.in_tok.value, sizeof(in_tok_buf));
 812         if (get_len < 0) {
 813                 printerr(0, "WARNING: failed parsing request\n");
 814                 goto out_err;
 815         }
 816         snd.in_tok.length = (size_t)get_len;
 817
 818         printerr(3, "in_tok:\n");
 819         print_hexl(3, snd.in_tok.value, snd.in_tok.length);
 820
 821         if (snd.in_handle.length != 0) { /* CONTINUE_INIT case */
 822                 if (snd.in_handle.length != sizeof(snd.ctx)) {
 823                         printerr(0, "WARNING: input handle has unexpected "
 824                                  "length %zu\n", snd.in_handle.length);
 825                         goto out_err;
 826                 }
 827                 /* in_handle is the context id stored in the out_handle
 828                  * for the GSS_S_CONTINUE_NEEDED case below.  */
 829                 memcpy(&snd.ctx, snd.in_handle.value, snd.in_handle.length);
 830         }
 831
 832         if (lustre_mech == LGSS_MECH_KRB5)
 833                 rc = handle_krb(&snd);
 834         else if (lustre_mech == LGSS_MECH_SK)
 835                 rc = handle_sk(&snd);
 836         else if (lustre_mech == LGSS_MECH_NULL)
 837                 rc = handle_null(&snd);
 838         else
 839                 printerr(0, "WARNING: Received or request for"
 840                          "subflavor that is not enabled: %d\n", lustre_mech);
 841
 842 out_err:
 843         /* Failures send a null token */
 844         if (rc == 0)
 845                 send_response(f, &snd.in_handle, &snd.in_tok, snd.maj_stat,
 846                               snd.min_stat, &snd.out_handle, &snd.out_tok);
 847         else
 848                 send_response(f, &snd.in_handle, &snd.in_tok, snd.maj_stat,
 849                               snd.min_stat, &null_token, &null_token);
 850
 851         /* cleanup buffers */
 852         if (snd.ctx_token.value != NULL)
 853                 free(ctx_token.value);
 854         if (snd.out_tok.value != NULL)
 855                 gss_release_buffer(&ignore_min_stat, &snd.out_tok);
 856
 857         /* For junk wire data just ignore */
 858 ignore:
 859         return 0;
 860 }