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
  36 #include <sys/param.h>
  37 #include <sys/stat.h>
  38
  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 #include <netdb.h>
  47
  48 #include "svcgssd.h"
  49 #include "gss_util.h"
  50 #include "err_util.h"
  51 #include "context.h"
  52 #include "cacheio.h"
  53 #include "lsupport.h"
  54
  55 extern char * mech2file(gss_OID mech);
  56 #define SVCGSSD_CONTEXT_CHANNEL "/proc/net/rpc/auth.ptlrpcs.context/channel"
  57 #define SVCGSSD_INIT_CHANNEL    "/proc/net/rpc/auth.ptlrpcs.init/channel"
  58
  59 #define TOKEN_BUF_SIZE          8192
  60
  61 struct svc_cred {
  62         uint32_t cr_remote;
  63         uint32_t cr_usr_root;
  64         uint32_t cr_usr_mds;
  65         uid_t    cr_uid;
  66         uid_t    cr_mapped_uid;
  67         uid_t    cr_gid;
  68 };
  69
  70 static int
  71 do_svc_downcall(gss_buffer_desc *out_handle, struct svc_cred *cred,
  72                 gss_OID mech, gss_buffer_desc *context_token)
  73 {
  74         FILE *f;
  75         char *fname = NULL;
  76         int err;
  77
  78         printerr(2, "doing downcall\n");
  79         if ((fname = mech2file(mech)) == NULL)
  80                 goto out_err;
  81         f = fopen(SVCGSSD_CONTEXT_CHANNEL, "w");
  82         if (f == NULL) {
  83                 printerr(0, "WARNING: unable to open downcall channel "
  84                              "%s: %s\n",
  85                              SVCGSSD_CONTEXT_CHANNEL, strerror(errno));
  86                 goto out_err;
  87         }
  88         qword_printhex(f, out_handle->value, out_handle->length);
  89         /* XXX are types OK for the rest of this? */
  90         qword_printint(f, 0x7fffffff); /*XXX need a better timeout */
  91         qword_printint(f, cred->cr_remote);
  92         qword_printint(f, cred->cr_usr_root);
  93         qword_printint(f, cred->cr_usr_mds);
  94         qword_printint(f, cred->cr_mapped_uid);
  95         qword_printint(f, cred->cr_uid);
  96         qword_printint(f, cred->cr_gid);
  97         qword_print(f, fname);
  98         qword_printhex(f, context_token->value, context_token->length);
  99         err = qword_eol(f);
 100         fclose(f);
 101         return err;
 102 out_err:
 103         printerr(0, "WARNING: downcall failed\n");
 104         return -1;
 105 }
 106
 107 struct gss_verifier {
 108         u_int32_t       flav;
 109         gss_buffer_desc body;
 110 };
 111
 112 #define RPCSEC_GSS_SEQ_WIN      5
 113
 114 static int
 115 send_response(FILE *f, gss_buffer_desc *in_handle, gss_buffer_desc *in_token,
 116               u_int32_t maj_stat, u_int32_t min_stat,
 117               gss_buffer_desc *out_handle, gss_buffer_desc *out_token)
 118 {
 119         char buf[2 * TOKEN_BUF_SIZE];
 120         char *bp = buf;
 121         int blen = sizeof(buf);
 122         /* XXXARG: */
 123         int g;
 124
 125         printerr(2, "sending null reply\n");
 126
 127         qword_addhex(&bp, &blen, in_handle->value, in_handle->length);
 128         qword_addhex(&bp, &blen, in_token->value, in_token->length);
 129         qword_addint(&bp, &blen, 0x7fffffff); /*XXX need a better timeout */
 130         qword_adduint(&bp, &blen, maj_stat);
 131         qword_adduint(&bp, &blen, min_stat);
 132         qword_addhex(&bp, &blen, out_handle->value, out_handle->length);
 133         qword_addhex(&bp, &blen, out_token->value, out_token->length);
 134         qword_addeol(&bp, &blen);
 135         if (blen <= 0) {
 136                 printerr(0, "WARNING: send_respsonse: message too long\n");
 137                 return -1;
 138         }
 139         g = open(SVCGSSD_INIT_CHANNEL, O_WRONLY);
 140         if (g == -1) {
 141                 printerr(0, "WARNING: open %s failed: %s\n",
 142                                 SVCGSSD_INIT_CHANNEL, strerror(errno));
 143                 return -1;
 144         }
 145         *bp = '\0';
 146         printerr(3, "writing message: %s", buf);
 147         if (write(g, buf, bp - buf) == -1) {
 148                 printerr(0, "WARNING: failed to write message\n");
 149                 close(g);
 150                 return -1;
 151         }
 152         close(g);
 153         return 0;
 154 }
 155
 156 #define rpc_auth_ok                     0
 157 #define rpc_autherr_badcred             1
 158 #define rpc_autherr_rejectedcred        2
 159 #define rpc_autherr_badverf             3
 160 #define rpc_autherr_rejectedverf        4
 161 #define rpc_autherr_tooweak             5
 162 #define rpcsec_gsserr_credproblem       13
 163 #define rpcsec_gsserr_ctxproblem        14
 164
 165 #if 0
 166 static void
 167 add_supplementary_groups(char *secname, char *name, struct svc_cred *cred)
 168 {
 169         int ret;
 170         static gid_t *groups = NULL;
 171
 172         cred->cr_ngroups = NGROUPS;
 173         ret = nfs4_gss_princ_to_grouplist(secname, name,
 174                         cred->cr_groups, &cred->cr_ngroups);
 175         if (ret < 0) {
 176                 groups = realloc(groups, cred->cr_ngroups*sizeof(gid_t));
 177                 ret = nfs4_gss_princ_to_grouplist(secname, name,
 178                                 groups, &cred->cr_ngroups);
 179                 if (ret < 0)
 180                         cred->cr_ngroups = 0;
 181                 else {
 182                         if (cred->cr_ngroups > NGROUPS)
 183                                 cred->cr_ngroups = NGROUPS;
 184                         memcpy(cred->cr_groups, groups,
 185                                         cred->cr_ngroups*sizeof(gid_t));
 186                 }
 187         }
 188 }
 189 #endif
 190
 191 #if 0
 192 static int
 193 get_ids(gss_name_t client_name, gss_OID mech, struct svc_cred *cred)
 194 {
 195         u_int32_t       maj_stat, min_stat;
 196         gss_buffer_desc name;
 197         char            *sname;
 198         int             res = -1;
 199         uid_t           uid, gid;
 200         gss_OID         name_type = GSS_C_NO_OID;
 201         char            *secname;
 202
 203         maj_stat = gss_display_name(&min_stat, client_name, &name, &name_type);
 204         if (maj_stat != GSS_S_COMPLETE) {
 205                 pgsserr("get_ids: gss_display_name",
 206                         maj_stat, min_stat, mech);
 207                 goto out;
 208         }
 209         if (name.length >= 0xffff || /* be certain name.length+1 doesn't overflow */
 210             !(sname = calloc(name.length + 1, 1))) {
 211                 printerr(0, "WARNING: get_ids: error allocating %d bytes "
 212                         "for sname\n", name.length + 1);
 213                 gss_release_buffer(&min_stat, &name);
 214                 goto out;
 215         }
 216         memcpy(sname, name.value, name.length);
 217         printerr(1, "sname = %s\n", sname);
 218         gss_release_buffer(&min_stat, &name);
 219
 220         res = -EINVAL;
 221         if ((secname = mech2file(mech)) == NULL) {
 222                 printerr(0, "WARNING: get_ids: error mapping mech to "
 223                         "file for name '%s'\n", sname);
 224                 goto out_free;
 225         }
 226         nfs4_init_name_mapping(NULL); /* XXX: should only do this once */
 227         res = nfs4_gss_princ_to_ids(secname, sname, &uid, &gid);
 228         if (res < 0) {
 229                 /*
 230                  * -ENOENT means there was no mapping, any other error
 231                  * value means there was an error trying to do the
 232                  * mapping.
 233                  * If there was no mapping, we send down the value -1
 234                  * to indicate that the anonuid/anongid for the export
 235                  * should be used.
 236                  */
 237                 if (res == -ENOENT) {
 238                         cred->cr_uid = -1;
 239                         cred->cr_gid = -1;
 240                         cred->cr_ngroups = 0;
 241                         res = 0;
 242                         goto out_free;
 243                 }
 244                 printerr(0, "WARNING: get_ids: failed to map name '%s' "
 245                         "to uid/gid: %s\n", sname, strerror(-res));
 246                 goto out_free;
 247         }
 248         cred->cr_uid = uid;
 249         cred->cr_gid = gid;
 250         add_supplementary_groups(secname, sname, cred);
 251         res = 0;
 252 out_free:
 253         free(sname);
 254 out:
 255         return res;
 256 }
 257 #endif
 258
 259 #if 0
 260 void
 261 print_hexl(int pri, unsigned char *cp, int length)
 262 {
 263         int i, j, jm;
 264         unsigned char c;
 265
 266         printerr(pri, "length %d\n",length);
 267         printerr(pri, "\n");
 268
 269         for (i = 0; i < length; i += 0x10) {
 270                 printerr(pri, "  %04x: ", (u_int)i);
 271                 jm = length - i;
 272                 jm = jm > 16 ? 16 : jm;
 273
 274                 for (j = 0; j < jm; j++) {
 275                         if ((j % 2) == 1)
 276                                 printerr(pri,"%02x ", (u_int)cp[i+j]);
 277                         else
 278                                 printerr(pri,"%02x", (u_int)cp[i+j]);
 279                 }
 280                 for (; j < 16; j++) {
 281                         if ((j % 2) == 1)
 282                                 printerr(pri,"   ");
 283                         else
 284                                 printerr(pri,"  ");
 285                 }
 286                 printerr(pri," ");
 287
 288                 for (j = 0; j < jm; j++) {
 289                         c = cp[i+j];
 290                         c = isprint(c) ? c : '.';
 291                         printerr(pri,"%c", c);
 292                 }
 293                 printerr(pri,"\n");
 294         }
 295 }
 296 #endif
 297
 298 static int
 299 get_ids(gss_name_t client_name, gss_OID mech, struct svc_cred *cred,
 300         lnet_nid_t nid, uint32_t lustre_svc)
 301 {
 302         u_int32_t       maj_stat, min_stat;
 303         gss_buffer_desc name;
 304         char            *sname, *realm, *slash;
 305         int             res = -1;
 306         gss_OID         name_type = GSS_C_NO_OID;
 307         struct passwd   *pw;
 308
 309         cred->cr_remote = cred->cr_usr_root = cred->cr_usr_mds = 0;
 310         cred->cr_uid = cred->cr_mapped_uid = cred->cr_gid = -1;
 311
 312         maj_stat = gss_display_name(&min_stat, client_name, &name, &name_type);
 313         if (maj_stat != GSS_S_COMPLETE) {
 314                 pgsserr("get_ids: gss_display_name",
 315                         maj_stat, min_stat, mech);
 316                 return -1;
 317         }
 318         if (name.length >= 0xffff || /* be certain name.length+1 doesn't overflow */
 319             !(sname = calloc(name.length + 1, 1))) {
 320                 printerr(0, "WARNING: get_ids: error allocating %d bytes "
 321                         "for sname\n", name.length + 1);
 322                 gss_release_buffer(&min_stat, &name);
 323                 return -1;
 324         }
 325         memcpy(sname, name.value, name.length);
 326         printerr(1, "authenticated %s from %016llx\n", sname, nid);
 327         gss_release_buffer(&min_stat, &name);
 328
 329         if (lustre_svc == LUSTRE_GSS_SVC_MDS)
 330                 lookup_mapping(sname, nid, &cred->cr_mapped_uid);
 331         else
 332                 cred->cr_mapped_uid = -1;
 333
 334         realm = strchr(sname, '@');
 335         if (!realm) {
 336                 printerr(0, "WARNNING: principal %s contains no realm name\n",
 337                          sname);
 338                 cred->cr_remote = (mds_local_realm != NULL);
 339         } else {
 340                 *realm++ = '\0';
 341                 if (!mds_local_realm)
 342                         cred->cr_remote = 1;
 343                 else
 344                         cred->cr_remote =
 345                                 (strcasecmp(mds_local_realm, realm) != 0);
 346         }
 347
 348         if (cred->cr_remote) {
 349                 if (cred->cr_mapped_uid != -1)
 350                         res = 0;
 351                 else if (lustre_svc == LUSTRE_GSS_SVC_OSS &&
 352                          strcmp(sname, "lustre_root") == 0)
 353                         res = 0;
 354                 else
 355                         printerr(0, "principal %s is remote without mapping\n",
 356                                  sname);
 357                 goto out_free;
 358         }
 359
 360         slash = strchr(sname, '/');
 361         if (slash)
 362                 *slash = '\0';
 363
 364         if (!(pw = getpwnam(sname))) {
 365                 /* If client use machine credential, we map it to root, which
 366                  * will subject to further mapping by root-squash in kernel.
 367                  *
 368                  * MDS service keytab is treated as special user, also mapped
 369                  * to root. OSS service keytab can't be used as a user.
 370                  */
 371                 if (!strcmp(sname, LUSTRE_ROOT_NAME)) {
 372                         printerr(2, "lustre_root principal, resolve to uid 0\n");
 373                         cred->cr_uid = 0;
 374                         cred->cr_usr_root = 1;
 375                 } else if (!strcmp(sname, GSSD_SERVICE_MDS)) {
 376                         printerr(2, "mds service principal, resolve to uid 0\n");
 377                         cred->cr_uid = 0;
 378                         cred->cr_usr_mds = 1;
 379                 } else {
 380                         cred->cr_uid = -1;
 381                         if (cred->cr_mapped_uid == -1) {
 382                                 printerr(0, "invalid user %s\n", sname);
 383                                 goto out_free;
 384                         }
 385                         printerr(2, "user %s mapped to %u\n",
 386                                  sname, cred->cr_mapped_uid);
 387                 }
 388         } else {
 389                 cred->cr_uid = pw->pw_uid;
 390                 printerr(2, "%s resolve to uid %u\n", sname, cred->cr_uid);
 391         }
 392
 393         res = 0;
 394 out_free:
 395         free(sname);
 396         return res;
 397 }
 398
 399 typedef struct gss_union_ctx_id_t {
 400         gss_OID         mech_type;
 401         gss_ctx_id_t    internal_ctx_id;
 402 } gss_union_ctx_id_desc, *gss_union_ctx_id_t;
 403
 404 /*
 405  * return -1 only if we detect error during reading from upcall channel,
 406  * all other cases return 0.
 407  */
 408 int
 409 handle_nullreq(FILE *f) {
 410         uint64_t                handle_seq;
 411         char                    in_tok_buf[TOKEN_BUF_SIZE];
 412         char                    in_handle_buf[15];
 413         char                    out_handle_buf[15];
 414         gss_buffer_desc         in_tok = {.value = in_tok_buf},
 415                                 out_tok = {.value = NULL},
 416                                 in_handle = {.value = in_handle_buf},
 417                                 out_handle = {.value = out_handle_buf},
 418                                 ctx_token = {.value = NULL},
 419                                 ignore_out_tok = {.value = NULL},
 420         /* XXX isn't there a define for this?: */
 421                                 null_token = {.value = NULL};
 422         uint32_t                lustre_svc;
 423         lnet_nid_t              nid;
 424         u_int32_t               ret_flags;
 425         gss_ctx_id_t            ctx = GSS_C_NO_CONTEXT;
 426         gss_name_t              client_name;
 427         gss_OID                 mech = GSS_C_NO_OID;
 428         gss_cred_id_t           svc_cred;
 429         u_int32_t               maj_stat = GSS_S_FAILURE, min_stat = 0;
 430         u_int32_t               ignore_min_stat;
 431         struct svc_cred         cred;
 432         static char             *lbuf = NULL;
 433         static int              lbuflen = 0;
 434         static char             *cp;
 435
 436         printerr(2, "handling null request\n");
 437
 438         if (readline(fileno(f), &lbuf, &lbuflen) != 1) {
 439                 printerr(0, "WARNING: handle_nullreq: "
 440                             "failed reading request\n");
 441                 return -1;
 442         }
 443
 444         cp = lbuf;
 445
 446         qword_get(&cp, (char *) &lustre_svc, sizeof(lustre_svc));
 447         qword_get(&cp, (char *) &nid, sizeof(nid));
 448         qword_get(&cp, (char *) &handle_seq, sizeof(handle_seq));
 449         printerr(1, "handling req: svc %u, nid %016llx, idx %llx\n",
 450                  lustre_svc, nid, handle_seq);
 451
 452         in_handle.length = (size_t) qword_get(&cp, in_handle.value,
 453                                               sizeof(in_handle_buf));
 454         printerr(3, "in_handle: \n");
 455         print_hexl(3, in_handle.value, in_handle.length);
 456
 457         in_tok.length = (size_t) qword_get(&cp, in_tok.value,
 458                                            sizeof(in_tok_buf));
 459         printerr(3, "in_tok: \n");
 460         print_hexl(3, in_tok.value, in_tok.length);
 461
 462         if (in_tok.length < 0) {
 463                 printerr(0, "WARNING: handle_nullreq: "
 464                             "failed parsing request\n");
 465                 goto out_err;
 466         }
 467
 468         if (in_handle.length != 0) { /* CONTINUE_INIT case */
 469                 if (in_handle.length != sizeof(ctx)) {
 470                         printerr(0, "WARNING: handle_nullreq: "
 471                                     "input handle has unexpected length %d\n",
 472                                     in_handle.length);
 473                         goto out_err;
 474                 }
 475                 /* in_handle is the context id stored in the out_handle
 476                  * for the GSS_S_CONTINUE_NEEDED case below.  */
 477                 memcpy(&ctx, in_handle.value, in_handle.length);
 478         }
 479
 480         svc_cred = gssd_select_svc_cred(lustre_svc);
 481         if (!svc_cred) {
 482                 printerr(0, "no service credential for svc %u\n", lustre_svc);
 483                 goto out_err;
 484         }
 485
 486         maj_stat = gss_accept_sec_context(&min_stat, &ctx, svc_cred,
 487                         &in_tok, GSS_C_NO_CHANNEL_BINDINGS, &client_name,
 488                         &mech, &out_tok, &ret_flags, NULL, NULL);
 489
 490         if (maj_stat == GSS_S_CONTINUE_NEEDED) {
 491                 printerr(1, "gss_accept_sec_context GSS_S_CONTINUE_NEEDED\n");
 492
 493                 /* Save the context handle for future calls */
 494                 out_handle.length = sizeof(ctx);
 495                 memcpy(out_handle.value, &ctx, sizeof(ctx));
 496                 goto continue_needed;
 497         }
 498         else if (maj_stat != GSS_S_COMPLETE) {
 499                 printerr(0, "WARNING: gss_accept_sec_context failed\n");
 500                 pgsserr("handle_nullreq: gss_accept_sec_context",
 501                         maj_stat, min_stat, mech);
 502                 goto out_err;
 503         }
 504
 505         if (get_ids(client_name, mech, &cred, nid, lustre_svc)) {
 506                 /* get_ids() prints error msg */
 507                 maj_stat = GSS_S_BAD_NAME; /* XXX ? */
 508                 gss_release_name(&ignore_min_stat, &client_name);
 509                 goto out_err;
 510         }
 511         gss_release_name(&ignore_min_stat, &client_name);
 512
 513         /* Context complete. Pass handle_seq in out_handle to use
 514          * for context lookup in the kernel. */
 515         out_handle.length = sizeof(handle_seq);
 516         memcpy(out_handle.value, &handle_seq, sizeof(handle_seq));
 517
 518         /* kernel needs ctx to calculate verifier on null response, so
 519          * must give it context before doing null call: */
 520         if (serialize_context_for_kernel(ctx, &ctx_token, mech)) {
 521                 printerr(0, "WARNING: handle_nullreq: "
 522                             "serialize_context_for_kernel failed\n");
 523                 maj_stat = GSS_S_FAILURE;
 524                 goto out_err;
 525         }
 526         /* We no longer need the gss context */
 527         gss_delete_sec_context(&ignore_min_stat, &ctx, &ignore_out_tok);
 528
 529         do_svc_downcall(&out_handle, &cred, mech, &ctx_token);
 530 continue_needed:
 531         send_response(f, &in_handle, &in_tok, maj_stat, min_stat,
 532                         &out_handle, &out_tok);
 533 out:
 534         if (ctx_token.value != NULL)
 535                 free(ctx_token.value);
 536         if (out_tok.value != NULL)
 537                 gss_release_buffer(&ignore_min_stat, &out_tok);
 538         return 0;
 539
 540 out_err:
 541         if (ctx != GSS_C_NO_CONTEXT)
 542                 gss_delete_sec_context(&ignore_min_stat, &ctx, &ignore_out_tok);
 543         send_response(f, &in_handle, &in_tok, maj_stat, min_stat,
 544                         &null_token, &null_token);
 545         goto out;
 546 }