usr/src/cmd/nscd/nscd_nswparse.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #include <stdlib.h>
  27 #include <limits.h>
  28 #include <string.h>
  29 #include <ctype.h>
  30
  31 #define __NSS_PRIVATE_INTERFACE
  32 #include "nsswitch_priv.h"
  33 #undef  __NSS_PRIVATE_INTERFACE
  34
  35 #define islabel(c)      (isalnum(c) || (c) == '_')
  36
  37 /*
  38  * The _nsw_getoneconfig_v1() in this file parses the switch policy
  39  * configuration for a switch database, e.g.,
  40  *
  41  * hosts: nis [NOTFOUND=return] files
  42  * or
  43  * printers: user files nis
  44  */
  45
  46 /*
  47  * Local routines
  48  */
  49 static char *skip(char **, char);
  50 static char *labelskip(char *);
  51 static char *spaceskip(char *);
  52 static void freeconf_v1(struct __nsw_switchconfig_v1 *);
  53 static int alldigits(char *);
  54
  55 /*
  56  *
  57  * With the "lookup control" feature, the default criteria for NIS
  58  * and any new services (e.g. ldap) will be:
  59  *     [SUCCESS=return  NOTFOUND=continue UNAVAIL=continue TRYAGAIN=forever]
  60  *
  61  * For backward compat, NIS via NIS server in DNS forwarding mode will be:
  62  *     [SUCCESS=return  NOTFOUND=continue UNAVAIL=continue TRYAGAIN=continue]
  63  *
  64  * And also for backward compat, the default criteria for DNS will be:
  65  *     [SUCCESS=return  NOTFOUND=continue UNAVAIL=continue TRYAGAIN=continue]
  66  */
  67
  68
  69
  70 /*
  71  * The BIND resolver normally will retry several times on server non-response.
  72  * But now with the "lookup control" feature, we don't want the resolver doing
  73  * many retries, rather we want it to return control (reasonably) quickly back
  74  * to the switch engine.  However, when TRYAGAIN=N or TRYAGAIN=forever is
  75  * not explicitly set by the admin in the conf file, we want the old "resolver
  76  * retry a few times" rather than no retries at all.
  77  */
  78 static int      dns_tryagain_retry = 3;
  79
  80 /*
  81  * For backward compat (pre "lookup control"), the dns default behavior is
  82  * soft lookup.
  83  */
  84 static void
  85 set_dns_default_lkp(struct __nsw_lookup_v1 *lkp)
  86 {
  87         if (strcasecmp(lkp->service_name, "dns") == 0) {
  88                 lkp->actions[__NSW_TRYAGAIN] =
  89                     __NSW_TRYAGAIN_NTIMES;
  90                 lkp->max_retries = dns_tryagain_retry;
  91         }
  92 }
  93
  94 static void
  95 freeconf_v1(struct __nsw_switchconfig_v1 *cfp)
  96 {
  97         if (cfp) {
  98                 free(cfp->dbase);
  99                 if (cfp->lookups) {
 100                         struct __nsw_lookup_v1 *nex, *cur;
 101                         for (cur = cfp->lookups; cur; cur = nex) {
 102                                 free(cur->service_name);
 103                                 nex = cur->next;
 104                                 free(cur);
 105                         }
 106                 }
 107                 free(cfp);
 108         }
 109 }
 110
 111 /* give the next non-alpha character */
 112 static char *
 113 labelskip(char *cur)
 114 {
 115         char *p = cur;
 116         while (islabel(*p))
 117                 ++p;
 118         return (p);
 119 }
 120
 121 /* give the next non-space character */
 122 static char *
 123 spaceskip(char *cur)
 124 {
 125         char *p = cur;
 126         while (*p == ' ' || *p == '\t')
 127                 ++p;
 128         return (p);
 129 }
 130
 131 /*
 132  * terminate the *cur pointed string by null only if it is
 133  * followed by "key" surrounded by zero or more spaces and
 134  * return value is the same as the original *cur pointer and
 135  * *cur pointer is advanced to the first non {space, key} char
 136  * followed by the key. Otherwise, return NULL and keep
 137  * *cur unchanged.
 138  */
 139 static char *
 140 skip(char **cur, char key)
 141 {
 142         char *p, *tmp;
 143         char *q = *cur;
 144         int found, tmpfound;
 145
 146         tmp = labelskip(*cur);
 147         p = tmp;
 148         found = (*p == key);
 149         if (found) {
 150                 *p++ = '\0'; /* overwrite the key */
 151                 p = spaceskip(p);
 152         } else {
 153                 while (*p == ' ' || *p == '\t') {
 154                         tmpfound = (*++p == key);
 155                         if (tmpfound) {
 156                                 found = tmpfound;
 157                                         /* null terminate the return token */
 158                                 *tmp = '\0';
 159                                 p++; /* skip the key */
 160                         }
 161                 }
 162         }
 163         if (!found)
 164                 return (NULL); /* *cur unchanged */
 165         *cur = p;
 166         return (q);
 167 }
 168
 169 /* Return 1 if the string contains all digits, else return 0. */
 170 static int
 171 alldigits(char *s)
 172 {
 173         for (; *s; s++)
 174                 if (!isdigit(*s))
 175                         return (0);
 176         return (1);
 177 }
 178
 179 struct __nsw_switchconfig_v1 *
 180 _nsw_getoneconfig_v1(const char *name, char *linep, enum __nsw_parse_err *errp)
 181         /* linep   Nota Bene: not const char *  */
 182         /* errp  Meanings are abused a bit      */
 183 {
 184         struct __nsw_switchconfig_v1 *cfp;
 185         struct __nsw_lookup_v1 *lkp, **lkq;
 186         int end_crit;
 187         action_t act;
 188         char *p, *tokenp;
 189
 190         *errp = __NSW_CONF_PARSE_SUCCESS;
 191
 192         if ((cfp = calloc(1, sizeof (struct __nsw_switchconfig_v1)))
 193             == NULL) {
 194                 *errp = __NSW_CONF_PARSE_SYSERR;
 195                 return (NULL);
 196         }
 197         cfp->dbase = strdup(name);
 198         lkq = &cfp->lookups;
 199
 200         /* linep points to a naming service name */
 201         for (;;) {
 202                 int i;
 203
 204                 /* white space following the last service */
 205                 if (*linep == '\0' || *linep == '\n') {
 206                         return (cfp);
 207                 }
 208                 if ((lkp = calloc(1, sizeof (struct __nsw_lookup_v1)))
 209                     == NULL) {
 210                         *errp = __NSW_CONF_PARSE_SYSERR;
 211                         freeconf_v1(cfp);
 212                         return (NULL);
 213                 }
 214
 215                 *lkq = lkp;
 216                 lkq = &lkp->next;
 217
 218                 for (i = 0; i < __NSW_STD_ERRS_V1; i++)
 219                         if (i == __NSW_SUCCESS)
 220                                 lkp->actions[i] = __NSW_RETURN;
 221                         else if (i == __NSW_TRYAGAIN)
 222                                 lkp->actions[i] = __NSW_TRYAGAIN_FOREVER;
 223                         else
 224                                 lkp->actions[i] = __NSW_CONTINUE;
 225
 226                 /* get criteria for the naming service */
 227                 if (tokenp = skip(&linep, '[')) { /* got criteria */
 228
 229                         /* premature end, illegal char following [ */
 230                         if (!islabel(*linep))
 231                                 goto barf_line;
 232                         lkp->service_name = strdup(tokenp);
 233                         cfp->num_lookups++;
 234
 235                         set_dns_default_lkp(lkp);
 236
 237                         end_crit = 0;
 238
 239                         /* linep points to a switch_err */
 240                         for (;;) {
 241                                 int ntimes = 0; /* try again max N times */
 242                                 int dns_continue = 0;
 243
 244                                 if ((tokenp = skip(&linep, '=')) == NULL) {
 245                                         goto barf_line;
 246                                 }
 247
 248                                 /* premature end, ill char following = */
 249                                 if (!islabel(*linep))
 250                                         goto barf_line;
 251
 252                                 /* linep points to the string following '=' */
 253                                 p = labelskip(linep);
 254                                 if (*p == ']')
 255                                         end_crit = 1;
 256                                 else if (*p != ' ' && *p != '\t')
 257                                         goto barf_line;
 258                                 *p++ = '\0'; /* null terminate linep */
 259                                 p = spaceskip(p);
 260                                 if (!end_crit) {
 261                                         if (*p == ']') {
 262                                         end_crit = 1;
 263                                         *p++ = '\0';
 264                                         } else if (*p == '\0' || *p == '\n') {
 265                                                 return (cfp);
 266                                         } else if (!islabel(*p))
 267                                         /* p better be the next switch_err */
 268                                                 goto barf_line;
 269                                 }
 270                                 if (strcasecmp(linep, __NSW_STR_RETURN) == 0)
 271                                         act = __NSW_RETURN;
 272                                 else if (strcasecmp(linep,
 273                                                     __NSW_STR_CONTINUE) == 0) {
 274                                         if (strcasecmp(lkp->service_name,
 275                                                     "dns") == 0 &&
 276                                                 strcasecmp(tokenp,
 277                                                         __NSW_STR_TRYAGAIN)
 278                                                         == 0) {
 279                                                 /*
 280                                                  * Add one more condition
 281                                                  * so it retries only if it's
 282                                                  * "dns [TRYAGAIN=continue]"
 283                                                  */
 284                                                 dns_continue = 1;
 285                                                 act = __NSW_TRYAGAIN_NTIMES;
 286                                         } else
 287                                                 act = __NSW_CONTINUE;
 288                                 } else if (strcasecmp(linep,
 289                                             __NSW_STR_FOREVER) == 0)
 290                                         act = __NSW_TRYAGAIN_FOREVER;
 291                                 else if (alldigits(linep)) {
 292                                         act = __NSW_TRYAGAIN_NTIMES;
 293                                         ntimes = atoi(linep);
 294                                         if (ntimes < 0 || ntimes > INT_MAX)
 295                                                 ntimes = 0;
 296                                 }
 297                                 else
 298                                         goto barf_line;
 299
 300                                 if (__NSW_SUCCESS_ACTION(act) &&
 301                                     strcasecmp(tokenp,
 302                                             __NSW_STR_SUCCESS) == 0) {
 303                                         lkp->actions[__NSW_SUCCESS] = act;
 304                                 } else if (__NSW_NOTFOUND_ACTION(act) &&
 305                                         strcasecmp(tokenp,
 306                                             __NSW_STR_NOTFOUND) == 0) {
 307                                         lkp->actions[__NSW_NOTFOUND] = act;
 308                                 } else if (__NSW_UNAVAIL_ACTION(act) &&
 309                                         strcasecmp(tokenp,
 310                                             __NSW_STR_UNAVAIL) == 0) {
 311                                         lkp->actions[__NSW_UNAVAIL] = act;
 312                                 } else if (__NSW_TRYAGAIN_ACTION(act) &&
 313                                         strcasecmp(tokenp,
 314                                             __NSW_STR_TRYAGAIN) == 0) {
 315                                         lkp->actions[__NSW_TRYAGAIN] = act;
 316                                         if (strcasecmp(lkp->service_name,
 317                                                     "nis") == 0)
 318                                                 lkp->actions[
 319                                                     __NSW_NISSERVDNS_TRYAGAIN]
 320                                                     = act;
 321                                         if (act == __NSW_TRYAGAIN_NTIMES)
 322                                                 lkp->max_retries =
 323                                                 dns_continue ?
 324                                                 dns_tryagain_retry : ntimes;
 325                                 } else {
 326                                         /*EMPTY*/
 327                                         /*
 328                                          * convert string tokenp to integer
 329                                          * and put in long_errs
 330                                          */
 331                                 }
 332                                 if (end_crit) {
 333                                         linep = spaceskip(p);
 334                                         if (*linep == '\0' || *linep == '\n')
 335                                                 return (cfp);
 336                                         break; /* process next naming service */
 337                                 }
 338                                 linep = p;
 339                         } /* end of while loop for a name service's criteria */
 340                 } else {
 341                         /*
 342                          * no criteria for this naming service.
 343                          * linep points to name service, but not null
 344                          * terminated.
 345                          */
 346                         p = labelskip(linep);
 347                         if (*p == '\0' || *p == '\n') {
 348                                 *p = '\0';
 349                                 lkp->service_name = strdup(linep);
 350                                 set_dns_default_lkp(lkp);
 351                                 cfp->num_lookups++;
 352                                 return (cfp);
 353                         }
 354                         if (*p != ' ' && *p != '\t')
 355                                 goto barf_line;
 356                         *p++ = '\0';
 357                         lkp->service_name = strdup(linep);
 358                         set_dns_default_lkp(lkp);
 359                         cfp->num_lookups++;
 360                         linep = spaceskip(p);
 361                 }
 362         } /* end of while(1) loop for a name service */
 363
 364 barf_line:
 365         freeconf_v1(cfp);
 366         *errp = __NSW_CONF_PARSE_NOPOLICY;
 367         return (NULL);
 368 }
 369
 370 int
 371 __nsw_freeconfig_v1(
 372         struct __nsw_switchconfig_v1 *conf)
 373 {
 374         freeconf_v1(conf);
 375         return (0);
 376 }