src/client/sandbox-server/main.c

   1 /* $Id$
   2  * filesystem sandbox server stub for libcaptive
   3  * Copyright (C) 2003 Jan Kratochvil <project-captive@jankratochvil.net>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; exactly version 2 of June 1991 is required
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  */
  18
  19
  20 #include "config.h"
  21
  22 #include <glib/gmessages.h>
  23 #include <stdlib.h>
  24 #include <glib/giochannel.h>
  25 #include <glib/gerror.h>
  26 #include <popt.h>
  27 #include <string.h>
  28 #include <stdio.h>
  29 #include <locale.h>
  30 #include "captive/options.h"
  31 #include <glib-object.h>
  32 #include "captive/macros.h"
  33 #include <sys/types.h>
  34 #include <sys/stat.h>
  35 #include <unistd.h>
  36 #include <dirent.h>
  37 #include <errno.h>
  38 #include <grp.h>
  39 #include <pwd.h>
  40 #include <fcntl.h>
  41 #include <sys/file.h>
  42 #include <sys/resource.h>
  43 #include <orbit/orb-core/corba-defs.h>
  44 #include "captive/client.h"
  45
  46 #ifdef HAVE_ORBIT_LINK
  47 char *link_get_tmpdir(void);
  48 void link_set_tmpdir(const char *dir);
  49 #else
  50 #include <linc/linc-protocol.h> /* for linc_set_tmpdir() */
  51 #endif
  52
  53
  54 /* Do not: #include "../../libcaptive/sandbox/split.h"  * for captive_sandbox_fd_closeup(); FIXME *
  55  * as it has libcaptive-dependent includes conditioned by ORBIT2.
  56  * FIXME: Unify this declaration:
  57  */
  58 void captive_sandbox_fd_closeup(int fd_first_to_delete);
  59 void captive_corba_sandbox_child(const gchar *chrooted_orbit_dir);
  60
  61
  62 /* CONFIG: */
  63
  64 /* FIXME: We hit linc-1.0.1/src/linc-protocols.c/linc_protocol_get_sockaddr_unix()
  65  * limit of socket pathname 64 characters.
  66  * With CHROOT_PATH_HASHKEY_LENGTH 12 "linc-%x-%x-%x%x" still does not fit completely.
  67  */
  68 #define CHROOT_PATH_HASHKEY_LENGTH (12)
  69
  70
  71 GQuark sandbox_server_main_error_quark(void)
  72 {
  73 GQuark r=0;
  74
  75         if (!r)
  76                 r=g_quark_from_static_string("sandbox-server");
  77
  78         return r;
  79 }
  80
  81
  82 static gchar *optarg_setuid=CAPTIVE_SANDBOX_SETUID;
  83 static gchar *optarg_setgid=CAPTIVE_SANDBOX_SETGID;
  84 static gchar *optarg_chroot=CAPTIVE_SANDBOX_CHROOT;
  85 static gint   optarg_no_rlimit=0;
  86
  87 static const struct poptOption popt_table[]={
  88 #define SANDBOX_SERVER_POPT(longname,argInfoP,argP,descripP,argDescripP) \
  89                 { \
  90                         longName: (longname), \
  91                         shortName: 0, \
  92                         argInfo: (argInfoP), \
  93                         arg: (void *)argP, \
  94                         val: 0, \
  95                         descrip: (descripP), \
  96                         argDescrip: (argDescripP), \
  97                 }
  98
  99                 SANDBOX_SERVER_POPT("setuid"   ,POPT_ARG_STRING,&optarg_setuid,
 100                                 N_("Username or UID to become; \"-\" for disable"),N_("UID")),
 101                 SANDBOX_SERVER_POPT("setgid"   ,POPT_ARG_STRING,&optarg_setgid,
 102                                 N_("Groupname or GID to become; \"-\" for disable"),N_("GID")),
 103                 SANDBOX_SERVER_POPT("chroot"   ,POPT_ARG_STRING,&optarg_chroot,
 104                                 N_("Pathname to directory for chroot(2); \"-\" for disable"),N_("directory")),
 105                 SANDBOX_SERVER_POPT("no-rlimit",POPT_ARG_NONE  ,&optarg_no_rlimit,
 106                                 N_("Disable setrlimit(2) restrictions"),NULL),
 107
 108 #undef SANDBOX_SERVER_POPT
 109                 POPT_AUTOHELP
 110                 POPT_TABLEEND
 111                 };
 112
 113
 114 static gchar *fatal_argv0;
 115
 116 static void fatal(const char *fmt,...)
 117 {
 118 va_list ap;
 119
 120         fprintf(stderr,"%s: ",fatal_argv0);
 121         va_start(ap,fmt);
 122         vfprintf(stderr,fmt,ap);
 123         va_end(ap);
 124         fprintf(stderr,"!\nAborting!\n");
 125         exit(EXIT_FAILURE);
 126         /* NOTREACHED */
 127         for (;;);
 128 }
 129
 130 static void check_dir_safety(const gchar *dir)
 131 {
 132 gchar *local_dir;
 133 const gchar *cs;
 134 static gint depth=0;
 135
 136         if (++depth>=1000)
 137                 fatal("Loop count >=%d during check_dir_safety(\"%s\")",depth,dir);
 138
 139         if (*dir!='/')
 140                 fatal("chroot path \"%s\" not absolute",dir);
 141         dir=captive_printf_alloca("%s/",dir);
 142         local_dir=(gchar *)captive_strdup_alloca(dir);
 143         for (cs=dir;cs;cs=strchr(cs+1,'/')) {
 144 struct stat statbuf;
 145
 146                 g_assert(*cs=='/');
 147                 /* Include the trailing '/' to resolve the root directory as "/". */
 148                 memcpy(local_dir,dir,cs+1-dir);
 149                 local_dir[cs+1-dir]=0;
 150                 if (lstat(local_dir,&statbuf))
 151                         fatal("lstat(\"%s\") of chroot path component: %m",local_dir);
 152                 if (S_ISLNK(statbuf.st_mode)) {
 153 char linkbuf[PATH_MAX];
 154 int linkbuflen;
 155
 156                         if (0>(linkbuflen=readlink(local_dir,linkbuf,sizeof(linkbuf)-1)))
 157                                 fatal("readlink(\"%s\") of chroot path component: %m",local_dir);
 158                         linkbuf[linkbuflen]=0;
 159                         check_dir_safety(linkbuf);
 160                         if (stat(local_dir,&statbuf))   /* NOT lstat(2) */
 161                                 fatal("stat(\"%s\") of chroot path component: %m",local_dir);
 162                         }
 163                 if (!S_ISDIR(statbuf.st_mode))
 164                         fatal("lstat/stat(\"%s\") of chroot path component is !S_ISDIR",local_dir);
 165                 if (statbuf.st_uid!=0)
 166                         fatal("lstat/stat(\"%s\") of chroot path component has UID %d !=0",local_dir,(int)statbuf.st_uid);
 167                 if (statbuf.st_gid!=0)
 168                         fatal("lstat/stat(\"%s\") of chroot path component has GID %d !=0",local_dir,(int)statbuf.st_gid);
 169                 if ((statbuf.st_mode&(S_IFDIR|S_ISVTX|0111)) != (S_IFDIR|0111))
 170                         fatal("lstat/stat(\"%s\") of chroot path component has mode 0%o !=04[01]111",local_dir,(int)statbuf.st_mode);
 171                 }
 172
 173         depth--;
 174 }
 175
 176 static void chrooted_unlink_recursive(const gchar *pathname)
 177 {
 178 DIR *dir;
 179 struct dirent *dirent;
 180 static gint depth=0;
 181 struct stat statbuf;
 182
 183         if (++depth>=1000)
 184                 fatal("Loop count >=%d during chrooted_unlink_recursive(\"%s\")",depth,pathname);
 185
 186         /* Security: Do not allow anyone to escape the sandbox directory by symlinks. */
 187         if (lstat(pathname,&statbuf))
 188                 fatal("Cannot lstat(\"%s\") to delete leftover sandbox files: %m",pathname);
 189         if (!S_ISDIR(statbuf.st_mode)) {
 190                 if (unlink(pathname))
 191                         fatal("Cannot unlink(\"%s\") to delete leftover sandbox files: %m",pathname);
 192                 goto done;
 193                 }
 194         if (!(dir=opendir(pathname)))
 195                 fatal("Cannot opendir(\"%s\") to delete leftover sandbox files: %m",pathname);
 196         while (errno=0,(dirent=readdir(dir))) {
 197 gchar *dirent_path;
 198
 199                 if (!strcmp(dirent->d_name,".") || !strcmp(dirent->d_name,".."))
 200                         continue;
 201                 dirent_path=g_strdup_printf("%s/%s",pathname,dirent->d_name);
 202                 chrooted_unlink_recursive(dirent_path);
 203                 g_free(dirent_path);
 204                 }
 205         if (errno)
 206                 fatal("Cannot readdir(\"%s\") during delete of leftover sandbox files: %m",pathname);
 207         if (closedir(dir))
 208                 fatal("Cannot closedir(\"%s\") during delete of leftover sandbox files: %m",pathname);
 209         if (rmdir(pathname))
 210                 fatal("Cannot rmdir(\"%s\") during delete of leftover sandbox files: %m",pathname);
 211
 212 done:
 213         depth--;
 214 }
 215
 216 static void chrooted_cleanuplockeddirs(const gchar *pathname,const gchar *prefix)
 217 {
 218 DIR *dir;
 219 struct dirent *dirent;
 220
 221         if (!(dir=opendir(pathname))) {
 222                 if (errno!=ENOTDIR)
 223                         fatal("Cannot opendir(\"%s\") to delete leftover sandbox files: %m",pathname);
 224                 /* errno==ENOTDIR, a regular file */
 225                 if (unlink(pathname))
 226                         fatal("Cannot unlink(\"%s\") to delete leftover sandbox files: %m",pathname);
 227                 return;
 228                 }
 229         while (errno=0,(dirent=readdir(dir))) {
 230 gchar *dirent_path;
 231 int direntfd;
 232
 233                 if (!strcmp(dirent->d_name,".") || !strcmp(dirent->d_name,".."))
 234                         continue;
 235                 if (strncmp(dirent->d_name,prefix,strlen(prefix)))
 236                         continue;
 237                 dirent_path=g_strdup_printf("%s/%s",pathname,dirent->d_name);
 238                 if (-1==(direntfd=open(dirent_path,O_RDONLY))) {
 239                         if (errno==ENOENT)      /* It could disappear in the meantime. */
 240                                 goto next_dirent_free_dirent_path;
 241                         fatal("Cannot open(\"%s\") as the child directory during delete of leftover sandbox files: %m",dirent_path);
 242                         }
 243                 if (flock(direntfd,LOCK_EX|LOCK_NB)) {
 244                         if (errno==EWOULDBLOCK) /* Valid directory in use. */
 245                                 goto next_dirent_close_direntfd;
 246                         fatal("Cannot flock(\"%s\",LOCK_EX|LOCK_NB) child directory during delete of leftover sandbox files: %m",dirent_path);
 247                         }
 248                 chrooted_unlink_recursive(dirent_path);
 249 next_dirent_close_direntfd:
 250                 if (close(direntfd))
 251                         fatal("Cannot close(\"%s\") child directory during delete of leftover sandbox files: %m",dirent_path);
 252 next_dirent_free_dirent_path:
 253                 g_free(dirent_path);
 254                 }
 255         if (errno)
 256                 fatal("Cannot readdir(\"%s\") during delete of leftover sandbox files: %m",pathname);
 257         if (closedir(dir))
 258                 fatal("Cannot closedir(\"%s\") during delete of leftover sandbox files: %m",pathname);
 259 }
 260
 261 static void chrooted_createdir(const gchar *dir,uid_t uid,gid_t gid,gboolean lock)
 262 {
 263 gint retries;
 264
 265         for (retries=0;retries<10;retries++) {
 266 struct stat statbuf;
 267 int dirfd;
 268
 269                 if (mkdir(dir,0711)) {
 270                         if (errno!=EEXIST)
 271                                 fatal("Failed to create chroot directory \"%s\": %m",dir);
 272                         chrooted_unlink_recursive(dir);
 273                         if (mkdir(dir,0711))
 274                                 fatal("Failed to create chroot directory \"%s\" after attempted unlink: %m",dir);
 275                         }
 276                 if (!lock)
 277                         break;
 278                 dirfd=open(dir,O_RDONLY);
 279                 if (dirfd==-1) {
 280                         if (errno!=ENOENT)
 281                                 fatal("Failed to open created chroot directory \"%s\" to lock it: %m",dir);
 282                         continue;
 283                         }
 284                 /* Do not use 'LOCK_NB' here as the garbage collector should release it soon. */
 285                 if (flock(dirfd,LOCK_EX))
 286                         fatal("Failed to lock created chroot directory \"%s\": %m",dir);
 287                 if (lstat(dir,&statbuf)) {
 288                         if (errno!=ENOENT)
 289                                 fatal("Failed to lstat(2) created chroot directory \"%s\": %m",dir);
 290                         if (close(dirfd))
 291                                 fatal("Failed to close created and locked chroot directory \"%s\": %m",dir);
 292                         continue;
 293                         }
 294                 /* Leave 'dirfd' open to leave it LOCK_EX-ed. */
 295                 break;
 296                 }
 297         if (chown(dir,uid,gid))
 298                 fatal("Failed to chown(\"%s\",%d,%d): %m",dir,uid,gid);
 299         if (chmod(dir,0711))    /* Just to be safe after chown(2); should be already done by mkdir(2). */
 300                 fatal("Failed to chmod(\"%s\",0%o): %m",dir,0711);
 301 }
 302
 303 static void sandbox_server_rlimit(int resource,const gchar *resource_string,rlim_t rlim_max)
 304 {
 305 struct rlimit rlim;
 306
 307         rlim.rlim_cur=rlim.rlim_max=rlim_max;
 308         if (setrlimit(resource,&rlim))
 309                 fatal("setrlimit(%s,%d): %m",resource_string,(int)rlim_max);
 310         if (getrlimit(resource,&rlim))
 311                 fatal("getrlimit(%s,%d): %m",resource_string,(int)rlim_max);
 312         if (rlim.rlim_cur!=rlim_max || rlim.rlim_max!=rlim_max)
 313                 fatal("Unsuccessful setrlimit(%s)",resource_string);
 314 }
 315
 316 static void sandbox_server_mkdir_p(const gchar *dirpathname)
 317 {
 318 gchar *pathname=(/* de-const */ gchar *)captive_strdup_alloca(dirpathname);
 319 gchar *gs,*gs2;
 320
 321         /* Missing mkdir(2) of the last component path is intentional: */
 322         for (gs=pathname;(gs2=strchr(gs,'/'));gs=gs2) {
 323                 *gs2='\0';
 324                 if (*pathname && mkdir(pathname,S_ISVTX|0777)) {
 325                         if (errno!=EEXIST)
 326                                 fatal("Failed to mkdir(\"%s\"): %m",pathname);
 327                         }
 328                 *gs2++='/';
 329                 }
 330 }
 331
 332 static const gchar *chrooted_orbit_dir;
 333
 334 static void chroot_setup(gboolean fragile)
 335 {
 336 uid_t want_uid=0;
 337 const gchar *want_uid_name=NULL;
 338 gid_t want_gid=0;
 339 char *endptr;
 340 const gchar *chroot_pid_hashkey_dir=NULL;
 341
 342         if (fragile) {
 343                 captive_sandbox_fd_closeup(2 /* STDERR */ +1);
 344                 clearenv();
 345                 }
 346
 347 #define CLEANEMPTY(var) G_STMT_START { \
 348                 if ((var) && (!*(var) || *(var)=='-')) \
 349                         (var)=NULL; \
 350                 } G_STMT_END
 351         CLEANEMPTY(optarg_setgid);
 352         CLEANEMPTY(optarg_setuid);
 353         CLEANEMPTY(optarg_chroot);
 354 #undef CLEANEMPTY
 355
 356         if (optarg_setgid) {
 357 long want_gidl;
 358
 359                 want_gidl=strtol(optarg_setgid,&endptr,10);
 360                 if (!endptr || !*endptr) {
 361                         want_gid=want_gidl;
 362                         if (want_gidl<=0 || want_gid!=(gid_t)want_gidl)
 363                                 fatal("Numeric setgid not parsable: %s",optarg_setgid);
 364                         }
 365                 else {
 366 struct group *want_gid_group=NULL;
 367                         if (!(want_gid_group=getgrnam(optarg_setgid)))
 368                                 fatal("Unable to query setgid group name \"%s\"",optarg_setgid);
 369                         want_gid=want_gid_group->gr_gid;
 370                         }
 371                 }
 372
 373         if (optarg_setuid) {
 374 long want_uidl;
 375 struct passwd *want_uid_passwd;
 376                 want_uidl=strtol(optarg_setuid,&endptr,10);
 377                 if (!endptr || !*endptr) {
 378                         want_uid=want_uidl;
 379                         if (want_uidl<=0 || want_uid!=(gid_t)want_uidl)
 380                                 fatal("Numeric setuid not parsable: %s",optarg_setuid);
 381                         }
 382                 else {
 383                         if (!(want_uid_passwd=getpwnam(optarg_setuid)))
 384                                 fatal("Unable to query setuid user name \"%s\"",optarg_setuid);
 385                         want_uid=want_uid_passwd->pw_uid;
 386                         }
 387                 if (!want_uid)
 388                         fatal("Unable to detect setuid UID");
 389                 if (!(want_uid_passwd=getpwuid(want_uid)))
 390                         fatal("Unable to query name of UID %d",(int)want_uid);
 391                 want_uid_name=captive_strdup_alloca(want_uid_passwd->pw_name);
 392                 }
 393
 394         /* Prevent: GLib-WARNING **: getpwuid_r(): failed due to unknown user id (42)
 395          * Try to invoke GLib g_get_any_init() before possible chroot(2) below.
 396          */
 397         g_get_user_name();
 398         g_get_real_name();
 399         g_get_home_dir();
 400         g_get_tmp_dir();
 401
 402         /* Pre-resolve "link_get_tmpdir" symbol to prevent its later failed
 403          * resolving in chroot(2) mode in Debian dynamic build.
 404          */
 405 #ifdef HAVE_ORBIT_LINK
 406         g_free(link_get_tmpdir());      /* returns g_strdup()ed string */
 407 #else
 408         g_free(linc_get_tmpdir());      /* returns g_strdup()ed string */
 409 #endif
 410
 411         if (fragile && !optarg_chroot)
 412                 fatal("Fragile setuid/root environment but no --chroot set");
 413         if (optarg_chroot) {
 414 const gchar *chroot_pid_dir;
 415 GRand *grand;
 416 gchar chroot_hashkey[CHROOT_PATH_HASHKEY_LENGTH+1],*s;
 417 gint gi;
 418
 419                 check_dir_safety(optarg_chroot);
 420                 if (!(grand=g_rand_new()))      /* I hope g_rand_new() is security-safe. It looks so. */
 421                         fatal("Cannot initialize random number generator g_rand_new()");
 422                 for (s=chroot_hashkey;s<chroot_hashkey+CHROOT_PATH_HASHKEY_LENGTH;s++) {
 423                         gi=g_rand_int_range(grand,0,10+26+26);
 424                         /**/ if (gi>=0 && gi<10)
 425                                 *s='0'+gi-(0);
 426                         else if (gi>=10+0 && gi<10+26)
 427                                 *s='a'+gi-(10);
 428                         else if (gi>=10+26+0 && gi<10+26+26)
 429                                 *s='A'+gi-(10+26);
 430                         else g_assert_not_reached();
 431                         }
 432                 g_rand_free(grand);
 433                 *s=0;
 434                 if (geteuid()==0) {     /* Not 'fragile' as we can be native 'root'. */
 435                         chrooted_cleanuplockeddirs(optarg_chroot,"s-");
 436                         chrooted_cleanuplockeddirs(captive_printf_alloca("%s/tmp",optarg_chroot),"captive-orbit-");
 437                         }
 438                 chroot_pid_dir=captive_printf_alloca("%s/s-%d",optarg_chroot,(int)getpid());
 439                 chrooted_createdir(chroot_pid_dir,(!optarg_setuid ? (uid_t)-1 : want_uid),(!optarg_setgid ? (gid_t)-1 : want_gid),
 440                                 TRUE);  /* lock */
 441                 chroot_pid_hashkey_dir=captive_printf_alloca("%s/%s",chroot_pid_dir,chroot_hashkey);
 442                 chrooted_createdir(chroot_pid_hashkey_dir,(!optarg_setuid ? (uid_t)-1 : want_uid),(!optarg_setgid ? (gid_t)-1 : want_gid),
 443                                 FALSE); /* lock */
 444                 if (chroot(chroot_pid_hashkey_dir))
 445                         fatal("Failed to chroot(\"%s\"): %m",chroot_pid_hashkey_dir);
 446                 if (chdir("/"))
 447                         fatal("Failed to chdir(\"%s\"): %m","/");
 448                 /* Now it is safe to set umask(0000) as we are protected by 'chroot_hashkey'.
 449                  * We need it to permit our spawning parent to hardlink its sockets to us.
 450                  */
 451                 umask(0000);
 452                 if (umask(0000)!=0000)
 453                         fatal("Failed to set umask(0%o): %m",0000);
 454                 printf("chroot_pid_hashkey_dir=%s\n",chroot_pid_hashkey_dir);
 455                 }
 456
 457         if (fragile && !optarg_setgid)
 458                 fatal("Fragile setuid/root environment but no --setgid set");
 459         if (optarg_setgid) {
 460                 if (!want_gid || setgid(want_gid))
 461                         fatal("Failed to setgid(%d)",(!want_gid ? -1 : (int)want_gid));
 462                 if (setgroups(1 /* size */,&want_gid))
 463                         fatal("Failed to setgroups(1,[%d])",(!want_gid ? -1 : (int)want_gid));
 464                 }
 465         if (fragile && !optarg_setuid)
 466                 fatal("Fragile setuid/root environment but no --setuid set");
 467         if (optarg_setuid) {
 468                 if (!want_uid || setuid(want_uid))
 469                         fatal("Failed to setuid(%d)",(!want_uid ? -1 : (int)want_uid));
 470                 }
 471
 472         /* Prepare /t for /t/o-$PID directories for ORBit2
 473          * and also for parent's hardlink to its /t/o-$pid directory. */
 474         if (optarg_chroot) {
 475 gchar *chrooted_orbit_dir_old;
 476
 477                 if (mkdir("/t",S_ISVTX|0777)) {
 478                         if (errno!=EEXIST)
 479                                 fatal("Failed to mkdir(\"%s\"): %m","/t");
 480                         }
 481                 if (mkdir("/etc",0700))
 482                         fatal("Failed to mkdir(\"%s\"): %m","/etc");
 483                 if (want_uid_name && want_uid && want_gid) {
 484 FILE *f;
 485                         if (!(f=fopen("/etc/passwd","w")))
 486                                 fatal("Failed to fopen(\"%s\",\"w\"): %m","/etc/passwd");
 487                         if (0>fprintf(f,"%s:*:%d:%d:%s:%s:/bin/false\n",want_uid_name,(int)want_uid,(int)want_gid,want_uid_name,optarg_chroot))
 488                                 fatal("Failed to fprintf(\"%s\"): %m","/etc/passwd");
 489                         if (fclose(f))
 490                                 fatal("Failed to fclose(\"%s\"): %m","/etc/passwd");
 491                         }
 492                 g_assert(chroot_pid_hashkey_dir!=NULL);
 493                 chrooted_orbit_dir=g_strdup_printf("%s/t/o-%d",chroot_pid_hashkey_dir,getpid());
 494                 /* Last pathname component is not created: */
 495                 sandbox_server_mkdir_p(chrooted_orbit_dir);
 496                 /* Prepare '/tmp' for the initial CORBA_ORB_init() default path.
 497                  * Workaround sandbox_server_mkdir_p() does not create last component.
 498                  * Do not use '/tmp' directly as some distributions may set custom
 499                  * tmpdir pathname by $ENV{"TMPDIR"} etc.
 500                  */
 501                 sandbox_server_mkdir_p(captive_printf_alloca("%s/",g_get_tmp_dir()));
 502                 /* Set '0700' to prevent: Wrong permissions for ...
 503                  * by linc-1.0.1-1/src/linc-protocols.c/make_local_tmpdir()
 504                  */
 505                 if (mkdir(chrooted_orbit_dir,0700)) {
 506                         /* Do not: g_assert(errno==EEXIST);
 507                          * as if 'optarg_chroot' the whole chroot(2)ed directory should be ours.
 508                          */
 509                         fatal("Cannot created chrooted_orbit_dir \"%s\": %m",chrooted_orbit_dir);
 510                         }
 511                 /* Init 'orb' to pass through its linc_set_tmpdir() to not to be overriden below. */
 512                 {
 513 CORBA_ORB orb;
 514 CORBA_Environment ev;
 515 int orb_argc=1;
 516 gchar *orb_argv[]={
 517                 (gchar *)captive_strdup_alloca("captive-sandbox-server"),
 518                 NULL};
 519
 520                         CORBA_exception_init(&ev);
 521                         /* libcaptive is single-threaded only, caller must lock it.
 522                          * If thread A spawned the sandbox while currently doing its own work
 523                          * and thread B calls the sandbox thread B waits on ORB_run()
 524                          * while the sandbox waits for the response of thread A ORB. Deadlock.
 525                          * "orbit-local-non-threaded-orb" requests thread unaware ORB.
 526                          */
 527                         orb=CORBA_ORB_init(&orb_argc,orb_argv,"orbit-local-non-threaded-orb",&ev);
 528                         if (orb==CORBA_OBJECT_NIL)
 529                                 fatal("Cannot initialize CORBA ORB (CORBA_OBJECT_NIL): %m");
 530                         if (ev._major!=CORBA_NO_EXCEPTION)
 531                                 fatal("Cannot initialize CORBA ORB (exception): %m");
 532                         }
 533 #ifdef HAVE_ORBIT_LINK
 534                 chrooted_orbit_dir_old=link_get_tmpdir();       /* returns g_strdup()ed string */
 535 #else
 536                 chrooted_orbit_dir_old=linc_get_tmpdir();       /* returns g_strdup()ed string */
 537 #endif
 538                 g_assert(chrooted_orbit_dir_old!=NULL);
 539 #ifdef HAVE_ORBIT_LINK
 540                 link_set_tmpdir(chrooted_orbit_dir);
 541 #else
 542                 linc_set_tmpdir(chrooted_orbit_dir);
 543 #endif
 544                 if (!*chrooted_orbit_dir_old)
 545                         fatal("Cannot detect chrooted_orbit_dir: --with-orbit-line incompatible with ORBit2 version");
 546                 if (rmdir(chrooted_orbit_dir_old))
 547                         fatal("Cannot remove old chrooted_orbit_dir \"%s\": %m",chrooted_orbit_dir_old);
 548                 g_free(chrooted_orbit_dir_old);
 549                 /* chmod(2) it to prevent mode limitation by
 550                  * active ulimit(2) of being executed by mount(8).
 551                  */
 552                 /* Set '0777' as our parent does not have 'captive' user permissions. */
 553                 if (chmod(chrooted_orbit_dir,S_ISVTX|0777))
 554                         fatal("Cannot chmod 0%o chrooted_orbit_dir \"%s\": %m",S_ISVTX|0777,chrooted_orbit_dir);
 555                 printf("chrooted_orbit_dir=%s\n",chrooted_orbit_dir);
 556                 }
 557
 558         if (fragile || !optarg_no_rlimit) {
 559 #define SANDBOX_SERVER_RLIMIT(what,how) sandbox_server_rlimit((what),G_STRINGIFY(what),(how))
 560                 SANDBOX_SERVER_RLIMIT(RLIMIT_NPROC,0);
 561                 SANDBOX_SERVER_RLIMIT(RLIMIT_MEMLOCK,0);
 562                 SANDBOX_SERVER_RLIMIT(RLIMIT_CORE,0);
 563                 SANDBOX_SERVER_RLIMIT(RLIMIT_FSIZE,0);
 564                 SANDBOX_SERVER_RLIMIT(RLIMIT_NOFILE,16);        /* >=6; newer ORBit2/link require >6 */
 565                 /* FIXME: Why flock(dirfd,...) in chrooted_createdir() succeeds?: */
 566                 SANDBOX_SERVER_RLIMIT(RLIMIT_LOCKS,0);
 567 #undef SANDBOX_SERVER_RLIMIT
 568                 }
 569
 570         if (fragile) {
 571 gid_t gid_list[2];
 572 int gid_list_size,i;
 573
 574                 if (getuid()!=want_uid)
 575                         fatal("getuid()=%d != want_uid=%d",(int)getuid(),(int)want_uid);
 576                 if (geteuid()!=want_uid)
 577                         fatal("geteuid()=%d != want_uid=%d",(int)geteuid(),(int)want_uid);
 578                 if (getgid()!=want_gid)
 579                         fatal("getgid()=%d != want_gid=%d",(int)getgid(),(int)want_gid);
 580                 if (getegid()!=want_gid)
 581                         fatal("getegid()=%d != want_gid=%d",(int)getegid(),(int)want_gid);
 582                 gid_list_size=getgroups(G_N_ELEMENTS(gid_list),gid_list);
 583                 for (i=0;i<gid_list_size;i++) {
 584                         if (gid_list[i]!=want_gid)
 585                                 fatal("getgroups() list member @%d %d != want_gid=%d",i,(int)gid_list[i],(int)want_gid);
 586                         }
 587                 }
 588 }
 589
 590
 591 int main(int argc,char **argv)
 592 {
 593 poptContext context;
 594 int errint;
 595 const char *cmd_arg;
 596 struct captive_options options;
 597 gboolean fragile;
 598
 599         g_log_set_always_fatal(~(0
 600                         |G_LOG_LEVEL_MESSAGE
 601                         |G_LOG_LEVEL_INFO
 602                         |G_LOG_LEVEL_DEBUG
 603                         ));
 604
 605         /* Do not do it later than chroot_setup() as it requires it.
 606          * On the other hand it is SETUID-fragile this way.
 607          */
 608         captive_standalone_init();
 609
 610         fatal_argv0=argv[0];
 611         fragile=(getuid()!=geteuid() || getuid()==0 || geteuid()==0);
 612
 613 #ifndef MAINTAINER_MODE
 614         if (fragile && (argc!=1 || argv[1]))
 615                 fatal("Arguments invalid as running in fragile setuid/root environment");
 616
 617         if (fragile)
 618                 chroot_setup(TRUE);
 619 #endif /* MAINTAINER_MODE */
 620
 621         captive_options_init(&options);
 622         captive_options=&options;       /* for parsing by 'CAPTIVE_POPT_INCLUDE' */
 623
 624         context=poptGetContext(
 625                         PACKAGE,        /* name */
 626                         argc,(/*en-const*/const char **)argv,   /* argc,argv */
 627                         popt_table,     /* options */
 628                         POPT_CONTEXT_POSIXMEHARDER);    /* flags; && !POPT_CONTEXT_KEEP_FIRST */
 629         if (context==NULL) {
 630                 g_assert_not_reached(); /* argument recognization args_error */
 631                 return EXIT_FAILURE;
 632                 }
 633         errint=poptReadDefaultConfig(context,
 634                         TRUE);  /* useEnv */
 635         if (errint!=0) {
 636                 g_assert_not_reached(); /* argument recognization args_error */
 637                 return EXIT_FAILURE;
 638                 }
 639         errint=poptGetNextOpt(context);
 640         if (errint!=-1) {
 641                 g_assert_not_reached(); /* some non-callbacked argument reached */
 642                 return EXIT_FAILURE;
 643                 }
 644         cmd_arg=poptPeekArg(context);
 645         if (cmd_arg) {
 646                 g_assert_not_reached(); /* some non-option argument reached */
 647                 return EXIT_FAILURE;
 648                 }
 649         /* 'cmd_arg'-style args gets cleared by 'poptFreeContext(context);' below */
 650         poptFreeContext(context);
 651
 652 #ifdef MAINTAINER_MODE
 653         chroot_setup(FALSE);
 654 #endif /* MAINTAINER_MODE */
 655
 656         captive_options=NULL;   /* already parsed by 'CAPTIVE_POPT_INCLUDE' */
 657
 658         captive_corba_sandbox_child(chrooted_orbit_dir);
 659
 660         g_assert_not_reached();
 661         return EXIT_SUCCESS;
 662 }