platform.c

   1 /* $Id: platform.c,v 1.14 2010/11/05 03:47:01 dtucker Exp $ */
   2
   3 /*
   4  * Copyright (c) 2006 Darren Tucker.  All rights reserved.
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include "config.h"
  20
  21 #include <sys/types.h>
  22 #include <unistd.h>
  23
  24 #include "platform.h"
  25
  26 #include "openbsd-compat/openbsd-compat.h"
  27
  28 extern int use_privsep;
  29
  30 void
  31 platform_pre_listen(void)
  32 {
  33 #ifdef LINUX_OOM_ADJUST
  34         /* Adjust out-of-memory killer so listening process is not killed */
  35         oom_adjust_setup();
  36 #endif
  37 }
  38
  39 void
  40 platform_pre_fork(void)
  41 {
  42 #ifdef USE_SOLARIS_PROCESS_CONTRACTS
  43         solaris_contract_pre_fork();
  44 #endif
  45 }
  46
  47 void
  48 platform_post_fork_parent(pid_t child_pid)
  49 {
  50 #ifdef USE_SOLARIS_PROCESS_CONTRACTS
  51         solaris_contract_post_fork_parent(child_pid);
  52 #endif
  53 }
  54
  55 void
  56 platform_post_fork_child(void)
  57 {
  58 #ifdef USE_SOLARIS_PROCESS_CONTRACTS
  59         solaris_contract_post_fork_child();
  60 #endif
  61 #ifdef LINUX_OOM_ADJUST
  62         oom_adjust_restore();
  63 #endif
  64 }
  65
  66 /* return 1 if we are running with privilege to swap UIDs, 0 otherwise */
  67 int
  68 platform_privileged_uidswap(void)
  69 {
  70 #ifdef HAVE_CYGWIN
  71         /* uid 0 is not special on Cygwin so always try */
  72         return 1;
  73 #else
  74         return (getuid() == 0 || geteuid() == 0);
  75 #endif
  76 }
  77
  78 /*
  79  * This gets called before switching UIDs, and is called even when sshd is
  80  * not running as root.
  81  */
  82 void
  83 platform_setusercontext(struct passwd *pw)
  84 {
  85 #ifdef WITH_SELINUX
  86         /* Cache selinux status for later use */
  87         (void)ssh_selinux_enabled();
  88 #endif
  89
  90 #ifdef USE_SOLARIS_PROJECTS
  91         /* if solaris projects were detected, set the default now */
  92         if (getuid() == 0 || geteuid() == 0)
  93                 solaris_set_default_project(pw);
  94 #endif
  95
  96 #if defined(HAVE_LOGIN_CAP) && defined (__bsdi__)
  97         if (getuid() == 0 || geteuid() == 0)
  98                 setpgid(0, 0);
  99 # endif
 100
 101 #if defined(HAVE_LOGIN_CAP) && defined(USE_PAM)
 102         /*
 103          * If we have both LOGIN_CAP and PAM, we want to establish creds
 104          * before calling setusercontext (in session.c:do_setusercontext).
 105          */
 106         if (getuid() == 0 || geteuid() == 0) {
 107                 if (options.use_pam) {
 108                         do_pam_setcred(use_privsep);
 109                 }
 110         }
 111 # endif /* USE_PAM */
 112 }
 113
 114 /*
 115  * This gets called after we've established the user's groups, and is only
 116  * called if sshd is running as root.
 117  */
 118 void
 119 platform_setusercontext_post_groups(struct passwd *pw)
 120 {
 121 #if !defined(HAVE_LOGIN_CAP) && defined(USE_PAM)
 122         /*
 123          * PAM credentials may take the form of supplementary groups.
 124          * These will have been wiped by the above initgroups() call.
 125          * Reestablish them here.
 126          */
 127         if (options.use_pam) {
 128                 do_pam_setcred(use_privsep);
 129         }
 130 #endif /* USE_PAM */
 131
 132 #if !defined(HAVE_LOGIN_CAP) && (defined(WITH_IRIX_PROJECT) || \
 133     defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY))
 134         irix_setusercontext(pw);
 135 #endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
 136
 137 #ifdef _AIX
 138         aix_usrinfo(pw);
 139 #endif /* _AIX */
 140
 141 #if !defined(HAVE_LOGIN_CAP) && defined(USE_LIBIAF)
 142         if (set_id(pw->pw_name) != 0) {
 143                 exit(1);
 144         }
 145 # endif /* USE_LIBIAF */
 146
 147 #ifdef HAVE_SETPCRED
 148         /*
 149          * If we have a chroot directory, we set all creds except real
 150          * uid which we will need for chroot.  If we don't have a
 151          * chroot directory, we don't override anything.
 152          */
 153         {
 154                 char **creds = NULL, *chroot_creds[] =
 155                     { "REAL_USER=root", NULL };
 156
 157                 if (options.chroot_directory != NULL &&
 158                     strcasecmp(options.chroot_directory, "none") != 0)
 159                         creds = chroot_creds;
 160
 161                 if (setpcred(pw->pw_name, creds) == -1)
 162                         fatal("Failed to set process credentials");
 163         }
 164 #endif /* HAVE_SETPCRED */
 165 #ifdef WITH_SELINUX
 166         ssh_selinux_setup_exec_context(pw->pw_name);
 167 #endif
 168 }
 169
 170 char *
 171 platform_krb5_get_principal_name(const char *pw_name)
 172 {
 173 #ifdef USE_AIX_KRB_NAME
 174         return aix_krb5_get_principal_name(pw_name);
 175 #else
 176         return NULL;
 177 #endif
 178 }