os/bs2000/os.c

   1 /* Licensed to the Apache Software Foundation (ASF) under one or more
   2  * contributor license agreements.  See the NOTICE file distributed with
   3  * this work for additional information regarding copyright ownership.
   4  * The ASF licenses this file to You under the Apache License, Version 2.0
   5  * (the "License"); you may not use this file except in compliance with
   6  * the License.  You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 /*
  18  * This file will include OS specific functions which are not inlineable.
  19  * Any inlineable functions should be defined in os-inline.c instead.
  20  */
  21
  22 #ifdef _OSD_POSIX
  23
  24 #include "os.h"
  25
  26 #include "httpd.h"
  27 #include "http_config.h"
  28 #include "http_log.h"
  29 #include "apr_lib.h"
  30
  31 #define USER_LEN 8
  32
  33 typedef enum
  34 {
  35     bs2_unknown,     /* not initialized yet. */
  36     bs2_noFORK,      /* no fork() because -X flag was specified */
  37     bs2_FORK,        /* only fork() because uid != 0 */
  38     bs2_UFORK        /* Normally, ufork() is used to switch identities. */
  39 } bs2_ForkType;
  40
  41 static bs2_ForkType forktype = bs2_unknown;
  42
  43
  44 static void ap_str_toupper(char *str)
  45 {
  46     while (*str) {
  47         *str = apr_toupper(*str);
  48         ++str;
  49     }
  50 }
  51
  52 /* Determine the method for forking off a child in such a way as to
  53  * set both the POSIX and BS2000 user id's to the unprivileged user.
  54  */
  55 static bs2_ForkType os_forktype(int one_process)
  56 {
  57     /* have we checked the OS version before? If yes return the previous
  58      * result - the OS release isn't going to change suddenly!
  59      */
  60     if (forktype == bs2_unknown) {
  61         /* not initialized yet */
  62
  63         /* No fork if the one_process option was set */
  64         if (one_process) {
  65             forktype = bs2_noFORK;
  66         }
  67         /* If the user is unprivileged, use the normal fork() only. */
  68         else if (getuid() != 0) {
  69             forktype = bs2_FORK;
  70         }
  71         else
  72             forktype = bs2_UFORK;
  73     }
  74     return forktype;
  75 }
  76
  77
  78
  79 /* This routine complements the setuid() call: it causes the BS2000 job
  80  * environment to be switched to the target user's user id.
  81  * That is important if CGI scripts try to execute native BS2000 commands.
  82  */
  83 int os_init_job_environment(server_rec *server, const char *user_name, int one_process)
  84 {
  85     bs2_ForkType            type = os_forktype(one_process);
  86
  87     /* We can be sure that no change to uid==0 is possible because of
  88      * the checks in http_core.c:set_user()
  89      */
  90
  91     if (one_process) {
  92
  93         type = forktype = bs2_noFORK;
  94
  95         ap_log_error(APLOG_MARK, APLOG_ERR, 0, server,
  96                      "The debug mode of Apache should only "
  97                      "be started by an unprivileged user!");
  98         return 0;
  99     }
 100
 101     return 0;
 102 }
 103
 104 /* BS2000 requires a "special" version of fork() before a setuid() call */
 105 pid_t os_fork(const char *user)
 106 {
 107     pid_t pid;
 108     char  username[USER_LEN+1];
 109
 110     switch (os_forktype(0)) {
 111
 112       case bs2_FORK:
 113         pid = fork();
 114         break;
 115
 116       case bs2_UFORK:
 117         apr_cpystrn(username, user, sizeof username);
 118
 119         /* Make user name all upper case - for some versions of ufork() */
 120         ap_str_toupper(username);
 121
 122         pid = ufork(username);
 123         if (pid == -1 && errno == EPERM) {
 124             ap_log_error(APLOG_MARK, APLOG_EMERG, errno,
 125                          NULL, "ufork: Possible mis-configuration "
 126                          "for user %s - Aborting.", user);
 127             exit(1);
 128         }
 129         break;
 130
 131       default:
 132         pid = 0;
 133         break;
 134     }
 135
 136     return pid;
 137 }
 138
 139 #else /* _OSD_POSIX */
 140 void bs2000_os_is_not_here()
 141 {
 142 }
 143 #endif /* _OSD_POSIX */