1 /*
   2  * Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 #ifndef CHILDPROC_MD_H
  27 #define CHILDPROC_MD_H
  28 
  29 #include <sys/types.h>
  30 
  31 #ifdef __APPLE__
  32 #include <crt_externs.h>
  33 #define environ (*_NSGetEnviron())
  34 #else
  35 /* This is one of the rare times it's more portable to declare an
  36  * external symbol explicitly, rather than via a system header.
  37  * The declaration is standardized as part of UNIX98, but there is
  38  * no standard (not even de-facto) header file where the
  39  * declaration is to be found.  See:
  40  * http://www.opengroup.org/onlinepubs/009695399/functions/environ.html
  41  * http://www.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_02.html
  42  *
  43  * "All identifiers in this volume of IEEE Std 1003.1-2001, except
  44  * environ, are defined in at least one of the headers" (!)
  45  */
  46 extern char **environ;
  47 #endif
  48 
  49 #ifdef __linux__
  50 #include <sched.h>
  51 #endif
  52 
  53 #ifndef STDIN_FILENO
  54 #define STDIN_FILENO 0
  55 #endif
  56 
  57 #ifndef STDOUT_FILENO
  58 #define STDOUT_FILENO 1
  59 #endif
  60 
  61 #ifndef STDERR_FILENO
  62 #define STDERR_FILENO 2
  63 #endif
  64 
  65 #ifndef SA_NOCLDSTOP
  66 #define SA_NOCLDSTOP 0
  67 #endif
  68 
  69 #ifndef SA_RESTART
  70 #define SA_RESTART 0
  71 #endif
  72 
  73 #define FAIL_FILENO (STDERR_FILENO + 1)
  74 
  75 /* TODO: Refactor. */
  76 #define RESTARTABLE(_cmd, _result) do { \
  77   do { \
  78     _result = _cmd; \
  79   } while((_result == -1) && (errno == EINTR)); \
  80 } while(0)
  81 
  82 /* These numbers must be the same as the Enum in ProcessImpl.java
  83  * Must be a better way of doing this.
  84  */
  85 #define MODE_FORK 1
  86 #define MODE_POSIX_SPAWN 2
  87 #define MODE_VFORK 3
  88 #define MODE_CLONE 4
  89 
  90 typedef struct _ChildStuff
  91 {
  92     int in[2];
  93     int out[2];
  94     int err[2];
  95     int fail[2];
  96     int childenv[2];
  97     int fds[3];
  98     int mode;
  99     const char **argv;
 100     int argc;
 101     const char **envv;
 102     const char *pdir;
 103     int redirectErrorStream;
 104     int sendAlivePing;
 105 } ChildStuff;
 106 
 107 /* following used in addition when mode is SPAWN */
 108 typedef struct _SpawnInfo {
 109     int nargv; /* number of argv array elements  */
 110     int argvBytes; /* total number of bytes in argv array */
 111     int nenvv; /* number of envv array elements  */
 112     int envvBytes; /* total number of bytes in envv array */
 113     int dirlen; /* length of home directory string */
 114     int nparentPathv; /* number of elements in parentPathv array */
 115     int parentPathvBytes; /* total number of bytes in parentPathv array */
 116 } SpawnInfo;
 117 
 118 /* If ChildStuff.sendAlivePing is true, child shall signal aliveness to
 119  * the parent the moment it gains consciousness, before any subsequent
 120  * pre-exec errors could happen.
 121  * This code must fit into an int and not be a valid errno value on any of
 122  * our platforms. */
 123 #define CHILD_IS_ALIVE      65535
 124 
 125 /**
 126  * The cached and split version of the JDK's effective PATH.
 127  * (We don't support putenv("PATH=...") in native code)
 128  */
 129 const char * const *parentPathv;
 130 
 131 ssize_t restartableWrite(int fd, const void *buf, size_t count);
 132 int restartableDup2(int fd_from, int fd_to);
 133 int closeSafely(int fd);
 134 int isAsciiDigit(char c);
 135 int closeDescriptors(void);
 136 int moveDescriptor(int fd_from, int fd_to);
 137 
 138 int magicNumber();
 139 ssize_t readFully(int fd, void *buf, size_t nbyte);
 140 void initVectorFromBlock(const char**vector, const char* block, int count);
 141 void execve_as_traditional_shell_script(const char *file,
 142                                         const char *argv[],
 143                                         const char *const envp[]);
 144 void execve_with_shell_fallback(int mode, const char *file,
 145                                 const char *argv[],
 146                                 const char *const envp[]);
 147 void JDK_execvpe(int mode, const char *file,
 148                  const char *argv[],
 149                  const char *const envp[]);
 150 int childProcess(void *arg);
 151 
 152 #endif