/*

 * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

#include "java.h"

/*

 * If app is "/foo/bin/javac", or "/foo/bin/sparcv9/javac" then put

 * "/foo" into buf.

 */

jboolean

GetApplicationHome(char *buf, jint bufsize)

{

    const char *execname = GetExecName();

    if (execname != NULL) {

        JLI_Snprintf(buf, bufsize, "%s", execname);

        buf[bufsize-1] = '\0';

    } else {

        return JNI_FALSE;

    }

    if (JLI_StrRChr(buf, '/') == 0) {

        buf[0] = '\0';

        return JNI_FALSE;

    }

    *(JLI_StrRChr(buf, '/')) = '\0';    /* executable file      */

    if (JLI_StrLen(buf) < 4 || JLI_StrRChr(buf, '/') == 0) {

        buf[0] = '\0';

        return JNI_FALSE;

    }

    if (JLI_StrCmp("/bin", buf + JLI_StrLen(buf) - 4) != 0)

        *(JLI_StrRChr(buf, '/')) = '\0';        /* sparcv9 or amd64     */

    if (JLI_StrLen(buf) < 4 || JLI_StrCmp("/bin", buf + JLI_StrLen(buf) - 4) != 0) {

        buf[0] = '\0';

        return JNI_FALSE;

    }

    *(JLI_StrRChr(buf, '/')) = '\0';    /* bin                  */

    return JNI_TRUE;

}

/*

 * Return true if the named program exists

 */

static int

ProgramExists(char *name)

{

    struct stat sb;

    if (stat(name, &sb) != 0) return 0;

    if (S_ISDIR(sb.st_mode)) return 0;

    return (sb.st_mode & S_IEXEC) != 0;

}

/*

 * Find a command in a directory, returning the path.

 */

static char *

Resolve(char *indir, char *cmd)

{

    char name[PATH_MAX + 2], *real;

    if ((JLI_StrLen(indir) + JLI_StrLen(cmd) + 1)  > PATH_MAX) return 0;

    JLI_Snprintf(name, sizeof(name), "%s%c%s", indir, FILE_SEPARATOR, cmd);

    if (!ProgramExists(name)) return 0;

    real = JLI_MemAlloc(PATH_MAX + 2);

    if (!realpath(name, real))

        JLI_StrCpy(real, name);

    return real;

}

/*

 * Find a path for the executable

 */

char *

FindExecName(char *program)

{

    char cwdbuf[PATH_MAX+2];

    char *path;

    char *tmp_path;

    char *f;

    char *result = NULL;

    /* absolute path? */

    if (*program == FILE_SEPARATOR ||

        (FILE_SEPARATOR=='\\' && JLI_StrRChr(program, ':')))

        return Resolve("", program+1);

    /* relative path? */

    if (JLI_StrRChr(program, FILE_SEPARATOR) != 0) {

        char buf[PATH_MAX+2];

        return Resolve(getcwd(cwdbuf, sizeof(cwdbuf)), program);

    }

    /* from search path? */

    path = getenv("PATH");

    if (!path || !*path) path = ".";

    tmp_path = JLI_MemAlloc(JLI_StrLen(path) + 2);

    JLI_StrCpy(tmp_path, path);

    for (f=tmp_path; *f && result==0; ) {

        char *s = f;

        while (*f && (*f != PATH_SEPARATOR)) ++f;

        if (*f) *f++ = 0;

        if (*s == FILE_SEPARATOR)

            result = Resolve(s, program);

        else {

            /* relative path element */

            char dir[2*PATH_MAX];

            JLI_Snprintf(dir, sizeof(dir), "%s%c%s", getcwd(cwdbuf, sizeof(cwdbuf)),

                    FILE_SEPARATOR, s);

            result = Resolve(dir, program);

        }

        if (result != 0) break;

    }

    JLI_MemFree(tmp_path);

    return result;

}

void JLI_ReportErrorMessage(const char* fmt, ...) {

    va_list vl;

    va_start(vl, fmt);

    vfprintf(stderr, fmt, vl);

    fprintf(stderr, "\n");

    va_end(vl);

}

void JLI_ReportErrorMessageSys(const char* fmt, ...) {

    va_list vl;

    char *emsg;

    /*

     * TODO: its safer to use strerror_r but is not available on

     * Solaris 8. Until then....

     */

    emsg = strerror(errno);

    if (emsg != NULL) {

        fprintf(stderr, "%s\n", emsg);

    }

    va_start(vl, fmt);

    vfprintf(stderr, fmt, vl);

    fprintf(stderr, "\n");

    va_end(vl);

}

void  JLI_ReportExceptionDescription(JNIEnv * env) {

  (*env)->ExceptionDescribe(env);

}

/*

 *      Since using the file system as a registry is a bit risky, perform

 *      additional sanity checks on the identified directory to validate

 *      it as a valid jre/sdk.

 *

 *      Return 0 if the tests fail; otherwise return non-zero (true).

 *

 *      Note that checking for anything more than the existence of an

 *      executable object at bin/java relative to the path being checked

 *      will break the regression tests.

 */

static int

CheckSanity(char *path, char *dir)

{

    char    buffer[PATH_MAX];

    if (JLI_StrLen(path) + JLI_StrLen(dir) + 11 > PATH_MAX)

        return (0);     /* Silently reject "impossibly" long paths */

    JLI_Snprintf(buffer, sizeof(buffer), "%s/%s/bin/java", path, dir);

    return ((access(buffer, X_OK) == 0) ? 1 : 0);

}

/*

 *      Determine if there is an acceptable JRE in the directory dirname.

 *      Upon locating the "best" one, return a fully qualified path to

 *      it. "Best" is defined as the most advanced JRE meeting the

 *      constraints contained in the manifest_info. If no JRE in this

 *      directory meets the constraints, return NULL.

 *

 *      Note that we don't check for errors in reading the directory

 *      (which would be done by checking errno).  This is because it

 *      doesn't matter if we get an error reading the directory, or

 *      we just don't find anything interesting in the directory.  We

 *      just return NULL in either case.

 *

 *      The historical names of j2sdk and j2re were changed to jdk and

 *      jre respecively as part of the 1.5 rebranding effort.  Since the

 *      former names are legacy on Linux, they must be recognized for

 *      all time.  Fortunately, this is a minor cost.

 */

static char

*ProcessDir(manifest_info *info, char *dirname)

{

    DIR     *dirp;

    struct dirent *dp;

    char    *best = NULL;

    int     offset;

    int     best_offset = 0;

    char    *ret_str = NULL;

    char    buffer[PATH_MAX];

    if ((dirp = opendir(dirname)) == NULL)

        return (NULL);

    do {

        if ((dp = readdir(dirp)) != NULL) {

            offset = 0;

            if ((JLI_StrNCmp(dp->d_name, "jre", 3) == 0) ||

                (JLI_StrNCmp(dp->d_name, "jdk", 3) == 0))

                offset = 3;

            else if (JLI_StrNCmp(dp->d_name, "j2re", 4) == 0)

                offset = 4;

            else if (JLI_StrNCmp(dp->d_name, "j2sdk", 5) == 0)

                offset = 5;

            if (offset > 0) {

                if ((JLI_AcceptableRelease(dp->d_name + offset,

                    info->jre_version)) && CheckSanity(dirname, dp->d_name))

                    if ((best == NULL) || (JLI_ExactVersionId(

                      dp->d_name + offset, best + best_offset) > 0)) {

                        if (best != NULL)

                            JLI_MemFree(best);

                        best = JLI_StringDup(dp->d_name);

                        best_offset = offset;

                    }

            }

        }

    } while (dp != NULL);

    (void) closedir(dirp);

    if (best == NULL)

        return (NULL);

    else {

        ret_str = JLI_MemAlloc(JLI_StrLen(dirname) + JLI_StrLen(best) + 2);

        sprintf(ret_str, "%s/%s", dirname, best);

        JLI_MemFree(best);

        return (ret_str);

    }

}

/*

 *      This is the global entry point. It examines the host for the optimal

 *      JRE to be used by scanning a set of directories.  The set of directories

 *      is platform dependent and can be overridden by the environment

 *      variable JAVA_VERSION_PATH.

 *

 *      This routine itself simply determines the set of appropriate

 *      directories before passing control onto ProcessDir().

 */

char*

LocateJRE(manifest_info* info)

{

    char        *path;

    char        *home;

    char        *target = NULL;

    char        *dp;

    char        *cp;

    /*

     * Start by getting JAVA_VERSION_PATH

     */

    if (info->jre_restrict_search) {

        path = JLI_StringDup(system_dir);

    } else if ((path = getenv("JAVA_VERSION_PATH")) != NULL) {

        path = JLI_StringDup(path);

    } else {

        if ((home = getenv("HOME")) != NULL) {

            path = (char *)JLI_MemAlloc(JLI_StrLen(home) + \

                        JLI_StrLen(system_dir) + JLI_StrLen(user_dir) + 2);

            sprintf(path, "%s%s:%s", home, user_dir, system_dir);

        } else {

            path = JLI_StringDup(system_dir);

        }

    }

    /*

     * Step through each directory on the path. Terminate the scan with

     * the first directory with an acceptable JRE.

     */

    cp = dp = path;

    while (dp != NULL) {

        cp = JLI_StrChr(dp, (int)':');

        if (cp != NULL)

            *cp = '\0';

        if ((target = ProcessDir(info, dp)) != NULL)

            break;

        dp = cp;

        if (dp != NULL)

            dp++;

    }

    JLI_MemFree(path);

    return (target);

}

/*

 * Given a path to a jre to execute, this routine checks if this process

 * is indeed that jre.  If not, it exec's that jre.

 *

 * We want to actually check the paths rather than just the version string

 * built into the executable, so that given version specification (and

 * JAVA_VERSION_PATH) will yield the exact same Java environment, regardless

 * of the version of the arbitrary launcher we start with.

 */

void

ExecJRE(char *jre, char **argv)

{

    char    wanted[PATH_MAX];

    const char* progname = GetProgramName();

    const char* execname = NULL;

    /*

     * Resolve the real path to the directory containing the selected JRE.

     */

    if (realpath(jre, wanted) == NULL) {

        JLI_ReportErrorMessage(JRE_ERROR9, jre);

        exit(1);

    }

    /*

     * Resolve the real path to the currently running launcher.

     */

    SetExecname(argv);

    execname = GetExecName();

    if (execname == NULL) {

        JLI_ReportErrorMessage(JRE_ERROR10);

        exit(1);

    }

    /*

     * If the path to the selected JRE directory is a match to the initial

     * portion of the path to the currently executing JRE, we have a winner!

     * If so, just return.

     */

    if (JLI_StrNCmp(wanted, execname, JLI_StrLen(wanted)) == 0)

        return;                 /* I am the droid you were looking for */

    /*

     * This should never happen (because of the selection code in SelectJRE),

     * but check for "impossibly" long path names just because buffer overruns

     * can be so deadly.

     */

    if (JLI_StrLen(wanted) + JLI_StrLen(progname) + 6 > PATH_MAX) {

        JLI_ReportErrorMessage(JRE_ERROR11);

        exit(1);

    }

    /*

     * Construct the path and exec it.

     */

    (void)JLI_StrCat(JLI_StrCat(wanted, "/bin/"), progname);

    argv[0] = JLI_StringDup(progname);

    if (JLI_IsTraceLauncher()) {

        int i;

        printf("ReExec Command: %s (%s)\n", wanted, argv[0]);

        printf("ReExec Args:");

        for (i = 1; argv[i] != NULL; i++)

            printf(" %s", argv[i]);

        printf("\n");

    }

    JLI_TraceLauncher("TRACER_MARKER:About to EXEC\n");

    (void)fflush(stdout);

    (void)fflush(stderr);

    execv(wanted, argv);

    JLI_ReportErrorMessageSys(JRE_ERROR12, wanted);

    exit(1);

}

/*

 * "Borrowed" from Solaris 10 where the unsetenv() function is being added

 * to libc thanks to SUSv3 (Standard Unix Specification, version 3). As

 * such, in the fullness of time this will appear in libc on all relevant

 * Solaris/Linux platforms and maybe even the Windows platform.  At that

 * time, this stub can be removed.

 *

 * This implementation removes the environment locking for multithreaded

 * applications.  (We don't have access to these mutexes within libc and

 * the launcher isn't multithreaded.)  Note that what remains is platform

 * independent, because it only relies on attributes that a POSIX environment

 * defines.

 *

 * Returns 0 on success, -1 on failure.

 *

 * Also removed was the setting of errno.  The only value of errno set

 * was EINVAL ("Invalid Argument").

 */

/*

 * s1(environ) is name=value

 * s2(name) is name(not the form of name=value).

 * if names match, return value of 1, else return 0

 */

static int

match_noeq(const char *s1, const char *s2)

{

        while (*s1 == *s2++) {

                if (*s1++ == '=')

                        return (1);

        }

        if (*s1 == '=' && s2[-1] == '\0')

                return (1);

        return (0);

}

/*

 * added for SUSv3 standard

 *

 * Delete entry from environ.

 * Do not free() memory!  Other threads may be using it.

 * Keep it around forever.

 */

static int

borrowed_unsetenv(const char *name)

{

        long    idx;            /* index into environ */

        if (name == NULL || *name == '\0' ||

            JLI_StrChr(name, '=') != NULL) {

                return (-1);

        }

        for (idx = 0; environ[idx] != NULL; idx++) {

                if (match_noeq(environ[idx], name))

                        break;

        }

        if (environ[idx] == NULL) {

                /* name not found but still a success */

                return (0);

        }

        /* squeeze up one entry */

        do {

                environ[idx] = environ[idx+1];

        } while (environ[++idx] != NULL);

        return (0);

}

/* --- End of "borrowed" code --- */

/*

 * Wrapper for unsetenv() function.

 */

int

UnsetEnv(char *name)

{

    return(borrowed_unsetenv(name));

}

const char *

jlong_format_specifier() {

    return "%lld";

}

jboolean

IsJavaw()

{

    /* noop on UNIX */

    return JNI_FALSE;

}

void

InitLauncher(jboolean javaw)

{

    JLI_SetTraceLauncher();

}

/*

 * The implementation for finding classes from the bootstrap

 * class loader, refer to java.h

 */

static FindClassFromBootLoader_t *findBootClass = NULL;

jclass

FindBootStrapClass(JNIEnv *env, const char* classname)

{

   if (findBootClass == NULL) {

       findBootClass = (FindClassFromBootLoader_t *)dlsym(RTLD_DEFAULT,

          "JVM_FindClassFromBootLoader");

       if (findBootClass == NULL) {

           JLI_ReportErrorMessage(DLL_ERROR4,

               "JVM_FindClassFromBootLoader");

           return NULL;

       }

   }

   return findBootClass(env, classname);

}