/*

 * Copyright (c) 2004, 2011, Oracle and/or its affiliates. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 *   - Redistributions of source code must retain the above copyright

 *     notice, this list of conditions and the following disclaimer.

 *

 *   - Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution.

 *

 *   - Neither the name of Oracle nor the names of its

 *     contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

/*

 * This source code is provided to illustrate the usage of a given feature

 * or technique and has been deliberately simplified. Additional steps

 * required for a production-quality application, such as security checks,

 * input validation and proper error handling, might not be present in

 * this sample code.

 */

#include <agent_util.h>

/* ------------------------------------------------------------------- */

/* Generic C utility functions */

/* Send message to stdout or whatever the data output location is */

void

stdout_message(const char * format, ...)

{

    va_list ap;

    va_start(ap, format);

    (void)vfprintf(stdout, format, ap);

    va_end(ap);

}

/* Send message to stderr or whatever the error output location is and exit  */

void

fatal_error(const char * format, ...)

{

    va_list ap;

    va_start(ap, format);

    (void)vfprintf(stderr, format, ap);

    (void)fflush(stderr);

    va_end(ap);

    exit(3);

}

/* Get a token from a string (strtok is not MT-safe)

 *    str       String to scan

 *    seps      Separation characters

 *    buf       Place to put results

 *    max       Size of buf

 *  Returns NULL if no token available or can't do the scan.

 */

char *

get_token(char *str, char *seps, char *buf, int max)

{

    int len;

    buf[0] = 0;

    if ( str==NULL || str[0]==0 ) {

        return NULL;

    }

    str += strspn(str, seps);

    if ( str[0]==0 ) {

        return NULL;

    }

    len = (int)strcspn(str, seps);

    if ( len >= max ) {

        return NULL;

    }

    (void)strncpy(buf, str, len);

    buf[len] = 0;

    return str+len;

}

/* Determines if a class/method is specified by a list item

 *   item       String that represents a pattern to match

 *                If it starts with a '*', then any class is allowed

 *                If it ends with a '*', then any method is allowed

 *   cname      Class name, e.g. "java.lang.Object"

 *   mname      Method name, e.g. "<init>"

 *  Returns 1(true) or 0(false).

 */

static int

covered_by_list_item(char *item, char *cname, char *mname)

{

    int      len;

    len = (int)strlen(item);

    if ( item[0]=='*' ) {

        if ( strncmp(mname, item+1, len-1)==0 ) {

            return 1;

        }

    } else if ( item[len-1]=='*' ) {

        if ( strncmp(cname, item, len-1)==0 ) {

            return 1;

        }

    } else {

        int cname_len;

        cname_len = (int)strlen(cname);

        if ( strncmp(cname, item, (len>cname_len?cname_len:len))==0 ) {

            if ( cname_len >= len ) {

                /* No method name supplied in item, we must have matched */

                return 1;

            } else {

                int mname_len;

                mname_len = (int)strlen(mname);

                item += cname_len+1;

                len -= cname_len+1;

                if ( strncmp(mname, item, (len>mname_len?mname_len:len))==0 ) {

                    return 1;

                }

            }

        }

    }

    return 0;

}

/* Determines if a class/method is specified by this list

 *   list       String of comma separated pattern items

 *   cname      Class name, e.g. "java.lang.Object"

 *   mname      Method name, e.g. "<init>"

 *  Returns 1(true) or 0(false).

 */

static int

covered_by_list(char *list, char *cname, char *mname)

{

    char  token[1024];

    char *next;

    if ( list[0] == 0 ) {

        return 0;

    }

    next = get_token(list, ",", token, sizeof(token));

    while ( next != NULL ) {

        if ( covered_by_list_item(token, cname, mname) ) {

            return 1;

        }

        next = get_token(next, ",", token, sizeof(token));

    }

    return 0;

}

/* Determines which class and methods we are interested in

 *   cname              Class name, e.g. "java.lang.Object"

 *   mname              Method name, e.g. "<init>"

 *   include_list       Empty or an explicit list for inclusion

 *   exclude_list       Empty or an explicit list for exclusion

 *  Returns 1(true) or 0(false).

 */

int

interested(char *cname, char *mname, char *include_list, char *exclude_list)

{

    if ( exclude_list!=NULL && exclude_list[0]!=0 &&

            covered_by_list(exclude_list, cname, mname) ) {

        return 0;

    }

    if ( include_list!=NULL && include_list[0]!=0 &&

            !covered_by_list(include_list, cname, mname) ) {

        return 0;

    }

    return 1;

}

/* ------------------------------------------------------------------- */

/* Generic JVMTI utility functions */

/* Every JVMTI interface returns an error code, which should be checked

 *   to avoid any cascading errors down the line.

 *   The interface GetErrorName() returns the actual enumeration constant

 *   name, making the error messages much easier to understand.

 */

void

check_jvmti_error(jvmtiEnv *jvmti, jvmtiError errnum, const char *str)

{

    if ( errnum != JVMTI_ERROR_NONE ) {

        char       *errnum_str;

        errnum_str = NULL;

        (void)(*jvmti)->GetErrorName(jvmti, errnum, &errnum_str);

        fatal_error("ERROR: JVMTI: %d(%s): %s\n", errnum,

                (errnum_str==NULL?"Unknown":errnum_str),

                (str==NULL?"":str));

    }

}

/* All memory allocated by JVMTI must be freed by the JVMTI Deallocate

 *   interface.

 */

void

deallocate(jvmtiEnv *jvmti, void *ptr)

{

    jvmtiError error;

    error = (*jvmti)->Deallocate(jvmti, ptr);

    check_jvmti_error(jvmti, error, "Cannot deallocate memory");

}

/* Allocation of JVMTI managed memory */

void *

allocate(jvmtiEnv *jvmti, jint len)

{

    jvmtiError error;

    void      *ptr;

    error = (*jvmti)->Allocate(jvmti, len, (unsigned char **)&ptr);

    check_jvmti_error(jvmti, error, "Cannot allocate memory");

    return ptr;

}

/* Add demo jar file to boot class path (the BCI Tracker class must be

 *     in the boot classpath)

 *

 *   WARNING: This code assumes that the jar file can be found at one of:

 *              ${JAVA_HOME}/demo/jvmti/${DEMO_NAME}/${DEMO_NAME}.jar

 *              ${JAVA_HOME}/../demo/jvmti/${DEMO_NAME}/${DEMO_NAME}.jar

 *            where JAVA_HOME may refer to the jre directory.

 *            Both these values are added to the boot classpath.

 *            These locations are only true for these demos, installed

 *            in the JDK area. Platform specific code could be used to

 *            find the location of the DLL or .so library, and construct a

 *            path name to the jar file, relative to the library location.

 */

void

add_demo_jar_to_bootclasspath(jvmtiEnv *jvmti, char *demo_name)

{

    jvmtiError error;

    char      *file_sep;

    int        max_len;

    char      *java_home;

    char       jar_path[FILENAME_MAX+1];

    java_home = NULL;

    error = (*jvmti)->GetSystemProperty(jvmti, "java.home", &java_home);

    check_jvmti_error(jvmti, error, "Cannot get java.home property value");

    if ( java_home == NULL || java_home[0] == 0 ) {

        fatal_error("ERROR: Java home not found\n");

    }

#ifdef WIN32

    file_sep = "\\";

#else

    file_sep = "/";

#endif

    max_len = (int)(strlen(java_home) + strlen(demo_name)*2 +

                         strlen(file_sep)*5 +

                         16 /* ".." "demo" "jvmti" ".jar" NULL */ );

    if ( max_len > (int)sizeof(jar_path) ) {

        fatal_error("ERROR: Path to jar file too long\n");

    }

    (void)strcpy(jar_path, java_home);

    (void)strcat(jar_path, file_sep);

    (void)strcat(jar_path, "demo");

    (void)strcat(jar_path, file_sep);

    (void)strcat(jar_path, "jvmti");

    (void)strcat(jar_path, file_sep);

    (void)strcat(jar_path, demo_name);

    (void)strcat(jar_path, file_sep);

    (void)strcat(jar_path, demo_name);

    (void)strcat(jar_path, ".jar");

    error = (*jvmti)->AddToBootstrapClassLoaderSearch(jvmti, (const char*)jar_path);

    check_jvmti_error(jvmti, error, "Cannot add to boot classpath");

    (void)strcpy(jar_path, java_home);

    (void)strcat(jar_path, file_sep);

    (void)strcat(jar_path, "..");

    (void)strcat(jar_path, file_sep);

    (void)strcat(jar_path, "demo");

    (void)strcat(jar_path, file_sep);

    (void)strcat(jar_path, "jvmti");

    (void)strcat(jar_path, file_sep);

    (void)strcat(jar_path, demo_name);

    (void)strcat(jar_path, file_sep);

    (void)strcat(jar_path, demo_name);

    (void)strcat(jar_path, ".jar");

    error = (*jvmti)->AddToBootstrapClassLoaderSearch(jvmti, (const char*)jar_path);

    check_jvmti_error(jvmti, error, "Cannot add to boot classpath");

}

/* ------------------------------------------------------------------- */