1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright 1998,2003 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /*
28 * This file contains native methods for the Java SLP implementation.
29 * So far this is just the syslog function.
30 *
31 * The file also contains two support functions, one for throwing exceptions
32 * given a class name, and one for correctly converting unicode Strings to C
33 * byte arrays.
34 */
35
36 #include <malloc.h>
37 #include <jni.h>
38 #include <syslog.h>
39
40 #define CLASS_JAVA_LANG_OUTOFMEMORYERROR "java/lang/OutOfMemoryError"
41 #define CLASS_JAVA_LANG_STRING "java/lang/String"
42
43 #define METHOD_GETBYTES "getBytes"
44
45 #define SIG_JAVA_LANG_STRING_GETBYTES "()[B"
46
47 /*
48 * Given a class name of an exception and a message attempt to throw
49 * a new instance of the exception.
50 */
51 static void
JNU_ThrowByName(JNIEnv * env,const char * name,const char * msg)52 JNU_ThrowByName(JNIEnv *env, const char *name, const char *msg)
53 {
54 jclass class = (*env)->FindClass(env, name);
55
56 /*
57 * If class is NULL FindClass() encountered a problem locating the
58 * desired class and has already called ThrowNew() with an
59 * exception.
60 */
61 if (class == NULL) {
62 return;
63 }
64
65 (*env)->ThrowNew(env, class, msg);
66 (*env)->DeleteLocalRef(env, class);
67 }
68
69 /*
70 * Convert a Java String into a native set of characters using the
71 * method String.getBytes(). This will ensure that the appropriate
72 * character set encoding will be used. This is necessary if the
73 * Java String uses unicode characters that cannot be easily
74 * encoded into native chars.
75 *
76 * The buffer returned must be released by using free() once it is
77 * finished with.
78 *
79 * This function returns NULL if an exception has been thrown during its
80 * execution.
81 */
82 static char
JNU_GetStringNativeChars(JNIEnv * env,jstring jstr)83 *JNU_GetStringNativeChars(JNIEnv *env, jstring jstr)
84 {
85 jclass class;
86 jmethodID method;
87 jint len;
88 jbyteArray bytes = NULL;
89 char *result = NULL;
90
91 /*
92 * Need a local reference for (1) FindClass(), (2) the bytes and
93 * (3) the FindClass() in ThrowByName() if all goes wrong.
94 */
95 if ((*env)->EnsureLocalCapacity(env, 3) < 0) {
96 JNU_ThrowByName(
97 env,
98 CLASS_JAVA_LANG_OUTOFMEMORYERROR,
99 NULL);
100
101 return (NULL);
102 }
103
104 class = (*env)->FindClass(env, CLASS_JAVA_LANG_STRING);
105
106 /*
107 * If class is NULL FindClass() encountered a problem locating the
108 * desired class and has already called ThrowNew() with an
109 * exception.
110 */
111 if (class == NULL) {
112 return (NULL);
113 }
114
115 method = (*env)->GetMethodID(
116 env,
117 class,
118 METHOD_GETBYTES,
119 SIG_JAVA_LANG_STRING_GETBYTES);
120
121 /*
122 * If method is NULL GetMethodID() encountered a problem
123 * locating the desired method and has already called
124 * ThrowNew() with an exception.
125 */
126 if (method != NULL) {
127 /*
128 * Call String.getBytes(), creating our temporary
129 * byte array
130 */
131 bytes = (*env)->CallObjectMethod(env, jstr, method);
132
133 /* See if CallObjectMethod() threw an exception */
134 if ((*env)->ExceptionCheck(env) == JNI_FALSE) {
135
136 len = (*env)->GetArrayLength(env, bytes);
137
138 /*
139 * Allocate a buffer for the native characters,
140 * need an extra char for string terminator.
141 * Note: calloc will provide the terminating
142 * '\0' for us.
143 */
144 result = (char *)calloc(len + 1, sizeof (char));
145
146 /*
147 * If allocation failed assume we are out of
148 * memory
149 */
150 if (result == NULL) {
151 JNU_ThrowByName(
152 env,
153 CLASS_JAVA_LANG_OUTOFMEMORYERROR,
154 NULL);
155 } else {
156 /*
157 * Copy the encoded bytes into the
158 * native string buffer
159 */
160 (*env)->GetByteArrayRegion(
161 env,
162 bytes,
163 0,
164 len,
165 (jbyte *)result);
166 }
167 }
168
169 if (bytes != NULL) {
170 (*env)->DeleteLocalRef(env, bytes);
171 }
172 }
173
174 /* Clean up by deleting the local references */
175 (*env)->DeleteLocalRef(env, class);
176
177 return (result);
178 }
179
180 /*
181 * Class: com_sun_slp_Syslog
182 * Method: syslog
183 * Signature: (ILjava/lang/String;)V
184 */
185 /* ARGSUSED */
186 JNIEXPORT
Java_com_sun_slp_Syslog_syslog(JNIEnv * env,jobject obj,jint priority,jstring jmsg)187 void JNICALL Java_com_sun_slp_Syslog_syslog(JNIEnv *env,
188 jobject obj,
189 jint priority,
190 jstring jmsg) {
191
192 char *msg = JNU_GetStringNativeChars(env, jmsg);
193
194 /*
195 * Check to see if the String conversion was successful,
196 * if it wasn't an exception will have already been thrown.
197 */
198 if (msg != NULL) {
199 openlog("slpd", LOG_PID, LOG_DAEMON);
200 syslog(priority, "%s", msg);
201 closelog();
202
203 free(msg);
204 }
205 }
206