fs/binfmt_java.c

 9083 /*
 9084  *  linux/fs/binfmt_java.c
 9085  *
 9086  *  Copyright (C) 1996  Brian A. Lantz
 9087  *  derived from binfmt_script.c
 9088  *
 9089  *  Simplified and modified to support binary java
 9090  *  interpreters by Tom May <ftom@netcom.com>.
 9091  */
 9092 
 9093 #include <linux/module.h>
 9094 #include <linux/string.h>
 9095 #include <linux/stat.h>
 9096 #include <linux/malloc.h>
 9097 #include <linux/binfmts.h>
 9098 #include <linux/init.h>
 9099 
 9100 #define _PATH_JAVA      "/usr/bin/java"
 9101 #define _PATH_APPLET    "/usr/bin/appletviewer"
 9102 
 9103 /*  These paths can be modified with sysctl().  */
 9104 
 9105 char binfmt_java_interpreter[65] = _PATH_JAVA;
 9106 char binfmt_java_appletviewer[65] = _PATH_APPLET;
 9107 
 Комментарий
 9108 static int do_load_java(struct linux_binprm *bprm,
 9109                         struct pt_regs *regs)
 9110 {
 9111   char *i_name;
 9112   int len;
 9113   int retval;
 9114   struct dentry * dentry;
 9115   unsigned char *ucp = (unsigned char *) bprm->buf;
 9116 
 9117   if ((ucp[0] != 0xca) || (ucp[1] != 0xfe) ||
 9118       (ucp[2] != 0xba) || (ucp[3] != 0xbe))
 9119     return -ENOEXEC;
 9120 
 9121   /* Fail if we're called recursively, e.g., the Java
 9122    * interpreter is a java binary.  */
 9123   if (bprm->java)
 9124     return -ENOEXEC;
 9125 
 9126   bprm->java = 1;
 9127 
 9128   dput(bprm->dentry);
 9129   bprm->dentry = NULL;
 9130 
 9131   /* Set args: [0] the name of the java interpreter
 9132    *           [1] name of java class to execute, which
 9133    *           is the filename without the path and
 9134    *           without trailing ".class".  Note that the
 9135    *           interpreter will use its own way to found
 9136    *           the class file (typically using
 9137    *           environment variable CLASSPATH), and may
 9138    *           in fact execute a different file from the
 9139    *           one we want.
 9140    *
 9141    * This is done in reverse order, because of how the
 9142    * user environment and arguments are stored.  */
 9143   remove_arg_zero(bprm);
 9144   len = strlen (bprm->filename);
 9145   if (len >= 6 &&
 9146       !strcmp(bprm->filename + len - 6, ".class"))
 9147     bprm->filename[len - 6] = 0;
 9148   if ((i_name = strrchr (bprm->filename, '/')) != NULL)
 9149     i_name++;
 9150   else
 9151     i_name = bprm->filename;
 9152   bprm->p = copy_strings(1, &i_name, bprm->page,
 9153                          bprm->p, 2);
 9154   bprm->argc++;
 9155 
 9156   i_name = binfmt_java_interpreter;
 9157   bprm->p = copy_strings(1, &i_name, bprm->page,
 9158                          bprm->p, 2);
 9159   bprm->argc++;
 9160 
 9161   if (!bprm->p)
 9162     return -E2BIG;
 9163   /* OK, now restart the process with the interpreter's
 9164    * dentry.  */
 9165   bprm->filename = binfmt_java_interpreter;
 9166   dentry = open_namei(binfmt_java_interpreter, 0, 0);
 9167   retval = PTR_ERR(dentry);
 9168   if (IS_ERR(dentry))
 9169     return retval;
 9170 
 9171   bprm->dentry = dentry;
 9172   retval = prepare_binprm(bprm);
 9173   if (retval < 0)
 9174     return retval;
 9175 
 9176   return search_binary_handler(bprm,regs);
 9177 }
 9178 
 9179 static int do_load_applet(struct linux_binprm *bprm,
 9180                           struct pt_regs *regs)
 9181 {
 9182   char *i_name;
 9183   struct dentry * dentry;
 9184   int retval;
 9185 
 9186   if (strncmp (bprm->buf, "<!--applet", 10))
 9187     return -ENOEXEC;
 9188 
 9189   dput(bprm->dentry);
 9190   bprm->dentry = NULL;
 9191 
 9192   /* Set args: [0] the name of the appletviewer
 9193    *           [1] filename of html file
 9194    *
 9195    * This is done in reverse order, because of how the
 9196    * user environment and arguments are stored.  */
 9197   remove_arg_zero(bprm);
 9198   i_name = bprm->filename;
 9199   bprm->p = copy_strings(1, &i_name, bprm->page,
 9200                          bprm->p, 2);
 9201   bprm->argc++;
 9202 
 9203   i_name = binfmt_java_appletviewer;
 9204   bprm->p = copy_strings(1, &i_name, bprm->page,
 9205                          bprm->p, 2);
 9206   bprm->argc++;
 9207 
 9208   if (!bprm->p)
 9209     return -E2BIG;
 9210   /* OK, now restart the process with the interpreter's
 9211    * dentry.  */
 9212   bprm->filename = binfmt_java_appletviewer;
 9213   dentry = open_namei(binfmt_java_appletviewer, 0, 0);
 9214   retval = PTR_ERR(dentry);
 9215   if (IS_ERR(dentry))
 9216     return retval;
 9217 
 9218   bprm->dentry = dentry;
 9219   retval = prepare_binprm(bprm);
 9220   if (retval < 0)
 9221     return retval;
 9222 
 9223   return search_binary_handler(bprm,regs);
 9224 }
 9225 
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 9226 static int load_java(struct linux_binprm *bprm,
 9227                      struct pt_regs *regs)
 9228 {
 9229   int retval;
 9230   MOD_INC_USE_COUNT;
 9231   retval = do_load_java(bprm,regs);
 9232   MOD_DEC_USE_COUNT;
 9233   return retval;
 9234 }
 9235 
 9236 static struct linux_binfmt java_format = {
 9237 #ifndef MODULE
 9238   NULL, 0, load_java, NULL, NULL
 9239 #else
 9240   NULL, &__this_module, load_java, NULL, NULL
 9241 #endif
 9242 };
 9243 
 9244 static int load_applet(struct linux_binprm *bprm,
 9245                        struct pt_regs *regs)
 9246 {
 9247   int retval;
 9248   MOD_INC_USE_COUNT;
 9249   retval = do_load_applet(bprm,regs);
 9250   MOD_DEC_USE_COUNT;
 9251   return retval;
 9252 }
 9253 
 9254 static struct linux_binfmt applet_format = {
 9255 #ifndef MODULE
 9256   NULL, 0, load_applet, NULL, NULL
 9257 #else
 9258   NULL, &__this_module, load_applet, NULL, NULL
 9259 #endif
 9260 };
 9261 
 9262 int __init init_java_binfmt(void)
 9263 {
 9264   register_binfmt(&java_format);
 9265   return register_binfmt(&applet_format);
 9266 }
 9267 
 9268 #ifdef MODULE
 9269 int init_module(void)
 9270 {
 9271   return init_java_binfmt();
 9272 }
 9273 
 9274 void cleanup_module( void) {
 9275   unregister_binfmt(&java_format);
 9276   unregister_binfmt(&applet_format);
 9277 }
 9278 #endif