crypto/dso/dso_dlfcn.c - third_party/openssl - Git at Google

 /*
  * Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
  * in the file LICENSE in the source distribution or at
  * https://www.openssl.org/source/license.html
  */

 /*
  * We need to do this early, because stdio.h includes the header files that
  * handle _GNU_SOURCE and other similar macros.  Defining it later is simply
  * too late, because those headers are protected from re- inclusion.
  */
 #ifndef _GNU_SOURCE
 # define _GNU_SOURCE            /* make sure dladdr is declared */
 #endif

 #include "dso_locl.h"

 #ifdef DSO_DLFCN

 # ifdef HAVE_DLFCN_H
 #  ifdef __osf__
 #   define __EXTENSIONS__
 #  endif
 #  include <dlfcn.h>
 #  define HAVE_DLINFO 1
 #  if defined(_AIX) || defined(__CYGWIN__) || \
      defined(__SCO_VERSION__) || defined(_SCO_ELF) || \
      (defined(__osf__) && !defined(RTLD_NEXT))     || \
      (defined(__OpenBSD__) && !defined(RTLD_SELF)) || \
         defined(__ANDROID__)
 #   undef HAVE_DLINFO
 #  endif
 # endif

 /* Part of the hack in "dlfcn_load" ... */
 # define DSO_MAX_TRANSLATED_SIZE 256

 static int dlfcn_load(DSO *dso);
 static int dlfcn_unload(DSO *dso);
 static DSO_FUNC_TYPE dlfcn_bind_func(DSO *dso, const char *symname);
 static char *dlfcn_name_converter(DSO *dso, const char *filename);
 static char *dlfcn_merger(DSO *dso, const char *filespec1,
                           const char *filespec2);
 static int dlfcn_pathbyaddr(void *addr, char *path, int sz);
 static void *dlfcn_globallookup(const char *name);

 static DSO_METHOD dso_meth_dlfcn = {
     "OpenSSL 'dlfcn' shared library method",
     dlfcn_load,
     dlfcn_unload,
     dlfcn_bind_func,
     NULL,                       /* ctrl */
     dlfcn_name_converter,
     dlfcn_merger,
     NULL,                       /* init */
     NULL,                       /* finish */
     dlfcn_pathbyaddr,
     dlfcn_globallookup
 };

 DSO_METHOD *DSO_METHOD_openssl(void)
 {
     return &dso_meth_dlfcn;
 }

 /*
  * Prior to using the dlopen() function, we should decide on the flag we
  * send. There's a few different ways of doing this and it's a messy
  * venn-diagram to match up which platforms support what. So as we don't have
  * autoconf yet, I'm implementing a hack that could be hacked further
  * relatively easily to deal with cases as we find them. Initially this is to
  * cope with OpenBSD.
  */
 # if defined(__OpenBSD__) || defined(__NetBSD__)
 #  ifdef DL_LAZY
 #   define DLOPEN_FLAG DL_LAZY
 #  else
 #   ifdef RTLD_NOW
 #    define DLOPEN_FLAG RTLD_NOW
 #   else
 #    define DLOPEN_FLAG 0
 #   endif
 #  endif
 # else
 #  define DLOPEN_FLAG RTLD_NOW  /* Hope this works everywhere else */
 # endif

 /*
  * For this DSO_METHOD, our meth_data STACK will contain; (i) the handle
  * (void*) returned from dlopen().
  */

 static int dlfcn_load(DSO *dso)
 {
     void *ptr = NULL;
     /* See applicable comments in dso_dl.c */
     char *filename = DSO_convert_filename(dso, NULL);
     int flags = DLOPEN_FLAG;

     if (filename == NULL) {
         DSOerr(DSO_F_DLFCN_LOAD, DSO_R_NO_FILENAME);
         goto err;
     }
 # ifdef RTLD_GLOBAL
     if (dso->flags & DSO_FLAG_GLOBAL_SYMBOLS)
         flags |= RTLD_GLOBAL;
 # endif
     ptr = dlopen(filename, flags);
     if (ptr == NULL) {
         DSOerr(DSO_F_DLFCN_LOAD, DSO_R_LOAD_FAILED);
         ERR_add_error_data(4, "filename(", filename, "): ", dlerror());
         goto err;
     }
     if (!sk_void_push(dso->meth_data, (char *)ptr)) {
         DSOerr(DSO_F_DLFCN_LOAD, DSO_R_STACK_ERROR);
         goto err;
     }
     /* Success */
     dso->loaded_filename = filename;
     return (1);
  err:
     /* Cleanup! */
     OPENSSL_free(filename);
     if (ptr != NULL)
         dlclose(ptr);
     return (0);
 }

 static int dlfcn_unload(DSO *dso)
 {
     void *ptr;
     if (dso == NULL) {
         DSOerr(DSO_F_DLFCN_UNLOAD, ERR_R_PASSED_NULL_PARAMETER);
         return (0);
     }
     if (sk_void_num(dso->meth_data) < 1)
         return (1);
     ptr = sk_void_pop(dso->meth_data);
     if (ptr == NULL) {
         DSOerr(DSO_F_DLFCN_UNLOAD, DSO_R_NULL_HANDLE);
         /*
          * Should push the value back onto the stack in case of a retry.
          */
         sk_void_push(dso->meth_data, ptr);
         return (0);
     }
     /* For now I'm not aware of any errors associated with dlclose() */
     dlclose(ptr);
     return (1);
 }

 static DSO_FUNC_TYPE dlfcn_bind_func(DSO *dso, const char *symname)
 {
     void *ptr;
     union {
         DSO_FUNC_TYPE sym;
         void *dlret;
     } u;

     if ((dso == NULL) || (symname == NULL)) {
         DSOerr(DSO_F_DLFCN_BIND_FUNC, ERR_R_PASSED_NULL_PARAMETER);
         return (NULL);
     }
     if (sk_void_num(dso->meth_data) < 1) {
         DSOerr(DSO_F_DLFCN_BIND_FUNC, DSO_R_STACK_ERROR);
         return (NULL);
     }
     ptr = sk_void_value(dso->meth_data, sk_void_num(dso->meth_data) - 1);
     if (ptr == NULL) {
         DSOerr(DSO_F_DLFCN_BIND_FUNC, DSO_R_NULL_HANDLE);
         return (NULL);
     }
     u.dlret = dlsym(ptr, symname);
     if (u.dlret == NULL) {
         DSOerr(DSO_F_DLFCN_BIND_FUNC, DSO_R_SYM_FAILURE);
         ERR_add_error_data(4, "symname(", symname, "): ", dlerror());
         return (NULL);
     }
     return u.sym;
 }

 static char *dlfcn_merger(DSO *dso, const char *filespec1,
                           const char *filespec2)
 {
     char *merged;

     if (!filespec1 && !filespec2) {
         DSOerr(DSO_F_DLFCN_MERGER, ERR_R_PASSED_NULL_PARAMETER);
         return (NULL);
     }
     /*
      * If the first file specification is a rooted path, it rules. same goes
      * if the second file specification is missing.
      */
     if (!filespec2 || (filespec1 != NULL && filespec1[0] == '/')) {
         merged = OPENSSL_strdup(filespec1);
         if (merged == NULL) {
             DSOerr(DSO_F_DLFCN_MERGER, ERR_R_MALLOC_FAILURE);
             return (NULL);
         }
     }
     /*
      * If the first file specification is missing, the second one rules.
      */
     else if (!filespec1) {
         merged = OPENSSL_strdup(filespec2);
         if (merged == NULL) {
             DSOerr(DSO_F_DLFCN_MERGER, ERR_R_MALLOC_FAILURE);
             return (NULL);
         }
     } else {
         /*
          * This part isn't as trivial as it looks.  It assumes that the
          * second file specification really is a directory, and makes no
          * checks whatsoever.  Therefore, the result becomes the
          * concatenation of filespec2 followed by a slash followed by
          * filespec1.
          */
         int spec2len, len;

         spec2len = strlen(filespec2);
         len = spec2len + strlen(filespec1);

         if (spec2len && filespec2[spec2len - 1] == '/') {
             spec2len--;
             len--;
         }
         merged = OPENSSL_malloc(len + 2);
         if (merged == NULL) {
             DSOerr(DSO_F_DLFCN_MERGER, ERR_R_MALLOC_FAILURE);
             return (NULL);
         }
         strcpy(merged, filespec2);
         merged[spec2len] = '/';
         strcpy(&merged[spec2len + 1], filespec1);
     }
     return (merged);
 }

 static char *dlfcn_name_converter(DSO *dso, const char *filename)
 {
     char *translated;
     int len, rsize, transform;

     len = strlen(filename);
     rsize = len + 1;
     transform = (strstr(filename, "/") == NULL);
     if (transform) {
         /* We will convert this to "%s.so" or "lib%s.so" etc */
         rsize += strlen(DSO_EXTENSION);    /* The length of ".so" */
         if ((DSO_flags(dso) & DSO_FLAG_NAME_TRANSLATION_EXT_ONLY) == 0)
             rsize += 3;         /* The length of "lib" */
     }
     translated = OPENSSL_malloc(rsize);
     if (translated == NULL) {
         DSOerr(DSO_F_DLFCN_NAME_CONVERTER, DSO_R_NAME_TRANSLATION_FAILED);
         return (NULL);
     }
     if (transform) {
         if ((DSO_flags(dso) & DSO_FLAG_NAME_TRANSLATION_EXT_ONLY) == 0)
             sprintf(translated, "lib%s" DSO_EXTENSION, filename);
         else
             sprintf(translated, "%s" DSO_EXTENSION, filename);
     } else
         sprintf(translated, "%s", filename);
     return (translated);
 }

 # ifdef __sgi
 /*-
 This is a quote from IRIX manual for dladdr(3c):

      <dlfcn.h> does not contain a prototype for dladdr or definition of
      Dl_info.  The #include <dlfcn.h>  in the SYNOPSIS line is traditional,
      but contains no dladdr prototype and no IRIX library contains an
      implementation.  Write your own declaration based on the code below.

      The following code is dependent on internal interfaces that are not
      part of the IRIX compatibility guarantee; however, there is no future
      intention to change this interface, so on a practical level, the code
      below is safe to use on IRIX.
 */
 #  include <rld_interface.h>
 #  ifndef _RLD_INTERFACE_DLFCN_H_DLADDR
 #   define _RLD_INTERFACE_DLFCN_H_DLADDR
 typedef struct Dl_info {
     const char *dli_fname;
     void *dli_fbase;
     const char *dli_sname;
     void *dli_saddr;
     int dli_version;
     int dli_reserved1;
     long dli_reserved[4];
 } Dl_info;
 #  else
 typedef struct Dl_info Dl_info;
 #  endif
 #  define _RLD_DLADDR             14

 static int dladdr(void *address, Dl_info *dl)
 {
     void *v;
     v = _rld_new_interface(_RLD_DLADDR, address, dl);
     return (int)v;
 }
 # endif                         /* __sgi */

 static int dlfcn_pathbyaddr(void *addr, char *path, int sz)
 {
 # ifdef HAVE_DLINFO
     Dl_info dli;
     int len;

     if (addr == NULL) {
         union {
             int (*f) (void *, char *, int);
             void *p;
         } t = {
             dlfcn_pathbyaddr
         };
         addr = t.p;
     }

     if (dladdr(addr, &dli)) {
         len = (int)strlen(dli.dli_fname);
         if (sz <= 0)
             return len + 1;
         if (len >= sz)
             len = sz - 1;
         memcpy(path, dli.dli_fname, len);
         path[len++] = 0;
         return len;
     }

     ERR_add_error_data(2, "dlfcn_pathbyaddr(): ", dlerror());
 # endif
     return -1;
 }

 static void *dlfcn_globallookup(const char *name)
 {
     void *ret = NULL, *handle = dlopen(NULL, RTLD_LAZY);

     if (handle) {
         ret = dlsym(handle, name);
         dlclose(handle);
     }

     return ret;
 }
 #endif                          /* DSO_DLFCN */
	/*
	* Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
	*
	* Licensed under the OpenSSL license (the "License"). You may not use
	* this file except in compliance with the License. You can obtain a copy
	* in the file LICENSE in the source distribution or at
	* https://www.openssl.org/source/license.html
	*/

	/*
	* We need to do this early, because stdio.h includes the header files that
	* handle _GNU_SOURCE and other similar macros. Defining it later is simply
	* too late, because those headers are protected from re- inclusion.
	*/
	#ifndef _GNU_SOURCE
	# define _GNU_SOURCE /* make sure dladdr is declared */
	#endif

	#include "dso_locl.h"

	#ifdef DSO_DLFCN

	# ifdef HAVE_DLFCN_H
	# ifdef __osf__
	# define __EXTENSIONS__
	# endif
	# include <dlfcn.h>
	# define HAVE_DLINFO 1
	# if defined(_AIX) \|\| defined(__CYGWIN__) \|\| \
	defined(__SCO_VERSION__) \|\| defined(_SCO_ELF) \|\| \
	(defined(__osf__) && !defined(RTLD_NEXT)) \|\| \
	(defined(__OpenBSD__) && !defined(RTLD_SELF)) \|\| \
	defined(__ANDROID__)
	# undef HAVE_DLINFO
	# endif
	# endif

	/* Part of the hack in "dlfcn_load" ... */
	# define DSO_MAX_TRANSLATED_SIZE 256

	static int dlfcn_load(DSO *dso);
	static int dlfcn_unload(DSO *dso);
	static DSO_FUNC_TYPE dlfcn_bind_func(DSO dso, const char symname);
	static char dlfcn_name_converter(DSO dso, const char *filename);
	static char dlfcn_merger(DSO dso, const char *filespec1,
	const char *filespec2);
	static int dlfcn_pathbyaddr(void addr, char path, int sz);
	static void dlfcn_globallookup(const char name);

	static DSO_METHOD dso_meth_dlfcn = {
	"OpenSSL 'dlfcn' shared library method",
	dlfcn_load,
	dlfcn_unload,
	dlfcn_bind_func,
	NULL, /* ctrl */
	dlfcn_name_converter,
	dlfcn_merger,
	NULL, /* init */
	NULL, /* finish */
	dlfcn_pathbyaddr,
	dlfcn_globallookup
	};

	DSO_METHOD *DSO_METHOD_openssl(void)
	{
	return &dso_meth_dlfcn;
	}

	/*
	* Prior to using the dlopen() function, we should decide on the flag we
	* send. There's a few different ways of doing this and it's a messy
	* venn-diagram to match up which platforms support what. So as we don't have
	* autoconf yet, I'm implementing a hack that could be hacked further
	* relatively easily to deal with cases as we find them. Initially this is to
	* cope with OpenBSD.
	*/
	# if defined(__OpenBSD__) \|\| defined(__NetBSD__)
	# ifdef DL_LAZY
	# define DLOPEN_FLAG DL_LAZY
	# else
	# ifdef RTLD_NOW
	# define DLOPEN_FLAG RTLD_NOW
	# else
	# define DLOPEN_FLAG 0
	# endif
	# endif
	# else
	# define DLOPEN_FLAG RTLD_NOW /* Hope this works everywhere else */
	# endif

	/*
	* For this DSO_METHOD, our meth_data STACK will contain; (i) the handle
	* (void*) returned from dlopen().
	*/

	static int dlfcn_load(DSO *dso)
	{
	void *ptr = NULL;
	/* See applicable comments in dso_dl.c */
	char *filename = DSO_convert_filename(dso, NULL);
	int flags = DLOPEN_FLAG;

	if (filename == NULL) {
	DSOerr(DSO_F_DLFCN_LOAD, DSO_R_NO_FILENAME);
	goto err;
	}
	# ifdef RTLD_GLOBAL
	if (dso->flags & DSO_FLAG_GLOBAL_SYMBOLS)
	flags \|= RTLD_GLOBAL;
	# endif
	ptr = dlopen(filename, flags);
	if (ptr == NULL) {
	DSOerr(DSO_F_DLFCN_LOAD, DSO_R_LOAD_FAILED);
	ERR_add_error_data(4, "filename(", filename, "): ", dlerror());
	goto err;
	}
	if (!sk_void_push(dso->meth_data, (char *)ptr)) {
	DSOerr(DSO_F_DLFCN_LOAD, DSO_R_STACK_ERROR);
	goto err;
	}
	/* Success */
	dso->loaded_filename = filename;
	return (1);
	err:
	/* Cleanup! */
	OPENSSL_free(filename);
	if (ptr != NULL)
	dlclose(ptr);
	return (0);
	}

	static int dlfcn_unload(DSO *dso)
	{
	void *ptr;
	if (dso == NULL) {
	DSOerr(DSO_F_DLFCN_UNLOAD, ERR_R_PASSED_NULL_PARAMETER);
	return (0);
	}
	if (sk_void_num(dso->meth_data) < 1)
	return (1);
	ptr = sk_void_pop(dso->meth_data);
	if (ptr == NULL) {
	DSOerr(DSO_F_DLFCN_UNLOAD, DSO_R_NULL_HANDLE);
	/*
	* Should push the value back onto the stack in case of a retry.
	*/
	sk_void_push(dso->meth_data, ptr);
	return (0);
	}
	/* For now I'm not aware of any errors associated with dlclose() */
	dlclose(ptr);
	return (1);
	}

	static DSO_FUNC_TYPE dlfcn_bind_func(DSO dso, const char symname)
	{
	void *ptr;
	union {
	DSO_FUNC_TYPE sym;
	void *dlret;
	} u;

	if ((dso == NULL) \|\| (symname == NULL)) {
	DSOerr(DSO_F_DLFCN_BIND_FUNC, ERR_R_PASSED_NULL_PARAMETER);
	return (NULL);
	}
	if (sk_void_num(dso->meth_data) < 1) {
	DSOerr(DSO_F_DLFCN_BIND_FUNC, DSO_R_STACK_ERROR);
	return (NULL);
	}
	ptr = sk_void_value(dso->meth_data, sk_void_num(dso->meth_data) - 1);
	if (ptr == NULL) {
	DSOerr(DSO_F_DLFCN_BIND_FUNC, DSO_R_NULL_HANDLE);
	return (NULL);
	}
	u.dlret = dlsym(ptr, symname);
	if (u.dlret == NULL) {
	DSOerr(DSO_F_DLFCN_BIND_FUNC, DSO_R_SYM_FAILURE);
	ERR_add_error_data(4, "symname(", symname, "): ", dlerror());
	return (NULL);
	}
	return u.sym;
	}

	static char dlfcn_merger(DSO dso, const char *filespec1,
	const char *filespec2)
	{
	char *merged;

	if (!filespec1 && !filespec2) {
	DSOerr(DSO_F_DLFCN_MERGER, ERR_R_PASSED_NULL_PARAMETER);
	return (NULL);
	}
	/*
	* If the first file specification is a rooted path, it rules. same goes
	* if the second file specification is missing.
	*/
	if (!filespec2 \|\| (filespec1 != NULL && filespec1[0] == '/')) {
	merged = OPENSSL_strdup(filespec1);
	if (merged == NULL) {
	DSOerr(DSO_F_DLFCN_MERGER, ERR_R_MALLOC_FAILURE);
	return (NULL);
	}
	}
	/*
	* If the first file specification is missing, the second one rules.
	*/
	else if (!filespec1) {
	merged = OPENSSL_strdup(filespec2);
	if (merged == NULL) {
	DSOerr(DSO_F_DLFCN_MERGER, ERR_R_MALLOC_FAILURE);
	return (NULL);
	}
	} else {
	/*
	* This part isn't as trivial as it looks. It assumes that the
	* second file specification really is a directory, and makes no
	* checks whatsoever. Therefore, the result becomes the
	* concatenation of filespec2 followed by a slash followed by
	* filespec1.
	*/
	int spec2len, len;

	spec2len = strlen(filespec2);
	len = spec2len + strlen(filespec1);

	if (spec2len && filespec2[spec2len - 1] == '/') {
	spec2len--;
	len--;
	}
	merged = OPENSSL_malloc(len + 2);
	if (merged == NULL) {
	DSOerr(DSO_F_DLFCN_MERGER, ERR_R_MALLOC_FAILURE);
	return (NULL);
	}
	strcpy(merged, filespec2);
	merged[spec2len] = '/';
	strcpy(&merged[spec2len + 1], filespec1);
	}
	return (merged);
	}

	static char dlfcn_name_converter(DSO dso, const char *filename)
	{
	char *translated;
	int len, rsize, transform;

	len = strlen(filename);
	rsize = len + 1;
	transform = (strstr(filename, "/") == NULL);
	if (transform) {
	/* We will convert this to "%s.so" or "lib%s.so" etc */
	rsize += strlen(DSO_EXTENSION); /* The length of ".so" */
	if ((DSO_flags(dso) & DSO_FLAG_NAME_TRANSLATION_EXT_ONLY) == 0)
	rsize += 3; /* The length of "lib" */
	}
	translated = OPENSSL_malloc(rsize);
	if (translated == NULL) {
	DSOerr(DSO_F_DLFCN_NAME_CONVERTER, DSO_R_NAME_TRANSLATION_FAILED);
	return (NULL);
	}
	if (transform) {
	if ((DSO_flags(dso) & DSO_FLAG_NAME_TRANSLATION_EXT_ONLY) == 0)
	sprintf(translated, "lib%s" DSO_EXTENSION, filename);
	else
	sprintf(translated, "%s" DSO_EXTENSION, filename);
	} else
	sprintf(translated, "%s", filename);
	return (translated);
	}

	# ifdef __sgi
	/*-
	This is a quote from IRIX manual for dladdr(3c):

	<dlfcn.h> does not contain a prototype for dladdr or definition of
	Dl_info. The #include <dlfcn.h> in the SYNOPSIS line is traditional,
	but contains no dladdr prototype and no IRIX library contains an
	implementation. Write your own declaration based on the code below.

	The following code is dependent on internal interfaces that are not
	part of the IRIX compatibility guarantee; however, there is no future
	intention to change this interface, so on a practical level, the code
	below is safe to use on IRIX.
	*/
	# include <rld_interface.h>
	# ifndef _RLD_INTERFACE_DLFCN_H_DLADDR
	# define _RLD_INTERFACE_DLFCN_H_DLADDR
	typedef struct Dl_info {
	const char *dli_fname;
	void *dli_fbase;
	const char *dli_sname;
	void *dli_saddr;
	int dli_version;
	int dli_reserved1;
	long dli_reserved[4];
	} Dl_info;
	# else
	typedef struct Dl_info Dl_info;
	# endif
	# define _RLD_DLADDR 14

	static int dladdr(void address, Dl_info dl)
	{
	void *v;
	v = _rld_new_interface(_RLD_DLADDR, address, dl);
	return (int)v;
	}
	# endif /* __sgi */

	static int dlfcn_pathbyaddr(void addr, char path, int sz)
	{
	# ifdef HAVE_DLINFO
	Dl_info dli;
	int len;

	if (addr == NULL) {
	union {
	int (f) (void , char *, int);
	void *p;
	} t = {
	dlfcn_pathbyaddr
	};
	addr = t.p;
	}

	if (dladdr(addr, &dli)) {
	len = (int)strlen(dli.dli_fname);
	if (sz <= 0)
	return len + 1;
	if (len >= sz)
	len = sz - 1;
	memcpy(path, dli.dli_fname, len);
	path[len++] = 0;
	return len;
	}

	ERR_add_error_data(2, "dlfcn_pathbyaddr(): ", dlerror());
	# endif
	return -1;
	}

	static void dlfcn_globallookup(const char name)
	{
	void ret = NULL, handle = dlopen(NULL, RTLD_LAZY);

	if (handle) {
	ret = dlsym(handle, name);
	dlclose(handle);
	}

	return ret;
	}
	#endif /* DSO_DLFCN */