Add DSO_global_lookup_func implementation. See commentary in dso_lib.c

for further details.

crypto/dso/dso.h

@@ -173,6 +173,9 @@ typedef struct dso_meth_st
 
 	/* Return pathname of the module containing location */
 	int (*pathbyaddr)(void *addr,char *path,int sz);
+	/* Perform global symbol lookup, i.e. among *all* modules,
+	 * see commentray in dso_lib.c for further details. */
+	DSO_FUNC_TYPE (*globallookup)(const char *symname);
 	} DSO_METHOD;
 
 /**********************************************************************/
@@ -357,6 +360,7 @@ void ERR_load_DSO_strings(void);
 #define DSO_F_WIN32_SPLITTER				 136
 #define DSO_F_WIN32_UNLOAD				 121
 #define DSO_F_PATHBYADDR				 137
+#define DSO_F_GLOBAL_LOOKUP_FUNC			 138
 
 /* Reason codes. */
 #define DSO_R_CTRL_FAILED				 100

crypto/dso/dso_dl.c

@@ -86,6 +86,7 @@ static int dl_ctrl(DSO *dso, int cmd, long larg, void *parg);
 static char *dl_name_converter(DSO *dso, const char *filename);
 static char *dl_merger(DSO *dso, const char *filespec1, const char *filespec2);
 static int dl_pathbyaddr(void *addr,char *path,int sz);
+static DSO_FUNC_TYPE dl_globallookup(const char *name);
 
 static DSO_METHOD dso_meth_dl = {
 	"OpenSSL 'dl' shared library method",
@@ -103,7 +104,8 @@ static DSO_METHOD dso_meth_dl = {
 	dl_merger,
 	NULL, /* init */
 	NULL, /* finish */
-	dl_pathbyaddr
+	dl_pathbyaddr,
+	dl_globallookup
 	};
 
 DSO_METHOD *DSO_METHOD_dl(void)
@@ -380,4 +382,12 @@ static int dl_pathbyaddr(void *addr,char *path,int sz)
 
 	return -1;
 	}
+
+static DSO_FUNC_TYPE dl_globallookup(const char *name)
+	{
+	DSO_FUNC_TYPE ret;
+	shl_t h = NULL;
+
+	return shl_findsym(&h,name,TYPE_UNDEFINED,&ret) ? NULL : ret;
+	}
 #endif /* DSO_DL */

crypto/dso/dso_dlfcn.c

@@ -99,6 +99,7 @@ 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 DSO_FUNC_TYPE dlfcn_globallookup(const char *name);
 
 static DSO_METHOD dso_meth_dlfcn = {
 	"OpenSSL 'dlfcn' shared library method",
@@ -116,7 +117,8 @@ static DSO_METHOD dso_meth_dlfcn = {
 	dlfcn_merger,
 	NULL, /* init */
 	NULL, /* finish */
-	dlfcn_pathbyaddr
+	dlfcn_pathbyaddr,
+	dlfcn_globallookup
 	};
 
 DSO_METHOD *DSO_METHOD_dlfcn(void)
@@ -443,4 +445,18 @@ static int dlfcn_pathbyaddr(void *addr,char *path,int sz)
 	ERR_add_error_data(4, "dlfcn_pathbyaddr(): ", dlerror());
 	return -1;
 	}
+
+static DSO_FUNC_TYPE dlfcn_globallookup(const char *name)
+	{
+	union { void *p; DSO_FUNC_TYPE f; } ret = { NULL };
+	void *handle = dlopen(NULL,RTLD_LAZY);
+	
+	if (handle)
+		{
+		ret.p = dlsym(handle,name);
+		dlclose(handle);
+		}
+
+	return ret.f;
+	}
 #endif /* DSO_DLFCN */

crypto/dso/dso_err.c

@@ -108,6 +108,7 @@ static ERR_STRING_DATA DSO_str_functs[]=
 {ERR_FUNC(DSO_F_WIN32_SPLITTER),	"WIN32_SPLITTER"},
 {ERR_FUNC(DSO_F_WIN32_UNLOAD),	"WIN32_UNLOAD"},
 {ERR_FUNC(DSO_F_PATHBYADDR),	"DSO_pathbyaddr"},
+{ERR_FUNC(DSO_F_GLOBAL_LOOKUP_FUNC),	"DSO_global_lookup_func"},
 {0,NULL}
 	};
 

crypto/dso/dso_lib.c

@@ -289,6 +289,7 @@ DSO_FUNC_TYPE DSO_bind_func(DSO *dso, const char *symname)
 		DSOerr(DSO_F_DSO_BIND_FUNC,DSO_R_UNSUPPORTED);
 		return(NULL);
 		}
+fprintf(stderr,"boo\n");
 	if((ret = dso->meth->dso_bind_func(dso, symname)) == NULL)
 		{
 		DSOerr(DSO_F_DSO_BIND_FUNC,DSO_R_SYM_FAILURE);
@@ -476,3 +477,23 @@ int DSO_pathbyaddr(void *addr,char *path,int sz)
 		}
 	return (*meth->pathbyaddr)(addr,path,sz);
 	}
+
+/* This function should be used with caution! It looks up symbols in
+ * *all* loaded modules and if module gets unloaded by somebody else
+ * attempt to dereference the pointer is doomed to have fatal
+ * consequences. Primary usage for this function is to probe *core*
+ * system functionality, e.g. check if getnameinfo(3) is available
+ * at run-time without bothering about OS-specific details such as
+ * libc.so.versioning or where does it actually reside: in libc
+ * itself or libsocket. */
+DSO_FUNC_TYPE DSO_global_lookup_func(const char *name)
+	{
+	DSO_METHOD *meth = default_DSO_meth;
+	if (meth == NULL) meth = DSO_METHOD_openssl();
+	if (meth->globallookup == NULL)
+		{
+		DSOerr(DSO_F_GLOBAL_LOOKUP_FUNC,DSO_R_UNSUPPORTED);
+		return NULL;
+		}
+	return (*meth->globallookup)(name);
+	}

crypto/dso/dso_win32.c

@@ -129,6 +129,7 @@ static char *win32_name_converter(DSO *dso, const char *filename);
 static char *win32_merger(DSO *dso, const char *filespec1,
 	const char *filespec2);
 static int win32_pathbyaddr(void *addr,char *path,int sz);
+static DSO_FUNC_TYPE win32_globallookup(const char *name);
 
 static const char *openssl_strnchr(const char *string, int c, size_t len);
 
@@ -148,7 +149,8 @@ static DSO_METHOD dso_meth_win32 = {
 	win32_merger,
 	NULL, /* init */
 	NULL, /* finish */
-	win32_pathbyaddr
+	win32_pathbyaddr,
+	win32_globallookup
 	};
 
 DSO_METHOD *DSO_METHOD_win32(void)
@@ -770,4 +772,65 @@ static int win32_pathbyaddr(void *addr,char *path,int sz)
 	FreeLibrary(dll);
 	return 0;
 	}
+
+static DSO_FUNC_TYPE win32_globallookup(const char *name)
+	{
+	HMODULE dll;
+	HANDLE hModuleSnap = INVALID_HANDLE_VALUE;
+	MODULEENTRY32 me32;
+	CREATETOOLHELP32SNAPSHOT create_snap;
+	CLOSETOOLHELP32SNAPSHOT  close_snap;
+	MODULE32 module_first, module_next;
+	FARPROC ret=NULL;
+
+	dll = LoadLibrary(TEXT(DLLNAME));
+	if (dll == NULL)
+		{
+		DSOerr(DSO_F_GLOBAL_LOOKUP_FUNC,DSO_R_UNSUPPORTED);
+		return NULL;
+		}
+
+	create_snap = (CREATETOOLHELP32SNAPSHOT)
+		GetProcAddress(dll,"CreateToolhelp32Snapshot");
+	if (create_snap == NULL)
+		{
+		FreeLibrary(dll);
+		DSOerr(DSO_F_GLOBAL_LOOKUP_FUNC,DSO_R_UNSUPPORTED);
+		return NULL;
+		}
+	/* We take the rest for granted... */
+#ifdef _WIN32_WCE
+	close_snap = (CLOSETOOLHELP32SNAPSHOT)
+		GetProcAddress(dll,"CloseToolhelp32Snapshot");
+#else
+	close_snap = (CLOSETOOLHELP32SNAPSHOT)CloseHandle;
+#endif
+	module_first = (MODULE32)GetProcAddress(dll,"Module32First");
+	module_next  = (MODULE32)GetProcAddress(dll,"Module32Next");
+
+	hModuleSnap = (*create_snap)(TH32CS_SNAPMODULE,0);
+	if( hModuleSnap == INVALID_HANDLE_VALUE ) return NULL;
+
+	me32.dwSize = sizeof(me32);
+
+	if (!(*module_first)(hModuleSnap,&me32))
+		{
+		(*close_snap)(hModuleSnap);
+		FreeLibrary(dll);
+		return NULL;
+		}
+
+	do	{
+		if (ret = GetProcAddress(me32.hModule,fname))
+			{
+			(*close_snap)(hModuleSnap);
+			FreeLibrary(dll);
+			return ret;
+			}
+		} while((*module_next)(hModuleSnap,&me32));
+
+	(*close_snap)(hModuleSnap); 
+	FreeLibrary(dll);
+	return NULL;
+	}
 #endif /* DSO_WIN32 */