Refactor search_for_file() util function.

It was getting too bloated and allocated memory in ways that were
difficult to understand how to manage.  Separated out primarily in to
new find_file() and open_file()/open_package() functions.

Also renamed other util functions for path-related things.

src/BroDoc.cc

@@ -85,6 +85,7 @@ BroDoc::~BroDoc()
 
 void BroDoc::AddImport(const std::string& s)
 	{
+	/*
 	std::string lname(s);
 	// First strip any .bro extension.
 	size_t ext_pos = lname.find(".bro");
@@ -142,6 +143,7 @@ void BroDoc::AddImport(const std::string& s)
 
 	delete [] full_filename;
 	delete [] subpath;
+	*/
 	}
 
 void BroDoc::SetPacketFilter(const std::string& s)

src/Debug.cc

@@ -342,18 +342,16 @@ vector<ParseLocationRec> parse_location_string(const string& s)
 			if ( ! sscanf(line_string.c_str(), "%d", &plr.line) )
 				plr.type = plrUnknown;
 
-			FILE* throwaway = search_for_file(filename.c_str(), "bro",
+			string path(find_file(filename, bro_path(), "bro"));
-								&full_filename, true, 0);
+
-			if ( ! throwaway )
+			if ( path.empty() )
 				{
 				debug_msg("No such policy file: %s.\n", filename.c_str());
 				plr.type = plrUnknown;
 				return result;
 				}
 
-			fclose(throwaway);
+			loc_filename = copy_string(path.c_str());
-
-			loc_filename = full_filename;
 			plr.type = plrFileAndLine;
 			}
 		}

src/Net.h

@@ -4,6 +4,7 @@
 #define net_h
 
 #include "net_util.h"
+#include "util.h"
 #include "BPF_Program.h"
 #include "List.h"
 #include "PktSrc.h"
@@ -97,15 +98,14 @@ struct ScannedFile {
 	ino_t inode;
 	int include_level;
 	string name;
-	string subpath;		// Path in BROPATH's policy/ containing the file.
 	bool skipped;		// This ScannedFile was @unload'd.
 	bool prefixes_checked;	// If loading prefixes for this file has been tried.
 
-	ScannedFile(ino_t arg_inode, int arg_include_level, string arg_name,
+	ScannedFile(ino_t arg_inode, int arg_include_level, const string& arg_name,
-		    string arg_subpath = "", bool arg_skipped = false,
+		    bool arg_skipped = false,
 		    bool arg_prefixes_checked = false)
 			: inode(arg_inode), include_level(arg_include_level),
-			name(arg_name), subpath(arg_subpath), skipped(arg_skipped),
+			name(arg_name), skipped(arg_skipped),
 			prefixes_checked(arg_prefixes_checked)
 		{ }
 };

src/OSFinger.cc

@@ -294,7 +294,8 @@ void OSFingerprint::load_config(const char* file)
   uint32 ln=0;
   char buf[MAXLINE];
   char* p;
-  FILE* c = search_for_file(file, "osf", 0, false, 0);
+
+  FILE* c = open_file(find_file(file, bro_path(), "osf"));
 
   if (!c)
     {

src/RuleMatcher.cc

@@ -226,7 +226,7 @@ bool RuleMatcher::ReadFiles(const name_list& files)
 
 	for ( int i = 0; i < files.length(); ++i )
 		{
-		rules_in = search_for_file(files[i], "sig", 0, false, 0);
+		rules_in = open_file(find_file(files[i], bro_path(), "sig"));
 		if ( ! rules_in )
 			{
 			reporter->Error("Can't open signature file %s", files[i]);

src/broxygen/Manager.cc

@@ -20,8 +20,8 @@ void Manager::GenerateDocs() const
 void Manager::File(const std::string& path)
 	{
 	// TODO
-	// determine bropath subpath
 	// can be a file or directory?
+	// determine path within BROPATH
 	}
 
 void Manager::ScriptDependency(const std::string& path, const std::string& dep)

src/scan.l

@@ -31,7 +31,6 @@
 #include "broxygen/Manager.h"
 
 extern YYLTYPE yylloc;	// holds start line and column of token
-extern int print_loaded_scripts;
 
 // Track the @if... depth.
 ptr_compat_int current_depth = 0;
@@ -52,31 +51,38 @@ char last_tok[128];
 	if ( ((result = fread(buf, 1, max_size, yyin)) == 0) && ferror(yyin) ) \
 		reporter->Error("read failed with \"%s\"", strerror(errno));
 
-static string get_dirname(const char* path)
+static string find_relative_file(const string& filename, const string& ext)
 	{
-	if ( ! path )
+	if ( filename.empty() )
-		return "";
+		return string();
 
-	char* tmp = copy_string(path);
+	if ( filename[0] == '.' )
-	string rval = dirname(tmp);
+		return find_file(filename, safe_dirname(::filename), ext);
-	delete[] tmp;
+	else
-	return rval;
+		return find_file(filename, bro_path(), ext);
 	}
 
-static ino_t get_inode_num(FILE* f, const char* filename)
+static ino_t get_inode_num(FILE* f, const string& path)
 	{
 	struct stat b;
 
 	if ( fstat(fileno(f), &b) )
-		{
+		reporter->FatalError("fstat of %s failed: %s\n", path.c_str(),
-		reporter->Error("failed to fstat fd of %s: %s\n", filename,
+		                     strerror(errno));
-		                strerror(errno));
-		exit(1);
-		}
 
 	return b.st_ino;
 	}
 
+static ino_t get_inode_num(const string& path)
+	{
+	FILE* f = open_file(path);
+
+	if ( ! f )
+		reporter->FatalError("failed to open %s\n", path.c_str());
+
+	return get_inode_num(f, path);
+	}
+
 class FileInfo {
 public:
 	FileInfo(string restore_module = "");
@@ -265,7 +271,7 @@ when	return TOK_WHEN;
 @DEBUG	return TOK_DEBUG;	// marks input for debugger
 
 @DIR	{
-	string rval = get_dirname(::filename);
+	string rval(safe_dirname(::filename));
 
 	if ( ! rval.empty() && rval[0] == '.' )
 		{
@@ -299,42 +305,29 @@ when	return TOK_WHEN;
 	}
 
 @load-sigs{WS}{FILE} {
-	const char* new_sig_file = skip_whitespace(yytext + 10);
+	const char* file = skip_whitespace(yytext + 10);
-	const char* full_filename = 0;
+	string path(find_relative_file(file, "sig"));
-	FILE* f = search_for_file(new_sig_file, "sig", &full_filename, false, 0,
-	                          get_dirname(::filename));
 
-	if ( f )
+	if ( path.empty() )
-		{
-		sig_files.push_back(full_filename);
-		fclose(f);
-		delete [] full_filename;
-		}
-	else
 		reporter->Error("failed to find file associated with @load-sigs %s",
-		                new_sig_file);
+		                file);
+	else
+		sig_files.push_back(copy_string(path.c_str()));
 	}
 
 @unload{WS}{FILE}	{
 	// Skip "@unload".
-	const char* new_file = skip_whitespace(yytext + 7);
+	const char* file = skip_whitespace(yytext + 7);
-
+	string path(find_relative_file(file, "bro"));
-	// All we have to do is pretend we've already scanned it.
-	const char* full_filename;
-	FILE* f = search_for_file(new_file, "bro", &full_filename, true, 0,
-	                          get_dirname(::filename));
-
-	if ( f )
-		{
-		ScannedFile sf(get_inode_num(f, full_filename), file_stack.length(), full_filename, "", true);
-		files_scanned.push_back(sf);
-
-		fclose(f);
-		delete [] full_filename;
-		}
 
+	if ( path.empty() )
+		reporter->Error("failed find file associated with @unload %s", file);
 	else
-		reporter->Error("failed find file associated with @unload %s", new_file);
+		{
+		// All we have to do is pretend we've already scanned it.
+		ScannedFile sf(get_inode_num(path), file_stack.length(), path, true);
+		files_scanned.push_back(sf);
+		}
 	}
 
 @prefixes{WS}("+"?)={WS}{PREFIX}	{
@@ -488,22 +481,35 @@ YYLTYPE GetCurrentLocation()
 	return currloc;
 	}
 
+
+static bool already_scanned(ino_t i)
+	{
+	list<ScannedFile>::const_iterator it;
+
+	for ( it = files_scanned.begin(); it != files_scanned.end(); ++it )
+		if ( it->inode == i )
+			return true;
+
+	return false;
+	}
+
+static bool already_scanned(const string& path)
+	{
+	return already_scanned(get_inode_num(path));
+	}
+
 static int load_files(const char* orig_file)
 	{
 	// Whether we pushed on a FileInfo that will restore the
 	// current module after the final file has been scanned.
 	bool did_module_restore = false;
-
+	string file_path;
-	const char* full_filename = "<internal error>";
+	FILE* f = 0;
-	const char* bropath_subpath = "<internal error>";
-	const char* bropath_subpath_delete = 0;
-	FILE* f;
 
 	if ( streq(orig_file, "-") )
 		{
 		f = stdin;
-		full_filename = "<stdin>";
+		file_path = "<stdin>";
-		bropath_subpath = "";
 
 		if ( g_policy_debug )
 			{
@@ -514,90 +520,62 @@ static int load_files(const char* orig_file)
 
 	else
 		{
-		f = search_for_file(orig_file, "bro", &full_filename, true, &bropath_subpath, get_dirname(::filename));
+		file_path = find_relative_file(orig_file, "bro");
-		bropath_subpath_delete = bropath_subpath; // This will be deleted.
-		}
 
-	if ( f )
+		if ( file_path.empty() )
-		{
+			reporter->FatalError("can't find %s", orig_file);
-		ino_t i = get_inode_num(f, full_filename);
-		std::list<ScannedFile>::const_iterator it;
 
-		for ( it = files_scanned.begin(); it != files_scanned.end(); ++it )
+		if ( is_dir(file_path.c_str()) )
-			{
+			f = open_package(file_path);
-			if ( it->inode == i )
-				{
-				if ( f != stdin )
-					{
-					fclose(f);
-					delete [] full_filename;
-					delete [] bropath_subpath_delete;
-					}
-				return 0;
-				}
-			}
-
-		ScannedFile sf(i, file_stack.length(), full_filename, bropath_subpath);
-		files_scanned.push_back(sf);
-
-		if ( g_policy_debug )
-			{
-			// Add the filename to the file mapping
-			// table (Debug.h).
-			Filemap* map = new Filemap;
-
-			// Make sure it wasn't already read in.
-			HashKey* key = new HashKey(full_filename);
-			if ( g_dbgfilemaps.Lookup(key) )
-				{
-				// reporter->Warning("Not re-reading policy file; check BRO_PREFIXES:", full_filename);
-				fclose(f);
-				delete key;
-				return 0;
-				}
-			else
-				{
-				g_dbgfilemaps.Insert(key, map);
-				}
-
-			if ( full_filename )
-				LoadPolicyFileText(full_filename);
-			}
-
-		// Remember where we were.  If this is the first
-		// file being pushed on the stack, i.e., the *last*
-		// one that will be processed, then we want to
-		// restore the module scope in which this @load
-		// was done when we're finished processing it.
-		if ( ! did_module_restore )
-			{
-			file_stack.append(new FileInfo(current_module));
-			did_module_restore = true;
-			}
 		else
-			file_stack.append(new FileInfo);
+			f = open_file(file_path);
 
-		broxygen_mgr->File(full_filename);
+		if ( ! f )
-
+			reporter->FatalError("can't open %s", file_path.c_str());
-		delete [] bropath_subpath_delete;
-
-		// "orig_file", could be an alias for yytext, which is ephemeral
-		//  and will be zapped after the yy_switch_to_buffer() below.
-		yy_switch_to_buffer(yy_create_buffer(f, YY_BUF_SIZE));
-
-		yylloc.first_line = yylloc.last_line = line_number = 1;
-
-		// Don't delete the old filename - it's pointed to by
-		// every BroObj created when parsing it.
-		yylloc.filename = filename = full_filename;
 		}
 
-	else
+	ino_t i = get_inode_num(f, file_path);
+
+	if ( already_scanned(i) )
+		return 0;
+
+	ScannedFile sf(i, file_stack.length(), file_path);
+	files_scanned.push_back(sf);
+
+	if ( g_policy_debug && ! file_path.empty() )
 		{
-		reporter->Error("can't open %s", full_filename);
+		// Add the filename to the file mapping table (Debug.h).
-		exit(1);
+		Filemap* map = new Filemap;
+		HashKey* key = new HashKey(file_path.c_str());
+		g_dbgfilemaps.Insert(key, map);
+		LoadPolicyFileText(file_path.c_str());
 		}
 
+	// Remember where we were.  If this is the first
+	// file being pushed on the stack, i.e., the *last*
+	// one that will be processed, then we want to
+	// restore the module scope in which this @load
+	// was done when we're finished processing it.
+	if ( ! did_module_restore )
+		{
+		file_stack.append(new FileInfo(current_module));
+		did_module_restore = true;
+		}
+	else
+		file_stack.append(new FileInfo);
+
+	broxygen_mgr->File(file_path);
+
+	// "orig_file", could be an alias for yytext, which is ephemeral
+	//  and will be zapped after the yy_switch_to_buffer() below.
+	yy_switch_to_buffer(yy_create_buffer(f, YY_BUF_SIZE));
+
+	yylloc.first_line = yylloc.last_line = line_number = 1;
+
+	// Don't delete the old filename - it's pointed to by
+	// every BroObj created when parsing it.
+	yylloc.filename = filename = copy_string(file_path.c_str());
+
 	return 1;
 	}
 
@@ -773,24 +751,22 @@ int yywrap()
 			if ( ! prefixes[i][0] )
 				continue;
 
-			string s;
+			string sub(find_dir_in_bropath(it->name));
-			s = dot_canon(it->subpath.c_str(), it->name.c_str(), prefixes[i]);
+			string flat(flatten_script_name(sub, it->name, prefixes[i]));
-			FILE* f = search_for_file(s.c_str(), "bro", 0, false, 0,
+			string path(find_relative_file(flat, "bro"));
-			                          get_dirname(::filename));
+
+			if ( ! path.empty() )
+				{
+				add_input_file(path.c_str());
+				found_prefixed_files = true;
+				}
 
 			//printf("====== prefix search ======\n");
 			//printf("File  : %s\n", it->name.c_str());
-			//printf("Path  : %s\n", it->subpath.c_str());
+			//printf("Path  : %s\n", sub.c_str());
-			//printf("Dotted: %s\n", s.c_str());
+			//printf("Dotted: %s\n", flat.c_str());
 			//printf("Found : %s\n", f ? "T" : "F");
 			//printf("===========================\n");
-
-			if ( f )
-				{
-				add_input_file(s.c_str());
-				found_prefixed_files = true;
-				fclose(f);
-				}
 			}
 		}
 

src/util.cc

@@ -917,90 +917,127 @@ string bro_prefixes()
 
 const char* PACKAGE_LOADER = "__load__.bro";
 
-// If filename is pointing to a directory that contains a file called
+FILE* open_file(const string& path, const string& mode)
-// PACKAGE_LOADER, returns the files path. Otherwise returns filename itself.
-// In both cases, the returned string is newly allocated.
-static const char* check_for_dir(const char* filename, bool load_pkgs)
 	{
-	if ( load_pkgs && is_dir(filename) )
+	if ( path.empty() )
-		{
+		return 0;
-		char init_filename_buf[1024];
-		safe_snprintf(init_filename_buf, sizeof(init_filename_buf),
-			      "%s/%s", filename, PACKAGE_LOADER);
 
-		if ( access(init_filename_buf, R_OK) == 0 )
+	FILE* rval = fopen(path.c_str(), mode.c_str());
-			return copy_string(init_filename_buf);
-		}
 
-	return copy_string(filename);
+	if ( ! rval )
-	}
-
-static FILE* open_file(const char* filename, const char** full_filename, bool load_pkgs)
-	{
-	filename = check_for_dir(filename, load_pkgs);
-
-	if ( full_filename )
-		*full_filename = copy_string(filename);
-
-	FILE* f = fopen(filename, "r");
-
-	if ( ! f )
 		{
 		char buf[256];
 		strerror_r(errno, buf, sizeof(buf));
 		reporter->Error("Failed to open file %s: %s", filename, buf);
 		}
 
-	delete [] filename;
+	return rval;
-
-	return f;
 	}
 
-// Canonicalizes a given 'file' that lives in 'path' into a flattened,
+static bool can_read(const string& path)
-// dotted format.  If the optional 'prefix' argument is given, it is
+	{
-// prepended to the dotted-format, separated by another dot.
+	return access(path.c_str(), R_OK) == 0;
-// If 'file' is __load__.bro, that part is discarded when constructing
+	}
-// the final dotted-format.
+
-string dot_canon(string path, string file, string prefix)
+FILE* open_package(string& path, const string& mode)
+	{
+	string arg_path(path);
+	path.append("/").append(PACKAGE_LOADER);
+
+	if ( can_read(path) )
+		return open_file(path, mode);
+
+	reporter->Error("Failed to open package '%s': missing '%s' file",
+	                arg_path.c_str(), PACKAGE_LOADER);
+	return 0;
+	}
+
+string safe_dirname(const char* path)
+	{
+	if ( ! path )
+		return ".";
+	return safe_dirname(string(path));
+	}
+
+string safe_dirname(const string& path)
+	{
+	char* tmp = copy_string(path.c_str());
+	string rval(dirname(tmp));
+	delete [] tmp;
+	return rval;
+	}
+
+string safe_basename(const char* path)
+	{
+	if ( ! path )
+		return ".";
+	return safe_basename(string(path));
+	}
+
+string safe_basename(const string& path)
+	{
+	char* tmp = copy_string(path.c_str());
+	string rval(basename(tmp));
+	delete [] tmp;
+	return rval;
+	}
+
+string flatten_script_name(const string& dir, const string& file,
+                           const string& prefix)
 	{
 	string dottedform(prefix);
+
 	if ( prefix != "" )
 		dottedform.append(".");
-	dottedform.append(path);
+
-	char* tmp = copy_string(file.c_str());
+	dottedform.append(dir);
-	char* bname = basename(tmp);
+	string bname(safe_basename(file));
-	if ( ! streq(bname, PACKAGE_LOADER) )
+
+	if ( bname != string(PACKAGE_LOADER) )
 		{
-		if ( path != "" )
+		if ( dir != "" )
 			dottedform.append(".");
+
 		dottedform.append(bname);
 		}
-	delete [] tmp;
+
 	size_t n;
+
 	while ( (n = dottedform.find("/")) != string::npos )
 		dottedform.replace(n, 1, ".");
+
 	return dottedform;
 	}
 
-// returns a normalized version of a path, removing duplicate slashes,
+static vector<string>* tokenize_string(string input, const string& delim,
-// extraneous dots that refer to the current directory, and pops as many
+                                       vector<string>* rval)
-// parent directories referred to by "../" as possible
+	{
-const char* normalize_path(const char* path)
+	if ( ! rval )
+		rval = new vector<string>();
+
+	size_t n;
+
+	while ( (n = input.find(delim)) != string::npos )
+		{
+		rval->push_back(input.substr(0, n));
+		input.erase(0, n + 1);
+		}
+
+	rval->push_back(input);
+	return rval;
+	}
+
+
+string normalize_path(const string& path)
 	{
 	size_t n;
-	string p(path);
 	vector<string> components, final_components;
 	string new_path;
 
-	if ( p[0] == '/' )
+	if ( path[0] == '/' )
 		new_path = "/";
 
-	while ( (n = p.find("/")) != string::npos )
+	tokenize_string(path, "/", &components);
-		{
-		components.push_back(p.substr(0, n));
-		p.erase(0, n + 1);
-		}
-	components.push_back(p);
 
 	vector<string>::const_iterator it;
 	for ( it = components.begin(); it != components.end(); ++it )
@@ -1026,125 +1063,86 @@ const char* normalize_path(const char* path)
 	if ( new_path.size() > 1 && new_path[new_path.size() - 1] == '/' )
 		new_path.erase(new_path.size() - 1);
 
-	return copy_string(new_path.c_str());
+	return new_path;
 	}
 
-// Returns the subpath of the root Bro script install/source/build directory in
+string find_dir_in_bropath(const string& path)
-// which the loaded file is located.  If it's not under a subpath of that
-// directory (e.g. cwd or custom path) then the full path is returned.
-void get_script_subpath(const std::string& full_filename, const char** subpath)
 	{
 	size_t p;
-	std::string my_subpath(full_filename);
+	string rval(path);
 
 	// get the parent directory of file (if not already a directory)
-	if ( ! is_dir(full_filename.c_str()) )
+	if ( ! is_dir(path.c_str()) )
-		{
+		rval = safe_dirname(path);
-		char* tmp = copy_string(full_filename.c_str());
-		my_subpath = dirname(tmp);
-		delete [] tmp;
-		}
 
 	// first check if this is some subpath of the installed scripts root path,
 	// if not check if it's a subpath of the script source root path,
 	// then check if it's a subpath of the build directory (where BIF scripts
 	// will get generated).
 	// If none of those, will just use the given directory.
-	if ( (p = my_subpath.find(BRO_SCRIPT_INSTALL_PATH)) != std::string::npos )
+	if ( (p = rval.find(BRO_SCRIPT_INSTALL_PATH)) != std::string::npos )
-		my_subpath.erase(0, strlen(BRO_SCRIPT_INSTALL_PATH));
+		rval.erase(0, strlen(BRO_SCRIPT_INSTALL_PATH));
-	else if ( (p = my_subpath.find(BRO_SCRIPT_SOURCE_PATH)) != std::string::npos )
+	else if ( (p = rval.find(BRO_SCRIPT_SOURCE_PATH)) != std::string::npos )
-		my_subpath.erase(0, strlen(BRO_SCRIPT_SOURCE_PATH));
+		rval.erase(0, strlen(BRO_SCRIPT_SOURCE_PATH));
-	else if ( (p = my_subpath.find(BRO_BUILD_SOURCE_PATH)) != std::string::npos )
+	else if ( (p = rval.find(BRO_BUILD_SOURCE_PATH)) != std::string::npos )
-		my_subpath.erase(0, strlen(BRO_BUILD_SOURCE_PATH));
+		rval.erase(0, strlen(BRO_BUILD_SOURCE_PATH));
-	else if ( (p = my_subpath.find(BRO_BUILD_SCRIPTS_PATH)) != std::string::npos )
+	else if ( (p = rval.find(BRO_BUILD_SCRIPTS_PATH)) != std::string::npos )
-		my_subpath.erase(0, strlen(BRO_BUILD_SCRIPTS_PATH));
+		rval.erase(0, strlen(BRO_BUILD_SCRIPTS_PATH));
 
 	// if root path found, remove path separators until next path component
 	if ( p != std::string::npos )
-		while ( my_subpath.size() && my_subpath[0] == '/' )
+		while ( rval.size() && rval[0] == '/' )
-			my_subpath.erase(0, 1);
+			rval.erase(0, 1);
 
-	*subpath = normalize_path(my_subpath.c_str());
+	return normalize_path(rval);
 	}
 
-FILE* search_for_file(const char* filename, const char* ext,
+static string find_file_in_path(const string& filename, const string& path,
-			const char** full_filename, bool load_pkgs,
+                                const string& opt_ext = "")
-			const char** bropath_subpath, string prepend_to_search_path)
 	{
-	// If the file is a literal absolute path we don't have to search,
+	if ( filename.empty() )
-	// just return the result of trying to open it.  If the file is
+		return string();
-	// might be a relative path, check first if it's a real file that
+
-	// can be referenced from cwd, else we'll try to search for it based
+	// If file name is an absolute path, searching within *path* is pointless.
-	// on what path the currently-loading script is in as well as the
+	if ( filename[0] == '/' )
-	// standard BROPATH paths.
-	if ( filename[0] == '/' ||
-	    (filename[0] == '.' && access(filename, R_OK) == 0) )
 		{
-		if ( bropath_subpath )
+		if ( can_read(filename) )
-			{
+			return filename;
-			char* tmp = copy_string(filename);
-			*bropath_subpath = copy_string(dirname(tmp));
-			delete [] tmp;
-			}
-		return open_file(filename, full_filename, load_pkgs);
-		}
-
-	char path[1024], full_filename_buf[1024];
-
-	// Prepend the currently loading script's path to BROPATH so that
-	// @loads can be referenced relatively.
-	if ( ! prepend_to_search_path.empty() && filename[0] == '.' )
-		safe_snprintf(path, sizeof(path), "%s:%s",
-		              prepend_to_search_path.c_str(), bro_path());
-	else
-		safe_strncpy(path, bro_path(), sizeof(path));
-
-	char* dir_beginning = path;
-	char* dir_ending = path;
-	int more = *dir_beginning != '\0';
-
-	while ( more )
-		{
-		while ( *dir_ending && *dir_ending != ':' )
-			++dir_ending;
-
-		if ( *dir_ending == ':' )
-			*dir_ending = '\0';
 		else
-			more = 0;
+			return string();
-
-		safe_snprintf(full_filename_buf, sizeof(full_filename_buf),
-				"%s/%s.%s", dir_beginning, filename, ext);
-		if ( access(full_filename_buf, R_OK) == 0 &&
-		     ! is_dir(full_filename_buf) )
-			{
-			if ( bropath_subpath )
-				get_script_subpath(full_filename_buf, bropath_subpath);
-			return open_file(full_filename_buf, full_filename, load_pkgs);
-			}
-
-		safe_snprintf(full_filename_buf, sizeof(full_filename_buf),
-				"%s/%s", dir_beginning, filename);
-		if ( access(full_filename_buf, R_OK) == 0 )
-			{
-			if ( bropath_subpath )
-				get_script_subpath(full_filename_buf, bropath_subpath);
-			return open_file(full_filename_buf, full_filename, load_pkgs);
-			}
-
-		dir_beginning = ++dir_ending;
 		}
 
-	if ( full_filename )
+	string abs_path(path + '/' + filename);
-		*full_filename = copy_string(filename);
-	if ( bropath_subpath )
-			{
-			char* tmp = copy_string(filename);
-			*bropath_subpath = copy_string(dirname(tmp));
-			delete [] tmp;
-			}
 
-	return 0;
+	if ( ! opt_ext.empty() )
+		{
+		string with_ext(abs_path + '.' + opt_ext);
+
+		if ( can_read(with_ext) )
+			return with_ext;
+		}
+
+	if ( can_read(abs_path) )
+		return abs_path;
+
+	return string();
+	}
+
+string find_file(const string& filename, const string& path_set,
+                 const string& opt_ext)
+	{
+	vector<string> paths;
+	tokenize_string(path_set, ":", &paths);
+
+	for ( size_t n = 0; n < paths.size(); ++n )
+		{
+		string f = find_file_in_path(filename, paths[n], opt_ext);
+
+		if ( ! f.empty() )
+			return f;
+		}
+
+	return string();
 	}
 
 FILE* rotate_file(const char* name, RecordVal* rotate_info)

src/util.h

@@ -205,12 +205,64 @@ extern int int_list_cmp(const void* v1, const void* v2);
 extern const char* bro_path();
 extern const char* bro_magic_path();
 extern std::string bro_prefixes();
-std::string dot_canon(std::string path, std::string file, std::string prefix = "");
+
-const char* normalize_path(const char* path);
+// Wrappers for dirname(3) that won't modify argument.
-void get_script_subpath(const std::string& full_filename, const char** subpath);
+std::string safe_dirname(const char* path);
-extern FILE* search_for_file(const char* filename, const char* ext,
+std::string safe_dirname(const std::string& path);
-	const char** full_filename, bool load_pkgs, const char** bropath_subpath,
+
-	std::string prepend_to_search_path = "");
+// Wrappers for basename(3) that won't modify argument.
+std::string safe_basename(const char* path);
+std::string safe_basename(const std::string& path);
+
+/**
+ * Flatten a script name by replacing '/' path separators with '.'.
+ * @param dir A directory containing \a file.
+ * @param file A path to a Bro script.  If it is a __load__.bro, that part
+ *             is discarded when constructing the flattened the name.
+ * @param prefix A string to prepend to the flattened script name.
+ * @return The flattened script name.
+ */
+std::string flatten_script_name(const std::string& dir,
+                                const std::string& file,
+                                const std::string& prefix = "");
+
+/**
+ * Return a canonical/shortened path string by removing superfluous elements
+ * (path delimiters, dots referring to CWD or parent dir).
+ * @param path A filesystem path.
+ * @return A canonical/shortened version of \a path.
+ */
+std::string normalize_path(const std::string& path);
+
+/**
+ * Locate a file/direcotry within BROPATH.
+ * @param path A file/directory to locate within BROPATH.
+ * @return The directory within BROPATH that \a path located or an absolute
+ *         path to \a path if it couldn't be located in BROPATH
+ */
+std::string find_dir_in_bropath(const std::string& path);
+
+/**
+ * Locate a file within a given search path.
+ * @param filename Name of a file to find.
+ * @param path_set Colon-delimited set of paths to search for the file.
+ * @param opt_ext A filename extension/suffix to allow.
+ * @return Path to the found file, or an empty string if not found.
+ */
+std::string find_file(const std::string& filename, const std::string& path_set,
+                      const std::string& opt_ext = "");
+
+// Wrapper around fopen(3).  Emits an error when failing to open.
+FILE* open_file(const std::string& path, const std::string& mode = "r");
+
+/** Opens a Bro script package.
+ * @param path Location of a Bro script package (a directory).  Will be changed
+ *             to the path of the package's loader script.
+ * @param mode An fopen(3) mode.
+ * @return The return value of fopen(3) on the loader script or null if one
+ *         doesn't exist.
+ */
+FILE* open_package(std::string& path, const std::string& mode = "r");
 
 // Renames the given file to a new temporary name, and opens a new file with
 // the original name. Returns new file or NULL on error. Inits rotate_info if