(svn r26489) -Codechange: properly account for the end of buffers in the file io code instead of assuming MAX_PATH is okay

1 files changed, 40 insertions, 32 deletions

diff --git a/src/fios.cpp b/src/fios.cpp
index ced425967..43d781b5d 100644
--- a/src/fios.cpp
+++ b/src/fios.cpp
@@ -31,6 +31,7 @@
 /* Variables to display file lists */
 SmallVector<FiosItem, 32> _fios_items;
 static char *_fios_path;
+static const char *_fios_path_last;
 SmallFiosItem _file_to_saveload;
 SortingBits _savegame_sort_order = SORT_BY_DATE | SORT_DESCENDING;
 
@@ -91,14 +92,12 @@ StringID FiosGetDescText(const char **path, uint64 *total_free)
  */
 const char *FiosBrowseTo(const FiosItem *item)
 {
-	char *path = _fios_path;
-
 	switch (item->type) {
 		case FIOS_TYPE_DRIVE:
 #if defined(WINCE)
-			snprintf(path, MAX_PATH, PATHSEP "");
+			seprintf(_fios_path, _fios_path_last, PATHSEP "");
 #elif defined(WIN32) || defined(__OS2__)
-			snprintf(path, MAX_PATH, "%c:" PATHSEP, item->title[0]);
+			seprintf(_fios_path, _fios_path_last, "%c:" PATHSEP, item->title[0]);
 #endif
 			/* FALL THROUGH */
 		case FIOS_TYPE_INVALID:
@@ -106,16 +105,16 @@ const char *FiosBrowseTo(const FiosItem *item)
 
 		case FIOS_TYPE_PARENT: {
 			/* Check for possible NULL ptr (not required for UNIXes, but AmigaOS-alikes) */
-			char *s = strrchr(path, PATHSEPCHAR);
-			if (s != NULL && s != path) {
+			char *s = strrchr(_fios_path, PATHSEPCHAR);
+			if (s != NULL && s != _fios_path) {
 				s[0] = '\0'; // Remove last path separator character, so we can go up one level.
 			}
-			s = strrchr(path, PATHSEPCHAR);
+			s = strrchr(_fios_path, PATHSEPCHAR);
 			if (s != NULL) {
 				s[1] = '\0'; // go up a directory
 #if defined(__MORPHOS__) || defined(__AMIGAOS__)
 			/* On MorphOS or AmigaOS paths look like: "Volume:directory/subdirectory" */
-			} else if ((s = strrchr(path, ':')) != NULL) {
+			} else if ((s = strrchr(_fios_path, ':')) != NULL) {
 				s[1] = '\0';
 #endif
 			}
@@ -123,12 +122,12 @@ const char *FiosBrowseTo(const FiosItem *item)
 		}
 
 		case FIOS_TYPE_DIR:
-			strcat(path, item->name);
-			strcat(path, PATHSEP);
+			strecat(_fios_path, item->name, _fios_path_last);
+			strecat(_fios_path, PATHSEP, _fios_path_last);
 			break;
 
 		case FIOS_TYPE_DIRECT:
-			snprintf(path, MAX_PATH, "%s", item->name);
+			seprintf(_fios_path, _fios_path_last, "%s", item->name);
 			break;
 
 		case FIOS_TYPE_FILE:
@@ -149,9 +148,9 @@ const char *FiosBrowseTo(const FiosItem *item)
  * @param path Directory path, may be \c NULL.
  * @param name Filename.
  * @param ext Filename extension (use \c "" for no extension).
- * @param size Size of \a buf.
+ * @param last Last element of buffer \a buf.
  */
-static void FiosMakeFilename(char *buf, const char *path, const char *name, const char *ext, size_t size)
+static void FiosMakeFilename(char *buf, const char *path, const char *name, const char *ext, const char *last)
 {
 	const char *period;
 
@@ -163,15 +162,15 @@ static void FiosMakeFilename(char *buf, const char *path, const char *name, cons
 		unsigned char sepchar = path[(strlen(path) - 1)];
 
 		if (sepchar != ':' && sepchar != '/') {
-			snprintf(buf, size, "%s" PATHSEP "%s%s", path, name, ext);
+			seprintf(buf, last, "%s" PATHSEP "%s%s", path, name, ext);
 		} else {
-			snprintf(buf, size, "%s%s%s", path, name, ext);
+			seprintf(buf, last, "%s%s%s", path, name, ext);
 		}
 	} else {
-		snprintf(buf, size, "%s%s", name, ext);
+		seprintf(buf, last, "%s%s", name, ext);
 	}
 #else
-	snprintf(buf, size, "%s" PATHSEP "%s%s", path, name, ext);
+	seprintf(buf, last, "%s" PATHSEP "%s%s", path, name, ext);
 #endif
 }
 
@@ -179,28 +178,28 @@ static void FiosMakeFilename(char *buf, const char *path, const char *name, cons
  * Make a save game or scenario filename from a name.
  * @param buf Destination buffer for saving the filename.
  * @param name Name of the file.
- * @param size Length of buffer \a buf.
+ * @param last Last element of buffer \a buf.
  */
-void FiosMakeSavegameName(char *buf, const char *name, size_t size)
+void FiosMakeSavegameName(char *buf, const char *name, const char *last)
 {
 	const char *extension = (_game_mode == GM_EDITOR) ? ".scn" : ".sav";
 
-	FiosMakeFilename(buf, _fios_path, name, extension, size);
+	FiosMakeFilename(buf, _fios_path, name, extension, _fios_path_last);
 }
 
 /**
  * Construct a filename for a height map.
  * @param buf Destination buffer.
  * @param name Filename.
- * @param size Size of \a buf.
+ * @param last Last element of buffer \a buf.
  */
-void FiosMakeHeightmapName(char *buf, const char *name, size_t size)
+void FiosMakeHeightmapName(char *buf, const char *name, const char *last)
 {
 	char ext[5];
 	ext[0] = '.';
 	strecpy(ext + 1, GetCurrentScreenshotExtension(), lastof(ext));
 
-	FiosMakeFilename(buf, _fios_path, name, ext, size);
+	FiosMakeFilename(buf, _fios_path, name, ext, _fios_path_last);
 }
 
 /**
@@ -211,7 +210,7 @@ bool FiosDelete(const char *name)
 {
 	char filename[512];
 
-	FiosMakeSavegameName(filename, name, lengthof(filename));
+	FiosMakeSavegameName(filename, name, lastof(filename));
 	return unlink(filename) == 0;
 }
 
@@ -326,7 +325,7 @@ static void FiosGetFileList(SaveLoadDialogMode mode, fios_getlist_callback_proc
 				fios->type = FIOS_TYPE_DIR;
 				fios->mtime = 0;
 				strecpy(fios->name, d_name, lastof(fios->name));
-				snprintf(fios->title, lengthof(fios->title), "%s" PATHSEP " (Directory)", d_name);
+				seprintf(fios->title, lastof(fios->title), "%s" PATHSEP " (Directory)", d_name);
 				str_validate(fios->title, lastof(fios->title));
 			}
 		}
@@ -430,13 +429,16 @@ FiosType FiosGetSavegameListCallback(SaveLoadDialogMode mode, const char *file,
 void FiosGetSavegameList(SaveLoadDialogMode mode)
 {
 	static char *fios_save_path = NULL;
+	static char *fios_save_path_last = NULL;
 
 	if (fios_save_path == NULL) {
 		fios_save_path = MallocT<char>(MAX_PATH);
-		FioGetDirectory(fios_save_path, MAX_PATH, SAVE_DIR);
+		fios_save_path_last = fios_save_path + MAX_PATH - 1;
+		FioGetDirectory(fios_save_path, fios_save_path_last, SAVE_DIR);
 	}
 
 	_fios_path = fios_save_path;
+	_fios_path_last = fios_save_path_last;
 
 	FiosGetFileList(mode, &FiosGetSavegameListCallback, NO_DIRECTORY);
 }
@@ -481,17 +483,20 @@ static FiosType FiosGetScenarioListCallback(SaveLoadDialogMode mode, const char
 void FiosGetScenarioList(SaveLoadDialogMode mode)
 {
 	static char *fios_scn_path = NULL;
+	static char *fios_scn_path_last = NULL;
 
 	/* Copy the default path on first run or on 'New Game' */
 	if (fios_scn_path == NULL) {
 		fios_scn_path = MallocT<char>(MAX_PATH);
-		FioGetDirectory(fios_scn_path, MAX_PATH, SCENARIO_DIR);
+		fios_scn_path_last = fios_scn_path + MAX_PATH - 1;
+		FioGetDirectory(fios_scn_path, fios_scn_path_last, SCENARIO_DIR);
 	}
 
 	_fios_path = fios_scn_path;
+	_fios_path_last = fios_scn_path_last;
 
 	char base_path[MAX_PATH];
-	FioGetDirectory(base_path, sizeof(base_path), SCENARIO_DIR);
+	FioGetDirectory(base_path, lastof(base_path), SCENARIO_DIR);
 
 	FiosGetFileList(mode, &FiosGetScenarioListCallback, (mode == SLD_LOAD_SCENARIO && strcmp(base_path, _fios_path) == 0) ? SCENARIO_DIR : NO_DIRECTORY);
 }
@@ -524,7 +529,7 @@ static FiosType FiosGetHeightmapListCallback(SaveLoadDialogMode mode, const char
 		Searchpath sp;
 		FOR_ALL_SEARCHPATHS(sp) {
 			char buf[MAX_PATH];
-			FioAppendDirectory(buf, sizeof(buf), sp, HEIGHTMAP_DIR);
+			FioAppendDirectory(buf, lastof(buf), sp, HEIGHTMAP_DIR);
 
 			if (strncmp(buf, it->second.tar_filename, strlen(buf)) == 0) {
 				match = true;
@@ -547,16 +552,19 @@ static FiosType FiosGetHeightmapListCallback(SaveLoadDialogMode mode, const char
 void FiosGetHeightmapList(SaveLoadDialogMode mode)
 {
 	static char *fios_hmap_path = NULL;
+	static char *fios_hmap_path_last = NULL;
 
 	if (fios_hmap_path == NULL) {
 		fios_hmap_path = MallocT<char>(MAX_PATH);
-		FioGetDirectory(fios_hmap_path, MAX_PATH, HEIGHTMAP_DIR);
+		fios_hmap_path_last = fios_hmap_path + MAX_PATH - 1;
+		FioGetDirectory(fios_hmap_path, fios_hmap_path_last, HEIGHTMAP_DIR);
 	}
 
 	_fios_path = fios_hmap_path;
+	_fios_path_last = fios_hmap_path_last;
 
 	char base_path[MAX_PATH];
-	FioGetDirectory(base_path, sizeof(base_path), HEIGHTMAP_DIR);
+	FioGetDirectory(base_path, lastof(base_path), HEIGHTMAP_DIR);
 
 	FiosGetFileList(mode, &FiosGetHeightmapListCallback, strcmp(base_path, _fios_path) == 0 ? HEIGHTMAP_DIR : NO_DIRECTORY);
 }
@@ -571,7 +579,7 @@ const char *FiosGetScreenshotDir()
 
 	if (fios_screenshot_path == NULL) {
 		fios_screenshot_path = MallocT<char>(MAX_PATH);
-		FioGetDirectory(fios_screenshot_path, MAX_PATH, SCREENSHOT_DIR);
+		FioGetDirectory(fios_screenshot_path, fios_screenshot_path + MAX_PATH - 1, SCREENSHOT_DIR);
 	}
 
 	return fios_screenshot_path;