tinyyarn

commit feadc201286680fd24ff628d73ed94b2c156e43f
parent 3fa604b57f2245aabc92cf35db177ce0ad00c284
Author: Richard Ipsum <richardipsum@vx21.xyz>
Date:   Mon,  5 Apr 2021 15:39:04 +0100

Replace strncpy with strlcpy

and remove some VLAs.

Diffstat:
M
Makefile
 | 
6
+++---
A
strlcpy.c
 | 
48
++++++++++++++++++++++++++++++++++++++++++++++++
M
tyarn.c
 | 
42
+++++++++++++++++++++++++++++++-----------

3 files changed, 82 insertions(+), 14 deletions(-)
diff --git a/Makefile b/Makefile
@@ -16,8 +16,8 @@ all: tyarn tyarn.so
 tyarn: tyarn.lua.in
 	sed 's|##LUA_INTERP##|$(LUA_INTERP)|' tyarn.lua.in > $@
 
-tyarn.so: tyarn.o
-	$(CC) $(CFLAGS) $(LDFLAGS) -shared -o $@ tyarn.o
+tyarn.so: tyarn.o strlcpy.o
+	$(CC) $(CFLAGS) $(LDFLAGS) -shared -o $@ tyarn.o strlcpy.o
 
 tyarn.o: tyarn.c
 	$(CC) -c -fPIC $(CFLAGS) -o $@ tyarn.c
@@ -33,6 +33,6 @@ uninstall: all
 	rm -f $(DESTDIR)$(LUA_CMOD_INST)/tyarn.so
 
 clean:
-	rm -f tyarn tyarn.o tyarn.so
+	rm -f tyarn *.o tyarn.so
 
 .PHONY: uninstall install clean all
diff --git a/strlcpy.c b/strlcpy.c
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+
+/*
+ * Copy src to string dst of size siz. At most siz-1 characters
+ * will be copied. Always NUL terminates (unless siz == 0).
+ * Returns strlen(src); if retval >= siz, truncation occurred.
+ */
+size_t
+strlcpy(char *dst, const char *src, size_t siz)
+{
+	char *d = dst;
+	const char *s = src;
+	size_t n = siz;
+	/* Copy as many bytes as will fit */
+	if (n != 0) {
+		while (--n != 0) {
+			if ((*d++ = *s++) == '\0')
+				break;
+		}
+	}
+	/* Not enough room in dst, add NUL and traverse rest of src */
+	if (n == 0) {
+		if (siz != 0)
+			*d = '\0'; /* NUL-terminate dst */
+		while (*s++)
+			;
+	}
+	return(s - src - 1); /* count does not include NUL */
+}
diff --git a/tyarn.c b/tyarn.c
@@ -43,6 +43,8 @@
 #include <sys/select.h>
 #include <regex.h>
 
+size_t strlcpy(char *, const char *, size_t);
+
 struct pipe_state {
     int fd;
     char *p;
@@ -132,13 +134,18 @@ static int tyarn_path_exists(lua_State *L)
 
 static int tyarn_mkdtemp(lua_State *L)
 {
-    const char *path = luaL_checkstring(L, 1);
-    char pathbuf[strlen(path) + 1];
+    const char *path;
+    char *pathbuf;
+    size_t pathbuf_size;
 
-    strncpy(pathbuf, path, sizeof (pathbuf));
+    path = luaL_checkstring(L, 1);
+    pathbuf_size = strlen(path) + 1;
+    pathbuf = xmalloc(pathbuf_size);
+    strlcpy(pathbuf, path, pathbuf_size);
 
     lua_pushstring(L, mkdtemp(pathbuf));
     lua_pushinteger(L, errno);
+    free(pathbuf);
     return 2;
 }
 
@@ -542,14 +549,21 @@ static int tyarn_unlink(lua_State *L)
 
 static int tyarn_mkstemp(lua_State *L)
 {
-    const char *path = luaL_checkstring(L, 1);
-    char template[strlen(path) + 1];
-    strncpy(template, path, sizeof (template));
-    int fd = mkstemp(template);
+    const char *path;
+    char *template;
+    int fd;
+    size_t template_size;
+
+    path = luaL_checkstring(L, 1);
+    template_size = strlen(path) + 1;
+    template = xmalloc(template_size);
+    strlcpy(template, path, template_size);
+    fd = mkstemp(template);
 
     if (fd == -1) {
         lua_pushnil(L);
         lua_pushstring(L, strerror(errno));
+        free(template);
         return 2;
     }
 
@@ -559,19 +573,25 @@ static int tyarn_mkstemp(lua_State *L)
      */
 
     lua_pushstring(L, template);
+    free(template);
     return 1;
 }
 
 static char *str_from_offs(const char *orig, regoff_t start, regoff_t end)
 {
-    char buf[strlen(orig) + 1];
-    char *p;
-    strncpy(buf, orig, sizeof (buf));
+    char *p, *buf, *newstr;
+    size_t bufsiz;
+
+    bufsiz = strlen(orig) + 1;
+    buf = xmalloc(bufsiz);
+    strlcpy(buf, orig, bufsiz);
 
     p = buf + start;
     buf[end] = '\0';
 
-    return xstrdup(p);
+    newstr = xstrdup(p);
+    free(buf);
+    return newstr;
 }
 
 static int tyarn_rematch(lua_State *L)