Handle invalid arguments to close()/fclose() better.

[coloredstderr/coloredstderr.git] / src / coloredstderr.c

diff --git a/src/coloredstderr.c b/src/coloredstderr.c
index e3cc1d6337bd8839b68df218494ee6de1862acbb..b7e71e17871d6f7c7411c4c922d48cfcb2530680 100644 (file)
--- a/src/coloredstderr.c
+++ b/src/coloredstderr.c
@@ -35,9 +35,17 @@
 #ifdef HAVE_ERROR_H
 # include <error.h>
 #endif
+#ifdef HAVE_STRUCT__IO_FILE__FILENO
+# include <libio.h>
+#endif
 
 /* Conflicting declaration in glibc. */
 #undef fwrite_unlocked
+/* These functions may be macros when compiling with hardening flags (fortify)
+ * which cause build failures when used in our hook macros below. Observed
+ * with Clang on Debian Wheezy. */
+#undef printf
+#undef fprintf
 
 
 /* Used by various functions, including debug(). */
@@ -236,6 +244,10 @@ HOOK_FILE2(int, putc_unlocked, stream,
            int, c, FILE *, stream)
 HOOK_FILE1(int, putchar_unlocked, stdout,
            int, c)
+/* glibc defines (_IO_)putc_unlocked() to __overflow() in some cases. */
+#ifdef HAVE_STRUCT__IO_FILE__FILENO
+HOOK_FD2(int, __overflow, f->_fileno, _IO_FILE *, f, int, ch)
+#endif
 
 /* perror(3) */
 HOOK_VOID1(void, perror, STDERR_FILENO,
@@ -384,14 +396,20 @@ static int (*real_close)(int);
 int close(int fd) {
     DLSYM_FUNCTION(real_close, "close");
 
-    close_fd(fd);
+    if (fd >= 0) {
+        close_fd(fd);
+    }
     return real_close(fd);
 }
 static int (*real_fclose)(FILE *);
 int fclose(FILE *fp) {
+    int fd;
+
     DLSYM_FUNCTION(real_fclose, "fclose");
 
-    close_fd(fileno(fp));
+    if (fp != NULL && (fd = fileno(fp)) >= 0) {
+        close_fd(fd);
+    }
     return real_fclose(fp);
 }
 
@@ -536,3 +554,13 @@ int execvp(char const *file, char * const argv[]) {
     update_environment();
     return real_execvp(file, argv);
 }
+
+#ifdef HAVE_EXECVPE
+extern char **environ;
+int execvpe(char const *file, char * const argv[], char * const envp[]) {
+    /* Fake the environment so we can reuse execvp(). */
+    environ = (char **)envp;
+
+    return execvp(file, argv);
+}
+#endif