From: Guy Harris <guy@alum.mit.edu>
Date: Mon, 13 Mar 2017 22:47:56 +0000 (-0700)
Subject: Have a strlcat() macro for UN*X platforms that lack it.
X-Git-Tag: libpcap-1.9-bp~863
X-Git-Url: https://git.tcpdump.org/libpcap/commitdiff_plain/e000478ecd3d7671d3fc65b50ad6fc8f39114d96?ds=sidebyside

Have a strlcat() macro for UN*X platforms that lack it.
---

diff --git a/config.h.in b/config.h.in
index fdb32745..290aba28 100644
--- a/config.h.in
+++ b/config.h.in
@@ -166,6 +166,9 @@
 /* Define to 1 if you have the <string.h> header file. */
 #undef HAVE_STRING_H
 
+/* Define to 1 if you have the `strlcat' function. */
+#undef HAVE_STRLCAT
+
 /* Define to 1 if you have the `strlcpy' function. */
 #undef HAVE_STRLCPY
 
diff --git a/configure b/configure
index b1f36030..b04cec7d 100755
--- a/configure
+++ b/configure
@@ -4937,7 +4937,7 @@ $as_echo "$ac_cv_lbl_gcc_fixincludes" >&6; }
 	    fi
     fi
 
-for ac_func in strerror strlcpy
+for ac_func in strerror strlcpy strlcat
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/configure.ac b/configure.ac
index c48c07fa..1d098799 100644
--- a/configure.ac
+++ b/configure.ac
@@ -160,7 +160,7 @@ esac
 
 AC_LBL_FIXINCLUDES
 
-AC_CHECK_FUNCS(strerror strlcpy)
+AC_CHECK_FUNCS(strerror strlcpy strlcat)
 
 needsnprintf=no
 AC_CHECK_FUNCS(vsnprintf snprintf,,
diff --git a/portability.h b/portability.h
index 8a6bf40e..117fe4dd 100644
--- a/portability.h
+++ b/portability.h
@@ -47,7 +47,7 @@ extern "C" {
  /*
   * Macro that does the same thing as strlcpy().
   */
- #ifdef _MSC_VER
+ #if defined(_MSC_VER) || defined(__MINGW32__)
   /*
    * strncpy_s() is supported at least back to Visual
    * Studio 2005.
@@ -63,6 +63,28 @@ extern "C" {
  #endif
 #endif
 
+#ifndef HAVE_STRLCAT
+ /*
+  * Macro that does the same thing as strlcat().
+  */
+ #if defined(_MSC_VER) || defined(__MINGW32__)
+  /*
+   * strncat_s() is supported at least back to Visual
+   * Studio 2005.
+   */
+  #define strlcat(x, y, z) \
+	strncat_s((x), (z), (y), _TRUNCATE)
+ #else
+  /*
+   * ANSI C says strncat() always null-terminates its first argument,
+   * so 1) we don't need to explicitly null-terminate the string
+   * ourselves and 2) we need to leave room for the null terminator.
+   */
+  #define strlcat(x, y, z) \
+	strncat((x), (y), (z) - strlen((x)) - 1)
+ #endif
+#endif
+
 /*
  * For flagging arguments as format strings in MSVC.
  */
@@ -87,11 +109,6 @@ extern "C" {
   FILE *fopen_safe(const char *filename, const char* mode);
 #endif
 
-#if defined(_MSC_VER) || defined(__MINGW32__)
-  #define strlcat(x, y, z) \
-	strncat_s((x), (z), (y), _TRUNCATE)
-#endif
-
 #ifdef _MSC_VER
   /*
    * MSVC.