From 9569fee882b5b26b9a9a506d6604255fbe0643ba Mon Sep 17 00:00:00 2001
From: Natalia Portillo <claunia@claunia.com>
Date: Tue, 30 Mar 2021 04:19:51 +0100
Subject: [PATCH] Dynamically load setxattr(2) in Linux.

---
 setter/src/darwin/xattr.c | 10 +++++-----
 setter/src/linux/xattr.c  | 33 ++++++++++++++++++++-------------
 setter/src/linux/xattr.h  |  2 ++
 3 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/setter/src/darwin/xattr.c b/setter/src/darwin/xattr.c
index 65fa041..5a8c760 100644
--- a/setter/src/darwin/xattr.c
+++ b/setter/src/darwin/xattr.c
@@ -38,11 +38,11 @@ void DarwinExtendedAttributes(const char* path)
     FILE*            file;
     int              rc;
     int              cRc;
-    _darwin_setxattr setxattr;
+    _darwin_setxattr darwin_setxattr;
 
-    setxattr = (_darwin_setxattr)dlsym(RTLD_DEFAULT, "setxattr");
+  darwin_setxattr = (_darwin_setxattr)dlsym(RTLD_DEFAULT, "setxattr");
 
-    if(!setxattr)
+    if(!darwin_setxattr)
     {
         log_write("Error loading setxattr(2) from libSystem: %s\n", dlerror());
         return;
@@ -82,7 +82,7 @@ void DarwinExtendedAttributes(const char* path)
     {
         fprintf(file, "This file has an extended attribute called \"com.ibm.os2.comment\" that is 72 bytes long.\n");
         fclose(file);
-        ret = setxattr("com.ibm.os2.comment", "user.com.ibm.os2.comment", CommentsEA, 72, 0, 0);
+        ret = darwin_setxattr("com.ibm.os2.comment", "user.com.ibm.os2.comment", CommentsEA, 72, 0, 0);
 
         if(ret) cRc = errno;
     }
@@ -96,7 +96,7 @@ void DarwinExtendedAttributes(const char* path)
     {
         fprintf(file, "This file has an extended attribute called \"com.ibm.os2.icon\" that is 3516 bytes long.\n");
         fclose(file);
-        ret = setxattr("com.ibm.os2.icon", "user.com.ibm.os2.icon", IconEA, 3516, 0, 0);
+        ret = darwin_setxattr("com.ibm.os2.icon", "user.com.ibm.os2.icon", IconEA, 3516, 0, 0);
 
         if(ret) cRc = errno;
     }
diff --git a/setter/src/linux/xattr.c b/setter/src/linux/xattr.c
index e3f20bb..9efe099 100644
--- a/setter/src/linux/xattr.c
+++ b/setter/src/linux/xattr.c
@@ -22,6 +22,9 @@ Aaru Data Preservation Suite
 Copyright (C) 2011-2021 Natalia Portillo
 *****************************************************************************/
 
+#define _GNU_SOURCE
+
+#include <dlfcn.h>
 #include <errno.h>
 #include <features.h>
 #include <stdio.h>
@@ -29,21 +32,26 @@ Copyright (C) 2011-2021 Natalia Portillo
 #include <sys/stat.h>
 #include <unistd.h>
 
-#include "../log.h"
-#include "linux.h"
 #include "xattr.h"
 
-#if((__GLIBC__ == 2) && (__GLIBC_MINOR__ >= 3)) || (__GLIBC__ > 2)
-#include <sys/xattr.h>
-#endif
+#include "../log.h"
+#include "linux.h"
 
 void LinuxExtendedAttributes(const char* path)
 {
-#if((__GLIBC__ == 2) && (__GLIBC_MINOR__ >= 3)) || (__GLIBC__ > 2)
-    int   ret;
-    FILE* file;
-    int   rc;
-    int   cRc;
+    int             ret;
+    FILE*           file;
+    int             rc;
+    int             cRc;
+    _linux_setxattr linux_setxattr;
+
+    linux_setxattr = (_linux_setxattr)dlsym(RTLD_DEFAULT, "setxattr");
+
+    if(!linux_setxattr)
+    {
+        log_write("Error loading setxattr(2) from libc: %s\n", dlerror());
+        return;
+    }
 
     ret = chdir(path);
 
@@ -79,7 +87,7 @@ void LinuxExtendedAttributes(const char* path)
     {
         fprintf(file, "This file has an extended attribute called \"com.ibm.os2.comment\" that is 72 bytes long.\n");
         fclose(file);
-        ret = setxattr("com.ibm.os2.comment", "user.com.ibm.os2.comment", CommentsEA, 72, XATTR_CREATE);
+        ret = linux_setxattr("com.ibm.os2.comment", "user.com.ibm.os2.comment", CommentsEA, 72, 0);
 
         if(ret) cRc = errno;
     }
@@ -93,10 +101,9 @@ void LinuxExtendedAttributes(const char* path)
     {
         fprintf(file, "This file has an extended attribute called \"com.ibm.os2.icon\" that is 3516 bytes long.\n");
         fclose(file);
-        ret = setxattr("com.ibm.os2.icon", "user.com.ibm.os2.icon", IconEA, 3516, XATTR_CREATE);
+        ret = linux_setxattr("com.ibm.os2.icon", "user.com.ibm.os2.icon", IconEA, 3516, 0);
 
         if(ret) cRc = errno;
     }
     log_write("\tFile with an extended attribute called \"com.ibm.os2.icon\", rc = %d, cRc = %d\n", rc, cRc);
-#endif
 }
diff --git a/setter/src/linux/xattr.h b/setter/src/linux/xattr.h
index 143d087..072be79 100644
--- a/setter/src/linux/xattr.h
+++ b/setter/src/linux/xattr.h
@@ -25,6 +25,8 @@ Copyright (C) 2011-2021 Natalia Portillo
 #ifndef AARU_FSTESTER_SETTER_SRC_LINUX_XATTR_H_
 #define AARU_FSTESTER_SETTER_SRC_LINUX_XATTR_H_
 
+typedef int (*_linux_setxattr)(const char* path, const char* name, const void* value, size_t size, int flags);
+
 static unsigned char CommentsEA[72] = {
     0x45, 0x00, 0x00, 0x00, 0x00, 0x09, 0x33, 0x00, 0x2E, 0x43, 0x4F, 0x4D, 0x4D, 0x45, 0x4E, 0x54, 0x53, 0x00,
     0xFD, 0xFF, 0x2E, 0x00, 0x54, 0x68, 0x69, 0x73, 0x20, 0x45, 0x41, 0x20, 0x63, 0x6F, 0x6E, 0x74, 0x61, 0x69,