From: WaLyong Cho <walyong.cho@gmail.com>
Date: Mon, 27 Jul 2015 17:40:50 +0000 (+0900)
Subject: util: add getxattr helper apis
X-Git-Tag: v225~117^2~2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7b9c9ab810eb8746cece22de1dfec375caf4cd13;p=thirdparty%2Fsystemd.git

util: add getxattr helper apis

To get xattr of given path or fd on newly allocated buffer, add new
helper api getxattr_malloc() and fgetxattr_malloc().
---

diff --git a/src/basic/util.c b/src/basic/util.c
index a968e2156d5..af58dc37663 100644
--- a/src/basic/util.c
+++ b/src/basic/util.c
@@ -6603,3 +6603,73 @@ int reset_uid_gid(void) {
 
         return 0;
 }
+
+int getxattr_malloc(const char *path, const char *name, char **value, bool allow_symlink) {
+        char *v;
+        size_t l;
+        ssize_t n;
+
+        assert(path);
+        assert(name);
+        assert(value);
+
+        for (l = 100; ; l = (size_t) n + 1) {
+                v = new0(char, l);
+                if (!v)
+                        return -ENOMEM;
+
+                if (allow_symlink)
+                        n = lgetxattr(path, name, v, l);
+                else
+                        n = getxattr(path, name, v, l);
+
+                if (n >= 0 && (size_t) n < l) {
+                        *value = v;
+                        return n;
+                }
+
+                free(v);
+
+                if (n < 0 && errno != ERANGE)
+                        return -errno;
+
+                if (allow_symlink)
+                        n = lgetxattr(path, name, NULL, 0);
+                else
+                        n = getxattr(path, name, NULL, 0);
+                if (n < 0)
+                        return -errno;
+        }
+}
+
+int fgetxattr_malloc(int fd, const char *name, char **value) {
+        char *v;
+        size_t l;
+        ssize_t n;
+
+        assert(fd >= 0);
+        assert(name);
+        assert(value);
+
+        for (l = 100; ; l = (size_t) n + 1) {
+                v = new0(char, l);
+                if (!v)
+                        return -ENOMEM;
+
+                n = fgetxattr(fd, name, v, l);
+
+                if (n >= 0 && (size_t) n < l) {
+                        *value = v;
+                        return n;
+                }
+
+                free(v);
+
+                if (n < 0 && errno != ERANGE)
+                        return -errno;
+
+                n = fgetxattr(fd, name, NULL, 0);
+                if (n < 0)
+                        return -errno;
+        }
+}
diff --git a/src/basic/util.h b/src/basic/util.h
index 88c44273d43..0a0fba90126 100644
--- a/src/basic/util.h
+++ b/src/basic/util.h
@@ -919,3 +919,6 @@ int parse_mode(const char *s, mode_t *ret);
 int mount_move_root(const char *path);
 
 int reset_uid_gid(void);
+
+int getxattr_malloc(const char *path, const char *name, char **value, bool allow_symlink);
+int fgetxattr_malloc(int fd, const char *name, char **value);