/*
- * <sys/xattr.h> wrapper functions.
+ * Wrapper functions for <sys/xattr.h> (or <attr/xattr.h>) and <sys/extattr.h>
*
* Authors:
* Daniel Drake (dsd@gentoo.org)
+ * Jonathan Pryor (jonpryor@vt.edu)
*
* Copyright (C) 2005 Daniel Drake
+ * Copyright (C) 2006 Jonathan Pryor
*/
#include <config.h>
-#ifdef HAVE_SYS_XATTR_H
+#if defined(HAVE_SYS_XATTR_H) || defined(HAVE_ATTR_ATTR_H) || defined(HAVE_SYS_EXTATTR_H)
#include <sys/types.h>
+
+/*
+ * Where available, we prefer to use the libc implementation of the xattr
+ * syscalls. However, we also support using libattr for this on systems where
+ * libc does not provide this (e.g. glibc-2.2 and older)
+ * (configure-time magic is used to select which library to link to)
+ */
+#ifdef HAVE_SYS_XATTR_H
+// libc
#include <sys/xattr.h>
+#define EA_UNIX
+#elif HAVE_ATTR_ATTR_H
+// libattr
+#include <attr/xattr.h>
+#define EA_UNIX
+#endif /* HAVE_SYS_XATTR_H */
+
+#ifdef HAVE_SYS_EXTATTR_H
+#include <sys/extattr.h>
+#include <sys/uio.h>
+#define EA_BSD
+#endif
+
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
#include "map.h"
#include "mph.h"
+/*
+ * Linux provides extended attributes through the <sys/xattr.h> API.
+ * Any file or link can have attributes assigned to it (provided that they are
+ * supported by the backing filesystem). Each attribute has to be placed in a
+ * namespace, of which "user" is the most common. Namespaces are specified as
+ * a prefix to the attribute name, proceeded by a '.' (e.g. user.myattribute)
+ *
+ * FreeBSD provides extended attributes through the <sys/extattr.h> API.
+ * Behaviour is very similar to Linux EA's, but the namespace is specified
+ * through an enum-style parameter rather than as a prefix to an attribute
+ * name. There are also differences in the behaviour of the "list attributes"
+ * system calls.
+ *
+ * This file merges the two implementations into a single API for use by the
+ * Mono.Unix.Syscall.*xattr methods. No matter which OS you are on, things
+ * should "just work" the same as anywhere else.
+ *
+ * The API provided here leans more towards the Linux implementation. Attribute
+ * namespaces are provided as prefixes to the attribute name (followed by '.').
+ * There is no limit to the namespaces accepted by the Linux side of this
+ * implementation, but you are obviously limited to the ones available to you
+ * on the system.
+ * FreeBSD namespaces have to be converted from the textual prefix into their
+ * relevant number so that they can be used in the FreeBSD system calls.
+ * This means that the only namespaces available are the ones known by in this
+ * file (see bsd_extattr_namespaces). However, you can also specify the
+ * numericalnamespace index yourself, by using an attribute name such as
+ * "5.myattr".
+ * (this will obviously fail on Linux, your code will no longer be 'portable')
+ *
+ * Linux {,l,f}setxattr calls have a flags parameter which allow you to control
+ * what should happen if an attribute with the same name does (or doesn't)
+ * already exist. The 'flags' parameter is available here, but because FreeBSD
+ * does not support this kind of refinement, it will fail on FreeBSD if you
+ * specify anything other than XATTR_AUTO (XATTR_AUTO will create the attribute
+ * if it doesn't already exist, and overwrite the existing attribute if it
+ * already set).
+ *
+ * For usage and behaviour information, see the monodoc documentation on the
+ * Mono.Unix.Syscall class.
+ */
+
G_BEGIN_DECLS
-gint32
-Mono_Posix_Syscall_setxattr (const char *path, const char *name, void *value, mph_size_t size, gint32 flags)
+//
+// HELPER FUNCTIONS
+//
+
+#ifdef EA_BSD
+
+struct BsdNamespaceInfo {
+ const char *name;
+ int value;
+};
+
+static struct BsdNamespaceInfo bsd_extattr_namespaces[] = {
+ {"user" , EXTATTR_NAMESPACE_USER},
+ {"system" , EXTATTR_NAMESPACE_SYSTEM}
+};
+
+static int bsd_check_flags (gint32 flags)
{
- int _flags;
- mph_return_if_size_t_overflow (size);
+ // BSD doesn't support flags, but always provides the same behaviour as
+ // XATTR_AUTO. So we enforce that here.
+ if (flags != Mono_Posix_XattrFlags_XATTR_AUTO) {
+ errno = EINVAL;
+ return -1;
+ }
+ return 0;
+}
+
+// On FreeBSD, we need to convert "user.blah" into namespace 1 and attribute
+// name "blah", or maybe "6.blah" into namespace 6 attribute "blah"
+static int
+bsd_handle_nsprefix (const char *name, char **_name, int *namespace)
+{
+ int i;
+ gchar **components = g_strsplit (name, ".", 2);
+
+ // Find namespace number from textual representation
+ for (i = 0; i < G_N_ELEMENTS(bsd_extattr_namespaces); i++)
+ if (strcmp (bsd_extattr_namespaces[i].name, components[0]) == 0) {
+ *namespace = bsd_extattr_namespaces[i].value;
+ break;
+ }
+
+ if (*namespace == 0) {
+ // Perhaps they specified the namespace number themselves..?
+ char *endptr;
+ *namespace = (int) strtol (components[0], &endptr, 10);
+ if (*endptr != '\0')
+ return -1;
+ }
+
+ *_name = g_strdup (components[1]);
+ g_strfreev (components);
+ return 0;
+}
+
+static void
+init_attrlists (char *attrlists[])
+{
+ memset (attrlists, 0, G_N_ELEMENTS(bsd_extattr_namespaces) * sizeof(char*));
+}
- if (Mono_Posix_FromXattrFlags (flags, &_flags) == -1)
+static void
+free_attrlists (char *attrlists[])
+{
+ int i;
+ for (i = 0; i < G_N_ELEMENTS(bsd_extattr_namespaces); i++)
+ g_free (attrlists[i]);
+}
+
+// Counts the number of attributes in the result of a
+// extattr_list_*() call. Note that the format of the data
+// is: \3one\3two\6eleven where the leading charaters represent the length
+// of the following attribute. (the description in the man-page is wrong)
+static unsigned int
+count_num_attrs (char *attrs, size_t size)
+{
+ size_t i = 0;
+ unsigned int num_attrs = 0;
+
+ if (!attrs || !size)
+ return 0;
+
+ while (i < size) {
+ num_attrs++;
+ i += attrs[i] + 1;
+ }
+
+ return num_attrs;
+}
+
+// Convert a BSD-style list buffer (see the description for count_num_attrs)
+// into a Linux-style NULL-terminated list including namespace prefix.
+static char
+*bsd_convert_list (const char *nsprefix, const char *src, size_t size, char *dest)
+{
+ size_t i = 0;
+ if (src == NULL || dest == NULL || size == 0)
+ return NULL;
+
+ while (i < size) {
+ // Read length
+ int attr_len = (int) src[i];
+ int prefix_len = strlen (nsprefix);
+
+ // Add namespace prefix
+ strncpy (dest, nsprefix, prefix_len);
+ dest[prefix_len] = '.';
+ dest += prefix_len + 1;
+
+ // Copy attribute
+ memcpy(dest, src + ++i, attr_len);
+
+ // NULL-terminate
+ i += attr_len;
+ dest[attr_len] = '\0';
+ dest += attr_len + 1;
+ }
+
+ return dest;
+}
+
+// Combine all the lists of attributes that we know about into a single
+// Linux-style buffer
+static ssize_t
+bsd_combine_lists (char *attrlists[], char *dest, size_t dest_size_needed, size_t dest_size)
+{
+ int i;
+ if (!dest)
+ return dest_size_needed;
+
+ if (dest_size < dest_size_needed) {
+ errno = ERANGE;
return -1;
+ }
+
+ for (i = 0; i < G_N_ELEMENTS(bsd_extattr_namespaces); i++)
+ if (attrlists[i])
+ dest = bsd_convert_list (bsd_extattr_namespaces[i].name, attrlists[i], strlen (attrlists[i]), dest);
+
+ return dest_size_needed;
+}
+
+static mph_ssize_t
+bsd_listxattr (const char *path, void *list, mph_size_t size)
+{
+ size_t full_size = 0;
+ int i;
+ char *attrlists[G_N_ELEMENTS(bsd_extattr_namespaces)];
+
+ init_attrlists (attrlists);
+ for (i = 0; i < G_N_ELEMENTS(bsd_extattr_namespaces); i++) {
+ size_t buf_size;
+ int num_attrs;
+
+ buf_size = (size_t) extattr_list_file (path, i + 1, NULL, 0);
+ if (buf_size == -1)
+ continue;
+
+ attrlists[i] = g_malloc0 (buf_size + 1);
+ buf_size = (size_t) extattr_list_file (path, i + 1, attrlists[i], buf_size);
+ if (buf_size == -1)
+ continue;
+
+ num_attrs = count_num_attrs(attrlists[i], buf_size);
+ full_size += buf_size + (num_attrs * (strlen (bsd_extattr_namespaces[i].name) + 1));
+ }
+
+ full_size = bsd_combine_lists (attrlists, (char *) list, full_size, size);
+ free_attrlists (attrlists);
+ return full_size;
+}
+
+static mph_ssize_t
+bsd_llistxattr (const char *path, void *list, mph_size_t size)
+{
+ size_t full_size = 0;
+ int i;
+ char *attrlists[G_N_ELEMENTS(bsd_extattr_namespaces)];
+ init_attrlists (attrlists);
+ for (i = 0; i < G_N_ELEMENTS(bsd_extattr_namespaces); i++) {
+ size_t buf_size;
+ int num_attrs;
+
+ buf_size = (size_t) extattr_list_link (path, i + 1, NULL, 0);
+ if (buf_size == -1)
+ continue;
+
+ attrlists[i] = g_malloc0 (buf_size + 1);
+ buf_size = (size_t) extattr_list_link (path, i + 1, attrlists[i], buf_size);
+ if (buf_size == -1)
+ continue;
+
+ num_attrs = count_num_attrs(attrlists[i], buf_size);
+ full_size += buf_size + (num_attrs * (strlen (bsd_extattr_namespaces[i].name) + 1));
+ }
+
+ full_size = bsd_combine_lists (attrlists, (char *) list, full_size, size);
+ free_attrlists (attrlists);
+ return full_size;
+}
+
+static mph_ssize_t
+bsd_flistxattr (int fd, void *list, mph_size_t size)
+{
+ size_t full_size = 0;
+ int i;
+ char *attrlists[G_N_ELEMENTS(bsd_extattr_namespaces)];
+
+ init_attrlists (attrlists);
+ for (i = 0; i < G_N_ELEMENTS(bsd_extattr_namespaces); i++) {
+ size_t buf_size;
+ int num_attrs;
+
+ buf_size = (size_t) extattr_list_fd (fd, i + 1, NULL, 0);
+ if (buf_size == -1)
+ continue;
+
+ attrlists[i] = g_malloc0 (buf_size + 1);
+ buf_size = (size_t) extattr_list_fd (fd, i + 1, attrlists[i], buf_size);
+ if (buf_size == -1)
+ continue;
+
+ num_attrs = count_num_attrs(attrlists[i], buf_size);
+ full_size += buf_size + (num_attrs * (strlen (bsd_extattr_namespaces[i].name) + 1));
+ }
+
+ full_size = bsd_combine_lists (attrlists, (char *) list, full_size, size);
+ free_attrlists (attrlists);
+ return full_size;
+}
+
+#endif /* EA_BSD */
+
+//
+// THE PROVIDED API
+//
+
+gint32
+Mono_Posix_Syscall_setxattr (const char *path, const char *name, unsigned char *value, mph_size_t size, gint32 flags)
+{
+ gint32 ret;
+ mph_return_if_size_t_overflow (size);
+
+#ifdef EA_UNIX
+ {
+ int _flags;
+ if (Mono_Posix_FromXattrFlags (flags, &_flags) == -1)
+ return -1;
#if __APPLE__
- return setxattr (path, name, value, size, 0, _flags);
-#else
- return setxattr (path, name, value, size, _flags);
-#endif
+ ret = setxattr (path, name, value, (size_t) size, 0, _flags);
+#else /* __APPLE__ */
+ ret = setxattr (path, name, value, (size_t) size, _flags);
+#endif /* __APPLE__ */
+ }
+#else /* EA_UNIX */
+ {
+ char *_name;
+ int namespace;
+ if (bsd_check_flags (flags) == -1)
+ return -1;
+ if (bsd_handle_nsprefix (name, &_name, &namespace) == -1)
+ return -1;
+ ret = extattr_set_file (path, namespace, _name, value, (size_t) size);
+ g_free (_name);
+ }
+#endif /* EA_UNIX */
+
+ return ret;
}
#if !__APPLE__
gint32
-Mono_Posix_Syscall_lsetxattr (const char *path, const char *name, void *value, mph_size_t size, gint32 flags)
+Mono_Posix_Syscall_lsetxattr (const char *path, const char *name, unsigned char *value, mph_size_t size, gint32 flags)
{
- int _flags;
+ gint32 ret;
mph_return_if_size_t_overflow (size);
- if (Mono_Posix_FromXattrFlags (flags, &_flags) == -1)
- return -1;
+#ifdef EA_UNIX
+ {
+ int _flags;
+ if (Mono_Posix_FromXattrFlags (flags, &_flags) == -1)
+ return -1;
+ ret = lsetxattr (path, name, value, size, _flags);
+ }
+#else /* EA_UNIX */
+ {
+ char *_name;
+ int namespace;
+ if (bsd_check_flags (flags) == -1)
+ return -1;
+ if (bsd_handle_nsprefix (name, &_name, &namespace) == -1)
+ return -1;
+ ret = extattr_set_link (path, namespace, _name, value, (size_t) size);
+ g_free (_name);
+ }
+#endif /* EA_UNIX */
- return lsetxattr (path, name, value, size, _flags);
+ return ret;
}
-#endif
+#endif /* !__APPLE__ */
gint32
-Mono_Posix_Syscall_fsetxattr (int fd, const char *name, void *value, mph_size_t size, gint32 flags)
+Mono_Posix_Syscall_fsetxattr (int fd, const char *name, unsigned char *value, mph_size_t size, gint32 flags)
{
- int _flags;
+ gint32 ret;
mph_return_if_size_t_overflow (size);
- if (Mono_Posix_FromXattrFlags (flags, &_flags) == -1)
- return -1;
-
+#ifdef EA_UNIX
+ {
+ int _flags;
+ if (Mono_Posix_FromXattrFlags (flags, &_flags) == -1)
+ return -1;
#if __APPLE__
- return fsetxattr (fd, name, value, (size_t) size, 0, _flags);
-#else
- return fsetxattr (fd, name, value, (size_t) size, _flags);
-#endif
+ ret = fsetxattr (fd, name, value, (size_t) size, 0, _flags);
+#else /* __APPLE__ */
+ ret = fsetxattr (fd, name, value, (size_t) size, _flags);
+#endif /* __APPLE__ */
+ }
+#else /* EA_UNIX */
+ {
+ char *_name;
+ int namespace;
+ if (bsd_check_flags (flags) == -1)
+ return -1;
+ if (bsd_handle_nsprefix (name, &_name, &namespace) == -1)
+ return -1;
+ ret = extattr_set_fd (fd, namespace, _name, value, (size_t) size);
+ g_free (_name);
+ }
+#endif /* EA_UNIX */
+ return ret;
}
mph_ssize_t
-Mono_Posix_Syscall_getxattr (const char *path, const char *name, void *value, mph_size_t size)
+Mono_Posix_Syscall_getxattr (const char *path, const char *name, unsigned char *value, mph_size_t size)
{
+ mph_ssize_t ret;
mph_return_if_size_t_overflow (size);
+
+#ifdef EA_UNIX
#if __APPLE__
- return getxattr (path, name, value, (size_t) size, 0, 0);
-#else
- return getxattr (path, name, value, (size_t) size);
-#endif
+ ret = getxattr (path, name, value, (size_t) size, 0, 0);
+#else /* __APPLE__ */
+ ret = getxattr (path, name, value, (size_t) size);
+#endif /* __APPLE__ */
+#else /* EA_UNIX */
+ {
+ char *_name;
+ int namespace;
+ if (bsd_handle_nsprefix (name, &_name, &namespace) == -1)
+ return -1;
+ ret = extattr_get_file (path, namespace, _name, value, (size_t) size);
+ g_free (_name);
+ }
+#endif /* EA_UNIX */
+
+ return ret;
}
#if !__APPLE__
mph_ssize_t
-Mono_Posix_Syscall_lgetxattr (const char *path, const char *name, void *value, mph_size_t size)
+Mono_Posix_Syscall_lgetxattr (const char *path, const char *name, unsigned char *value, mph_size_t size)
{
+ mph_ssize_t ret;
mph_return_if_size_t_overflow (size);
- return lgetxattr (path, name, value, (size_t) size);
+
+#ifdef EA_UNIX
+ ret = lgetxattr (path, name, value, (size_t) size);
+#else /* EA_UNIX */
+ {
+ char *_name;
+ int namespace;
+ if (bsd_handle_nsprefix (name, &_name, &namespace) == -1)
+ return -1;
+ ret = extattr_get_link (path, namespace, _name, value, (size_t) size);
+ g_free (_name);
+ }
+#endif /* EA_UNIX */
+
+ return ret;
}
-#endif
+#endif /* !__APPLE__ */
mph_ssize_t
-Mono_Posix_Syscall_fgetxattr (int fd, const char *name, void *value, mph_size_t size)
+Mono_Posix_Syscall_fgetxattr (int fd, const char *name, unsigned char *value, mph_size_t size)
{
+ mph_ssize_t ret;
mph_return_if_size_t_overflow (size);
+
+#ifdef EA_UNIX
#if __APPLE__
- return fgetxattr (fd, name, value, (size_t) size, 0, 0);
-#else
- return fgetxattr (fd, name, value, (size_t) size);
-#endif
+ ret = fgetxattr (fd, name, value, (size_t) size, 0, 0);
+#else /* __APPLE__ */
+ ret = fgetxattr (fd, name, value, (size_t) size);
+#endif /* __APPLE__ */
+#else /* EA_UNIX */
+ {
+ char *_name;
+ int namespace;
+ if (bsd_handle_nsprefix (name, &_name, &namespace) == -1)
+ return -1;
+ ret = extattr_get_fd (fd, namespace, _name, value, (size_t) size);
+ g_free (_name);
+ }
+#endif /* EA_UNIX */
+
+ return ret;
}
mph_ssize_t
-Mono_Posix_Syscall_listxattr (const char *path, void *list, mph_size_t size)
+Mono_Posix_Syscall_listxattr (const char *path, unsigned char *list, mph_size_t size)
{
mph_return_if_size_t_overflow (size);
+
+#ifdef EA_UNIX
#if __APPLE__
- return listxattr (path, (char *) list, (size_t) size, 0);
-#else
- return listxattr (path, (char *) list, (size_t) size);
-#endif
+ return listxattr (path, (char*) list, (size_t) size, 0);
+#else /* __APPLE__ */
+ return listxattr (path, (char*) list, (size_t) size);
+#endif /* __APPLE__ */
+#else /* EA_UNIX */
+ return bsd_listxattr (path, list, size);
+#endif /* EA_UNIX */
}
#if !__APPLE__
mph_ssize_t
-Mono_Posix_Syscall_llistxattr (const char *path, void *list, mph_size_t size)
+Mono_Posix_Syscall_llistxattr (const char *path, unsigned char *list, mph_size_t size)
{
mph_return_if_size_t_overflow (size);
- return llistxattr (path, (char *) list, (size_t) size);
+
+#ifdef EA_UNIX
+ return llistxattr (path, (char*) list, (size_t) size);
+#else /* EA_UNIX */
+ return bsd_llistxattr (path, list, size);
+#endif /* EA_UNIX */
}
-#endif
+#endif /* !__APPLE__ */
mph_ssize_t
-Mono_Posix_Syscall_flistxattr (int fd, void *list, mph_size_t size)
+Mono_Posix_Syscall_flistxattr (int fd, unsigned char *list, mph_size_t size)
{
mph_return_if_size_t_overflow (size);
+
+#ifdef EA_UNIX
#if __APPLE__
- return flistxattr (fd, (char *) list, (size_t) size, 0);
-#else
- return flistxattr (fd, (char *) list, (size_t) size);
-#endif
+ return flistxattr (fd, (char*) list, (size_t) size, 0);
+#else /* __APPLE__ */
+ return flistxattr (fd, (char*) list, (size_t) size);
+#endif /* __APPLE__ */
+#else /* EA_UNIX */
+ return bsd_flistxattr (fd, list, size);
+#endif /* EA_UNIX */
+}
+
+gint32
+Mono_Posix_Syscall_removexattr (const char *path, const char *name)
+{
+ gint32 ret;
+
+#ifdef EA_UNIX
+#if __APPLE__
+ ret = removexattr (path, name, 0);
+#else /* __APPLE__ */
+ ret = removexattr (path, name);
+#endif /* __APPLE__ */
+#else /* EA_UNIX */
+ {
+ char *_name;
+ int namespace;
+ if (bsd_handle_nsprefix (name, &_name, &namespace) == -1)
+ return -1;
+ ret = extattr_delete_file (path, namespace, _name);
+ g_free (_name);
+ }
+#endif /* EA_UNIX */
+
+ return ret;
+}
+
+#if !__APPLE__
+gint32
+Mono_Posix_Syscall_lremovexattr (const char *path, const char *name)
+{
+ gint32 ret;
+
+#ifdef EA_UNIX
+ ret = lremovexattr (path, name);
+#else /* EA_UNIX */
+ {
+ char *_name;
+ int namespace;
+ if (bsd_handle_nsprefix (name, &_name, &namespace) == -1)
+ return -1;
+ ret = extattr_delete_link (path, namespace, _name);
+ g_free (_name);
+ }
+#endif /* EA_UNIX */
+
+ return ret;
+}
+#endif /* !__APPLE__ */
+
+gint32
+Mono_Posix_Syscall_fremovexattr (int fd, const char *name)
+{
+ gint32 ret;
+
+#ifdef EA_UNIX
+#if __APPLE__
+ ret = fremovexattr (fd, name, 0);
+#else /* __APPLE__ */
+ ret = fremovexattr (fd, name);
+#endif /* __APPLE__ */
+#else /* EA_UNIX */
+ {
+ char *_name;
+ int namespace;
+ if (bsd_handle_nsprefix (name, &_name, &namespace) == -1)
+ return -1;
+ ret = extattr_delete_fd (fd, namespace, _name);
+ g_free (_name);
+ }
+#endif /* EA_UNIX */
+
+ return ret;
}
G_END_DECLS
-#endif /* def HAVE_ATTR_XATTR_H */
+#endif /* HAVE_SYS_XATTR_H || HAVE_ATTR_ATTR_H || HAVE_SYS_EXTATTR_H */
/*
* vim: noexpandtab
projects / mono.git / blobdiff