X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=support%2Fsys-xattr.c;h=fc03f7ee95a97fd728e63f2933e00a6284de2132;hb=3fd6c71d194d8ff65c72b24578d2fd08d057ba6f;hp=a5729a86921d99378517d0a29f1d8a526cfc90c6;hpb=ff228e1c801bda9666b6edab3ee962e05edcf480;p=mono.git diff --git a/support/sys-xattr.c b/support/sys-xattr.c index a5729a86921..fc03f7ee95a 100644 --- a/support/sys-xattr.c +++ b/support/sys-xattr.c @@ -1,108 +1,628 @@ /* - * wrapper functions. + * Wrapper functions for (or ) and * * Authors: * Daniel Drake (dsd@gentoo.org) + * Jonathan Pryor (jonpryor@vt.edu) * * Copyright (C) 2005 Daniel Drake + * Copyright (C) 2006 Jonathan Pryor */ #include -#ifdef HAVE_SYS_XATTR_H +#if defined(HAVE_SYS_XATTR_H) || defined(HAVE_ATTR_ATTR_H) || defined(HAVE_SYS_EXTATTR_H) #include + +/* + * 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 +#define EA_UNIX +#elif HAVE_ATTR_ATTR_H +// libattr +#include +#define EA_UNIX +#endif /* HAVE_SYS_XATTR_H */ + +#ifdef HAVE_SYS_EXTATTR_H +#include +#include +#define EA_BSD +#endif + #include #include #include +#include +#include #include "map.h" #include "mph.h" +/* + * Linux provides extended attributes through the 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 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 +// +// 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) +{ + // 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*)); +} + +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, char *value, mph_size_t size, gint32 flags) +Mono_Posix_Syscall_setxattr (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; +#if __APPLE__ + 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 setxattr (path, name, value, size, _flags); + return ret; } +#if !__APPLE__ gint32 -Mono_Posix_Syscall_lsetxattr (const char *path, const char *name, char *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 /* !__APPLE__ */ gint32 -Mono_Posix_Syscall_fsetxattr (int fd, const char *name, char *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__ + 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 lsetxattr (fd, name, value, (size_t) size, _flags); + 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); - return getxattr (path, name, value, (size_t) size); + +#ifdef EA_UNIX +#if __APPLE__ + 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 /* !__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); - return fgetxattr (fd, name, value, (size_t) size); + +#ifdef EA_UNIX +#if __APPLE__ + 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, char *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); - return listxattr (path, list, (size_t) size); + +#ifdef EA_UNIX +#if __APPLE__ + 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, char *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, 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 /* !__APPLE__ */ mph_ssize_t -Mono_Posix_Syscall_flistxattr (int fd, char *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); - return flistxattr (fd, list, (size_t) size); + +#ifdef EA_UNIX +#if __APPLE__ + 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