/*
* Copyright (C) 2024 Olaf Wintermann <olaf.wintermann@gmail.com>
*
* Permission to use, copy, modify, and/or distribute this software for
* anypurpose with or without fee is hereby granted.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include "libxattr.h"
#include <errno.h>
#include <sys/types.h>
#include <string.h>
#define LIST_BUF_LEN 1024
#define LIST_ARRAY_LEN 8
#define ATTR_BUF_LEN 1024
static int strarray_add(char ***array_ptr, size_t *pos, size_t *len, char *str) {
char **array = *array_ptr;
size_t array_pos = *pos;
size_t array_len = *len;
if(array_pos >= array_len) {
size_t newlen = array_len * 2;
char **new_array = realloc(array, newlen * sizeof(char*));
if(!new_array) {
return 1;
}
*len = array_len;
array = new_array;
*array_ptr = new_array;
}
array[array_pos] = str;
*pos = array_pos + 1;
return 0;
}
static void strarray_free(char **array, size_t nelm) {
for(size_t i=0;i<nelm;i++) {
free(array[i]);
}
free(array);
}
#ifdef __linux__
#define XATTR_SUPPORTED
#include <sys/xattr.h>
static char ** parse_xattrlist(char *buf, ssize_t length, ssize_t *nelm) {
size_t arraylen = LIST_ARRAY_LEN;
size_t arraypos = 0;
char **array = malloc(LIST_ARRAY_LEN * sizeof(char*));
if(!array) {
*nelm = -1;
return NULL;
}
char *name = NULL;
for(int i=0;i<length;i++) {
if(!name && buf[i] == '.') {
name = buf + i + 1;
}
if(buf[i] == '\0') {
char *attrname = strdup(name);
if(!attrname) {
strarray_free(array, arraypos);
*nelm = -1;
return NULL;
}
if(strarray_add(&array, &arraypos, &arraylen, attrname)) {
strarray_free(array, arraypos);
*nelm = -1;
return NULL;
}
name = NULL;
}
}
if(arraypos == 0) {
free(array);
array = NULL;
}
*nelm = arraypos;
return array;
}
char ** xattr_list(const char *path, ssize_t *nelm) {
char *list = malloc(LIST_BUF_LEN);
if(!list) {
*nelm = -1;
return NULL;
}
ssize_t len = listxattr(path, list, LIST_BUF_LEN);
if(len == -1) {
switch(errno) {
case ERANGE: {
// buffer too, get size of attribute list
ssize_t newlen = listxattr(path, NULL, 0);
if(newlen > 0) {
// second try
char *new_list = realloc(list, newlen);
if(!new_list) {
free(list);
*nelm = -1;
return NULL;
}
list = new_list;
len = listxattr(path, list, newlen);
if(len != -1) {
// this time it worked
break;
}
}
}
default: {
free(list);
*nelm = -1;
return NULL;
}
}
}
char **ret = parse_xattrlist(list, len, nelm);
free(list);
return ret;
}
static char* name2nsname(const char *name) {
// add the 'user' namespace to the name
size_t namelen = strlen(name);
char *attrname = malloc(8 + namelen);
if(!attrname) {
return NULL;
}
memcpy(attrname, "user.", 5);
memcpy(attrname+5, name, namelen + 1);
return attrname;
}
char * xattr_get(const char *path, const char *attr, ssize_t *len) {
char *attrname = name2nsname(attr);
if(!attrname) {
*len = -1;
return NULL;
}
char *buf = malloc(ATTR_BUF_LEN);
if(!buf) {
*len = -1;
free(attrname);
return NULL;
}
ssize_t vlen = getxattr(path, attrname, buf, ATTR_BUF_LEN - 1);
if(vlen < 0) {
switch(errno) {
case ERANGE: {
ssize_t attrlen = getxattr(path, attrname, NULL, 0);
if(attrlen > 0) {
free(buf);
buf = malloc(attrlen + 1);
if(!buf) {
*len = -1;
free(attrname);
return NULL;
}
vlen = getxattr(path, attrname, buf, attrlen);
if(vlen > 0) {
break;
}
}
}
default: {
*len = -1;
free(buf);
free(attrname);
return NULL;
}
}
}
buf[vlen] = 0;
free(attrname);
*len = vlen;
return buf;
}
int xattr_set(const char *path, const char *name, const void *value, size_t len) {
char *attrname = name2nsname(name);
if(!attrname) {
return 1;
}
int ret = setxattr(path, attrname, value, len, 0);
free(attrname);
return ret;
}
int xattr_remove(const char *path, const char *name) {
char *attrname = name2nsname(name);
if(!attrname) {
return 1;
}
int ret = removexattr(path, attrname);
free(attrname);
return ret;
}
#endif /* Linux */
#ifdef __APPLE__
#define XATTR_SUPPORTED
#include <sys/xattr.h>
static char ** parse_xattrlist(char *buf, ssize_t length, ssize_t *nelm) {
size_t arraylen = LIST_ARRAY_LEN;
size_t arraypos = 0;
char **array = malloc(LIST_ARRAY_LEN * sizeof(char*));
char *name = buf;
for(int i=0;i<length;i++) {
if(buf[i] == '\0') {
char *attrname = strdup(name);
if(strarray_add(&array, &arraypos, &arraylen, attrname)) {
strarray_free(array, arraypos);
*nelm = -1;
return NULL;
}
name = buf + i + 1;
}
}
if(arraypos == 0) {
free(array);
array = NULL;
}
*nelm = arraypos;
return array;
}
char ** xattr_list(const char *path, ssize_t *nelm) {
char *list = malloc(LIST_BUF_LEN);
if(!list) {
*nelm = -1;
return NULL;
}
ssize_t len = listxattr(path, list, LIST_BUF_LEN, 0);
if(len == -1) {
switch(errno) {
case ERANGE: {
// buffer too, get size of attribute list
ssize_t newlen = listxattr(path, NULL, 0, 0);
if(newlen > 0) {
// second try
char *new_list = realloc(list, newlen);
if(!new_list) {
free(list);
*nelm = -1;
return NULL;
}
list = new_list;
len = listxattr(path, list, newlen, 0);
if(len != -1) {
// this time it worked
break;
}
}
}
default: {
free(list);
*nelm = -1;
return NULL;
}
}
}
char **ret = parse_xattrlist(list, len, nelm);
free(list);
return ret;
}
char * xattr_get(const char *path, const char *attr, ssize_t *len) {
// get attribute length
ssize_t attrlen = getxattr(path, attr, NULL, 0, 0, 0);
if(attrlen < 0) {
*len = -1;
return NULL;
}
char *buf = malloc(attrlen + 1);
if(!buf) {
*len = -1;
return NULL;
}
ssize_t vlen = getxattr(path, attr, buf, attrlen, 0, 0);
if(vlen < 0) {
*len = -1;
free(buf);
return NULL;
}
buf[vlen] = 0;
*len = vlen;
return buf;
}
int xattr_set(const char *path, const char *name, const void *value, size_t len) {
int ret = setxattr(path, name, value, len, 0, 0);
return ret;
}
int xattr_remove(const char *path, const char *name) {
return removexattr(path, name, 0);
}
#endif /* Apple */
#ifdef __sun
#define XATTR_SUPPORTED
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <fcntl.h>
static int open_attrfile(const char *path, const char *attr, int oflag) {
int file = open(path, O_RDONLY);
if(file == -1) {
return -1;
}
int attrfile = openat(file, attr, oflag, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
close(file);
return attrfile;
}
char ** xattr_list(const char *path, ssize_t *nelm) {
*nelm = -1;
int attrdir = open_attrfile(path, ".", O_RDONLY|O_XATTR);
if(attrdir == -1) {
return NULL;
}
DIR *dir = fdopendir(attrdir);
if(!dir) {
close(attrdir);
return NULL;
}
size_t arraylen = LIST_ARRAY_LEN;
size_t arraypos = 0;
char **array = malloc(LIST_ARRAY_LEN * sizeof(char*));
if(!array) {
closedir(dir);
*nelm = -1;
return NULL;
}
struct dirent *ent;
while((ent = readdir(dir)) != NULL) {
if(!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, "..") || !strcmp(ent->d_name, "SUNWattr_ro") || !strcmp(ent->d_name, "SUNWattr_rw")) {
continue;
}
char *name = strdup(ent->d_name);
if(strarray_add(&array, &arraypos, &arraylen, name)) {
strarray_free(array, arraypos);
*nelm = -1;
closedir(dir);
return NULL;
}
}
closedir(dir);
*nelm = arraypos;
return array;
}
char * xattr_get(const char *path, const char *attr, ssize_t *len) {
*len = -1;
int attrfile = open_attrfile(path, attr, O_RDONLY|O_XATTR);
if(attrfile == -1) {
return NULL;
}
struct stat s;
if(fstat(attrfile, &s)) {
close(attrfile);
return NULL;
}
size_t bufsize = (size_t)s.st_size;
char *buf = malloc(bufsize + 1);
if(!buf) {
close(attrfile);
return NULL;
}
char *b = buf;
size_t cur = 0;
while(cur < bufsize) {
ssize_t r = read(attrfile, buf + cur, bufsize - cur);
if(r <= 0) {
break;
}
cur += r;
}
close(attrfile);
if(cur != bufsize) {
free(buf);
return NULL;
}
buf[cur] = 0;
*len = (ssize_t)bufsize;
return buf;
}
int xattr_set(const char *path, const char *name, const void *value, size_t len) {
int attrfile = open_attrfile(path, name, O_CREAT|O_WRONLY|O_XATTR|O_TRUNC);
if(attrfile == -1) {
return -1;
}
const char *p = value;
size_t remaining = len;
while(remaining > 0) {
ssize_t w = write(attrfile, p, remaining);
if(w <= 0) {
break;
}
p += w;
remaining -= w;
}
close(attrfile);
return remaining > 0 ? -1 : 0;
}
int xattr_remove(const char *path, const char *name) {
int attrdir = open_attrfile(path, ".", O_RDONLY|O_XATTR);
if(attrdir == -1) {
return -1;
}
int ret = unlinkat(attrdir, name, 0);
close(attrdir);
return ret;
}
#endif /* Sun */
#ifdef __FreeBSD__
#define XATTR_SUPPORTED
#include <sys/types.h>
#include <sys/extattr.h>
static char ** parse_xattrlist(char *buf, ssize_t length, ssize_t *nelm) {
size_t arraylen = LIST_ARRAY_LEN;
size_t arraypos = 0;
char **array = malloc(LIST_ARRAY_LEN * sizeof(char*));
if(!array) {
*nelm = -1;
return NULL;
}
for(int i=0;i<length;i++) {
int namelen = buf[i];
char *name = buf + i + 1;
char *attrname = malloc(namelen + 1);
if(!attrname) {
strarray_free(array, arraypos);
*nelm = -1;
return NULL;
}
memcpy(attrname, name, namelen);
attrname[namelen] = 0;
if(strarray_add(&array, &arraypos, &arraylen, attrname)) {
strarray_free(array, arraypos);
*nelm = -1;
return NULL;
}
i += namelen;
}
if(arraypos == 0) {
free(array);
array = NULL;
}
*nelm = arraypos;
return array;
}
char ** xattr_list(const char *path, ssize_t *nelm) {
*nelm = -1;
ssize_t lslen = extattr_list_file(path, EXTATTR_NAMESPACE_USER, NULL, 0);
if(lslen <= 0) {
if(lslen == 0) {
*nelm = 0;
}
return NULL;
}
char *list = malloc(lslen);
if(!list) {
return NULL;
}
ssize_t len = extattr_list_file(path, EXTATTR_NAMESPACE_USER, list, lslen);
if(len == -1) {
free(list);
return NULL;
}
char **ret = parse_xattrlist(list, len, nelm);
free(list);
return ret;
}
char * xattr_get(const char *path, const char *attr, ssize_t *len) {
// get attribute length
ssize_t attrlen = extattr_get_file(path, EXTATTR_NAMESPACE_USER, attr, NULL, 0);
if(attrlen < 0) {
*len = -1;
return NULL;
}
char *buf = malloc(attrlen + 1);
ssize_t vlen = extattr_get_file(path, EXTATTR_NAMESPACE_USER, attr, buf, attrlen);
if(vlen < 0) {
*len = -1;
free(buf);
return NULL;
}
buf[attrlen] = 0;
*len = vlen;
return buf;
}
int xattr_set(const char *path, const char *name, const void *value, size_t len) {
int ret = extattr_set_file(path, EXTATTR_NAMESPACE_USER, name, value, len);
return ret >= 0 ? 0 : ret;
}
int xattr_remove(const char *path, const char *name) {
return extattr_delete_file(path, EXTATTR_NAMESPACE_USER, name);
}
#endif /* FreeBSD */
#ifndef XATTR_SUPPORTED
char ** xattr_list(const char *path, ssize_t *nelm) {
*nelm = -1;
return NULL;
}
char * xattr_get(const char *path, const char *attr, ssize_t *len) {
*len = -1;
return NULL;
}
int xattr_set(const char *path, const char *name, const void *value, size_t len) {
return -1;
}
int xattr_remove(const char *path, const char *name) {
return -1;
}
#endif /* unsupported platform */
void xattr_free_list(char **attrnames, ssize_t nelm) {
if(attrnames) {
for(int i=0;i<nelm;i++) {
free(attrnames[i]);
}
free(attrnames);
}
}