UNIXworkcode

/* * Copyright 2019 Olaf Wintermann * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE 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); } }