/*** This file is part of systemd. Copyright 2011,2013 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <errno.h> #include <stdbool.h> #include "acl-util.h" #include "alloc-util.h" #include "string-util.h" #include "strv.h" #include "user-util.h" #include "util.h" int acl_find_uid(acl_t acl, uid_t uid, acl_entry_t *entry) { acl_entry_t i; int r; assert(acl); assert(entry); for (r = acl_get_entry(acl, ACL_FIRST_ENTRY, &i); r > 0; r = acl_get_entry(acl, ACL_NEXT_ENTRY, &i)) { acl_tag_t tag; uid_t *u; bool b; if (acl_get_tag_type(i, &tag) < 0) return -errno; if (tag != ACL_USER) continue; u = acl_get_qualifier(i); if (!u) return -errno; b = *u == uid; acl_free(u); if (b) { *entry = i; return 1; } } if (r < 0) return -errno; return 0; } int calc_acl_mask_if_needed(acl_t *acl_p) { acl_entry_t i; int r; bool need = false; assert(acl_p); for (r = acl_get_entry(*acl_p, ACL_FIRST_ENTRY, &i); r > 0; r = acl_get_entry(*acl_p, ACL_NEXT_ENTRY, &i)) { acl_tag_t tag; if (acl_get_tag_type(i, &tag) < 0) return -errno; if (tag == ACL_MASK) return 0; if (IN_SET(tag, ACL_USER, ACL_GROUP)) need = true; } if (r < 0) return -errno; if (need && acl_calc_mask(acl_p) < 0) return -errno; return need; } int add_base_acls_if_needed(acl_t *acl_p, const char *path) { acl_entry_t i; int r; bool have_user_obj = false, have_group_obj = false, have_other = false; struct stat st; _cleanup_(acl_freep) acl_t basic = NULL; assert(acl_p); for (r = acl_get_entry(*acl_p, ACL_FIRST_ENTRY, &i); r > 0; r = acl_get_entry(*acl_p, ACL_NEXT_ENTRY, &i)) { acl_tag_t tag; if (acl_get_tag_type(i, &tag) < 0) return -errno; if (tag == ACL_USER_OBJ) have_user_obj = true; else if (tag == ACL_GROUP_OBJ) have_group_obj = true; else if (tag == ACL_OTHER) have_other = true; if (have_user_obj && have_group_obj && have_other) return 0; } if (r < 0) return -errno; r = stat(path, &st); if (r < 0) return -errno; basic = acl_from_mode(st.st_mode); if (!basic) return -errno; for (r = acl_get_entry(basic, ACL_FIRST_ENTRY, &i); r > 0; r = acl_get_entry(basic, ACL_NEXT_ENTRY, &i)) { acl_tag_t tag; acl_entry_t dst; if (acl_get_tag_type(i, &tag) < 0) return -errno; if ((tag == ACL_USER_OBJ && have_user_obj) || (tag == ACL_GROUP_OBJ && have_group_obj) || (tag == ACL_OTHER && have_other)) continue; r = acl_create_entry(acl_p, &dst); if (r < 0) return -errno; r = acl_copy_entry(dst, i); if (r < 0) return -errno; } if (r < 0) return -errno; return 0; } int acl_search_groups(const char *path, char ***ret_groups) { _cleanup_strv_free_ char **g = NULL; _cleanup_(acl_free) acl_t acl = NULL; bool ret = false; acl_entry_t entry; int r; assert(path); acl = acl_get_file(path, ACL_TYPE_DEFAULT); if (!acl) return -errno; r = acl_get_entry(acl, ACL_FIRST_ENTRY, &entry); for (;;) { _cleanup_(acl_free_gid_tpp) gid_t *gid = NULL; acl_tag_t tag; if (r < 0) return -errno; if (r == 0) break; if (acl_get_tag_type(entry, &tag) < 0) return -errno; if (tag != ACL_GROUP) goto next; gid = acl_get_qualifier(entry); if (!gid) return -errno; if (in_gid(*gid) > 0) { if (!ret_groups) return true; ret = true; } if (ret_groups) { char *name; name = gid_to_name(*gid); if (!name) return -ENOMEM; r = strv_consume(&g, name); if (r < 0) return r; } next: r = acl_get_entry(acl, ACL_NEXT_ENTRY, &entry); } if (ret_groups) { *ret_groups = g; g = NULL; } return ret; } int parse_acl(const char *text, acl_t *acl_access, acl_t *acl_default, bool want_mask) { _cleanup_free_ char **a = NULL, **d = NULL; /* strings are not be freed */ _cleanup_strv_free_ char **split; char **entry; int r = -EINVAL; _cleanup_(acl_freep) acl_t a_acl = NULL, d_acl = NULL; split = strv_split(text, ","); if (!split) return -ENOMEM; STRV_FOREACH(entry, split) { char *p; p = startswith(*entry, "default:"); if (!p) p = startswith(*entry, "d:"); if (p) r = strv_push(&d, p); else r = strv_push(&a, *entry); if (r < 0) return r; } if (!strv_isempty(a)) { _cleanup_free_ char *join; join = strv_join(a, ","); if (!join) return -ENOMEM; a_acl = acl_from_text(join); if (!a_acl) return -errno; if (want_mask) { r = calc_acl_mask_if_needed(&a_acl); if (r < 0) return r; } } if (!strv_isempty(d)) { _cleanup_free_ char *join; join = strv_join(d, ","); if (!join) return -ENOMEM; d_acl = acl_from_text(join); if (!d_acl) return -errno; if (want_mask) { r = calc_acl_mask_if_needed(&d_acl); if (r < 0) return r; } } *acl_access = a_acl; *acl_default = d_acl; a_acl = d_acl = NULL; return 0; } static int acl_entry_equal(acl_entry_t a, acl_entry_t b) { acl_tag_t tag_a, tag_b; if (acl_get_tag_type(a, &tag_a) < 0) return -errno; if (acl_get_tag_type(b, &tag_b) < 0) return -errno; if (tag_a != tag_b) return false; switch (tag_a) { case ACL_USER_OBJ: case ACL_GROUP_OBJ: case ACL_MASK: case ACL_OTHER: /* can have only one of those */ return true; case ACL_USER: { _cleanup_(acl_free_uid_tpp) uid_t *uid_a = NULL, *uid_b = NULL; uid_a = acl_get_qualifier(a); if (!uid_a) return -errno; uid_b = acl_get_qualifier(b); if (!uid_b) return -errno; return *uid_a == *uid_b; } case ACL_GROUP: { _cleanup_(acl_free_gid_tpp) gid_t *gid_a = NULL, *gid_b = NULL; gid_a = acl_get_qualifier(a); if (!gid_a) return -errno; gid_b = acl_get_qualifier(b); if (!gid_b) return -errno; return *gid_a == *gid_b; } default: assert_not_reached("Unknown acl tag type"); } } static int find_acl_entry(acl_t acl, acl_entry_t entry, acl_entry_t *out) { acl_entry_t i; int r; for (r = acl_get_entry(acl, ACL_FIRST_ENTRY, &i); r > 0; r = acl_get_entry(acl, ACL_NEXT_ENTRY, &i)) { r = acl_entry_equal(i, entry); if (r < 0) return r; if (r > 0) { *out = i; return 1; } } if (r < 0) return -errno; return 0; } int acls_for_file(const char *path, acl_type_t type, acl_t new, acl_t *acl) { _cleanup_(acl_freep) acl_t old; acl_entry_t i; int r; old = acl_get_file(path, type); if (!old) return -errno; for (r = acl_get_entry(new, ACL_FIRST_ENTRY, &i); r > 0; r = acl_get_entry(new, ACL_NEXT_ENTRY, &i)) { acl_entry_t j; r = find_acl_entry(old, i, &j); if (r < 0) return r; if (r == 0) if (acl_create_entry(&old, &j) < 0) return -errno; if (acl_copy_entry(j, i) < 0) return -errno; } if (r < 0) return -errno; *acl = old; old = NULL; return 0; } int add_acls_for_user(int fd, uid_t uid) { _cleanup_(acl_freep) acl_t acl = NULL; acl_entry_t entry; acl_permset_t permset; int r; acl = acl_get_fd(fd); if (!acl) return -errno; r = acl_find_uid(acl, uid, &entry); if (r <= 0) { if (acl_create_entry(&acl, &entry) < 0 || acl_set_tag_type(entry, ACL_USER) < 0 || acl_set_qualifier(entry, &uid) < 0) return -errno; } /* We do not recalculate the mask unconditionally here, * so that the fchmod() mask above stays intact. */ if (acl_get_permset(entry, &permset) < 0 || acl_add_perm(permset, ACL_READ) < 0) return -errno; r = calc_acl_mask_if_needed(&acl); if (r < 0) return r; return acl_set_fd(fd, acl); }