src/basic/user-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 /***
   5   This file is part of systemd.
   6
   7   Copyright 2010 Lennart Poettering
   8
   9   systemd is free software; you can redistribute it and/or modify it
  10   under the terms of the GNU Lesser General Public License as published by
  11   the Free Software Foundation; either version 2.1 of the License, or
  12   (at your option) any later version.
  13
  14   systemd is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   Lesser General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public License
  20   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  21 ***/
  22
  23 #include <grp.h>
  24 #include <gshadow.h>
  25 #include <pwd.h>
  26 #include <shadow.h>
  27 #include <stdbool.h>
  28 #include <stdint.h>
  29 #include <sys/types.h>
  30 #include <unistd.h>
  31
  32 bool uid_is_valid(uid_t uid);
  33
  34 static inline bool gid_is_valid(gid_t gid) {
  35         return uid_is_valid((uid_t) gid);
  36 }
  37
  38 int parse_uid(const char *s, uid_t* ret_uid);
  39
  40 static inline int parse_gid(const char *s, gid_t *ret_gid) {
  41         return parse_uid(s, (uid_t*) ret_gid);
  42 }
  43
  44 char* getlogname_malloc(void);
  45 char* getusername_malloc(void);
  46
  47 int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **home, const char **shell);
  48 int get_user_creds_clean(const char **username, uid_t *uid, gid_t *gid, const char **home, const char **shell);
  49 int get_group_creds(const char **groupname, gid_t *gid);
  50
  51 char* uid_to_name(uid_t uid);
  52 char* gid_to_name(gid_t gid);
  53
  54 int in_gid(gid_t gid);
  55 int in_group(const char *name);
  56
  57 int get_home_dir(char **ret);
  58 int get_shell(char **_ret);
  59
  60 int reset_uid_gid(void);
  61
  62 int take_etc_passwd_lock(const char *root);
  63
  64 #define UID_INVALID ((uid_t) -1)
  65 #define GID_INVALID ((gid_t) -1)
  66
  67 #define UID_NOBODY ((uid_t) 65534U)
  68 #define GID_NOBODY ((gid_t) 65534U)
  69
  70 #define ETC_PASSWD_LOCK_PATH "/etc/.pwd.lock"
  71
  72 static inline bool uid_is_dynamic(uid_t uid) {
  73         return DYNAMIC_UID_MIN <= uid && uid <= DYNAMIC_UID_MAX;
  74 }
  75
  76 static inline bool gid_is_dynamic(gid_t gid) {
  77         return uid_is_dynamic((uid_t) gid);
  78 }
  79
  80 static inline bool uid_is_system(uid_t uid) {
  81         return uid <= SYSTEM_UID_MAX;
  82 }
  83
  84 static inline bool gid_is_system(gid_t gid) {
  85         return gid <= SYSTEM_GID_MAX;
  86 }
  87
  88 /* The following macros add 1 when converting things, since UID 0 is a valid UID, while the pointer
  89  * NULL is special */
  90 #define PTR_TO_UID(p) ((uid_t) (((uintptr_t) (p))-1))
  91 #define UID_TO_PTR(u) ((void*) (((uintptr_t) (u))+1))
  92
  93 #define PTR_TO_GID(p) ((gid_t) (((uintptr_t) (p))-1))
  94 #define GID_TO_PTR(u) ((void*) (((uintptr_t) (u))+1))
  95
  96 static inline bool userns_supported(void) {
  97         return access("/proc/self/uid_map", F_OK) >= 0;
  98 }
  99
 100 bool valid_user_group_name(const char *u);
 101 bool valid_user_group_name_or_id(const char *u);
 102 bool valid_gecos(const char *d);
 103 bool valid_home(const char *p);
 104
 105 static inline bool valid_shell(const char *p) {
 106         /* We have the same requirements, so just piggy-back on the home check.
 107          *
 108          * Let's ignore /etc/shells because this is only applicable to real and
 109          * not system users. It is also incompatible with the idea of empty /etc.
 110          */
 111         return valid_home(p);
 112 }
 113
 114 int maybe_setgroups(size_t size, const gid_t *list);
 115
 116 bool synthesize_nobody(void);
 117
 118 int fgetpwent_sane(FILE *stream, struct passwd **pw);
 119 int fgetspent_sane(FILE *stream, struct spwd **sp);
 120 int fgetgrent_sane(FILE *stream, struct group **gr);
 121 int putpwent_sane(const struct passwd *pw, FILE *stream);
 122 int putspent_sane(const struct spwd *sp, FILE *stream);
 123 int putgrent_sane(const struct group *gr, FILE *stream);
 124 #ifdef ENABLE_GSHADOW
 125 int fgetsgent_sane(FILE *stream, struct sgrp **sg);
 126 int putsgent_sane(const struct sgrp *sg, FILE *stream);
 127 #endif