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
  10 #include <grp.h>
  11 #include <gshadow.h>
  12 #include <pwd.h>
  13 #include <shadow.h>
  14 #include <stdbool.h>
  15 #include <stdint.h>
  16 #include <sys/types.h>
  17 #include <unistd.h>
  18
  19 bool uid_is_valid(uid_t uid);
  20
  21 static inline bool gid_is_valid(gid_t gid) {
  22         return uid_is_valid((uid_t) gid);
  23 }
  24
  25 int parse_uid(const char *s, uid_t* ret_uid);
  26
  27 static inline int parse_gid(const char *s, gid_t *ret_gid) {
  28         return parse_uid(s, (uid_t*) ret_gid);
  29 }
  30
  31 char* getlogname_malloc(void);
  32 char* getusername_malloc(void);
  33
  34 int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **home, const char **shell);
  35 int get_user_creds_clean(const char **username, uid_t *uid, gid_t *gid, const char **home, const char **shell);
  36 int get_group_creds(const char **groupname, gid_t *gid);
  37
  38 char* uid_to_name(uid_t uid);
  39 char* gid_to_name(gid_t gid);
  40
  41 int in_gid(gid_t gid);
  42 int in_group(const char *name);
  43
  44 int get_home_dir(char **ret);
  45 int get_shell(char **_ret);
  46
  47 int reset_uid_gid(void);
  48
  49 int take_etc_passwd_lock(const char *root);
  50
  51 #define UID_INVALID ((uid_t) -1)
  52 #define GID_INVALID ((gid_t) -1)
  53
  54 #define UID_NOBODY ((uid_t) 65534U)
  55 #define GID_NOBODY ((gid_t) 65534U)
  56
  57 #define ETC_PASSWD_LOCK_PATH "/etc/.pwd.lock"
  58
  59 static inline bool uid_is_dynamic(uid_t uid) {
  60         return DYNAMIC_UID_MIN <= uid && uid <= DYNAMIC_UID_MAX;
  61 }
  62
  63 static inline bool gid_is_dynamic(gid_t gid) {
  64         return uid_is_dynamic((uid_t) gid);
  65 }
  66
  67 static inline bool uid_is_system(uid_t uid) {
  68         return uid <= SYSTEM_UID_MAX;
  69 }
  70
  71 static inline bool gid_is_system(gid_t gid) {
  72         return gid <= SYSTEM_GID_MAX;
  73 }
  74
  75 /* The following macros add 1 when converting things, since UID 0 is a valid UID, while the pointer
  76  * NULL is special */
  77 #define PTR_TO_UID(p) ((uid_t) (((uintptr_t) (p))-1))
  78 #define UID_TO_PTR(u) ((void*) (((uintptr_t) (u))+1))
  79
  80 #define PTR_TO_GID(p) ((gid_t) (((uintptr_t) (p))-1))
  81 #define GID_TO_PTR(u) ((void*) (((uintptr_t) (u))+1))
  82
  83 static inline bool userns_supported(void) {
  84         return access("/proc/self/uid_map", F_OK) >= 0;
  85 }
  86
  87 bool valid_user_group_name(const char *u);
  88 bool valid_user_group_name_or_id(const char *u);
  89 bool valid_gecos(const char *d);
  90 bool valid_home(const char *p);
  91
  92 static inline bool valid_shell(const char *p) {
  93         /* We have the same requirements, so just piggy-back on the home check.
  94          *
  95          * Let's ignore /etc/shells because this is only applicable to real and
  96          * not system users. It is also incompatible with the idea of empty /etc.
  97          */
  98         return valid_home(p);
  99 }
 100
 101 int maybe_setgroups(size_t size, const gid_t *list);
 102
 103 bool synthesize_nobody(void);
 104
 105 int fgetpwent_sane(FILE *stream, struct passwd **pw);
 106 int fgetspent_sane(FILE *stream, struct spwd **sp);
 107 int fgetgrent_sane(FILE *stream, struct group **gr);
 108 int putpwent_sane(const struct passwd *pw, FILE *stream);
 109 int putspent_sane(const struct spwd *sp, FILE *stream);
 110 int putgrent_sane(const struct group *gr, FILE *stream);
 111 #ifdef ENABLE_GSHADOW
 112 int fgetsgent_sane(FILE *stream, struct sgrp **sg);
 113 int putsgent_sane(const struct sgrp *sg, FILE *stream);
 114 #endif