Systems can suffer power interruptions whilst .lock files are in /etc, preventing scripts and other automation tools from updating shadow's files which persist across boots. This commit replaces that mechanism with file locking to avoid problems of power interruption/crashing. Minor tweak to groupmems man page, requested by 'xx' on IRC. Signed-off-by: ed neville <ed@s5h.net>
		
			
				
	
	
		
			146 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			146 lines
		
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * SPDX-FileCopyrightText: 1990 - 1994, Julianne Frances Haugh
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 * SPDX-FileCopyrightText: 1996 - 2000, Marek Michałkiewicz
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 * SPDX-FileCopyrightText: 2001 - 2005, Tomasz Kłoczko
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 * SPDX-FileCopyrightText: 2007 - 2010, Nicolas François
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 *
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 * SPDX-License-Identifier: BSD-3-Clause
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 */
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/* $Id$ */
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#ifndef COMMONIO_H
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#define COMMONIO_H
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#include "defines.h" /* bool */
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/*
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 * Linked list entry.
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 */
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struct commonio_entry {
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	/*@null@*/char *line;
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	/*@null@*/void *eptr;		/* struct passwd, struct spwd, ... */
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	/*@dependent@*/ /*@null@*/struct commonio_entry *prev;
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	/*@owned@*/ /*@null@*/struct commonio_entry *next;
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	bool changed:1;
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};
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/*
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 * Operations depending on database type: passwd, group, shadow etc.
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 */
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struct commonio_ops {
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	/*
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	 * Make a copy of the object (for example, struct passwd)
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	 * and all strings pointed by it, in malloced memory.
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	 */
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	/*@null@*/ /*@only@*/void *(*dup) (const void *);
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	/*
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	 * free() the object including any strings pointed by it.
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	 */
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	void (*free) (/*@out@*/ /*@only@*/void *);
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	/*
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	 * Return the name of the object (for example, pw_name
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	 * for struct passwd).
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	 */
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	const char *(*getname) (const void *);
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	/*
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	 * Parse a string, return object (in static area -
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	 * should be copied using the dup operation above).
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	 */
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	void *(*parse) (const char *);
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	/*
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	 * Write the object to the file (this calls putpwent()
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	 * for struct passwd, for example).
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	 */
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	int (*put) (const void *, FILE *);
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	/*
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	 * fgets and fputs (can be replaced by versions that
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	 * understand line continuation conventions).
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	 */
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	/*@null@*/char *(*fgets) (/*@returned@*/ /*@out@*/char *s, int n, FILE *stream);
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	int (*fputs) (const char *, FILE *);
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	/*
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	 * open_hook and close_hook.
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	 * If non NULL, these functions will be called after the database
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	 * is open or before it is closed.
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	 * They return 0 on failure and 1 on success.
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	 */
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	/*@null@*/int (*open_hook) (void);
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	/*@null@*/int (*close_hook) (void);
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};
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/*
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 * Database structure.
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 */
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struct commonio_db {
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	/*
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	 * Name of the data file.
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	 */
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	char filename[1024];
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	/*
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	 * Operations from above.
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	 */
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	/*@observer@*/const struct commonio_ops *ops;
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	/*
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	 * Currently open file stream.
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	 */
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	/*@dependent@*/ /*@null@*/FILE *fp;
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#ifdef WITH_SELINUX
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	/*@null@*/char *scontext;
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#endif
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	/*
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	 * Default permissions and owner for newly created data file.
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         */
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	mode_t st_mode;
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	uid_t st_uid;
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	gid_t st_gid;
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	/*
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	 * Head, tail, current position in linked list.
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	 */
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	/*@owned@*/ /*@null@*/struct commonio_entry *head;
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	/*@dependent@*/ /*@null@*/struct commonio_entry *tail;
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	/*@dependent@*/ /*@null@*/struct commonio_entry *cursor;
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	/*
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	 * Various flags.
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	 */
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	bool changed:1;
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	bool isopen:1;
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	bool locked:1;
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	bool readonly:1;
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	bool setname:1;
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};
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extern int commonio_setname (struct commonio_db *, const char *);
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extern bool commonio_present (const struct commonio_db *db);
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extern int commonio_lock (struct commonio_db *);
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extern int commonio_lock_nowait (struct commonio_db *, bool log);
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extern int do_fcntl_lock (const char *file, bool log, short type);
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extern int commonio_open (struct commonio_db *, int);
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extern /*@observer@*/ /*@null@*/const void *commonio_locate (struct commonio_db *, const char *);
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extern int commonio_update (struct commonio_db *, const void *);
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#ifdef ENABLE_SUBIDS
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extern int commonio_append (struct commonio_db *, const void *);
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#endif				/* ENABLE_SUBIDS */
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extern int commonio_remove (struct commonio_db *, const char *);
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extern int commonio_rewind (struct commonio_db *);
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extern /*@observer@*/ /*@null@*/const void *commonio_next (struct commonio_db *);
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extern int commonio_close (struct commonio_db *);
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extern int commonio_unlock (struct commonio_db *);
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extern void commonio_del_entry (struct commonio_db *,
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                                const struct commonio_entry *);
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extern int commonio_sort_wrt (struct commonio_db *shadow,
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                              const struct commonio_db *passwd);
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extern int commonio_sort (struct commonio_db *db,
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                          int (*cmp) (const void *, const void *));
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#endif
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