1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  *
21  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
22  * Use is subject to license terms.
23  */
24 
25 
26 #ifndef _DEVINFO_DEVLINK_H
27 #define	_DEVINFO_DEVLINK_H
28 
29 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 #ifdef	__cplusplus
32 extern "C" {
33 #endif
34 
35 #define	_POSIX_PTHREAD_SEMANTICS	/* For readdir_r */
36 
37 #include <stdio.h>
38 #include <unistd.h>
39 #include <fcntl.h>
40 #include <string.h>
41 #include <thread.h>
42 #include <synch.h>
43 #include <libdevinfo.h>
44 #include <limits.h>
45 #include <stdlib.h>
46 #include <dirent.h>
47 #include <regex.h>
48 #include <errno.h>
49 #include <stdarg.h>
50 #include <sys/uio.h>
51 #include <sys/types.h>
52 #include <sys/stat.h>
53 #include <sys/time.h>
54 #include <sys/mman.h>
55 #include <sys/wait.h>
56 #include <door.h>
57 #include <signal.h>
58 #include <sys/statvfs.h>
59 
60 struct db_link {
61 	uint32_t attr;		/* primary or secondary */
62 	uint32_t path;		/* link path */
63 	uint32_t content;	/* link content */
64 	uint32_t sib;		/* next link for same minor */
65 };
66 
67 struct db_minor {
68 	uint32_t name;		/* minor name */
69 	uint32_t nodetype;	/* minor node type */
70 	uint32_t sib;		/* next minor for same node */
71 	uint32_t link;		/* next minor for same node */
72 };
73 
74 struct db_node {
75 	uint32_t path;		/* node path */
76 	uint32_t sib;		/* node's sibling */
77 	uint32_t child;		/* first child for this node */
78 	uint32_t minor;		/* first minor for node */
79 };
80 
81 typedef enum db_seg {
82 	DB_NODE = 0,
83 	DB_MINOR,
84 	DB_LINK,
85 	DB_STR,
86 	DB_TYPES,	/* Number of non-header segments */
87 	DB_HEADER
88 } db_seg_t;
89 
90 struct db_hdr {
91 	uint32_t magic;			/* Magic number	*/
92 	uint32_t vers;			/* database format version */
93 	uint32_t root_idx;		/* index for root node */
94 	uint32_t dngl_idx;		/* head of DB dangling links */
95 	uint32_t page_sz;		/* page size for mmap alignment	*/
96 	uint32_t update_count;		/* updates since last /dev synch up */
97 	uint32_t nelems[DB_TYPES];	/* Number of elements of each type */
98 };
99 
100 
101 typedef	struct cache_link {
102 	char   *path;			/* link path */
103 	char   *content;		/* link content	*/
104 	uint_t attr;			/* link attributes */
105 	struct cache_link *hash;	/* next link on same hash chain */
106 	struct cache_link *sib;		/* next link for same minor */
107 	struct cache_minor *minor;	/* minor for this link */
108 } cache_link_t;
109 
110 typedef	struct cache_minor {
111 	char *name;			/* minor name */
112 	char *nodetype;			/* minor nodetype */
113 	struct cache_node *node;	/* node for this minor */
114 	struct cache_minor *sib;	/* next minor for same node */
115 	struct cache_link *link;	/* first link pointing to minor */
116 } cache_minor_t;
117 
118 typedef struct cache_node {
119 	char	*path;			/* path	*/
120 	struct cache_node *parent;	/* node's parent */
121 	struct cache_node *sib;		/* node's sibling */
122 	struct cache_node *child;	/* first child for this node */
123 	struct cache_minor *minor;	/* first minor for node */
124 } cache_node_t;
125 
126 struct cache {
127 	uint_t	flags;			/* cache state */
128 	uint_t	update_count;		/* updates since /dev synchronization */
129 	uint_t	hash_sz;		/* number of hash chains */
130 	cache_link_t **hash;		/* hash table */
131 	cache_node_t *root;		/* root of cache tree */
132 	cache_link_t *dngl;		/* list of dangling links */
133 	cache_minor_t *last_minor;	/* last minor looked up	*/
134 };
135 
136 struct db {
137 	int db_fd;			/* database file */
138 	uint_t flags;			/* database open mode */
139 	struct db_hdr *hdr;		/* DB header */
140 	int  seg_prot[DB_TYPES];	/* protection for  segments */
141 	caddr_t seg_base[DB_TYPES];	/* base address for segments */
142 };
143 
144 struct di_devlink_handle {
145 	char *dev_dir;			/* <root-dir>/dev */
146 	char *db_dir;			/* <root-dir>/etc/dev */
147 	uint_t	flags;			/* handle flags	*/
148 	uint_t  error;			/* records errors encountered */
149 	int lock_fd;			/* lock file for updates */
150 	struct cache cache;
151 	struct db db;
152 };
153 
154 typedef struct link_desc {
155 	regex_t *regp;
156 	const char *minor_path;
157 	uint_t flags;
158 	void *arg;
159 	int (*fcn)(di_devlink_t, void *);
160 	int retval;
161 } link_desc_t;
162 
163 struct tnode {
164 	void *node;
165 	int flags;
166 	struct di_devlink_handle *handle;
167 };
168 
169 struct di_devlink {
170 	char *rel_path;
171 	char *abs_path;
172 	char *content;
173 	int type;
174 };
175 
176 typedef struct recurse {
177 	void *data;
178 	int (*fcn)(struct di_devlink_handle *, void *, const char *);
179 } recurse_t;
180 
181 /*
182  * Debug levels currently defined.
183  */
184 typedef enum {
185 	DBG_ERR = 1,
186 	DBG_INFO,
187 	DBG_STEP,
188 	DBG_ALL
189 } debug_level_t;
190 
191 
192 #define	DB_MAGIC	0xBAC2ACAB
193 #define	DB_FILE		".devlink_db"
194 #define	DB_TMP		".devlink_db_tmp"
195 #define	DB_LOCK		".devlink_db_lock"
196 #define	DB_PERMS	(S_IRUSR | S_IRGRP | S_IROTH | S_IWUSR)
197 #define	DB_LOCK_PERMS	DB_PERMS
198 #define	DB_VERSION	1
199 
200 #define	DB_NIL		0
201 
202 #define	DEV		"/dev"
203 #define	ETCDEV		"/etc/dev"
204 #define	DEVICES_SUFFIX	"ices"
205 
206 #define	HDR_LEN			sizeof (struct db_hdr)
207 
208 #define	AVG_CHAIN_SIZE		20   /* Average number of links per chain */
209 #define	MIN_HASH_SIZE		1024 /* Min number of chains in hash table */
210 #define	MAX_UPDATE_INTERVAL	5 /* Max DB writes before synching with /dev */
211 #define	MAX_LOCK_RETRY		5 /* Max attempts at locking the update lock */
212 
213 
214 /*
215  * Various flags private to the implementation
216  */
217 #define	A_PRIMARY		0x0001U
218 #define	A_SECONDARY		0x0002U
219 #define	A_LINK_TYPES		0x0003U	/* Mask */
220 #define	A_VALID			0x0004U
221 
222 #define	TYPE_DB			0x0008U
223 #define	TYPE_CACHE		0x0010U
224 #define	CREATE_FLAG		0x0020U
225 
226 #define	INSERT_HEAD		0x0040U
227 #define	INSERT_TAIL		0x0080U
228 #define	OPEN_RDWR		0x0100U
229 #define	OPEN_RDONLY		0x0200U
230 #define	OPEN_FLAGS		0x0300U	/* Mask */
231 #define	UNLINK_FROM_HASH	0x0400U
232 
233 #define	SET_VALID_ATTR(a)	((a) |= A_VALID)
234 #define	CLR_VALID_ATTR(a)	((a) &= ~A_VALID)
235 #define	GET_VALID_ATTR(a)	((a) & A_VALID)
236 
237 #define	SET_DB_ERR(h)	((h)->error = 1)
238 #define	DB_ERR(h)	((h)->error)
239 
240 #define	LOOKUP_DB(f)	((f) & TYPE_DB)
241 #define	LOOKUP_CACHE(f)	((f) & TYPE_CACHE)
242 #define	CREATE_ELEM(f)	((f) & CREATE_FLAG)
243 
244 #define	IS_RDWR(f)	(((f) & OPEN_FLAGS) == OPEN_RDWR)
245 #define	IS_RDONLY(f)	(((f) & OPEN_FLAGS) == OPEN_RDONLY)
246 
247 #define	HDL_RDWR(h)	(((h)->flags & OPEN_FLAGS) == OPEN_RDWR)
248 #define	HDL_RDONLY(h)	(((h)->flags & OPEN_FLAGS) == OPEN_RDONLY)
249 
250 #define	CACHE(h)		(&(h)->cache)
251 #define	CACHE_ROOT(h)		(CACHE(h)->root)
252 #define	CACHE_HASH(h, i)	(CACHE(h)->hash[i])
253 #define	CACHE_LAST(h)	(CACHE(h)->last_minor)
254 #define	CACHE_EMPTY(h)	(CACHE(h)->root == NULL && CACHE(h)->dngl == NULL)
255 
256 #define	DB(h)			(&(h)->db)
257 #define	DB_HDR(h)		(DB(h)->hdr)
258 #define	DB_NUM(h, t)		(DB_HDR(h)->nelems[t])
259 #define	DB_SEG(h, t)		(DB(h)->seg_base[t])
260 #define	DB_SEG_PROT(h, t)	(DB(h)->seg_prot[t])
261 
262 #define	DB_OPEN(h)	(DB_HDR(h) != NULL)
263 #define	DB_RDWR(h)	((DB(h)->flags & OPEN_FLAGS) == OPEN_RDWR)
264 #define	DB_RDONLY(h)	((DB(h)->flags & OPEN_FLAGS) == OPEN_RDONLY)
265 
266 #define	DB_EMPTY(h)	(DB_HDR(h)->root_idx == DB_NIL && \
267 			    DB_HDR(h)->dngl_idx == DB_NIL)
268 
269 #define	TYPE_NONE(f)	(((f) & DI_LINK_TYPES) == 0)
270 #define	TYPE_PRI(f)	(((f) & DI_LINK_TYPES) == DI_PRIMARY_LINK)
271 #define	TYPE_SEC(f)	(((f) & DI_LINK_TYPES) == DI_SECONDARY_LINK)
272 #define	LINK_TYPE(f)	((f) & DI_LINK_TYPES)
273 #define	VALID_TYPE(f)	(TYPE_NONE(f) || TYPE_PRI(f) || TYPE_SEC(f))
274 
275 #define	VALID_STR(h, i, s)   ((i) + strlen(s) + 1 <= DB_HDR(h)->nelems[DB_STR])
276 #define	VALID_INDEX(h, t, i) ((i) < DB_HDR(h)->nelems[t])
277 
278 /*
279  * Environment variables used by DEBUG version of code.
280  */
281 #define	SKIP_DB		"DEBUG_SKIP_DB"
282 #define	SKIP_LAST_CACHE	"DEBUG_SKIP_LAST_CACHE"
283 #define	ALT_DB_DIR	"DEBUG_ALT_DB_DIR"
284 
285 /*
286  * Function prototypes
287  */
288 static struct di_devlink_handle *handle_alloc(const char *dev_dir,
289     uint_t flags);
290 static int cache_alloc(struct di_devlink_handle *hdp);
291 static int open_db(struct di_devlink_handle *hdp, int flags);
292 static int invalid_db(struct di_devlink_handle *hdp, size_t fsize, long pg_sz);
293 static int read_nodes(struct di_devlink_handle *hdp, cache_node_t *pcnp,
294     uint32_t nidx);
295 static int read_minors(struct di_devlink_handle *hdp, cache_node_t *pcnp,
296     uint32_t nidx);
297 static int read_links(struct di_devlink_handle *hdp, cache_minor_t *pcmp,
298     uint32_t nidx);
299 static int init_hdr(struct di_devlink_handle *hdp, long page_sz,
300     uint32_t *count);
301 static size_t size_db(struct di_devlink_handle *hdp, long page_sz,
302     uint32_t *count);
303 static size_t seg_size(struct di_devlink_handle *hdp, int seg);
304 
305 static cache_node_t *node_insert(struct di_devlink_handle *hdp,
306     cache_node_t *pcnp, const char *path, int insert);
307 static cache_minor_t *minor_insert(struct di_devlink_handle *hdp,
308     cache_node_t *pcnp, const char *name, const char *nodetype,
309     cache_minor_t **prev);
310 static cache_link_t *link_insert(struct di_devlink_handle *hdp,
311     cache_minor_t *mnp, const char *path, const char *content, uint32_t attr);
312 
313 static void minor_delete(di_devlink_handle_t hdp, cache_minor_t *cmnp);
314 static void link_delete(di_devlink_handle_t hdp, cache_link_t *clp);
315 
316 static int write_nodes(struct di_devlink_handle *hdp, struct db_node *pdnp,
317     cache_node_t *cnp, uint32_t *next);
318 static int write_minors(struct di_devlink_handle *hdp, struct db_node *pdnp,
319     cache_minor_t *cmnp, uint32_t *next);
320 static int write_links(struct di_devlink_handle *hdp, struct db_minor *pdmp,
321     cache_link_t *clp, uint32_t *next);
322 static void rm_link_from_hash(struct di_devlink_handle *hdp, cache_link_t *clp);
323 static uint32_t write_string(struct di_devlink_handle *hdp, const char *str,
324     uint32_t *next);
325 static int close_db(struct di_devlink_handle *hdp);
326 static void cache_free(struct di_devlink_handle *hdp);
327 static void handle_free(struct di_devlink_handle **pp);
328 static void resolve_dangling_links(struct di_devlink_handle *hdp);
329 static void subtree_free(struct di_devlink_handle *hdp, cache_node_t **pp);
330 static void node_free(cache_node_t **pp);
331 static void minor_free(struct di_devlink_handle *hdp, cache_minor_t **pp);
332 static void link_free(cache_link_t **pp);
333 static void count_node(cache_node_t *cnp, uint32_t *count);
334 static void count_minor(cache_minor_t *mnp, uint32_t *count);
335 static void count_link(cache_link_t *clp, uint32_t *count);
336 static void count_string(const char *str, uint32_t *count);
337 static int visit_node(const char *path, void *arg);
338 static int walk_tree(char *cur, void *arg,
339     int (*node_callback)(const char *path, void *arg));
340 static void *lookup_node(struct di_devlink_handle *hdp, char *path,
341     const int flags);
342 static cache_link_t *add_link(struct di_devlink_handle *hdp, const char *link,
343     const char *content, int primary);
344 
345 static void *lookup_minor(struct di_devlink_handle *hdp, const char *minor_path,
346     const char *nodetype, const int flags);
347 static cache_link_t *link_hash(di_devlink_handle_t hdp, const char *link,
348     uint_t flags);
349 
350 static void hash_insert(struct di_devlink_handle *hdp, cache_link_t *clp);
351 static uint_t hashfn(struct di_devlink_handle *hdp, const char *str);
352 static void get_db_path(struct di_devlink_handle *hdp, const char *fname,
353     char *buf, size_t blen);
354 
355 static struct db_node *get_node(struct di_devlink_handle *hdp, uint32_t idx);
356 static struct db_node *set_node(struct di_devlink_handle *hdp, uint32_t idx);
357 
358 static struct db_minor *get_minor(struct di_devlink_handle *hdp, uint32_t idx);
359 static struct db_minor *set_minor(struct di_devlink_handle *hdp, uint32_t idx);
360 
361 static struct db_link *get_link(struct di_devlink_handle *hdp, uint32_t idx);
362 static struct db_link *set_link(struct di_devlink_handle *hdp, uint32_t idx);
363 
364 static char *get_string(struct di_devlink_handle *hdp, uint32_t idx);
365 static char *set_string(struct di_devlink_handle *hdp, uint32_t idx);
366 
367 static void *map_seg(struct di_devlink_handle *hdp, uint32_t idx, int prot,
368     db_seg_t seg);
369 
370 static int walk_db(struct di_devlink_handle *hdp, link_desc_t *linkp);
371 static int walk_all_links(struct di_devlink_handle *hdp, link_desc_t *linkp);
372 static int walk_matching_links(struct di_devlink_handle *hdp,
373     link_desc_t *linkp);
374 static int visit_link(struct di_devlink_handle *hdp, link_desc_t *linkp,
375     struct di_devlink *vlp);
376 
377 static void walk_cache_minor(di_devlink_handle_t hdp, const char *mpath,
378     link_desc_t *linkp);
379 static int walk_cache_links(di_devlink_handle_t hdp, cache_link_t *clp,
380     link_desc_t *linkp);
381 static void walk_all_cache(di_devlink_handle_t hdp, link_desc_t *linkp);
382 static int cache_dev_link(struct di_devlink_handle *hdp, void *data,
383     const char *link_path);
384 
385 static int walk_dev(struct di_devlink_handle *hdp, link_desc_t *linkp);
386 static int recurse_dev(struct di_devlink_handle *hdp, recurse_t *rp);
387 static int do_recurse(const char *dir, struct di_devlink_handle *hdp,
388     recurse_t *rp, int *retp);
389 
390 static int check_attr(uint32_t attr);
391 static int attr2type(uint32_t attr);
392 
393 static int check_args(link_desc_t *linkp);
394 
395 static void *get_last_node(struct di_devlink_handle *hdp, const char *path,
396     int flags);
397 static void *get_last_minor(struct di_devlink_handle *hdp,
398     const char *devfs_path, const char *minor_name, int flags);
399 static void set_last_minor(struct di_devlink_handle *hdp, cache_minor_t *cmnp,
400     int flags);
401 
402 static int enter_update_lock(struct di_devlink_handle *hdp);
403 static void exit_update_lock(struct di_devlink_handle *hdp);
404 
405 static char *minor_colon(const char *path);
406 static const char *rel_path(struct di_devlink_handle *hdp, const char *path);
407 static int link_flag(uint_t flags);
408 static int s_readlink(const char *link, char *buf, size_t blen);
409 static cache_minor_t *link2minor(struct di_devlink_handle *hdp,
410     cache_link_t *clp);
411 static int link_cmp(cache_link_t *clp, const char *content, int type);
412 static void delete_unused_nodes(di_devlink_handle_t hdp, cache_node_t *cnp);
413 static void delete_unused_minor(di_devlink_handle_t hdp, cache_minor_t *cmnp);
414 static int synchronize_db(di_devlink_handle_t hdp);
415 static void dprintf(debug_level_t msglevel, const char *fmt, ...);
416 static di_devlink_handle_t devlink_snapshot(const char *root_dir);
417 static int devlink_create(const char *root, const char *name);
418 static int dca_init(const char *name, struct dca_off *dcp);
419 static void exec_cmd(const char *root, struct dca_off *dcp);
420 static int do_exec(const char *path, char *const argv[]);
421 static int start_daemon(const char *root);
422 static void daemon_call(const char *root, struct dca_off *dcp);
423 
424 int is_minor_node(const char *contents, const char **mn_root);
425 
426 #ifdef	__cplusplus
427 }
428 #endif
429 
430 #endif /* _DEVINFO_DEVLINK_H */
431