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 2009 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 #ifdef	__cplusplus
30 extern "C" {
31 #endif
32 
33 #define	_POSIX_PTHREAD_SEMANTICS	/* For readdir_r */
34 
35 #include <stdio.h>
36 #include <unistd.h>
37 #include <fcntl.h>
38 #include <string.h>
39 #include <thread.h>
40 #include <synch.h>
41 #include <libdevinfo.h>
42 #include <limits.h>
43 #include <stdlib.h>
44 #include <dirent.h>
45 #include <regex.h>
46 #include <errno.h>
47 #include <stdarg.h>
48 #include <sys/uio.h>
49 #include <sys/types.h>
50 #include <sys/stat.h>
51 #include <sys/time.h>
52 #include <sys/mman.h>
53 #include <sys/wait.h>
54 #include <door.h>
55 #include <signal.h>
56 #include <sys/statvfs.h>
57 
58 struct db_link {
59 	uint32_t attr;		/* primary or secondary */
60 	uint32_t path;		/* link path */
61 	uint32_t content;	/* link content */
62 	uint32_t sib;		/* next link for same minor */
63 };
64 
65 struct db_minor {
66 	uint32_t name;		/* minor name */
67 	uint32_t nodetype;	/* minor node type */
68 	uint32_t sib;		/* next minor for same node */
69 	uint32_t link;		/* next minor for same node */
70 };
71 
72 struct db_node {
73 	uint32_t path;		/* node path */
74 	uint32_t sib;		/* node's sibling */
75 	uint32_t child;		/* first child for this node */
76 	uint32_t minor;		/* first minor for node */
77 };
78 
79 typedef enum db_seg {
80 	DB_NODE = 0,
81 	DB_MINOR,
82 	DB_LINK,
83 	DB_STR,
84 	DB_TYPES,	/* Number of non-header segments */
85 	DB_HEADER
86 } db_seg_t;
87 
88 struct db_hdr {
89 	uint32_t magic;			/* Magic number	*/
90 	uint32_t vers;			/* database format version */
91 	uint32_t root_idx;		/* index for root node */
92 	uint32_t dngl_idx;		/* head of DB dangling links */
93 	uint32_t page_sz;		/* page size for mmap alignment	*/
94 	uint32_t update_count;		/* updates since last /dev synch up */
95 	uint32_t nelems[DB_TYPES];	/* Number of elements of each type */
96 };
97 
98 
99 typedef	struct cache_link {
100 	char   *path;			/* link path */
101 	char   *content;		/* link content	*/
102 	uint_t attr;			/* link attributes */
103 	struct cache_link *hash;	/* next link on same hash chain */
104 	struct cache_link *sib;		/* next link for same minor */
105 	struct cache_minor *minor;	/* minor for this link */
106 } cache_link_t;
107 
108 typedef	struct cache_minor {
109 	char *name;			/* minor name */
110 	char *nodetype;			/* minor nodetype */
111 	struct cache_node *node;	/* node for this minor */
112 	struct cache_minor *sib;	/* next minor for same node */
113 	struct cache_link *link;	/* first link pointing to minor */
114 } cache_minor_t;
115 
116 typedef struct cache_node {
117 	char	*path;			/* path	*/
118 	struct cache_node *parent;	/* node's parent */
119 	struct cache_node *sib;		/* node's sibling */
120 	struct cache_node *child;	/* first child for this node */
121 	struct cache_minor *minor;	/* first minor for node */
122 } cache_node_t;
123 
124 struct cache {
125 	uint_t	flags;			/* cache state */
126 	uint_t	update_count;		/* updates since /dev synchronization */
127 	uint_t	hash_sz;		/* number of hash chains */
128 	cache_link_t **hash;		/* hash table */
129 	cache_node_t *root;		/* root of cache tree */
130 	cache_link_t *dngl;		/* list of dangling links */
131 	cache_minor_t *last_minor;	/* last minor looked up	*/
132 };
133 
134 struct db {
135 	int db_fd;			/* database file */
136 	uint_t flags;			/* database open mode */
137 	struct db_hdr *hdr;		/* DB header */
138 	int  seg_prot[DB_TYPES];	/* protection for  segments */
139 	caddr_t seg_base[DB_TYPES];	/* base address for segments */
140 };
141 
142 struct di_devlink_handle {
143 	char *dev_dir;			/* <root-dir>/dev */
144 	char *db_dir;			/* <root-dir>/etc/dev */
145 	uint_t	flags;			/* handle flags	*/
146 	uint_t  error;			/* records errors encountered */
147 	int lock_fd;			/* lock file for updates */
148 	struct cache cache;
149 	struct db db;
150 };
151 
152 typedef struct link_desc {
153 	regex_t *regp;
154 	const char *minor_path;
155 	uint_t flags;
156 	void *arg;
157 	int (*fcn)(di_devlink_t, void *);
158 	int retval;
159 } link_desc_t;
160 
161 struct tnode {
162 	void *node;
163 	int flags;
164 	struct di_devlink_handle *handle;
165 };
166 
167 struct di_devlink {
168 	char *rel_path;
169 	char *abs_path;
170 	char *content;
171 	int type;
172 };
173 
174 typedef struct recurse {
175 	void *data;
176 	int (*fcn)(struct di_devlink_handle *, void *, const char *);
177 } recurse_t;
178 
179 /*
180  * Debug levels currently defined.
181  */
182 typedef enum {
183 	DBG_ERR = 1,
184 	DBG_LCK,
185 	DBG_INFO,
186 	DBG_STEP,
187 	DBG_ALL
188 } debug_level_t;
189 
190 
191 #define	DB_MAGIC	0xBAC2ACAB
192 #define	DB_FILE		".devlink_db"
193 #define	DB_TMP		".devlink_db_tmp"
194 #define	DB_LOCK		".devlink_db_lock"
195 #define	DB_PERMS	(S_IRUSR | S_IRGRP | S_IROTH | S_IWUSR)
196 #define	DB_LOCK_PERMS	DB_PERMS
197 #define	DB_VERSION	1
198 
199 #define	DB_NIL		0
200 
201 #define	DEV		"/dev"
202 #define	ETCDEV		"/etc/dev"
203 #define	DEVICES_SUFFIX	"ices"
204 
205 #define	HDR_LEN			sizeof (struct db_hdr)
206 
207 #define	AVG_CHAIN_SIZE		20   /* Average number of links per chain */
208 #define	MIN_HASH_SIZE		1024 /* Min number of chains in hash table */
209 #define	MAX_UPDATE_INTERVAL	5 /* Max DB writes before synching with /dev */
210 #define	MAX_LOCK_RETRY		5 /* Max attempts at locking the update lock */
211 
212 /*
213  * Various flags private to the implementation
214  */
215 #define	A_PRIMARY		0x0001U
216 #define	A_SECONDARY		0x0002U
217 #define	A_LINK_TYPES		0x0003U	/* Mask */
218 #define	A_VALID			0x0004U
219 
220 #define	TYPE_DB			0x0008U
221 #define	TYPE_CACHE		0x0010U
222 #define	CREATE_FLAG		0x0020U
223 
224 #define	INSERT_HEAD		0x0040U
225 #define	INSERT_TAIL		0x0080U
226 #define	OPEN_RDWR		0x0100U
227 #define	OPEN_RDONLY		0x0200U
228 #define	OPEN_FLAGS		0x0300U	/* Mask */
229 #define	UNLINK_FROM_HASH	0x0400U
230 
231 #define	SET_VALID_ATTR(a)	((a) |= A_VALID)
232 #define	CLR_VALID_ATTR(a)	((a) &= ~A_VALID)
233 #define	GET_VALID_ATTR(a)	((a) & A_VALID)
234 
235 #define	SET_DB_ERR(h)	((h)->error = 1)
236 #define	DB_ERR(h)	((h)->error)
237 
238 #define	LOOKUP_DB(f)	((f) & TYPE_DB)
239 #define	LOOKUP_CACHE(f)	((f) & TYPE_CACHE)
240 #define	CREATE_ELEM(f)	((f) & CREATE_FLAG)
241 
242 #define	IS_RDWR(f)	(((f) & OPEN_FLAGS) == OPEN_RDWR)
243 #define	IS_RDONLY(f)	(((f) & OPEN_FLAGS) == OPEN_RDONLY)
244 
245 #define	HDL_RDWR(h)	(((h)->flags & OPEN_FLAGS) == OPEN_RDWR)
246 #define	HDL_RDONLY(h)	(((h)->flags & OPEN_FLAGS) == OPEN_RDONLY)
247 
248 #define	CACHE(h)		(&(h)->cache)
249 #define	CACHE_ROOT(h)		(CACHE(h)->root)
250 #define	CACHE_HASH(h, i)	(CACHE(h)->hash[i])
251 #define	CACHE_LAST(h)	(CACHE(h)->last_minor)
252 #define	CACHE_EMPTY(h)	(CACHE(h)->root == NULL && CACHE(h)->dngl == NULL)
253 
254 #define	DB(h)			(&(h)->db)
255 #define	DB_HDR(h)		(DB(h)->hdr)
256 #define	DB_NUM(h, t)		(DB_HDR(h)->nelems[t])
257 #define	DB_SEG(h, t)		(DB(h)->seg_base[t])
258 #define	DB_SEG_PROT(h, t)	(DB(h)->seg_prot[t])
259 
260 #define	DB_OPEN(h)	(DB_HDR(h) != NULL)
261 #define	DB_RDWR(h)	((DB(h)->flags & OPEN_FLAGS) == OPEN_RDWR)
262 #define	DB_RDONLY(h)	((DB(h)->flags & OPEN_FLAGS) == OPEN_RDONLY)
263 
264 #define	DB_EMPTY(h)	(DB_HDR(h)->root_idx == DB_NIL && \
265 			    DB_HDR(h)->dngl_idx == DB_NIL)
266 
267 #define	TYPE_NONE(f)	(((f) & DI_LINK_TYPES) == 0)
268 #define	TYPE_PRI(f)	(((f) & DI_LINK_TYPES) == DI_PRIMARY_LINK)
269 #define	TYPE_SEC(f)	(((f) & DI_LINK_TYPES) == DI_SECONDARY_LINK)
270 #define	LINK_TYPE(f)	((f) & DI_LINK_TYPES)
271 #define	VALID_TYPE(f)	(TYPE_NONE(f) || TYPE_PRI(f) || TYPE_SEC(f))
272 
273 #define	VALID_STR(h, i, s)   ((i) + strlen(s) + 1 <= DB_HDR(h)->nelems[DB_STR])
274 #define	VALID_INDEX(h, t, i) ((i) < DB_HDR(h)->nelems[t])
275 
276 /*
277  * Environment variables used by DEBUG version of code.
278  */
279 #define	SKIP_DB		"DEBUG_SKIP_DB"
280 #define	SKIP_LAST_CACHE	"DEBUG_SKIP_LAST_CACHE"
281 #define	ALT_DB_DIR	"DEBUG_ALT_DB_DIR"
282 
283 /*
284  * Function prototypes
285  */
286 static struct di_devlink_handle *handle_alloc(const char *dev_dir,
287     uint_t flags);
288 static int cache_alloc(struct di_devlink_handle *hdp);
289 static int open_db(struct di_devlink_handle *hdp, int flags);
290 static int invalid_db(struct di_devlink_handle *hdp, size_t fsize, long pg_sz);
291 static int read_nodes(struct di_devlink_handle *hdp, cache_node_t *pcnp,
292     uint32_t nidx);
293 static int read_minors(struct di_devlink_handle *hdp, cache_node_t *pcnp,
294     uint32_t nidx);
295 static int read_links(struct di_devlink_handle *hdp, cache_minor_t *pcmp,
296     uint32_t nidx);
297 static int init_hdr(struct di_devlink_handle *hdp, long page_sz,
298     uint32_t *count);
299 static size_t size_db(struct di_devlink_handle *hdp, long page_sz,
300     uint32_t *count);
301 static size_t seg_size(struct di_devlink_handle *hdp, int seg);
302 
303 static cache_node_t *node_insert(struct di_devlink_handle *hdp,
304     cache_node_t *pcnp, const char *path, int insert);
305 static cache_minor_t *minor_insert(struct di_devlink_handle *hdp,
306     cache_node_t *pcnp, const char *name, const char *nodetype,
307     cache_minor_t **prev);
308 static cache_link_t *link_insert(struct di_devlink_handle *hdp,
309     cache_minor_t *mnp, const char *path, const char *content, uint32_t attr);
310 
311 static void minor_delete(di_devlink_handle_t hdp, cache_minor_t *cmnp);
312 static void link_delete(di_devlink_handle_t hdp, cache_link_t *clp);
313 
314 static int write_nodes(struct di_devlink_handle *hdp, struct db_node *pdnp,
315     cache_node_t *cnp, uint32_t *next);
316 static int write_minors(struct di_devlink_handle *hdp, struct db_node *pdnp,
317     cache_minor_t *cmnp, uint32_t *next);
318 static int write_links(struct di_devlink_handle *hdp, struct db_minor *pdmp,
319     cache_link_t *clp, uint32_t *next);
320 static void rm_link_from_hash(struct di_devlink_handle *hdp, cache_link_t *clp);
321 static uint32_t write_string(struct di_devlink_handle *hdp, const char *str,
322     uint32_t *next);
323 static int close_db(struct di_devlink_handle *hdp);
324 static void cache_free(struct di_devlink_handle *hdp);
325 static void handle_free(struct di_devlink_handle **pp);
326 static void resolve_dangling_links(struct di_devlink_handle *hdp);
327 static void subtree_free(struct di_devlink_handle *hdp, cache_node_t **pp);
328 static void node_free(cache_node_t **pp);
329 static void minor_free(struct di_devlink_handle *hdp, cache_minor_t **pp);
330 static void link_free(cache_link_t **pp);
331 static void count_node(cache_node_t *cnp, uint32_t *count);
332 static void count_minor(cache_minor_t *mnp, uint32_t *count);
333 static void count_link(cache_link_t *clp, uint32_t *count);
334 static void count_string(const char *str, uint32_t *count);
335 static int visit_node(const char *path, void *arg);
336 static int walk_tree(char *cur, void *arg,
337     int (*node_callback)(const char *path, void *arg));
338 static void *lookup_node(struct di_devlink_handle *hdp, char *path,
339     const int flags);
340 static cache_link_t *add_link(struct di_devlink_handle *hdp, const char *link,
341     const char *content, int primary);
342 
343 static void *lookup_minor(struct di_devlink_handle *hdp, const char *minor_path,
344     const char *nodetype, const int flags);
345 static cache_link_t *link_hash(di_devlink_handle_t hdp, const char *link,
346     uint_t flags);
347 
348 static void hash_insert(struct di_devlink_handle *hdp, cache_link_t *clp);
349 static uint_t hashfn(struct di_devlink_handle *hdp, const char *str);
350 static void get_db_path(struct di_devlink_handle *hdp, const char *fname,
351     char *buf, size_t blen);
352 
353 static struct db_node *get_node(struct di_devlink_handle *hdp, uint32_t idx);
354 static struct db_node *set_node(struct di_devlink_handle *hdp, uint32_t idx);
355 
356 static struct db_minor *get_minor(struct di_devlink_handle *hdp, uint32_t idx);
357 static struct db_minor *set_minor(struct di_devlink_handle *hdp, uint32_t idx);
358 
359 static struct db_link *get_link(struct di_devlink_handle *hdp, uint32_t idx);
360 static struct db_link *set_link(struct di_devlink_handle *hdp, uint32_t idx);
361 
362 static char *get_string(struct di_devlink_handle *hdp, uint32_t idx);
363 static char *set_string(struct di_devlink_handle *hdp, uint32_t idx);
364 
365 static void *map_seg(struct di_devlink_handle *hdp, uint32_t idx, int prot,
366     db_seg_t seg);
367 
368 static int walk_db(struct di_devlink_handle *hdp, link_desc_t *linkp);
369 static int walk_all_links(struct di_devlink_handle *hdp, link_desc_t *linkp);
370 static int walk_matching_links(struct di_devlink_handle *hdp,
371     link_desc_t *linkp);
372 static int visit_link(struct di_devlink_handle *hdp, link_desc_t *linkp,
373     struct di_devlink *vlp);
374 
375 static void walk_cache_minor(di_devlink_handle_t hdp, const char *mpath,
376     link_desc_t *linkp);
377 static int walk_cache_links(di_devlink_handle_t hdp, cache_link_t *clp,
378     link_desc_t *linkp);
379 static void walk_all_cache(di_devlink_handle_t hdp, link_desc_t *linkp);
380 static int cache_dev_link(struct di_devlink_handle *hdp, void *data,
381     const char *link_path);
382 
383 static int walk_dev(struct di_devlink_handle *hdp, link_desc_t *linkp);
384 static int recurse_dev(struct di_devlink_handle *hdp, recurse_t *rp);
385 static int do_recurse(const char *dir, struct di_devlink_handle *hdp,
386     recurse_t *rp, int *retp);
387 
388 static int check_attr(uint32_t attr);
389 static int attr2type(uint32_t attr);
390 
391 static int check_args(link_desc_t *linkp);
392 
393 static void *get_last_node(struct di_devlink_handle *hdp, const char *path,
394     int flags);
395 static void *get_last_minor(struct di_devlink_handle *hdp,
396     const char *devfs_path, const char *minor_name, int flags);
397 static void set_last_minor(struct di_devlink_handle *hdp, cache_minor_t *cmnp,
398     int flags);
399 
400 static int enter_db_lock(struct di_devlink_handle *hdp, const char *root_dir);
401 static void exit_db_lock(struct di_devlink_handle *hdp);
402 
403 static char *minor_colon(const char *path);
404 static const char *rel_path(struct di_devlink_handle *hdp, const char *path);
405 static int link_flag(uint_t flags);
406 static int s_readlink(const char *link, char *buf, size_t blen);
407 static cache_minor_t *link2minor(struct di_devlink_handle *hdp,
408     cache_link_t *clp);
409 static int link_cmp(cache_link_t *clp, const char *content, int type);
410 static void delete_unused_nodes(di_devlink_handle_t hdp, cache_node_t *cnp);
411 static void delete_unused_minor(di_devlink_handle_t hdp, cache_minor_t *cmnp);
412 static int synchronize_db(di_devlink_handle_t hdp);
413 static void dprintf(debug_level_t msglevel, const char *fmt, ...);
414 static di_devlink_handle_t devlink_snapshot(const char *root_dir);
415 static int devlink_create(const char *root, const char *name, int dca_flags);
416 static int dca_init(const char *name, struct dca_off *dcp, int dca_flags);
417 static void exec_cmd(const char *root, struct dca_off *dcp);
418 static int do_exec(const char *path, char *const argv[]);
419 static int start_daemon(const char *root, int install);
420 static int daemon_call(const char *root, struct dca_off *dcp);
421 
422 int is_minor_node(const char *contents, const char **mn_root);
423 char *s_realpath(const char *path, char *resolved_path);
424 
425 #ifdef	__cplusplus
426 }
427 #endif
428 
429 #endif /* _DEVINFO_DEVLINK_H */
430