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      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 2007 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_LCK,
    187 	DBG_INFO,
    188 	DBG_STEP,
    189 	DBG_ALL
    190 } debug_level_t;
    191 
    192 
    193 #define	DB_MAGIC	0xBAC2ACAB
    194 #define	DB_FILE		".devlink_db"
    195 #define	DB_TMP		".devlink_db_tmp"
    196 #define	DB_LOCK		".devlink_db_lock"
    197 #define	DB_PERMS	(S_IRUSR | S_IRGRP | S_IROTH | S_IWUSR)
    198 #define	DB_LOCK_PERMS	DB_PERMS
    199 #define	DB_VERSION	1
    200 
    201 #define	DB_NIL		0
    202 
    203 #define	DEV		"/dev"
    204 #define	ETCDEV		"/etc/dev"
    205 #define	DEVICES_SUFFIX	"ices"
    206 
    207 #define	HDR_LEN			sizeof (struct db_hdr)
    208 
    209 #define	AVG_CHAIN_SIZE		20   /* Average number of links per chain */
    210 #define	MIN_HASH_SIZE		1024 /* Min number of chains in hash table */
    211 #define	MAX_UPDATE_INTERVAL	5 /* Max DB writes before synching with /dev */
    212 #define	MAX_LOCK_RETRY		5 /* Max attempts at locking the update lock */
    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_db_lock(struct di_devlink_handle *hdp, const char *root_dir);
    403 static void exit_db_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, int dca_flags);
    418 static int dca_init(const char *name, struct dca_off *dcp, int dca_flags);
    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 char *s_realpath(const char *path, char *resolved_path);
    426 
    427 #ifdef	__cplusplus
    428 }
    429 #endif
    430 
    431 #endif /* _DEVINFO_DEVLINK_H */
    432