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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 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