usr/src/lib/libdevinfo/devinfo_devlink.h

   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 */