/*++ /* NAME /* dict 3 /* SUMMARY /* dictionary manager /* SYNOPSIS /* #include <dict.h> /* /* extern int dict_unknown_allowed; /* extern int dict_errno; /* /* void dict_register(dict_name, dict_info) /* const char *dict_name; /* DICT *dict_info; /* /* DICT *dict_handle(dict_name) /* const char *dict_name; /* /* void dict_unregister(dict_name) /* const char *dict_name; /* /* void dict_update(dict_name, member, value) /* const char *dict_name; /* const char *member; /* const char *value; /* /* const char *dict_lookup(dict_name, member) /* const char *dict_name; /* const char *member; /* /* int dict_delete(dict_name, member) /* const char *dict_name; /* const char *member; /* /* int dict_sequence(dict_name, func, member, value) /* const char *dict_name; /* int func; /* const char **member; /* const char **value; /* /* const char *dict_eval(dict_name, string, int recursive) /* const char *dict_name; /* const char *string; /* int recursive; /* /* int dict_walk(action, context) /* void (*action)(dict_name, dict_handle, context) /* char *context; /* /* const char *dict_changed_name() /* AUXILIARY FUNCTIONS /* void dict_load_file(dict_name, path) /* const char *dict_name; /* const char *path; /* /* void dict_load_fp(dict_name, fp) /* const char *dict_name; /* VSTREAM *fp; /* /* const char *dict_flags_str(dict_flags) /* int dict_flags; /* DESCRIPTION /* This module maintains a collection of name-value dictionaries. /* Each dictionary has its own name and has its own methods to read /* or update members. Examples of dictionaries that can be accessed /* in this manner are the global UNIX-style process environment, /* hash tables, NIS maps, DBM files, and so on. Dictionary values /* are not limited to strings but can be arbitrary objects as long /* as they can be represented by character pointers. /* FEATURES /* .fi /* .ad /* Notable features of this module are: /* .IP "macro expansion (string-valued dictionaries only)" /* Macros of the form $\fIname\fR can be expanded to the current /* value of \fIname\fR. The forms $(\fIname\fR) and ${\fIname\fR} are /* also supported. /* .IP "unknown names" /* References to unknown dictionary or dictionary member names either /* default to an empty dictionary or null pointer value, or cause a /* run-time error. The behavior is controlled by the global /* \fIdict_unknown_allowed\fR boolean variable. /* .PP /* dict_register() adds a new dictionary, including access methods, /* to the list of known dictionaries, or increments the reference /* count for an existing (name, dictionary) pair. Otherwise, it is /* an error to pass an existing name (this would cause a memory leak). /* /* dict_handle() returns the generic dictionary handle of the /* named dictionary, or a null pointer when the named dictionary /* is not found. /* /* dict_unregister() decrements the reference count of the named /* dictionary. When the reference count reaches zero, dict_unregister() /* breaks the (name, dictionary) association and executes the /* dictionary's optional \fIremove\fR method. /* /* dict_update() updates the value of the named dictionary member. /* The dictionary member and the named dictionary are instantiated /* on the fly. /* /* dict_lookup() returns the value of the named member (i.e. without /* expanding macros in the member value). The \fIdict_name\fR argument /* specifies the dictionary to search. The result is a null pointer /* when no value is found, otherwise the result is owned by the /* underlying dictionary method. Make a copy if the result is to be /* modified, or if the result is to survive multiple dict_lookup() calls. /* /* dict_delete() removes the named member from the named dictionary. /* The result value is zero when the member was found. /* /* dict_sequence() steps through the named dictionary and returns /* keys and values in some implementation-defined order. The func /* argument is DICT_SEQ_FUN_FIRST to set the cursor to the first /* entry or DICT_SEQ_FUN_NEXT to select the next entry. The result /* is owned by the underlying dictionary method. Make a copy if the /* result is to be modified, or if the result is to survive multiple /* dict_sequence() calls. The result value is zero when a member /* was found. /* /* dict_eval() expands macro references in the specified string. /* The result is owned by the dictionary manager. Make a copy if the /* result is to survive multiple dict_eval() calls. When the /* \fIrecursive\fR argument is non-zero, macro references in macro /* lookup results are expanded recursively. /* /* dict_walk() iterates over all registered dictionaries in some /* arbitrary order, and invokes the specified action routine with /* as arguments: /* .IP "const char *dict_name" /* Dictionary name. /* .IP "DICT *dict_handle" /* Generic dictionary handle. /* .IP "char *context" /* Application context from the caller. /* .PP /* dict_changed_name() returns non-zero when any dictionary needs to /* be re-opened because it has changed or because it was unlinked. /* A non-zero result is the name of a changed dictionary. /* /* dict_load_file() reads name-value entries from the named file. /* Lines that begin with whitespace are concatenated to the preceding /* line (the newline is deleted). /* Each entry is stored in the dictionary named by \fIdict_name\fR. /* /* dict_load_fp() reads name-value entries from an open stream. /* It has the same semantics as the dict_load_file() function. /* /* dict_flags_str() returns a printable representation of the /* specified dictionary flags. The result is overwritten upon /* each call. /* SEE ALSO /* htable(3) /* BUGS /* DIAGNOSTICS /* Fatal errors: out of memory, reference to unknown name, /* malformed macro name. /* /* The lookup routines may set the \fIdict_errno\fR variable when /* they were unable to find the requested result. The lookup /* routines must reset \fIdict_errno\fR before each lookup operation. /* \fIdict_errno\fR can have the following values: /* .IP DICT_ERR_RETRY /* The dictionary was temporarily unavailable. This can happen /* with network-based services. /* LICENSE /* .ad /* .fi /* The Secure Mailer license must be distributed with this software. /* AUTHOR(S) /* Wietse Venema /* IBM T.J. Watson Research /* P.O. Box 704 /* Yorktown Heights, NY 10598, USA /*--*/ /* System libraries. */ #include "sys_defs.h" #include <sys/stat.h> #include <fcntl.h> #include <ctype.h> #include <string.h> #include <time.h> /* Utility library. */ #include "msg.h" #include "htable.h" #include "mymalloc.h" #include "vstream.h" #include "vstring.h" #include "readlline.h" #include "mac_expand.h" #include "stringops.h" #include "iostuff.h" #include "name_mask.h" #include "dict.h" #include "dict_ht.h" /* * By default, use a sane default for an unknown name. */ int dict_unknown_allowed = 1; int dict_errno = 0; static HTABLE *dict_table; /* * Each (name, dictionary) instance has a reference count. The count is part * of the name, not the dictionary. The same dictionary may be registered * under multiple names. The structure below keeps track of instances and * reference counts. */ typedef struct { DICT *dict; int refcount; } DICT_NODE; #define dict_node(dict) \ (dict_table ? (DICT_NODE *) htable_find(dict_table, dict) : 0) #define STR(x) vstring_str(x) /* dict_register - make association with dictionary */ void dict_register(const char *dict_name, DICT *dict_info) { const char *myname = "dict_register"; DICT_NODE *node; if (dict_table == 0) dict_table = htable_create(0); if ((node = dict_node(dict_name)) == 0) { node = (DICT_NODE *) mymalloc(sizeof(*node)); node->dict = dict_info; node->refcount = 0; htable_enter(dict_table, dict_name, (char *) node); } else if (dict_info != node->dict) msg_fatal("%s: dictionary name exists: %s", myname, dict_name); node->refcount++; if (msg_verbose > 1) msg_info("%s: %s %d", myname, dict_name, node->refcount); } /* dict_handle - locate generic dictionary handle */ DICT *dict_handle(const char *dict_name) { DICT_NODE *node; return ((node = dict_node(dict_name)) != 0 ? node->dict : 0); } /* dict_node_free - dict_unregister() callback */ static void dict_node_free(char *ptr) { DICT_NODE *node = (DICT_NODE *) ptr; DICT *dict = node->dict; if (dict->close) dict->close(dict); myfree((char *) node); } /* dict_unregister - break association with named dictionary */ void dict_unregister(const char *dict_name) { const char *myname = "dict_unregister"; DICT_NODE *node; if ((node = dict_node(dict_name)) == 0) msg_panic("non-existing dictionary: %s", dict_name); if (msg_verbose > 1) msg_info("%s: %s %d", myname, dict_name, node->refcount); if (--(node->refcount) == 0) htable_delete(dict_table, dict_name, dict_node_free); } /* dict_update - replace or add dictionary entry */ void dict_update(const char *dict_name, const char *member, const char *value) { const char *myname = "dict_update"; DICT_NODE *node; DICT *dict; if ((node = dict_node(dict_name)) == 0) { if (dict_unknown_allowed == 0) msg_fatal("%s: unknown dictionary: %s", myname, dict_name); dict = dict_ht_open(dict_name, O_CREAT | O_RDWR, 0); dict_register(dict_name, dict); } else dict = node->dict; if (msg_verbose > 1) msg_info("%s: %s = %s", myname, member, value); dict->update(dict, member, value); } /* dict_lookup - look up dictionary entry */ const char *dict_lookup(const char *dict_name, const char *member) { const char *myname = "dict_lookup"; DICT_NODE *node; DICT *dict; const char *ret = 0; if ((node = dict_node(dict_name)) == 0) { if (dict_unknown_allowed == 0) msg_fatal("%s: unknown dictionary: %s", myname, dict_name); } else { dict = node->dict; ret = dict->lookup(dict, member); if (ret == 0 && dict_unknown_allowed == 0) msg_fatal("dictionary %s: unknown member: %s", dict_name, member); } if (msg_verbose > 1) msg_info("%s: %s = %s", myname, member, ret ? ret : "(notfound)"); return (ret); } /* dict_delete - delete dictionary entry */ int dict_delete(const char *dict_name, const char *member) { const char *myname = "dict_delete"; DICT_NODE *node; DICT *dict; int result; if ((node = dict_node(dict_name)) == 0) { if (dict_unknown_allowed == 0) msg_fatal("%s: unknown dictionary: %s", myname, dict_name); dict = dict_ht_open(dict_name, O_CREAT | O_RDWR, 0); dict_register(dict_name, dict); } else dict = node->dict; if (msg_verbose > 1) msg_info("%s: delete %s", myname, member); if ((result = dict->delete(dict, member)) != 0 && dict_unknown_allowed == 0) msg_fatal("%s: dictionary %s: unknown member: %s", myname, dict_name, member); return (result); } /* dict_sequence - traverse dictionary */ int dict_sequence(const char *dict_name, const int func, const char **member, const char **value) { const char *myname = "dict_sequence"; DICT_NODE *node; DICT *dict; if ((node = dict_node(dict_name)) == 0) { if (dict_unknown_allowed == 0) msg_fatal("%s: unknown dictionary: %s", myname, dict_name); dict = dict_ht_open(dict_name, O_CREAT | O_RDWR, 0); dict_register(dict_name, dict); } else dict = node->dict; if (msg_verbose > 1) msg_info("%s: sequence func %d", myname, func); return (dict->sequence(dict, func, member, value)); } /* dict_load_file - read entries from text file */ void dict_load_file(const char *dict_name, const char *path) { VSTREAM *fp; struct stat st; time_t before; time_t after; /* * Read the file again if it is hot. This may result in reading a partial * parameter name when a file changes in the middle of a read. */ for (before = time((time_t *) 0); /* see below */ ; before = after) { if ((fp = vstream_fopen(path, O_RDONLY, 0)) == 0) msg_fatal("open %s: %m", path); dict_load_fp(dict_name, fp); if (fstat(vstream_fileno(fp), &st) < 0) msg_fatal("fstat %s: %m", path); if (vstream_ferror(fp) || vstream_fclose(fp)) msg_fatal("read %s: %m", path); after = time((time_t *) 0); if (st.st_mtime < before - 1 || st.st_mtime > after) break; if (msg_verbose > 1) msg_info("pausing to let %s cool down", path); doze(300000); } } /* dict_load_fp - read entries from open stream */ void dict_load_fp(const char *dict_name, VSTREAM *fp) { VSTRING *buf; char *member; char *val; int lineno; const char *err; buf = vstring_alloc(100); lineno = 0; while (readlline(buf, fp, &lineno)) { if ((err = split_nameval(STR(buf), &member, &val)) != 0) msg_fatal("%s, line %d: %s: \"%s\"", VSTREAM_PATH(fp), lineno, err, STR(buf)); dict_update(dict_name, member, val); } vstring_free(buf); } /* dict_eval_lookup - macro parser call-back routine */ static const char *dict_eval_lookup(const char *key, int unused_type, char *dict_name) { const char *pp; /* * XXX how would one recover? */ if ((pp = dict_lookup(dict_name, key)) == 0 && dict_errno != 0) msg_fatal("dictionary %s: lookup %s: temporary error", dict_name, key); return (pp); } /* dict_eval - expand embedded dictionary references */ const char *dict_eval(const char *dict_name, const char *value, int recursive) { const char *myname = "dict_eval"; static VSTRING *buf; int status; /* * Initialize. */ if (buf == 0) buf = vstring_alloc(10); /* * Expand macros, possibly recursively. */ #define DONT_FILTER (char *) 0 status = mac_expand(buf, value, recursive ? MAC_EXP_FLAG_RECURSE : MAC_EXP_FLAG_NONE, DONT_FILTER, dict_eval_lookup, (char *) dict_name); if (status & MAC_PARSE_ERROR) msg_fatal("dictionary %s: macro processing error", dict_name); if (msg_verbose > 1) { if (strcmp(value, STR(buf)) != 0) msg_info("%s: expand %s -> %s", myname, value, STR(buf)); else msg_info("%s: const %s", myname, value); } return (STR(buf)); } /* dict_walk - iterate over all dictionaries in arbitrary order */ void dict_walk(DICT_WALK_ACTION action, char *ptr) { HTABLE_INFO **ht_info_list; HTABLE_INFO **ht; HTABLE_INFO *h; ht_info_list = htable_list(dict_table); for (ht = ht_info_list; (h = *ht) != 0; ht++) action(h->key, (DICT *) h->value, ptr); myfree((char *) ht_info_list); } /* dict_changed_name - see if any dictionary has changed */ const char *dict_changed_name(void) { const char *myname = "dict_changed_name"; struct stat st; HTABLE_INFO **ht_info_list; HTABLE_INFO **ht; HTABLE_INFO *h; const char *status; DICT *dict; ht_info_list = htable_list(dict_table); for (status = 0, ht = ht_info_list; status == 0 && (h = *ht) != 0; ht++) { dict = ((DICT_NODE *) h->value)->dict; if (dict->stat_fd < 0) /* not file-based */ continue; if (dict->mtime == 0) /* not bloody likely */ msg_warn("%s: table %s: null time stamp", myname, h->key); if (fstat(dict->stat_fd, &st) < 0) msg_fatal("%s: fstat: %m", myname); if (st.st_mtime != dict->mtime || st.st_nlink == 0) status = h->key; } myfree((char *) ht_info_list); return (status); } /* dict_changed - backwards compatibility */ int dict_changed(void) { return (dict_changed_name() != 0); } /* * Mapping between flag names and flag values. */ static const NAME_MASK dict_mask[] = { "warn_dup", (1 << 0), /* if file, warn about dups */ "ignore_dup", (1 << 1), /* if file, ignore dups */ "try0null", (1 << 2), /* do not append 0 to key/value */ "try1null", (1 << 3), /* append 0 to key/value */ "fixed", (1 << 4), /* fixed key map */ "pattern", (1 << 5), /* keys are patterns */ "lock", (1 << 6), /* lock before access */ "replace", (1 << 7), /* if file, replace dups */ "sync_update", (1 << 8), /* if file, sync updates */ "debug", (1 << 9), /* log access */ "no_regsub", (1 << 11), /* disallow regexp substitution */ "no_proxy", (1 << 12), /* disallow proxy mapping */ "no_unauth", (1 << 13), /* disallow unauthenticated data */ "fold_fix", (1 << 14), /* case-fold with fixed-case key map */ "fold_mul", (1 << 15), /* case-fold with multi-case key map */ }; /* dict_flags_str - convert mask to string for debugging purposes */ const char *dict_flags_str(int dict_flags) { static VSTRING *buf = 0; if (buf == 0) buf = vstring_alloc(1); return (str_name_mask_opt(buf, "dictionary flags", dict_mask, dict_flags, NAME_MASK_RETURN | NAME_MASK_PIPE)); }