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-rw-r--r--src/util/dict_random.c179
1 files changed, 179 insertions, 0 deletions
diff --git a/src/util/dict_random.c b/src/util/dict_random.c
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+/*++
+/* NAME
+/* dict_random 3
+/* SUMMARY
+/* dictionary manager interface for randomized tables
+/* SYNOPSIS
+/* #include <dict_random.h>
+/*
+/* DICT *dict_random_open(name, open_flags, dict_flags)
+/* const char *name;
+/* int open_flags;
+/* int dict_flags;
+/* DESCRIPTION
+/* dict_random_open() opens an in-memory, read-only, table.
+/* Example: "\fBrandmap:{\fIresult_1, ... ,result_n}\fR".
+/*
+/* Each table query returns a random choice from the specified
+/* results. Other table access methods are not supported.
+/*
+/* The first and last characters of the "randmap:" table name
+/* must be '{' and '}'. Within these, individual maps are
+/* separated with comma or whitespace.
+/* SEE ALSO
+/* dict(3) generic dictionary manager
+/* 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
+/*
+/* Wietse Venema
+/* Google, Inc.
+/* 111 8th Avenue
+/* New York, NY 10011, USA
+/*--*/
+
+/* System library. */
+
+#include <sys_defs.h>
+#include <string.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+#include <myrand.h>
+#include <stringops.h>
+#include <dict_random.h>
+
+/* Application-specific. */
+
+typedef struct {
+ DICT dict; /* generic members */
+ ARGV *replies; /* reply values */
+} DICT_RANDOM;
+
+#define STR(x) vstring_str(x)
+
+/* dict_random_lookup - find randomized-table entry */
+
+static const char *dict_random_lookup(DICT *dict, const char *unused_query)
+{
+ DICT_RANDOM *dict_random = (DICT_RANDOM *) dict;
+
+ DICT_ERR_VAL_RETURN(dict, DICT_ERR_NONE,
+ dict_random->replies->argv[myrand() % dict_random->replies->argc]);
+}
+
+/* dict_random_close - disassociate from randomized table */
+
+static void dict_random_close(DICT *dict)
+{
+ DICT_RANDOM *dict_random = (DICT_RANDOM *) dict;
+
+ if (dict_random->replies)
+ argv_free(dict_random->replies);
+ dict_free(dict);
+}
+
+static char *dict_random_parse_name(DICT *dict, ARGV **argv,
+ const char *string,
+ const char *delim,
+ const char *parens)
+{
+ ARGV *argvp = argv_alloc(1);
+ char *saved_string = mystrdup(string);
+ char *bp = saved_string;
+ char *arg;
+ VSTRING *b64 = 0;
+ char *err = 0;
+
+ while ((arg = mystrtokq(&bp, delim, parens)) != 0) {
+ if (dict->flags & DICT_FLAG_SRC_RHS_IS_FILE) {
+ if ((b64 = dict_file_to_b64(dict, arg)) != 0) {
+ argv_add(argvp, vstring_str(b64), (char *) 0);
+ } else {
+ err = dict_file_get_error(dict);
+ break;
+ }
+ } else {
+ argv_add(argvp, arg, (char *) 0);
+ }
+ }
+ argv_terminate(argvp);
+ myfree(saved_string);
+ *argv = argvp;
+ return (err);
+}
+
+/* dict_random_open - open a randomized table */
+
+DICT *dict_random_open(const char *name, int open_flags, int dict_flags)
+{
+ DICT_RANDOM *dict_random;
+ char *saved_name = 0;
+ size_t len;
+ char *err = 0;
+
+ /*
+ * Clarity first. Let the optimizer worry about redundant code.
+ */
+#define DICT_RANDOM_RETURN(x) do { \
+ DICT *__d = (x); \
+ if (saved_name != 0) \
+ myfree(saved_name); \
+ if (err != 0) \
+ myfree(err); \
+ return (__d); \
+ } while (0)
+
+ /*
+ * Sanity checks.
+ */
+ if (open_flags != O_RDONLY)
+ DICT_RANDOM_RETURN(dict_surrogate(DICT_TYPE_RANDOM, name,
+ open_flags, dict_flags,
+ "%s:%s map requires O_RDONLY access mode",
+ DICT_TYPE_RANDOM, name));
+
+ /*
+ * Bundle up preliminary results.
+ */
+ dict_random =
+ (DICT_RANDOM *) dict_alloc(DICT_TYPE_RANDOM, name, sizeof(*dict_random));
+ dict_random->dict.lookup = dict_random_lookup;
+ dict_random->dict.close = dict_random_close;
+ dict_random->dict.flags = dict_flags | DICT_FLAG_PATTERN;
+ dict_random->replies = 0;
+ dict_random->dict.owner.status = DICT_OWNER_TRUSTED;
+ dict_random->dict.owner.uid = 0;
+
+ /*
+ * Split the table name into its constituent parts.
+ */
+ if ((len = balpar(name, CHARS_BRACE)) == 0 || name[len] != 0
+ || *(saved_name = mystrndup(name + 1, len - 2)) == 0
+ || (err = dict_random_parse_name(&dict_random->dict,
+ &dict_random->replies, saved_name,
+ CHARS_COMMA_SP, CHARS_BRACE)) != 0
+ || dict_random->replies->argc == 0) {
+ dict_random_close(&dict_random->dict);
+ DICT_RANDOM_RETURN(err == 0 ?
+ dict_surrogate(DICT_TYPE_RANDOM, name,
+ open_flags, dict_flags,
+ "bad syntax: \"%s:%s\"; "
+ "need \"%s:{value...}\"",
+ DICT_TYPE_RANDOM, name,
+ DICT_TYPE_RANDOM) :
+ dict_surrogate(DICT_TYPE_RANDOM, name,
+ open_flags, dict_flags,
+ "%s", err));
+ }
+ dict_file_purge_buffers(&dict_random->dict);
+ DICT_RANDOM_RETURN(DICT_DEBUG (&dict_random->dict));
+}