chiark / gitweb /
remove len == 0 check, the index root is always '\0'
[elogind.git] / udev / udev-rules.c
index 876aa7671343f677d259a454731cc967d9fec7e3..df9fc7877da2c2d7bfa46f0ebb81e5a7b9d0f5da 100644 (file)
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2008 Alan Jenkins <alan-jenkins@tuffmail.co.uk>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -16,6 +17,7 @@
  */
 
 #include <stddef.h>
+#include <limits.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
@@ -30,6 +32,7 @@
 
 #define PREALLOC_TOKEN                 2048
 #define PREALLOC_STRBUF                        32 * 1024
+#define PREALLOC_TRIE                  256
 
 struct uid_gid {
        unsigned int name_off;
@@ -39,7 +42,18 @@ struct uid_gid {
        };
 };
 
-/* KEY=="", KEY!="", KEY+="", KEY="", KEY:="" */
+struct trie_node {
+       /* this node's first child */
+       unsigned int child_idx;
+       /* the next child of our parent node's child list */
+       unsigned int next_child_idx;
+       /* this node's last child (shortcut for append) */
+       unsigned int last_child_idx;
+       unsigned int value_off;
+       unsigned short value_len;
+       unsigned char key;
+};
+
 struct udev_rules {
        struct udev *udev;
        int resolve_names;
@@ -55,7 +69,12 @@ struct udev_rules {
        size_t buf_max;
        unsigned int buf_count;
 
-       /* during rule parsing, we cache uid/gid lookup results */
+       /* during rule parsing, strings are indexed to find duplicates */
+       struct trie_node *trie_nodes;
+       unsigned int trie_nodes_cur;
+       unsigned int trie_nodes_max;
+
+       /* during rule parsing, uid/gid lookup results are cached */
        struct uid_gid *uids;
        unsigned int uids_cur;
        unsigned int uids_max;
@@ -64,6 +83,7 @@ struct udev_rules {
        unsigned int gids_max;
 };
 
+/* KEY=="", KEY!="", KEY+="", KEY="", KEY:="" */
 enum operation_type {
        OP_UNSET,
 
@@ -141,23 +161,23 @@ enum token_type {
        TK_END,
 };
 
-/* we try to pack stuff in a way that we take only 16 bytes per token */
+/* we try to pack stuff in a way that we take only 12 bytes per token */
 struct token {
        union {
-               unsigned short type;            /* same as in rule and key */
+               unsigned char type;             /* same as in rule and key */
                struct {
-                       unsigned short type;
-                       unsigned short flags;
-                       unsigned int next_rule;
+                       unsigned char type;
+                       unsigned char flags;
+                       unsigned short token_count;
                        unsigned int label_off;
                        unsigned short filename_off;
                        unsigned short filename_line;
                } rule;
                struct {
-                       unsigned short type;
-                       unsigned short flags;
-                       unsigned short op;
-                       unsigned short glob;
+                       unsigned char type;
+                       unsigned char flags;
+                       unsigned char op;
+                       unsigned char glob;
                        unsigned int value_off;
                        union {
                                unsigned int attr_off;
@@ -184,80 +204,95 @@ struct rule_tmp {
 };
 
 #ifdef DEBUG
-static const char *operation_str[] = {
-       [OP_UNSET] =            "UNSET",
-       [OP_MATCH] =            "match",
-       [OP_NOMATCH] =          "nomatch",
-       [OP_MATCH_MAX] =        "MATCH_MAX",
-
-       [OP_ADD] =              "add",
-       [OP_ASSIGN] =           "assign",
-       [OP_ASSIGN_FINAL] =     "assign-final",
-};
+static const char *operation_str(enum operation_type type)
+{
+       static const char *operation_strs[] = {
+               [OP_UNSET] =            "UNSET",
+               [OP_MATCH] =            "match",
+               [OP_NOMATCH] =          "nomatch",
+               [OP_MATCH_MAX] =        "MATCH_MAX",
+
+               [OP_ADD] =              "add",
+               [OP_ASSIGN] =           "assign",
+               [OP_ASSIGN_FINAL] =     "assign-final",
+}      ;
+
+       return operation_strs[type];
+}
 
-static const char *string_glob_str[] = {
-       [GL_UNSET] =            "UNSET",
-       [GL_PLAIN] =            "plain",
-       [GL_GLOB] =             "glob",
-       [GL_SPLIT] =            "split",
-       [GL_SPLIT_GLOB] =       "split-glob",
-       [GL_SOMETHING] =        "split-glob",
-       [GL_FORMAT] =           "format",
-};
+static const char *string_glob_str(enum string_glob_type type)
+{
+       static const char *string_glob_strs[] = {
+               [GL_UNSET] =            "UNSET",
+               [GL_PLAIN] =            "plain",
+               [GL_GLOB] =             "glob",
+               [GL_SPLIT] =            "split",
+               [GL_SPLIT_GLOB] =       "split-glob",
+               [GL_SOMETHING] =        "split-glob",
+               [GL_FORMAT] =           "format",
+       };
 
-static const char *token_str[] = {
-       [TK_UNSET] =                    "UNSET",
-       [TK_RULE] =                     "RULE",
-
-       [TK_M_ACTION] =                 "M ACTION",
-       [TK_M_DEVPATH] =                "M DEVPATH",
-       [TK_M_KERNEL] =                 "M KERNEL",
-       [TK_M_DEVLINK] =                "M DEVLINK",
-       [TK_M_NAME] =                   "M NAME",
-       [TK_M_ENV] =                    "M ENV",
-       [TK_M_SUBSYSTEM] =              "M SUBSYSTEM",
-       [TK_M_DRIVER] =                 "M DRIVER",
-       [TK_M_WAITFOR] =                "M WAITFOR",
-       [TK_M_ATTR] =                   "M ATTR",
-
-       [TK_M_PARENTS_MIN] =        "M PARENTS_MIN",
-       [TK_M_KERNELS] =                "M KERNELS",
-       [TK_M_SUBSYSTEMS] =             "M SUBSYSTEMS",
-       [TK_M_DRIVERS] =                "M DRIVERS",
-       [TK_M_ATTRS] =                  "M ATTRS",
-       [TK_M_PARENTS_MAX] =            "M PARENTS_MAX",
-
-       [TK_M_TEST] =                   "M TEST",
-       [TK_M_PROGRAM] =                "M PROGRAM",
-       [TK_M_IMPORT_FILE] =            "M IMPORT_FILE",
-       [TK_M_IMPORT_PROG] =            "M IMPORT_PROG",
-       [TK_M_IMPORT_PARENT] =          "M MPORT_PARENT",
-       [TK_M_RESULT] =                 "M RESULT",
-       [TK_M_MAX] =                    "M MAX",
-
-       [TK_A_IGNORE_DEVICE] =          "A IGNORE_DEVICE",
-       [TK_A_STRING_ESCAPE_NONE] =     "A STRING_ESCAPE_NONE",
-       [TK_A_STRING_ESCAPE_REPLACE] =  "A STRING_ESCAPE_REPLACE",
-       [TK_A_NUM_FAKE_PART] =          "A NUM_FAKE_PART",
-       [TK_A_DEVLINK_PRIO] =           "A DEVLINK_PRIO",
-       [TK_A_OWNER] =                  "A OWNER",
-       [TK_A_GROUP] =                  "A GROUP",
-       [TK_A_MODE] =                   "A MODE",
-       [TK_A_OWNER_ID] =               "A OWNER_ID",
-       [TK_A_GROUP_ID] =               "A GROUP_ID",
-       [TK_A_MODE_ID] =                "A MODE_ID",
-       [TK_A_ENV] =                    "A ENV",
-       [TK_A_NAME] =                   "A NAME",
-       [TK_A_DEVLINK] =                "A DEVLINK",
-       [TK_A_EVENT_TIMEOUT] =          "A EVENT_TIMEOUT",
-       [TK_A_IGNORE_REMOVE] =          "A IGNORE_REMOVE",
-       [TK_A_ATTR] =                   "A ATTR",
-       [TK_A_RUN] =                    "A RUN",
-       [TK_A_GOTO] =                   "A GOTO",
-       [TK_A_LAST_RULE] =              "A LAST_RULE",
-
-       [TK_END] =                      "END",
-};
+       return string_glob_strs[type];
+}
+
+static const char *token_str(enum token_type type)
+{
+       static const char *token_strs[] = {
+               [TK_UNSET] =                    "UNSET",
+               [TK_RULE] =                     "RULE",
+
+               [TK_M_ACTION] =                 "M ACTION",
+               [TK_M_DEVPATH] =                "M DEVPATH",
+               [TK_M_KERNEL] =                 "M KERNEL",
+               [TK_M_DEVLINK] =                "M DEVLINK",
+               [TK_M_NAME] =                   "M NAME",
+               [TK_M_ENV] =                    "M ENV",
+               [TK_M_SUBSYSTEM] =              "M SUBSYSTEM",
+               [TK_M_DRIVER] =                 "M DRIVER",
+               [TK_M_WAITFOR] =                "M WAITFOR",
+               [TK_M_ATTR] =                   "M ATTR",
+
+               [TK_M_PARENTS_MIN] =            "M PARENTS_MIN",
+               [TK_M_KERNELS] =                "M KERNELS",
+               [TK_M_SUBSYSTEMS] =             "M SUBSYSTEMS",
+               [TK_M_DRIVERS] =                "M DRIVERS",
+               [TK_M_ATTRS] =                  "M ATTRS",
+               [TK_M_PARENTS_MAX] =            "M PARENTS_MAX",
+
+               [TK_M_TEST] =                   "M TEST",
+               [TK_M_PROGRAM] =                "M PROGRAM",
+               [TK_M_IMPORT_FILE] =            "M IMPORT_FILE",
+               [TK_M_IMPORT_PROG] =            "M IMPORT_PROG",
+               [TK_M_IMPORT_PARENT] =          "M MPORT_PARENT",
+               [TK_M_RESULT] =                 "M RESULT",
+               [TK_M_MAX] =                    "M MAX",
+
+               [TK_A_IGNORE_DEVICE] =          "A IGNORE_DEVICE",
+               [TK_A_STRING_ESCAPE_NONE] =     "A STRING_ESCAPE_NONE",
+               [TK_A_STRING_ESCAPE_REPLACE] =  "A STRING_ESCAPE_REPLACE",
+               [TK_A_NUM_FAKE_PART] =          "A NUM_FAKE_PART",
+               [TK_A_DEVLINK_PRIO] =           "A DEVLINK_PRIO",
+               [TK_A_OWNER] =                  "A OWNER",
+               [TK_A_GROUP] =                  "A GROUP",
+               [TK_A_MODE] =                   "A MODE",
+               [TK_A_OWNER_ID] =               "A OWNER_ID",
+               [TK_A_GROUP_ID] =               "A GROUP_ID",
+               [TK_A_MODE_ID] =                "A MODE_ID",
+               [TK_A_ENV] =                    "A ENV",
+               [TK_A_NAME] =                   "A NAME",
+               [TK_A_DEVLINK] =                "A DEVLINK",
+               [TK_A_EVENT_TIMEOUT] =          "A EVENT_TIMEOUT",
+               [TK_A_IGNORE_REMOVE] =          "A IGNORE_REMOVE",
+               [TK_A_ATTR] =                   "A ATTR",
+               [TK_A_RUN] =                    "A RUN",
+               [TK_A_GOTO] =                   "A GOTO",
+               [TK_A_LAST_RULE] =              "A LAST_RULE",
+
+               [TK_END] =                      "END",
+       };
+
+       return token_strs[type];
+}
 
 static void dump_token(struct udev_rules *rules, struct token *token)
 {
@@ -272,12 +307,11 @@ static void dump_token(struct udev_rules *rules, struct token *token)
                {
                        const char *tks_ptr = (char *)rules->tokens;
                        const char *tk_ptr = (char *)token;
-                       unsigned int off = tk_ptr - tks_ptr;
+                       unsigned int idx = (tk_ptr - tks_ptr) / sizeof(struct token);
 
-                       dbg(rules->udev, "* RULE %s:%u, off: %u(%u), next: %u, label: '%s', flags: 0x%02x\n",
+                       dbg(rules->udev, "* RULE %s:%u, token: %u, count: %u, label: '%s', flags: 0x%02x\n",
                            &rules->buf[token->rule.filename_off], token->rule.filename_line,
-                           off / (unsigned int) sizeof(struct token), off,
-                           token->rule.next_rule,
+                           idx, token->rule.token_count,
                            &rules->buf[token->rule.label_off],
                            token->rule.flags);
                        break;
@@ -305,7 +339,7 @@ static void dump_token(struct udev_rules *rules, struct token *token)
        case TK_A_MODE:
        case TK_A_RUN:
                dbg(rules->udev, "%s %s '%s'(%s)\n",
-                   token_str[type], operation_str[op], value, string_glob_str[glob]);
+                   token_str(type), operation_str(op), value, string_glob_str(glob));
                break;
        case TK_M_ATTR:
        case TK_M_ATTRS:
@@ -313,42 +347,42 @@ static void dump_token(struct udev_rules *rules, struct token *token)
        case TK_A_ATTR:
        case TK_A_ENV:
                dbg(rules->udev, "%s %s '%s' '%s'(%s)\n",
-                   token_str[type], operation_str[op], attr, value, string_glob_str[glob]);
+                   token_str(type), operation_str(op), attr, value, string_glob_str(glob));
                break;
        case TK_A_IGNORE_DEVICE:
        case TK_A_STRING_ESCAPE_NONE:
        case TK_A_STRING_ESCAPE_REPLACE:
        case TK_A_LAST_RULE:
        case TK_A_IGNORE_REMOVE:
-               dbg(rules->udev, "%s\n", token_str[type]);
+               dbg(rules->udev, "%s\n", token_str(type));
                break;
        case TK_M_TEST:
                dbg(rules->udev, "%s %s '%s'(%s) %#o\n",
-                   token_str[type], operation_str[op], value, string_glob_str[glob], token->key.mode);
+                   token_str(type), operation_str(op), value, string_glob_str(glob), token->key.mode);
                break;
        case TK_A_NUM_FAKE_PART:
-               dbg(rules->udev, "%s %u\n", token_str[type], token->key.num_fake_part);
+               dbg(rules->udev, "%s %u\n", token_str(type), token->key.num_fake_part);
                break;
        case TK_A_DEVLINK_PRIO:
-               dbg(rules->udev, "%s %s %u\n", token_str[type], operation_str[op], token->key.devlink_prio);
+               dbg(rules->udev, "%s %s %u\n", token_str(type), operation_str(op), token->key.devlink_prio);
                break;
        case TK_A_OWNER_ID:
-               dbg(rules->udev, "%s %s %u\n", token_str[type], operation_str[op], token->key.uid);
+               dbg(rules->udev, "%s %s %u\n", token_str(type), operation_str(op), token->key.uid);
                break;
        case TK_A_GROUP_ID:
-               dbg(rules->udev, "%s %s %u\n", token_str[type], operation_str[op], token->key.gid);
+               dbg(rules->udev, "%s %s %u\n", token_str(type), operation_str(op), token->key.gid);
                break;
        case TK_A_MODE_ID:
-               dbg(rules->udev, "%s %s %#o\n", token_str[type], operation_str[op], token->key.mode);
+               dbg(rules->udev, "%s %s %#o\n", token_str(type), operation_str(op), token->key.mode);
                break;
        case TK_A_EVENT_TIMEOUT:
-               dbg(rules->udev, "%s %s %u\n", token_str[type], operation_str[op], token->key.event_timeout);
+               dbg(rules->udev, "%s %s %u\n", token_str(type), operation_str(op), token->key.event_timeout);
                break;
        case TK_A_GOTO:
-               dbg(rules->udev, "%s '%s' %u\n", token_str[type], value, token->key.rule_goto);
+               dbg(rules->udev, "%s '%s' %u\n", token_str(type), value, token->key.rule_goto);
                break;
        case TK_END:
-               dbg(rules->udev, "* %s\n", token_str[type]);
+               dbg(rules->udev, "* %s\n", token_str(type));
                break;
        case TK_M_PARENTS_MIN:
        case TK_M_PARENTS_MAX:
@@ -372,31 +406,25 @@ static void dump_rules(struct udev_rules *rules)
                dump_token(rules, &rules->tokens[i]);
 }
 #else
-static const char **operation_str;
-static const char **token_str;
+static inline const char *operation_str(enum operation_type type) { return NULL; }
+static inline const char *token_str(enum token_type type) { return NULL; }
 static inline void dump_token(struct udev_rules *rules, struct token *token) {}
 static inline void dump_rules(struct udev_rules *rules) {}
 #endif /* DEBUG */
 
-/* we could lookup and return existing strings, or tails of strings */
-static int add_string(struct udev_rules *rules, const char *str)
+static int add_new_string(struct udev_rules *rules, const char *str, size_t bytes)
 {
-       size_t len = strlen(str)+1;
        int off;
 
-       /* offset 0 is always '\0' */
-       if (str[0] == '\0')
-               return 0;
-
        /* grow buffer if needed */
-       if (rules->buf_cur + len+1 >= rules->buf_max) {
+       if (rules->buf_cur + bytes+1 >= rules->buf_max) {
                char *buf;
                unsigned int add;
 
                /* double the buffer size */
                add = rules->buf_max;
-               if (add < len * 8)
-                       add = len * 8;
+               if (add < bytes * 8)
+                       add = bytes * 8;
 
                buf = realloc(rules->buf, rules->buf_max + add);
                if (buf == NULL)
@@ -406,15 +434,101 @@ static int add_string(struct udev_rules *rules, const char *str)
                rules->buf_max += add;
        }
        off = rules->buf_cur;
-       memcpy(&rules->buf[rules->buf_cur], str, len);
-       rules->buf_cur += len;
+       memcpy(&rules->buf[rules->buf_cur], str, bytes);
+       rules->buf_cur += bytes;
        rules->buf_count++;
        return off;
 }
 
-static int add_token(struct udev_rules *rules, struct token *token)
+static int add_string(struct udev_rules *rules, const char *str)
 {
+       unsigned int node_idx;
+       struct trie_node *new_node;
+       unsigned int new_node_idx;
+       unsigned char key;
+       unsigned short len;
+       unsigned int depth;
+       unsigned int off;
+       struct trie_node *parent;
+
+       /* walk trie, start from last character of str to find matching tails */
+       len = strlen(str);
+       key = str[len-1];
+       node_idx = 0;
+       for (depth = 0; depth <= len; depth++) {
+               struct trie_node *node;
+               unsigned int child_idx;
+
+               node = &rules->trie_nodes[node_idx];
+               off = node->value_off + node->value_len - len;
+
+               /* match against current node */
+               if (depth == len || (node->value_len >= len && memcmp(&rules->buf[off], str, len) == 0))
+                       return off;
+
+               /* lookup child node */
+               key = str[len - 1 - depth];
+               child_idx = node->child_idx;
+               while (child_idx > 0) {
+                       struct trie_node *child;
+
+                       child = &rules->trie_nodes[child_idx];
+                       if (child->key == key)
+                               break;
+                       child_idx = child->next_child_idx;
+               }
+               if (child_idx == 0)
+                       break;
+               node_idx = child_idx;
+       }
+
+       /* string not found, add it */
+       off = add_new_string(rules, str, len + 1);
 
+       /* grow trie nodes if needed */
+       if (rules->trie_nodes_cur >= rules->trie_nodes_max) {
+               struct trie_node *nodes;
+               unsigned int add;
+
+               /* double the buffer size */
+               add = rules->trie_nodes_max;
+               if (add < 8)
+                       add = 8;
+
+               nodes = realloc(rules->trie_nodes, (rules->trie_nodes_max + add) * sizeof(struct trie_node));
+               if (nodes == NULL)
+                       return -1;
+               dbg(rules->udev, "extend trie nodes from %u to %u\n",
+                   rules->trie_nodes_max, rules->trie_nodes_max + add);
+               rules->trie_nodes = nodes;
+               rules->trie_nodes_max += add;
+       }
+
+       /* get a new node */
+       new_node_idx = rules->trie_nodes_cur;
+       rules->trie_nodes_cur++;
+       new_node = &rules->trie_nodes[new_node_idx];
+       memset(new_node, 0x00, sizeof(struct trie_node));
+       new_node->value_off = off;
+       new_node->value_len = len;
+       new_node->key = key;
+
+       /* join the parent's child list */
+       parent = &rules->trie_nodes[node_idx];
+       if (parent->child_idx == 0) {
+               parent->child_idx = new_node_idx;
+       } else {
+               struct trie_node *last_child;
+
+               last_child = &rules->trie_nodes[parent->last_child_idx];
+               last_child->next_child_idx = new_node_idx;
+       }
+       parent->last_child_idx = new_node_idx;
+       return off;
+}
+
+static int add_token(struct udev_rules *rules, struct token *token)
+{
        /* grow buffer if needed */
        if (rules->token_cur+1 >= rules->token_max) {
                struct token *tokens;
@@ -827,7 +941,7 @@ static int get_key(struct udev *udev, char **line, char **key, enum operation_ty
                return -1;
        temp[0] = '\0';
        temp++;
-       dbg(udev, "%s '%s'-'%s'\n", operation_str[*op], *key, *value);
+       dbg(udev, "%s '%s'-'%s'\n", operation_str(*op), *key, *value);
 
        /* move line to next key */
        *line = temp;
@@ -1439,12 +1553,14 @@ static int add_rule(struct udev_rules *rules, char *line,
                goto invalid;
 
        /* add rule token */
+       rule_tmp.rule.rule.token_count = 1 + rule_tmp.token_cur;
        if (add_token(rules, &rule_tmp.rule) != 0)
                goto invalid;
 
        /* add tokens to list, sorted by type */
        if (sort_token(rules, &rule_tmp) != 0)
                goto invalid;
+
        return 0;
 invalid:
        err(rules->udev, "invalid rule '%s:%u'\n", filename, lineno);
@@ -1525,7 +1641,6 @@ static int parse_file(struct udev_rules *rules, const char *filename, unsigned s
 
 static int add_matching_files(struct udev *udev, struct udev_list_node *file_list, const char *dirname, const char *suffix)
 {
-       struct dirent *ent;
        DIR *dir;
        char filename[UTIL_PATH_SIZE];
 
@@ -1537,26 +1652,28 @@ static int add_matching_files(struct udev *udev, struct udev_list_node *file_lis
        }
 
        while (1) {
-               ent = readdir(dir);
-               if (ent == NULL || ent->d_name[0] == '\0')
+               struct dirent *dent;
+
+               dent = readdir(dir);
+               if (dent == NULL || dent->d_name[0] == '\0')
                        break;
 
-               if ((ent->d_name[0] == '.') || (ent->d_name[0] == '#'))
+               if (dent->d_name[0] == '.')
                        continue;
 
                /* look for file matching with specified suffix */
                if (suffix != NULL) {
                        const char *ext;
 
-                       ext = strrchr(ent->d_name, '.');
+                       ext = strrchr(dent->d_name, '.');
                        if (ext == NULL)
                                continue;
                        if (strcmp(ext, suffix) != 0)
                                continue;
                }
-               dbg(udev, "put file '%s/%s' into list\n", dirname, ent->d_name);
+               dbg(udev, "put file '%s/%s' into list\n", dirname, dent->d_name);
 
-               snprintf(filename, sizeof(filename), "%s/%s", dirname, ent->d_name);
+               snprintf(filename, sizeof(filename), "%s/%s", dirname, dent->d_name);
                filename[sizeof(filename)-1] = '\0';
                udev_list_entry_add(udev, file_list, filename, NULL, 1, 1);
        }
@@ -1571,9 +1688,7 @@ struct udev_rules *udev_rules_new(struct udev *udev, int resolve_names)
        struct stat statbuf;
        struct udev_list_node file_list;
        struct udev_list_entry *file_loop, *file_tmp;
-       unsigned int prev_rule;
        struct token end_token;
-       unsigned int i;
 
        rules = malloc(sizeof(struct udev_rules));
        if (rules == NULL)
@@ -1588,6 +1703,7 @@ struct udev_rules *udev_rules_new(struct udev *udev, int resolve_names)
        if (rules->tokens == NULL)
                return NULL;
        rules->token_max = PREALLOC_TOKEN;
+
        rules->buf = malloc(PREALLOC_STRBUF);
        if (rules->buf == NULL)
                return NULL;
@@ -1598,6 +1714,14 @@ struct udev_rules *udev_rules_new(struct udev *udev, int resolve_names)
        dbg(udev, "prealloc %zu bytes tokens (%u * %zu bytes), %zu bytes buffer\n",
            rules->token_max * sizeof(struct token), rules->token_max, sizeof(struct token), rules->buf_max);
 
+       rules->trie_nodes = malloc(PREALLOC_TRIE * sizeof(struct trie_node));
+       if (rules->trie_nodes == NULL)
+               return NULL;
+       rules->trie_nodes_max = PREALLOC_TRIE;
+       /* offset 0 is the trie root, with an empty string */
+       memset(rules->trie_nodes, 0x00, sizeof(struct trie_node));
+       rules->trie_nodes_cur = 1;
+
        if (udev_get_rules_path(udev) != NULL) {
                /* custom rules location for testing */
                add_matching_files(udev, &file_list, udev_get_rules_path(udev), ".rules");
@@ -1689,15 +1813,6 @@ struct udev_rules *udev_rules_new(struct udev *udev, int resolve_names)
        end_token.type = TK_END;
        add_token(rules, &end_token);
 
-       /* link all TK_RULE tokens to be able to fast-forward to next TK_RULE */
-       prev_rule = 0;
-       for (i = 1; i < rules->token_cur; i++) {
-               if (rules->tokens[i].type == TK_RULE) {
-                       rules->tokens[prev_rule].rule.next_rule = i;
-                       prev_rule = i;
-               }
-       }
-
        /* shrink allocated token and string buffer */
        if (rules->token_cur < rules->token_max) {
                struct token *tokens;
@@ -1717,8 +1832,17 @@ struct udev_rules *udev_rules_new(struct udev *udev, int resolve_names)
                        rules->buf_max = rules->buf_cur;
                }
        }
-       info(udev, "shrunk to %lu bytes tokens (%u * %zu bytes), %zu bytes buffer\n",
+       info(udev, "rules use %zu bytes tokens (%u * %zu bytes), %zu bytes buffer\n",
             rules->token_max * sizeof(struct token), rules->token_max, sizeof(struct token), rules->buf_max);
+       info(udev, "temporary index used %zu bytes (%u * %zu bytes)\n",
+            rules->trie_nodes_cur * sizeof(struct trie_node),
+            rules->trie_nodes_cur, sizeof(struct trie_node));
+
+       /* cleanup trie */
+       free(rules->trie_nodes);
+       rules->trie_nodes = NULL;
+       rules->trie_nodes_cur = 0;
+       rules->trie_nodes_max = 0;
 
        /* cleanup uid/gid cache */
        free(rules->uids);
@@ -1740,6 +1864,7 @@ void udev_rules_unref(struct udev_rules *rules)
                return;
        free(rules->tokens);
        free(rules->buf);
+       free(rules->trie_nodes);
        free(rules->uids);
        free(rules->gids);
        free(rules);
@@ -1798,7 +1923,7 @@ static int match_key(struct udev_rules *rules, struct token *token, const char *
                                        pos[0] = '\0';
                                        pos = &pos[1];
                                }
-                               dbg(rules->udev, "match %s '%s' <-> '%s'\n", token_str[token->type], key_value, val);
+                               dbg(rules->udev, "match %s '%s' <-> '%s'\n", token_str(token->type), key_value, val);
                                match = (fnmatch(key_value, val, 0) == 0);
                                if (match)
                                        break;
@@ -1815,14 +1940,14 @@ static int match_key(struct udev_rules *rules, struct token *token, const char *
        }
 
        if (match && (token->key.op == OP_MATCH)) {
-               dbg(rules->udev, "%s is true (matching value)\n", token_str[token->type]);
+               dbg(rules->udev, "%s is true (matching value)\n", token_str(token->type));
                return 0;
        }
        if (!match && (token->key.op == OP_NOMATCH)) {
-               dbg(rules->udev, "%s is true (non-matching value)\n", token_str[token->type]);
+               dbg(rules->udev, "%s is true (non-matching value)\n", token_str(token->type));
                return 0;
        }
-       dbg(rules->udev, "%s is not true\n", token_str[token->type]);
+       dbg(rules->udev, "%s is not true\n", token_str(token->type));
        return -1;
 }
 
@@ -1885,8 +2010,6 @@ int udev_rules_apply_to_event(struct udev_rules *rules, struct udev_event *event
        cur = &rules->tokens[0];
        rule = cur;
        while (1) {
-               unsigned int idx;
-
                dump_token(rules, cur);
                switch (cur->type) {
                case TK_RULE:
@@ -2426,10 +2549,8 @@ int udev_rules_apply_to_event(struct udev_rules *rules, struct udev_event *event
                continue;
        nomatch:
                /* fast-forward to next rule */
-               idx = rule->rule.next_rule;
-               if (idx == 0)
-                       return 0;
-               dbg(rules->udev, "forward to rule: %u\n", idx);
-               cur = &rules->tokens[idx];
+               cur = rule + rule->rule.token_count;
+               dbg(rules->udev, "forward to rule: %u\n",
+                                (unsigned int) (cur - rules->tokens));
        }
 }