diff --git a/lib/pengine/rules.c b/lib/pengine/rules.c index 3b9b0fe903..41413f5179 100644 --- a/lib/pengine/rules.c +++ b/lib/pengine/rules.c @@ -1,979 +1,978 @@ /* * Copyright (C) 2004 Andrew Beekhof * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include #include #include #include #include #include #include #include #include #include CRM_TRACE_INIT_DATA(pe_rules); crm_time_t *parse_xml_duration(crm_time_t * start, xmlNode * duration_spec); gboolean test_date_expression(xmlNode * time_expr, crm_time_t * now); gboolean cron_range_satisfied(crm_time_t * now, xmlNode * cron_spec); gboolean test_attr_expression(xmlNode * expr, GHashTable * hash, crm_time_t * now); gboolean pe_test_attr_expression_re(xmlNode * expr, GHashTable * hash, crm_time_t * now, pe_re_match_data_t * match_data); gboolean test_role_expression(xmlNode * expr, enum rsc_role_e role, crm_time_t * now); gboolean test_ruleset(xmlNode * ruleset, GHashTable * node_hash, crm_time_t * now) { gboolean ruleset_default = TRUE; xmlNode *rule = NULL; for (rule = __xml_first_child(ruleset); rule != NULL; rule = __xml_next_element(rule)) { if (crm_str_eq((const char *)rule->name, XML_TAG_RULE, TRUE)) { ruleset_default = FALSE; if (test_rule(rule, node_hash, RSC_ROLE_UNKNOWN, now)) { return TRUE; } } } return ruleset_default; } gboolean test_rule(xmlNode * rule, GHashTable * node_hash, enum rsc_role_e role, crm_time_t * now) { return pe_test_rule_re(rule, node_hash, role, now, NULL); } gboolean pe_test_rule_re(xmlNode * rule, GHashTable * node_hash, enum rsc_role_e role, crm_time_t * now, pe_re_match_data_t * match_data) { xmlNode *expr = NULL; gboolean test = TRUE; gboolean empty = TRUE; gboolean passed = TRUE; gboolean do_and = TRUE; const char *value = NULL; rule = expand_idref(rule, NULL); value = crm_element_value(rule, XML_RULE_ATTR_BOOLEAN_OP); if (safe_str_eq(value, "or")) { do_and = FALSE; passed = FALSE; } crm_trace("Testing rule %s", ID(rule)); for (expr = __xml_first_child(rule); expr != NULL; expr = __xml_next_element(expr)) { test = pe_test_expression_re(expr, node_hash, role, now, match_data); empty = FALSE; if (test && do_and == FALSE) { crm_trace("Expression %s/%s passed", ID(rule), ID(expr)); return TRUE; } else if (test == FALSE && do_and) { crm_trace("Expression %s/%s failed", ID(rule), ID(expr)); return FALSE; } } if (empty) { crm_err("Invalid Rule %s: rules must contain at least one expression", ID(rule)); } crm_trace("Rule %s %s", ID(rule), passed ? "passed" : "failed"); return passed; } gboolean test_expression(xmlNode * expr, GHashTable * node_hash, enum rsc_role_e role, crm_time_t * now) { return pe_test_expression_re(expr, node_hash, role, now, NULL); } gboolean pe_test_expression_re(xmlNode * expr, GHashTable * node_hash, enum rsc_role_e role, crm_time_t * now, pe_re_match_data_t * match_data) { gboolean accept = FALSE; const char *uname = NULL; switch (find_expression_type(expr)) { case nested_rule: accept = pe_test_rule_re(expr, node_hash, role, now, match_data); break; case attr_expr: case loc_expr: /* these expressions can never succeed if there is * no node to compare with */ if (node_hash != NULL) { accept = pe_test_attr_expression_re(expr, node_hash, now, match_data); } break; case time_expr: accept = test_date_expression(expr, now); break; case role_expr: accept = test_role_expression(expr, role, now); break; case version_expr: - if (node_hash && - g_hash_table_lookup_extended(node_hash, "#ra-version", NULL, NULL)) { + if (node_hash && g_hash_table_contains(node_hash, "#ra-version")) { accept = test_attr_expression(expr, node_hash, now); } else { // we are going to test it when we have ra-version accept = TRUE; } break; default: CRM_CHECK(FALSE /* bad type */ , return FALSE); accept = FALSE; } if (node_hash) { uname = g_hash_table_lookup(node_hash, "#uname"); } crm_trace("Expression %s %s on %s", ID(expr), accept ? "passed" : "failed", uname ? uname : "all nodes"); return accept; } enum expression_type find_expression_type(xmlNode * expr) { const char *tag = NULL; const char *attr = NULL; attr = crm_element_value(expr, XML_EXPR_ATTR_ATTRIBUTE); tag = crm_element_name(expr); if (safe_str_eq(tag, "date_expression")) { return time_expr; } else if (safe_str_eq(tag, XML_TAG_RULE)) { return nested_rule; } else if (safe_str_neq(tag, "expression")) { return not_expr; } else if (safe_str_eq(attr, "#uname") || safe_str_eq(attr, "#kind") || safe_str_eq(attr, "#id")) { return loc_expr; } else if (safe_str_eq(attr, "#role")) { return role_expr; } else if (safe_str_eq(attr, "#ra-version")) { return version_expr; } return attr_expr; } gboolean test_role_expression(xmlNode * expr, enum rsc_role_e role, crm_time_t * now) { gboolean accept = FALSE; const char *op = NULL; const char *value = NULL; if (role == RSC_ROLE_UNKNOWN) { return accept; } value = crm_element_value(expr, XML_EXPR_ATTR_VALUE); op = crm_element_value(expr, XML_EXPR_ATTR_OPERATION); if (safe_str_eq(op, "defined")) { if (role > RSC_ROLE_STARTED) { accept = TRUE; } } else if (safe_str_eq(op, "not_defined")) { if (role < RSC_ROLE_SLAVE && role > RSC_ROLE_UNKNOWN) { accept = TRUE; } } else if (safe_str_eq(op, "eq")) { if (text2role(value) == role) { accept = TRUE; } } else if (safe_str_eq(op, "ne")) { /* we will only test "ne" wtih master/slave roles style */ if (role < RSC_ROLE_SLAVE && role > RSC_ROLE_UNKNOWN) { accept = FALSE; } else if (text2role(value) != role) { accept = TRUE; } } return accept; } gboolean test_attr_expression(xmlNode * expr, GHashTable * hash, crm_time_t * now) { return pe_test_attr_expression_re(expr, hash, now, NULL); } gboolean pe_test_attr_expression_re(xmlNode * expr, GHashTable * hash, crm_time_t * now, pe_re_match_data_t * match_data) { gboolean accept = FALSE; gboolean attr_allocated = FALSE; int cmp = 0; const char *h_val = NULL; const char *op = NULL; const char *type = NULL; const char *attr = NULL; const char *value = NULL; attr = crm_element_value(expr, XML_EXPR_ATTR_ATTRIBUTE); op = crm_element_value(expr, XML_EXPR_ATTR_OPERATION); value = crm_element_value(expr, XML_EXPR_ATTR_VALUE); type = crm_element_value(expr, XML_EXPR_ATTR_TYPE); if (attr == NULL || op == NULL) { pe_err("Invalid attribute or operation in expression" " (\'%s\' \'%s\' \'%s\')", crm_str(attr), crm_str(op), crm_str(value)); return FALSE; } if (match_data) { char *resolved_attr = pe_expand_re_matches(attr, match_data); if (resolved_attr) { attr = (const char *) resolved_attr; attr_allocated = TRUE; } } if (hash != NULL) { h_val = (const char *)g_hash_table_lookup(hash, attr); } if (attr_allocated) { free((char *)attr); attr = NULL; } if (value != NULL && h_val != NULL) { if (type == NULL) { if (safe_str_eq(op, "lt") || safe_str_eq(op, "lte") || safe_str_eq(op, "gt") || safe_str_eq(op, "gte")) { type = "number"; } else { type = "string"; } crm_trace("Defaulting to %s based comparison for '%s' op", type, op); } if (safe_str_eq(type, "string")) { cmp = strcasecmp(h_val, value); } else if (safe_str_eq(type, "number")) { int h_val_f = crm_parse_int(h_val, NULL); int value_f = crm_parse_int(value, NULL); if (h_val_f < value_f) { cmp = -1; } else if (h_val_f > value_f) { cmp = 1; } else { cmp = 0; } } else if (safe_str_eq(type, "version")) { cmp = compare_version(h_val, value); } } else if (value == NULL && h_val == NULL) { cmp = 0; } else if (value == NULL) { cmp = 1; } else { cmp = -1; } if (safe_str_eq(op, "defined")) { if (h_val != NULL) { accept = TRUE; } } else if (safe_str_eq(op, "not_defined")) { if (h_val == NULL) { accept = TRUE; } } else if (safe_str_eq(op, "eq")) { if ((h_val == value) || cmp == 0) { accept = TRUE; } } else if (safe_str_eq(op, "ne")) { if ((h_val == NULL && value != NULL) || (h_val != NULL && value == NULL) || cmp != 0) { accept = TRUE; } } else if (value == NULL || h_val == NULL) { /* the comparision is meaningless from this point on */ accept = FALSE; } else if (safe_str_eq(op, "lt")) { if (cmp < 0) { accept = TRUE; } } else if (safe_str_eq(op, "lte")) { if (cmp <= 0) { accept = TRUE; } } else if (safe_str_eq(op, "gt")) { if (cmp > 0) { accept = TRUE; } } else if (safe_str_eq(op, "gte")) { if (cmp >= 0) { accept = TRUE; } } return accept; } /* As per the nethack rules: * * moon period = 29.53058 days ~= 30, year = 365.2422 days * days moon phase advances on first day of year compared to preceding year * = 365.2422 - 12*29.53058 ~= 11 * years in Metonic cycle (time until same phases fall on the same days of * the month) = 18.6 ~= 19 * moon phase on first day of year (epact) ~= (11*(year%19) + 29) % 30 * (29 as initial condition) * current phase in days = first day phase + days elapsed in year * 6 moons ~= 177 days * 177 ~= 8 reported phases * 22 * + 11/22 for rounding * * 0-7, with 0: new, 4: full */ static int phase_of_the_moon(crm_time_t * now) { uint32_t epact, diy, goldn; uint32_t y; crm_time_get_ordinal(now, &y, &diy); goldn = (y % 19) + 1; epact = (11 * goldn + 18) % 30; if ((epact == 25 && goldn > 11) || epact == 24) epact++; return ((((((diy + epact) * 6) + 11) % 177) / 22) & 7); } static gboolean decodeNVpair(const char *srcstring, char separator, char **name, char **value) { int lpc = 0; int len = 0; const char *temp = NULL; CRM_ASSERT(name != NULL && value != NULL); *name = NULL; *value = NULL; crm_trace("Attempting to decode: [%s]", srcstring); if (srcstring != NULL) { len = strlen(srcstring); while (lpc <= len) { if (srcstring[lpc] == separator) { *name = calloc(1, lpc + 1); if (*name == NULL) { break; /* and return FALSE */ } memcpy(*name, srcstring, lpc); (*name)[lpc] = '\0'; /* this sucks but as the strtok manpage says.. * it *is* a bug */ len = len - lpc; len--; if (len <= 0) { *value = NULL; } else { *value = calloc(1, len + 1); if (*value == NULL) { break; /* and return FALSE */ } temp = srcstring + lpc + 1; memcpy(*value, temp, len); (*value)[len] = '\0'; } return TRUE; } lpc++; } } if (*name != NULL) { free(*name); *name = NULL; } *name = NULL; *value = NULL; return FALSE; } #define cron_check(xml_field, time_field) \ value = crm_element_value(cron_spec, xml_field); \ if(value != NULL) { \ gboolean pass = TRUE; \ decodeNVpair(value, '-', &value_low, &value_high); \ if(value_low == NULL) { \ value_low = strdup(value); \ } \ value_low_i = crm_parse_int(value_low, "0"); \ value_high_i = crm_parse_int(value_high, "-1"); \ if(value_high_i < 0) { \ if(value_low_i != time_field) { \ pass = FALSE; \ } \ } else if(value_low_i > time_field) { \ pass = FALSE; \ } else if(value_high_i < time_field) { \ pass = FALSE; \ } \ free(value_low); \ free(value_high); \ if(pass == FALSE) { \ crm_debug("Condition '%s' in %s: failed", value, xml_field); \ return pass; \ } \ crm_debug("Condition '%s' in %s: passed", value, xml_field); \ } gboolean cron_range_satisfied(crm_time_t * now, xmlNode * cron_spec) { const char *value = NULL; char *value_low = NULL; char *value_high = NULL; int value_low_i = 0; int value_high_i = 0; uint32_t h, m, s, y, d, w; CRM_CHECK(now != NULL, return FALSE); crm_time_get_timeofday(now, &h, &m, &s); cron_check("seconds", s); cron_check("minutes", m); cron_check("hours", h); crm_time_get_gregorian(now, &y, &m, &d); cron_check("monthdays", d); cron_check("months", m); cron_check("years", y); crm_time_get_ordinal(now, &y, &d); cron_check("yeardays", d); crm_time_get_isoweek(now, &y, &w, &d); cron_check("weekyears", y); cron_check("weeks", w); cron_check("weekdays", d); cron_check("moon", phase_of_the_moon(now)); return TRUE; } #define update_field(xml_field, time_fn) \ value = crm_element_value(duration_spec, xml_field); \ if(value != NULL) { \ int value_i = crm_parse_int(value, "0"); \ time_fn(end, value_i); \ } crm_time_t * parse_xml_duration(crm_time_t * start, xmlNode * duration_spec) { crm_time_t *end = NULL; const char *value = NULL; end = crm_time_new(NULL); crm_time_set(end, start); update_field("years", crm_time_add_years); update_field("months", crm_time_add_months); update_field("weeks", crm_time_add_weeks); update_field("days", crm_time_add_days); update_field("hours", crm_time_add_hours); update_field("minutes", crm_time_add_minutes); update_field("seconds", crm_time_add_seconds); return end; } gboolean test_date_expression(xmlNode * time_expr, crm_time_t * now) { crm_time_t *start = NULL; crm_time_t *end = NULL; const char *value = NULL; const char *op = crm_element_value(time_expr, "operation"); xmlNode *duration_spec = NULL; xmlNode *date_spec = NULL; gboolean passed = FALSE; crm_trace("Testing expression: %s", ID(time_expr)); duration_spec = first_named_child(time_expr, "duration"); date_spec = first_named_child(time_expr, "date_spec"); value = crm_element_value(time_expr, "start"); if (value != NULL) { start = crm_time_new(value); } value = crm_element_value(time_expr, "end"); if (value != NULL) { end = crm_time_new(value); } if (start != NULL && end == NULL && duration_spec != NULL) { end = parse_xml_duration(start, duration_spec); } if (op == NULL) { op = "in_range"; } if (safe_str_eq(op, "date_spec") || safe_str_eq(op, "in_range")) { if (start != NULL && crm_time_compare(start, now) > 0) { passed = FALSE; } else if (end != NULL && crm_time_compare(end, now) < 0) { passed = FALSE; } else if (safe_str_eq(op, "in_range")) { passed = TRUE; } else { passed = cron_range_satisfied(now, date_spec); } } else if (safe_str_eq(op, "gt") && crm_time_compare(start, now) < 0) { passed = TRUE; } else if (safe_str_eq(op, "lt") && crm_time_compare(end, now) > 0) { passed = TRUE; } else if (safe_str_eq(op, "eq") && crm_time_compare(start, now) == 0) { passed = TRUE; } else if (safe_str_eq(op, "neq") && crm_time_compare(start, now) != 0) { passed = TRUE; } crm_time_free(start); crm_time_free(end); return passed; } typedef struct sorted_set_s { int score; const char *name; const char *special_name; xmlNode *attr_set; } sorted_set_t; static gint sort_pairs(gconstpointer a, gconstpointer b) { const sorted_set_t *pair_a = a; const sorted_set_t *pair_b = b; if (a == NULL && b == NULL) { return 0; } else if (a == NULL) { return 1; } else if (b == NULL) { return -1; } if (safe_str_eq(pair_a->name, pair_a->special_name)) { return -1; } else if (safe_str_eq(pair_b->name, pair_a->special_name)) { return 1; } if (pair_a->score < pair_b->score) { return 1; } else if (pair_a->score > pair_b->score) { return -1; } return 0; } static void populate_hash(xmlNode * nvpair_list, GHashTable * hash, gboolean overwrite, xmlNode * top) { const char *name = NULL; const char *value = NULL; const char *old_value = NULL; xmlNode *list = nvpair_list; xmlNode *an_attr = NULL; name = crm_element_name(list->children); if (safe_str_eq(XML_TAG_ATTRS, name)) { list = list->children; } for (an_attr = __xml_first_child(list); an_attr != NULL; an_attr = __xml_next_element(an_attr)) { if (crm_str_eq((const char *)an_attr->name, XML_CIB_TAG_NVPAIR, TRUE)) { xmlNode *ref_nvpair = expand_idref(an_attr, top); name = crm_element_value(an_attr, XML_NVPAIR_ATTR_NAME); if (name == NULL) { name = crm_element_value(ref_nvpair, XML_NVPAIR_ATTR_NAME); } crm_trace("Setting attribute: %s", name); value = crm_element_value(an_attr, XML_NVPAIR_ATTR_VALUE); if (value == NULL) { value = crm_element_value(ref_nvpair, XML_NVPAIR_ATTR_VALUE); } if (name == NULL || value == NULL) { continue; } old_value = g_hash_table_lookup(hash, name); if (safe_str_eq(value, "#default")) { if (old_value) { crm_trace("Removing value for %s (%s)", name, value); g_hash_table_remove(hash, name); } continue; } else if (old_value == NULL) { g_hash_table_insert(hash, strdup(name), strdup(value)); } else if (overwrite) { crm_debug("Overwriting value of %s: %s -> %s", name, old_value, value); g_hash_table_replace(hash, strdup(name), strdup(value)); } } } } static xmlNode* get_versioned_rule(xmlNode * attr_set) { xmlNode * rule = NULL; xmlNode * expr = NULL; for (rule = __xml_first_child(attr_set); rule != NULL; rule = __xml_next_element(rule)) { if (crm_str_eq((const char *)rule->name, XML_TAG_RULE, TRUE)) { for (expr = __xml_first_child(rule); expr != NULL; expr = __xml_next_element(expr)) { if (find_expression_type(expr) == version_expr) { return rule; } } } } return NULL; } static gboolean versioned_attr(xmlNode * versioned_attrs, const char * name) { xmlNode *attrs = NULL; xmlNode *attr = NULL; if (!name) { return FALSE; } for (attrs = __xml_first_child(versioned_attrs); attrs != NULL; attrs = __xml_next_element(attrs)) { for (attr = __xml_first_child(attrs); attr != NULL; attr = __xml_next_element(attr)) { if (safe_str_eq(crm_element_value(attr, XML_NVPAIR_ATTR_NAME), name)) { return TRUE; } } } return FALSE; } static void add_versioned_attributes(xmlNode * attr_set, xmlNode * versioned_attrs) { xmlNode *attr_set_copy = NULL; xmlNode *rule = NULL; CRM_CHECK(versioned_attrs != NULL, return); attr_set_copy = copy_xml(attr_set); rule = get_versioned_rule(attr_set_copy); if (rule) { xmlNode *expr = __xml_first_child(rule); while (expr != NULL) { if (find_expression_type(expr) != version_expr) { xmlNode *node = expr; expr = __xml_next_element(expr); free_xml(node); } else { expr = __xml_next_element(expr); } } } else { xmlNode *attr = __xml_first_child(attr_set_copy); while (attr != NULL) { if (safe_str_eq((const char*) attr->name, XML_TAG_RULE)) { free_xml(attr_set_copy); return; } else if (!versioned_attr(versioned_attrs, crm_element_value(attr, XML_NVPAIR_ATTR_NAME))) { xmlNode *node = attr; attr = __xml_next_element(attr); free_xml(node); } else { attr = __xml_next_element(attr); } } if (!xml_has_children(attr_set_copy)) { free_xml(attr_set_copy); return; } } add_node_nocopy(versioned_attrs, NULL, attr_set_copy); } typedef struct unpack_data_s { gboolean overwrite; GHashTable *node_hash; void *hash; crm_time_t *now; xmlNode *top; } unpack_data_t; static void unpack_attr_set(gpointer data, gpointer user_data) { sorted_set_t *pair = data; unpack_data_t *unpack_data = user_data; if (test_ruleset(pair->attr_set, unpack_data->node_hash, unpack_data->now) == FALSE) { return; } if (get_versioned_rule(pair->attr_set) && !(unpack_data->node_hash && - g_hash_table_lookup_extended(unpack_data->node_hash, "#ra-version", NULL, NULL))) { + g_hash_table_contains(unpack_data->node_hash, "#ra-version"))) { // we haven't actually tested versioned expressions yet return; } crm_trace("Adding attributes from %s", pair->name); populate_hash(pair->attr_set, unpack_data->hash, unpack_data->overwrite, unpack_data->top); } static void unpack_versioned_attr_set(gpointer data, gpointer user_data) { sorted_set_t *pair = data; unpack_data_t *unpack_data = user_data; if (test_ruleset(pair->attr_set, unpack_data->node_hash, unpack_data->now) == FALSE) { return; } add_versioned_attributes(pair->attr_set, unpack_data->hash); } static GListPtr make_pairs_and_populate_data(xmlNode * top, xmlNode * xml_obj, const char *set_name, GHashTable * node_hash, void * hash, const char *always_first, gboolean overwrite, crm_time_t * now, unpack_data_t * data) { GListPtr unsorted = NULL; const char *score = NULL; sorted_set_t *pair = NULL; xmlNode *attr_set = NULL; if (xml_obj == NULL) { crm_trace("No instance attributes"); return NULL; } crm_trace("Checking for attributes"); for (attr_set = __xml_first_child(xml_obj); attr_set != NULL; attr_set = __xml_next_element(attr_set)) { /* Uncertain if set_name == NULL check is strictly necessary here */ if (set_name == NULL || crm_str_eq((const char *)attr_set->name, set_name, TRUE)) { pair = NULL; attr_set = expand_idref(attr_set, top); if (attr_set == NULL) { continue; } pair = calloc(1, sizeof(sorted_set_t)); pair->name = ID(attr_set); pair->special_name = always_first; pair->attr_set = attr_set; score = crm_element_value(attr_set, XML_RULE_ATTR_SCORE); pair->score = char2score(score); unsorted = g_list_prepend(unsorted, pair); } } if (pair != NULL) { data->hash = hash; data->node_hash = node_hash; data->now = now; data->overwrite = overwrite; data->top = top; } if (unsorted) { return g_list_sort(unsorted, sort_pairs); } return NULL; } void unpack_instance_attributes(xmlNode * top, xmlNode * xml_obj, const char *set_name, GHashTable * node_hash, GHashTable * hash, const char *always_first, gboolean overwrite, crm_time_t * now) { unpack_data_t data; GListPtr pairs = make_pairs_and_populate_data(top, xml_obj, set_name, node_hash, hash, always_first, overwrite, now, &data); if (pairs) { g_list_foreach(pairs, unpack_attr_set, &data); g_list_free_full(pairs, free); } } void pe_unpack_versioned_attributes(xmlNode * top, xmlNode * xml_obj, const char *set_name, GHashTable * node_hash, xmlNode * hash, crm_time_t * now) { unpack_data_t data; GListPtr pairs = make_pairs_and_populate_data(top, xml_obj, set_name, node_hash, hash, NULL, FALSE, now, &data); if (pairs) { g_list_foreach(pairs, unpack_versioned_attr_set, &data); g_list_free_full(pairs, free); } } char * pe_expand_re_matches(const char *string, pe_re_match_data_t *match_data) { size_t len = 0; int i; const char *p, *last_match_index; char *p_dst, *result = NULL; if (!string || string[0] == '\0' || !match_data) { return NULL; } p = last_match_index = string; while (*p) { if (*p == '%' && *(p + 1) && isdigit(*(p + 1))) { i = *(p + 1) - '0'; if (match_data->nregs >= i && match_data->pmatch[i].rm_so != -1 && match_data->pmatch[i].rm_eo > match_data->pmatch[i].rm_so) { len += p - last_match_index + (match_data->pmatch[i].rm_eo - match_data->pmatch[i].rm_so); last_match_index = p + 2; } p++; } p++; } len += p - last_match_index + 1; /* FIXME: Excessive? */ if (len - 1 <= 0) { return NULL; } p_dst = result = calloc(1, len); p = string; while (*p) { if (*p == '%' && *(p + 1) && isdigit(*(p + 1))) { i = *(p + 1) - '0'; if (match_data->nregs >= i && match_data->pmatch[i].rm_so != -1 && match_data->pmatch[i].rm_eo > match_data->pmatch[i].rm_so) { /* rm_eo can be equal to rm_so, but then there is nothing to do */ int match_len = match_data->pmatch[i].rm_eo - match_data->pmatch[i].rm_so; memcpy(p_dst, match_data->string + match_data->pmatch[i].rm_so, match_len); p_dst += match_len; } p++; } else { *(p_dst) = *(p); p_dst++; } p++; } return result; }