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/* Copyright 2001-2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "mod_nss.h"
/* _________________________________________________________________
**
** Expression Evaluation
** _________________________________________________________________
*/
static BOOL nss_expr_eval_comp(request_rec *, nss_expr *);
static char *nss_expr_eval_word(request_rec *, nss_expr *);
static char *nss_expr_eval_func_file(request_rec *, char *);
static int nss_expr_eval_strcmplex(char *, char *);
BOOL nss_expr_eval(request_rec *r, nss_expr *node)
{
switch (node->node_op) {
case op_True: {
return TRUE;
}
case op_False: {
return FALSE;
}
case op_Not: {
nss_expr *e = (nss_expr *)node->node_arg1;
return (!nss_expr_eval(r, e));
}
case op_Or: {
nss_expr *e1 = (nss_expr *)node->node_arg1;
nss_expr *e2 = (nss_expr *)node->node_arg2;
return (nss_expr_eval(r, e1) || nss_expr_eval(r, e2));
}
case op_And: {
nss_expr *e1 = (nss_expr *)node->node_arg1;
nss_expr *e2 = (nss_expr *)node->node_arg2;
return (nss_expr_eval(r, e1) && nss_expr_eval(r, e2));
}
case op_Comp: {
nss_expr *e = (nss_expr *)node->node_arg1;
return nss_expr_eval_comp(r, e);
}
default: {
nss_expr_error = "Internal evaluation error: Unknown expression node";
return FALSE;
}
}
}
static BOOL nss_expr_eval_comp(request_rec *r, nss_expr *node)
{
switch (node->node_op) {
case op_EQ: {
nss_expr *e1 = (nss_expr *)node->node_arg1;
nss_expr *e2 = (nss_expr *)node->node_arg2;
return (strcmp(nss_expr_eval_word(r, e1), nss_expr_eval_word(r, e2)) == 0);
}
case op_NE: {
nss_expr *e1 = (nss_expr *)node->node_arg1;
nss_expr *e2 = (nss_expr *)node->node_arg2;
return (strcmp(nss_expr_eval_word(r, e1), nss_expr_eval_word(r, e2)) != 0);
}
case op_LT: {
nss_expr *e1 = (nss_expr *)node->node_arg1;
nss_expr *e2 = (nss_expr *)node->node_arg2;
return (nss_expr_eval_strcmplex(nss_expr_eval_word(r, e1), nss_expr_eval_word(r, e2)) < 0);
}
case op_LE: {
nss_expr *e1 = (nss_expr *)node->node_arg1;
nss_expr *e2 = (nss_expr *)node->node_arg2;
return (nss_expr_eval_strcmplex(nss_expr_eval_word(r, e1), nss_expr_eval_word(r, e2)) <= 0);
}
case op_GT: {
nss_expr *e1 = (nss_expr *)node->node_arg1;
nss_expr *e2 = (nss_expr *)node->node_arg2;
return (nss_expr_eval_strcmplex(nss_expr_eval_word(r, e1), nss_expr_eval_word(r, e2)) > 0);
}
case op_GE: {
nss_expr *e1 = (nss_expr *)node->node_arg1;
nss_expr *e2 = (nss_expr *)node->node_arg2;
return (nss_expr_eval_strcmplex(nss_expr_eval_word(r, e1), nss_expr_eval_word(r, e2)) >= 0);
}
case op_IN: {
nss_expr *e1 = (nss_expr *)node->node_arg1;
nss_expr *e2 = (nss_expr *)node->node_arg2;
nss_expr *e3;
char *w1 = nss_expr_eval_word(r, e1);
BOOL found = FALSE;
do {
e3 = (nss_expr *)e2->node_arg1;
e2 = (nss_expr *)e2->node_arg2;
if (strcmp(w1, nss_expr_eval_word(r, e3)) == 0) {
found = TRUE;
break;
}
} while (e2 != NULL);
return found;
}
case op_REG: {
nss_expr *e1;
nss_expr *e2;
char *word;
ap_regex_t *regex;
e1 = (nss_expr *)node->node_arg1;
e2 = (nss_expr *)node->node_arg2;
word = nss_expr_eval_word(r, e1);
regex = (ap_regex_t *)(e2->node_arg1);
return (ap_regexec(regex, word, 0, NULL, 0) == 0);
}
case op_NRE: {
nss_expr *e1;
nss_expr *e2;
char *word;
ap_regex_t *regex;
e1 = (nss_expr *)node->node_arg1;
e2 = (nss_expr *)node->node_arg2;
word = nss_expr_eval_word(r, e1);
regex = (ap_regex_t *)(e2->node_arg1);
return !(ap_regexec(regex, word, 0, NULL, 0) == 0);
}
default: {
nss_expr_error = "Internal evaluation error: Unknown expression node";
return FALSE;
}
}
}
static char *nss_expr_eval_word(request_rec *r, nss_expr *node)
{
switch (node->node_op) {
case op_Digit: {
char *string = (char *)node->node_arg1;
return string;
}
case op_String: {
char *string = (char *)node->node_arg1;
return string;
}
case op_Var: {
char *var = (char *)node->node_arg1;
char *val = nss_var_lookup(r->pool, r->server, r->connection, r, var);
return (val == NULL ? "" : val);
}
case op_Func: {
char *name = (char *)node->node_arg1;
nss_expr *args = (nss_expr *)node->node_arg2;
if (strEQ(name, "file"))
return nss_expr_eval_func_file(r, (char *)(args->node_arg1));
else {
nss_expr_error = "Internal evaluation error: Unknown function name";
return "";
}
}
default: {
nss_expr_error = "Internal evaluation error: Unknown expression node";
return FALSE;
}
}
}
static char *nss_expr_eval_func_file(request_rec *r, char *filename)
{
apr_file_t *fp;
char *buf;
apr_off_t offset;
apr_size_t len;
apr_finfo_t finfo;
if (apr_file_open(&fp, filename, APR_READ|APR_BUFFERED,
APR_OS_DEFAULT, r->pool) != APR_SUCCESS) {
nss_expr_error = "Cannot open file";
return "";
}
apr_file_info_get(&finfo, APR_FINFO_SIZE, fp);
if ((finfo.size + 1) != ((apr_size_t)finfo.size + 1)) {
nss_expr_error = "Huge file cannot be read";
apr_file_close(fp);
return "";
}
len = (apr_size_t)finfo.size;
if (len == 0) {
buf = (char *)apr_palloc(r->pool, sizeof(char) * 1);
*buf = NUL;
}
else {
if ((buf = (char *)apr_palloc(r->pool, sizeof(char)*(len+1))) == NULL) {
nss_expr_error = "Cannot allocate memory";
apr_file_close(fp);
return "";
}
offset = 0;
apr_file_seek(fp, APR_SET, &offset);
if (apr_file_read(fp, buf, &len) != APR_SUCCESS) {
nss_expr_error = "Cannot read from file";
apr_file_close(fp);
return "";
}
buf[len] = NUL;
}
apr_file_close(fp);
return buf;
}
/* a variant of strcmp(3) which works correctly also for number strings */
static int nss_expr_eval_strcmplex(char *cpNum1, char *cpNum2)
{
int i, n1, n2;
if (cpNum1 == NULL)
return -1;
if (cpNum2 == NULL)
return +1;
n1 = strlen(cpNum1);
n2 = strlen(cpNum2);
if (n1 > n2)
return 1;
if (n1 < n2)
return -1;
for (i = 0; i < n1; i++) {
if (cpNum1[i] > cpNum2[i])
return 1;
if (cpNum1[i] < cpNum2[i])
return -1;
}
return 0;
}
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