blob: 2912f082adada220e6ea805a42fa423de29401f3 [file] [log] [blame]
/*
* ACL management functions.
*
* Copyright 2000-2007 Willy Tarreau <w@1wt.eu>
*
* 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 the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <stdio.h>
#include <string.h>
#include <common/config.h>
#include <common/mini-clist.h>
#include <common/standard.h>
#include <proto/acl.h>
#include <types/acl.h>
#include <types/proxy.h>
#include <types/session.h>
/* List head of all known ACL keywords */
static struct acl_kw_list acl_keywords = {
.list = LIST_HEAD_INIT(acl_keywords.list)
};
/* This one always returns 1 because its only purpose is to check that the
* value is present, which is already checked by getval().
*/
int acl_match_pst(struct acl_test *test, struct acl_pattern *pattern)
{
return 1;
}
/* NB: For two strings to be identical, it is required that their lengths match */
int acl_match_str(struct acl_test *test, struct acl_pattern *pattern)
{
if (pattern->len != test->len)
return 0;
if (strncmp(pattern->ptr.str, test->ptr, test->len) == 0)
return 1;
return 0;
}
/* Checks that the pattern matches the beginning of the tested string. */
int acl_match_beg(struct acl_test *test, struct acl_pattern *pattern)
{
if (pattern->len > test->len)
return 0;
if (strncmp(pattern->ptr.str, test->ptr, pattern->len) != 0)
return 0;
return 1;
}
/* Checks that the pattern matches the end of the tested string. */
int acl_match_end(struct acl_test *test, struct acl_pattern *pattern)
{
if (pattern->len > test->len)
return 0;
if (strncmp(pattern->ptr.str, test->ptr + test->len - pattern->len, pattern->len) != 0)
return 0;
return 1;
}
/* Checks that the pattern is included inside the tested string.
* NB: Suboptimal, should be rewritten using a Boyer-Moore method.
*/
int acl_match_sub(struct acl_test *test, struct acl_pattern *pattern)
{
char *end;
char *c;
if (pattern->len > test->len)
return 0;
end = test->ptr + test->len - pattern->len;
for (c = test->ptr; c <= end; c++) {
if (*c != *pattern->ptr.str)
continue;
if (strncmp(pattern->ptr.str, c, pattern->len) == 0)
return 1;
}
return 0;
}
/* This one is used by other real functions. It checks that the pattern is
* included inside the tested string, but enclosed between the specified
* delimitor, or a '/' or a '?' or at the beginning or end of the string.
* The delimitor is stripped at the beginning or end of the pattern are
* ignored.
*/
static int match_word(struct acl_test *test, struct acl_pattern *pattern, char delim)
{
int may_match;
char *c, *end;
char *ps;
int pl;
pl = pattern->len;
ps = pattern->ptr.str;
while (pl > 0 && *ps == delim) {
pl--;
ps++;
}
while (pl > 0 && *(ps + pl - 1) == delim)
pl--;
if (pl > test->len)
return 0;
may_match = 1;
end = test->ptr + test->len - pl;
for (c = test->ptr; c <= end; c++) {
if (*c == '/' || *c == delim || *c == '?') {
may_match = 1;
continue;
}
if (may_match && (*c == *ps) &&
(strncmp(ps, c, pl) == 0) &&
(c == end || c[pl] == '/' || c[pl] == delim || c[pl] == '?'))
return 1;
may_match = 0;
}
return 0;
}
/* Checks that the pattern is included inside the tested string, but enclosed
* between slashes or at the beginning or end of the string. Slashes at the
* beginning or end of the pattern are ignored.
*/
int acl_match_dir(struct acl_test *test, struct acl_pattern *pattern)
{
return match_word(test, pattern, '/');
}
/* Checks that the pattern is included inside the tested string, but enclosed
* between dots or at the beginning or end of the string. Dots at the beginning
* or end of the pattern are ignored.
*/
int acl_match_dom(struct acl_test *test, struct acl_pattern *pattern)
{
return match_word(test, pattern, '.');
}
/* Checks that the integer in <test> is included between min and max */
int acl_match_range(struct acl_test *test, struct acl_pattern *pattern)
{
if ((pattern->val.range.min <= test->i) &&
(test->i <= pattern->val.range.max))
return 1;
return 0;
}
int acl_match_min(struct acl_test *test, struct acl_pattern *pattern)
{
if (pattern->val.range.min <= test->i)
return 1;
return 0;
}
int acl_match_max(struct acl_test *test, struct acl_pattern *pattern)
{
if (test->i <= pattern->val.range.max)
return 1;
return 0;
}
/* Parse a string. It is allocated and duplicated. */
int acl_parse_str(const char *text, struct acl_pattern *pattern)
{
int len;
len = strlen(text);
pattern->ptr.str = strdup(text);
if (!pattern->ptr.str)
return 0;
pattern->len = len;
return 1;
}
/* Parse an integer. It is put both in min and max. */
int acl_parse_int(const char *text, struct acl_pattern *pattern)
{
pattern->val.range.min = pattern->val.range.max = __str2ui(text);
return 1;
}
/* Parse a range of integers delimited by either ':' or '-'. If only one
* integer is read, it is set as both min and max.
*/
int acl_parse_range(const char *text, struct acl_pattern *pattern)
{
unsigned int i, j, last;
last = i = 0;
while (1) {
j = (*text++);
if ((j == '-' || j == ':') && !last) {
last++;
pattern->val.range.min = i;
i = 0;
continue;
}
j -= '0';
if (j > 9)
// also catches the terminating zero
break;
i *= 10;
i += j;
}
if (!last)
pattern->val.range.min = i;
pattern->val.range.max = i;
return 1;
}
/*
* Registers the ACL keyword list <kwl> as a list of valid keywords for next
* parsing sessions.
*/
void acl_register_keywords(struct acl_kw_list *kwl)
{
LIST_ADDQ(&acl_keywords.list, &kwl->list);
}
/*
* Unregisters the ACL keyword list <kwl> from the list of valid keywords.
*/
void acl_unregister_keywords(struct acl_kw_list *kwl)
{
LIST_DEL(&kwl->list);
LIST_INIT(&kwl->list);
}
/* Return a pointer to the ACL <name> within the list starting at <head>, or
* NULL if not found.
*/
struct acl *find_acl_by_name(const char *name, struct list *head)
{
struct acl *acl;
list_for_each_entry(acl, head, list) {
if (strcmp(acl->name, name) == 0)
return acl;
}
return NULL;
}
/* Return a pointer to the ACL keyword <kw>, or NULL if not found. Note that if
* <kw> contains an opening parenthesis, only the left part of it is checked.
*/
struct acl_keyword *find_acl_kw(const char *kw)
{
int index;
const char *kwend;
struct acl_kw_list *kwl;
kwend = strchr(kw, '(');
if (!kwend)
kwend = kw + strlen(kw);
list_for_each_entry(kwl, &acl_keywords.list, list) {
for (index = 0; kwl->kw[index].kw != NULL; index++) {
if ((strncmp(kwl->kw[index].kw, kw, kwend - kw) == 0) &&
kwl->kw[index].kw[kwend-kw] == 0)
return &kwl->kw[index];
}
}
return NULL;
}
static void free_pattern(struct acl_pattern *pat)
{
if (pat->ptr.ptr)
free(pat->ptr.ptr);
free(pat);
}
static void free_pattern_list(struct list *head)
{
struct acl_pattern *pat, *tmp;
list_for_each_entry_safe(pat, tmp, head, list)
free_pattern(pat);
}
static struct acl_expr *prune_acl_expr(struct acl_expr *expr)
{
free_pattern_list(&expr->patterns);
LIST_INIT(&expr->patterns);
if (expr->arg.str)
free(expr->arg.str);
expr->kw->use_cnt--;
return expr;
}
/* Parse an ACL expression starting at <args>[0], and return it.
* Right now, the only accepted syntax is :
* <subject> [<value>...]
*/
struct acl_expr *parse_acl_expr(const char **args)
{
__label__ out_return, out_free_expr, out_free_pattern;
struct acl_expr *expr;
struct acl_keyword *aclkw;
struct acl_pattern *pattern;
const char *arg;
aclkw = find_acl_kw(args[0]);
if (!aclkw || !aclkw->parse)
goto out_return;
expr = (struct acl_expr *)calloc(1, sizeof(*expr));
if (!expr)
goto out_return;
expr->kw = aclkw;
aclkw->use_cnt++;
LIST_INIT(&expr->patterns);
expr->arg.str = NULL;
arg = strchr(args[0], '(');
if (arg != NULL) {
char *end, *arg2;
/* there is an argument in the form "subject(arg)" */
arg++;
end = strchr(arg, ')');
if (!end)
goto out_free_expr;
arg2 = (char *)calloc(1, end - arg + 1);
if (!arg2)
goto out_free_expr;
memcpy(arg2, arg, end - arg);
arg2[end-arg] = '\0';
expr->arg.str = arg2;
}
/* now parse all patterns */
args++;
while (**args) {
pattern = (struct acl_pattern *)calloc(1, sizeof(*pattern));
if (!pattern)
goto out_free_expr;
if (!aclkw->parse(*args, pattern))
goto out_free_pattern;
LIST_ADDQ(&expr->patterns, &pattern->list);
args++;
}
return expr;
out_free_pattern:
free_pattern(pattern);
out_free_expr:
prune_acl_expr(expr);
free(expr);
out_return:
return NULL;
}
/* Parse an ACL with the name starting at <args>[0], and with a list of already
* known ACLs in <acl>. If the ACL was not in the list, it will be added.
* A pointer to that ACL is returned.
*
* args syntax: <aclname> <acl_expr>
*/
struct acl *parse_acl(const char **args, struct list *known_acl)
{
__label__ out_return, out_free_acl_expr, out_free_name;
struct acl *cur_acl;
struct acl_expr *acl_expr;
char *name;
acl_expr = parse_acl_expr(args + 1);
if (!acl_expr)
goto out_return;
cur_acl = find_acl_by_name(args[0], known_acl);
if (!cur_acl) {
name = strdup(args[0]);
if (!name)
goto out_free_acl_expr;
cur_acl = (struct acl *)calloc(1, sizeof(*cur_acl));
if (cur_acl == NULL)
goto out_free_name;
LIST_INIT(&cur_acl->expr);
LIST_ADDQ(known_acl, &cur_acl->list);
cur_acl->name = name;
}
LIST_ADDQ(&cur_acl->expr, &acl_expr->list);
return cur_acl;
out_free_name:
free(name);
out_free_acl_expr:
prune_acl_expr(acl_expr);
free(acl_expr);
out_return:
return NULL;
}
/* Purge everything in the acl_cond <cond>, then return <cond>. */
struct acl_cond *prune_acl_cond(struct acl_cond *cond)
{
struct acl_term_suite *suite, *tmp_suite;
struct acl_term *term, *tmp_term;
/* iterate through all term suites and free all terms and all suites */
list_for_each_entry_safe(suite, tmp_suite, &cond->suites, list) {
list_for_each_entry_safe(term, tmp_term, &suite->terms, list)
free(term);
free(suite);
}
return cond;
}
/* Parse an ACL condition starting at <args>[0], relying on a list of already
* known ACLs passed in <known_acl>. The new condition is returned (or NULL in
* case of low memory). Supports multiple conditions separated by "or".
*/
struct acl_cond *parse_acl_cond(const char **args, struct list *known_acl, int pol)
{
__label__ out_return, out_free_suite, out_free_term;
int arg;
int neg = 0;
const char *word;
struct acl *cur_acl;
struct acl_term *cur_term;
struct acl_term_suite *cur_suite;
struct acl_cond *cond;
cond = (struct acl_cond *)calloc(1, sizeof(*cond));
if (cond == NULL)
goto out_return;
LIST_INIT(&cond->list);
LIST_INIT(&cond->suites);
cond->pol = pol;
cur_suite = NULL;
for (arg = 0; *args[arg]; arg++) {
word = args[arg];
/* remove as many exclamation marks as we can */
while (*word == '!') {
neg = !neg;
word++;
}
/* an empty word is allowed because we cannot force the user to
* always think about not leaving exclamation marks alone.
*/
if (!*word)
continue;
if (strcasecmp(word, "or") == 0) {
/* new term suite */
cur_suite = NULL;
neg = 0;
continue;
}
/* search for <word> in the known ACL names */
cur_acl = find_acl_by_name(word, known_acl);
if (cur_acl == NULL)
goto out_free_suite;
cur_term = (struct acl_term *)calloc(1, sizeof(*cur_term));
if (cur_term == NULL)
goto out_free_suite;
cur_term->acl = cur_acl;
cur_term->neg = neg;
if (!cur_suite) {
cur_suite = (struct acl_term_suite *)calloc(1, sizeof(*cur_suite));
if (cur_term == NULL)
goto out_free_term;
LIST_INIT(&cur_suite->terms);
LIST_ADDQ(&cond->suites, &cur_suite->list);
}
LIST_ADDQ(&cur_suite->terms, &cur_term->list);
}
return cond;
out_free_term:
free(cur_term);
out_free_suite:
prune_acl_cond(cond);
free(cond);
out_return:
return NULL;
}
/* Execute condition <cond> and return 0 if test fails or 1 if test succeeds.
* This function only computes the condition, it does not apply the polarity
* required by IF/UNLESS, it's up to the caller to do this.
*/
int acl_exec_cond(struct acl_cond *cond, struct proxy *px, struct session *l4, void *l7)
{
__label__ fetch_next;
struct acl_term_suite *suite;
struct acl_term *term;
struct acl_expr *expr;
struct acl *acl;
struct acl_pattern *pattern;
struct acl_test test;
int acl_res, pat_res, suite_res, cond_res;
/* we're doing a logical OR between conditions so we initialize to FAIL */
cond_res = ACL_PAT_FAIL;
list_for_each_entry(suite, &cond->suites, list) {
/* evaluate condition suite <suite>. We stop at the first term
* which does not return ACL_PAT_PASS.
*/
/* we're doing a logical AND between terms, so we must set the
* initial value to PASS.
*/
suite_res = ACL_PAT_PASS;
list_for_each_entry(term, &suite->terms, list) {
acl = term->acl;
/* FIXME: use cache !
* check acl->cache_idx for this.
*/
/* ACL result not cached. Let's scan all the expressions
* and use the first one to match.
*/
acl_res = ACL_PAT_FAIL;
list_for_each_entry(expr, &acl->expr, list) {
test.flags = test.len = 0;
fetch_next:
if (!expr->kw->fetch(px, l4, l7, expr->arg.str, &test))
continue;
/* apply all tests to this value */
list_for_each_entry(pattern, &expr->patterns, list) {
pat_res = expr->kw->match(&test, pattern);
if (pat_res & ACL_PAT_MISS) {
/* there is at least one test which might be worth retrying later. */
acl_res |= ACL_PAT_MISS;
continue;
} else if (pat_res & ACL_PAT_PASS) {
/* we found one ! */
acl_res |= ACL_PAT_PASS;
break;
}
}
/*
* OK now we have the result of this expression in expr_res.
* - we have the PASS bit set if at least one pattern matched ;
* - we have the MISS bit set if at least one pattern may match
* later so that we should not cache a failure ;
*
* Then if (PASS || !MISS) we can cache the result, and put
* (test.flags & ACL_TEST_F_VOLATILE) in the cache flags.
*
* FIXME: implement cache.
*
*/
/* now we may have some cleanup to do */
if (test.flags & ACL_TEST_F_MUST_FREE) {
free(test.ptr);
test.len = 0;
}
if (acl_res & ACL_PAT_PASS)
break;
/* prepare to test another expression */
acl_res = ACL_PAT_FAIL;
if (test.flags & ACL_TEST_F_FETCH_MORE)
goto fetch_next;
}
/*
* Here we have the result of an ACL (cached or not).
* ACLs are combined, negated or not, to form conditions.
*/
acl_res &= ACL_PAT_PASS;
if (term->neg)
acl_res ^= ACL_PAT_PASS;
suite_res &= acl_res;
if (!(suite_res & ACL_PAT_PASS))
break;
}
cond_res |= suite_res;
if (cond_res & ACL_PAT_PASS)
break;
}
return (cond_res & ACL_PAT_PASS) ? 1 : 0;
}
/************************************************************************/
/* All supported keywords must be declared here. */
/************************************************************************/
/* Note: must not be declared <const> as its list will be overwritten */
static struct acl_kw_list acl_kws = {{ },{
#if 0
{ "time", acl_parse_time, acl_fetch_time, acl_match_time },
#endif
{ NULL, NULL, NULL, NULL }
}};
__attribute__((constructor))
static void __acl_init(void)
{
acl_register_keywords(&acl_kws);
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/