blob: ed41e91ed07f3fc269aa4f89105423d850bf9210 [file] [log] [blame]
/*
* ACL management functions.
*
* Copyright 2000-2008 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 <ctype.h>
#include <stdio.h>
#include <string.h>
#include <common/config.h>
#include <common/mini-clist.h>
#include <common/standard.h>
#include <proto/acl.h>
/* The capabilities of filtering hooks describe the type of information
* available to each of them.
*/
const unsigned int filt_cap[] = {
[ACL_HOOK_REQ_FE_TCP] = ACL_USE_TCP4_ANY|ACL_USE_TCP6_ANY|ACL_USE_TCP_ANY,
[ACL_HOOK_REQ_FE_TCP_CONTENT] = ACL_USE_TCP4_ANY|ACL_USE_TCP6_ANY|ACL_USE_TCP_ANY|ACL_USE_L4REQ_ANY,
[ACL_HOOK_REQ_FE_HTTP_IN] = ACL_USE_TCP4_ANY|ACL_USE_TCP6_ANY|ACL_USE_TCP_ANY|ACL_USE_L4REQ_ANY|ACL_USE_L7REQ_ANY|ACL_USE_HDR_ANY,
[ACL_HOOK_REQ_FE_SWITCH] = ACL_USE_TCP4_ANY|ACL_USE_TCP6_ANY|ACL_USE_TCP_ANY|ACL_USE_L4REQ_ANY|ACL_USE_L7REQ_ANY|ACL_USE_HDR_ANY,
[ACL_HOOK_REQ_BE_TCP_CONTENT] = ACL_USE_TCP4_ANY|ACL_USE_TCP6_ANY|ACL_USE_TCP_ANY|ACL_USE_L4REQ_ANY|ACL_USE_L7REQ_ANY|ACL_USE_HDR_ANY,
[ACL_HOOK_REQ_BE_HTTP_IN] = ACL_USE_TCP4_ANY|ACL_USE_TCP6_ANY|ACL_USE_TCP_ANY|ACL_USE_L4REQ_ANY|ACL_USE_L7REQ_ANY|ACL_USE_HDR_ANY,
[ACL_HOOK_REQ_BE_SWITCH] = ACL_USE_TCP4_ANY|ACL_USE_TCP6_ANY|ACL_USE_TCP_ANY|ACL_USE_L4REQ_ANY|ACL_USE_L7REQ_ANY|ACL_USE_HDR_ANY,
[ACL_HOOK_REQ_FE_HTTP_OUT] = ACL_USE_TCP4_ANY|ACL_USE_TCP6_ANY|ACL_USE_TCP_ANY|ACL_USE_L4REQ_ANY|ACL_USE_L7REQ_ANY|ACL_USE_HDR_ANY,
[ACL_HOOK_REQ_BE_HTTP_OUT] = ACL_USE_TCP4_ANY|ACL_USE_TCP6_ANY|ACL_USE_TCP_ANY|ACL_USE_L4REQ_ANY|ACL_USE_L7REQ_ANY|ACL_USE_HDR_ANY,
[ACL_HOOK_RTR_BE_TCP_CONTENT] = ACL_USE_REQ_PERMANENT|ACL_USE_REQ_CACHEABLE|ACL_USE_L4RTR_ANY,
[ACL_HOOK_RTR_BE_HTTP_IN] = ACL_USE_REQ_PERMANENT|ACL_USE_REQ_CACHEABLE|ACL_USE_L4RTR_ANY|ACL_USE_L7RTR_ANY,
[ACL_HOOK_RTR_FE_TCP_CONTENT] = ACL_USE_REQ_PERMANENT|ACL_USE_REQ_CACHEABLE|ACL_USE_L4RTR_ANY|ACL_USE_L7RTR_ANY,
[ACL_HOOK_RTR_FE_HTTP_IN] = ACL_USE_REQ_PERMANENT|ACL_USE_REQ_CACHEABLE|ACL_USE_L4RTR_ANY|ACL_USE_L7RTR_ANY,
[ACL_HOOK_RTR_BE_HTTP_OUT] = ACL_USE_REQ_PERMANENT|ACL_USE_REQ_CACHEABLE|ACL_USE_L4RTR_ANY|ACL_USE_L7RTR_ANY,
[ACL_HOOK_RTR_FE_HTTP_OUT] = ACL_USE_REQ_PERMANENT|ACL_USE_REQ_CACHEABLE|ACL_USE_L4RTR_ANY|ACL_USE_L7RTR_ANY,
};
/* List head of all known ACL keywords */
static struct acl_kw_list acl_keywords = {
.list = LIST_HEAD_INIT(acl_keywords.list)
};
/*
* These functions are only used for debugging complex configurations.
*/
/* force TRUE to be returned at the fetch level */
static int
acl_fetch_true(struct proxy *px, struct session *l4, void *l7, int dir,
struct acl_expr *expr, struct acl_test *test)
{
test->flags |= ACL_TEST_F_SET_RES_PASS;
return 1;
}
/* wait for more data as long as possible, then return TRUE. This should be
* used with content inspection.
*/
static int
acl_fetch_wait_end(struct proxy *px, struct session *l4, void *l7, int dir,
struct acl_expr *expr, struct acl_test *test)
{
if (dir & ACL_PARTIAL) {
test->flags |= ACL_TEST_F_MAY_CHANGE;
return 0;
}
test->flags |= ACL_TEST_F_SET_RES_PASS;
return 1;
}
/* force FALSE to be returned at the fetch level */
static int
acl_fetch_false(struct proxy *px, struct session *l4, void *l7, int dir,
struct acl_expr *expr, struct acl_test *test)
{
test->flags |= ACL_TEST_F_SET_RES_FAIL;
return 1;
}
/*
* These functions are exported and may be used by any other component.
*/
/* ignore the current line */
int acl_parse_nothing(const char **text, struct acl_pattern *pattern, int *opaque)
{
return 1;
}
/* always fake a data retrieval */
int acl_fetch_nothing(struct proxy *px, struct session *l4, void *l7, int dir,
struct acl_expr *expr, struct acl_test *test)
{
return 1;
}
/* always return false */
int acl_match_nothing(struct acl_test *test, struct acl_pattern *pattern)
{
return ACL_PAT_FAIL;
}
/* 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)
{
int icase;
if (pattern->len != test->len)
return ACL_PAT_FAIL;
icase = pattern->flags & ACL_PAT_F_IGNORE_CASE;
if ((icase && strncasecmp(pattern->ptr.str, test->ptr, test->len) == 0) ||
(!icase && strncmp(pattern->ptr.str, test->ptr, test->len) == 0))
return ACL_PAT_PASS;
return ACL_PAT_FAIL;
}
/* Executes a regex. It needs to change the data. If it is marked READ_ONLY
* then it will be allocated and duplicated in place so that others may use
* it later on. Note that this is embarrassing because we always try to avoid
* allocating memory at run time.
*/
int acl_match_reg(struct acl_test *test, struct acl_pattern *pattern)
{
char old_char;
int ret;
if (unlikely(test->flags & ACL_TEST_F_READ_ONLY)) {
char *new_str;
new_str = calloc(1, test->len + 1);
if (!new_str)
return ACL_PAT_FAIL;
memcpy(new_str, test->ptr, test->len);
new_str[test->len] = 0;
if (test->flags & ACL_TEST_F_MUST_FREE)
free(test->ptr);
test->ptr = new_str;
test->flags |= ACL_TEST_F_MUST_FREE;
test->flags &= ~ACL_TEST_F_READ_ONLY;
}
old_char = test->ptr[test->len];
test->ptr[test->len] = 0;
if (regexec(pattern->ptr.reg, test->ptr, 0, NULL, 0) == 0)
ret = ACL_PAT_PASS;
else
ret = ACL_PAT_FAIL;
test->ptr[test->len] = old_char;
return ret;
}
/* Checks that the pattern matches the beginning of the tested string. */
int acl_match_beg(struct acl_test *test, struct acl_pattern *pattern)
{
int icase;
if (pattern->len > test->len)
return ACL_PAT_FAIL;
icase = pattern->flags & ACL_PAT_F_IGNORE_CASE;
if ((icase && strncasecmp(pattern->ptr.str, test->ptr, pattern->len) != 0) ||
(!icase && strncmp(pattern->ptr.str, test->ptr, pattern->len) != 0))
return ACL_PAT_FAIL;
return ACL_PAT_PASS;
}
/* Checks that the pattern matches the end of the tested string. */
int acl_match_end(struct acl_test *test, struct acl_pattern *pattern)
{
int icase;
if (pattern->len > test->len)
return ACL_PAT_FAIL;
icase = pattern->flags & ACL_PAT_F_IGNORE_CASE;
if ((icase && strncasecmp(pattern->ptr.str, test->ptr + test->len - pattern->len, pattern->len) != 0) ||
(!icase && strncmp(pattern->ptr.str, test->ptr + test->len - pattern->len, pattern->len) != 0))
return ACL_PAT_FAIL;
return ACL_PAT_PASS;
}
/* 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)
{
int icase;
char *end;
char *c;
if (pattern->len > test->len)
return ACL_PAT_FAIL;
end = test->ptr + test->len - pattern->len;
icase = pattern->flags & ACL_PAT_F_IGNORE_CASE;
if (icase) {
for (c = test->ptr; c <= end; c++) {
if (tolower(*c) != tolower(*pattern->ptr.str))
continue;
if (strncasecmp(pattern->ptr.str, c, pattern->len) == 0)
return ACL_PAT_PASS;
}
} else {
for (c = test->ptr; c <= end; c++) {
if (*c != *pattern->ptr.str)
continue;
if (strncmp(pattern->ptr.str, c, pattern->len) == 0)
return ACL_PAT_PASS;
}
}
return ACL_PAT_FAIL;
}
/* 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.
*/
static int match_word(struct acl_test *test, struct acl_pattern *pattern, char delim)
{
int may_match, icase;
char *c, *end;
char *ps;
int pl;
pl = pattern->len;
ps = pattern->ptr.str;
while (pl > 0 && (*ps == delim || *ps == '/' || *ps == '?')) {
pl--;
ps++;
}
while (pl > 0 &&
(ps[pl - 1] == delim || ps[pl - 1] == '/' || ps[pl - 1] == '?'))
pl--;
if (pl > test->len)
return ACL_PAT_FAIL;
may_match = 1;
icase = pattern->flags & ACL_PAT_F_IGNORE_CASE;
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)
continue;
if (icase) {
if ((tolower(*c) == tolower(*ps)) &&
(strncasecmp(ps, c, pl) == 0) &&
(c == end || c[pl] == '/' || c[pl] == delim || c[pl] == '?'))
return ACL_PAT_PASS;
} else {
if ((*c == *ps) &&
(strncmp(ps, c, pl) == 0) &&
(c == end || c[pl] == '/' || c[pl] == delim || c[pl] == '?'))
return ACL_PAT_PASS;
}
may_match = 0;
}
return ACL_PAT_FAIL;
}
/* 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_int(struct acl_test *test, struct acl_pattern *pattern)
{
if ((!pattern->val.range.min_set || pattern->val.range.min <= test->i) &&
(!pattern->val.range.max_set || test->i <= pattern->val.range.max))
return ACL_PAT_PASS;
return ACL_PAT_FAIL;
}
int acl_match_ip(struct acl_test *test, struct acl_pattern *pattern)
{
struct in_addr *s;
if (test->i != AF_INET)
return ACL_PAT_FAIL;
s = (void *)test->ptr;
if (((s->s_addr ^ pattern->val.ipv4.addr.s_addr) & pattern->val.ipv4.mask.s_addr) == 0)
return ACL_PAT_PASS;
return ACL_PAT_FAIL;
}
/* Parse a string. It is allocated and duplicated. */
int acl_parse_str(const char **text, struct acl_pattern *pattern, int *opaque)
{
int len;
len = strlen(*text);
pattern->ptr.str = strdup(*text);
if (!pattern->ptr.str)
return 0;
pattern->len = len;
return 1;
}
/* Free data allocated by acl_parse_reg */
static void acl_free_reg(void *ptr) {
regfree((regex_t *)ptr);
}
/* Parse a regex. It is allocated. */
int acl_parse_reg(const char **text, struct acl_pattern *pattern, int *opaque)
{
regex_t *preg;
int icase;
preg = calloc(1, sizeof(regex_t));
if (!preg)
return 0;
icase = (pattern->flags & ACL_PAT_F_IGNORE_CASE) ? REG_ICASE : 0;
if (regcomp(preg, *text, REG_EXTENDED | REG_NOSUB | icase) != 0) {
free(preg);
return 0;
}
pattern->ptr.reg = preg;
pattern->freeptrbuf = &acl_free_reg;
return 1;
}
/* Parse a range of positive integers delimited by either ':' or '-'. If only
* one integer is read, it is set as both min and max. An operator may be
* specified as the prefix, among this list of 5 :
*
* 0:eq, 1:gt, 2:ge, 3:lt, 4:le
*
* The default operator is "eq". It supports range matching. Ranges are
* rejected for other operators. The operator may be changed at any time.
* The operator is stored in the 'opaque' argument.
*
*/
int acl_parse_int(const char **text, struct acl_pattern *pattern, int *opaque)
{
signed long long i;
unsigned int j, last, skip = 0;
const char *ptr = *text;
while (!isdigit((unsigned char)*ptr)) {
if (strcmp(ptr, "eq") == 0) *opaque = 0;
else if (strcmp(ptr, "gt") == 0) *opaque = 1;
else if (strcmp(ptr, "ge") == 0) *opaque = 2;
else if (strcmp(ptr, "lt") == 0) *opaque = 3;
else if (strcmp(ptr, "le") == 0) *opaque = 4;
else
return 0;
skip++;
ptr = text[skip];
}
last = i = 0;
while (1) {
j = *ptr++;
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 && *opaque >= 1 && *opaque <= 4)
/* having a range with a min or a max is absurd */
return 0;
if (!last)
pattern->val.range.min = i;
pattern->val.range.max = i;
switch (*opaque) {
case 0: /* eq */
pattern->val.range.min_set = 1;
pattern->val.range.max_set = 1;
break;
case 1: /* gt */
pattern->val.range.min++; /* gt = ge + 1 */
case 2: /* ge */
pattern->val.range.min_set = 1;
pattern->val.range.max_set = 0;
break;
case 3: /* lt */
pattern->val.range.max--; /* lt = le - 1 */
case 4: /* le */
pattern->val.range.min_set = 0;
pattern->val.range.max_set = 1;
break;
}
return skip + 1;
}
/* Parse a range of positive 2-component versions delimited by either ':' or
* '-'. The version consists in a major and a minor, both of which must be
* smaller than 65536, because internally they will be represented as a 32-bit
* integer.
* If only one version is read, it is set as both min and max. Just like for
* pure integers, an operator may be specified as the prefix, among this list
* of 5 :
*
* 0:eq, 1:gt, 2:ge, 3:lt, 4:le
*
* The default operator is "eq". It supports range matching. Ranges are
* rejected for other operators. The operator may be changed at any time.
* The operator is stored in the 'opaque' argument. This allows constructs
* such as the following one :
*
* acl obsolete_ssl ssl_req_proto lt 3
* acl unsupported_ssl ssl_req_proto gt 3.1
* acl valid_ssl ssl_req_proto 3.0-3.1
*
*/
int acl_parse_dotted_ver(const char **text, struct acl_pattern *pattern, int *opaque)
{
signed long long i;
unsigned int j, last, skip = 0;
const char *ptr = *text;
while (!isdigit((unsigned char)*ptr)) {
if (strcmp(ptr, "eq") == 0) *opaque = 0;
else if (strcmp(ptr, "gt") == 0) *opaque = 1;
else if (strcmp(ptr, "ge") == 0) *opaque = 2;
else if (strcmp(ptr, "lt") == 0) *opaque = 3;
else if (strcmp(ptr, "le") == 0) *opaque = 4;
else
return 0;
skip++;
ptr = text[skip];
}
last = i = 0;
while (1) {
j = *ptr++;
if (j == '.') {
/* minor part */
if (i >= 65536)
return 0;
i <<= 16;
continue;
}
if ((j == '-' || j == ':') && !last) {
last++;
if (i < 65536)
i <<= 16;
pattern->val.range.min = i;
i = 0;
continue;
}
j -= '0';
if (j > 9)
// also catches the terminating zero
break;
i = (i & 0xFFFF0000) + (i & 0xFFFF) * 10;
i += j;
}
/* if we only got a major version, let's shift it now */
if (i < 65536)
i <<= 16;
if (last && *opaque >= 1 && *opaque <= 4)
/* having a range with a min or a max is absurd */
return 0;
if (!last)
pattern->val.range.min = i;
pattern->val.range.max = i;
switch (*opaque) {
case 0: /* eq */
pattern->val.range.min_set = 1;
pattern->val.range.max_set = 1;
break;
case 1: /* gt */
pattern->val.range.min++; /* gt = ge + 1 */
case 2: /* ge */
pattern->val.range.min_set = 1;
pattern->val.range.max_set = 0;
break;
case 3: /* lt */
pattern->val.range.max--; /* lt = le - 1 */
case 4: /* le */
pattern->val.range.min_set = 0;
pattern->val.range.max_set = 1;
break;
}
return skip + 1;
}
/* Parse an IP address and an optional mask in the form addr[/mask].
* The addr may either be an IPv4 address or a hostname. The mask
* may either be a dotted mask or a number of bits. Returns 1 if OK,
* otherwise 0.
*/
int acl_parse_ip(const char **text, struct acl_pattern *pattern, int *opaque)
{
if (str2net(*text, &pattern->val.ipv4.addr, &pattern->val.ipv4.mask))
return 1;
else
return 0;
}
/*
* 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) {
if (pat->freeptrbuf)
pat->freeptrbuf(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;
int opaque, patflags;
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;
expr->arg_len = 0;
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_len = end - arg;
expr->arg.str = arg2;
}
args++;
/* check for options before patterns. Supported options are :
* -i : ignore case for all patterns by default
* -f : read patterns from those files
* -- : everything after this is not an option
*/
patflags = 0;
while (**args == '-') {
if ((*args)[1] == 'i')
patflags |= ACL_PAT_F_IGNORE_CASE;
else if ((*args)[1] == 'f')
patflags |= ACL_PAT_F_FROM_FILE;
else if ((*args)[1] == '-') {
args++;
break;
}
else
break;
args++;
}
/* now parse all patterns */
opaque = 0;
while (**args) {
int ret;
pattern = (struct acl_pattern *)calloc(1, sizeof(*pattern));
if (!pattern)
goto out_free_expr;
pattern->flags = patflags;
ret = aclkw->parse(args, pattern, &opaque);
if (!ret)
goto out_free_pattern;
LIST_ADDQ(&expr->patterns, &pattern->list);
args += ret;
}
return expr;
out_free_pattern:
free_pattern(pattern);
out_free_expr:
prune_acl_expr(expr);
free(expr);
out_return:
return NULL;
}
/* Purge everything in the acl <acl>, then return <acl>. */
struct acl *prune_acl(struct acl *acl) {
struct acl_expr *expr, *exprb;
free(acl->name);
list_for_each_entry_safe(expr, exprb, &acl->expr, list) {
LIST_DEL(&expr->list);
prune_acl_expr(expr);
free(expr);
}
return acl;
}
/* 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;
if (invalid_char(*args))
goto out_return;
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;
}
cur_acl->requires |= acl_expr->kw->requires;
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;
}
/* Some useful ACLs provided by default. Only those used are allocated. */
const struct {
const char *name;
const char *expr[4]; /* put enough for longest expression */
} default_acl_list[] = {
{ .name = "TRUE", .expr = {"always_true",""}},
{ .name = "FALSE", .expr = {"always_false",""}},
{ .name = "LOCALHOST", .expr = {"src","127.0.0.1/8",""}},
{ .name = "HTTP_1.0", .expr = {"req_ver","1.0",""}},
{ .name = "HTTP_1.1", .expr = {"req_ver","1.1",""}},
{ .name = "METH_CONNECT", .expr = {"method","CONNECT",""}},
{ .name = "METH_GET", .expr = {"method","GET","HEAD",""}},
{ .name = "METH_HEAD", .expr = {"method","HEAD",""}},
{ .name = "METH_OPTIONS", .expr = {"method","OPTIONS",""}},
{ .name = "METH_POST", .expr = {"method","POST",""}},
{ .name = "METH_TRACE", .expr = {"method","TRACE",""}},
{ .name = "HTTP_URL_ABS", .expr = {"url_reg","^[^/:]*://",""}},
{ .name = "HTTP_URL_SLASH", .expr = {"url_beg","/",""}},
{ .name = "HTTP_URL_STAR", .expr = {"url","*",""}},
{ .name = "HTTP_CONTENT", .expr = {"hdr_val(content-length)","gt","0",""}},
{ .name = "REQ_CONTENT", .expr = {"req_len","gt","0",""}},
{ .name = "WAIT_END", .expr = {"wait_end",""}},
{ .name = NULL, .expr = {""}}
};
/* Find a default ACL from the default_acl list, compile it and return it.
* If the ACL is not found, NULL is returned. In theory, it cannot fail,
* except when default ACLs are broken, in which case it will return NULL.
* If <known_acl> is not NULL, the ACL will be queued at its tail.
*/
struct acl *find_acl_default(const char *acl_name, 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;
int index;
for (index = 0; default_acl_list[index].name != NULL; index++) {
if (strcmp(acl_name, default_acl_list[index].name) == 0)
break;
}
if (default_acl_list[index].name == NULL)
return NULL;
acl_expr = parse_acl_expr((const char **)default_acl_list[index].expr);
if (!acl_expr)
goto out_return;
name = strdup(acl_name);
if (!name)
goto out_free_acl_expr;
cur_acl = (struct acl *)calloc(1, sizeof(*cur_acl));
if (cur_acl == NULL)
goto out_free_name;
cur_acl->name = name;
LIST_INIT(&cur_acl->expr);
LIST_ADDQ(&cur_acl->expr, &acl_expr->list);
if (known_acl)
LIST_ADDQ(known_acl, &cur_acl->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, neg;
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;
neg = 0;
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 || strcmp(word, "||") == 0) {
/* new term suite */
cur_suite = NULL;
neg = 0;
continue;
}
/* search for <word> in the known ACL names. If we do not find
* it, let's look for it in the default ACLs, and if found, add
* it to the list of ACLs of this proxy. This makes it possible
* to override them.
*/
cur_acl = find_acl_by_name(word, known_acl);
if (cur_acl == NULL) {
cur_acl = find_acl_default(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;
cond->requires |= cur_acl->requires;
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);
neg = 0;
}
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 either ACL_PAT_FAIL, ACL_PAT_MISS or
* ACL_PAT_PASS depending on the test results. ACL_PAT_MISS may only be
* returned if <dir> contains ACL_PARTIAL, indicating that incomplete data
* is being examined.
* 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 using something like
* this :
*
* res = acl_pass(res);
* if (res == ACL_PAT_MISS)
* return 0;
* if (cond->pol == ACL_COND_UNLESS)
* res = !res;
*/
int acl_exec_cond(struct acl_cond *cond, struct proxy *px, struct session *l4, void *l7, int dir)
{
__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, suite_res, cond_res;
/* We're doing a logical OR between conditions so we initialize to FAIL.
* The MISS status is propagated down from the suites.
*/
cond_res = ACL_PAT_FAIL;
list_for_each_entry(suite, &cond->suites, list) {
/* Evaluate condition suite <suite>. We stop at the first term
* which returns ACL_PAT_FAIL. The MISS status is still propagated
* in case of uncertainty in the result.
*/
/* 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) {
/* we need to reset context and flags */
memset(&test, 0, sizeof(test));
fetch_next:
if (!expr->kw->fetch(px, l4, l7, dir, expr, &test)) {
/* maybe we could not fetch because of missing data */
if (test.flags & ACL_TEST_F_MAY_CHANGE && dir & ACL_PARTIAL)
acl_res |= ACL_PAT_MISS;
continue;
}
if (test.flags & ACL_TEST_F_RES_SET) {
if (test.flags & ACL_TEST_F_RES_PASS)
acl_res |= ACL_PAT_PASS;
else
acl_res |= ACL_PAT_FAIL;
}
else {
/* call the match() function for all tests on this value */
list_for_each_entry(pattern, &expr->patterns, list) {
acl_res |= expr->kw->match(&test, pattern);
if (acl_res == ACL_PAT_PASS)
break;
}
}
/*
* OK now acl_res holds the result of this expression
* as one of ACL_PAT_FAIL, ACL_PAT_MISS or ACL_PAT_PASS.
*
* Then if (!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;
}
/* we're ORing these terms, so a single PASS is enough */
if (acl_res == ACL_PAT_PASS)
break;
if (test.flags & ACL_TEST_F_FETCH_MORE)
goto fetch_next;
/* sometimes we know the fetched data is subject to change
* later and give another chance for a new match (eg: request
* size, time, ...)
*/
if (test.flags & ACL_TEST_F_MAY_CHANGE && dir & ACL_PARTIAL)
acl_res |= ACL_PAT_MISS;
}
/*
* Here we have the result of an ACL (cached or not).
* ACLs are combined, negated or not, to form conditions.
*/
if (term->neg)
acl_res = acl_neg(acl_res);
suite_res &= acl_res;
/* we're ANDing these terms, so a single FAIL is enough */
if (suite_res == ACL_PAT_FAIL)
break;
}
cond_res |= suite_res;
/* we're ORing these terms, so a single PASS is enough */
if (cond_res == ACL_PAT_PASS)
break;
}
return cond_res;
}
/* Reports a pointer to the first ACL used in condition <cond> which requires
* at least one of the USE_FLAGS in <require>. Returns NULL if none matches.
* The construct is almost the same as for acl_exec_cond() since we're walking
* down the ACL tree as well. It is important that the tree is really walked
* through and never cached, because that way, this function can be used as a
* late check.
*/
struct acl *cond_find_require(struct acl_cond *cond, unsigned int require)
{
struct acl_term_suite *suite;
struct acl_term *term;
struct acl *acl;
list_for_each_entry(suite, &cond->suites, list) {
list_for_each_entry(term, &suite->terms, list) {
acl = term->acl;
if (acl->requires & require)
return acl;
}
}
return NULL;
}
/************************************************************************/
/* 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 = {{ },{
{ "always_true", acl_parse_nothing, acl_fetch_true, acl_match_nothing, ACL_USE_NOTHING },
{ "always_false", acl_parse_nothing, acl_fetch_false, acl_match_nothing, ACL_USE_NOTHING },
{ "wait_end", acl_parse_nothing, acl_fetch_wait_end, acl_match_nothing, ACL_USE_NOTHING },
#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:
*/