RepoMirrors
/
haproxy
mirror of http://git.haproxy.org/git/haproxy.git/
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
haproxy/src/acl.c

1378 lines
40 KiB
C
Raw Blame History

/*
* ACL management functions.
*
* Copyright 2000-2013 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 <import/ebsttree.h>
#include <haproxy/acl.h>
#include <haproxy/api.h>
#include <haproxy/arg.h>
#include <haproxy/auth.h>
#include <haproxy/errors.h>
#include <haproxy/global.h>
#include <haproxy/list.h>
#include <haproxy/pattern.h>
#include <haproxy/proxy-t.h>
#include <haproxy/sample.h>
#include <haproxy/stick_table.h>
#include <haproxy/tools.h>
#include <haproxy/cfgparse.h>
/* List head of all known ACL keywords */
static struct acl_kw_list acl_keywords = {
.list = LIST_HEAD_INIT(acl_keywords.list)
};
/* input values are 0 or 3, output is the same */
static inline enum acl_test_res pat2acl(struct pattern *pat)
{
if (pat)
return ACL_TEST_PASS;
else
return ACL_TEST_FAIL;
}
/*
* 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_APPEND(&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_DELETE(&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 or a comma, 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 = kw;
while (is_idchar(*kwend))
kwend++;
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 struct acl_expr *prune_acl_expr(struct acl_expr *expr)
{
struct arg *arg;
pattern_prune(&expr->pat);
for (arg = expr->smp->arg_p; arg; arg++) {
if (arg->type == ARGT_STOP)
break;
if (arg->type == ARGT_STR || arg->unresolved) {
chunk_destroy(&arg->data.str);
arg->unresolved = 0;
}
}
release_sample_expr(expr->smp);
return expr;
}
/* Parse an ACL expression starting at <args>[0], and return it. If <err> is
* not NULL, it will be filled with a pointer to an error message in case of
* error. This pointer must be freeable or NULL. <al> is an arg_list serving
* as a list head to report missing dependencies. It may be NULL if such
* dependencies are not allowed.
*
* Right now, the only accepted syntax is :
* <subject> [<value>...]
*/
struct acl_expr *parse_acl_expr(const char **args, char **err, struct arg_list *al,
const char *file, int line)
{
__label__ out_return, out_free_expr;
struct acl_expr *expr;
struct acl_keyword *aclkw;
int refflags, patflags;
const char *arg;
struct sample_expr *smp = NULL;
int idx = 0;
char *ckw = NULL;
const char *endt;
int cur_type;
int nbargs;
int operator = STD_OP_EQ;
int op;
int contain_colon, have_dot;
const char *dot;
signed long long value, minor;
/* The following buffer contain two numbers, a ':' separator and the final \0. */
char buffer[NB_LLMAX_STR + 1 + NB_LLMAX_STR + 1];
int is_loaded;
int unique_id;
char *error;
struct pat_ref *ref;
struct pattern_expr *pattern_expr;
int load_as_map = 0;
int acl_conv_found = 0;
/* First, we look for an ACL keyword. And if we don't find one, then
* we look for a sample fetch expression starting with a sample fetch
* keyword.
*/
if (al) {
al->ctx = ARGC_ACL; // to report errors while resolving args late
al->kw = *args;
al->conv = NULL;
}
aclkw = find_acl_kw(args[0]);
if (aclkw) {
/* OK we have a real ACL keyword */
/* build new sample expression for this ACL */
smp = calloc(1, sizeof(*smp));
if (!smp) {
memprintf(err, "out of memory when parsing ACL expression");
goto out_return;
}
LIST_INIT(&(smp->conv_exprs));
smp->fetch = aclkw->smp;
smp->arg_p = empty_arg_list;
/* look for the beginning of the subject arguments */
for (arg = args[0]; is_idchar(*arg); arg++)
;
/* At this point, we have :
* - args[0] : beginning of the keyword
* - arg : end of the keyword, first character not part of keyword
*/
nbargs = make_arg_list(arg, -1, smp->fetch->arg_mask, &smp->arg_p,
err, &endt, NULL, al);
if (nbargs < 0) {
/* note that make_arg_list will have set <err> here */
memprintf(err, "ACL keyword '%s' : %s", aclkw->kw, *err);
goto out_free_smp;
}
if (!smp->arg_p) {
smp->arg_p = empty_arg_list;
}
else if (smp->fetch->val_args && !smp->fetch->val_args(smp->arg_p, err)) {
/* invalid keyword argument, error must have been
* set by val_args().
*/
memprintf(err, "in argument to '%s', %s", aclkw->kw, *err);
goto out_free_smp;
}
/* look for the beginning of the converters list. Those directly attached
* to the ACL keyword are found just after the comma.
* If we find any converter, then we don't use the ACL keyword's match
* anymore but the one related to the converter's output type.
*/
if (!sample_parse_expr_cnv((char **)args, NULL, NULL, err, al, file, line, smp, endt)) {
if (err)
memprintf(err, "ACL keyword '%s' : %s", aclkw->kw, *err);
goto out_free_smp;
}
acl_conv_found = !LIST_ISEMPTY(&smp->conv_exprs);
}
else {
/* This is not an ACL keyword, so we hope this is a sample fetch
* keyword that we're going to transparently use as an ACL. If
* so, we retrieve a completely parsed expression with args and
* convs already done.
*/
smp = sample_parse_expr((char **)args, &idx, file, line, err, al, NULL);
if (!smp) {
memprintf(err, "%s in ACL expression '%s'", *err, *args);
goto out_return;
}
}
/* get last effective output type for smp */
cur_type = smp_expr_output_type(smp);
expr = calloc(1, sizeof(*expr));
if (!expr) {
memprintf(err, "out of memory when parsing ACL expression");
goto out_free_smp;
}
pattern_init_head(&expr->pat);
expr->pat.expect_type = cur_type;
expr->smp = smp;
expr->kw = smp->fetch->kw;
smp = NULL; /* don't free it anymore */
if (aclkw && !acl_conv_found) {
expr->kw = aclkw->kw;
expr->pat.parse = aclkw->parse ? aclkw->parse : pat_parse_fcts[aclkw->match_type];
expr->pat.index = aclkw->index ? aclkw->index : pat_index_fcts[aclkw->match_type];
expr->pat.match = aclkw->match ? aclkw->match : pat_match_fcts[aclkw->match_type];
expr->pat.prune = aclkw->prune ? aclkw->prune : pat_prune_fcts[aclkw->match_type];
}
if (!expr->pat.parse) {
/* Parse/index/match functions depend on the expression type,
* so we have to map them now. Some types can be automatically
* converted.
*/
switch (cur_type) {
case SMP_T_BOOL:
expr->pat.parse = pat_parse_fcts[PAT_MATCH_BOOL];
expr->pat.index = pat_index_fcts[PAT_MATCH_BOOL];
expr->pat.match = pat_match_fcts[PAT_MATCH_BOOL];
expr->pat.prune = pat_prune_fcts[PAT_MATCH_BOOL];
expr->pat.expect_type = pat_match_types[PAT_MATCH_BOOL];
break;
case SMP_T_SINT:
expr->pat.parse = pat_parse_fcts[PAT_MATCH_INT];
expr->pat.index = pat_index_fcts[PAT_MATCH_INT];
expr->pat.match = pat_match_fcts[PAT_MATCH_INT];
expr->pat.prune = pat_prune_fcts[PAT_MATCH_INT];
expr->pat.expect_type = pat_match_types[PAT_MATCH_INT];
break;
case SMP_T_ADDR:
case SMP_T_IPV4:
case SMP_T_IPV6:
expr->pat.parse = pat_parse_fcts[PAT_MATCH_IP];
expr->pat.index = pat_index_fcts[PAT_MATCH_IP];
expr->pat.match = pat_match_fcts[PAT_MATCH_IP];
expr->pat.prune = pat_prune_fcts[PAT_MATCH_IP];
expr->pat.expect_type = pat_match_types[PAT_MATCH_IP];
break;
case SMP_T_STR:
expr->pat.parse = pat_parse_fcts[PAT_MATCH_STR];
expr->pat.index = pat_index_fcts[PAT_MATCH_STR];
expr->pat.match = pat_match_fcts[PAT_MATCH_STR];
expr->pat.prune = pat_prune_fcts[PAT_MATCH_STR];
expr->pat.expect_type = pat_match_types[PAT_MATCH_STR];
break;
}
}
/* Additional check to protect against common mistakes */
if (expr->pat.parse && cur_type != SMP_T_BOOL && !*args[1]) {
ha_warning("parsing acl keyword '%s' :\n"
" no pattern to match against were provided, so this ACL will never match.\n"
" If this is what you intended, please add '--' to get rid of this warning.\n"
" If you intended to match only for existence, please use '-m found'.\n"
" If you wanted to force an int to match as a bool, please use '-m bool'.\n"
"\n",
args[0]);
}
args++;
/* check for options before patterns. Supported options are :
* -i : ignore case for all patterns by default
* -f : read patterns from those files
* -m : force matching method (must be used before -f)
* -M : load the file as map file
* -u : force the unique id of the acl
* -- : everything after this is not an option
*/
refflags = PAT_REF_ACL;
patflags = 0;
is_loaded = 0;
unique_id = -1;
while (**args == '-') {
if (strcmp(*args, "-i") == 0)
patflags |= PAT_MF_IGNORE_CASE;
else if (strcmp(*args, "-n") == 0)
patflags |= PAT_MF_NO_DNS;
else if (strcmp(*args, "-u") == 0) {
unique_id = strtol(args[1], &error, 10);
if (*error != '\0') {
memprintf(err, "the argument of -u must be an integer");
goto out_free_expr;
}
/* Check if this id is really unique. */
if (pat_ref_lookupid(unique_id)) {
memprintf(err, "the id is already used");
goto out_free_expr;
}
args++;
}
else if (strcmp(*args, "-f") == 0) {
if (!expr->pat.parse) {
memprintf(err, "matching method must be specified first (using '-m') when using a sample fetch of this type ('%s')", expr->kw);
goto out_free_expr;
}
if (!pattern_read_from_file(&expr->pat, refflags, args[1], patflags, load_as_map, err, file, line))
goto out_free_expr;
is_loaded = 1;
args++;
}
else if (strcmp(*args, "-m") == 0) {
int idx;
if (is_loaded) {
memprintf(err, "'-m' must only be specified before patterns and files in parsing ACL expression");
goto out_free_expr;
}
idx = pat_find_match_name(args[1]);
if (idx < 0) {
memprintf(err, "unknown matching method '%s' when parsing ACL expression", args[1]);
goto out_free_expr;
}
/* Note: -m found is always valid, bool/int are compatible, str/bin/reg/len are compatible */
if (idx != PAT_MATCH_FOUND && !sample_casts[cur_type][pat_match_types[idx]]) {
memprintf(err, "matching method '%s' cannot be used with fetch keyword '%s'", args[1], expr->kw);
goto out_free_expr;
}
expr->pat.parse = pat_parse_fcts[idx];
expr->pat.index = pat_index_fcts[idx];
expr->pat.match = pat_match_fcts[idx];
expr->pat.prune = pat_prune_fcts[idx];
expr->pat.expect_type = pat_match_types[idx];
args++;
}
else if (strcmp(*args, "-M") == 0) {
refflags |= PAT_REF_MAP;
load_as_map = 1;
}
else if (strcmp(*args, "--") == 0) {
args++;
break;
}
else {
memprintf(err, "'%s' is not a valid ACL option. Please use '--' before any pattern beginning with a '-'", args[0]);
goto out_free_expr;
break;
}
args++;
}
if (!expr->pat.parse) {
memprintf(err, "matching method must be specified first (using '-m') when using a sample fetch of this type ('%s')", expr->kw);
goto out_free_expr;
}
/* Create displayed reference */
snprintf(trash.area, trash.size, "acl '%s' file '%s' line %d",
expr->kw, file, line);
trash.area[trash.size - 1] = '\0';
/* Create new pattern reference. */
ref = pat_ref_newid(unique_id, trash.area, PAT_REF_ACL);
if (!ref) {
memprintf(err, "memory error");
goto out_free_expr;
}
/* Create new pattern expression associated to this reference. */
pattern_expr = pattern_new_expr(&expr->pat, ref, patflags, err, NULL);
if (!pattern_expr)
goto out_free_expr;
/* now parse all patterns */
while (**args) {
arg = *args;
/* Compatibility layer. Each pattern can parse only one string per pattern,
* but the pat_parser_int() and pat_parse_dotted_ver() parsers were need
* optionally two operators. The first operator is the match method: eq,
* le, lt, ge and gt. pat_parse_int() and pat_parse_dotted_ver() functions
* can have a compatibility syntax based on ranges:
*
* pat_parse_int():
*
* "eq x" -> "x" or "x:x"
* "le x" -> ":x"
* "lt x" -> ":y" (with y = x - 1)
* "ge x" -> "x:"
* "gt x" -> "y:" (with y = x + 1)
*
* pat_parse_dotted_ver():
*
* "eq x.y" -> "x.y" or "x.y:x.y"
* "le x.y" -> ":x.y"
* "lt x.y" -> ":w.z" (with w.z = x.y - 1)
* "ge x.y" -> "x.y:"
* "gt x.y" -> "w.z:" (with w.z = x.y + 1)
*
* If y is not present, assume that is "0".
*
* The syntax eq, le, lt, ge and gt are proper to the acl syntax. The
* following block of code detect the operator, and rewrite each value
* in parsable string.
*/
if (expr->pat.parse == pat_parse_int ||
expr->pat.parse == pat_parse_dotted_ver) {
/* Check for operator. If the argument is operator, memorise it and
* continue to the next argument.
*/
op = get_std_op(arg);
if (op != -1) {
operator = op;
args++;
continue;
}
/* Check if the pattern contain ':' or '-' character. */
contain_colon = (strchr(arg, ':') || strchr(arg, '-'));
/* If the pattern contain ':' or '-' character, give it to the parser as is.
* If no contain ':' and operator is STD_OP_EQ, give it to the parser as is.
* In other case, try to convert the value according with the operator.
*/
if (!contain_colon && operator != STD_OP_EQ) {
/* Search '.' separator. */
dot = strchr(arg, '.');
if (!dot) {
have_dot = 0;
minor = 0;
dot = arg + strlen(arg);
}
else
have_dot = 1;
/* convert the integer minor part for the pat_parse_dotted_ver() function. */
if (expr->pat.parse == pat_parse_dotted_ver && have_dot) {
if (strl2llrc(dot+1, strlen(dot+1), &minor) != 0) {
memprintf(err, "'%s' is neither a number nor a supported operator", arg);
goto out_free_expr;
}
if (minor >= 65536) {
memprintf(err, "'%s' contains too large a minor value", arg);
goto out_free_expr;
}
}
/* convert the integer value for the pat_parse_int() function, and the
* integer major part for the pat_parse_dotted_ver() function.
*/
if (strl2llrc(arg, dot - arg, &value) != 0) {
memprintf(err, "'%s' is neither a number nor a supported operator", arg);
goto out_free_expr;
}
if (expr->pat.parse == pat_parse_dotted_ver) {
if (value >= 65536) {
memprintf(err, "'%s' contains too large a major value", arg);
goto out_free_expr;
}
value = (value << 16) | (minor & 0xffff);
}
switch (operator) {
case STD_OP_EQ: /* this case is not possible. */
memprintf(err, "internal error");
goto out_free_expr;
case STD_OP_GT:
value++; /* gt = ge + 1 */
__fallthrough;
case STD_OP_GE:
if (expr->pat.parse == pat_parse_int)
snprintf(buffer, NB_LLMAX_STR+NB_LLMAX_STR+2, "%lld:", value);
else
snprintf(buffer, NB_LLMAX_STR+NB_LLMAX_STR+2, "%lld.%lld:",
value >> 16, value & 0xffff);
arg = buffer;
break;
case STD_OP_LT:
value--; /* lt = le - 1 */
__fallthrough;
case STD_OP_LE:
if (expr->pat.parse == pat_parse_int)
snprintf(buffer, NB_LLMAX_STR+NB_LLMAX_STR+2, ":%lld", value);
else
snprintf(buffer, NB_LLMAX_STR+NB_LLMAX_STR+2, ":%lld.%lld",
value >> 16, value & 0xffff);
arg = buffer;
break;
}
}
}
/* Add sample to the reference, and try to compile it fior each pattern
* using this value.
*/
if (!pat_ref_add(ref, arg, NULL, err))
goto out_free_expr;
args++;
}
return expr;
out_free_expr:
prune_acl_expr(expr);
free(expr);
out_free_smp:
free(ckw);
free(smp);
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_DELETE(&expr->list);
prune_acl_expr(expr);
free(expr);
}
return acl;
}
/* Walk the ACL tree, following nested acl() sample fetches, for no more than
* max_recurse evaluations. Returns -1 if a recursive loop is detected, 0 if
* the max_recurse was reached, otherwise the number of max_recurse left.
*/
static int parse_acl_recurse(struct acl *acl, struct acl_expr *expr, int max_recurse)
{
struct acl_term *term;
struct acl_sample *sample;
if (strcmp(expr->smp->fetch->kw, "acl") != 0)
return max_recurse;
if (--max_recurse <= 0)
return 0;
sample = (struct acl_sample *)expr->smp->arg_p->data.ptr;
list_for_each_entry(term, &sample->suite.terms, list) {
if (term->acl == acl)
return -1;
list_for_each_entry(expr, &term->acl->expr, list) {
max_recurse = parse_acl_recurse(acl, expr, max_recurse);
if (max_recurse <= 0)
return max_recurse;
}
}
return max_recurse;
}
/* 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. If the ACL has an empty name, then it's
* an anonymous one and it won't be merged with any other one. If <err> is not
* NULL, it will be filled with an appropriate error. This pointer must be
* freeable or NULL. <al> is the arg_list serving as a head for unresolved
* dependencies. It may be NULL if such dependencies are not allowed.
*
* args syntax: <aclname> <acl_expr>
*/
struct acl *parse_acl(const char **args, struct list *known_acl, char **err, struct arg_list *al,
const char *file, int line)
{
__label__ out_return, out_free_acl_expr, out_free_name;
struct acl *cur_acl;
struct acl_expr *acl_expr;
char *name;
const char *pos;
if (**args && (pos = invalid_char(*args))) {
memprintf(err, "invalid character in ACL name : '%c'", *pos);
goto out_return;
}
acl_expr = parse_acl_expr(args + 1, err, al, file, line);
if (!acl_expr) {
/* parse_acl_expr will have filled <err> here */
goto out_return;
}
/* Check for args beginning with an opening parenthesis just after the
* subject, as this is almost certainly a typo. Right now we can only
* emit a warning, so let's do so.
*/
if (!strchr(args[1], '(') && *args[2] == '(')
ha_warning("parsing acl '%s' :\n"
" matching '%s' for pattern '%s' is likely a mistake and probably\n"
" not what you want. Maybe you need to remove the extraneous space before '('.\n"
" If you are really sure this is not an error, please insert '--' between the\n"
" match and the pattern to make this warning message disappear.\n",
args[0], args[1], args[2]);
if (*args[0])
cur_acl = find_acl_by_name(args[0], known_acl);
else
cur_acl = NULL;
if (cur_acl) {
int ret = parse_acl_recurse(cur_acl, acl_expr, ACL_MAX_RECURSE);
if (ret <= 0) {
if (ret < 0)
memprintf(err, "have a recursive loop");
else
memprintf(err, "too deep acl() tree");
goto out_free_acl_expr;
}
} else {
name = strdup(args[0]);
if (!name) {
memprintf(err, "out of memory when parsing ACL");
goto out_free_acl_expr;
}
cur_acl = calloc(1, sizeof(*cur_acl));
if (cur_acl == NULL) {
memprintf(err, "out of memory when parsing ACL");
goto out_free_name;
}
LIST_INIT(&cur_acl->expr);
LIST_APPEND(known_acl, &cur_acl->list);
cur_acl->name = name;
}
/* We want to know what features the ACL needs (typically HTTP parsing),
* and where it may be used. If an ACL relies on multiple matches, it is
* OK if at least one of them may match in the context where it is used.
*/
cur_acl->use |= acl_expr->smp->fetch->use;
cur_acl->val |= acl_expr->smp->fetch->val;
LIST_APPEND(&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","::1",""}},
{ .name = "HTTP", .expr = {"req.proto_http",""}},
{ .name = "HTTP_1.0", .expr = {"req.ver","1.0",""}},
{ .name = "HTTP_1.1", .expr = {"req.ver","1.1",""}},
{ .name = "HTTP_2.0", .expr = {"req.ver","2.0",""}},
{ .name = "HTTP_3.0", .expr = {"req.ver","3.0",""}},
{ .name = "METH_CONNECT", .expr = {"method","CONNECT",""}},
{ .name = "METH_DELETE", .expr = {"method","DELETE",""}},
{ .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_PUT", .expr = {"method","PUT",""}},
{ .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 = {"req.hdr_val(content-length)","gt","0",""}},
{ .name = "RDP_COOKIE", .expr = {"req.rdp_cookie_cnt","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. If <err> is
* not NULL, it will be filled with an error message if an error occurs. This
* pointer must be freeable or NULL. <al> is an arg_list serving as a list head
* to report missing dependencies. It may be NULL if such dependencies are not
* allowed.
*/
static struct acl *find_acl_default(const char *acl_name, struct list *known_acl,
char **err, struct arg_list *al,
const char *file, int line)
{
__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) {
memprintf(err, "no such ACL : '%s'", acl_name);
return NULL;
}
acl_expr = parse_acl_expr((const char **)default_acl_list[index].expr, err, al, file, line);
if (!acl_expr) {
/* parse_acl_expr must have filled err here */
goto out_return;
}
name = strdup(acl_name);
if (!name) {
memprintf(err, "out of memory when building default ACL '%s'", acl_name);
goto out_free_acl_expr;
}
cur_acl = calloc(1, sizeof(*cur_acl));
if (cur_acl == NULL) {
memprintf(err, "out of memory when building default ACL '%s'", acl_name);
goto out_free_name;
}
cur_acl->name = name;
cur_acl->use |= acl_expr->smp->fetch->use;
cur_acl->val |= acl_expr->smp->fetch->val;
LIST_INIT(&cur_acl->expr);
LIST_APPEND(&cur_acl->expr, &acl_expr->list);
if (known_acl)
LIST_APPEND(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;
}
/* 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". If
* <err> is not NULL, it will be filled with a pointer to an error message in
* case of error, that the caller is responsible for freeing. The initial
* location must either be freeable or NULL. The list <al> serves as a list head
* for unresolved dependencies. It may be NULL if such dependencies are not
* allowed.
*/
struct acl_cond *parse_acl_cond(const char **args, struct list *known_acl,
enum acl_cond_pol pol, char **err, struct arg_list *al,
const char *file, int line)
{
__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;
unsigned int suite_val;
cond = calloc(1, sizeof(*cond));
if (cond == NULL) {
memprintf(err, "out of memory when parsing condition");
goto out_return;
}
LIST_INIT(&cond->list);
LIST_INIT(&cond->suites);
cond->pol = pol;
cond->val = 0;
cur_suite = NULL;
suite_val = ~0U;
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 */
cond->val |= suite_val;
suite_val = ~0U;
cur_suite = NULL;
neg = 0;
continue;
}
if (strcmp(word, "{") == 0) {
/* we may have a complete ACL expression between two braces,
* find the last one.
*/
int arg_end = arg + 1;
const char **args_new;
while (*args[arg_end] && strcmp(args[arg_end], "}") != 0)
arg_end++;
if (!*args[arg_end]) {
memprintf(err, "missing closing '}' in condition");
goto out_free_suite;
}
args_new = calloc(1, (arg_end - arg + 1) * sizeof(*args_new));
if (!args_new) {
memprintf(err, "out of memory when parsing condition");
goto out_free_suite;
}
args_new[0] = "";
memcpy(args_new + 1, args + arg + 1, (arg_end - arg) * sizeof(*args_new));
args_new[arg_end - arg] = "";
cur_acl = parse_acl(args_new, known_acl, err, al, file, line);
free(args_new);
if (!cur_acl) {
/* note that parse_acl() must have filled <err> here */
goto out_free_suite;
}
arg = arg_end;
}
else {
/* 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, err, al, file, line);
if (cur_acl == NULL) {
/* note that find_acl_default() must have filled <err> here */
goto out_free_suite;
}
}
}
cur_term = calloc(1, sizeof(*cur_term));
if (cur_term == NULL) {
memprintf(err, "out of memory when parsing condition");
goto out_free_suite;
}
cur_term->acl = cur_acl;
cur_term->neg = neg;
/* Here it is a bit complex. The acl_term_suite is a conjunction
* of many terms. It may only be used if all of its terms are
* usable at the same time. So the suite's validity domain is an
* AND between all ACL keywords' ones. But, the global condition
* is valid if at least one term suite is OK. So it's an OR between
* all of their validity domains. We could emit a warning as soon
* as suite_val is null because it means that the last ACL is not
* compatible with the previous ones. Let's remain simple for now.
*/
cond->use |= cur_acl->use;
suite_val &= cur_acl->val;
if (!cur_suite) {
cur_suite = calloc(1, sizeof(*cur_suite));
if (cur_suite == NULL) {
memprintf(err, "out of memory when parsing condition");
goto out_free_term;
}
LIST_INIT(&cur_suite->terms);
LIST_APPEND(&cond->suites, &cur_suite->list);
}
LIST_APPEND(&cur_suite->terms, &cur_term->list);
neg = 0;
}
cond->val |= suite_val;
return cond;
out_free_term:
free(cur_term);
out_free_suite:
free_acl_cond(cond);
out_return:
return NULL;
}
/* Builds an ACL condition starting at the if/unless keyword. The complete
* condition is returned. NULL is returned in case of error or if the first
* word is neither "if" nor "unless". It automatically sets the file name and
* the line number in the condition for better error reporting, and sets the
* HTTP initialization requirements in the proxy. If <err> is not NULL, it will
* be filled with a pointer to an error message in case of error, that the
* caller is responsible for freeing. The initial location must either be
* freeable or NULL.
*/
struct acl_cond *build_acl_cond(const char *file, int line, struct list *known_acl,
struct proxy *px, const char **args, char **err)
{
enum acl_cond_pol pol = ACL_COND_NONE;
struct acl_cond *cond = NULL;
if (err)
*err = NULL;
if (strcmp(*args, "if") == 0) {
pol = ACL_COND_IF;
args++;
}
else if (strcmp(*args, "unless") == 0) {
pol = ACL_COND_UNLESS;
args++;
}
else {
memprintf(err, "conditions must start with either 'if' or 'unless'");
return NULL;
}
cond = parse_acl_cond(args, known_acl, pol, err, &px->conf.args, file, line);
if (!cond) {
/* note that parse_acl_cond must have filled <err> here */
return NULL;
}
cond->file = file;
cond->line = line;
px->http_needed |= !!(cond->use & SMP_USE_HTTP_ANY);
return cond;
}
/* Execute condition <cond> and return either ACL_TEST_FAIL, ACL_TEST_MISS or
* ACL_TEST_PASS depending on the test results. ACL_TEST_MISS may only be
* returned if <opt> does not contain SMP_OPT_FINAL, indicating that incomplete
* data is being examined. The function automatically sets SMP_OPT_ITERATE. 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_TEST_MISS)
* return 0;
* if (cond->pol == ACL_COND_UNLESS)
* res = !res;
*/
enum acl_test_res acl_exec_cond(struct acl_cond *cond, struct proxy *px, struct session *sess, struct stream *strm, unsigned int opt)
{
__label__ fetch_next;
struct acl_term_suite *suite;
struct acl_term *term;
struct acl_expr *expr;
struct acl *acl;
struct sample smp;
enum acl_test_res acl_res, suite_res, cond_res;
/* ACLs are iterated over all values, so let's always set the flag to
* indicate this to the fetch functions.
*/
opt |= SMP_OPT_ITERATE;
/* 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_TEST_FAIL;
list_for_each_entry(suite, &cond->suites, list) {
/* Evaluate condition suite <suite>. We stop at the first term
* which returns ACL_TEST_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_TEST_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_TEST_FAIL;
list_for_each_entry(expr, &acl->expr, list) {
/* we need to reset context and flags */
memset(&smp, 0, sizeof(smp));
fetch_next:
if (!sample_process(px, sess, strm, opt, expr->smp, &smp)) {
/* maybe we could not fetch because of missing data */
if (smp.flags & SMP_F_MAY_CHANGE && !(opt & SMP_OPT_FINAL))
acl_res |= ACL_TEST_MISS;
continue;
}
acl_res |= pat2acl(pattern_exec_match(&expr->pat, &smp, 0));
/*
* OK now acl_res holds the result of this expression
* as one of ACL_TEST_FAIL, ACL_TEST_MISS or ACL_TEST_PASS.
*
* Then if (!MISS) we can cache the result, and put
* (smp.flags & SMP_F_VOLATILE) in the cache flags.
*
* FIXME: implement cache.
*
*/
/* we're ORing these terms, so a single PASS is enough */
if (acl_res == ACL_TEST_PASS)
break;
if (smp.flags & SMP_F_NOT_LAST)
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 (smp.flags & SMP_F_MAY_CHANGE && !(opt & SMP_OPT_FINAL))
acl_res |= ACL_TEST_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 or MISS is enough */
if (suite_res != ACL_TEST_PASS)
break;
}
cond_res |= suite_res;
/* we're ORing these terms, so a single PASS is enough */
if (cond_res == ACL_TEST_PASS)
break;
}
return cond_res;
}
/* Returns a pointer to the first ACL conflicting with usage at place <where>
* which is one of the SMP_VAL_* bits indicating a check place, or NULL if
* no conflict is found. Only full conflicts are detected (ACL is not usable).
* Use the next function to check for useless keywords.
*/
const struct acl *acl_cond_conflicts(const struct acl_cond *cond, unsigned int where)
{
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->val & where))
return acl;
}
}
return NULL;
}
/* Returns a pointer to the first ACL and its first keyword to conflict with
* usage at place <where> which is one of the SMP_VAL_* bits indicating a check
* place. Returns true if a conflict is found, with <acl> and <kw> set (if non
* null), or false if not conflict is found. The first useless keyword is
* returned.
*/
int acl_cond_kw_conflicts(const struct acl_cond *cond, unsigned int where, struct acl const **acl, char const **kw)
{
struct acl_term_suite *suite;
struct acl_term *term;
struct acl_expr *expr;
list_for_each_entry(suite, &cond->suites, list) {
list_for_each_entry(term, &suite->terms, list) {
list_for_each_entry(expr, &term->acl->expr, list) {
if (!(expr->smp->fetch->val & where)) {
if (acl)
*acl = term->acl;
if (kw)
*kw = expr->kw;
return 1;
}
}
}
}
return 0;
}
/*
* Find targets for userlist and groups in acl. Function returns the number
* of errors or OK if everything is fine. It must be called only once sample
* fetch arguments have been resolved (after smp_resolve_args()).
*/
int acl_find_targets(struct proxy *p)
{
struct acl *acl;
struct acl_expr *expr;
struct pattern_list *pattern;
int cfgerr = 0;
struct pattern_expr_list *pexp;
list_for_each_entry(acl, &p->acl, list) {
list_for_each_entry(expr, &acl->expr, list) {
if (strcmp(expr->kw, "http_auth_group") == 0) {
/* Note: the ARGT_USR argument may only have been resolved earlier
* by smp_resolve_args().
*/
if (expr->smp->arg_p->unresolved) {
ha_alert("Internal bug in proxy %s: %sacl %s %s() makes use of unresolved userlist '%s'. Please report this.\n",
p->id, *acl->name ? "" : "anonymous ", acl->name, expr->kw,
expr->smp->arg_p->data.str.area);
cfgerr++;
continue;
}
if (LIST_ISEMPTY(&expr->pat.head)) {
ha_alert("proxy %s: acl %s %s(): no groups specified.\n",
p->id, acl->name, expr->kw);
cfgerr++;
continue;
}
/* For each pattern, check if the group exists. */
list_for_each_entry(pexp, &expr->pat.head, list) {
if (LIST_ISEMPTY(&pexp->expr->patterns)) {
ha_alert("proxy %s: acl %s %s(): no groups specified.\n",
p->id, acl->name, expr->kw);
cfgerr++;
continue;
}
list_for_each_entry(pattern, &pexp->expr->patterns, list) {
/* this keyword only has one argument */
if (!check_group(expr->smp->arg_p->data.usr, pattern->pat.ptr.str)) {
ha_alert("proxy %s: acl %s %s(): invalid group '%s'.\n",
p->id, acl->name, expr->kw, pattern->pat.ptr.str);
cfgerr++;
}
}
}
}
}
}
return cfgerr;
}
/* initializes ACLs by resolving the sample fetch names they rely upon.
* Returns 0 on success, otherwise an error.
*/
int init_acl()
{
int err = 0;
int index;
const char *name;
struct acl_kw_list *kwl;
struct sample_fetch *smp;
list_for_each_entry(kwl, &acl_keywords.list, list) {
for (index = 0; kwl->kw[index].kw != NULL; index++) {
name = kwl->kw[index].fetch_kw;
if (!name)
name = kwl->kw[index].kw;
smp = find_sample_fetch(name, strlen(name));
if (!smp) {
ha_alert("Critical internal error: ACL keyword '%s' relies on sample fetch '%s' which was not registered!\n",
kwl->kw[index].kw, name);
err++;
continue;
}
kwl->kw[index].smp = smp;
}
}
return err;
}
/* dump known ACL keywords on stdout */
void acl_dump_kwd(void)
{
struct acl_kw_list *kwl;
const struct acl_keyword *kwp, *kw;
const char *name;
int index;
for (kw = kwp = NULL;; kwp = kw) {
list_for_each_entry(kwl, &acl_keywords.list, list) {
for (index = 0; kwl->kw[index].kw != NULL; index++) {
if (strordered(kwp ? kwp->kw : NULL,
kwl->kw[index].kw,
kw != kwp ? kw->kw : NULL))
kw = &kwl->kw[index];
}
}
if (kw == kwp)
break;
name = kw->fetch_kw;
if (!name)
name = kw->kw;
printf("%s = %s -m %s\n", kw->kw, name, pat_match_names[kw->match_type]);
}
}
/* Purge everything in the acl_cond <cond>, then free <cond> */
void free_acl_cond(struct acl_cond *cond)
{
struct acl_term_suite *suite, *suiteb;
struct acl_term *term, *termb;
if (!cond)
return;
list_for_each_entry_safe(suite, suiteb, &cond->suites, list) {
list_for_each_entry_safe(term, termb, &suite->terms, list) {
LIST_DELETE(&term->list);
free(term);
}
LIST_DELETE(&suite->list);
free(suite);
}
free(cond);
}
static int smp_fetch_acl(const struct arg *args, struct sample *smp, const char *kw, void *private)
{
struct acl_sample *acl_sample = (struct acl_sample *)args->data.ptr;
enum acl_test_res ret;
ret = acl_exec_cond(&acl_sample->cond, smp->px, smp->sess, smp->strm, smp->opt);
if (ret == ACL_TEST_MISS)
return 0;
smp->data.u.sint = ret == ACL_TEST_PASS;
smp->data.type = SMP_T_BOOL;
return 1;
}
int smp_fetch_acl_parse(struct arg *args, char **err_msg)
{
struct acl_sample *acl_sample;
char *name;
int i;
for (i = 0; args[i].type != ARGT_STOP; i++)
;
acl_sample = calloc(1, sizeof(struct acl_sample) + sizeof(struct acl_term) * i);
LIST_INIT(&acl_sample->suite.terms);
LIST_INIT(&acl_sample->cond.suites);
LIST_APPEND(&acl_sample->cond.suites, &acl_sample->suite.list);
acl_sample->cond.val = ~0U; // the keyword is valid everywhere for now.
args->data.ptr = acl_sample;
for (i = 0; args[i].type != ARGT_STOP; i++) {
name = args[i].data.str.area;
if (name[0] == '!') {
acl_sample->terms[i].neg = 1;
name++;
}
if (!(acl_sample->terms[i].acl = find_acl_by_name(name, &curproxy->acl))) {
memprintf(err_msg, "ACL '%s' not found", name);
goto err;
}
acl_sample->cond.use |= acl_sample->terms[i].acl->use;
acl_sample->cond.val &= acl_sample->terms[i].acl->val;
LIST_APPEND(&acl_sample->suite.terms, &acl_sample->terms[i].list);
}
return 1;
err:
free(acl_sample);
return 0;
}
/************************************************************************/
/* All supported sample and ACL keywords must be declared here. */
/************************************************************************/
/* Note: must not be declared <const> as its list will be overwritten.
* Please take care of keeping this list alphabetically sorted.
*/
static struct acl_kw_list acl_kws = {ILH, {
{ /* END */ },
}};
INITCALL1(STG_REGISTER, acl_register_keywords, &acl_kws);
static struct sample_fetch_kw_list smp_kws = {ILH, {
{ "acl", smp_fetch_acl, ARG12(1,STR,STR,STR,STR,STR,STR,STR,STR,STR,STR,STR,STR), smp_fetch_acl_parse, SMP_T_BOOL, SMP_USE_CONST },
{ /* END */ },
}};
INITCALL1(STG_REGISTER, sample_register_fetches, &smp_kws);
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/
Reference in New Issue View Git Blame Copy Permalink