src/acl.c

/*
 * 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 <common/config.h>
#include <common/mini-clist.h>
#include <common/standard.h>
#include <common/uri_auth.h>

#include <types/global.h>

#include <proto/acl.h>
#include <proto/arg.h>
#include <proto/auth.h>
#include <proto/channel.h>
#include <proto/log.h>
#include <proto/proxy.h>
#include <proto/sample.h>
#include <proto/stick_table.h>

#include <ebsttree.h>

/* List head of all known ACL keywords */
static struct acl_kw_list acl_keywords = {
	.list = LIST_HEAD_INIT(acl_keywords.list)
};

static char *acl_match_names[ACL_MATCH_NUM] = {
	[ACL_MATCH_FOUND] = "found",
	[ACL_MATCH_BOOL]  = "bool",
	[ACL_MATCH_INT]   = "int",
	[ACL_MATCH_IP]    = "ip",
	[ACL_MATCH_BIN]   = "bin",
	[ACL_MATCH_LEN]   = "len",
	[ACL_MATCH_STR]   = "str",
	[ACL_MATCH_BEG]   = "beg",
	[ACL_MATCH_SUB]   = "sub",
	[ACL_MATCH_DIR]   = "dir",
	[ACL_MATCH_DOM]   = "dom",
	[ACL_MATCH_END]   = "end",
	[ACL_MATCH_REG]   = "reg",
};

static int (*acl_parse_fcts[ACL_MATCH_NUM])(const char **, struct acl_pattern *, int *, char **) = {
	[ACL_MATCH_FOUND] = acl_parse_nothing,
	[ACL_MATCH_BOOL]  = acl_parse_nothing,
	[ACL_MATCH_INT]   = acl_parse_int,
	[ACL_MATCH_IP]    = acl_parse_ip,
	[ACL_MATCH_BIN]   = acl_parse_bin,
	[ACL_MATCH_LEN]   = acl_parse_int,
	[ACL_MATCH_STR]   = acl_parse_str,
	[ACL_MATCH_BEG]   = acl_parse_str,
	[ACL_MATCH_SUB]   = acl_parse_str,
	[ACL_MATCH_DIR]   = acl_parse_str,
	[ACL_MATCH_DOM]   = acl_parse_str,
	[ACL_MATCH_END]   = acl_parse_str,
	[ACL_MATCH_REG]   = acl_parse_reg,
};

static int (*acl_match_fcts[ACL_MATCH_NUM])(struct sample *, struct acl_pattern *) = {
	[ACL_MATCH_FOUND] = NULL,
	[ACL_MATCH_BOOL]  = acl_match_nothing,
	[ACL_MATCH_INT]   = acl_match_int,
	[ACL_MATCH_IP]    = acl_match_ip,
	[ACL_MATCH_BIN]   = acl_match_bin,
	[ACL_MATCH_LEN]   = acl_match_len,
	[ACL_MATCH_STR]   = acl_match_str,
	[ACL_MATCH_BEG]   = acl_match_beg,
	[ACL_MATCH_SUB]   = acl_match_sub,
	[ACL_MATCH_DIR]   = acl_match_dir,
	[ACL_MATCH_DOM]   = acl_match_dom,
	[ACL_MATCH_END]   = acl_match_end,
	[ACL_MATCH_REG]   = acl_match_reg,
};

/* return the ACL_MATCH_* index for match name "name", or < 0 if not found */
static int acl_find_match_name(const char *name)
{
	int i;

	for (i = 0; i < ACL_MATCH_NUM; i++)
		if (strcmp(name, acl_match_names[i]) == 0)
			return i;
	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, char **err)
{
	return 1;
}

/* always return false */
int acl_match_nothing(struct sample *smp, 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 sample *smp, struct acl_pattern *pattern)
{
	int icase;

	if (pattern->len != smp->data.str.len)
		return ACL_PAT_FAIL;

	icase = pattern->flags & ACL_PAT_F_IGNORE_CASE;
	if ((icase && strncasecmp(pattern->ptr.str, smp->data.str.str, smp->data.str.len) == 0) ||
	    (!icase && strncmp(pattern->ptr.str, smp->data.str.str, smp->data.str.len) == 0))
		return ACL_PAT_PASS;
	return ACL_PAT_FAIL;
}

/* NB: For two binaries buf to be identical, it is required that their lengths match */
int acl_match_bin(struct sample *smp, struct acl_pattern *pattern)
{
	if (pattern->len != smp->data.str.len)
		return ACL_PAT_FAIL;

	if (memcmp(pattern->ptr.str, smp->data.str.str, smp->data.str.len) == 0)
		return ACL_PAT_PASS;
	return ACL_PAT_FAIL;
}

/* Lookup a string in the expression's pattern tree. The node is returned if it
 * exists, otherwise NULL.
 */
static void *acl_lookup_str(struct sample *smp, struct acl_expr *expr)
{
	/* data are stored in a tree */
	struct ebmb_node *node;
	char prev;

	/* we may have to force a trailing zero on the test pattern */
	prev = smp->data.str.str[smp->data.str.len];
	if (prev)
		smp->data.str.str[smp->data.str.len] = '\0';
	node = ebst_lookup(&expr->pattern_tree, smp->data.str.str);
	if (prev)
		smp->data.str.str[smp->data.str.len] = prev;
	return node;
}

/* Executes a regex. It temporarily changes the data to add a trailing zero,
 * and restores the previous character when leaving.
 */
int acl_match_reg(struct sample *smp, struct acl_pattern *pattern)
{
	char old_char;
	int ret;

	old_char = smp->data.str.str[smp->data.str.len];
	smp->data.str.str[smp->data.str.len] = 0;

	if (regex_exec(pattern->ptr.reg, smp->data.str.str, smp->data.str.len) == 0)
		ret = ACL_PAT_PASS;
	else
		ret = ACL_PAT_FAIL;

	smp->data.str.str[smp->data.str.len] = old_char;
	return ret;
}

/* Checks that the pattern matches the beginning of the tested string. */
int acl_match_beg(struct sample *smp, struct acl_pattern *pattern)
{
	int icase;

	if (pattern->len > smp->data.str.len)
		return ACL_PAT_FAIL;

	icase = pattern->flags & ACL_PAT_F_IGNORE_CASE;
	if ((icase && strncasecmp(pattern->ptr.str, smp->data.str.str, pattern->len) != 0) ||
	    (!icase && strncmp(pattern->ptr.str, smp->data.str.str, 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 sample *smp, struct acl_pattern *pattern)
{
	int icase;

	if (pattern->len > smp->data.str.len)
		return ACL_PAT_FAIL;
	icase = pattern->flags & ACL_PAT_F_IGNORE_CASE;
	if ((icase && strncasecmp(pattern->ptr.str, smp->data.str.str + smp->data.str.len - pattern->len, pattern->len) != 0) ||
	    (!icase && strncmp(pattern->ptr.str, smp->data.str.str + smp->data.str.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 sample *smp, struct acl_pattern *pattern)
{
	int icase;
	char *end;
	char *c;

	if (pattern->len > smp->data.str.len)
		return ACL_PAT_FAIL;

	end = smp->data.str.str + smp->data.str.len - pattern->len;
	icase = pattern->flags & ACL_PAT_F_IGNORE_CASE;
	if (icase) {
		for (c = smp->data.str.str; 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 = smp->data.str.str; 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;
}

/* Background: Fast way to find a zero byte in a word
 * http://graphics.stanford.edu/~seander/bithacks.html#ZeroInWord
 * hasZeroByte = (v - 0x01010101UL) & ~v & 0x80808080UL;
 *
 * To look for 4 different byte values, xor the word with those bytes and
 * then check for zero bytes:
 *
 * v = (((unsigned char)c * 0x1010101U) ^ delimiter)
 * where <delimiter> is the 4 byte values to look for (as an uint)
 * and <c> is the character that is being tested
 */
static inline unsigned int is_delimiter(unsigned char c, unsigned int mask)
{
	mask ^= (c * 0x01010101); /* propagate the char to all 4 bytes */
	return (mask - 0x01010101) & ~mask & 0x80808080U;
}

static inline unsigned int make_4delim(unsigned char d1, unsigned char d2, unsigned char d3, unsigned char d4)
{
	return d1 << 24 | d2 << 16 | d3 << 8 | d4;
}

/* This one is used by other real functions. It checks that the pattern is
 * included inside the tested string, but enclosed between the specified
 * delimiters or at the beginning or end of the string. The delimiters are
 * provided as an unsigned int made by make_4delim() and match up to 4 different
 * delimiters. Delimiters are stripped at the beginning and end of the pattern.
 */
static int match_word(struct sample *smp, struct acl_pattern *pattern, unsigned int delimiters)
{
	int may_match, icase;
	char *c, *end;
	char *ps;
	int pl;

	pl = pattern->len;
	ps = pattern->ptr.str;

	while (pl > 0 && is_delimiter(*ps, delimiters)) {
		pl--;
		ps++;
	}

	while (pl > 0 && is_delimiter(ps[pl - 1], delimiters))
		pl--;

	if (pl > smp->data.str.len)
		return ACL_PAT_FAIL;

	may_match = 1;
	icase = pattern->flags & ACL_PAT_F_IGNORE_CASE;
	end = smp->data.str.str + smp->data.str.len - pl;
	for (c = smp->data.str.str; c <= end; c++) {
		if (is_delimiter(*c, delimiters)) {
			may_match = 1;
			continue;
		}

		if (!may_match)
			continue;

		if (icase) {
			if ((tolower(*c) == tolower(*ps)) &&
			    (strncasecmp(ps, c, pl) == 0) &&
			    (c == end || is_delimiter(c[pl], delimiters)))
				return ACL_PAT_PASS;
		} else {
			if ((*c == *ps) &&
			    (strncmp(ps, c, pl) == 0) &&
			    (c == end || is_delimiter(c[pl], delimiters)))
				return ACL_PAT_PASS;
		}
		may_match = 0;
	}
	return ACL_PAT_FAIL;
}

/* Checks that the pattern is included inside the tested string, but enclosed
 * between the delimiters '?' or '/' or at the beginning or end of the string.
 * Delimiters at the beginning or end of the pattern are ignored.
 */
int acl_match_dir(struct sample *smp, struct acl_pattern *pattern)
{
	return match_word(smp, pattern, make_4delim('/', '?', '?', '?'));
}

/* Checks that the pattern is included inside the tested string, but enclosed
 * between the delmiters '/', '?', '.' or ":" or at the beginning or end of
 * the string. Delimiters at the beginning or end of the pattern are ignored.
 */
int acl_match_dom(struct sample *smp, struct acl_pattern *pattern)
{
	return match_word(smp, pattern, make_4delim('/', '?', '.', ':'));
}

/* Checks that the integer in <test> is included between min and max */
int acl_match_int(struct sample *smp, struct acl_pattern *pattern)
{
	if ((!pattern->val.range.min_set || pattern->val.range.min <= smp->data.uint) &&
	    (!pattern->val.range.max_set || smp->data.uint <= pattern->val.range.max))
		return ACL_PAT_PASS;
	return ACL_PAT_FAIL;
}

/* Checks that the length of the pattern in <test> is included between min and max */
int acl_match_len(struct sample *smp, struct acl_pattern *pattern)
{
	if ((!pattern->val.range.min_set || pattern->val.range.min <= smp->data.str.len) &&
	    (!pattern->val.range.max_set || smp->data.str.len <= pattern->val.range.max))
		return ACL_PAT_PASS;
	return ACL_PAT_FAIL;
}

int acl_match_ip(struct sample *smp, struct acl_pattern *pattern)
{
	unsigned int v4; /* in network byte order */
	struct in6_addr *v6;
	int bits, pos;
	struct in6_addr tmp6;

	if (pattern->type == SMP_T_IPV4) {
		if (smp->type == SMP_T_IPV4) {
			v4 = smp->data.ipv4.s_addr;
		}
		else if (smp->type == SMP_T_IPV6) {
			/* v4 match on a V6 sample. We want to check at least for
			 * the following forms :
			 *   - ::ffff:ip:v4 (ipv4 mapped)
			 *   - ::0000:ip:v4 (old ipv4 mapped)
			 *   - 2002:ip:v4:: (6to4)
			 */
			if (*(uint32_t*)&smp->data.ipv6.s6_addr[0] == 0 &&
			    *(uint32_t*)&smp->data.ipv6.s6_addr[4]  == 0 &&
			    (*(uint32_t*)&smp->data.ipv6.s6_addr[8] == 0 ||
			     *(uint32_t*)&smp->data.ipv6.s6_addr[8] == htonl(0xFFFF))) {
				v4 = *(uint32_t*)&smp->data.ipv6.s6_addr[12];
			}
			else if (*(uint16_t*)&smp->data.ipv6.s6_addr[0] == htons(0x2002)) {
				v4 = htonl((ntohs(*(uint16_t*)&smp->data.ipv6.s6_addr[2]) << 16) +
				            ntohs(*(uint16_t*)&smp->data.ipv6.s6_addr[4]));
			}
			else
				return ACL_PAT_FAIL;
		}
		else
			return ACL_PAT_FAIL;

		if (((v4 ^ pattern->val.ipv4.addr.s_addr) & pattern->val.ipv4.mask.s_addr) == 0)
			return ACL_PAT_PASS;
		else
			return ACL_PAT_FAIL;
	}
	else if (pattern->type == SMP_T_IPV6) {
		if (smp->type == SMP_T_IPV4) {
			/* Convert the IPv4 sample address to IPv4 with the
			 * mapping method using the ::ffff: prefix.
			 */
			memset(&tmp6, 0, 10);
			*(uint16_t*)&tmp6.s6_addr[10] = htons(0xffff);
			*(uint32_t*)&tmp6.s6_addr[12] = smp->data.ipv4.s_addr;
			v6 = &tmp6;
		}
		else if (smp->type == SMP_T_IPV6) {
			v6 = &smp->data.ipv6;
		}
		else {
			return ACL_PAT_FAIL;
		}

		bits = pattern->val.ipv6.mask;
		for (pos = 0; bits > 0; pos += 4, bits -= 32) {
			v4 = *(uint32_t*)&v6->s6_addr[pos] ^ *(uint32_t*)&pattern->val.ipv6.addr.s6_addr[pos];
			if (bits < 32)
				v4 &= htonl((~0U) << (32-bits));
			if (v4)
				return ACL_PAT_FAIL;
		}
		return ACL_PAT_PASS;
	}
	return ACL_PAT_FAIL;
}

/* Lookup an IPv4 address in the expression's pattern tree using the longest
 * match method. The node is returned if it exists, otherwise NULL.
 */
static void *acl_lookup_ip(struct sample *smp, struct acl_expr *expr)
{
	struct in_addr *s;

	if (smp->type != SMP_T_IPV4)
		return ACL_PAT_FAIL;

	s = &smp->data.ipv4;
	return ebmb_lookup_longest(&expr->pattern_tree, &s->s_addr);
}

/* Parse a string. It is allocated and duplicated. */
int acl_parse_str(const char **text, struct acl_pattern *pattern, int *opaque, char **err)
{
	int len;

	len  = strlen(*text);
	pattern->type = SMP_T_CSTR;

	if (pattern->flags & ACL_PAT_F_TREE_OK) {
		/* we're allowed to put the data in a tree whose root is pointed
		 * to by val.tree.
		 */
		struct ebmb_node *node;

		node = calloc(1, sizeof(*node) + len + 1);
		if (!node) {
			memprintf(err, "out of memory while loading string pattern");
			return 0;
		}
		memcpy(node->key, *text, len + 1);
		if (ebst_insert(pattern->val.tree, node) != node)
			free(node); /* was a duplicate */
		pattern->flags |= ACL_PAT_F_TREE; /* this pattern now contains a tree */
		return 1;
	}

	pattern->ptr.str = strdup(*text);
	if (!pattern->ptr.str) {
		memprintf(err, "out of memory while loading string pattern");
		return 0;
	}
	pattern->len = len;
	return 1;
}

/* Parse a binary written in hexa. It is allocated. */
int acl_parse_bin(const char **text, struct acl_pattern *pattern, int *opaque, char **err)
{
	int len;
	const char *p = *text;
	int i,j;

	len  = strlen(p);
	if (len%2) {
		memprintf(err, "an even number of hex digit is expected");
		return 0;
	}

	pattern->type = SMP_T_CBIN;
	pattern->len = len >> 1;
	pattern->ptr.str = malloc(pattern->len);
	if (!pattern->ptr.str) {
		memprintf(err, "out of memory while loading string pattern");
		return 0;
	}

	i = j = 0;
	while (j < pattern->len) {
		if (!ishex(p[i++]))
			goto bad_input;
		if (!ishex(p[i++]))
			goto bad_input;
		pattern->ptr.str[j++] =  (hex2i(p[i-2]) << 4) + hex2i(p[i-1]);
	}
	return 1;

bad_input:
	memprintf(err, "an hex digit is expected (found '%c')", p[i-1]);
	free(pattern->ptr.str);
	return 0;
}

/* Parse and concatenate all further strings into one. */
int
acl_parse_strcat(const char **text, struct acl_pattern *pattern, int *opaque, char **err)
{

	int len = 0, i;
	char *s;

	for (i = 0; *text[i]; i++)
		len += strlen(text[i])+1;

	pattern->type = SMP_T_CSTR;
	pattern->ptr.str = s = calloc(1, len);
	if (!pattern->ptr.str) {
		memprintf(err, "out of memory while loading pattern");
		return 0;
	}

	for (i = 0; *text[i]; i++)
		s += sprintf(s, i?" %s":"%s", text[i]);

	pattern->len = len;

	return i;
}

/* Free data allocated by acl_parse_reg */
static void acl_free_reg(void *ptr)
{
	regex_free(ptr);
}

/* Parse a regex. It is allocated. */
int acl_parse_reg(const char **text, struct acl_pattern *pattern, int *opaque, char **err)
{
	regex *preg;
	int icase;

	preg = calloc(1, sizeof(*preg));

	if (!preg) {
		memprintf(err, "out of memory while loading pattern");
		return 0;
	}

#ifdef USE_PCRE_JIT
	icase = (pattern->flags & ACL_PAT_F_IGNORE_CASE) ? PCRE_CASELESS : 0;
	preg->reg = pcre_compile(*text, PCRE_NO_AUTO_CAPTURE | icase, NULL, NULL,
		NULL);
	if (!preg->reg) {
		free(preg);
		memprintf(err, "regex '%s' is invalid", *text);
		return 0;
	}

	preg->extra = pcre_study(preg->reg, PCRE_STUDY_JIT_COMPILE, NULL);
	if (!preg->extra) {
		pcre_free(preg->reg);
		free(preg);
		memprintf(err, "failed to compile regex '%s'", *text);
		return 0;
	}
#else
	icase = (pattern->flags & ACL_PAT_F_IGNORE_CASE) ? REG_ICASE : 0;
	if (regcomp(preg, *text, REG_EXTENDED | REG_NOSUB | icase) != 0) {
		free(preg);
		memprintf(err, "regex '%s' is invalid", *text);
		return 0;
	}
#endif

	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.
 *
 * If err is non-NULL, an error message will be returned there on errors and
 * the caller will have to free it.
 *
 */
int acl_parse_int(const char **text, struct acl_pattern *pattern, int *opaque, char **err)
{
	signed long long i;
	unsigned int j, last, skip = 0;
	const char *ptr = *text;

	pattern->type = SMP_T_UINT;
	while (!isdigit((unsigned char)*ptr)) {
		switch (get_std_op(ptr)) {
		case STD_OP_EQ: *opaque = 0; break;
		case STD_OP_GT: *opaque = 1; break;
		case STD_OP_GE: *opaque = 2; break;
		case STD_OP_LT: *opaque = 3; break;
		case STD_OP_LE: *opaque = 4; break;
		default:
			memprintf(err, "'%s' is neither a number nor a supported operator", ptr);
			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 */
		memprintf(err, "integer range '%s' specified with a comparison operator", text[skip]);
		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, char **err)
{
	signed long long i;
	unsigned int j, last, skip = 0;
	const char *ptr = *text;


	while (!isdigit((unsigned char)*ptr)) {
		switch (get_std_op(ptr)) {
		case STD_OP_EQ: *opaque = 0; break;
		case STD_OP_GT: *opaque = 1; break;
		case STD_OP_GE: *opaque = 2; break;
		case STD_OP_LT: *opaque = 3; break;
		case STD_OP_LE: *opaque = 4; break;
		default:
			memprintf(err, "'%s' is neither a number nor a supported operator", ptr);
			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 */
		memprintf(err, "version range '%s' specified with a comparison operator", text[skip]);
		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. NOTE: IP address patterns are typed (IPV4/IPV6).
 */
int acl_parse_ip(const char **text, struct acl_pattern *pattern, int *opaque, char **err)
{
	struct eb_root *tree = NULL;
	if (pattern->flags & ACL_PAT_F_TREE_OK)
		tree = pattern->val.tree;

	if (str2net(*text, &pattern->val.ipv4.addr, &pattern->val.ipv4.mask)) {
		unsigned int mask = ntohl(pattern->val.ipv4.mask.s_addr);
		struct ebmb_node *node;
		/* check if the mask is contiguous so that we can insert the
		 * network into the tree. A continuous mask has only ones on
		 * the left. This means that this mask + its lower bit added
		 * once again is null.
		 */
		pattern->type = SMP_T_IPV4;
		if (mask + (mask & -mask) == 0 && tree) {
			mask = mask ? 33 - flsnz(mask & -mask) : 0; /* equals cidr value */
			/* FIXME: insert <addr>/<mask> into the tree here */
			node = calloc(1, sizeof(*node) + 4); /* reserve 4 bytes for IPv4 address */
			if (!node) {
				memprintf(err, "out of memory while loading IPv4 pattern");
				return 0;
			}
			memcpy(node->key, &pattern->val.ipv4.addr, 4); /* network byte order */
			node->node.pfx = mask;
			if (ebmb_insert_prefix(tree, node, 4) != node)
				free(node); /* was a duplicate */
			pattern->flags |= ACL_PAT_F_TREE;
			return 1;
		}
		return 1;
	}
	else if (str62net(*text, &pattern->val.ipv6.addr, &pattern->val.ipv6.mask)) {
		/* no tree support right now */
		pattern->type = SMP_T_IPV6;
		return 1;
	}
	else {
		memprintf(err, "'%s' is not a valid IPv4 or IPv6 address", *text);
		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;
}

/* NB: does nothing if <pat> is NULL */
static void free_pattern(struct acl_pattern *pat)
{
	if (!pat)
		return;

	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 void free_pattern_tree(struct eb_root *root)
{
	struct eb_node *node, *next;
	node = eb_first(root);
	while (node) {
		next = eb_next(node);
		free(node);
		node = next;
	}
}

static struct acl_expr *prune_acl_expr(struct acl_expr *expr)
{
	struct arg *arg;

	free_pattern_list(&expr->patterns);
	free_pattern_tree(&expr->pattern_tree);
	LIST_INIT(&expr->patterns);

	for (arg = expr->args; arg; arg++) {
		if (arg->type == ARGT_STOP)
			break;
		if (arg->type == ARGT_STR || arg->unresolved) {
			free(arg->data.str.str);
			arg->data.str.str = NULL;
			arg->unresolved = 0;
		}
	}

	if (expr->args != empty_arg_list)
		free(expr->args);
	return expr;
}


/* Reads patterns from a file. If <err_msg> is non-NULL, an error message will
 * be returned there on errors and the caller will have to free it.
 */
static int acl_read_patterns_from_file(struct acl_expr *expr,
                                       const char *filename, int patflags,
                                       char **err)
{
	FILE *file;
	char *c;
	const char *args[2];
	struct acl_pattern *pattern;
	int opaque;
	int ret = 0;
	int line = 0;

	file = fopen(filename, "r");
	if (!file) {
		memprintf(err, "failed to open pattern file <%s>", filename);
		return 0;
	}

	/* now parse all patterns. The file may contain only one pattern per
	 * line. If the line contains spaces, they will be part of the pattern.
	 * The pattern stops at the first CR, LF or EOF encountered.
	 */
	opaque = 0;
	pattern = NULL;
	args[1] = "";
	while (fgets(trash.str, trash.size, file) != NULL) {
		line++;
		c = trash.str;

		/* ignore lines beginning with a dash */
		if (*c == '#')
			continue;

		/* strip leading spaces and tabs */
		while (*c == ' ' || *c == '\t')
			c++;


		args[0] = c;
		while (*c && *c != '\n' && *c != '\r')
			c++;
		*c = 0;

		/* empty lines are ignored too */
		if (c == args[0])
			continue;

		/* we keep the previous pattern along iterations as long as it's not used */
		if (!pattern)
			pattern = (struct acl_pattern *)malloc(sizeof(*pattern));
		if (!pattern) {
			memprintf(err, "out of memory when loading patterns from file <%s>", filename);
			goto out_close;
		}

		memset(pattern, 0, sizeof(*pattern));
		pattern->flags = patflags;

		if (!(pattern->flags & ACL_PAT_F_IGNORE_CASE) &&
		    (expr->match == acl_match_str || expr->match == acl_match_ip)) {
			/* we pre-set the data pointer to the tree's head so that functions
			 * which are able to insert in a tree know where to do that.
			 */
			pattern->flags |= ACL_PAT_F_TREE_OK;
			pattern->val.tree = &expr->pattern_tree;
		}

		pattern->type = SMP_TYPES; /* unspecified type by default */
		if (!expr->parse(args, pattern, &opaque, err))
			goto out_free_pattern;

		/* if the parser did not feed the tree, let's chain the pattern to the list */
		if (!(pattern->flags & ACL_PAT_F_TREE)) {
			LIST_ADDQ(&expr->patterns, &pattern->list);
			pattern = NULL; /* get a new one */
		}
	}

	ret = 1; /* success */

 out_free_pattern:
	free_pattern(pattern);
 out_close:
	fclose(file);
	return ret;
}

/* 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.
 *
 * Right now, the only accepted syntax is :
 * <subject> [<value>...]
 */
struct acl_expr *parse_acl_expr(const char **args, char **err)
{
	__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;
	struct sample_fetch *smp = NULL;

	/* First, we lookd for an ACL keyword. And if we don't find one, then
	 * we look for a sample fetch keyword.
	 */
	aclkw = find_acl_kw(args[0]);
	if (!aclkw || !aclkw->parse) {
		const char *kwend;

		kwend = strchr(args[0], '(');
		if (!kwend)
			kwend = args[0] + strlen(args[0]);
		smp = find_sample_fetch(args[0], kwend - args[0]);

		if (!smp) {
			memprintf(err, "unknown ACL or sample keyword '%s'", *args);
			goto out_return;
		}
	}

	expr = (struct acl_expr *)calloc(1, sizeof(*expr));
	if (!expr) {
		memprintf(err, "out of memory when parsing ACL expression");
		goto out_return;
	}

	expr->kw = aclkw ? aclkw->kw : smp->kw;
	LIST_INIT(&expr->patterns);
	expr->pattern_tree = EB_ROOT_UNIQUE;
	expr->parse = aclkw ? aclkw->parse : NULL;
	expr->match = aclkw ? aclkw->match : NULL;
	expr->args = empty_arg_list;
	expr->smp = aclkw ? aclkw->smp : smp;

	arg = strchr(args[0], '(');
	if (expr->smp->arg_mask) {
		int nbargs = 0;
		char *end;

		if (arg != NULL) {
			/* there are 0 or more arguments in the form "subject(arg[,arg]*)" */
			arg++;
			end = strchr(arg, ')');
			if (!end) {
				memprintf(err, "missing closing ')' after arguments to ACL keyword '%s'", expr->kw);
				goto out_free_expr;
			}

			/* Parse the arguments. Note that currently we have no way to
			 * report parsing errors, hence the NULL in the error pointers.
			 * An error is also reported if some mandatory arguments are
			 * missing.
			 */
			nbargs = make_arg_list(arg, end - arg, expr->smp->arg_mask, &expr->args,
					       err, NULL, NULL);
			if (nbargs < 0) {
				/* note that make_arg_list will have set <err> here */
				memprintf(err, "in argument to '%s', %s", expr->kw, *err);
				goto out_free_expr;
			}

			if (!expr->args)
				expr->args = empty_arg_list;

			if (expr->smp->val_args && !expr->smp->val_args(expr->args, err)) {
				/* invalid keyword argument, error must have been
				 * set by val_args().
				 */
				memprintf(err, "in argument to '%s', %s", expr->kw, *err);
				goto out_free_expr;
			}
		}
		else if (ARGM(expr->smp->arg_mask) == 1) {
			int type = (expr->smp->arg_mask >> 4) & 15;

			/* If a proxy is noted as a mandatory argument, we'll fake
			 * an empty one so that acl_find_targets() resolves it as
			 * the current one later.
			 */
			if (type != ARGT_FE && type != ARGT_BE && type != ARGT_TAB) {
				memprintf(err, "ACL keyword '%s' expects %d arguments", expr->kw, ARGM(expr->smp->arg_mask));
				goto out_free_expr;
			}

			/* Build an arg list containing the type as an empty string
			 * and the usual STOP.
			 */
			expr->args = calloc(2, sizeof(*expr->args));
			expr->args[0].type = type;
			expr->args[0].unresolved = 1;
			expr->args[0].data.str.str = strdup("");
			expr->args[0].data.str.len = 1;
			expr->args[0].data.str.len = 0;
			expr->args[1].type = ARGT_STOP;
		}
		else if (ARGM(expr->smp->arg_mask)) {
			/* there were some mandatory arguments */
			memprintf(err, "ACL keyword '%s' expects %d arguments", expr->kw, ARGM(expr->smp->arg_mask));
			goto out_free_expr;
		}
	}
	else {
		if (arg) {
			/* no argument expected */
			memprintf(err, "ACL keyword '%s' takes no argument", expr->kw);
			goto out_free_expr;
		}
	}

	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)
	 *   -- : 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') {
			if (!expr->parse) {
				memprintf(err, "matching method must be specified first (using '-m') when using a sample fetch ('%s')", expr->kw);
				goto out_free_expr;
			}

			if (!acl_read_patterns_from_file(expr, args[1], patflags | ACL_PAT_F_FROM_FILE, err))
				goto out_free_expr;
			args++;
		}
		else if ((*args)[1] == 'm') {
			int idx;

			if (!LIST_ISEMPTY(&expr->patterns) || !eb_is_empty(&expr->pattern_tree)) {
				memprintf(err, "'-m' must only be specified before patterns and files in parsing ACL expression");
				goto out_free_expr;
			}

			idx = acl_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 == ACL_MATCH_FOUND ||                           /* -m found */
			    ((idx == ACL_MATCH_BOOL || idx == ACL_MATCH_INT) && /* -m bool/int */
			     (expr->smp->out_type == SMP_T_BOOL ||
			      expr->smp->out_type == SMP_T_UINT ||
			      expr->smp->out_type == SMP_T_SINT)) ||
			    (idx == ACL_MATCH_IP &&                             /* -m ip */
			     (expr->smp->out_type == SMP_T_IPV4 ||
			      expr->smp->out_type == SMP_T_IPV6)) ||
			    ((idx == ACL_MATCH_BIN || idx == ACL_MATCH_LEN || idx == ACL_MATCH_STR ||
			      idx == ACL_MATCH_BEG || idx == ACL_MATCH_SUB || idx == ACL_MATCH_DIR ||
			      idx == ACL_MATCH_DOM || idx == ACL_MATCH_END || idx == ACL_MATCH_REG) &&  /* strings */
			     (expr->smp->out_type == SMP_T_STR ||
			      expr->smp->out_type == SMP_T_BIN ||
			      expr->smp->out_type == SMP_T_CSTR ||
			      expr->smp->out_type == SMP_T_CBIN))) {
				expr->parse = acl_parse_fcts[idx];
				expr->match = acl_match_fcts[idx];
			}
			else {
				memprintf(err, "matching method '%s' cannot be used with fetch keyword '%s'", args[1], expr->kw);
				goto out_free_expr;
			}
			args++;
		}
		else if ((*args)[1] == '-') {
			args++;
			break;
		}
		else
			break;
		args++;
	}

	if (!expr->parse) {
		memprintf(err, "matching method must be specified first (using '-m') when using a sample fetch ('%s')", expr->kw);
		goto out_free_expr;
	}

	/* now parse all patterns */
	opaque = 0;
	while (**args) {
		int ret;
		pattern = (struct acl_pattern *)calloc(1, sizeof(*pattern));
		if (!pattern) {
			memprintf(err, "out of memory when parsing ACL pattern");
			goto out_free_expr;
		}
		pattern->flags = patflags;

		pattern->type = SMP_TYPES; /* unspecified type */
		ret = expr->parse(args, pattern, &opaque, err);
		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. 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.
 *
 * args syntax: <aclname> <acl_expr>
 */
struct acl *parse_acl(const char **args, struct list *known_acl, char **err)
{
	__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);
	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] == '(')
		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) {
		name = strdup(args[0]);
		if (!name) {
			memprintf(err, "out of memory when parsing ACL");
			goto out_free_acl_expr;
		}
		cur_acl = (struct 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_ADDQ(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->use;
	cur_acl->val |= acl_expr->smp->val;
	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",           .expr = {"req_proto_http",""}},
	{ .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 = "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.
 */
struct acl *find_acl_default(const char *acl_name, struct list *known_acl, char **err)
{
	__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);
	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 = (struct 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->use;
	cur_acl->val |= acl_expr->smp->val;
	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". 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 *parse_acl_cond(const char **args, struct list *known_acl, int pol, char **err)
{
	__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 = (struct acl_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);
			free(args_new);

			if (!cur_acl) {
				/* note that parse_acl() must have filled <err> here */
				goto out_free_suite;
			}
			word = args[arg + 1];
			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);
				if (cur_acl == NULL) {
					/* note that find_acl_default() must have filled <err> here */
					goto out_free_suite;
				}
			}
		}

		cur_term = (struct acl_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 = (struct acl_term_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_ADDQ(&cond->suites, &cur_suite->list);
		}
		LIST_ADDQ(&cur_suite->terms, &cur_term->list);
		neg = 0;
	}

	cond->val |= suite_val;
	return cond;

 out_free_term:
	free(cur_term);
 out_free_suite:
	prune_acl_cond(cond);
	free(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 intiailization 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 proxy *px, const char **args, char **err)
{
	int pol = ACL_COND_NONE;
	struct acl_cond *cond = NULL;

	if (err)
		*err = NULL;

	if (!strcmp(*args, "if")) {
		pol = ACL_COND_IF;
		args++;
	}
	else if (!strcmp(*args, "unless")) {
		pol = ACL_COND_UNLESS;
		args++;
	}
	else {
		memprintf(err, "conditions must start with either 'if' or 'unless'");
		return NULL;
	}

	cond = parse_acl_cond(args, &px->acl, pol, err);
	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_PAT_FAIL, ACL_PAT_MISS or
 * ACL_PAT_PASS depending on the test results. ACL_PAT_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_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, unsigned int opt)
{
	__label__ fetch_next;
	struct acl_term_suite *suite;
	struct acl_term *term;
	struct acl_expr *expr;
	struct acl *acl;
	struct acl_pattern *pattern;
	struct sample smp;
	int 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_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(&smp, 0, sizeof(smp));
			fetch_next:
				if (!expr->smp->process(px, l4, l7, opt, expr->args, &smp)) {
					/* maybe we could not fetch because of missing data */
					if (smp.flags & SMP_F_MAY_CHANGE && !(opt & SMP_OPT_FINAL))
						acl_res |= ACL_PAT_MISS;
					continue;
				}

				if (smp.type == SMP_T_BOOL) {
					if (smp.data.uint)
						acl_res |= ACL_PAT_PASS;
					else
						acl_res |= ACL_PAT_FAIL;
				}
				else if (!expr->match) {
					/* just check for existence */
					acl_res |= ACL_PAT_PASS;
				}
				else {
					if (!eb_is_empty(&expr->pattern_tree)) {
						/* a tree is present, let's check what type it is */
						if (expr->match == acl_match_str)
							acl_res |= acl_lookup_str(&smp, expr) ? ACL_PAT_PASS : ACL_PAT_FAIL;
						else if (expr->match == acl_match_ip)
							acl_res |= acl_lookup_ip(&smp, expr) ? ACL_PAT_PASS : ACL_PAT_FAIL;
					}

					/* call the match() function for all tests on this value */
					list_for_each_entry(pattern, &expr->patterns, list) {
						if (acl_res == ACL_PAT_PASS)
							break;
						acl_res |= expr->match(&smp, pattern);
					}
				}
				/*
				 * 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
				 * (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_PAT_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_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;
}

/* 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->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.
 */
int
acl_find_targets(struct proxy *p)
{

	struct acl *acl;
	struct acl_expr *expr;
	struct acl_pattern *pattern;
	struct userlist *ul;
	struct arg *arg;
	int cfgerr = 0;

	list_for_each_entry(acl, &p->acl, list) {
		list_for_each_entry(expr, &acl->expr, list) {
			for (arg = expr->args; arg && arg->type != ARGT_STOP; arg++) {
				if (!arg->unresolved)
					continue;
				else if (arg->type == ARGT_SRV) {
					struct proxy *px;
					struct server *srv;
					char *pname, *sname;

					if (!arg->data.str.len) {
						Alert("proxy %s: acl '%s' %s(): missing server name.\n",
						      p->id, acl->name, expr->kw);
						cfgerr++;
						continue;
					}

					pname = arg->data.str.str;
					sname = strrchr(pname, '/');

					if (sname)
						*sname++ = '\0';
					else {
						sname = pname;
						pname = NULL;
					}

					px = p;
					if (pname) {
						px = findproxy(pname, PR_CAP_BE);
						if (!px) {
							Alert("proxy %s: acl '%s' %s(): unable to find proxy '%s'.\n",
							      p->id, acl->name, expr->kw, pname);
							cfgerr++;
							continue;
						}
					}

					srv = findserver(px, sname);
					if (!srv) {
						Alert("proxy %s: acl '%s' %s(): unable to find server '%s'.\n",
						      p->id, acl->name, expr->kw, sname);
						cfgerr++;
						continue;
					}

					free(arg->data.str.str);
					arg->data.str.str = NULL;
					arg->unresolved = 0;
					arg->data.srv = srv;
				}
				else if (arg->type == ARGT_FE) {
					struct proxy *prx = p;
					char *pname = p->id;

					if (arg->data.str.len) {
						pname = arg->data.str.str;
						prx = findproxy(pname, PR_CAP_FE);
					}

					if (!prx) {
						Alert("proxy %s: acl '%s' %s(): unable to find frontend '%s'.\n",
						      p->id, acl->name, expr->kw, pname);
						cfgerr++;
						continue;
					}

					if (!(prx->cap & PR_CAP_FE)) {
						Alert("proxy %s: acl '%s' %s(): proxy '%s' has no frontend capability.\n",
						      p->id, acl->name, expr->kw, pname);
						cfgerr++;
						continue;
					}

					free(arg->data.str.str);
					arg->data.str.str = NULL;
					arg->unresolved = 0;
					arg->data.prx = prx;
				}
				else if (arg->type == ARGT_BE) {
					struct proxy *prx = p;
					char *pname = p->id;

					if (arg->data.str.len) {
						pname = arg->data.str.str;
						prx = findproxy(pname, PR_CAP_BE);
					}

					if (!prx) {
						Alert("proxy %s: acl '%s' %s(): unable to find backend '%s'.\n",
						      p->id, acl->name, expr->kw, pname);
						cfgerr++;
						continue;
					}

					if (!(prx->cap & PR_CAP_BE)) {
						Alert("proxy %s: acl '%s' %s(): proxy '%s' has no backend capability.\n",
						      p->id, acl->name, expr->kw, pname);
						cfgerr++;
						continue;
					}

					free(arg->data.str.str);
					arg->data.str.str = NULL;
					arg->unresolved = 0;
					arg->data.prx = prx;
				}
				else if (arg->type == ARGT_TAB) {
					struct proxy *prx = p;
					char *pname = p->id;

					if (arg->data.str.len) {
						pname = arg->data.str.str;
						prx = find_stktable(pname);
					}

					if (!prx) {
						Alert("proxy %s: acl '%s' %s(): unable to find table '%s'.\n",
						      p->id, acl->name, expr->kw, pname);
						cfgerr++;
						continue;
					}


					if (!prx->table.size) {
						Alert("proxy %s: acl '%s' %s(): no table in proxy '%s'.\n",
						      p->id, acl->name, expr->kw, pname);
						cfgerr++;
						continue;
					}

					free(arg->data.str.str);
					arg->data.str.str = NULL;
					arg->unresolved = 0;
					arg->data.prx = prx;
				}
				else if (arg->type == ARGT_USR) {
					if (!arg->data.str.len) {
						Alert("proxy %s: acl '%s' %s(): missing userlist name.\n",
						      p->id, acl->name, expr->kw);
						cfgerr++;
						continue;
					}

					if (p->uri_auth && p->uri_auth->userlist &&
					    !strcmp(p->uri_auth->userlist->name, arg->data.str.str))
						ul = p->uri_auth->userlist;
					else
						ul = auth_find_userlist(arg->data.str.str);

					if (!ul) {
						Alert("proxy %s: acl '%s' %s(%s): unable to find userlist.\n",
						      p->id, acl->name, expr->kw, arg->data.str.str);
						cfgerr++;
						continue;
					}

					free(arg->data.str.str);
					arg->data.str.str = NULL;
					arg->unresolved = 0;
					arg->data.usr = ul;
				}
			} /* end of args processing */

			/* don't try to resolve groups if we're not certain of having
			 * resolved userlists first.
			 */
			if (cfgerr)
				break;

			if (!strcmp(expr->kw, "http_auth_group")) {
				/* note: argument resolved above thanks to ARGT_USR */

				if (LIST_ISEMPTY(&expr->patterns)) {
					Alert("proxy %s: acl %s %s(): no groups specified.\n",
						p->id, acl->name, expr->kw);
					cfgerr++;
					continue;
				}

				list_for_each_entry(pattern, &expr->patterns, list) {
					/* this keyword only has one argument */
					pattern->val.group_mask = auth_resolve_groups(expr->args->data.usr, pattern->ptr.str);

					free(pattern->ptr.str);
					pattern->ptr.str = NULL;
					pattern->len = 0;

					if (!pattern->val.group_mask) {
						Alert("proxy %s: acl %s %s(): invalid group(s).\n",
							p->id, acl->name, expr->kw);
						cfgerr++;
						continue;
					}
				}
			}
		}
	}

	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) {
				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;
}

/************************************************************************/
/*       All supported sample fetch functions must be declared here     */
/************************************************************************/

/* force TRUE to be returned at the fetch level */
static int
smp_fetch_true(struct proxy *px, struct session *s, void *l7, unsigned int opt,
               const struct arg *args, struct sample *smp)
{
	smp->type = SMP_T_BOOL;
	smp->data.uint = 1;
	return 1;
}

/* force FALSE to be returned at the fetch level */
static int
smp_fetch_false(struct proxy *px, struct session *s, void *l7, unsigned int opt,
                const struct arg *args, struct sample *smp)
{
	smp->type = SMP_T_BOOL;
	smp->data.uint = 0;
	return 1;
}


/************************************************************************/
/*      All supported sample and ACL keywords must be declared here.    */
/************************************************************************/

/* Note: must not be declared <const> as its list will be overwritten.
 * Note: fetches that may return multiple types must be declared as the lowest
 * common denominator, the type that can be casted into all other ones. For
 * instance IPv4/IPv6 must be declared IPv4.
 */
static struct sample_fetch_kw_list smp_kws = {{ },{
	{ "always_false", smp_fetch_false, 0, NULL, SMP_T_BOOL, SMP_USE_INTRN },
	{ "always_true",  smp_fetch_true,  0, NULL, SMP_T_BOOL, SMP_USE_INTRN },
	{ /* END */ },
}};


/* 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 = {{ },{
	{ "always_false", NULL, acl_parse_nothing, acl_match_nothing },
	{ "always_true",  NULL, acl_parse_nothing, acl_match_nothing },
	{ /* END */ },
}};


__attribute__((constructor))
static void __acl_init(void)
{
	sample_register_fetches(&smp_kws);
	acl_register_keywords(&acl_kws);
}


/*
 * Local variables:
 *  c-indent-level: 8
 *  c-basic-offset: 8
 * End:
 */