--- /dev/null
+/*************************************************
+* Perl-Compatible Regular Expressions *
+*************************************************/
+
+/* PCRE is a library of functions to support regular expressions whose syntax
+and semantics are as close as possible to those of the Perl 5 language.
+
+ Written by Philip Hazel
+ Original API code Copyright (c) 1997-2012 University of Cambridge
+ New API code Copyright (c) 2016-2018 University of Cambridge
+
+-----------------------------------------------------------------------------
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice,
+ this list of conditions and the following disclaimer.
+
+ * Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+
+ * Neither the name of the University of Cambridge nor the names of its
+ contributors may be used to endorse or promote products derived from
+ this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+-----------------------------------------------------------------------------
+*/
+
+
+/* This module contains a single function that scans through a compiled pattern
+until it finds a capturing bracket with the given number, or, if the number is
+negative, an instance of OP_REVERSE for a lookbehind. The function is called
+from pcre2_compile.c and also from pcre2_study.c when finding the minimum
+matching length. */
+
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "pcre2_internal.h"
+
+
+/*************************************************
+* Scan compiled regex for specific bracket *
+*************************************************/
+
+/*
+Arguments:
+ code points to start of expression
+ utf TRUE in UTF mode
+ number the required bracket number or negative to find a lookbehind
+
+Returns: pointer to the opcode for the bracket, or NULL if not found
+*/
+
+PCRE2_SPTR
+PRIV(find_bracket)(PCRE2_SPTR code, BOOL utf, int number)
+{
+for (;;)
+ {
+ PCRE2_UCHAR c = *code;
+
+ if (c == OP_END) return NULL;
+
+ /* XCLASS is used for classes that cannot be represented just by a bit map.
+ This includes negated single high-valued characters. CALLOUT_STR is used for
+ callouts with string arguments. In both cases the length in the table is
+ zero; the actual length is stored in the compiled code. */
+
+ if (c == OP_XCLASS) code += GET(code, 1);
+ else if (c == OP_CALLOUT_STR) code += GET(code, 1 + 2*LINK_SIZE);
+
+ /* Handle lookbehind */
+
+ else if (c == OP_REVERSE)
+ {
+ if (number < 0) return (PCRE2_UCHAR *)code;
+ code += PRIV(OP_lengths)[c];
+ }
+
+ /* Handle capturing bracket */
+
+ else if (c == OP_CBRA || c == OP_SCBRA ||
+ c == OP_CBRAPOS || c == OP_SCBRAPOS)
+ {
+ int n = (int)GET2(code, 1+LINK_SIZE);
+ if (n == number) return (PCRE2_UCHAR *)code;
+ code += PRIV(OP_lengths)[c];
+ }
+
+ /* Otherwise, we can get the item's length from the table, except that for
+ repeated character types, we have to test for \p and \P, which have an extra
+ two bytes of parameters, and for MARK/PRUNE/SKIP/THEN with an argument, we
+ must add in its length. */
+
+ else
+ {
+ switch(c)
+ {
+ case OP_TYPESTAR:
+ case OP_TYPEMINSTAR:
+ case OP_TYPEPLUS:
+ case OP_TYPEMINPLUS:
+ case OP_TYPEQUERY:
+ case OP_TYPEMINQUERY:
+ case OP_TYPEPOSSTAR:
+ case OP_TYPEPOSPLUS:
+ case OP_TYPEPOSQUERY:
+ if (code[1] == OP_PROP || code[1] == OP_NOTPROP) code += 2;
+ break;
+
+ case OP_TYPEUPTO:
+ case OP_TYPEMINUPTO:
+ case OP_TYPEEXACT:
+ case OP_TYPEPOSUPTO:
+ if (code[1 + IMM2_SIZE] == OP_PROP || code[1 + IMM2_SIZE] == OP_NOTPROP)
+ code += 2;
+ break;
+
+ case OP_MARK:
+ case OP_COMMIT_ARG:
+ case OP_PRUNE_ARG:
+ case OP_SKIP_ARG:
+ case OP_THEN_ARG:
+ code += code[1];
+ break;
+ }
+
+ /* Add in the fixed length from the table */
+
+ code += PRIV(OP_lengths)[c];
+
+ /* In UTF-8 and UTF-16 modes, opcodes that are followed by a character may be
+ followed by a multi-byte character. The length in the table is a minimum, so
+ we have to arrange to skip the extra bytes. */
+
+#ifdef MAYBE_UTF_MULTI
+ if (utf) switch(c)
+ {
+ case OP_CHAR:
+ case OP_CHARI:
+ case OP_NOT:
+ case OP_NOTI:
+ case OP_EXACT:
+ case OP_EXACTI:
+ case OP_NOTEXACT:
+ case OP_NOTEXACTI:
+ case OP_UPTO:
+ case OP_UPTOI:
+ case OP_NOTUPTO:
+ case OP_NOTUPTOI:
+ case OP_MINUPTO:
+ case OP_MINUPTOI:
+ case OP_NOTMINUPTO:
+ case OP_NOTMINUPTOI:
+ case OP_POSUPTO:
+ case OP_POSUPTOI:
+ case OP_NOTPOSUPTO:
+ case OP_NOTPOSUPTOI:
+ case OP_STAR:
+ case OP_STARI:
+ case OP_NOTSTAR:
+ case OP_NOTSTARI:
+ case OP_MINSTAR:
+ case OP_MINSTARI:
+ case OP_NOTMINSTAR:
+ case OP_NOTMINSTARI:
+ case OP_POSSTAR:
+ case OP_POSSTARI:
+ case OP_NOTPOSSTAR:
+ case OP_NOTPOSSTARI:
+ case OP_PLUS:
+ case OP_PLUSI:
+ case OP_NOTPLUS:
+ case OP_NOTPLUSI:
+ case OP_MINPLUS:
+ case OP_MINPLUSI:
+ case OP_NOTMINPLUS:
+ case OP_NOTMINPLUSI:
+ case OP_POSPLUS:
+ case OP_POSPLUSI:
+ case OP_NOTPOSPLUS:
+ case OP_NOTPOSPLUSI:
+ case OP_QUERY:
+ case OP_QUERYI:
+ case OP_NOTQUERY:
+ case OP_NOTQUERYI:
+ case OP_MINQUERY:
+ case OP_MINQUERYI:
+ case OP_NOTMINQUERY:
+ case OP_NOTMINQUERYI:
+ case OP_POSQUERY:
+ case OP_POSQUERYI:
+ case OP_NOTPOSQUERY:
+ case OP_NOTPOSQUERYI:
+ if (HAS_EXTRALEN(code[-1])) code += GET_EXTRALEN(code[-1]);
+ break;
+ }
+#else
+ (void)(utf); /* Keep compiler happy by referencing function argument */
+#endif /* MAYBE_UTF_MULTI */
+ }
+ }
+}
+
+/* End of pcre2_find_bracket.c */
projects / ossec-hids.git / blobdiff