[Audit-test-developer] [PATCH 2/9] utils: add screl-parser.py, syscall relevancy parser

[Jiri J. <jja...@re...>]

Signed-off-by: Jiri Jaburek <jja...@re...>
---
 audit-test/utils/screl-parser.py | 153 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 153 insertions(+)
 create mode 100755 audit-test/utils/screl-parser.py

diff --git a/audit-test/utils/screl-parser.py b/audit-test/utils/screl-parser.py
new file mode 100755
index 0000000..b3d554e
--- /dev/null
+++ b/audit-test/utils/screl-parser.py
@@ -0,0 +1,153 @@
+#!/usr/bin/python
+###############################################################################
+#   Copyright (c) 2014 Red Hat, Inc. All rights reserved.
+#
+#   This copyrighted material is made available to anyone wishing
+#   to use, modify, copy, or redistribute it subject to the terms
+#   and conditions of the GNU General Public License version 2.
+#
+#   This program is distributed in the hope that it will be
+#   useful, but WITHOUT ANY WARRANTY; without even the implied
+#   warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+#   PURPOSE. See the GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public
+#   License along with this program; if not, write to the Free
+#   Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+#   Boston, MA 02110-1301, USA.
+###############################################################################
+#
+# AUTHOR: Jiri Jaburek <jja...@re...>
+#
+# This is a parser for the 'syscall relevancy' file, which specifies relevant
+# (existing) syscalls on various architectures. Based on such info, this parser
+# prints out (to stdout) a list of syscall names that are relevant to the
+# current architecture.
+#
+# For more, see docs/syscall-relevancy.txt.
+#
+
+import sys
+from fnmatch import fnmatch
+
+#
+# helpers functions
+#
+
+# fatal error
+def syntaxerr(msg):
+    print >> sys.stderr, "syntax error on line %d:" % linenr, msg
+    sys.exit(2)
+
+# strip whitespaces, cut off comments
+def sanitize_line(line):
+    return line.strip().split('#')[0]
+
+#
+# parsing (recursive) functions
+#
+
+def parse_archspec(tok):
+    tok = tok.split(':', 2)
+    if len(tok) > 2:
+        syntaxerr("unexpected extra %s" % '`:\'')
+
+    arch = bits = None
+    if len(tok) == 2:
+        (arch, bits) = tok
+    else:
+        (arch,) = tok
+
+    # matching
+    if fnmatch(in_arch, arch) or arch == 'all':
+        if bits:
+            return (bits == in_mode)
+        else:
+            return True
+    else:
+        return False
+
+def parse_neg(tok):
+    if tok and tok[0] == '!':
+        return (tok[1:], True)
+    return (tok, False)
+
+def parse_archlist(toklist, aliases):
+    for tok in toklist.split(','):
+        # negation
+        (tok, neg) = parse_neg(tok)
+
+        if not tok:
+            syntaxerr("empty archspec")
+
+        # if archspec is alias, recurse into it, if it matches, stop
+        if aliases.has_key(tok):
+            (match, verdict) = parse_archlist(aliases[tok], aliases)
+            if match:
+                return (match, (verdict ^ neg))
+            continue
+
+        # if archspec matches current arch, stop
+        if parse_archspec(tok):
+            return (True, not neg)
+
+    return (False, False)
+
+def parse_line_syscall(line, aliases):
+    # line with only syscall - not relevant anywhere, skip
+    if len(line) == 1:
+        return
+    if len(line) > 2:
+        syntaxerr("syscall definition has >2 columns")
+
+    (syscall, archlist) = line
+
+    # if the syscall matched the archlist *and* is relevant
+    # (not matched -> exclude, matched negative archspec -> exclude)
+    (matched, verdict) = parse_archlist(archlist, aliases)
+    if matched and verdict == True:    
+        print syscall
+
+def parse_line_alias(line):
+    # line with only word ('alias')
+    if len(line) == 1:
+        syntaxerr("missing alias name")
+    if len(line) > 3:
+        syntaxerr("alias definition >3 columns")
+
+    (name, archlist) = line[1:]
+    return dict(((name, archlist),))
+
+def parse_line(line):
+    if not hasattr(parse_line, "aliases"):
+        parse_line.aliases = {}
+
+    line = sanitize_line(line)
+    # line without any useful content
+    if not line:
+        return
+
+    # len(line) > 0 due to ^^^
+    line = line.split(None, 3)
+
+    if line[0] == 'alias':
+        alias = parse_line_alias(line)
+        parse_line.aliases.update(alias)
+    else:
+        parse_line_syscall(line, parse_line.aliases)
+
+#
+# main
+#
+
+if len(sys.argv) < 4:
+    print >> sys.stderr, "usage: %s <filename> <arch> <mode>" % sys.argv[0]
+    sys.exit(2)
+
+(in_file, in_arch, in_mode) = sys.argv[1:]
+linenr = 0
+
+with open(in_file, 'r') as f:
+    for line in f:
+        linenr += 1
+        parse_line(line)
-- 
1.8.3.1