diff --git a/utilities/checkpatch.py b/utilities/checkpatch.py
new file mode 100755
index 000000000..de5061406
--- /dev/null
+++ b/utilities/checkpatch.py
@@ -0,0 +1,1006 @@
+#!/usr/bin/env python
+# Copyright (c) 2016, 2017 Red Hat, Inc.
+# Copyright (c) 2018 Nicira, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import print_function
+
+import email
+import getopt
+import os
+import re
+import sys
+
+RETURN_CHECK_INITIAL_STATE = 0
+RETURN_CHECK_STATE_WITH_RETURN = 1
+RETURN_CHECK_AWAITING_BRACE = 2
+EXIT_FAILURE = 1
+__errors = 0
+__warnings = 0
+empty_return_check_state = 0
+print_file_name = None
+checking_file = False
+total_line = 0
+colors = False
+spellcheck_comments = False
+quiet = False
+spell_check_dict = None
+
+
+def open_spell_check_dict():
+    import enchant
+
+    try:
+        extra_keywords = ['ovs', 'vswitch', 'vswitchd', 'ovs-vswitchd',
+                          'netdev', 'selinux', 'ovs-ctl', 'dpctl', 'ofctl',
+                          'openvswitch', 'dpdk', 'hugepage', 'hugepages',
+                          'pmd', 'upcall', 'vhost', 'rx', 'tx', 'vhostuser',
+                          'openflow', 'qsort', 'rxq', 'txq', 'perf', 'stats',
+                          'struct', 'int', 'char', 'bool', 'upcalls', 'nicira',
+                          'bitmask', 'ipv4', 'ipv6', 'tcp', 'tcp4', 'tcpv4',
+                          'udp', 'udp4', 'udpv4', 'icmp', 'icmp4', 'icmpv6',
+                          'vlan', 'vxlan', 'cksum', 'csum', 'checksum',
+                          'ofproto', 'numa', 'mempool', 'mempools', 'mbuf',
+                          'mbufs', 'hmap', 'cmap', 'smap', 'dhcpv4', 'dhcp',
+                          'dhcpv6', 'opts', 'metadata', 'geneve', 'mutex',
+                          'netdev', 'netdevs', 'subtable', 'virtio', 'qos',
+                          'policer', 'datapath', 'tunctl', 'attr', 'ethernet',
+                          'ether', 'defrag', 'defragment', 'loopback', 'sflow',
+                          'acl', 'initializer', 'recirc', 'xlated', 'unclosed',
+                          'netlink', 'msec', 'usec', 'nsec', 'ms', 'us', 'ns',
+                          'kilobits', 'kbps', 'kilobytes', 'megabytes', 'mbps',
+                          'gigabytes', 'gbps', 'megabits', 'gigabits', 'pkts',
+                          'tuple', 'miniflow', 'megaflow', 'conntrack',
+                          'vlans', 'vxlans', 'arg', 'tpid', 'xbundle',
+                          'xbundles', 'mbundle', 'mbundles', 'netflow',
+                          'localnet', 'odp', 'pre', 'dst', 'dest', 'src',
+                          'ethertype', 'cvlan', 'ips', 'msg', 'msgs',
+                          'liveness', 'userspace', 'eventmask', 'datapaths',
+                          'slowpath', 'fastpath', 'multicast', 'unicast',
+                          'revalidation', 'namespace', 'qdisc', 'uuid',
+                          'ofport', 'subnet', 'revalidation', 'revalidator',
+                          'revalidate', 'l2', 'l3', 'l4', 'openssl', 'mtu',
+                          'ifindex', 'enum', 'enums', 'http', 'https', 'num',
+                          'vconn', 'vconns', 'conn', 'nat', 'memset', 'memcmp',
+                          'strcmp', 'strcasecmp', 'tc', 'ufid', 'api',
+                          'ofpbuf', 'ofpbufs', 'hashmaps', 'hashmap', 'deref',
+                          'dereference', 'hw', 'prio', 'sendmmsg', 'sendmsg',
+                          'malloc', 'free', 'alloc', 'pid', 'ppid', 'pgid',
+                          'uid', 'gid', 'sid', 'utime', 'stime', 'cutime',
+                          'cstime', 'vsize', 'rss', 'rsslim', 'whcan', 'gtime',
+                          'eip', 'rip', 'cgtime', 'dbg', 'gw', 'sbrec', 'bfd',
+                          'sizeof', 'pmds', 'nic', 'nics', 'hwol', 'encap',
+                          'decap', 'tlv', 'tlvs', 'decapsulation', 'fd',
+                          'cacheline', 'xlate', 'skiplist', 'idl',
+                          'comparator', 'natting', 'alg', 'pasv', 'epasv',
+                          'wildcard', 'nated', 'amd64', 'x86_64',
+                          'recirculation']
+
+        global spell_check_dict
+        spell_check_dict = enchant.Dict("en_US")
+        for kw in extra_keywords:
+            spell_check_dict.add(kw)
+
+        return True
+    except:
+        return False
+
+
+def get_color_end():
+    global colors
+    if colors:
+        return "\033[00m"
+    return ""
+
+
+def get_red_begin():
+    global colors
+    if colors:
+        return "\033[91m"
+    return ""
+
+
+def get_yellow_begin():
+    global colors
+    if colors:
+        return "\033[93m"
+    return ""
+
+
+def print_error(message):
+    global __errors
+    print("%sERROR%s: %s" % (get_red_begin(), get_color_end(), message))
+
+    __errors = __errors + 1
+
+
+def print_warning(message):
+    global __warnings
+    print("%sWARNING%s: %s" % (get_yellow_begin(), get_color_end(), message))
+
+    __warnings = __warnings + 1
+
+
+def reset_counters():
+    global __errors, __warnings, total_line
+
+    __errors = 0
+    __warnings = 0
+    total_line = 0
+
+
+# These are keywords whose names are normally followed by a space and
+# something in parentheses (usually an expression) then a left curly brace.
+#
+# 'do' almost qualifies but it's also used as "do { ... } while (...);".
+__parenthesized_constructs = 'if|for|while|switch|[_A-Z]+FOR_*EACH[_A-Z0-9]*'
+
+__regex_added_line = re.compile(r'^\+{1,2}[^\+][\w\W]*')
+__regex_subtracted_line = re.compile(r'^\-{1,2}[^\-][\w\W]*')
+__regex_leading_with_whitespace_at_all = re.compile(r'^\s+')
+__regex_leading_with_spaces = re.compile(r'^ +[\S]+')
+__regex_trailing_whitespace = re.compile(r'[^\S]+$')
+__regex_single_line_feed = re.compile(r'^\f$')
+__regex_for_if_missing_whitespace = re.compile(r' +(%s)[\(]'
+                                               % __parenthesized_constructs)
+__regex_for_if_too_much_whitespace = re.compile(r' +(%s)  +[\(]'
+                                                % __parenthesized_constructs)
+__regex_for_if_parens_whitespace = \
+    re.compile(r' +(%s) \( +[\s\S]+\)' % __parenthesized_constructs)
+__regex_is_for_if_single_line_bracket = \
+    re.compile(r'^ +(%s) \(.*\)' % __parenthesized_constructs)
+__regex_ends_with_bracket = \
+    re.compile(r'[^\s]\) {(\s+/\*[\s\Sa-zA-Z0-9\.,\?\*/+-]*)?$')
+__regex_ptr_declaration_missing_whitespace = re.compile(r'[a-zA-Z0-9]\*[^*]')
+__regex_is_comment_line = re.compile(r'^\s*(/\*|\*\s)')
+__regex_has_comment = re.compile(r'.*(/\*|\*\s)')
+__regex_has_c99_comment = re.compile(r'.*//.*$')
+__regex_trailing_operator = re.compile(r'^[^ ]* [^ ]*[?:]$')
+__regex_conditional_else_bracing = re.compile(r'^\s*else\s*{?$')
+__regex_conditional_else_bracing2 = re.compile(r'^\s*}\selse\s*$')
+__regex_has_xxx_mark = re.compile(r'.*xxx.*', re.IGNORECASE)
+__regex_added_doc_rst = re.compile(
+                    r'\ndiff .*Documentation/.*rst\nnew file mode')
+__regex_empty_return = re.compile(r'\s*return;')
+__regex_if_macros = re.compile(r'^ +(%s) \([\S][\s\S]+[\S]\) { \\' %
+                               __parenthesized_constructs)
+
+skip_leading_whitespace_check = False
+skip_trailing_whitespace_check = False
+skip_block_whitespace_check = False
+skip_signoff_check = False
+
+# Don't enforce character limit on files that include these characters in their
+# name, as they may have legitimate reasons to have longer lines.
+#
+# Python isn't checked as flake8 performs these checks during build.
+line_length_blacklist = re.compile(
+    r'\.(am|at|etc|in|m4|mk|patch|py)$|debian/rules')
+
+# Don't enforce a requirement that leading whitespace be all spaces on
+# files that include these characters in their name, since these kinds
+# of files need lines with leading tabs.
+leading_whitespace_blacklist = re.compile(r'\.(mk|am|at)$|debian/rules')
+
+
+def is_subtracted_line(line):
+    """Returns TRUE if the line in question has been removed."""
+    return __regex_subtracted_line.search(line) is not None
+
+
+def is_added_line(line):
+    """Returns TRUE if the line in question is an added line.
+    """
+    global checking_file
+    return __regex_added_line.search(line) is not None or checking_file
+
+
+def added_line(line):
+    """Returns the line formatted properly by removing diff syntax"""
+    global checking_file
+    if not checking_file:
+        return line[1:]
+    return line
+
+
+def leading_whitespace_is_spaces(line):
+    """Returns TRUE if the leading whitespace in added lines is spaces
+    """
+    if skip_leading_whitespace_check:
+        return True
+    if (__regex_leading_with_whitespace_at_all.search(line) is not None and
+            __regex_single_line_feed.search(line) is None):
+        return __regex_leading_with_spaces.search(line) is not None
+
+    return True
+
+
+def trailing_whitespace_or_crlf(line):
+    """Returns TRUE if the trailing characters is whitespace
+    """
+    if skip_trailing_whitespace_check:
+        return False
+    return (__regex_trailing_whitespace.search(line) is not None and
+            __regex_single_line_feed.search(line) is None)
+
+
+def if_and_for_whitespace_checks(line):
+    """Return TRUE if there is appropriate whitespace after if, for, while
+    """
+    if skip_block_whitespace_check:
+        return True
+    if (__regex_for_if_missing_whitespace.search(line) is not None or
+            __regex_for_if_too_much_whitespace.search(line) is not None or
+            __regex_for_if_parens_whitespace.search(line)):
+        return False
+    return True
+
+
+def if_and_for_end_with_bracket_check(line):
+    """Return TRUE if there is not a bracket at the end of an if, for, while
+       block which fits on a single line ie: 'if (foo)'"""
+
+    def balanced_parens(line):
+        """This is a rather naive counter - it won't deal with quotes"""
+        balance = 0
+        for letter in line:
+            if letter == '(':
+                balance += 1
+            elif letter == ')':
+                balance -= 1
+        return balance == 0
+
+    if __regex_is_for_if_single_line_bracket.search(line) is not None:
+        if not balanced_parens(line):
+            return True
+
+        if __regex_ends_with_bracket.search(line) is None and \
+           __regex_if_macros.match(line) is None:
+            return False
+    if __regex_conditional_else_bracing.match(line) is not None:
+        return False
+    if __regex_conditional_else_bracing2.match(line) is not None:
+        return False
+    return True
+
+
+def pointer_whitespace_check(line):
+    """Return TRUE if there is no space between a pointer name and the
+       asterisk that denotes this is a apionter type, ie: 'struct foo*'"""
+    return __regex_ptr_declaration_missing_whitespace.search(line) is not None
+
+
+def line_length_check(line):
+    """Return TRUE if the line length is too long"""
+    if len(line) > 79:
+        print_warning("Line is %d characters long (recommended limit is 79)"
+                      % len(line))
+        return True
+    return False
+
+
+def is_comment_line(line):
+    """Returns TRUE if the current line is part of a block comment."""
+    return __regex_is_comment_line.match(line) is not None
+
+
+def has_comment(line):
+    """Returns TRUE if the current line contains a comment or is part of
+       a block comment."""
+    return __regex_has_comment.match(line) is not None
+
+
+def has_c99_comment(line):
+    """Returns TRUE if the current line contains C99 style comment (//)."""
+    return __regex_has_c99_comment.match(line) is not None
+
+
+def trailing_operator(line):
+    """Returns TRUE if the current line ends with an operatorsuch as ? or :"""
+    return __regex_trailing_operator.match(line) is not None
+
+
+def has_xxx_mark(line):
+    """Returns TRUE if the current line contains 'xxx'."""
+    return __regex_has_xxx_mark.match(line) is not None
+
+
+def filter_comments(current_line, keep=False):
+    """remove all of the c-style comments in a line"""
+    STATE_NORMAL = 0
+    STATE_COMMENT_SLASH = 1
+    STATE_COMMENT_CONTENTS = 3
+    STATE_COMMENT_END_SLASH = 4
+
+    state = STATE_NORMAL
+    sanitized_line = ''
+    check_state = STATE_NORMAL
+    only_whitespace = True
+
+    if keep:
+        check_state = STATE_COMMENT_CONTENTS
+
+    for c in current_line:
+        if c == '/':
+            if state == STATE_NORMAL:
+                state = STATE_COMMENT_SLASH
+            elif state == STATE_COMMENT_SLASH:
+                # This is for c++ style comments.  We will warn later
+                return sanitized_line[:1]
+            elif state == STATE_COMMENT_END_SLASH:
+                c = ''
+                state = STATE_NORMAL
+        elif c == '*':
+            if only_whitespace:
+                # just assume this is a continuation from the previous line
+                # as a comment
+                state = STATE_COMMENT_END_SLASH
+            elif state == STATE_COMMENT_SLASH:
+                state = STATE_COMMENT_CONTENTS
+                sanitized_line = sanitized_line[:-1]
+            elif state == STATE_COMMENT_CONTENTS:
+                state = STATE_COMMENT_END_SLASH
+        elif state == STATE_COMMENT_END_SLASH:
+            # Need to re-introduce the star from the previous state, since
+            # it may have been clipped by the state check below.
+            c = '*' + c
+            state = STATE_COMMENT_CONTENTS
+        elif state == STATE_COMMENT_SLASH:
+            # Need to re-introduce the slash from the previous state, since
+            # it may have been clipped by the state check below.
+            c = '/' + c
+            state = STATE_NORMAL
+
+        if state != check_state:
+            c = ''
+
+        if not c.isspace():
+            only_whitespace = False
+
+        sanitized_line += c
+
+    return sanitized_line
+
+
+def check_comment_spelling(line):
+    if not spell_check_dict or not spellcheck_comments:
+        return False
+
+    comment_words = filter_comments(line, True).replace(':', ' ').split(' ')
+    for word in comment_words:
+        skip = False
+        strword = re.subn(r'\W+', '', word)[0].replace(',', '')
+        if len(strword) and not spell_check_dict.check(strword.lower()):
+            if any([check_char in word
+                    for check_char in ['=', '(', '-', '_', '/', '\'']]):
+                skip = True
+
+            # special case the '.'
+            if '.' in word and not word.endswith('.'):
+                skip = True
+
+            # skip proper nouns and references to macros
+            if strword.isupper() or (strword[0].isupper() and
+                                     strword[1:].islower()):
+                skip = True
+
+            # skip words that start with numbers
+            if strword.startswith(tuple('0123456789')):
+                skip = True
+
+            if not skip:
+                print_warning("Check for spelling mistakes (e.g. \"%s\")"
+                              % strword)
+                return True
+
+    return False
+
+
+def __check_doc_is_listed(text, doctype, docdir, docfile):
+    if doctype == 'rst':
+        beginre = re.compile(r'\+\+\+.*{}/index.rst'.format(docdir))
+        docre = re.compile(r'\n\+.*{}'.format(docfile.replace('.rst', '')))
+    elif doctype == 'automake':
+        beginre = re.compile(r'\+\+\+.*Documentation/automake.mk')
+        docre = re.compile(r'\n\+\t{}/{}'.format(docdir, docfile))
+    else:
+        raise NotImplementedError("Invalid doctype: {}".format(doctype))
+
+    res = beginre.search(text)
+    if res is None:
+        return True
+
+    hunkstart = res.span()[1]
+    hunkre = re.compile(r'\n(---|\+\+\+) (\S+)')
+    res = hunkre.search(text[hunkstart:])
+    if res is None:
+        hunkend = len(text)
+    else:
+        hunkend = hunkstart + res.span()[0]
+
+    hunk = text[hunkstart:hunkend]
+    # find if the file is being added.
+    if docre.search(hunk) is not None:
+        return False
+
+    return True
+
+
+def __check_new_docs(text, doctype):
+    """Check if the documentation is listed properly. If doctype is 'rst' then
+       the index.rst is checked. If the doctype is 'automake' then automake.mk
+       is checked. Returns TRUE if the new file is not listed."""
+    failed = False
+    new_docs = __regex_added_doc_rst.findall(text)
+    for doc in new_docs:
+        docpathname = doc.split(' ')[2]
+        gitdocdir, docfile = os.path.split(docpathname.rstrip('\n'))
+        if docfile == "index.rst":
+            continue
+
+        if gitdocdir.startswith('a/'):
+            docdir = gitdocdir.replace('a/', '', 1)
+        else:
+            docdir = gitdocdir
+
+        if __check_doc_is_listed(text, doctype, docdir, docfile):
+            if doctype == 'rst':
+                print_warning("New doc {} not listed in {}/index.rst".format(
+                              docfile, docdir))
+            elif doctype == 'automake':
+                print_warning("New doc {} not listed in "
+                              "Documentation/automake.mk".format(docfile))
+            else:
+                raise NotImplementedError("Invalid doctype: {}".format(
+                                          doctype))
+
+            failed = True
+
+    return failed
+
+
+def check_doc_docs_automake(text):
+    return __check_new_docs(text, 'automake')
+
+
+def check_new_docs_index(text):
+    return __check_new_docs(text, 'rst')
+
+
+def empty_return_with_brace(line):
+    """Returns TRUE if a function contains a return; followed
+       by one or more line feeds and terminates with a '}'
+       at start of line"""
+
+    def empty_return(line):
+        """Returns TRUE if a function has a 'return;'"""
+        return __regex_empty_return.match(line) is not None
+
+    global empty_return_check_state
+    if empty_return_check_state == RETURN_CHECK_INITIAL_STATE \
+       and empty_return(line):
+        empty_return_check_state = RETURN_CHECK_STATE_WITH_RETURN
+    elif empty_return_check_state == RETURN_CHECK_STATE_WITH_RETURN \
+         and (re.match(r'^}$', line) or len(line) == 0):
+        if re.match('^}$', line):
+            empty_return_check_state = RETURN_CHECK_AWAITING_BRACE
+    else:
+        empty_return_check_state = RETURN_CHECK_INITIAL_STATE
+
+    if empty_return_check_state == RETURN_CHECK_AWAITING_BRACE:
+        empty_return_check_state = RETURN_CHECK_INITIAL_STATE
+        return True
+
+    return False
+
+
+file_checks = [
+        {'regex': __regex_added_doc_rst,
+         'check': check_new_docs_index},
+        {'regex': __regex_added_doc_rst,
+         'check': check_doc_docs_automake}
+]
+
+checks = [
+    {'regex': None,
+     'match_name': lambda x: not line_length_blacklist.search(x),
+     'check': lambda x: line_length_check(x)},
+
+    {'regex': None,
+     'match_name': lambda x: not leading_whitespace_blacklist.search(x),
+     'check': lambda x: not leading_whitespace_is_spaces(x),
+     'print': lambda: print_warning("Line has non-spaces leading whitespace")},
+
+    {'regex': None, 'match_name': None,
+     'check': lambda x: trailing_whitespace_or_crlf(x),
+     'print': lambda: print_warning("Line has trailing whitespace")},
+
+    {'regex': r'(\.c|\.h)(\.in)?$', 'match_name': None,
+     'prereq': lambda x: not is_comment_line(x),
+     'check': lambda x: not if_and_for_whitespace_checks(x),
+     'print': lambda: print_error("Improper whitespace around control block")},
+
+    {'regex': r'(\.c|\.h)(\.in)?$', 'match_name': None,
+     'prereq': lambda x: not is_comment_line(x),
+     'check': lambda x: not if_and_for_end_with_bracket_check(x),
+     'print': lambda: print_error("Inappropriate bracing around statement")},
+
+    {'regex': r'(\.c|\.h)(\.in)?$', 'match_name': None,
+     'prereq': lambda x: not is_comment_line(x),
+     'check': lambda x: pointer_whitespace_check(x),
+     'print':
+     lambda: print_error("Inappropriate spacing in pointer declaration")},
+
+    {'regex': r'(\.c|\.h)(\.in)?$', 'match_name': None,
+     'prereq': lambda x: not is_comment_line(x),
+     'check': lambda x: trailing_operator(x),
+     'print':
+     lambda: print_error("Line has '?' or ':' operator at end of line")},
+
+    {'regex': r'(\.c|\.h)(\.in)?$', 'match_name': None,
+     'prereq': lambda x: has_comment(x),
+     'check': lambda x: has_xxx_mark(x),
+     'print': lambda: print_warning("Comment with 'xxx' marker")},
+
+    {'regex': r'(\.c|\.h)(\.in)?$', 'match_name': None,
+     'prereq': lambda x: not is_comment_line(x),
+     'check': lambda x: has_c99_comment(x),
+     'print': lambda: print_error("C99 style comment")},
+
+    {'regex': r'(\.c|\.h)(\.in)?$', 'match_name': None,
+     'prereq': lambda x: has_comment(x),
+     'check': lambda x: check_comment_spelling(x)},
+
+    {'regex': r'(\.c|\.h)(\.in)?$', 'match_name': None,
+     'check': lambda x: empty_return_with_brace(x),
+     'interim_line': True,
+     'print':
+     lambda: print_warning("Empty return followed by brace, consider omitting")
+     },
+]
+
+
+def regex_function_factory(func_name):
+    regex = re.compile(r'\b%s\([^)]*\)' % func_name)
+    return lambda x: regex.search(x) is not None
+
+
+def regex_error_factory(description):
+    return lambda: print_error(description)
+
+
+std_functions = [
+        ('malloc', 'Use xmalloc() in place of malloc()'),
+        ('calloc', 'Use xcalloc() in place of calloc()'),
+        ('realloc', 'Use xrealloc() in place of realloc()'),
+        ('strdup', 'Use xstrdup() in place of strdup()'),
+        ('asprintf', 'Use xasprintf() in place of asprintf()'),
+        ('vasprintf', 'Use xvasprintf() in place of vasprintf()'),
+        ('strcpy', 'Use ovs_strlcpy() in place of strcpy()'),
+        ('strlcpy', 'Use ovs_strlcpy() in place of strlcpy()'),
+        ('strncpy', 'Use ovs_strzcpy() in place of strncpy()'),
+        ('strerror', 'Use ovs_strerror() in place of strerror()'),
+        ('sleep', 'Use xsleep() in place of sleep()'),
+        ('abort', 'Use ovs_abort() in place of abort()'),
+        ('assert', 'Use ovs_assert() in place of assert()'),
+        ('error', 'Use ovs_error() in place of error()'),
+]
+checks += [
+    {'regex': r'(\.c|\.h)(\.in)?$',
+     'match_name': None,
+     'prereq': lambda x: not is_comment_line(x),
+     'check': regex_function_factory(function_name),
+     'print': regex_error_factory(description)}
+    for (function_name, description) in std_functions]
+
+
+def regex_operator_factory(operator):
+    regex = re.compile(r'^[^#][^"\']*[^ "]%s[^ "\'][^"]*' % operator)
+    return lambda x: regex.search(filter_comments(x)) is not None
+
+
+infix_operators = \
+    [re.escape(op) for op in ['%', '<<', '>>', '<=', '>=', '==', '!=',
+            '^', '|', '&&', '||', '?:', '=', '+=', '-=', '*=', '/=', '%=',
+            '&=', '^=', '|=', '<<=', '>>=']] \
+    + [r'[^<" ]<[^=" ]',
+       r'[^\->" ]>[^=" ]',
+       r'[^ !()/"]\*[^/]',
+       r'[^ !&()"]&',
+       r'[^" +(]\+[^"+;]',
+       r'[^" \-(]\-[^"\->;]',
+       r'[^" <>=!^|+\-*/%&]=[^"=]',
+       r'[^* ]/[^* ]']
+checks += [
+    {'regex': r'(\.c|\.h)(\.in)?$', 'match_name': None,
+     'prereq': lambda x: not is_comment_line(x),
+     'check': regex_operator_factory(operator),
+     'print': lambda: print_warning("Line lacks whitespace around operator")}
+    for operator in infix_operators]
+
+
+def get_file_type_checks(filename):
+    """Returns the list of checks for a file based on matching the filename
+       against regex."""
+    global checks
+    checkList = []
+    for check in checks:
+        if check['regex'] is None and check['match_name'] is None:
+            checkList.append(check)
+        if check['regex'] is not None and \
+           re.compile(check['regex']).search(filename) is not None:
+            checkList.append(check)
+        elif check['match_name'] is not None and check['match_name'](filename):
+            checkList.append(check)
+    return checkList
+
+
+def run_checks(current_file, line, lineno):
+    """Runs the various checks for the particular line.  This will take
+       filename into account."""
+    global checking_file, total_line
+    print_line = False
+    for check in get_file_type_checks(current_file):
+        if 'prereq' in check and not check['prereq'](line):
+            continue
+        if check['check'](line):
+            if 'print' in check:
+                check['print']()
+            print_line = True
+
+    if print_line:
+        if checking_file:
+            print("%s:%d:" % (current_file, lineno))
+        else:
+            print("#%d FILE: %s:%d:" % (total_line, current_file, lineno))
+        print("%s\n" % line)
+
+
+def interim_line_check(current_file, line, lineno):
+    """Runs the various checks for the particular interim line.  This will
+       take filename into account, and will check for the 'interim_line'
+       key before running the check."""
+    global checking_file, total_line
+    print_line = False
+    for check in get_file_type_checks(current_file):
+        if 'prereq' in check and not check['prereq'](line):
+            continue
+        if 'interim_line' in check and check['interim_line']:
+            if check['check'](line):
+                if 'print' in check:
+                    check['print']()
+                    print_line = True
+
+    if print_line:
+        if checking_file:
+            print("%s:%d:" % (current_file, lineno))
+        else:
+            print("#%d FILE: %s:%d:" % (total_line, current_file, lineno))
+        print("%s\n" % line)
+
+
+def run_file_checks(text):
+    """Runs the various checks for the text."""
+    for check in file_checks:
+        if check['regex'].search(text) is not None:
+            check['check'](text)
+
+
+def ovs_checkpatch_parse(text, filename, author=None, committer=None):
+    global print_file_name, total_line, checking_file, \
+        empty_return_check_state
+
+    PARSE_STATE_HEADING = 0
+    PARSE_STATE_DIFF_HEADER = 1
+    PARSE_STATE_CHANGE_BODY = 2
+
+    lineno = 0
+    signatures = []
+    co_authors = []
+    parse = 0
+    current_file = filename if checking_file else ''
+    previous_file = ''
+    seppatch = re.compile(r'^---([\w]*| \S+)$')
+    hunks = re.compile(r'^(---|\+\+\+) (\S+)')
+    hunk_differences = re.compile(
+        r'^@@ ([0-9-+]+),([0-9-+]+) ([0-9-+]+),([0-9-+]+) @@')
+    is_author = re.compile(r'^(Author|From): (.*)$', re.I | re.M | re.S)
+    is_committer = re.compile(r'^(Commit: )(.*)$', re.I | re.M | re.S)
+    is_signature = re.compile(r'^(Signed-off-by: )(.*)$',
+                              re.I | re.M | re.S)
+    is_co_author = re.compile(r'^(Co-authored-by: )(.*)$',
+                              re.I | re.M | re.S)
+    is_gerrit_change_id = re.compile(r'(\s*(change-id: )(.*))$',
+                                     re.I | re.M | re.S)
+
+    reset_counters()
+
+    for line in text.splitlines():
+        if current_file != previous_file:
+            previous_file = current_file
+
+        lineno = lineno + 1
+        total_line = total_line + 1
+        if len(line) <= 0:
+            continue
+
+        if checking_file:
+            parse = PARSE_STATE_CHANGE_BODY
+
+        if parse == PARSE_STATE_DIFF_HEADER:
+            match = hunks.match(line)
+            if match:
+                parse = PARSE_STATE_CHANGE_BODY
+                current_file = match.group(2)[2:]
+                print_file_name = current_file
+            continue
+        elif parse == PARSE_STATE_HEADING:
+            if seppatch.match(line):
+                parse = PARSE_STATE_DIFF_HEADER
+                if not skip_signoff_check:
+
+                    # Check that the patch has an author, that the
+                    # author is not among the co-authors, and that the
+                    # co-authors are unique.
+                    if not author:
+                        print_error("Patch lacks author.")
+                        continue
+                    if " via " in author or "@openvswitch.org" in author:
+                        print_error("Author should not be mailing list.")
+                        continue
+                    if author in co_authors:
+                        print_error("Author should not be also be co-author.")
+                        continue
+                    if len(set(co_authors)) != len(co_authors):
+                        print_error("Duplicate co-author.")
+
+                    # Check that the author, all co-authors, and the
+                    # committer (if any) signed off.
+                    if author not in signatures:
+                        print_error("Author %s needs to sign off." % author)
+                    for ca in co_authors:
+                        if ca not in signatures:
+                            print_error("Co-author %s needs to sign off." % ca)
+                            break
+                    if (committer
+                        and author != committer
+                        and committer not in signatures):
+                        print_error("Committer %s needs to sign off."
+                                    % committer)
+
+                    # Check for signatures that we do not expect.
+                    # This is only a warning because there can be,
+                    # rarely, a signature chain.
+                    #
+                    # If we don't have a known committer, and there is
+                    # a single extra sign-off, then do not warn
+                    # because that extra sign-off is probably the
+                    # committer.
+                    extra_sigs = [x for x in signatures
+                                  if x not in co_authors
+                                  and x != author
+                                  and x != committer]
+                    if len(extra_sigs) > 1 or (committer and extra_sigs):
+                        print_warning("Unexpected sign-offs from developers "
+                                      "who are not authors or co-authors or "
+                                      "committers: %s"
+                                      % ", ".join(extra_sigs))
+            elif is_committer.match(line):
+                committer = is_committer.match(line).group(2)
+            elif is_author.match(line):
+                author = is_author.match(line).group(2)
+            elif is_signature.match(line):
+                m = is_signature.match(line)
+                signatures.append(m.group(2))
+            elif is_co_author.match(line):
+                m = is_co_author.match(line)
+                co_authors.append(m.group(2))
+            elif is_gerrit_change_id.match(line):
+                print_error(
+                    "Remove Gerrit Change-Id's before submitting upstream.")
+                print("%d: %s\n" % (lineno, line))
+        elif parse == PARSE_STATE_CHANGE_BODY:
+            newfile = hunks.match(line)
+            if newfile:
+                current_file = newfile.group(2)[2:]
+                print_file_name = current_file
+                continue
+            reset_line_number = hunk_differences.match(line)
+            if reset_line_number:
+                empty_return_check_state = RETURN_CHECK_INITIAL_STATE
+                lineno = int(reset_line_number.group(3))
+                if lineno < 0:
+                    lineno = -1 * lineno
+                lineno -= 1
+
+            if is_subtracted_line(line):
+                lineno -= 1
+                continue
+
+            cmp_line = added_line(line)
+
+            if not is_added_line(line):
+                interim_line_check(current_file, cmp_line, lineno)
+                continue
+
+            # Skip files which have /datapath in them, since they are
+            # linux or windows coding standards
+            if current_file.startswith('datapath'):
+                continue
+            if current_file.startswith('include/linux'):
+                continue
+            # "sparse" includes could be copy-pasted from different sources
+            # like DPDK or Linux and could contain workarounds not suitable
+            # for a common style.
+            if current_file.startswith('include/sparse'):
+                continue
+            run_checks(current_file, cmp_line, lineno)
+
+    run_file_checks(text)
+    if __errors or __warnings:
+        return EXIT_FAILURE
+    return 0
+
+
+def usage():
+    print("""\
+Open vSwitch checkpatch.py
+Checks a patch for trivial mistakes.
+usage:
+%s [options] [PATCH1 [PATCH2 ...] | -f SOURCE1 [SOURCE2 ...] | -1 | -2 | ...]
+
+Input options:
+-f|--check-file                Arguments are source files, not patches.
+-1, -2, ...                    Check recent commits in this repo.
+
+Check options:
+-h|--help                      This help message
+-b|--skip-block-whitespace     Skips the if/while/for whitespace tests
+-l|--skip-leading-whitespace   Skips the leading whitespace test
+-q|--quiet                     Only print error and warning information
+-s|--skip-signoff-lines        Tolerate missing Signed-off-by line
+-S|--spellcheck-comments       Check C comments for possible spelling mistakes
+-t|--skip-trailing-whitespace  Skips the trailing whitespace test"""
+          % sys.argv[0])
+
+
+def ovs_checkpatch_print_result():
+    global quiet, __warnings, __errors, total_line
+
+    if __errors or __warnings:
+        print("Lines checked: %d, Warnings: %d, Errors: %d\n" %
+              (total_line, __warnings, __errors))
+    elif not quiet:
+        print("Lines checked: %d, no obvious problems found\n" % (total_line))
+
+
+def ovs_checkpatch_file(filename):
+    try:
+        mail = email.message_from_file(open(filename, 'r'))
+    except:
+        print_error("Unable to parse file '%s'. Is it a patch?" % filename)
+        return -1
+
+    for part in mail.walk():
+        if part.get_content_maintype() == 'multipart':
+            continue
+    result = ovs_checkpatch_parse(part.get_payload(decode=False), filename,
+                                  mail.get('Author', mail['From']),
+                                  mail['Commit'])
+    ovs_checkpatch_print_result()
+    return result
+
+
+def partition(pred, iterable):
+    """Returns [[trues], [falses]], where [trues] is the items in
+    'iterable' that satisfy 'pred' and [falses] is all the rest."""
+    trues = []
+    falses = []
+    for item in iterable:
+        if pred(item):
+            trues.append(item)
+        else:
+            falses.append(item)
+    return trues, falses
+
+
+if __name__ == '__main__':
+    try:
+        numeric_options, args = partition(lambda s: re.match('-[0-9]+$', s),
+                                          sys.argv[1:])
+        n_patches = int(numeric_options[-1][1:]) if numeric_options else 0
+
+        optlist, args = getopt.getopt(args, 'bhlstfSq',
+                                      ["check-file",
+                                       "help",
+                                       "skip-block-whitespace",
+                                       "skip-leading-whitespace",
+                                       "skip-signoff-lines",
+                                       "skip-trailing-whitespace",
+                                       "spellcheck-comments",
+                                       "quiet"])
+    except:
+        print("Unknown option encountered. Please rerun with -h for help.")
+        sys.exit(EXIT_FAILURE)
+
+    for o, a in optlist:
+        if o in ("-h", "--help"):
+            usage()
+            sys.exit(0)
+        elif o in ("-b", "--skip-block-whitespace"):
+            skip_block_whitespace_check = True
+        elif o in ("-l", "--skip-leading-whitespace"):
+            skip_leading_whitespace_check = True
+        elif o in ("-s", "--skip-signoff-lines"):
+            skip_signoff_check = True
+        elif o in ("-t", "--skip-trailing-whitespace"):
+            skip_trailing_whitespace_check = True
+        elif o in ("-f", "--check-file"):
+            checking_file = True
+        elif o in ("-S", "--spellcheck-comments"):
+            if not open_spell_check_dict():
+                print("WARNING: The enchant library isn't available.")
+                print("         Please install python enchant.")
+            else:
+                spellcheck_comments = True
+        elif o in ("-q", "--quiet"):
+            quiet = True
+        else:
+            print("Unknown option '%s'" % o)
+            sys.exit(EXIT_FAILURE)
+
+    if sys.stdout.isatty():
+        colors = True
+
+    if n_patches:
+        status = 0
+
+        git_log = 'git log --no-color --no-merges --pretty=format:"%H %s" '
+        with os.popen(git_log + '-%d' % n_patches, 'r') as f:
+            commits = f.read().split("\n")
+
+        for i in reversed(range(0, n_patches)):
+            revision, name = commits[i].split(" ", 1)
+            f = os.popen('''git format-patch -1 --stdout --pretty=format:"\
+Author: %an <%ae>
+Commit: %cn <%ce>
+Subject: %s
+
+%b" ''' + revision, 'r')
+            patch = f.read()
+            f.close()
+
+            if not quiet:
+                print('== Checking %s ("%s") ==' % (revision[0:12], name))
+            result = ovs_checkpatch_parse(patch, revision)
+            ovs_checkpatch_print_result()
+            if result:
+                status = EXIT_FAILURE
+        sys.exit(status)
+
+    if not args:
+        if sys.stdin.isatty():
+            usage()
+            sys.exit(EXIT_FAILURE)
+        result = ovs_checkpatch_parse(sys.stdin.read(), '-')
+        ovs_checkpatch_print_result()
+        sys.exit(result)
+
+    status = 0
+    for filename in args:
+        if not quiet:
+            print('== Checking "%s" ==' % filename)
+        result = ovs_checkpatch_file(filename)
+        if result:
+            status = EXIT_FAILURE
+    sys.exit(status)
