diff --git a/src/http.c b/src/http.c
new file mode 100644
index 0000000..ad620a9
--- /dev/null
+++ b/src/http.c
@@ -0,0 +1,185 @@
+/*
+ * HTTP semantics
+ *
+ * Copyright 2000-2018 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 <common/config.h>
+#include <common/http.h>
+
+/* It is about twice as fast on recent architectures to lookup a byte in a
+ * table than to perform a boolean AND or OR between two tests. Refer to
+ * RFC2616/RFC5234/RFC7230 for those chars. A token is any ASCII char that is
+ * neither a separator nor a CTL char. An http ver_token is any ASCII which can
+ * be found in an HTTP version, which includes 'H', 'T', 'P', '/', '.' and any
+ * digit. Note: please do not overwrite values in assignment since gcc-2.95
+ * will not handle them correctly. It's worth noting that chars 128..255 are
+ * nothing, not even control chars.
+ */
+const unsigned char http_char_classes[256] = {
+	[  0] = HTTP_FLG_CTL,
+	[  1] = HTTP_FLG_CTL,
+	[  2] = HTTP_FLG_CTL,
+	[  3] = HTTP_FLG_CTL,
+	[  4] = HTTP_FLG_CTL,
+	[  5] = HTTP_FLG_CTL,
+	[  6] = HTTP_FLG_CTL,
+	[  7] = HTTP_FLG_CTL,
+	[  8] = HTTP_FLG_CTL,
+	[  9] = HTTP_FLG_SPHT | HTTP_FLG_LWS | HTTP_FLG_SEP | HTTP_FLG_CTL,
+	[ 10] = HTTP_FLG_CRLF | HTTP_FLG_LWS | HTTP_FLG_CTL,
+	[ 11] = HTTP_FLG_CTL,
+	[ 12] = HTTP_FLG_CTL,
+	[ 13] = HTTP_FLG_CRLF | HTTP_FLG_LWS | HTTP_FLG_CTL,
+	[ 14] = HTTP_FLG_CTL,
+	[ 15] = HTTP_FLG_CTL,
+	[ 16] = HTTP_FLG_CTL,
+	[ 17] = HTTP_FLG_CTL,
+	[ 18] = HTTP_FLG_CTL,
+	[ 19] = HTTP_FLG_CTL,
+	[ 20] = HTTP_FLG_CTL,
+	[ 21] = HTTP_FLG_CTL,
+	[ 22] = HTTP_FLG_CTL,
+	[ 23] = HTTP_FLG_CTL,
+	[ 24] = HTTP_FLG_CTL,
+	[ 25] = HTTP_FLG_CTL,
+	[ 26] = HTTP_FLG_CTL,
+	[ 27] = HTTP_FLG_CTL,
+	[ 28] = HTTP_FLG_CTL,
+	[ 29] = HTTP_FLG_CTL,
+	[ 30] = HTTP_FLG_CTL,
+	[ 31] = HTTP_FLG_CTL,
+	[' '] = HTTP_FLG_SPHT | HTTP_FLG_LWS | HTTP_FLG_SEP,
+	['!'] = HTTP_FLG_TOK,
+	['"'] = HTTP_FLG_SEP,
+	['#'] = HTTP_FLG_TOK,
+	['$'] = HTTP_FLG_TOK,
+	['%'] = HTTP_FLG_TOK,
+	['&'] = HTTP_FLG_TOK,
+	[ 39] = HTTP_FLG_TOK,
+	['('] = HTTP_FLG_SEP,
+	[')'] = HTTP_FLG_SEP,
+	['*'] = HTTP_FLG_TOK,
+	['+'] = HTTP_FLG_TOK,
+	[','] = HTTP_FLG_SEP,
+	['-'] = HTTP_FLG_TOK,
+	['.'] = HTTP_FLG_TOK | HTTP_FLG_VER,
+	['/'] = HTTP_FLG_SEP | HTTP_FLG_VER,
+	['0'] = HTTP_FLG_TOK | HTTP_FLG_VER | HTTP_FLG_DIG,
+	['1'] = HTTP_FLG_TOK | HTTP_FLG_VER | HTTP_FLG_DIG,
+	['2'] = HTTP_FLG_TOK | HTTP_FLG_VER | HTTP_FLG_DIG,
+	['3'] = HTTP_FLG_TOK | HTTP_FLG_VER | HTTP_FLG_DIG,
+	['4'] = HTTP_FLG_TOK | HTTP_FLG_VER | HTTP_FLG_DIG,
+	['5'] = HTTP_FLG_TOK | HTTP_FLG_VER | HTTP_FLG_DIG,
+	['6'] = HTTP_FLG_TOK | HTTP_FLG_VER | HTTP_FLG_DIG,
+	['7'] = HTTP_FLG_TOK | HTTP_FLG_VER | HTTP_FLG_DIG,
+	['8'] = HTTP_FLG_TOK | HTTP_FLG_VER | HTTP_FLG_DIG,
+	['9'] = HTTP_FLG_TOK | HTTP_FLG_VER | HTTP_FLG_DIG,
+	[':'] = HTTP_FLG_SEP,
+	[';'] = HTTP_FLG_SEP,
+	['<'] = HTTP_FLG_SEP,
+	['='] = HTTP_FLG_SEP,
+	['>'] = HTTP_FLG_SEP,
+	['?'] = HTTP_FLG_SEP,
+	['@'] = HTTP_FLG_SEP,
+	['A'] = HTTP_FLG_TOK,
+	['B'] = HTTP_FLG_TOK,
+	['C'] = HTTP_FLG_TOK,
+	['D'] = HTTP_FLG_TOK,
+	['E'] = HTTP_FLG_TOK,
+	['F'] = HTTP_FLG_TOK,
+	['G'] = HTTP_FLG_TOK,
+	['H'] = HTTP_FLG_TOK | HTTP_FLG_VER,
+	['I'] = HTTP_FLG_TOK,
+	['J'] = HTTP_FLG_TOK,
+	['K'] = HTTP_FLG_TOK,
+	['L'] = HTTP_FLG_TOK,
+	['M'] = HTTP_FLG_TOK,
+	['N'] = HTTP_FLG_TOK,
+	['O'] = HTTP_FLG_TOK,
+	['P'] = HTTP_FLG_TOK | HTTP_FLG_VER,
+	['Q'] = HTTP_FLG_TOK,
+	['R'] = HTTP_FLG_TOK | HTTP_FLG_VER,
+	['S'] = HTTP_FLG_TOK | HTTP_FLG_VER,
+	['T'] = HTTP_FLG_TOK | HTTP_FLG_VER,
+	['U'] = HTTP_FLG_TOK,
+	['V'] = HTTP_FLG_TOK,
+	['W'] = HTTP_FLG_TOK,
+	['X'] = HTTP_FLG_TOK,
+	['Y'] = HTTP_FLG_TOK,
+	['Z'] = HTTP_FLG_TOK,
+	['['] = HTTP_FLG_SEP,
+	[ 92] = HTTP_FLG_SEP,
+	[']'] = HTTP_FLG_SEP,
+	['^'] = HTTP_FLG_TOK,
+	['_'] = HTTP_FLG_TOK,
+	['`'] = HTTP_FLG_TOK,
+	['a'] = HTTP_FLG_TOK,
+	['b'] = HTTP_FLG_TOK,
+	['c'] = HTTP_FLG_TOK,
+	['d'] = HTTP_FLG_TOK,
+	['e'] = HTTP_FLG_TOK,
+	['f'] = HTTP_FLG_TOK,
+	['g'] = HTTP_FLG_TOK,
+	['h'] = HTTP_FLG_TOK,
+	['i'] = HTTP_FLG_TOK,
+	['j'] = HTTP_FLG_TOK,
+	['k'] = HTTP_FLG_TOK,
+	['l'] = HTTP_FLG_TOK,
+	['m'] = HTTP_FLG_TOK,
+	['n'] = HTTP_FLG_TOK,
+	['o'] = HTTP_FLG_TOK,
+	['p'] = HTTP_FLG_TOK,
+	['q'] = HTTP_FLG_TOK,
+	['r'] = HTTP_FLG_TOK,
+	['s'] = HTTP_FLG_TOK,
+	['t'] = HTTP_FLG_TOK,
+	['u'] = HTTP_FLG_TOK,
+	['v'] = HTTP_FLG_TOK,
+	['w'] = HTTP_FLG_TOK,
+	['x'] = HTTP_FLG_TOK,
+	['y'] = HTTP_FLG_TOK,
+	['z'] = HTTP_FLG_TOK,
+	['{'] = HTTP_FLG_SEP,
+	['|'] = HTTP_FLG_TOK,
+	['}'] = HTTP_FLG_SEP,
+	['~'] = HTTP_FLG_TOK,
+	[127] = HTTP_FLG_CTL,
+};
+
+const struct ist http_known_methods[HTTP_METH_OTHER] = {
+	[HTTP_METH_OPTIONS] = IST("OPTIONS"),
+	[HTTP_METH_GET]     = IST("GET"),
+	[HTTP_METH_HEAD]    = IST("HEAD"),
+	[HTTP_METH_POST]    = IST("POST"),
+	[HTTP_METH_PUT]     = IST("PUT"),
+	[HTTP_METH_DELETE]  = IST("DELETE"),
+	[HTTP_METH_TRACE]   = IST("TRACE"),
+	[HTTP_METH_CONNECT] = IST("CONNECT"),
+};
+
+/*
+ * returns a known method among HTTP_METH_* or HTTP_METH_OTHER for all unknown
+ * ones.
+ */
+enum http_meth_t find_http_meth(const char *str, const int len)
+{
+	const struct ist m = ist2(str, len);
+
+	if      (isteq(m, ist("GET")))     return HTTP_METH_GET;
+	else if (isteq(m, ist("HEAD")))    return HTTP_METH_HEAD;
+	else if (isteq(m, ist("POST")))    return HTTP_METH_POST;
+	else if (isteq(m, ist("CONNECT"))) return HTTP_METH_CONNECT;
+	else if (isteq(m, ist("PUT")))     return HTTP_METH_PUT;
+	else if (isteq(m, ist("OPTIONS"))) return HTTP_METH_OPTIONS;
+	else if (isteq(m, ist("DELETE")))  return HTTP_METH_DELETE;
+	else if (isteq(m, ist("TRACE")))   return HTTP_METH_TRACE;
+	else                               return HTTP_METH_OTHER;
+}