blob: cd266cdee0a90ca652d28b735809a815c54bec17 [file] [log] [blame]
/*
* General protocol-agnostic payload-based sample fetches and ACLs
*
* 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 <stdlib.h>
#include <string.h>
#include <proto/acl.h>
#include <proto/arg.h>
#include <proto/channel.h>
#include <proto/pattern.h>
#include <proto/payload.h>
#include <proto/sample.h>
/************************************************************************/
/* All supported sample fetch functions must be declared here */
/************************************************************************/
/* wait for more data as long as possible, then return TRUE. This should be
* used with content inspection.
*/
static int
smp_fetch_wait_end(struct proxy *px, struct session *s, void *l7, unsigned int opt,
const struct arg *args, struct sample *smp, const char *kw)
{
if (!(opt & SMP_OPT_FINAL)) {
smp->flags |= SMP_F_MAY_CHANGE;
return 0;
}
smp->type = SMP_T_BOOL;
smp->data.uint = 1;
return 1;
}
/* return the number of bytes in the request buffer */
static int
smp_fetch_len(struct proxy *px, struct session *s, void *l7, unsigned int opt,
const struct arg *args, struct sample *smp, const char *kw)
{
struct channel *chn = ((opt & SMP_OPT_DIR) == SMP_OPT_DIR_RES) ? s->rep : s->req;
if (!s || !chn)
return 0;
smp->type = SMP_T_UINT;
smp->data.uint = chn->buf->i;
smp->flags = SMP_F_VOLATILE | SMP_F_MAY_CHANGE;
return 1;
}
/* returns the type of SSL hello message (mainly used to detect an SSL hello) */
static int
smp_fetch_ssl_hello_type(struct proxy *px, struct session *s, void *l7, unsigned int opt,
const struct arg *args, struct sample *smp, const char *kw)
{
int hs_len;
int hs_type, bleft;
struct channel *chn;
const unsigned char *data;
if (!s)
goto not_ssl_hello;
chn = ((opt & SMP_OPT_DIR) == SMP_OPT_DIR_RES) ? s->rep : s->req;
bleft = chn->buf->i;
data = (const unsigned char *)chn->buf->p;
if (!bleft)
goto too_short;
if ((*data >= 0x14 && *data <= 0x17) || (*data == 0xFF)) {
/* SSLv3 header format */
if (bleft < 9)
goto too_short;
/* ssl version 3 */
if ((data[1] << 16) + data[2] < 0x00030000)
goto not_ssl_hello;
/* ssl message len must present handshake type and len */
if ((data[3] << 8) + data[4] < 4)
goto not_ssl_hello;
/* format introduced with SSLv3 */
hs_type = (int)data[5];
hs_len = ( data[6] << 16 ) + ( data[7] << 8 ) + data[8];
/* not a full handshake */
if (bleft < (9 + hs_len))
goto too_short;
}
else {
goto not_ssl_hello;
}
smp->type = SMP_T_UINT;
smp->data.uint = hs_type;
smp->flags = SMP_F_VOLATILE;
return 1;
too_short:
smp->flags = SMP_F_MAY_CHANGE;
not_ssl_hello:
return 0;
}
/* Return the version of the SSL protocol in the request. It supports both
* SSLv3 (TLSv1) header format for any message, and SSLv2 header format for
* the hello message. The SSLv3 format is described in RFC 2246 p49, and the
* SSLv2 format is described here, and completed p67 of RFC 2246 :
* http://wp.netscape.com/eng/security/SSL_2.html
*
* Note: this decoder only works with non-wrapping data.
*/
static int
smp_fetch_req_ssl_ver(struct proxy *px, struct session *s, void *l7, unsigned int opt,
const struct arg *args, struct sample *smp, const char *kw)
{
int version, bleft, msg_len;
const unsigned char *data;
if (!s || !s->req)
return 0;
msg_len = 0;
bleft = s->req->buf->i;
if (!bleft)
goto too_short;
data = (const unsigned char *)s->req->buf->p;
if ((*data >= 0x14 && *data <= 0x17) || (*data == 0xFF)) {
/* SSLv3 header format */
if (bleft < 5)
goto too_short;
version = (data[1] << 16) + data[2]; /* version: major, minor */
msg_len = (data[3] << 8) + data[4]; /* record length */
/* format introduced with SSLv3 */
if (version < 0x00030000)
goto not_ssl;
/* message length between 1 and 2^14 + 2048 */
if (msg_len < 1 || msg_len > ((1<<14) + 2048))
goto not_ssl;
bleft -= 5; data += 5;
} else {
/* SSLv2 header format, only supported for hello (msg type 1) */
int rlen, plen, cilen, silen, chlen;
if (*data & 0x80) {
if (bleft < 3)
goto too_short;
/* short header format : 15 bits for length */
rlen = ((data[0] & 0x7F) << 8) | data[1];
plen = 0;
bleft -= 2; data += 2;
} else {
if (bleft < 4)
goto too_short;
/* long header format : 14 bits for length + pad length */
rlen = ((data[0] & 0x3F) << 8) | data[1];
plen = data[2];
bleft -= 3; data += 2;
}
if (*data != 0x01)
goto not_ssl;
bleft--; data++;
if (bleft < 8)
goto too_short;
version = (data[0] << 16) + data[1]; /* version: major, minor */
cilen = (data[2] << 8) + data[3]; /* cipher len, multiple of 3 */
silen = (data[4] << 8) + data[5]; /* session_id_len: 0 or 16 */
chlen = (data[6] << 8) + data[7]; /* 16<=challenge length<=32 */
bleft -= 8; data += 8;
if (cilen % 3 != 0)
goto not_ssl;
if (silen && silen != 16)
goto not_ssl;
if (chlen < 16 || chlen > 32)
goto not_ssl;
if (rlen != 9 + cilen + silen + chlen)
goto not_ssl;
/* focus on the remaining data length */
msg_len = cilen + silen + chlen + plen;
}
/* We could recursively check that the buffer ends exactly on an SSL
* fragment boundary and that a possible next segment is still SSL,
* but that's a bit pointless. However, we could still check that
* all the part of the request which fits in a buffer is already
* there.
*/
if (msg_len > buffer_max_len(s->req) + s->req->buf->data - s->req->buf->p)
msg_len = buffer_max_len(s->req) + s->req->buf->data - s->req->buf->p;
if (bleft < msg_len)
goto too_short;
/* OK that's enough. We have at least the whole message, and we have
* the protocol version.
*/
smp->type = SMP_T_UINT;
smp->data.uint = version;
smp->flags = SMP_F_VOLATILE;
return 1;
too_short:
smp->flags = SMP_F_MAY_CHANGE;
not_ssl:
return 0;
}
/* Try to extract the Server Name Indication that may be presented in a TLS
* client hello handshake message. The format of the message is the following
* (cf RFC5246 + RFC6066) :
* TLS frame :
* - uint8 type = 0x16 (Handshake)
* - uint16 version >= 0x0301 (TLSv1)
* - uint16 length (frame length)
* - TLS handshake :
* - uint8 msg_type = 0x01 (ClientHello)
* - uint24 length (handshake message length)
* - ClientHello :
* - uint16 client_version >= 0x0301 (TLSv1)
* - uint8 Random[32] (4 first ones are timestamp)
* - SessionID :
* - uint8 session_id_len (0..32) (SessionID len in bytes)
* - uint8 session_id[session_id_len]
* - CipherSuite :
* - uint16 cipher_len >= 2 (Cipher length in bytes)
* - uint16 ciphers[cipher_len/2]
* - CompressionMethod :
* - uint8 compression_len >= 1 (# of supported methods)
* - uint8 compression_methods[compression_len]
* - optional client_extension_len (in bytes)
* - optional sequence of ClientHelloExtensions (as many bytes as above):
* - uint16 extension_type = 0 for server_name
* - uint16 extension_len
* - opaque extension_data[extension_len]
* - uint16 server_name_list_len (# of bytes here)
* - opaque server_names[server_name_list_len bytes]
* - uint8 name_type = 0 for host_name
* - uint16 name_len
* - opaque hostname[name_len bytes]
*/
static int
smp_fetch_ssl_hello_sni(struct proxy *px, struct session *s, void *l7, unsigned int opt,
const struct arg *args, struct sample *smp, const char *kw)
{
int hs_len, ext_len, bleft;
struct channel *chn;
unsigned char *data;
if (!s)
goto not_ssl_hello;
chn = ((opt & SMP_OPT_DIR) == SMP_OPT_DIR_RES) ? s->rep : s->req;
bleft = chn->buf->i;
data = (unsigned char *)chn->buf->p;
/* Check for SSL/TLS Handshake */
if (!bleft)
goto too_short;
if (*data != 0x16)
goto not_ssl_hello;
/* Check for TLSv1 or later (SSL version >= 3.1) */
if (bleft < 3)
goto too_short;
if (data[1] < 0x03 || data[2] < 0x01)
goto not_ssl_hello;
if (bleft < 5)
goto too_short;
hs_len = (data[3] << 8) + data[4];
if (hs_len < 1 + 3 + 2 + 32 + 1 + 2 + 2 + 1 + 1 + 2 + 2)
goto not_ssl_hello; /* too short to have an extension */
data += 5; /* enter TLS handshake */
bleft -= 5;
/* Check for a complete client hello starting at <data> */
if (bleft < 1)
goto too_short;
if (data[0] != 0x01) /* msg_type = Client Hello */
goto not_ssl_hello;
/* Check the Hello's length */
if (bleft < 4)
goto too_short;
hs_len = (data[1] << 16) + (data[2] << 8) + data[3];
if (hs_len < 2 + 32 + 1 + 2 + 2 + 1 + 1 + 2 + 2)
goto not_ssl_hello; /* too short to have an extension */
/* We want the full handshake here */
if (bleft < hs_len)
goto too_short;
data += 4;
/* Start of the ClientHello message */
if (data[0] < 0x03 || data[1] < 0x01) /* TLSv1 minimum */
goto not_ssl_hello;
ext_len = data[34]; /* session_id_len */
if (ext_len > 32 || ext_len > (hs_len - 35)) /* check for correct session_id len */
goto not_ssl_hello;
/* Jump to cipher suite */
hs_len -= 35 + ext_len;
data += 35 + ext_len;
if (hs_len < 4 || /* minimum one cipher */
(ext_len = (data[0] << 8) + data[1]) < 2 || /* minimum 2 bytes for a cipher */
ext_len > hs_len)
goto not_ssl_hello;
/* Jump to the compression methods */
hs_len -= 2 + ext_len;
data += 2 + ext_len;
if (hs_len < 2 || /* minimum one compression method */
data[0] < 1 || data[0] > hs_len) /* minimum 1 bytes for a method */
goto not_ssl_hello;
/* Jump to the extensions */
hs_len -= 1 + data[0];
data += 1 + data[0];
if (hs_len < 2 || /* minimum one extension list length */
(ext_len = (data[0] << 8) + data[1]) > hs_len - 2) /* list too long */
goto not_ssl_hello;
hs_len = ext_len; /* limit ourselves to the extension length */
data += 2;
while (hs_len >= 4) {
int ext_type, name_type, srv_len, name_len;
ext_type = (data[0] << 8) + data[1];
ext_len = (data[2] << 8) + data[3];
if (ext_len > hs_len - 4) /* Extension too long */
goto not_ssl_hello;
if (ext_type == 0) { /* Server name */
if (ext_len < 2) /* need one list length */
goto not_ssl_hello;
srv_len = (data[4] << 8) + data[5];
if (srv_len < 4 || srv_len > hs_len - 6)
goto not_ssl_hello; /* at least 4 bytes per server name */
name_type = data[6];
name_len = (data[7] << 8) + data[8];
if (name_type == 0) { /* hostname */
smp->type = SMP_T_CSTR;
smp->data.str.str = (char *)data + 9;
smp->data.str.len = name_len;
smp->flags = SMP_F_VOLATILE;
return 1;
}
}
hs_len -= 4 + ext_len;
data += 4 + ext_len;
}
/* server name not found */
goto not_ssl_hello;
too_short:
smp->flags = SMP_F_MAY_CHANGE;
not_ssl_hello:
return 0;
}
/* Fetch the request RDP cookie identified in <cname>:<clen>, or any cookie if
* <clen> is empty (cname is then ignored). It returns the data into sample <smp>.
* Note: this decoder only works with non-wrapping data.
*/
int
fetch_rdp_cookie_name(struct session *s, struct sample *smp, const char *cname, int clen)
{
int bleft;
const unsigned char *data;
if (!s || !s->req)
return 0;
smp->flags = 0;
smp->type = SMP_T_CSTR;
bleft = s->req->buf->i;
if (bleft <= 11)
goto too_short;
data = (const unsigned char *)s->req->buf->p + 11;
bleft -= 11;
if (bleft <= 7)
goto too_short;
if (strncasecmp((const char *)data, "Cookie:", 7) != 0)
goto not_cookie;
data += 7;
bleft -= 7;
while (bleft > 0 && *data == ' ') {
data++;
bleft--;
}
if (clen) {
if (bleft <= clen)
goto too_short;
if ((data[clen] != '=') ||
strncasecmp(cname, (const char *)data, clen) != 0)
goto not_cookie;
data += clen + 1;
bleft -= clen + 1;
} else {
while (bleft > 0 && *data != '=') {
if (*data == '\r' || *data == '\n')
goto not_cookie;
data++;
bleft--;
}
if (bleft < 1)
goto too_short;
if (*data != '=')
goto not_cookie;
data++;
bleft--;
}
/* data points to cookie value */
smp->data.str.str = (char *)data;
smp->data.str.len = 0;
while (bleft > 0 && *data != '\r') {
data++;
bleft--;
}
if (bleft < 2)
goto too_short;
if (data[0] != '\r' || data[1] != '\n')
goto not_cookie;
smp->data.str.len = (char *)data - smp->data.str.str;
smp->flags = SMP_F_VOLATILE;
return 1;
too_short:
smp->flags = SMP_F_MAY_CHANGE;
not_cookie:
return 0;
}
/* Fetch the request RDP cookie identified in the args, or any cookie if no arg
* is passed. It is usable both for ACL and for samples. Note: this decoder
* only works with non-wrapping data. Accepts either 0 or 1 argument. Argument
* is a string (cookie name), other types will lead to undefined behaviour.
*/
int
smp_fetch_rdp_cookie(struct proxy *px, struct session *s, void *l7, unsigned int opt,
const struct arg *args, struct sample *smp, const char *kw)
{
return fetch_rdp_cookie_name(s, smp, args ? args->data.str.str : NULL, args ? args->data.str.len : 0);
}
/* returns either 1 or 0 depending on whether an RDP cookie is found or not */
static int
smp_fetch_rdp_cookie_cnt(struct proxy *px, struct session *s, void *l7, unsigned int opt,
const struct arg *args, struct sample *smp, const char *kw)
{
int ret;
ret = smp_fetch_rdp_cookie(px, s, l7, opt, args, smp, kw);
if (smp->flags & SMP_F_MAY_CHANGE)
return 0;
smp->flags = SMP_F_VOLATILE;
smp->type = SMP_T_UINT;
smp->data.uint = ret;
return 1;
}
/* extracts part of a payload with offset and length at a given position */
static int
smp_fetch_payload_lv(struct proxy *px, struct session *s, void *l7, unsigned int opt,
const struct arg *arg_p, struct sample *smp, const char *kw)
{
unsigned int len_offset = arg_p[0].data.uint;
unsigned int len_size = arg_p[1].data.uint;
unsigned int buf_offset;
unsigned int buf_size = 0;
struct channel *chn;
int i;
/* Format is (len offset, len size, buf offset) or (len offset, len size) */
/* by default buf offset == len offset + len size */
/* buf offset could be absolute or relative to len offset + len size if prefixed by + or - */
if (!s)
return 0;
chn = ((opt & SMP_OPT_DIR) == SMP_OPT_DIR_RES) ? s->rep : s->req;
if (!chn)
return 0;
if (len_offset + len_size > chn->buf->i)
goto too_short;
for (i = 0; i < len_size; i++) {
buf_size = (buf_size << 8) + ((unsigned char *)chn->buf->p)[i + len_offset];
}
/* buf offset may be implicit, absolute or relative */
buf_offset = len_offset + len_size;
if (arg_p[2].type == ARGT_UINT)
buf_offset = arg_p[2].data.uint;
else if (arg_p[2].type == ARGT_SINT)
buf_offset += arg_p[2].data.sint;
if (!buf_size || buf_size > chn->buf->size || buf_offset + buf_size > chn->buf->size) {
/* will never match */
smp->flags = 0;
return 0;
}
if (buf_offset + buf_size > chn->buf->i)
goto too_short;
/* init chunk as read only */
smp->type = SMP_T_CBIN;
chunk_initlen(&smp->data.str, chn->buf->p + buf_offset, 0, buf_size);
smp->flags = SMP_F_VOLATILE;
return 1;
too_short:
smp->flags = SMP_F_MAY_CHANGE;
return 0;
}
/* extracts some payload at a fixed position and length */
static int
smp_fetch_payload(struct proxy *px, struct session *s, void *l7, unsigned int opt,
const struct arg *arg_p, struct sample *smp, const char *kw)
{
unsigned int buf_offset = arg_p[0].data.uint;
unsigned int buf_size = arg_p[1].data.uint;
struct channel *chn;
if (!s)
return 0;
chn = ((opt & SMP_OPT_DIR) == SMP_OPT_DIR_RES) ? s->rep : s->req;
if (!chn)
return 0;
if (buf_size > chn->buf->size || buf_offset + buf_size > chn->buf->size) {
/* will never match */
smp->flags = 0;
return 0;
}
if (buf_offset + buf_size > chn->buf->i)
goto too_short;
/* init chunk as read only */
smp->type = SMP_T_CBIN;
chunk_initlen(&smp->data.str, chn->buf->p + buf_offset, 0, buf_size ? buf_size : (chn->buf->i - buf_offset));
smp->flags = SMP_F_VOLATILE;
if (!buf_size && !channel_full(chn) && !channel_input_closed(chn))
smp->flags |= SMP_F_MAY_CHANGE;
return 1;
too_short:
smp->flags = SMP_F_MAY_CHANGE;
return 0;
}
/* This function is used to validate the arguments passed to a "payload_lv" fetch
* keyword. This keyword allows two positive integers and an optional signed one,
* with the second one being strictly positive and the third one being greater than
* the opposite of the two others if negative. It is assumed that the types are
* already the correct ones. Returns 0 on error, non-zero if OK. If <err_msg> 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.
*/
static int val_payload_lv(struct arg *arg, char **err_msg)
{
if (!arg[1].data.uint) {
memprintf(err_msg, "payload length must be > 0");
return 0;
}
if (arg[2].type == ARGT_SINT &&
(int)(arg[0].data.uint + arg[1].data.uint + arg[2].data.sint) < 0) {
memprintf(err_msg, "payload offset too negative");
return 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 = {ILH, {
{ "payload", smp_fetch_payload, ARG2(2,UINT,UINT), NULL, SMP_T_CBIN, SMP_USE_L6REQ|SMP_USE_L6RES },
{ "payload_lv", smp_fetch_payload_lv, ARG3(2,UINT,UINT,SINT), val_payload_lv, SMP_T_CBIN, SMP_USE_L6REQ|SMP_USE_L6RES },
{ "rdp_cookie", smp_fetch_rdp_cookie, ARG1(0,STR), NULL, SMP_T_CSTR, SMP_USE_L6REQ },
{ "rdp_cookie_cnt", smp_fetch_rdp_cookie_cnt, ARG1(0,STR), NULL, SMP_T_UINT, SMP_USE_L6REQ },
{ "rep_ssl_hello_type", smp_fetch_ssl_hello_type, 0, NULL, SMP_T_UINT, SMP_USE_L6RES },
{ "req_len", smp_fetch_len, 0, NULL, SMP_T_UINT, SMP_USE_L6REQ },
{ "req_ssl_hello_type", smp_fetch_ssl_hello_type, 0, NULL, SMP_T_UINT, SMP_USE_L6REQ },
{ "req_ssl_sni", smp_fetch_ssl_hello_sni, 0, NULL, SMP_T_CSTR, SMP_USE_L6REQ },
{ "req_ssl_ver", smp_fetch_req_ssl_ver, 0, NULL, SMP_T_UINT, SMP_USE_L6REQ },
{ "req.len", smp_fetch_len, 0, NULL, SMP_T_UINT, SMP_USE_L6REQ },
{ "req.payload", smp_fetch_payload, ARG2(2,UINT,UINT), NULL, SMP_T_CBIN, SMP_USE_L6REQ },
{ "req.payload_lv", smp_fetch_payload_lv, ARG3(2,UINT,UINT,SINT), val_payload_lv, SMP_T_CBIN, SMP_USE_L6REQ },
{ "req.rdp_cookie", smp_fetch_rdp_cookie, ARG1(0,STR), NULL, SMP_T_CSTR, SMP_USE_L6REQ },
{ "req.rdp_cookie_cnt", smp_fetch_rdp_cookie_cnt, ARG1(0,STR), NULL, SMP_T_UINT, SMP_USE_L6REQ },
{ "req.ssl_hello_type", smp_fetch_ssl_hello_type, 0, NULL, SMP_T_UINT, SMP_USE_L6REQ },
{ "req.ssl_sni", smp_fetch_ssl_hello_sni, 0, NULL, SMP_T_CSTR, SMP_USE_L6REQ },
{ "req.ssl_ver", smp_fetch_req_ssl_ver, 0, NULL, SMP_T_UINT, SMP_USE_L6REQ },
{ "res.len", smp_fetch_len, 0, NULL, SMP_T_UINT, SMP_USE_L6RES },
{ "res.payload", smp_fetch_payload, ARG2(2,UINT,UINT), NULL, SMP_T_CBIN, SMP_USE_L6RES },
{ "res.payload_lv", smp_fetch_payload_lv, ARG3(2,UINT,UINT,SINT), val_payload_lv, SMP_T_CBIN, SMP_USE_L6RES },
{ "res.ssl_hello_type", smp_fetch_ssl_hello_type, 0, NULL, SMP_T_UINT, SMP_USE_L6RES },
{ "wait_end", smp_fetch_wait_end, 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 = {ILH, {
{ "payload", "req.payload", pat_parse_str, pat_match_str },
{ "payload_lv", "req.payload_lv", pat_parse_str, pat_match_str },
{ "req_rdp_cookie", "req.rdp_cookie", pat_parse_str, pat_match_str },
{ "req_rdp_cookie_cnt", "req.rdp_cookie_cnt", pat_parse_int, pat_match_int },
{ "req_ssl_sni", "req.ssl_sni", pat_parse_str, pat_match_str },
{ "req_ssl_ver", "req.ssl_ver", pat_parse_dotted_ver, pat_match_int },
{ /* END */ },
}};
__attribute__((constructor))
static void __payload_init(void)
{
sample_register_fetches(&smp_kws);
acl_register_keywords(&acl_kws);
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/