This patch add option crc32c (PP2_TYPE_CRC32C) to proxy protocol v2.
It compute the checksum of proxy protocol v2 header as describe in
"doc/proxy-protocol.txt".
This patch implement proxy protocol v2 options related to crypto information:
ssl-cipher (PP2_SUBTYPE_SSL_CIPHER), cert-sig (PP2_SUBTYPE_SSL_SIG_ALG) and
cert-key (PP2_SUBTYPE_SSL_KEY_ALG).
A number of counters have been added at special places helping better
understanding certain bug reports. These counters are maintained per
thread and are shown using "show activity" on the CLI. The "clear
counters" commands also reset these counters. The output is sent as a
single write(), which currently produces up to about 7 kB of data for
64 threads. If more counters are added, it may be necessary to write
into multiple buffers, or to reset the counters.
To backport to 1.8 to help collect more detailed bug reports.
It looks like two version of the protocol exist as reported by
Andreas Mahnke. This patch add support for both legacy and standard CIP
protocol according to NetScaler specifications.
Original informations about the client are stored in the CIP encapsulated
IP header, hence there is no need to consider original IP packet length
to determine if data are missing. Instead this change detect missing
data if the remaining buffer is large enough to contain a minimal IP and
TCP header and if the buffer has as much data as CIP is telling.
There is minimal gain in checking first the IP header length and then
the TCP header length since we always want to capture information about
both protocols.
IPv4 length calculation was incorrect since IPv4 ip_len actually defines
the total length of IPv4 header and following data.
Buffer line is manually incremented in order to progress in the trash
buffer but calculation are made omitting this manual offset.
This leads to random packets being rejected with the following error:
HTTP/1: Truncated NetScaler Client IP header received
Instead, once original IP header is found, use the IP header length
without considering the CIP encapsulation.
During the migration to the second version of the pools, the new
functions and pool pointers were all called "pool_something2()" and
"pool2_something". Now there's no more pool v1 code and it's a real
pain to still have to deal with this. Let's clean this up now by
removing the "2" everywhere, and by renaming the pool heads
"pool_head_something".
This patch introduces a new struct conn_stream. It's the stream-side of
a multiplexed connection. A pool is created and destroyed on exit. For
now the conn_streams are not used at all.
A new sample fetch function reports either 1 or 2 for the on-wire encoding,
to indicate if the request was received using the HTTP/1.x format or HTTP/2
format. Note that it reports the on-wire encoding, not the version presented
in the request header.
This will possibly have to evolve if it becomes necessary to report the
encoding on the server side as well.
Selecting a mux based on ALPN and the proxy mode will quickly become a
pain. This commit provides new functions to register/lookup a mux based
on the ALPN string and the proxy mode to make this easier. Given that
we're not supposed to support a wide range of muxes, the lookup should
not have any measurable performance impact.
For HTTP/2 and QUIC, we'll need to deal with multiplexed streams inside
a connection. After quite a long brainstorming, it appears that the
connection interface to the existing streams is appropriate just like
the connection interface to the lower layers. In fact we need to have
the mux layer in the middle of the connection, between the transport
and the data layer.
A mux can exist on two directions/sides. On the inbound direction, it
instanciates new streams from incoming connections, while on the outbound
direction it muxes streams into outgoing connections. The difference is
visible on the mux->init() call : in one case, an upper context is already
known (outgoing connection), and in the other case, the upper context is
not yet known (incoming connection) and will have to be allocated by the
mux. The session doesn't have to create the new streams anymore, as this
is performed by the mux itself.
This patch introduces this and creates a pass-through mux called
"mux_pt" which is used for all new connections and which only
calls the data layer's recv,send,wake() calls. One incoming stream
is immediately created when init() is called on the inbound direction.
There should not be any visible impact.
Note that the connection's mux is purposely not set until the session
is completed so that we don't accidently run with the wrong mux. This
must not cause any issue as the xprt_done_cb function is always called
prior to using mux's recv/send functions.
In transport-layer functions (snd_buf/rcv_buf), it's very problematic
never to know if polling changes made to the connection will be propagated
or not. This has led to some conn_cond_update_polling() calls being placed
at a few places to cover both the cases where the function is called from
the upper layer and when it's called from the lower layer. With the arrival
of the MUX, this becomes even more complicated, as the upper layer will not
have to manipulate anything from the connection layer directly and will not
have to push such updates directly either. But the snd_buf functions will
need to see their updates committed when called from upper layers.
The solution here is to introduce a connection flag set by the connection
handler (and possibly any other similar place) indicating that the caller
is committed to applying such changes on return. This way, the called
functions will be able to apply such changes by themselves before leaving
when the flag is not set, and the upper layer will not have to care about
that anymore.
These flags are not exactly for the data layer, they instead indicate
what is expected from the transport layer. Since we're going to split
the connection between the transport and the data layers to insert a
mux layer, it's important to have a clear idea of what each layer does.
All function conn_data_* used to manipulate these flags were renamed to
conn_xprt_*.
The ->init() callback of the connection's data layer was only used to
complete the session's initialisation since sessions and streams were
split apart in 1.6. The problem is that it creates a big confusion in
the layers' roles as the session has to register a dummy data layer
when waiting for a handshake to complete, then hand it off to the
stream which will replace it.
The real need is to notify that the transport has finished initializing.
This should enable a better splitting between these layers.
This patch thus introduces a connection-specific callback called
xprt_done_cb() which informs about handshake successes or failures. With
this, data->init() can disappear, CO_FL_INIT_DATA as well, and we don't
need to register a dummy data->wake() callback to be notified of errors.
Till now connections used to rely exclusively on file descriptors. It
was planned in the past that alternative solutions would be implemented,
leading to member "union t" presenting sock.fd only for now.
With QUIC, the connection will need to continue to exist but will not
rely on a file descriptor but a connection ID.
So this patch introduces a "connection handle" which is either a file
descriptor or a connection ID, to replace the existing "union t". We've
now removed the intermediate "struct sock" which was never used. There
is no functional change at all, though the struct connection was inflated
by 32 bits on 64-bit platforms due to alignment.
It's more efficient this way, as it allows to flush a send buffer before
receiving data in the other one. This can lead to a slightly faster buffer
recycling, thus slightly less memory and a small performance increase by
using a hotter cache.
Very early in the connection rework process leading to v1.5-dev12, commit
56a77e5 ("MEDIUM: connection: complete the polling cleanups") marked the
end of use for this flag which since was never set anymore, but it continues
to be tested. Let's kill it now.
This flag is always set when we end up here, for each and every data
layer (idle, stream-interface, checks), and continuing to test it
leaves a big risk of forgetting to set it as happened once already
before 1.5-dev13.
It could make sense to backport this into stable branches as part of
the connection flag fixes, after some cool down period.
Despite the previous commit working fine on all tests, it's still not
sufficient to completely address the problem. If the connection handler
is called with an event validating an L4 connection but some handshakes
remain (eg: accept-proxy), it will still wake the function up, which
will not report the activity, and will not detect a change once the
handshake it complete so it will not notify the ->wake() handler.
In fact the only reason why the ->wake() handler is still called here
is because after dropping the last handshake, we try to call ->recv()
and ->send() in turn and change the flags in order to detect a data
activity. But if for any reason the data layer is not interested in
reading nor writing, it will not get these events.
A cleaner way to address this is to call the ->wake() handler only
on definitive status changes (shut, error), on real data activity,
and on a complete connection setup, measured as CONNECTED with no
more handshake pending.
It could be argued that the handshake flags have to be made part of
the condition to set CO_FL_CONNECTED but that would currently break
a part of the health checks. Also a handshake could appear at any
moment even after a connection is established so we'd lose the
ability to detect a second end of handshake.
For now the situation around CO_FL_CONNECTED is not clean :
- session_accept() only sets CO_FL_CONNECTED if there's no pending
handshake ;
- conn_fd_handler() will set it once L4 and L6 are complete, which
will do what session_accept() above refrained from doing even if
an accept_proxy handshake is still pending ;
- ssl_sock_infocbk() and ssl_sock_handshake() consider that a
handshake performed with CO_FL_CONNECTED set is a renegociation ;
=> they should instead filter on CO_FL_WAIT_L6_CONN
- all ssl_fc_* sample fetch functions wait for CO_FL_CONNECTED before
accepting to fetch information
=> they should also get rid of any pending handshake
- smp_fetch_fc_rcvd_proxy() uses !CO_FL_CONNECTED instead of
CO_FL_ACCEPT_PROXY
- health checks (standard and tcp-checks) don't check for HANDSHAKE
and may report a successful check based on CO_FL_CONNECTED while
not yet done (eg: send buffer full on send_proxy).
This patch aims at solving some of these side effects in a backportable
way before this is reworked in depth :
- we need to call ->wake() to report connection success, measure
connection time, notify that the data layer is ready and update
the data layer after activity ; this has to be done either if
we switch from pending {L4,L6}_CONN to nothing with no handshakes
left, or if we notice some handshakes were pending and are now
done.
- we document that CO_FL_CONNECTED exactly means "L4 connection
setup confirmed at least once, L6 connection setup confirmed
at least once or not necessary, all this regardless of any
possibly remaining handshakes or future L6 negociations".
This patch also renames CO_FL_CONN_STATUS to the more explicit
CO_FL_NOTIFY_DATA, and works around the previous flags trick consiting
in setting an impossible combination of flags to notify the data layer,
by simply clearing the current flags.
This fix should be backported to 1.7, 1.6 and 1.5.
Matthias Fechner reported a regression in 1.7.3 brought by the backport
of commit 819efbf ("BUG/MEDIUM: tcp: don't poll for write when connect()
succeeds"), causing some connections to fail to establish once in a while.
While this commit itself was a fix for a bad sequencing of connection
events, it in fact unveiled a much deeper bug going back to the connection
rework era in v1.5-dev12 : 8f8c92f ("MAJOR: connection: add a new
CO_FL_CONNECTED flag").
It's worth noting that in a lab reproducing a similar environment as
Matthias' about only 1 every 19000 connections exhibit this behaviour,
making the issue not so easy to observe. A trick to make the problem
more observable consists in disabling non-blocking mode on the socket
before calling connect() and re-enabling it later, so that connect()
always succeeds. Then it becomes 100% reproducible.
The problem is that this CO_FL_CONNECTED flag is tested after deciding to
call the data layer (typically the stream interface but might be a health
check as well), and that the decision to call the data layer relies on a
change of one of the flags covered by the CO_FL_CONN_STATE set, which is
made of CO_FL_CONNECTED among others.
Before the fix above, this bug couldn't appear with TCP but it could
appear with Unix sockets. Indeed, connect() was always considered
blocking so the CO_FL_WAIT_L4_CONN connection flag was always set, and
polling for write events was always enabled. This used to guarantee that
the conn_fd_handler() could detect a change among the CO_FL_CONN_STATE
flags.
Now with the fix above, if a connect() immediately succeeds for non-ssl
connection with send-proxy enabled, and no data in the buffer (thus TCP
mode only), the CO_FL_WAIT_L4_CONN flag is not set, the lack of data in
the buffer doesn't enable polling flags for the data layer, the
CO_FL_CONNECTED flag is not set due to send-proxy still being pending,
and once send-proxy is done, its completion doesn't cause the data layer
to be woken up due to the fact that CO_FL_CONNECT is still not present
and that the CO_FL_SEND_PROXY flag is not watched in CO_FL_CONN_STATE.
Then no progress is made when data are received from the client (and
attempted to be forwarded), because a CF_WRITE_NULL (or CF_WRITE_PARTIAL)
flag is needed for the stream-interface state to turn from SI_ST_CON to
SI_ST_EST, allowing ->chk_snd() to be called when new data arrive. And
the only way to set this flag is to call the data layer of course.
After the connect timeout, the connection gets killed and if in the mean
time some data have accumulated in the buffer, the retry will succeed.
This patch fixes this situation by simply placing the update of
CO_FL_CONNECTED where it should have been, before the check for a flag
change needed to wake up the data layer and not after.
This fix must be backported to 1.7, 1.6 and 1.5. Versions not having
the patch above are still affected for unix sockets.
Special thanks to Matthias Fechner who provided a very detailed bug
report with a bisection designating the faulty patch, and to Olivier
Houchard for providing full access to a pretty similar environment where
the issue could first be reproduced.
fc_rcvd_proxy : boolean
Returns true if the client initiated the connection with a PROXY protocol
header.
A flag is added on the struct connection if a PROXY header is successfully
parsed.
There are still a lot of #ifdef USE_OPENSSL in the code (still 43
occurences) because we never know if we can directly access ssl_sock
or not. This patch attacks the problem differently by providing a
way for transport layers to register themselves and for users to
retrieve the pointer. Unregistered transport layers will point to NULL
so it will be easy to check if SSL is registered or not. The mechanism
is very inexpensive as it relies on a two-entries array of pointers,
so the performance will not be affected.
Originally, tcphdr's source and dest from Linux were used to get the
source and port which led to a build issue on BSD oses.
To avoid side problems related to network then we just use an internal
struct as we need only those two fields.
When NetScaler application switch is used as L3+ switch, informations
regarding the original IP and TCP headers are lost as a new TCP
connection is created between the NetScaler and the backend server.
NetScaler provides a feature to insert in the TCP data the original data
that can then be consumed by the backend server.
Specifications and documentations from NetScaler:
https://support.citrix.com/article/CTX205670https://www.citrix.com/blogs/2016/04/25/how-to-enable-client-ip-in-tcpip-option-of-netscaler/
When CIP is enabled on the NetScaler, then a TCP packet is inserted just after
the TCP handshake. This is composed as:
- CIP magic number : 4 bytes
Both sender and receiver have to agree on a magic number so that
they both handle the incoming data as a NetScaler Client IP insertion
packet.
- Header length : 4 bytes
Defines the length on the remaining data.
- IP header : >= 20 bytes if IPv4, 40 bytes if IPv6
Contains the header of the last IP packet sent by the client during TCP
handshake.
- TCP header : >= 20 bytes
Contains the header of the last TCP packet sent by the client during TCP
handshake.
When compiled with GCC 6, the IP address specified for a frontend was
ignored and HAProxy was listening on all addresses instead. This is
caused by an incomplete copy of a "struct sockaddr_storage".
With the GNU Libc, "struct sockaddr_storage" is defined as this:
struct sockaddr_storage
{
sa_family_t ss_family;
unsigned long int __ss_align;
char __ss_padding[(128 - (2 * sizeof (unsigned long int)))];
};
Doing an aggregate copy (ss1 = ss2) is different than using memcpy():
only members of the aggregate have to be copied. Notably, padding can be
or not be copied. In GCC 6, some optimizations use this fact and if a
"struct sockaddr_storage" contains a "struct sockaddr_in", the port and
the address are part of the padding (between sa_family and __ss_align)
and can be not copied over.
Therefore, we replace any aggregate copy by a memcpy(). There is another
place using the same pattern. We also fix a function receiving a "struct
sockaddr_storage" by copy instead of by reference. Since it only needs a
read-only copy, the function is converted to request a reference.
There's quite some inconsistency in the internal API. listener_accept()
which is the main accept() function returns void but is declared as int
in the include file. It's assigned to proto->accept() for all stream
protocols where an int is expected but the result is never checked (nor
is it documented by the way). This proto->accept() is in turn assigned
to fd->iocb() which is supposed to return an int composed of FD_WAIT_*
flags, but which is never checked either.
So let's fix all this mess :
- nobody checks accept()'s return
- nobody checks iocb()'s return
- nobody sets a return value
=> let's mark all these functions void and keep the current ones intact.
Additionally we now include listener.h from listener.c to ensure we won't
silently hide this incoherency in the future.
Note that this patch could/should be backported to 1.6 and even 1.5 to
simplify debugging sessions.
Until now, the code assumed that it can get the offset to the first TLV
header just by subtracting the length of the TLV part from the length of
the complete buffer. However, if the buffer contains actual data after
the header, this computation is flawed and leads to haproxy trying to
parse TLV headers from the proxied data.
This change fixes this by making sure that the offset to the first TLV
header is calculated based from the start of the buffer -- simply by
adding the size of the proxy protocol v2 header plus the address
family-dependent size of the address information block.
With HTTP/2, we'll have to support multiplexed streams. A stream is in
fact the largest part of what we currently call a session, it has buffers,
logs, etc.
In order to catch any error, this commit removes any reference to the
struct session and tries to rename most "session" occurrences in function
names to "stream" and "sess" to "strm" when that's related to a session.
The files stream.{c,h} were added and session.{c,h} removed.
The session will be reintroduced later and a few parts of the stream
will progressively be moved overthere. It will more or less contain
only what we need in an embryonic session.
Sample fetch functions and converters will have to change a bit so
that they'll use an L5 (session) instead of what's currently called
"L4" which is in fact L6 for now.
Once all changes are completed, we should see approximately this :
L7 - http_txn
L6 - stream
L5 - session
L4 - connection | applet
There will be at most one http_txn per stream, and a same session will
possibly be referenced by multiple streams. A connection will point to
a session and to a stream. The session will hold all the information
we need to keep even when we don't yet have a stream.
Some more cleanup is needed because some code was already far from
being clean. The server queue management still refers to sessions at
many places while comments talk about connections. This will have to
be cleaned up once we have a server-side connection pool manager.
Stream flags "SN_*" still need to be renamed, it doesn't seem like
any of them will need to move to the session.
It's now called conn_sock_drain() to make it clear that it only reads
at the sock layer and not at the data layer. The function was too big
to remain inlined and it's used at a few places where size counts.
This function is an equivalent to send() which operates over a connection
instead of a file descriptor. It checks that the control layer is ready
and that it's allowed to send. If automatically enables polling if it
cannot send. It simplifies the return checks by returning zero in all
cases where it cannot send so that the caller only has to care about
negative values indicating errors.
This patch makes it possible to create binds and servers in separate
namespaces. This can be used to proxy between multiple completely independent
virtual networks (with possibly overlapping IP addresses) and a
non-namespace-aware proxy implementation that supports the proxy protocol (v2).
The setup is something like this:
net1 on VLAN 1 (namespace 1) -\
net2 on VLAN 2 (namespace 2) -- haproxy ==== proxy (namespace 0)
net3 on VLAN 3 (namespace 3) -/
The proxy is configured to make server connections through haproxy and sending
the expected source/target addresses to haproxy using the proxy protocol.
The network namespace setup on the haproxy node is something like this:
= 8< =
$ cat setup.sh
ip netns add 1
ip link add link eth1 type vlan id 1
ip link set eth1.1 netns 1
ip netns exec 1 ip addr add 192.168.91.2/24 dev eth1.1
ip netns exec 1 ip link set eth1.$id up
...
= 8< =
= 8< =
$ cat haproxy.cfg
frontend clients
bind 127.0.0.1:50022 namespace 1 transparent
default_backend scb
backend server
mode tcp
server server1 192.168.122.4:2222 namespace 2 send-proxy-v2
= 8< =
A bind line creates the listener in the specified namespace, and connections
originating from that listener also have their network namespace set to
that of the listener.
A server line either forces the connection to be made in a specified
namespace or may use the namespace from the client-side connection if that
was set.
For more documentation please read the documentation included in the patch
itself.
Signed-off-by: KOVACS Tamas <ktamas@balabit.com>
Signed-off-by: Sarkozi Laszlo <laszlo.sarkozi@balabit.com>
Signed-off-by: KOVACS Krisztian <hidden@balabit.com>
Previously, if hdr_v2->len was less than the length of the protocol
specific address information we could have read after the end of the
buffer and initialize the sockaddr structure with junk.
Signed-off-by: KOVACS Krisztian <hidden@balabit.com>
[WT: this is only tagged medium since proxy protocol is only used from
trusted sources]
This must be backported to 1.5.
There are two sample commands to get information about the presence of a
client certificate.
ssl_fc_has_crt is true if there is a certificate present in the current
connection
ssl_c_used is true if there is a certificate present in the session.
If a session has stopped and resumed, then ssl_c_used could be true, while
ssl_fc_has_crt is false.
In the client byte of the TLS TLV of Proxy Protocol V2, there is only one
bit to indicate whether a certificate is present on the connection. The
attached patch adds a second bit to indicate the presence for the session.
This maintains backward compatibility.
[wt: this should be backported to 1.5 to help maintain compatibility
between versions]
Last commit 77d1f01 ("BUG/MEDIUM: connection: fix memory corruption
when building a proxy v2 header") was wrong, using &cn_trash instead
of cn_trash resulting in a warning and the client's SSL cert CN not
being stored at the proper location.
Thanks to Lukas Tribus for spotting this quickly.
This should be backported to 1.5 after the patch above is backported.
'ssl_sock_get_common_name' applied to a connection was also renamed
'ssl_sock_get_remote_common_name'. Currently, this function is only used
with protocol PROXYv2 to retrieve the client certificate's common name.
A further usage could be to retrieve the server certificate's common name
on an outgoing connection.
