It's commonly needed to know how many SSL asymmetric keys are computed
per second on either side (frontend or backend), and to know the SSL
session reuse ratio. Now we compute these values and report them in
"show info".
Currently exp_replace() (which is used in reqrep/reqirep) is
vulnerable to a buffer overrun. I have been able to reproduce it using
the attached configuration file and issuing the following command:
wget -O - -S -q http://localhost:8000/`perl -e 'print "a"x4000'`/cookie.php
Str was being checked only in in while (str) and it was possible to
read past that when more than one character was being accessed in the
loop.
WT:
Note that this bug is only marked MEDIUM because configurations
capable of triggering this bug are very unlikely to exist at all due
to the fact that most rewrites consist in static string additions
that largely fit into the reserved area (8kB by default).
This fix should also be backported to 1.4 and possibly even 1.3 since
it seems to have been present since 1.1 or so.
Config:
-------
global
maxconn 500
stats socket /tmp/haproxy.sock mode 600
defaults
timeout client 1000
timeout connect 5000
timeout server 5000
retries 1
option redispatch
listen stats
bind :8080
mode http
stats enable
stats uri /stats
stats show-legends
listen tcp_1
bind :8000
mode http
maxconn 400
balance roundrobin
reqrep ^([^\ :]*)\ /(.*)/(.*)\.php(.*) \1\ /\3.php?arg=\2\2\2\2\2\2\2\2\2\2\2\2\2\4
server srv1 127.0.0.1:9000 check port 9000 inter 1000 fall 1
server srv2 127.0.0.1:9001 check port 9001 inter 1000 fall 1
Agent will have the ability to return a weight without indicating an
up/down status. Currently this is not possible, so let's add a 5th
result CHK_RES_NEUTRAL for this purpose. It has been mapped to the
unused HCHK_STATUS_CHECKED which already serves as a neutral delimitor
between initiated checks and those returning a result.
Instead of enabling/disabling maintenance mode and drain mode separately
using 4 actions, we now offer 3 simplified actions :
- set state to READY
- set state to DRAIN
- set state to MAINT
They have the benefit of reporting the same state as displayed on the page,
and of doing the double-switch atomically eg when switching from drain to
maint.
Note that the old actions are still supported for users running scripts.
This patch adds support for a new "drain" mode. So now we have 3 admin
modes for a server :
- READY
- DRAIN
- MAINT
The drain mode disables load balancing but leaves the server up. It can
coexist with maint, except that maint has precedence. It is also inherited
from tracked servers, so just like maint, it's represented with 2 bits.
New functions were designed to set/clear each flag and to propagate the
changes to tracking servers when relevant, and to log the changes. Existing
functions srv_set_adm_maint() and srv_set_adm_ready() were replaced to make
use of the new functions.
Currently the drain mode is not yet used, however the whole logic was tested
with all combinations of set/clear of both flags in various orders to catch
all corner cases.
This function was taken from check_set_server_drain(). It does not
consider health checks at all and only sets a server to stopping
provided it's not in maintenance and is not currently stopped. The
resulting state will be STOPPING. The state change is propagated
to tracked servers.
For now the function is not used, but the goal is to split health
checks status from server status and to be able to change a server's
state regardless of health checks statuses.
This function was taken from check_set_server_up(). It does not consider
health checks at all and only sets a server up provided it's not in
maintenance. The resulting state may be either RUNNING or STARTING
depending on the presence of a slowstart or not. The state change is
propagated to tracked servers.
For now the function is not used, but the goal is to split health
checks status from server status and to be able to change a server's
state regardless of health checks statuses.
This function was extracted from check_set_server_down(). In only
manipulates the server state and does not consider the health checks
at all, nor does it modify their status. It takes a reason message to
report in logs, however it passes NULL when recursing through the
trackers chain.
For now the function is not used, but the goal is to split health
checks status from server status and to be able to change a server's
state regardless of health checks statuses.
srv_adm_append_status() was renamed srv_append_status() since it's no
more dedicated to maintenance mode. It now supports a reason which if
not null is appended to the output string.
We don't have to handle the maintenance transition here anymore so we
can simplify the functions and conditions. This also means that we don't
need the disable/enable functions but only a function to switch to each
new state.
It's worth mentionning that at this stage there are still confusions
between the server state and the checks states. For example, the health
check's state is adjusted from tracked servers changing state, while it
should not be.
This change now involves a new flag SRV_ADMF_IMAINT to note that the
maintenance status of a server is inherited from another server. Thus,
we know at each server level in the chain if it's running, in forced
maintenance or in a maintenance status because it tracks another server,
or even in both states.
Disabling a server propagates this flag down to other servers. Enabling
a server flushes the flag down. A server becomes up again once both of
its flags are cleared.
Two new functions "srv_adm_set_maint()" and "srv_adm_set_ready()" are used to
manipulate this maintenance status. They're used by the CLI and the stats
page.
Now the stats page always says "MAINT" instead of "MAINT(via)" and it's
only the chk/down field which reports "via x/y" when the status is
inherited from another server, but it doesn't say it when a server was
forced into maintenance. The CSV output indicates "MAINT (via x/y)"
instead of only "MAINT(via)". This is the most accurate representation.
One important thing is that now entering/leaving maintenance for a
tracking server correctly follows the state of the tracked server.
Checks.c has become a total mess. A number of proxy or server maintenance
and queue management functions were put there probably because they were
used there, but that makes the code untouchable. And that's without saying
that their names does not always relate to what they really do!
So let's do a first pass by moving these ones :
- set_backend_down() => backend.c
- redistribute_pending() => queue.c:pendconn_redistribute()
- check_for_pending() => queue.c:pendconn_grab_from_px()
- shutdown_sessions => server.c:srv_shutdown_sessions()
- shutdown_backup_sessions => server.c:srv_shutdown_backup_sessions()
All of them were moved at once.
Servers used to have 3 flags to store a state, now they have 4 states
instead. This avoids lots of confusion for the 4 remaining undefined
states.
The encoding from the previous to the new states can be represented
this way :
SRV_STF_RUNNING
| SRV_STF_GOINGDOWN
| | SRV_STF_WARMINGUP
| | |
0 x x SRV_ST_STOPPED
1 0 0 SRV_ST_RUNNING
1 0 1 SRV_ST_STARTING
1 1 x SRV_ST_STOPPING
Note that the case where all bits were set used to exist and was randomly
dealt with. For example, the task was not stopped, the throttle value was
still updated and reported in the stats and in the http_server_state header.
It was the same if the server was stopped by the agent or for maintenance.
It's worth noting that the internal function names are still quite confusing.
Now we introduce srv->admin and srv->prev_admin which are bitfields
containing one bit per source of administrative status (maintenance only
for now). For the sake of backwards compatibility we implement a single
source (ADMF_FMAINT) but the code already checks any source (ADMF_MAINT)
where the STF_MAINTAIN bit was previously checked. This will later allow
us to add ADMF_IMAINT for maintenance mode inherited from tracked servers.
Along doing these changes, it appeared that some places will need to be
revisited when implementing the inherited bit, this concerns all those
modifying the ADMF_FMAINT bit (enable/disable actions on the CLI or stats
page), and the checks to report "via" on the stats page. But currently
the code is harmless.
Till now, the server's state and flags were all saved as a single bit
field. It causes some difficulties because we'd like to have an enum
for the state and separate flags.
This commit starts by splitting them in two distinct fields. The first
one is srv->state (with its counter-part srv->prev_state) which are now
enums, but which still contain bits (SRV_STF_*).
The flags now lie in their own field (srv->flags).
The function srv_is_usable() was updated to use the enum as input, since
it already used to deal only with the state.
Note that currently, the maintenance mode is still in the state for
simplicity, but it must move as well.
When run in daemon mode (i.e. with at least one forked process) and using
the epoll poller, sending USR1 (graceful shutdown) to the worker processes
can cause some workers to start running at 100% CPU. Precondition is having
an established HTTP keep-alive connection when the signal is received.
The cloned (during fork) listening sockets do not get closed in the parent
process, thus they do not get removed from the epoll set automatically
(see man 7 epoll). This can lead to the process receiving epoll events
that it doesn't feel responsible for, resulting in an endless loop around
epoll_wait() delivering these events.
The solution is to explicitly remove these file descriptors from the epoll
set. To not degrade performance, care was taken to only do this when
neccessary, i.e. when the file descriptor was cloned during fork.
Signed-off-by: Conrad Hoffmann <conrad@soundcloud.com>
[wt: a backport to 1.4 could be studied though chances to catch the bug are low]
We used to call srv_is_usable() with either the current state and weights
or the previous ones. This causes trouble for future changes, so let's first
split it in two variants :
- srv_is_usable(srv) considers the current status
- srv_was_usable(srv) considers the previous status
Detecting that a server's status has changed is a bit messy, as well
as it is to commit the status changes. We'll have to add new conditions
soon and we'd better avoid to multiply the number of touched locations
with the high risk of forgetting them.
This commit introduces :
- srv_lb_status_changed() to report if the status changed from the
previously committed one ;
- svr_lb_commit_status() to commit the current status
The function is now used by all load-balancing algorithms.
This flag is only a copy of (srv->uweight == 0), so better get rid of
it to reduce some of the confusion that remains in the code, and use
a simple function to return this state based on this weight instead.
Long-lived sessions are often subject to half-closed sessions resulting in
a lot of sessions appearing in FIN_WAIT state in the system tables, and no
way for haproxy to get rid of them. This typically happens because clients
suddenly disconnect without sending any packet (eg: FIN or RST was lost in
the path), and while the server detects this using an applicative heart
beat, haproxy does not close the connection.
This patch adds two new timeouts : "timeout client-fin" and
"timeout server-fin". The former allows one to override the client-facing
timeout when a FIN has been received or sent. The latter does the same for
server-facing connections, which is less useful.
git.1wt.eu is painfully slow and some people experience issues with
it. Better hide it and only advertise git.haproxy.org which is mirrored
on a faster server.
Also replace haproxy.1wt.eu with www.haproxy.org in the download URL
which appears in the stats page.
Being able to map prefixes to values is already used for IPv4/IPv6
but was not yet used with strings. It can be very convenient to map
directories to server farms but large lists may be slow.
By using ebmb_insert_prefix() and ebmb_lookup_longest(), we can
insert strings with their own length as a prefix, and lookup
candidate strings and ensure that the longest matching one will
be returned, which is the longest string matching the entry.
The is_addr() function indicates if an address is set and is an IPv4
or IPv6 address. Let's rename it is_inet_addr() and make is_addr()
also accept AF_UNIX addresses.
Some consistency checks cannot be performed between frontends, backends
and peers at the moment because there is no way to check for intersection
between processes bound to some processes when the number of processes is
higher than the number of bits in a word.
So first, let's limit the number of processes to the machine's word size.
This means nbproc will be limited to 32 on 32-bit machines and 64 on 64-bit
machines. This is far more than enough considering that configs rarely go
above 16 processes due to scalability and management issues, so 32 or 64
should be fine.
This way we'll ensure we can always build a mask of all the processes a
section is bound to.
This commit modifies the PROXY protocol V2 specification to support headers
longer than 255 bytes allowing for optional extensions. It implements the
PROXY protocol V2 which is a binary representation of V1. This will make
parsing more efficient for clients who will know in advance exactly how
many bytes to read. Also, it defines and implements some optional PROXY
protocol V2 extensions to send information about downstream SSL/TLS
connections. Support for PROXY protocol V1 remains unchanged.
Process shared mutex seems not supported on some OSs (FreeBSD).
This patch checks errors on mutex lock init to fallback
on a private session cache (per process cache) in error cases.
Trying to build with an old gcc and glibc revealed that we must not
state "inline" in our _syscall* definitions since it's already present
in the declaration making use of the _syscall* macros.
On the mailing list, seri0528@naver.com reported an issue when
using balance url_param or balance uri. The request would sometimes
stall forever.
Cyril Bont managed to reproduce it with the configuration below :
listen test :80
mode http
balance url_param q
hash-type consistent
server s demo.1wt.eu:80
and found it appeared with this commit : 80a92c0 ("BUG/MEDIUM: http:
don't start to forward request data before the connect").
The bug is subtle but real. The problem is that the HTTP request
forwarding analyzer refrains from starting to parse the request
body when some LB algorithms might need the body contents, in order
to preserve the data pointer and avoid moving things around during
analysis in case a redispatch is later needed. And in order to detect
that the connection establishes, it watches the response channel's
CF_READ_ATTACHED flag.
The problem is that a request analyzer is not subscribed to a response
channel, so it will only see changes when woken for other (generally
correlated) reasons, such as the fact that part of the request could
be sent. And since the CF_READ_ATTACHED flag is cleared once leaving
process_session(), it is important not to miss it. It simply happens
that sometimes the server starts to respond in a sequence that validates
the connection in the middle of process_session(), that it is detected
after the analysers, and that the newly assigned CF_READ_ATTACHED is
not used to detect that the request analysers need to be called again,
then the flag is lost.
The CF_WAKE_WRITE flag doesn't work either because it's cleared upon
entry into process_session(), ie if we spend more than one call not
connecting.
Thus we need a new flag to tell the connection initiator that we are
specifically interested in being notified about connection establishment.
This new flag is CF_WAKE_CONNECT. It is set by the requester, and is
cleared once the connection succeeds, where CF_WAKE_ONCE is set instead,
causing the request analysers to be scanned again.
For future versions, some better options will have to be considered :
- let all analysers subscribe to both request and response events ;
- let analysers subscribe to stream interface events (reduces number
of useless calls)
- change CF_WAKE_WRITE's semantics to persist across calls to
process_session(), but that is different from validating a
connection establishment (eg: no data sent, or no data to send)
The bug was introduced in 1.5-dev23, no backport is needed.
Till now we used to return a pointer to a rule, but that makes it
complicated to later add support for registering new actions which
may fail. For example, the redirect may fail if the response is too
large to fit into the buffer.
So instead let's return a verdict. But we needed the pointer to the
last rule to get the address of a redirect and to get the realm used
by the auth page. So these pieces of code have moved into the function
and they produce a verdict.
Last fix did address the issue for inlined patterns, but it was not
enough because the flags are lost as well when updating patterns
dynamically over the CLI.
Also if the same file was used once with -i and another time without
-i, their references would have been merged and both would have used
the same matching method.
It's appear that the patterns have two types of flags. The first
ones are relative to the pattern matching, and the second are
relative to the pattern storage. The pattern matching flags are
the same for all the patterns of one expression. Now they are
stored in the expression. The storage flags are information
returned by the pattern mathing function. This information is
relative to each entry and is stored in the "struct pattern".
Now, the expression matching flags are forwarded to the parse
and index functions. These flags are stored during the
configuration parsing, and they are used during the parse and
index actions.
This issue was introduced in dev23 with the major pattern rework,
and is a continuation of commit a631fc8 ("BUG/MAJOR: patterns: -i
and -n are ignored for inlined patterns"). No backport is needed.
These flags are only passed to pattern_read_from_file() which
loads the patterns from a file. The functions used to parse the
patterns from the current line do not provide the means to pass
the pattern flags so they're lost.
This issue was introduced in dev23 with the major pattern rework,
and was reported by Graham Morley. No backport is needed.
Using the previous callback, it's trivial to block the heartbeat attack,
first we control the message length, then we emit an SSL error if it is
out of bounds. A special log is emitted, indicating that a heartbleed
attack was stopped so that they are not confused with other failures.
That way, haproxy can protect itself even when running on an unpatched
SSL stack. Tests performed with openssl-1.0.1c indicate a total success.
Users have seen a huge increase in the rate of SSL handshake failures
starting from 2014/04/08 with the release of the Heartbleed OpenSSL
vulnerability (CVE-2014-0160). Haproxy can detect that a heartbeat
was received in the incoming handshake, and such heartbeats are not
supposed to be common, so let's log a different message when a
handshake error happens after a heartbeat is detected.
This patch only adds the new message and the new code.
The http_(res|req)_keywords_register() functions allow to register
new keywords.
You need to declare a keyword list:
struct http_req_action_kw_list test_kws = {
.scope = "testscope",
.kw = {
{ "test", parse_test },
{ NULL, NULL },
}
};
and a parsing function:
int parse_test(const char **args, int *cur_arg, struct proxy *px, struct http_req_rule *rule, char **err)
{
rule->action = HTTP_REQ_ACT_CUSTOM_STOP;
rule->action_ptr = action_function;
return 0;
}
http_req_keywords_register(&test_kws);
The HTTP_REQ_ACT_CUSTOM_STOP action stops evaluation of rules after
your rule, HTTP_REQ_ACT_CUSTOM_CONT permits the evaluation of rules
after your rule.
This patch allows manipulation of ACL and MAP content thanks to any
information available in a session: source IP address, HTTP request or
response header, etc...
It's an update "on the fly" of the content of the map/acls. This means
it does not resist to reload or restart of HAProxy.
Finn Arne Gangstad suggested that we should have the ability to break
keep-alive when the target server has reached its maxconn and that a
number of connections are present in the queue. After some discussion
around his proposed patch, the following solution was suggested : have
a per-proxy setting to fix a limit to the number of queued connections
on a server after which we break keep-alive. This ensures that even in
high latency networks where keep-alive is beneficial, we try to find a
different server.
This patch is partially based on his original proposal and implements
this configurable threshold.
All the code inherited from version 1.1 still holds a lot ot sessions
called "t" because in 1.1 they were tasks. This naming is very annoying
and sometimes even confusing, for example in code involving tables.
Let's get rid of this once for all and before 1.5-final.
Nothing changed beyond just carefully renaming these variables.
This basically reimplements commit f3221f9 ("MEDIUM: stats: add support
for HTTP keep-alive on the stats page") which was reverted by commit
51437d2 after Igor Chan reported a broken stats page caused by the bug
fix by previous commit.
