*) Added IPv6 and UNIX-domain socket support in "debug_connection"
directive.
*) New function ngx_http_get_forwarded_addr() to look up real client
address.
On input it takes an original address, string in the X-Forwarded-For format
and its length, list of trusted proxies, and a flag indicating to perform
the recursive search. On output it returns NGX_OK and the "deepest" valid
address in a chain, or NGX_DECLINED. It supports AF_INET and AF_INET6.
Additionally, original address and/or proxy may be specified as AF_UNIX.
*) Realip: chains of trusted proxies and IPv6 support.
The module now supports recursive search of client address through
the chain of trusted proxies, controlled by the "real_ip_recursive"
directive (closes#2). It also gets full IPv6 support (closes#44)
and canonical value of the $client_addr variable on address change.
Example:
real_ip_header X-Forwarded-For;
set_real_ip_from 127.0.0.0/8;
set_real_ip_from ::1;
set_real_ip_from unix:;
real_ip_recursive on;
*) Geo: chains of trusted proxies and partial IPv6 support.
The module now supports recursive search of client address through
the chain of trusted proxies, controlled by the "proxy_recursive"
directive in the "geo" block. It also gets partial IPv6 support:
now proxies may be specified with IPv6 addresses.
Example:
geo $test {
...
proxy 127.0.0.1;
proxy ::1;
proxy_recursive;
}
There's also a slight change in behavior. When original client
address (as specified by the "geo" directive) is one of the
trusted proxies, and the value of the X-Forwarded-For request
header cannot not be parsed as a valid address, an original client
address will be used for lookup. Previously, 255.255.255.255 was
used in this case.
*) Geoip: trusted proxies support and partial IPv6 support.
The module now supports recursive search of client address through the
chain of trusted proxies (closes#100), in the same scope as the geo
module. Proxies are listed by the "geoip_proxy" directive, recursive
search is enabled by the "geoip_proxy_recursive" directive. IPv6 is
partially supported: proxies may be specified with IPv6 addresses.
Example:
geoip_country .../GeoIP.dat;
geoip_proxy 127.0.0.1;
geoip_proxy ::1;
geoip_proxy 10.0.0.0/8;
geoip_proxy_recursive on;
*) Upstream: smooth weighted round-robin balancing.
For edge case weights like { 5, 1, 1 } we now produce { a, a, b, a, c, a, a }
sequence instead of { c, b, a, a, a, a, a } produced previously.
Algorithm is as follows: on each peer selection we increase current_weight
of each eligible peer by its weight, select peer with greatest current_weight
and reduce its current_weight by total number of weight points distributed
among peers.
In case of { 5, 1, 1 } weights this gives the following sequence of
current_weight's:
a b c
0 0 0 (initial state)
5 1 1 (a selected)
-2 1 1
3 2 2 (a selected)
-4 2 2
1 3 3 (b selected)
1 -4 3
6 -3 4 (a selected)
-1 -3 4
4 -2 5 (c selected)
4 -2 -2
9 -1 -1 (a selected)
2 -1 -1
7 0 0 (a selected)
0 0 0
To preserve weight reduction in case of failures the effective_weight
variable was introduced, which usually matches peer's weight, but is
reduced temporarily on peer failures.
This change also fixes loop with backup servers and proxy_next_upstream
http_404 (ticket #47), and skipping alive upstreams in some cases if there
are multiple dead ones (ticket #64).
*) Upstream: fixed ip_hash rebalancing with the "down" flag.
Due to weight being set to 0 for down peers, order of peers after sorting
wasn't the same as without the "down" flag (with down peers at the end),
resulting in client rebalancing for clients on other servers. The only
rebalancing which should happen after adding "down" to a server is one
for clients on the server.
The problem was introduced in r1377 (which fixed endless loop by setting
weight to 0 for down servers). The loop is no longer possible with new
smooth algorithm, so preserving original weight is safe.
*) Fixed possible request hang with filter finalization.
With r->filter_finalize set the ngx_http_finalize_connection() wasn't
called from ngx_http_finalize_request() called with NGX_OK, resulting in
r->main->count not being decremented, thus causing request hang in some
rare situations.
Patch by Yichun Zhang (agentzh).
*) Fixed segfault with filter_finalize introduced in r4621 (1.3.0).
See the following thread for more details:
http://mailman.nginx.org/pipermail/nginx-devel/2012-May/002190.html
In case of EMFILE/ENFILE returned from accept() we disable accept events,
and (in case of no accept mutex used) arm timer to re-enable them later.
With accept mutex we just drop it, and rely on normal accept mutex handling
to re-enable accept events once it's acquired again.
As we now handle errors in question, logging level was changed to "crit"
(instead of "alert" used for unknown errors).
Note: the code might call ngx_enable_accept_events() multiple times if
there are many listen sockets. The ngx_enable_accept_events() function was
modified to check if connection is already active (via c->read->active) and
skip it then, thus making multiple calls safe.
The following code resulted in incorrect escaping of uri and possible
segfault:
location / {
rewrite ^(.*) $1?c=$1;
return 200 "$uri";
}
If there were arguments in a rewrite's replacement string, and length was
actually calculated (due to duplicate captures as in the example above,
or variables present), the is_args flag was set and incorrectly copied
after length calculation. This resulted in escaping applied to the uri part
of the replacement, resulting in incorrect escaping. Additionally, buffer
was allocated without escaping expected, thus this also resulted in buffer
overrun and possible segfault.
Fastcgi: fixed padding handling on fixed-size records.
Padding was incorrectly ignored on end request, empty stdout and stderr
fastcgi records. This resulted in protocol desynchronization if fastcgi
application used these records with padding for some reason.
Reported by Ilia Vinokurov.
Added r->state reset on fastcgi/scgi/uwsgi request start.
Failing to do so results in problems if 400 or 414 requests are
redirected to fastcgi/scgi/uwsgi upstream, as well as after invalid
headers got from upstream. This was already fixed for proxy in r3478,
but fastcgi (the only affected protocol at that time) was missed.
Reported by Matthieu Tourne.
On internal redirects this happens via ngx_http_handler() call, which is
not called on named location redirect. As a result incorrect write handler
remained (if previously set) and this might cause incorrect behaviour (likely
request hang).
Patch by Yichun Zhang (agentzh).
*) Fixed segmentation fault in ngx_resolver_create_name_query().
If name passed for resolution was { 0, NULL } (e.g. as a result
of name server returning CNAME pointing to ".") pointer wrapped
to (void *) -1 resulting in segmentation fault on an attempt to
dereference it.
Reported by Lanshun Zhou.
*) Resolver: protection from duplicate responses.
If we already had CNAME in resolver node (i.e. rn->cnlen and rn->u.cname
set), and got additional response with A record, it resulted in rn->cnlen
set and rn->u.cname overwritten by rn->u.addr (or rn->u.addrs), causing
segmentation fault later in ngx_resolver_free_node() on an attempt to free
overwritten rn->u.cname. The opposite (i.e. CNAME got after A) might cause
similar problems as well.
The proxy module context may be NULL in case of filter finalization
(e.g. by image_filter) followed by an internal redirect. This needs
some better handling, but for now just check if ctx is still here.
The problem occured if first uri in try_files was shorter than request uri,
resulting in reserve being 0 and hence allocation skipped. The bug was
introduced in r4584 (1.1.19).
Instead of checking if there is events{} section present in configuration
in init_module handler we now do the same in init_conf handler. This
allows master process to detect incorrect configuration early and
reject it.
We now stop on IOV_MAX iovec entries only if we are going to add new one,
i.e. next buffer can't be coalesced into last iovec.
This also fixes incorrect checks for trailer creation on FreeBSD and
Mac OS X, header.nelts was checked instead of trailer.nelts.
The "complete" flag wasn't cleared on loop iteration start, resulting in
broken behaviour if there were more than IOV_MAX buffers and first
iteration was fully completed (and hence the "complete" flag was set
to 1).
Previous (incorrect) behaviour was to inherit ipv6 rules separately from
ipv4 ones. Now all rules are either inherited (if there are no rules
defined at current level) or not (if there are any rules defined).
Integer overflow is undefined behaviour in C and this indeed caused
problems on Solaris/SPARC (at least in some cases). Fix is to
subtract unsigned integers instead, and then cast result to a signed
one, which is implementation-defined behaviour and used to work.
Strictly speaking, we should compare (unsigned) result with the maximum
value of the corresponding signed integer type instead, this will be
defined behaviour. This will require much more changes though, and
considered to be overkill for now.
Such upstreams cause CPU hog later in the code as number of peers isn't
expected to be 0. Currently this may happen either if there are only backup
servers defined in an upstream block, or if server with ipv6 address used
in an upstream block.
