Commit Graph

9 Commits

Author SHA1 Message Date
Willy Tarreau
144f84a09d MEDIUM: task: extend the state field to 32 bits
It's been too short for quite a while now and is now full. It's still
time to extend it to 32-bits since we have room for this without
wasting any space, so we now gained 16 new bits for future flags.

The values were not reassigned just in case there would be a few
hidden u16 or short somewhere in which these flags are placed (as
it used to be the case with stream->pending_events).

The patch is tagged MEDIUM because this required to update the task's
process() prototype to use an int instead of a short, that's quite a
bunch of places.
2021-03-05 08:30:08 +01:00
Willy Tarreau
61cfdf4fd8 CLEANUP: tree-wide: replace free(x);x=NULL with ha_free(&x)
This makes the code more readable and less prone to copy-paste errors.
In addition, it allows to place some __builtin_constant_p() predicates
to trigger a link-time error in case the compiler knows that the freed
area is constant. It will also produce compile-time error if trying to
free something that is not a regular pointer (e.g. a function).

The DEBUG_MEM_STATS macro now also defines an instance for ha_free()
so that all these calls can be checked.

178 occurrences were converted. The vast majority of them were handled
by the following Coccinelle script, some slightly refined to better deal
with "&*x" or with long lines:

  @ rule @
  expression E;
  @@
  - free(E);
  - E = NULL;
  + ha_free(&E);

It was verified that the resulting code is the same, more or less a
handful of cases where the compiler optimized slightly differently
the temporary variable that holds the copy of the pointer.

A non-negligible amount of {free(str);str=NULL;str_len=0;} are still
present in the config part (mostly header names in proxies). These
ones should also be cleaned for the same reasons, and probably be
turned into ist strings.
2021-02-26 21:21:09 +01:00
Christopher Faulet
69beaa91d5 REORG: server: Export and rename some functions updating server info
Some static functions are now exported and renamed to follow the same
pattern of other exported functions. Here is the list :

 * update_server_fqdn: Renamed to srv_update_fqdn and exported
 * update_server_check_addr_port: renamed to srv_update_check_addr_port and exported
 * update_server_agent_addr_port: renamed to srv_update_agent_addr_port and exported
 * update_server_addr: renamed to srv_update_addr
 * update_server_addr_potr: renamed to srv_update_addr_port
 * srv_prepare_for_resolution: exported

This change is mandatory to move all functions dealing with the server-state
files in a separate file.
2021-02-25 10:02:39 +01:00
Christopher Faulet
52d4d30109 BUG/MEDIUM: resolvers: Reset server address and port for obselete SRV records
When a SRV record expires, the ip/port assigned to the associated server are
now removed. Otherwise, the server is stopped but keeps its ip/port while
the server hostname is removed. It is confusing when the servers state are
retrieve on the CLI and may be a problem if saved in a server-state
file. Because the reload may fail because of this inconsistency.

Here is an example:

 * Declare a server template in a backend, using the resolver <dns>

server-template test 2 _http._tcp.example.com resolvers dns check

 * 2 SRV records are announced with the corresponding additional
   records. Thus, 2 servers are filled. Here is the "show servers state"
   output :

2 frt 1 test1 192.168.1.1 2 64 0 1 2 15 3 4 6 0 0 0 http1.example.com 8001 _http._tcp.example.com 0 0 - - 0
2 frt 2 test2 192.168.1.2 2 64 0 1 1 15 3 4 6 0 0 0 http2.example.com 8002 _http._tcp.example.com 0 0 - - 0

 * Then, one additional record is removed (or a SRV record is removed, the
   result is the same). Here is the new "show servers state" output :

2 frt 1 test1 192.168.1.1 2 64 0 1 38 15 3 4 6 0 0 0 http1.example.com 8001 _http._tcp.example.com 0 0 - - 0
2 frt 2 test2 192.168.1.2 0 96 0 1 19 15 3 0 14 0 0 0 - 8002 _http._tcp.example.com 0 0 - - 0

On reload, if a server-state file is used, this leads to undefined behaviors
depending on the configuration.

This patch should be backported as far as 2.0.
2021-02-24 21:58:45 +01:00
Baptiste Assmann
b4badf720c BUG/MINOR: resolvers: new callback to properly handle SRV record errors
When a SRV record was created, it used to register the regular server name
resolution callbacks. That said, SRV records and regular server name
resolution don't work the same way, furthermore on error management.

This patch introduces a new call back to manage DNS errors related to
the SRV queries.

this fixes github issue #50.

Backport status: 2.3, 2.2, 2.1, 2.0
2021-02-24 21:58:45 +01:00
Christopher Faulet
a331a1e8eb BUG/MINOR: resolvers: Only renew TTL for SRV records with an additional record
If no additional record is associated to a SRV record, its TTL must not be
renewed. Otherwise the entry never expires. Thus once announced a first
time, the entry remains blocked on the same IP/port except if a new announce
replaces the old one.

Now, the TTL is updated if a SRV record is received while a matching
existing one is found with an additional record or when an new additional
record is assigned to an existing SRV record.

This patch should be backported as far as 2.2.
2021-02-24 21:58:45 +01:00
Christopher Faulet
9c246a4b6c BUG/MINOR: resolvers: Fix condition to release received ARs if not assigned
At the end of resolv_validate_dns_response(), if a received additionnal
record is not assigned to an existing server record, it is released. But the
condition to do so is buggy. If "answer_record" (the received AR) is not
assigned, "tmp_record" is not a valid record object. It is just a dummy
record "representing" the head of the record list.

Now, the condition is far cleaner. This patch must be backported as far as
2.2.
2021-02-24 21:58:45 +01:00
Emeric Brun
56fc5d9ebc MEDIUM: resolvers: add supports of TCP nameservers in resolvers.
This patch introduce the new line "server" to set a TCP
nameserver in a "resolvers" section:

server <name> <address> [param*]
  Used to configure a DNS TCP or stream server. This supports for all
  "server" parameters found in 5.2 paragraph. Some of these parameters
  are irrelevant for DNS resolving. Note: currently 4 queries are pipelined
  on the same connections. A batch of idle connections are removed every
  5 seconds. "maxconn" can be configured to limit the amount of those
  concurrent connections and TLS should also usable if the server supports
. The current implementation limits to 4 pipelined

The name of the line in configuration is open to discussion
and could be changed before the next release.
2021-02-13 10:03:46 +01:00
Emeric Brun
c943799c86 MEDIUM: resolvers/dns: split dns.c into dns.c and resolvers.c
This patch splits current dns.c into two files:

The first dns.c contains code related to DNS message exchange over UDP
and in future other TCP. We try to remove depencies to resolving
to make it usable by other stuff as DNS load balancing.

The new resolvers.c inherit of the code specific to the actual
resolvers.

Note:
It was really difficult to obtain a clean diff dur to the amount
of moved code.

Note2:
Counters and stuff related to stats is not cleany separated because
currently counters for both layers are merged and hard to separate
for now.
2021-02-13 10:03:46 +01:00