If 'namespace' keyword is used in the backend server settings or/and in the
bind string, it means that haproxy process will call setns() to change its
default namespace to the configured one and then, it will create a
socket in this new namespace. setns() syscall requires CAP_SYS_ADMIN
capability in the process Effective set (see man 2 setns). Otherwise, the
process must be run as root.
To avoid to run haproxy as root, let's add cap_sys_admin capability in the
same way as we already added the support for some other network capabilities.
As CAP_SYS_ADMIN belongs to CAP_SYS_* capabilities type, let's add a separate
flag LSTCHK_SYSADM for it. This flag is set, if the 'namespace' keyword was
found during configuration parsing. The flag may be unset only in
prepare_caps_for_setuid() or in prepare_caps_from_permitted_set(), which
inspect process EUID/RUID and Effective and Permitted capabilities sets.
If system doesn't support Linux capabilities or 'cap_sys_admin' was not set
in 'setcap', but 'namespace' keyword is presented in the configuration, we
keep the previous strict behaviour. Process, that has changed uid to the
non-priviledged user, will terminate with alert. This alert invites the user
to recheck its configuration.
In the case, when haproxy will start and run under a non-root user and
'cap_sys_admin' is not set, but 'namespace' keyword is presented, this patch
does not change previous behaviour as well. We'll still let the user to try
its configuration, but we inform via warning, that unexpected things, like
socket creation errors, may occur.
When interface keyword is used multiple times within the same bind line,
the previous value isn't checked and is rewritten as-is, resulting in a
small memory leak.
Ensuring the interface name is first freed before assigning it to a new
value.
This may be backported to every stable versions.
[Note for 2.2, the fix must be performed in bind_parse_interface() from
proto_tcp.c, directly within the listener's loop, also ha_free() was
not available so free() must be used instead]
It's set per bind line ("tfo") and only used in tcp_bind_listener() so
there's no point keeping the address family tests, let's just store the
flag in the bind_conf under the name BC_O_TCP_FO.
This option is set per bind line, and was only set stored when the
address family is AF_INET4 or AF_INET6. That's pointless since it's
used only in tcp_bind_listener() which is only used for such families
as well, so it can now be moved to the bind_conf under the name
BC_O_DEF_ACCEPT.
These two arguments were only set and only used with tcpv4/tcpv6. Let's
just store them into the bind_conf instead of duplicating them for all
listeners since they're fixed per "bind" line.
There were plenty of leftovers from old code that were never removed
and that are not needed at all since these files do not use any
definition depending on fcntl.h, let's drop them.
Prepare the server parsing API to support dynamic servers.
- define a new parsing flag to be used for dynamic servers
- each keyword contains a new field dynamic_ok to indicate if it can be
used for a dynamic server. For now, no keyword are supported.
- do not copy settings from the default server for a new dynamic server.
- a dynamic server is created in a maintenance mode and requires an
explicit 'enable server' command.
- a new server flag named SRV_F_DYNAMIC is created. This flag is set for
all servers created at runtime. It might be useful later, for example
to know if a server can be purged.
FreeBSD has a kernel feature (accf) and a sockopt flag similar to the
Linux's TCP_DEFER_ACCEPT to filter incoming data upon ACK. The main
difference is the filter needs to be placed when the socket actually
listens.
Since commit 37bafdcbb ("MINOR: sock_inet: move the IPv4/v6 transparent mode code
to sock_inet"), build options for transparent proxying are registered twice.
This patch removes the older one.
The new RX_O_FOREIGN, RX_O_V6ONLY and RX_O_V4V6 options are now set into
the rx_settings part during the parsing, so that we don't need to adjust
them in each and every listener anymore. We have to keep both v4v6 and
v6only due to the precedence from v6only over v4v6.
The netns is common to all listeners/receivers and is used to bind the
listening socket so it must be in the receiver settings and not in the
listener. This removes some yet another set of unnecessary loops.
The interface is common to all listeners/receivers and is used to bind
the listening socket so it must be in the receiver settings and not in
the listener. This removes some unnecessary loops.
Let's continue the cleanup and get rid of all bind and server keywords
parsers from proto_tcp.c. They're now moved to cfgparse-tcp.c, just as
was done for ssl before 2.2 release. Nothing has changed beyond this.
Now proto_tcp.c is clean and only contains code related to binding and
connecting.
