doc: Rename socket_wrapper.1.txt to socket_wrapper.1.adoc

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>

1 files changed, 133 insertions, 0 deletions

diff --git a/doc/socket_wrapper.1.adoc b/doc/socket_wrapper.1.adoc
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+socket_wrapper(1)
+=================
+:revdate: 2021-02-01
+:author: Samba Team
+
+NAME
+----
+
+socket_wrapper - A library passing all socket communications through unix sockets.
+
+SYNOPSIS
+--------
+
+LD_PRELOAD=libsocket_wrapper.so SOCKET_WRAPPER_DIR=/tmp/tmp.bQRELqDrhM SOCKET_WRAPPER_DEFAULT_IFACE=10 *./myapplication*
+
+DESCRIPTION
+-----------
+
+socket_wrapper aims to help client/server software development teams willing to
+gain full functional test coverage. It makes possible to run several instances
+of the full software stack on the same machine and perform locally functional
+testing of complex network configurations.
+
+- Redirects all network communication to happen over Unix sockets.
+- Support for IPv4 and IPv6 socket and addressing emulation.
+- Ability to capture network traffic in pcap format.
+- Passing IP sockets (up to 6) via SCM_RIGHTS is supported,
+  but pcap support only works reliable if the socket is used
+  by a single process at a time.
+
+ENVIRONMENT VARIABLES
+---------------------
+
+*SOCKET_WRAPPER_DIR*::
+
+The user defines a directory where to put all the unix sockets using the
+environment variable "SOCKET_WRAPPER_DIR=/path/to/socket_dir". When a server
+opens a port or a client wants to connect, socket_wrapper will translate IP
+addresses to a special socket_wrapper name and look for the relevant Unix
+socket in the SOCKET_WRAPPER_DIR.
+
+*SOCKET_WRAPPER_IPV4_NETWORK*::
+
+By default the loopback IPv4 network "127.0.0.0/8" and the
+"127.0.0.x" can be used. In order to make more realistic testing
+possible it is possible to use the "10.0.0.0/8" IPv4 network instead.
+But note within "10.0.0.0/8" only "10.53.57.<ID>" can be used,
+but the broadcast address is "10.255.255.255".
+The following two value are allowed:
+SOCKET_WRAPPER_IPV4_NETWORK="127.0.0.0" (the default) and
+SOCKET_WRAPPER_IPV4_NETWORK="10.53.57.0".
+
+*SOCKET_WRAPPER_DEFAULT_IFACE*::
+
+Additionally, the default interface to be used by an application is defined with
+"SOCKET_WRAPPER_DEFAULT_IFACE=<ID>" where the valid range for <ID> starts with 1
+(the default) and ends with 64. This is analogous to use the IPv4 addresses
+"127.0.0.<ID>"/"10.53.57.<ID>" or IPv6 addresses "fd00::5357:5f<IDx>" (where
+<IDx> is a hexadecimal presentation of <ID>). You should always set the default
+interface. If you listen on INADDR_ANY then it will use the default interface to
+listen on.
+
+*SOCKET_WRAPPER_PCAP_FILE*::
+
+When debugging, it is often interesting to investigate the network traffic
+between the client and server within your application. If you define
+SOCKET_WRAPPER_PCAP_FILE=/path/to/file.pcap, socket_wrapper will dump all your
+network traffic to the specified file. After the test has been finished you're
+able to open the file for example with Wireshark.
+
+*SOCKET_WRAPPER_MTU*::
+
+With this variable you can change the MTU size. However we do not recomment to
+do that as the default size of 1500 byte is best for formatting PCAP files.
+
+The minimum value you can set is 512 and the maximum 32768.
+
+*SOCKET_WRAPPER_MAX_SOCKETS*::
+
+This variable can be used to set the maximum number of sockets to be used by
+an application.
+
+The default value is set to 65535 and the maximum 256000.
+
+*SOCKET_WRAPPER_DEBUGLEVEL*::
+
+If you need to see what is going on in socket_wrapper itself or try to find a
+bug, you can enable logging support in socket_wrapper if you built it with
+debug symbols.
+
+- 0 = ERROR
+- 1 = WARNING
+- 2 = DEBUG
+- 3 = TRACE
+
+*SOCKET_WRAPPER_DISABLE_DEEPBIND*::
+
+This allows you to disable deep binding in socket_wrapper. This is useful for
+running valgrind tools or sanitizers like (address, undefined, thread).
+
+*SOCKET_WRAPPER_DIR_ALLOW_ORIG*::
+
+SOCKET_WRAPPER_DIR is resolved by socket_wrapper using realpath(3).
+Given that Unix sockets are constructed relative to this directory,
+the resulting path can sometimes be too long to allow valid socket
+paths to be constructed due to length restrictions.  Setting this
+variable (to any value) allows socket_wrapper to fall back to the
+original value of SOCKET_WRAPPER_DIR if realpath(3) makes it too long
+to be usable.
+
+EXAMPLE
+-------
+
+  # Open a console and create a directory for the unix sockets.
+  $ mktemp -d
+  /tmp/tmp.bQRELqDrhM
+
+  # Then start nc to listen for network traffic using the temporary directory.
+  $ LD_PRELOAD=libsocket_wrapper.so \
+    SOCKET_WRAPPER_DIR=/tmp/tmp.bQRELqDrhM \
+    SOCKET_WRAPPER_DEFAULT_IFACE=10 nc -v -l 127.0.0.10 7
+
+  # (If nc, listens on 0.0.0.0 then listener will be open on 127.0.0.10 because
+  #  it is the default interface)
+
+  # Now open another console and start 'nc' as a client to connect to the server:
+  $ LD_PRELOAD=libsocket_wrapper.so \
+    SOCKET_WRAPPER_DIR=/tmp/tmp.bQRELqDrhM \
+    SOCKET_WRAPPER_DEFAULT_IFACE=100 nc -v 127.0.0.10 7
+
+  # (The client will use the address 127.0.0.100 when connecting to the server)
+  # Now you can type 'Hello!' which will be sent to the server and should appear
+  # in the console output of the server.