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| author | Laurent Bercot <ska-skaware@skarnet.org> | 2023-09-30 05:40:04 +0000 |
|---|---|---|
| committer | Laurent Bercot <ska@appnovation.com> | 2023-09-30 05:40:04 +0000 |
| commit | bef76b45f480aa41209efdec09fc6bb0bfde7cbe (patch) | |
| tree | bb3945da0504c569ff325829bf5f895f8e355039 /doc/s6-tcpserver4.html | |
| parent | a068a3256fab3b77b7d1bc9ce201c954a9b00c94 (diff) | |
| download | s6-networking-bef76b45f480aa41209efdec09fc6bb0bfde7cbe.tar.xz | |
Great Tcpserver Unification. Prepare for 2.6.0.0.
Signed-off-by: Laurent Bercot <ska@appnovation.com>
Diffstat (limited to 'doc/s6-tcpserver4.html')
| -rw-r--r-- | doc/s6-tcpserver4.html | 137 |
1 files changed, 0 insertions, 137 deletions
diff --git a/doc/s6-tcpserver4.html b/doc/s6-tcpserver4.html deleted file mode 100644 index bc1bd5e..0000000 --- a/doc/s6-tcpserver4.html +++ /dev/null @@ -1,137 +0,0 @@ -<html> - <head> - <meta name="viewport" content="width=device-width, initial-scale=1.0" /> - <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> - <meta http-equiv="Content-Language" content="en" /> - <title>s6-networking: the s6-tcpserver4 program</title> - <meta name="Description" content="s6-networking: the s6-tcpserver4 program" /> - <meta name="Keywords" content="s6-networking s6-tcpserver4 tcpserver ucspi tcp server super-server ipv4" /> - <!-- <link rel="stylesheet" type="text/css" href="//skarnet.org/default.css" /> --> - </head> -<body> - -<p> -<a href="index.html">s6-networking</a><br /> -<a href="//skarnet.org/software/">Software</a><br /> -<a href="//skarnet.org/">skarnet.org</a> -</p> - -<h1> The <tt>s6-tcpserver4</tt> program </h1> - -<p> -<tt>s6-tcpserver4</tt> is a super-server for IPv4 TCP -connections. It accepts connections from clients, and forks a -program to handle each connection. -</p> - -<h2> Interface </h2> - -<pre> - s6-tcpserver4 [ -1 ] [ -v <em>verbosity</em> ] [ -c <em>maxconn</em> ] [ -C <em>localmaxconn</em> ] [ -b <em>backlog</em> ] [ -G <em>gidlist</em> ] [ -g <em>gid</em> ] [ -u <em>uid</em> ] [ -U ] <em>ip</em> <em>port</em> <em>prog...</em> -</pre> - -<ul> - <li> s6-tcpserver4 binds to local IPv4 address <em>ip</em>, -port <em>port</em>. </li> - <li> It closes its stdin and stdout. </li> - <li> For every TCP connection to this address and port, it -forks. The child sets some environment variables, then -executes <em>prog...</em> with stdin reading from the network -socket and stdout writing to it. </li> - <li> Depending on the verbosity level, it logs what it does to stderr. </li> - <li> It runs until killed by a signal. Depending on the received -signal, it may kill its children before exiting. </li> - <li> s6-tcpserver4 actually doesn't do any of this itself. It is -a wrapper, rewriting the command line and executing into a chain -of programs that perform those duties. </li> -</ul> - -<h2> Environment variables </h2> - -<p> - For each connection, an instance of <em>prog...</em> is spawned with -the following variables set: -</p> - -<ul> - <li> PROTO: always set to TCP </li> - <li> TCPREMOTEIP: set to the originating address </li> - <li> TCPREMOTEPORT: set to the originating port </li> - <li> TCPCONNNUM: set to the number of connections originating from -the same IP address </li> -</ul> - -<h2> Options </h2> - -<ul> - <li> <tt>-1</tt> : write <em>port</em> to stdout, before -closing it, right after binding and listening to the network socket. -If stdout is suitably redirected, this can be used by monitoring -programs to check when the server is ready to accept connections. </li> - <li> <tt>-v <em>verbosity</em></tt> : be more or less verbose. -By default, <em>verbosity</em> is 1: print warning messages to stderr. -0 means only print fatal error messages ; 2 means print status and -connection information for every client. </li> - <li> <tt>-c <em>maxconn</em></tt> : accept at most -<em>maxconn</em> concurrent connections. Default is 40. It is -impossible to set it higher than 1000. </li> - <li> <tt>-C <em>localmaxconn</em></tt> : accept at most -<em>localmaxconn</em> connections from the same IP address. -Default is 40. It is impossible to set it higher than <em>maxconn</em>. </li> - <li> <tt>-b <em>backlog</em></tt> : set a maximum of -<em>backlog</em> backlog connections on the socket. Extra -connection attempts will rejected by the kernel. </li> - <li> <tt>-G <em>gidlist</em></tt> : change s6-tcpserver4's -supplementary group list to <em>gidlist</em> after binding the socket. -This is only valid when run as root. <em>gidlist</em> must be a -comma-separated list of numerical group IDs. </li> - <li> <tt>-g <em>gid</em></tt> : change s6-tcpserver4's group id -to <em>gid</em> after binding the socket. This is only valid when run -as root. </li> - <li> <tt>-u <em>uid</em></tt> : change s6-tcpserver4's user id -to <em>uid</em> after binding the socket. This is only valid when run -as root. </li> - <li> <tt>-U</tt> : change s6-tcpserver4's user id, group id and -supplementary group list -according to the values of the UID, GID and GIDLIST environment variables -after binding the socket. This is only valid when run as root. -This can be used with the -<a href="//skarnet.org/software/s6/s6-envuidgid.html">s6-envuidgid</a> -program to easily script a service that binds to a privileged socket -then drops its privileges to those of a named non-root account. </li> -</ul> - -<h2> Signals </h2> - -<ul> - <li> SIGTERM: exit. </li> - <li> SIGHUP: send a SIGTERM and a SIGCONT to all children. </li> - <li> SIGQUIT: send a SIGTERM and a SIGCONT to all children, then exit. </li> - <li> SIGABRT: send a SIGKILL to all children, then exit. </li> -</ul> - -<h2> Notes </h2> - -<ul> - <li> Unlike its ancestor -<a href="https://cr.yp.to/ucspi-tcp/tcpserver.html">tcpserver</a>, -s6-tcpserver4 performs just the bare minimum: the point is to have a -very small and very fast process to serve connections with the least -possible overhead. Features such as additional environment variables, -access control and DNS resolution are provided -via the <a href="s6-tcpserver-access.html">s6-tcpserver-access</a> -program. </li> - <li> In previous releases of s6-networking, s6-tcpserver4 was -monolithic: it did the work of -<a href="s6-tcpserver4-socketbinder.html">s6-tcpserver4-socketbinder</a>, -<a href="//skarnet.org/software/s6/s6-applyuidgid.html">s6-applyuidgid</a> and -<a href="s6-tcpserver4d.html">s6-tcpserver4d</a> itself. The functionality has now -been split into several different programs because some service startup -schemes require the daemon to get its socket from an external -program instead of creating and binding it itself. The most obvious -application of this is upgrading a long-lived process without -losing existing connections. </li> -</ul> - -</body> -</html> |