From 0cf2caa41ea69981e9e957d5cfdd9ead68207267 Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Sun, 10 Oct 2010 07:47:14 +0200 Subject: [PATCH] unix.7: Document the autobind feature Signed-off-by: Michael Kerrisk --- man7/unix.7 | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/man7/unix.7 b/man7/unix.7 index 60570b9d0..3ee333d61 100644 --- a/man7/unix.7 +++ b/man7/unix.7 @@ -150,6 +150,23 @@ ancillary message. When this option is set and the socket is not yet connected a unique name in the abstract namespace will be generated automatically. Expects an integer boolean flag. +.SS Autobind Feature +If a +.BR bind () +call specifies +.I addrlen +as +.IR sizeof(sa_family_t) , +.\" i.e. sizeof(short) +or the +.BR SO_PASSCRED +socket option was specified for a socket that was +not explicitly bound to an address, +then the socket is autobound to an abstract address. +The address consists of a null byte +followed by 5 bytes in the character set +.IR [0-9a-f] . +(Thus, there is a limit of 2^20 autobind addresses.) .SS Sockets API The following paragraphs describe domain-specific details and unsupported features of the sockets API for Unix domain sockets on Linux.