fixes #1041 Abstract socket address for IPC

fixes #1326 Linux IPC could use fchmod
fixes #1327 getsockname on ipc may not work

This introduces an abstract:// style transport, which on Linux
results in using the abstract socket with the given name (not
including the leading NULL byte).  A new NNG_AF_ABSTRACT is
provided.  Auto bind abstract sockets are also supported.

While here we have inlined the aios for the POSIX ipc pipe
objects, eliminating at least one set of failure paths, and
have also performed various other cleanups.

A unix:// alias is available on POSIX systems, which acts just
like ipc:// (and is fact just an alias).  This is supplied so
that in the future we can add support for AF_UNIX on Windows.

We've also absorbed the ipcperms test into the new ipc_test suite.

Finally we are now enforcing that IPC path names on Windows are
not over the maximum size, rather than just silently truncating
them.

1 files changed, 16 insertions, 12 deletions

diff --git a/docs/man/nng_sockaddr.5.adoc b/docs/man/nng_sockaddr.5.adoc
index cf347f66..cd10cab4 100644
--- a/docs/man/nng_sockaddr.5.adoc
+++ b/docs/man/nng_sockaddr.5.adoc
@@ -20,21 +20,23 @@ nng_sockaddr - socket address
 #include <nng/nng.h>
 
 typedef union nng_sockaddr {
-    uint16_t            s_family;
-    nng_sockaddr_ipc    s_ipc;
-    nng_sockaddr_inproc s_inproc;
-    nng_sockaddr_in     s_in;
-    nng_sockaddr_in6    s_in6;
-    nng_sockaddr_zt     s_zt;
+    uint16_t              s_family;
+    nng_sockaddr_ipc      s_ipc;
+    nng_sockaddr_inproc   s_inproc;
+    nng_sockaddr_in       s_in;
+    nng_sockaddr_in6      s_in6;
+    nng_sockaddr_zt       s_zt;
+    nng_sockaddr_abstract s_abstract;
 } nng_sockaddr;
 
 enum sockaddr_family {
-    NNG_AF_UNSPEC = 0,
-    NNG_AF_INPROC = 1,
-    NNG_AF_IPC    = 2,
-    NNG_AF_INET   = 3,
-    NNG_AF_INET6  = 4,
-    NNG_AF_ZT     = 5,
+    NNG_AF_UNSPEC   = 0,
+    NNG_AF_INPROC   = 1,
+    NNG_AF_IPC      = 2,
+    NNG_AF_INET     = 3,
+    NNG_AF_INET6    = 4,
+    NNG_AF_ZT       = 5,
+    NNG_AF_ABSTRACT = 6
 };
 ----
 
@@ -70,12 +72,14 @@ The values of `s_family` are as follows:
 `NNG_AF_INET`:: Address for TCP/IP (v4) communication.  The `s_in` member is valid.
 `NNG_AF_INET6`:: Address for TCP/IP (v6) communication.  The `s_in6` member is valid.
 `NNG_AF_ZT`:: Address for ZeroTier transport (xref:nng_zerotier.7.adoc[nng_zerotier(7)]).  The `s_zt` member is valid.
+`NNG_AF_ABSTRACT`:: Address for an abstract UNIX domain socket.  The `s_abstract` member is valid.
 
 Please see the manual pages for each individual type for more information.
 
 == SEE ALSO
 
 [.text-left]
+xref:nng_sockaddr_abstract.5.adoc[nng_sockaddr_abstract(5)],
 xref:nng_sockaddr_in.5.adoc[nng_sockaddr_in(5)],
 xref:nng_sockaddr_in6.5.adoc[nng_sockaddr_in6(5)],
 xref:nng_sockaddr_inproc.5.adoc[nng_sockaddr_inproc(5)],