Replace nng_pipe_get_addr, nng_stream_get_addr, and the NNG_OPT_REMADDR option.

More direct access methods are provided instead.

This results in much lower friction when using, and is a step on the path
to removing NNG_OPT_LOCADDR as well.

We need to figure a solution for NNG_OPT_LOCADDR for dialers; for
listeners there is little use in it either, and it will be removed.
(Dialers will probably get a new NNG_OPT_BIND_IP option.)

1 files changed, 28 insertions, 0 deletions

diff --git a/docs/ref/migrate/nng1.md b/docs/ref/migrate/nng1.md
index 52b786cc..6e0a1143 100644
--- a/docs/ref/migrate/nng1.md
+++ b/docs/ref/migrate/nng1.md
@@ -173,6 +173,13 @@ address separated by a semicolon. This was provided for legacy libnanomsg
 compatibility, and is no longer offered. The correct way to specify a
 local address is by setting `NNG_OPT_LOCADDR` on the dialer.
 
+## Support for Remote Address Options Removed
+
+The `NNG_OPT_REMADDR` option is removed. For streams and pipes, there are
+[`nng_stream_peer_addr`] and [`nng_pipe_peer_addr`] functions. For dialers
+and stream dialers, the application should track the relevant information
+used to configure the listener.
+
 ## IPC Option Type Changes
 
 The types of [`NNG_OPT_PEER_GID`], [`NNG_OPT_PEER_PID`], [`NNG_OPT_PEER_UID`], and [`NNG_OPT_PEER_ZONEID`]
@@ -247,6 +254,9 @@ such as one ending in a suffix like `_bool` (to access a `bool` typed option).
 
 ## Stream Options
 
+The `nng_stream_get_addr` function is removed.
+Use the new [`nng_stream_peer_addr`] or [`nng_stream_peer_self_addr`] instead.
+
 The ability to set options on streams after they have been created is no longer present.
 (It turns out that this was not very useful.) All functions `nng_stream_set_xxx` are removed.
 For tuning the `NNG_OPT_TCP_NODELAY` or similar properties, set the option on the listener
@@ -277,6 +287,10 @@ before bringing them into the socket itself.
 The `NNG_OPT_TCP_BOUND_PORT` port is renamed to just [`NNG_OPT_BOUND_PORT`],
 and is available for listeners using transports based on either TCP or UDP.
 
+The `nng_pipe_get_addr` function has been removed, and replaced with the new
+[`nng_pipe_peer_addr`] and [`nng_pipe_self_addr`] functions. These should be
+easier to use.
+
 ## Socket Options
 
 The `NNG_OPT_PROTO`, `NNG_OPT_PROTONAME`, `NNG_OPT_PEER`, and `NNG_OPT_PEERNAME` options
@@ -401,4 +415,18 @@ The Layer 2 special ZeroTier transport has been removed.
 It is possible to use NNG with ZeroTier using TCP/IP, and a future update
 is planned to provided coexistence between ZeroTier & the native stack's TCP/IP using lwIP.
 
+## Abstract Autobinding No Longer Supported
+
+As we have removed `NNG_OPT_LOCADDR` for listeners, it is no longer possible to meaningfully
+use autobinding with abstract sockets on Linux. This is trivially worked around by using a
+large (say 128-bit) random integer as the name.
+
+This can be done via using of [`nng_random`] combined with `sprintf`, as the following example demonstrates:
+
+```c
+char url[256];
+snprintf(url, sizeof (url), `abstract://my-app-%08x-%08x-%08x-%08x",
+    nni_random(), nni_random(), nni_random(), nni_random());
+```
+
 {{#include ../xref.md}}