dgram: add source-specific multicast support

This adds RFC 4607 support for IPv4 and IPv6.

Co-Authored-By: Nicolas Thumann <46975855+n-thumann@users.noreply.github.com>
Co-Authored-By: Rich Trott <rtrott@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/15735
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/doc/api/dgram.md b/doc/api/dgram.md
index 9efd14c89e..894f64f36e 100644
--- a/doc/api/dgram.md
+++ b/doc/api/dgram.md
@@ -123,6 +123,21 @@ if (cluster.isMaster) {
 }
 ```
 
+### socket.addSourceSpecificMembership(sourceAddress, groupAddress\[, multicastInterface\])
+<!-- YAML
+added: REPLACEME
+-->
+* `sourceAddress` {string}
+* `groupAddress` {string}
+* `multicastInterface` {string}
+
+Tells the kernel to join a source-specific multicast channel at the given
+`sourceAddress` and `groupAddress`, using the `multicastInterface` with the
+`IP_ADD_SOURCE_MEMBERSHIP` socket option. If the `multicastInterface` argument
+is not specified, the operating system will choose one interface and will add
+membership to it. To add membership to every available interface, call
+`socket.addSourceSpecificMembership()` multiple times, once per interface.
+
 ### socket.address()
 <!-- YAML
 added: v0.1.99
@@ -297,6 +312,24 @@ never have reason to call this.
 If `multicastInterface` is not specified, the operating system will attempt to
 drop membership on all valid interfaces.
 
+### socket.dropSourceSpecificMembership(sourceAddress, groupAddress\[, multicastInterface\])
+<!-- YAML
+added: REPLACEME
+-->
+
+* `sourceAddress` {string}
+* `groupAddress` {string}
+* `multicastInterface` {string}
+
+Instructs the kernel to leave a source-specific multicast channel at the given
+`sourceAddress` and `groupAddress` using the `IP_DROP_SOURCE_MEMBERSHIP`
+socket option. This method is automatically called by the kernel when the
+socket is closed or the process terminates, so most apps will never have
+reason to call this.
+
+If `multicastInterface` is not specified, the operating system will attempt to
+drop membership on all valid interfaces.
+
 ### socket.getRecvBufferSize()
 <!-- YAML
 added: v8.7.0