Merge bitcoin/bitcoin#25426: net: add new method Sock::GetSockName() that wraps getsockname() and use it in GetBindAddress()

a8d6abba5ec4ae2a3375e9be0b739f298899eca2 net: change GetBindAddress() to take Sock argument (Vasil Dimov)
748dbcd9f29dbe4110da8a06f08e3eefa95f5321 net: add new method Sock::GetSockName() that wraps getsockname() (Vasil Dimov)

Pull request description:

  _This is a piece of #21878, chopped off to ease review._

  Wrap the syscall `getsockname()` in `Sock::GetSockName()` and change `GetBindAddress()` to take a `Sock` argument so that it can use the wrapper.

  This further encapsulates syscalls inside the `Sock` class and makes the callers mockable.

ACKs for top commit:
  laanwj:
    Code review ACK a8d6abba5ec4ae2a3375e9be0b739f298899eca2

Tree-SHA512: 3a73463258c0057487fb3fd67215816b03a1c5160f45e45930eaeef86bb3611ec385794cdb08339aa074feba8ad67cd2bfd3836f6cbd40834e15d933214a05dc

1 files changed, 7 insertions, 0 deletions

diff --git a/src/util/sock.h b/src/util/sock.h
index 5ca5f1b91b..73ceb0b62c 100644
--- a/src/util/sock.h
+++ b/src/util/sock.h
@@ -114,6 +114,13 @@ public:
                                          const void* opt_val,
                                          socklen_t opt_len) const;
 
+    /**
+     * getsockname(2) wrapper. Equivalent to
+     * `getsockname(this->Get(), name, name_len)`. Code that uses this
+     * wrapper can be unit tested if this method is overridden by a mock Sock implementation.
+     */
+    [[nodiscard]] virtual int GetSockName(sockaddr* name, socklen_t* name_len) const;
+
     using Event = uint8_t;
 
     /**