From: David Lamparter <equinox@opensourcerouting.org>
Date: Wed, 30 Nov 2022 10:19:14 +0000 (+0100)
Subject: lib: add a transparent union for sockaddrs
X-Git-Tag: base_10.0~307^2
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=bf098b4a11a42e123fbfef664027b2ba183a31c4;p=mirror%2Ffrr.git

lib: add a transparent union for sockaddrs

As with "prefixptr"/"prefixconstptr", this allows function prototypes to
say "just give me any sockaddr" typing-wise, without having the compiler
complain that a "struct sockaddr_in" is not a "struct sockaddr".

(Split off from other changes that start using this.)

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
---

diff --git a/lib/sockunion.h b/lib/sockunion.h
index e507255999..675855e2b6 100644
--- a/lib/sockunion.h
+++ b/lib/sockunion.h
@@ -7,6 +7,8 @@
 #ifndef _ZEBRA_SOCKUNION_H
 #define _ZEBRA_SOCKUNION_H
 
+#include "compiler.h"
+
 #include "privs.h"
 #include "if.h"
 #include <sys/un.h>
@@ -27,8 +29,40 @@ union sockunion {
 	struct sockaddr_mpls smpls;
 	struct sockaddr_rtlabel rtlabel;
 #endif
+
+	/* sockaddr_storage is guaranteed to be larger than the others */
+	struct sockaddr_storage sa_storage;
 };
 
+/* clang-format off */
+/* for functions that want to accept any sockaddr pointer without casts */
+union sockaddrptr {
+	uniontype(sockaddrptr, union sockunion, su)
+	uniontype(sockaddrptr, struct sockaddr, sa)
+	uniontype(sockaddrptr, struct sockaddr_in, sin)
+	uniontype(sockaddrptr, struct sockaddr_in6, sin6)
+	uniontype(sockaddrptr, struct sockaddr_un, sun)
+#ifdef __OpenBSD__
+	uniontype(sockaddrptr, struct sockaddr_mpls, smpls)
+	uniontype(sockaddrptr, struct sockaddr_rtlabel, rtlabel)
+#endif
+	uniontype(sockaddrptr, struct sockaddr_storage, sa_storage)
+} TRANSPARENT_UNION;
+
+union sockaddrconstptr {
+	uniontype(sockaddrconstptr, const union sockunion, su)
+	uniontype(sockaddrconstptr, const struct sockaddr, sa)
+	uniontype(sockaddrconstptr, const struct sockaddr_in, sin)
+	uniontype(sockaddrconstptr, const struct sockaddr_in6, sin6)
+	uniontype(sockaddrconstptr, const struct sockaddr_un, sun)
+#ifdef __OpenBSD__
+	uniontype(sockaddrconstptr, const struct sockaddr_mpls, smpls)
+	uniontype(sockaddrconstptr, const struct sockaddr_rtlabel, rtlabel)
+#endif
+	uniontype(sockaddrconstptr, const struct sockaddr_storage, sa_storage)
+} TRANSPARENT_UNION;
+/* clang-format on */
+
 enum connect_result { connect_error, connect_success, connect_in_progress };
 
 /* Default address family. */