commit 75716fd6ed1a99a0e601b2820363b17d7c0333a7
from: Thomas Adam <thomas@xteddy.org>
date: Sat Aug 27 17:51:57 2022 UTC

portable: sockets: handle sa_len/ss_len portably

In the sockaddr_storage struct, there can be a ss_len field.  This is
seen on some BSDs, but not Linux.  Since this isn't POSIX-specific,
there's no guarantee it will be available on all systems.

commit - 0b75e088e5e7799559ddc81934e9d06c29f10c5b
commit + 75716fd6ed1a99a0e601b2820363b17d7c0333a7
blob - c7430a2ac5b8b9bbade860a42ce3959bcf0449a0
blob + 554ab266ff55ce404d9d1fe773286dbbadbfeb51
--- configure.ac
+++ configure.ac
@@ -83,6 +83,35 @@ AC_TYPE_UINT8_T
 # Check for ifgroupreq which is only available on BSD.
 AC_CHECK_TYPES([struct ifgroupreq])
 
+# Check for sockaddr_storage.  On some systems, ss_len is filled out, although
+# this is not mandated by POSIX, and hence systems such as linux, don't have
+# it.
+AC_CHECK_TYPES([struct sockaddr_storage], [], [], [
+#include <sys/types.h>
+#include <sys/socket.h>
+])
+
+# Same thing as sockaddr_storage above, only now check if the member exists in
+# the struct as well.
+AC_CHECK_MEMBERS([struct sockaddr_storage.ss_len], , ,
+	[ #include <netdb.h>
+	  #include <netinet/in.h>
+	  #include <sys/socket.h> ]
+)
+
+AC_CHECK_MEMBERS([struct sockaddr.sa_len], , ,
+	[ #include <netdb.h>
+	  #include <netinet/in.h>
+	  #include <sys/socket.h> ]
+)
+
+# Both checks above will result in:
+#
+# HAVE_STRUCT_SOCKADDR_AS_LEN
+# SS_LEN
+#
+# Either being defined or not.
+
 # Look for library needed for flock.
 AC_SEARCH_LIBS(flock, bsd)
 
blob - c59d9dd4fdcf5133bae8ce3411896c675c37f956
blob + f007a7588d8c6facc9de0df884df46e60482a84d
--- gotwebd/sockets.c
+++ gotwebd/sockets.c
@@ -524,7 +524,7 @@ sockets_create_socket(struct address *a, in_port_t por
 		return -1;
 	}
 
-	if (bind(fd, (struct sockaddr *)&a->ss, a->ss.ss_len) == -1) {
+	if (bind(fd, (struct sockaddr *)&a->ss, SS_LEN(&a->ss)) == -1) {
 		close(fd);
 		log_info("%s: can't bind to port %d", __func__,
 		    ntohs(port));
blob - 9b586119d4d22d75fd6373a77e85867d2cc3ab1c
blob + 8d52a920333aebf6b2466dcbb50e15c4bae98549
--- include/got_compat.h
+++ include/got_compat.h
@@ -200,8 +200,36 @@ void uuid_to_string(uuid_t *, char **, uint32_t *);
 #define SHA1Init	SHA1_Init
 #define SHA1Update	SHA1_Update
 #define SHA1Final	SHA1_Final
+#endif
+
+/*
+ * The following SA_LEN/SS_LEN dance comes from various source, notably
+ * OpenSMTP by way of OpenNTPD and OpenBGPD (thanks everyone!).  got-portable
+ * has tweaked a lot of the following macros to suit the needs of
+ * got-portable.
+ */
+
+/* From OpenNTPD portable */
+#if !defined(SA_LEN)
+# if defined(HAVE_STRUCT_SOCKADDR_SA_LEN)
+#  define SA_LEN(x)	((x)->sa_len)
+# else
+#  define SA_LEN(x)     ((x)->sa_family == AF_INET6 ? \
+			sizeof(struct sockaddr_in6) : \
+			sizeof(struct sockaddr_in))
+# endif
+
 #endif
 
+/* From OpenBGPD portable */
+#if !defined(SS_LEN)
+# if defined(HAVE_STRUCT_SOCKADDR_STORAGE_SS_LEN)
+#  define SS_LEN(x)  ((x)->ss_len)
+# else
+#  define SS_LEN(x)  SA_LEN((struct sockaddr *)(x))
+# endif
+#endif
+
 #ifndef HAVE_ASPRINTF
 /* asprintf.c */
 int		 asprintf(char **, const char *, ...);