Move determination of socket buffer sizes from startup to the first time a

socket is used.  The previous code structure assumed that AF_INET sockets
were always available, which is an invalid assumption on IPv6-only systems.

This merges the fololowing revisions from NetBSD:
src/usr.bin/ftp/main.c 1.120
src/usr.bin/ftp/util.c 1.156

PR:		bin/162661
Tested by:	bz
Obtained from:	NetBSD
MFC after:	1 week

2 files changed, 27 insertions, 31 deletions

diff --git a/contrib/tnftp/src/main.c b/contrib/tnftp/src/main.c
index c2d922b..b987324 100644
--- a/contrib/tnftp/src/main.c
+++ b/contrib/tnftp/src/main.c
@@ -146,9 +146,8 @@ main(int volatile argc, char **volatile argv)
 	struct passwd *pw;
 	char *cp, *ep, *anonpass, *upload_path, *src_addr;
 	const char *anonuser;
-	int dumbterm, s, isupload;
+	int dumbterm, isupload;
 	size_t len;
-	socklen_t slen;
 
 	tzset();
 #if 0	/* tnftp */	/* XXX */
@@ -213,35 +212,6 @@ main(int volatile argc, char **volatile argv)
 	if (cp != NULL && strlcpy(netrc, cp, sizeof(netrc)) >= sizeof(netrc))
 		errx(1, "$NETRC `%s': %s", cp, strerror(ENAMETOOLONG));
 
-	/*
-	 * Get the default socket buffer sizes if we don't already have them.
-	 * It doesn't matter which socket we do this to, because on the first
-	 * call no socket buffer sizes will have been modified, so we are
-	 * guaranteed to get the system defaults.
-	 */
-	s = socket(AF_INET, SOCK_STREAM, 0);
-	if (s == -1)
-		err(1, "Can't create socket to determine default socket sizes");
-	slen = sizeof(rcvbuf_size);
-	if (getsockopt(s, SOL_SOCKET, SO_RCVBUF,
-	    (void *)&rcvbuf_size, &slen) == -1)
-		err(1, "Unable to get default rcvbuf size");
-	slen = sizeof(sndbuf_size);
-	if (getsockopt(s, SOL_SOCKET, SO_SNDBUF,
-	    (void *)&sndbuf_size, &slen) == -1)
-		err(1, "Unable to get default sndbuf size");
-	(void)close(s);
-					/* sanity check returned buffer sizes */
-	if (rcvbuf_size <= 0)
-		rcvbuf_size = 8 * 1024;
-	if (sndbuf_size <= 0)
-		sndbuf_size = 8 * 1024;
-
-	if (sndbuf_size > 8 * 1024 * 1024)
-		sndbuf_size = 8 * 1024 * 1024;
-	if (rcvbuf_size > 8 * 1024 * 1024)
-		rcvbuf_size = 8 * 1024 * 1024;
-
 	marg_sl = ftp_sl_init();
 	if ((tmpdir = getenv("TMPDIR")) == NULL)
 		tmpdir = _PATH_TMP;
diff --git a/contrib/tnftp/src/util.c b/contrib/tnftp/src/util.c
index 366b194..bf46f02 100644
--- a/contrib/tnftp/src/util.c
+++ b/contrib/tnftp/src/util.c
@@ -1060,6 +1060,32 @@ strsuftoi(const char *arg)
 void
 setupsockbufsize(int sock)
 {
+	socklen_t slen;
+
+	if (0 == rcvbuf_size) {
+		slen = sizeof(rcvbuf_size);
+		if (getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
+		    (void *)&rcvbuf_size, &slen) == -1)
+			err(1, "Unable to determine rcvbuf size");
+		if (rcvbuf_size <= 0)
+			rcvbuf_size = 8 * 1024;
+		if (rcvbuf_size > 8 * 1024 * 1024)
+			rcvbuf_size = 8 * 1024 * 1024;
+		DPRINTF("setupsockbufsize: rcvbuf_size determined as %d\n",
+		    rcvbuf_size);
+	}
+	if (0 == sndbuf_size) {
+		slen = sizeof(sndbuf_size);
+		if (getsockopt(sock, SOL_SOCKET, SO_SNDBUF,
+		    (void *)&sndbuf_size, &slen) == -1)
+			err(1, "Unable to determine sndbuf size");
+		if (sndbuf_size <= 0)
+			sndbuf_size = 8 * 1024;
+		if (sndbuf_size > 8 * 1024 * 1024)
+			sndbuf_size = 8 * 1024 * 1024;
+		DPRINTF("setupsockbufsize: sndbuf_size determined as %d\n",
+		    sndbuf_size);
+	}
 
 	if (setsockopt(sock, SOL_SOCKET, SO_SNDBUF,
 	    (void *)&sndbuf_size, sizeof(sndbuf_size)) == -1)