From: Alan T. DeKok <aland@freeradius.org>
Date: Thu, 7 Aug 2025 14:59:17 +0000 (-0400)
Subject: on TCP EOF, flush all writes, and shut down the BIOs
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d2e4ffeb7c96cead1a9a86b452e53e8d95a983db;p=thirdparty%2Ffreeradius-server.git

on TCP EOF, flush all writes, and shut down the BIOs
---

diff --git a/src/lib/bio/base.c b/src/lib/bio/base.c
index 0e00171cec9..f1dbf637846 100644
--- a/src/lib/bio/base.c
+++ b/src/lib/bio/base.c
@@ -98,27 +98,24 @@ ssize_t fr_bio_shutdown_write(UNUSED fr_bio_t *bio, UNUSED void *packet_ctx, UNU
 int fr_bio_shutdown(fr_bio_t *bio)
 {
 	int rcode;
-	fr_bio_t *this, *first;
+	fr_bio_t *head, *this;
 	fr_bio_common_t *my;
 
 	/*
 	 *	Find the first bio in the chain.
 	 */
-	for (this = bio; fr_bio_prev(this) != NULL; this = fr_bio_prev(this)) {
-		/* nothing */
-	}
-	first = this;
+	head = fr_bio_head(bio);
 
 	/*
 	 *	We're in the process of shutting down, don't call ourselves recursively.
 	 */
-	my = (fr_bio_common_t *) this;
+	my = (fr_bio_common_t *) head;
 	if (my->bio.read == fr_bio_shutdown_read) return 0;
 
 	/*
 	 *	Walk back down the chain, calling the shutdown functions.
 	 */
-	for (/* nothing */; this != NULL; this = fr_bio_next(this)) {
+	for (this = head; this != NULL; this = fr_bio_next(this)) {
 		my = (fr_bio_common_t *) this;
 
 		if (my->priv_cb.shutdown) {
@@ -136,10 +133,10 @@ int fr_bio_shutdown(fr_bio_t *bio)
 	 *	Call the application shutdown routine to tell it that
 	 *	the BIO has been successfully shut down.
 	 */
-	my = (fr_bio_common_t *) first;
+	my = (fr_bio_common_t *) head;
 
 	if (my->cb.shutdown) {
-		rcode = my->cb.shutdown(first);
+		rcode = my->cb.shutdown(head);
 		if (rcode < 0) return rcode;
 		my->cb.shutdown = NULL;
 	}
diff --git a/src/lib/bio/base.h b/src/lib/bio/base.h
index cf2b65b4f67..c5a3134ea59 100644
--- a/src/lib/bio/base.h
+++ b/src/lib/bio/base.h
@@ -137,6 +137,17 @@ static inline CC_HINT(nonnull) fr_bio_t *fr_bio_next(fr_bio_t *bio)
 	return fr_dlist_entry_to_item(offsetof(fr_bio_t, entry), next);
 }
 
+static inline CC_HINT(nonnull) fr_bio_t *fr_bio_head(fr_bio_t *bio)
+{
+	fr_bio_t *this, *prev;
+
+	for (this = bio; (prev = fr_bio_prev(this)) != NULL; this = prev) {
+		/* nothing */
+	}
+
+	return this;
+}
+
 /** Read raw data from a bio
  *
  *  @param bio		the binary IO handler
diff --git a/src/lib/bio/fd.c b/src/lib/bio/fd.c
index 44262a905f9..5dabcca8387 100644
--- a/src/lib/bio/fd.c
+++ b/src/lib/bio/fd.c
@@ -144,6 +144,18 @@ static ssize_t fr_bio_fd_read_stream(fr_bio_t *bio, UNUSED void *packet_ctx, voi
 retry:
 	rcode = read(my->info.socket.fd, buffer, size);
 	if (rcode == 0) {
+		fr_bio_t *head;
+
+		/*
+		 *	Flush any pending writes, shut down the BIO, and then mark it as EOF.
+		 */
+		head = fr_bio_head(bio);
+
+		(void) fr_bio_write(head, NULL, NULL, SIZE_MAX);
+
+		rcode = fr_bio_shutdown(head);
+		if (rcode < 0) return rcode;
+
 		fr_bio_eof(bio);
 		return 0;
 	}