first try at fr_bio_fd_accept()

which creates a new BIO from a parent of type LISTEN

src/lib/bio/fd.c

@@ -961,7 +961,7 @@ static ssize_t fr_bio_fd_read_accept(fr_bio_t *bio, void *packet_ctx, void *buff
 }
 
 
-int fr_bio_fd_init_accept(fr_bio_fd_t *my)
+int fr_bio_fd_init_listen(fr_bio_fd_t *my)
 {
 	my->bio.read = fr_bio_fd_read_accept;
 	my->bio.write = fr_bio_null_write;
@@ -1262,7 +1262,7 @@ int fr_bio_fd_connect_full(fr_bio_t *bio, fr_event_list_t *el, fr_bio_callback_t
 	 *	The caller may just call us without caring about what the underlying BIO is.  In which case we
 	 *	need to be safe.
 	 */
-	if ((my->info.socket.af == AF_FILE_BIO) || (my->info.type == FR_BIO_FD_ACCEPT)) {
+	if ((my->info.socket.af == AF_FILE_BIO) || (my->info.type == FR_BIO_FD_LISTEN)) {
 		fr_bio_fd_set_open(my);
 		goto connected;
 	}
@@ -1363,6 +1363,7 @@ int fr_bio_fd_write_only(fr_bio_t *bio)
 		break;
 
 	case FR_BIO_FD_CONNECTED:
+	case FR_BIO_FD_ACCEPTED:
 		/*
 		 *	Further reads are disallowed.
 		 */
@@ -1372,11 +1373,114 @@ int fr_bio_fd_write_only(fr_bio_t *bio)
 		}
 		break;
 
-	case FR_BIO_FD_ACCEPT:
+	case FR_BIO_FD_LISTEN:
 		fr_strerror_const("Only unconnected sockets can be marked 'write-only'");
 		return -1;
 	}
 
 	my->bio.read = fr_bio_fd_read_discard;
 	return 0;
 }
+
+/** Alternative to calling fr_bio_read() on new socket.
+ *
+ */
+int fr_bio_fd_accept(TALLOC_CTX *ctx, fr_bio_t **out_p, fr_bio_t *bio)
+{
+	int fd, tries = 0;
+	int rcode;
+	fr_bio_fd_t *my = talloc_get_type_abort(bio, fr_bio_fd_t);
+	socklen_t salen;
+	struct sockaddr_storage sockaddr;
+	fr_bio_fd_t *out;
+	fr_bio_fd_config_t *cfg;
+
+	salen = sizeof(sockaddr);
+	*out_p = NULL;
+
+	fr_assert(my->info.type == FR_BIO_FD_LISTEN);
+	fr_assert(my->info.socket.type == SOCK_STREAM);
+
+retry:
+#ifdef __linux__
+	/*
+	 *	Set these flags immediately on the new socket.
+	 */
+	fd = accept4(my->info.socket.fd, (struct sockaddr *) &sockaddr, &salen, SOCK_NONBLOCK | SOCK_CLOEXEC);
+#else
+	fd = accept(my->info.socket.fd, (struct sockaddr *) &sockaddr, &salen);
+#endif
+	if (fd < 0) {
+		switch (errno) {
+		case EINTR:
+			/*
+			 *	Try a few times before giving up.
+			 */
+			tries++;
+			if (tries <= my->max_tries) goto retry;
+			return 0;
+
+			/*
+			 *	We can ignore these errors.
+			 */
+		case ECONNABORTED:
+#if defined(EWOULDBLOCK) && (EWOULDBLOCK != EAGAIN)
+		case EWOULDBLOCK:
+#endif
+		case EAGAIN:
+#ifdef EPERM
+		case EPERM:
+#endif
+#ifdef ETIMEDOUT
+		case ETIMEDOUT:
+#endif
+			return 0;
+
+		default:
+			/*
+			 *	Some other error, it's fatal.
+			 */
+			fr_bio_shutdown(&my->bio);
+			break;
+		}
+
+		return fr_bio_error(IO);
+	}
+
+	/*
+	 *	Allocate the base BIO and set it up.
+	 */
+	out = (fr_bio_fd_t *) fr_bio_fd_alloc(ctx, NULL, my->offset);
+	if (!out) {
+		close(fd);
+		return fr_bio_error(GENERIC);
+	}
+
+	/*
+	 *	We have a file descriptor.  Initialize the configuration with the new information.
+	 */
+	cfg = talloc_memdup(out, my->info.cfg, sizeof(*my->info.cfg));
+	if (!cfg) {
+		fr_strerror_const("Out of memory");
+		close(fd);
+		talloc_free(out);
+		return fr_bio_error(GENERIC);
+	}
+
+	/*
+	 *	Set the type to ACCEPTED, and set up the rest of the callbacks to match.
+	 */
+	cfg->type = FR_BIO_FD_ACCEPTED;
+	out->info.socket.fd = fd;
+
+	rcode = fr_bio_fd_open(bio, cfg);
+	if (rcode < 0) {
+		talloc_free(out);
+		return rcode;
+	}
+
+	fr_assert(out->info.type == FR_BIO_FD_CONNECTED);
+
+	*out_p = (fr_bio_t *) out;
+	return 1;
+}

src/lib/bio/fd.h

@@ -63,8 +63,9 @@ typedef enum {
 					// updates #fr_bio_fd_packet_ctx_t for reads,
 					// uses #fr_bio_fd_packet_ctx_t for writes
 	FR_BIO_FD_CONNECTED,		//!< connected client sockets (UDP or TCP)
-	FR_BIO_FD_ACCEPT,		//!< returns new fd in buffer on fr_bio_read()
+	FR_BIO_FD_LISTEN,		//!< returns new fd in buffer on fr_bio_read() or fr_bio_fd_accept()
 					// updates #fr_bio_fd_packet_ctx_t on successful FD read.
+	FR_BIO_FD_ACCEPTED,		//!< temporarily until it's connected.
 } fr_bio_fd_type_t;
 
 /** Configuration for sockets
@@ -139,3 +140,5 @@ int		fr_bio_fd_open(fr_bio_t *bio, fr_bio_fd_config_t const *cfg) CC_HINT(nonnul
 int		fr_bio_fd_write_only(fr_bio_t *bio) CC_HINT(nonnull);
 
 int		fr_bio_fd_reopen(fr_bio_t *bio) CC_HINT(nonnull);
+
+int		fr_bio_fd_accept(TALLOC_CTX *ctx, fr_bio_t **out, fr_bio_t *bio)  CC_HINT(nonnull);

src/lib/bio/fd_open.c

@@ -751,10 +751,19 @@ int fr_bio_fd_open(fr_bio_t *bio, fr_bio_fd_config_t const *cfg)
 			}
 		}
 
-		fd = socket(my->info.socket.af, my->info.socket.type, protocol);
-		if (fd < 0) {
-			fr_strerror_printf("Failed opening socket: %s", fr_syserror(errno));
-			return -1;
+		/*
+		 *	It's already opened, so we don't need to do that.
+		 */
+		if (cfg->type == FR_BIO_FD_ACCEPTED) {
+			fd = my->info.socket.fd;
+			fr_assert(fd >= 0);
+
+		} else {
+			fd = socket(my->info.socket.af, my->info.socket.type, protocol);
+			if (fd < 0) {
+				fr_strerror_printf("Failed opening socket: %s", fr_syserror(errno));
+				return -1;
+			}
 		}
 
 	} else if (cfg->path) {
@@ -928,10 +937,31 @@ int fr_bio_fd_open(fr_bio_t *bio, fr_bio_fd_config_t const *cfg)
 		if (fr_bio_fd_init_connected(my) < 0) goto fail;
 		break;
 
+	case FR_BIO_FD_ACCEPTED:
+#ifdef SO_NOSIGPIPE
+		/*
+		 *	Although the server ignore SIGPIPE, some operating systems like BSD and OSX ignore the
+		 *	ignoring.
+		 *
+		 *	Fortunately, those operating systems usually support SO_NOSIGPIPE.  We set that to prevent
+		 *	them raising the signal in the first place.
+		 */
+		{
+			int on = 1;
+
+			setsockopt(my->info.socket.fd, SOL_SOCKET, SO_NOSIGPIPE, &on, sizeof(on));
+		}
+#endif
+
+		my->info.type = FR_BIO_FD_CONNECTED;
+
+                if (fr_bio_fd_init_common(my) < 0) goto fail;
+		break;
+
 		/*
 		 *	Server socket which listens for new stream connections
 		 */
-	case FR_BIO_FD_ACCEPT:
+	case FR_BIO_FD_LISTEN:
 		fr_assert(my->info.socket.type == SOCK_STREAM);
 
 		switch (my->info.socket.af) {
@@ -956,7 +986,7 @@ int fr_bio_fd_open(fr_bio_t *bio, fr_bio_fd_config_t const *cfg)
 			goto fail;
 		}
 
-		if (fr_bio_fd_init_accept(my) < 0) goto fail;
+		if (fr_bio_fd_init_listen(my) < 0) goto fail;
 		break;
 	}
 

src/lib/bio/fd_priv.h

@@ -64,6 +64,6 @@ int	fr_bio_fd_init_common(fr_bio_fd_t *my);
 
 int	fr_bio_fd_init_connected(fr_bio_fd_t *my);
 
-int	fr_bio_fd_init_accept(fr_bio_fd_t *my);
+int	fr_bio_fd_init_listen(fr_bio_fd_t *my);
 
 int	fr_bio_fd_socket_name(fr_bio_fd_t *my);

src/lib/bio/network.c

@@ -133,9 +133,10 @@ fr_bio_t *fr_bio_network_alloc(TALLOC_CTX *ctx, fr_ipaddr_t const *allow, fr_ipa
 		break;
 
 	case FR_BIO_FD_CONNECTED:
+	case FR_BIO_FD_ACCEPTED:
 		return NULL;
 
-	case FR_BIO_FD_ACCEPT:
+	case FR_BIO_FD_LISTEN:
 		break;
 	}
 

src/listen/control/proto_control_unix.c

@@ -412,7 +412,7 @@ static int mod_open(fr_listen_t *li)
 	fr_assert(!thread->connection);
 
 	cfg = (fr_bio_fd_config_t) {
-		.type = FR_BIO_FD_ACCEPT,
+		.type = FR_BIO_FD_LISTEN,
 		.socket_type = SOCK_STREAM,
 		.path = inst->filename,
 		.uid = inst->uid,