stream: New library for bidirectional streams (e.g. TCP, SSL, Unix sockets).

This code is heavily based on the vconn code.  Eventually we should make
the stream-based vconns (currently that's all of them) a wrapper around
streams, but I haven't done that yet.

SSL is not implemented yet.

lib/stream-unix.c

@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2008, 2009 Nicira Networks.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+#include "stream.h"
+#include <assert.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <netdb.h>
+#include <poll.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "packets.h"
+#include "poll-loop.h"
+#include "socket-util.h"
+#include "util.h"
+#include "stream-provider.h"
+#include "stream-fd.h"
+
+#include "vlog.h"
+#define THIS_MODULE VLM_stream_unix
+
+/* Active UNIX socket. */
+
+/* Number of unix sockets created so far, to ensure binding path uniqueness. */
+static int n_unix_sockets;
+
+static int
+unix_open(const char *name, char *suffix, struct stream **streamp)
+{
+    const char *connect_path = suffix;
+    char *bind_path;
+    int fd;
+
+    bind_path = xasprintf("/tmp/stream-unix.%ld.%d",
+                          (long int) getpid(), n_unix_sockets++);
+    fd = make_unix_socket(SOCK_STREAM, true, false, bind_path, connect_path);
+    if (fd < 0) {
+        VLOG_ERR("%s: connection to %s failed: %s",
+                 bind_path, connect_path, strerror(-fd));
+        free(bind_path);
+        return -fd;
+    }
+
+    return new_fd_stream(name, fd, check_connection_completion(fd),
+                         bind_path, streamp);
+}
+
+struct stream_class unix_stream_class = {
+    "unix",                     /* name */
+    unix_open,                  /* open */
+    NULL,                       /* close */
+    NULL,                       /* connect */
+    NULL,                       /* recv */
+    NULL,                       /* send */
+    NULL,                       /* wait */
+};
+
+/* Passive UNIX socket. */
+
+static int punix_accept(int fd, const struct sockaddr *sa, size_t sa_len,
+                        struct stream **streamp);
+
+static int
+punix_open(const char *name UNUSED, char *suffix, struct pstream **pstreamp)
+{
+    int fd, error;
+
+    fd = make_unix_socket(SOCK_STREAM, true, true, suffix, NULL);
+    if (fd < 0) {
+        VLOG_ERR("%s: binding failed: %s", suffix, strerror(errno));
+        return errno;
+    }
+
+    error = set_nonblocking(fd);
+    if (error) {
+        close(fd);
+        return error;
+    }
+
+    if (listen(fd, 10) < 0) {
+        error = errno;
+        VLOG_ERR("%s: listen: %s", name, strerror(error));
+        close(fd);
+        return error;
+    }
+
+    return new_fd_pstream("punix", fd, punix_accept,
+                          xstrdup(suffix), pstreamp);
+}
+
+static int
+punix_accept(int fd, const struct sockaddr *sa, size_t sa_len,
+             struct stream **streamp)
+{
+    const struct sockaddr_un *sun = (const struct sockaddr_un *) sa;
+    int name_len = get_unix_name_len(sa_len);
+    char name[128];
+
+    if (name_len > 0) {
+        snprintf(name, sizeof name, "unix:%.*s", name_len, sun->sun_path);
+    } else {
+        strcpy(name, "unix");
+    }
+    return new_fd_stream(name, fd, 0, NULL, streamp);
+}
+
+struct pstream_class punix_pstream_class = {
+    "punix",
+    punix_open,
+    NULL,
+    NULL,
+    NULL
+};
+