afb-socket: Separate socket creation

The objective is to have a well identified and
possibly reusable internally.

Change-Id: Icdb6ce7d85ae26373cfe4f0b492fe97b74ed747c
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

1 files changed, 264 insertions, 0 deletions

diff --git a/src/afb-socket.c b/src/afb-socket.c
new file mode 100644
index 00000000..c6402d42
--- /dev/null
+++ b/src/afb-socket.c
@@ -0,0 +1,264 @@
+/*
+ * Copyright (C) 2015-2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * 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.
+ */
+
+#define _GNU_SOURCE
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <endian.h>
+#include <netdb.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include "afb-fdev.h"
+#include "afb-socket.h"
+#include "afb-systemd.h"
+#include "fdev.h"
+#include "verbose.h"
+
+#define BACKLOG  5
+
+/******************************************************************************/
+
+static int open_unix(const char *spec, int server)
+{
+	int fd, rc, abstract;
+	struct sockaddr_un addr;
+	size_t length;
+
+	abstract = spec[0] == '@';
+
+	/* check the length */
+	length = strlen(spec);
+	if (length >= 108) {
+		errno = ENAMETOOLONG;
+		return -1;
+	}
+
+	/* remove the file on need */
+	if (server && !abstract)
+		unlink(spec);
+
+	/* create a  socket */
+	fd = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (fd < 0)
+		return fd;
+
+	/* prepare address  */
+	memset(&addr, 0, sizeof addr);
+	addr.sun_family = AF_UNIX;
+	strcpy(addr.sun_path, spec);
+	if (abstract)
+		addr.sun_path[0] = 0; /* implement abstract sockets */
+
+	if (server) {
+		rc = bind(fd, (struct sockaddr *) &addr, (socklen_t)(sizeof addr));
+	} else {
+		rc = connect(fd, (struct sockaddr *) &addr, (socklen_t)(sizeof addr));
+	}
+	if (rc < 0) {
+		close(fd);
+		return rc;
+	}
+	return fd;
+}
+
+static int open_inet(const char *spec, int server)
+{
+	int rc, fd;
+	const char *service, *host, *api;
+	struct addrinfo hint, *rai, *iai;
+
+	/* scan the uri */
+	api = strrchr(spec, '/');
+	service = strrchr(spec, ':');
+	if (api == NULL || service == NULL || api < service) {
+		errno = EINVAL;
+		return -1;
+	}
+	host = strndupa(spec, service++ - spec);
+	service = strndupa(service, api - service);
+
+	/* get addr */
+	memset(&hint, 0, sizeof hint);
+	hint.ai_family = AF_INET;
+	hint.ai_socktype = SOCK_STREAM;
+	rc = getaddrinfo(host, service, &hint, &rai);
+	if (rc != 0) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	/* get the socket */
+	iai = rai;
+	while (iai != NULL) {
+		fd = socket(iai->ai_family, iai->ai_socktype, iai->ai_protocol);
+		if (fd >= 0) {
+			if (server) {
+				rc = bind(fd, iai->ai_addr, iai->ai_addrlen);
+			} else {
+				rc = connect(fd, iai->ai_addr, iai->ai_addrlen);
+			}
+			if (rc == 0) {
+				freeaddrinfo(rai);
+				return fd;
+			}
+			close(fd);
+		}
+		iai = iai->ai_next;
+	}
+	freeaddrinfo(rai);
+	return -1;
+}
+
+static int open_systemd(const char *spec)
+{
+#if defined(NO_SYSTEMD_ACTIVATION)
+	errno = EAFNOSUPPORT;
+	fd = -1;
+#else
+	return afb_systemd_fds_for(spec);
+#endif
+}
+
+/******************************************************************************/
+
+enum type {
+	Type_Inet,
+	Type_Systemd,
+	Type_Unix
+};
+
+struct entry
+{
+	const char *prefix;
+	unsigned type: 2;
+	unsigned noreuseaddr: 1;
+	unsigned nolisten: 1;
+};
+
+static struct entry entries[] = { /* default at first place */
+	{
+		.prefix = "tcp:",
+		.type = Type_Inet
+	},
+	{
+		.prefix = "sd:",
+		.type = Type_Systemd,
+		.noreuseaddr = 1,
+		.nolisten = 1
+	},
+	{
+		.prefix = "unix:",
+		.type = Type_Unix
+	}
+};
+
+/******************************************************************************/
+
+/* get the entry of the uri by searching to its prefix */
+static struct entry *get_entry(const char *uri, int *offset)
+{
+	int l, search = 1, i = (int)(sizeof entries / sizeof * entries);
+
+	while (search) {
+		if (!i) {
+			l = 0;
+			search = 0;
+		} else {
+			i--;
+			l = (int)strlen(entries[i].prefix);
+			search = strncmp(uri, entries[i].prefix, l);
+		}
+	}
+
+	*offset = l;
+	return &entries[i];
+}
+
+static int open_any(const char *uri, int server)
+{
+	int fd, rc, offset;
+	struct entry *e;
+
+	/* search for the entry */
+	e = get_entry(uri, &offset);
+
+	/* get the names */
+
+	uri += offset;
+
+	/* open the socket */
+	switch (e->type) {
+	case Type_Unix:
+		fd = open_unix(uri, server);
+		break;
+	case Type_Inet:
+		fd = open_inet(uri, server);
+		break;
+	case Type_Systemd:
+		fd = open_systemd(uri);
+		break;
+	default:
+		errno = EAFNOSUPPORT;
+		fd = -1;
+		break;
+	}
+	if (fd < 0)
+		return -1;
+
+	/* set it up */
+	fcntl(fd, F_SETFD, FD_CLOEXEC);
+	fcntl(fd, F_SETFL, O_NONBLOCK);
+	if (server) {
+		if (!e->noreuseaddr) {
+			rc = 1;
+			setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &rc, sizeof rc);
+		}
+		if (!e->nolisten)
+			listen(fd, BACKLOG);
+	}
+	return fd;
+}
+
+struct fdev *afb_socket_open(const char *uri, int server)
+{
+	int fd;
+	struct fdev *fdev;
+
+	fd = open_any(uri, server);
+	if (fd < 0)
+		goto error;
+
+	fdev = afb_fdev_create(fd);
+	if (!fdev)
+		goto error2;
+
+	return fdev;
+
+error2:
+	close(fd);
+error:
+	ERROR("can't make %s socket for %s", server ? "server" : "client", uri);
+	return NULL;
+}
+