stemodem: Add RTNL functionality managing CAIF Network Interfaces.

2 files changed, 369 insertions, 0 deletions

diff --git a/drivers/stemodem/caif_rtnl.c b/drivers/stemodem/caif_rtnl.c
new file mode 100644
index 00000000..4ce24017
--- /dev/null
+++ b/drivers/stemodem/caif_rtnl.c
@@ -0,0 +1,340 @@
+/*
+ *
+ *  oFono - Open Source Telephony
+ *
+ *  Copyright (C) 2010 ST-Ericsson AB.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <net/if.h>
+#include <net/if_arp.h>
+#include <fcntl.h>
+#include <linux/rtnetlink.h>
+
+#include <glib.h>
+
+#include <ofono/log.h>
+
+#include "if_caif.h"
+#include "caif_rtnl.h"
+
+#define NLMSG_TAIL(nmsg) \
+	((struct rtattr *) (((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
+
+#define RTNL_MSG_SIZE 4096
+
+struct rtnl_msg {
+	struct nlmsghdr n;
+	struct ifinfomsg i;
+	char data[RTNL_MSG_SIZE];
+};
+
+struct iplink_req {
+	guint32 rtnlmsg_seqnr;
+	gpointer user_data;
+	caif_rtnl_create_cb_t callback;
+};
+
+static GSList *pending_requests;
+static guint32 rtnl_seqnr;
+static guint rtnl_watch;
+static GIOChannel *rtnl_channel;
+
+static struct iplink_req *find_request(guint32 seq)
+{
+	GSList *list;
+
+	for (list = pending_requests; list; list = list->next) {
+		struct iplink_req *req = list->data;
+
+		if (req->rtnlmsg_seqnr == seq)
+			return req;
+	}
+
+	return NULL;
+}
+
+static void parse_newlink_param(struct ifinfomsg *msg, int size,
+						int *ifindex, char *ifname)
+{
+	struct rtattr *attr;
+
+	for (attr = IFLA_RTA(msg); RTA_OK(attr, size);
+		attr = RTA_NEXT(attr, size)) {
+
+		if (attr->rta_type == IFLA_IFNAME &&
+				ifname != NULL) {
+
+			strncpy(ifname, RTA_DATA(attr), IF_NAMESIZE);
+			ifname[IF_NAMESIZE-1] = '\0';
+			break;
+		}
+	}
+
+	*ifindex = msg->ifi_index;
+}
+
+static void parse_rtnl_message(const void *buf, size_t len)
+{
+	struct ifinfomsg *msg;
+	struct iplink_req *req = NULL;
+	char ifname[IF_NAMESIZE];
+	int ifindex;
+
+	while (len > 0) {
+		const struct nlmsghdr *hdr = buf;
+
+		if (!NLMSG_OK(hdr, len))
+			break;
+
+		switch (hdr->nlmsg_type) {
+		case RTM_NEWLINK:
+			req = g_slist_nth_data(pending_requests, 0);
+			if (req == NULL)
+				break;
+
+			msg = (struct ifinfomsg *) NLMSG_DATA(hdr);
+			parse_newlink_param(msg, IFA_PAYLOAD(hdr),
+							&ifindex, ifname);
+
+			if (req->callback)
+				req->callback(ifindex, ifname, req->user_data);
+			break;
+
+		case NLMSG_ERROR:
+			req = find_request(hdr->nlmsg_seq);
+			if (req == NULL)
+				break;
+
+			DBG("nlmsg error req");
+			if (req->callback)
+				req->callback(-1, ifname, req->user_data);
+			break;
+		default:
+			break;
+		}
+
+		len -= hdr->nlmsg_len;
+		buf += hdr->nlmsg_len;
+
+		if (req) {
+			pending_requests = g_slist_remove(pending_requests,
+								req);
+			g_free(req);
+			req = NULL;
+		}
+	}
+}
+
+static int add_attribute(struct nlmsghdr *n, unsigned int maxlen, int type,
+				const void *data, int datalen)
+{
+	int len = RTA_LENGTH(datalen);
+	struct rtattr *rta;
+
+	if ((NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len)) > maxlen) {
+		DBG("attribute to large for message %d %d %d\n",
+				n->nlmsg_len, len, maxlen);
+		return -1;
+	}
+
+	rta = NLMSG_TAIL(n);
+	rta->rta_type = type;
+	rta->rta_len = len;
+	memcpy(RTA_DATA(rta), data, datalen);
+	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
+
+	return 0;
+}
+
+static void prep_rtnl_req(struct rtnl_msg *msg, int reqtype, guint seqnr)
+{
+	msg->n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
+	msg->n.nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE|NLM_F_EXCL;
+	msg->n.nlmsg_type = reqtype;
+	msg->n.nlmsg_seq = seqnr;
+	msg->i.ifi_family = AF_UNSPEC;
+}
+
+static gboolean netlink_event(GIOChannel *chan,
+				GIOCondition cond, gpointer data)
+{
+	unsigned char buf[RTNL_MSG_SIZE];
+	int len;
+	int sk = g_io_channel_unix_get_fd(rtnl_channel);
+
+	if (cond & (G_IO_NVAL | G_IO_HUP | G_IO_ERR)) {
+		rtnl_watch = 0;
+		return FALSE;
+	}
+
+	memset(buf, 0, sizeof(buf));
+	len = recv(sk, (void *)&buf, sizeof(buf), MSG_DONTWAIT);
+	if (len < 0) {
+		if (len == -EAGAIN)
+			return TRUE;
+		rtnl_watch = 0;
+		return FALSE;
+	}
+
+	parse_rtnl_message(buf, len);
+
+	return TRUE;
+}
+
+int caif_rtnl_init(void)
+{
+	struct sockaddr_nl addr;
+	int sk, err;
+
+	sk = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
+	if (sk < 0)
+		return sk;
+
+	memset(&addr, 0, sizeof(addr));
+	addr.nl_family = AF_NETLINK;
+	addr.nl_groups = RTMGRP_LINK;
+
+	err = bind(sk, (struct sockaddr *) &addr, sizeof(addr));
+	if (err < 0) {
+		close(sk);
+		return err;
+	}
+
+	rtnl_channel = g_io_channel_unix_new(sk);
+	g_io_channel_set_flags(rtnl_channel, G_IO_FLAG_NONBLOCK, NULL);
+	g_io_channel_set_close_on_unref(rtnl_channel, TRUE);
+
+	rtnl_watch = g_io_add_watch(rtnl_channel,
+				G_IO_IN | G_IO_NVAL | G_IO_HUP | G_IO_ERR,
+				netlink_event, NULL);
+
+	return 0;
+}
+
+void caif_rtnl_exit(void)
+{
+	GSList *list;
+
+	if (rtnl_watch > 0)
+		g_source_remove(rtnl_watch);
+
+	g_io_channel_unref(rtnl_channel);
+
+	for (list = pending_requests; list; list = list->next) {
+		struct iplink_req *req = list->data;
+		g_free(req);
+	}
+
+	g_slist_free(pending_requests);
+}
+
+int caif_rtnl_create_interface(int type, int connid, int loop,
+				caif_rtnl_create_cb_t cb, void *user_data)
+{
+	struct iplink_req *req;
+	struct sockaddr_nl addr;
+	int err, sk;
+	struct rtnl_msg msg;
+	struct rtattr *linkinfo;
+	struct rtattr *data_start;
+
+	req = g_try_new0(struct iplink_req, 1);
+	if (req == NULL)
+		return -ENOMEM;
+
+	req->user_data = user_data;
+	req->callback = cb;
+	memset(&msg, 0, RTNL_MSG_SIZE);
+
+	req->rtnlmsg_seqnr = ++rtnl_seqnr;
+	prep_rtnl_req(&msg, RTM_NEWLINK, req->rtnlmsg_seqnr);
+
+	linkinfo = NLMSG_TAIL(&msg.n);
+	add_attribute(&msg.n, sizeof(msg), IFLA_LINKINFO,
+			NULL, 0);
+	add_attribute(&msg.n, sizeof(msg), IFLA_INFO_KIND,
+			"caif", 4);
+	data_start = NLMSG_TAIL(&msg.n);
+	add_attribute(&msg.n, sizeof(msg), IFLA_INFO_DATA,
+			NULL, 0);
+
+	switch (type) {
+	case IFLA_CAIF_IPV4_CONNID:
+	case IFLA_CAIF_IPV6_CONNID:
+		add_attribute(&msg.n, sizeof(msg),
+				type, &connid,
+				sizeof(connid));
+		break;
+
+	case __IFLA_CAIF_UNSPEC:
+	case IFLA_CAIF_LOOPBACK:
+	case __IFLA_CAIF_MAX:
+		DBG("unsupported linktype");
+		return -EINVAL;
+	}
+
+	if (loop) {
+		add_attribute(&msg.n, sizeof(msg),
+				IFLA_CAIF_LOOPBACK, &loop, sizeof(loop));
+	}
+
+	data_start->rta_len = (void *)NLMSG_TAIL(&msg.n) - (void *)data_start;
+	linkinfo->rta_len = (void *)NLMSG_TAIL(&msg.n) - (void *)linkinfo;
+
+	memset(&addr, 0, sizeof(addr));
+	addr.nl_family = AF_NETLINK;
+	sk = g_io_channel_unix_get_fd(rtnl_channel);
+	err = sendto(sk, &msg, msg.n.nlmsg_len, 0,
+			(struct sockaddr *) &addr, sizeof(addr));
+	if (err < 0)
+		goto error;
+
+	pending_requests = g_slist_append(pending_requests, req);
+	return 0;
+
+error:
+	g_free(req);
+	return err;
+}
+
+int caif_rtnl_delete_interface(int ifid)
+{
+	struct sockaddr_nl addr;
+	struct rtnl_msg msg;
+	int err;
+	int sk = g_io_channel_unix_get_fd(rtnl_channel);
+
+	memset(&msg, 0, sizeof(msg));
+	prep_rtnl_req(&msg, RTM_DELLINK, ++rtnl_seqnr);
+	msg.i.ifi_index = ifid;
+	memset(&addr, 0, sizeof(addr));
+	addr.nl_family = AF_NETLINK;
+
+	err = sendto(sk, &msg, msg.n.nlmsg_len, 0,
+			(struct sockaddr *) &addr, sizeof(addr));
+	if (err < 0)
+		return err;
+
+	return 0;
+}
diff --git a/drivers/stemodem/caif_rtnl.h b/drivers/stemodem/caif_rtnl.h
new file mode 100644
index 00000000..9e44b086
--- /dev/null
+++ b/drivers/stemodem/caif_rtnl.h
@@ -0,0 +1,29 @@
+/*
+ *
+ *  oFono - Open Source Telephony
+ *
+ *  Copyright (C) 2010 ST-Ericsson AB.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+typedef void (*caif_rtnl_create_cb_t) (int ifindex, char *ifname,
+							void *user_data);
+
+extern int caif_rtnl_create_interface(int type, int connid, int loop,
+				caif_rtnl_create_cb_t cb, void *user_data);
+extern int caif_rtnl_delete_interface(int ifid);
+
+extern int caif_rtnl_init(void);
+extern void caif_rtnl_exit(void);