Add libctrl, an SNMP-like control interface

In contrast to the VTY interface the control interface is meant to be
used by programs.
This patch adds basic support, no commands are defined.

1 files changed, 369 insertions, 0 deletions

diff --git a/openbsc/src/libctrl/control_if.c b/openbsc/src/libctrl/control_if.c
new file mode 100644
index 00000000..a607b10b
--- /dev/null
+++ b/openbsc/src/libctrl/control_if.c
@@ -0,0 +1,369 @@
+/* SNMP-like status interface
+ *
+ * (C) 2010-2011 by Daniel Willmann <daniel@totalueberwachung.de>
+ * (C) 2010-2011 by On-Waves
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <arpa/inet.h>
+
+#include <netinet/tcp.h>
+
+#include <sys/fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+
+#include <openbsc/control_cmd.h>
+#include <openbsc/debug.h>
+#include <openbsc/e1_input.h>
+#include <openbsc/gsm_data.h>
+#include <openbsc/ipaccess.h>
+#include <openbsc/socket.h>
+#include <openbsc/subchan_demux.h>
+
+#include <openbsc/abis_rsl.h>
+#include <openbsc/abis_nm.h>
+
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/talloc.h>
+
+#include <osmocom/gsm/tlv.h>
+
+#include <osmocom/vty/command.h>
+#include <osmocom/vty/vector.h>
+
+struct ctrl_handle {
+	struct osmo_fd listen_fd;
+	struct gsm_network *gsmnet;
+};
+
+vector ctrl_node_vec;
+
+int ctrl_cmd_send(struct osmo_wqueue *queue, struct ctrl_cmd *cmd)
+{
+	int ret;
+	struct msgb *msg;
+
+	msg = ctrl_cmd_make(cmd);
+	if (!msg) {
+		LOGP(DINP, LOGL_ERROR, "Could not generate msg\n");
+		return -1;
+	}
+
+	ipaccess_prepend_header_ext(msg, IPAC_PROTO_EXT_CTRL);
+	ipaccess_prepend_header(msg, IPAC_PROTO_OSMO);
+
+	ret = osmo_wqueue_enqueue(queue, msg);
+	if (ret != 0) {
+		LOGP(DINP, LOGL_ERROR, "Failed to enqueue the command.\n");
+		msgb_free(msg);
+	}
+	return ret;
+}
+
+int ctrl_cmd_handle(struct ctrl_cmd *cmd, void *data)
+{
+	char *token, *request;
+	int num, i, j, ret, node;
+	struct gsm_network *gsmnet = data;
+
+	struct gsm_network *net = NULL;
+	struct gsm_bts *bts = NULL;
+	struct gsm_bts_trx *trx = NULL;
+	struct gsm_bts_trx_ts *ts = NULL;
+	vector vline, cmdvec, cmds_vec;
+
+	ret = CTRL_CMD_ERROR;
+	cmd->reply = "Someone forgot to fill in the reply.";
+	cmd->node = NULL;
+	node = CTRL_NODE_ROOT;
+
+	request = talloc_strdup(tall_bsc_ctx, cmd->variable);
+	if (!request)
+		goto err;
+
+	for (i=0;i<strlen(request);i++) {
+		if (request[i] == '.')
+			request[i] = ' ';
+	}
+
+	vline = cmd_make_strvec(request);
+	talloc_free(request);
+	if (!vline)
+		goto err;
+
+	for (i=0;i<vector_active(vline);i++) {
+		token = vector_slot(vline, i);
+		/* TODO: We need to make sure that the following chars are digits
+		 * and/or use strtol to check if number conversion was successful
+		 * Right now something like net.bts_stats will not work */
+		if (!strcmp(token, "net")) {
+			net = gsmnet;
+			if (!net)
+				break;
+			cmd->node = net;
+			node = CTRL_NODE_NET;
+		} else if (!strncmp(token, "bts", 3)) {
+			if (!net)
+				break;
+			num = atoi(&token[3]);
+			bts = gsm_bts_num(net, num);
+			if (!bts)
+				break;
+			cmd->node = bts;
+			node = CTRL_NODE_BTS;
+		} else if (!strncmp(token, "trx", 3)) {
+			if (!bts)
+				break;
+			num = atoi(&token[3]);
+			trx = gsm_bts_trx_num(bts, num);
+			if (!trx)
+				break;
+			cmd->node = trx;
+			node = CTRL_NODE_TRX;
+		} else if (!strncmp(token, "ts", 2)) {
+			if (!trx)
+				break;
+			num = atoi(&token[2]);
+			if ((num >= 0) && (num < TRX_NR_TS))
+				ts = &trx->ts[num];
+			if (!ts)
+				break;
+			cmd->node = ts;
+			node = CTRL_NODE_TS;
+		} else {
+			/* If we're here the rest must be the command */
+			cmdvec = vector_init(vector_active(vline)-i);
+			for (j=i; j<vector_active(vline); j++) {
+				vector_set(cmdvec, vector_slot(vline, j));
+			}
+
+			/* Get the command vector of the right node */
+			cmds_vec = vector_lookup(ctrl_node_vec, node);
+
+			if (!cmds_vec) {
+				cmd->reply = "Command not found";
+				vector_free(cmdvec);
+				break;
+			}
+
+			ret = ctrl_cmd_exec(cmdvec, cmd, cmds_vec, data);
+
+			vector_free(cmdvec);
+			break;
+		}
+	}
+
+	cmd_free_strvec(vline);
+
+err:
+	if (ret == CTRL_CMD_ERROR)
+		cmd->type = CTRL_TYPE_ERROR;
+	return ret;
+}
+
+static void control_close_conn(struct ctrl_connection *ccon)
+{
+	close(ccon->write_queue.bfd.fd);
+	osmo_fd_unregister(&ccon->write_queue.bfd);
+	if (ccon->closed_cb)
+		ccon->closed_cb(ccon);
+	talloc_free(ccon);
+}
+
+static int handle_control_read(struct osmo_fd * bfd)
+{
+	int ret = -1, error;
+	struct osmo_wqueue *queue;
+	struct ctrl_connection *ccon;
+	struct ipaccess_head *iph;
+	struct ipaccess_head_ext *iph_ext;
+	struct msgb *msg;
+	struct ctrl_cmd *cmd;
+	struct ctrl_handle *ctrl = bfd->data;
+
+	queue = container_of(bfd, struct osmo_wqueue, bfd);
+	ccon = container_of(queue, struct ctrl_connection, write_queue);
+
+	msg = ipaccess_read_msg(bfd, &error);
+
+	if (!msg) {
+		if (error == 0)
+			LOGP(DINP, LOGL_INFO, "The control connection was closed\n");
+		else
+			LOGP(DINP, LOGL_ERROR, "Failed to parse ip access message: %d\n", error);
+
+		goto err;
+	}
+
+	if (msg->len < sizeof(*iph) + sizeof(*iph_ext)) {
+		LOGP(DINP, LOGL_ERROR, "The message is too short.\n");
+		goto err;
+	}
+
+	iph = (struct ipaccess_head *) msg->data;
+	if (iph->proto != IPAC_PROTO_OSMO) {
+		LOGP(DINP, LOGL_ERROR, "Protocol mismatch. We got 0x%x\n", iph->proto);
+		goto err;
+	}
+
+	iph_ext = (struct ipaccess_head_ext *) iph->data;
+	if (iph_ext->proto != IPAC_PROTO_EXT_CTRL) {
+		LOGP(DINP, LOGL_ERROR, "Extended protocol mismatch. We got 0x%x\n", iph_ext->proto);
+		goto err;
+	}
+
+	msg->l2h = iph_ext->data;
+
+	cmd = ctrl_cmd_parse(ccon, msg);
+
+	if (cmd) {
+		cmd->ccon = ccon;
+		if (ctrl_cmd_handle(cmd, ctrl->gsmnet) != CTRL_CMD_HANDLED) {
+			ctrl_cmd_send(queue, cmd);
+			talloc_free(cmd);
+		}
+	} else {
+		cmd = talloc_zero(ccon, struct ctrl_cmd);
+		if (!cmd)
+			goto err;
+		LOGP(DINP, LOGL_ERROR, "Command parser error.\n");
+		cmd->type = CTRL_TYPE_ERROR;
+		cmd->id = "err";
+		cmd->reply = "Command parser error.";
+		ctrl_cmd_send(queue, cmd);
+		talloc_free(cmd);
+	}
+
+	msgb_free(msg);
+	return 0;
+
+err:
+	control_close_conn(ccon);
+	msgb_free(msg);
+	return ret;
+}
+
+static int control_write_cb(struct osmo_fd *bfd, struct msgb *msg)
+{
+	int rc;
+
+	rc = write(bfd->fd, msg->data, msg->len);
+	if (rc != msg->len)
+		LOGP(DINP, LOGL_ERROR, "Failed to write message to the control connection.\n");
+
+	return rc;
+}
+
+static struct ctrl_connection *ctrl_connection_alloc(void *ctx)
+{
+	struct ctrl_connection *ccon = talloc_zero(ctx, struct ctrl_connection);
+	if (!ccon)
+		return NULL;
+
+	osmo_wqueue_init(&ccon->write_queue, 100);
+	/* Error handling here? */
+
+	INIT_LLIST_HEAD(&ccon->cmds);
+	return ccon;
+}
+
+static int listen_fd_cb(struct osmo_fd *listen_bfd, unsigned int what)
+{
+	int ret, fd, on;
+	struct ctrl_connection *ccon;
+	struct sockaddr_in sa;
+	socklen_t sa_len = sizeof(sa);
+
+
+	if (!(what & BSC_FD_READ))
+		return 0;
+
+	fd = accept(listen_bfd->fd, (struct sockaddr *) &sa, &sa_len);
+	if (fd < 0) {
+		perror("accept");
+		return fd;
+	}
+	LOGP(DINP, LOGL_INFO, "accept()ed new control connection from %s\n",
+		inet_ntoa(sa.sin_addr));
+
+	on = 1;
+	ret = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on));
+	if (ret != 0) {
+		LOGP(DNAT, LOGL_ERROR, "Failed to set TCP_NODELAY: %s\n", strerror(errno));
+		close(fd);
+		return ret;
+	}
+	ccon = ctrl_connection_alloc(listen_bfd->data);
+	if (!ccon) {
+		LOGP(DINP, LOGL_ERROR, "Failed to allocate.\n");
+		close(fd);
+		return -1;
+	}
+
+	ccon->write_queue.bfd.data = listen_bfd->data;
+	ccon->write_queue.bfd.fd = fd;
+	ccon->write_queue.bfd.when = BSC_FD_READ;
+	ccon->write_queue.read_cb = handle_control_read;
+	ccon->write_queue.write_cb = control_write_cb;
+
+	ret = osmo_fd_register(&ccon->write_queue.bfd);
+	if (ret < 0) {
+		LOGP(DINP, LOGL_ERROR, "Could not register FD.\n");
+		close(ccon->write_queue.bfd.fd);
+		talloc_free(ccon);
+	}
+
+	return ret;
+}
+
+int controlif_setup(struct gsm_network *gsmnet, uint16_t port)
+{
+	int ret;
+	struct ctrl_handle *ctrl;
+
+	ctrl = talloc_zero(tall_bsc_ctx, struct ctrl_handle);
+	if (!ctrl)
+		return -ENOMEM;
+
+	ctrl->gsmnet = gsmnet;
+
+	ctrl_node_vec = vector_init(5);
+	if (!ctrl_node_vec)
+		return -ENOMEM;
+
+	/* Listen for control connections */
+	ret = make_sock(&ctrl->listen_fd, IPPROTO_TCP, 0, port,
+			0, listen_fd_cb, ctrl);
+	if (ret < 0) {
+		talloc_free(ctrl);
+		return ret;
+	}
+
+	return ret;
+}