nat: Move the ctrl handling code into a separate file

Move to the control command handling out of the main file into
a dedicated module. There are still some calls embedded into the
main code but it will be moved soon.

1 files changed, 324 insertions, 0 deletions

diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat_ctrl.c b/openbsc/src/osmo-bsc_nat/bsc_nat_ctrl.c
new file mode 100644
index 000000000..32ae0681b
--- /dev/null
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat_ctrl.c
@@ -0,0 +1,324 @@
+/*
+ * (C) 2011-2012 by Holger Hans Peter Freyther
+ * (C) 2011-2012 by On-Waves
+ * (C) 2011 by Daniel Willmann
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <osmocom/core/talloc.h>
+
+#include <openbsc/control_cmd.h>
+#include <openbsc/control_if.h>
+
+#include <openbsc/bsc_nat.h>
+
+#include <unistd.h>
+
+
+#define NAT_MAX_CTRL_ID 65535
+
+static struct bsc_nat *g_nat;
+
+static int bsc_id_unused(int id, struct bsc_connection *bsc)
+{
+	struct bsc_cmd_list *pending;
+
+	llist_for_each_entry(pending, &bsc->cmd_pending, list_entry) {
+		if (pending->nat_id == id)
+			return 0;
+	}
+	return 1;
+}
+
+static int get_next_free_bsc_id(struct bsc_connection *bsc)
+{
+	int new_id, overflow = 0;
+
+	new_id = bsc->last_id;
+
+	do {
+		new_id++;
+		if (new_id == NAT_MAX_CTRL_ID) {
+			new_id = 1;
+			overflow++;
+		}
+
+		if (bsc_id_unused(new_id, bsc)) {
+			bsc->last_id = new_id;
+			return new_id;
+		}
+	} while (overflow != 2);
+
+	return -1;
+}
+
+void bsc_nat_ctrl_del_pending(struct bsc_cmd_list *pending)
+{
+	llist_del(&pending->list_entry);
+	osmo_timer_del(&pending->timeout);
+	talloc_free(pending->cmd);
+	talloc_free(pending);
+}
+
+static struct bsc_cmd_list *bsc_get_pending(struct bsc_connection *bsc, char *id_str)
+{
+	struct bsc_cmd_list *cmd_entry;
+	int id = atoi(id_str);
+	if (id == 0)
+		return NULL;
+
+	llist_for_each_entry(cmd_entry, &bsc->cmd_pending, list_entry) {
+		if (cmd_entry->nat_id == id) {
+			return cmd_entry;
+		}
+	}
+	return NULL;
+}
+
+int bsc_nat_handle_ctrlif_msg(struct bsc_connection *bsc, struct msgb *msg)
+{
+	struct ctrl_cmd *cmd;
+	struct bsc_cmd_list *pending;
+	char *var, *id;
+
+	cmd = ctrl_cmd_parse(bsc, msg);
+	msgb_free(msg);
+
+	if (!cmd) {
+		cmd = talloc_zero(bsc, struct ctrl_cmd);
+		if (!cmd) {
+			LOGP(DNAT, LOGL_ERROR, "OOM!\n");
+			return -ENOMEM;
+		}
+		cmd->type = CTRL_TYPE_ERROR;
+		cmd->id = "err";
+		cmd->reply = "Failed to parse command.";
+		goto err;
+	}
+
+	if (bsc->cfg && !llist_empty(&bsc->cfg->lac_list)) {
+		if (cmd->variable) {
+			var = talloc_asprintf(cmd, "net.0.bsc.%i.%s", bsc->cfg->nr,
+					   cmd->variable);
+			if (!var) {
+				cmd->type = CTRL_TYPE_ERROR;
+				cmd->reply = "OOM";
+				goto err;
+			}
+			talloc_free(cmd->variable);
+			cmd->variable = var;
+		}
+
+		/* We have to handle TRAPs before matching pending */
+		if (cmd->type == CTRL_TYPE_TRAP) {
+			ctrl_cmd_send_to_all(bsc->nat->ctrl, cmd);
+			talloc_free(cmd);
+			return 0;
+		}
+
+		/* Find the pending command */
+		pending = bsc_get_pending(bsc, cmd->id);
+		if (pending) {
+			id = talloc_strdup(cmd, pending->cmd->id);
+			if (!id) {
+				cmd->type = CTRL_TYPE_ERROR;
+				cmd->reply = "OOM";
+				goto err;
+			}
+			cmd->id = id;
+			ctrl_cmd_send(&pending->ccon->write_queue, cmd);
+			bsc_nat_ctrl_del_pending(pending);
+		} else {
+			/* We need to handle TRAPS here */
+			if ((cmd->type != CTRL_TYPE_ERROR) &&
+			    (cmd->type != CTRL_TYPE_TRAP)) {
+				LOGP(DNAT, LOGL_NOTICE, "Got control message "
+					"from BSC without pending entry\n");
+				cmd->type = CTRL_TYPE_ERROR;
+				cmd->reply = "No request outstanding";
+				goto err;
+			}
+		}
+	}
+	talloc_free(cmd);
+	return 0;
+err:
+	ctrl_cmd_send(&bsc->write_queue, cmd);
+	talloc_free(cmd);
+	return 0;
+}
+
+static void pending_timeout_cb(void *data)
+{
+	struct bsc_cmd_list *pending = data;
+	LOGP(DNAT, LOGL_ERROR, "Command timed out\n");
+	pending->cmd->type = CTRL_TYPE_ERROR;
+	pending->cmd->reply = "Command timed out";
+	ctrl_cmd_send(&pending->ccon->write_queue, pending->cmd);
+
+	bsc_nat_ctrl_del_pending(pending);
+}
+
+static void ctrl_conn_closed_cb(struct ctrl_connection *connection)
+{
+	struct bsc_connection *bsc;
+	struct bsc_cmd_list *pending, *tmp;
+
+	llist_for_each_entry(bsc, &g_nat->bsc_connections, list_entry) {
+		llist_for_each_entry_safe(pending, tmp, &bsc->cmd_pending, list_entry) {
+			if (pending->ccon == connection)
+				bsc_nat_ctrl_del_pending(pending);
+		}
+	}
+}
+
+static int forward_to_bsc(struct ctrl_cmd *cmd)
+{
+	int ret = CTRL_CMD_HANDLED;
+	struct ctrl_cmd *bsc_cmd = NULL;
+	struct bsc_connection *bsc;
+	struct bsc_cmd_list *pending;
+	unsigned int nr;
+	char *nr_str, *tmp, *saveptr;
+
+	/* Skip over the beginning (bsc.) */
+	tmp = strtok_r(cmd->variable, ".", &saveptr);
+	tmp = strtok_r(NULL, ".", &saveptr);
+	tmp = strtok_r(NULL, ".", &saveptr);
+	nr_str = strtok_r(NULL, ".", &saveptr);
+	if (!nr_str) {
+		cmd->reply = "command incomplete";
+		goto err;
+	}
+	nr = atoi(nr_str);
+
+	tmp = strtok_r(NULL, "\0", &saveptr);
+	if (!tmp) {
+		cmd->reply = "command incomplete";
+		goto err;
+	}
+
+	llist_for_each_entry(bsc, &g_nat->bsc_connections, list_entry) {
+		if (!bsc->cfg)
+			continue;
+		if (!bsc->authenticated)
+			continue;
+		if (bsc->cfg->nr == nr) {
+			/* Add pending command to list */
+			pending = talloc_zero(bsc, struct bsc_cmd_list);
+			if (!pending) {
+				cmd->reply = "OOM";
+				goto err;
+			}
+
+			pending->nat_id = get_next_free_bsc_id(bsc);
+			if (pending->nat_id < 0) {
+				cmd->reply = "No free ID found";
+				goto err;
+			}
+
+			bsc_cmd = ctrl_cmd_cpy(bsc, cmd);
+			if (!bsc_cmd) {
+				cmd->reply = "Could not forward command";
+				goto err;
+			}
+
+			talloc_free(bsc_cmd->id);
+			bsc_cmd->id = talloc_asprintf(bsc_cmd, "%i", pending->nat_id);
+			if (!bsc_cmd->id) {
+				cmd->reply = "OOM";
+				goto err;
+			}
+
+			talloc_free(bsc_cmd->variable);
+			bsc_cmd->variable = talloc_strdup(bsc_cmd, tmp);
+			if (!bsc_cmd->variable) {
+				cmd->reply = "OOM";
+				goto err;
+			}
+
+			if (ctrl_cmd_send(&bsc->write_queue, bsc_cmd)) {
+				cmd->reply = "Sending failed";
+				goto err;
+			}
+			pending->ccon = cmd->ccon;
+			pending->ccon->closed_cb = ctrl_conn_closed_cb;
+			pending->cmd = cmd;
+
+			/* Setup the timeout */
+			pending->timeout.data = pending;
+			pending->timeout.cb = pending_timeout_cb;
+			/* TODO: Make timeout configurable */
+			osmo_timer_schedule(&pending->timeout, 10, 0);
+			llist_add_tail(&pending->list_entry, &bsc->cmd_pending);
+
+			goto done;
+		}
+	}
+	/* We end up here if there's no bsc to handle our LAC */
+	cmd->reply = "no BSC with this nr";
+err:
+	ret = CTRL_CMD_ERROR;
+done:
+	if (bsc_cmd)
+		talloc_free(bsc_cmd);
+	return ret;
+
+}
+
+
+CTRL_CMD_DEFINE(fwd_cmd, "net 0 bsc *");
+static int get_fwd_cmd(struct ctrl_cmd *cmd, void *data)
+{
+	return forward_to_bsc(cmd);
+}
+
+static int set_fwd_cmd(struct ctrl_cmd *cmd, void *data)
+{
+	return forward_to_bsc(cmd);
+}
+
+static int verify_fwd_cmd(struct ctrl_cmd *cmd, const char *value, void *data)
+{
+	return 0;
+}
+
+struct ctrl_handle *bsc_nat_controlif_setup(struct bsc_nat *nat, int port)
+{
+	struct ctrl_handle *ctrl;
+	int rc;
+
+
+	ctrl = controlif_setup(NULL, 4250);
+	if (!ctrl) {
+		fprintf(stderr, "Failed to initialize the control interface. Exiting.\n");
+		return NULL;
+	}
+
+	rc = ctrl_cmd_install(CTRL_NODE_ROOT, &cmd_fwd_cmd);
+	if (rc) {
+		fprintf(stderr, "Failed to install the control command. Exiting.\n");
+		osmo_fd_unregister(&ctrl->listen_fd);
+		close(ctrl->listen_fd.fd);
+		talloc_free(ctrl);
+		return NULL;
+	}
+
+	g_nat = nat;
+	return ctrl;
+}
+