3 is the latest approved patch-set.
No files were changed between the latest approved patch-set and the submitted one.


proxy: implement power measurement emulation

Add the TRXC MEASURE command, used by the MS side (trxcon) to probe
RF power on a given frequency.  Scan all powered-on channels on the
requested frequency: if found, report the RSSI it would be measured
at using the same path-loss formula (or FAKE_RSSI override) as burst
forwarding;  if not, report a fixed noise floor.

The noise floor is configurable via the new 'pm-rssi-noise' VTY
command under the 'proxy' node (default -110 dBm).

Change-Id: I9be028ae9c1a20caf24327b7ee81eeeabbda0634
Related: OS#6672
---
M proxy/include/osmocom/proxy/path_sim.h
M proxy/include/osmocom/proxy/proxy.h
M proxy/src/ctrl_cmd.c
M proxy/src/path_sim.c
M proxy/src/proxy.c
M proxy/src/vty.c
6 files changed, 74 insertions(+), 0 deletions(-)

diff --git a/proxy/include/osmocom/proxy/path_sim.h b/proxy/include/osmocom/proxy/path_sim.h
index d27a3b1..c263eea 100644
--- a/proxy/include/osmocom/proxy/path_sim.h
+++ b/proxy/include/osmocom/proxy/path_sim.h
@@ -30,3 +30,4 @@
 		    struct proxy_trx_chan *dst,
 		    const struct osmo_trxd_burst_req *br,
 		    const struct proxy_trx_chan *src);
+int path_sim_measure(uint32_t freq_hz, int rssi_noise);
diff --git a/proxy/include/osmocom/proxy/proxy.h b/proxy/include/osmocom/proxy/proxy.h
index 080ff53..2d17ce9 100644
--- a/proxy/include/osmocom/proxy/proxy.h
+++ b/proxy/include/osmocom/proxy/proxy.h
@@ -13,8 +13,12 @@
 #define PROXY_DEFAULT_MS_NAME		"ms"
 #define PROXY_DEFAULT_MS_PORT		6700
 
+/*! RSSI (dBm) reported by MEASURE for a frequency with no Tx found on it */
+#define PROXY_DEFAULT_PM_RSSI_NOISE	-110
+
 struct proxy_ctx {
 	char *bind_addr;
+	int path_sim_noise_dbm; /*!< dBm, MEASURE result for frequencies with no Tx found */
 	struct llist_head trx_list; /*!< struct proxy_trx::list */
 };
 
diff --git a/proxy/src/ctrl_cmd.c b/proxy/src/ctrl_cmd.c
index 449fe81..9a86bb1 100644
--- a/proxy/src/ctrl_cmd.c
+++ b/proxy/src/ctrl_cmd.c
@@ -29,6 +29,7 @@
 #include <osmocom/trx/ep.h>
 #include <osmocom/trx/trxc.h>
 
+#include <osmocom/proxy/proxy.h>
 #include <osmocom/proxy/trx.h>
 #include <osmocom/proxy/path_sim.h>
 #include <osmocom/proxy/logging.h>
@@ -36,6 +37,7 @@
 /* Not part of the well-known OSMO_TRXC_CMD_* verbs (libosmo-trx/trxc.h) since
  * they are specific to this transceiver's RF path simulation. */
 #define CTRL_CMD_SETTA		"SETTA"
+#define CTRL_CMD_MEASURE	"MEASURE"
 #define CTRL_CMD_FAKE_TOA	"FAKE_TOA"
 #define CTRL_CMD_FAKE_RSSI	"FAKE_RSSI"
 #define CTRL_CMD_FAKE_CI	"FAKE_CI"
@@ -274,6 +276,23 @@
 		  "Dropping %d burst(s), every %d frame(s)\n", amount, period);
 }
 
+static void ctrl_cmd_measure(struct proxy_trx *trx, unsigned int chan,
+			     const struct osmo_trxc_msg *cmd, struct osmo_trxc_msg *rsp)
+{
+	int freq_khz, rssi;
+
+	if (osmo_trxc_msg_params_scan(cmd, "%d", &freq_khz) != 1) {
+		LOGP_TRXCH(trx, chan, DTRXC, LOGL_ERROR,
+			   "%s(): Failed to parse target frequency: '%s'\n",
+			   __func__, osmo_trxc_msg_name(cmd));
+		rsp->status = 1;
+		return;
+	}
+
+	rssi = path_sim_measure(freq_khz * 1000, g_proxy_ctx->path_sim_noise_dbm);
+	snprintf(rsp->params, sizeof(rsp->params), "%d %d", freq_khz, rssi);
+}
+
 void osmo_trx_ep_rx_ctrl_msg(struct osmo_trx_ep *ep, unsigned int chan,
 			     const struct osmo_trxc_msg *cmd)
 {
@@ -304,6 +323,8 @@
 		ctrl_cmd_rfmute(trx, chan, cmd, &rsp);
 	} else if (!strcmp(cmd->cmd, CTRL_CMD_SETTA)) {
 		ctrl_cmd_setta(trx, chan, cmd, &rsp);
+	} else if (!strcmp(cmd->cmd, CTRL_CMD_MEASURE)) {
+		ctrl_cmd_measure(trx, chan, cmd, &rsp);
 	} else if (!strcmp(cmd->cmd, CTRL_CMD_FAKE_TOA)) {
 		ctrl_cmd_fake_toa(trx, chan, cmd, &rsp);
 	} else if (!strcmp(cmd->cmd, CTRL_CMD_FAKE_RSSI)) {
diff --git a/proxy/src/path_sim.c b/proxy/src/path_sim.c
index b835f76..d51c20a 100644
--- a/proxy/src/path_sim.c
+++ b/proxy/src/path_sim.c
@@ -27,6 +27,7 @@
 
 #include <osmocom/trx/trxd.h>
 
+#include <osmocom/proxy/proxy.h>
 #include <osmocom/proxy/trx.h>
 #include <osmocom/proxy/path_sim.h>
 
@@ -119,3 +120,34 @@
 	bi->ci_cb = dst->path_sim.ci + path_sim_jitter(dst->path_sim.ci_jitter);
 	bi->flags |= OSMO_TRXD_F_CI_CB;
 }
+
+static int path_sim_measure_rssi(const struct proxy_trx_chan *tx)
+{
+	if (tx->path_sim.flags & PATH_SIM_F_FAKE_RSSI)
+		return tx->path_sim.rssi;
+
+	return (tx->path_sim.tx_power - tx->path_sim.tx_att) - PATH_SIM_PATH_LOSS_DEFAULT;
+}
+
+/*! Emulate a power measurement (MEASURE CTRL command) on a given Tx
+ * frequency: if some powered-on channel is currently transmitting on it,
+ * return the RSSI it would be measured at (same path-loss formula, or
+ * FAKE_RSSI override, as path_sim_apply()); otherwise return rssi_noise. */
+int path_sim_measure(uint32_t freq_hz, int rssi_noise)
+{
+	struct proxy_trx *trx;
+
+	llist_for_each_entry(trx, &g_proxy_ctx->trx_list, list) {
+		unsigned int chan;
+
+		if (!trx->powered)
+			continue;
+
+		for (chan = 0; chan < trx->num_chans; chan++) {
+			if (trx->chans[chan].tx_freq == freq_hz)
+				return path_sim_measure_rssi(&trx->chans[chan]);
+		}
+	}
+
+	return rssi_noise;
+}
diff --git a/proxy/src/proxy.c b/proxy/src/proxy.c
index b194bc9..4495909 100644
--- a/proxy/src/proxy.c
+++ b/proxy/src/proxy.c
@@ -45,6 +45,7 @@
 		return NULL;
 
 	proxy->bind_addr = talloc_strdup(proxy, PROXY_DEFAULT_BIND_ADDR);
+	proxy->path_sim_noise_dbm = PROXY_DEFAULT_PM_RSSI_NOISE;
 	INIT_LLIST_HEAD(&proxy->trx_list);
 
 	return proxy;
diff --git a/proxy/src/vty.c b/proxy/src/vty.c
index ec986d0..aa8288a 100644
--- a/proxy/src/vty.c
+++ b/proxy/src/vty.c
@@ -91,6 +91,19 @@
 	return CMD_SUCCESS;
 }
 
+DEFUN(cfg_proxy_pm_rssi_noise,
+      cfg_proxy_pm_rssi_noise_cmd,
+      "pm-rssi-noise <-150-0>",
+      "Set the RSSI reported by MEASURE for a frequency with no Tx found\n"
+      "RSSI in dBm\n")
+{
+	struct proxy_ctx *proxy = vty->index;
+
+	proxy->path_sim_noise_dbm = atoi(argv[0]);
+
+	return CMD_SUCCESS;
+}
+
 DEFUN(cfg_proxy_ep,
       cfg_proxy_ep_cmd,
       "ep NAME",
@@ -220,6 +233,7 @@
 	vty_out(vty, "proxy%s", VTY_NEWLINE);
 	if (g_proxy_ctx->bind_addr)
 		vty_out(vty, " bind-addr %s%s", g_proxy_ctx->bind_addr, VTY_NEWLINE);
+	vty_out(vty, " pm-rssi-noise %d%s", g_proxy_ctx->path_sim_noise_dbm, VTY_NEWLINE);
 
 	llist_for_each_entry(trx, &g_proxy_ctx->trx_list, list) {
 		const char *raddr = osmo_trx_ep_get_raddr(trx->ep);
@@ -322,6 +336,7 @@
 	install_element(CONFIG_NODE, &cfg_proxy_cmd);
 	install_node(&proxy_node, config_write_proxy);
 	install_element(PROXY_NODE, &cfg_proxy_bind_addr_cmd);
+	install_element(PROXY_NODE, &cfg_proxy_pm_rssi_noise_cmd);
 	install_element(PROXY_NODE, &cfg_proxy_ep_cmd);
 	install_element(PROXY_NODE, &cfg_no_proxy_ep_cmd);
 

