Sample output:
# iw dev wlan0 survey dump
Survey data from wlan0
frequency: 2412 MHz
noise: -92 dBm
Signed-off-by: Holger Schurig <holgerschurig@xxxxxxxxx>
--- iw.orig/Makefile
+++ iw/Makefile
@@ -15,7 +15,7 @@
CFLAGS += -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -Werror-implicit-function-declaration
OBJS = iw.o genl.o event.o info.o phy.o \
- interface.o ibss.o station.o util.o \
+ interface.o ibss.o station.o survey.o util.o \
mesh.o mpath.o scan.o reg.o version.o \
reason.o status.o connect.o link.o
OBJS += sections.o
--- /dev/null
+++ iw/survey.c
@@ -0,0 +1,66 @@
+#include <net/if.h>
+#include <errno.h>
+#include <string.h>
+
+#include <netlink/genl/genl.h>
+#include <netlink/genl/family.h>
+#include <netlink/genl/ctrl.h>
+#include <netlink/msg.h>
+#include <netlink/attr.h>
+
+#include "nl80211.h"
+#include "iw.h"
+
+SECTION(survey);
+
+static int print_survey_handler(struct nl_msg *msg, void *arg)
+{
+ struct nlattr *tb[NL80211_ATTR_MAX + 1];
+ struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
+ struct nlattr *sinfo[NL80211_SURVEY_INFO_MAX + 1];
+ char dev[20];
+
+ static struct nla_policy survey_policy[NL80211_SURVEY_INFO_MAX + 1] = {
+ [NL80211_SURVEY_INFO_FREQUENCY] = { .type = NLA_U32 },
+ [NL80211_SURVEY_INFO_NOISE] = { .type = NLA_U8 },
+ };
+
+ nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
+ genlmsg_attrlen(gnlh, 0), NULL);
+
+ if_indextoname(nla_get_u32(tb[NL80211_ATTR_IFINDEX]), dev);
+ printf("Survey data from %s\n", dev);
+
+ if (!tb[NL80211_ATTR_SURVEY_INFO]) {
+ fprintf(stderr, "survey data missing!");
+ return NL_SKIP;
+ }
+
+ if (nla_parse_nested(sinfo, NL80211_SURVEY_INFO_MAX,
+ tb[NL80211_ATTR_SURVEY_INFO],
+ survey_policy)) {
+ fprintf(stderr, "failed to parse nested attributes!\n");
+ return NL_SKIP;
+ }
+
+ if (sinfo[NL80211_SURVEY_INFO_FREQUENCY])
+ printf("\tfrequency:\t%u MHz\n",
+ nla_get_u32(sinfo[NL80211_SURVEY_INFO_FREQUENCY]));
+ if (sinfo[NL80211_SURVEY_INFO_NOISE])
+ printf("\tnoise:\t\t%d dBm\n",
+ (int8_t)nla_get_u8(sinfo[NL80211_SURVEY_INFO_NOISE]));
+ return NL_SKIP;
+}
+
+static int handle_survey_dump(struct nl80211_state *state,
+ struct nl_cb *cb,
+ struct nl_msg *msg,
+ int argc, char **argv)
+{
+ nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, print_survey_handler, NULL);
+ return 0;
+}
+COMMAND(survey, dump, NULL,
+ NL80211_CMD_GET_SURVEY, NLM_F_DUMP, CIB_NETDEV, handle_survey_dump,
+ "List all gathered channel survey data");
+
--- iw.orig/nl80211.h
+++ iw/nl80211.h
@@ -160,6 +160,11 @@
* @NL80211_CMD_SCAN_ABORTED: scan was aborted, for unspecified reasons,
* partial scan results may be available
*
+ * @NL80211_CMD_GET_SURVEY: get survey resuls, e.g. channel occupation
+ * or noise level
+ * @NL80211_CMD_NEW_SURVEY_RESULTS: survey data notification (as a reply to
+ * NL80211_CMD_GET_SURVEY and on the "scan" multicast group)
+ *
* @NL80211_CMD_REG_CHANGE: indicates to userspace the regulatory domain
* has been changed and provides details of the request information
* that caused the change such as who initiated the regulatory request
@@ -341,6 +346,9 @@
NL80211_CMD_SET_WIPHY_NETNS,
+ NL80211_CMD_GET_SURVEY,
+ NL80211_CMD_NEW_SURVEY_RESULTS,
+
/* add new commands above here */
/* used to define NL80211_CMD_MAX below */
@@ -584,6 +592,10 @@
* changed then the list changed and the dump should be repeated
* completely from scratch.
*
+ * @NL80211_ATTR_SURVEY_INFO: survey information about a channel, part of
+ * the survey response for %NL80211_CMD_GET_SURVEY, nested attribute
+ * containing info as possible, see &enum survey_info.
+ *
* @NL80211_ATTR_MAX: highest attribute number currently defined
* @__NL80211_ATTR_AFTER_LAST: internal use
*/
@@ -714,6 +726,8 @@
NL80211_ATTR_PID,
+ NL80211_ATTR_SURVEY_INFO,
+
/* add attributes here, update the policy in nl80211.c */
__NL80211_ATTR_AFTER_LAST,
@@ -1117,6 +1131,26 @@
};
/**
+ * enum nl80211_survey_info - survey information
+ *
+ * These attribute types are used with %NL80211_ATTR_SURVEY_INFO
+ * when getting information about a survey.
+ *
+ * @__NL80211_SURVEY_INFO_INVALID: attribute number 0 is reserved
+ * @NL80211_SURVEY_INFO_FREQUENCY: center frequency of channel
+ * @NL80211_SURVEY_INFO_NOISE: noise level of channel (u8, dBm)
+ */
+enum nl80211_survey_info {
+ __NL80211_SURVEY_INFO_INVALID,
+ NL80211_SURVEY_INFO_FREQUENCY,
+ NL80211_SURVEY_INFO_NOISE,
+
+ /* keep last */
+ __NL80211_SURVEY_INFO_AFTER_LAST,
+ NL80211_SURVEY_INFO_MAX = __NL80211_SURVEY_INFO_AFTER_LAST - 1
+};
+
+/**
* enum nl80211_mntr_flags - monitor configuration flags
*
* Monitor configuration flags.
--
http://www.holgerschurig.de
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