survey.c

   1 #include <net/if.h>
   2 #include <errno.h>
   3 #include <string.h>
   4
   5 #include <netlink/genl/genl.h>
   6 #include <netlink/genl/family.h>
   7 #include <netlink/genl/ctrl.h>
   8 #include <netlink/msg.h>
   9 #include <netlink/attr.h>
  10
  11 #include "nl80211.h"
  12 #include "iw.h"
  13
  14 SECTION(survey);
  15
  16 static int print_survey_handler(struct nl_msg *msg, void *arg)
  17 {
  18         struct nlattr *tb[NL80211_ATTR_MAX + 1];
  19         struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
  20         struct nlattr *sinfo[NL80211_SURVEY_INFO_MAX + 1];
  21         char dev[20];
  22
  23         static struct nla_policy survey_policy[NL80211_SURVEY_INFO_MAX + 1] = {
  24                 [NL80211_SURVEY_INFO_FREQUENCY] = { .type = NLA_U32 },
  25                 [NL80211_SURVEY_INFO_NOISE] = { .type = NLA_U8 },
  26         };
  27
  28         nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
  29                   genlmsg_attrlen(gnlh, 0), NULL);
  30
  31         if_indextoname(nla_get_u32(tb[NL80211_ATTR_IFINDEX]), dev);
  32         printf("Survey data from %s\n", dev);
  33
  34         if (!tb[NL80211_ATTR_SURVEY_INFO]) {
  35                 fprintf(stderr, "survey data missing!\n");
  36                 return NL_SKIP;
  37         }
  38
  39         if (nla_parse_nested(sinfo, NL80211_SURVEY_INFO_MAX,
  40                              tb[NL80211_ATTR_SURVEY_INFO],
  41                              survey_policy)) {
  42                 fprintf(stderr, "failed to parse nested attributes!\n");
  43                 return NL_SKIP;
  44         }
  45
  46         if (sinfo[NL80211_SURVEY_INFO_FREQUENCY])
  47                 printf("\tfrequency:\t%u MHz\n",
  48                         nla_get_u32(sinfo[NL80211_SURVEY_INFO_FREQUENCY]));
  49         if (sinfo[NL80211_SURVEY_INFO_NOISE])
  50                 printf("\tnoise:\t\t%d dBm\n",
  51                         (int8_t)nla_get_u8(sinfo[NL80211_SURVEY_INFO_NOISE]));
  52         return NL_SKIP;
  53 }
  54
  55 static int handle_survey_dump(struct nl80211_state *state,
  56                                struct nl_cb *cb,
  57                                struct nl_msg *msg,
  58                                int argc, char **argv)
  59 {
  60         nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, print_survey_handler, NULL);
  61         return 0;
  62 }
  63 COMMAND(survey, dump, NULL,
  64         NL80211_CMD_GET_SURVEY, NLM_F_DUMP, CIB_NETDEV, handle_survey_dump,
  65         "List all gathered channel survey data");
  66