scan.c

   1 #include <net/if.h>
   2 #include <errno.h>
   3 #include <string.h>
   4 #include <ctype.h>
   5 #include <stdbool.h>
   6
   7 #include <netlink/genl/genl.h>
   8 #include <netlink/genl/family.h>
   9 #include <netlink/genl/ctrl.h>
  10 #include <netlink/msg.h>
  11 #include <netlink/attr.h>
  12
  13 #include "nl80211.h"
  14 #include "iw.h"
  15
  16 struct scan_params {
  17         bool unknown;
  18 };
  19
  20 static int handle_scan(struct nl80211_state *state,
  21                        struct nl_cb *cb,
  22                        struct nl_msg *msg,
  23                        int argc, char **argv)
  24 {
  25         struct nl_msg *ssids = NULL;
  26         int err = -ENOBUFS;
  27
  28         ssids = nlmsg_alloc();
  29         if (!ssids)
  30                 return -ENOMEM;
  31         NLA_PUT(ssids, 1, 0, "");
  32         nla_put_nested(msg, NL80211_ATTR_SCAN_SSIDS, ssids);
  33
  34         err = 0;
  35  nla_put_failure:
  36         nlmsg_free(ssids);
  37         return err;
  38 }
  39 COMMAND(scan, trigger, NULL,
  40         NL80211_CMD_TRIGGER_SCAN, 0, CIB_NETDEV, handle_scan);
  41
  42 typedef void (*printfn)(unsigned char type, unsigned char len, unsigned char *data);
  43
  44 static void print_ssid(unsigned char type, unsigned char len, unsigned char *data)
  45 {
  46         int i;
  47         printf("\tSSID: ");
  48         for (i=0; i<len; i++) {
  49                 if (isprint(data[i]))
  50                         printf("%c", data[i]);
  51                 else
  52                         printf("\\x%.2x", data[i]);
  53         }
  54         printf("\n");
  55 }
  56
  57 static void print_supprates(unsigned char type, unsigned char len, unsigned char *data)
  58 {
  59         int i;
  60
  61         if (type == 1)
  62                 printf("\tSupported rates: ");
  63         else
  64                 printf("\tExtended supported rates: ");
  65
  66         for (i=0; i<len; i++) {
  67                 int r = data[i] & 0x7f;
  68                 printf("%d.%d%s ", r/2, 5*(r&1), data[i] & 0x80 ? "*":"");
  69         }
  70         printf("\n");
  71 }
  72
  73 static void print_ds(unsigned char type, unsigned char len, unsigned char *data)
  74 {
  75         printf("\tDS Parameter set: channel %d\n", data[0]);
  76 }
  77
  78 static void print_ign(unsigned char type, unsigned char len, unsigned char *data)
  79 {
  80         /* ignore for now, not too useful */
  81 }
  82
  83 static const printfn ieprinters[] = {
  84         [0] = print_ssid,
  85         [1] = print_supprates,
  86         [3] = print_ds,
  87         [5] = print_ign,
  88         [50] = print_supprates,
  89 };
  90
  91 static void print_vendor(unsigned char len, unsigned char *data,
  92                          struct scan_params *params)
  93 {
  94         int i;
  95
  96         /* currently _all_ vendor IEs are unknown (not parsed) */
  97         if (!params->unknown)
  98                 return;
  99
 100         printf("\tVendor specific: OUI %.2x:%.2x:%.2x, data: ",
 101                 data[0], data[1], data[2]);
 102         for (i=3; i<len; i++)
 103                 printf("\\x%.2x", data[i]);
 104         printf("\n");
 105 }
 106
 107 static void print_ies(unsigned char *ie, int ielen, struct scan_params *params)
 108 {
 109         while (ielen >= 2 && ielen >= ie[1]) {
 110                 if (ie[0] < ARRAY_SIZE(ieprinters) && ieprinters[ie[0]]) {
 111                         ieprinters[ie[0]](ie[0], ie[1], ie + 2);
 112                 } else if (ie[0] == 221 /* vendor */) {
 113                         print_vendor(ie[1], ie + 2, params);
 114                 } else if (params->unknown) {
 115                         int i;
 116
 117                         printf("\tUnknown IE (%d): ", ie[0]);
 118                         for (i=0; i<ie[1]; i++)
 119                                 printf("\\x%.2x", ie[2+i]);
 120                         printf("\n");
 121                 }
 122                 ielen -= ie[1] + 2;
 123                 ie += ie[1] + 2;
 124         }
 125 }
 126
 127 static int print_bss_handler(struct nl_msg *msg, void *arg)
 128 {
 129         struct nlattr *tb[NL80211_ATTR_MAX + 1];
 130         struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
 131         struct nlattr *bss[NL80211_BSS_MAX + 1];
 132         char mac_addr[20], dev[20];
 133         static struct nla_policy bss_policy[NL80211_BSS_MAX + 1] = {
 134                 [NL80211_BSS_TSF] = { .type = NLA_U64 },
 135                 [NL80211_BSS_FREQUENCY] = { .type = NLA_U32 },
 136                 [NL80211_BSS_BSSID] = { },
 137                 [NL80211_BSS_BEACON_INTERVAL] = { .type = NLA_U16 },
 138                 [NL80211_BSS_CAPABILITY] = { .type = NLA_U16 },
 139                 [NL80211_BSS_INFORMATION_ELEMENTS] = { },
 140                 [NL80211_BSS_SIGNAL_MBM] = { .type = NLA_U32 },
 141                 [NL80211_BSS_SIGNAL_UNSPEC] = { .type = NLA_U8 },
 142         };
 143
 144         nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
 145                   genlmsg_attrlen(gnlh, 0), NULL);
 146
 147         if (!tb[NL80211_ATTR_BSS]) {
 148                 fprintf(stderr, "bss info missing!");
 149                 return NL_SKIP;
 150         }
 151         if (nla_parse_nested(bss, NL80211_BSS_MAX,
 152                              tb[NL80211_ATTR_BSS],
 153                              bss_policy)) {
 154                 fprintf(stderr, "failed to parse nested attributes!");
 155                 return NL_SKIP;
 156         }
 157
 158         if (!bss[NL80211_BSS_BSSID])
 159                 return NL_SKIP;
 160
 161         mac_addr_n2a(mac_addr, nla_data(bss[NL80211_BSS_BSSID]));
 162         if_indextoname(nla_get_u32(tb[NL80211_ATTR_IFINDEX]), dev);
 163         printf("BSS %s (on %s)\n", mac_addr, dev);
 164
 165         if (bss[NL80211_BSS_TSF]) {
 166                 unsigned long long tsf;
 167                 tsf = (unsigned long long)nla_get_u64(bss[NL80211_BSS_TSF]);
 168                 printf("\tTSF: %llu usec (%llud, %.2lld:%.2llu:%.2llu)\n",
 169                         tsf, tsf/1000/1000/60/60/24, (tsf/1000/1000/60/60) % 24,
 170                         (tsf/1000/1000/60) % 60, (tsf/1000/1000) % 60);
 171         }
 172         if (bss[NL80211_BSS_FREQUENCY])
 173                 printf("\tfreq: %d\n",
 174                         nla_get_u32(bss[NL80211_BSS_FREQUENCY]));
 175         if (bss[NL80211_BSS_BEACON_INTERVAL])
 176                 printf("\tbeacon interval: %d\n",
 177                         nla_get_u16(bss[NL80211_BSS_BEACON_INTERVAL]));
 178         if (bss[NL80211_BSS_CAPABILITY])
 179                 printf("\tcapability: 0x%.4x\n",
 180                         nla_get_u16(bss[NL80211_BSS_CAPABILITY]));
 181         if (bss[NL80211_BSS_SIGNAL_MBM]) {
 182                 int s = nla_get_u32(bss[NL80211_BSS_SIGNAL_MBM]);
 183                 printf("\tsignal: %d.%.2d dBm\n", s/100, s%100);
 184         }
 185         if (bss[NL80211_BSS_SIGNAL_UNSPEC]) {
 186                 unsigned char s = nla_get_u8(bss[NL80211_BSS_SIGNAL_UNSPEC]);
 187                 printf("\tsignal: %d/100\n", s);
 188         }
 189         if (bss[NL80211_BSS_INFORMATION_ELEMENTS])
 190                 print_ies(nla_data(bss[NL80211_BSS_INFORMATION_ELEMENTS]),
 191                           nla_len(bss[NL80211_BSS_INFORMATION_ELEMENTS]),
 192                           arg);
 193
 194         return NL_SKIP;
 195 }
 196
 197 static struct scan_params scan_params;
 198
 199 static int handle_scan_dump(struct nl80211_state *state,
 200                             struct nl_cb *cb,
 201                             struct nl_msg *msg,
 202                             int argc, char **argv)
 203 {
 204         if (argc > 1)
 205                 return 1;
 206
 207         scan_params.unknown = false;
 208         if (argc == 1 && !strcmp(argv[0], "-u"))
 209                 scan_params.unknown = true;
 210
 211         nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, print_bss_handler,
 212                   &scan_params);
 213         return 0;
 214 }
 215 COMMAND(scan, dump, "[-u]",
 216         NL80211_CMD_GET_SCAN, NLM_F_DUMP, CIB_NETDEV, handle_scan_dump);
 217
 218 static int handle_scan_combined(struct nl80211_state *state,
 219                                 struct nl_cb *cb,
 220                                 struct nl_msg *msg,
 221                                 int argc, char **argv)
 222 {
 223         static char *trig_argv[] = {
 224                 NULL,
 225                 "scan",
 226                 "trigger",
 227         };
 228         static char *dump_argv[] = {
 229                 NULL,
 230                 "scan",
 231                 "dump",
 232         };
 233         static const __u32 cmds[] = {
 234                 NL80211_CMD_NEW_SCAN_RESULTS,
 235                 NL80211_CMD_SCAN_ABORTED,
 236         };
 237         int err;
 238
 239         trig_argv[0] = argv[0];
 240         err = handle_cmd(state, II_NETDEV, ARRAY_SIZE(trig_argv), trig_argv);
 241         if (err)
 242                 return err;
 243
 244         if (listen_events(state, ARRAY_SIZE(cmds), cmds) ==
 245                                         NL80211_CMD_SCAN_ABORTED) {
 246                 printf("scan aborted!\n");
 247                 return 0;
 248         }
 249
 250         dump_argv[0] = argv[0];
 251         return handle_cmd(state, II_NETDEV, ARRAY_SIZE(dump_argv), dump_argv);
 252 }
 253 TOPLEVEL(scan, NULL, 0, 0, CIB_NETDEV, handle_scan_combined);