1 files changed, 196 insertions, 68 deletions

diff --git a/iw_scan.c b/iw_scan.c
index c701718..740bdff 100644
--- a/iw_scan.c
+++ b/iw_scan.c
@@ -519,7 +519,7 @@ static int iw_extract_event_stream(struct stream_descr *stream,
 	return 1;
 }
 
-static void iw_extract_ie(struct iw_event *iwe, struct scan_result *sr)
+static void iw_extract_ie(struct iw_event *iwe, struct scan_entry *sr)
 {
 	const uint8_t wpa1_oui[3] = { 0x00, 0x50, 0xf2 };
 	uint8_t *buffer = iwe->u.data.pointer;
@@ -549,64 +549,77 @@ static void iw_extract_ie(struct iw_event *iwe, struct scan_result *sr)
 /*----------------- End of code copied from iwlib -----------------------*/
 
 /*
- * Ordering functions for scan results
+ * Ordering functions for scan results: all return true for a < b.
  */
-/* Order by ascending frequency. */
-static int cmp_chan(const struct scan_result *a, const struct scan_result *b)
+
+/* Order by frequency. */
+static bool cmp_freq(const struct scan_entry *a, const struct scan_entry *b)
 {
 	return a->freq < b->freq;
 }
 
-static int cmp_chan_rev(const struct scan_result *a, const struct scan_result *b)
+/* Order by signal strength. */
+static bool cmp_sig(const struct scan_entry *a, const struct scan_entry *b)
 {
-	return cmp_chan(b, a);
+	return a->qual.level < b->qual.level;
 }
 
-/* Order by descending signal strength. */
-static int cmp_sig(const struct scan_result *a, const struct scan_result *b)
+/* Order by ESSID, organize entries with same ESSID by frequency and signal. */
+static bool cmp_essid(const struct scan_entry *a, const struct scan_entry *b)
 {
-	return a->qual.level - b->qual.level;
+	int res = strncmp(a->essid, b->essid, IW_ESSID_MAX_SIZE);
+
+	return res == 0 ? (a->freq == b->freq ? cmp_sig(a, b) : cmp_freq(a, b))
+			: res < 0;
 }
 
-/* Order by ascending frequency first, then by descending signal strength. */
-static int cmp_chan_sig(const struct scan_result *a, const struct scan_result *b)
+/* Order by frequency, grouping channels by ESSID. */
+static bool cmp_chan(const struct scan_entry *a, const struct scan_entry *b)
 {
-	return a->freq == b->freq ? cmp_sig(a, b) : cmp_chan(a, b);
+	return a->freq == b->freq ? cmp_essid(a, b) : cmp_freq(a, b);
 }
 
-/* Show open access points first, ordered by mode. */
-static int cmp_open(const struct scan_result *a, const struct scan_result *b)
+/* Order by frequency first, then by signal strength. */
+static bool cmp_chan_sig(const struct scan_entry *a, const struct scan_entry *b)
 {
-	return a->has_key > b->has_key;
+	return a->freq == b->freq ? cmp_sig(a, b) : cmp_chan(a, b);
 }
 
-/* Sort (open) access points by descending signal strength. */
-static int cmp_open_sig(const struct scan_result *a, const struct scan_result *b)
+/* Order by openness (open access points frist). */
+static bool cmp_open(const struct scan_entry *a, const struct scan_entry *b)
 {
-	return a->has_key == b->has_key ? cmp_sig(a, b) : cmp_open(a, b);
+	return a->has_key < b->has_key;
 }
 
-/* Sort (open) access points by ascending frequency, then by descending signal. */
-static int cmp_open_chan_sig(const struct scan_result *a, const struct scan_result *b)
+/* Sort (open) access points by signal strength. */
+static bool cmp_open_sig(const struct scan_entry *a, const struct scan_entry *b)
 {
-	return a->has_key == b->has_key ? cmp_chan_sig(a, b) : cmp_open(a, b);
+	return a->has_key == b->has_key ? cmp_sig(a, b) : cmp_open(a, b);
 }
 
-static int (*scan_cmp[])(const struct scan_result *, const struct scan_result *) = {
+static bool (*scan_cmp[])(const struct scan_entry *, const struct scan_entry *) = {
 	[SO_CHAN]	= cmp_chan,
-	[SO_CHAN_REV]	= cmp_chan_rev,
 	[SO_SIGNAL]	= cmp_sig,
+	[SO_ESSID]	= cmp_essid,
 	[SO_OPEN]	= cmp_open,
 	[SO_CHAN_SIG]	= cmp_chan_sig,
-	[SO_OPEN_SIG]	= cmp_open_sig,
-	[SO_OPEN_CH_SI]	= cmp_open_chan_sig
+	[SO_OPEN_SIG]	= cmp_open_sig
 };
 
-struct scan_result *get_scan_list(int skfd, const char *ifname, int we_version)
+/**
+ * Produce ranked list of scan results.
+ * @ifname:     interface name to run scan on
+ * @we_version: version of the WE extensions (needed internally)
+ */
+static struct scan_entry *get_scan_list(const char *ifname, int we_version)
 {
-	struct scan_result *head = NULL;
+	struct scan_entry *head = NULL, **tailp = &head;
 	struct iwreq wrq;
 	int wait, waited = 0;
+	int skfd = socket(AF_INET, SOCK_DGRAM, 0);
+
+	if (skfd < 0)
+		err_sys("%s: can not open socket", __func__);
 	/*
 	 * Some drivers may return very large scan results, either because there
 	 * are many cells, or there are many large elements. Do not bother to
@@ -620,7 +633,7 @@ struct scan_result *get_scan_list(int skfd, const char *ifname, int we_version)
 	memset(&wrq, 0, sizeof(wrq));
 	strncpy(wrq.ifr_ifrn.ifrn_name, ifname, IFNAMSIZ);
 	if (ioctl(skfd, SIOCSIWSCAN, &wrq) < 0)
-		return NULL;
+		goto done;
 
 	/* Larger initial timeout of 250ms between set and first get */
 	for (wait = 250; (waited += wait) < MAX_SCAN_WAIT; wait = 100) {
@@ -641,7 +654,7 @@ struct scan_result *get_scan_list(int skfd, const char *ifname, int we_version)
 	if (wrq.u.data.length) {
 		struct iw_event iwe;
 		struct stream_descr stream;
-		struct scan_result *new = NULL;
+		struct scan_entry *new = NULL;
 		int f = 0;		/* Idea taken from waproamd */
 
 		memset(&stream, 0, sizeof(stream));
@@ -686,37 +699,53 @@ struct scan_result *get_scan_list(int skfd, const char *ifname, int we_version)
 				break;
 			}
 			if (f == 127) {
-				struct scan_result *cur = head, **prev = &head;
-
-				while (cur && scan_cmp[conf.scan_sort_order](cur, new) > 0)
-					prev = &cur->next, cur = cur->next;
-
-				*prev     = new;
-				new->next = cur;
-				new       = NULL;
-				f = 0;
+				f      = 0;
+				*tailp = new;
+				tailp  = &new->next;
+				new    = NULL;
 			}
 		}
-		free(new);	/* may have been allocated but not filled in */
+		free(new);	/* may have been allocated, but not filled in */
 	}
+done:
+	close(skfd);
 	return head;
 }
 
-void free_scan_result(struct scan_result *head)
+/*
+ * Simple sort routine.
+ * FIXME: use hash or tree to store entries, a list to display them.
+ */
+void sort_scan_list(struct scan_entry **headp)
+{
+	struct scan_entry *head = NULL, *cur, *new = *headp, **prev;
+
+	while (new) {
+		for (cur = head, prev = &head; cur &&
+		     conf.scan_sort_asc == scan_cmp[conf.scan_sort_order](cur, new);
+		     prev = &cur->next, cur = cur->next)
+			;
+		*prev = new;
+		new = new->next;
+		(*prev)->next = cur;
+	}
+	*headp = head;
+}
+
+static void free_scan_list(struct scan_entry *head)
 {
 	if (head) {
-		free_scan_result(head->next);
+		free_scan_list(head->next);
 		free(head);
 	}
 }
 
 /*
- * Channel statistics
+ * 	Channel statistics shown at the bottom of scan screen.
  */
 
-
 /*
- * For lfind, it compares key value with array member, needs to
+ * For lsearch, it compares key value with array member, needs to
  * return 0 if they are the same, non-0 otherwise.
  */
 static int cmp_key(const void *a, const void *b)
@@ -727,41 +756,140 @@ static int cmp_key(const void *a, const void *b)
 /* For quick-sorting the array in descending order of counts */
 static int cmp_cnt(const void *a, const void *b)
 {
-	if (conf.scan_sort_order == SO_CHAN_REV)
+	if (conf.scan_sort_order == SO_CHAN && !conf.scan_sort_asc)
 		return ((struct cnt *)a)->count - ((struct cnt *)b)->count;
 	return ((struct cnt *)b)->count - ((struct cnt *)a)->count;
 }
 
-struct cnt *channel_stats(struct scan_result *head,
-			  struct iw_range *iw_range, int *max_cnt)
+/**
+ * Fill in sr->channel_stats (must not have been allocated yet).
+ */
+static void compute_channel_stats(struct scan_result *sr)
 {
-	struct scan_result *cur;
-	struct cnt *arr = NULL, *bin, key = {0, 0};
-	size_t cnt = 0, n = 0;
-
-	for (cur = head; cur; cur = cur->next)
-		cnt++;
-	if (!cnt)
-		return NULL;
-
-	arr = calloc(cnt, sizeof(key));
-	for (cur = head; cur && n < *max_cnt; cur = cur->next) {
-		key.val = freq_to_channel(cur->freq, iw_range);
-
-		if (key.val >= 0) {
-			bin = lsearch(&key, arr, &n, sizeof(key), cmp_key);
+	struct scan_entry *cur;
+	struct cnt *bin, key = {0, 0};
+	size_t n = 0;
+
+	if (!sr->num.entries)
+		return;
+
+	sr->channel_stats = calloc(sr->num.entries, sizeof(key));
+	for (cur = sr->head; cur; cur = cur->next) {
+		if (cur->chan >= 0) {
+			key.val = cur->chan;
+			bin = lsearch(&key, sr->channel_stats, &n, sizeof(key), cmp_key);
 			if (bin)
 				bin->count++;
 		}
 	}
 
-	if (n < *max_cnt)
-		*max_cnt = n;
 	if (n > 0) {
-		qsort(arr, n, sizeof(key), cmp_cnt);
+		qsort(sr->channel_stats, n, sizeof(key), cmp_cnt);
 	} else {
-		free(arr);
-		return NULL;
+		free(sr->channel_stats);
+		sr->channel_stats = NULL;
 	}
-	return arr;
+	sr->num.ch_stats = n < MAX_CH_STATS ? n : MAX_CH_STATS;
+}
+
+/*
+ *	Scan results.
+ */
+void scan_result_init(struct scan_result *sr)
+{
+	memset(sr, 0, sizeof(*sr));
+	iw_getinf_range(conf_ifname(), &sr->range);
+	pthread_mutex_init(&sr->mutex, NULL);
+}
+
+void scan_result_fini(struct scan_result *sr)
+{
+	free_scan_list(sr->head);
+	free(sr->channel_stats);
+	pthread_mutex_destroy(&sr->mutex);
+}
+
+/** The actual scan thread. */
+void *do_scan(void *sr_ptr)
+{
+	struct scan_result *sr = (struct scan_result *)sr_ptr;
+	struct scan_entry *cur;
+
+	pthread_detach(pthread_self());
+
+	do {
+		pthread_mutex_lock(&sr->mutex);
+
+		free_scan_list(sr->head);
+		free(sr->channel_stats);
+
+		sr->head          = NULL;
+		sr->channel_stats = NULL;
+		sr->msg[0]        = '\0';
+		sr->max_essid_len = MAX_ESSID_LEN;
+		memset(&(sr->num), 0, sizeof(sr->num));
+
+		sr->head = get_scan_list(conf_ifname(), sr->range.we_version_compiled);
+		if (!sr->head) {
+			switch(errno) {
+			case EPERM:
+				/* Don't try to read leftover results, it does not work reliably. */
+				if (!has_net_admin_capability())
+					snprintf(sr->msg, sizeof(sr->msg),
+						 "This screen requires CAP_NET_ADMIN permissions");
+				break;
+			case EFAULT:
+				/*
+				 * EFAULT can occur after a window resizing event and is temporary.
+				 * It may also occur when the interface is down, hence defer handling.
+				 */
+				break;
+			case EINTR:
+			case EBUSY:
+			case EAGAIN:
+				/* Temporary errors. */
+				snprintf(sr->msg, sizeof(sr->msg), "Waiting for scan data on %s ...", conf_ifname());
+				break;
+			case ENETDOWN:
+				snprintf(sr->msg, sizeof(sr->msg), "Interface %s is down - setting it up ...", conf_ifname());
+				if (if_set_up(conf_ifname()) < 0)
+					err_sys("Can not bring up interface '%s'", conf_ifname());
+				break;
+			case E2BIG:
+				/*
+				 * This is a driver issue, since already using the largest possible
+				 * scan buffer. See comments in iwlist.c of wireless tools.
+				 */
+				snprintf(sr->msg, sizeof(sr->msg),
+					 "No scan on %s: Driver returned too much data", conf_ifname());
+				break;
+			case 0:
+				snprintf(sr->msg, sizeof(sr->msg), "Empty scan results on %s", conf_ifname());
+				break;
+			default:
+				snprintf(sr->msg, sizeof(sr->msg),
+					 "Scan failed on %s: %s", conf_ifname(), strerror(errno));
+			}
+		}
+
+		for (cur = sr->head; cur; cur = cur->next) {
+			if (str_is_ascii(cur->essid))
+				sr->max_essid_len = clamp(strlen(cur->essid),
+							  sr->max_essid_len,
+							  IW_ESSID_MAX_SIZE);
+			iw_sanitize(&sr->range, &cur->qual, &cur->dbm);
+			cur->chan = freq_to_channel(cur->freq, &sr->range);
+			if (cur->freq >= 5e9)
+				sr->num.five_gig++;
+			else if (cur->freq >= 2e9)
+				sr->num.two_gig++;
+			sr->num.entries += 1;
+			sr->num.open    += !cur->has_key;
+		}
+		compute_channel_stats(sr);
+
+		pthread_mutex_unlock(&sr->mutex);
+	} while (usleep(conf.stat_iv * 1000) == 0);
+
+	return NULL;
 }