batman-adv: tvlv - gateway download/upload bandwidth container

Prior to this patch batman-adv read the advertised uplink bandwidth
from userspace and compressed this information into a single byte
called "gateway class".
Now the download & upload bandwidth information is sent as-is. No
userspace change is necessary since the sysfs API always allowed
to specify a bandwidth.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Spyros Gasteratos <morfeas3000@gmail.com>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

1 files changed, 147 insertions, 83 deletions

diff --git a/net/batman-adv/gateway_common.c b/net/batman-adv/gateway_common.c
index 84bb2b18d711..b211b0f9cb78 100644
--- a/net/batman-adv/gateway_common.c
+++ b/net/batman-adv/gateway_common.c
@@ -21,64 +21,23 @@
 #include "gateway_common.h"
 #include "gateway_client.h"
 
-/* calculates the gateway class from kbit */
-static void batadv_kbit_to_gw_bandwidth(int down, int up, long *gw_srv_class)
-{
-	int mdown = 0, tdown, tup, difference;
-	uint8_t sbit, part;
-
-	*gw_srv_class = 0;
-	difference = 0x0FFFFFFF;
-
-	/* test all downspeeds */
-	for (sbit = 0; sbit < 2; sbit++) {
-		for (part = 0; part < 16; part++) {
-			tdown = 32 * (sbit + 2) * (1 << part);
-
-			if (abs(tdown - down) < difference) {
-				*gw_srv_class = (sbit << 7) + (part << 3);
-				difference = abs(tdown - down);
-				mdown = tdown;
-			}
-		}
-	}
-
-	/* test all upspeeds */
-	difference = 0x0FFFFFFF;
-
-	for (part = 0; part < 8; part++) {
-		tup = ((part + 1) * (mdown)) / 8;
-
-		if (abs(tup - up) < difference) {
-			*gw_srv_class = (*gw_srv_class & 0xF8) | part;
-			difference = abs(tup - up);
-		}
-	}
-}
-
-/* returns the up and downspeeds in kbit, calculated from the class */
-void batadv_gw_bandwidth_to_kbit(uint8_t gw_srv_class, int *down, int *up)
-{
-	int sbit = (gw_srv_class & 0x80) >> 7;
-	int dpart = (gw_srv_class & 0x78) >> 3;
-	int upart = (gw_srv_class & 0x07);
-
-	if (!gw_srv_class) {
-		*down = 0;
-		*up = 0;
-		return;
-	}
-
-	*down = 32 * (sbit + 2) * (1 << dpart);
-	*up = ((upart + 1) * (*down)) / 8;
-}
-
+/**
+ * batadv_parse_gw_bandwidth - parse supplied string buffer to extract download
+ *  and upload bandwidth information
+ * @net_dev: the soft interface net device
+ * @buff: string buffer to parse
+ * @down: pointer holding the returned download bandwidth information
+ * @up: pointer holding the returned upload bandwidth information
+ *
+ * Returns false on parse error and true otherwise.
+ */
 static bool batadv_parse_gw_bandwidth(struct net_device *net_dev, char *buff,
-				      int *up, int *down)
+				      uint32_t *down, uint32_t *up)
 {
-	int ret, multi = 1;
+	enum batadv_bandwidth_units bw_unit_type = BATADV_BW_UNIT_KBIT;
 	char *slash_ptr, *tmp_ptr;
 	long ldown, lup;
+	int ret;
 
 	slash_ptr = strchr(buff, '/');
 	if (slash_ptr)
@@ -88,10 +47,10 @@ static bool batadv_parse_gw_bandwidth(struct net_device *net_dev, char *buff,
 		tmp_ptr = buff + strlen(buff) - 4;
 
 		if (strnicmp(tmp_ptr, "mbit", 4) == 0)
-			multi = 1024;
+			bw_unit_type = BATADV_BW_UNIT_MBIT;
 
 		if ((strnicmp(tmp_ptr, "kbit", 4) == 0) ||
-		    (multi > 1))
+		    (bw_unit_type == BATADV_BW_UNIT_MBIT))
 			*tmp_ptr = '\0';
 	}
 
@@ -103,20 +62,28 @@ static bool batadv_parse_gw_bandwidth(struct net_device *net_dev, char *buff,
 		return false;
 	}
 
-	*down = ldown * multi;
+	switch (bw_unit_type) {
+	case BATADV_BW_UNIT_MBIT:
+		*down = ldown * 10;
+		break;
+	case BATADV_BW_UNIT_KBIT:
+	default:
+		*down = ldown / 100;
+		break;
+	}
 
 	/* we also got some upload info */
 	if (slash_ptr) {
-		multi = 1;
+		bw_unit_type = BATADV_BW_UNIT_KBIT;
 
 		if (strlen(slash_ptr + 1) > 4) {
 			tmp_ptr = slash_ptr + 1 - 4 + strlen(slash_ptr + 1);
 
 			if (strnicmp(tmp_ptr, "mbit", 4) == 0)
-				multi = 1024;
+				bw_unit_type = BATADV_BW_UNIT_MBIT;
 
 			if ((strnicmp(tmp_ptr, "kbit", 4) == 0) ||
-			    (multi > 1))
+			    (bw_unit_type == BATADV_BW_UNIT_MBIT))
 				*tmp_ptr = '\0';
 		}
 
@@ -128,52 +95,149 @@ static bool batadv_parse_gw_bandwidth(struct net_device *net_dev, char *buff,
 			return false;
 		}
 
-		*up = lup * multi;
+		switch (bw_unit_type) {
+		case BATADV_BW_UNIT_MBIT:
+			*up = lup * 10;
+			break;
+		case BATADV_BW_UNIT_KBIT:
+		default:
+			*up = lup / 100;
+			break;
+		}
 	}
 
 	return true;
 }
 
+/**
+ * batadv_gw_tvlv_container_update - update the gw tvlv container after gateway
+ *  setting change
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+void batadv_gw_tvlv_container_update(struct batadv_priv *bat_priv)
+{
+	struct batadv_tvlv_gateway_data gw;
+	uint32_t down, up;
+	char gw_mode;
+
+	gw_mode = atomic_read(&bat_priv->gw_mode);
+
+	switch (gw_mode) {
+	case BATADV_GW_MODE_OFF:
+	case BATADV_GW_MODE_CLIENT:
+		batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_GW, 1);
+		break;
+	case BATADV_GW_MODE_SERVER:
+		down = atomic_read(&bat_priv->gw.bandwidth_down);
+		up = atomic_read(&bat_priv->gw.bandwidth_up);
+		gw.bandwidth_down = htonl(down);
+		gw.bandwidth_up = htonl(up);
+		batadv_tvlv_container_register(bat_priv, BATADV_TVLV_GW, 1,
+					       &gw, sizeof(gw));
+		break;
+	}
+}
+
 ssize_t batadv_gw_bandwidth_set(struct net_device *net_dev, char *buff,
 				size_t count)
 {
 	struct batadv_priv *bat_priv = netdev_priv(net_dev);
-	long gw_bandwidth_tmp = 0;
-	int up = 0, down = 0;
+	uint32_t down_curr, up_curr, down_new = 0, up_new = 0;
 	bool ret;
 
-	ret = batadv_parse_gw_bandwidth(net_dev, buff, &up, &down);
+	down_curr = (unsigned int)atomic_read(&bat_priv->gw.bandwidth_down);
+	up_curr = (unsigned int)atomic_read(&bat_priv->gw.bandwidth_up);
+
+	ret = batadv_parse_gw_bandwidth(net_dev, buff, &down_new, &up_new);
 	if (!ret)
 		goto end;
 
-	if ((!down) || (down < 256))
-		down = 2000;
-
-	if (!up)
-		up = down / 5;
+	if (!down_new)
+		down_new = 1;
 
-	batadv_kbit_to_gw_bandwidth(down, up, &gw_bandwidth_tmp);
+	if (!up_new)
+		up_new = down_new / 5;
 
-	/* the gw bandwidth we guessed above might not match the given
-	 * speeds, hence we need to calculate it back to show the number
-	 * that is going to be propagated
-	 */
-	batadv_gw_bandwidth_to_kbit((uint8_t)gw_bandwidth_tmp, &down, &up);
+	if (!up_new)
+		up_new = 1;
 
-	if (atomic_read(&bat_priv->gw_bandwidth) == gw_bandwidth_tmp)
+	if ((down_curr == down_new) && (up_curr == up_new))
 		return count;
 
 	batadv_gw_deselect(bat_priv);
 	batadv_info(net_dev,
-		    "Changing gateway bandwidth from: '%i' to: '%ld' (propagating: %d%s/%d%s)\n",
-		    atomic_read(&bat_priv->gw_bandwidth), gw_bandwidth_tmp,
-		    (down > 2048 ? down / 1024 : down),
-		    (down > 2048 ? "MBit" : "KBit"),
-		    (up > 2048 ? up / 1024 : up),
-		    (up > 2048 ? "MBit" : "KBit"));
+		    "Changing gateway bandwidth from: '%u.%u/%u.%u MBit' to: '%u.%u/%u.%u MBit'\n",
+		    down_curr / 10, down_curr % 10, up_curr / 10, up_curr % 10,
+		    down_new / 10, down_new % 10, up_new / 10, up_new % 10);
 
-	atomic_set(&bat_priv->gw_bandwidth, gw_bandwidth_tmp);
+	atomic_set(&bat_priv->gw.bandwidth_down, down_new);
+	atomic_set(&bat_priv->gw.bandwidth_up, up_new);
+	batadv_gw_tvlv_container_update(bat_priv);
 
 end:
 	return count;
 }
+
+/**
+ * batadv_gw_tvlv_ogm_handler_v1 - process incoming gateway tvlv container
+ * @bat_priv: the bat priv with all the soft interface information
+ * @orig: the orig_node of the ogm
+ * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
+ * @tvlv_value: tvlv buffer containing the gateway data
+ * @tvlv_value_len: tvlv buffer length
+ */
+static void batadv_gw_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
+					  struct batadv_orig_node *orig,
+					  uint8_t flags,
+					  void *tvlv_value,
+					  uint16_t tvlv_value_len)
+{
+	struct batadv_tvlv_gateway_data gateway, *gateway_ptr;
+
+	/* only fetch the tvlv value if the handler wasn't called via the
+	 * CIFNOTFND flag and if there is data to fetch
+	 */
+	if ((flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) ||
+	    (tvlv_value_len < sizeof(gateway))) {
+		gateway.bandwidth_down = 0;
+		gateway.bandwidth_up = 0;
+	} else {
+		gateway_ptr = tvlv_value;
+		gateway.bandwidth_down = gateway_ptr->bandwidth_down;
+		gateway.bandwidth_up = gateway_ptr->bandwidth_up;
+		if ((gateway.bandwidth_down == 0) ||
+		    (gateway.bandwidth_up == 0)) {
+			gateway.bandwidth_down = 0;
+			gateway.bandwidth_up = 0;
+		}
+	}
+
+	batadv_gw_node_update(bat_priv, orig, &gateway);
+
+	/* restart gateway selection if fast or late switching was enabled */
+	if ((gateway.bandwidth_down != 0) &&
+	    (atomic_read(&bat_priv->gw_mode) == BATADV_GW_MODE_CLIENT) &&
+	    (atomic_read(&bat_priv->gw_sel_class) > 2))
+		batadv_gw_check_election(bat_priv, orig);
+}
+
+/**
+ * batadv_gw_init - initialise the gateway handling internals
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+void batadv_gw_init(struct batadv_priv *bat_priv)
+{
+	batadv_tvlv_handler_register(bat_priv, batadv_gw_tvlv_ogm_handler_v1,
+				     NULL, BATADV_TVLV_GW, 1,
+				     BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
+}
+
+/**
+ * batadv_gw_free - free the gateway handling internals
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+void batadv_gw_free(struct batadv_priv *bat_priv)
+{
+	batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_GW, 1);
+	batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_GW, 1);
+}