1 files changed, 274 insertions, 0 deletions
diff --git a/net/batman-adv/gateway_common.c b/net/batman-adv/gateway_common.c
new file mode 100644
index 000000000..d65ff1007
--- /dev/null
+++ b/net/batman-adv/gateway_common.c
@@ -0,0 +1,274 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2009-2020  B.A.T.M.A.N. contributors:
+ *
+ * Marek Lindner
+ */
+
+#include "gateway_common.h"
+#include "main.h"
+
+#include <linux/atomic.h>
+#include <linux/byteorder/generic.h>
+#include <linux/errno.h>
+#include <linux/kstrtox.h>
+#include <linux/limits.h>
+#include <linux/math64.h>
+#include <linux/netdevice.h>
+#include <linux/stddef.h>
+#include <linux/string.h>
+#include <uapi/linux/batadv_packet.h>
+#include <uapi/linux/batman_adv.h>
+
+#include "gateway_client.h"
+#include "log.h"
+#include "tvlv.h"
+
+/**
+ * batadv_parse_throughput() - parse supplied string buffer to extract
+ *  throughput information
+ * @net_dev: the soft interface net device
+ * @buff: string buffer to parse
+ * @description: text shown when throughput string cannot be parsed
+ * @throughput: pointer holding the returned throughput information
+ *
+ * Return: false on parse error and true otherwise.
+ */
+bool batadv_parse_throughput(struct net_device *net_dev, char *buff,
+			     const char *description, u32 *throughput)
+{
+	enum batadv_bandwidth_units bw_unit_type = BATADV_BW_UNIT_KBIT;
+	u64 lthroughput;
+	char *tmp_ptr;
+	int ret;
+
+	if (strlen(buff) > 4) {
+		tmp_ptr = buff + strlen(buff) - 4;
+
+		if (strncasecmp(tmp_ptr, "mbit", 4) == 0)
+			bw_unit_type = BATADV_BW_UNIT_MBIT;
+
+		if (strncasecmp(tmp_ptr, "kbit", 4) == 0 ||
+		    bw_unit_type == BATADV_BW_UNIT_MBIT)
+			*tmp_ptr = '\0';
+	}
+
+	ret = kstrtou64(buff, 10, &lthroughput);
+	if (ret) {
+		batadv_err(net_dev,
+			   "Invalid throughput speed for %s: %s\n",
+			   description, buff);
+		return false;
+	}
+
+	switch (bw_unit_type) {
+	case BATADV_BW_UNIT_MBIT:
+		/* prevent overflow */
+		if (U64_MAX / 10 < lthroughput) {
+			batadv_err(net_dev,
+				   "Throughput speed for %s too large: %s\n",
+				   description, buff);
+			return false;
+		}
+
+		lthroughput *= 10;
+		break;
+	case BATADV_BW_UNIT_KBIT:
+	default:
+		lthroughput = div_u64(lthroughput, 100);
+		break;
+	}
+
+	if (lthroughput > U32_MAX) {
+		batadv_err(net_dev,
+			   "Throughput speed for %s too large: %s\n",
+			   description, buff);
+		return false;
+	}
+
+	*throughput = lthroughput;
+
+	return true;
+}
+
+/**
+ * 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
+ *
+ * Return: false on parse error and true otherwise.
+ */
+static bool batadv_parse_gw_bandwidth(struct net_device *net_dev, char *buff,
+				      u32 *down, u32 *up)
+{
+	char *slash_ptr;
+	bool ret;
+
+	slash_ptr = strchr(buff, '/');
+	if (slash_ptr)
+		*slash_ptr = 0;
+
+	ret = batadv_parse_throughput(net_dev, buff, "download gateway speed",
+				      down);
+	if (!ret)
+		return false;
+
+	/* we also got some upload info */
+	if (slash_ptr) {
+		ret = batadv_parse_throughput(net_dev, slash_ptr + 1,
+					      "upload gateway speed", up);
+		if (!ret)
+			return false;
+	}
+
+	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;
+	u32 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;
+	}
+}
+
+/**
+ * batadv_gw_bandwidth_set() - Parse and set download/upload gateway bandwidth
+ *  from supplied string buffer
+ * @net_dev: netdev struct of the soft interface
+ * @buff: the buffer containing the user data
+ * @count: number of bytes in the buffer
+ *
+ * Return: 'count' on success or a negative error code in case of failure
+ */
+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);
+	u32 down_curr;
+	u32 up_curr;
+	u32 down_new = 0;
+	u32 up_new = 0;
+	bool ret;
+
+	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)
+		return -EINVAL;
+
+	if (!down_new)
+		down_new = 1;
+
+	if (!up_new)
+		up_new = down_new / 5;
+
+	if (!up_new)
+		up_new = 1;
+
+	if (down_curr == down_new && up_curr == up_new)
+		return count;
+
+	batadv_gw_reselect(bat_priv);
+	batadv_info(net_dev,
+		    "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_down, down_new);
+	atomic_set(&bat_priv->gw.bandwidth_up, up_new);
+	batadv_gw_tvlv_container_update(bat_priv);
+
+	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,
+					  u8 flags,
+					  void *tvlv_value, u16 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 (gateway.bandwidth_down != 0 &&
+	    atomic_read(&bat_priv->gw.mode) == BATADV_GW_MODE_CLIENT)
+		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)
+{
+	if (bat_priv->algo_ops->gw.init_sel_class)
+		bat_priv->algo_ops->gw.init_sel_class(bat_priv);
+	else
+		atomic_set(&bat_priv->gw.sel_class, 1);
+
+	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);
+}