1 /* Copyright (C) 2009-2012 B.A.T.M.A.N. contributors:
2  *
3  * Marek Lindner
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of version 2 of the GNU General Public
7  * License as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17  * 02110-1301, USA
18  */
19 
20 #include "main.h"
21 #include "gateway_common.h"
22 #include "gateway_client.h"
23 
24 /* calculates the gateway class from kbit */
25 static void batadv_kbit_to_gw_bandwidth(int down, int up, long *gw_srv_class)
26 {
27 	int mdown = 0, tdown, tup, difference;
28 	uint8_t sbit, part;
29 
30 	*gw_srv_class = 0;
31 	difference = 0x0FFFFFFF;
32 
33 	/* test all downspeeds */
34 	for (sbit = 0; sbit < 2; sbit++) {
35 		for (part = 0; part < 16; part++) {
36 			tdown = 32 * (sbit + 2) * (1 << part);
37 
38 			if (abs(tdown - down) < difference) {
39 				*gw_srv_class = (sbit << 7) + (part << 3);
40 				difference = abs(tdown - down);
41 				mdown = tdown;
42 			}
43 		}
44 	}
45 
46 	/* test all upspeeds */
47 	difference = 0x0FFFFFFF;
48 
49 	for (part = 0; part < 8; part++) {
50 		tup = ((part + 1) * (mdown)) / 8;
51 
52 		if (abs(tup - up) < difference) {
53 			*gw_srv_class = (*gw_srv_class & 0xF8) | part;
54 			difference = abs(tup - up);
55 		}
56 	}
57 }
58 
59 /* returns the up and downspeeds in kbit, calculated from the class */
60 void batadv_gw_bandwidth_to_kbit(uint8_t gw_srv_class, int *down, int *up)
61 {
62 	int sbit = (gw_srv_class & 0x80) >> 7;
63 	int dpart = (gw_srv_class & 0x78) >> 3;
64 	int upart = (gw_srv_class & 0x07);
65 
66 	if (!gw_srv_class) {
67 		*down = 0;
68 		*up = 0;
69 		return;
70 	}
71 
72 	*down = 32 * (sbit + 2) * (1 << dpart);
73 	*up = ((upart + 1) * (*down)) / 8;
74 }
75 
76 static bool batadv_parse_gw_bandwidth(struct net_device *net_dev, char *buff,
77 				      int *up, int *down)
78 {
79 	int ret, multi = 1;
80 	char *slash_ptr, *tmp_ptr;
81 	long ldown, lup;
82 
83 	slash_ptr = strchr(buff, '/');
84 	if (slash_ptr)
85 		*slash_ptr = 0;
86 
87 	if (strlen(buff) > 4) {
88 		tmp_ptr = buff + strlen(buff) - 4;
89 
90 		if (strnicmp(tmp_ptr, "mbit", 4) == 0)
91 			multi = 1024;
92 
93 		if ((strnicmp(tmp_ptr, "kbit", 4) == 0) ||
94 		    (multi > 1))
95 			*tmp_ptr = '\0';
96 	}
97 
98 	ret = kstrtol(buff, 10, &ldown);
99 	if (ret) {
100 		batadv_err(net_dev,
101 			   "Download speed of gateway mode invalid: %s\n",
102 			   buff);
103 		return false;
104 	}
105 
106 	*down = ldown * multi;
107 
108 	/* we also got some upload info */
109 	if (slash_ptr) {
110 		multi = 1;
111 
112 		if (strlen(slash_ptr + 1) > 4) {
113 			tmp_ptr = slash_ptr + 1 - 4 + strlen(slash_ptr + 1);
114 
115 			if (strnicmp(tmp_ptr, "mbit", 4) == 0)
116 				multi = 1024;
117 
118 			if ((strnicmp(tmp_ptr, "kbit", 4) == 0) ||
119 			    (multi > 1))
120 				*tmp_ptr = '\0';
121 		}
122 
123 		ret = kstrtol(slash_ptr + 1, 10, &lup);
124 		if (ret) {
125 			batadv_err(net_dev,
126 				   "Upload speed of gateway mode invalid: %s\n",
127 				   slash_ptr + 1);
128 			return false;
129 		}
130 
131 		*up = lup * multi;
132 	}
133 
134 	return true;
135 }
136 
137 ssize_t batadv_gw_bandwidth_set(struct net_device *net_dev, char *buff,
138 				size_t count)
139 {
140 	struct batadv_priv *bat_priv = netdev_priv(net_dev);
141 	long gw_bandwidth_tmp = 0;
142 	int up = 0, down = 0;
143 	bool ret;
144 
145 	ret = batadv_parse_gw_bandwidth(net_dev, buff, &up, &down);
146 	if (!ret)
147 		goto end;
148 
149 	if ((!down) || (down < 256))
150 		down = 2000;
151 
152 	if (!up)
153 		up = down / 5;
154 
155 	batadv_kbit_to_gw_bandwidth(down, up, &gw_bandwidth_tmp);
156 
157 	/* the gw bandwidth we guessed above might not match the given
158 	 * speeds, hence we need to calculate it back to show the number
159 	 * that is going to be propagated
160 	 */
161 	batadv_gw_bandwidth_to_kbit((uint8_t)gw_bandwidth_tmp, &down, &up);
162 
163 	if (atomic_read(&bat_priv->gw_bandwidth) == gw_bandwidth_tmp)
164 		return count;
165 
166 	batadv_gw_deselect(bat_priv);
167 	batadv_info(net_dev,
168 		    "Changing gateway bandwidth from: '%i' to: '%ld' (propagating: %d%s/%d%s)\n",
169 		    atomic_read(&bat_priv->gw_bandwidth), gw_bandwidth_tmp,
170 		    (down > 2048 ? down / 1024 : down),
171 		    (down > 2048 ? "MBit" : "KBit"),
172 		    (up > 2048 ? up / 1024 : up),
173 		    (up > 2048 ? "MBit" : "KBit"));
174 
175 	atomic_set(&bat_priv->gw_bandwidth, gw_bandwidth_tmp);
176 
177 end:
178 	return count;
179 }
180