1 /*
2  * Copyright (C) 2009-2010 B.A.T.M.A.N. contributors:
3  *
4  * Marek Lindner
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of version 2 of the GNU General Public
8  * License as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18  * 02110-1301, USA
19  *
20  */
21 
22 #include "main.h"
23 #include "gateway_common.h"
24 #include "gateway_client.h"
25 
26 /* calculates the gateway class from kbit */
27 static void kbit_to_gw_bandwidth(int down, int up, long *gw_srv_class)
28 {
29 	int mdown = 0, tdown, tup, difference;
30 	uint8_t sbit, part;
31 
32 	*gw_srv_class = 0;
33 	difference = 0x0FFFFFFF;
34 
35 	/* test all downspeeds */
36 	for (sbit = 0; sbit < 2; sbit++) {
37 		for (part = 0; part < 16; part++) {
38 			tdown = 32 * (sbit + 2) * (1 << part);
39 
40 			if (abs(tdown - down) < difference) {
41 				*gw_srv_class = (sbit << 7) + (part << 3);
42 				difference = abs(tdown - down);
43 				mdown = tdown;
44 			}
45 		}
46 	}
47 
48 	/* test all upspeeds */
49 	difference = 0x0FFFFFFF;
50 
51 	for (part = 0; part < 8; part++) {
52 		tup = ((part + 1) * (mdown)) / 8;
53 
54 		if (abs(tup - up) < difference) {
55 			*gw_srv_class = (*gw_srv_class & 0xF8) | part;
56 			difference = abs(tup - up);
57 		}
58 	}
59 }
60 
61 /* returns the up and downspeeds in kbit, calculated from the class */
62 void gw_bandwidth_to_kbit(uint8_t gw_srv_class, int *down, int *up)
63 {
64 	char sbit = (gw_srv_class & 0x80) >> 7;
65 	char dpart = (gw_srv_class & 0x78) >> 3;
66 	char upart = (gw_srv_class & 0x07);
67 
68 	if (!gw_srv_class) {
69 		*down = 0;
70 		*up = 0;
71 		return;
72 	}
73 
74 	*down = 32 * (sbit + 2) * (1 << dpart);
75 	*up = ((upart + 1) * (*down)) / 8;
76 }
77 
78 static bool parse_gw_bandwidth(struct net_device *net_dev, char *buff,
79 			       long *up, long *down)
80 {
81 	int ret, multi = 1;
82 	char *slash_ptr, *tmp_ptr;
83 
84 	slash_ptr = strchr(buff, '/');
85 	if (slash_ptr)
86 		*slash_ptr = 0;
87 
88 	if (strlen(buff) > 4) {
89 		tmp_ptr = buff + strlen(buff) - 4;
90 
91 		if (strnicmp(tmp_ptr, "mbit", 4) == 0)
92 			multi = 1024;
93 
94 		if ((strnicmp(tmp_ptr, "kbit", 4) == 0) ||
95 			(multi > 1))
96 			*tmp_ptr = '\0';
97 	}
98 
99 	ret = strict_strtoul(buff, 10, down);
100 	if (ret) {
101 		bat_err(net_dev,
102 			"Download speed of gateway mode invalid: %s\n",
103 			buff);
104 		return false;
105 	}
106 
107 	*down *= multi;
108 
109 	/* we also got some upload info */
110 	if (slash_ptr) {
111 		multi = 1;
112 
113 		if (strlen(slash_ptr + 1) > 4) {
114 			tmp_ptr = slash_ptr + 1 - 4 + strlen(slash_ptr + 1);
115 
116 			if (strnicmp(tmp_ptr, "mbit", 4) == 0)
117 				multi = 1024;
118 
119 			if ((strnicmp(tmp_ptr, "kbit", 4) == 0) ||
120 				(multi > 1))
121 				*tmp_ptr = '\0';
122 		}
123 
124 		ret = strict_strtoul(slash_ptr + 1, 10, up);
125 		if (ret) {
126 			bat_err(net_dev,
127 				"Upload speed of gateway mode invalid: "
128 				"%s\n", slash_ptr + 1);
129 			return false;
130 		}
131 
132 		*up *= multi;
133 	}
134 
135 	return true;
136 }
137 
138 ssize_t gw_bandwidth_set(struct net_device *net_dev, char *buff, size_t count)
139 {
140 	struct bat_priv *bat_priv = netdev_priv(net_dev);
141 	long gw_bandwidth_tmp = 0, up = 0, down = 0;
142 	bool ret;
143 
144 	ret = parse_gw_bandwidth(net_dev, buff, &up, &down);
145 	if (!ret)
146 		goto end;
147 
148 	if ((!down) || (down < 256))
149 		down = 2000;
150 
151 	if (!up)
152 		up = down / 5;
153 
154 	kbit_to_gw_bandwidth(down, up, &gw_bandwidth_tmp);
155 
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 	gw_bandwidth_to_kbit((uint8_t)gw_bandwidth_tmp,
162 			     (int *)&down, (int *)&up);
163 
164 	gw_deselect(bat_priv);
165 	bat_info(net_dev, "Changing gateway bandwidth from: '%i' to: '%ld' "
166 		 "(propagating: %ld%s/%ld%s)\n",
167 		 atomic_read(&bat_priv->gw_bandwidth), gw_bandwidth_tmp,
168 		 (down > 2048 ? down / 1024 : down),
169 		 (down > 2048 ? "MBit" : "KBit"),
170 		 (up > 2048 ? up / 1024 : up),
171 		 (up > 2048 ? "MBit" : "KBit"));
172 
173 	atomic_set(&bat_priv->gw_bandwidth, gw_bandwidth_tmp);
174 
175 end:
176 	return count;
177 }
178