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1 | 1 | <?php |
2 | | - |
3 | | -/* |
4 | | -
|
5 | | - This script uses the local copy of the ip-to-country.com |
6 | | - database available on all php.net mirror sites to find |
7 | | - out what country the user is in. This data is stored in |
8 | | - a cookie for future usage, and another check is only done, |
9 | | - if the cookie is expired. |
10 | | -
|
11 | | - We have an index to speed up the search. The first line of |
12 | | - the index file contains the step value used to create the |
13 | | - index. The IP should be divided by this number, when an |
14 | | - appropriate index entry is searched for. Then CSV formatted |
15 | | - lines are placed in the file with the division results and |
16 | | - starting indexes (pointing to the data file). |
17 | | -
|
18 | | - The data file has a fixed record size format to ease |
19 | | - fseek()ing. The format of the database is: |
20 | | -
|
21 | | - n records representing IP range and country relations |
22 | | - the format of a record is: |
23 | | -
|
24 | | - - starting IP number [10 bytes, padded with zeros from left] |
25 | | - - ending IP number [10 bytes, padded with zeros from left] |
26 | | - - ISO country code [3 bytes / letters] |
27 | | - - newline [1 byte: \n] |
28 | | -
|
29 | | - IP numbers can be created with i2c_ip2num(). |
30 | | -
|
31 | | - Some things to consider: |
32 | | -
|
33 | | - - Now 'NA' is stored in the cookie (no country detected). |
34 | | - This is partly for safety reasons, not to bog down the |
35 | | - server with country detection in case the data files are |
36 | | - not there, or they are bogus, or the user has a non listed |
37 | | - IP. |
38 | | -*/ |
39 | | - |
40 | | -// Start the detection |
41 | | -i2c_go(); |
42 | | - |
43 | | -// Try to find out the country of the user and |
44 | | -// set a cookie in the browser (in case there is no |
45 | | -// cookie already storing this information) |
46 | | -function i2c_go() |
47 | | -{ |
48 | | - global $COUNTRY; |
49 | | - |
50 | | - // Get the real IP of the user |
51 | | - $ipnum = i2c_realip(); |
52 | | - |
53 | | - // User already has a country detected with this IP stored |
54 | | - if (!empty($_COOKIE['COUNTRY']) && strpos($_COOKIE['COUNTRY'], ',') !== false) { |
55 | | - list($COUNTRY, $storedip) = explode(",", $_COOKIE['COUNTRY']); |
56 | | - if ($storedip == $ipnum) { return true; } |
57 | | - } |
58 | | - |
59 | | - // Convert the IP number to some useable form for searching |
60 | | - $ipn = (float) sprintf("%u", ip2long($ipnum)); |
61 | | - |
62 | | - // Find the index to start search from |
63 | | - $idx = i2c_search_in_index($ipn); |
64 | | - |
65 | | - // If we were unable to find any helpful entry |
66 | | - // in the index do not search, as it would take |
67 | | - // a very long time. It is an error, if we have |
68 | | - // not found anything in the index |
69 | | - if ($idx !== false) { |
70 | | - $country = i2c_search_in_db($ipn, $idx); |
71 | | - } else { |
72 | | - $country = 'NA'; |
73 | | - } |
74 | | - |
75 | | - // Set global variable for further usage |
76 | | - $COUNTRY = $country; |
77 | | - |
78 | | - // Set the country in a cookie for a week |
79 | | - return mirror_setcookie("COUNTRY", "$country,$ipnum", 60 * 60 * 24 * 7); |
80 | | - |
81 | | -} |
82 | | - |
83 | | -// Find nearest index entry for IP number |
84 | | -function i2c_search_in_index($ip) |
85 | | -{ |
86 | | - // Indexed part and record number to jump to |
87 | | - $idxpart = 0; $recnum = 0; |
88 | | - |
89 | | - // Open the index file for reading |
90 | | - $dbidx = fopen( |
91 | | - __DIR__ . "/../backend/ip-to-country.idx", |
92 | | - "r", |
93 | | - ); |
94 | | - if (!$dbidx) { return false; } |
95 | | - |
96 | | - // Read in granularity from index file and |
97 | | - // convert current IP to something useful |
98 | | - $granularity = (int) fgets($dbidx, 64); |
99 | | - if (!$granularity) { |
100 | | - // The file is empty (demo file) |
101 | | - return false; |
102 | | - } |
103 | | - $ip_chunk = (int) ($ip / $granularity); |
104 | | - |
105 | | - // Loop till we can read the file |
106 | | - while (!feof($dbidx)) { |
107 | | - |
108 | | - // Get CSV data from index file |
109 | | - $data = fgetcsv($dbidx, 100); |
110 | | - |
111 | | - // Compare current index part with our IP |
112 | | - if ($ip_chunk >= $idxpart && $ip_chunk < (int) $data[0]) { |
113 | | - return [$recnum, (int) $data[1]]; |
114 | | - } |
115 | | - |
116 | | - // Store for next compare |
117 | | - $idxpart = (int) $data[0]; |
118 | | - $recnum = (int) $data[1]; |
119 | | - } |
120 | | - |
121 | | - // Return record number found |
122 | | - return [$recnum, -1]; |
123 | | -} |
124 | | - |
125 | | -// Find the country searching from record $idx |
126 | | -// $ip should be an IP number and not an IP address |
127 | | -function i2c_search_in_db($ip, $idx) |
128 | | -{ |
129 | | - // Default range and country |
130 | | - $range_start = 0; $range_end = 0; |
131 | | - $country = "NA"; |
132 | | - |
133 | | - // Open DB for reading |
134 | | - $ipdb = fopen( |
135 | | - $_SERVER['DOCUMENT_ROOT'] . "/backend/ip-to-country.db", |
136 | | - "r", |
137 | | - ); |
138 | | - |
139 | | - // Return with "NA" in case of we cannot open the db |
140 | | - if (!$ipdb) { return $country; } |
141 | | - |
142 | | - // Jump to record $idx |
143 | | - fseek($ipdb, ($idx[0] ? (($idx[0] - 1) * 24) : 0)); |
144 | | - |
145 | | - // Read records until we hit the end of the file, |
146 | | - // or we find the range where this IP is, or we |
147 | | - // reach the next indexed part [where the IP should |
148 | | - // not be found, so there is no point in searching further] |
149 | | - while (!feof($ipdb) && !($range_start <= $ip && $range_end >= $ip)) { |
150 | | - |
151 | | - // We had run out of the indexed region, |
152 | | - // where we expected to find the IP |
153 | | - if ($idx[1] != -1 && $idx[0] > $idx[1]) { |
154 | | - $country = "NA"; break; |
155 | | - } |
156 | | - |
157 | | - // Try to read record |
158 | | - $record = fread($ipdb, 24); |
159 | | - |
160 | | - // Unable to read the record => error |
161 | | - if (strlen($record) != 24) { $country = "NA"; break; } |
162 | | - |
163 | | - // Split the record to it's parts |
164 | | - $range_start = (float) substr($record, 0, 10); |
165 | | - $range_end = (float) substr($record, 10, 10); |
166 | | - $country = substr($record, 20, 3); |
167 | | - |
168 | | - // Getting closer to the end of the indexed region |
169 | | - $idx[0] += 1; |
170 | | - } |
171 | | - |
172 | | - // Close datafile |
173 | | - fclose($ipdb); |
174 | | - |
175 | | - // Return with the country found |
176 | | - return $country; |
177 | | -} |
178 | | - |
179 | | -// Check if the current country is valid |
180 | | -function i2c_valid_country() |
181 | | -{ |
182 | | - global $COUNTRY, $COUNTRIES; |
183 | | - return (!empty($COUNTRY) && $COUNTRY != "NA" && isset($COUNTRIES[$COUNTRY])); |
184 | | -} |
185 | | - |
186 | 2 | // Returns the real IP address of the user |
187 | 3 | function i2c_realip() |
188 | 4 | { |
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