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ee40139d MT |
1 | /* This file is part of the IPFire Firewall. |
2 | * | |
3 | * This program is distributed under the terms of the GNU General Public | |
4 | * Licence. See the file COPYING for details. */ | |
5 | ||
7ef66b61 MT |
6 | #define _BSD_SOURCE |
7 | #define _XOPEN_SOURCE | |
8 | ||
ee40139d MT |
9 | #include <stdio.h> |
10 | #include <stdlib.h> | |
11 | #include <string.h> | |
7ef66b61 | 12 | #include <time.h> |
ee40139d MT |
13 | |
14 | #include "libsmooth.h" | |
15 | #include "setuid.h" | |
16 | ||
17 | #define CAPTIVE_PORTAL_SETTINGS CONFIG_ROOT "/captive/settings" | |
18 | #define ETHERNET_SETTINGS CONFIG_ROOT "/ethernet/settings" | |
19 | ||
20 | #define CLIENTS CONFIG_ROOT "/captive/clients" | |
21 | #define IPTABLES "/sbin/iptables --wait" | |
22 | #define HTTP_PORT 80 | |
23 | #define REDIRECT_PORT 1013 | |
24 | ||
25 | typedef struct client { | |
26 | char etheraddr[STRING_SIZE]; | |
27 | char ipaddr[STRING_SIZE]; | |
7ef66b61 MT |
28 | time_t time_start; |
29 | int expires; | |
ee40139d MT |
30 | |
31 | struct client* next; | |
32 | } client_t; | |
33 | ||
7ef66b61 MT |
34 | static time_t parse_time(const char* s) { |
35 | int t = 0; | |
ee40139d | 36 | |
7ef66b61 MT |
37 | if (sscanf(s, "%d", &t) == 1) { |
38 | return (time_t)t; | |
ee40139d MT |
39 | } |
40 | ||
41 | return -1; | |
42 | } | |
43 | ||
7ef66b61 | 44 | static char* format_time(const time_t* t) { |
ee40139d | 45 | char buffer[STRING_SIZE]; |
7ef66b61 MT |
46 | |
47 | struct tm* tm = gmtime(t); | |
48 | if (tm == NULL) | |
49 | return NULL; | |
50 | ||
51 | strftime(buffer, sizeof(buffer), "%Y-%m-%dT%H:%M", tm); | |
ee40139d MT |
52 | |
53 | return strdup(buffer); | |
54 | } | |
55 | ||
56 | static client_t* read_clients(char* filename) { | |
57 | FILE* f = NULL; | |
58 | ||
59 | if (!(f = fopen(filename, "r"))) { | |
60 | fprintf(stderr, "Could not open configuration file: %s\n", filename); | |
61 | return NULL;; | |
62 | } | |
63 | ||
64 | char line[STRING_SIZE]; | |
65 | ||
66 | client_t* client_first = NULL; | |
67 | client_t* client_last = NULL; | |
68 | client_t* client_curr; | |
69 | ||
70 | while ((fgets(line, STRING_SIZE, f) != NULL)) { | |
71 | if (line[strlen(line) - 1] == '\n') | |
72 | line[strlen(line) - 1] = '\0'; | |
73 | ||
74 | client_curr = (client_t*)malloc(sizeof(client_t)); | |
75 | memset(client_curr, 0, sizeof(client_t)); | |
76 | ||
77 | if (client_first == NULL) | |
78 | client_first = client_curr; | |
79 | else | |
80 | client_last->next = client_curr; | |
81 | client_last = client_curr; | |
82 | ||
83 | unsigned int count = 0; | |
84 | char* lineptr = line; | |
85 | while (1) { | |
86 | if (!*lineptr) | |
87 | break; | |
88 | ||
89 | char* word = lineptr; | |
90 | while (*lineptr != '\0') { | |
91 | if (*lineptr == ',') { | |
92 | *lineptr = '\0'; | |
93 | lineptr++; | |
94 | break; | |
95 | } | |
96 | lineptr++; | |
97 | } | |
98 | ||
99 | switch (count++) { | |
100 | // Ethernet address | |
101 | case 1: | |
102 | strcpy(client_curr->etheraddr, word); | |
103 | break; | |
104 | ||
105 | // IP address | |
106 | case 2: | |
107 | strcpy(client_curr->ipaddr, word); | |
108 | break; | |
109 | ||
110 | // Start time | |
111 | case 3: | |
112 | client_curr->time_start = parse_time(word); | |
113 | break; | |
114 | ||
7ef66b61 | 115 | // Expire duration |
ee40139d | 116 | case 4: |
7ef66b61 | 117 | client_curr->expires = atoi(word); |
ee40139d MT |
118 | break; |
119 | ||
120 | default: | |
121 | break; | |
122 | } | |
123 | } | |
124 | } | |
125 | ||
126 | if (f) | |
127 | fclose(f); | |
128 | ||
129 | return client_first; | |
130 | } | |
131 | ||
132 | static void flush_chains() { | |
133 | // filter | |
134 | safe_system(IPTABLES " -F CAPTIVE_PORTAL"); | |
135 | safe_system(IPTABLES " -F CAPTIVE_PORTAL_CLIENTS"); | |
136 | ||
137 | // nat | |
138 | safe_system(IPTABLES " -t nat -F CAPTIVE_PORTAL"); | |
139 | } | |
140 | ||
141 | static int add_client_rules(const client_t* clients) { | |
142 | char command[STRING_SIZE]; | |
143 | char match[STRING_SIZE]; | |
144 | ||
145 | while (clients) { | |
7ef66b61 MT |
146 | time_t expires = clients->time_start + clients->expires; |
147 | ||
148 | char* time_start = format_time(&clients->time_start); | |
149 | char* time_end = format_time(&expires); | |
ee40139d MT |
150 | |
151 | snprintf(match, sizeof(match), "-s %s -m mac --mac-source %s" | |
7ef66b61 MT |
152 | " -m time --datestart %s --datestop %s", clients->ipaddr, |
153 | clients->etheraddr, time_start, time_end); | |
ee40139d MT |
154 | |
155 | free(time_start); | |
156 | free(time_end); | |
157 | ||
158 | // filter | |
159 | snprintf(command, sizeof(command), IPTABLES " -A CAPTIVE_PORTAL_CLIENTS" | |
160 | " %s -j RETURN", match); | |
161 | safe_system(command); | |
162 | ||
163 | // nat | |
164 | snprintf(command, sizeof(command), IPTABLES " -t nat -A CAPTIVE_PORTAL" | |
165 | " %s -j RETURN", match); | |
166 | safe_system(command); | |
167 | ||
168 | // Move on to the next client | |
169 | clients = clients->next; | |
170 | } | |
171 | ||
172 | return 0; | |
173 | } | |
174 | ||
175 | static char* get_key(struct keyvalue* settings, char* key) { | |
176 | char value[STRING_SIZE]; | |
177 | ||
178 | if (!findkey(settings, key, value)) | |
179 | return NULL; | |
180 | ||
181 | return strdup(value); | |
182 | } | |
183 | ||
184 | static int add_interface_rule(const char* intf, int allow_webif_access) { | |
185 | int r; | |
186 | char command[STRING_SIZE]; | |
187 | ||
188 | if ((intf == NULL) || (strlen(intf) == 0)) { | |
189 | fprintf(stderr, "Empty interface given\n"); | |
190 | return -1; | |
191 | } | |
192 | ||
193 | snprintf(command, sizeof(command), IPTABLES " -A CAPTIVE_PORTAL -i %s" | |
194 | " -j CAPTIVE_PORTAL_CLIENTS", intf); | |
195 | r = safe_system(command); | |
196 | if (r) | |
197 | return r; | |
198 | ||
199 | #if 0 | |
200 | snprintf(command, sizeof(command), IPTABLES " -A CAPTIVE_PORTAL -o %s" | |
201 | " -j CAPTIVE_PORTAL_CLIENTS", intf); | |
202 | r = safe_system(command); | |
203 | if (r) | |
204 | return r; | |
205 | #endif | |
206 | ||
207 | if (allow_webif_access) { | |
208 | snprintf(command, sizeof(command), IPTABLES " -A CAPTIVE_PORTAL_CLIENTS" | |
209 | " -i %s -p tcp --dport 444 -j RETURN", intf); | |
210 | r = safe_system(command); | |
211 | if (r) | |
212 | return r; | |
213 | } | |
214 | ||
215 | // Redirect all unauthenticated clients | |
216 | snprintf(command, sizeof(command), IPTABLES " -t nat -A CAPTIVE_PORTAL -i %s" | |
217 | " -p tcp --dport %d -j REDIRECT --to-ports %d", intf, HTTP_PORT, REDIRECT_PORT); | |
218 | r = safe_system(command); | |
219 | if (r) | |
220 | return r; | |
221 | ||
222 | return 0; | |
223 | } | |
224 | ||
225 | static int add_interface_rules(struct keyvalue* captive_portal_settings, struct keyvalue* ethernet_settings) { | |
226 | const char* intf; | |
227 | char* setting; | |
228 | int r = 0; | |
229 | ||
230 | setting = get_key(captive_portal_settings, "ENABLE_GREEN"); | |
231 | if (setting && (strcmp(setting, "on") == 0)) { | |
232 | free(setting); | |
233 | ||
234 | intf = get_key(ethernet_settings, "GREEN_DEV"); | |
235 | r = add_interface_rule(intf, /* allow webif access from green */ 1); | |
236 | if (r) | |
237 | return r; | |
238 | } | |
239 | ||
240 | setting = get_key(captive_portal_settings, "ENABLE_BLUE"); | |
241 | if (setting && (strcmp(setting, "on") == 0)) { | |
242 | free(setting); | |
243 | ||
244 | intf = get_key(ethernet_settings, "BLUE_DEV"); | |
245 | r = add_interface_rule(intf, /* do not allow webif access */ 0); | |
246 | if (r) | |
247 | return r; | |
248 | } | |
249 | ||
250 | // Always pass DNS packets through all firewall rules | |
251 | r = safe_system(IPTABLES " -A CAPTIVE_PORTAL_CLIENTS -p udp --dport 53 -j RETURN"); | |
252 | if (r) | |
253 | return r; | |
254 | ||
255 | r = safe_system(IPTABLES " -A CAPTIVE_PORTAL_CLIENTS -p tcp --dport 53 -j RETURN"); | |
256 | if (r) | |
257 | return r; | |
258 | ||
259 | char command[STRING_SIZE]; | |
260 | snprintf(command, sizeof(command), IPTABLES " -A CAPTIVE_PORTAL_CLIENTS" | |
261 | " -p tcp --dport %d -j RETURN", REDIRECT_PORT); | |
262 | r = safe_system(command); | |
263 | if (r) | |
264 | return r; | |
265 | ||
266 | // Add the last rule | |
267 | r = safe_system(IPTABLES " -A CAPTIVE_PORTAL_CLIENTS -j DROP"); | |
268 | if (r) | |
269 | return r; | |
270 | ||
271 | return r; | |
272 | } | |
273 | ||
274 | int main(int argc, char** argv) { | |
275 | int r = 0; | |
276 | char* intf = NULL; | |
277 | client_t* clients = NULL; | |
278 | ||
279 | if (!(initsetuid())) | |
280 | exit(2); | |
281 | ||
282 | struct keyvalue* ethernet_settings = initkeyvalues(); | |
283 | if (!readkeyvalues(ethernet_settings, ETHERNET_SETTINGS)) { | |
284 | fprintf(stderr, "Could not read %s\n", ETHERNET_SETTINGS); | |
285 | r = 1; | |
286 | goto END; | |
287 | } | |
288 | ||
289 | struct keyvalue* captive_portal_settings = initkeyvalues(); | |
290 | if (!readkeyvalues(captive_portal_settings, CAPTIVE_PORTAL_SETTINGS)) { | |
291 | fprintf(stderr, "Could not read %s\n", CAPTIVE_PORTAL_SETTINGS); | |
292 | r = 1; | |
293 | goto END; | |
294 | } | |
295 | ||
296 | clients = read_clients(CLIENTS); | |
297 | ||
298 | // Clean up all old rules | |
299 | flush_chains(); | |
300 | ||
301 | // Add all client rules | |
302 | r = add_client_rules(clients); | |
303 | if (r) | |
304 | goto END; | |
305 | ||
306 | // Add all interface rules | |
307 | r = add_interface_rules(captive_portal_settings, ethernet_settings); | |
308 | if (r) | |
309 | goto END; | |
310 | ||
311 | END: | |
312 | while (clients) { | |
313 | client_t* head = clients; | |
314 | clients = clients->next; | |
315 | ||
316 | free(head); | |
317 | } | |
318 | ||
319 | if (ethernet_settings) | |
320 | freekeyvalues(ethernet_settings); | |
321 | ||
322 | if (captive_portal_settings) | |
323 | freekeyvalues(captive_portal_settings); | |
324 | ||
325 | if (intf) | |
326 | free(intf); | |
327 | ||
328 | return r; | |
329 | } |