1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
|
/*
* (C) 2013 by Christian Hesse <mail@eworm.de>
*
* This software may be used and distributed according to the terms
* of the GNU General Public License, incorporated herein by reference.
*
* This is an example code skeleton provided by vim-skeleton.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <avahi-client/client.h>
#include <avahi-client/lookup.h>
#include <avahi-common/simple-watch.h>
#include <avahi-common/malloc.h>
#include <avahi-common/error.h>
#include <curl/curl.h>
#include <microhttpd.h>
#define PAGE307 "<html><head><title>307 temporary redirect</title>" \
"</head><body>307 temporary redirect: " \
"<a href=\"%s\">%s</a></body></html>"
#define PAGE404 "<html><head><title>404 Not Found</title>" \
"</head><body>404 Not Found: %s</body></html>"
#define PORT 7077
#define SERVICE "_pacserve._tcp"
/* is there any other way than storing things in global struct? */
struct hosts {
char * host;
uint16_t port;
struct hosts * next;
};
/* global variables */
struct hosts * hosts = NULL;
static AvahiSimplePoll *simple_poll = NULL;
static void resolve_callback(AvahiServiceResolver *r, AVAHI_GCC_UNUSED AvahiIfIndex interface, AVAHI_GCC_UNUSED AvahiProtocol protocol,
AvahiResolverEvent event, const char *name, const char *type, const char *domain, const char *host, const AvahiAddress *address,
AVAHI_GCC_UNUSED uint16_t port, AVAHI_GCC_UNUSED AvahiStringList *txt, AVAHI_GCC_UNUSED AvahiLookupResultFlags flags,
AVAHI_GCC_UNUSED void* userdata) {
struct hosts * tmphosts = hosts;
assert(r);
/* Called whenever a service has been resolved successfully or timed out */
switch (event) {
case AVAHI_RESOLVER_FAILURE:
fprintf(stderr, "(Resolver) Failed to resolve service '%s' of type '%s' in domain '%s': %s\n",
name, type, domain, avahi_strerror(avahi_client_errno(avahi_service_resolver_get_client(r))));
break;
case AVAHI_RESOLVER_FOUND: {
// char a[AVAHI_ADDRESS_STR_MAX];
// avahi_address_snprint(a, sizeof(a), address);
// fprintf(stderr, "%s %s\n", host, a);
while (tmphosts->host != NULL) {
if (strcmp(tmphosts->host, host) == 0) {
# if defined DEBUG
printf("Host is already in the list: %s\n", host);
# endif
goto out;
}
tmphosts = tmphosts->next;
}
printf("Adding host: %s, port %d\n", host, port);
tmphosts->host = strdup(host);
tmphosts->port = 15678;
tmphosts->next = realloc(tmphosts->next, sizeof(struct hosts));
tmphosts = tmphosts->next;
tmphosts->host = NULL;
tmphosts->next = NULL;
}
}
out:
avahi_service_resolver_free(r);
}
static void browse_callback(AvahiServiceBrowser *b, AvahiIfIndex interface, AvahiProtocol protocol, AvahiBrowserEvent event, const char *name,
const char *type, const char *domain, AVAHI_GCC_UNUSED AvahiLookupResultFlags flags, void* userdata) {
AvahiClient *c = userdata;
assert(b);
/* Called whenever a new services becomes available on the LAN or is removed from the LAN */
switch (event) {
case AVAHI_BROWSER_FAILURE:
fprintf(stderr, "(Browser) %s\n", avahi_strerror(avahi_client_errno(avahi_service_browser_get_client(b))));
avahi_simple_poll_quit(simple_poll);
return;
case AVAHI_BROWSER_NEW:
// fprintf(stderr, "(Browser) NEW: service '%s' of type '%s' in domain '%s'\n", name, type, domain);
/* We ignore the returned resolver object. In the callback
* function we free it. If the server is terminated before
* the callback function is called the server will free
* the resolver for us. */
if (!(avahi_service_resolver_new(c, interface, protocol, name, type, domain, AVAHI_PROTO_UNSPEC, 0, resolve_callback, c)))
fprintf(stderr, "Failed to resolve service '%s': %s\n", name, avahi_strerror(avahi_client_errno(c)));
break;
case AVAHI_BROWSER_REMOVE:
// fprintf(stderr, "(Browser) REMOVE: service '%s' of type '%s' in domain '%s'\n", name, type, domain);
/* TODO: remove host */
// if (!(avahi_service_resolver_new(c, interface, protocol, name, type, domain, AVAHI_PROTO_UNSPEC, 0, resolve_callback, c)))
// fprintf(stderr, "Failed to resolve service '%s': %s\n", name, avahi_strerror(avahi_client_errno(c)));
break;
case AVAHI_BROWSER_ALL_FOR_NOW:
case AVAHI_BROWSER_CACHE_EXHAUSTED:
// fprintf(stderr, "(Browser) %s\n", event == AVAHI_BROWSER_CACHE_EXHAUSTED ? "CACHE_EXHAUSTED" : "ALL_FOR_NOW");
break;
}
}
static void client_callback(AvahiClient *c, AvahiClientState state, AVAHI_GCC_UNUSED void * userdata) {
assert(c);
/* Called whenever the client or server state changes */
if (state == AVAHI_CLIENT_FAILURE) {
fprintf(stderr, "Server connection failure: %s\n", avahi_strerror(avahi_client_errno(c)));
avahi_simple_poll_quit(simple_poll);
}
}
int get_content(const char * host, const uint16_t port, const char * url) {
CURL *curl;
CURLcode res;
unsigned int http_code;
curl_global_init(CURL_GLOBAL_ALL);
if ((curl = curl_easy_init()) != NULL) {
curl_easy_setopt(curl, CURLOPT_URL, url);
/* example.com is redirected, so we tell libcurl to follow redirection */
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
/* set user agent */
curl_easy_setopt(curl, CURLOPT_USERAGENT, "pacredir/" VERSION);
/* do not receive body */
curl_easy_setopt(curl, CURLOPT_NOBODY, 1);
/* get it! */
if (curl_easy_perform(curl) != CURLE_OK) {
fprintf(stderr, "Could not connect to server %s on port %d.\n", host, port);
/* TODO remove or disable */
return -1;
}
if ((res = curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &http_code)) != CURLE_OK) {
fprintf(stderr, "curl_easy_getinfo() failed: %s\n", curl_easy_strerror(res));
return -1;
}
// printf("%s: %d\n", url, http_code);
/* always cleanup */
curl_easy_cleanup(curl);
}
/* we're done with libcurl, so clean it up */
curl_global_cleanup();
return http_code;
}
static int ahc_echo(void * cls, struct MHD_Connection * connection, const char * uri, const char * method,
const char * version, const char * upload_data, size_t * upload_data_size, void ** ptr) {
static int dummy;
struct MHD_Response * response;
int ret;
struct hosts * tmphosts = hosts;
char * url = NULL, * page;
const char * basename;
int http_code = 0;
/* we want to filename, not the path */
basename = uri;
while (strstr(basename, "/") != NULL)
basename = strstr(basename, "/") + 1;
if (strcmp(method, "GET") != 0)
return MHD_NO; /* unexpected method */
if (&dummy != *ptr) {
/* The first time only the headers are valid,
* do not respond in the first round... */
*ptr = &dummy;
return MHD_YES;
}
if (*upload_data_size != 0)
return MHD_NO; /* upload data in a GET!? */
*ptr = NULL; /* clear context pointer */
/* try to find a server */
while (tmphosts->host != NULL) {
url = malloc(10 + strlen(tmphosts->host) + 5 + strlen(basename));
sprintf(url, "http://%s:%d/%s", tmphosts->host, tmphosts->port, basename);
printf("Trying %s\n", url);
if ((http_code = get_content(tmphosts->host, tmphosts->port, url)) == MHD_HTTP_OK) {
break;
}
tmphosts = tmphosts->next;
}
/* give response */
if (http_code == MHD_HTTP_OK) {
printf("Redirecting to %s\n", url);
page = malloc(strlen(PAGE307) + strlen(url) + strlen(basename) + 1);
sprintf(page, PAGE307, url, basename);
response = MHD_create_response_from_data(strlen(url), (void*) url, MHD_NO, MHD_NO);
ret = MHD_add_response_header(response, "Location", url);
ret = MHD_queue_response(connection, MHD_HTTP_TEMPORARY_REDIRECT, response);
} else {
printf("File %s Not found, giving up.\n", basename);
page = malloc(strlen(PAGE404) + strlen(basename) + 1);
sprintf(page, PAGE404, basename);
response = MHD_create_response_from_data(strlen(page), (void*) page, MHD_NO, MHD_NO);
ret = MHD_queue_response(connection, MHD_HTTP_NOT_FOUND, response);
}
MHD_destroy_response(response);
free(page);
if (url != NULL)
free(url);
return ret;
}
int main(int argc, char ** argv) {
AvahiClient *client = NULL;
AvahiServiceBrowser *sb = NULL;
int error;
int ret = 1;
struct MHD_Daemon * mhd;
printf("Starting pacredir/" VERSION "\n");
/* allocate first struct element as dummy */
hosts = malloc(sizeof(struct hosts));
hosts->host = NULL;
hosts->port = 0;
hosts->next = NULL;
/* Allocate main loop object */
if (!(simple_poll = avahi_simple_poll_new())) {
fprintf(stderr, "Failed to create simple poll object.\n");
goto fail;
}
/* Allocate a new client */
client = avahi_client_new(avahi_simple_poll_get(simple_poll), 0, client_callback, NULL, &error);
/* Check wether creating the client object succeeded */
if (!client) {
fprintf(stderr, "Failed to create client: %s\n", avahi_strerror(error));
goto fail;
}
/* Create the service browser */
if (!(sb = avahi_service_browser_new(client, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, SERVICE, NULL, 0, browse_callback, client))) {
fprintf(stderr, "Failed to create service browser: %s\n", avahi_strerror(avahi_client_errno(client)));
goto fail;
}
if ((mhd = MHD_start_daemon(MHD_USE_THREAD_PER_CONNECTION, PORT, NULL, NULL, &ahc_echo, NULL, MHD_OPTION_END)) == NULL) {
fprintf(stderr, "Could not start daemon on port %d.\n", PORT);
return EXIT_FAILURE;
}
/* Run the main loop */
avahi_simple_poll_loop(simple_poll);
MHD_stop_daemon(mhd);
ret = EXIT_SUCCESS;
fail:
/* Cleanup things */
if (sb)
avahi_service_browser_free(sb);
if (client)
avahi_client_free(client);
if (simple_poll)
avahi_simple_poll_free(simple_poll);
return ret;
}
// vim: set syntax=c:
|