initial commit

author: Christian Hesse <mail@eworm.de> 2013-10-25 23:48:38 +0200
committer: Christian Hesse <mail@eworm.de> 2013-10-25 23:48:38 +0200
commit: cfe74022706ded43da15264606cc58e62caa8452 (patch)
tree: 06dc1635e1942f2dd104927e7eaa916f74323e2f /pacredir.c
parent: 2add64f0904e151ca9e160cd8a880945bfd0c940 (diff)
download: pacredir-cfe74022706ded43da15264606cc58e62caa8452.tar.gz
pacredir-cfe74022706ded43da15264606cc58e62caa8452.tar.zst
1 files changed, 316 insertions, 0 deletions
diff --git a/pacredir.c b/pacredir.c
new file mode 100644
index 0000000..2025f04
--- /dev/null
+++ b/pacredir.c
@@ -0,0 +1,316 @@
+/*
+ * (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:
author	Christian Hesse <mail@eworm.de>	2013-10-25 23:48:38 +0200
committer	Christian Hesse <mail@eworm.de>	2013-10-25 23:48:38 +0200
commit	cfe74022706ded43da15264606cc58e62caa8452 (patch)
tree	06dc1635e1942f2dd104927e7eaa916f74323e2f /pacredir.c
parent	2add64f0904e151ca9e160cd8a880945bfd0c940 (diff)
download	pacredir-cfe74022706ded43da15264606cc58e62caa8452.tar.gz pacredir-cfe74022706ded43da15264606cc58e62caa8452.tar.zst