/*

* Copyright 2010 Toshiyuki Suzumura

*

* Licensed under the Apache License, Version 2.0 (the "License");

* you may not use this file except in compliance with the License.

* You may obtain a copy of the License at

*

* http://www.apache.org/licenses/LICENSE-2.0

*

* Unless required by applicable law or agreed to in writing, software

* distributed under the License is distributed on an "AS IS" BASIS,

* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

* See the License for the specific language governing permissions and

* limitations under the License.

*

*/

#include "httpd.h"

#include "http_config.h"

#include "http_protocol.h"

#include "http_request.h"

#include "http_log.h"

#include "ap_config.h"

#include "apr_lib.h"

#include "apr_strings.h"

#include "apr_tables.h"

#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <netdb.h>

#include <unistd.h>

#include <errno.h>

#include <string.h>

#define MULTICAST_INDEX "X-Multicast-Index"

static const char VERSION[] = "mod_multicast_index/0.1";

static const char CONFIG_MULTICAST[] = MULTICAST_INDEX;

static const char X_INDEX_200[] = MULTICAST_INDEX "_200";

static const char X_INDEX_404[] = MULTICAST_INDEX "_404";

module AP_MODULE_DECLARE_DATA multicast_index_module;

#define AP_LOG_DEBUG(rec, fmt, ...) ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, rec, fmt, ##__VA_ARGS__)

#define AP_LOG_INFO(rec, fmt, ...) ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, rec, "[multicast_idx] " fmt, ##__VA_ARGS__)

#define AP_LOG_WARN(rec, fmt, ...) ap_log_rerror(APLOG_MARK, APLOG_WARNING,0, rec, "[multicast_idx] " fmt, ##__VA_ARGS__)

#define AP_LOG_ERR(rec, fmt, ...) ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, rec, "[multicast_idx] " fmt, ##__VA_ARGS__)

// Config store

typedef struct {

struct sockaddr* addr;

size_t len;

} addr_in_t;

typedef struct {

apr_pool_t* pool;

int enabled;

addr_in_t multicast_interface;

addr_in_t multicast_address;

} multicast_conf;

//

// Main functions.

//

static char* unescape_specialchars(apr_pool_t* pool, const char* str)

{

char* p, *r = apr_pstrdup(pool, str);

for(p=r; p[0]!='\0'; p++) {

if((p[0]=='%') && (p[1]!='\0')) {

switch(p[1]) {

case 'r':

p[0]='\r'; break;

case 'n':

p[0]='\n'; break;

default:

break;

}

memmove(p+1, p+2, strlen(p+1));

}

}

return r;

}

// Multicast packet.

static apr_status_t multicast_packet(request_rec* rec, multicast_conf* conf, const char* _msg)

{

int r, s = socket(AF_INET, SOCK_DGRAM, 0);

char* msg = unescape_specialchars(rec->pool, _msg);

AP_LOG_DEBUG(rec, "unescaped string: %s", msg);

r = setsockopt(s, SOL_IP, IP_MULTICAST_IF, conf->multicast_interface.addr, conf->multicast_interface.len);

if(r!=0) {

r = errno;

AP_LOG_ERR(rec, "setsockopt() failed - %s(%d)", strerror(r), r);

goto FINALLY;

}

r = connect(s, conf->multicast_address.addr, conf->multicast_address.len);

if(r!=0) {

r = errno;

AP_LOG_ERR(rec, "connect() failed - %s(%d)", strerror(r), r);

goto FINALLY;

}

r = send(s, msg, strlen(msg), 0);

r = (r>=0)? APR_SUCCESS: errno;

FINALLY:

if(s>=0) {

shutdown(s, SHUT_RDWR);

close(s);

}

return r;

}

// Multicast "404 Not Found."

static apr_status_t multicast_404_not_found(request_rec* rec, multicast_conf* conf)

{

const char* msg = apr_table_get(rec->headers_in, X_INDEX_404);

if(msg==NULL) msg = apr_psprintf(rec->pool, "%s:%s Not found.\n", rec->hostname, rec->uri);

return multicast_packet(rec, conf, msg);

}

// Multicast "200 OK."

static apr_status_t multicast_200_ok(request_rec* rec, multicast_conf* conf)

{

const char* msg = apr_table_get(rec->headers_in, X_INDEX_200);

if(msg==NULL) msg = apr_psprintf(rec->pool, "%s:%s Found.\n", rec->hostname, rec->uri);

return multicast_packet(rec, conf, msg);

}

// Multicast index handler

static int multicast_index_handler(request_rec *rec)

{

multicast_conf* conf = ap_get_module_config(rec->per_dir_config, &multicast_index_module);

apr_status_t status = APR_SUCCESS;

apr_finfo_t finfo;

apr_dir_t* dir;

if(strcasecmp(rec->handler, MULTICAST_INDEX)) return DECLINED;

if(!conf || !conf->enabled) return DECLINED;

if(rec->method_number!=M_GET) return DECLINED;

// setup content-type of response.

rec->content_type = "text/json";

// do request

status = apr_dir_open(&dir, rec->filename, rec->pool);

if(status!=APR_SUCCESS) {

// 404 Not Found.

rec->status = HTTP_NOT_FOUND;

return multicast_404_not_found(rec, conf);

}

// 200 OK.

if(!rec->header_only) {

int the_first = TRUE;

ap_rputs("[", rec);

while((status=apr_dir_read(&finfo, APR_FINFO_NAME|APR_FINFO_TYPE, dir))==APR_SUCCESS) {

if((strcmp(finfo.name, ".")==0) || (strcmp(finfo.name, "..")==0)) continue;

if(the_first) { the_first = FALSE; } else { ap_rputs(",", rec); }

switch(finfo.filetype) {

case APR_DIR:

ap_rprintf(rec, "\"%s/\"", finfo.name);

break;

case APR_REG:

ap_rprintf(rec, "\"%s\"", finfo.name);

break;

case APR_LNK:

ap_rprintf(rec, "\"%s@\"", finfo.name);

break;

default:

break;

}

}

ap_rputs("]\n", rec);

rec->status = HTTP_OK;

}

apr_dir_close(dir);

return multicast_200_ok(rec, conf);

}

//

// Configurators, and Register.

//

static void* config_create(apr_pool_t* p, char* path)

{

multicast_conf* conf = apr_palloc(p, sizeof(multicast_conf));

memset(conf, 0, sizeof(conf));

conf->pool = p;

conf->enabled = FALSE;

return conf;

}

// string to addr_in

static const char* string_to_addr_in(apr_pool_t* p, const char* param, const char* port, addr_in_t* addr_in)

{

struct addrinfo hints, *result;

int r;

memset(&hints, 0, sizeof(hints));

hints.ai_flags = 0;

hints.ai_family = AF_INET;

hints.ai_socktype = SOCK_DGRAM;

hints.ai_protocol = 0;

hints.ai_canonname = NULL;

hints.ai_addr = NULL;

hints.ai_next = NULL;

r = getaddrinfo(param, port, &hints, &result);

if(r!=0) return "getaddrinfo() failed.";

addr_in->addr = apr_pmemdup(p, result->ai_addr, result->ai_addrlen);

addr_in->len = result->ai_addrlen;

freeaddrinfo(result);

return NULL;

}

static const char* config_address_slot(cmd_parms* cmd, void* _conf, \

const char* param1, const char* param2, const char* param3)

{

const char* r;

multicast_conf* conf = _conf;

r = string_to_addr_in(conf->pool, param1, NULL, &(conf->multicast_interface));

if(r==NULL) {

r = string_to_addr_in(conf->pool, param2, param3, &(conf->multicast_address));

}

conf->enabled = (r==NULL)? TRUE: FALSE;

return r;

}

static const command_rec config_cmds[] = {

AP_INIT_TAKE3(CONFIG_MULTICAST, config_address_slot, NULL, OR_OPTIONS, "Multicast options."),

{ NULL },

};

static void multicast_index_register_hooks(apr_pool_t *p)

{

ap_hook_handler(multicast_index_handler, NULL, NULL, APR_HOOK_MIDDLE);

}

// Dispatch list for API hooks.

module AP_MODULE_DECLARE_DATA multicast_index_module = {

STANDARD20_MODULE_STUFF,

config_create, // create per-dir config structures

NULL, // merge per-dir config structures

NULL, // create per-server config structures

NULL, // merge per-server config structures

config_cmds, // table of config file commands

multicast_index_register_hooks // register hooks

};