connection.c

/* -*- c-basic-offset: 4; indent-tabs-mode: nil; -*- */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef HAVE_POLL
#include <sys/poll.h>
#endif

#ifndef _WIN32
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#else
#include <winsock2.h>
#define snprintf _snprintf
#define strcasecmp stricmp
#define strncasecmp strnicmp
#endif

#include "os.h"

#include "thread.h"
#include "avl.h"
#include "sock.h"
#include "log.h"
#include "httpp.h"

#include "config.h"
#include "global.h"
#include "util.h"
#include "connection.h"
#include "refbuf.h"
#include "client.h"
#include "stats.h"
#include "logging.h"
#include "xslt.h"
#include "fserve.h"

#include "yp.h"
#include "source.h"
#include "format.h"
#include "format_mp3.h"
#include "event.h"
#include "admin.h"

#define CATMODULE "connection"

typedef struct con_queue_tag {
    connection_t *con;
    struct con_queue_tag *next;
} con_queue_t;

typedef struct _thread_queue_tag {
    thread_type *thread_id;
    struct _thread_queue_tag *next;
} thread_queue_t;

static mutex_t _connection_mutex;
static unsigned long _current_id = 0;
static int _initialized = 0;
static cond_t _pool_cond;

static con_queue_t *_queue = NULL;
static mutex_t _queue_mutex;

static thread_queue_t *_conhands = NULL;

rwlock_t _source_shutdown_rwlock;

static void *_handle_connection(void *arg);

void connection_initialize(void)
{
    if (_initialized) return;
    
    thread_mutex_create(&_connection_mutex);
    thread_mutex_create(&_queue_mutex);
    thread_rwlock_create(&_source_shutdown_rwlock);
    thread_cond_create(&_pool_cond);
    thread_cond_create(&global.shutdown_cond);

    _initialized = 1;
}

void connection_shutdown(void)
{
    if (!_initialized) return;
    
    thread_cond_destroy(&global.shutdown_cond);
    thread_cond_destroy(&_pool_cond);
    thread_rwlock_destroy(&_source_shutdown_rwlock);
    thread_mutex_destroy(&_queue_mutex);
    thread_mutex_destroy(&_connection_mutex);

    _initialized = 0;
}

static unsigned long _next_connection_id(void)
{
    unsigned long id;

    thread_mutex_lock(&_connection_mutex);
    id = _current_id++;
    thread_mutex_unlock(&_connection_mutex);

    return id;
}

connection_t *create_connection(sock_t sock, char *ip) {
    connection_t *con;
    con = (connection_t *)malloc(sizeof(connection_t));
    memset(con, 0, sizeof(connection_t));
    con->sock = sock;
    con->con_time = time(NULL);
    con->id = _next_connection_id();
    con->ip = ip;

    con->event_number = EVENT_NO_EVENT;
    con->event = NULL;

    return con;
}

static int wait_for_serversock(int timeout)
{
#ifdef HAVE_POLL
    struct pollfd ufds[MAX_LISTEN_SOCKETS];
    int i, ret;

    for(i=0; i < global.server_sockets; i++) {
        ufds[i].fd = global.serversock[i];
        ufds[i].events = POLLIN;
        ufds[i].revents = 0;
    }

    ret = poll(ufds, global.server_sockets, timeout);
    if(ret < 0) {
        return -2;
    }
    else if(ret == 0) {
        return -1;
    }
    else {
        for(i=0; i < global.server_sockets; i++) {
            if(ufds[i].revents == POLLIN)
                return ufds[i].fd;
        }
        return -1; /* Shouldn't happen */
    }
#else
    fd_set rfds;
    struct timeval tv, *p=NULL;
    int i, ret;
    int max = -1;

    FD_ZERO(&rfds);

    for(i=0; i < global.server_sockets; i++) {
        FD_SET(global.serversock[i], &rfds);
        if(global.serversock[i] > max)
            max = global.serversock[i];
    }

    if(timeout >= 0) {
        tv.tv_sec = timeout/1000;
        tv.tv_usec = (timeout % 1000) * 1000;
        p = &tv;
    }

    ret = select(max+1, &rfds, NULL, NULL, p);
    if(ret < 0) {
        return -2;
    }
    else if(ret == 0) {
        return -1;
    }
    else {
        for(i=0; i < global.server_sockets; i++) {
            if(FD_ISSET(global.serversock[i], &rfds))
                return global.serversock[i];
        }
        return -1; /* Should be impossible, stop compiler warnings */
    }
#endif
}

static connection_t *_accept_connection(void)
{
    int sock;
    connection_t *con;
    char *ip;
    int serversock; 

    serversock = wait_for_serversock(100);
    if(serversock < 0)
        return NULL;

    /* malloc enough room for a full IP address (including ipv6) */
    ip = (char *)malloc(MAX_ADDR_LEN);

    sock = sock_accept(serversock, ip, MAX_ADDR_LEN);
    if (sock >= 0) {
        con = create_connection(sock, ip);

        return con;
    }

    if (!sock_recoverable(sock_error()))
        WARN2("accept() failed with error %d: %s", sock_error(), strerror(sock_error()));
    
    free(ip);

    return NULL;
}

static void _add_connection(connection_t *con)
{
    con_queue_t *node;

    node = (con_queue_t *)malloc(sizeof(con_queue_t));
    
    thread_mutex_lock(&_queue_mutex);
    node->con = con;
    node->next = _queue;
    _queue = node;
    thread_mutex_unlock(&_queue_mutex);

}

static void _signal_pool(void)
{
    thread_cond_signal(&_pool_cond);
}

static void _push_thread(thread_queue_t **queue, thread_type *thread_id)
{
    /* create item */
    thread_queue_t *item = (thread_queue_t *)malloc(sizeof(thread_queue_t));
    item->thread_id = thread_id;
    item->next = NULL;


    thread_mutex_lock(&_queue_mutex);
    if (*queue == NULL) {
        *queue = item;
    } else {
        item->next = *queue;
        *queue = item;
    }
    thread_mutex_unlock(&_queue_mutex);
}

static thread_type *_pop_thread(thread_queue_t **queue)
{
    thread_type *id;
    thread_queue_t *item;

    thread_mutex_lock(&_queue_mutex);

    item = *queue;
    if (item == NULL) {
        thread_mutex_unlock(&_queue_mutex);
        return NULL;
    }

    *queue = item->next;
    item->next = NULL;
    id = item->thread_id;
    free(item);

    thread_mutex_unlock(&_queue_mutex);

    return id;
}

static void _build_pool(void)
{
    ice_config_t *config;
    int i;
    thread_type *tid;
    char buff[64];
    int threadpool_size;

    config = config_get_config();
    threadpool_size = config->threadpool_size;
    config_release_config();

    for (i = 0; i < threadpool_size; i++) {
        snprintf(buff, 64, "Connection Thread #%d", i);
        tid = thread_create(buff, _handle_connection, NULL, THREAD_ATTACHED);
        _push_thread(&_conhands, tid);
    }
}

static void _destroy_pool(void)
{
    thread_type *id;
    int i;

    i = 0;

    thread_cond_broadcast(&_pool_cond);
    id = _pop_thread(&_conhands);
    while (id != NULL) {
        thread_join(id);
        _signal_pool();
        id = _pop_thread(&_conhands);
    }
}

void connection_accept_loop(void)
{
    connection_t *con;

    _build_pool();

    while (global.running == ICE_RUNNING) {
        con = _accept_connection();

        if (con) {
            _add_connection(con);
            _signal_pool();
        }
    }

    /* Give all the other threads notification to shut down */
    thread_cond_broadcast(&global.shutdown_cond);

    _destroy_pool();

    /* wait for all the sources to shutdown */
    thread_rwlock_wlock(&_source_shutdown_rwlock);
    thread_rwlock_unlock(&_source_shutdown_rwlock);
}

static connection_t *_get_connection(void)
{
    con_queue_t *node = NULL;
    con_queue_t *oldnode = NULL;
    connection_t *con = NULL;

    thread_mutex_lock(&_queue_mutex);
    if (_queue) {
        node = _queue;
        while (node->next) {
            oldnode = node;
            node = node->next;
        }
        
        /* node is now the last node
        ** and oldnode is the previous one, or NULL
        */
        if (oldnode) oldnode->next = NULL;
        else (_queue) = NULL;
    }
    thread_mutex_unlock(&_queue_mutex);

    if (node) {
        con = node->con;
        free(node);
    }

    return con;
}

void connection_inject_event(int eventnum, void *event_data) {
    connection_t *con = calloc(1, sizeof(connection_t));

    con->event_number = eventnum;
    con->event = event_data;

    _add_connection(con);
    _signal_pool();
}

/* TODO: Make this return an appropriate error code so that we can use HTTP
 * codes where appropriate
 */
int connection_create_source(client_t *client, connection_t *con, http_parser_t *parser, char *mount) {
    source_t *source;
    char *contenttype;
    mount_proxy *mountproxy, *mountinfo = NULL;
    int source_limit;
    ice_config_t *config;

    config = config_get_config();
    source_limit = config->source_limit;
    config_release_config();

    /* check to make sure this source wouldn't
    ** be over the limit
    */
    global_lock();
    if (global.sources >= source_limit) {
        INFO1("Source (%s) logged in, but there are too many sources", mount);
        global_unlock();
        return 0;
    }
    global.sources++;
    global_unlock();

    stats_event_inc(NULL, "sources");
    
    config = config_get_config();
    mountproxy = config->mounts;
    thread_mutex_lock(&(config_locks()->mounts_lock));
    config_release_config();

    while(mountproxy) {
        if(!strcmp(mountproxy->mountname, mount)) {
            mountinfo = mountproxy;
            break;
        }
        mountproxy = mountproxy->next;
    }

    contenttype = httpp_getvar(parser, "content-type");

    if (contenttype != NULL) {
        format_type_t format = format_get_type(contenttype);
        if (format == FORMAT_ERROR) {
            WARN1("Content-type \"%s\" not supported, dropping source", contenttype);
            thread_mutex_unlock(&(config_locks()->mounts_lock));
            goto fail;
        } else {
            source = source_create(client, con, parser, mount, 
                    format, mountinfo);
            thread_mutex_unlock(&(config_locks()->mounts_lock));
        }
    } else {
        format_type_t format = FORMAT_TYPE_MP3;
        ERROR0("No content-type header, falling back to backwards compatibility mode for icecast 1.x relays. Assuming content is mp3.");
        source = source_create(client, con, parser, mount, format, mountinfo);
        thread_mutex_unlock(&(config_locks()->mounts_lock));
    }

    source->send_return = 1;
    source->shutdown_rwlock = &_source_shutdown_rwlock;
    sock_set_blocking(con->sock, SOCK_NONBLOCK);
    thread_create("Source Thread", source_main, (void *)source, THREAD_DETACHED);
    return 1;

fail:
    global_lock();
    global.sources--;
    global_unlock();

    stats_event_dec(NULL, "sources");
    return 0;
}

static int _check_pass_http(http_parser_t *parser, 
        char *correctuser, char *correctpass)
{
    /* This will look something like "Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==" */
    char *header = httpp_getvar(parser, "authorization");
    char *userpass, *tmp;
    char *username, *password;

    if(header == NULL)
        return 0;

    if(strncmp(header, "Basic ", 6))
        return 0;

    userpass = util_base64_decode(header+6);
    if(userpass == NULL) {
        WARN1("Base64 decode of Authorization header \"%s\" failed",
                header+6);
        return 0;
    }

    tmp = strchr(userpass, ':');
    if(!tmp) {
        free(userpass);
        return 0;
    }
    *tmp = 0;
    username = userpass;
    password = tmp+1;

    if(strcmp(username, correctuser) || strcmp(password, correctpass)) {
        free(userpass);
        return 0;
    }
    free(userpass);

    return 1;
}

static int _check_pass_icy(http_parser_t *parser, char *correctpass)
{
    char *password;

    password = httpp_getvar(parser, HTTPP_VAR_ICYPASSWORD);
    if(!password)
        return 0;

    if (strcmp(password, correctpass))
        return 0;
    else
        return 1;
}

static int _check_pass_ice(http_parser_t *parser, char *correctpass)
{
    char *password;

    password = httpp_getvar(parser, "ice-password");
    if(!password)
        password = "";

    if (strcmp(password, correctpass))
        return 0;
    else
        return 1;
}

int connection_check_admin_pass(http_parser_t *parser)
{
    ice_config_t *config = config_get_config();
    char *pass = config->admin_password;
    char *user = config->admin_username;
    config_release_config();

    if(!pass || !user)
        return 0;

    return _check_pass_http(parser, user, pass);
}

int connection_check_source_pass(http_parser_t *parser, char *mount)
{
    ice_config_t *config = config_get_config();
    char *pass = config->source_password;
    char *user = "source";
    int ret;
    int ice_login = config->ice_login;
    char *protocol;

    mount_proxy *mountinfo = config->mounts;
    thread_mutex_lock(&(config_locks()->mounts_lock));
    config_release_config();

    while(mountinfo) {
        if(!strcmp(mountinfo->mountname, mount)) {
            if(mountinfo->password)
                pass = mountinfo->password;
            if(mountinfo->username)
                user = mountinfo->username;
            break;
        }
        mountinfo = mountinfo->next;
    }

    thread_mutex_unlock(&(config_locks()->mounts_lock));

    if(!pass) {
        WARN0("No source password set, rejecting source");
        return 0;
    }

    protocol = httpp_getvar(parser, HTTPP_VAR_PROTOCOL);
    if(protocol != NULL && !strcmp(protocol, "ICY")) {
        ret = _check_pass_icy(parser, pass);
    }
    else {
        ret = _check_pass_http(parser, user, pass);
        if(!ret && ice_login)
        {
            ret = _check_pass_ice(parser, pass);
            if(ret)
                WARN0("Source is using deprecated icecast login");
        }
    }
    return ret;
}

static void _handle_source_request(connection_t *con, 
        http_parser_t *parser, char *uri)
{
    client_t *client;

    client = client_create(con, parser);

    INFO1("Source logging in at mountpoint \"%s\"", uri);
    stats_event_inc(NULL, "source_connections");
                
    if (!connection_check_source_pass(parser, uri)) {
        INFO1("Source (%s) attempted to login with invalid or missing password", uri);
        client_send_401(client);
        return;
    }

    /* check to make sure this source has
    ** a unique mountpoint
    */

    avl_tree_rlock(global.source_tree);
    if (source_find_mount(uri) != NULL) {
        avl_tree_unlock(global.source_tree);
        INFO1("Source tried to log in as %s, but mountpoint is already used", uri);
        client_send_404(client, "Mountpoint in use");
        return;
    }
    avl_tree_unlock(global.source_tree);

    if (!connection_create_source(client, con, parser, uri)) {
        client_send_404(client, "Mountpoint in use");
    }
}

static void _handle_stats_request(connection_t *con, 
        http_parser_t *parser, char *uri)
{
    stats_connection_t *stats;

    stats_event_inc(NULL, "stats_connections");
                
    if (!connection_check_admin_pass(parser)) {
        ERROR0("Bad password for stats connection");
        connection_close(con);
        httpp_destroy(parser);
        return;
    }
                    
    stats_event_inc(NULL, "stats");
                    
    /* create stats connection and create stats handler thread */
    stats = (stats_connection_t *)malloc(sizeof(stats_connection_t));
    stats->parser = parser;
    stats->con = con;
                    
    thread_create("Stats Connection", stats_connection, (void *)stats, THREAD_DETACHED);
}

static void _handle_get_request(connection_t *con,
        http_parser_t *parser, char *uri)
{
    char *fullpath;
    client_t *client;
    int bytes;
    struct stat statbuf;
    source_t *source;
    int fileserve;
    char *host;
    int port;
    ice_config_t *config;
    int client_limit;

    config = config_get_config();
    fileserve = config->fileserve;
    host = config->hostname;
    port = config->port;
    client_limit = config->client_limit;
    config_release_config();


    DEBUG0("Client connected");

    /* make a client */
    client = client_create(con, parser);
    stats_event_inc(NULL, "client_connections");
                    
    /* there are several types of HTTP GET clients
    ** media clients, which are looking for a source (eg, URI = /stream.ogg)
    ** stats clients, which are looking for /admin/stats.xml
    ** and director server authorizers, which are looking for /GUID-xxxxxxxx 
    ** (where xxxxxx is the GUID in question) - this isn't implemented yet.
    ** we need to handle the latter two before the former, as the latter two
    ** aren't subject to the limits.
    */
    /* TODO: add GUID-xxxxxx */

    /* Dispatch all admin requests */
    if (strncmp(uri, "/admin/", 7) == 0) {
        admin_handle_request(client, uri);
        return;
    }

    /* Here we are parsing the URI request to see
    ** if the extension is .xsl, if so, then process
    ** this request as an XSLT request
    */
    fullpath = util_get_path_from_normalised_uri(uri);
    if (util_check_valid_extension(fullpath) == XSLT_CONTENT) {
        /* If the file exists, then transform it, otherwise, write a 404 */
        if (stat(fullpath, &statbuf) == 0) {
            DEBUG0("Stats request, sending XSL transformed stats");
            client->respcode = 200;
            bytes = sock_write(client->con->sock, 
                    "HTTP/1.0 200 OK\r\nContent-Type: text/html\r\n\r\n");
            if(bytes > 0) client->con->sent_bytes = bytes;
            stats_transform_xslt(client, fullpath);
            client_destroy(client);
        }
        else {
            client_send_404(client, "The file you requested could not be found");
        }
        free(fullpath);
        return;
    }
    else if(fileserve && stat(fullpath, &statbuf) == 0) 
    {
        fserve_client_create(client, fullpath);
        free(fullpath);
        return;
    }
    free(fullpath);

    if(strcmp(util_get_extension(uri), "m3u") == 0) {
        char *sourceuri = strdup(uri);
        char *dot = strrchr(sourceuri, '.');
        *dot = 0;
        avl_tree_rlock(global.source_tree);
        source = source_find_mount(sourceuri);
           if (source) {
            client->respcode = 200;
            bytes = sock_write(client->con->sock,
                    "HTTP/1.0 200 OK\r\n"
                    "Content-Type: audio/x-mpegurl\r\n\r\n"
                    "http://%s:%d%s", 
                    host, 
                    port,
                    sourceuri
                    );
            if(bytes > 0) client->con->sent_bytes = bytes;
            client_destroy(client);
        }
        else if(fileserve) {
            fullpath = util_get_path_from_normalised_uri(sourceuri);
            if(stat(fullpath, &statbuf) == 0) {
                fserve_client_create(client, fullpath);
                free(fullpath);
            }
            else {
                free(fullpath);
                fullpath = util_get_path_from_normalised_uri(uri);
                if(stat(fullpath, &statbuf) == 0) {
                    fserve_client_create(client, fullpath);
                    free(fullpath);
                }
                else {
                    free(fullpath);
                    client_send_404(client, 
                            "The file you requested could not be found");
                }
            }
        }
        else {
            client_send_404(client, "The file you requested could not be found");
        }
        avl_tree_unlock(global.source_tree);
        free(sourceuri);
        return;
    }

    global_lock();
    if (global.clients >= client_limit) {
        client_send_504(client,
                "The server is already full. Try again later.");
        global_unlock();
        return;
    }
    global_unlock();
                    
    avl_tree_rlock(global.source_tree);
    source = source_find_mount(uri);
    if (source) {
        DEBUG0("Source found for client");
                        
        global_lock();
        if (global.clients >= client_limit) {
            client_send_504(client, 
                    "The server is already full. Try again later.");
            global_unlock();
            avl_tree_unlock(global.source_tree);
            return;
        }
        else if(source->max_listeners != -1 && 
                source->listeners >= source->max_listeners) 
        {
            client_send_504(client, 
                    "Too many clients on this mountpoint. Try again later.");
            global_unlock();
            avl_tree_unlock(global.source_tree);
            return;
        }
        global.clients++;
        global_unlock();
                        
        client->format_data = source->format->create_client_data(
                source->format, source, client);

        source->format->client_send_headers(source->format, source, client);
                        
        bytes = sock_write(client->con->sock, "\r\n");
        if(bytes > 0) client->con->sent_bytes += bytes;
                            
        sock_set_blocking(client->con->sock, SOCK_NONBLOCK);
        sock_set_nodelay(client->con->sock);
                        
        avl_tree_wlock(source->pending_tree);
        avl_insert(source->pending_tree, (void *)client);
        avl_tree_unlock(source->pending_tree);
    }
                    
    avl_tree_unlock(global.source_tree);
                    
    if (!source) {
        DEBUG0("Source not found for client");
        client_send_404(client, "The source you requested could not be found.");
    }
}

static void *_handle_connection(void *arg)
{
    char header[4096];
    connection_t *con;
    http_parser_t *parser;
    char *rawuri, *uri;
    client_t *client;

    while (global.running == ICE_RUNNING) {
        memset(header, 0, 4096);

        thread_cond_wait(&_pool_cond);
        if (global.running != ICE_RUNNING) break;

        /* grab a connection and set the socket to blocking */
        while ((con = _get_connection())) {

            /* Handle meta-connections */
            if(con->event_number > 0) {
                switch(con->event_number) {
                    case EVENT_CONFIG_READ:
                        event_config_read(con->event);
                        break;
                    default:
                        ERROR1("Unknown event number: %d", con->event_number);
                        break;
                }
                free(con);
                continue;
            }

            stats_event_inc(NULL, "connections");

            sock_set_blocking(con->sock, SOCK_BLOCK);

            /* fill header with the http header */
            if (util_read_header(con->sock, header, 4096) == 0) {
                /* either we didn't get a complete header, or we timed out */
                connection_close(con);
                continue;
            }

            parser = httpp_create_parser();
            httpp_initialize(parser, NULL);
            if (httpp_parse(parser, header, strlen(header))) {
                /* handle the connection or something */
                
                if (strcmp("ICE",  httpp_getvar(parser, HTTPP_VAR_PROTOCOL)) &&
                    strcmp("HTTP", httpp_getvar(parser, HTTPP_VAR_PROTOCOL))) {
                    ERROR0("Bad HTTP protocol detected");
                    connection_close(con);
                    httpp_destroy(parser);
                    continue;
                }

                rawuri = httpp_getvar(parser, HTTPP_VAR_URI);
                uri = util_normalise_uri(rawuri);

                if(!uri) {
                    client = client_create(con, parser);
                    client_send_404(client, "The path you requested was invalid");
                    continue;
                }

                if (parser->req_type == httpp_req_source) {
                    _handle_source_request(con, parser, uri);
                }
                else if (parser->req_type == httpp_req_stats) {
                    _handle_stats_request(con, parser, uri);
                }
                else if (parser->req_type == httpp_req_get) {
                    _handle_get_request(con, parser, uri);
                }
                else {
                    ERROR0("Wrong request type from client");
                    connection_close(con);
                    httpp_destroy(parser);
                }

                free(uri);
            } 
            else if(httpp_parse_icy(parser, header, strlen(header))) {
                /* TODO: Map incoming icy connections to /icy_0, etc. */
                char mount[20];
                int i = 0;

                strcpy(mount, "/");

                avl_tree_rlock(global.source_tree);
                while(source_find_mount(mount) != NULL) {
                    sprintf(mount, "/icy_%d", i++);
                }
                avl_tree_unlock(global.source_tree);

                _handle_source_request(con, parser, mount);
            }
            else {
                ERROR0("HTTP request parsing failed");
                connection_close(con);
                httpp_destroy(parser);
                continue;
            }
        }
    }

    thread_exit(0);

    return NULL;
}

void connection_close(connection_t *con)
{
    sock_close(con->sock);
    if (con->ip) free(con->ip);
    if (con->host) free(con->host);
    free(con);
}