[paraslash.git] / udp_send.c

/*
 * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
 *
 * Licensed under the GPL v2. For licencing details see COPYING.
 */

/** \file udp_send.c Para_server's udp sender. */


#include <sys/time.h>
#include <dirent.h>

#include "server.cmdline.h"
#include "para.h"
#include "error.h"
#include "string.h"
#include "afh.h"
#include "afs.h"
#include "server.h"
#include "vss.h"
#include "list.h"
#include "send.h"
#include "portable_io.h"
#include "udp_header.h"
#include "net.h"
#include "fd.h"
#include "sched.h"
#include "close_on_fork.h"
#include "chunk_queue.h"

/** Describes one entry in the list of targets for the udp sender. */
struct udp_target {
        /** The position of this target in the list of targets. */
        struct list_head node;
        /** The hostname (DNS name or IPv4/v6 address string). */
        char host[MAX_HOSTLEN];
        /** The UDP port. */
        int port;
        /** The socket fd. */
        int fd;
        /** The list of queued chunks for this fd. */
        struct chunk_queue *cq;
};

static struct list_head targets;
static int sender_status;

static void udp_close_target(struct udp_target *ut)
{
        if (ut->fd < 0)
                return;
        close(ut->fd);
        del_close_on_fork_list(ut->fd);
        cq_destroy(ut->cq);
        ut->cq = NULL;
        ut->fd = -1;
}

static void udp_delete_target(struct udp_target *ut, const char *msg)
{
        PARA_NOTICE_LOG("deleting %s#%d (%s) from list\n", ut->host,
                ut->port, msg);
        udp_close_target(ut);
        list_del(&ut->node);
        free(ut);
}

/**
 * Perform AF-independent multicast sender setup.
 *
 * \param fd    The connected socket descriptor.
 * \param ttl   UDPv4 multicast TTL or UDPv6 multicast number of hops.
 *              Use -1 to mean default, 0..255 otherwise.
 * \param iface The outgoing multicast interface, or NULL for the default.
 *
 * \return Zero if okay, negative on error.
 */
static int mcast_sender_setup(struct udp_target *ut, int ttl, char *iface)
{
        struct sockaddr_storage ss;
        socklen_t sslen = sizeof(ss);

        const int on = 1;
        int id = iface == NULL ? 0 : if_nametoindex(iface);

        if (getpeername(ut->fd, (struct sockaddr *)&ss, &sslen) < 0)
                goto err;

        if (iface != NULL && id == 0)
                PARA_WARNING_LOG("could not resolve interface %s, using default", iface);

        /* RFC 3493, 5.2: -1 means 'use kernel default' */
        if (ttl < 0 || ttl > 255)
                ttl = -1;

        switch (ss.ss_family) {
        case AF_INET:
                if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
                        return 0;
                if (id != 0) {
#ifdef HAVE_IP_MREQN
                        struct ip_mreqn mn;

                        memset(&mn, 0, sizeof(mn));
                        mn.imr_ifindex = id;
                        if (setsockopt(ut->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
                                goto err;
#else
                        PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
#endif
                }
                /*
                 * Enable receiving multicast messages generated on the local host
                 * At least on Linux, this is enabled by default.
                 */
                if (setsockopt(ut->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
                        break;

                /* Default: use local subnet (do not flood out into the WAN) */
                if (ttl == -1)
                        ttl = 1;
                if (setsockopt(ut->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
                        break;
                return 0;
        case AF_INET6:
                if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
                        return 0;
                if (id != 0 &&
                    setsockopt(ut->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
                        break;
                if (setsockopt(ut->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
                        break;
                if (setsockopt(ut->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
                        break;
                return 0;
        default:
                PARA_ERROR_LOG("address family %d not supported", ss.ss_family);
                return -E_ADDRESS_LOOKUP;
        }
err:
        return -ERRNO_TO_PARA_ERROR(errno);
}

/** The maximal size of the per-target chunk queue. */
#define UDP_CQ_BYTES 40000

static int udp_init_session(struct udp_target *ut)
{
        int ret;
        char *iface = NULL;

        if (ut->fd >= 0) /* nothing to do */
                return 0;

        ret = makesock(AF_UNSPEC, IPPROTO_UDP, 0, ut->host, ut->port);
        if (ret < 0)
                return ret;
        ut->fd = ret;

        if (conf.udp_mcast_iface_given)
                iface = conf.udp_mcast_iface_arg;

        ret = mcast_sender_setup(ut, conf.udp_ttl_arg, iface);
        if (ret < 0) {
                close(ut->fd);
                return ret;
        }

        ret = mark_fd_nonblocking(ut->fd);
        if (ret < 0) {
                close(ut->fd);
                return ret;
        }
        add_close_on_fork_list(ut->fd);
        ut->cq = cq_new(UDP_CQ_BYTES);
        PARA_NOTICE_LOG("sending to udp %s#%d\n", ut->host, ut->port);
        return 1;
}

static void udp_send_buf(char *buf, size_t len)
{
        struct udp_target *ut, *tmp;
        int ret;

        list_for_each_entry_safe(ut, tmp, &targets, node) {
                ret = udp_init_session(ut);
                if (ret < 0) {
                        udp_delete_target(ut, para_strerror(-ret));
                        continue;
                }
                ret = send_queued_chunks(ut->fd, ut->cq, 0);
                if (ret < 0) {
                        udp_delete_target(ut, para_strerror(-ret));
                        continue;
                }
                if (!len)
                        continue;
                if (!ret) { /* still data left in the queue */
                        ret = cq_enqueue(ut->cq, buf, len);
                        if (ret < 0) {
                                udp_delete_target(ut, para_strerror(-ret));
                                continue;
                        }
                }
                ret = write_nonblock(ut->fd, buf, len, 0);
                if (ret < 0) {
                        udp_delete_target(ut, para_strerror(-ret));
                        continue;
                }
                if (ret != len) {
                        ret = cq_enqueue(ut->cq, buf + ret, len - ret);
                        if (ret < 0) {
                                udp_delete_target(ut, para_strerror(-ret));
                                continue;
                        }
                }
        }
}

static void udp_shutdown_targets(void)
{
        char buf[UDP_AUDIO_HEADER_LEN];
        struct udp_target *ut, *tmp;
        struct udp_audio_header uah = {
                .stream_type = UDP_UNKNOWN_STREAM,
                .packet_type = UDP_EOF_PACKET,
        };

        write_udp_audio_header(buf, &uah);
        list_for_each_entry_safe(ut, tmp, &targets, node) {
                if (ut->fd < 0)
                        continue;
                write(ut->fd, buf, UDP_AUDIO_HEADER_LEN);
                udp_close_target(ut);
        }
}

static int need_extra_header(long unsigned current_chunk)
{
        static struct timeval last_header;
        struct timeval diff;

        if (!current_chunk)
                return 0;
        tv_diff(now, &last_header, &diff);
        if (tv2ms(&diff) < conf.udp_header_interval_arg)
                return 0;
        last_header = *now;
        return 1;
}

static void udp_send(long unsigned current_chunk, __a_unused long unsigned chunks_sent,
                const char *buf, size_t len, const char *header_buf,
                size_t header_len)
{
        char *sendbuf;
        size_t sendbuf_len;
        struct timeval *chunk_tv;
        struct udp_audio_header uah;

//      PARA_NOTICE_LOG("len: %zd, header_len: %zd\n", len, header_len);
        if (sender_status != SENDER_ON)
                return;

        /* we might not yet know the chunk time */
        chunk_tv = vss_chunk_time();
        if (!chunk_tv)
                return;
        if (list_empty(&targets))
                return;
        uah.stream_type = header_len? UDP_HEADER_STREAM : UDP_PLAIN_STREAM;
        uah.header_len = need_extra_header(current_chunk)? header_len : 0;
        if (!current_chunk)
                uah.packet_type = UDP_BOF_PACKET;
        else if (uah.header_len)
                uah.packet_type = UDP_HEADER_PACKET;
        else
                uah.packet_type = UDP_DATA_PACKET;
        uah.payload_len = uah.header_len + len;
        sendbuf_len = UDP_AUDIO_HEADER_LEN + uah.payload_len;
        sendbuf = para_malloc(sendbuf_len);
        write_udp_audio_header(sendbuf, &uah);
        if (uah.header_len)
                memcpy(sendbuf + UDP_AUDIO_HEADER_LEN, header_buf,
                        uah.header_len);
        memcpy(sendbuf + UDP_AUDIO_HEADER_LEN + uah.header_len, buf, len);
        udp_send_buf(sendbuf, sendbuf_len);
        free(sendbuf);
}

static int udp_com_on(__a_unused struct sender_command_data *scd)
{
        sender_status = SENDER_ON;
        return 1;
}

static int udp_com_off(__a_unused struct sender_command_data *scd)
{
        udp_shutdown_targets();
        sender_status = SENDER_OFF;
        return 1;
}

static int udp_com_delete(struct sender_command_data *scd)
{
        struct udp_target *ut, *tmp;

        list_for_each_entry_safe(ut, tmp, &targets, node) {
                /* Unspecified port means wildcard port match */
                if (scd->port > 0 && scd->port != ut->port)
                        continue;
                if (strcmp(ut->host, scd->host))
                        continue;
                udp_delete_target(ut, "com_delete");
        }
        return 1;
}

static void udp_add_target(const char *host, int port)
{
        struct udp_target *ut = para_calloc(sizeof(struct udp_target));

        strncpy(ut->host, host, sizeof(ut->host));
        ut->port = port > 0 ? port : conf.udp_default_port_arg;
        ut->fd = -1; /* not yet connected */
        PARA_INFO_LOG("adding to target list (%s#%d)\n",
                      ut->host, ut->port);
        para_list_add(&ut->node, &targets);
}

static int udp_com_add(struct sender_command_data *scd)
{
        udp_add_target(scd->host, scd->port);
        return 1;
}

static char *udp_info(void)
{
        struct udp_target *ut;
        char *ret, *tgts = NULL;

        list_for_each_entry(ut, &targets, node) {
                bool is_v6 = strchr(ut->host, ':') != NULL;
                char *tmp = make_message("%s%s%s%s:%d ", tgts ? : "",
                                         is_v6 ? "[" : "", ut->host,
                                         is_v6 ? "]" : "", ut->port);
                free(tgts);
                tgts = tmp;
        }
        ret = make_message(
                "udp sender:\n"
                "\tstatus: %s\n"
                "\tport: udp %d\n"
                "\ttargets: %s\n",
                (sender_status == SENDER_ON)? "on" : "off",
                conf.udp_default_port_arg,
                tgts? tgts : "(none)"
        );
        free(tgts);
        return ret;
}

static void udp_init_target_list(void)
{
        char    host[MAX_HOSTLEN];
        int     port, i;

        INIT_LIST_HEAD(&targets);
        for (i = 0; i < conf.udp_target_given; i++)
                if (parse_url(conf.udp_target_arg[i], host,
                                        sizeof(host), &port) == NULL)
                        PARA_CRIT_LOG("syntax error for udp target option "
                                      "#%d, ignoring\n", i);
                else
                        udp_add_target(host, port);
}

static char *udp_help(void)
{
        return make_message(
                "usage: {on|off}\n"
                "usage: {add|delete} host[:port]\n"
                "examples: add 224.0.1.38:1500  (IPv4 multicast)\n"
                "          add 10.10.1.42       (using default port)\n"
                "          add [FF05::42]:1500  (IPv6 multicast)\n"
                "          add [::1]            (IPv6 localhost/default port)\n"
                "          delete myhost.net    (host with port wildcard)\n"
                "          delete [badc0de::1]  (IPv6 with port wildcard)\n"
        );
}

/**
 * The init function of para_server's udp sender.
 *
 * \param s Pointer to the http sender struct.
 *
 * It initializes all function pointers of \a s and the list of udp targets.
 */
void udp_send_init(struct sender *s)
{
        INIT_LIST_HEAD(&targets);
        s->info = udp_info;
        s->help = udp_help;
        s->send = udp_send;
        s->pre_select = NULL;
        s->post_select = NULL;
        s->shutdown_clients = udp_shutdown_targets;
        s->client_cmds[SENDER_ON] = udp_com_on;
        s->client_cmds[SENDER_OFF] = udp_com_off;
        s->client_cmds[SENDER_DENY] = NULL;
        s->client_cmds[SENDER_ALLOW] = NULL;
        s->client_cmds[SENDER_ADD] = udp_com_add;
        s->client_cmds[SENDER_DELETE] = udp_com_delete;
        sender_status = SENDER_OFF;
        udp_init_target_list();
        if (!conf.udp_no_autostart_given)
                sender_status = SENDER_ON;
        PARA_DEBUG_LOG("udp sender init complete\n");
}