pulseaudio/src/modules/module-raop-sink.c

/* $Id$ */

/***
  This file is part of PulseAudio.

  Copyright 2004-2006 Lennart Poettering
  Copyright 2008      Colin Guthrie

  PulseAudio is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published
  by the Free Software Foundation; either version 2 of the License,
  or (at your option) any later version.

  PulseAudio is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with PulseAudio; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  USA.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>
#include <sys/stat.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <limits.h>
#include <sys/ioctl.h>
#include <poll.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include <openssl/aes.h>
#include <openssl/rsa.h>
#include <openssl/engine.h>

#include <pulse/xmalloc.h>

#include <pulsecore/core-error.h>
#include <pulsecore/sink.h>
#include <pulsecore/module.h>
#include <pulsecore/core-util.h>
#include <pulsecore/modargs.h>
#include <pulsecore/log.h>
#include <pulsecore/thread.h>
#include <pulsecore/thread-mq.h>
#include <pulsecore/random.h>
#include <pulsecore/rtpoll.h>

#include "rtp.h"
#include "sdp.h"
#include "sap.h"
#include "rtsp.h"
#include "base64.h"


#include "module-raop-sink-symdef.h"

#define JACK_STATUS_DISCONNECTED 0
#define JACK_STATUS_CONNECTED 1

#define JACK_TYPE_ANALOG 0
#define JACK_TYPE_DIGITAL 1

#define VOLUME_DEF -30
#define VOLUME_MIN -144
#define VOLUME_MAX 0


PA_MODULE_AUTHOR("Colin Guthrie");
PA_MODULE_DESCRIPTION("RAOP Sink (Apple Airport)");
PA_MODULE_VERSION(PACKAGE_VERSION);
PA_MODULE_LOAD_ONCE(FALSE);
PA_MODULE_USAGE(
        "server=<address> "
        "sink_name=<name for the sink> "
        "format=<sample format> "
        "channels=<number of channels> "
        "rate=<sample rate>"
        "channel_map=<channel map>");

#define DEFAULT_SINK_NAME "airtunes"
#define AES_CHUNKSIZE 16

struct userdata {
    pa_core *core;
    pa_module *module;
    pa_sink *sink;

    pa_thread *thread;
    pa_thread_mq thread_mq;
    pa_rtpoll *rtpoll;

    char *server_name;

    // Encryption Related bits
    AES_KEY aes;
    uint8_t aes_iv[AES_CHUNKSIZE]; // initialization vector for aes-cbc
    uint8_t aes_nv[AES_CHUNKSIZE]; // next vector for aes-cbc
    uint8_t aes_key[AES_CHUNKSIZE]; // key for aes-cbc

    pa_rtsp_context *rtsp;
    //pa_socket_client *client;
    pa_memchunk memchunk;

    pa_rtpoll_item *rtpoll_item;
};

static const char* const valid_modargs[] = {
    "server",
    "rate",
    "format",
    "channels",
    "sink_name",
    "channel_map",
    NULL
};

static int rsa_encrypt(uint8_t *text, int len, uint8_t *res) {
    char n[] =
        "59dE8qLieItsH1WgjrcFRKj6eUWqi+bGLOX1HL3U3GhC/j0Qg90u3sG/1CUtwC"
        "5vOYvfDmFI6oSFXi5ELabWJmT2dKHzBJKa3k9ok+8t9ucRqMd6DZHJ2YCCLlDR"
        "KSKv6kDqnw4UwPdpOMXziC/AMj3Z/lUVX1G7WSHCAWKf1zNS1eLvqr+boEjXuB"
        "OitnZ/bDzPHrTOZz0Dew0uowxf/+sG+NCK3eQJVxqcaJ/vEHKIVd2M+5qL71yJ"
        "Q+87X6oV3eaYvt3zWZYD6z5vYTcrtij2VZ9Zmni/UAaHqn9JdsBWLUEpVviYnh"
        "imNVvYFZeCXg/IdTQ+x4IRdiXNv5hEew==";
    char e[] = "AQAB";
    uint8_t modules[256];
    uint8_t exponent[8];
    int size;
    RSA *rsa;

    rsa = RSA_new();
    size = pa_base64_decode(n, modules);
    rsa->n = BN_bin2bn(modules, size, NULL);
    size = pa_base64_decode(e, exponent);
    rsa->e = BN_bin2bn(exponent, size, NULL);

    size = RSA_public_encrypt(len, text, res, rsa, RSA_PKCS1_OAEP_PADDING);
    RSA_free(rsa);
    return size;
}

static int aes_encrypt(struct userdata *u, uint8_t *data, int size)
{
    uint8_t *buf;
    int i=0, j;

    pa_assert(u);

    memcpy(u->aes_nv, u->aes_iv, AES_CHUNKSIZE);
    while (i+AES_CHUNKSIZE <= size) {
        buf = data + i;
        for (j=0; j<AES_CHUNKSIZE; ++j)
            buf[j] ^= u->aes_nv[j];

        AES_encrypt(buf, buf, &u->aes);
        memcpy(u->aes_nv, buf, AES_CHUNKSIZE);
        i += AES_CHUNKSIZE;
    }
    return i;
}

static int sink_process_msg(pa_msgobject *o, int code, void *data, int64_t offset, pa_memchunk *chunk) {
    struct userdata *u = PA_SINK(o)->userdata;

    switch (code) {

        case PA_SINK_MESSAGE_GET_LATENCY: {
            size_t n = 0;
            //int l;

#ifdef TIOCINQ
            /*
            if (ioctl(u->fd, TIOCINQ, &l) >= 0 && l > 0)
                n = (size_t) l;
            */
#endif

            n += u->memchunk.length;

            *((pa_usec_t*) data) = pa_bytes_to_usec(n, &u->sink->sample_spec);
            break;
        }
    }

    return pa_sink_process_msg(o, code, data, offset, chunk);
}

static void thread_func(void *userdata) {
    struct userdata *u = userdata;
    //int write_type = 0;

    pa_assert(u);

    pa_log_debug("Thread starting up");

    pa_thread_mq_install(&u->thread_mq);
    pa_rtpoll_install(u->rtpoll);

    for (;;) {
        struct pollfd *pollfd;
        int ret;

        pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);

        /* Render some data and write it to the fifo */
        if (u->sink->thread_info.state == PA_SINK_RUNNING && pollfd->revents) {
            ssize_t l;
            void *p;

            if (u->memchunk.length <= 0)
                pa_sink_render(u->sink, PIPE_BUF, &u->memchunk);

            pa_assert(u->memchunk.length > 0);

            p = pa_memblock_acquire(u->memchunk.memblock);
            //l = pa_write(u->fd, (uint8_t*) p + u->memchunk.index, u->memchunk.length, &write_type);
            // Fake the length of the "write".
            l = u->memchunk.length;
            pa_memblock_release(u->memchunk.memblock);

            pa_assert(l != 0);

            if (l < 0) {

                if (errno == EINTR)
                    continue;
                else if (errno != EAGAIN) {
                    pa_log("Failed to write data to FIFO: %s", pa_cstrerror(errno));
                    goto fail;
                }

            } else {

                u->memchunk.index += l;
                u->memchunk.length -= l;

                if (u->memchunk.length <= 0) {
                    pa_memblock_unref(u->memchunk.memblock);
                    pa_memchunk_reset(&u->memchunk);
                }

                pollfd->revents = 0;
            }
        }

        /* Hmm, nothing to do. Let's sleep */
        pollfd->events = u->sink->thread_info.state == PA_SINK_RUNNING ? POLLOUT : 0;

        if ((ret = pa_rtpoll_run(u->rtpoll, TRUE)) < 0)
            goto fail;

        if (ret == 0)
            goto finish;

        pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);

        if (pollfd->revents & ~POLLOUT) {
            pa_log("FIFO shutdown.");
            goto fail;
        }
    }

fail:
    /* If this was no regular exit from the loop we have to continue
     * processing messages until we received PA_MESSAGE_SHUTDOWN */
    pa_asyncmsgq_post(u->thread_mq.outq, PA_MSGOBJECT(u->core), PA_CORE_MESSAGE_UNLOAD_MODULE, u->module, 0, NULL, NULL);
    pa_asyncmsgq_wait_for(u->thread_mq.inq, PA_MESSAGE_SHUTDOWN);

finish:
    pa_log_debug("Thread shutting down");
}

int pa__init(pa_module*m) {
    struct userdata *u;
    //struct stat st;
    pa_sample_spec ss;
    pa_channel_map map;
    pa_modargs *ma;
    char *t;
    struct pollfd *pollfd;

    pa_assert(m);

    if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
        pa_log("Failed to parse module arguments.");
        goto fail;
    }

    ss = m->core->default_sample_spec;
    if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) {
        pa_log("Invalid sample format specification or channel map");
        goto fail;
    }

    u = pa_xnew0(struct userdata, 1);
    u->core = m->core;
    u->module = m;
    m->userdata = u;

    // Initialise the AES encryption system
    pa_random_seed();
    pa_random(u->aes_iv, sizeof(u->aes_iv));
    pa_random(u->aes_key, sizeof(u->aes_key));
    memcpy(u->aes_nv, u->aes_iv, sizeof(u->aes_nv));
    AES_set_encrypt_key(u->aes_key, 128, &u->aes);

    pa_memchunk_reset(&u->memchunk);
    pa_thread_mq_init(&u->thread_mq, m->core->mainloop);
    u->rtpoll = pa_rtpoll_new();
    pa_rtpoll_item_new_asyncmsgq(u->rtpoll, PA_RTPOLL_EARLY, u->thread_mq.inq);

    u->server_name = pa_xstrdup(pa_modargs_get_value(ma, "server", NULL));

    // Open a connection to the server... this is just to connect and test....
    /*
    mkfifo(u->filename, 0666);
    if ((u->fd = open(u->filename, O_RDWR|O_NOCTTY)) < 0) {
        pa_log("open('%s'): %s", u->filename, pa_cstrerror(errno));
        goto fail;
    }

    pa_make_fd_cloexec(u->fd);
    pa_make_fd_nonblock(u->fd);

    if (fstat(u->fd, &st) < 0) {
        pa_log("fstat('%s'): %s", u->filename, pa_cstrerror(errno));
        goto fail;
    }

    if (!S_ISFIFO(st.st_mode)) {
        pa_log("'%s' is not a FIFO.", u->filename);
        goto fail;
    }
    */
    if (!(u->sink = pa_sink_new(m->core, __FILE__, pa_modargs_get_value(ma, "sink_name", DEFAULT_SINK_NAME), 0, &ss, &map))) {
        pa_log("Failed to create sink.");
        goto fail;
    }

    u->sink->parent.process_msg = sink_process_msg;
    u->sink->userdata = u;
    u->sink->flags = PA_SINK_LATENCY;

    pa_sink_set_module(u->sink, m);
    pa_sink_set_asyncmsgq(u->sink, u->thread_mq.inq);
    pa_sink_set_rtpoll(u->sink, u->rtpoll);
    pa_sink_set_description(u->sink, t = pa_sprintf_malloc("Airtunes sink '%s'", u->server_name));
    pa_xfree(t);

    u->rtpoll_item = pa_rtpoll_item_new(u->rtpoll, PA_RTPOLL_NEVER, 1);
    pollfd = pa_rtpoll_item_get_pollfd(u->rtpoll_item, NULL);
    //pollfd->fd = u->fd;
    pollfd->events = pollfd->revents = 0;

    if (!(u->thread = pa_thread_new(thread_func, u))) {
        pa_log("Failed to create thread.");
        goto fail;
    }

    pa_sink_put(u->sink);

    pa_modargs_free(ma);

    return 0;

fail:
    if (ma)
        pa_modargs_free(ma);

    pa__done(m);

    return -1;
}

void pa__done(pa_module*m) {
    struct userdata *u;

    pa_assert(m);

    if (!(u = m->userdata))
        return;

    if (u->sink)
        pa_sink_unlink(u->sink);

    if (u->thread) {
        pa_asyncmsgq_send(u->thread_mq.inq, NULL, PA_MESSAGE_SHUTDOWN, NULL, 0, NULL);
        pa_thread_free(u->thread);
    }

    pa_thread_mq_done(&u->thread_mq);

    if (u->sink)
        pa_sink_unref(u->sink);

    if (u->memchunk.memblock)
       pa_memblock_unref(u->memchunk.memblock);

    if (u->rtpoll_item)
        pa_rtpoll_item_free(u->rtpoll_item);

    if (u->rtpoll)
        pa_rtpoll_free(u->rtpoll);

    pa_xfree(u->server_name);
    pa_xfree(u);
}