PeerStreamer

/*

 * TCP protocol

 * Copyright (c) 2002 Fabrice Bellard

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg 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 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include "avformat.h"

#include <unistd.h>

#include "internal.h"

#include "network.h"

#include "os_support.h"

#if HAVE_POLL_H

#include <poll.h>

#endif

#include <sys/time.h>

typedef struct TCPContext {

    int fd;

} TCPContext;

/* return non zero if error */

static int tcp_open(URLContext *h, const char *uri, int flags)

{

    struct addrinfo hints, *ai, *cur_ai;

    int port, fd = -1;

    TCPContext *s = NULL;

    int ret;

    socklen_t optlen;

    char hostname[1024],proto[1024],path[1024];

    char portstr[10];

    av_url_split(proto, sizeof(proto), NULL, 0, hostname, sizeof(hostname),

        &port, path, sizeof(path), uri);

    if (strcmp(proto,"tcp") || port <= 0 || port >= 65536)

        return AVERROR(EINVAL);

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

    hints.ai_family = AF_UNSPEC;

    hints.ai_socktype = SOCK_STREAM;

    snprintf(portstr, sizeof(portstr), "%d", port);

    ret = getaddrinfo(hostname, portstr, &hints, &ai);

    if (ret) {

        av_log(NULL, AV_LOG_ERROR,

               "Failed to resolve hostname %s: %s\n",

               hostname, gai_strerror(ret));

        return AVERROR(EIO);

    }

    cur_ai = ai;

 restart:

    fd = socket(cur_ai->ai_family, cur_ai->ai_socktype, cur_ai->ai_protocol);

    if (fd < 0)

        goto fail;

    ff_socket_nonblock(fd, 1);

 redo:

    ret = connect(fd, cur_ai->ai_addr, cur_ai->ai_addrlen);

    if (ret < 0) {

        struct pollfd p = {fd, POLLOUT, 0};

        if (ff_neterrno() == AVERROR(EINTR)) {

            if (url_interrupt_cb()) {

                ret = AVERROR_EXIT;

                goto fail1;

            }

            goto redo;

        }

        if (ff_neterrno() != AVERROR(EINPROGRESS) &&

            ff_neterrno() != AVERROR(EAGAIN))

            goto fail;

        /* wait until we are connected or until abort */

        for(;;) {

            if (url_interrupt_cb()) {

                ret = AVERROR_EXIT;

                goto fail1;

            }

            ret = poll(&p, 1, 100);

            if (ret > 0)

                break;

        }

        /* test error */

        optlen = sizeof(ret);

        getsockopt (fd, SOL_SOCKET, SO_ERROR, &ret, &optlen);

        if (ret != 0) {

            av_log(NULL, AV_LOG_ERROR,

                   "TCP connection to %s:%d failed: %s\n",

                   hostname, port, strerror(ret));

            goto fail;

        }

    }

    s = av_malloc(sizeof(TCPContext));

    if (!s) {

        freeaddrinfo(ai);

        return AVERROR(ENOMEM);

    }

    h->priv_data = s;

    h->is_streamed = 1;

    s->fd = fd;

    freeaddrinfo(ai);

    return 0;

 fail:

    if (cur_ai->ai_next) {

        /* Retry with the next sockaddr */

        cur_ai = cur_ai->ai_next;

        if (fd >= 0)

            closesocket(fd);

        goto restart;

    }

    ret = AVERROR(EIO);

 fail1:

    if (fd >= 0)

        closesocket(fd);

    freeaddrinfo(ai);

    return ret;

}

static int tcp_wait_fd(int fd, int write)

{

    int ev = write ? POLLOUT : POLLIN;

    struct pollfd p = { .fd = fd, .events = ev, .revents = 0 };

    int ret;

    ret = poll(&p, 1, 100);

    return ret < 0 ? ff_neterrno() : p.revents & ev ? 0 : AVERROR(EAGAIN);

}

static int tcp_read(URLContext *h, uint8_t *buf, int size)

{

    TCPContext *s = h->priv_data;

    int ret;

    if (!(h->flags & URL_FLAG_NONBLOCK)) {

        ret = tcp_wait_fd(s->fd, 0);

        if (ret < 0)

            return ret;

    }

    ret = recv(s->fd, buf, size, 0);

    return ret < 0 ? ff_neterrno() : ret;

}

static int tcp_write(URLContext *h, const uint8_t *buf, int size)

{

    TCPContext *s = h->priv_data;

    int ret;

    if (!(h->flags & URL_FLAG_NONBLOCK)) {

        ret = tcp_wait_fd(s->fd, 1);

        if (ret < 0)

            return ret;

    }

    ret = send(s->fd, buf, size, 0);

    return ret < 0 ? ff_neterrno() : ret;

}

static int tcp_close(URLContext *h)

{

    TCPContext *s = h->priv_data;

    closesocket(s->fd);

    av_free(s);

    return 0;

}

static int tcp_get_file_handle(URLContext *h)

{

    TCPContext *s = h->priv_data;

    return s->fd;

}

URLProtocol ff_tcp_protocol = {

    "tcp",

    tcp_open,

    tcp_read,

    tcp_write,

    NULL, /* seek */

    tcp_close,

    .url_get_file_handle = tcp_get_file_handle,

};