yading@11: /*
yading@11:  * SCTP protocol
yading@11:  * Copyright (c) 2012 Luca Barbato
yading@11:  *
yading@11:  * This file is part of Libav.
yading@11:  *
yading@11:  * Libav is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * Libav is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with Libav; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: /**
yading@11:  * @file
yading@11:  *
yading@11:  * sctp url_protocol
yading@11:  *
yading@11:  * url syntax: sctp://host:port[?option=val...]
yading@11:  * option: 'listen'        : listen for an incoming connection
yading@11:  *         'max_streams=n' : set the maximum number of streams
yading@11:  *         'reuse=1'       : enable reusing the socket [TBD]
yading@11:  *
yading@11:  * by setting the maximum number of streams the protocol will use the
yading@11:  * first two bytes of the incoming/outgoing buffer to store the
yading@11:  * stream number of the packet being read/written.
yading@11:  * @see sctp_read
yading@11:  * @see sctp_write
yading@11:  */
yading@11: 
yading@11: 
yading@11: #include <netinet/in.h>
yading@11: #include <netinet/sctp.h>
yading@11: 
yading@11: #include "config.h"
yading@11: 
yading@11: #if HAVE_POLL_H
yading@11: #include <poll.h>
yading@11: #endif
yading@11: 
yading@11: #include "libavutil/intreadwrite.h"
yading@11: #include "libavutil/parseutils.h"
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: #include "network.h"
yading@11: #include "os_support.h"
yading@11: #include "url.h"
yading@11: 
yading@11: /*
yading@11:  * The sctp_recvmsg and sctp_sendmsg functions are part of the user
yading@11:  * library that offers support
yading@11:  * for the SCTP kernel Implementation. The main purpose of this
yading@11:  * code is to provide the SCTP Socket API mappings for user
yading@11:  * application to interface with the SCTP in kernel.
yading@11:  *
yading@11:  * This implementation is based on the Socket API Extensions for SCTP
yading@11:  * defined in <draft-ietf-tsvwg-sctpsocket-10.txt>
yading@11:  *
yading@11:  * Copyright (c) 2003 International Business Machines, Corp.
yading@11:  *
yading@11:  * Written or modified by:
yading@11:  *  Ryan Layer <rmlayer@us.ibm.com>
yading@11:  */
yading@11: 
yading@11: static int ff_sctp_recvmsg(int s, void *msg, size_t len, struct sockaddr *from,
yading@11:                            socklen_t *fromlen, struct sctp_sndrcvinfo *sinfo,
yading@11:                            int *msg_flags)
yading@11: {
yading@11:     int recvb;
yading@11:     struct iovec iov;
yading@11:     char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
yading@11:     struct msghdr inmsg  = { 0 };
yading@11:     struct cmsghdr *cmsg = NULL;
yading@11: 
yading@11:     iov.iov_base = msg;
yading@11:     iov.iov_len  = len;
yading@11: 
yading@11:     inmsg.msg_name       = from;
yading@11:     inmsg.msg_namelen    = fromlen ? *fromlen : 0;
yading@11:     inmsg.msg_iov        = &iov;
yading@11:     inmsg.msg_iovlen     = 1;
yading@11:     inmsg.msg_control    = incmsg;
yading@11:     inmsg.msg_controllen = sizeof(incmsg);
yading@11: 
yading@11:     if ((recvb = recvmsg(s, &inmsg, msg_flags ? *msg_flags : 0)) < 0)
yading@11:         return recvb;
yading@11: 
yading@11:     if (fromlen)
yading@11:         *fromlen   = inmsg.msg_namelen;
yading@11:     if (msg_flags)
yading@11:         *msg_flags = inmsg.msg_flags;
yading@11: 
yading@11:     for (cmsg = CMSG_FIRSTHDR(&inmsg); cmsg != NULL;
yading@11:          cmsg = CMSG_NXTHDR(&inmsg, cmsg)) {
yading@11:         if ((IPPROTO_SCTP == cmsg->cmsg_level) &&
yading@11:             (SCTP_SNDRCV  == cmsg->cmsg_type))
yading@11:             break;
yading@11:     }
yading@11: 
yading@11:     /* Copy sinfo. */
yading@11:     if (cmsg)
yading@11:         memcpy(sinfo, CMSG_DATA(cmsg), sizeof(struct sctp_sndrcvinfo));
yading@11: 
yading@11:     return recvb;
yading@11: }
yading@11: 
yading@11: static int ff_sctp_send(int s, const void *msg, size_t len,
yading@11:                         const struct sctp_sndrcvinfo *sinfo, int flags)
yading@11: {
yading@11:     struct msghdr outmsg;
yading@11:     struct iovec iov;
yading@11: 
yading@11:     outmsg.msg_name       = NULL;
yading@11:     outmsg.msg_namelen    = 0;
yading@11:     outmsg.msg_iov        = &iov;
yading@11:     iov.iov_base          = (void*)msg;
yading@11:     iov.iov_len           = len;
yading@11:     outmsg.msg_iovlen     = 1;
yading@11:     outmsg.msg_controllen = 0;
yading@11: 
yading@11:     if (sinfo) {
yading@11:         char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
yading@11:         struct cmsghdr *cmsg;
yading@11: 
yading@11:         outmsg.msg_control    = outcmsg;
yading@11:         outmsg.msg_controllen = sizeof(outcmsg);
yading@11:         outmsg.msg_flags      = 0;
yading@11: 
yading@11:         cmsg             = CMSG_FIRSTHDR(&outmsg);
yading@11:         cmsg->cmsg_level = IPPROTO_SCTP;
yading@11:         cmsg->cmsg_type  = SCTP_SNDRCV;
yading@11:         cmsg->cmsg_len   = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
yading@11: 
yading@11:         outmsg.msg_controllen = cmsg->cmsg_len;
yading@11:         memcpy(CMSG_DATA(cmsg), sinfo, sizeof(struct sctp_sndrcvinfo));
yading@11:     }
yading@11: 
yading@11:     return sendmsg(s, &outmsg, flags);
yading@11: }
yading@11: 
yading@11: typedef struct SCTPContext {
yading@11:     int fd;
yading@11:     int max_streams;
yading@11:     struct sockaddr_storage dest_addr;
yading@11:     socklen_t dest_addr_len;
yading@11: } SCTPContext;
yading@11: 
yading@11: static int sctp_open(URLContext *h, const char *uri, int flags)
yading@11: {
yading@11:     struct addrinfo *ai, *cur_ai;
yading@11:     struct addrinfo hints             = { 0 };
yading@11:     struct sctp_event_subscribe event = { 0 };
yading@11:     struct sctp_initmsg initparams    = { 0 };
yading@11:     int port;
yading@11:     int fd         = -1;
yading@11:     SCTPContext *s = h->priv_data;
yading@11:     const char *p;
yading@11:     char buf[256];
yading@11:     int ret, listen_socket = 0;
yading@11:     char hostname[1024], proto[1024], path[1024];
yading@11:     char portstr[10];
yading@11: 
yading@11:     av_url_split(proto, sizeof(proto), NULL, 0, hostname, sizeof(hostname),
yading@11:                  &port, path, sizeof(path), uri);
yading@11:     if (strcmp(proto, "sctp"))
yading@11:         return AVERROR(EINVAL);
yading@11:     if (port <= 0 || port >= 65536) {
yading@11:         av_log(s, AV_LOG_ERROR, "Port missing in uri\n");
yading@11:         return AVERROR(EINVAL);
yading@11:     }
yading@11: 
yading@11:     s->max_streams = 0;
yading@11:     p = strchr(uri, '?');
yading@11:     if (p) {
yading@11:         if (av_find_info_tag(buf, sizeof(buf), "listen", p))
yading@11:             listen_socket = 1;
yading@11:         if (av_find_info_tag(buf, sizeof(buf), "max_streams", p))
yading@11:             s->max_streams = strtol(buf, NULL, 10);
yading@11:     }
yading@11: 
yading@11:     hints.ai_family   = AF_UNSPEC;
yading@11:     hints.ai_socktype = SOCK_STREAM;
yading@11:     snprintf(portstr, sizeof(portstr), "%d", port);
yading@11:     ret = getaddrinfo(hostname, portstr, &hints, &ai);
yading@11:     if (ret) {
yading@11:         av_log(h, AV_LOG_ERROR, "Failed to resolve hostname %s: %s\n",
yading@11:                hostname, gai_strerror(ret));
yading@11:         return AVERROR(EIO);
yading@11:     }
yading@11: 
yading@11:     cur_ai = ai;
yading@11: 
yading@11:     fd = socket(cur_ai->ai_family, SOCK_STREAM, IPPROTO_SCTP);
yading@11:     if (fd < 0)
yading@11:         goto fail;
yading@11: 
yading@11:     s->dest_addr_len = sizeof(s->dest_addr);
yading@11: 
yading@11:     if (listen_socket) {
yading@11:         int fd1;
yading@11:         ret = bind(fd, cur_ai->ai_addr, cur_ai->ai_addrlen);
yading@11:         listen(fd, 100);
yading@11:         fd1 = accept(fd, NULL, NULL);
yading@11:         closesocket(fd);
yading@11:         fd  = fd1;
yading@11:     } else
yading@11:         ret = connect(fd, cur_ai->ai_addr, cur_ai->ai_addrlen);
yading@11: 
yading@11:     ff_socket_nonblock(fd, 1);
yading@11: 
yading@11:     event.sctp_data_io_event = 1;
yading@11:     /* TODO: Subscribe to more event types and handle them */
yading@11: 
yading@11:     if (setsockopt(fd, IPPROTO_SCTP, SCTP_EVENTS, &event,
yading@11:                    sizeof(event)) != 0) {
yading@11:         av_log(h, AV_LOG_ERROR,
yading@11:                "SCTP ERROR: Unable to subscribe to events\n");
yading@11:         goto fail;
yading@11:     }
yading@11: 
yading@11:     if (s->max_streams) {
yading@11:         initparams.sinit_max_instreams = s->max_streams;
yading@11:         initparams.sinit_num_ostreams  = s->max_streams;
yading@11:         if (setsockopt(fd, IPPROTO_SCTP, SCTP_INITMSG, &initparams,
yading@11:                        sizeof(initparams)) < 0)
yading@11:             av_log(h, AV_LOG_ERROR,
yading@11:                    "SCTP ERROR: Unable to initialize socket max streams %d\n",
yading@11:                    s->max_streams);
yading@11:     }
yading@11: 
yading@11:     h->priv_data   = s;
yading@11:     h->is_streamed = 1;
yading@11:     s->fd          = fd;
yading@11:     freeaddrinfo(ai);
yading@11:     return 0;
yading@11: 
yading@11: fail:
yading@11:     ret = AVERROR(EIO);
yading@11:     freeaddrinfo(ai);
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: static int sctp_wait_fd(int fd, int write)
yading@11: {
yading@11:     int ev          = write ? POLLOUT : POLLIN;
yading@11:     struct pollfd p = { .fd = fd, .events = ev, .revents = 0 };
yading@11:     int ret;
yading@11: 
yading@11:     ret = poll(&p, 1, 100);
yading@11:     return ret < 0 ? ff_neterrno() : p.revents & ev ? 0 : AVERROR(EAGAIN);
yading@11: }
yading@11: 
yading@11: static int sctp_read(URLContext *h, uint8_t *buf, int size)
yading@11: {
yading@11:     SCTPContext *s = h->priv_data;
yading@11:     int ret;
yading@11: 
yading@11:     if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
yading@11:         ret = sctp_wait_fd(s->fd, 0);
yading@11:         if (ret < 0)
yading@11:             return ret;
yading@11:     }
yading@11: 
yading@11:     if (s->max_streams) {
yading@11:         /*StreamId is introduced as a 2byte code into the stream*/
yading@11:         struct sctp_sndrcvinfo info = { 0 };
yading@11:         ret = ff_sctp_recvmsg(s->fd, buf + 2, size - 2, NULL, 0, &info, 0);
yading@11:         AV_WB16(buf, info.sinfo_stream);
yading@11:         ret = ret < 0 ? ret : ret + 2;
yading@11:     } else
yading@11:         ret = recv(s->fd, buf, size, 0);
yading@11: 
yading@11:     return ret < 0 ? ff_neterrno() : ret;
yading@11: }
yading@11: 
yading@11: static int sctp_write(URLContext *h, const uint8_t *buf, int size)
yading@11: {
yading@11:     SCTPContext *s = h->priv_data;
yading@11:     int ret;
yading@11: 
yading@11:     if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
yading@11:         ret = sctp_wait_fd(s->fd, 1);
yading@11:         if (ret < 0)
yading@11:             return ret;
yading@11:     }
yading@11: 
yading@11:     if (s->max_streams) {
yading@11:         /*StreamId is introduced as a 2byte code into the stream*/
yading@11:         struct sctp_sndrcvinfo info = { 0 };
yading@11:         info.sinfo_stream           = AV_RB16(buf);
yading@11:         if (info.sinfo_stream > s->max_streams) {
yading@11:             av_log(h, AV_LOG_ERROR, "bad input data\n");
yading@11:             return AVERROR(EINVAL);
yading@11:         }
yading@11:         ret = ff_sctp_send(s->fd, buf + 2, size - 2, &info, MSG_EOR);
yading@11:     } else
yading@11:         ret = send(s->fd, buf, size, 0);
yading@11: 
yading@11:     return ret < 0 ? ff_neterrno() : ret;
yading@11: }
yading@11: 
yading@11: static int sctp_close(URLContext *h)
yading@11: {
yading@11:     SCTPContext *s = h->priv_data;
yading@11:     closesocket(s->fd);
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int sctp_get_file_handle(URLContext *h)
yading@11: {
yading@11:     SCTPContext *s = h->priv_data;
yading@11:     return s->fd;
yading@11: }
yading@11: 
yading@11: URLProtocol ff_sctp_protocol = {
yading@11:     .name                = "sctp",
yading@11:     .url_open            = sctp_open,
yading@11:     .url_read            = sctp_read,
yading@11:     .url_write           = sctp_write,
yading@11:     .url_close           = sctp_close,
yading@11:     .url_get_file_handle = sctp_get_file_handle,
yading@11:     .priv_data_size      = sizeof(SCTPContext),
yading@11:     .flags               = URL_PROTOCOL_FLAG_NETWORK,
yading@11: };