sctp: Initial tcp-alike sctp support with streams

Signed-off-by: Jordi Ortiz <nenjordi@gmail.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

configure

@@ -1110,6 +1110,7 @@ HAVE_LIST="
     memalign
     mkstemp
     mmap
+    netinet_sctp_h
     poll_h
     posix_memalign
     round
@@ -1513,6 +1514,7 @@ mmst_protocol_deps="network"
 rtmp_protocol_deps="!librtmp_protocol"
 rtmp_protocol_select="tcp_protocol"
 rtp_protocol_select="udp_protocol"
+sctp_protocol_deps="network netinet_sctp_h"
 tcp_protocol_deps="network"
 tls_protocol_deps_any="openssl gnutls"
 tls_protocol_select="tcp_protocol"
@@ -2846,6 +2848,7 @@ if enabled network; then
     check_type netinet/in.h "struct sockaddr_in6"
     check_type "sys/types.h sys/socket.h" "struct sockaddr_storage"
     check_struct "sys/types.h sys/socket.h" "struct sockaddr" sa_len
+    check_header netinet/sctp.h
     # Prefer arpa/inet.h over winsock2
     if check_header arpa/inet.h ; then
         check_func closesocket

libavformat/Makefile

@@ -348,6 +348,7 @@ OBJS-$(CONFIG_MD5_PROTOCOL)              += md5proto.o
 OBJS-$(CONFIG_PIPE_PROTOCOL)             += file.o
 OBJS-$(CONFIG_RTMP_PROTOCOL)             += rtmpproto.o rtmppkt.o
 OBJS-$(CONFIG_RTP_PROTOCOL)              += rtpproto.o
+OBJS-$(CONFIG_SCTP_PROTOCOL)             += sctp.o
 OBJS-$(CONFIG_TCP_PROTOCOL)              += tcp.o
 OBJS-$(CONFIG_TLS_PROTOCOL)              += tls.o
 OBJS-$(CONFIG_UDP_PROTOCOL)              += udp.o

libavformat/allformats.c

@@ -257,6 +257,7 @@ void av_register_all(void)
     REGISTER_PROTOCOL (PIPE, pipe);
     REGISTER_PROTOCOL (RTMP, rtmp);
     REGISTER_PROTOCOL (RTP, rtp);
+    REGISTER_PROTOCOL (SCTP, sctp);
     REGISTER_PROTOCOL (TCP, tcp);
     REGISTER_PROTOCOL (TLS, tls);
     REGISTER_PROTOCOL (UDP, udp);

libavformat/sctp.c

@@ -0,0 +1,328 @@
+/*
+ * SCTP protocol
+ * Copyright (c) 2012 Luca Barbato
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ *
+ * sctp url_protocol
+ *
+ * url syntax: sctp://host:port[?option=val...]
+ * option: 'listen'        : listen for an incoming connection
+ *         'max_streams=n' : set the maximum number of streams
+ *         'reuse=1'       : enable reusing the socket [TBD]
+ *
+ * by setting the maximum number of streams the protocol will use the
+ * first two bytes of the incoming/outgoing buffer to store the
+ * stream number of the packet being read/written.
+ * @see sctp_read
+ * @see sctp_write
+ */
+
+
+#include <netinet/in.h>
+#include <netinet/sctp.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+#include "config.h"
+
+#if HAVE_POLL_H
+#include <poll.h>
+#endif
+
+#include "libavutil/intreadwrite.h"
+#include "libavutil/parseutils.h"
+#include "avformat.h"
+#include "internal.h"
+#include "network.h"
+#include "os_support.h"
+#include "url.h"
+
+/*
+ * The sctp_recvmsg and sctp_sendmsg functions are part of the user
+ * library that offers support
+ * for the SCTP kernel Implementation. The main purpose of this
+ * code is to provide the SCTP Socket API mappings for user
+ * application to interface with the SCTP in kernel.
+ *
+ * This implementation is based on the Socket API Extensions for SCTP
+ * defined in <draft-ietf-tsvwg-sctpsocket-10.txt>
+ *
+ * Copyright (c) 2003 International Business Machines, Corp.
+ *
+ * Written or modified by:
+ *  Ryan Layer <rmlayer@us.ibm.com>
+ */
+
+static int ff_sctp_recvmsg(int s, void *msg, size_t len, struct sockaddr *from,
+                           socklen_t *fromlen, struct sctp_sndrcvinfo *sinfo,
+                           int *msg_flags)
+{
+    int recvb;
+    struct iovec iov;
+    char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
+    struct msghdr inmsg  = { 0 };
+    struct cmsghdr *cmsg = NULL;
+
+    iov.iov_base = msg;
+    iov.iov_len  = len;
+
+    inmsg.msg_name       = from;
+    inmsg.msg_namelen    = fromlen ? *fromlen : 0;
+    inmsg.msg_iov        = &iov;
+    inmsg.msg_iovlen     = 1;
+    inmsg.msg_control    = incmsg;
+    inmsg.msg_controllen = sizeof(incmsg);
+
+    if ((recvb = recvmsg(s, &inmsg, msg_flags ? *msg_flags : 0)) < 0)
+        return recvb;
+
+    if (fromlen)
+        *fromlen   = inmsg.msg_namelen;
+    if (msg_flags)
+        *msg_flags = inmsg.msg_flags;
+
+    for (cmsg = CMSG_FIRSTHDR(&inmsg); cmsg != NULL;
+         cmsg = CMSG_NXTHDR(&inmsg, cmsg)) {
+        if ((IPPROTO_SCTP == cmsg->cmsg_level) &&
+            (SCTP_SNDRCV  == cmsg->cmsg_type))
+            break;
+    }
+
+    /* Copy sinfo. */
+    if (cmsg)
+        memcpy(sinfo, CMSG_DATA(cmsg), sizeof(struct sctp_sndrcvinfo));
+
+    return recvb;
+}
+
+static int ff_sctp_send(int s, const void *msg, size_t len,
+                        const struct sctp_sndrcvinfo *sinfo, int flags)
+{
+    struct msghdr outmsg;
+    struct iovec iov;
+
+    outmsg.msg_name       = NULL;
+    outmsg.msg_namelen    = 0;
+    outmsg.msg_iov        = &iov;
+    iov.iov_base          = msg;
+    iov.iov_len           = len;
+    outmsg.msg_iovlen     = 1;
+    outmsg.msg_controllen = 0;
+
+    if (sinfo) {
+        char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
+        struct cmsghdr *cmsg;
+
+        outmsg.msg_control    = outcmsg;
+        outmsg.msg_controllen = sizeof(outcmsg);
+        outmsg.msg_flags      = 0;
+
+        cmsg             = CMSG_FIRSTHDR(&outmsg);
+        cmsg->cmsg_level = IPPROTO_SCTP;
+        cmsg->cmsg_type  = SCTP_SNDRCV;
+        cmsg->cmsg_len   = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
+
+        outmsg.msg_controllen = cmsg->cmsg_len;
+        memcpy(CMSG_DATA(cmsg), sinfo, sizeof(struct sctp_sndrcvinfo));
+    }
+
+    return sendmsg(s, &outmsg, flags);
+}
+
+typedef struct SCTPContext {
+    int fd;
+    int max_streams;
+    struct sockaddr_storage dest_addr;
+    socklen_t dest_addr_len;
+} SCTPContext;
+
+static int sctp_open(URLContext *h, const char *uri, int flags)
+{
+    struct addrinfo *ai, *cur_ai;
+    struct addrinfo hints             = { 0 };
+    struct sctp_event_subscribe event = { 0 };
+    struct sctp_initmsg initparams    = { 0 };
+    int port;
+    int fd         = -1;
+    SCTPContext *s = h->priv_data;
+    const char *p;
+    char buf[256];
+    int ret, listen_socket = 0;
+    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,"sctp") || port <= 0 || port >= 65536)
+        return AVERROR(EINVAL);
+
+    s->max_streams = 0;
+    p = strchr(uri, '?');
+    if (p) {
+        if (av_find_info_tag(buf, sizeof(buf), "listen", p))
+            listen_socket = 1;
+        if (av_find_info_tag(buf, sizeof(buf), "max_streams", p))
+            s->max_streams = strtol(buf, NULL, 10);
+    }
+
+    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(h, AV_LOG_ERROR, "Failed to resolve hostname %s: %s\n",
+               hostname, gai_strerror(ret));
+        return AVERROR(EIO);
+    }
+
+    cur_ai = ai;
+
+    fd = socket(cur_ai->ai_family, SOCK_STREAM, IPPROTO_SCTP);
+    if (fd < 0)
+        goto fail;
+
+    s->dest_addr_len = sizeof(s->dest_addr);
+
+    if (listen_socket) {
+        int fd1;
+        ret = bind(fd, cur_ai->ai_addr, cur_ai->ai_addrlen);
+        listen(fd, 100);
+        fd1 = accept(fd, NULL, NULL);
+        closesocket(fd);
+        fd  = fd1;
+    } else
+        ret = connect(fd, cur_ai->ai_addr, cur_ai->ai_addrlen);
+
+    ff_socket_nonblock(fd, 1);
+
+    event.sctp_data_io_event = 1;
+    /* TODO: Subscribe to more event types and handle them */
+
+    if (setsockopt(fd, IPPROTO_SCTP, SCTP_EVENTS, &event,
+                   sizeof(event)) != 0) {
+        av_log(h, AV_LOG_ERROR,
+               "SCTP ERROR: Unable to subscribe to events\n");
+        goto fail;
+    }
+
+    if (s->max_streams) {
+        initparams.sinit_max_instreams = s->max_streams;
+        initparams.sinit_num_ostreams  = s->max_streams;
+        if (setsockopt(fd, SOL_SCTP, SCTP_INITMSG, &initparams,
+                       sizeof(initparams)) < 0)
+            av_log(h, AV_LOG_ERROR,
+                   "SCTP ERROR: Unable to initialize socket max streams %d\n",
+                   s->max_streams);
+    }
+
+    h->priv_data   = s;
+    h->is_streamed = 1;
+    s->fd          = fd;
+    freeaddrinfo(ai);
+    return 0;
+
+fail:
+    ret = AVERROR(EIO);
+    freeaddrinfo(ai);
+    return ret;
+}
+
+static int sctp_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 sctp_read(URLContext *h, uint8_t *buf, int size)
+{
+    SCTPContext *s = h->priv_data;
+    int ret;
+
+    if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
+        ret = sctp_wait_fd(s->fd, 0);
+        if (ret < 0)
+            return ret;
+    }
+
+    if (s->max_streams) {
+        /*StreamId is introduced as a 2byte code into the stream*/
+        struct sctp_sndrcvinfo info = { 0 };
+        ret = ff_sctp_recvmsg(s->fd, buf + 2, size - 2, NULL, 0, &info, 0);
+        AV_WB16(buf, info.sinfo_stream);
+        ret = ret < 0 ? ret : ret + 2;
+    } else
+        ret = recv(s->fd, buf, size, 0);
+
+    return ret < 0 ? ff_neterrno() : ret;
+}
+
+static int sctp_write(URLContext *h, const uint8_t *buf, int size)
+{
+    SCTPContext *s = h->priv_data;
+    int ret;
+
+    if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
+        ret = sctp_wait_fd(s->fd, 1);
+        if (ret < 0)
+            return ret;
+    }
+
+    if (s->max_streams) {
+        /*StreamId is introduced as a 2byte code into the stream*/
+        struct sctp_sndrcvinfo info = { 0 };
+        info.sinfo_stream           = AV_RB16(buf);
+        if (info.sinfo_stream > s->max_streams)
+            abort();
+        ret = ff_sctp_send(s->fd, buf + 2, size - 2, &info, MSG_EOR);
+    } else
+        ret = send(s->fd, buf, size, 0);
+
+    return ret < 0 ? ff_neterrno() : ret;
+}
+
+static int sctp_close(URLContext *h)
+{
+    SCTPContext *s = h->priv_data;
+    closesocket(s->fd);
+    return 0;
+}
+
+static int sctp_get_file_handle(URLContext *h)
+{
+    SCTPContext *s = h->priv_data;
+    return s->fd;
+}
+
+URLProtocol ff_sctp_protocol = {
+    .name                = "sctp",
+    .url_open            = sctp_open,
+    .url_read            = sctp_read,
+    .url_write           = sctp_write,
+    .url_close           = sctp_close,
+    .url_get_file_handle = sctp_get_file_handle,
+    .priv_data_size      = sizeof(SCTPContext),
+    .flags               = URL_PROTOCOL_FLAG_NETWORK,
+};