FFmpeg/libavformat/sctp.c
Anton Khirnov 2758cdedfb lavf: reorganize URLProtocols
Instead of a linked list constructed at av_register_all(), store them
in a constant array of pointers.

Since no registration is necessary now, this removes some global state
from lavf. This will also allow the urlprotocol layer caller to limit
the available protocols in a simple and flexible way in the following
commits.
2016-02-22 11:30:58 +01:00

371 lines
11 KiB
C

/*
* 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 "config.h"
#if HAVE_POLL_H
#include <poll.h>
#endif
#include "libavutil/intreadwrite.h"
#include "libavutil/parseutils.h"
#include "libavutil/opt.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.
* To avoid build-time clashes the functions sport an ff_-prefix here.
* The main purpose of this code is to provide the SCTP Socket API
* mappings for user applications to interface with SCTP in the 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 = { 0 };
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 | MSG_NOSIGNAL);
}
typedef struct SCTPContext {
const AVClass *class;
int fd;
int listen;
int timeout;
int listen_timeout;
int max_streams;
struct sockaddr_storage dest_addr;
} SCTPContext;
#define OFFSET(x) offsetof(SCTPContext, x)
#define D AV_OPT_FLAG_DECODING_PARAM
#define E AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
{ "listen", "Listen for incoming connections", OFFSET(listen), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, .flags = D|E },
{ "timeout", "Connection timeout (in milliseconds)", OFFSET(timeout), AV_OPT_TYPE_INT, { .i64 = 10000 }, INT_MIN, INT_MAX, .flags = D|E },
{ "listen_timeout", "Bind timeout (in milliseconds)", OFFSET(listen_timeout), AV_OPT_TYPE_INT, { .i64 = -1 }, INT_MIN, INT_MAX, .flags = D|E },
{ "max_streams", "Max stream to allocate", OFFSET(max_streams), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT16_MAX, .flags = D|E },
{ NULL }
};
static const AVClass sctp_class = {
.class_name = "sctp",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
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;
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"))
return AVERROR(EINVAL);
if (port <= 0 || port >= 65536) {
av_log(s, AV_LOG_ERROR, "Port missing in uri\n");
return AVERROR(EINVAL);
}
p = strchr(uri, '?');
if (p) {
if (av_find_info_tag(buf, sizeof(buf), "listen", p))
s->listen = 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;
restart:
fd = ff_socket(cur_ai->ai_family, SOCK_STREAM, IPPROTO_SCTP);
if (fd < 0) {
ret = ff_neterrno();
goto fail;
}
if (s->listen) {
if ((fd = ff_listen_bind(fd, cur_ai->ai_addr, cur_ai->ai_addrlen,
s->listen_timeout, h)) < 0) {
ret = fd;
goto fail1;
}
} else {
if ((ret = ff_listen_connect(fd, cur_ai->ai_addr, cur_ai->ai_addrlen,
s->timeout, h, !!cur_ai->ai_next)) < 0) {
if (ret == AVERROR_EXIT)
goto fail1;
else
goto fail;
}
}
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 fail1;
}
if (s->max_streams) {
initparams.sinit_max_instreams = s->max_streams;
initparams.sinit_num_ostreams = s->max_streams;
if (setsockopt(fd, IPPROTO_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);
ret = ff_neterrno();
goto fail1;
}
}
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);
ret = 0;
goto restart;
}
fail1:
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)
return AVERROR_BUG;
ret = ff_sctp_send(s->fd, buf + 2, size - 2, &info, MSG_EOR);
} else
ret = send(s->fd, buf, size, MSG_NOSIGNAL);
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;
}
const 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,
.priv_data_class = &sctp_class,
};