lavf: add SFTP protocol via libssh

Signed-off-by: Lukasz Marek <lukasz.m.luki@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Changelog

@@ -30,6 +30,7 @@ version <next>
 - Error Resilient AAC syntax (ER AAC LC) decoding
 - Low Delay AAC (ER AAC LD) decoding
 - mux chapters in ASF files
+- SFTP protocol (via libssh)
 
 
 version 2.0:

configure

@@ -225,6 +225,7 @@ External library support:
   --enable-libshine        enable fixed-point MP3 encoding via libshine [no]
   --enable-libsoxr         enable Include libsoxr resampling [no]
   --enable-libspeex        enable Speex de/encoding via libspeex [no]
+  --enable-libssh          enable SFTP protocol via libssh [no]
   --enable-libstagefright-h264  enable H.264 decoding via libstagefright [no]
   --enable-libtheora       enable Theora encoding via libtheora [no]
   --enable-libtwolame      enable MP2 encoding via libtwolame [no]
@@ -1191,6 +1192,7 @@ EXTERNAL_LIBRARY_LIST="
     libshine
     libsoxr
     libspeex
+    libssh
     libstagefright_h264
     libtheora
     libtwolame
@@ -2158,6 +2160,7 @@ librtmpe_protocol_deps="librtmp"
 librtmps_protocol_deps="librtmp"
 librtmpt_protocol_deps="librtmp"
 librtmpte_protocol_deps="librtmp"
+libssh_protocol_deps="libssh"
 mmsh_protocol_select="http_protocol"
 mmst_protocol_select="network"
 rtmp_protocol_deps="!librtmp_protocol"
@@ -4241,6 +4244,7 @@ enabled librtmp           && require_pkg_config librtmp librtmp/rtmp.h RTMP_Sock
 enabled libschroedinger   && require_pkg_config schroedinger-1.0 schroedinger/schro.h schro_init
 enabled libshine          && require_pkg_config shine shine/layer3.h shine_encode_buffer
 enabled libsoxr           && require libsoxr soxr.h soxr_create -lsoxr
+enabled libssh            && require_pkg_config libssh libssh/sftp.h sftp_init
 enabled libspeex          && require libspeex speex/speex.h speex_decoder_init -lspeex
 enabled libstagefright_h264 && require_cpp libstagefright_h264 "binder/ProcessState.h media/stagefright/MetaData.h
     media/stagefright/MediaBufferGroup.h media/stagefright/MediaDebug.h media/stagefright/MediaDefs.h

doc/protocols.texi

@@ -520,6 +520,38 @@ The Real-Time Messaging Protocol tunneled through HTTPS (RTMPTS) is used
 for streaming multimedia content within HTTPS requests to traverse
 firewalls.
 
+@section libssh
+
+Secure File Transfer Protocol via libssh
+
+Allow to read from or write to remote resources using SFTP protocol.
+
+Following syntax is required.
+
+@example
+sftp://[user[:password]@@]server[:port]/path/to/remote/resource.mpeg
+@end example
+
+This protocol accepts the following options.
+
+@table @option
+@item timeout
+Set timeout of socket I/O operations used by the underlying low level
+operation. By default it is set to -1, which means that the timeout
+is not specified.
+
+@item truncate
+Truncate existing files on write, if set to 1. A value of 0 prevents
+truncating. Default value is 1.
+
+@end table
+
+Example: Play a file stored on remote server.
+
+@example
+ffplay sftp://user:password@@server_address:22/home/user/resource.mpeg
+@end example
+
 @section librtmp rtmp, rtmpe, rtmps, rtmpt, rtmpte
 
 Real-Time Messaging Protocol and its variants supported through

libavformat/Makefile

@@ -425,6 +425,7 @@ OBJS-$(CONFIG_LIBNUT_DEMUXER)            += libnut.o
 OBJS-$(CONFIG_LIBNUT_MUXER)              += libnut.o
 OBJS-$(CONFIG_LIBQUVI_DEMUXER)           += libquvi.o
 OBJS-$(CONFIG_LIBRTMP)                   += librtmp.o
+OBJS-$(CONFIG_LIBSSH_PROTOCOL)           += libssh.o
 
 # protocols I/O
 OBJS-$(CONFIG_APPLEHTTP_PROTOCOL)        += hlsproto.o

libavformat/allformats.c

@@ -348,4 +348,5 @@ void av_register_all(void)
     REGISTER_PROTOCOL(LIBRTMPS,         librtmps);
     REGISTER_PROTOCOL(LIBRTMPT,         librtmpt);
     REGISTER_PROTOCOL(LIBRTMPTE,        librtmpte);
+    REGISTER_PROTOCOL(LIBSSH,           libssh);
 }

libavformat/libssh.c

+/*
+ * Copyright (c) 2013 Lukasz Marek <lukasz.m.luki@gmail.com>
+ *
+ * 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 <fcntl.h>
+#include <libssh/sftp.h>
+#include "libavutil/avstring.h"
+#include "libavutil/opt.h"
+#include "avformat.h"
+#include "internal.h"
+#include "url.h"
+
+typedef struct {
+    const AVClass *class;
+    ssh_session session;
+    sftp_session sftp;
+    sftp_file file;
+    int64_t filesize;
+    int rw_timeout;
+    int trunc;
+} LIBSSHContext;
+
+static int libssh_close(URLContext *h)
+{
+    LIBSSHContext *s = h->priv_data;
+    if (s->file)
+        sftp_close(s->file);
+    if (s->sftp)
+        sftp_free(s->sftp);
+    if (s->session) {
+        ssh_disconnect(s->session);
+        ssh_free(s->session);
+    }
+    return 0;
+}
+
+static int libssh_open(URLContext *h, const char *url, int flags)
+{
+    static const int verbosity = SSH_LOG_NOLOG;
+    LIBSSHContext *s = h->priv_data;
+    char proto[10], path[MAX_URL_SIZE], hostname[1024], credencials[1024];
+    int port = 22, access, ret;
+    long timeout = s->rw_timeout * 1000;
+    const char *user = NULL, *pass = NULL;
+    char *end = NULL;
+    sftp_attributes stat;
+
+    av_url_split(proto, sizeof(proto),
+                 credencials, sizeof(credencials),
+                 hostname, sizeof(hostname),
+                 &port,
+                 path, sizeof(path),
+                 url);
+
+    if (port <= 0 || port > 65535)
+        port = 22;
+
+    if (!(s->session = ssh_new())) {
+        ret = AVERROR(ENOMEM);
+        goto fail;
+    }
+    user = av_strtok(credencials, ":", &end);
+    pass = av_strtok(end, ":", &end);
+    ssh_options_set(s->session, SSH_OPTIONS_HOST, hostname);
+    ssh_options_set(s->session, SSH_OPTIONS_PORT, &port);
+    ssh_options_set(s->session, SSH_OPTIONS_LOG_VERBOSITY, &verbosity);
+    if (timeout > 0)
+        ssh_options_set(s->session, SSH_OPTIONS_TIMEOUT_USEC, &timeout);
+    if (user)
+        ssh_options_set(s->session, SSH_OPTIONS_USER, user);
+
+    if (ssh_connect(s->session) != SSH_OK) {
+        av_log(h, AV_LOG_ERROR, "Connection failed. %s\n", ssh_get_error(s->session));
+        ret = AVERROR(EIO);
+        goto fail;
+    }
+
+    if (pass && ssh_userauth_password(s->session, NULL, pass) != SSH_AUTH_SUCCESS) {
+        av_log(h, AV_LOG_ERROR, "Error authenticating with password: %s\n", ssh_get_error(s->session));
+        ret = AVERROR(EACCES);
+        goto fail;
+    }
+
+    if (!(s->sftp = sftp_new(s->session))) {
+        av_log(h, AV_LOG_ERROR, "SFTP session creation failed: %s\n", ssh_get_error(s->session));
+        ret = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    if (sftp_init(s->sftp) != SSH_OK) {
+        av_log(h, AV_LOG_ERROR, "Error initializing sftp session: %s\n", ssh_get_error(s->session));
+        ret = AVERROR(EIO);
+        goto fail;
+    }
+
+    if ((flags & AVIO_FLAG_WRITE) && (flags & AVIO_FLAG_READ)) {
+        access = O_CREAT | O_RDWR;
+        if (s->trunc)
+            access |= O_TRUNC;
+    } else if (flags & AVIO_FLAG_WRITE) {
+        access = O_CREAT | O_WRONLY;
+        if (s->trunc)
+            access |= O_TRUNC;
+    } else {
+        access = O_RDONLY;
+    }
+
+    if (!(s->file = sftp_open(s->sftp, path, access, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH))) {
+        av_log(h, AV_LOG_ERROR, "Error opening sftp file: %s\n", ssh_get_error(s->session));
+        ret = AVERROR(EIO);
+        goto fail;
+    }
+
+    if (!(stat = sftp_fstat(s->file))) {
+        av_log(h, AV_LOG_WARNING, "Cannot stat remote file %s.\n", path);
+        s->filesize = -1;
+    } else {
+        s->filesize = stat->size;
+        sftp_attributes_free(stat);
+    }
+
+    return 0;
+
+  fail:
+    libssh_close(h);
+    return ret;
+}
+
+static int64_t libssh_seek(URLContext *h, int64_t pos, int whence)
+{
+    LIBSSHContext *s = h->priv_data;
+    int64_t newpos;
+
+    if (s->filesize == -1 && (whence == AVSEEK_SIZE || whence == SEEK_END)) {
+        av_log(h, AV_LOG_ERROR, "Error during seeking.\n");
+        return AVERROR(EIO);
+    }
+
+    switch(whence) {
+    case AVSEEK_SIZE:
+        return s->filesize;
+    case SEEK_SET:
+        newpos = pos;
+        break;
+    case SEEK_CUR:
+        newpos = sftp_tell64(s->file);
+        break;
+    case SEEK_END:
+        newpos = s->filesize + pos;
+        break;
+    default:
+        return AVERROR(EINVAL);
+    }
+
+    if (sftp_seek64(s->file, newpos)) {
+        av_log(h, AV_LOG_ERROR, "Error during seeking.\n");
+        return AVERROR(EIO);
+    }
+
+    return newpos;
+}
+
+static int libssh_read(URLContext *h, unsigned char *buf, int size)
+{
+    LIBSSHContext *s = h->priv_data;
+    int bytes_read;
+
+    if ((bytes_read = sftp_read(s->file, buf, size)) < 0) {
+        av_log(h, AV_LOG_ERROR, "Read error.\n");
+        return AVERROR(EIO);
+    }
+    return bytes_read;
+}
+
+static int libssh_write(URLContext *h, const unsigned char *buf, int size)
+{
+    LIBSSHContext *s = h->priv_data;
+    int bytes_written;
+
+    if ((bytes_written = sftp_write(s->file, buf, size)) < 0) {
+        av_log(h, AV_LOG_ERROR, "Write error.\n");
+        return AVERROR(EIO);
+    }
+    return bytes_written;
+}
+
+#define OFFSET(x) offsetof(LIBSSHContext, x)
+#define D AV_OPT_FLAG_DECODING_PARAM
+#define E AV_OPT_FLAG_ENCODING_PARAM
+static const AVOption options[] = {
+    {"timeout", "set timeout of socket I/O operations", OFFSET(rw_timeout), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, D|E },
+    {"truncate", "Truncate existing files on write", OFFSET(trunc), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, E },
+    {NULL}
+};
+
+static const AVClass libssh_context_class = {
+    .class_name     = "libssh",
+    .item_name      = av_default_item_name,
+    .option         = options,
+    .version        = LIBAVUTIL_VERSION_INT,
+};
+
+URLProtocol ff_libssh_protocol = {
+    .name                = "sftp",
+    .url_open            = libssh_open,
+    .url_read            = libssh_read,
+    .url_write           = libssh_write,
+    .url_seek            = libssh_seek,
+    .url_close           = libssh_close,
+    .priv_data_size      = sizeof(LIBSSHContext),
+    .priv_data_class     = &libssh_context_class,
+    .flags               = URL_PROTOCOL_FLAG_NETWORK,
+};