From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id B598140EDB for ; Thu, 10 Feb 2022 01:20:15 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 2F60668B192; Thu, 10 Feb 2022 03:20:13 +0200 (EET) Received: from mail-wr1-f45.google.com (mail-wr1-f45.google.com [209.85.221.45]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 83E9668B05A for ; Thu, 10 Feb 2022 03:20:06 +0200 (EET) Received: by mail-wr1-f45.google.com with SMTP id f17so6917613wrx.1 for ; Wed, 09 Feb 2022 17:20:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=v53I/OrVY3jckIGQZUKs42EoOeSnrlE1t1LuC8Am1XI=; b=U8ugw8XgRZOnWcuNRR0g5fGOUIv5v+R/4ADo0MVB5EjrVJwBX4EEqlFoS1LlU9l8R3 FxJQ/RHE+6xr+AfyPcEhIut8ILh7JSh0n4oyfU2G8EviqnBV+HcBXM7pqWbfsDtfn7gP NPb+ZTn5Jg4Ght8ORY75Qqg3fm+8J9/VOuHUr0fMlswmNKkI2AoYyhTsipcSOt8xURaS mugjmOwYiJ05NZEWRtEC7np1yabBw6lrwRSahxHd5iltl3ks01FpVa0gu5i3DAdgo2R4 r4aE0oXbwRjP5/y1jM1WMgO15WKjOuISh/TxnsIVv+tp6Unc5YAUGS4tN694P/V/rugC u0tA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=v53I/OrVY3jckIGQZUKs42EoOeSnrlE1t1LuC8Am1XI=; b=Zfalk2tBhnKXzR9NX4FtuGUoZEKfn6yGuRicZMNA4N8l8l+obMZgH+R3TZRhg9/9ID HDfvrB/ttbfqLwzljm8dBJaK/vC/yYHmKo0zpSAlhm2X4DeiQm30IrZIiuQYs9+RXCyi RpskNsKNgb4ou7ti737Kx5uTu3ojSi5t6vbjOCBz5A9WQwVIQIL9zCggkYtE/8PIawqa 847R83QoQFcf1p4FMACZCQq8/kklgN3nrJu9ibEyg4H2WzsWUFU+XpB36ROJx1B4ohqF pameBymJxfzq3t31j8S4Lb1shTZGB+H3sfXx8WMK+eZEyBeW5kZD8rf+zEotNvEvGCYC MVGA== X-Gm-Message-State: AOAM5321KfOr5+XyowgRqmsoNAZQMCPMDeqJ5FOa3rX3CY3+GjGJ9YF7 i8t/BCGQzhZETxSJVd3gD7SEq/zU8GNsR8uxVweaRazOwXk= X-Google-Smtp-Source: ABdhPJwhLvAXKKfmRJZXpAnvo+JkEwdLHQhQwHXn305P6wbVYvN2eHBmDfAzdAh6OrqL3mwGGRdkYy3nd3W/vC1CEuU= X-Received: by 2002:a05:6000:2c2:: with SMTP id o2mr4256108wry.30.1644456004964; Wed, 09 Feb 2022 17:20:04 -0800 (PST) MIME-Version: 1.0 References: <20220210011352.11582-1-markg85@gmail.com> <20220210011352.11582-2-markg85@gmail.com> In-Reply-To: <20220210011352.11582-2-markg85@gmail.com> From: Mark Gaiser Date: Thu, 10 Feb 2022 02:18:33 +0100 Message-ID: To: FFmpeg development discussions and patches X-Content-Filtered-By: Mailman/MimeDel 2.1.29 Subject: Re: [FFmpeg-devel] [PATCH v5 1/1] avformat: Add IPFS protocol support. X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: On Thu, Feb 10, 2022 at 2:15 AM Mark Gaiser wrote: > This patch adds support for: > - ffplay ipfs:// > - ffplay ipns:// > > IPFS data can be played from so called "ipfs gateways". > A gateway is essentially a webserver that gives access to the > distributed IPFS network. > > This protocol support (ipfs and ipns) therefore translates > ipfs:// and ipns:// to a http:// url. This resulting url is > then handled by the http protocol. It could also be https > depending on the gateway provided. > > To use this protocol, a gateway must be provided. > If you do nothing it will try to find it in your > $HOME/.ipfs/gateway file. The ways to set it manually are: > 1. Define a -gateway to the gateway. > 2. Define $IPFS_GATEWAY with the full http link to the gateway. > 3. Define $IPFS_PATH and point it to the IPFS data path. > 4. Have IPFS running in your local user folder (under $HOME/.ipfs). > > Signed-off-by: Mark Gaiser > --- > configure | 2 + > doc/protocols.texi | 30 ++++ > libavformat/Makefile | 2 + > libavformat/ipfsgateway.c | 326 ++++++++++++++++++++++++++++++++++++++ > libavformat/protocols.c | 2 + > 5 files changed, 362 insertions(+) > create mode 100644 libavformat/ipfsgateway.c > > diff --git a/configure b/configure > index 5b19a35f59..6ff09e7974 100755 > --- a/configure > +++ b/configure > @@ -3585,6 +3585,8 @@ udp_protocol_select="network" > udplite_protocol_select="network" > unix_protocol_deps="sys_un_h" > unix_protocol_select="network" > +ipfs_protocol_select="https_protocol" > +ipns_protocol_select="https_protocol" > > # external library protocols > libamqp_protocol_deps="librabbitmq" > diff --git a/doc/protocols.texi b/doc/protocols.texi > index d207df0b52..7c9c0a4808 100644 > --- a/doc/protocols.texi > +++ b/doc/protocols.texi > @@ -2025,5 +2025,35 @@ decoding errors. > > @end table > > +@section ipfs > + > +InterPlanetary File System (IPFS) protocol support. One can access files > stored > +on the IPFS network through so called gateways. Those are http(s) > endpoints. > +This protocol wraps the IPFS native protocols (ipfs:// and ipns://) to be > send > +to such a gateway. Users can (and should) host their own node which means > this > +protocol will use your local machine gateway to access files on the IPFS > network. > + > +If a user doesn't have a node of their own then the public gateway > dweb.link is > +used by default. > + > +You can use this protocol in 2 ways. Using IPFS: > +@example > +ffplay ipfs://QmbGtJg23skhvFmu9mJiePVByhfzu5rwo74MEkVDYAmF5T > +@end example > + > +Or the IPNS protocol (IPNS is mutable IPFS): > +@example > +ffplay ipns://QmbGtJg23skhvFmu9mJiePVByhfzu5rwo74MEkVDYAmF5T > +@end example > + > +You can also change the gateway to be used: > + > +@table @option > + > +@item gateway > +Defines the gateway to use. When nothing is provided the protocol will > first try > +your local gateway. If that fails dweb.link will be used. > + > +@end table > > @c man end PROTOCOLS > diff --git a/libavformat/Makefile b/libavformat/Makefile > index 3dc6a479cc..4edce8420f 100644 > --- a/libavformat/Makefile > +++ b/libavformat/Makefile > @@ -656,6 +656,8 @@ OBJS-$(CONFIG_SRTP_PROTOCOL) += > srtpproto.o srtp.o > OBJS-$(CONFIG_SUBFILE_PROTOCOL) += subfile.o > OBJS-$(CONFIG_TEE_PROTOCOL) += teeproto.o tee_common.o > OBJS-$(CONFIG_TCP_PROTOCOL) += tcp.o > +OBJS-$(CONFIG_IPFS_PROTOCOL) += ipfsgateway.o > +OBJS-$(CONFIG_IPNS_PROTOCOL) += ipfsgateway.o > TLS-OBJS-$(CONFIG_GNUTLS) += tls_gnutls.o > TLS-OBJS-$(CONFIG_LIBTLS) += tls_libtls.o > TLS-OBJS-$(CONFIG_MBEDTLS) += tls_mbedtls.o > diff --git a/libavformat/ipfsgateway.c b/libavformat/ipfsgateway.c > new file mode 100644 > index 0000000000..9ebced10c7 > --- /dev/null > +++ b/libavformat/ipfsgateway.c > @@ -0,0 +1,326 @@ > +/* > + * IPFS and IPNS protocol support through IPFS Gateway. > + * Copyright (c) 2022 Mark Gaiser > + * > + * 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 "libavutil/avassert.h" > +#include "libavutil/avstring.h" > +#include "libavutil/internal.h" > +#include "libavutil/opt.h" > +#include "libavutil/tree.h" > +#include > +#if HAVE_IO_H > +#include > +#endif > +#if HAVE_UNISTD_H > +#include > +#endif > +#include "os_support.h" > +#include "url.h" > +#include > +#include > + > +typedef struct IPFSGatewayContext { > + AVClass *class; > + URLContext *inner; > + char *gateway; > +} IPFSGatewayContext; > + > +// A best-effort way to find the IPFS gateway. > +// Only the most appropiate gateway is set. It's not actually requested > +// (http call) to prevent a potential slowdown in startup. A potential > timeout > +// is handled by the HTTP protocol. > +static int populate_ipfs_gateway(URLContext *h, char *gateway) > +{ > + char ipfs_full_data_folder[PATH_MAX]; > + char ipfs_gateway_file[PATH_MAX]; > + struct stat st; > + int stat_ret = 0; > + int ret = AVERROR(EINVAL); > + FILE *gateway_file = NULL; > + char gateway_file_data[PATH_MAX]; > + > + // We could already have a gateway (it would have been passed as > -gateway). > + if (*gateway != '\0') { > + ret = 1; > + goto err; > + } > + > + // Test $IPFS_GATEWAY. > + if (getenv("IPFS_GATEWAY") != NULL) { > + snprintf(gateway, PATH_MAX, "%s", getenv("IPFS_GATEWAY")); > + ret = 1; > + goto err; > + } else > + av_log(h, AV_LOG_DEBUG, "$IPFS_GATEWAY is empty.\n"); > + > + // We need to know the IPFS folder to - eventually - read the > contents of > + // the "gateway" file which would tell us the gateway to use. > + if (getenv("IPFS_PATH") == NULL) { > + av_log(h, AV_LOG_DEBUG, "$IPFS_PATH is empty.\n"); > + > + // Try via the home folder. > + if (getenv("HOME") == NULL) { > + av_log(h, AV_LOG_ERROR, "$HOME appears to be empty.\n"); > + ret = AVERROR(EINVAL); > + goto err; > + } > + > + // Verify the composed path fits. > + if (snprintf(ipfs_full_data_folder, PATH_MAX, "%s/.ipfs/", > + getenv("HOME")) > PATH_MAX) { > + av_log(h, AV_LOG_ERROR, "The IPFS data path exceeds the max > path length (%i)\n", PATH_MAX); > + ret = AVERROR(EINVAL); > + goto err; > + } > + > + // Stat the folder. > + // It should exist in a default IPFS setup when run as local user. > +#ifndef _WIN32 > + stat_ret = stat(ipfs_full_data_folder, &st); > +#else > + stat_ret = win32_stat(ipfs_full_data_folder, &st); > +#endif > + if (stat_ret < 0) { > + av_log(h, AV_LOG_INFO, "Unable to find IPFS folder. We > tried:\n"); > + av_log(h, AV_LOG_INFO, "- $IPFS_PATH, which was empty.\n"); > + av_log(h, AV_LOG_INFO, "- $HOME/.ipfs (full uri: %s) which > doesn't exist.\n", ipfs_full_data_folder); > + ret = AVERROR(ENOENT); > + goto err; > + } > Just to mention this before I get it as feedback, again :) I really like to keep the folder detection and the log lines. I changed them to INFO lines. This information does help to debug, as a user using ffmpeg, to see if something is wrong in paths. I did try this with fopen(... "r+") but it didn't seem to work as "folder exists" check hence the ifdef is still there. > + } else > + snprintf(ipfs_full_data_folder, PATH_MAX, "%s", > getenv("IPFS_PATH")); > + > + // Copy the fully composed gateway path into ipfs_gateway_file. > + if (snprintf(ipfs_gateway_file, PATH_MAX, "%sgateway", > + ipfs_full_data_folder) > PATH_MAX) { > + av_log(h, AV_LOG_ERROR, "The IPFS gateway file path exceeds the > max path length (%i)\n", PATH_MAX); > + ret = AVERROR(ENOENT); > + goto err; > + } > + > + // Get the contents of the gateway file. > + gateway_file = av_fopen_utf8(ipfs_gateway_file, "r"); > + if (!gateway_file) { > + av_log(h, AV_LOG_ERROR, "The IPFS gateway file (full uri: %s) > doesn't exist. Is the gateway enabled?\n", ipfs_gateway_file); > + ret = AVERROR(ENOENT); > + goto err; > + } > + > + // Read a single line (fgets stops at new line mark). > + fgets(gateway_file_data, PATH_MAX - 1, gateway_file); > + > + // Replace the last char with \0 > + gateway_file_data[PATH_MAX - 1] = 0; > + > + // Replace first occurence of end of line with \0 > + gateway_file_data[strcspn(gateway_file_data, "\r\n")] = 0; > + > + // If strlen finds anything longer then 0 characters then we have a > + // potential gateway url. > + if (strlen(gateway_file_data) < 1) { > + av_log(h, AV_LOG_ERROR, "The IPFS gateway file (full uri: %s) > appears to be empty. Is the gateway started?\n", ipfs_gateway_file); > + ret = AVERROR(EILSEQ); > + goto err; > + } > + > + // At this point gateway_file_data contains at least something. > + // Copy it into gateway. > + if (snprintf(gateway, PATH_MAX, "%s", gateway_file_data) > 0) { > + ret = 1; > + goto err; > + } else > + av_log(h, AV_LOG_DEBUG, "Unknown error in the IPFS gateway > file.\n"); > + > +err: > + if (gateway_file) > + fclose(gateway_file); > + > + return ret; > +} > + > +// For now just makes sure that the gateway ends in url we expect. > +// Like http://localhost:8080/. > +// Explicitly with the traling slash. > +static int sanitize_ipfs_gateway(URLContext *h, char *gateway) > +{ > + const char *url_without_protocol; > + int ret = 1; > + > + // Test if the gateway starts with either http:// or https:// > + // The remainder is stored in url_without_protocol > + if (av_stristart(gateway, "http://", &url_without_protocol) == 0 > + && av_stristart(gateway, "https://", &url_without_protocol) == > 0) { > + av_log(h, AV_LOG_ERROR, "The gateway URL didn't start with http:// > or https:// and is therefore invalid.\n"); > + ret = AVERROR(EILSEQ); > + goto err; > + } > + > + // We now know the remainder of the url without the protocol. Check > it for > + // some length. At least 1 character. > + if (strlen(url_without_protocol) < 1) { > + av_log(h, AV_LOG_ERROR, "The gateway url (without the protocol > part) is too short to be a valid URL.\n"); > + ret = AVERROR(EILSEQ); > + goto err; > + } > + > + > + if (gateway[strlen(gateway) - 1] != '/') { > + // Check if we have enough room to add a '/' > + // We already know that it's bigger then 0 because that's handled > + // in populate_ipfs_gateway > + > + if (strlen(gateway) < (PATH_MAX - 2)) { > + // We have room. Get the length and add a '/' and a '\0' > + int gateway_length = strlen(gateway); > + gateway[gateway_length] = '/'; > + gateway[gateway_length + 1] = '\0'; > + } else > + av_log(h, AV_LOG_ERROR, "The gateway url is longer then the > allowed max path length (%i).\n", PATH_MAX); > + > + ret = 1; > + goto err; > + } > + > +err: > + return ret; > +} > + > +static int translate_ipfs_to_http(URLContext *h, const char *uri, > + int flags, AVDictionary **options) > +{ > + const char *ipfs_cid; > + char *fulluri = NULL; > + char ipfs_gateway[PATH_MAX]; > + int ret; > + IPFSGatewayContext *c = h->priv_data; > + > + // Test for ipfs://, ipfs:, ipns:// and ipns:. This prefix is > stripped from > + // the string leaving just the CID in ipfs_cid. > + int is_ipfs = av_stristart(uri, "ipfs://", &ipfs_cid); > + int is_ipns = av_stristart(uri, "ipns://", &ipfs_cid); > + > + // We must have either ipns or ipfs. > + if (!is_ipfs && !is_ipns) { > + ret = AVERROR(EINVAL); > + av_log(h, AV_LOG_ERROR, "Unsupported url %s\n", uri); > + goto err; > + } > + > + // Pppulate ipfs_gateway with whatever is in c->gateway > + if (c->gateway != NULL) > + snprintf(ipfs_gateway, sizeof(ipfs_gateway), "%s", c->gateway); > + else > + ipfs_gateway[0] = '\0'; > + > + // Populate the IPFS gateway if we have any. > + // If not, inform the user how to properly set one. > + ret = populate_ipfs_gateway(h, &ipfs_gateway[0]); > + > + if (ret < 1) { > + av_log(h, AV_LOG_ERROR, "No IPFS gateway was set. Make sure a > local IPFS instance is running.\n"); > + av_log(h, AV_LOG_INFO, "There are multiple options to define this > gateway. The below options are in order of precedence:\n"); > + av_log(h, AV_LOG_INFO, "1. Define a -gateway to the gateway > without trailing forward slash.\n"); > + av_log(h, AV_LOG_INFO, "2. Define $IPFS_GATEWAY with the full > http link to the gateway without trailing forward slash.\n"); > + av_log(h, AV_LOG_INFO, "3. Define $IPFS_PATH and point it to the > IPFS data path.\n"); > + av_log(h, AV_LOG_INFO, "4. Have IPFS running in your local user > folder (under $HOME/.ipfs).\n"); > + av_log(h, AV_LOG_INFO, "In all path cases, a file named gateway > is expected. See https://github.com/ipfs/specs/issues/261 for more > information.\n"); > + goto err; > + } > + > + // Sanitize the gateway to a format we expect. > + ret = sanitize_ipfs_gateway(h, &ipfs_gateway[0]); > + > + if (ret < 1) > + goto err; > + > + // Concatenate the url. > + // This ends up with something like: http://localhost:8080/ipfs/Qm... > .. > + fulluri = av_asprintf("%s%s%s", ipfs_gateway, > + (is_ipns) ? "ipns/" : "ipfs/", > + ipfs_cid); > + > + // Pass the URL back to FFMpeg's protocol handler. > + if ((ret = ffurl_open_whitelist(&c->inner, fulluri, flags, > + &h->interrupt_callback, options, > + h->protocol_whitelist, > + h->protocol_blacklist, h)) > + < 0) { > + av_log(h, AV_LOG_ERROR, "Unable to open resource: %s\n", fulluri); > + goto err; > + } > + > +err: > + av_free(fulluri); > + return ret; > +} > + > +static int ipfs_read(URLContext *h, unsigned char *buf, int size) > +{ > + IPFSGatewayContext *c = h->priv_data; > + return ffurl_read(c->inner, buf, size); > +} > + > +static int64_t ipfs_seek(URLContext *h, int64_t pos, int whence) > +{ > + IPFSGatewayContext *c = h->priv_data; > + return ffurl_seek(c->inner, pos, whence); > +} > + > +static int ipfs_close(URLContext *h) > +{ > + IPFSGatewayContext *c = h->priv_data; > + av_free(c->gateway); > + return ffurl_closep(&c->inner); > +} > + > +#define OFFSET(x) offsetof(IPFSGatewayContext, x) > + > +static const AVOption options[] = { > + {"gateway", "The gateway to ask for IPFS data.", OFFSET(gateway), > AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, AV_OPT_FLAG_DECODING_PARAM}, > + {NULL}, > +}; > + > +static const AVClass ipfs_context_class = { > + .class_name = "IPFS", > + .item_name = av_default_item_name, > + .option = options, > + .version = LIBAVUTIL_VERSION_INT, > +}; > + > +const URLProtocol ff_ipfs_protocol = { > + .name = "ipfs", > + .url_open2 = translate_ipfs_to_http, > + .url_read = ipfs_read, > + .url_seek = ipfs_seek, > + .url_close = ipfs_close, > + .priv_data_size = sizeof(IPFSGatewayContext), > + .priv_data_class = &ipfs_context_class, > +}; > + > +const URLProtocol ff_ipns_protocol = { > + .name = "ipns", > + .url_open2 = translate_ipfs_to_http, > + .url_read = ipfs_read, > + .url_seek = ipfs_seek, > + .url_close = ipfs_close, > + .priv_data_size = sizeof(IPFSGatewayContext), > + .priv_data_class = &ipfs_context_class, > +}; > diff --git a/libavformat/protocols.c b/libavformat/protocols.c > index 948fae411f..675b684bd3 100644 > --- a/libavformat/protocols.c > +++ b/libavformat/protocols.c > @@ -73,6 +73,8 @@ extern const URLProtocol ff_libsrt_protocol; > extern const URLProtocol ff_libssh_protocol; > extern const URLProtocol ff_libsmbclient_protocol; > extern const URLProtocol ff_libzmq_protocol; > +extern const URLProtocol ff_ipfs_protocol; > +extern const URLProtocol ff_ipns_protocol; > > #include "libavformat/protocol_list.c" > > -- > 2.35.1 > > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".