On Wed, Apr 6, 2022 at 2:02 PM Mark Gaiser <mark...@gmail.com> wrote:
> This patch adds support for: > - ffplay ipfs://<cid> > - ffplay ipns://<cid> > > 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 <url> 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 <mark...@gmail.com> > --- > configure | 2 + > doc/protocols.texi | 30 ++++ > libavformat/Makefile | 2 + > libavformat/ipfsgateway.c | 339 ++++++++++++++++++++++++++++++++++++++ > libavformat/protocols.c | 2 + > 5 files changed, 375 insertions(+) > create mode 100644 libavformat/ipfsgateway.c > > diff --git a/configure b/configure > index e4d36aa639..55af90957a 100755 > --- a/configure > +++ b/configure > @@ -3579,6 +3579,8 @@ 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..90a9eefde0 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 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 d7182d6bd8..e3233fd7ac 100644 > --- a/libavformat/Makefile > +++ b/libavformat/Makefile > @@ -660,6 +660,8 @@ 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..05fd37bbc5 > --- /dev/null > +++ b/libavformat/ipfsgateway.c > @@ -0,0 +1,339 @@ > +/* > + * 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 "libavutil/avstring.h" > +#include "libavutil/opt.h" > +#include <sys/stat.h> > +#include "os_support.h" > +#include "url.h" > + > +typedef struct IPFSGatewayContext { > + AVClass *class; > + URLContext *inner; > + // Is filled by the -gateway argument and not changed after. > + char *gateway; > + // If the above gateway is non null, it will be copied into this > buffer. > + // Else this buffer will contain the auto detected gateway. > + // In either case, the gateway to use will be in this buffer. > + char gateway_buffer[PATH_MAX]; > +} 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) > +{ > + IPFSGatewayContext *c = h->priv_data; > + 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; > + > + // Test $IPFS_GATEWAY. > + if (getenv("IPFS_GATEWAY") != NULL) { > + if (snprintf(c->gateway_buffer, sizeof(c->gateway_buffer), "%s", > + getenv("IPFS_GATEWAY")) > + >= sizeof(c->gateway_buffer)) { > + av_log(h, AV_LOG_WARNING, > + "The IPFS_GATEWAY environment variable " > + "exceeds the maximum length. " > + "We allow a max of %zu characters\n", > + sizeof(c->gateway_buffer)); > + ret = AVERROR(EINVAL); > + goto err; > + } > + > + ret = 1; > + goto err; > + } else > + av_log(h, AV_LOG_DEBUG, "$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, "$IPFS_PATH is empty.\n"); > + > + // Try via the home folder. > + if (getenv("HOME") == NULL) { > + av_log(h, AV_LOG_WARNING, "$HOME appears to be empty.\n"); > + ret = AVERROR(EINVAL); > + goto err; > + } > + > + // Verify the composed path fits. > + if (snprintf(ipfs_full_data_folder, sizeof(ipfs_full_data_folder), > + "%s/.ipfs/", getenv("HOME")) > + >= sizeof(ipfs_full_data_folder)) { > + av_log(h, AV_LOG_WARNING, > + "The IPFS data path exceeds the " > + "max path length (%zu)\n", > + sizeof(ipfs_full_data_folder)); > + ret = AVERROR(EINVAL); > + goto err; > + } > + > + // Stat the folder. > + // It should exist in a default IPFS setup when run as local user. > + stat_ret = stat(ipfs_full_data_folder, &st); > + > + 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; > + } > + } else { > + if (snprintf(ipfs_full_data_folder, > sizeof(ipfs_full_data_folder), "%s", > + getenv("IPFS_PATH")) > + >= sizeof(ipfs_full_data_folder)) { > + av_log(h, AV_LOG_WARNING, > + "The IPFS_PATH environment variable " > + "exceeds the maximum length. " > + "We allow a max of %zu characters\n", > + sizeof(c->gateway_buffer)); > + ret = AVERROR(EINVAL); > + goto err; > + } > + } > + > + // Copy the fully composed gateway path into ipfs_gateway_file. > + if (snprintf(ipfs_gateway_file, sizeof(ipfs_gateway_file), > "%sgateway", > + ipfs_full_data_folder) > + >= sizeof(ipfs_gateway_file)) { > + av_log(h, AV_LOG_WARNING, > + "The IPFS gateway file path exceeds " > + "the max path length (%zu)\n", > + sizeof(ipfs_gateway_file)); > + 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_WARNING, > + "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). > + if (!fgets(c->gateway_buffer, sizeof(c->gateway_buffer) - 1, > gateway_file)) { > + av_log(h, AV_LOG_WARNING, "Unable to read from file (full uri: > %s).\n", > + ipfs_gateway_file); > + ret = AVERROR(ENOENT); > + goto err; > + } > + > + // Replace first occurence of end of line with \0 > + c->gateway_buffer[strcspn(c->gateway_buffer, "\r\n")] = 0; > + > + // If strlen finds anything longer then 0 characters then we have a > + // potential gateway url. > + if (*c->gateway_buffer == '\0') { > + av_log(h, AV_LOG_WARNING, > + "The IPFS gateway file (full uri: %s) appears to be empty. > " > + "Is the gateway started?\n", > + ipfs_gateway_file); > + ret = AVERROR(EILSEQ); > + goto err; > + } else { > + // We're done, the c->gateway_buffer has something that looks > valid. > + ret = 1; > + goto err; > + } > + > +err: > + if (gateway_file) > + fclose(gateway_file); > + > + return ret; > +} > + > +static int translate_ipfs_to_http(URLContext *h, const char *uri, int > flags, AVDictionary **options) > +{ > + const char *ipfs_cid; > + char *fulluri = NULL; > + 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_WARNING, "Unsupported url %s\n", uri); > + goto err; > + } > + > + // If the CID has a length greater then 0 then we assume we have a > proper working one. > + // It could still be wrong but in that case the gateway should save > us and > + // ruturn a 403 error. The http protocol handles this. > + if (strlen(ipfs_cid) < 1) { > + av_log(h, AV_LOG_WARNING, "A CID must be provided.\n"); > + ret = AVERROR(EILSEQ); > + goto err; > + } > + > + // Populate c->gateway_buffer with whatever is in c->gateway > + if (c->gateway != NULL) { > + if (snprintf(c->gateway_buffer, sizeof(c->gateway_buffer), "%s", > + c->gateway) > + >= sizeof(c->gateway_buffer)) { > + av_log(h, AV_LOG_WARNING, > + "The -gateway parameter is too long. " > + "We allow a max of %zu characters\n", > + sizeof(c->gateway_buffer)); > + ret = AVERROR(EINVAL); > + goto err; > + } > + } else { > + // Populate the IPFS gateway if we have any. > + // If not, inform the user how to properly set one. > + ret = populate_ipfs_gateway(h); > + > + if (ret < 1) { > + // We fallback on dweb.link (managed by Protocol Labs). > + snprintf(c->gateway_buffer, sizeof(c->gateway_buffer), " > https://dweb.link"); > + > + av_log(h, AV_LOG_WARNING, > + "IPFS does not appear to be running. " > + "You’re now using the public gateway at dweb.link.\n"); > + av_log(h, AV_LOG_INFO, > + "Installing IPFS locally is recommended to " > + "improve performance and reliability, " > + "and not share all your activity with a single IPFS > gateway.\n" > + "There are multiple options to define this gateway.\n" > + "1. Call ffmpeg with a gateway param, " > + "without a trailing slash: -gateway <url>.\n" > + "2. Define an $IPFS_GATEWAY environment variable with > the " > + "full HTTP URL to the gateway " > + "without trailing forward slash.\n" > + "3. Define an $IPFS_PATH environment variable " > + "and point it to the IPFS data path " > + "- this is typically ~/.ipfs\n"); > + } > + } > + > + // Test if the gateway starts with either http:// or https:// > + if (av_stristart(c->gateway_buffer, "http://", NULL) == 0 > + && av_stristart(c->gateway_buffer, "https://", NULL) == 0) { > + av_log(h, AV_LOG_WARNING, > + "The gateway URL didn't start with http:// or " > + "https:// and is therefore invalid.\n"); > + ret = AVERROR(EILSEQ); > + goto err; > + } > + > + // Concatenate the url. > + // This ends up with something like: http://localhost:8080/ipfs/Qm... > .. > + // The format of "%s%s%s%s" is the following: > + // 1st %s = The gateway. > + // 2nd %s = If the gateway didn't end in a slash, add a "/". > Otherwise it's an empty string > + // 3rd %s = Either ipns/ or ipfs/. > + // 4th %s = The IPFS CID (Qm..., bafy..., ...). > + fulluri = av_asprintf("%s%s%s%s", > + c->gateway_buffer, > + (c->gateway_buffer[strlen(c->gateway_buffer) - > 1] == '/') ? "" : "/", > + (is_ipns) ? "ipns/" : "ipfs/", > + ipfs_cid); > + > + if (!fulluri) { > + av_log(h, AV_LOG_ERROR, "Failed to compose the URL\n"); > + ret = AVERROR(ENOMEM); > + goto err; > + } > + > + // Pass the URL back to FFMpeg's protocol handler. > + ret = ffurl_open_whitelist(&c->inner, fulluri, flags, > + &h->interrupt_callback, options, > + h->protocol_whitelist, > + h->protocol_blacklist, h); > + if (ret < 0) { > + av_log(h, AV_LOG_WARNING, "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; > + 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 d07563cd0c..6ee62a598a 100644 > --- a/libavformat/protocols.c > +++ b/libavformat/protocols.c > @@ -71,6 +71,8 @@ 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 > > I just keep pinging... :) Well.. This is the one to be merged, right? _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".