diff options
| -rwxr-xr-x | configure | 2 | ||||
| -rw-r--r-- | doc/protocols.texi | 30 | ||||
| -rw-r--r-- | libavformat/Makefile | 2 | ||||
| -rw-r--r-- | libavformat/ipfsgateway.c | 341 | ||||
| -rw-r--r-- | libavformat/protocols.c | 2 | ||||
| -rw-r--r-- | libavformat/version.h | 2 |
6 files changed, 378 insertions, 1 deletions
@@ -3581,6 +3581,8 @@ 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..ed37e552dd --- /dev/null +++ b/libavformat/ipfsgateway.c @@ -0,0 +1,341 @@ +/* + * 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" + "- $IPFS_PATH, which was empty.\n" + "- $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" diff --git a/libavformat/version.h b/libavformat/version.h index 683184d5da..d8fc959f19 100644 --- a/libavformat/version.h +++ b/libavformat/version.h @@ -31,7 +31,7 @@ #include "version_major.h" -#define LIBAVFORMAT_VERSION_MINOR 21 +#define LIBAVFORMAT_VERSION_MINOR 22 #define LIBAVFORMAT_VERSION_MICRO 100 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \ |