Re: [FFmpeg-devel] [PATCH v4 1/1] avformat: Add IPFS protocol support.
ons 2022-02-09 klockan 18:36 +0100 skrev Mark Gaiser: > > > Thank you so much for all the valuable feedback! It's much > appreciated :) > > I'll fix all the still open issues and send another patch mail > somewhere > later this week. > Question though, as this seems to be heading towards the final patch > version. How do you prefer to see the next patch round? > > 1. As it's done currently. You don't see what's different. > 2. As a 1/2 and 2/2 patch where 2/2 would be the a diff on top of 1/2 > with > the review feedback applied. > > Either is fine with me. > But I fear that a split patch mail (so 1/2 with the code as is right > now > and 2/2 with the feedback changes) could potentially waste people's > time if > they comment on something that is fixed in the feedback patch. Submit patches as you want them in the source tree. Writing patches to patches not yet committed makes little sense. /Tomas ___ 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".
Re: [FFmpeg-devel] [PATCH v4 1/1] avformat: Add IPFS protocol support.
On Wed, Feb 9, 2022 at 6:36 PM Mark Gaiser wrote:
> On Mon, Feb 7, 2022 at 4:09 PM Tomas Härdin wrote:
>
>> fre 2022-02-04 klockan 15:12 +0100 skrev Mark Gaiser:
>> > On Fri, Feb 4, 2022 at 12:10 PM Tomas Härdin
>> > wrote:
>> >
>> > > tor 2022-02-03 klockan 18:29 +0100 skrev Mark Gaiser:
>> > > >
>> > > > +typedef struct IPFSGatewayContext {
>> > > > +AVClass *class;
>> > > > +URLContext *inner;
>> > > > +char *gateway;
>> > >
>> > > Consider two separate variables. One for AVOption and one for the
>> > > dynamically allocated string. Or put the latter on the stack.
>> > >
>> >
>> > There always needs to be a gateway so why is reusing that variable an
>> > issue?
>> > I'm fine splitting it up but I'd like to understand the benefit of it
>> > as
>> > currently I don't see that benefit.
>>
>> Because of the way AVOption memory allocation works
>>
>> >
>> > > > +static int populate_ipfs_gateway(URLContext *h)
>> > > > +{
>> > > > +IPFSGatewayContext *c = h->priv_data;
>> > > > +char *ipfs_full_data_folder = NULL;
>> > > > +char *ipfs_gateway_file = NULL;
>> > >
>> > > These can be char[PATH_MAX]
>> > >
>> >
>> > Oke, will do.
>> > C code question though.
>> > How do I use av_asprintf on stack arrays like that?
>>
>> snprintf(). Also be careful with PATH_MAX and +-1 bytes for the NUL.
>>
>> >
>> > > Again, there is no reason to stat this. Just try opening the
>> > > gateway
>> > > file directly.
>> > >
>> >
>> > This is a folder, not a file.
>> >
>> > The other stat that was here too was a file, I replaced that with an
>> > fopen.
>> > It smells sketchy to me to (ab)use fopen to check if a folder exists.
>> > There's stat for that.
>>
>> You don't need to check whether the folder exists at all. The only
>> thing that accomplishes is some AV_LOG_DEBUG prints that won't even get
>> compiled in unless a users builds with -g (I think). It's not sketchy -
>> it's spec'd behavior.
>>
>> >
>> >
>> > >
>> > > > +
>> > > > +// Read a single line (fgets stops at new line mark).
>> > > > +fgets(gateway_file_data, sizeof(gateway_file_data) - 1,
>> > > > gateway_file);
>> > >
>> > > This can result in gateway_file_data not being NUL terminated
>> >
>> >
>> > > > +
>> > > > +// Replace first occurence of end of line to \0
>> > > > +gateway_file_data[strcspn(gateway_file_data, "\r\n")] = 0;
>> > >
>> > > What if the file uses \n or no newlines at all?
>> > >
>> >
>> > Right.
>> > So I guess the fix here is:
>> > 1. Initialize gateway_file_data so all bytes are zero
>> > 2. read a line
>> > 3. set the last byte of gateway_file_data to 0
>> >
>> > Now any text in the string will be the gateway.
>> >
>> > Is that a proper fix?
>>
>> Yes always putting a NUL at the end works. You don't need to initialize
>> with zero in that case. fgets() will NUL terminate except when there's
>> an error like the line being too long.
>>
>> >
>> >
>> > > > +err:
>> > > > +if (gateway_file)
>> > > > +fclose(gateway_file);
>> > > > +
>> > > > +av_free(ipfs_full_data_folder);
>> > > > +av_free(ipfs_gateway_file);
>> > >
>> > > This is not cleaning up dynamic allocations of c->gateway
>> > >
>> >
>> > So I should do that in ipfs_close, right?
>>
>> That's one place to do it yes. I forget whether _close() is called in
>> case of errors. av_freep() will set the pointer to NULL after freeing
>> so no double-frees occur.
>>
>> >
>> > >
>> > >
>> > > > +// Test if the gateway starts with either http:// or
>> > > > https://
>> > > > +// The remainder is stored in url_without_protocol
>> > > > +if (av_stristart(uri, "http://;, _without_protocol) == 0
>> > > > +&& av_stristart(uri, "https://;, _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 = -2;
>> > > > +goto err;
>> > > > +}
>> > >
>> > > I guess restricting this to HTTP schemes is OK. Or are there non-
>> > > HTTP
>> > > gateways for this?
>> > >
>> >
>> > No.
>> > At least not from the IPFS camp.
>> > The IPFS software creates a gateway and that is specifically an http
>> > gateway.
>> > Users can put that behind a proxy making it (potentially) a https
>> > gateway
>> > but that's about it.
>>
>> I see. I guess if any user puts this stuff behind gopher:// or
>> something then that's their problem.
>>
>> >
>> > >
>> > > > +if (last_gateway_char != '/') {
>> > > > +c->gateway = av_asprintf("%s/", c->gateway);
>> > >
>> > > Yet another leak
>> > >
>> >
>> > Please tell me how to fix this one.
>> > As you can see, I need the c->gateway value to copy and add a "/" to
>> > it.
>> >
>> > In C++ this would just be a dead simple append ;)
>>
>> Ensure there's enough space for '/' and a NUL and just write that to
>> the end.
>>
>> snprintf() can do all of this if used appropriately. For example to
>> conditionally append "/" you can put %s
Re: [FFmpeg-devel] [PATCH v4 1/1] avformat: Add IPFS protocol support.
On Mon, Feb 7, 2022 at 4:09 PM Tomas Härdin wrote:
> fre 2022-02-04 klockan 15:12 +0100 skrev Mark Gaiser:
> > On Fri, Feb 4, 2022 at 12:10 PM Tomas Härdin
> > wrote:
> >
> > > tor 2022-02-03 klockan 18:29 +0100 skrev Mark Gaiser:
> > > >
> > > > +typedef struct IPFSGatewayContext {
> > > > +AVClass *class;
> > > > +URLContext *inner;
> > > > +char *gateway;
> > >
> > > Consider two separate variables. One for AVOption and one for the
> > > dynamically allocated string. Or put the latter on the stack.
> > >
> >
> > There always needs to be a gateway so why is reusing that variable an
> > issue?
> > I'm fine splitting it up but I'd like to understand the benefit of it
> > as
> > currently I don't see that benefit.
>
> Because of the way AVOption memory allocation works
>
> >
> > > > +static int populate_ipfs_gateway(URLContext *h)
> > > > +{
> > > > +IPFSGatewayContext *c = h->priv_data;
> > > > +char *ipfs_full_data_folder = NULL;
> > > > +char *ipfs_gateway_file = NULL;
> > >
> > > These can be char[PATH_MAX]
> > >
> >
> > Oke, will do.
> > C code question though.
> > How do I use av_asprintf on stack arrays like that?
>
> snprintf(). Also be careful with PATH_MAX and +-1 bytes for the NUL.
>
> >
> > > Again, there is no reason to stat this. Just try opening the
> > > gateway
> > > file directly.
> > >
> >
> > This is a folder, not a file.
> >
> > The other stat that was here too was a file, I replaced that with an
> > fopen.
> > It smells sketchy to me to (ab)use fopen to check if a folder exists.
> > There's stat for that.
>
> You don't need to check whether the folder exists at all. The only
> thing that accomplishes is some AV_LOG_DEBUG prints that won't even get
> compiled in unless a users builds with -g (I think). It's not sketchy -
> it's spec'd behavior.
>
> >
> >
> > >
> > > > +
> > > > +// Read a single line (fgets stops at new line mark).
> > > > +fgets(gateway_file_data, sizeof(gateway_file_data) - 1,
> > > > gateway_file);
> > >
> > > This can result in gateway_file_data not being NUL terminated
> >
> >
> > > > +
> > > > +// Replace first occurence of end of line to \0
> > > > +gateway_file_data[strcspn(gateway_file_data, "\r\n")] = 0;
> > >
> > > What if the file uses \n or no newlines at all?
> > >
> >
> > Right.
> > So I guess the fix here is:
> > 1. Initialize gateway_file_data so all bytes are zero
> > 2. read a line
> > 3. set the last byte of gateway_file_data to 0
> >
> > Now any text in the string will be the gateway.
> >
> > Is that a proper fix?
>
> Yes always putting a NUL at the end works. You don't need to initialize
> with zero in that case. fgets() will NUL terminate except when there's
> an error like the line being too long.
>
> >
> >
> > > > +err:
> > > > +if (gateway_file)
> > > > +fclose(gateway_file);
> > > > +
> > > > +av_free(ipfs_full_data_folder);
> > > > +av_free(ipfs_gateway_file);
> > >
> > > This is not cleaning up dynamic allocations of c->gateway
> > >
> >
> > So I should do that in ipfs_close, right?
>
> That's one place to do it yes. I forget whether _close() is called in
> case of errors. av_freep() will set the pointer to NULL after freeing
> so no double-frees occur.
>
> >
> > >
> > >
> > > > +// Test if the gateway starts with either http:// or
> > > > https://
> > > > +// The remainder is stored in url_without_protocol
> > > > +if (av_stristart(uri, "http://;, _without_protocol) == 0
> > > > +&& av_stristart(uri, "https://;, _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 = -2;
> > > > +goto err;
> > > > +}
> > >
> > > I guess restricting this to HTTP schemes is OK. Or are there non-
> > > HTTP
> > > gateways for this?
> > >
> >
> > No.
> > At least not from the IPFS camp.
> > The IPFS software creates a gateway and that is specifically an http
> > gateway.
> > Users can put that behind a proxy making it (potentially) a https
> > gateway
> > but that's about it.
>
> I see. I guess if any user puts this stuff behind gopher:// or
> something then that's their problem.
>
> >
> > >
> > > > +if (last_gateway_char != '/') {
> > > > +c->gateway = av_asprintf("%s/", c->gateway);
> > >
> > > Yet another leak
> > >
> >
> > Please tell me how to fix this one.
> > As you can see, I need the c->gateway value to copy and add a "/" to
> > it.
> >
> > In C++ this would just be a dead simple append ;)
>
> Ensure there's enough space for '/' and a NUL and just write that to
> the end.
>
> snprintf() can do all of this if used appropriately. For example to
> conditionally append "/" you can put %s in the format string and the
> ternary
>
> needs_slash ? "/" : ""
>
> as the associated argument
>
> /Tomas
>
>
Thank you so much for all the valuable feedback! It's much appreciated :)
I'll fix all the still open
Re: [FFmpeg-devel] [PATCH v4 1/1] avformat: Add IPFS protocol support.
fre 2022-02-04 klockan 15:12 +0100 skrev Mark Gaiser:
> On Fri, Feb 4, 2022 at 12:10 PM Tomas Härdin
> wrote:
>
> > tor 2022-02-03 klockan 18:29 +0100 skrev Mark Gaiser:
> > >
> > > +typedef struct IPFSGatewayContext {
> > > + AVClass *class;
> > > + URLContext *inner;
> > > + char *gateway;
> >
> > Consider two separate variables. One for AVOption and one for the
> > dynamically allocated string. Or put the latter on the stack.
> >
>
> There always needs to be a gateway so why is reusing that variable an
> issue?
> I'm fine splitting it up but I'd like to understand the benefit of it
> as
> currently I don't see that benefit.
Because of the way AVOption memory allocation works
>
> > > +static int populate_ipfs_gateway(URLContext *h)
> > > +{
> > > + IPFSGatewayContext *c = h->priv_data;
> > > + char *ipfs_full_data_folder = NULL;
> > > + char *ipfs_gateway_file = NULL;
> >
> > These can be char[PATH_MAX]
> >
>
> Oke, will do.
> C code question though.
> How do I use av_asprintf on stack arrays like that?
snprintf(). Also be careful with PATH_MAX and +-1 bytes for the NUL.
>
> > Again, there is no reason to stat this. Just try opening the
> > gateway
> > file directly.
> >
>
> This is a folder, not a file.
>
> The other stat that was here too was a file, I replaced that with an
> fopen.
> It smells sketchy to me to (ab)use fopen to check if a folder exists.
> There's stat for that.
You don't need to check whether the folder exists at all. The only
thing that accomplishes is some AV_LOG_DEBUG prints that won't even get
compiled in unless a users builds with -g (I think). It's not sketchy -
it's spec'd behavior.
>
>
> >
> > > +
> > > + // Read a single line (fgets stops at new line mark).
> > > + fgets(gateway_file_data, sizeof(gateway_file_data) - 1,
> > > gateway_file);
> >
> > This can result in gateway_file_data not being NUL terminated
>
>
> > > +
> > > + // Replace first occurence of end of line to \0
> > > + gateway_file_data[strcspn(gateway_file_data, "\r\n")] = 0;
> >
> > What if the file uses \n or no newlines at all?
> >
>
> Right.
> So I guess the fix here is:
> 1. Initialize gateway_file_data so all bytes are zero
> 2. read a line
> 3. set the last byte of gateway_file_data to 0
>
> Now any text in the string will be the gateway.
>
> Is that a proper fix?
Yes always putting a NUL at the end works. You don't need to initialize
with zero in that case. fgets() will NUL terminate except when there's
an error like the line being too long.
>
>
> > > +err:
> > > + if (gateway_file)
> > > + fclose(gateway_file);
> > > +
> > > + av_free(ipfs_full_data_folder);
> > > + av_free(ipfs_gateway_file);
> >
> > This is not cleaning up dynamic allocations of c->gateway
> >
>
> So I should do that in ipfs_close, right?
That's one place to do it yes. I forget whether _close() is called in
case of errors. av_freep() will set the pointer to NULL after freeing
so no double-frees occur.
>
> >
> >
> > > + // Test if the gateway starts with either http:// or
> > > https://
> > > + // The remainder is stored in url_without_protocol
> > > + if (av_stristart(uri, "http://;, _without_protocol) == 0
> > > + && av_stristart(uri, "https://;, _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 = -2;
> > > + goto err;
> > > + }
> >
> > I guess restricting this to HTTP schemes is OK. Or are there non-
> > HTTP
> > gateways for this?
> >
>
> No.
> At least not from the IPFS camp.
> The IPFS software creates a gateway and that is specifically an http
> gateway.
> Users can put that behind a proxy making it (potentially) a https
> gateway
> but that's about it.
I see. I guess if any user puts this stuff behind gopher:// or
something then that's their problem.
>
> >
> > > + if (last_gateway_char != '/') {
> > > + c->gateway = av_asprintf("%s/", c->gateway);
> >
> > Yet another leak
> >
>
> Please tell me how to fix this one.
> As you can see, I need the c->gateway value to copy and add a "/" to
> it.
>
> In C++ this would just be a dead simple append ;)
Ensure there's enough space for '/' and a NUL and just write that to
the end.
snprintf() can do all of this if used appropriately. For example to
conditionally append "/" you can put %s in the format string and the
ternary
needs_slash ? "/" : ""
as the associated argument
/Tomas
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Re: [FFmpeg-devel] [PATCH v4 1/1] avformat: Add IPFS protocol support.
On Fri, Feb 4, 2022 at 12:10 PM Tomas Härdin wrote:
> tor 2022-02-03 klockan 18:29 +0100 skrev Mark Gaiser:
> >
> > +typedef struct IPFSGatewayContext {
> > +AVClass *class;
> > +URLContext *inner;
> > +char *gateway;
>
> Consider two separate variables. One for AVOption and one for the
> dynamically allocated string. Or put the latter on the stack.
>
There always needs to be a gateway so why is reusing that variable an issue?
I'm fine splitting it up but I'd like to understand the benefit of it as
currently I don't see that benefit.
> > +} 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.
> > +//
> > +// Return codes can be:
> > +// 1 : A potential gateway is found and set in c->gateway
> > +// -1: The IPFS data folder could not be found
> > +// -2: The gateway file could not be found
> > +// -3: The gateway file is found but empty
> > +// -4: $HOME is empty
> > +// -9: Unhandled error
>
> What Michael meant with better return codes is using AVERROR_* :)
>
Hey, first attempt at an ffmpeg contribution here. I didn't know that at
all. ;)
But yeah, will do!
> > +static int populate_ipfs_gateway(URLContext *h)
> > +{
> > +IPFSGatewayContext *c = h->priv_data;
> > +char *ipfs_full_data_folder = NULL;
> > +char *ipfs_gateway_file = NULL;
>
> These can be char[PATH_MAX]
>
Oke, will do.
C code question though.
How do I use av_asprintf on stack arrays like that?
I kinda like to prevent using something different just to later figure out
that there was an av_ function that would be far better :)
> > +struct stat st;
> > +int stat_ret = 0;
> > +int ret = -9;
> > +FILE *gateway_file = NULL;
> > +char gateway_file_data[1000];
>
> A maximum URL length of 999?
>
There doesn't seem to be a hard limit on url's..
It even seems to be browser dependent. Chrome apparently allows it up to
2MB, firefox up to 64k.
I'm just going to use PATH_MAX here too which seems plenty with 4096 bytes.
IPFS url's can be rather lengthy though so I do like to keep enough room
for it.
> > +
> > +// First, test if there already is a path in c->gateway. If it
> > is then it
> > +// was provided as cli arument and should be used. It takes
> > precdence.
> > +if (c->gateway != NULL) {
> > +ret = 1;
> > +goto err;
> > +}
> > +
> > +// Test $IPFS_GATEWAY.
> > +if (getenv("IPFS_GATEWAY") != NULL) {
> > +av_free(c->gateway);
>
> Useless since c->gateway is NULL
>
> > +
> > +// 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, );
> > +#else
> > +stat_ret = win32_stat(ipfs_full_data_folder, );
> > +#endif
>
> Again, there is no reason to stat this. Just try opening the gateway
> file directly.
>
This is a folder, not a file.
The other stat that was here too was a file, I replaced that with an fopen.
It smells sketchy to me to (ab)use fopen to check if a folder exists.
There's stat for that.
>
> > +
> > +// Read a single line (fgets stops at new line mark).
> > +fgets(gateway_file_data, sizeof(gateway_file_data) - 1,
> > gateway_file);
>
> This can result in gateway_file_data not being NUL terminated
> > +
> > +// Replace first occurence of end of line to \0
> > +gateway_file_data[strcspn(gateway_file_data, "\r\n")] = 0;
>
> What if the file uses \n or no newlines at all?
>
Right.
So I guess the fix here is:
1. Initialize gateway_file_data so all bytes are zero
2. read a line
3. set the last byte of gateway_file_data to 0
Now any text in the string will be the gateway.
Is that a proper fix?
> > +err:
> > +if (gateway_file)
> > +fclose(gateway_file);
> > +
> > +av_free(ipfs_full_data_folder);
> > +av_free(ipfs_gateway_file);
>
> This is not cleaning up dynamic allocations of c->gateway
>
So I should do that in ipfs_close, right?
>
> > +// -3: The gateway url part (without the protocol) is too short. We
> > expect 3
> > +// characters minimal. So http://aaa would be the bare minimal.
>
> http://1 is valid I think. It means http://0.0.0.1
Right, 1 character it is.
I thought I'd go for a common sense approach as in "it can't possibly be
smaller than..."
But I suppose just forcing any character to be there is fine too.
>
>
> > +// Test if the gateway starts with either http:// or https://
> > +// The remainder is stored in url_without_protocol
> > +if (av_stristart(uri, "http://;, _without_protocol) == 0
> > +&& av_stristart(uri, "https://;, _without_protocol) ==
> > 0) {
> > +av_log(h, AV_LOG_ERROR, "The gateway URL didn't start with
> > http:// or https:// and is therefore invalid.\n");
> > +
Re: [FFmpeg-devel] [PATCH v4 1/1] avformat: Add IPFS protocol support.
tor 2022-02-03 klockan 18:29 +0100 skrev Mark Gaiser:
>
> +typedef struct IPFSGatewayContext {
> + AVClass *class;
> + URLContext *inner;
> + char *gateway;
Consider two separate variables. One for AVOption and one for the
dynamically allocated string. Or put the latter on the stack.
> +} 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.
> +//
> +// Return codes can be:
> +// 1 : A potential gateway is found and set in c->gateway
> +// -1: The IPFS data folder could not be found
> +// -2: The gateway file could not be found
> +// -3: The gateway file is found but empty
> +// -4: $HOME is empty
> +// -9: Unhandled error
What Michael meant with better return codes is using AVERROR_* :)
> +static int populate_ipfs_gateway(URLContext *h)
> +{
> + IPFSGatewayContext *c = h->priv_data;
> + char *ipfs_full_data_folder = NULL;
> + char *ipfs_gateway_file = NULL;
These can be char[PATH_MAX]
> + struct stat st;
> + int stat_ret = 0;
> + int ret = -9;
> + FILE *gateway_file = NULL;
> + char gateway_file_data[1000];
A maximum URL length of 999?
> +
> + // First, test if there already is a path in c->gateway. If it
> is then it
> + // was provided as cli arument and should be used. It takes
> precdence.
> + if (c->gateway != NULL) {
> + ret = 1;
> + goto err;
> + }
> +
> + // Test $IPFS_GATEWAY.
> + if (getenv("IPFS_GATEWAY") != NULL) {
> + av_free(c->gateway);
Useless since c->gateway is NULL
> +
> + // 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, );
> +#else
> + stat_ret = win32_stat(ipfs_full_data_folder, );
> +#endif
Again, there is no reason to stat this. Just try opening the gateway
file directly.
> +
> + // Read a single line (fgets stops at new line mark).
> + fgets(gateway_file_data, sizeof(gateway_file_data) - 1,
> gateway_file);
This can result in gateway_file_data not being NUL terminated
> +
> + // Replace first occurence of end of line to \0
> + gateway_file_data[strcspn(gateway_file_data, "\r\n")] = 0;
What if the file uses \n or no newlines at all?
> +err:
> + if (gateway_file)
> + fclose(gateway_file);
> +
> + av_free(ipfs_full_data_folder);
> + av_free(ipfs_gateway_file);
This is not cleaning up dynamic allocations of c->gateway
> +// -3: The gateway url part (without the protocol) is too short. We
> expect 3
> +// characters minimal. So http://aaa would be the bare minimal.
http://1 is valid I think. It means http://0.0.0.1
> + // Test if the gateway starts with either http:// or https://
> + // The remainder is stored in url_without_protocol
> + if (av_stristart(uri, "http://;, _without_protocol) == 0
> + && av_stristart(uri, "https://;, _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 = -2;
> + goto err;
> + }
I guess restricting this to HTTP schemes is OK. Or are there non-HTTP
gateways for this?
> + if (last_gateway_char != '/') {
> + c->gateway = av_asprintf("%s/", c->gateway);
Yet another leak
> // Sanitize the gateway to a format we expect.
> +if (sanitize_ipfs_gateway(h) < 1)
> +goto err;
This will return unset ret, thus leaking data from the stack
> +static int ipfs_close(URLContext *h)
> +{
> + IPFSGatewayContext *c = h->priv_data;
Here is where you'd put any deallocations
The quality of this patch is making me re-affirm what I've already said
viz parsing. bash+sed is superior.
/Tomas
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[FFmpeg-devel] [PATCH v4 1/1] avformat: Add IPFS protocol support.
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 | 329 ++
libavformat/protocols.c | 2 +
5 files changed, 365 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 00..72d431eac3
--- /dev/null
+++ b/libavformat/ipfsgateway.c
@@ -0,0 +1,329 @@
+/*
+ * 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;
+}
