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construct/matrix/vm_inject.cc

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12 KiB
C++

// Matrix Construct
//
// Copyright (C) Matrix Construct Developers, Authors & Contributors
// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice is present in all copies. The
// full license for this software is available in the LICENSE file.
namespace ircd::m::vm
{
static fault inject3(eval &, json::iov &, const json::iov &);
static fault inject1(eval &, json::iov &, const json::iov &);
}
///
/// Figure 1:
/// in . <-- injection
/// ===:::::::==//
/// | ||||||| // <-- these functions
/// | \\|// //|
/// | ||| // | | acceleration
/// | |||// | |
/// | |||/ | |
/// | ||| | V
/// | !!! |
/// | * | <----- nozzle
/// | ///|||\\\ |
/// |/|/|/|\|\|\| <---- propagation cone
/// _/|/|/|/|\|\|\|\_
/// out
///
ircd::m::vm::fault
ircd::m::vm::inject(eval &eval,
json::iov &event,
const json::iov &contents)
{
// We need a copts structure in addition to the opts structure in order
// to inject a new event. If one isn't supplied a default is referenced.
eval.copts = !eval.copts?
&vm::default_copts:
eval.copts;
// Note that the regular opts is unconditionally overridden because the
// user should have provided copts instead.
assert(!eval.opts || eval.opts == eval.copts);
eval.opts = eval.copts;
// copts inherits from opts; for the purpose of this frame we consider
// the options structure to be all of it.
assert(eval.opts);
assert(eval.copts);
const auto &opts
{
*eval.copts
};
// This semaphore gets unconditionally pinged when this scope ends.
const scope_notify notify
{
vm::dock
};
// The count of contexts currently conducting an event injection is
// incremented here and decremented at unwind.
const scope_count eval_injecting
{
eval::injecting
};
// Set a member pointer to the json::iov currently being composed. This
// allows other parallel evals to have deep access to exactly what this
// eval is attempting to do.
const scope_restore eval_issue
{
eval.issue, &event
};
// Common indicator which will determine if several branches are taken as
// a room create event has several special cases.
const bool is_room_create
{
event.at("type") == "m.room.create"
};
// The eval structure has a direct room::id reference for interface
// convenience so people don't have to figure out what room (if any)
// this injection is targeting. That reference might already be set
// by the user as a hint; if not, we attempt to set it here and tie
// it to the duration of this frame.
const scope_restore eval_room_id
{
eval.room_id,
!eval.room_id && event.has("room_id") && valid(id::ROOM, event.at("room_id"))?
string_view{event.at("room_id")}:
string_view{eval.room_id}
};
const scope_restore eval_room_internal
{
eval.room_internal,
eval.room_internal?
eval.room_internal:
eval.room_id && my(room::id(eval.room_id))?
m::internal(eval.room_id):
false
};
// Attempt to resolve the room version at this point for interface
// exposure at vm::eval::room_version.
char room_version_buf[room::VERSION_MAX_SIZE];
const scope_restore eval_room_version
{
eval.room_version,
// If the eval.room_version interface reference is already set to
// something we assume the room_version has alreandy been resolved
eval.room_version?
eval.room_version:
// If the options had a room_version set, consider that the room
// version. The user has already resolved the room version and is
// hinting us as an optimization.
eval.opts->room_version?
eval.opts->room_version:
// If this is an m.room.create event then we're lucky that the best
// room version information is in the spec location.
is_room_create && contents.has("room_version")?
string_view{contents.at("room_version")}:
// If this is an EDU or some kind of feature without a room_id then
// we'll leave this blank.
!eval.room_id?
string_view{}:
// Make a query to find the version. The version string will be hosted
// by the stack buffer.
m::version(room_version_buf, room{eval.room_id}, std::nothrow)
};
// Conditionally add the room_id from the eval structure to the actual
// event iov being injected. This is the inverse of the above satisfying
// the case where the room_id is supplied via the reference, not the iov;
// in the end we want that reference in both places.
const json::iov::add room_id_
{
event, eval.room_id && !event.has("room_id"),
{
"room_id", [&eval]() -> json::value
{
return eval.room_id;
}
}
};
// XXX: should move outside if lazy static initialization is problem.
static conf::item<size_t> prev_limit
{
{ "name", "ircd.m.vm.inject.prev.limit" },
{ "default", 16L },
{
"description",
"Events created by this server will only"
" reference a maximum of this many prev_events."
},
};
// Ad hoc number of bytes we'll need for each prev_events reference in
// a v1 event. We don't use the hashes in prev_events, so we just need
// space for one worst-case event_id and some JSON.
static const size_t prev_scalar_v1
{
(id::MAX_SIZE + 1) * 2
};
// Ad hoc number of bytes we'll need for each prev_events reference in
// a sha256-b64 event_id format.
static const size_t prev_scalar_v3
{
// " $ XX " ,
1 + 1 + 43 + 1 + 1 + 1
};
const auto &prev_scalar
{
eval.room_version == "1" || eval.room_version == "2"?
prev_scalar_v1:
prev_scalar_v3
};
const bool add_prev_events
{
!is_room_create
&& opts.prop_mask.has("prev_events")
&& !event.has("prev_events")
&& eval.room_id
};
// The buffer we'll be composing the prev_events JSON array into.
const unique_buffer<mutable_buffer> prev_buf
{
add_prev_events?
std::min(size_t(prev_limit) * (prev_scalar + 1), event::MAX_SIZE):
0UL
};
// Conduct the prev_events composition into our buffer. This sub returns
// a finished json::array in our buffer as well as a depth integer for
// the event which will be using the references.
const room::head head
{
add_prev_events?
room::head{room{eval.room_id}}:
room::head{}
};
const room::head::generate prev_events
{
prev_buf, head,
{
16, // .limit = 16,
true, // !eval.room_internal, // .need_top_head = true for non-internal rooms
!eval.room_internal, // .need_my_head = true for non-internal rooms
eval.room_version // .version = eval.room_version,
}
};
// Add the prev_events
const json::iov::add prev_events_
{
event, add_prev_events && !empty(prev_events.array),
{
"prev_events", [&prev_events]() -> json::value
{
return prev_events.array;
}
}
};
const auto &depth
{
prev_events.depth[1]
};
// Conditionally add the depth property to the event iov.
const json::iov::set depth_
{
event, opts.prop_mask.has("depth") && !event.has("depth"),
{
"depth", [&depth]() noexcept
{
// When the depth value is undefined_number it was intended
// that no depth should appear in the event JSON so that value
// is preserved; we also don't overflow the integer, so if the
// depth is at max value that is preserved too.
return
depth == std::numeric_limits<int64_t>::max() ||
depth == json::undefined_number?
json::value{depth}:
depth >= -1?
json::value{depth + 1}:
json::value{json::undefined_number};
}
}
};
const bool add_auth_events
{
!is_room_create
&& opts.prop_mask.has("auth_events")
&& !event.has("auth_events")
&& eval.room_id
};
// The auth_events have more deterministic properties.
static const size_t auth_buf_sz{m::id::MAX_SIZE * 4};
const unique_buffer<mutable_buffer> auth_buf
{
add_auth_events? auth_buf_sz : 0UL
};
// Conditionally compose the auth events. efault to an empty array.
const json::array auth_events
{
add_auth_events?
room::auth::generate(auth_buf, m::room{eval.room_id}, m::event{event}):
json::empty_array
};
// Conditionally add the auth_events to the event iov.
const json::iov::add auth_events_
{
event, add_auth_events,
{
"auth_events", [&auth_events]() -> json::value
{
return auth_events;
}
}
};
// Add our network name.
const json::iov::add origin_
{
event, opts.prop_mask.has("origin"),
{
"origin", []() -> json::value
{
return my_host();
}
}
};
// Add the current time.
const json::iov::add origin_server_ts_
{
event, opts.prop_mask.has("origin_server_ts"),
{
"origin_server_ts", [&opts]
{
return json::value
{
opts.ts == milliseconds::min()?
ircd::time<milliseconds>():
opts.ts.count()
};
}
}
};
return eval.room_version == "1" || eval.room_version == "2"?
inject1(eval, event, contents):
inject3(eval, event, contents);
}
/// Old event branch
ircd::m::vm::fault
ircd::m::vm::inject1(eval &eval,
json::iov &event,
const json::iov &contents)
{
assert(eval.copts);
const auto &opts
{
*eval.copts
};
// event_id
assert(eval.room_version);
const event::id &event_id
{
opts.prop_mask.has("event_id")?
eval.event_id.assigned(make_id(m::event{event}, eval.room_version, eval.event_id)):
event::id{}
};
const json::iov::add event_id_
{
event, !empty(event_id),
{
"event_id", [&event_id]() -> json::value
{
return event_id;
}
}
};
// Stringify the event content into buffer
const json::strung content
{
contents
};
// hashes
char hashes_buf[384];
const string_view hashes
{
opts.prop_mask.has("hashes")?
m::event::hashes(hashes_buf, event, content):
string_view{}
};
const json::iov::add hashes_
{
event, opts.prop_mask.has("hashes") && !empty(hashes),
{
"hashes", [&hashes]() -> json::value
{
return hashes;
}
}
};
// sigs
char sigs_buf[384];
const string_view sigs
{
opts.prop_mask.has("signatures")?
m::event::signatures(sigs_buf, event, contents):
string_view{}
};
const json::iov::add sigs_
{
event, opts.prop_mask.has("signatures"),
{
"signatures", [&sigs]() -> json::value
{
return sigs;
}
}
};
const json::iov::push content_
{
event, { "content", content },
};
const m::event event_tuple
{
event, event_id
};
if(opts.debuglog_precommit)
log::debug
{
log, "Issuing: %s", pretty_oneline(event_tuple)
};
const vector_view events
{
&event_tuple, 1
};
return execute(eval, events);
}
/// New event branch
ircd::m::vm::fault
ircd::m::vm::inject3(eval &eval,
json::iov &event,
const json::iov &contents)
{
assert(eval.copts);
const auto &opts
{
*eval.copts
};
// Stringify the event content into buffer
const json::strung content
{
contents
};
// Compute the content hash into buffer.
char hashes_buf[384];
const string_view hashes
{
opts.prop_mask.has("hashes")?
m::event::hashes(hashes_buf, event, content):
string_view{}
};
// Add the content hash to the event iov.
const json::iov::add hashes_
{
event, opts.prop_mask.has("hashes") && !empty(hashes),
{
"hashes", [&hashes]() -> json::value
{
return hashes;
}
}
};
// Compute the signature into buffer.
char sigs_buf[384];
const string_view sigs
{
opts.prop_mask.has("signatures")?
m::event::signatures(sigs_buf, event, contents):
string_view{}
};
// Add the signature to the event iov.
const json::iov::add sigs_
{
event, opts.prop_mask.has("signatures"),
{
"signatures", [&sigs]() -> json::value
{
return sigs;
}
}
};
// Add the content to the event iov
const json::iov::push content_
{
event, { "content", content },
};
// Compute the event_id (reference hash) into the buffer
// in the eval interface so it persists longer than this stack.
const event::id &event_id
{
opts.prop_mask.has("event_id")?
eval.event_id.assigned(make_id(m::event{event}, eval.room_version, eval.event_id)):
event::id{}
};
// Transform the json iov into a json tuple
const m::event event_tuple
{
event, event_id
};
if(opts.debuglog_precommit)
log::debug
{
log, "Issuing: %s", pretty_oneline(event_tuple)
};
const vector_view events
{
&event_tuple, 1
};
return execute(eval, events);
}