[PATCH 1/3] netbox: allow to create a netbox connection from existing socket

[Vladislav Shpilevoy <v.shpilevoy@tarantool.org>]

It is needed to create a binary console connection, when a
socket is already created and a greeting is read and decoded.
---
 src/box/lua/net_box.lua   | 85 ++++++++++++++++++++++++++++++++---------------
 test/box/net.box.result   | 78 +++++++++++++++++++++++++++++++++++++++++--
 test/box/net.box.test.lua | 33 ++++++++++++++++--
 3 files changed, 166 insertions(+), 30 deletions(-)

diff --git a/src/box/lua/net_box.lua b/src/box/lua/net_box.lua
index 87c8c548b..f3f69f52f 100644
--- a/src/box/lua/net_box.lua
+++ b/src/box/lua/net_box.lua
@@ -121,7 +121,8 @@ local function next_id(id) return band(id + 1, 0x7FFFFFFF) end
 -- Suggestion for callback writers: sleep a few secs before approving
 -- reconnect.
 --
-local function create_transport(host, port, user, password, callback)
+local function create_transport(host, port, user, password, callback,
+                                existing_connection, greeting)
     -- check / normalize credentials
     if user == nil and password ~= nil then
         box.error(E_PROC_LUA, 'net.box: user is not defined')
@@ -368,26 +369,34 @@ local function create_transport(host, port, user, password, callback)
     -- in this function, a connection could not be deleted.
     --
     protocol_sm = function ()
+        local err, msg
         local tm_begin, tm = fiber.clock(), callback('fetch_connect_timeout')
-        connection = socket.tcp_connect(host, port, tm)
-        if connection == nil then
-            return error_sm(E_NO_CONNECTION, errno.strerror(errno()))
-        end
-        local size = IPROTO_GREETING_SIZE
-        local err, msg = send_and_recv(size, tm - (fiber.clock() - tm_begin))
-        if err then
-            return error_sm(err, msg)
-        end
-        local g = decode_greeting(ffi.string(recv_buf.rpos, size))
-        recv_buf.rpos = recv_buf.rpos + size
-        if not g then
-            return error_sm(E_NO_CONNECTION, 'Can\'t decode handshake')
+        if existing_connection then
+            connection = existing_connection
+            existing_connection = nil
+            assert(greeting)
+            assert(greeting.protocol ~= 'Lua console')
+        else
+            connection = socket.tcp_connect(host, port, tm)
+            if connection == nil then
+                return error_sm(E_NO_CONNECTION, errno.strerror(errno()))
+            end
+            local size = IPROTO_GREETING_SIZE
+            err, msg = send_and_recv(size, tm - (fiber.clock() - tm_begin))
+            if err then
+                return error_sm(err, msg)
+            end
+            greeting = decode_greeting(ffi.string(recv_buf.rpos, size))
+            recv_buf.rpos = recv_buf.rpos + size
+            if not greeting then
+                return error_sm(E_NO_CONNECTION, 'Can\'t decode handshake')
+            end
         end
-        err, msg = callback('handshake', g)
+        err, msg = callback('handshake', greeting)
         if err then
             return error_sm(err, msg)
         end
-        if g.protocol == 'Lua console' then
+        if greeting.protocol == 'Lua console' then
             local setup_delimiter = 'require("console").delimiter("$EOF$")\n'
             method_codec.inject(send_buf, nil, nil, setup_delimiter)
             local err, response = send_and_recv_console()
@@ -399,10 +408,11 @@ local function create_transport(host, port, user, password, callback)
             local rid = next_request_id
             set_state('active')
             return console_sm(rid)
-        elseif g.protocol == 'Binary' then
-            return iproto_auth_sm(g.salt)
+        elseif greeting.protocol == 'Binary' then
+            return iproto_auth_sm(greeting.salt)
         else
-            return error_sm(E_NO_CONNECTION, 'Unknown protocol: ' .. g.protocol)
+            return error_sm(E_NO_CONNECTION,
+                            'Unknown protocol: '..greeting.protocol)
         end
     end
 
@@ -541,14 +551,16 @@ end
 -- Now it is necessary to have a strong ref to callback somewhere or
 -- it is GC-ed prematurely. We wrap close() method, stashing the
 -- ref in an upvalue (close() performance doesn't matter much.)
-local create_transport = function(host, port, user, password, callback)
+local create_transport = function(host, port, user, password, callback,
+                                  existing_connection, greeting)
     local weak_refs = setmetatable({callback = callback}, {__mode = 'v'})
     local function weak_callback(...)
         local callback = weak_refs.callback
         if callback then return callback(...) end
     end
-    local transport = create_transport(host, port, user,
-                                       password, weak_callback)
+    local transport = create_transport(host, port, user, password,
+                                       weak_callback, existing_connection,
+                                       greeting)
     local transport_close = transport.close
     local gc_hook = ffi.gc(ffi.new('char[1]'), function()
         pcall(transport_close)
@@ -612,8 +624,7 @@ local console_mt = {
 
 local space_metatable, index_metatable
 
-local function connect(...)
-    local host, port, opts = parse_connect_params(...)
+local function do_connect(host, port, opts, existing_connection, greeting)
     local user, password = opts.user, opts.password; opts.password = nil
     local last_reconnect_error
     local remote = {host = host, port = port, opts = opts, state = 'initial'}
@@ -679,7 +690,8 @@ local function connect(...)
     remote._on_schema_reload = trigger.new("on_schema_reload")
     remote._on_disconnect = trigger.new("on_disconnect")
     remote._on_connect = trigger.new("on_connect")
-    remote._transport = create_transport(host, port, user, password, callback)
+    remote._transport = create_transport(host, port, user, password, callback,
+                                         existing_connection, greeting)
     remote._transport.connect()
     if opts.wait_connected ~= false then
         remote._transport.wait_state('active', tonumber(opts.wait_connected))
@@ -687,6 +699,25 @@ local function connect(...)
     return remote
 end
 
+local function connect(...)
+    local host, port, opts = parse_connect_params(...)
+    return do_connect(host, port, opts)
+end
+
+local function wrap_socket(connection, greeting, url, opts)
+    if connection == nil or type(greeting) ~= 'table' then
+        error('Usage: netbox.wrap_socket(socket, greeting, [opts])')
+    end
+    if greeting.protocol == 'Lua console' then
+        error('Can not wrap console socket')
+    end
+    opts = opts or {}
+    if not opts.user and not opts.password then
+        opts.user, opts.password = url.login, url.password
+    end
+    return do_connect(url.host, url.service, opts, connection, greeting)
+end
+
 local function check_remote_arg(remote, method)
     if type(remote) ~= 'table' then
         local fmt = 'Use remote:%s(...) instead of remote.%s(...):'
@@ -1112,7 +1143,9 @@ end
 local this_module = {
     create_transport = create_transport,
     connect = connect,
-    new = connect -- Tarantool < 1.7.1 compatibility
+    new = connect, -- Tarantool < 1.7.1 compatibility,
+    decode_greeting = internal.decode_greeting,
+    wrap_socket = wrap_socket,
 }
 
 function this_module.timeout(timeout, ...)
diff --git a/test/box/net.box.result b/test/box/net.box.result
index 46d85b327..cb9410085 100644
--- a/test/box/net.box.result
+++ b/test/box/net.box.result
@@ -2292,12 +2292,86 @@ weak.c
 ---
 - null
 ...
-box.schema.user.revoke('guest', 'execute', 'universe')
+--
+-- gh-2677: netbox supports console connections, that complicates
+-- both console and netbox. It was necessary because before a
+-- connection is established, a console does not known is it
+-- binary or text protocol, and netbox could not be created from
+-- existing socket.
+--
+box.schema.user.grant('guest','read,write,execute','universe')
+---
+...
+urilib = require('uri')
+---
+...
+uri = urilib.parse(tostring(box.cfg.listen))
+---
+...
+s = socket.tcp_connect(uri.host, uri.service)
+---
+...
+greeting = s:read({chunk = 128})
+---
+...
+greeting = net.decode_greeting(greeting)
+---
+...
+c = net.wrap_socket(s, greeting, uri)
+---
+...
+c.state
+---
+- active
+...
+a = 100
+---
+...
+function kek(args) return {1, 2, 3, args} end
+---
+...
+c:eval('a = 200')
+---
+...
+a
+---
+- 200
+...
+c:call('kek', {300})
+---
+- [1, 2, 3, 300]
+...
+s = box.schema.create_space('test')
+---
+...
+pk = s:create_index('pk')
+---
+...
+c:reload_schema()
+---
+...
+c.space.test:replace{1}
+---
+- [1]
+...
+c.space.test:get{1}
+---
+- [1]
+...
+c.space.test:delete{1}
+---
+- [1]
+...
+s:drop()
 ---
 ...
 c:close()
 ---
 ...
-c = nil
+c.state
+---
+- closed
+...
+box.schema.user.revoke('guest', 'read,write,execute', 'universe')
 ---
 ...
diff --git a/test/box/net.box.test.lua b/test/box/net.box.test.lua
index 87e26f84c..487401514 100644
--- a/test/box/net.box.test.lua
+++ b/test/box/net.box.test.lua
@@ -937,6 +937,35 @@ collectgarbage('collect')
 -- connection is deleted by 'collect'.
 weak.c
 
-box.schema.user.revoke('guest', 'execute', 'universe')
+--
+-- gh-2677: netbox supports console connections, that complicates
+-- both console and netbox. It was necessary because before a
+-- connection is established, a console does not known is it
+-- binary or text protocol, and netbox could not be created from
+-- existing socket.
+--
+box.schema.user.grant('guest','read,write,execute','universe')
+urilib = require('uri')
+uri = urilib.parse(tostring(box.cfg.listen))
+s = socket.tcp_connect(uri.host, uri.service)
+greeting = s:read({chunk = 128})
+greeting = net.decode_greeting(greeting)
+c = net.wrap_socket(s, greeting, uri)
+c.state
+
+a = 100
+function kek(args) return {1, 2, 3, args} end
+c:eval('a = 200')
+a
+c:call('kek', {300})
+s = box.schema.create_space('test')
+pk = s:create_index('pk')
+c:reload_schema()
+c.space.test:replace{1}
+c.space.test:get{1}
+c.space.test:delete{1}
+s:drop()
 c:close()
-c = nil
+c.state
+
+box.schema.user.revoke('guest', 'read,write,execute', 'universe')
-- 
2.14.3 (Apple Git-98)