#!/usr/bin/env lua
-- ***********************************************************************
--
-- Copyright 2019 by Sean Conner.
--
-- This program is free software: you can redistribute it and/or modify it
-- under the terms of the GNU General Public License as published by the
-- Free Software Foundation, either version 3 of the License, or (at your
-- option) any later version.
--
-- This program 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 General
-- Public License for more details.
--
-- You should have received a copy of the GNU General Public License along
-- with this program. If not, see <http://www.gnu.org/licenses/>;.
--
-- Comments, questions and criticisms can be sent to: sean@conman.org
--
-- ***********************************************************************
-- luacheck: ignore 611
local syslog = require "org.conman.syslog"
local signal = require "org.conman.signal"
local nfl = require "org.conman.nfl"
local tcp = require "org.conman.nfl.tcp"
local exit = require "org.conman.const.exit"
local lpeg = require "lpeg"
local setugid = require "port70.setugid"
math.randomseed(require("org.conman.math").seed())
require("org.conman.fsys.magic"):flags('mime')
-- ************************************************************************
if #arg == 0 then
io.stderr:write(string.format("usage: %s configfile\n",arg[0]))
os.exit(exit.USAGE,true)
end
local CONF = {} do
local conf,err = loadfile(arg[1],"t",CONF)
if not conf then
io.stderr:write(string.format("%s: %s\n",arg[1],err))
os.exit(exit.CONFIG,true)
end
conf()
if not CONF.syslog then
CONF.syslog = { ident = 'gopher' , facility = 'daemon' }
else
CONF.syslog.ident = CONF.syslog.ident or 'gopher'
CONF.syslog.facility = CONF.syslog.facility or 'daemon'
end
syslog.open(CONF.syslog.ident,CONF.syslog.facility)
if not CONF.network
or not CONF.network.host then
syslog('critical',"%s: missing or bad network configuration",arg[1])
io.stderr:write(string.format("%s: missing or bad network configuration",arg[1]),"\n")
os.exit(exit.CONFIG,true)
end
if not CONF.network.addr then
CONF.network.addr = "::"
end
if not CONF.network.port then
CONF.network.port = 70
end
if not CONF.redirect then
CONF.redirect = { permanent = {} , gone = {} }
else
CONF.redirect.permanent = CONF.redirect.permanent or {}
CONF.redirect.gone = CONF.redirect.gone or {}
end
package.loaded['port70.CONF'] = CONF
if not CONF.handlers or #CONF.handlers == 0 then
syslog('critical',"%s: at least one handler needs to be defined",arg[1])
io.stderr:write(string.format("%s: at least one handler needs to be defined",arg[1]),"\n")
os.exit(exit.CONFIG,true)
end
local function loadmodule(info)
local function notfound()
return false,"Selector not found"
end
if not info.selector then
syslog('error',"%q: missing selector field",info.module or "")
io.stderr:write(string.format("%q: missing selector field",info.module or ""),"\n")
info.selector = ""
info.code = { handler = notfound }
return
end
if not info.module then
syslog('error',"%q: missing module field",info.selector or "")
io.stderr:write(string.format("%q: missing module field",info.selector or ""),"\n")
info.code = { handler = notfound }
return
end
local okay,mod = pcall(require,info.module)
if not okay then
syslog('error',"%q %s",info.selector,mod)
io.stderr:write(string.format("%q %s",info.selector,mod),"\n")
info.code = { handler = notfound }
return
end
if type(mod) ~= 'table' then
syslog('error',"%q module %s not supported",info.selector,info.module)
io.stderr:write(string.format("%q module %s not supported",info.selector,info.module),"\n")
info.code = { handler = notfound }
return
end
if not mod.handler then
syslog('error',"%q missing %s.handler()",info.selector,info.module)
io.stderr:write(string.format("%q missing %s.handler()",info.selector,info.module),"\n")
mod.handler = notfound
return
end
if mod.init then
okay,err = mod.init(info)
if not okay then
syslog('error',"%q %s=%s",info.selector,info.module,err)
io.stderr:write(string.format("%q %s=%s",info.selector,info.module,err),"\n")
mod.handler = notfound
return
end
end
info.code = mod
end
table.sort(CONF.handlers,function(a,b)
return #a.selector == #b.selector and a.selector < b.selector
or #a.selector > #b.selector
end)
for i,info in ipairs(CONF.handlers) do
if i < #CONF.handlers and info.selector == CONF.handlers[i+1].selector then
syslog('warning',"duplicate selector %q found",info.selector)
io.stderr:write(string.format("duplicate selector %q found",info.selector),"\n")
end
loadmodule(info)
end
end
local mklink = require "port70.mklink" -- XXX hack
-- ************************************************************************
local redirect_subst do
local replace = lpeg.C(lpeg.P"$" * lpeg.R"09") * lpeg.Carg(1)
/ function(c,t)
c = tonumber(c:sub(2,-1))
return t[c]
end
local char = replace + lpeg.P(1)
redirect_subst = lpeg.Cs(char^1)
end
local function redirect(ios,selector)
for _,rule in ipairs(CONF.redirect.permanent) do
local match = table.pack(selector:match(rule[1]))
if #match > 0 then
ios:write(mklink {
type = 'error',
display = "Permanent redirect",
selector = redirect_subst:match(rule[2],1,match)
})
return true
end
end
for _,pattern in ipairs(CONF.redirect.gone) do
if selector:match(pattern) then
ios:write(mklink {
type = 'error',
display = "Gone",
selector = selector
})
return true
end
end
end
-- ************************************************************************
local parserequest = lpeg.C(lpeg.R" ~"^0)
* (lpeg.P"\t" * lpeg.C(lpeg.R" ~"^1))^-1
* lpeg.P(-1)
+ lpeg.Cc(nil)
local function main(ios)
local request = ios:read("*l")
if not request then
syslog(
'info',
"remote=%s status=false request=%q bytes=%d",
ios.__remote.addr,
"",
0
)
ios:close()
end
local selector,search = parserequest:match(request)
local binary = false
local okay = false
local found = false
if selector then
if redirect(ios,selector) then
found = true -- but it's been moved, or it's gone
else
for _,info in ipairs(CONF.handlers) do
if selector:sub(1,#info.selector) == info.selector then
found = true
local req =
{
selector = info.selector,
rest = selector:sub(#info.selector + 1,-1),
search = search,
remote = ios.__remote,
}
okay,binary = info.code.handler(info,req,ios)
break
end
end
end
else
ios:write(mklink { type = 'error' , display = "Bad request" , selector = selector })
end
if not found then
ios:write(mklink { type = 'error' , display = "Selector not found" , selector = selector })
end
if not binary then
ios:write(".\r\n")
end
syslog(
'info',
"remote=%s status=%s request=%q bytes=%d",
ios.__remote.addr,
tostring(okay),
request,
ios.__wbytes
)
ios:close()
end
-- ************************************************************************
local okay,err = tcp.listen(CONF.network.addr,CONF.network.port,main)
if not okay then
io.stderr:write(string.format("%s: %s\n",arg[1],err))
syslog('error',"%s: %s",arg[1],err)
os.exit(exit.OSERR,true)
end
if not setugid(CONF.user) then
os.exit(exit.CONF,true)
end
signal.catch('int')
signal.catch('term')
syslog('info',"entering service")
nfl.server_eventloop(function() return signal.caught() end)
for _,info in ipairs(CONF.handlers) do
if info.fini then
local ok,status = pcall(info.code.fini,info)
if not ok then
syslog('error',"%s: %s",info.module,status)
end
end
end
os.exit(true,true)
.
Response:
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