moonbridge
view moonbridge_io.c @ 297:dd0ec48592e7
Bugfix regarding waiting for child processes in moonbridge_io.poll(...)
| author | jbe | 
|---|---|
| date | Sat Jun 17 22:43:44 2017 +0200 (2017-06-17) | 
| parents | ce109800ae2d | 
| children | 09d6428fdf6c | 
 line source
     2 #ifndef __has_include
     3 #define __has_include(x) 0
     4 #endif
     6 #include <stdlib.h>
     7 #include <stdint.h>
     8 #include <string.h>
     9 #include <errno.h>
    10 #include <unistd.h>
    11 #include <signal.h>
    12 #include <fcntl.h>
    13 #include <sys/stat.h>
    14 #include <sys/socket.h>
    15 #include <sys/un.h>
    16 #include <netinet/in.h>
    17 #include <netinet/tcp.h>
    18 #include <sys/select.h>
    19 #include <time.h>
    20 #include <netdb.h>
    21 #include <arpa/inet.h>
    22 #include <sys/types.h>
    23 #include <sys/wait.h>
    24 #if defined(__linux__) || __has_include(<bsd/unistd.h>)
    25 #include <bsd/unistd.h>
    26 #endif
    28 #ifdef MOONBR_IO_USE_TLS
    29 #include <tls.h>
    30 #endif
    32 #include <lua.h>
    33 #include <lauxlib.h>
    34 #include <lualib.h>
    36 #include <assert.h>
    38 #define MOONBR_IO_MAXSTRERRORLEN 80
    39 #define MOONBR_IO_READBUFLEN 4096
    40 #define MOONBR_IO_WRITEBUFLEN 4096
    42 #define MOONBR_IO_LISTEN_BACKLOG 1024
    44 #define MOONBR_IO_STRERROR_R_MSG "Error detail unavailable due to noncompliant strerror_r() implementation"
    45 #define moonbr_io_prepare_errmsg() \
    46   char errmsg[MOONBR_IO_MAXSTRERRORLEN] = MOONBR_IO_STRERROR_R_MSG; \
    47   strerror_r(errno, errmsg, MOONBR_IO_MAXSTRERRORLEN)
    48 #define moonbr_io_return_prepared_errmsg() \
    49   lua_pushnil(L); \
    50   lua_pushstring(L, errmsg); \
    51   return 2
    52 #define moonbr_io_return_errmsg() \
    53   do { \
    54     moonbr_io_prepare_errmsg(); \
    55     moonbr_io_return_prepared_errmsg(); \
    56   } while (0)
    58 #define MOONBR_IO_HANDLE_MT_REGKEY "moonbridge_io_handle"
    59 #define MOONBR_IO_HANDLE_PUBLIC_MT_REGKEY "moonbridge_io_handle_public"
    60 #define MOONBR_IO_LISTENER_MT_REGKEY "moonbridge_io_listener"
    61 #define MOONBR_IO_CHILD_MT_REGKEY "moonbridge_io_child"
    62 #define MOONBR_IO_CHILD_PT_REGKEY "moonbridge_io_child_pt"
    64 #ifdef MOONBR_IO_USE_TLS
    66 #define MOONBR_IO_TLSCONF_MT_REGKEY "moonbridge_io_tlsconf"
    68 typedef struct {
    69   struct tls_config *config;
    70   int server;
    71 } moonbr_io_tlsconf_t;
    73 #endif /* MOONBR_IO_USE_TLS */
    75 typedef struct {
    76   int fd;
    77   int issock;
    78   sa_family_t addrfam;
    79   int finished;
    80   int closed;
    81   int nonblocking;
    82   int nopush;
    83   int readerr;
    84   int readbufin;
    85   int readbufout;
    86   int writeerr;
    87   size_t writeleft;
    88   size_t flushedleft;
    89 #if LUA_VERSION_NUM >= 503
    90   lua_Integer writeqin;
    91   lua_Integer writeqout;
    92 #else
    93   int writeqin;
    94   int writeqout;
    95 #endif
    96   size_t writeqoff;
    97   int writebufin;
    98   int writebufout;
    99   char readbuf[MOONBR_IO_READBUFLEN];
   100   char writebuf[MOONBR_IO_WRITEBUFLEN];
   101 #ifdef MOONBR_IO_USE_TLS
   102   struct tls *tls;
   103   struct tls *servertls;
   104   int tlshandshake;
   105   int tlsclosing;
   106 #endif
   107 } moonbr_io_handle_t;
   109 typedef struct {
   110   int fd;
   111   sa_family_t addrfam;
   112   int nonblocking;
   113 } moonbr_io_listener_t;
   115 typedef struct {
   116   pid_t pid;
   117 } moonbr_io_child_t;
   119 volatile sig_atomic_t moonbr_io_sigterm_flag = 0;
   120 volatile sig_atomic_t moonbr_io_sigchld_flag = 0;
   122 static int moonbr_io_yield(lua_State *L) {
   123   return lua_yield(L, lua_gettop(L));
   124 }
   126 #if LUA_VERSION_NUM >= 503
   127 static int moonbr_io_cont_returnall(lua_State *L, int status, lua_KContext ctx) {
   128 #else
   129 static int moonbr_io_cont_returnall(lua_State *L) {
   130 #endif
   131   return lua_gettop(L);
   132 }
   134 #define moonbr_io_yield_wrapper(yieldfunc, callfunc) \
   135   static int yieldfunc(lua_State *L) { \
   136     int args; \
   137     lua_pushcfunction(L, callfunc); \
   138     lua_insert(L, 1); \
   139     args = lua_gettop(L); \
   140     lua_pushcfunction(L, moonbr_io_yield); \
   141     lua_insert(L, 3); \
   142     lua_callk(L, args, LUA_MULTRET, 0, moonbr_io_cont_returnall); \
   143     return lua_gettop(L); \
   144   }
   146 static int moonbr_io_handle_set_nonblocking(lua_State *L, moonbr_io_handle_t *handle, int nonblocking) {
   147   int flags;
   148   if (handle->nonblocking == nonblocking) return 0;
   149   flags = fcntl(handle->fd, F_GETFL, 0);
   150   if (flags == -1) return -1;
   151   if (nonblocking) flags |= O_NONBLOCK;
   152   else flags &= ~O_NONBLOCK;
   153   if (fcntl(handle->fd, F_SETFL, flags) == -1) return -1;
   154   handle->nonblocking = nonblocking;
   155   return 0;
   156 }
   158 static int moonbr_io_handle_set_linger(lua_State *L, moonbr_io_handle_t *handle, int timeout) {
   159   struct linger lingerval = { 0, };
   160   if (!handle->issock) return 0;
   161   if (timeout >= 0) {
   162     lingerval.l_onoff = 1;
   163     lingerval.l_linger = timeout;
   164   }
   165   if (setsockopt(handle->fd, SOL_SOCKET, SO_LINGER, &lingerval, sizeof(lingerval))) return -1;
   166   return 0;
   167 }
   169 static inline int moonbr_io_handle_set_nopush(lua_State *L, moonbr_io_handle_t *handle, int nopush) {
   170 #if defined(TCP_NOPUSH) || defined(TCP_CORK)
   171   if (
   172     !(handle->addrfam == AF_INET6 || handle->addrfam == AF_INET) ||
   173     handle->nopush == nopush
   174   ) return 0;
   175 #if defined(TCP_NOPUSH)
   176   if (setsockopt(handle->fd, IPPROTO_TCP, TCP_NOPUSH, &nopush, sizeof(nopush))) return -1;
   177 #elif defined(TCP_CORK)
   178   if (setsockopt(handle->fd, IPPROTO_TCP, TCP_CORK, &nopush, sizeof(nopush))) return -1;
   179 #endif
   180   handle->nopush = nopush;
   181 #else
   182 #warning Neither TCP_NOPUSH nor TCP_CORK is available
   183 #endif
   184   return 0;
   185 }
   187 static int moonbr_io_read_impl(lua_State *L, int nonblocking, int drain) {
   188   moonbr_io_handle_t *handle;
   189   lua_Integer maxread;
   190   const char *terminatorstr;
   191   size_t terminatorlen;
   192   char terminator = 0;  /* initialize to avoid compiler warning */
   193   luaL_Buffer luabuf;
   194   size_t luabufcnt = 0;
   195   int remaining;
   196   char *terminatorpos;
   197   ssize_t bytesread;
   198   handle = luaL_checkudata(L, 1, MOONBR_IO_HANDLE_MT_REGKEY);
   199   maxread = luaL_optinteger(L, 2, -1);
   200   terminatorstr = luaL_optlstring(L, 3, "", &terminatorlen);
   201   if (terminatorlen) {
   202     luaL_argcheck(L, terminatorlen == 1, 3, "single byte expected");
   203     terminator = terminatorstr[0];
   204   }
   205   lua_settop(L, 1);  /* return handle on drain, terminator string may be garbage collected */
   206   if (handle->closed) luaL_error(L, "Attempt to read from a closed I/O handle");
   207   if (handle->readerr) {
   208     lua_pushnil(L);
   209     lua_pushliteral(L, "Previous read error");
   210     return 2;
   211   }
   212   if (handle->fd < 0) {
   213     /* fake EOF to simulate shutdown */
   214     if (!drain) lua_pushliteral(L, "");
   215     else lua_pushinteger(L, 0);
   216     lua_pushliteral(L, "eof");
   217     return 2;
   218   }
   219   handle->readerr = 1;
   220   if (moonbr_io_handle_set_nonblocking(L, handle, nonblocking)) moonbr_io_return_errmsg();
   221   if (!drain) luaL_buffinit(L, &luabuf);
   222   while (1) {
   223     remaining = -1;
   224     terminatorpos = NULL;
   225     if (
   226       maxread >= 0 &&
   227       handle->readbufin - handle->readbufout >= (size_t)maxread - luabufcnt
   228     ) {
   229       remaining = (size_t)maxread - luabufcnt;
   230       if (terminatorlen) {
   231         terminatorpos = memchr(
   232           handle->readbuf + handle->readbufout,
   233           terminator,
   234           remaining
   235         );
   236       }
   237     } else if (terminatorlen) {
   238       terminatorpos = memchr(
   239         handle->readbuf + handle->readbufout,
   240         terminator,
   241         handle->readbufin - handle->readbufout
   242       );
   243     }
   244     if (terminatorpos) remaining = 1 + (
   245       terminatorpos - (handle->readbuf + handle->readbufout)
   246     );
   247     if (remaining >= 0) {
   248       if (!drain) {
   249         luaL_addlstring(
   250           &luabuf,
   251           handle->readbuf + handle->readbufout,
   252           remaining
   253         );
   254         luaL_pushresult(&luabuf);
   255       } else {
   256         lua_pushinteger(L, luabufcnt + remaining);
   257       }
   258       if (terminatorpos) lua_pushliteral(L, "term");
   259       else lua_pushliteral(L, "maxlen");
   260       handle->readbufout += remaining;
   261       if (handle->readbufout == handle->readbufin) {
   262         handle->readbufin = 0;
   263         handle->readbufout = 0;
   264       }
   265       handle->readerr = 0;
   266       return 2;
   267     }
   268     if (!drain) luaL_addlstring(
   269       &luabuf,
   270       handle->readbuf + handle->readbufout,
   271       handle->readbufin - handle->readbufout
   272     );
   273     luabufcnt += handle->readbufin - handle->readbufout;
   274     handle->readbufout = 0;
   275 #ifdef MOONBR_IO_USE_TLS
   276     if (handle->tls) {
   277       do {
   278         if (!handle->tlshandshake) {
   279           do bytesread = tls_handshake(handle->tls);
   280           while (!nonblocking && (bytesread == TLS_WANT_POLLIN || bytesread == TLS_WANT_POLLOUT));
   281           if (bytesread == TLS_WANT_POLLIN || bytesread == TLS_WANT_POLLOUT) {
   282             handle->tlshandshake = bytesread;
   283             errno = EAGAIN;
   284             break;
   285           }
   286           if (bytesread < 0) {
   287             lua_pushnil(L);
   288             lua_pushstring(L, tls_error(handle->tls));
   289             return 2;
   290           }
   291           handle->tlshandshake = 1;
   292         }
   293         do bytesread = tls_read(handle->tls, handle->readbuf, MOONBR_IO_READBUFLEN);
   294         while (!nonblocking && (bytesread == TLS_WANT_POLLIN || bytesread == TLS_WANT_POLLOUT));
   295         if (bytesread == TLS_WANT_POLLIN || bytesread == TLS_WANT_POLLOUT) {
   296           errno = EAGAIN;
   297           break;
   298         }
   299         if (bytesread < 0) {
   300           lua_pushnil(L);
   301           lua_pushstring(L, tls_error(handle->tls));
   302           return 2;
   303         }
   304       } while (0);
   305     }
   306     else
   307 #endif
   308     do bytesread = read(handle->fd, handle->readbuf, MOONBR_IO_READBUFLEN);
   309     while (bytesread < 0 && (errno == EINTR));
   310     if (
   311       bytesread == 0 || (
   312         nonblocking &&
   313         bytesread < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)
   314       )
   315     ) {
   316       handle->readbufin = 0;
   317       if (!drain) luaL_pushresult(&luabuf);
   318       else lua_pushinteger(L, luabufcnt);
   319       if (bytesread == 0) lua_pushliteral(L, "eof");
   320       else lua_pushliteral(L, "block");
   321       handle->readerr = 0;
   322       return 2;
   323     }
   324     if (bytesread < 0) moonbr_io_return_errmsg();
   325     handle->readbufin = bytesread;
   326   }
   327 }
   329 static int moonbr_io_read(lua_State *L) {
   330   return moonbr_io_read_impl(L, 0, 0);
   331 }
   333 static int moonbr_io_read_nb(lua_State *L) {
   334   return moonbr_io_read_impl(L, 1, 0);
   335 }
   337 static int moonbr_io_drain(lua_State *L) {
   338   return moonbr_io_read_impl(L, 0, 1);
   339 }
   341 static int moonbr_io_drain_nb(lua_State *L) {
   342   return moonbr_io_read_impl(L, 1, 1);
   343 }
   345 #if LUA_VERSION_NUM >= 503
   346 static int moonbr_io_read_cont(lua_State *L, int status, lua_KContext ctx) {
   347 #else
   348 static int moonbr_io_read_cont(lua_State *L) {
   349 #endif
   350   lua_Integer remaining;
   351   size_t len;
   352 #if !(LUA_VERSION_NUM >= 503)
   353   int ctx = 0;
   354   lua_getctx(L, &ctx);
   355 #endif
   356   remaining = lua_tointeger(L, 3);
   357   while (1) {
   358     lua_pushcfunction(L, moonbr_io_read_nb);
   359     lua_pushvalue(L, 1);
   360     lua_pushvalue(L, 3);
   361     lua_pushvalue(L, 4);
   362     lua_call(L, 3, 2);
   363     if (lua_isnil(L, -2)) return 2;
   364     lua_insert(L, -2);
   365     len = lua_rawlen(L, -1);
   366     if (ctx == 0) {
   367       lua_replace(L, 5);
   368       ctx = 1;
   369     } else if (ctx == 1) {
   370       lua_pushvalue(L, 5);
   371       lua_newtable(L);
   372       lua_replace(L, 5);
   373       lua_rawseti(L, 5, 2);
   374       lua_rawseti(L, 5, 1);
   375       ctx = 2;
   376     } else {
   377       lua_rawseti(L, 5, lua_rawlen(L, 5) + 1);
   378     }
   379     if (strcmp(lua_tostring(L, -1), "block") != 0) break;
   380     lua_pop(L, 1);
   381     if (remaining >= 0 && len) {
   382       remaining -= len;
   383       lua_pushinteger(L, remaining);
   384       lua_replace(L, 3);
   385     }
   386     lua_pushvalue(L, 2);
   387     lua_callk(L, 0, 0, ctx, moonbr_io_read_cont);
   388   }
   389   if (ctx == 1) {
   390     lua_pushvalue(L, 5);
   391   } else {
   392     luaL_Buffer buf;
   393     lua_Integer i, chunkcount;
   394     chunkcount = lua_rawlen(L, 5);
   395     luaL_buffinit(L, &buf);
   396     for (i=1; i<=chunkcount && i>0; i++) {
   397       lua_rawgeti(L, 5, i);
   398       luaL_addvalue(&buf);
   399     }
   400     luaL_pushresult(&buf);
   401   }
   402   lua_pushvalue(L, -2);
   403   return 2;
   404 }
   406 static int moonbr_io_read_call(lua_State *L) {
   407   lua_settop(L, 4);
   408   lua_pushnil(L);
   409 #if LUA_VERSION_NUM >= 503
   410   return moonbr_io_read_cont(L, 0, 0);
   411 #else
   412   return moonbr_io_read_cont(L);
   413 #endif
   414 }
   416 moonbr_io_yield_wrapper(moonbr_io_read_yield, moonbr_io_read_call);
   418 #if LUA_VERSION_NUM >= 503
   419 static int moonbr_io_drain_cont(lua_State *L, int status, lua_KContext ctx) {
   420 #else
   421 static int moonbr_io_drain_cont(lua_State *L) {
   422 #endif
   423   lua_Integer remaining, len;
   424   size_t totallen = 0;
   425 #if !(LUA_VERSION_NUM >= 503)
   426   int ctx = 0;
   427   lua_getctx(L, &ctx);
   428 #endif
   429   remaining = lua_tointeger(L, 3);
   430   while (1) {
   431     lua_pushcfunction(L, moonbr_io_drain_nb);
   432     lua_pushvalue(L, 1);
   433     lua_pushvalue(L, 3);
   434     lua_pushvalue(L, 4);
   435     lua_call(L, 3, 2);
   436     if (lua_isnil(L, -2)) return 2;
   437     lua_insert(L, -2);
   438     len = lua_tointeger(L, -1);
   439     lua_pop(L, 1);
   440     totallen += len;
   441     if (strcmp(lua_tostring(L, -1), "block") != 0) break;
   442     lua_pop(L, 1);
   443     if (remaining >= 0 && len) {
   444       remaining -= len;
   445       lua_pushinteger(L, remaining);
   446       lua_replace(L, 3);
   447     }
   448     lua_pushvalue(L, 2);
   449     lua_callk(L, 0, 0, ctx, moonbr_io_drain_cont);
   450   }
   451   lua_pushinteger(L, totallen);
   452   lua_pushvalue(L, -2);
   453   return 2;
   454 }
   456 static int moonbr_io_drain_call(lua_State *L) {
   457 #if LUA_VERSION_NUM >= 503
   458   return moonbr_io_drain_cont(L, 0, 0);
   459 #else
   460   return moonbr_io_drain_cont(L);
   461 #endif
   462 }
   464 moonbr_io_yield_wrapper(moonbr_io_drain_yield, moonbr_io_drain_call);
   466 #ifdef MOONBR_IO_USE_TLS
   468 #define moonbr_io_write_tls(buf, buflen) \
   469   if (handle->tls) { \
   470     do { \
   471       if (!handle->tlshandshake) { \
   472         do written = tls_handshake(handle->tls); \
   473         while (!nonblocking && (written == TLS_WANT_POLLIN || written == TLS_WANT_POLLOUT)); \
   474         if (written == TLS_WANT_POLLIN || written == TLS_WANT_POLLOUT) { \
   475           handle->tlshandshake = written; \
   476           errno = EAGAIN; \
   477           break; \
   478         } \
   479         if (written < 0) { \
   480           lua_pushnil(L); \
   481           lua_pushstring(L, tls_error(handle->tls)); \
   482           return 2; \
   483         } \
   484         handle->tlshandshake = 1; \
   485       } \
   486       do written = tls_write(handle->tls, (buf), (buflen)); \
   487       while (!nonblocking && (written == TLS_WANT_POLLIN || written == TLS_WANT_POLLOUT)); \
   488       if (written == TLS_WANT_POLLIN || written == TLS_WANT_POLLOUT) { \
   489         errno = EAGAIN; \
   490         break; \
   491       } \
   492       if (written < 0) { \
   493         lua_pushnil(L); \
   494         lua_pushstring(L, tls_error(handle->tls)); \
   495         return 2; \
   496       } \
   497     } while (0); \
   498   } \
   499   else
   501 #endif /* MOONBR_IO_USE_TLS */
   503 static int moonbr_io_write_impl(lua_State *L, int nonblocking, int flush) {
   504   moonbr_io_handle_t *handle;
   505   int i, top;
   506   const char *str;
   507   size_t strlen;
   508   ssize_t written;
   509   handle = luaL_checkudata(L, 1, MOONBR_IO_HANDLE_MT_REGKEY);
   510   if (handle->closed) luaL_error(L, "Attempt to write to a closed I/O handle");
   511   if (handle->finished) luaL_error(L, "Attempt to write to a finished I/O handle");
   512   if (handle->writeerr) {
   513     lua_pushnil(L);
   514     lua_pushliteral(L, "Previous write error");
   515     return 2;
   516   }
   517   handle->writeerr = 1;
   518   if (moonbr_io_handle_set_nonblocking(L, handle, nonblocking)) moonbr_io_return_errmsg();
   519   top = lua_gettop(L);
   520   lua_getuservalue(L, 1);
   521   lua_getfield(L, -1, "writequeue");
   522   for (i=2; i<=top; i++) {
   523     luaL_checklstring(L, i, &strlen);
   524     lua_pushvalue(L, i);
   525     lua_rawseti(L, -2, handle->writeqin++);
   526     handle->writeleft += strlen;
   527   }
   528   if (flush) handle->flushedleft = handle->writeleft;
   529   while (handle->writeqout != handle->writeqin) {
   530     lua_rawgeti(L, -1, handle->writeqout);
   531     str = lua_tolstring(L, -1, &strlen);
   532     while (handle->writeqoff < strlen) {
   533       if (
   534         strlen - handle->writeqoff <
   535         MOONBR_IO_WRITEBUFLEN - handle->writebufin
   536       ) {
   537         memcpy(
   538           handle->writebuf + handle->writebufin,
   539           str + handle->writeqoff,
   540           strlen - handle->writeqoff
   541         );
   542         handle->writebufin += strlen - handle->writeqoff;
   543         break;
   544       } else {
   545         memcpy(
   546           handle->writebuf + handle->writebufin,
   547           str + handle->writeqoff,
   548           MOONBR_IO_WRITEBUFLEN - handle->writebufin
   549         );
   550         handle->writeqoff += MOONBR_IO_WRITEBUFLEN - handle->writebufin;
   551         handle->writebufin = MOONBR_IO_WRITEBUFLEN;
   552         while (handle->writebufout < MOONBR_IO_WRITEBUFLEN) {
   553           if (moonbr_io_handle_set_nopush(L, handle, 1)) moonbr_io_return_errmsg();
   554 #ifdef MOONBR_IO_USE_TLS
   555           moonbr_io_write_tls(
   556             handle->writebuf + handle->writebufout,
   557             MOONBR_IO_WRITEBUFLEN - handle->writebufout
   558           )
   559 #endif
   560           written = write(
   561             handle->fd,
   562             handle->writebuf + handle->writebufout,
   563             MOONBR_IO_WRITEBUFLEN - handle->writebufout
   564           );
   565           if (written < 0) {
   566             if (nonblocking && (errno == EAGAIN || errno == EWOULDBLOCK)) {
   567               goto moonbr_io_write_impl_block;
   568             } else if (errno != EINTR) moonbr_io_return_errmsg();
   569           } else {
   570             handle->writebufout += written;
   571             handle->writeleft -= written;
   572             if (handle->flushedleft) {
   573               if (written >= handle->flushedleft) {
   574                 handle->flushedleft = 0;
   575                 if (moonbr_io_handle_set_nopush(L, handle, 0)) moonbr_io_return_errmsg();
   576               } else {
   577                 handle->flushedleft -= written;
   578               }
   579             }
   580           }
   581         }
   582         handle->writebufin = 0;
   583         handle->writebufout = 0;
   584       }
   585     }
   586     handle->writeqoff = 0;
   587     lua_pop(L, 1);
   588     lua_pushnil(L);
   589     lua_rawseti(L, -2, handle->writeqout++);
   590   }
   591   while (handle->flushedleft) {
   592     if (moonbr_io_handle_set_nopush(L, handle, 1)) moonbr_io_return_errmsg();
   593 #ifdef MOONBR_IO_USE_TLS
   594     moonbr_io_write_tls(
   595       handle->writebuf + handle->writebufout,
   596       handle->writebufin - handle->writebufout
   597     )
   598 #endif
   599     written = write(
   600       handle->fd,
   601       handle->writebuf + handle->writebufout,
   602       handle->writebufin - handle->writebufout
   603     );
   604     if (written < 0) {
   605       if (nonblocking && (errno == EAGAIN || errno == EWOULDBLOCK)) {
   606         goto moonbr_io_write_impl_block;
   607       } else if (errno != EINTR) moonbr_io_return_errmsg();
   608     } else {
   609       handle->writebufout += written;
   610       handle->writeleft -= written;
   611       if (handle->flushedleft) {
   612         if (written >= handle->flushedleft) {
   613           handle->flushedleft = 0;
   614           if (moonbr_io_handle_set_nopush(L, handle, 0)) moonbr_io_return_errmsg();
   615         } else {
   616           handle->flushedleft -= written;
   617         }
   618       }
   619     }
   620   }
   621   if (handle->writebufout == handle->writebufin) {
   622     handle->writebufin = 0;
   623     handle->writebufout = 0;
   624   }
   625   if (nonblocking) lua_pushinteger(L, 0);
   626   else lua_pushvalue(L, 1);
   627   handle->writeerr = 0;
   628   return 1;
   629   moonbr_io_write_impl_block:
   630   lua_pushinteger(L, handle->writeleft);
   631   handle->writeerr = 0;
   632   return 1;
   633 }
   635 static int moonbr_io_write(lua_State *L) {
   636   return moonbr_io_write_impl(L, 0, 0);
   637 }
   639 static int moonbr_io_write_nb(lua_State *L) {
   640   return moonbr_io_write_impl(L, 1, 0);
   641 }
   643 static int moonbr_io_flush(lua_State *L) {
   644   return moonbr_io_write_impl(L, 0, 1);
   645 }
   647 static int moonbr_io_flush_nb(lua_State *L) {
   648   return moonbr_io_write_impl(L, 1, 1);
   649 }
   651 #if LUA_VERSION_NUM >= 503
   652 static int moonbr_io_write_cont(lua_State *L, int status, lua_KContext ctx) {
   653 #else
   654 static int moonbr_io_write_cont(lua_State *L) {
   655 #endif
   656   while (1) {
   657     lua_pushcfunction(L, moonbr_io_write_nb);
   658     lua_pushvalue(L, 1);
   659     lua_call(L, 1, 2);
   660     if (lua_isnil(L, -2)) return 2;
   661     if (!lua_tointeger(L, -2)) {
   662       lua_pushvalue(L, 1);
   663       return 1;
   664     }
   665     lua_pop(L, 2);
   666     lua_pushvalue(L, 2);
   667     lua_callk(L, 0, 0, 0, moonbr_io_write_cont);
   668   }
   669 }
   671 static int moonbr_io_write_call(lua_State *L) {
   672   lua_pushcfunction(L, moonbr_io_write_nb);
   673   lua_insert(L, 3);
   674   lua_pushvalue(L, 1);
   675   lua_insert(L, 4);
   676   lua_call(L, lua_gettop(L) - 3, 2);
   677   if (lua_isnil(L, -2)) return 2;
   678   if (!lua_tointeger(L, -2)) {
   679     lua_pushvalue(L, 1);
   680     return 1;
   681   }
   682 #if LUA_VERSION_NUM >= 503
   683   return moonbr_io_write_cont(L, 0, 0);
   684 #else
   685   return moonbr_io_write_cont(L);
   686 #endif
   687 }
   689 moonbr_io_yield_wrapper(moonbr_io_write_yield, moonbr_io_write_call);
   691 static int moonbr_io_flush_call(lua_State *L) {
   692   lua_pushcfunction(L, moonbr_io_flush_nb);
   693   lua_insert(L, 3);
   694   lua_pushvalue(L, 1);
   695   lua_insert(L, 4);
   696   lua_call(L, lua_gettop(L) - 3, 2);
   697   if (lua_isnil(L, -2)) return 2;
   698   if (!lua_tointeger(L, -2)) {
   699     lua_pushvalue(L, 1);
   700     return 1;
   701   }
   702 #if LUA_VERSION_NUM >= 503
   703   return moonbr_io_write_cont(L, 0, 0);
   704 #else
   705   return moonbr_io_write_cont(L);
   706 #endif
   707 }
   709 moonbr_io_yield_wrapper(moonbr_io_flush_yield, moonbr_io_flush_call);
   711 static int moonbr_io_finish(lua_State *L) {
   712   moonbr_io_handle_t *handle;
   713   handle = luaL_checkudata(L, 1, MOONBR_IO_HANDLE_MT_REGKEY);
   714   if (handle->closed) luaL_error(L, "Attempt to finish a closed I/O handle");
   715   if (handle->finished) luaL_error(L, "Attempt to finish a finished I/O handle");
   716   if (handle->writeleft) {
   717     lua_pushcfunction(L, moonbr_io_flush);
   718     lua_pushvalue(L, 1);
   719     if (lua_pcall(L, 1, 2, 0)) {
   720       handle->finished = 1;
   721       lua_error(L);
   722     }
   723     if (!lua_toboolean(L, -2)) {
   724       handle->finished = 1;
   725       return 2;
   726     }
   727   }
   728   handle->finished = 1;
   729 #ifdef MOONBR_IO_USE_TLS
   730   if ((handle->addrfam == AF_INET6 || handle->addrfam == AF_INET) && !handle->tls) {
   731 #else
   732   if (handle->addrfam == AF_INET6 || handle->addrfam == AF_INET) {
   733 #endif
   734     if (shutdown(handle->fd, SHUT_WR)) moonbr_io_return_errmsg();
   735   } else {
   736 #ifdef MOONBR_IO_USE_TLS
   737     if (handle->tls) {
   738       int status;
   739       if (moonbr_io_handle_set_nonblocking(L, handle, 1)) moonbr_io_return_errmsg();
   740       do status = tls_close(handle->tls);
   741       while (status == TLS_WANT_POLLIN || status == TLS_WANT_POLLOUT);
   742       if (status) {
   743         close(handle->fd);
   744         handle->fd = -1;
   745         lua_pushnil(L);
   746         lua_pushstring(L, tls_error(handle->tls));
   747         return 2;
   748       }
   749     }
   750 #endif
   751     if (close(handle->fd)) {
   752       handle->fd = -1;
   753       moonbr_io_return_errmsg();
   754     }
   755     handle->fd = -1;  /* fake EOF on read */
   756   }
   757   lua_pushboolean(L, 1);
   758   return 1;
   759 }
   761 static int moonbr_io_close_impl(lua_State *L, int nonblocking, int reset) {
   762   moonbr_io_handle_t *handle;
   763   handle = luaL_checkudata(L, 1, MOONBR_IO_HANDLE_MT_REGKEY);
   764   if (handle->closed) luaL_error(L, "Attempt to close a closed I/O handle");
   765   if (!reset && handle->fd >= 0) {
   766     if (handle->writeleft) {
   767       lua_pushcfunction(L, nonblocking ? moonbr_io_flush_nb : moonbr_io_flush);
   768       lua_pushvalue(L, 1);
   769       if (lua_pcall(L, 1, 2, 0)) {
   770         handle->closed = 1;
   771         close(handle->fd);
   772         handle->fd = -1;
   773         lua_error(L);
   774       }
   775       if (!nonblocking) handle->closed = 1;  /* TODO: handle nonblocking case */
   776       if (!lua_toboolean(L, -2)) {
   777         close(handle->fd);
   778         handle->fd = -1;
   779         return 2;
   780       }
   781 #if LUA_VERSION_NUM >= 503
   782       if (nonblocking && lua_tointeger(L, -2)) {
   783 #else
   784       if (nonblocking && lua_tonumber(L, -2)) {
   785 #endif
   786         lua_pushliteral(L, "flush");
   787         lua_pushvalue(L, -3);
   788         return 2;
   789       }
   790     } else {
   791       handle->closed = 1;
   792     }
   793 #ifdef MOONBR_IO_USE_TLS
   794     if (handle->tls) {
   795       int status;
   796       if (moonbr_io_handle_set_nonblocking(L, handle, nonblocking)) moonbr_io_return_errmsg();
   797       do status = tls_close(handle->tls);
   798       while (!nonblocking && (status == TLS_WANT_POLLIN || status == TLS_WANT_POLLOUT));
   799       if (status == TLS_WANT_POLLIN || status == TLS_WANT_POLLOUT) {
   800         handle->tlsclosing = status;  /* TODO: handle polling */
   801         lua_pushliteral(L, "close");
   802         return 1;
   803       }
   804       if (status) {
   805         close(handle->fd);
   806         handle->fd = -1;
   807         lua_pushnil(L);
   808         lua_pushstring(L, tls_error(handle->tls));
   809         return 2;
   810       }
   811     }
   812 #endif
   813     if (moonbr_io_handle_set_linger(L, handle, -1)) {
   814       moonbr_io_prepare_errmsg();
   815       close(handle->fd);
   816       handle->fd = -1;
   817       moonbr_io_return_prepared_errmsg();
   818     }
   819   } else {
   820     handle->closed = 1;
   821   }
   822   if (handle->fd >= 0) {
   823     if (close(handle->fd)) {
   824       handle->fd = -1;
   825       moonbr_io_return_errmsg();
   826     }
   827     handle->fd = -1;
   828   }
   829   lua_pushboolean(L, 1);
   830   return 1;
   832 }
   834 static int moonbr_io_close(lua_State *L) {
   835   return moonbr_io_close_impl(L, 0, 0);
   836 }
   838 static int moonbr_io_reset(lua_State *L) {
   839   return moonbr_io_close_impl(L, 0, 1);
   840 }
   842 static int moonbr_io_handlegc(lua_State *L) {
   843   moonbr_io_handle_t *handle;
   844   handle = luaL_checkudata(L, 1, MOONBR_IO_HANDLE_MT_REGKEY);
   845   if (handle->fd >= 0) {
   846     lua_pushcfunction(L, moonbr_io_reset);
   847     lua_pushvalue(L, 1);
   848     lua_pushinteger(L, 0);
   849     lua_call(L, 2, 0);
   850   }
   851 #ifdef MOONBR_IO_USE_TLS
   852   if (handle->tls) {
   853     tls_free(handle->tls);
   854     handle->tls = NULL;
   855   }
   856   if (handle->servertls) {
   857     tls_free(handle->servertls);
   858     handle->servertls = NULL;
   859   }
   860 #endif
   861   return 0;
   862 }
   864 void moonbr_io_closehandle(lua_State *L, int idx, int reset) {
   865   moonbr_io_handle_t *handle;
   866   handle = luaL_checkudata(L, idx, MOONBR_IO_HANDLE_MT_REGKEY);
   867   if (!handle->closed) {
   868     lua_pushcfunction(L, reset ? moonbr_io_reset : moonbr_io_close);
   869     lua_pushvalue(L, idx < 0 ? idx-1 : idx);
   870     lua_call(L, 1, 0);
   871   }
   872 }
   874 static int moonbr_io_pushhandle_impl(lua_State *L) {
   875   int *fd;
   876   moonbr_io_handle_t *handle;
   877   struct sockaddr addr;
   878   socklen_t addrlen;
   879   fd = lua_touserdata(L, 1);
   880   handle = lua_newuserdata(L, sizeof(moonbr_io_handle_t));
   881   handle->fd = -1;  /* avoid closing incomplete handle */
   882   addrlen = sizeof(addr);
   883   if (getsockname(*fd, &addr, &addrlen)) {
   884     if (errno != ENOTSOCK) {
   885       moonbr_io_prepare_errmsg();
   886       luaL_error(L, "Unexpected error when examining socket: %s", errmsg);
   887     }
   888     handle->issock = 0;
   889   } else {
   890     handle->issock = 1;
   891     handle->addrfam = addr.sa_family;
   892   }
   893   handle->finished = 0;
   894   handle->closed = 0;
   895   handle->nonblocking = -1;
   896   handle->nopush = -1;
   897   handle->readerr = 0;
   898   handle->readbufin = 0;
   899   handle->readbufout = 0;
   900   handle->writeerr = 0;
   901   handle->writeleft = 0;
   902   handle->flushedleft = 0;
   903   handle->writeqin = 0;
   904   handle->writeqout = 0;
   905   handle->writeqoff = 0;
   906   handle->writebufin = 0;
   907   handle->writebufout = 0;
   908 #ifdef MOONBR_IO_USE_TLS
   909   handle->tls = NULL;
   910   handle->servertls = NULL;
   911   handle->tlshandshake = 0;
   912   handle->tlsclosing = 0;
   913 #endif
   914   handle->fd = *fd;  /* required for set_linger call */
   915   if (moonbr_io_handle_set_linger(L, handle, 0)) {
   916     moonbr_io_prepare_errmsg();
   917     handle->fd = -1;
   918     luaL_error(L, "Unexpected error while setting SO_LINGER with setsockopt: %s", errmsg);
   919   }
   920   handle->fd = -1;  /* avoid closing incomplete handle */
   921   luaL_setmetatable(L, MOONBR_IO_HANDLE_MT_REGKEY);
   922   lua_newtable(L);  // uservalue
   923   lua_newtable(L);
   924   lua_setfield(L, -2, "writequeue");
   925   lua_newtable(L);  // public
   926   if (handle->addrfam == AF_INET6) {
   927     struct sockaddr_in6 addr_in6;
   928     char addrstrbuf[INET6_ADDRSTRLEN];
   929     const char *addrstr;
   930     addrlen = sizeof(addr_in6);
   931     if (getsockname(*fd, (struct sockaddr *)&addr_in6, &addrlen)) {
   932       moonbr_io_prepare_errmsg();
   933       luaL_error(L, "Could not determine local IP address/port: %s", errmsg);
   934     }
   935     if (addrlen > sizeof(addr_in6)) {
   936       luaL_error(L, "Could not determine local IP address/port: buffer size exceeded");
   937     }
   938     addrstr = inet_ntop(AF_INET6, addr_in6.sin6_addr.s6_addr, addrstrbuf, sizeof(addrstrbuf));
   939     if (!addrstr) {
   940       moonbr_io_prepare_errmsg();
   941       luaL_error(L, "Could not format local IP address: %s", errmsg);
   942     } else {
   943       lua_pushstring(L, addrstr);
   944       lua_setfield(L, -2, "local_ip6");
   945     }
   946     lua_pushinteger(L, ntohs(addr_in6.sin6_port));
   947     lua_setfield(L, -2, "local_tcpport");
   948     if (getpeername(*fd, (struct sockaddr *)&addr_in6, &addrlen)) {
   949       moonbr_io_prepare_errmsg();
   950       luaL_error(L, "Could not determine remote IP address/port: %s", errmsg);
   951     }
   952     if (addrlen > sizeof(addr_in6)) {
   953       luaL_error(L, "Could not determine remote IP address/port: buffer size exceeded");
   954     }
   955     addrstr = inet_ntop(AF_INET6, addr_in6.sin6_addr.s6_addr, addrstrbuf, sizeof(addrstrbuf));
   956     if (!addrstr) {
   957       moonbr_io_prepare_errmsg();
   958       luaL_error(L, "Could not format remote IP address: %s", errmsg);
   959     } else {
   960       lua_pushstring(L, addrstr);
   961       lua_setfield(L, -2, "remote_ip6");
   962     }
   963     lua_pushinteger(L, ntohs(addr_in6.sin6_port));
   964     lua_setfield(L, -2, "remote_tcpport");
   965   } else if (handle->addrfam == AF_INET) {
   966     struct sockaddr_in addr_in;
   967     char addrstrbuf[INET_ADDRSTRLEN];
   968     const char *addrstr;
   969     addrlen = sizeof(addr_in);
   970     if (getsockname(*fd, (struct sockaddr *)&addr_in, &addrlen)) {
   971       moonbr_io_prepare_errmsg();
   972       luaL_error(L, "Could not determine local IP address/port: %s", errmsg);
   973     }
   974     if (addrlen > sizeof(addr_in)) {
   975       luaL_error(L, "Could not determine local IP address/port: buffer size exceeded");
   976     }
   977     addrstr = inet_ntop(AF_INET, &addr_in.sin_addr.s_addr, addrstrbuf, sizeof(addrstrbuf));
   978     if (!addrstr) {
   979       moonbr_io_prepare_errmsg();
   980       luaL_error(L, "Could not format local IP address: %s", errmsg);
   981     } else {
   982       lua_pushstring(L, addrstr);
   983       lua_setfield(L, -2, "local_ip4");
   984     }
   985     lua_pushinteger(L, ntohs(addr_in.sin_port));
   986     lua_setfield(L, -2, "local_tcpport");
   987     if (getpeername(*fd, (struct sockaddr *)&addr_in, &addrlen)) {
   988       moonbr_io_prepare_errmsg();
   989       luaL_error(L, "Could not determine remote IP address/port: %s", errmsg);
   990     }
   991     if (addrlen > sizeof(addr_in)) {
   992       luaL_error(L, "Could not determine remote IP address/port: buffer size exceeded");
   993     }
   994     addrstr = inet_ntop(AF_INET, &addr_in.sin_addr.s_addr, addrstrbuf, sizeof(addrstrbuf));
   995     if (!addrstr) {
   996       moonbr_io_prepare_errmsg();
   997       luaL_error(L, "Could not format remote IP address: %s", errmsg);
   998     } else {
   999       lua_pushstring(L, addrstr);
  1000       lua_setfield(L, -2, "remote_ip4");
  1001     }
  1002     lua_pushinteger(L, ntohs(addr_in.sin_port));
  1003     lua_setfield(L, -2, "remote_tcpport");
  1004   }
  1005   luaL_setmetatable(L, MOONBR_IO_HANDLE_PUBLIC_MT_REGKEY);
  1006   lua_setfield(L, -2, "public");
  1007   lua_setuservalue(L, -2);
  1008   handle->fd = *fd;
  1009   *fd = -1;  /* closing is now handled by garbage collection */
  1010   return 1;
  1011 }
  1013 void moonbr_io_pushhandle(lua_State *L, int fd) {
  1014   lua_pushcfunction(L, moonbr_io_pushhandle_impl);
  1015   lua_pushlightuserdata(L, &fd);
  1016   if (lua_pcall(L, 1, 1, 0)) {
  1017     if (fd != -1) close(fd);  // TODO: correct to close file descriptor here?
  1018     lua_error(L);
  1019   }
  1020 }
  1022 static int moonbr_io_handleindex(lua_State *L) {
  1023   luaL_checkudata(L, 1, MOONBR_IO_HANDLE_MT_REGKEY);
  1024   luaL_checkany(L, 2);
  1025   lua_getuservalue(L, 1);
  1026   lua_getfield(L, -1, "public");
  1027   lua_pushvalue(L, 2);
  1028   lua_gettable(L, -2);
  1029   return 1;
  1030 }
  1032 static int moonbr_io_handlenewindex(lua_State *L) {
  1033   luaL_checkudata(L, 1, MOONBR_IO_HANDLE_MT_REGKEY);
  1034   luaL_checkany(L, 2);
  1035   luaL_checkany(L, 3);
  1036   lua_getuservalue(L, 1);
  1037   lua_getfield(L, -1, "public");
  1038   lua_pushvalue(L, 2);
  1039   lua_pushvalue(L, 3);
  1040   lua_settable(L, -3);
  1041   return 0;
  1042 }
  1044 static int moonbr_io_localconnect_impl(lua_State *L, int nonblocking) {
  1045   const char *path;
  1046   struct sockaddr_un sockaddr = { .sun_family = AF_LOCAL };
  1047   const int path_maxlen = sizeof(struct sockaddr_un) - (
  1048     (void *)sockaddr.sun_path - (void *)&sockaddr
  1049   ) - 1;  /* one byte for termination */
  1050   int sock;
  1051   path = luaL_checkstring(L, 1);
  1052   if (strlen(path) > path_maxlen) luaL_error(L, "Path too long; only %i characters allowed", path_maxlen);
  1053   strcpy(sockaddr.sun_path, path);
  1054   sock = socket(
  1055     PF_LOCAL,
  1056     SOCK_STREAM | SOCK_CLOEXEC | (nonblocking ? SOCK_NONBLOCK : 0),
  1057     0
  1058   );
  1059   if (sock < 0) moonbr_io_return_errmsg();
  1060   if (connect(sock, (struct sockaddr *)&sockaddr, sizeof(sockaddr))) {
  1061     if (!nonblocking && errno == EINTR) {
  1062       moonbr_io_prepare_errmsg();
  1063       close(sock);
  1064       moonbr_io_return_prepared_errmsg();
  1065     } else if (!(nonblocking && (errno == EINPROGRESS || errno == EINTR))) moonbr_io_return_errmsg();
  1066   }
  1067   moonbr_io_pushhandle(L, sock);
  1068   return 1;
  1069 }
  1071 static int moonbr_io_localconnect(lua_State *L) {
  1072   return moonbr_io_localconnect_impl(L, 0);
  1073 }
  1075 static int moonbr_io_localconnect_nb(lua_State *L) {
  1076   return moonbr_io_localconnect_impl(L, 1);
  1077 }
  1079 static int moonbr_io_tcpconnect_impl(lua_State *L, int nonblocking) {
  1080   const char *host, *port;
  1081   struct addrinfo hints = { 0, };
  1082   struct addrinfo *res, *addrinfo;
  1083   int errcode;
  1084   int sock;
  1085   host = luaL_checkstring(L, 1);
  1086   port = luaL_checkstring(L, 2);
  1087   hints.ai_family = AF_UNSPEC;
  1088   hints.ai_socktype = SOCK_STREAM;
  1089   hints.ai_protocol = IPPROTO_TCP;
  1090   hints.ai_flags = AI_ADDRCONFIG;
  1091   errcode = getaddrinfo(host, port, &hints, &res);
  1092   if (errcode) {
  1093     freeaddrinfo(res);
  1094     if (errcode == EAI_SYSTEM) {
  1095       moonbr_io_prepare_errmsg();
  1096       lua_pushnil(L);
  1097       lua_pushfstring(L, "%s: %s", gai_strerror(errcode), errmsg);
  1098     } else {
  1099       lua_pushnil(L);
  1100       lua_pushstring(L, gai_strerror(errcode));
  1101     }
  1102     return 2;
  1103   }
  1104   for (addrinfo=res; addrinfo; addrinfo=addrinfo->ai_next) {
  1105     if (addrinfo->ai_family == AF_INET6) goto moonbr_io_tcpconnect_found;
  1106   }
  1107   for (addrinfo=res; addrinfo; addrinfo=addrinfo->ai_next) {
  1108     if (addrinfo->ai_family == AF_INET) goto moonbr_io_tcpconnect_found;
  1109   }
  1110   addrinfo = res;
  1111   moonbr_io_tcpconnect_found:
  1112   sock = socket(
  1113     addrinfo->ai_family,  /* NOTE: not correctly using PF_* but AF_* constants here */
  1114     addrinfo->ai_socktype | SOCK_CLOEXEC | (nonblocking ? SOCK_NONBLOCK : 0),
  1115     addrinfo->ai_protocol
  1116   );
  1117   if (sock < 0) {
  1118     moonbr_io_prepare_errmsg();
  1119     freeaddrinfo(res);
  1120     moonbr_io_return_prepared_errmsg();
  1121   }
  1122   if (connect(sock, addrinfo->ai_addr, addrinfo->ai_addrlen)) {
  1123     freeaddrinfo(res);
  1124     if (!nonblocking && errno == EINTR) {
  1125       moonbr_io_prepare_errmsg();
  1126       close(sock);
  1127       moonbr_io_return_prepared_errmsg();
  1128     } else if (!(nonblocking && (errno == EINPROGRESS || errno == EINTR))) moonbr_io_return_errmsg();
  1129   } else {
  1130     freeaddrinfo(res);
  1131   }
  1132   moonbr_io_pushhandle(L, sock);
  1133   return 1;
  1134 }
  1136 static int moonbr_io_tcpconnect(lua_State *L) {
  1137   return moonbr_io_tcpconnect_impl(L, 0);
  1138 }
  1140 static int moonbr_io_tcpconnect_nb(lua_State *L) {
  1141   return moonbr_io_tcpconnect_impl(L, 1);
  1142 }
  1144 static int moonbr_io_locallisten(lua_State *L) {
  1145   moonbr_io_listener_t *listener;
  1146   const char *path;
  1147   struct stat sb;
  1148   struct sockaddr_un sockaddr = { .sun_family = AF_LOCAL };
  1149   const int path_maxlen = sizeof(struct sockaddr_un) - (
  1150     (void *)sockaddr.sun_path - (void *)&sockaddr
  1151   ) - 1;  /* one byte for termination */
  1152   int sock;
  1153   path = luaL_checkstring(L, 1);
  1154   if (strlen(path) > path_maxlen) luaL_error(L, "Path too long; only %i characters allowed", path_maxlen);
  1155   strcpy(sockaddr.sun_path, path);
  1156   if (stat(path, &sb) == 0) {
  1157     if (S_ISSOCK(sb.st_mode)) unlink(path);
  1158   }
  1159   listener = lua_newuserdata(L, sizeof(moonbr_io_listener_t));
  1160   listener->fd = -1;
  1161   luaL_setmetatable(L, MOONBR_IO_LISTENER_MT_REGKEY);
  1162   sock = socket(
  1163     PF_LOCAL,
  1164     SOCK_STREAM | SOCK_CLOEXEC,
  1165     0
  1166   );
  1167   if (sock < 0) moonbr_io_return_errmsg();
  1168   if (bind(sock, (struct sockaddr *)&sockaddr, sizeof(sockaddr))) {
  1169     moonbr_io_prepare_errmsg();
  1170     close(sock);
  1171     moonbr_io_return_prepared_errmsg();
  1172   }
  1173   if (listen(sock, MOONBR_IO_LISTEN_BACKLOG)) {
  1174     moonbr_io_prepare_errmsg();
  1175     close(sock);
  1176     moonbr_io_return_prepared_errmsg();
  1177   }
  1178   listener->fd = sock;
  1179   listener->addrfam = AF_LOCAL;
  1180   listener->nonblocking = -1;
  1181   return 1;
  1182 }
  1184 static int moonbr_io_tcplisten(lua_State *L) {
  1185   moonbr_io_listener_t *listener;
  1186   const char *host, *port;
  1187   struct addrinfo hints = { 0, };
  1188   struct addrinfo *res, *addrinfo;
  1189   int errcode;
  1190   int sock;
  1191   host = luaL_optstring(L, 1, NULL);
  1192   port = luaL_checkstring(L, 2);
  1193   listener = lua_newuserdata(L, sizeof(moonbr_io_listener_t));
  1194   listener->fd = -1;
  1195   luaL_setmetatable(L, MOONBR_IO_LISTENER_MT_REGKEY);
  1196   hints.ai_family = AF_UNSPEC;
  1197   hints.ai_socktype = SOCK_STREAM;
  1198   hints.ai_protocol = IPPROTO_TCP;
  1199   hints.ai_flags = AI_ADDRCONFIG | AI_PASSIVE;
  1200   errcode = getaddrinfo(host, port, &hints, &res);
  1201   if (errcode) {
  1202     freeaddrinfo(res);
  1203     if (errcode == EAI_SYSTEM) {
  1204       moonbr_io_prepare_errmsg();
  1205       lua_pushnil(L);
  1206       lua_pushfstring(L, "%s: %s", gai_strerror(errcode), errmsg);
  1207     } else {
  1208       lua_pushnil(L);
  1209       lua_pushstring(L, gai_strerror(errcode));
  1210     }
  1211     return 2;
  1212   }
  1213   for (addrinfo=res; addrinfo; addrinfo=addrinfo->ai_next) {
  1214     if (addrinfo->ai_family == AF_INET6) goto moonbr_io_tcpconnect_found;
  1215   }
  1216   for (addrinfo=res; addrinfo; addrinfo=addrinfo->ai_next) {
  1217     if (addrinfo->ai_family == AF_INET) goto moonbr_io_tcpconnect_found;
  1218   }
  1219   addrinfo = res;
  1220   moonbr_io_tcpconnect_found:
  1221   listener->addrfam = addrinfo->ai_family;
  1222   sock = socket(
  1223     addrinfo->ai_family,  /* NOTE: not correctly using PF_* but AF_* constants here */
  1224     addrinfo->ai_socktype | SOCK_CLOEXEC,
  1225     addrinfo->ai_protocol
  1226   );
  1227   if (sock < 0) {
  1228     moonbr_io_prepare_errmsg();
  1229     freeaddrinfo(res);
  1230     moonbr_io_return_prepared_errmsg();
  1231   }
  1232   {
  1233     static const int reuseval = 1;
  1234     if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &reuseval, sizeof(reuseval))) {
  1235       moonbr_io_prepare_errmsg();
  1236       freeaddrinfo(res);
  1237       close(sock);
  1238       lua_pushnil(L);
  1239       lua_pushfstring(L, "Error while setting SO_REUSEADDR with setsockopt: %s", errmsg);
  1240       return 2;
  1241     }
  1242   }
  1243   if (bind(sock, addrinfo->ai_addr, addrinfo->ai_addrlen)) {
  1244     moonbr_io_prepare_errmsg();
  1245     freeaddrinfo(res);
  1246     close(sock);
  1247     moonbr_io_return_prepared_errmsg();
  1248   }
  1249   freeaddrinfo(res);
  1250   if (listen(sock, MOONBR_IO_LISTEN_BACKLOG)) {
  1251     moonbr_io_prepare_errmsg();
  1252     close(sock);
  1253     moonbr_io_return_prepared_errmsg();
  1254   }
  1255   listener->fd = sock;
  1256   listener->nonblocking = -1;
  1257   return 1;
  1258 }
  1260 static int moonbr_io_accept_impl(lua_State *L, int nonblocking) {
  1261   moonbr_io_listener_t *listener;
  1262   int fd;
  1263   listener = luaL_checkudata(L, 1, MOONBR_IO_LISTENER_MT_REGKEY);
  1264   if (listener->fd < 0) luaL_error(L, "Attempt to use a closed listener");
  1265   if (listener->nonblocking != nonblocking) {
  1266     int flags;
  1267     flags = fcntl(listener->fd, F_GETFL, 0);
  1268     if (flags == -1) {
  1269       moonbr_io_prepare_errmsg();
  1270       close(listener->fd);
  1271       listener->fd = -1;
  1272       luaL_error(L, "Unexpected error in fcntl call: %s", errmsg);
  1273     }
  1274     if (nonblocking) flags |= O_NONBLOCK;
  1275     else flags &= ~O_NONBLOCK;
  1276     if (fcntl(listener->fd, F_SETFL, flags) == -1) {
  1277       moonbr_io_prepare_errmsg();
  1278       close(listener->fd);
  1279       listener->fd = -1;
  1280       luaL_error(L, "Unexpected error in fcntl call: %s", errmsg);
  1281     }
  1282     listener->nonblocking = nonblocking;
  1283   }
  1284   while (1) {
  1285 #if defined(__linux__) && !defined(_GNU_SOURCE)
  1286     fd = accept(listener->fd, NULL, NULL);
  1287     if (fd != -1) {
  1288       if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1) {
  1289         moonbr_io_prepare_errmsg();
  1290         close(listener->fd);
  1291         listener->fd = -1;
  1292         close(fd);
  1293         luaL_error(L, "Unexpected error in fcntl call: %s", errmsg);
  1294       }
  1295     }
  1296 #else
  1297     fd = accept4(listener->fd, NULL, NULL, SOCK_CLOEXEC);
  1298 #endif
  1299     if (fd < 0) {
  1300       if (nonblocking && (errno == EAGAIN || errno == EWOULDBLOCK)) {
  1301         lua_pushboolean(L, 0);
  1302         lua_pushliteral(L, "No incoming connection pending");
  1303         return 2;
  1304       } else if (errno != EINTR) moonbr_io_return_errmsg();
  1305     } else {
  1306       moonbr_io_pushhandle(L, fd);
  1307       return 1;
  1308     }
  1309   }
  1310 }
  1312 static int moonbr_io_accept(lua_State *L) {
  1313   return moonbr_io_accept_impl(L, 0);
  1314 }
  1316 static int moonbr_io_accept_nb(lua_State *L) {
  1317   return moonbr_io_accept_impl(L, 1);
  1318 }
  1320 static int moonbr_io_unlisten(lua_State *L) {
  1321   moonbr_io_listener_t *listener;
  1322   struct sockaddr_un addr;
  1323   socklen_t addrlen;
  1324   struct stat sb;
  1325   listener = luaL_checkudata(L, 1, MOONBR_IO_LISTENER_MT_REGKEY);
  1326   if (listener->fd < 0) luaL_error(L, "Attempt to close a closed listener");
  1327   addrlen = sizeof(addr);
  1328   if (getsockname(listener->fd, (struct sockaddr *)&addr, &addrlen)) addrlen = 0;
  1329   if (close(listener->fd)) {
  1330     moonbr_io_prepare_errmsg();
  1331     listener->fd = -1;
  1332     if (addrlen && addrlen <= sizeof(addr)) {
  1333       if (stat(addr.sun_path, &sb) == 0) {
  1334         if (S_ISSOCK(sb.st_mode)) unlink(addr.sun_path);
  1335       }
  1336     }
  1337     moonbr_io_return_prepared_errmsg();
  1338   }
  1339   listener->fd = -1;
  1340   if (addrlen && addrlen <= sizeof(addr)) {
  1341     if (stat(addr.sun_path, &sb) == 0) {
  1342       if (S_ISSOCK(sb.st_mode)) unlink(addr.sun_path);
  1343     }
  1344   }
  1345   lua_pushboolean(L, 1);
  1346   return 1;
  1347 }
  1349 static int moonbr_io_listenergc(lua_State *L) {
  1350   moonbr_io_listener_t *listener;
  1351   listener = luaL_checkudata(L, 1, MOONBR_IO_LISTENER_MT_REGKEY);
  1352   if (listener->fd >= 0) close(listener->fd);
  1353   listener->fd = -1;
  1354   return 0;
  1355 }
  1357 static int moonbr_io_exec(lua_State *L) {
  1358   char **argv;
  1359   int i, argc;
  1360   int sockin[2], sockout[2], sockerr[2];
  1361   volatile int errorcond = 0;
  1362   volatile char errmsgbuf[MOONBR_IO_MAXSTRERRORLEN] = MOONBR_IO_STRERROR_R_MSG;
  1363   moonbr_io_child_t *child;
  1364   argc = lua_gettop(L);
  1365   argv = lua_newuserdata(L, (argc + 1) * sizeof(char *));
  1366   for (i=0; i<argc; i++) argv[i] = (char *)luaL_checkstring(L, i+1);
  1367   argv[argc] = NULL;
  1368   child = lua_newuserdata(L, sizeof(moonbr_io_child_t));
  1369   child->pid = 0;
  1370   lua_newtable(L);
  1371   lua_setuservalue(L, -2);
  1372   luaL_setmetatable(L, MOONBR_IO_CHILD_MT_REGKEY);
  1373   if (socketpair(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, sockin)) {
  1374     moonbr_io_prepare_errmsg();
  1375     lua_pushnil(L);
  1376     lua_pushfstring(L, "Could not create socket pair: %s", errmsg);
  1377     return 2;
  1378   }
  1379   if (socketpair(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, sockout)) {
  1380     moonbr_io_prepare_errmsg();
  1381     close(sockin[0]);
  1382     close(sockin[1]);
  1383     lua_pushnil(L);
  1384     lua_pushfstring(L, "Could not create socket pair: %s", errmsg);
  1385     return 2;
  1386   }
  1387   if (socketpair(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, sockerr)) {
  1388     moonbr_io_prepare_errmsg();
  1389     close(sockin[0]);
  1390     close(sockin[1]);
  1391     close(sockout[0]);
  1392     close(sockout[1]);
  1393     lua_pushnil(L);
  1394     lua_pushfstring(L, "Could not create socket pair: %s", errmsg);
  1395     return 2;
  1396   }
  1397   child->pid = vfork();
  1398   if (child->pid == -1) {
  1399     moonbr_io_prepare_errmsg();
  1400     close(sockin[0]);
  1401     close(sockin[1]);
  1402     close(sockout[0]);
  1403     close(sockout[1]);
  1404     close(sockerr[0]);
  1405     close(sockerr[1]);
  1406     lua_pushnil(L);
  1407     lua_pushfstring(L, "Could not fork: %s", errmsg);
  1408     return 2;
  1409   }
  1410   if (!child->pid) {
  1411     if (dup2(sockin[1], 0) == -1) goto moonbr_io_exec_error1;
  1412     if (dup2(sockout[1], 1) == -1) goto moonbr_io_exec_error1;
  1413     if (dup2(sockerr[1], 2) == -1) goto moonbr_io_exec_error1;
  1414     closefrom(3);
  1415     if (fcntl(0, F_SETFD, 0) == -1) goto moonbr_io_exec_error1;
  1416     if (fcntl(1, F_SETFD, 0) == -1) goto moonbr_io_exec_error1;
  1417     if (fcntl(2, F_SETFD, 0) == -1) goto moonbr_io_exec_error1;
  1418     if (execvp(argv[0], argv)) {
  1419       errorcond = 2;
  1420       strerror_r(errno, (char *)errmsgbuf, MOONBR_IO_MAXSTRERRORLEN);
  1421       _exit(0);
  1422     }
  1423     moonbr_io_exec_error1:
  1424     errorcond = 1;
  1425     strerror_r(errno, (char *)errmsgbuf, MOONBR_IO_MAXSTRERRORLEN);
  1426     _exit(0);
  1427   }
  1428   close(sockin[1]);
  1429   close(sockout[1]);
  1430   close(sockerr[1]);
  1431   if (errorcond) {
  1432     int status;
  1433     close(sockin[0]);
  1434     close(sockout[0]);
  1435     close(sockerr[0]);
  1436     while (waitpid(child->pid, &status, 0) == -1) {
  1437       if (errno != EINTR) {
  1438         moonbr_io_prepare_errmsg();
  1439         luaL_error(L, "Error in waitpid call after unsuccessful exec: %s", errmsg);
  1440       }
  1441     }
  1442     child->pid = 0;
  1443     lua_pushnil(L);
  1444     if (errorcond == 2) lua_pushfstring(L, "Could not execute: %s", errmsgbuf);
  1445     else lua_pushfstring(L, "Error in fork: %s", errmsgbuf);
  1446     return 2;
  1447   }
  1448   lua_pushcfunction(L, moonbr_io_pushhandle_impl);
  1449   lua_pushlightuserdata(L, &sockin[0]);
  1450   if (lua_pcall(L, 1, 1, 0)) {
  1451     if (sockin[0] != -1) close(sockin[0]);
  1452     close(sockout[0]);
  1453     close(sockerr[0]);
  1454     goto moonbr_io_exec_error2;
  1455   }
  1456   lua_setfield(L, -2, "stdin");
  1457   lua_pushcfunction(L, moonbr_io_pushhandle_impl);
  1458   lua_pushlightuserdata(L, &sockout[0]);
  1459   if (lua_pcall(L, 1, 1, 0)) {
  1460     if (sockout[0] != -1) close(sockout[0]);
  1461     close(sockerr[0]);
  1462     goto moonbr_io_exec_error2;
  1463   }
  1464   lua_setfield(L, -2, "stdout");
  1465   lua_pushcfunction(L, moonbr_io_pushhandle_impl);
  1466   lua_pushlightuserdata(L, &sockerr[0]);
  1467   if (lua_pcall(L, 1, 1, 0)) {
  1468     if (sockerr[0] != -1) close(sockerr[0]);
  1469     goto moonbr_io_exec_error2;
  1470   }
  1471   lua_setfield(L, -2, "stderr");
  1472   return 1;
  1473   moonbr_io_exec_error2:
  1474   {
  1475     int status;
  1476     while (waitpid(child->pid, &status, 0) == -1) {
  1477       if (errno != EINTR) {
  1478         moonbr_io_prepare_errmsg();
  1479         luaL_error(L, "Error in waitpid call after error creating socket handles: %s", errmsg);
  1480       }
  1481     }
  1482   }
  1483   child->pid = 0;
  1484   return lua_error(L);
  1485 }
  1487 static int moonbr_io_childindex(lua_State *L) {
  1488   luaL_checkudata(L, 1, MOONBR_IO_CHILD_MT_REGKEY);
  1489   luaL_checkany(L, 2);
  1490   lua_getuservalue(L, 1);
  1491   lua_pushvalue(L, 2);
  1492   lua_gettable(L, -2);
  1493   if (lua_isnil(L, -1)) {
  1494     luaL_getmetatable(L, MOONBR_IO_CHILD_PT_REGKEY);
  1495     lua_pushvalue(L, 2);
  1496     lua_gettable(L, -2);
  1497   }
  1498   return 1;
  1499 }
  1501 static int moonbr_io_childnewindex(lua_State *L) {
  1502   luaL_checkudata(L, 1, MOONBR_IO_CHILD_MT_REGKEY);
  1503   luaL_checkany(L, 2);
  1504   luaL_checkany(L, 3);
  1505   lua_getuservalue(L, 1);
  1506   lua_pushvalue(L, 2);
  1507   lua_pushvalue(L, 3);
  1508   lua_settable(L, -3);
  1509   return 0;
  1510 }
  1512 static int moonbr_io_childgc(lua_State *L) {
  1513   moonbr_io_child_t *child;
  1514   child = luaL_checkudata(L, 1, MOONBR_IO_CHILD_MT_REGKEY);
  1515   if (child->pid) {
  1516     int status;
  1517     int pid = child->pid;
  1518     child->pid = 0;
  1519     if (kill(pid, SIGKILL)) {
  1520       moonbr_io_prepare_errmsg();
  1521       luaL_error(L, "Error in kill call during garbage collection: %s", errmsg);
  1522     }
  1523     while (waitpid(pid, &status, 0) == -1) {
  1524       if (errno != EINTR) {
  1525         moonbr_io_prepare_errmsg();
  1526         luaL_error(L, "Error in waitpid call during garbage collection: %s", errmsg);
  1527       }
  1528     }
  1529   }
  1530   return 0;
  1531 }
  1533 static int moonbr_io_kill(lua_State *L) {
  1534   moonbr_io_child_t *child;
  1535   int sig;
  1536   child = luaL_checkudata(L, 1, MOONBR_IO_CHILD_MT_REGKEY);
  1537   sig = luaL_optinteger(L, 2, SIGKILL);
  1538   if (!child->pid) luaL_error(L, "Attempt to kill an already collected child process");
  1539   if (kill(child->pid, sig)) {
  1540     moonbr_io_prepare_errmsg();
  1541     luaL_error(L, "Error in kill call: %s", errmsg);
  1542   }
  1543   lua_settop(L, 1);
  1544   return 1;
  1545 }
  1547 static int moonbr_io_wait_impl(lua_State *L, int nonblocking) {
  1548   moonbr_io_child_t *child;
  1549   pid_t waitedpid;
  1550   int status;
  1551   child = luaL_checkudata(L, 1, MOONBR_IO_CHILD_MT_REGKEY);
  1552   if (!child->pid) luaL_error(L, "Attempt to wait for an already collected child process");
  1553   while ((waitedpid = waitpid(child->pid, &status, nonblocking ? WNOHANG : 0)) == -1) {
  1554     if (errno != EINTR) {
  1555       moonbr_io_prepare_errmsg();
  1556       luaL_error(L, "Error in waitpid call: %s", errmsg);
  1557     }
  1558   }
  1559   if (!waitedpid) {
  1560     lua_pushboolean(L, 0);
  1561     lua_pushliteral(L, "Process is still running");
  1562     return 2;
  1563   } else {
  1564     child->pid = 0;
  1565     if (WIFEXITED(status)) {
  1566       lua_pushinteger(L, WEXITSTATUS(status));
  1567     } else if (WIFSIGNALED(status)) {
  1568       lua_pushinteger(L, -WTERMSIG(status));
  1569     } else {
  1570       luaL_error(L, "Unexpected status value returned by waitpid call");
  1571     }
  1572     return 1;
  1573   }
  1574 }
  1576 static int moonbr_io_wait(lua_State *L) {
  1577   return moonbr_io_wait_impl(L, 0);
  1578 }
  1580 static int moonbr_io_wait_nb(lua_State *L) {
  1581   return moonbr_io_wait_impl(L, 1);
  1582 }
  1584 #if LUA_VERSION_NUM >= 503
  1585 static int moonbr_io_wait_cont(lua_State *L, int status, lua_KContext ctx) {
  1586 #else
  1587 static int moonbr_io_wait_cont(lua_State *L) {
  1588 #endif
  1589 #if !(LUA_VERSION_NUM >= 503)
  1590   int ctx = 0;
  1591   lua_getctx(L, &ctx);
  1592 #endif
  1593   while (1) {
  1594     lua_pushcfunction(L, moonbr_io_wait_nb);
  1595     lua_pushvalue(L, 1);
  1596     lua_call(L, 1, 1);
  1597     if (!lua_isnil(L, -1)) break;
  1598     lua_pushvalue(L, 2);
  1599     lua_callk(L, 0, 0, ctx, moonbr_io_wait_cont);
  1600   }
  1601   return 1;
  1602 }
  1604 static int moonbr_io_wait_call(lua_State *L) {
  1605   lua_settop(L, 2);
  1606 #if LUA_VERSION_NUM >= 503
  1607   return moonbr_io_wait_cont(L, 0, 0);
  1608 #else
  1609   return moonbr_io_wait_cont(L);
  1610 #endif
  1611 }
  1613 moonbr_io_yield_wrapper(moonbr_io_wait_yield, moonbr_io_wait_call);
  1615 static void moonbr_io_sigterm_handler(int sig) {
  1616   moonbr_io_sigterm_flag = 1;
  1617 }
  1619 static void moonbr_io_sigchld_handler(int sig) {
  1620   moonbr_io_sigchld_flag = 1;
  1621 }
  1623 int moonbr_io_catch_sigterm(lua_State *L) {
  1624   signal(SIGTERM, moonbr_io_sigterm_handler);
  1625   return 0;
  1626 }
  1628 static int moonbr_io_getpid(lua_State *L) {
  1629   lua_pushinteger(L, getpid());
  1630   return 1;
  1631 }
  1633 #ifdef MOONBR_IO_USE_TLS
  1635 #define moonbr_io_poll_tls() \
  1636   if (!handle->tlshandshake) { \
  1637     force_wakeup = 1; \
  1638     continue; \
  1639   } \
  1640   if (handle->tlshandshake == TLS_WANT_POLLIN) { \
  1641     if (fd < 0) { \
  1642       force_wakeup = 1; \
  1643       continue; \
  1644     } \
  1645     FD_SET(fd, &readfds); \
  1646     if (fd+1 > nfds) nfds = fd+1; \
  1647     continue; \
  1648   } \
  1649   if (handle->tlshandshake == TLS_WANT_POLLOUT) { \
  1650     if (fd < 0) { \
  1651       force_wakeup = 1; \
  1652       continue; \
  1653     } \
  1654     FD_SET(fd, &writefds); \
  1655     if (fd+1 > nfds) nfds = fd+1; \
  1656     continue; \
  1657   } \
  1658   while (0)
  1660 #endif /* MOONBR_IO_USE_TLS */
  1662 static int moonbr_io_poll(lua_State *L) {
  1663   moonbr_io_handle_t *handle;
  1664   moonbr_io_listener_t *listener;
  1665   moonbr_io_child_t *child;
  1666   int fd, isnum;
  1667   int nfds = 0;
  1668   fd_set readfds, writefds, exceptfds;
  1669   struct timespec timeout = {0, };
  1670   int force_wakeup = 0;
  1671   int use_timeout = 0;  // negative for negative timeout
  1672   int check_sigterm = 0;
  1673   int check_sigchld = 0;
  1674   int childstatus;
  1675   sigset_t mask, orig_mask;
  1676   int status;
  1677   FD_ZERO(&readfds);
  1678   FD_ZERO(&writefds);
  1679   FD_ZERO(&exceptfds);
  1680   if (!lua_isnoneornil(L, 1)) {
  1681     luaL_checktype(L, 1, LUA_TTABLE);
  1682     for (lua_pushnil(L); lua_next(L, 1); lua_pop(L, 1)) {
  1683       if (lua_toboolean(L, -1)) {
  1684         handle = luaL_testudata(L, -2, MOONBR_IO_HANDLE_MT_REGKEY);
  1685         if (handle) {
  1686           if (handle->closed) luaL_error(L, "Attempt to poll a closed connection");
  1687           fd = handle->fd;
  1688 #if MOONBR_IO_USE_TLS
  1689           moonbr_io_poll_tls();
  1690 #endif
  1691           if (
  1692             fd < 0 ||  /* fake EOF to simulate shutdown if fd < 0 */
  1693             handle->readbufin != handle->readbufout  /* data pending in buffer */
  1694           ) {
  1695             force_wakeup = 1;
  1696             continue;
  1697           }
  1698         } else {
  1699           listener = luaL_testudata(L, -2, MOONBR_IO_LISTENER_MT_REGKEY);
  1700           if (listener) {
  1701             fd = listener->fd;
  1702             if (fd < 0) luaL_error(L, "Attempt to poll a closed listener");
  1703           } else {
  1704             child = luaL_testudata(L, -2, MOONBR_IO_CHILD_MT_REGKEY);
  1705             if (child) {
  1706               if (!check_sigchld) {
  1707                 check_sigchld = 1;
  1708                 moonbr_io_sigchld_flag = 0;
  1709                 signal(SIGCHLD, moonbr_io_sigchld_handler);
  1710               }
  1711               if (waitpid(child->pid, &childstatus, WNOHANG|WNOWAIT) != -1) {
  1712                 force_wakeup = 1;
  1713               } else if (errno != ECHILD && errno != EINTR) {
  1714                 moonbr_io_prepare_errmsg();
  1715                 luaL_error(L, "Error in waitpid call: %s", errmsg);
  1716               }
  1717               continue;
  1718             } else {
  1719               fd = lua_tointegerx(L, -2, &isnum);
  1720               if (!isnum) luaL_error(L, "Expected integer (file descriptor), I/O handle, or listener in table key");
  1721             }
  1722           }
  1723         }
  1724         if (fd < 0 || fd >= FD_SETSIZE) luaL_error(L, "File descriptor out of valid range");
  1725         FD_SET(fd, &readfds);
  1726         if (fd+1 > nfds) nfds = fd+1;
  1727       }
  1728     }
  1729   }
  1730   if (!lua_isnoneornil(L, 2)) {
  1731     luaL_checktype(L, 2, LUA_TTABLE);
  1732     for (lua_pushnil(L); lua_next(L, 2); lua_pop(L, 1)) {
  1733       if (lua_toboolean(L, -1)) {
  1734         handle = luaL_testudata(L, -2, MOONBR_IO_HANDLE_MT_REGKEY);
  1735         if (handle) {
  1736           if (handle->closed) luaL_error(L, "Attempt to poll a closed connection");
  1737           if (handle->finished) luaL_error(L, "Attempt to write-poll a finished connection");
  1738           fd = handle->fd;
  1739 #if MOONBR_IO_USE_TLS
  1740           moonbr_io_poll_tls();
  1741 #endif
  1742         } else {
  1743           listener = luaL_testudata(L, -2, MOONBR_IO_LISTENER_MT_REGKEY);
  1744           if (listener) luaL_error(L, "Attempt to write-poll a listener");
  1745           fd = lua_tointegerx(L, -2, &isnum);
  1746           if (!isnum) luaL_error(L, "Expected integer (file descriptor) or I/O handle in table key");
  1747         }
  1748         if (fd < 0 || fd >= FD_SETSIZE) luaL_error(L, "File descriptor out of valid range");
  1749         FD_SET(fd, &writefds);
  1750         if (fd+1 > nfds) nfds = fd+1;
  1751       }
  1752     }
  1753   }
  1754   if (!lua_isnoneornil(L, 3)) {
  1755     lua_Number n;
  1756     n = lua_tonumberx(L, 3, &isnum);
  1757     if (isnum && n<0) {
  1758       use_timeout = -1;
  1759     } else if (isnum && n>=0 && n<100000000) {
  1760       use_timeout = 1;
  1761       timeout.tv_sec = n;
  1762       timeout.tv_nsec = 1e9 * (n - timeout.tv_sec);
  1763     } else {
  1764       luaL_argcheck(L, 0, 3, "not a valid timeout");
  1765     }
  1766   }
  1767   if (use_timeout < 0) force_wakeup = 1;
  1768   if (!lua_isnoneornil(L, 4)) luaL_checktype(L, 4, LUA_TBOOLEAN);
  1769   check_sigterm = lua_toboolean(L, 4);
  1770   if ((check_sigterm || check_sigchld) && !force_wakeup) {
  1771     sigemptyset(&mask);
  1772     if (check_sigterm) sigaddset(&mask, SIGTERM);
  1773     if (check_sigchld) sigaddset(&mask, SIGCHLD);
  1774     if (sigprocmask(SIG_BLOCK, &mask, &orig_mask)) abort();
  1775   }
  1776   if (check_sigterm && moonbr_io_sigterm_flag) {
  1777     if (!force_wakeup) {
  1778       if (sigprocmask(SIG_SETMASK, &orig_mask, NULL)) abort();
  1779     }
  1780     lua_pushboolean(L, 0);
  1781     lua_pushliteral(L, "SIGTERM received");
  1782     lua_pushboolean(L, 1);
  1783     return 3;
  1784   }
  1785   if (check_sigchld && !force_wakeup && moonbr_io_sigchld_flag) {
  1786     if (sigprocmask(SIG_SETMASK, &orig_mask, NULL)) abort();
  1787     force_wakeup = 1;
  1788   }
  1789   if (use_timeout < 0) {
  1790     lua_pushboolean(L, 0);
  1791     lua_pushliteral(L, "Timeout");
  1792     if (check_sigterm) {
  1793       lua_pushboolean(L, 0);
  1794       return 3;
  1795     } else {
  1796       return 2;
  1797     }
  1798   }
  1799   if (!force_wakeup) {
  1800     status = pselect(
  1801       nfds, &readfds, &writefds, &exceptfds,
  1802       use_timeout ? &timeout : NULL,
  1803       check_sigterm ? &orig_mask : NULL
  1804     );
  1805     if (check_sigterm) {
  1806       if (sigprocmask(SIG_SETMASK, &orig_mask, NULL)) abort();
  1807       if (moonbr_io_sigterm_flag) {
  1808         lua_pushboolean(L, 0);
  1809         lua_pushliteral(L, "SIGTERM received");
  1810         lua_pushboolean(L, 1);
  1811         return 3;
  1812       }
  1813     }
  1814     if (status == -1) {
  1815       if (errno == EINTR) {
  1816         lua_pushboolean(L, 1);
  1817         return 1;
  1818       } else {
  1819         moonbr_io_prepare_errmsg();
  1820         return luaL_error(L, "Unexpected error during \"select\" system call: %s", errmsg);
  1821       }
  1822     } else if (status == 0) {
  1823       lua_pushboolean(L, 0);
  1824       lua_pushliteral(L, "Timeout");
  1825       if (check_sigterm) {
  1826         lua_pushboolean(L, 0);
  1827         return 3;
  1828       } else {
  1829         return 2;
  1830       }
  1831     }
  1832   }
  1833   lua_pushboolean(L, 1);
  1834   return 1;
  1835 }
  1837 static int moonbr_io_timeref(lua_State *L) {
  1838   lua_Number sub;
  1839   struct timespec tp;
  1840   sub = luaL_optnumber(L, 1, 0);
  1841   if (clock_gettime(CLOCK_MONOTONIC, &tp)) {
  1842     return luaL_error(L, "Could not access CLOCK_MONOTONIC");
  1843   }
  1844   lua_pushnumber(L, tp.tv_sec + tp.tv_nsec / 1.0e9 - sub);
  1845   return 1;
  1846 }
  1848 #ifdef MOONBR_IO_USE_TLS
  1850 #define moonbr_io_tlsconf_string(name, field, func) \
  1851   /* NOTE: use valuetype = lua_getfield(...) for LUA_VERSION_NUM >= 503 */ \
  1852   lua_getfield(L, 1, (field)); \
  1853   valuetype = lua_type(L, -1); \
  1854   if (valuetype != LUA_TNIL) { \
  1855     luaL_argcheck(L, valuetype == LUA_TSTRING, 1, "field \"" field "\" is not a string"); \
  1856     value = lua_tostring(L, -1); \
  1857     if (func(tlsconf->config, value)) { \
  1858       lua_pushnil(L); \
  1859       lua_pushfstring(L, "Could not set " name " \"%s\"", value); \
  1860       return 2; \
  1861     } \
  1862   } \
  1863   lua_pop(L, 1);
  1865 #define moonbr_io_tlsconf_binary(name, field, func) \
  1866   /* NOTE: use valuetype = lua_getfield(...) for LUA_VERSION_NUM >= 503 */ \
  1867   lua_getfield(L, 1, (field)); \
  1868   valuetype = lua_type(L, -1); \
  1869   if (valuetype != LUA_TNIL) { \
  1870     luaL_argcheck(L, valuetype == LUA_TSTRING, 1, "field \"" field "\" is not a string"); \
  1871     value = lua_tolstring(L, -1, &valuelen); \
  1872     if (func(tlsconf->config, (void *)value, valuelen)) { \
  1873       lua_pushnil(L); \
  1874       lua_pushliteral(L, "Could not set " name); \
  1875       return 2; \
  1876     } \
  1877   } \
  1878   lua_pop(L, 1);
  1880 static int moonbr_io_tlsconf(lua_State *L) {
  1881   moonbr_io_tlsconf_t *tlsconf;
  1882   int valuetype;
  1883   const char *value;
  1884   size_t valuelen;
  1885   luaL_checktype(L, 1, LUA_TTABLE);
  1886   tlsconf = lua_newuserdata(L, sizeof(moonbr_io_tlsconf_t));
  1887   tlsconf->config = tls_config_new();
  1888   if (!tlsconf->config) {
  1889     return luaL_error(L, "Could not allocate memory for TLS configuration");
  1890   }
  1891   luaL_setmetatable(L, MOONBR_IO_TLSCONF_MT_REGKEY);
  1892   lua_getfield(L, 1, "mode");
  1893   value = lua_tostring(L, -1);
  1894   if (value && !strcmp(value, "server")) tlsconf->server = 1;
  1895   else if (value && !strcmp(value, "client")) tlsconf->server = 0;
  1896   else luaL_argcheck(L, 0, 1, "field \"mode\" must be set to \"server\" or \"client\"");
  1897   lua_pop(L, 1);
  1898   moonbr_io_tlsconf_string("CA file",          "ca_file",   tls_config_set_ca_file);
  1899   moonbr_io_tlsconf_string("CA path",          "ca_path",   tls_config_set_ca_path);
  1900   moonbr_io_tlsconf_binary("CA",               "ca_mem",    tls_config_set_ca_mem);
  1901   moonbr_io_tlsconf_string("certificate file", "cert_file", tls_config_set_cert_file);
  1902   moonbr_io_tlsconf_binary("certificate",      "cert_mem",  tls_config_set_cert_mem);
  1903   moonbr_io_tlsconf_string("key file",         "key_file",  tls_config_set_key_file);
  1904   moonbr_io_tlsconf_binary("key",              "key_mem",   tls_config_set_key_mem);
  1905 #if LUA_VERSION_NUM >= 503
  1906   valuetype = lua_getfield(L, 1, "verify_client");
  1907 #else
  1908   lua_getfield(L, 1, "verify_client");
  1909 #endif
  1910   if (lua_toboolean(L, -1)) {
  1911     value = lua_tostring(L, -1);
  1912     if (value && !strcmp(value, "required")) {
  1913       tls_config_verify_client(tlsconf->config);
  1914     } else if (value && !strcmp(value, "optional")) {
  1915       tls_config_verify_client_optional(tlsconf->config);
  1916     } else {
  1917       luaL_argcheck(L, 0, 1, "field \"verify_client\" must be set to \"required\", \"optional\", or be false or nil");
  1918     }
  1919   }
  1920   lua_pop(L, 1);
  1921   // TODO: configurable legacy support
  1922   // tls_config_set_protocols(tlsconf->config, TLS_PROTOCOLS_ALL);
  1923   // tls_config_set_ciphers(tlsconf->config, "legacy");
  1924   return 1;
  1925 }
  1927 static int moonbr_io_tlsconfgc(lua_State *L) {
  1928   moonbr_io_tlsconf_t *tlsconf;
  1929   tlsconf = luaL_checkudata(L, 1, MOONBR_IO_TLSCONF_MT_REGKEY);
  1930   if (tlsconf->config) tls_config_free(tlsconf->config);
  1931   tlsconf->config = NULL;
  1932   return 0;
  1933 }
  1935 static int moonbr_io_starttls(lua_State *L) {
  1936   moonbr_io_handle_t *handle;
  1937   moonbr_io_tlsconf_t *tlsconf;
  1938   const char *servername;
  1939   struct tls *tls, *tls2;
  1940   handle = luaL_checkudata(L, 1, MOONBR_IO_HANDLE_MT_REGKEY);
  1941   if (lua_type(L, 2) == LUA_TTABLE) {
  1942     lua_pushcfunction(L, moonbr_io_tlsconf);
  1943     lua_pushvalue(L, 2);
  1944     lua_call(L, 1, 2);
  1945     if (lua_isnil(L, -2)) return 2;
  1946     lua_pop(L, 1);
  1947     lua_replace(L, 2);
  1948   }
  1949   tlsconf = luaL_checkudata(L, 2, MOONBR_IO_TLSCONF_MT_REGKEY);
  1950   if (handle->closed) return luaL_error(L, "Attempt to start TLS on a closed I/O handle");
  1951   if (handle->finished) return luaL_error(L, "Attempt to start TLS on a finished I/O handle");
  1952   if (handle->tls) return luaL_error(L, "Attempt to start TLS twice");
  1953   if (handle->readbufin || handle->writebufin) {
  1954     return luaL_error(L, "Attempt to start TLS on an I/O handle with non-empty buffers");
  1955   }
  1956   if (tlsconf->server) tls = tls_server();
  1957   else {
  1958     servername = luaL_checkstring(L, 3);
  1959     tls = tls_client();
  1960   }
  1961   if (!tls) {
  1962     return luaL_error(L, "Could not allocate memory for TLS context");
  1963   }
  1964   if (tls_configure(tls, tlsconf->config)) goto moonbr_io_starttls_error;
  1965   if (tlsconf->server) {
  1966     if (tls_accept_socket(tls, &tls2, handle->fd)) goto moonbr_io_starttls_error;
  1967     handle->servertls = tls;
  1968     handle->tls = tls2;
  1969   } else {
  1970     if (tls_connect_socket(tls, handle->fd, servername)) goto moonbr_io_starttls_error;
  1971     handle->tls = tls;
  1972   }
  1973   lua_settop(L, 1);
  1974   return 1;
  1975   moonbr_io_starttls_error:
  1976   lua_pushnil(L);
  1977   lua_pushstring(L, tls_error(tls));
  1978   tls_free(tls);
  1979   return 2;
  1980 }
  1982 #endif /* MOONBR_IO_USE_TLS */
  1984 static const struct luaL_Reg moonbr_io_handle_methods[] = {
  1985   {"read", moonbr_io_read},
  1986   {"read_nb", moonbr_io_read_nb},
  1987   {"read_call", moonbr_io_read_call},
  1988   {"read_yield", moonbr_io_read_yield},
  1989   {"drain", moonbr_io_drain},
  1990   {"drain_nb", moonbr_io_drain_nb},
  1991   {"drain_call", moonbr_io_drain_call},
  1992   {"drain_yield", moonbr_io_drain_yield},
  1993   {"write", moonbr_io_write},
  1994   {"write_nb", moonbr_io_write_nb},
  1995   {"write_call", moonbr_io_write_call},
  1996   {"write_yield", moonbr_io_write_yield},
  1997   {"flush", moonbr_io_flush},
  1998   {"flush_nb", moonbr_io_flush_nb},
  1999   {"flush_call", moonbr_io_flush_call},
  2000   {"flush_yield", moonbr_io_flush_yield},
  2001   {"finish", moonbr_io_finish},
  2002   {"close", moonbr_io_close},
  2003   {"reset", moonbr_io_reset},
  2004 #ifdef MOONBR_IO_USE_TLS
  2005   {"starttls", moonbr_io_starttls},
  2006 #endif
  2007   {NULL, NULL}
  2008 };
  2010 static const struct luaL_Reg moonbr_io_handle_metamethods[] = {
  2011   {"__index", moonbr_io_handleindex},
  2012   {"__newindex", moonbr_io_handlenewindex},
  2013   {"__gc", moonbr_io_handlegc},
  2014   {NULL, NULL}
  2015 };
  2017 static const struct luaL_Reg moonbr_io_listener_methods[] = {
  2018   {"accept", moonbr_io_accept},
  2019   {"accept_nb", moonbr_io_accept_nb},
  2020   {"close", moonbr_io_unlisten},
  2021   {NULL, NULL}
  2022 };
  2024 static const struct luaL_Reg moonbr_io_listener_metamethods[] = {
  2025   {"__gc", moonbr_io_listenergc},
  2026   {NULL, NULL}
  2027 };
  2029 static const struct luaL_Reg moonbr_io_child_methods[] = {
  2030   {"kill", moonbr_io_kill},
  2031   {"wait", moonbr_io_wait},
  2032   {"wait_nb", moonbr_io_wait_nb},
  2033   {"wait_call", moonbr_io_wait_call},
  2034   {"wait_yield", moonbr_io_wait_yield},
  2035   {NULL, NULL}
  2036 };
  2038 static const struct luaL_Reg moonbr_io_child_metamethods[] = {
  2039   {"__index", moonbr_io_childindex},
  2040   {"__newindex", moonbr_io_childnewindex},
  2041   {"__gc", moonbr_io_childgc},
  2042   {NULL, NULL}
  2043 };
  2045 static const struct luaL_Reg moonbr_io_module_funcs[] = {
  2046   {"localconnect", moonbr_io_localconnect},
  2047   {"localconnect_nb", moonbr_io_localconnect_nb},
  2048   {"tcpconnect", moonbr_io_tcpconnect},
  2049   {"tcpconnect_nb", moonbr_io_tcpconnect_nb},
  2050   {"locallisten", moonbr_io_locallisten},
  2051   {"tcplisten", moonbr_io_tcplisten},
  2052   {"exec", moonbr_io_exec},
  2053   {"catch_sigterm", moonbr_io_catch_sigterm},
  2054   {"getpid", moonbr_io_getpid},
  2055   {"poll", moonbr_io_poll},
  2056   {"timeref", moonbr_io_timeref},
  2057 #ifdef MOONBR_IO_USE_TLS
  2058   {"tlsconf", moonbr_io_tlsconf},
  2059 #endif
  2060   {NULL, NULL}
  2061 };
  2063 #ifdef MOONBR_IO_USE_TLS
  2065 static const struct luaL_Reg moonbr_io_tlsconf_metamethods[] = {
  2066   {"__gc", moonbr_io_tlsconfgc},
  2067   {NULL, NULL}
  2068 };
  2070 #endif /* MOONBR_IO_USE_TLS */
  2072 int luaopen_moonbridge_io(lua_State *L) {
  2074   signal(SIGPIPE, SIG_IGN);  /* generate I/O errors instead of signal 13 */
  2076   lua_newtable(L);  // module
  2078   lua_newtable(L);  // public metatable
  2079   lua_newtable(L);  // handle methods
  2080   luaL_setfuncs(L, moonbr_io_handle_methods, 0);
  2081   lua_pushvalue(L, -1);
  2082   lua_setfield(L, -4, "handle_pt");
  2083   lua_setfield(L, -2, "__index");
  2084   lua_setfield(L, LUA_REGISTRYINDEX, MOONBR_IO_HANDLE_PUBLIC_MT_REGKEY);
  2086   lua_newtable(L);  // handle metatable
  2087   luaL_setfuncs(L, moonbr_io_handle_metamethods, 0);
  2088   lua_pushvalue(L, -1);
  2089   lua_setfield(L, -3, "handle_mt");
  2090   lua_setfield(L, LUA_REGISTRYINDEX, MOONBR_IO_HANDLE_MT_REGKEY);
  2092   lua_newtable(L);  // listener metatable
  2093   luaL_setfuncs(L, moonbr_io_listener_metamethods, 0);
  2094   lua_newtable(L);  // listener methods
  2095   luaL_setfuncs(L, moonbr_io_listener_methods, 0);
  2096   lua_pushvalue(L, -1);
  2097   lua_setfield(L, -4, "listener_pt");
  2098   lua_setfield(L, -2, "__index");
  2099   lua_pushvalue(L, -1);
  2100   lua_setfield(L, -3, "listener_mt");
  2101   lua_setfield(L, LUA_REGISTRYINDEX, MOONBR_IO_LISTENER_MT_REGKEY);
  2103   lua_newtable(L);  // child methods
  2104   luaL_setfuncs(L, moonbr_io_child_methods, 0);
  2105   lua_pushvalue(L, -1);
  2106   lua_setfield(L, -3, "child_pt");
  2107   lua_setfield(L, LUA_REGISTRYINDEX, MOONBR_IO_CHILD_PT_REGKEY);
  2108   lua_newtable(L);  // child metatable
  2109   luaL_setfuncs(L, moonbr_io_child_metamethods, 0);
  2110   lua_pushvalue(L, -1);
  2111   lua_setfield(L, -3, "child_mt");
  2112   lua_setfield(L, LUA_REGISTRYINDEX, MOONBR_IO_CHILD_MT_REGKEY);
  2114 #ifdef MOONBR_IO_USE_TLS
  2115   if(tls_init()) {
  2116     return luaL_error(L, "Could not initialize TLS library");
  2117   }
  2118   lua_newtable(L);  // tlsconf metatable
  2119   luaL_setfuncs(L, moonbr_io_tlsconf_metamethods, 0);
  2120   lua_pushvalue(L, -1);
  2121   lua_setfield(L, -3, "tlsconf_mt");
  2122   lua_setfield(L, LUA_REGISTRYINDEX, MOONBR_IO_TLSCONF_MT_REGKEY);
  2123 #endif
  2125   moonbr_io_pushhandle(L, 0);
  2126   lua_setfield(L, -2, "stdin");
  2127   moonbr_io_pushhandle(L, 1);
  2128   lua_setfield(L, -2, "stdout");
  2129   moonbr_io_pushhandle(L, 2);
  2130   lua_setfield(L, -2, "stderr");
  2132   luaL_setfuncs(L, moonbr_io_module_funcs, 0);
  2133   return 1;
  2135 }
