libs/nixio/src/io.c

   1 /*
   2  * nixio - Linux I/O library for lua
   3  *
   4  *   Copyright (C) 2009 Steven Barth <steven@midlink.org>
   5  *
   6  *  Licensed under the Apache License, Version 2.0 (the "License");
   7  *  you may not use this file except in compliance with the License.
   8  *  You may obtain a copy of the License at
   9  *
  10  *      http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  *  Unless required by applicable law or agreed to in writing, software
  13  *  distributed under the License is distributed on an "AS IS" BASIS,
  14  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  *  See the License for the specific language governing permissions and
  16  *  limitations under the License.
  17  */
  18
  19 #include "nixio.h"
  20 #include <errno.h>
  21 #include <string.h>
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <sys/types.h>
  25
  26
  27 /**
  28  * send() / sendto() helper
  29  */
  30 static int nixio_sock__sendto(lua_State *L, int to) {
  31         nixio_sock *sock = nixio__checksock(L);
  32         struct sockaddr *addr = NULL;
  33         socklen_t alen = 0;
  34         int argoff = 2;
  35
  36         if (to) {
  37                 argoff += 2;
  38                 const char *address = luaL_checkstring(L, 3);
  39                 struct sockaddr_storage addrstor;
  40                 addr = (struct sockaddr*)&addrstor;
  41
  42                 nixio_addr naddr;
  43                 memset(&naddr, 0, sizeof(naddr));
  44                 strncpy(naddr.host, address, sizeof(naddr.host) - 1);
  45                 naddr.port = (uint16_t)luaL_checkinteger(L, 4);
  46                 naddr.family = sock->domain;
  47
  48                 if (nixio__addr_write(&naddr, addr)) {
  49                         return nixio__perror_s(L);
  50                 }
  51         }
  52
  53         size_t len;
  54         ssize_t sent;
  55         const char *data = luaL_checklstring(L, 2, &len);
  56
  57         if (lua_gettop(L) > argoff) {
  58                 int offset = luaL_optint(L, argoff + 1, 0);
  59                 if (offset) {
  60                         if (offset < len) {
  61                                 data += offset;
  62                                 len -= offset;
  63                         } else {
  64                                 len = 0;
  65                         }
  66                 }
  67
  68                 unsigned int wlen = luaL_optint(L, argoff + 2, len);
  69                 if (wlen < len) {
  70                         len = wlen;
  71                 }
  72         }
  73
  74         do {
  75                 sent = sendto(sock->fd, data, len, 0, addr, alen);
  76         } while(sent == -1 && errno == EINTR);
  77         if (sent >= 0) {
  78                 lua_pushinteger(L, sent);
  79                 return 1;
  80         } else {
  81                 return nixio__perror_s(L);
  82         }
  83 }
  84
  85 /**
  86  * send(data)
  87  */
  88 static int nixio_sock_send(lua_State *L) {
  89         return nixio_sock__sendto(L, 0);
  90 }
  91
  92 /**
  93  * sendto(data, address, port)
  94  */
  95 static int nixio_sock_sendto(lua_State *L) {
  96         return nixio_sock__sendto(L, 1);
  97 }
  98
  99
 100 /**
 101  * recv() / recvfrom() helper
 102  */
 103 static int nixio_sock__recvfrom(lua_State *L, int from) {
 104         nixio_sock *sock = nixio__checksock(L);
 105         char buffer[NIXIO_BUFFERSIZE];
 106         struct sockaddr_storage addrobj;
 107         uint req = luaL_checkinteger(L, 2);
 108         int readc;
 109
 110         if (from && sock->domain != AF_INET && sock->domain != AF_INET6) {
 111                 return luaL_argerror(L, 1, "supported families: inet, inet6");
 112         }
 113
 114         struct sockaddr *addr = (from) ? (struct sockaddr*)&addrobj : NULL;
 115         socklen_t alen = (from) ? sizeof(addrobj) : 0;
 116
 117         /* We limit the readsize to NIXIO_BUFFERSIZE */
 118         req = (req > NIXIO_BUFFERSIZE) ? NIXIO_BUFFERSIZE : req;
 119
 120         do {
 121                 readc = recvfrom(sock->fd, buffer, req, 0, addr, &alen);
 122         } while (readc == -1 && errno == EINTR);
 123
 124 #ifdef __WINNT__
 125         if (readc < 0) {
 126                 int e = WSAGetLastError();
 127                 if (e == WSAECONNRESET || e == WSAECONNABORTED || e == WSAESHUTDOWN) {
 128                         readc = 0;
 129                 }
 130         }
 131 #endif
 132
 133         if (readc < 0) {
 134                 return nixio__perror_s(L);
 135         } else {
 136                 lua_pushlstring(L, buffer, readc);
 137
 138                 if (!from) {
 139                         return 1;
 140                 } else {
 141                         nixio_addr naddr;
 142                         if (!nixio__addr_parse(&naddr, (struct sockaddr *)&addrobj)) {
 143                                 lua_pushstring(L, naddr.host);
 144                                 lua_pushinteger(L, naddr.port);
 145                                 return 3;
 146                         } else {
 147                                 return 1;
 148                         }
 149                 }
 150         }
 151 }
 152
 153 /**
 154  * recv(count)
 155  */
 156 static int nixio_sock_recv(lua_State *L) {
 157         return nixio_sock__recvfrom(L, 0);
 158 }
 159
 160 /**
 161  * recvfrom(count)
 162  */
 163 static int nixio_sock_recvfrom(lua_State *L) {
 164         return nixio_sock__recvfrom(L, 1);
 165 }
 166
 167
 168 /* module table */
 169 static const luaL_reg M[] = {
 170         {"send",        nixio_sock_send},
 171         {"sendto",      nixio_sock_sendto},
 172         {"recv",        nixio_sock_recv},
 173         {"recvfrom",nixio_sock_recvfrom},
 174         {"write",       nixio_sock_send},
 175         {"read",        nixio_sock_recv},
 176         {NULL,                  NULL}
 177 };
 178
 179 void nixio_open_io(lua_State *L) {
 180         lua_pushvalue(L, -2);
 181         luaL_register(L, NULL, M);
 182         lua_pop(L, 1);
 183 }