1 files changed, 283 insertions, 0 deletions
diff --git a/src/l_tcp.c b/src/l_tcp.c
new file mode 100644
index 0000000..1a4da9f
--- /dev/null
+++ b/src/l_tcp.c
@@ -0,0 +1,283 @@
+/*
+ *  gcsd
+ *
+ *  gcsd the generic command sequencer daemon can be used to serialize 
+ *  commands sent over various paralell communication channels to a
+ *  single command output. It can be seen as a multiplexer for any
+ *  kind of communication between a single resource and various clients
+ *  which want to submit commands to it or query information from it.
+ *  gcsd is written in C and Lua. The goal is to provide an easy to 
+ *  understand high level API based on Lua which can be used to
+ *  implement the business logic of the so formed multiplexer daemon.
+ *  
+ *
+ *  Copyright (C) 2009-2010 Markus Grueneis <gimpf@spreadspace.org>
+ *                          Christian Pointner <equinox@spreadspace.org>
+ *
+ *  This file is part of gcsd.
+ *
+ *  gcsd 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
+ *  any later version.
+ *
+ *  gcsd 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 gcsd. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <lua.h>
+#include <lauxlib.h>
+
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+
+#include "l_tcp.h"
+
+#include "datatypes.h"
+#include "log.h"
+
+typedef struct {
+  socklen_t len_;
+  struct sockaddr_storage addr_;
+} tcp_endpoint_t;
+#define LUA_TCP_UDATA_NAME "tcp_endpoint_t"
+
+
+static tcp_endpoint_t* newtcpendudata(lua_State *L)
+{
+  tcp_endpoint_t* end = (tcp_endpoint_t*)lua_newuserdata(L, sizeof(tcp_endpoint_t));
+  memset(end, 0, sizeof(end));
+  luaL_newmetatable(L, LUA_TCP_UDATA_NAME);
+  lua_setmetatable(L, -2);
+  return end;
+}
+
+static char* tcp_endpoint_to_string(tcp_endpoint_t* e)
+{
+  size_t addrstr_len = 0;
+  char addrstr[INET6_ADDRSTRLEN + 1], portstr[6], *ret;
+  char addrport_sep = ':';
+  
+  switch(e->addr_.ss_family)
+  {
+  case AF_INET: addrport_sep = ':'; break;
+  case AF_INET6: addrport_sep = '.'; break;
+  case AF_UNSPEC: return NULL;
+  default: asprintf(&ret, "unknown address type"); return ret;
+  }
+
+  int errcode  = getnameinfo((struct sockaddr *)&(e->addr_), e->len_, addrstr, sizeof(addrstr), portstr, sizeof(portstr), NI_NUMERICHOST | NI_NUMERICSERV);
+  if (errcode != 0) return NULL;
+  asprintf(&ret, "%s%c%s", addrstr, addrport_sep ,portstr);
+  return ret;
+}
+
+static int init_listener(tcp_endpoint_t* end)
+{
+  int fd = socket(end->addr_.ss_family, SOCK_STREAM, 0);
+  if(fd < 0) {
+    log_printf(ERROR, "tcp: Error on opening socket: %s", strerror(errno));
+    return -1;
+  }
+
+  int on = 1;
+  int ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+  if(ret) {
+    log_printf(ERROR, "tcp: Error on setsockopt(): %s", strerror(errno));
+    return -1;
+  }
+  if(end->addr_.ss_family == AF_INET6) {
+    if(setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)))
+      log_printf(WARNING, "tcp: failed to set IPV6_V6ONLY socket option: %s", strerror(errno));
+  }
+
+  char* ls = tcp_endpoint_to_string(end);
+  ret = bind(fd, (struct sockaddr *)&(end->addr_), end->len_);
+  if(ret) {
+    log_printf(ERROR, "tcp: Error on bind(%s): %s", ls ? ls:"", strerror(errno));
+    if(ls) free(ls);
+    return -1;
+  }
+
+  ret = listen(fd, 0);
+  if(ret) {
+    log_printf(ERROR, "tcp: Error on listen(): %s", strerror(errno));
+    if(ls) free(ls);
+    return -1;
+  }
+
+  log_printf(NOTICE, "tcp: listening on: %s", ls ? ls:"(null)");
+  if(ls) free(ls);
+
+  return fd;
+}
+
+static int l_tcp_server(lua_State *L)
+{
+  const char* addr = luaL_optstring(L, 1, "*");
+  if(!strcmp(addr, "*") || !strlen(addr)) addr = NULL;
+  const char* port = luaL_checkstring(L, 2);
+  int af = luaL_optint(L, 3, 0);
+  
+  struct addrinfo hints, *res;
+  res = NULL;
+  memset (&hints, 0, sizeof (hints));
+  hints.ai_socktype = SOCK_STREAM;
+  hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
+  switch(af) {
+  case 4: hints.ai_family = AF_INET; break;
+  case 6: hints.ai_family = AF_INET6; break;
+  default: hints.ai_family = AF_UNSPEC; break;
+  }
+
+  int errcode = getaddrinfo(addr, port, &hints, &res);
+      // TODO: better error handling (no lua error)
+  if(errcode != 0)
+    luaL_error(L, "tcp: resolver error: %s", gai_strerror(errcode));
+  if(!res)
+    luaL_error(L, "tcp: no address found!");
+
+  lua_newtable(L);
+
+  int idx = 1;
+  struct addrinfo* r = res;
+  while(r) {
+    lua_pushinteger(L, idx++);
+    lua_newtable(L);
+
+    lua_pushliteral(L, "local_end");
+    tcp_endpoint_t* end = newtcpendudata(L);
+    memcpy(&(end->addr_), r->ai_addr, r->ai_addrlen);
+    end->len_ = r->ai_addrlen;
+    lua_settable(L, -3);
+
+    int fd = init_listener(end);
+    if(fd < 0) {
+      freeaddrinfo(res);
+      luaL_error(L, "tcp: Error at server init");
+    }
+
+    lua_pushliteral(L, "fd");
+    lua_pushinteger(L, fd);
+    lua_settable(L, -3);
+
+    lua_settable(L, -3);
+    r = r->ai_next;
+  }
+  freeaddrinfo(res);
+
+  return 1;
+}
+
+static int l_tcp_accept(lua_State *L)
+{
+  int fd = luaL_checkint(L, 1);
+  tcp_endpoint_t* remote_addr = newtcpendudata(L);
+  remote_addr->len_ = sizeof(remote_addr->addr_);
+  int new_client = accept(fd, (struct sockaddr *)&(remote_addr->addr_), &remote_addr->len_);
+  if(new_client == -1) {
+    lua_pushnil(L);
+    lua_pushstring(L, strerror(errno));
+    return 2;
+  }
+  char* rs = tcp_endpoint_to_string(remote_addr);
+  log_printf(INFO, "new client from %s (fd=%d)", rs ? rs:"(null)", new_client);
+  if(rs) free(rs);
+
+  lua_pushinteger(L, new_client);
+  lua_insert(L, -2);
+  return 2;
+}
+
+static int l_tcp_client(lua_State *L)
+{
+      // TODO: implement this
+  return 0;
+}
+
+static int l_tcp_connect(lua_State *L)
+{
+      // TODO: implement this
+  return 0;
+}
+
+static int l_tcp_recv(lua_State *L)
+{
+  int fd = luaL_checkint(L,1);
+  size_t len = luaL_checkint(L,2);
+  char* data = malloc(len);
+  if(!data) {
+    lua_pushnil(L);
+    lua_pushstring(L, "bad alloc");
+    return 2;
+  }
+    
+  int ret = recv(fd, data, len, 0);
+  
+  if(ret == -1) {
+    lua_pushnil(L);
+// FIXXXXXME: strerror is not threadsafe!!!
+    lua_pushstring(L, strerror(errno));
+    free(data);
+    return 2;
+  }
+  lua_pushlstring(L, data, ret);
+  free(data);
+  return 1;
+}
+
+static int l_tcp_send(lua_State *L)
+{
+  int fd = luaL_checkint(L,1);
+  size_t len = 0;
+  const char* data = luaL_checklstring(L, 2, &len);
+  
+  int ret = send(fd, data, len, 0);
+  
+  if(ret == -1) {
+    lua_pushnil(L);
+// FIXXXXXME: strerror is not threadsafe!!!
+    lua_pushstring(L, strerror(errno));
+    return 2;
+  }
+  lua_pushinteger(L, ret);
+  return 1;
+}
+
+static int l_tcp_endtostring(lua_State *L)
+{
+  tcp_endpoint_t* e = (tcp_endpoint_t*)luaL_checkudata(L, 1, LUA_TCP_UDATA_NAME);
+  char* es = tcp_endpoint_to_string(e);
+  if(!es)
+    luaL_error(L, "bad alloc");
+
+  lua_pushstring(L, es);
+  free(es);
+  return 1;
+}
+
+static const struct luaL_reg tcp_funcs [] = {
+  { "server", l_tcp_server },
+  { "accept", l_tcp_accept },
+  { "client", l_tcp_client },
+  { "connect", l_tcp_connect },
+  { "recv", l_tcp_recv },
+  { "send", l_tcp_send },
+  { "endtostring", l_tcp_endtostring },
+  { NULL, NULL }
+};
+
+LUALIB_API int luaopen_tcp(lua_State *L) 
+{
+  luaL_register(L, LUA_TCPLIBNAME, tcp_funcs);
+  return 1;
+}