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#include <errno.h>
#include <fcntl.h>
#include <lauxlib.h>
#include <lua.h>
#include <lualib.h>
#include <netdb.h>
#include <poll.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
#include "http.h"
/// Tries to create, bind and start listening on INET server socket.
/// \param node Hostname
/// \param service Port
/// \return File descriptor of the socket or -1 in case of an error
/// \see getaddrinfo(3)
// TODO: Handle UNIX sockets
int make_server(const char * node, const char * service)
{
struct addrinfo hints = {
.ai_family = AF_UNSPEC,
.ai_socktype = SOCK_STREAM,
.ai_flags = AI_PASSIVE,
};
struct addrinfo * result;
struct addrinfo * it;
if (0 != getaddrinfo(node, service, &hints, &result))
{
return -1; // TODO: Handle errors properly
}
int server;
for (it = result; it != NULL; it = it->ai_next)
{
server = socket(it->ai_family, it->ai_socktype, it->ai_protocol);
if (-1 == server)
continue;
if (-1 == fcntl(server, F_SETFL, (fcntl(server, F_GETFL, 0) | O_NONBLOCK)))
{
close(server);
continue;
}
if (0 == bind(server, it->ai_addr,it->ai_addrlen))
break;
close(server);
}
if (it == NULL)
{
server = -1; // TODO: Handle errors properly
}
freeaddrinfo(result);
if (-1 == server || -1 == listen(server, 5))
{
return -1; // TODO: Handle errors properly
}
return server;
}
/// Progresses the connection for a client and shifts it back in the array.
/// `pfd` must be at least `shift_by + 1`-th element of the array.
/// \param L Server's Lua state
/// \param pfd Element in array processed by poll
/// \param data Pointer to data associated with the client
/// \param shift_by Element will be moved by in array this many indices
/// \return Shift value for next handler
/// \see poll(2)
int handle_client(lua_State * L, struct pollfd * pfd, char ** data, const int shift_by)
{
if (0 == pfd->revents)
{
return shift_by;
}
if (~(POLLIN | POLLOUT) & pfd->revents)
{
return -1; // TODO: Handle errors properly
}
if (-1 == collect_request(pfd->fd, data))
{
return -1; // TODO: Handle errors properly
}
lua_getglobal(L, "Handler");
lua_pushstring(L, *data);
lua_call(L, 1, 1);
size_t length;
const char * body = lua_tolstring(L, -1, &length);
if (NULL != body)
{
respond_with_body(pfd->fd, STATUS_OK, body, (int) length);
}
close(pfd->fd);
(pfd - shift_by)->fd = -1;
(pfd - shift_by)->events = pfd->events;
free(*data);
*data = NULL;
return shift_by + 1;
}
/// Accepts awaiting connections if any.
/// \param fdv Array of descriptors for poll
/// \param fdc Number of valid descriptors in the array including the server
/// \param size Size limit for the array
/// \return Number of valid descriptors in the array or -1 if an error occurred.
/// \see poll(2)
int handle_server(struct pollfd * fdv, int fdc, const int size)
{
if (0 == fdv[0].revents)
{
return fdc;
}
while (size > fdc + 1 && -1 != (fdv[fdc].fd = accept(fdv[0].fd, NULL, NULL)))
{
fdv[fdc].events = POLLIN | POLLOUT;
fdc++;
}
if (errno != EWOULDBLOCK && errno != EAGAIN)
{
return -1;
}
return fdc;
}
/// Standard entry point for the program.
/// \param argc Argument count
/// \param argv Argument array
/// \return Error code
int main(int argc, char ** argv)
{
lua_State * L = luaL_newstate();
luaL_openlibs(L);
if (LUA_OK != luaL_dofile(L, "default.lua"))
{
return 2; // TODO: Document error codes/print usage information
}
if (2 != argc)
{
return 1; // TODO: Document error codes/print usage information
}
static const int max_clients = 200;
int fdc = 0;
char * data[max_clients];
struct pollfd fdv[max_clients];
memset(data, 0, sizeof(data));
memset(fdv, 0, sizeof(fdv));
fdv[0].fd = make_server(NULL, argv[1]);
fdv[0].events = POLLIN;
fdc++;
while (0 < fdc && -1 != poll(fdv, fdc, -1))
{
int shift_by = 0;
for (int i = 1; i < fdc; ++i)
{
shift_by = handle_client(L, &fdv[i], &data[i], shift_by);
}
fdc = handle_server(fdv, fdc - shift_by, max_clients);
}
}
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