openwrtv4/package/uhttpd/src/uhttpd-lua.c
2010-03-29 09:26:02 +00:00

548 lines
11 KiB
C

/*
* uhttpd - Tiny single-threaded httpd - Lua handler
*
* Copyright (C) 2010 Jo-Philipp Wich <xm@subsignal.org>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "uhttpd.h"
#include "uhttpd-utils.h"
#include "uhttpd-lua.h"
static int uh_lua_recv(lua_State *L)
{
size_t length;
char buffer[UH_LIMIT_MSGHEAD];
ssize_t rlen = 0;
fd_set reader;
struct timeval timeout;
length = luaL_checknumber(L, 1);
if( (length > 0) && (length <= sizeof(buffer)) )
{
FD_ZERO(&reader);
FD_SET(fileno(stdin), &reader);
/* fail after 0.1s */
timeout.tv_sec = 0;
timeout.tv_usec = 100000;
/* check whether fd is readable */
if( select(fileno(stdin) + 1, &reader, NULL, NULL, &timeout) > 0 )
{
/* receive data */
rlen = read(fileno(stdin), buffer, length);
lua_pushnumber(L, rlen);
if( rlen > 0 )
{
lua_pushlstring(L, buffer, rlen);
return 2;
}
return 1;
}
/* no, timeout and actually no data */
lua_pushnumber(L, -2);
return 1;
}
/* parameter error */
lua_pushnumber(L, -3);
return 1;
}
static int uh_lua_send_common(lua_State *L, int chunked)
{
size_t length;
const char *buffer;
char chunk[16];
ssize_t slen = 0;
buffer = luaL_checklstring(L, 1, &length);
if( chunked )
{
if( length > 0 )
{
snprintf(chunk, sizeof(chunk), "%X\r\n", length);
slen = write(fileno(stdout), chunk, strlen(chunk));
slen += write(fileno(stdout), buffer, length);
slen += write(fileno(stdout), "\r\n", 2);
}
else
{
slen = write(fileno(stdout), "0\r\n\r\n", 5);
}
}
else
{
slen = write(fileno(stdout), buffer, length);
}
lua_pushnumber(L, slen);
return 1;
}
static int uh_lua_send(lua_State *L)
{
return uh_lua_send_common(L, 0);
}
static int uh_lua_sendc(lua_State *L)
{
return uh_lua_send_common(L, 1);
}
static int uh_lua_urldecode(lua_State *L)
{
size_t inlen, outlen;
const char *inbuf;
char outbuf[UH_LIMIT_MSGHEAD];
inbuf = luaL_checklstring(L, 1, &inlen);
outlen = uh_urldecode(outbuf, sizeof(outbuf), inbuf, inlen);
lua_pushlstring(L, outbuf, outlen);
return 1;
}
lua_State * uh_lua_init(const char *handler)
{
lua_State *L = lua_open();
const char *err_str = NULL;
/* Load standard libaries */
luaL_openlibs(L);
/* build uhttpd api table */
lua_newtable(L);
/* register global send and receive functions */
lua_pushcfunction(L, uh_lua_recv);
lua_setfield(L, -2, "recv");
lua_pushcfunction(L, uh_lua_send);
lua_setfield(L, -2, "send");
lua_pushcfunction(L, uh_lua_sendc);
lua_setfield(L, -2, "sendc");
lua_pushcfunction(L, uh_lua_urldecode);
lua_setfield(L, -2, "urldecode");
/* _G.uhttpd = { ... } */
lua_setfield(L, LUA_GLOBALSINDEX, "uhttpd");
/* load Lua handler */
switch( luaL_loadfile(L, handler) )
{
case LUA_ERRSYNTAX:
fprintf(stderr,
"Lua handler contains syntax errors, unable to continue\n");
exit(1);
case LUA_ERRMEM:
fprintf(stderr,
"Lua handler ran out of memory, unable to continue\n");
exit(1);
case LUA_ERRFILE:
fprintf(stderr,
"Lua cannot open the handler script, unable to continue\n");
exit(1);
default:
/* compile Lua handler */
switch( lua_pcall(L, 0, 0, 0) )
{
case LUA_ERRRUN:
err_str = luaL_checkstring(L, -1);
fprintf(stderr,
"Lua handler had runtime error, unable to continue\n"
"Error: %s\n", err_str
);
exit(1);
case LUA_ERRMEM:
err_str = luaL_checkstring(L, -1);
fprintf(stderr,
"Lua handler ran out of memory, unable to continue\n"
"Error: %s\n", err_str
);
exit(1);
default:
/* test handler function */
lua_getglobal(L, UH_LUA_CALLBACK);
if( ! lua_isfunction(L, -1) )
{
fprintf(stderr,
"Lua handler provides no " UH_LUA_CALLBACK "(), unable to continue\n");
exit(1);
}
lua_pop(L, 1);
break;
}
break;
}
return L;
}
void uh_lua_request(struct client *cl, struct http_request *req, lua_State *L)
{
int i, data_sent;
int content_length = 0;
int buflen = 0;
int fd_max = 0;
char *query_string;
const char *prefix = cl->server->conf->lua_prefix;
const char *err_str = NULL;
int rfd[2] = { 0, 0 };
int wfd[2] = { 0, 0 };
char buf[UH_LIMIT_MSGHEAD];
pid_t child;
fd_set reader;
fd_set writer;
struct sigaction sa;
struct timeval timeout;
/* spawn pipes for me->child, child->me */
if( (pipe(rfd) < 0) || (pipe(wfd) < 0) )
{
uh_http_sendhf(cl, 500, "Internal Server Error",
"Failed to create pipe: %s", strerror(errno));
if( rfd[0] > 0 ) close(rfd[0]);
if( rfd[1] > 0 ) close(rfd[1]);
if( wfd[0] > 0 ) close(wfd[0]);
if( wfd[1] > 0 ) close(wfd[1]);
return;
}
switch( (child = fork()) )
{
case -1:
uh_http_sendhf(cl, 500, "Internal Server Error",
"Failed to fork child: %s", strerror(errno));
break;
case 0:
/* restore SIGTERM */
sa.sa_flags = 0;
sa.sa_handler = SIG_DFL;
sigemptyset(&sa.sa_mask);
sigaction(SIGTERM, &sa, NULL);
/* close loose pipe ends */
close(rfd[0]);
close(wfd[1]);
/* patch stdout and stdin to pipes */
dup2(rfd[1], 1);
dup2(wfd[0], 0);
/* put handler callback on stack */
lua_getglobal(L, UH_LUA_CALLBACK);
/* build env table */
lua_newtable(L);
/* request method */
switch(req->method)
{
case UH_HTTP_MSG_GET:
lua_pushstring(L, "GET");
break;
case UH_HTTP_MSG_HEAD:
lua_pushstring(L, "HEAD");
break;
case UH_HTTP_MSG_POST:
lua_pushstring(L, "POST");
break;
}
lua_setfield(L, -2, "REQUEST_METHOD");
/* request url */
lua_pushstring(L, req->url);
lua_setfield(L, -2, "REQUEST_URI");
/* script name */
lua_pushstring(L, cl->server->conf->lua_prefix);
lua_setfield(L, -2, "SCRIPT_NAME");
/* query string, path info */
if( (query_string = strchr(req->url, '?')) != NULL )
{
lua_pushstring(L, query_string + 1);
lua_setfield(L, -2, "QUERY_STRING");
if( (int)(query_string - req->url) > strlen(prefix) )
{
lua_pushlstring(L,
&req->url[strlen(prefix)],
(int)(query_string - req->url) - strlen(prefix)
);
lua_setfield(L, -2, "PATH_INFO");
}
}
else if( strlen(req->url) > strlen(prefix) )
{
lua_pushstring(L, &req->url[strlen(prefix)]);
lua_setfield(L, -2, "PATH_INFO");
}
/* http protcol version */
lua_pushnumber(L, floor(req->version * 10) / 10);
lua_setfield(L, -2, "HTTP_VERSION");
if( req->version > 1.0 )
lua_pushstring(L, "HTTP/1.1");
else
lua_pushstring(L, "HTTP/1.0");
lua_setfield(L, -2, "SERVER_PROTOCOL");
/* address information */
lua_pushstring(L, sa_straddr(&cl->peeraddr));
lua_setfield(L, -2, "REMOTE_ADDR");
lua_pushinteger(L, sa_port(&cl->peeraddr));
lua_setfield(L, -2, "REMOTE_PORT");
lua_pushstring(L, sa_straddr(&cl->servaddr));
lua_setfield(L, -2, "SERVER_ADDR");
lua_pushinteger(L, sa_port(&cl->servaddr));
lua_setfield(L, -2, "SERVER_PORT");
/* essential env vars */
foreach_header(i, req->headers)
{
if( !strcasecmp(req->headers[i], "Content-Length") )
{
lua_pushnumber(L, atoi(req->headers[i+1]));
lua_setfield(L, -2, "CONTENT_LENGTH");
}
else if( !strcasecmp(req->headers[i], "Content-Type") )
{
lua_pushstring(L, req->headers[i+1]);
lua_setfield(L, -2, "CONTENT_TYPE");
}
}
/* misc. headers */
lua_newtable(L);
foreach_header(i, req->headers)
{
if( strcasecmp(req->headers[i], "Content-Length") &&
strcasecmp(req->headers[i], "Content-Type")
) {
lua_pushstring(L, req->headers[i+1]);
lua_setfield(L, -2, req->headers[i]);
}
}
lua_setfield(L, -2, "headers");
/* call */
switch( lua_pcall(L, 1, 0, 0) )
{
case LUA_ERRMEM:
case LUA_ERRRUN:
err_str = luaL_checkstring(L, -1);
if( ! err_str )
err_str = "Unknown error";
printf(
"HTTP/%.1f 500 Internal Server Error\r\n"
"Connection: close\r\n"
"Content-Type: text/plain\r\n"
"Content-Length: %i\r\n\r\n"
"Lua raised a runtime error:\n %s\n",
req->version, 31 + strlen(err_str), err_str
);
break;
default:
break;
}
close(wfd[0]);
close(rfd[1]);
exit(0);
break;
/* parent; handle I/O relaying */
default:
/* close unneeded pipe ends */
close(rfd[1]);
close(wfd[0]);
/* max watch fd */
fd_max = max(rfd[0], wfd[1]) + 1;
/* find content length */
if( req->method == UH_HTTP_MSG_POST )
{
foreach_header(i, req->headers)
{
if( ! strcasecmp(req->headers[i], "Content-Length") )
{
content_length = atoi(req->headers[i+1]);
break;
}
}
}
#define ensure(x) \
do { if( x < 0 ) goto out; } while(0)
data_sent = 0;
timeout.tv_sec = cl->server->conf->script_timeout;
timeout.tv_usec = 0;
/* I/O loop, watch our pipe ends and dispatch child reads/writes from/to socket */
while( 1 )
{
FD_ZERO(&reader);
FD_ZERO(&writer);
FD_SET(rfd[0], &reader);
FD_SET(wfd[1], &writer);
/* wait until we can read or write or both */
if( select_intr(fd_max, &reader,
(content_length > -1) ? &writer : NULL, NULL,
(data_sent < 1) ? &timeout : NULL) > 0
) {
/* ready to write to Lua child */
if( FD_ISSET(wfd[1], &writer) )
{
/* there is unread post data waiting */
if( content_length > 0 )
{
/* read it from socket ... */
if( (buflen = uh_tcp_recv(cl, buf, min(content_length, sizeof(buf)))) > 0 )
{
/* ... and write it to child's stdin */
if( write(wfd[1], buf, buflen) < 0 )
perror("write()");
content_length -= buflen;
}
/* unexpected eof! */
else
{
if( write(wfd[1], "", 0) < 0 )
perror("write()");
content_length = 0;
}
}
/* there is no more post data, close pipe to child's stdin */
else if( content_length > -1 )
{
close(wfd[1]);
content_length = -1;
}
}
/* ready to read from Lua child */
if( FD_ISSET(rfd[0], &reader) )
{
/* read data from child ... */
if( (buflen = read(rfd[0], buf, sizeof(buf))) > 0 )
{
/* pass through buffer to socket */
ensure(uh_tcp_send(cl, buf, buflen));
data_sent = 1;
}
/* looks like eof from child */
else
{
/* error? */
if( ! data_sent )
uh_http_sendhf(cl, 500, "Internal Server Error",
"The Lua child did not produce any response");
break;
}
}
}
/* timeout exceeded or interrupted by SIGCHLD */
else
{
if( (errno != EINTR) && ! data_sent )
{
ensure(uh_http_sendhf(cl, 504, "Gateway Timeout",
"The Lua script took too long to produce "
"a response"));
}
break;
}
}
out:
close(rfd[0]);
close(wfd[1]);
if( !kill(child, 0) )
{
kill(child, SIGTERM);
waitpid(child, NULL, 0);
}
break;
}
}
void uh_lua_close(lua_State *L)
{
lua_close(L);
}