openwrt-owl/package/uhttpd/src/uhttpd-cgi.c

567 lines
13 KiB
C

/*
* uhttpd - Tiny single-threaded httpd - CGI handler
*
* Copyright (C) 2010-2012 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-cgi.h"
static bool
uh_cgi_header_parse(struct http_response *res, char *buf, int len, int *off)
{
char *bufptr = NULL;
char *hdrname = NULL;
int hdrcount = 0;
int pos = 0;
if (((bufptr = strfind(buf, len, "\r\n\r\n", 4)) != NULL) ||
((bufptr = strfind(buf, len, "\n\n", 2)) != NULL))
{
*off = (int)(bufptr - buf) + ((bufptr[0] == '\r') ? 4 : 2);
memset(res, 0, sizeof(*res));
res->statuscode = 200;
res->statusmsg = "OK";
bufptr = &buf[0];
for (pos = 0; pos < *off; pos++)
{
if (!hdrname && (buf[pos] == ':'))
{
buf[pos++] = 0;
if ((pos < len) && (buf[pos] == ' '))
pos++;
if (pos < len)
{
hdrname = bufptr;
bufptr = &buf[pos];
}
}
else if ((buf[pos] == '\r') || (buf[pos] == '\n'))
{
if (! hdrname)
break;
buf[pos++] = 0;
if ((pos < len) && (buf[pos] == '\n'))
pos++;
if (pos <= len)
{
if ((hdrcount+1) < array_size(res->headers))
{
if (!strcasecmp(hdrname, "Status"))
{
res->statuscode = atoi(bufptr);
if (res->statuscode < 100)
res->statuscode = 200;
if (((bufptr = strchr(bufptr, ' ')) != NULL) &&
(&bufptr[1] != 0))
{
res->statusmsg = &bufptr[1];
}
D("CGI: HTTP/1.x %03d %s\n",
res->statuscode, res->statusmsg);
}
else
{
D("CGI: HTTP: %s: %s\n", hdrname, bufptr);
res->headers[hdrcount++] = hdrname;
res->headers[hdrcount++] = bufptr;
}
bufptr = &buf[pos];
hdrname = NULL;
}
else
{
return false;
}
}
}
}
return true;
}
return false;
}
static char * uh_cgi_header_lookup(struct http_response *res,
const char *hdrname)
{
int i;
foreach_header(i, res->headers)
{
if (!strcasecmp(res->headers[i], hdrname))
return res->headers[i+1];
}
return NULL;
}
static void uh_cgi_shutdown(struct uh_cgi_state *state)
{
close(state->rfd);
close(state->wfd);
free(state);
}
static bool uh_cgi_socket_cb(struct client *cl)
{
int i, len, hdroff;
char buf[UH_LIMIT_MSGHEAD];
struct uh_cgi_state *state = (struct uh_cgi_state *)cl->priv;
struct http_response *res = &state->cl->response;
struct http_request *req = &state->cl->request;
/* there is unread post data waiting */
while (state->content_length > 0)
{
/* remaining data in http head buffer ... */
if (state->cl->httpbuf.len > 0)
{
len = min(state->content_length, state->cl->httpbuf.len);
D("CGI: Child(%d) feed %d HTTP buffer bytes\n",
state->cl->proc.pid, len);
memcpy(buf, state->cl->httpbuf.ptr, len);
state->cl->httpbuf.len -= len;
state->cl->httpbuf.ptr +=len;
}
/* read it from socket ... */
else
{
len = uh_tcp_recv(state->cl, buf,
min(state->content_length, sizeof(buf)));
if ((len < 0) && ((errno == EAGAIN) || (errno == EWOULDBLOCK)))
break;
D("CGI: Child(%d) feed %d/%d TCP socket bytes\n",
state->cl->proc.pid, len,
min(state->content_length, sizeof(buf)));
}
if (len)
state->content_length -= len;
else
state->content_length = 0;
/* ... write to CGI process */
len = uh_raw_send(state->wfd, buf, len,
cl->server->conf->script_timeout);
/* explicit EOF notification for the child */
if (state->content_length <= 0)
close(state->wfd);
}
/* try to read data from child */
while ((len = uh_raw_recv(state->rfd, buf, sizeof(buf), -1)) > 0)
{
/* we have not pushed out headers yet, parse input */
if (!state->header_sent)
{
/* try to parse header ... */
memcpy(state->httpbuf, buf, len);
if (uh_cgi_header_parse(res, state->httpbuf, len, &hdroff))
{
/* write status */
ensure_out(uh_http_sendf(state->cl, NULL,
"HTTP/%.1f %03d %s\r\n"
"Connection: close\r\n",
req->version, res->statuscode, res->statusmsg));
/* add Content-Type if no Location or Content-Type */
if (!uh_cgi_header_lookup(res, "Location") &&
!uh_cgi_header_lookup(res, "Content-Type"))
{
ensure_out(uh_http_send(state->cl, NULL,
"Content-Type: text/plain\r\n", -1));
}
/* if request was HTTP 1.1 we'll respond chunked */
if ((req->version > 1.0) &&
!uh_cgi_header_lookup(res, "Transfer-Encoding"))
{
ensure_out(uh_http_send(state->cl, NULL,
"Transfer-Encoding: chunked\r\n", -1));
}
/* write headers from CGI program */
foreach_header(i, res->headers)
{
ensure_out(uh_http_sendf(state->cl, NULL, "%s: %s\r\n",
res->headers[i], res->headers[i+1]));
}
/* terminate header */
ensure_out(uh_http_send(state->cl, NULL, "\r\n", -1));
state->header_sent = true;
/* push out remaining head buffer */
if (hdroff < len)
{
D("CGI: Child(%d) relaying %d rest bytes\n",
state->cl->proc.pid, len - hdroff);
ensure_out(uh_http_send(state->cl, req,
&buf[hdroff], len - hdroff));
}
}
/* ... failed and head buffer exceeded */
else
{
/* I would do this ...
*
* uh_cgi_error_500(cl, req,
* "The CGI program generated an "
* "invalid response:\n\n");
*
* ... but in order to stay as compatible as possible,
* treat whatever we got as text/plain response and
* build the required headers here.
*/
ensure_out(uh_http_sendf(state->cl, NULL,
"HTTP/%.1f 200 OK\r\n"
"Content-Type: text/plain\r\n"
"%s\r\n",
req->version, (req->version > 1.0)
? "Transfer-Encoding: chunked\r\n" : ""
));
state->header_sent = true;
D("CGI: Child(%d) relaying %d invalid bytes\n",
state->cl->proc.pid, len);
ensure_out(uh_http_send(state->cl, req, buf, len));
}
}
else
{
/* headers complete, pass through buffer to socket */
D("CGI: Child(%d) relaying %d normal bytes\n",
state->cl->proc.pid, len);
ensure_out(uh_http_send(state->cl, req, buf, len));
}
}
/* got EOF or read error from child */
if ((len == 0) ||
((errno != EAGAIN) && (errno != EWOULDBLOCK) && (len == -1)))
{
D("CGI: Child(%d) presumed dead [%s]\n",
state->cl->proc.pid, strerror(errno));
goto out;
}
return true;
out:
if (!state->header_sent)
{
if (state->cl->timeout.pending)
uh_http_sendhf(state->cl, 502, "Bad Gateway",
"The CGI process did not produce any response\n");
else
uh_http_sendhf(state->cl, 504, "Gateway Timeout",
"The CGI process took too long to produce a "
"response\n");
}
else
{
uh_http_send(state->cl, req, "", 0);
}
uh_cgi_shutdown(state);
return false;
}
bool uh_cgi_request(struct client *cl, struct path_info *pi,
struct interpreter *ip)
{
int i;
int rfd[2] = { 0, 0 };
int wfd[2] = { 0, 0 };
pid_t child;
struct uh_cgi_state *state;
struct http_request *req = &cl->request;
/* allocate state */
if (!(state = malloc(sizeof(*state))))
{
uh_http_sendhf(cl, 500, "Internal Server Error", "Out of memory");
return false;
}
/* spawn pipes for me->child, child->me */
if ((pipe(rfd) < 0) || (pipe(wfd) < 0))
{
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]);
uh_http_sendhf(cl, 500, "Internal Server Error",
"Failed to create pipe: %s\n", strerror(errno));
return false;
}
/* fork off child process */
switch ((child = fork()))
{
/* oops */
case -1:
uh_http_sendhf(cl, 500, "Internal Server Error",
"Failed to fork child: %s\n", strerror(errno));
return false;
/* exec child */
case 0:
#ifdef DEBUG
sleep(atoi(getenv("UHTTPD_SLEEP_ON_FORK") ?: "0"));
#endif
/* close loose pipe ends */
close(rfd[0]);
close(wfd[1]);
/* patch stdout and stdin to pipes */
dup2(rfd[1], 1);
dup2(wfd[0], 0);
/* avoid leaking our pipe into child-child processes */
fd_cloexec(rfd[1]);
fd_cloexec(wfd[0]);
/* check for regular, world-executable file _or_ interpreter */
if (((pi->stat.st_mode & S_IFREG) &&
(pi->stat.st_mode & S_IXOTH)) || (ip != NULL))
{
/* build environment */
clearenv();
/* common information */
setenv("GATEWAY_INTERFACE", "CGI/1.1", 1);
setenv("SERVER_SOFTWARE", "uHTTPd", 1);
setenv("PATH", "/sbin:/usr/sbin:/bin:/usr/bin", 1);
#ifdef HAVE_TLS
/* https? */
if (cl->tls)
setenv("HTTPS", "on", 1);
#endif
/* addresses */
setenv("SERVER_NAME", sa_straddr(&cl->servaddr), 1);
setenv("SERVER_ADDR", sa_straddr(&cl->servaddr), 1);
setenv("SERVER_PORT", sa_strport(&cl->servaddr), 1);
setenv("REMOTE_HOST", sa_straddr(&cl->peeraddr), 1);
setenv("REMOTE_ADDR", sa_straddr(&cl->peeraddr), 1);
setenv("REMOTE_PORT", sa_strport(&cl->peeraddr), 1);
/* path information */
setenv("SCRIPT_NAME", pi->name, 1);
setenv("SCRIPT_FILENAME", pi->phys, 1);
setenv("DOCUMENT_ROOT", pi->root, 1);
setenv("QUERY_STRING", pi->query ? pi->query : "", 1);
if (pi->info)
setenv("PATH_INFO", pi->info, 1);
/* REDIRECT_STATUS, php-cgi wants it */
switch (req->redirect_status)
{
case 404:
setenv("REDIRECT_STATUS", "404", 1);
break;
default:
setenv("REDIRECT_STATUS", "200", 1);
break;
}
/* http version */
if (req->version > 1.0)
setenv("SERVER_PROTOCOL", "HTTP/1.1", 1);
else
setenv("SERVER_PROTOCOL", "HTTP/1.0", 1);
/* request method */
switch (req->method)
{
case UH_HTTP_MSG_GET:
setenv("REQUEST_METHOD", "GET", 1);
break;
case UH_HTTP_MSG_HEAD:
setenv("REQUEST_METHOD", "HEAD", 1);
break;
case UH_HTTP_MSG_POST:
setenv("REQUEST_METHOD", "POST", 1);
break;
}
/* request url */
setenv("REQUEST_URI", req->url, 1);
/* remote user */
if (req->realm)
setenv("REMOTE_USER", req->realm->user, 1);
/* request message headers */
foreach_header(i, req->headers)
{
if (!strcasecmp(req->headers[i], "Accept"))
setenv("HTTP_ACCEPT", req->headers[i+1], 1);
else if (!strcasecmp(req->headers[i], "Accept-Charset"))
setenv("HTTP_ACCEPT_CHARSET", req->headers[i+1], 1);
else if (!strcasecmp(req->headers[i], "Accept-Encoding"))
setenv("HTTP_ACCEPT_ENCODING", req->headers[i+1], 1);
else if (!strcasecmp(req->headers[i], "Accept-Language"))
setenv("HTTP_ACCEPT_LANGUAGE", req->headers[i+1], 1);
else if (!strcasecmp(req->headers[i], "Authorization"))
setenv("HTTP_AUTHORIZATION", req->headers[i+1], 1);
else if (!strcasecmp(req->headers[i], "Connection"))
setenv("HTTP_CONNECTION", req->headers[i+1], 1);
else if (!strcasecmp(req->headers[i], "Cookie"))
setenv("HTTP_COOKIE", req->headers[i+1], 1);
else if (!strcasecmp(req->headers[i], "Host"))
setenv("HTTP_HOST", req->headers[i+1], 1);
else if (!strcasecmp(req->headers[i], "Referer"))
setenv("HTTP_REFERER", req->headers[i+1], 1);
else if (!strcasecmp(req->headers[i], "User-Agent"))
setenv("HTTP_USER_AGENT", req->headers[i+1], 1);
else if (!strcasecmp(req->headers[i], "Content-Type"))
setenv("CONTENT_TYPE", req->headers[i+1], 1);
else if (!strcasecmp(req->headers[i], "Content-Length"))
setenv("CONTENT_LENGTH", req->headers[i+1], 1);
}
/* execute child code ... */
if (chdir(pi->root))
perror("chdir()");
if (ip != NULL)
execl(ip->path, ip->path, pi->phys, NULL);
else
execl(pi->phys, pi->phys, NULL);
/* in case it fails ... */
printf("Status: 500 Internal Server Error\r\n\r\n"
"Unable to launch the requested CGI program:\n"
" %s: %s\n", ip ? ip->path : pi->phys, strerror(errno));
}
/* 403 */
else
{
printf("Status: 403 Forbidden\r\n\r\n"
"Access to this resource is forbidden\n");
}
close(wfd[0]);
close(rfd[1]);
exit(0);
break;
/* parent; handle I/O relaying */
default:
memset(state, 0, sizeof(*state));
state->cl = cl;
state->cl->proc.pid = child;
/* close unneeded pipe ends */
close(rfd[1]);
close(wfd[0]);
D("CGI: Child(%d) created: rfd(%d) wfd(%d)\n", child, rfd[0], wfd[1]);
state->content_length = cl->httpbuf.len;
/* find content length */
if (req->method == UH_HTTP_MSG_POST)
{
foreach_header(i, req->headers)
{
if (!strcasecmp(req->headers[i], "Content-Length"))
{
state->content_length = atoi(req->headers[i+1]);
break;
}
}
}
state->rfd = rfd[0];
fd_nonblock(state->rfd);
state->wfd = wfd[1];
fd_nonblock(state->wfd);
cl->cb = uh_cgi_socket_cb;
cl->priv = state;
break;
}
return true;
}