xref: /lighttpd1.4/src/http_cgi.c (revision 5c2f5577)
1 /*
2  * http_cgi - Common Gateway Interface (CGI) interfaces (RFC 3875)
3  *
4  * Copyright(c) 2016-2017 Glenn Strauss gstrauss()gluelogic.com  All rights reserved
5  * License: BSD 3-clause (same as lighttpd)
6  */
7 #include "first.h"
8 
9 #include "http_cgi.h"
10 
11 #include "sys-socket.h"
12 #include <string.h>
13 
14 #include "base.h"
15 #include "array.h"
16 #include "buffer.h"
17 #include "chunk.h"
18 #include "log.h"
19 #include "http_header.h"
20 #include "sock_addr.h"
21 
22 handler_t
23 http_cgi_local_redir (request_st * const r)
24 {
25     /* [RFC3875] The Common Gateway Interface (CGI) Version 1.1
26      * [RFC3875] 6.2.2 Local Redirect Response
27      *
28      *    The CGI script can return a URI path and query-string
29      *    ('local-pathquery') for a local resource in a Location header field.
30      *    This indicates to the server that it should reprocess the request
31      *    using the path specified.
32      *
33      *      local-redir-response = local-Location NL
34      *
35      *    The script MUST NOT return any other header fields or a message-body,
36      *    and the server MUST generate the response that it would have produced
37      *    in response to a request containing the URL
38      *
39      *      scheme "://" server-name ":" server-port local-pathquery
40      *
41      * (While not required by the RFC, do not send local-redir back to same URL
42      *  since CGI should have handled it internally if it really wanted to do
43      *  that internally)
44      */
45 
46     size_t ulen = buffer_string_length(&r->uri.path);
47     const buffer *vb = http_header_response_get(r, HTTP_HEADER_LOCATION,
48                                                 CONST_STR_LEN("Location"));
49     if (NULL != vb
50         && vb->ptr[0] == '/'
51         && (0 != strncmp(vb->ptr, r->uri.path.ptr, ulen)
52             || (   vb->ptr[ulen] != '\0'
53                 && vb->ptr[ulen] != '/'
54                 && vb->ptr[ulen] != '?'))
55         && !light_btst(r->resp_htags, HTTP_HEADER_STATUS)
56         && 1 == r->resp_headers.used /*"Location"; no "Status" or NPH response*/
57         && r->http_status >= 300 && r->http_status < 400) {
58         if (++r->loops_per_request > 5) {
59             log_error(r->conf.errh, __FILE__, __LINE__,
60               "too many internal loops while processing request: %s",
61               r->target_orig.ptr);
62             r->http_status = 500; /* Internal Server Error */
63             r->resp_body_started = 0;
64             r->handler_module = NULL;
65             return HANDLER_FINISHED;
66         }
67 
68         buffer_copy_buffer(&r->target, vb);
69 
70         if (r->reqbody_length) {
71             if (r->reqbody_length != r->reqbody_queue.bytes_in)
72                 r->keep_alive = 0;
73             r->reqbody_length = 0;
74             chunkqueue_reset(&r->reqbody_queue);
75         }
76 
77         if (r->http_status != 307 && r->http_status != 308) {
78             /* Note: request body (if any) sent to initial dynamic handler
79              * and is not available to the internal redirect */
80             r->http_method = HTTP_METHOD_GET;
81         }
82 
83         /*(caller must reset request as follows)*/
84         /*http_response_reset(r);*/ /*(sets r->http_status = 0)*/
85         /*plugins_call_handle_request_reset(r);*/
86 
87         return HANDLER_COMEBACK;
88     }
89 
90     return HANDLER_GO_ON;
91 }
92 
93 
94 int
95 http_cgi_headers (request_st * const r, http_cgi_opts * const opts, http_cgi_header_append_cb cb, void *vdata)
96 {
97     /* CGI-SPEC 6.1.2, FastCGI spec 6.3 and SCGI spec */
98 
99     /* note: string ptrs passed to cb() func must not be NULL */
100 
101     int rc = 0;
102     buffer * const tb = r->tmp_buf;
103     const char *s;
104     size_t n;
105     char buf[INET6_ADDRSTRLEN + 1]; /*(also larger than LI_ITOSTRING_LENGTH)*/
106 
107     /* (CONTENT_LENGTH must be first for SCGI) */
108     if (!opts->authorizer)
109         rc |= cb(vdata, CONST_STR_LEN("CONTENT_LENGTH"),
110                  buf, li_itostrn(buf,sizeof(buf),r->reqbody_length));
111 
112     if (!buffer_string_is_empty(&r->uri.query))
113         rc |= cb(vdata, CONST_STR_LEN("QUERY_STRING"),
114                         CONST_BUF_LEN(&r->uri.query));
115     else
116         rc |= cb(vdata, CONST_STR_LEN("QUERY_STRING"),
117                         CONST_STR_LEN(""));
118 
119     if (!buffer_string_is_empty(opts->strip_request_uri)) {
120         /**
121          * /app1/index/list
122          *
123          * stripping /app1 or /app1/ should lead to
124          *
125          * /index/list
126          *
127          */
128         size_t len = buffer_string_length(opts->strip_request_uri);
129         if ('/' == opts->strip_request_uri->ptr[len-1])
130             --len;
131 
132         if (buffer_string_length(&r->target_orig) >= len
133             && 0 == memcmp(r->target_orig.ptr,
134                            opts->strip_request_uri->ptr, len)
135             && r->target_orig.ptr[len] == '/') {
136             rc |= cb(vdata, CONST_STR_LEN("REQUEST_URI"),
137                             r->target_orig.ptr+len,
138                             buffer_string_length(&r->target_orig)-len);
139         }
140         else
141             rc |= cb(vdata, CONST_STR_LEN("REQUEST_URI"),
142                             CONST_BUF_LEN(&r->target_orig));
143     }
144     else
145         rc |= cb(vdata, CONST_STR_LEN("REQUEST_URI"),
146                         CONST_BUF_LEN(&r->target_orig));
147 
148     if (!buffer_is_equal(&r->target, &r->target_orig))
149         rc |= cb(vdata, CONST_STR_LEN("REDIRECT_URI"),
150                         CONST_BUF_LEN(&r->target));
151 
152     /* set REDIRECT_STATUS for php compiled with --force-redirect
153      * (if REDIRECT_STATUS has not already been set by error handler) */
154     if (0 == r->error_handler_saved_status)
155         rc |= cb(vdata, CONST_STR_LEN("REDIRECT_STATUS"),
156                         CONST_STR_LEN("200"));
157 
158     /*
159      * SCRIPT_NAME, PATH_INFO and PATH_TRANSLATED according to
160      * http://cgi-spec.golux.com/draft-coar-cgi-v11-03-clean.html
161      * (6.1.14, 6.1.6, 6.1.7)
162      */
163     if (!opts->authorizer) {
164         rc |= cb(vdata, CONST_STR_LEN("SCRIPT_NAME"),
165                         CONST_BUF_LEN(&r->uri.path));
166         if (!buffer_string_is_empty(&r->pathinfo)) {
167             rc |= cb(vdata, CONST_STR_LEN("PATH_INFO"),
168                             CONST_BUF_LEN(&r->pathinfo));
169             /* PATH_TRANSLATED is only defined if PATH_INFO is set
170              * Note: not implemented: re-url-encode '?' '=' ';' for
171              * (RFC 3875 4.1.6) */
172             if (!buffer_string_is_empty(opts->docroot))
173                 buffer_copy_buffer(tb, opts->docroot);
174             else
175                 buffer_copy_buffer(tb, &r->physical.basedir);
176             buffer_append_path_len(tb, CONST_BUF_LEN(&r->pathinfo));
177             rc |= cb(vdata, CONST_STR_LEN("PATH_TRANSLATED"),
178                             CONST_BUF_LEN(tb));
179         }
180     }
181 
182    /*
183     * SCRIPT_FILENAME and DOCUMENT_ROOT for php
184     * The PHP manual http://www.php.net/manual/en/reserved.variables.php
185     * treatment of PATH_TRANSLATED is different from the one of CGI specs.
186     * (see php.ini cgi.fix_pathinfo = 1 config parameter)
187     */
188 
189     if (!buffer_string_is_empty(opts->docroot)) {
190         /* alternate docroot, e.g. for remote FastCGI or SCGI server */
191         buffer_copy_buffer(tb, opts->docroot);
192         buffer_append_path_len(tb, CONST_BUF_LEN(&r->uri.path));
193         rc |= cb(vdata, CONST_STR_LEN("SCRIPT_FILENAME"),
194                         CONST_BUF_LEN(tb));
195         rc |= cb(vdata, CONST_STR_LEN("DOCUMENT_ROOT"),
196                         CONST_BUF_LEN(opts->docroot));
197     }
198     else {
199         if (opts->break_scriptfilename_for_php) {
200             /* php.ini config cgi.fix_pathinfo = 1 need a broken SCRIPT_FILENAME
201              * to find out what PATH_INFO is itself
202              *
203              * see src/sapi/cgi_main.c, init_request_info()
204              */
205             buffer_copy_buffer(tb, &r->physical.path);
206             buffer_append_path_len(tb, CONST_BUF_LEN(&r->pathinfo));
207             rc |= cb(vdata, CONST_STR_LEN("SCRIPT_FILENAME"),
208                             CONST_BUF_LEN(tb));
209         }
210         else
211             rc |= cb(vdata, CONST_STR_LEN("SCRIPT_FILENAME"),
212                             CONST_BUF_LEN(&r->physical.path));
213         rc |= cb(vdata, CONST_STR_LEN("DOCUMENT_ROOT"),
214                         CONST_BUF_LEN(&r->physical.basedir));
215     }
216 
217     s = get_http_method_name(r->http_method);
218     force_assert(s);
219     rc |= cb(vdata, CONST_STR_LEN("REQUEST_METHOD"), s, strlen(s));
220 
221     s = get_http_version_name(r->http_version);
222     force_assert(s);
223     rc |= cb(vdata, CONST_STR_LEN("SERVER_PROTOCOL"), s, strlen(s));
224 
225     rc |= cb(vdata, CONST_STR_LEN("SERVER_SOFTWARE"),
226                     CONST_BUF_LEN(r->conf.server_tag));
227 
228     rc |= cb(vdata, CONST_STR_LEN("GATEWAY_INTERFACE"),
229                     CONST_STR_LEN("CGI/1.1"));
230 
231     rc |= cb(vdata, CONST_STR_LEN("REQUEST_SCHEME"),
232                     CONST_BUF_LEN(&r->uri.scheme));
233 
234     if (buffer_is_equal_string(&r->uri.scheme, CONST_STR_LEN("https")))
235         rc |= cb(vdata, CONST_STR_LEN("HTTPS"), CONST_STR_LEN("on"));
236 
237     const connection * const con = r->con;
238     const server_socket * const srv_sock = con->srv_socket;
239     const size_t tlen = buffer_string_length(srv_sock->srv_token);
240     n = srv_sock->srv_token_colon;
241     if (n < tlen) { /*(n != tlen)*/
242         s = srv_sock->srv_token->ptr+n+1;
243         n = tlen - (n+1);
244     }
245     else {
246         s = "0";
247         n = 1;
248     }
249     rc |= cb(vdata, CONST_STR_LEN("SERVER_PORT"), s, n);
250 
251     n = 0;
252     switch (sock_addr_get_family(&srv_sock->addr)) {
253       case AF_INET:
254       case AF_INET6:
255         if (sock_addr_is_addr_wildcard(&srv_sock->addr)) {
256             sock_addr addrbuf;
257             socklen_t addrlen = sizeof(addrbuf);
258             if (0 == getsockname(con->fd,(struct sockaddr *)&addrbuf,&addrlen)){
259                 /* future: might add a one- or two- element cache
260                  * or use sock_addr_cache_inet_ntop_copy_buffer() into tb */
261                 s = sock_addr_inet_ntop(&addrbuf, buf, sizeof(buf));
262                 if (s)
263                     n = strlen(s);
264                 else
265                     s = "";
266             }
267             else
268                 s = "";
269         }
270         else {
271             s = srv_sock->srv_token->ptr;
272             n = srv_sock->srv_token_colon;
273         }
274         break;
275       default:
276         s = "";
277         break;
278     }
279     rc |= cb(vdata, CONST_STR_LEN("SERVER_ADDR"), s, n);
280 
281     if (!buffer_string_is_empty(r->server_name)) {
282         n = buffer_string_length(r->server_name);
283         s = r->server_name->ptr;
284         if (s[0] == '[') {
285             const char *colon = strstr(s, "]:");
286             if (colon) n = (colon + 1) - s;
287         }
288         else {
289             const char *colon = strchr(s, ':');
290             if (colon) n = colon - s;
291         }
292     } /* else set to be same as SERVER_ADDR (above) */
293     rc |= cb(vdata, CONST_STR_LEN("SERVER_NAME"), s, n);
294 
295     rc |= cb(vdata, CONST_STR_LEN("REMOTE_ADDR"),
296                     CONST_BUF_LEN(con->dst_addr_buf));
297 
298     rc |= cb(vdata, CONST_STR_LEN("REMOTE_PORT"), buf,
299              li_utostrn(buf,sizeof(buf),sock_addr_get_port(&con->dst_addr)));
300 
301     for (n = 0; n < r->rqst_headers.used; n++) {
302         data_string *ds = (data_string *)r->rqst_headers.data[n];
303         if (!buffer_string_is_empty(&ds->value) && !buffer_is_empty(&ds->key)) {
304             /* Security: Do not emit HTTP_PROXY in environment.
305              * Some executables use HTTP_PROXY to configure
306              * outgoing proxy.  See also https://httpoxy.org/ */
307             if (ds->ext == HTTP_HEADER_OTHER
308                 && buffer_eq_icase_slen(&ds->key, CONST_STR_LEN("Proxy"))) {
309                 continue;
310             }
311             buffer_copy_string_encoded_cgi_varnames(tb,
312                                                     CONST_BUF_LEN(&ds->key), 1);
313             rc |= cb(vdata, CONST_BUF_LEN(tb),
314                             CONST_BUF_LEN(&ds->value));
315         }
316     }
317 
318     con->srv->request_env(r);
319 
320     for (n = 0; n < r->env.used; n++) {
321         data_string *ds = (data_string *)r->env.data[n];
322         if (!buffer_is_empty(&ds->value) && !buffer_is_empty(&ds->key)) {
323             buffer_copy_string_encoded_cgi_varnames(tb,
324                                                     CONST_BUF_LEN(&ds->key), 0);
325             rc |= cb(vdata, CONST_BUF_LEN(tb),
326                             CONST_BUF_LEN(&ds->value));
327         }
328     }
329 
330     return rc;
331 }
332