xref: /lighttpd1.4/src/http_cgi.c (revision a1eba3c8)
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         && 1 == r->resp_headers.used /*"Location"; no "Status" or NPH response*/
56         && r->http_status >= 300 && r->http_status < 400) {
57         if (++r->loops_per_request > 5) {
58             log_error(r->conf.errh, __FILE__, __LINE__,
59               "too many internal loops while processing request: %s",
60               r->target_orig.ptr);
61             r->http_status = 500; /* Internal Server Error */
62             r->resp_body_started = 0;
63             r->handler_module = NULL;
64             return HANDLER_FINISHED;
65         }
66 
67         buffer_copy_buffer(&r->target, vb);
68 
69         if (r->reqbody_length) {
70             if (r->reqbody_length != r->reqbody_queue.bytes_in)
71                 r->keep_alive = 0;
72             r->reqbody_length = 0;
73             chunkqueue_reset(&r->reqbody_queue);
74         }
75 
76         if (r->http_status != 307 && r->http_status != 308) {
77             /* Note: request body (if any) sent to initial dynamic handler
78              * and is not available to the internal redirect */
79             r->http_method = HTTP_METHOD_GET;
80         }
81 
82         /*(caller must reset request as follows)*/
83         /*http_response_reset(r);*/ /*(sets r->http_status = 0)*/
84         /*plugins_call_handle_request_reset(r);*/
85 
86         return HANDLER_COMEBACK;
87     }
88 
89     return HANDLER_GO_ON;
90 }
91 
92 
93 static void
94 http_cgi_encode_varname (buffer * const b, const char * const restrict s, const size_t len, const int is_http_header)
95 {
96     char * const restrict p = buffer_string_prepare_copy(b, len + 5);
97     size_t i, j = 0;
98 
99     if (is_http_header) {
100       #if 0 /*(special-cased in caller that sets is_http_header)*/
101         if (len == 12 && buffer_eq_icase_ssn(s, "Content-Type", 12)) {
102             buffer_copy_string_len(b, CONST_STR_LEN("CONTENT_TYPE"));
103             return;
104         }
105       #endif
106         memcpy(p, "HTTP_", 5);
107         j = 5; /* "HTTP_" */
108     }
109 
110     for (i = 0; i < len; ++i) {/* uppercase alpha, pass numeric, map rest '_' */
111         const unsigned char c = s[i];
112         p[j++] = light_isalpha(c) ? c & ~0x20 : light_isdigit(c) ? c : '_';
113     }
114     buffer_string_set_length(b, j);
115 }
116 
117 
118 int
119 http_cgi_headers (request_st * const r, http_cgi_opts * const opts, http_cgi_header_append_cb cb, void *vdata)
120 {
121     /* CGI-SPEC 6.1.2, FastCGI spec 6.3 and SCGI spec */
122 
123     /* note: string ptrs passed to cb() func must not be NULL */
124 
125     int rc = 0;
126     buffer * const tb = r->tmp_buf;
127     const char *s;
128     size_t n;
129     char buf[INET6_ADDRSTRLEN + 1]; /*(also larger than LI_ITOSTRING_LENGTH)*/
130 
131     /* (CONTENT_LENGTH must be first for SCGI) */
132     if (!opts->authorizer)
133         rc |= cb(vdata, CONST_STR_LEN("CONTENT_LENGTH"),
134                  buf, li_itostrn(buf,sizeof(buf),r->reqbody_length));
135 
136     if (!buffer_string_is_empty(&r->uri.query))
137         rc |= cb(vdata, CONST_STR_LEN("QUERY_STRING"),
138                         CONST_BUF_LEN(&r->uri.query));
139     else
140         rc |= cb(vdata, CONST_STR_LEN("QUERY_STRING"),
141                         CONST_STR_LEN(""));
142 
143     if (!buffer_string_is_empty(opts->strip_request_uri)) {
144         /**
145          * /app1/index/list
146          *
147          * stripping /app1 or /app1/ should lead to
148          *
149          * /index/list
150          *
151          */
152         size_t len = buffer_string_length(opts->strip_request_uri);
153         if ('/' == opts->strip_request_uri->ptr[len-1])
154             --len;
155 
156         if (buffer_string_length(&r->target_orig) >= len
157             && 0 == memcmp(r->target_orig.ptr,
158                            opts->strip_request_uri->ptr, len)
159             && r->target_orig.ptr[len] == '/') {
160             rc |= cb(vdata, CONST_STR_LEN("REQUEST_URI"),
161                             r->target_orig.ptr+len,
162                             buffer_string_length(&r->target_orig)-len);
163         }
164         else
165             rc |= cb(vdata, CONST_STR_LEN("REQUEST_URI"),
166                             CONST_BUF_LEN(&r->target_orig));
167     }
168     else
169         rc |= cb(vdata, CONST_STR_LEN("REQUEST_URI"),
170                         CONST_BUF_LEN(&r->target_orig));
171 
172     if (!buffer_is_equal(&r->target, &r->target_orig))
173         rc |= cb(vdata, CONST_STR_LEN("REDIRECT_URI"),
174                         CONST_BUF_LEN(&r->target));
175 
176     /* set REDIRECT_STATUS for php compiled with --force-redirect
177      * (if REDIRECT_STATUS has not already been set by error handler) */
178     if (0 == r->error_handler_saved_status)
179         rc |= cb(vdata, CONST_STR_LEN("REDIRECT_STATUS"),
180                         CONST_STR_LEN("200"));
181 
182     /*
183      * SCRIPT_NAME, PATH_INFO and PATH_TRANSLATED according to
184      * http://cgi-spec.golux.com/draft-coar-cgi-v11-03-clean.html
185      * (6.1.14, 6.1.6, 6.1.7)
186      */
187     if (!opts->authorizer) {
188         rc |= cb(vdata, CONST_STR_LEN("SCRIPT_NAME"),
189                         CONST_BUF_LEN(&r->uri.path));
190         if (!buffer_string_is_empty(&r->pathinfo)) {
191             rc |= cb(vdata, CONST_STR_LEN("PATH_INFO"),
192                             CONST_BUF_LEN(&r->pathinfo));
193             /* PATH_TRANSLATED is only defined if PATH_INFO is set
194              * Note: not implemented: re-url-encode '?' '=' ';' for
195              * (RFC 3875 4.1.6) */
196             const buffer * const bd = (!buffer_string_is_empty(opts->docroot))
197               ? opts->docroot
198               : &r->physical.basedir;
199             buffer_copy_path_len2(tb, CONST_BUF_LEN(bd),
200                                       CONST_BUF_LEN(&r->pathinfo));
201             rc |= cb(vdata, CONST_STR_LEN("PATH_TRANSLATED"),
202                             CONST_BUF_LEN(tb));
203         }
204     }
205 
206    /*
207     * SCRIPT_FILENAME and DOCUMENT_ROOT for php
208     * The PHP manual http://www.php.net/manual/en/reserved.variables.php
209     * treatment of PATH_TRANSLATED is different from the one of CGI specs.
210     * (see php.ini cgi.fix_pathinfo = 1 config parameter)
211     */
212 
213     if (!buffer_string_is_empty(opts->docroot)) {
214         /* alternate docroot, e.g. for remote FastCGI or SCGI server */
215         buffer_copy_path_len2(tb, CONST_BUF_LEN(opts->docroot),
216                                   CONST_BUF_LEN(&r->uri.path));
217         rc |= cb(vdata, CONST_STR_LEN("SCRIPT_FILENAME"),
218                         CONST_BUF_LEN(tb));
219         rc |= cb(vdata, CONST_STR_LEN("DOCUMENT_ROOT"),
220                         CONST_BUF_LEN(opts->docroot));
221     }
222     else {
223         if (opts->break_scriptfilename_for_php) {
224             /* php.ini config cgi.fix_pathinfo = 1 need a broken SCRIPT_FILENAME
225              * to find out what PATH_INFO is itself
226              *
227              * see src/sapi/cgi_main.c, init_request_info()
228              */
229             buffer_copy_path_len2(tb, CONST_BUF_LEN(&r->physical.path),
230                                       CONST_BUF_LEN(&r->pathinfo));
231             rc |= cb(vdata, CONST_STR_LEN("SCRIPT_FILENAME"),
232                             CONST_BUF_LEN(tb));
233         }
234         else
235             rc |= cb(vdata, CONST_STR_LEN("SCRIPT_FILENAME"),
236                             CONST_BUF_LEN(&r->physical.path));
237         rc |= cb(vdata, CONST_STR_LEN("DOCUMENT_ROOT"),
238                         CONST_BUF_LEN(&r->physical.basedir));
239     }
240 
241     s = get_http_method_name(r->http_method);
242     force_assert(s);
243     rc |= cb(vdata, CONST_STR_LEN("REQUEST_METHOD"), s, strlen(s));
244 
245     s = get_http_version_name(r->http_version);
246     force_assert(s);
247     rc |= cb(vdata, CONST_STR_LEN("SERVER_PROTOCOL"), s, strlen(s));
248 
249     rc |= cb(vdata, CONST_STR_LEN("SERVER_SOFTWARE"),
250                     CONST_BUF_LEN(r->conf.server_tag));
251 
252     rc |= cb(vdata, CONST_STR_LEN("GATEWAY_INTERFACE"),
253                     CONST_STR_LEN("CGI/1.1"));
254 
255     rc |= cb(vdata, CONST_STR_LEN("REQUEST_SCHEME"),
256                     CONST_BUF_LEN(&r->uri.scheme));
257 
258     if (buffer_is_equal_string(&r->uri.scheme, CONST_STR_LEN("https")))
259         rc |= cb(vdata, CONST_STR_LEN("HTTPS"), CONST_STR_LEN("on"));
260 
261     const connection * const con = r->con;
262     const server_socket * const srv_sock = con->srv_socket;
263     const size_t tlen = buffer_string_length(srv_sock->srv_token);
264     n = srv_sock->srv_token_colon;
265     if (n < tlen) { /*(n != tlen)*/
266         s = srv_sock->srv_token->ptr+n+1;
267         n = tlen - (n+1);
268     }
269     else {
270         s = "0";
271         n = 1;
272     }
273     rc |= cb(vdata, CONST_STR_LEN("SERVER_PORT"), s, n);
274 
275     n = 0;
276     switch (sock_addr_get_family(&srv_sock->addr)) {
277       case AF_INET:
278       case AF_INET6:
279         if (sock_addr_is_addr_wildcard(&srv_sock->addr)) {
280             sock_addr addrbuf;
281             socklen_t addrlen = sizeof(addrbuf);
282             if (0 == getsockname(con->fd,(struct sockaddr *)&addrbuf,&addrlen)){
283                 /* future: might add a one- or two- element cache
284                  * or use sock_addr_cache_inet_ntop_copy_buffer() into tb */
285                 s = sock_addr_inet_ntop(&addrbuf, buf, sizeof(buf));
286                 if (s)
287                     n = strlen(s);
288                 else
289                     s = "";
290             }
291             else
292                 s = "";
293         }
294         else {
295             s = srv_sock->srv_token->ptr;
296             n = srv_sock->srv_token_colon;
297         }
298         break;
299       default:
300         s = "";
301         break;
302     }
303     rc |= cb(vdata, CONST_STR_LEN("SERVER_ADDR"), s, n);
304 
305     if (!buffer_string_is_empty(r->server_name)) {
306         n = buffer_string_length(r->server_name);
307         s = r->server_name->ptr;
308         if (s[0] == '[') {
309             const char *colon = strstr(s, "]:");
310             if (colon) n = (colon + 1) - s;
311         }
312         else {
313             const char *colon = strchr(s, ':');
314             if (colon) n = colon - s;
315         }
316     } /* else set to be same as SERVER_ADDR (above) */
317     rc |= cb(vdata, CONST_STR_LEN("SERVER_NAME"), s, n);
318 
319     rc |= cb(vdata, CONST_STR_LEN("REMOTE_ADDR"),
320                     CONST_BUF_LEN(con->dst_addr_buf));
321 
322     rc |= cb(vdata, CONST_STR_LEN("REMOTE_PORT"), buf,
323              li_utostrn(buf,sizeof(buf),sock_addr_get_port(&con->dst_addr)));
324 
325     for (n = 0; n < r->rqst_headers.used; n++) {
326         data_string *ds = (data_string *)r->rqst_headers.data[n];
327         if (!buffer_string_is_empty(&ds->value) && !buffer_is_empty(&ds->key)) {
328             /* Security: Do not emit HTTP_PROXY in environment.
329              * Some executables use HTTP_PROXY to configure
330              * outgoing proxy.  See also https://httpoxy.org/ */
331             if (ds->ext == HTTP_HEADER_OTHER
332                 && buffer_eq_icase_slen(&ds->key, CONST_STR_LEN("Proxy"))) {
333                 continue;
334             }
335             else if (ds->ext == HTTP_HEADER_CONTENT_TYPE)
336                 buffer_copy_string_len(tb, CONST_STR_LEN("CONTENT_TYPE"));
337             else
338                 http_cgi_encode_varname(tb, CONST_BUF_LEN(&ds->key), 1);
339             rc |= cb(vdata, CONST_BUF_LEN(tb),
340                             CONST_BUF_LEN(&ds->value));
341         }
342     }
343 
344     con->srv->request_env(r);
345 
346     for (n = 0; n < r->env.used; n++) {
347         data_string *ds = (data_string *)r->env.data[n];
348         if (!buffer_is_empty(&ds->value) && !buffer_is_empty(&ds->key)) {
349             http_cgi_encode_varname(tb, CONST_BUF_LEN(&ds->key), 0);
350             rc |= cb(vdata, CONST_BUF_LEN(tb),
351                             CONST_BUF_LEN(&ds->value));
352         }
353     }
354 
355     return rc;
356 }
357