xref: /lighttpd1.4/src/http_cgi.c (revision 0ccf30c0)
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_clen(&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         buffer_clear(&r->pathinfo);
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         /*r->con->srv->plugins_request_reset(r);*/
86 
87         return HANDLER_COMEBACK;
88     }
89 
90     return HANDLER_GO_ON;
91 }
92 
93 
94 static void
95 http_cgi_encode_varname (buffer * const b, const char * const restrict s, const size_t len, const int is_http_header)
96 {
97     char * const restrict p = buffer_string_prepare_copy(b, len + 5);
98     size_t i, j = 0;
99 
100     if (is_http_header) {
101       #if 0 /*(special-cased in caller that sets is_http_header)*/
102         if (len == 12 && buffer_eq_icase_ssn(s, "Content-Type", 12)) {
103             buffer_copy_string_len(b, CONST_STR_LEN("CONTENT_TYPE"));
104             return;
105         }
106       #endif
107         memcpy(p, "HTTP_", 5);
108         j = 5; /* "HTTP_" */
109     }
110 
111     for (i = 0; i < len; ++i) {/* uppercase alpha, pass numeric, map rest '_' */
112         const unsigned char c = s[i];
113         p[j++] = light_isalpha(c) ? c & ~0x20 : light_isdigit(c) ? c : '_';
114     }
115     buffer_truncate(b, j);
116 }
117 
118 
119 int
120 http_cgi_headers (request_st * const r, http_cgi_opts * const opts, http_cgi_header_append_cb cb, void *vdata)
121 {
122     /* CGI-SPEC 6.1.2, FastCGI spec 6.3 and SCGI spec */
123 
124     /* note: string ptrs passed to cb() func must not be NULL */
125 
126     int rc = 0;
127     uint32_t len;
128     buffer * const tb = r->tmp_buf;
129     const char *s;
130     size_t n;
131     char buf[INET6_ADDRSTRLEN + 1]; /*(also larger than LI_ITOSTRING_LENGTH)*/
132 
133     /* (CONTENT_LENGTH must be first for SCGI) */
134     if (!opts->authorizer)
135         rc |= cb(vdata, CONST_STR_LEN("CONTENT_LENGTH"),
136                  buf, li_itostrn(buf,sizeof(buf),r->reqbody_length));
137 
138     n = buffer_clen(&r->uri.query);
139     rc |= cb(vdata, CONST_STR_LEN("QUERY_STRING"),
140                     n ? r->uri.query.ptr : "", n);
141 
142     s = r->target_orig.ptr;
143     n = buffer_clen(&r->target_orig);
144     len = opts->strip_request_uri ? buffer_clen(opts->strip_request_uri) : 0;
145     if (len) {
146         /* e.g. /app1/index/list
147          *      stripping /app1 or /app1/ should lead to /index/list
148          *      (trailing slash removed from strip_request_uri at config time)*/
149         if (n < len || 0 != memcmp(s, opts->strip_request_uri->ptr, len)
150             || s[len] != '/')
151             len = 0;
152     }
153     rc |= cb(vdata, CONST_STR_LEN("REQUEST_URI"), s+len, n-len);
154 
155     if (!buffer_is_equal(&r->target, &r->target_orig))
156         rc |= cb(vdata, CONST_STR_LEN("REDIRECT_URI"),
157                         BUF_PTR_LEN(&r->target));
158 
159     /* set REDIRECT_STATUS for php compiled with --force-redirect
160      * (if REDIRECT_STATUS has not already been set by error handler) */
161     if (0 == r->error_handler_saved_status)
162         rc |= cb(vdata, CONST_STR_LEN("REDIRECT_STATUS"),
163                         CONST_STR_LEN("200"));
164 
165     /*
166      * SCRIPT_NAME, PATH_INFO and PATH_TRANSLATED according to
167      * http://cgi-spec.golux.com/draft-coar-cgi-v11-03-clean.html
168      * (6.1.14, 6.1.6, 6.1.7)
169      */
170     if (!opts->authorizer) {
171         rc |= cb(vdata, CONST_STR_LEN("SCRIPT_NAME"),
172                         BUF_PTR_LEN(&r->uri.path));
173         if (!buffer_is_blank(&r->pathinfo)) {
174             rc |= cb(vdata, CONST_STR_LEN("PATH_INFO"),
175                             BUF_PTR_LEN(&r->pathinfo));
176             /* PATH_TRANSLATED is only defined if PATH_INFO is set
177              * Note: not implemented: re-url-encode '?' '=' ';' for
178              * (RFC 3875 4.1.6) */
179             const buffer * const bd = (opts->docroot)
180               ? opts->docroot
181               : &r->physical.basedir;
182             buffer_copy_path_len2(tb, BUF_PTR_LEN(bd),
183                                       BUF_PTR_LEN(&r->pathinfo));
184             rc |= cb(vdata, CONST_STR_LEN("PATH_TRANSLATED"),
185                             BUF_PTR_LEN(tb));
186         }
187     }
188 
189    /*
190     * SCRIPT_FILENAME and DOCUMENT_ROOT for php
191     * The PHP manual http://www.php.net/manual/en/reserved.variables.php
192     * treatment of PATH_TRANSLATED is different from the one of CGI specs.
193     * (see php.ini cgi.fix_pathinfo = 1 config parameter)
194     */
195 
196     if (opts->docroot) {
197         /* alternate docroot, e.g. for remote FastCGI or SCGI server */
198         buffer_copy_path_len2(tb, BUF_PTR_LEN(opts->docroot),
199                                   BUF_PTR_LEN(&r->uri.path));
200         rc |= cb(vdata, CONST_STR_LEN("SCRIPT_FILENAME"),
201                         BUF_PTR_LEN(tb));
202         rc |= cb(vdata, CONST_STR_LEN("DOCUMENT_ROOT"),
203                         BUF_PTR_LEN(opts->docroot));
204     }
205     else {
206         if (opts->break_scriptfilename_for_php) {
207             /* php.ini config cgi.fix_pathinfo = 1 need a broken SCRIPT_FILENAME
208              * to find out what PATH_INFO is itself
209              *
210              * see src/sapi/cgi_main.c, init_request_info()
211              */
212             buffer_copy_path_len2(tb, BUF_PTR_LEN(&r->physical.path),
213                                       BUF_PTR_LEN(&r->pathinfo));
214             rc |= cb(vdata, CONST_STR_LEN("SCRIPT_FILENAME"),
215                             BUF_PTR_LEN(tb));
216         }
217         else
218             rc |= cb(vdata, CONST_STR_LEN("SCRIPT_FILENAME"),
219                             BUF_PTR_LEN(&r->physical.path));
220         rc |= cb(vdata, CONST_STR_LEN("DOCUMENT_ROOT"),
221                         BUF_PTR_LEN(&r->physical.basedir));
222     }
223 
224     const buffer * const m = http_method_buf(r->http_method);
225     rc |= cb(vdata, CONST_STR_LEN("REQUEST_METHOD"), BUF_PTR_LEN(m));
226 
227     s = get_http_version_name(r->http_version);
228     force_assert(s);
229     rc |= cb(vdata, CONST_STR_LEN("SERVER_PROTOCOL"), s, strlen(s));
230 
231     if (r->conf.server_tag) {
232         s = r->conf.server_tag->ptr;
233         n = buffer_clen(r->conf.server_tag);
234     }
235     else {
236         s = "";
237         n = 0;
238     }
239     rc |= cb(vdata, CONST_STR_LEN("SERVER_SOFTWARE"), s, n);
240 
241     rc |= cb(vdata, CONST_STR_LEN("GATEWAY_INTERFACE"),
242                     CONST_STR_LEN("CGI/1.1"));
243 
244     rc |= cb(vdata, CONST_STR_LEN("REQUEST_SCHEME"),
245                     BUF_PTR_LEN(&r->uri.scheme));
246 
247     if (buffer_is_equal_string(&r->uri.scheme, CONST_STR_LEN("https")))
248         rc |= cb(vdata, CONST_STR_LEN("HTTPS"), CONST_STR_LEN("on"));
249 
250     const connection * const con = r->con;
251     const server_socket * const srv_sock = con->srv_socket;
252     const size_t tlen = buffer_clen(srv_sock->srv_token);
253     n = srv_sock->srv_token_colon;
254     if (n < tlen) { /*(n != tlen)*/
255         s = srv_sock->srv_token->ptr+n+1;
256         n = tlen - (n+1);
257     }
258     else {
259         s = "0";
260         n = 1;
261     }
262     rc |= cb(vdata, CONST_STR_LEN("SERVER_PORT"), s, n);
263 
264     n = 0;
265     switch (sock_addr_get_family(&srv_sock->addr)) {
266       case AF_INET:
267       case AF_INET6:
268         if (sock_addr_is_addr_wildcard(&srv_sock->addr)) {
269             sock_addr addrbuf;
270             socklen_t addrlen = sizeof(addrbuf);
271             if (0 == getsockname(con->fd,(struct sockaddr *)&addrbuf,&addrlen)){
272                 /* future: might add a one- or two- element cache
273                  * or use sock_addr_cache_inet_ntop_copy_buffer() into tb */
274                 s = sock_addr_inet_ntop(&addrbuf, buf, sizeof(buf));
275                 if (s)
276                     n = strlen(s);
277                 else
278                     s = "";
279             }
280             else
281                 s = "";
282         }
283         else {
284             s = srv_sock->srv_token->ptr;
285             n = srv_sock->srv_token_colon;
286         }
287         break;
288       default:
289         s = "";
290         break;
291     }
292     rc |= cb(vdata, CONST_STR_LEN("SERVER_ADDR"), s, n);
293 
294     n = buffer_clen(r->server_name);
295     if (n) {
296         s = r->server_name->ptr;
297         if (s[0] == '[') {
298             const char *colon = strstr(s, "]:");
299             if (colon) n = (colon + 1) - s;
300         }
301         else {
302             const char *colon = strchr(s, ':');
303             if (colon) n = colon - s;
304         }
305     } /* else set to be same as SERVER_ADDR (above) */
306     rc |= cb(vdata, CONST_STR_LEN("SERVER_NAME"), s, n);
307 
308     rc |= cb(vdata, CONST_STR_LEN("REMOTE_ADDR"),
309                     BUF_PTR_LEN(r->dst_addr_buf));
310 
311     rc |= cb(vdata, CONST_STR_LEN("REMOTE_PORT"), buf,
312              li_utostrn(buf, sizeof(buf), sock_addr_get_port(r->dst_addr)));
313 
314     for (n = 0; n < r->rqst_headers.used; n++) {
315         data_string *ds = (data_string *)r->rqst_headers.data[n];
316         if (!buffer_is_blank(&ds->value) && !buffer_is_unset(&ds->key)) {
317             /* Security: Do not emit HTTP_PROXY in environment.
318              * Some executables use HTTP_PROXY to configure
319              * outgoing proxy.  See also https://httpoxy.org/ */
320             if (ds->ext == HTTP_HEADER_OTHER
321                 && buffer_eq_icase_slen(&ds->key, CONST_STR_LEN("Proxy"))) {
322                 continue;
323             }
324             else if (ds->ext == HTTP_HEADER_CONTENT_TYPE)
325                 buffer_copy_string_len(tb, CONST_STR_LEN("CONTENT_TYPE"));
326             else
327                 http_cgi_encode_varname(tb, BUF_PTR_LEN(&ds->key), 1);
328             rc |= cb(vdata, BUF_PTR_LEN(tb),
329                             BUF_PTR_LEN(&ds->value));
330         }
331     }
332 
333     con->srv->request_env(r);
334 
335     for (n = 0; n < r->env.used; n++) {
336         data_string *ds = (data_string *)r->env.data[n];
337         if (!buffer_is_unset(&ds->value) && !buffer_is_unset(&ds->key)) {
338             http_cgi_encode_varname(tb, BUF_PTR_LEN(&ds->key), 0);
339             rc |= cb(vdata, BUF_PTR_LEN(tb),
340                             BUF_PTR_LEN(&ds->value));
341         }
342     }
343 
344     return rc;
345 }
346