xref: /lighttpd1.4/src/mod_proxy.c (revision 891007fb)
1 #include "first.h"
2 
3 #include <string.h>
4 #include <stdlib.h>
5 
6 #include "gw_backend.h"
7 #include "base.h"
8 #include "array.h"
9 #include "buffer.h"
10 #include "fdevent.h"
11 #include "http_kv.h"
12 #include "http_header.h"
13 #include "log.h"
14 #include "sock_addr.h"
15 #include "status_counter.h"
16 
17 /**
18  *
19  * HTTP reverse proxy
20  *
21  * TODO:      - HTTP/1.1
22  *            - HTTP/1.1 persistent connection with upstream servers
23  */
24 
25 /* (future: might split struct and move part to http-header-glue.c) */
26 typedef struct http_header_remap_opts {
27     const array *urlpaths;
28     const array *hosts_request;
29     const array *hosts_response;
30     int force_http10;
31     int https_remap;
32     int upgrade;
33     int connect_method;
34     /*(not used in plugin_config, but used in handler_ctx)*/
35     const buffer *http_host;
36     const buffer *forwarded_host;
37     const data_string *forwarded_urlpath;
38 } http_header_remap_opts;
39 
40 typedef enum {
41 	PROXY_FORWARDED_NONE         = 0x00,
42 	PROXY_FORWARDED_FOR          = 0x01,
43 	PROXY_FORWARDED_PROTO        = 0x02,
44 	PROXY_FORWARDED_HOST         = 0x04,
45 	PROXY_FORWARDED_BY           = 0x08,
46 	PROXY_FORWARDED_REMOTE_USER  = 0x10
47 } proxy_forwarded_t;
48 
49 typedef struct {
50     gw_plugin_config gw; /* start must match layout of gw_plugin_config */
51     unsigned int replace_http_host;
52     unsigned int forwarded;
53     http_header_remap_opts header;
54 } plugin_config;
55 
56 typedef struct {
57     PLUGIN_DATA;
58     pid_t srv_pid; /* must match layout of gw_plugin_data through conf member */
59     plugin_config conf;
60     plugin_config defaults;
61 } plugin_data;
62 
63 static int proxy_check_extforward;
64 
65 typedef struct {
66 	gw_handler_ctx gw;
67 	http_response_opts opts;
68 	plugin_config conf;
69 } handler_ctx;
70 
71 
72 INIT_FUNC(mod_proxy_init) {
73     return calloc(1, sizeof(plugin_data));
74 }
75 
76 
77 static void mod_proxy_free_config(plugin_data * const p)
78 {
79     if (NULL == p->cvlist) return;
80     /* (init i to 0 if global context; to 1 to skip empty global context) */
81     for (int i = !p->cvlist[0].v.u2[1], used = p->nconfig; i < used; ++i) {
82         config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0];
83         for (; -1 != cpv->k_id; ++cpv) {
84             switch (cpv->k_id) {
85               case 5: /* proxy.header */
86                 if (cpv->vtype == T_CONFIG_LOCAL) free(cpv->v.v);
87                 break;
88               default:
89                 break;
90             }
91         }
92     }
93 }
94 
95 
96 FREE_FUNC(mod_proxy_free) {
97     plugin_data * const p = p_d;
98     mod_proxy_free_config(p);
99     gw_free(p);
100 }
101 
102 static void mod_proxy_merge_config_cpv(plugin_config * const pconf, const config_plugin_value_t * const cpv)
103 {
104     switch (cpv->k_id) { /* index into static config_plugin_keys_t cpk[] */
105       case 0: /* proxy.server */
106         if (cpv->vtype == T_CONFIG_LOCAL) {
107             gw_plugin_config * const gw = cpv->v.v;
108             pconf->gw.exts      = gw->exts;
109             pconf->gw.exts_auth = gw->exts_auth;
110             pconf->gw.exts_resp = gw->exts_resp;
111         }
112         break;
113       case 1: /* proxy.balance */
114         /*if (cpv->vtype == T_CONFIG_LOCAL)*//*always true here for this param*/
115             pconf->gw.balance = (int)cpv->v.u;
116         break;
117       case 2: /* proxy.debug */
118         pconf->gw.debug = (int)cpv->v.u;
119         break;
120       case 3: /* proxy.map-extensions */
121         pconf->gw.ext_mapping = cpv->v.a;
122         break;
123       case 4: /* proxy.forwarded */
124         /*if (cpv->vtype == T_CONFIG_LOCAL)*//*always true here for this param*/
125             pconf->forwarded = cpv->v.u;
126         break;
127       case 5: /* proxy.header */
128         /*if (cpv->vtype == T_CONFIG_LOCAL)*//*always true here for this param*/
129         pconf->header = *(http_header_remap_opts *)cpv->v.v; /*(copies struct)*/
130         break;
131       case 6: /* proxy.replace-http-host */
132         pconf->replace_http_host = cpv->v.u;
133         break;
134       default:/* should not happen */
135         return;
136     }
137 }
138 
139 
140 static void mod_proxy_merge_config(plugin_config * const pconf, const config_plugin_value_t *cpv)
141 {
142     do {
143         mod_proxy_merge_config_cpv(pconf, cpv);
144     } while ((++cpv)->k_id != -1);
145 }
146 
147 
148 static void mod_proxy_patch_config(request_st * const r, plugin_data * const p)
149 {
150     memcpy(&p->conf, &p->defaults, sizeof(plugin_config));
151     for (int i = 1, used = p->nconfig; i < used; ++i) {
152         if (config_check_cond(r, (uint32_t)p->cvlist[i].k_id))
153             mod_proxy_merge_config(&p->conf, p->cvlist+p->cvlist[i].v.u2[0]);
154     }
155 }
156 
157 
158 static unsigned int mod_proxy_parse_forwarded(server *srv, const array *a)
159 {
160     unsigned int forwarded = 0;
161     for (uint32_t j = 0, used = a->used; j < used; ++j) {
162         proxy_forwarded_t param;
163         data_unset *du = a->data[j];
164         if (buffer_eq_slen(&du->key, CONST_STR_LEN("by")))
165             param = PROXY_FORWARDED_BY;
166         else if (buffer_eq_slen(&du->key, CONST_STR_LEN("for")))
167             param = PROXY_FORWARDED_FOR;
168         else if (buffer_eq_slen(&du->key, CONST_STR_LEN("host")))
169             param = PROXY_FORWARDED_HOST;
170         else if (buffer_eq_slen(&du->key, CONST_STR_LEN("proto")))
171             param = PROXY_FORWARDED_PROTO;
172         else if (buffer_eq_slen(&du->key, CONST_STR_LEN("remote_user")))
173             param = PROXY_FORWARDED_REMOTE_USER;
174         else {
175             log_error(srv->errh, __FILE__, __LINE__,
176               "proxy.forwarded keys must be one of: "
177               "by, for, host, proto, remote_user, but not: %s", du->key.ptr);
178             return UINT_MAX;
179         }
180         int val = config_plugin_value_tobool(du, 2);
181         if (2 == val) {
182             log_error(srv->errh, __FILE__, __LINE__,
183               "proxy.forwarded values must be one of: "
184               "0, 1, enable, disable; error for key: %s", du->key.ptr);
185             return UINT_MAX;
186         }
187         if (val)
188             forwarded |= param;
189     }
190     return forwarded;
191 }
192 
193 
194 static http_header_remap_opts * mod_proxy_parse_header_opts(server *srv, const array *a)
195 {
196     http_header_remap_opts header;
197     memset(&header, 0, sizeof(header));
198     for (uint32_t j = 0, used = a->used; j < used; ++j) {
199         data_array *da = (data_array *)a->data[j];
200         if (buffer_eq_slen(&da->key, CONST_STR_LEN("https-remap"))) {
201             int val = config_plugin_value_tobool((data_unset *)da, 2);
202             if (2 == val) {
203                 log_error(srv->errh, __FILE__, __LINE__,
204                   "unexpected value for proxy.header; "
205                   "expected \"https-remap\" => \"enable\" or \"disable\"");
206                 return NULL;
207             }
208             header.https_remap = val;
209             continue;
210         }
211         else if (buffer_eq_slen(&da->key, CONST_STR_LEN("force-http10"))) {
212             int val = config_plugin_value_tobool((data_unset *)da, 2);
213             if (2 == val) {
214                 log_error(srv->errh, __FILE__, __LINE__,
215                   "unexpected value for proxy.header; "
216                   "expected \"force-http10\" => \"enable\" or \"disable\"");
217                 return NULL;
218             }
219             header.force_http10 = val;
220             continue;
221         }
222         else if (buffer_eq_slen(&da->key, CONST_STR_LEN("upgrade"))) {
223             int val = config_plugin_value_tobool((data_unset *)da, 2);
224             if (2 == val) {
225                 log_error(srv->errh, __FILE__, __LINE__,
226                   "unexpected value for proxy.header; "
227                   "expected \"upgrade\" => \"enable\" or \"disable\"");
228                 return NULL;
229             }
230             header.upgrade = val;
231             continue;
232         }
233         else if (buffer_eq_slen(&da->key, CONST_STR_LEN("connect"))) {
234             int val = config_plugin_value_tobool((data_unset *)da, 2);
235             if (2 == val) {
236                 log_error(srv->errh, __FILE__, __LINE__,
237                   "unexpected value for proxy.header; "
238                   "expected \"connect\" => \"enable\" or \"disable\"");
239                 return NULL;
240             }
241             header.connect_method = val;
242             continue;
243         }
244         if (da->type != TYPE_ARRAY || !array_is_kvstring(&da->value)) {
245             log_error(srv->errh, __FILE__, __LINE__,
246               "unexpected value for proxy.header; "
247               "expected ( \"param\" => ( \"key\" => \"value\" ) ) near key %s",
248               da->key.ptr);
249             return NULL;
250         }
251         if (buffer_eq_slen(&da->key, CONST_STR_LEN("map-urlpath"))) {
252             header.urlpaths = &da->value;
253         }
254         else if (buffer_eq_slen(&da->key, CONST_STR_LEN("map-host-request"))) {
255             header.hosts_request = &da->value;
256         }
257         else if (buffer_eq_slen(&da->key, CONST_STR_LEN("map-host-response"))) {
258             header.hosts_response = &da->value;
259         }
260         else {
261             log_error(srv->errh, __FILE__, __LINE__,
262               "unexpected key for proxy.header; "
263               "expected ( \"param\" => ( \"key\" => \"value\" ) ) near key %s",
264               da->key.ptr);
265             return NULL;
266         }
267     }
268 
269     http_header_remap_opts *opts = malloc(sizeof(header));
270     force_assert(opts);
271     memcpy(opts, &header, sizeof(header));
272     return opts;
273 }
274 
275 
276 SETDEFAULTS_FUNC(mod_proxy_set_defaults)
277 {
278     static const config_plugin_keys_t cpk[] = {
279       { CONST_STR_LEN("proxy.server"),
280         T_CONFIG_ARRAY_KVARRAY,
281         T_CONFIG_SCOPE_CONNECTION }
282      ,{ CONST_STR_LEN("proxy.balance"),
283         T_CONFIG_STRING,
284         T_CONFIG_SCOPE_CONNECTION }
285      ,{ CONST_STR_LEN("proxy.debug"),
286         T_CONFIG_INT,
287         T_CONFIG_SCOPE_CONNECTION }
288      ,{ CONST_STR_LEN("proxy.map-extensions"),
289         T_CONFIG_ARRAY_KVSTRING,
290         T_CONFIG_SCOPE_CONNECTION }
291      ,{ CONST_STR_LEN("proxy.forwarded"),
292         T_CONFIG_ARRAY_KVANY,
293         T_CONFIG_SCOPE_CONNECTION }
294      ,{ CONST_STR_LEN("proxy.header"),
295         T_CONFIG_ARRAY_KVANY,
296         T_CONFIG_SCOPE_CONNECTION }
297      ,{ CONST_STR_LEN("proxy.replace-http-host"),
298         T_CONFIG_BOOL,
299         T_CONFIG_SCOPE_CONNECTION }
300      ,{ NULL, 0,
301         T_CONFIG_UNSET,
302         T_CONFIG_SCOPE_UNSET }
303     };
304 
305     plugin_data * const p = p_d;
306     if (!config_plugin_values_init(srv, p, cpk, "mod_proxy"))
307         return HANDLER_ERROR;
308 
309     /* process and validate config directives
310      * (init i to 0 if global context; to 1 to skip empty global context) */
311     for (int i = !p->cvlist[0].v.u2[1]; i < p->nconfig; ++i) {
312         config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0];
313         gw_plugin_config *gw = NULL;
314         for (; -1 != cpv->k_id; ++cpv) {
315             switch (cpv->k_id) {
316               case 0: /* proxy.server */
317                 gw = calloc(1, sizeof(gw_plugin_config));
318                 force_assert(gw);
319                 if (!gw_set_defaults_backend(srv, (gw_plugin_data *)p, cpv->v.a,
320                                              gw, 0, cpk[cpv->k_id].k)) {
321                     gw_plugin_config_free(gw);
322                     return HANDLER_ERROR;
323                 }
324                 /* error if "mode" = "authorizer";
325                  * proxy can not act as authorizer */
326                 /*(check after gw_set_defaults_backend())*/
327                 if (gw->exts_auth && gw->exts_auth->used) {
328                     log_error(srv->errh, __FILE__, __LINE__,
329                       "%s must not define any hosts with "
330                       "attribute \"mode\" = \"authorizer\"", cpk[cpv->k_id].k);
331                     gw_plugin_config_free(gw);
332                     return HANDLER_ERROR;
333                 }
334                 cpv->v.v = gw;
335                 cpv->vtype = T_CONFIG_LOCAL;
336                 break;
337               case 1: /* proxy.balance */
338                 cpv->v.u = (unsigned int)gw_get_defaults_balance(srv, cpv->v.b);
339                 break;
340               case 2: /* proxy.debug */
341               case 3: /* proxy.map-extensions */
342                 break;
343               case 4: /* proxy.forwarded */
344                 cpv->v.u = mod_proxy_parse_forwarded(srv, cpv->v.a);
345                 if (UINT_MAX == cpv->v.u) return HANDLER_ERROR;
346                 cpv->vtype = T_CONFIG_LOCAL;
347                 break;
348               case 5: /* proxy.header */
349                 cpv->v.v = mod_proxy_parse_header_opts(srv, cpv->v.a);
350                 if (NULL == cpv->v.v) return HANDLER_ERROR;
351                 cpv->vtype = T_CONFIG_LOCAL;
352                 break;
353               case 6: /* proxy.replace-http-host */
354                 break;
355               default:/* should not happen */
356                 break;
357             }
358         }
359 
360         /* disable check-local for all exts (default enabled) */
361         if (gw && gw->exts) { /*(check after gw_set_defaults_backend())*/
362             gw_exts_clear_check_local(gw->exts);
363         }
364     }
365 
366     /* default is 0 */
367     /*p->defaults.balance = (unsigned int)gw_get_defaults_balance(srv, NULL);*/
368 
369     p->defaults.header.force_http10 =
370       srv->srvconf.feature_flags
371       && config_plugin_value_tobool(
372            array_get_element_klen(srv->srvconf.feature_flags,
373                                   CONST_STR_LEN("proxy.force-http10")), 0);
374 
375     /* initialize p->defaults from global config context */
376     if (p->nconfig > 0 && p->cvlist->v.u2[1]) {
377         const config_plugin_value_t *cpv = p->cvlist + p->cvlist->v.u2[0];
378         if (-1 != cpv->k_id)
379             mod_proxy_merge_config(&p->defaults, cpv);
380     }
381 
382     /* special-case behavior if mod_extforward is loaded */
383     for (uint32_t i = 0; i < srv->srvconf.modules->used; ++i) {
384         buffer *m = &((data_string *)srv->srvconf.modules->data[i])->value;
385         if (buffer_eq_slen(m, CONST_STR_LEN("mod_extforward"))) {
386             proxy_check_extforward = 1;
387             break;
388         }
389     }
390 
391     return HANDLER_GO_ON;
392 }
393 
394 
395 /* (future: might move to http-header-glue.c) */
396 static const buffer * http_header_remap_host_match (buffer *b, size_t off, http_header_remap_opts *remap_hdrs, int is_req, size_t alen)
397 {
398     const array *hosts = is_req
399       ? remap_hdrs->hosts_request
400       : remap_hdrs->hosts_response;
401     if (hosts) {
402         const char * const s = b->ptr+off;
403         for (size_t i = 0, used = hosts->used; i < used; ++i) {
404             const data_string * const ds = (data_string *)hosts->data[i];
405             const buffer *k = &ds->key;
406             size_t mlen = buffer_string_length(k);
407             if (1 == mlen && k->ptr[0] == '-') {
408                 /* match with authority provided in Host (if is_req)
409                  * (If no Host in client request, then matching against empty
410                  *  string will probably not match, and no remap will be
411                  *  performed) */
412                 k = is_req
413                   ? remap_hdrs->http_host
414                   : remap_hdrs->forwarded_host;
415                 if (NULL == k) continue;
416                 mlen = buffer_string_length(k);
417             }
418             if (buffer_eq_icase_ss(s, alen, k->ptr, mlen)) {
419                 if (buffer_is_equal_string(&ds->value, CONST_STR_LEN("-"))) {
420                     return remap_hdrs->http_host;
421                 }
422                 else if (!buffer_string_is_empty(&ds->value)) {
423                     /*(save first matched request host for response match)*/
424                     if (is_req && NULL == remap_hdrs->forwarded_host)
425                         remap_hdrs->forwarded_host = &ds->value;
426                     return &ds->value;
427                 } /*(else leave authority as-is and stop matching)*/
428                 break;
429             }
430         }
431     }
432     return NULL;
433 }
434 
435 
436 /* (future: might move to http-header-glue.c) */
437 static size_t http_header_remap_host (buffer *b, size_t off, http_header_remap_opts *remap_hdrs, int is_req, size_t alen)
438 {
439     const buffer * const m =
440       http_header_remap_host_match(b, off, remap_hdrs, is_req, alen);
441     if (NULL == m) return alen; /*(no match; return original authority length)*/
442 
443     buffer_substr_replace(b, off, alen, m);
444     return buffer_string_length(m); /*(length of replacement authority)*/
445 }
446 
447 
448 /* (future: might move to http-header-glue.c) */
449 static size_t http_header_remap_urlpath (buffer *b, size_t off, http_header_remap_opts *remap_hdrs, int is_req)
450 {
451     const array *urlpaths = remap_hdrs->urlpaths;
452     if (urlpaths) {
453         const char * const s = b->ptr+off;
454         const size_t plen = buffer_string_length(b) - off; /*(urlpath len)*/
455         if (is_req) { /* request */
456             for (size_t i = 0, used = urlpaths->used; i < used; ++i) {
457                 const data_string * const ds = (data_string *)urlpaths->data[i];
458                 const size_t mlen = buffer_string_length(&ds->key);
459                 if (mlen <= plen && 0 == memcmp(s, ds->key.ptr, mlen)) {
460                     if (NULL == remap_hdrs->forwarded_urlpath)
461                         remap_hdrs->forwarded_urlpath = ds;
462                     buffer_substr_replace(b, off, mlen, &ds->value);
463                     return buffer_string_length(&ds->value);/*(replacement len)*/
464                 }
465             }
466         }
467         else {        /* response; perform reverse map */
468             if (NULL != remap_hdrs->forwarded_urlpath) {
469                 const data_string * const ds = remap_hdrs->forwarded_urlpath;
470                 const size_t mlen = buffer_string_length(&ds->value);
471                 if (mlen <= plen && 0 == memcmp(s, ds->value.ptr, mlen)) {
472                     buffer_substr_replace(b, off, mlen, &ds->key);
473                     return buffer_string_length(&ds->key); /*(replacement len)*/
474                 }
475             }
476             for (size_t i = 0, used = urlpaths->used; i < used; ++i) {
477                 const data_string * const ds = (data_string *)urlpaths->data[i];
478                 const size_t mlen = buffer_string_length(&ds->value);
479                 if (mlen <= plen && 0 == memcmp(s, ds->value.ptr, mlen)) {
480                     buffer_substr_replace(b, off, mlen, &ds->key);
481                     return buffer_string_length(&ds->key); /*(replacement len)*/
482                 }
483             }
484         }
485     }
486     return 0;
487 }
488 
489 
490 /* (future: might move to http-header-glue.c) */
491 static void http_header_remap_uri (buffer *b, size_t off, http_header_remap_opts *remap_hdrs, int is_req)
492 {
493     /* find beginning of URL-path (might be preceded by scheme://authority
494      * (caller should make sure any leading whitespace is prior to offset) */
495     if (b->ptr[off] != '/') {
496         char *s = b->ptr+off;
497         size_t alen; /*(authority len (host len))*/
498         size_t slen; /*(scheme len)*/
499         const buffer *m;
500         /* skip over scheme and authority of URI to find beginning of URL-path
501          * (value might conceivably be relative URL-path instead of URI) */
502         if (NULL == (s = strchr(s, ':')) || s[1] != '/' || s[2] != '/') return;
503         slen = s - (b->ptr+off);
504         s += 3;
505         off = (size_t)(s - b->ptr);
506         if (NULL != (s = strchr(s, '/'))) {
507             alen = (size_t)(s - b->ptr) - off;
508             if (0 == alen) return; /*(empty authority, e.g. "http:///")*/
509         }
510         else {
511             alen = buffer_string_length(b) - off;
512             if (0 == alen) return; /*(empty authority, e.g. "http:///")*/
513             buffer_append_string_len(b, CONST_STR_LEN("/"));
514         }
515 
516         /* remap authority (if configured) and set offset to url-path */
517         m = http_header_remap_host_match(b, off, remap_hdrs, is_req, alen);
518         if (NULL != m) {
519             if (remap_hdrs->https_remap
520                 && (is_req ? 5==slen && 0==memcmp(b->ptr+off-slen-3,"https",5)
521                            : 4==slen && 0==memcmp(b->ptr+off-slen-3,"http",4))){
522                 if (is_req) {
523                     memcpy(b->ptr+off-slen-3+4,"://",3);  /*("https"=>"http")*/
524                     --off;
525                     ++alen;
526                 }
527                 else {/*(!is_req)*/
528                     memcpy(b->ptr+off-slen-3+4,"s://",4); /*("http" =>"https")*/
529                     ++off;
530                     --alen;
531                 }
532             }
533             buffer_substr_replace(b, off, alen, m);
534             alen = buffer_string_length(m);/*(length of replacement authority)*/
535         }
536         off += alen;
537     }
538 
539     /* remap URLs (if configured) */
540     http_header_remap_urlpath(b, off, remap_hdrs, is_req);
541 }
542 
543 
544 /* (future: might move to http-header-glue.c) */
545 static void http_header_remap_setcookie (buffer *b, size_t off, http_header_remap_opts *remap_hdrs)
546 {
547     /* Given the special-case of Set-Cookie and the (too) loosely restricted
548      * characters allowed, for best results, the Set-Cookie value should be the
549      * entire string in b from offset to end of string.  In response headers,
550      * lighttpd may concatenate multiple Set-Cookie headers into single entry
551      * in r->resp_headers, separated by "\r\nSet-Cookie: " */
552     for (char *s = b->ptr+off, *e; *s; s = e) {
553         size_t len;
554         {
555             while (*s != ';' && *s != '\n' && *s != '\0') ++s;
556             if (*s == '\n') {
557                 /*(include +1 for '\n', but leave ' ' for ++s below)*/
558                 s += sizeof("Set-Cookie:");
559             }
560             if ('\0' == *s) return;
561             do { ++s; } while (*s == ' ' || *s == '\t');
562             if ('\0' == *s) return;
563             e = s+1;
564             if ('=' == *s) continue;
565             /*(interested only in Domain and Path attributes)*/
566             while (*e != '=' && *e != '\0') ++e;
567             if ('\0' == *e) return;
568             ++e;
569             switch ((int)(e - s - 1)) {
570               case 4:
571                 if (buffer_eq_icase_ssn(s, "path", 4)) {
572                     if (*e == '"') ++e;
573                     if (*e != '/') continue;
574                     off = (size_t)(e - b->ptr);
575                     len = http_header_remap_urlpath(b, off, remap_hdrs, 0);
576                     e = b->ptr+off+len; /*(b may have been reallocated)*/
577                     continue;
578                 }
579                 break;
580               case 6:
581                 if (buffer_eq_icase_ssn(s, "domain", 6)) {
582                     size_t alen = 0;
583                     if (*e == '"') ++e;
584                     if (*e == '.') ++e;
585                     if (*e == ';') continue;
586                     off = (size_t)(e - b->ptr);
587                     for (char c; (c = e[alen]) != ';' && c != ' ' && c != '\t'
588                                           && c != '\r' && c != '\0'; ++alen);
589                     len = http_header_remap_host(b, off, remap_hdrs, 0, alen);
590                     e = b->ptr+off+len; /*(b may have been reallocated)*/
591                     continue;
592                 }
593                 break;
594               default:
595                 break;
596             }
597         }
598     }
599 }
600 
601 
602 static void buffer_append_string_backslash_escaped(buffer *b, const char *s, size_t len) {
603     /* (future: might move to buffer.c) */
604     size_t j = 0;
605     char *p;
606 
607     buffer_string_prepare_append(b, len*2 + 4);
608     p = b->ptr + buffer_string_length(b);
609 
610     for (size_t i = 0; i < len; ++i) {
611         int c = s[i];
612         if (c == '"' || c == '\\' || c == 0x7F || (c < 0x20 && c != '\t'))
613             p[j++] = '\\';
614         p[j++] = c;
615     }
616 
617     buffer_commit(b, j);
618 }
619 
620 static void proxy_set_Forwarded(connection * const con, request_st * const r, const unsigned int flags) {
621     buffer *b = NULL, *efor = NULL, *eproto = NULL, *ehost = NULL;
622     int semicolon = 0;
623 
624     if (proxy_check_extforward) {
625         efor   =
626           http_header_env_get(r, CONST_STR_LEN("_L_EXTFORWARD_ACTUAL_FOR"));
627         eproto =
628           http_header_env_get(r, CONST_STR_LEN("_L_EXTFORWARD_ACTUAL_PROTO"));
629         ehost  =
630           http_header_env_get(r, CONST_STR_LEN("_L_EXTFORWARD_ACTUAL_HOST"));
631     }
632 
633     /* note: set "Forwarded" prior to updating X-Forwarded-For (below) */
634 
635     if (flags)
636         b = http_header_request_get(r, HTTP_HEADER_FORWARDED, CONST_STR_LEN("Forwarded"));
637 
638     if (flags && NULL == b) {
639         const buffer *xff =
640           http_header_request_get(r, HTTP_HEADER_X_FORWARDED_FOR, CONST_STR_LEN("X-Forwarded-For"));
641         http_header_request_set(r, HTTP_HEADER_FORWARDED,
642                                 CONST_STR_LEN("Forwarded"),
643                                 CONST_STR_LEN("x")); /*(must not be blank for _get below)*/
644       #ifdef __COVERITY__
645         force_assert(NULL != b); /*(not NULL because created directly above)*/
646       #endif
647         b = http_header_request_get(r, HTTP_HEADER_FORWARDED, CONST_STR_LEN("Forwarded"));
648         buffer_clear(b);
649         if (NULL != xff) {
650             /* use X-Forwarded-For contents to seed Forwarded */
651             char *s = xff->ptr;
652             size_t used = buffer_string_length(xff);
653             for (size_t i=0, j, ipv6; i < used; ++i) {
654                 while (s[i] == ' ' || s[i] == '\t' || s[i] == ',') ++i;
655                 if (s[i] == '\0') break;
656                 j = i;
657                 do {
658                     ++i;
659                 } while (s[i]!=' ' && s[i]!='\t' && s[i]!=',' && s[i]!='\0');
660                 buffer_append_string_len(b, CONST_STR_LEN("for="));
661                 /* over-simplified test expecting only IPv4 or IPv6 addresses,
662                  * (not expecting :port, so treat existence of colon as IPv6,
663                  *  and not expecting unix paths, especially not containing ':')
664                  * quote all strings, backslash-escape since IPs not validated*/
665                 ipv6 = (NULL != memchr(s+j, ':', i-j)); /*(over-simplified) */
666                 buffer_append_string_len(b, CONST_STR_LEN("\""));
667                 if (ipv6)
668                     buffer_append_string_len(b, CONST_STR_LEN("["));
669                 buffer_append_string_backslash_escaped(b, s+j, i-j);
670                 if (ipv6)
671                     buffer_append_string_len(b, CONST_STR_LEN("]"));
672                 buffer_append_string_len(b, CONST_STR_LEN("\""));
673                 buffer_append_string_len(b, CONST_STR_LEN(", "));
674             }
675         }
676     } else if (flags) { /*(NULL != b)*/
677         buffer_append_string_len(b, CONST_STR_LEN(", "));
678     }
679 
680     if (flags & PROXY_FORWARDED_FOR) {
681         int family = sock_addr_get_family(&con->dst_addr);
682         buffer_append_string_len(b, CONST_STR_LEN("for="));
683         if (NULL != efor) {
684             /* over-simplified test expecting only IPv4 or IPv6 addresses,
685              * (not expecting :port, so treat existence of colon as IPv6,
686              *  and not expecting unix paths, especially not containing ':')
687              * quote all strings and backslash-escape since IPs not validated
688              * (should be IP from original con->dst_addr_buf,
689              *  so trustable and without :port) */
690             int ipv6 = (NULL != strchr(efor->ptr, ':'));
691             buffer_append_string_len(b, CONST_STR_LEN("\""));
692             if (ipv6) buffer_append_string_len(b, CONST_STR_LEN("["));
693             buffer_append_string_backslash_escaped(
694               b, CONST_BUF_LEN(efor));
695             if (ipv6) buffer_append_string_len(b, CONST_STR_LEN("]"));
696             buffer_append_string_len(b, CONST_STR_LEN("\""));
697         } else if (family == AF_INET) {
698             /*(Note: if :port is added, then must be quoted-string:
699              * e.g. for="...:port")*/
700             buffer_append_string_buffer(b, con->dst_addr_buf);
701         } else if (family == AF_INET6) {
702             buffer_append_string_len(b, CONST_STR_LEN("\"["));
703             buffer_append_string_buffer(b, con->dst_addr_buf);
704             buffer_append_string_len(b, CONST_STR_LEN("]\""));
705         } else {
706             buffer_append_string_len(b, CONST_STR_LEN("\""));
707             buffer_append_string_backslash_escaped(
708               b, CONST_BUF_LEN(con->dst_addr_buf));
709             buffer_append_string_len(b, CONST_STR_LEN("\""));
710         }
711         semicolon = 1;
712     }
713 
714     if (flags & PROXY_FORWARDED_BY) {
715         int family = sock_addr_get_family(&con->srv_socket->addr);
716         /* Note: getsockname() and inet_ntop() are expensive operations.
717          * (recommendation: do not to enable by=... unless required)
718          * future: might use con->srv_socket->srv_token if addr is not
719          *   INADDR_ANY or in6addr_any, but must omit optional :port
720          *   from con->srv_socket->srv_token for consistency */
721 
722         if (semicolon) buffer_append_string_len(b, CONST_STR_LEN(";"));
723         buffer_append_string_len(b, CONST_STR_LEN("by="));
724         buffer_append_string_len(b, CONST_STR_LEN("\""));
725       #ifdef HAVE_SYS_UN_H
726         /* special-case: might need to encode unix domain socket path */
727         if (family == AF_UNIX) {
728             buffer_append_string_backslash_escaped(
729               b, CONST_BUF_LEN(con->srv_socket->srv_token));
730         }
731         else
732       #endif
733         {
734             sock_addr addr;
735             socklen_t addrlen = sizeof(addr);
736             if (0 == getsockname(con->fd,(struct sockaddr *)&addr, &addrlen)) {
737                 sock_addr_stringify_append_buffer(b, &addr);
738             }
739         }
740         buffer_append_string_len(b, CONST_STR_LEN("\""));
741         semicolon = 1;
742     }
743 
744     if (flags & PROXY_FORWARDED_PROTO) {
745         /* expecting "http" or "https"
746          * (not checking if quoted-string and encoding needed) */
747         if (semicolon) buffer_append_string_len(b, CONST_STR_LEN(";"));
748         buffer_append_string_len(b, CONST_STR_LEN("proto="));
749         if (NULL != eproto) {
750             buffer_append_string_buffer(b, eproto);
751         } else if (con->srv_socket->is_ssl) {
752             buffer_append_string_len(b, CONST_STR_LEN("https"));
753         } else {
754             buffer_append_string_len(b, CONST_STR_LEN("http"));
755         }
756         semicolon = 1;
757     }
758 
759     if (flags & PROXY_FORWARDED_HOST) {
760         if (NULL != ehost) {
761             if (semicolon)
762                 buffer_append_string_len(b, CONST_STR_LEN(";"));
763             buffer_append_string_len(b, CONST_STR_LEN("host=\""));
764             buffer_append_string_backslash_escaped(
765               b, CONST_BUF_LEN(ehost));
766             buffer_append_string_len(b, CONST_STR_LEN("\""));
767             semicolon = 1;
768         } else if (!buffer_string_is_empty(r->http_host)) {
769             if (semicolon)
770                 buffer_append_string_len(b, CONST_STR_LEN(";"));
771             buffer_append_string_len(b, CONST_STR_LEN("host=\""));
772             buffer_append_string_backslash_escaped(
773               b, CONST_BUF_LEN(r->http_host));
774             buffer_append_string_len(b, CONST_STR_LEN("\""));
775             semicolon = 1;
776         }
777     }
778 
779     if (flags & PROXY_FORWARDED_REMOTE_USER) {
780         const buffer *remote_user =
781           http_header_env_get(r, CONST_STR_LEN("REMOTE_USER"));
782         if (NULL != remote_user) {
783             if (semicolon)
784                 buffer_append_string_len(b, CONST_STR_LEN(";"));
785             buffer_append_string_len(b, CONST_STR_LEN("remote_user=\""));
786             buffer_append_string_backslash_escaped(
787               b, CONST_BUF_LEN(remote_user));
788             buffer_append_string_len(b, CONST_STR_LEN("\""));
789             /*semicolon = 1;*/
790         }
791     }
792 
793     /* legacy X-* headers, including X-Forwarded-For */
794 
795     b = (NULL != efor) ? efor : con->dst_addr_buf;
796     http_header_request_set(r, HTTP_HEADER_X_FORWARDED_FOR,
797                             CONST_STR_LEN("X-Forwarded-For"),
798                             CONST_BUF_LEN(b));
799 
800     b = (NULL != ehost) ? ehost : r->http_host;
801     if (!buffer_string_is_empty(b)) {
802         http_header_request_set(r, HTTP_HEADER_OTHER,
803                                 CONST_STR_LEN("X-Host"),
804                                 CONST_BUF_LEN(b));
805         http_header_request_set(r, HTTP_HEADER_OTHER,
806                                 CONST_STR_LEN("X-Forwarded-Host"),
807                                 CONST_BUF_LEN(b));
808     }
809 
810     b = (NULL != eproto) ? eproto : &r->uri.scheme;
811     http_header_request_set(r, HTTP_HEADER_X_FORWARDED_PROTO,
812                             CONST_STR_LEN("X-Forwarded-Proto"),
813                             CONST_BUF_LEN(b));
814 }
815 
816 
817 static handler_t proxy_stdin_append(gw_handler_ctx *hctx) {
818     /*handler_ctx *hctx = (handler_ctx *)gwhctx;*/
819     chunkqueue * const req_cq = &hctx->r->reqbody_queue;
820     const off_t req_cqlen = chunkqueue_length(req_cq);
821     if (req_cqlen) {
822         /* XXX: future: use http_chunk_len_append() */
823         buffer * const tb = hctx->r->tmp_buf;
824         buffer_clear(tb);
825         buffer_append_uint_hex_lc(tb, (uintmax_t)req_cqlen);
826         buffer_append_string_len(tb, CONST_STR_LEN("\r\n"));
827 
828         const off_t len = (off_t)buffer_string_length(tb)
829                         + 2 /*(+2 end chunk "\r\n")*/
830                         + req_cqlen;
831         if (-1 != hctx->wb_reqlen)
832             hctx->wb_reqlen += (hctx->wb_reqlen >= 0) ? len : -len;
833 
834         (chunkqueue_is_empty(&hctx->wb) || hctx->wb.first->type == MEM_CHUNK)
835                                           /* else FILE_CHUNK for temp file */
836           ? chunkqueue_append_mem(&hctx->wb, CONST_BUF_LEN(tb))
837           : chunkqueue_append_mem_min(&hctx->wb, CONST_BUF_LEN(tb));
838         chunkqueue_steal(&hctx->wb, req_cq, req_cqlen);
839 
840         chunkqueue_append_mem_min(&hctx->wb, CONST_STR_LEN("\r\n"));
841     }
842 
843     if (hctx->wb.bytes_in == hctx->wb_reqlen) {/*hctx->r->reqbody_length >= 0*/
844         /* terminate STDIN */
845         chunkqueue_append_mem(&hctx->wb, CONST_STR_LEN("0\r\n\r\n"));
846         hctx->wb_reqlen += (int)sizeof("0\r\n\r\n");
847     }
848 
849     return HANDLER_GO_ON;
850 }
851 
852 
853 static handler_t proxy_create_env(gw_handler_ctx *gwhctx) {
854 	handler_ctx *hctx = (handler_ctx *)gwhctx;
855 	request_st * const r = hctx->gw.r;
856 	const int remap_headers = (NULL != hctx->conf.header.urlpaths
857 				   || NULL != hctx->conf.header.hosts_request);
858 	size_t rsz = (size_t)(r->read_queue.bytes_out - hctx->gw.wb.bytes_in);
859 	if (rsz >= 65536) rsz = r->rqst_header_len;
860 	buffer * const b = chunkqueue_prepend_buffer_open_sz(&hctx->gw.wb, rsz);
861 
862 	/* build header */
863 
864 	/* request line */
865 	http_method_append(b, r->http_method);
866 	buffer_append_string_len(b, CONST_STR_LEN(" "));
867 	buffer_append_string_buffer(b, &r->target);
868 	if (remap_headers)
869 		http_header_remap_uri(b, buffer_string_length(b) - buffer_string_length(&r->target), &hctx->conf.header, 1);
870 
871 	if (!hctx->conf.header.force_http10)
872 		buffer_append_string_len(b, CONST_STR_LEN(" HTTP/1.1\r\n"));
873 	else
874 		buffer_append_string_len(b, CONST_STR_LEN(" HTTP/1.0\r\n"));
875 
876 	if (hctx->conf.replace_http_host && !buffer_string_is_empty(hctx->gw.host->id)) {
877 		if (hctx->gw.conf.debug > 1) {
878 			log_error(r->conf.errh, __FILE__, __LINE__,
879 			  "proxy - using \"%s\" as HTTP Host", hctx->gw.host->id->ptr);
880 		}
881 		buffer_append_string_len(b, CONST_STR_LEN("Host: "));
882 		buffer_append_string_buffer(b, hctx->gw.host->id);
883 		buffer_append_string_len(b, CONST_STR_LEN("\r\n"));
884 	} else if (!buffer_string_is_empty(r->http_host)) {
885 		buffer_append_string_len(b, CONST_STR_LEN("Host: "));
886 		buffer_append_string_buffer(b, r->http_host);
887 		if (remap_headers) {
888 			size_t alen = buffer_string_length(r->http_host);
889 			http_header_remap_host(b, buffer_string_length(b) - alen, &hctx->conf.header, 1, alen);
890 		}
891 		buffer_append_string_len(b, CONST_STR_LEN("\r\n"));
892 	}
893 
894 	/* "Forwarded" and legacy X- headers */
895 	proxy_set_Forwarded(r->con, r, hctx->conf.forwarded);
896 
897 	if (r->reqbody_length > 0
898 	    || (0 == r->reqbody_length
899 		&& !http_method_get_or_head(r->http_method))) {
900 		/* set Content-Length if client sent Transfer-Encoding: chunked
901 		 * and not streaming to backend (request body has been fully received) */
902 		const buffer *vb = http_header_request_get(r, HTTP_HEADER_CONTENT_LENGTH, CONST_STR_LEN("Content-Length"));
903 		if (NULL == vb) {
904 			char buf[LI_ITOSTRING_LENGTH];
905 			http_header_request_set(r, HTTP_HEADER_CONTENT_LENGTH, CONST_STR_LEN("Content-Length"),
906 			                        buf, li_itostrn(buf, sizeof(buf), r->reqbody_length));
907 		}
908 	}
909 	else if (!hctx->conf.header.force_http10
910 	         && -1 == r->reqbody_length
911 	         && (r->conf.stream_request_body
912 	             & (FDEVENT_STREAM_REQUEST | FDEVENT_STREAM_REQUEST_BUFMIN))) {
913 		hctx->gw.stdin_append = proxy_stdin_append; /* stream chunked body */
914 		buffer_append_string_len(b, CONST_STR_LEN("Transfer-Encoding: chunked\r\n"));
915 	}
916 
917 	/* request header */
918 	const buffer *connhdr = NULL;
919 	const buffer *te = NULL;
920 	const buffer *upgrade = NULL;
921 	for (size_t i = 0, used = r->rqst_headers.used; i < used; ++i) {
922 		const data_string * const ds = (data_string *)r->rqst_headers.data[i];
923 		switch (ds->ext) {
924 		default:
925 			break;
926 		case HTTP_HEADER_TE:
927 			if (hctx->conf.header.force_http10 || r->http_version == HTTP_VERSION_1_0) continue;
928 			/* ignore if not exactly "trailers" */
929 			if (!buffer_eq_icase_slen(&ds->value, CONST_STR_LEN("trailers"))) continue;
930 			te = &ds->value;
931 			break;
932 		case HTTP_HEADER_HOST:
933 			continue; /*(handled further above)*/
934 		case HTTP_HEADER_UPGRADE:
935 			if (hctx->conf.header.force_http10 || r->http_version == HTTP_VERSION_1_0) continue;
936 			if (!hctx->conf.header.upgrade) continue;
937 			upgrade = &ds->value;
938 			break;
939 		case HTTP_HEADER_CONNECTION:
940 			connhdr = &ds->value;
941 			continue;
942 		case HTTP_HEADER_SET_COOKIE:
943 			continue; /*(response header only; avoid accidental reflection)*/
944 		case HTTP_HEADER_OTHER:
945 			if (buffer_eq_icase_slen(&ds->key, CONST_STR_LEN("Proxy-Connection"))) continue;
946 			/* Do not emit HTTP_PROXY in environment.
947 			 * Some executables use HTTP_PROXY to configure
948 			 * outgoing proxy.  See also https://httpoxy.org/ */
949 			if (buffer_eq_icase_slen(&ds->key, CONST_STR_LEN("Proxy"))) continue;
950 			break;
951 		case HTTP_HEADER_EXPECT:
952 			/* Do not forward Expect: 100-continue
953 			 * since we do not handle "HTTP/1.1 100 Continue" response */
954 			continue;
955 		}
956 
957 		const uint32_t klen = buffer_string_length(&ds->key);
958 		const uint32_t vlen = buffer_string_length(&ds->value);
959 		if (0 == klen || 0 == vlen) continue;
960 
961 		if (buffer_string_space(b) < klen + vlen + 4) {
962 			size_t extend = b->size * 2 - buffer_string_length(b);
963 			extend = extend > klen + vlen + 4 ? extend : klen + vlen + 4 + 4095;
964 			buffer_string_prepare_append(b, extend);
965 		}
966 
967 		buffer_append_string_len(b, ds->key.ptr, klen);
968 		buffer_append_string_len(b, CONST_STR_LEN(": "));
969 		buffer_append_string_len(b, ds->value.ptr, vlen);
970 		buffer_append_string_len(b, CONST_STR_LEN("\r\n"));
971 
972 		if (!remap_headers) continue;
973 
974 		/* check for hdrs for which to remap URIs in-place after append to b */
975 
976 		switch (klen) {
977 		default:
978 			continue;
979 	      #if 0 /* "URI" is HTTP response header (non-standard; historical in Apache) */
980 		case 3:
981 			if (ds->ext == HTTP_HEADER_OTHER && buffer_eq_icase_slen(&ds->key, CONST_STR_LEN("URI"))) break;
982 			continue;
983 	      #endif
984 	      #if 0 /* "Location" is HTTP response header */
985 		case 8:
986 			if (ds->ext == HTTP_HEADER_LOCATION) break;
987 			continue;
988 	      #endif
989 		case 11: /* "Destination" is WebDAV request header */
990 			if (ds->ext == HTTP_HEADER_OTHER && buffer_eq_icase_slen(&ds->key, CONST_STR_LEN("Destination"))) break;
991 			continue;
992 		case 16: /* "Content-Location" may be HTTP request or response header */
993 			if (ds->ext == HTTP_HEADER_CONTENT_LOCATION) break;
994 			continue;
995 		}
996 
997 		http_header_remap_uri(b, buffer_string_length(b) - vlen - 2, &hctx->conf.header, 1);
998 	}
999 
1000 	if (connhdr && !hctx->conf.header.force_http10 && r->http_version >= HTTP_VERSION_1_1
1001 	    && !buffer_eq_icase_slen(connhdr, CONST_STR_LEN("close"))) {
1002 		/* mod_proxy always sends Connection: close to backend */
1003 		buffer_append_string_len(b, CONST_STR_LEN("Connection: close"));
1004 		/* (future: might be pedantic and also check Connection header for each
1005 		 * token using http_header_str_contains_token() */
1006 		if (!buffer_string_is_empty(te))
1007 			buffer_append_string_len(b, CONST_STR_LEN(", te"));
1008 		if (!buffer_string_is_empty(upgrade))
1009 			buffer_append_string_len(b, CONST_STR_LEN(", upgrade"));
1010 		buffer_append_string_len(b, CONST_STR_LEN("\r\n\r\n"));
1011 	}
1012 	else    /* mod_proxy always sends Connection: close to backend */
1013 		buffer_append_string_len(b, CONST_STR_LEN("Connection: close\r\n\r\n"));
1014 
1015 	hctx->gw.wb_reqlen = buffer_string_length(b);
1016 	chunkqueue_prepend_buffer_commit(&hctx->gw.wb);
1017 
1018 	if (r->reqbody_length) {
1019 		if (r->reqbody_length > 0)
1020 			hctx->gw.wb_reqlen += r->reqbody_length; /* total req size */
1021 		else /* as-yet-unknown total request size (Transfer-Encoding: chunked)*/
1022 			hctx->gw.wb_reqlen = -hctx->gw.wb_reqlen;
1023 		if (hctx->gw.stdin_append == proxy_stdin_append)
1024 			proxy_stdin_append(&hctx->gw);
1025 		else
1026 			chunkqueue_append_chunkqueue(&hctx->gw.wb, &r->reqbody_queue);
1027 	}
1028 
1029 	status_counter_inc(CONST_STR_LEN("proxy.requests"));
1030 	return HANDLER_GO_ON;
1031 }
1032 
1033 
1034 static handler_t proxy_create_env_connect(gw_handler_ctx *gwhctx) {
1035 	handler_ctx *hctx = (handler_ctx *)gwhctx;
1036 	request_st * const r = hctx->gw.r;
1037 	r->http_status = 200; /* OK */
1038 	r->resp_body_started = 1;
1039 	gw_set_transparent(&hctx->gw);
1040 	http_response_upgrade_read_body_unknown(r);
1041 
1042 	status_counter_inc(CONST_STR_LEN("proxy.requests"));
1043 	return HANDLER_GO_ON;
1044 }
1045 
1046 
1047 static handler_t proxy_response_headers(request_st * const r, struct http_response_opts_t *opts) {
1048     /* response headers just completed */
1049     handler_ctx *hctx = (handler_ctx *)opts->pdata;
1050 
1051     if (light_btst(r->resp_htags, HTTP_HEADER_UPGRADE)) {
1052         if (hctx->conf.header.upgrade && r->http_status == 101) {
1053             /* 101 Switching Protocols; transition to transparent proxy */
1054             gw_set_transparent(&hctx->gw);
1055             http_response_upgrade_read_body_unknown(r);
1056         }
1057         else {
1058             light_bclr(r->resp_htags, HTTP_HEADER_UPGRADE);
1059           #if 0
1060             /* preserve prior questionable behavior; likely broken behavior
1061              * anyway if backend thinks connection is being upgraded but client
1062              * does not receive Connection: upgrade */
1063             http_header_response_unset(r, HTTP_HEADER_UPGRADE,
1064                                        CONST_STR_LEN("Upgrade"))
1065           #endif
1066         }
1067     }
1068 
1069     /* rewrite paths, if needed */
1070 
1071     if (NULL == hctx->conf.header.urlpaths
1072         && NULL == hctx->conf.header.hosts_response)
1073         return HANDLER_GO_ON;
1074 
1075     if (light_btst(r->resp_htags, HTTP_HEADER_LOCATION)) {
1076         buffer *vb = http_header_response_get(r, HTTP_HEADER_LOCATION, CONST_STR_LEN("Location"));
1077         if (vb) http_header_remap_uri(vb, 0, &hctx->conf.header, 0);
1078     }
1079     if (light_btst(r->resp_htags, HTTP_HEADER_CONTENT_LOCATION)) {
1080         buffer *vb = http_header_response_get(r, HTTP_HEADER_CONTENT_LOCATION, CONST_STR_LEN("Content-Location"));
1081         if (vb) http_header_remap_uri(vb, 0, &hctx->conf.header, 0);
1082     }
1083     if (light_btst(r->resp_htags, HTTP_HEADER_SET_COOKIE)) {
1084         buffer *vb = http_header_response_get(r, HTTP_HEADER_SET_COOKIE, CONST_STR_LEN("Set-Cookie"));
1085         if (vb) http_header_remap_setcookie(vb, 0, &hctx->conf.header);
1086     }
1087 
1088     return HANDLER_GO_ON;
1089 }
1090 
1091 static handler_t mod_proxy_check_extension(request_st * const r, void *p_d) {
1092 	plugin_data *p = p_d;
1093 	handler_t rc;
1094 
1095 	if (NULL != r->handler_module) return HANDLER_GO_ON;
1096 
1097 	mod_proxy_patch_config(r, p);
1098 	if (NULL == p->conf.gw.exts) return HANDLER_GO_ON;
1099 
1100 	rc = gw_check_extension(r, (gw_plugin_data *)p, 1, sizeof(handler_ctx));
1101 	if (HANDLER_GO_ON != rc) return rc;
1102 
1103 	if (r->handler_module == p->self) {
1104 		handler_ctx *hctx = r->plugin_ctx[p->id];
1105 		hctx->gw.create_env = proxy_create_env;
1106 		hctx->gw.response = chunk_buffer_acquire();
1107 		hctx->gw.opts.backend = BACKEND_PROXY;
1108 		hctx->gw.opts.pdata = hctx;
1109 		hctx->gw.opts.headers = proxy_response_headers;
1110 
1111 		hctx->conf = p->conf; /*(copies struct)*/
1112 		hctx->conf.header.http_host = r->http_host;
1113 		hctx->conf.header.upgrade  &= (r->http_version == HTTP_VERSION_1_1);
1114 		/* mod_proxy currently sends all backend requests as http.
1115 		 * https-remap is a flag since it might not be needed if backend
1116 		 * honors Forwarded or X-Forwarded-Proto headers, e.g. by using
1117 		 * lighttpd mod_extforward or similar functionality in backend*/
1118 		if (hctx->conf.header.https_remap) {
1119 			hctx->conf.header.https_remap =
1120 			  buffer_is_equal_string(&r->uri.scheme, CONST_STR_LEN("https"));
1121 		}
1122 
1123 		if (r->http_method == HTTP_METHOD_CONNECT) {
1124 			/*(note: not requiring HTTP/1.1 due to too many non-compliant
1125 			 * clients such as 'openssl s_client')*/
1126 			if (hctx->conf.header.connect_method) {
1127 				hctx->gw.create_env = proxy_create_env_connect;
1128 			}
1129 			else {
1130 				r->http_status = 405; /* Method Not Allowed */
1131 				r->handler_module = NULL;
1132 				return HANDLER_FINISHED;
1133 			}
1134 		}
1135 	}
1136 
1137 	return HANDLER_GO_ON;
1138 }
1139 
1140 
1141 int mod_proxy_plugin_init(plugin *p);
1142 int mod_proxy_plugin_init(plugin *p) {
1143 	p->version      = LIGHTTPD_VERSION_ID;
1144 	p->name         = "proxy";
1145 
1146 	p->init         = mod_proxy_init;
1147 	p->cleanup      = mod_proxy_free;
1148 	p->set_defaults = mod_proxy_set_defaults;
1149 	p->handle_request_reset    = gw_handle_request_reset;
1150 	p->handle_uri_clean        = mod_proxy_check_extension;
1151 	p->handle_subrequest       = gw_handle_subrequest;
1152 	p->handle_trigger          = gw_handle_trigger;
1153 	p->handle_waitpid          = gw_handle_waitpid_cb;
1154 
1155 	return 0;
1156 }
1157