xref: /lighttpd1.4/src/request.c (revision 06df2716)
1 /*
2  * request - HTTP request processing
3  *
4  * Fully-rewritten from original EXCEPT for request_check_hostname()
5  * Copyright(c) 2018 Glenn Strauss gstrauss()gluelogic.com  All rights reserved
6  * License: BSD 3-clause (same as lighttpd)
7  */
8 #include "first.h"
9 
10 #include "request.h"
11 #include "burl.h"
12 #include "http_header.h"
13 #include "http_kv.h"
14 #include "log.h"
15 #include "sock_addr.h"
16 
17 #include <limits.h>
18 #include <stdlib.h>
19 #include <string.h>
20 
21 static int request_check_hostname(buffer * const host) {
22 	enum { DOMAINLABEL, TOPLABEL } stage = TOPLABEL;
23 	size_t i;
24 	int label_len = 0;
25 	size_t host_len, hostport_len;
26 	char *colon;
27 	int is_ip = -1; /* -1 don't know yet, 0 no, 1 yes */
28 	int level = 0;
29 
30 	/*
31 	 *       hostport      = host [ ":" port ]
32 	 *       host          = hostname | IPv4address | IPv6address
33 	 *       hostname      = *( domainlabel "." ) toplabel [ "." ]
34 	 *       domainlabel   = alphanum | alphanum *( alphanum | "-" ) alphanum
35 	 *       toplabel      = alpha | alpha *( alphanum | "-" ) alphanum
36 	 *       IPv4address   = 1*digit "." 1*digit "." 1*digit "." 1*digit
37 	 *       IPv6address   = "[" ... "]"
38 	 *       port          = *digit
39 	 */
40 
41 	/* IPv6 address */
42 	if (host->ptr[0] == '[') {
43 		char *c = host->ptr + 1;
44 		int colon_cnt = 0;
45 
46 		/* check the address inside [...] */
47 		for (; *c && *c != ']'; c++) {
48 			if (*c == ':') {
49 				if (++colon_cnt > 7) {
50 					return -1;
51 				}
52 			} else if (!light_isxdigit(*c) && '.' != *c) {
53 				return -1;
54 			}
55 		}
56 
57 		/* missing ] */
58 		if (!*c) {
59 			return -1;
60 		}
61 
62 		/* check port */
63 		if (*(c+1) == ':') {
64 			for (c += 2; *c; c++) {
65 				if (!light_isdigit(*c)) {
66 					return -1;
67 				}
68 			}
69 		}
70 		else if ('\0' != *(c+1)) {
71 			/* only a port is allowed to follow [...] */
72 			return -1;
73 		}
74 		return 0;
75 	}
76 
77 	hostport_len = host_len = buffer_string_length(host);
78 
79 	if (NULL != (colon = memchr(host->ptr, ':', host_len))) {
80 		char *c = colon + 1;
81 
82 		/* check portnumber */
83 		for (; *c; c++) {
84 			if (!light_isdigit(*c)) return -1;
85 		}
86 
87 		/* remove the port from the host-len */
88 		host_len = colon - host->ptr;
89 	}
90 
91 	/* Host is empty */
92 	if (host_len == 0) return -1;
93 
94 	/* if the hostname ends in a "." strip it */
95 	if (host->ptr[host_len-1] == '.') {
96 		/* shift port info one left */
97 		if (NULL != colon) memmove(colon-1, colon, hostport_len - host_len);
98 		buffer_string_set_length(host, --hostport_len);
99 		if (--host_len == 0) return -1;
100 	}
101 
102 
103 	/* scan from the right and skip the \0 */
104 	for (i = host_len; i-- > 0; ) {
105 		const char c = host->ptr[i];
106 
107 		switch (stage) {
108 		case TOPLABEL:
109 			if (c == '.') {
110 				/* only switch stage, if this is not the last character */
111 				if (i != host_len - 1) {
112 					if (label_len == 0) {
113 						return -1;
114 					}
115 
116 					/* check the first character at right of the dot */
117 					if (is_ip == 0) {
118 						if (!light_isalnum(host->ptr[i+1])) {
119 							return -1;
120 						}
121 					} else if (!light_isdigit(host->ptr[i+1])) {
122 						is_ip = 0;
123 					} else if ('-' == host->ptr[i+1]) {
124 						return -1;
125 					} else {
126 						/* just digits */
127 						is_ip = 1;
128 					}
129 
130 					stage = DOMAINLABEL;
131 
132 					label_len = 0;
133 					level++;
134 				} else if (i == 0) {
135 					/* just a dot and nothing else is evil */
136 					return -1;
137 				}
138 			} else if (i == 0) {
139 				/* the first character of the hostname */
140 				if (!light_isalnum(c)) {
141 					return -1;
142 				}
143 				label_len++;
144 			} else {
145 				if (c != '-' && !light_isalnum(c)) {
146 					return -1;
147 				}
148 				if (is_ip == -1) {
149 					if (!light_isdigit(c)) is_ip = 0;
150 				}
151 				label_len++;
152 			}
153 
154 			break;
155 		case DOMAINLABEL:
156 			if (is_ip == 1) {
157 				if (c == '.') {
158 					if (label_len == 0) {
159 						return -1;
160 					}
161 
162 					label_len = 0;
163 					level++;
164 				} else if (!light_isdigit(c)) {
165 					return -1;
166 				} else {
167 					label_len++;
168 				}
169 			} else {
170 				if (c == '.') {
171 					if (label_len == 0) {
172 						return -1;
173 					}
174 
175 					/* c is either - or alphanum here */
176 					if ('-' == host->ptr[i+1]) {
177 						return -1;
178 					}
179 
180 					label_len = 0;
181 					level++;
182 				} else if (i == 0) {
183 					if (!light_isalnum(c)) {
184 						return -1;
185 					}
186 					label_len++;
187 				} else {
188 					if (c != '-' && !light_isalnum(c)) {
189 						return -1;
190 					}
191 					label_len++;
192 				}
193 			}
194 
195 			break;
196 		}
197 	}
198 
199 	/* a IP has to consist of 4 parts */
200 	if (is_ip == 1 && level != 3) {
201 		return -1;
202 	}
203 
204 	if (label_len == 0) {
205 		return -1;
206 	}
207 
208 	return 0;
209 }
210 
211 int http_request_host_normalize(buffer * const b, const int scheme_port) {
212     /*
213      * check for and canonicalize numeric IP address and portnum (optional)
214      * (IP address may be followed by ":portnum" (optional))
215      * - IPv6: "[...]"
216      * - IPv4: "x.x.x.x"
217      * - IPv4: 12345678   (32-bit decimal number)
218      * - IPv4: 012345678  (32-bit octal number)
219      * - IPv4: 0x12345678 (32-bit hex number)
220      *
221      * allow any chars (except ':' and '\0' and stray '[' or ']')
222      *   (other code may check chars more strictly or more pedantically)
223      * ':'  delimits (optional) port at end of string
224      * "[]" wraps IPv6 address literal
225      * '\0' should have been rejected earlier were it present
226      *
227      * any chars includes, but is not limited to:
228      * - allow '-' any where, even at beginning of word
229      *     (security caution: might be confused for cmd flag if passed to shell)
230      * - allow all-digit TLDs
231      *     (might be mistaken for IPv4 addr by inet_aton()
232      *      unless non-digits appear in subdomain)
233      */
234 
235     /* Note: not using getaddrinfo() since it does not support "[]" around IPv6
236      * and is not as lenient as inet_aton() and inet_addr() for IPv4 strings.
237      * Not using inet_pton() (when available) on IPv4 for similar reasons. */
238 
239     const char * const p = b->ptr;
240     const size_t blen = buffer_string_length(b);
241     long port = 0;
242 
243     if (*p != '[') {
244         char * const colon = (char *)memchr(p, ':', blen);
245         if (colon) {
246             if (*p == ':') return -1; /*(empty host then port, or naked IPv6)*/
247             if (colon[1] != '\0') {
248                 char *e;
249                 port = strtol(colon+1, &e, 0); /*(allow decimal, octal, hex)*/
250                 if (0 < port && port <= USHRT_MAX && *e == '\0') {
251                     /* valid port */
252                 } else {
253                     return -1;
254                 }
255             } /*(else ignore stray colon at string end)*/
256             buffer_string_set_length(b, (size_t)(colon - p)); /*(remove port str)*/
257         }
258 
259         if (light_isdigit(*p)) do {
260             /* (IPv4 address literal or domain starting w/ digit (e.g. 3com))*/
261             /* (check one-element cache of normalized IPv4 address string) */
262             static struct { char s[INET_ADDRSTRLEN]; size_t n; } laddr;
263             size_t n = colon ? (size_t)(colon - p) : blen;
264             sock_addr addr;
265             if (n == laddr.n && 0 == memcmp(p, laddr.s, n)) break;
266             if (1 == sock_addr_inet_pton(&addr, p, AF_INET, 0)) {
267                 sock_addr_inet_ntop_copy_buffer(b, &addr);
268                 n = buffer_string_length(b);
269                 if (n < sizeof(laddr.s)) memcpy(laddr.s, b->ptr, (laddr.n = n));
270             }
271         } while (0);
272     } else do { /* IPv6 addr */
273       #if defined(HAVE_IPV6) && defined(HAVE_INET_PTON)
274 
275         /* (check one-element cache of normalized IPv4 address string) */
276         static struct { char s[INET6_ADDRSTRLEN]; size_t n; } laddr;
277         sock_addr addr;
278         char *bracket = b->ptr+blen-1;
279         char *percent = strchr(b->ptr+1, '%');
280         size_t len;
281         int rc;
282         char buf[INET6_ADDRSTRLEN+16]; /*(+16 for potential %interface name)*/
283         if (blen <= 2) return -1; /*(invalid "[]")*/
284         if (*bracket != ']') {
285             bracket = (char *)memchr(b->ptr+1, ']', blen-1);
286             if (NULL == bracket || bracket[1] != ':'  || bracket - b->ptr == 1){
287                return -1;
288             }
289             if (bracket[2] != '\0') { /*(ignore stray colon at string end)*/
290                 char *e;
291                 port = strtol(bracket+2, &e, 0); /*(allow decimal, octal, hex)*/
292                 if (0 < port && port <= USHRT_MAX && *e == '\0') {
293                     /* valid port */
294                 } else {
295                     return -1;
296                 }
297             }
298         }
299 
300         len = (size_t)((percent ? percent : bracket) - (b->ptr+1));
301         if (laddr.n == len && 0 == memcmp(laddr.s, b->ptr+1, len)) {
302             /* truncate after ']' and re-add normalized port, if needed */
303             buffer_string_set_length(b, (size_t)(bracket - b->ptr + 1));
304             break;
305         }
306 
307         *bracket = '\0';/*(terminate IPv6 string)*/
308         if (percent) *percent = '\0'; /*(remove %interface from address)*/
309         rc = sock_addr_inet_pton(&addr, b->ptr+1, AF_INET6, 0);
310         if (percent) *percent = '%'; /*(restore %interface)*/
311         *bracket = ']'; /*(restore bracket)*/
312         if (1 != rc) return -1;
313 
314         sock_addr_inet_ntop(&addr, buf, sizeof(buf));
315         len = strlen(buf);
316         if (percent) {
317             if (percent > bracket) return -1;
318             if (len + (size_t)(bracket - percent) >= sizeof(buf)) return -1;
319             if (len < sizeof(laddr.s)) memcpy(laddr.s, buf, (laddr.n = len));
320             memcpy(buf+len, percent, (size_t)(bracket - percent));
321             len += (size_t)(bracket - percent);
322         }
323         buffer_string_set_length(b, 1); /* truncate after '[' */
324         buffer_append_string_len(b, buf, len);
325         buffer_append_string_len(b, CONST_STR_LEN("]"));
326 
327       #else
328 
329         return -1;
330 
331       #endif
332     } while (0);
333 
334     if (0 != port && port != scheme_port) {
335         buffer_append_string_len(b, CONST_STR_LEN(":"));
336         buffer_append_int(b, (int)port);
337     }
338 
339     return 0;
340 }
341 
342 int http_request_host_policy (buffer * const b, const unsigned int http_parseopts, const int scheme_port) {
343     return (((http_parseopts & HTTP_PARSEOPT_HOST_STRICT)
344              && 0 != request_check_hostname(b))
345             || ((http_parseopts & HTTP_PARSEOPT_HOST_NORMALIZE)
346                 && 0 != http_request_host_normalize(b, scheme_port)));
347 }
348 
349 __attribute_pure__ /*(could be even more strict and use __attribute_const__)*/
350 static int request_uri_is_valid_char(const unsigned char c) {
351 	return (c > 32 && c != 127 && c != 255);
352 }
353 
354 __attribute_cold__
355 __attribute_noinline__
356 static int http_request_header_line_invalid(request_st * const restrict r, const int status, const char * const restrict msg) {
357     if (r->conf.log_request_header_on_error) {
358         if (msg) log_error(r->conf.errh, __FILE__, __LINE__, "%s", msg);
359     }
360     return status;
361 }
362 
363 __attribute_cold__
364 __attribute_noinline__
365 static int http_request_header_char_invalid(request_st * const restrict r, const char ch, const char * const restrict msg) {
366     if (r->conf.log_request_header_on_error) {
367         if ((unsigned char)ch > 32 && ch != 127) {
368             log_error(r->conf.errh, __FILE__, __LINE__, "%s ('%c')", msg, ch);
369         }
370         else {
371             log_error(r->conf.errh, __FILE__, __LINE__, "%s (0x%x)", msg, ch);
372         }
373     }
374     return 400;
375 }
376 
377 /* add header to list of headers
378  * certain headers are also parsed
379  * might drop a header if deemed unnecessary/broken
380  *
381  * returns 0 on success, HTTP status on error
382  */
383 static int http_request_parse_single_header(request_st * const restrict r, const enum http_header_e id, const char * const restrict k, const size_t klen, const char * const restrict v, const size_t vlen) {
384     buffer **saveb = NULL;
385 
386     /*
387      * Note: k might not be '\0'-terminated
388      * Note: v is not '\0'-terminated, and ends with whitespace
389      *   (one of '\r' '\n' ' ' '\t')
390      */
391 
392     switch (id) {
393       /*case HTTP_HEADER_OTHER:*/
394       default:
395         break;
396       case HTTP_HEADER_HOST:
397         if (!(r->rqst_htags & HTTP_HEADER_HOST)) {
398             saveb = &r->http_host;
399             if (vlen >= 1024) { /*(expecting < 256)*/
400                 return http_request_header_line_invalid(r, 400, "uri-authority too long -> 400");
401             }
402         }
403         else if (NULL != r->http_host
404                  && buffer_is_equal_string(r->http_host, v, vlen)) {
405             /* ignore all Host: headers if match authority in request line */
406             return 0; /* ignore header */
407         }
408         else {
409             return http_request_header_line_invalid(r, 400, "duplicate Host header -> 400");
410         }
411         break;
412       case HTTP_HEADER_CONNECTION:
413         /* "Connection: close" is common case if header is present */
414         if ((vlen == 5 && buffer_eq_icase_ssn(v, CONST_STR_LEN("close")))
415             || http_header_str_contains_token(v,vlen,CONST_STR_LEN("close"))) {
416             r->keep_alive = 0;
417             break;
418         }
419         if (http_header_str_contains_token(v,vlen,CONST_STR_LEN("keep-alive"))){
420             r->keep_alive = 1;
421             break;
422         }
423         break;
424       case HTTP_HEADER_CONTENT_TYPE:
425         if (r->rqst_htags & HTTP_HEADER_CONTENT_TYPE) {
426             return http_request_header_line_invalid(r, 400, "duplicate Content-Type header -> 400");
427         }
428         break;
429       case HTTP_HEADER_IF_NONE_MATCH:
430         /* if dup, only the first one will survive */
431         if (r->rqst_htags & HTTP_HEADER_IF_NONE_MATCH) {
432             return 0; /* ignore header */
433         }
434         break;
435       case HTTP_HEADER_CONTENT_LENGTH:
436         if (!(r->rqst_htags & HTTP_HEADER_CONTENT_LENGTH)) {
437             /*(trailing whitespace was removed from vlen)*/
438             char *err;
439             off_t clen = strtoll(v, &err, 10);
440             if (clen >= 0 && err == v+vlen && light_isdigit(v[0])) {
441                 /* (set only if not set to -1 by Transfer-Encoding: chunked) */
442                 if (0 == r->reqbody_length) r->reqbody_length = clen;
443             }
444             else {
445                 return http_request_header_line_invalid(r, 400, "invalid Content-Length header -> 400");
446             }
447         }
448         else {
449             return http_request_header_line_invalid(r, 400, "duplicate Content-Length header -> 400");
450         }
451         break;
452       case HTTP_HEADER_HTTP2_SETTINGS:
453         if (r->rqst_htags & HTTP_HEADER_HTTP2_SETTINGS) {
454             return http_request_header_line_invalid(r, 400, "duplicate HTTP2-Settings header -> 400");
455         }
456         break;
457       case HTTP_HEADER_IF_MODIFIED_SINCE:
458         if (r->rqst_htags & HTTP_HEADER_IF_MODIFIED_SINCE) {
459             /* Proxies sometimes send dup headers
460              * if they are the same we ignore the second
461              * if not, we raise an error */
462             const buffer *vb =
463               http_header_request_get(r, HTTP_HEADER_IF_MODIFIED_SINCE,
464                                       CONST_STR_LEN("If-Modified-Since"));
465             if (vb && buffer_is_equal_caseless_string(vb, v, vlen)) {
466                 /* ignore it if they are the same */
467                 return 0; /* ignore header */
468             }
469             else {
470                 return http_request_header_line_invalid(r, 400, "duplicate If-Modified-Since header -> 400");
471             }
472         }
473         break;
474       case HTTP_HEADER_TRANSFER_ENCODING:
475         if (HTTP_VERSION_1_1 != r->http_version) {
476             return http_request_header_line_invalid(r, 400,
477               HTTP_VERSION_1_0 == r->http_version
478                 ? "HTTP/1.0 with Transfer-Encoding (bad HTTP/1.0 proxy?) -> 400"
479                 : "HTTP/2 with Transfer-Encoding is invalid -> 400");
480         }
481 
482         if (!buffer_eq_icase_ss(v, vlen, CONST_STR_LEN("chunked"))) {
483             /* Transfer-Encoding might contain additional encodings,
484              * which are not currently supported by lighttpd */
485             return http_request_header_line_invalid(r, 501, NULL); /* Not Implemented */
486         }
487         r->reqbody_length = -1;
488 
489         /* Transfer-Encoding is a hop-by-hop header,
490          * which must not be blindly forwarded to backends */
491         return 0; /* skip header */
492     }
493 
494     http_header_request_append(r, id, k, klen, v, vlen);
495 
496     if (saveb) {
497         *saveb = http_header_request_get(r, id, k, klen);
498     }
499 
500     return 0;
501 }
502 
503 __attribute_cold__
504 static int http_request_parse_proto_loose(request_st * const restrict r, const char * const restrict ptr, const size_t len, const unsigned int http_parseopts) {
505     const char * proto = memchr(ptr, ' ', len);
506     if (NULL == proto)
507         return http_request_header_line_invalid(r, 400, "incomplete request line -> 400");
508     proto = memchr(proto+1, ' ', len - (proto+1 - ptr));
509     if (NULL == proto)
510         return http_request_header_line_invalid(r, 400, "incomplete request line -> 400");
511     ++proto;
512 
513     if (proto[0]=='H' && proto[1]=='T' && proto[2]=='T' && proto[3]=='P' && proto[4] == '/') {
514         if (proto[5] == '1' && proto[6] == '.' && (proto[7] == '1' || proto[7] == '0')) {
515             /* length already checked before calling this routine */
516             /* (len != (size_t)(proto - ptr + 8)) */
517             if (http_parseopts & HTTP_PARSEOPT_HEADER_STRICT) /*(http_header_strict)*/
518                 return http_request_header_line_invalid(r, 400, "incomplete request line -> 400");
519             r->http_version = (proto[7] == '1') ? HTTP_VERSION_1_1 : HTTP_VERSION_1_0;
520         }
521         else
522             return http_request_header_line_invalid(r, 505, "unknown HTTP version -> 505");
523     }
524     else
525         return http_request_header_line_invalid(r, 400, "unknown protocol -> 400");
526 
527     /* keep-alive default: HTTP/1.1 -> true; HTTP/1.0 -> false */
528     r->keep_alive = (HTTP_VERSION_1_0 != r->http_version);
529 
530     return 0;
531 }
532 
533 __attribute_cold__
534 static const char * http_request_parse_reqline_uri(request_st * const restrict r, const char * const restrict uri, const size_t len, const unsigned int http_parseopts) {
535     const char *nuri;
536     if ((len > 7 && buffer_eq_icase_ssn(uri, "http://", 7)
537         && NULL != (nuri = memchr(uri + 7, '/', len-7)))
538        ||
539        (len > 8 && buffer_eq_icase_ssn(uri, "https://", 8)
540         && NULL != (nuri = memchr(uri + 8, '/', len-8)))) {
541         const char * const host = uri + (uri[4] == ':' ? 7 : 8);
542         const size_t hostlen = nuri - host;
543         if (0 == hostlen || hostlen >= 1024) { /*(expecting < 256)*/
544             http_request_header_line_invalid(r, 400, "uri-authority empty or too long -> 400");
545             return NULL;
546         }
547         /* Insert as host header */
548         http_header_request_set(r, HTTP_HEADER_HOST, CONST_STR_LEN("Host"), host, hostlen);
549         r->http_host = http_header_request_get(r, HTTP_HEADER_HOST, CONST_STR_LEN("Host"));
550         return nuri;
551     } else if (!(http_parseopts & HTTP_PARSEOPT_HEADER_STRICT) /*(!http_header_strict)*/
552            || (HTTP_METHOD_CONNECT == r->http_method && (uri[0] == ':' || light_isdigit(uri[0])))
553            || (HTTP_METHOD_OPTIONS == r->http_method && uri[0] == '*' && 1 == len)) {
554         /* (permitted) */
555         return uri;
556     } else {
557         http_request_header_line_invalid(r, 400, "request-URI parse error -> 400");
558         return NULL;
559     }
560 }
561 
562 
563 __attribute_cold__
564 __attribute_noinline__
565 static int http_request_parse_header_other(request_st * const restrict r, const char * const restrict k, const int klen, const unsigned int http_header_strict);
566 
567 
568 int
569 http_request_validate_pseudohdrs (request_st * const restrict r, const int scheme, const unsigned int http_parseopts)
570 {
571     /* :method is required to indicate method
572      * CONNECT method must have :method and :authority
573      * All other methods must have at least :method :scheme :path */
574 
575     if (HTTP_METHOD_UNSET == r->http_method)
576         return http_request_header_line_invalid(r, 400,
577           "missing pseudo-header method -> 400");
578 
579     if (HTTP_METHOD_CONNECT != r->http_method) {
580         if (!scheme)
581             return http_request_header_line_invalid(r, 400,
582               "missing pseudo-header scheme -> 400");
583 
584         if (buffer_string_is_empty(&r->target))
585             return http_request_header_line_invalid(r, 400,
586               "missing pseudo-header path -> 400");
587 
588         const char * const uri = r->target.ptr;
589         if (*uri != '/') { /* (common case: (*uri == '/')) */
590             if (uri[0] != '*' || uri[1] != '\0'
591                 || HTTP_METHOD_OPTIONS != r->http_method)
592                 return http_request_header_line_invalid(r, 400,
593                   "invalid pseudo-header path -> 400");
594         }
595     }
596     else { /* HTTP_METHOD_CONNECT */
597         if (NULL == r->http_host)
598             return http_request_header_line_invalid(r, 400,
599               "missing pseudo-header authority -> 400");
600         if (!buffer_string_is_empty(&r->target) || scheme)
601             return http_request_header_line_invalid(r, 400,
602               "invalid pseudo-header with CONNECT -> 400");
603         /*(reuse uri and ulen to assign to r->target)*/
604         buffer_copy_buffer(&r->target, r->http_host);
605     }
606     buffer_copy_buffer(&r->target_orig, &r->target);
607 
608     /* r->http_host, if set, is checked with http_request_host_policy()
609      * in http_request_parse() */
610 
611     /* copied and modified from end of http_request_parse_reqline() */
612 
613     /* check uri for invalid characters */
614     const unsigned int http_header_strict =
615       (http_parseopts & HTTP_PARSEOPT_HEADER_STRICT);
616     if (http_header_strict
617         && (http_parseopts & HTTP_PARSEOPT_URL_NORMALIZE_CTRLS_REJECT))
618         return 0; /* URI will be checked in http_request_parse_target() */
619 
620     const uint32_t ulen = buffer_string_length(&r->target);
621     const uint8_t * const uri = (uint8_t *)r->target.ptr;
622     if (http_header_strict) {
623         for (uint32_t i = 0; i < ulen; ++i) {
624             if (!request_uri_is_valid_char(uri[i]))
625                 return http_request_header_char_invalid(r, uri[i],
626                   "invalid character in URI -> 400");
627         }
628     }
629     else {
630         if (NULL != memchr(uri, '\0', ulen))
631             return http_request_header_char_invalid(r, '\0',
632               "invalid character in header -> 400");
633     }
634 
635     return 0;
636 }
637 
638 
639 int
640 http_request_parse_header (request_st * const restrict r, http_header_parse_ctx * const restrict hpctx)
641 {
642     const char * const restrict k = hpctx->k;
643     const char * const restrict v = hpctx->v;
644     const uint32_t klen = hpctx->klen;
645     const uint32_t vlen = hpctx->vlen;
646 
647     if (0 == klen)
648         return http_request_header_line_invalid(r, 400,
649           "invalid header key -> 400");
650     if (0 == vlen)
651         return http_request_header_line_invalid(r, 400,
652           "invalid header value -> 400");
653 
654     if ((hpctx->hlen += klen + vlen + 4) > hpctx->max_request_field_size) {
655         /*(configurable with server.max-request-field-size; default 8k)*/
656       #if 1 /* emit to error log for people sending large headers */
657         log_error(r->conf.errh, __FILE__, __LINE__,
658                   "oversized request header -> 431");
659         return 431; /* Request Header Fields Too Large */
660       #else
661         /* 431 Request Header Fields Too Large */
662         return http_request_header_line_invalid(r, 431,
663           "oversized request header -> 431");
664       #endif
665     }
666 
667     if (2 == klen && k[0] == 't' && k[1] == 'e'
668         && !buffer_eq_icase_ss(v, vlen, CONST_STR_LEN("trailers")))
669         return http_request_header_line_invalid(r, 400,
670           "invalid TE header value with HTTP/2 -> 400");
671 
672     if (!hpctx->trailers) {
673         if (*k == ':') {
674             /* HTTP/2 request pseudo-header fields */
675             if (!hpctx->pseudo) /*(pseudo header after non-pseudo header)*/
676                 return http_request_header_line_invalid(r, 400,
677                   "invalid pseudo-header -> 400");
678             switch (klen-1) {
679               case 4:
680                 if (0 == memcmp(k+1, "path", 4)) {
681                     if (!buffer_string_is_empty(&r->target))
682                         return http_request_header_line_invalid(r, 400,
683                           "repeated pseudo-header -> 400");
684                     buffer_copy_string_len(&r->target, v, vlen);
685                     return 0;
686                 }
687                 break;
688               case 6:
689                 if (0 == memcmp(k+1, "method", 6)) {
690                     if (HTTP_METHOD_UNSET != r->http_method)
691                         return http_request_header_line_invalid(r, 400,
692                           "repeated pseudo-header -> 400");
693                     r->http_method = get_http_method_key(v, vlen);
694                     if (HTTP_METHOD_UNSET >= r->http_method)
695                         return http_request_header_line_invalid(r, 501,
696                           "unknown http-method -> 501");
697                     return 0;
698                 }
699                 else if (0 == memcmp(k+1, "scheme", 6)) {
700                     if (hpctx->scheme)
701                         return http_request_header_line_invalid(r, 400,
702                           "repeated pseudo-header -> 400");
703                     switch (vlen) {/*(validated, but then ignored)*/
704                       case 5: /* "https" */
705                         if (v[4]!='s') break;
706                         __attribute_fallthrough__
707                       case 4: /* "http" */
708                         if (v[0]=='h' && v[1]=='t' && v[2]=='t' && v[3]=='p') {
709                             hpctx->scheme = 1;
710                             return 0;
711                         }
712                         break;
713                       default:
714                         break;
715                     }
716                     return http_request_header_line_invalid(r, 400,
717                       "unknown pseudo-header scheme -> 400");
718                 }
719                 break;
720               case 9:
721                 if (0 == memcmp(k+1, "authority", 9)) {
722                     if (r->http_host)
723                         return http_request_header_line_invalid(r, 400,
724                           "repeated pseudo-header -> 400");
725                     if (vlen >= 1024) /*(expecting < 256)*/
726                         return http_request_header_line_invalid(r, 400,
727                           "invalid pseudo-header authority too long -> 400");
728                     /* insert as host header */
729                     http_header_request_set(r, HTTP_HEADER_HOST,
730                                             CONST_STR_LEN("host"), v, vlen);
731                     r->http_host =
732                       http_header_request_get(r, HTTP_HEADER_HOST,
733                                               CONST_STR_LEN("Host"));
734                     return 0;
735                 }
736                 break;
737               default:
738                 break;
739             }
740             return http_request_header_line_invalid(r, 400,
741               "invalid pseudo-header -> 400");
742         }
743         else { /*(non-pseudo headers)*/
744             if (hpctx->pseudo) { /*(transition to non-pseudo headers)*/
745                 hpctx->pseudo = 0;
746                 int status =
747                   http_request_validate_pseudohdrs(r, hpctx->scheme,
748                                                    hpctx->http_parseopts);
749                 if (0 != status) return status;
750             }
751 
752             const unsigned int http_header_strict =
753               (hpctx->http_parseopts & HTTP_PARSEOPT_HEADER_STRICT);
754 
755             for (uint32_t j = 0; j < klen; ++j) {
756                 if ((k[j] >= 'a' && k[j] <= 'z') || k[j] == '-')
757                     continue; /*(common cases)*/
758                 if (k[j] >= 'A' && k[j] <= 'Z')
759                     return 400;
760                 if (0 != http_request_parse_header_other(r, k+j, klen-j,
761                                                          http_header_strict))
762                     return 400;
763                 break;
764             }
765 
766             if (http_header_strict) {
767                 for (uint32_t j = 0; j < vlen; ++j) {
768                     if ((((uint8_t *)v)[j] < 32 && v[j] != '\t') || v[j]==127)
769                         return http_request_header_char_invalid(r, v[j],
770                           "invalid character in header -> 400");
771                 }
772             }
773             else {
774                 if (NULL != memchr(v, '\0', vlen))
775                     return http_request_header_char_invalid(r, '\0',
776                       "invalid character in header -> 400");
777             }
778 
779             const enum http_header_e id = http_header_hkey_get(k, klen);
780             return http_request_parse_single_header(r, id, k, klen, v, vlen);
781         }
782     }
783     else { /*(trailers)*/
784         /* ignore trailers (after required HPACK decoding) if streaming
785          * request body to backend since headers have already been sent
786          * to backend via Common Gateway Interface (CGI) (CGI, FastCGI,
787          * SCGI, etc) or HTTP/1.1 (proxy) (mod_proxy does not currently
788          * support using HTTP/2 to connect to backends) */
789       #if 0 /* (if needed, save flag in hpctx instead of fdevent.h dependency)*/
790         if (r->conf.stream_request_body & FDEVENT_STREAM_REQUEST)
791             return 0;
792       #endif
793         /* Note: do not unconditionally merge into headers since if
794          * headers had already been sent to backend, then mod_accesslog
795          * logging of request headers might be inaccurate.
796          * Many simple backends do not support HTTP/1.1 requests sending
797          * Transfer-Encoding: chunked, and even those that do might not
798          * handle trailers.  Some backends do not even support HTTP/1.1.
799          * For all these reasons, ignore trailers if streaming request
800          * body to backend.  Revisit in future if adding support for
801          * connecting to backends using HTTP/2 (with explicit config
802          * option to force connecting to backends using HTTP/2) */
803 
804         /* XXX: TODO: request trailers not handled if streaming reqbody
805          * XXX: must ensure that trailers are not disallowed field-names
806          */
807 
808         return 0;
809     }
810 }
811 
812 
813 static int http_request_parse_reqline(request_st * const restrict r, const char * const restrict ptr, const unsigned short * const restrict hoff, const unsigned int http_parseopts) {
814     size_t len = hoff[2];
815 
816     /* parse the first line of the request
817      * <method> <uri> <protocol>\r\n
818      * */
819     if (len < 13) /* minimum len with (!http_header_strict): "x x HTTP/1.0\n" */
820         return http_request_header_line_invalid(r, 400, "invalid request line (too short) -> 400");
821     if (ptr[len-2] == '\r')
822         len-=2;
823     else if (!(http_parseopts & HTTP_PARSEOPT_HEADER_STRICT)) /*(!http_header_strict)*/
824         len-=1;
825     else
826         return http_request_header_line_invalid(r, 400, "missing CR before LF in header -> 400");
827 
828     /*
829      * RFC7230:
830      *   HTTP-version  = HTTP-name "/" DIGIT "." DIGIT
831      *   HTTP-name     = %x48.54.54.50 ; "HTTP", case-sensitive
832      */
833 
834     /* protocol is expected to be " HTTP/1.1" or " HTTP/1.0" at end of line */
835     union proto_un {
836       char c[8];
837       uint64_t u;
838     };
839     static const union proto_un http_1_1 = {{'H','T','T','P','/','1','.','1'}};
840     static const union proto_un http_1_0 = {{'H','T','T','P','/','1','.','0'}};
841     const char *p = ptr + len - 8;
842     union proto_un proto8;
843     proto8.c[0]=p[0]; proto8.c[1]=p[1]; proto8.c[2]=p[2]; proto8.c[3]=p[3];
844     proto8.c[4]=p[4]; proto8.c[5]=p[5]; proto8.c[6]=p[6]; proto8.c[7]=p[7];
845     if (p[-1] == ' ' && http_1_1.u == proto8.u) {
846         r->http_version = HTTP_VERSION_1_1;
847         r->keep_alive = 1; /* keep-alive default: HTTP/1.1 -> true */
848     }
849     else if (p[-1] == ' ' && http_1_0.u == proto8.u) {
850         r->http_version = HTTP_VERSION_1_0;
851         r->keep_alive = 0; /* keep-alive default: HTTP/1.0 -> false */
852     }
853     else {
854         int status = http_request_parse_proto_loose(r,ptr,len,http_parseopts);
855         if (0 != status) return status;
856         /*(space char must exist if http_request_parse_proto_loose() succeeds)*/
857         for (p = ptr + len - 9; p[-1] != ' '; --p) ;
858     }
859 
860     /* method is expected to be a short string in the general case */
861     size_t i = 0;
862     while (ptr[i] != ' ') ++i;
863   #if 0 /*(space must exist if protocol was parsed successfully)*/
864     while (i < len && ptr[i] != ' ') ++i;
865     if (ptr[i] != ' ')
866         return http_request_header_line_invalid(r, 400, "incomplete request line -> 400");
867   #endif
868 
869     r->http_method = get_http_method_key(ptr, i);
870     if (HTTP_METHOD_UNSET >= r->http_method)
871         return http_request_header_line_invalid(r, 501, "unknown http-method -> 501");
872 
873     const char *uri = ptr + i + 1;
874 
875     if (uri == p)
876         return http_request_header_line_invalid(r, 400, "no uri specified -> 400");
877     len = (size_t)(p - uri - 1);
878 
879     if (*uri != '/') { /* (common case: (*uri == '/')) */
880         uri = http_request_parse_reqline_uri(r, uri, len, http_parseopts);
881         if (NULL == uri) return 400;
882         len = (size_t)(p - uri - 1);
883     }
884 
885     if (0 == len)
886         return http_request_header_line_invalid(r, 400, "no uri specified -> 400");
887 
888     /* check uri for invalid characters */
889     if (http_parseopts & HTTP_PARSEOPT_HEADER_STRICT) { /* http_header_strict */
890         if ((http_parseopts & HTTP_PARSEOPT_URL_NORMALIZE_CTRLS_REJECT)) {
891             /* URI will be checked in http_request_parse_target() */
892         }
893         else {
894             for (i = 0; i < len; ++i) {
895                 if (!request_uri_is_valid_char(uri[i]))
896                     return http_request_header_char_invalid(r, uri[i], "invalid character in URI -> 400");
897             }
898         }
899     }
900     else {
901         /* check entire set of request headers for '\0' */
902         if (NULL != memchr(ptr, '\0', hoff[hoff[0]]))
903             return http_request_header_char_invalid(r, '\0', "invalid character in header -> 400");
904     }
905 
906     buffer_copy_string_len(&r->target, uri, len);
907     buffer_copy_string_len(&r->target_orig, uri, len);
908     return 0;
909 }
910 
911 int http_request_parse_target(request_st * const r, int scheme_port) {
912     /* URI is parsed into components at start of request and may
913      * also be re-parsed upon HANDLER_COMEBACK during the request
914      * r->target is expected to be a "/url-part?query-part"
915      *   (and *not* a fully-qualified URI starting https://...)
916      * r->uri.authority is expected to be parsed elsewhere into r->http_host
917      */
918 
919     /**
920      * prepare strings
921      *
922      * - uri.path
923      * - uri.query
924      *
925      */
926 
927     /**
928      * Name according to RFC 2396
929      *
930      * - scheme
931      * - authority
932      * - path
933      * - query
934      *
935      * (scheme)://(authority)(path)?(query)#fragment
936      *
937      */
938 
939     /* take initial scheme value from connection-level state
940      * (request r->uri.scheme can be overwritten for later,
941      *  for example by mod_extforward or mod_magnet) */
942     if (scheme_port == 443)
943         buffer_copy_string_len(&r->uri.scheme, CONST_STR_LEN("https"));
944     else
945         buffer_copy_string_len(&r->uri.scheme, CONST_STR_LEN("http"));
946 
947     buffer * const target = &r->target;
948     if (r->http_method == HTTP_METHOD_CONNECT
949         || (r->http_method == HTTP_METHOD_OPTIONS
950             && target->ptr[0] == '*'
951             && target->ptr[1] == '\0')) {
952         /* CONNECT ... (or) OPTIONS * ... */
953         buffer_copy_buffer(&r->uri.path, target);
954         buffer_clear(&r->uri.query);
955         return 0;
956     }
957 
958     char *qstr;
959     if (r->conf.http_parseopts & HTTP_PARSEOPT_URL_NORMALIZE) {
960         /*uint32_t len = (uint32_t)buffer_string_length(target);*/
961         int qs = burl_normalize(target, r->tmp_buf, r->conf.http_parseopts);
962         if (-2 == qs) {
963             log_error(r->conf.errh, __FILE__, __LINE__,
964               "invalid character in URI -> 400 %s",
965               target->ptr);
966             return 400; /* Bad Request */
967         }
968         qstr = (-1 == qs) ? NULL : target->ptr+qs;
969       #if 0  /* future: might enable here, or below for all requests */
970         /* (Note: total header size not recalculated on HANDLER_COMEBACK
971          *  even if other request headers changed during processing)
972          * (If (0 != r->loops_per_request), then the generated
973          *  request is too large.  Should a different error be returned?) */
974         r->rqst_header_len -= len;
975         len = buffer_string_length(target);
976         r->rqst_header_len += len;
977         if (len > MAX_HTTP_REQUEST_URI) {
978             return 414; /* 414 Request-URI Too Long */
979         }
980         if (r->rqst_header_len > MAX_HTTP_REQUEST_HEADER) {
981             log_error(r->conf.errh, __FILE__, __LINE__,
982               "request header fields too large: %u -> 431",
983               r->rqst_header_len);
984             return 431; /* Request Header Fields Too Large */
985         }
986       #endif
987     }
988     else {
989         size_t rlen = buffer_string_length(target);
990         qstr = memchr(target->ptr, '#', rlen);/* discard fragment */
991         if (qstr) {
992             rlen = (size_t)(qstr - target->ptr);
993             buffer_string_set_length(target, rlen);
994         }
995         qstr = memchr(target->ptr, '?', rlen);
996     }
997 
998     /** extract query string from target */
999     const char * const pstr = target->ptr;
1000     const uint32_t rlen = buffer_string_length(target);
1001     uint32_t plen;
1002     if (NULL != qstr) {
1003         plen = (uint32_t)(qstr - pstr);
1004         buffer_copy_string_len(&r->uri.query, qstr + 1, rlen - plen - 1);
1005     }
1006     else {
1007         plen = rlen;
1008         buffer_clear(&r->uri.query);
1009     }
1010     buffer_copy_string_len(&r->uri.path, pstr, plen);
1011 
1012     /* decode url to path
1013      *
1014      * - decode url-encodings  (e.g. %20 -> ' ')
1015      * - remove path-modifiers (e.g. /../)
1016      */
1017 
1018     buffer_urldecode_path(&r->uri.path);
1019     buffer_path_simplify(&r->uri.path, &r->uri.path);
1020     if (r->uri.path.ptr[0] != '/') {
1021         log_error(r->conf.errh, __FILE__, __LINE__,
1022           "uri-path does not begin with '/': %s -> 400", r->uri.path.ptr);
1023         return 400; /* Bad Request */
1024     }
1025 
1026     return 0;
1027 }
1028 
1029 __attribute_cold__
1030 __attribute_noinline__
1031 static int http_request_parse_header_other(request_st * const restrict r, const char * const restrict k, const int klen, const unsigned int http_header_strict) {
1032     for (int i = 0; i < klen; ++i) {
1033         if (light_isalpha(k[i]) || k[i] == '-') continue; /*(common cases)*/
1034         /**
1035          * 1*<any CHAR except CTLs or separators>
1036          * CTLs == 0-31 + 127, CHAR = 7-bit ascii (0..127)
1037          *
1038          */
1039         switch(k[i]) {
1040         case ' ':
1041         case '\t':
1042             return http_request_header_line_invalid(r, 400, "WS character in key -> 400");
1043         case '(':
1044         case ')':
1045         case '<':
1046         case '>':
1047         case '@':
1048         case ',':
1049         case ';':
1050         case '\\':
1051         case '\"':
1052         case '/':
1053         case '[':
1054         case ']':
1055         case '?':
1056         case '=':
1057         case '{':
1058         case '}':
1059             return http_request_header_char_invalid(r, k[i], "invalid character in header key -> 400");
1060         default:
1061             if (http_header_strict ? (k[i] < 32 || ((unsigned char *)k)[i] >= 127) : k[i] == '\0')
1062                 return http_request_header_char_invalid(r, k[i], "invalid character in header key -> 400");
1063             break; /* ok */
1064         }
1065     }
1066     return 0;
1067 }
1068 
1069 static int http_request_parse_headers(request_st * const restrict r, char * const restrict ptr, const unsigned short * const restrict hoff, const unsigned int http_parseopts) {
1070     const unsigned int http_header_strict = (http_parseopts & HTTP_PARSEOPT_HEADER_STRICT);
1071 
1072   #if 0 /*(not checked here; will later result in invalid label for HTTP header)*/
1073     int i = hoff[2];
1074 
1075     if (ptr[i] == ' ' || ptr[i] == '\t') {
1076         return http_request_header_line_invalid(r, 400, "WS at the start of first line -> 400");
1077     }
1078   #endif
1079 
1080     for (int i = 2; i < hoff[0]; ++i) {
1081         const char *k = ptr + hoff[i];
1082         /* one past last line hoff[hoff[0]] is to final "\r\n" */
1083         char *end = ptr + hoff[i+1];
1084 
1085         const char *colon = memchr(k, ':', end - k);
1086         if (NULL == colon)
1087             return http_request_header_line_invalid(r, 400, "invalid header missing ':' -> 400");
1088 
1089         const char *v = colon + 1;
1090 
1091         /* RFC7230 Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing
1092          * 3.2.4.  Field Parsing
1093          * [...]
1094          * No whitespace is allowed between the header field-name and colon.  In
1095          * the past, differences in the handling of such whitespace have led to
1096          * security vulnerabilities in request routing and response handling.  A
1097          * server MUST reject any received request message that contains
1098          * whitespace between a header field-name and colon with a response code
1099          * of 400 (Bad Request).  A proxy MUST remove any such whitespace from a
1100          * response message before forwarding the message downstream.
1101          */
1102         /* (line k[-1] is always preceded by a '\n',
1103          *  including first header after request-line,
1104          *  so no need to check colon != k) */
1105         if (colon[-1] == ' ' || colon[-1] == '\t') {
1106             if (http_header_strict) {
1107                 return http_request_header_line_invalid(r, 400, "invalid whitespace between field-name and colon -> 400");
1108             }
1109             else {
1110                 /* remove trailing whitespace from key(if !http_header_strict)*/
1111                 do { --colon; } while (colon[-1] == ' ' || colon[-1] == '\t');
1112             }
1113         }
1114 
1115         const int klen = (int)(colon - k);
1116         if (0 == klen)
1117             return http_request_header_line_invalid(r, 400, "invalid header key -> 400");
1118         const enum http_header_e id = http_header_hkey_get(k, klen);
1119 
1120         if (id == HTTP_HEADER_OTHER) {
1121             for (int j = 0; j < klen; ++j) {
1122                 if (light_isalpha(k[j]) || k[j] == '-') continue; /*(common cases)*/
1123                 if (0 != http_request_parse_header_other(r, k+j, klen-j, http_header_strict))
1124                     return 400;
1125                 break;
1126             }
1127         }
1128 
1129         /* remove leading whitespace from value */
1130         while (*v == ' ' || *v == '\t') ++v;
1131 
1132         for (; i+1 <= hoff[0]; ++i) {
1133             end = ptr + hoff[i+1];
1134             if (end[0] != ' ' && end[0] != '\t') break;
1135 
1136             /* line folding */
1137           #ifdef __COVERITY__
1138             force_assert(end - k >= 2);
1139           #endif
1140             if (end[-2] == '\r')
1141                 end[-2] = ' ';
1142             else if (http_header_strict)
1143                 return http_request_header_line_invalid(r, 400, "missing CR before LF in header -> 400");
1144             end[-1] = ' ';
1145         }
1146       #ifdef __COVERITY__
1147         /*(buf holding k has non-zero request-line, so end[-2] valid)*/
1148         force_assert(end >= k + 2);
1149       #endif
1150         if (end[-2] == '\r')
1151             --end;
1152         else if (http_header_strict)
1153             return http_request_header_line_invalid(r, 400, "missing CR before LF in header -> 400");
1154         /* remove trailing whitespace from value (+ remove '\r\n') */
1155         /* (line k[-1] is always preceded by a '\n',
1156          *  including first header after request-line,
1157          *  so no need to check (end != k)) */
1158         do { --end; } while (end[-1] == ' ' || end[-1] == '\t');
1159 
1160         const int vlen = (int)(end - v);
1161         /* empty header-fields are not allowed by HTTP-RFC, we just ignore them */
1162         if (vlen <= 0) continue; /* ignore header */
1163 
1164         if (http_header_strict) {
1165             for (int j = 0; j < vlen; ++j) {
1166                 if ((((unsigned char *)v)[j] < 32 && v[j] != '\t') || v[j]==127)
1167                     return http_request_header_char_invalid(r, v[j], "invalid character in header -> 400");
1168             }
1169         } /* else URI already checked in http_request_parse_reqline() for any '\0' */
1170 
1171         int status = http_request_parse_single_header(r, id, k, (size_t)klen, v, (size_t)vlen);
1172         if (0 != status) return status;
1173     }
1174 
1175     return 0;
1176 }
1177 
1178 
1179 static int
1180 http_request_parse (request_st * const restrict r, const int scheme_port)
1181 {
1182     int status = http_request_parse_target(r, scheme_port);
1183     if (0 != status) return status;
1184 
1185     /*(r->http_host might not be set until after parsing request headers)*/
1186     buffer_copy_buffer(&r->uri.authority, r->http_host);/*(copy even if empty)*/
1187     buffer_to_lower(&r->uri.authority);
1188 
1189     /* post-processing */
1190     const unsigned int http_parseopts = r->conf.http_parseopts;
1191 
1192     /* check hostname field if it is set */
1193     if (r->http_host) {
1194         if (0 != http_request_host_policy(r->http_host,
1195                                           http_parseopts, scheme_port))
1196             return http_request_header_line_invalid(r, 400, "Invalid Hostname -> 400");
1197     }
1198     else {
1199         if (r->http_version >= HTTP_VERSION_1_1)
1200             return http_request_header_line_invalid(r, 400, "HTTP/1.1 but Host missing -> 400");
1201     }
1202 
1203     if (0 == r->reqbody_length) {
1204         /* POST requires Content-Length (or Transfer-Encoding)
1205          * (-1 == r->reqbody_length when Transfer-Encoding: chunked)*/
1206         if (HTTP_METHOD_POST == r->http_method
1207             && !(r->rqst_htags & HTTP_HEADER_CONTENT_LENGTH)) {
1208             return http_request_header_line_invalid(r, 411, "POST-request, but content-length missing -> 411");
1209         }
1210     }
1211     else {
1212         /* (-1 == r->reqbody_length when Transfer-Encoding: chunked)*/
1213         if (-1 == r->reqbody_length
1214             && (r->rqst_htags & HTTP_HEADER_CONTENT_LENGTH)) {
1215             /* RFC7230 Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing
1216              * 3.3.3.  Message Body Length
1217              * [...]
1218              * If a message is received with both a Transfer-Encoding and a
1219              * Content-Length header field, the Transfer-Encoding overrides the
1220              * Content-Length.  Such a message might indicate an attempt to
1221              * perform request smuggling (Section 9.5) or response splitting
1222              * (Section 9.4) and ought to be handled as an error.  A sender MUST
1223              * remove the received Content-Length field prior to forwarding such
1224              * a message downstream.
1225              */
1226             const unsigned int http_header_strict =
1227               (http_parseopts & HTTP_PARSEOPT_HEADER_STRICT);
1228             if (http_header_strict) {
1229                 return http_request_header_line_invalid(r, 400, "invalid Transfer-Encoding + Content-Length -> 400");
1230             }
1231             else {
1232                 /* ignore Content-Length */
1233                 http_header_request_unset(r, HTTP_HEADER_CONTENT_LENGTH, CONST_STR_LEN("Content-Length"));
1234             }
1235         }
1236         if (http_method_get_or_head(r->http_method)
1237             && !(http_parseopts & HTTP_PARSEOPT_METHOD_GET_BODY)) {
1238             return http_request_header_line_invalid(r, 400, "GET/HEAD with content-length -> 400");
1239         }
1240     }
1241 
1242     return 0;
1243 }
1244 
1245 
1246 static int
1247 http_request_parse_hoff (request_st * const restrict r, char * const restrict hdrs, const unsigned short * const restrict hoff, const int scheme_port)
1248 {
1249     /*
1250      * Request: "^(GET|POST|HEAD|...) ([^ ]+(\\?[^ ]+|)) (HTTP/1\\.[01])$"
1251      * Header : "^([-a-zA-Z]+): (.+)$"
1252      * End    : "^$"
1253      */
1254 
1255     int status;
1256     const unsigned int http_parseopts = r->conf.http_parseopts;
1257 
1258     status = http_request_parse_reqline(r, hdrs, hoff, http_parseopts);
1259     if (0 != status) return status;
1260 
1261     status = http_request_parse_headers(r, hdrs, hoff, http_parseopts);
1262     if (0 != status) return status;
1263 
1264     return http_request_parse(r, scheme_port);
1265 }
1266 
1267 
1268 static void
1269 http_request_headers_fin (request_st * const restrict r)
1270 {
1271     if (0 == r->http_status) {
1272       #if 0
1273         r->conditional_is_valid = (1 << COMP_SERVER_SOCKET)
1274                                 | (1 << COMP_HTTP_SCHEME)
1275                                 | (1 << COMP_HTTP_HOST)
1276                                 | (1 << COMP_HTTP_REMOTE_IP)
1277                                 | (1 << COMP_HTTP_REQUEST_METHOD)
1278                                 | (1 << COMP_HTTP_URL)
1279                                 | (1 << COMP_HTTP_QUERY_STRING)
1280                                 | (1 << COMP_HTTP_REQUEST_HEADER);
1281       #else
1282         /* all config conditions are valid after parsing header
1283          * (set all bits; remove dependency on plugin_config.h) */
1284         r->conditional_is_valid = ~0u;
1285       #endif
1286     }
1287     else {
1288         r->keep_alive = 0;
1289         r->reqbody_length = 0;
1290     }
1291 }
1292 
1293 
1294 void
1295 http_request_headers_process (request_st * const restrict r, char * const restrict hdrs, const unsigned short * const restrict hoff, const int scheme_port)
1296 {
1297     r->http_status = http_request_parse_hoff(r, hdrs, hoff, scheme_port);
1298 
1299     http_request_headers_fin(r);
1300 
1301     if (0 != r->http_status) {
1302         if (r->conf.log_request_header_on_error) {
1303             /*(http_request_parse_headers() modifies hdrs only to
1304              * undo line-wrapping in-place using spaces)*/
1305             log_error(r->conf.errh, __FILE__, __LINE__,
1306               "request-header:\n%.*s", (int)r->rqst_header_len, hdrs);
1307         }
1308     }
1309 }
1310 
1311 
1312 void
1313 http_request_headers_process_h2 (request_st * const restrict r, const int scheme_port)
1314 {
1315     if (0 == r->http_status)
1316         r->http_status = http_request_parse(r, scheme_port);
1317 
1318     if (0 == r->http_status) {
1319         if (r->rqst_htags & HTTP_HEADER_CONNECTION)
1320             r->http_status = http_request_header_line_invalid(r, 400,
1321               "invalid Connection header with HTTP/2 -> 400");
1322     }
1323 
1324     http_request_headers_fin(r);
1325 
1326   #if 0 /* not supported; headers not collected into a single buf for HTTP/2 */
1327     if (0 != r->http_status) {
1328         if (r->conf.log_request_header_on_error) {
1329             log_error(r->conf.errh, __FILE__, __LINE__,
1330               "request-header:\n%.*s", (int)r->rqst_header_len, hdrs);
1331         }
1332     }
1333   #endif
1334 
1335     /* ignore Upgrade if using HTTP/2 */
1336     if (r->rqst_htags & HTTP_HEADER_UPGRADE)
1337         http_header_request_unset(r, HTTP_HEADER_UPGRADE,
1338                                   CONST_STR_LEN("upgrade"));
1339     /* XXX: should filter out other hop-by-hop connection headers, too */
1340 }
1341