xref: /plan9/sys/src/cmd/webfs/http.c (revision 499069debb03e99ea217d35fd87fb49e96918a92)
1 #include <u.h>
2 #include <libc.h>
3 #include <bio.h>
4 #include <ip.h>
5 #include <plumb.h>
6 #include <thread.h>
7 #include <fcall.h>
8 #include <9p.h>
9 #include <libsec.h>
10 #include <auth.h>
11 #include "dat.h"
12 #include "fns.h"
13 
14 char PostContentType[] = "application/octet-stream";
15 int httpdebug;
16 
17 typedef struct HttpState HttpState;
18 struct HttpState
19 {
20 	int fd;
21 	Client *c;
22 	char *location;
23 	char *setcookie;
24 	char *netaddr;
25 	char *credentials;
26 	char autherror[ERRMAX];
27 	Ibuf	b;
28 };
29 
30 static void
31 location(HttpState *hs, char *value)
32 {
33 	if(hs->location == nil)
34 		hs->location = estrdup(value);
35 }
36 
37 static void
38 contenttype(HttpState *hs, char *value)
39 {
40 	if(hs->c->contenttype == nil)
41 		hs->c->contenttype = estrdup(value);
42 }
43 
44 static void
45 setcookie(HttpState *hs, char *value)
46 {
47 	char *s, *t;
48 	Fmt f;
49 
50 	s = hs->setcookie;
51 	fmtstrinit(&f);
52 	if(s)
53 		fmtprint(&f, "%s", s);
54 	fmtprint(&f, "set-cookie: ");
55 	fmtprint(&f, "%s", value);
56 	fmtprint(&f, "\n");
57 	t = fmtstrflush(&f);
58 	if(t){
59 		free(s);
60 		hs->setcookie = t;
61 	}
62 }
63 
64 static char*
65 unquote(char *s, char **ps)
66 {
67 	char *p;
68 
69 	if(*s != '"'){
70 		p = strpbrk(s, " \t\r\n");
71 		*p++ = 0;
72 		*ps = p;
73 		return s;
74 	}
75 	for(p=s+1; *p; p++){
76 		if(*p == '\"'){
77 			*p++ = 0;
78 			break;
79 		}
80 		if(*p == '\\' && *(p+1)){
81 			p++;
82 			continue;
83 		}
84 	}
85 	memmove(s, s+1, p-(s+1));
86 	s[p-(s+1)] = 0;
87 	*ps = p;
88 	return s;
89 }
90 
91 static char*
92 servername(char *addr)
93 {
94 	char *p;
95 
96 	if(strncmp(addr, "tcp!", 4) == 0
97 	|| strncmp(addr, "net!", 4) == 0)
98 		addr += 4;
99 	addr = estrdup(addr);
100 	p = addr+strlen(addr);
101 	if(p>addr && *(p-1) == 's')
102 		p--;
103 	if(p>addr+5 && strcmp(p-5, "!http") == 0)
104 		p[-5] = 0;
105 	return addr;
106 }
107 
108 void
109 wwwauthenticate(HttpState *hs, char *line)
110 {
111 	char cred[64], *user, *pass, *realm, *s, *spec, *name;
112 	Fmt fmt;
113 	UserPasswd *up;
114 
115 	spec = nil;
116 	up = nil;
117 	cred[0] = 0;
118 	hs->autherror[0] = 0;
119 	if(cistrncmp(line, "basic ", 6) != 0){
120 		werrstr("unknown auth: %s", line);
121 		goto error;
122 	}
123 	line += 6;
124 	if(cistrncmp(line, "realm=", 6) != 0){
125 		werrstr("missing realm: %s", line);
126 		goto error;
127 	}
128 	line += 6;
129 	user = hs->c->url->user;
130 	pass = hs->c->url->passwd;
131 	if(user==nil || pass==nil){
132 		realm = unquote(line, &line);
133 		fmtstrinit(&fmt);
134 		name = servername(hs->netaddr);
135 		fmtprint(&fmt, "proto=pass service=http server=%q realm=%q", name, realm);
136 		free(name);
137 		if(hs->c->url->user)
138 			fmtprint(&fmt, " user=%q", hs->c->url->user);
139 		spec = fmtstrflush(&fmt);
140 		if(spec == nil)
141 			goto error;
142 		if((up = auth_getuserpasswd(nil, "%s", spec)) == nil)
143 			goto error;
144 		user = up->user;
145 		pass = up->passwd;
146 	}
147 	if((s = smprint("%s:%s", user, pass)) == nil)
148 		goto error;
149 	free(up);
150 	enc64(cred, sizeof(cred), (uchar*)s, strlen(s));
151 	memset(s, 0, strlen(s));
152 	free(s);
153 	hs->credentials = smprint("Basic %s", cred);
154 	if(hs->credentials == nil)
155 		goto error;
156 	return;
157 
158 error:
159 	free(up);
160 	free(spec);
161 	snprint(hs->autherror, sizeof hs->autherror, "%r");
162 }
163 
164 struct {
165 	char *name;									/* Case-insensitive */
166 	void (*fn)(HttpState *hs, char *value);
167 } hdrtab[] = {
168 	{ "location:", location },
169 	{ "content-type:", contenttype },
170 	{ "set-cookie:", setcookie },
171 	{ "www-authenticate:", wwwauthenticate },
172 };
173 
174 static int
175 httprcode(HttpState *hs)
176 {
177 	int n;
178 	char *p;
179 	char buf[256];
180 
181 	n = readline(&hs->b, buf, sizeof(buf)-1);
182 	if(n <= 0)
183 		return n;
184 	if(httpdebug)
185 		fprint(2, "-> %s\n", buf);
186 	p = strchr(buf, ' ');
187 	if(memcmp(buf, "HTTP/", 5) != 0 || p == nil){
188 		werrstr("bad response from server");
189 		return -1;
190 	}
191 	buf[n] = 0;
192 	return atoi(p+1);
193 }
194 
195 /*
196  *  read a single mime header, collect continuations.
197  *
198  *  this routine assumes that there is a blank line twixt
199  *  the header and the message body, otherwise bytes will
200  *  be lost.
201  */
202 static int
203 getheader(HttpState *hs, char *buf, int n)
204 {
205 	char *p, *e;
206 	int i;
207 
208 	n--;
209 	p = buf;
210 	for(e = p + n; ; p += i){
211 		i = readline(&hs->b, p, e-p);
212 		if(i < 0)
213 			return i;
214 
215 		if(p == buf){
216 			/* first line */
217 			if(strchr(buf, ':') == nil)
218 				break;		/* end of headers */
219 		} else {
220 			/* continuation line */
221 			if(*p != ' ' && *p != '\t'){
222 				unreadline(&hs->b, p);
223 				*p = 0;
224 				break;		/* end of this header */
225 			}
226 		}
227 	}
228 
229 	if(httpdebug)
230 		fprint(2, "-> %s\n", buf);
231 	return p-buf;
232 }
233 
234 static int
235 httpheaders(HttpState *hs)
236 {
237 	char buf[2048];
238 	char *p;
239 	int i, n;
240 
241 	for(;;){
242 		n = getheader(hs, buf, sizeof(buf));
243 		if(n < 0)
244 			return -1;
245 		if(n == 0)
246 			return 0;
247 		//	print("http header: '%.*s'\n", n, buf);
248 		for(i = 0; i < nelem(hdrtab); i++){
249 			n = strlen(hdrtab[i].name);
250 			if(cistrncmp(buf, hdrtab[i].name, n) == 0){
251 				/* skip field name and leading white */
252 				p = buf + n;
253 				while(*p == ' ' || *p == '\t')
254 					p++;
255 				(*hdrtab[i].fn)(hs, p);
256 				break;
257 			}
258 		}
259 	}
260 	return 0;
261 }
262 
263 int
264 httpopen(Client *c, Url *url)
265 {
266 	int fd, code, redirect, authenticate;
267 	char *cookies;
268 	Ioproc *io;
269 	HttpState *hs;
270 
271 	if(httpdebug)
272 		fprint(2, "httpopen\n");
273 	io = c->io;
274 	hs = emalloc(sizeof(*hs));
275 	hs->c = c;
276 	hs->netaddr = estrdup(netmkaddr(url->host, 0, url->scheme));
277 	c->aux = hs;
278 	if(httpdebug)
279 		fprint(2, "dial %s\n", hs->netaddr);
280 	fd = iotlsdial(io, hs->netaddr, 0, 0, 0, url->ischeme==UShttps);
281 	if(fd < 0){
282 	Error:
283 		if(httpdebug)
284 			fprint(2, "iodial: %r\n");
285 		free(hs->netaddr);
286 		close(hs->fd);
287 		hs->fd = -1;
288 		free(hs);
289 		c->aux = nil;
290 		return -1;
291 	}
292 	hs->fd = fd;
293 	if(httpdebug)
294 		fprint(2, "<- %s %s HTTP/1.0\n<- Host: %s\n",
295 			c->havepostbody? "POST": " GET", url->http.page_spec, url->host);
296 	ioprint(io, fd, "%s %s HTTP/1.0\r\nHost: %s\r\n",
297 		c->havepostbody? "POST" : "GET", url->http.page_spec, url->host);
298 	if(httpdebug)
299 		fprint(2, "<- User-Agent: %s\n", c->ctl.useragent);
300 	if(c->ctl.useragent)
301 		ioprint(io, fd, "User-Agent: %s\r\n", c->ctl.useragent);
302 	if(c->ctl.sendcookies){
303 		/* should we use url->page here?  sometimes it is nil. */
304 		cookies = httpcookies(url->host, url->http.page_spec, 0);
305 		if(cookies && cookies[0])
306 			ioprint(io, fd, "%s", cookies);
307 		if(httpdebug)
308 			fprint(2, "<- %s", cookies);
309 		free(cookies);
310 	}
311 	if(c->havepostbody){
312 		ioprint(io, fd, "Content-type: %s\r\n", PostContentType);
313 		ioprint(io, fd, "Content-length: %ud\r\n", c->npostbody);
314 		if(httpdebug){
315 			fprint(2, "<- Content-type: %s\n", PostContentType);
316 			fprint(2, "<- Content-length: %ud\n", c->npostbody);
317 		}
318 	}
319 	if(c->authenticate){
320 		ioprint(io, fd, "Authorization: %s\r\n", c->authenticate);
321 		if(httpdebug)
322 			fprint(2, "<- Authorization: %s\n", c->authenticate);
323 	}
324 	ioprint(io, fd, "\r\n");
325 	if(c->havepostbody)
326 		if(iowrite(io, fd, c->postbody, c->npostbody) != c->npostbody)
327 			goto Error;
328 
329 	c->havepostbody = 0;
330 	redirect = 0;
331 	authenticate = 0;
332 	initibuf(&hs->b, io, fd);
333 	code = httprcode(hs);
334 
335 	switch(code){
336 	case -1:	/* connection timed out */
337 		goto Error;
338 
339 /*
340 	case Eof:
341 		werrstr("EOF from HTTP server");
342 		goto Error;
343 */
344 
345 	case 200:	/* OK */
346 	case 201:	/* Created */
347 	case 202:	/* Accepted */
348 	case 204:	/* No Content */
349 #ifdef NOT_DEFINED
350 		if(ofile == nil && r->start != 0)
351 			sysfatal("page changed underfoot");
352 #endif
353 		break;
354 
355 	case 206:	/* Partial Content */
356 		werrstr("Partial Content (206)");
357 		goto Error;
358 
359 	case 301:	/* Moved Permanently */
360 	case 302:	/* Moved Temporarily */
361 		redirect = 1;
362 		break;
363 
364 	case 304:	/* Not Modified */
365 		break;
366 
367 	case 400:	/* Bad Request */
368 		werrstr("Bad Request (400)");
369 		goto Error;
370 
371 	case 401:	/* Unauthorized */
372 		if(c->authenticate){
373 			werrstr("Authentication failed (401)");
374 			goto Error;
375 		}
376 		authenticate = 1;
377 		break;
378 	case 402:	/* ??? */
379 		werrstr("Unauthorized (402)");
380 		goto Error;
381 
382 	case 403:	/* Forbidden */
383 		werrstr("Forbidden by server (403)");
384 		goto Error;
385 
386 	case 404:	/* Not Found */
387 		werrstr("Not found on server (404)");
388 		goto Error;
389 
390 	case 405:	/* Method Not Allowed  */
391 		werrstr("Method not allowed (405)");
392 		goto Error;
393 
394 	case 407:	/* Proxy auth */
395 		werrstr("Proxy authentication required (407)");
396 		goto Error;
397 
398 	case 500:	/* Internal server error */
399 		werrstr("Server choked (500)");
400 		goto Error;
401 
402 	case 501:	/* Not implemented */
403 		werrstr("Server can't do it (501)");
404 		goto Error;
405 
406 	case 502:	/* Bad gateway */
407 		werrstr("Bad gateway (502)");
408 		goto Error;
409 
410 	case 503:	/* Service unavailable */
411 		werrstr("Service unavailable (503)");
412 		goto Error;
413 
414 	default:
415 		/* Bogus: we should treat unknown code XYZ as code X00 */
416 		werrstr("Unknown response code %d", code);
417 		goto Error;
418 	}
419 
420 	if(httpheaders(hs) < 0)
421 		goto Error;
422 	if(c->ctl.acceptcookies && hs->setcookie)
423 		httpsetcookie(hs->setcookie, url->host, url->path);
424 	if(authenticate){
425 		if(!hs->credentials){
426 			if(hs->autherror[0])
427 				werrstr("%s", hs->autherror);
428 			else
429 				werrstr("unauthorized; no www-authenticate: header");
430 			return -1;
431 		}
432 		c->authenticate = hs->credentials;
433 		hs->credentials = nil;
434 	}
435 	if(redirect){
436 		if(!hs->location){
437 			werrstr("redirection without Location: header");
438 			return -1;
439 		}
440 		c->redirect = hs->location;
441 		hs->location = nil;
442 	}
443 	return 0;
444 }
445 
446 int
447 httpread(Client *c, Req *r)
448 {
449 	char *dst;
450 	HttpState *hs;
451 	int n;
452 	long rlen, tot, len;
453 
454 	hs = c->aux;
455 	dst = r->ofcall.data;
456 	len = r->ifcall.count;
457 	tot = 0;
458 	while (tot < len){
459 		rlen = len - tot;
460 		n = readibuf(&hs->b, dst + tot, rlen);
461 		if(n == 0)
462 			break;
463 		else if(n < 0){
464 			if(tot == 0)
465 				return -1;
466 			else
467 				return tot;
468 		}
469 		tot += n;
470 	}
471 	r->ofcall.count = tot;
472 	return 0;
473 }
474 
475 void
476 httpclose(Client *c)
477 {
478 	HttpState *hs;
479 
480 	hs = c->aux;
481 	if(hs == nil)
482 		return;
483 	ioclose(c->io, hs->fd);
484 	hs->fd = -1;
485 	free(hs->location);
486 	free(hs->setcookie);
487 	free(hs->netaddr);
488 	free(hs->credentials);
489 	free(hs);
490 	c->aux = nil;
491 }
492 
493