1 /*-
2 * Copyright (c) 1998-2004 Dag-Erling Smørgrav
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: stable/10/lib/libfetch/fetch.c 357582 2020-02-05 18:26:50Z emaste $");
31
32 #include <sys/param.h>
33 #include <sys/errno.h>
34
35 #include <ctype.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39
40 #include "fetch.h"
41 #include "common.h"
42
43 auth_t fetchAuthMethod;
44 int fetchLastErrCode;
45 char fetchLastErrString[MAXERRSTRING];
46 int fetchTimeout;
47 int fetchRestartCalls = 1;
48 int fetchDebug;
49
50
51 /*** Local data **************************************************************/
52
53 /*
54 * Error messages for parser errors
55 */
56 #define URL_MALFORMED 1
57 #define URL_BAD_SCHEME 2
58 #define URL_BAD_PORT 3
59 static struct fetcherr url_errlist[] = {
60 { URL_MALFORMED, FETCH_URL, "Malformed URL" },
61 { URL_BAD_SCHEME, FETCH_URL, "Invalid URL scheme" },
62 { URL_BAD_PORT, FETCH_URL, "Invalid server port" },
63 { -1, FETCH_UNKNOWN, "Unknown parser error" }
64 };
65
66
67 /*** Public API **************************************************************/
68
69 /*
70 * Select the appropriate protocol for the URL scheme, and return a
71 * read-only stream connected to the document referenced by the URL.
72 * Also fill out the struct url_stat.
73 */
74 FILE *
fetchXGet(struct url * URL,struct url_stat * us,const char * flags)75 fetchXGet(struct url *URL, struct url_stat *us, const char *flags)
76 {
77
78 if (us != NULL) {
79 us->size = -1;
80 us->atime = us->mtime = 0;
81 }
82 if (strcasecmp(URL->scheme, SCHEME_FILE) == 0)
83 return (fetchXGetFile(URL, us, flags));
84 else if (strcasecmp(URL->scheme, SCHEME_FTP) == 0)
85 return (fetchXGetFTP(URL, us, flags));
86 else if (strcasecmp(URL->scheme, SCHEME_HTTP) == 0)
87 return (fetchXGetHTTP(URL, us, flags));
88 else if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0)
89 return (fetchXGetHTTP(URL, us, flags));
90 url_seterr(URL_BAD_SCHEME);
91 return (NULL);
92 }
93
94 /*
95 * Select the appropriate protocol for the URL scheme, and return a
96 * read-only stream connected to the document referenced by the URL.
97 */
98 FILE *
fetchGet(struct url * URL,const char * flags)99 fetchGet(struct url *URL, const char *flags)
100 {
101 return (fetchXGet(URL, NULL, flags));
102 }
103
104 /*
105 * Select the appropriate protocol for the URL scheme, and return a
106 * write-only stream connected to the document referenced by the URL.
107 */
108 FILE *
fetchPut(struct url * URL,const char * flags)109 fetchPut(struct url *URL, const char *flags)
110 {
111
112 if (strcasecmp(URL->scheme, SCHEME_FILE) == 0)
113 return (fetchPutFile(URL, flags));
114 else if (strcasecmp(URL->scheme, SCHEME_FTP) == 0)
115 return (fetchPutFTP(URL, flags));
116 else if (strcasecmp(URL->scheme, SCHEME_HTTP) == 0)
117 return (fetchPutHTTP(URL, flags));
118 else if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0)
119 return (fetchPutHTTP(URL, flags));
120 url_seterr(URL_BAD_SCHEME);
121 return (NULL);
122 }
123
124 /*
125 * Select the appropriate protocol for the URL scheme, and return the
126 * size of the document referenced by the URL if it exists.
127 */
128 int
fetchStat(struct url * URL,struct url_stat * us,const char * flags)129 fetchStat(struct url *URL, struct url_stat *us, const char *flags)
130 {
131
132 if (us != NULL) {
133 us->size = -1;
134 us->atime = us->mtime = 0;
135 }
136 if (strcasecmp(URL->scheme, SCHEME_FILE) == 0)
137 return (fetchStatFile(URL, us, flags));
138 else if (strcasecmp(URL->scheme, SCHEME_FTP) == 0)
139 return (fetchStatFTP(URL, us, flags));
140 else if (strcasecmp(URL->scheme, SCHEME_HTTP) == 0)
141 return (fetchStatHTTP(URL, us, flags));
142 else if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0)
143 return (fetchStatHTTP(URL, us, flags));
144 url_seterr(URL_BAD_SCHEME);
145 return (-1);
146 }
147
148 /*
149 * Select the appropriate protocol for the URL scheme, and return a
150 * list of files in the directory pointed to by the URL.
151 */
152 struct url_ent *
fetchList(struct url * URL,const char * flags)153 fetchList(struct url *URL, const char *flags)
154 {
155
156 if (strcasecmp(URL->scheme, SCHEME_FILE) == 0)
157 return (fetchListFile(URL, flags));
158 else if (strcasecmp(URL->scheme, SCHEME_FTP) == 0)
159 return (fetchListFTP(URL, flags));
160 else if (strcasecmp(URL->scheme, SCHEME_HTTP) == 0)
161 return (fetchListHTTP(URL, flags));
162 else if (strcasecmp(URL->scheme, SCHEME_HTTPS) == 0)
163 return (fetchListHTTP(URL, flags));
164 url_seterr(URL_BAD_SCHEME);
165 return (NULL);
166 }
167
168 /*
169 * Attempt to parse the given URL; if successful, call fetchXGet().
170 */
171 FILE *
fetchXGetURL(const char * URL,struct url_stat * us,const char * flags)172 fetchXGetURL(const char *URL, struct url_stat *us, const char *flags)
173 {
174 struct url *u;
175 FILE *f;
176
177 if ((u = fetchParseURL(URL)) == NULL)
178 return (NULL);
179
180 f = fetchXGet(u, us, flags);
181
182 fetchFreeURL(u);
183 return (f);
184 }
185
186 /*
187 * Attempt to parse the given URL; if successful, call fetchGet().
188 */
189 FILE *
fetchGetURL(const char * URL,const char * flags)190 fetchGetURL(const char *URL, const char *flags)
191 {
192 return (fetchXGetURL(URL, NULL, flags));
193 }
194
195 /*
196 * Attempt to parse the given URL; if successful, call fetchPut().
197 */
198 FILE *
fetchPutURL(const char * URL,const char * flags)199 fetchPutURL(const char *URL, const char *flags)
200 {
201 struct url *u;
202 FILE *f;
203
204 if ((u = fetchParseURL(URL)) == NULL)
205 return (NULL);
206
207 f = fetchPut(u, flags);
208
209 fetchFreeURL(u);
210 return (f);
211 }
212
213 /*
214 * Attempt to parse the given URL; if successful, call fetchStat().
215 */
216 int
fetchStatURL(const char * URL,struct url_stat * us,const char * flags)217 fetchStatURL(const char *URL, struct url_stat *us, const char *flags)
218 {
219 struct url *u;
220 int s;
221
222 if ((u = fetchParseURL(URL)) == NULL)
223 return (-1);
224
225 s = fetchStat(u, us, flags);
226
227 fetchFreeURL(u);
228 return (s);
229 }
230
231 /*
232 * Attempt to parse the given URL; if successful, call fetchList().
233 */
234 struct url_ent *
fetchListURL(const char * URL,const char * flags)235 fetchListURL(const char *URL, const char *flags)
236 {
237 struct url *u;
238 struct url_ent *ue;
239
240 if ((u = fetchParseURL(URL)) == NULL)
241 return (NULL);
242
243 ue = fetchList(u, flags);
244
245 fetchFreeURL(u);
246 return (ue);
247 }
248
249 /*
250 * Make a URL
251 */
252 struct url *
fetchMakeURL(const char * scheme,const char * host,int port,const char * doc,const char * user,const char * pwd)253 fetchMakeURL(const char *scheme, const char *host, int port, const char *doc,
254 const char *user, const char *pwd)
255 {
256 struct url *u;
257
258 if (!scheme || (!host && !doc)) {
259 url_seterr(URL_MALFORMED);
260 return (NULL);
261 }
262
263 if (port < 0 || port > 65535) {
264 url_seterr(URL_BAD_PORT);
265 return (NULL);
266 }
267
268 /* allocate struct url */
269 if ((u = calloc(1, sizeof(*u))) == NULL) {
270 fetch_syserr();
271 return (NULL);
272 }
273
274 if ((u->doc = strdup(doc ? doc : "/")) == NULL) {
275 fetch_syserr();
276 free(u);
277 return (NULL);
278 }
279
280 #define seturl(x) snprintf(u->x, sizeof(u->x), "%s", x)
281 seturl(scheme);
282 seturl(host);
283 seturl(user);
284 seturl(pwd);
285 #undef seturl
286 u->port = port;
287 u->netrcfd = -2;
288
289 return (u);
290 }
291
292 /*
293 * Return value of the given hex digit.
294 */
295 static int
fetch_hexval(char ch)296 fetch_hexval(char ch)
297 {
298
299 if (ch >= '0' && ch <= '9')
300 return (ch - '0');
301 else if (ch >= 'a' && ch <= 'f')
302 return (ch - 'a' + 10);
303 else if (ch >= 'A' && ch <= 'F')
304 return (ch - 'A' + 10);
305 return (-1);
306 }
307
308 /*
309 * Decode percent-encoded URL component from src into dst, stopping at end
310 * of string, or at @ or : separators. Returns a pointer to the unhandled
311 * part of the input string (null terminator, @, or :). No terminator is
312 * written to dst (it is the caller's responsibility).
313 */
314 static const char *
fetch_pctdecode(char * dst,const char * src,size_t dlen)315 fetch_pctdecode(char *dst, const char *src, size_t dlen)
316 {
317 int d1, d2;
318 char c;
319 const char *s;
320
321 for (s = src; *s != '\0' && *s != '@' && *s != ':'; s++) {
322 if (s[0] == '%' && (d1 = fetch_hexval(s[1])) >= 0 &&
323 (d2 = fetch_hexval(s[2])) >= 0 && (d1 > 0 || d2 > 0)) {
324 c = d1 << 4 | d2;
325 s += 2;
326 } else {
327 c = *s;
328 }
329 if (dlen-- > 0)
330 *dst++ = c;
331 else
332 return (NULL);
333 }
334 return (s);
335 }
336
337 /*
338 * Split an URL into components. URL syntax is:
339 * [method:/][/[user[:pwd]@]host[:port]/][document]
340 * This almost, but not quite, RFC1738 URL syntax.
341 */
342 struct url *
fetchParseURL(const char * URL)343 fetchParseURL(const char *URL)
344 {
345 char *doc;
346 const char *p, *q;
347 struct url *u;
348 int i;
349
350 /* allocate struct url */
351 if ((u = calloc(1, sizeof(*u))) == NULL) {
352 fetch_syserr();
353 return (NULL);
354 }
355 u->netrcfd = -2;
356
357 /* scheme name */
358 if ((p = strstr(URL, ":/"))) {
359 snprintf(u->scheme, URL_SCHEMELEN+1,
360 "%.*s", (int)(p - URL), URL);
361 URL = ++p;
362 /*
363 * Only one slash: no host, leave slash as part of document
364 * Two slashes: host follows, strip slashes
365 */
366 if (URL[1] == '/')
367 URL = (p += 2);
368 } else {
369 p = URL;
370 }
371 if (!*URL || *URL == '/' || *URL == '.' ||
372 (u->scheme[0] == '\0' &&
373 strchr(URL, '/') == NULL && strchr(URL, ':') == NULL))
374 goto nohost;
375
376 p = strpbrk(URL, "/@");
377 if (p && *p == '@') {
378 /* username */
379 q = fetch_pctdecode(u->user, URL, URL_USERLEN);
380 if (q == NULL)
381 goto ouch;
382
383 /* password */
384 if (*q == ':') {
385 q = fetch_pctdecode(u->pwd, q + 1, URL_PWDLEN);
386 if (q == NULL)
387 goto ouch;
388 }
389 p++;
390 } else {
391 p = URL;
392 }
393
394 /* hostname */
395 if (*p == '[' && (q = strchr(p + 1, ']')) != NULL &&
396 (*++q == '\0' || *q == '/' || *q == ':')) {
397 if ((i = q - p) > MAXHOSTNAMELEN)
398 i = MAXHOSTNAMELEN;
399 strncpy(u->host, p, i);
400 p = q;
401 } else {
402 for (i = 0; *p && (*p != '/') && (*p != ':'); p++)
403 if (i < MAXHOSTNAMELEN)
404 u->host[i++] = *p;
405 }
406
407 /* port */
408 if (*p == ':') {
409 for (q = ++p; *q && (*q != '/'); q++)
410 if (isdigit((unsigned char)*q))
411 u->port = u->port * 10 + (*q - '0');
412 else {
413 /* invalid port */
414 url_seterr(URL_BAD_PORT);
415 goto ouch;
416 }
417 p = q;
418 }
419
420 nohost:
421 /* document */
422 if (!*p)
423 p = "/";
424
425 if (strcasecmp(u->scheme, SCHEME_HTTP) == 0 ||
426 strcasecmp(u->scheme, SCHEME_HTTPS) == 0) {
427 const char hexnums[] = "0123456789abcdef";
428
429 /* percent-escape whitespace. */
430 if ((doc = malloc(strlen(p) * 3 + 1)) == NULL) {
431 fetch_syserr();
432 goto ouch;
433 }
434 u->doc = doc;
435 while (*p != '\0') {
436 if (!isspace((unsigned char)*p)) {
437 *doc++ = *p++;
438 } else {
439 *doc++ = '%';
440 *doc++ = hexnums[((unsigned int)*p) >> 4];
441 *doc++ = hexnums[((unsigned int)*p) & 0xf];
442 p++;
443 }
444 }
445 *doc = '\0';
446 } else if ((u->doc = strdup(p)) == NULL) {
447 fetch_syserr();
448 goto ouch;
449 }
450
451 DEBUG(fprintf(stderr,
452 "scheme: \"%s\"\n"
453 "user: \"%s\"\n"
454 "password: \"%s\"\n"
455 "host: \"%s\"\n"
456 "port: \"%d\"\n"
457 "document: \"%s\"\n",
458 u->scheme, u->user, u->pwd,
459 u->host, u->port, u->doc));
460
461 return (u);
462
463 ouch:
464 free(u);
465 return (NULL);
466 }
467
468 /*
469 * Free a URL
470 */
471 void
fetchFreeURL(struct url * u)472 fetchFreeURL(struct url *u)
473 {
474 free(u->doc);
475 free(u);
476 }
477