git-worktree.txt: recommend 'git worktree remove' over manual deletion
[git] / http-walker.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "walker.h"
4 #include "http.h"
5 #include "list.h"
6 #include "transport.h"
7 #include "packfile.h"
8
9 struct alt_base {
10         char *base;
11         int got_indices;
12         struct packed_git *packs;
13         struct alt_base *next;
14 };
15
16 enum object_request_state {
17         WAITING,
18         ABORTED,
19         ACTIVE,
20         COMPLETE
21 };
22
23 struct object_request {
24         struct walker *walker;
25         unsigned char sha1[20];
26         struct alt_base *repo;
27         enum object_request_state state;
28         struct http_object_request *req;
29         struct list_head node;
30 };
31
32 struct alternates_request {
33         struct walker *walker;
34         const char *base;
35         struct strbuf *url;
36         struct strbuf *buffer;
37         struct active_request_slot *slot;
38         int http_specific;
39 };
40
41 struct walker_data {
42         const char *url;
43         int got_alternates;
44         struct alt_base *alt;
45 };
46
47 static LIST_HEAD(object_queue_head);
48
49 static void fetch_alternates(struct walker *walker, const char *base);
50
51 static void process_object_response(void *callback_data);
52
53 static void start_object_request(struct walker *walker,
54                                  struct object_request *obj_req)
55 {
56         struct active_request_slot *slot;
57         struct http_object_request *req;
58
59         req = new_http_object_request(obj_req->repo->base, obj_req->sha1);
60         if (req == NULL) {
61                 obj_req->state = ABORTED;
62                 return;
63         }
64         obj_req->req = req;
65
66         slot = req->slot;
67         slot->callback_func = process_object_response;
68         slot->callback_data = obj_req;
69
70         /* Try to get the request started, abort the request on error */
71         obj_req->state = ACTIVE;
72         if (!start_active_slot(slot)) {
73                 obj_req->state = ABORTED;
74                 release_http_object_request(req);
75                 return;
76         }
77 }
78
79 static void finish_object_request(struct object_request *obj_req)
80 {
81         if (finish_http_object_request(obj_req->req))
82                 return;
83
84         if (obj_req->req->rename == 0)
85                 walker_say(obj_req->walker, "got %s\n", sha1_to_hex(obj_req->sha1));
86 }
87
88 static void process_object_response(void *callback_data)
89 {
90         struct object_request *obj_req =
91                 (struct object_request *)callback_data;
92         struct walker *walker = obj_req->walker;
93         struct walker_data *data = walker->data;
94         struct alt_base *alt = data->alt;
95
96         process_http_object_request(obj_req->req);
97         obj_req->state = COMPLETE;
98
99         /* Use alternates if necessary */
100         if (missing_target(obj_req->req)) {
101                 fetch_alternates(walker, alt->base);
102                 if (obj_req->repo->next != NULL) {
103                         obj_req->repo =
104                                 obj_req->repo->next;
105                         release_http_object_request(obj_req->req);
106                         start_object_request(walker, obj_req);
107                         return;
108                 }
109         }
110
111         finish_object_request(obj_req);
112 }
113
114 static void release_object_request(struct object_request *obj_req)
115 {
116         if (obj_req->req !=NULL && obj_req->req->localfile != -1)
117                 error("fd leakage in release: %d", obj_req->req->localfile);
118
119         list_del(&obj_req->node);
120         free(obj_req);
121 }
122
123 #ifdef USE_CURL_MULTI
124 static int fill_active_slot(struct walker *walker)
125 {
126         struct object_request *obj_req;
127         struct list_head *pos, *tmp, *head = &object_queue_head;
128
129         list_for_each_safe(pos, tmp, head) {
130                 obj_req = list_entry(pos, struct object_request, node);
131                 if (obj_req->state == WAITING) {
132                         if (has_sha1_file(obj_req->sha1))
133                                 obj_req->state = COMPLETE;
134                         else {
135                                 start_object_request(walker, obj_req);
136                                 return 1;
137                         }
138                 }
139         }
140         return 0;
141 }
142 #endif
143
144 static void prefetch(struct walker *walker, unsigned char *sha1)
145 {
146         struct object_request *newreq;
147         struct walker_data *data = walker->data;
148
149         newreq = xmalloc(sizeof(*newreq));
150         newreq->walker = walker;
151         hashcpy(newreq->sha1, sha1);
152         newreq->repo = data->alt;
153         newreq->state = WAITING;
154         newreq->req = NULL;
155
156         http_is_verbose = walker->get_verbosely;
157         list_add_tail(&newreq->node, &object_queue_head);
158
159 #ifdef USE_CURL_MULTI
160         fill_active_slots();
161         step_active_slots();
162 #endif
163 }
164
165 static int is_alternate_allowed(const char *url)
166 {
167         const char *protocols[] = {
168                 "http", "https", "ftp", "ftps"
169         };
170         int i;
171
172         if (http_follow_config != HTTP_FOLLOW_ALWAYS) {
173                 warning("alternate disabled by http.followRedirects: %s", url);
174                 return 0;
175         }
176
177         for (i = 0; i < ARRAY_SIZE(protocols); i++) {
178                 const char *end;
179                 if (skip_prefix(url, protocols[i], &end) &&
180                     starts_with(end, "://"))
181                         break;
182         }
183
184         if (i >= ARRAY_SIZE(protocols)) {
185                 warning("ignoring alternate with unknown protocol: %s", url);
186                 return 0;
187         }
188         if (!is_transport_allowed(protocols[i], 0)) {
189                 warning("ignoring alternate with restricted protocol: %s", url);
190                 return 0;
191         }
192
193         return 1;
194 }
195
196 static void process_alternates_response(void *callback_data)
197 {
198         struct alternates_request *alt_req =
199                 (struct alternates_request *)callback_data;
200         struct walker *walker = alt_req->walker;
201         struct walker_data *cdata = walker->data;
202         struct active_request_slot *slot = alt_req->slot;
203         struct alt_base *tail = cdata->alt;
204         const char *base = alt_req->base;
205         const char null_byte = '\0';
206         char *data;
207         int i = 0;
208
209         if (alt_req->http_specific) {
210                 if (slot->curl_result != CURLE_OK ||
211                     !alt_req->buffer->len) {
212
213                         /* Try reusing the slot to get non-http alternates */
214                         alt_req->http_specific = 0;
215                         strbuf_reset(alt_req->url);
216                         strbuf_addf(alt_req->url, "%s/objects/info/alternates",
217                                     base);
218                         curl_easy_setopt(slot->curl, CURLOPT_URL,
219                                          alt_req->url->buf);
220                         active_requests++;
221                         slot->in_use = 1;
222                         if (slot->finished != NULL)
223                                 (*slot->finished) = 0;
224                         if (!start_active_slot(slot)) {
225                                 cdata->got_alternates = -1;
226                                 slot->in_use = 0;
227                                 if (slot->finished != NULL)
228                                         (*slot->finished) = 1;
229                         }
230                         return;
231                 }
232         } else if (slot->curl_result != CURLE_OK) {
233                 if (!missing_target(slot)) {
234                         cdata->got_alternates = -1;
235                         return;
236                 }
237         }
238
239         fwrite_buffer((char *)&null_byte, 1, 1, alt_req->buffer);
240         alt_req->buffer->len--;
241         data = alt_req->buffer->buf;
242
243         while (i < alt_req->buffer->len) {
244                 int posn = i;
245                 while (posn < alt_req->buffer->len && data[posn] != '\n')
246                         posn++;
247                 if (data[posn] == '\n') {
248                         int okay = 0;
249                         int serverlen = 0;
250                         struct alt_base *newalt;
251                         if (data[i] == '/') {
252                                 /*
253                                  * This counts
254                                  * http://git.host/pub/scm/linux.git/
255                                  * -----------here^
256                                  * so memcpy(dst, base, serverlen) will
257                                  * copy up to "...git.host".
258                                  */
259                                 const char *colon_ss = strstr(base,"://");
260                                 if (colon_ss) {
261                                         serverlen = (strchr(colon_ss + 3, '/')
262                                                      - base);
263                                         okay = 1;
264                                 }
265                         } else if (!memcmp(data + i, "../", 3)) {
266                                 /*
267                                  * Relative URL; chop the corresponding
268                                  * number of subpath from base (and ../
269                                  * from data), and concatenate the result.
270                                  *
271                                  * The code first drops ../ from data, and
272                                  * then drops one ../ from data and one path
273                                  * from base.  IOW, one extra ../ is dropped
274                                  * from data than path is dropped from base.
275                                  *
276                                  * This is not wrong.  The alternate in
277                                  *     http://git.host/pub/scm/linux.git/
278                                  * to borrow from
279                                  *     http://git.host/pub/scm/linus.git/
280                                  * is ../../linus.git/objects/.  You need
281                                  * two ../../ to borrow from your direct
282                                  * neighbour.
283                                  */
284                                 i += 3;
285                                 serverlen = strlen(base);
286                                 while (i + 2 < posn &&
287                                        !memcmp(data + i, "../", 3)) {
288                                         do {
289                                                 serverlen--;
290                                         } while (serverlen &&
291                                                  base[serverlen - 1] != '/');
292                                         i += 3;
293                                 }
294                                 /* If the server got removed, give up. */
295                                 okay = strchr(base, ':') - base + 3 <
296                                        serverlen;
297                         } else if (alt_req->http_specific) {
298                                 char *colon = strchr(data + i, ':');
299                                 char *slash = strchr(data + i, '/');
300                                 if (colon && slash && colon < data + posn &&
301                                     slash < data + posn && colon < slash) {
302                                         okay = 1;
303                                 }
304                         }
305                         if (okay) {
306                                 struct strbuf target = STRBUF_INIT;
307                                 strbuf_add(&target, base, serverlen);
308                                 strbuf_add(&target, data + i, posn - i);
309                                 if (!strbuf_strip_suffix(&target, "objects")) {
310                                         warning("ignoring alternate that does"
311                                                 " not end in 'objects': %s",
312                                                 target.buf);
313                                         strbuf_release(&target);
314                                 } else if (is_alternate_allowed(target.buf)) {
315                                         warning("adding alternate object store: %s",
316                                                 target.buf);
317                                         newalt = xmalloc(sizeof(*newalt));
318                                         newalt->next = NULL;
319                                         newalt->base = strbuf_detach(&target, NULL);
320                                         newalt->got_indices = 0;
321                                         newalt->packs = NULL;
322
323                                         while (tail->next != NULL)
324                                                 tail = tail->next;
325                                         tail->next = newalt;
326                                 } else {
327                                         strbuf_release(&target);
328                                 }
329                         }
330                 }
331                 i = posn + 1;
332         }
333
334         cdata->got_alternates = 1;
335 }
336
337 static void fetch_alternates(struct walker *walker, const char *base)
338 {
339         struct strbuf buffer = STRBUF_INIT;
340         struct strbuf url = STRBUF_INIT;
341         struct active_request_slot *slot;
342         struct alternates_request alt_req;
343         struct walker_data *cdata = walker->data;
344
345         /*
346          * If another request has already started fetching alternates,
347          * wait for them to arrive and return to processing this request's
348          * curl message
349          */
350 #ifdef USE_CURL_MULTI
351         while (cdata->got_alternates == 0) {
352                 step_active_slots();
353         }
354 #endif
355
356         /* Nothing to do if they've already been fetched */
357         if (cdata->got_alternates == 1)
358                 return;
359
360         /* Start the fetch */
361         cdata->got_alternates = 0;
362
363         if (walker->get_verbosely)
364                 fprintf(stderr, "Getting alternates list for %s\n", base);
365
366         strbuf_addf(&url, "%s/objects/info/http-alternates", base);
367
368         /*
369          * Use a callback to process the result, since another request
370          * may fail and need to have alternates loaded before continuing
371          */
372         slot = get_active_slot();
373         slot->callback_func = process_alternates_response;
374         alt_req.walker = walker;
375         slot->callback_data = &alt_req;
376
377         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
378         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
379         curl_easy_setopt(slot->curl, CURLOPT_URL, url.buf);
380
381         alt_req.base = base;
382         alt_req.url = &url;
383         alt_req.buffer = &buffer;
384         alt_req.http_specific = 1;
385         alt_req.slot = slot;
386
387         if (start_active_slot(slot))
388                 run_active_slot(slot);
389         else
390                 cdata->got_alternates = -1;
391
392         strbuf_release(&buffer);
393         strbuf_release(&url);
394 }
395
396 static int fetch_indices(struct walker *walker, struct alt_base *repo)
397 {
398         int ret;
399
400         if (repo->got_indices)
401                 return 0;
402
403         if (walker->get_verbosely)
404                 fprintf(stderr, "Getting pack list for %s\n", repo->base);
405
406         switch (http_get_info_packs(repo->base, &repo->packs)) {
407         case HTTP_OK:
408         case HTTP_MISSING_TARGET:
409                 repo->got_indices = 1;
410                 ret = 0;
411                 break;
412         default:
413                 repo->got_indices = 0;
414                 ret = -1;
415         }
416
417         return ret;
418 }
419
420 static int http_fetch_pack(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
421 {
422         struct packed_git *target;
423         int ret;
424         struct slot_results results;
425         struct http_pack_request *preq;
426
427         if (fetch_indices(walker, repo))
428                 return -1;
429         target = find_sha1_pack(sha1, repo->packs);
430         if (!target)
431                 return -1;
432
433         if (walker->get_verbosely) {
434                 fprintf(stderr, "Getting pack %s\n",
435                         sha1_to_hex(target->sha1));
436                 fprintf(stderr, " which contains %s\n",
437                         sha1_to_hex(sha1));
438         }
439
440         preq = new_http_pack_request(target, repo->base);
441         if (preq == NULL)
442                 goto abort;
443         preq->lst = &repo->packs;
444         preq->slot->results = &results;
445
446         if (start_active_slot(preq->slot)) {
447                 run_active_slot(preq->slot);
448                 if (results.curl_result != CURLE_OK) {
449                         error("Unable to get pack file %s\n%s", preq->url,
450                               curl_errorstr);
451                         goto abort;
452                 }
453         } else {
454                 error("Unable to start request");
455                 goto abort;
456         }
457
458         ret = finish_http_pack_request(preq);
459         release_http_pack_request(preq);
460         if (ret)
461                 return ret;
462
463         return 0;
464
465 abort:
466         return -1;
467 }
468
469 static void abort_object_request(struct object_request *obj_req)
470 {
471         release_object_request(obj_req);
472 }
473
474 static int fetch_object(struct walker *walker, unsigned char *sha1)
475 {
476         char *hex = sha1_to_hex(sha1);
477         int ret = 0;
478         struct object_request *obj_req = NULL;
479         struct http_object_request *req;
480         struct list_head *pos, *head = &object_queue_head;
481
482         list_for_each(pos, head) {
483                 obj_req = list_entry(pos, struct object_request, node);
484                 if (!hashcmp(obj_req->sha1, sha1))
485                         break;
486         }
487         if (obj_req == NULL)
488                 return error("Couldn't find request for %s in the queue", hex);
489
490         if (has_sha1_file(obj_req->sha1)) {
491                 if (obj_req->req != NULL)
492                         abort_http_object_request(obj_req->req);
493                 abort_object_request(obj_req);
494                 return 0;
495         }
496
497 #ifdef USE_CURL_MULTI
498         while (obj_req->state == WAITING)
499                 step_active_slots();
500 #else
501         start_object_request(walker, obj_req);
502 #endif
503
504         /*
505          * obj_req->req might change when fetching alternates in the callback
506          * process_object_response; therefore, the "shortcut" variable, req,
507          * is used only after we're done with slots.
508          */
509         while (obj_req->state == ACTIVE)
510                 run_active_slot(obj_req->req->slot);
511
512         req = obj_req->req;
513
514         if (req->localfile != -1) {
515                 close(req->localfile);
516                 req->localfile = -1;
517         }
518
519         /*
520          * we turned off CURLOPT_FAILONERROR to avoid losing a
521          * persistent connection and got CURLE_OK.
522          */
523         if (req->http_code >= 300 && req->curl_result == CURLE_OK &&
524                         (starts_with(req->url, "http://") ||
525                          starts_with(req->url, "https://"))) {
526                 req->curl_result = CURLE_HTTP_RETURNED_ERROR;
527                 xsnprintf(req->errorstr, sizeof(req->errorstr),
528                           "HTTP request failed");
529         }
530
531         if (obj_req->state == ABORTED) {
532                 ret = error("Request for %s aborted", hex);
533         } else if (req->curl_result != CURLE_OK &&
534                    req->http_code != 416) {
535                 if (missing_target(req))
536                         ret = -1; /* Be silent, it is probably in a pack. */
537                 else
538                         ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)",
539                                     req->errorstr, req->curl_result,
540                                     req->http_code, hex);
541         } else if (req->zret != Z_STREAM_END) {
542                 walker->corrupt_object_found++;
543                 ret = error("File %s (%s) corrupt", hex, req->url);
544         } else if (hashcmp(obj_req->sha1, req->real_sha1)) {
545                 ret = error("File %s has bad hash", hex);
546         } else if (req->rename < 0) {
547                 ret = error("unable to write sha1 filename %s",
548                             sha1_file_name(req->sha1));
549         }
550
551         release_http_object_request(req);
552         release_object_request(obj_req);
553         return ret;
554 }
555
556 static int fetch(struct walker *walker, unsigned char *sha1)
557 {
558         struct walker_data *data = walker->data;
559         struct alt_base *altbase = data->alt;
560
561         if (!fetch_object(walker, sha1))
562                 return 0;
563         while (altbase) {
564                 if (!http_fetch_pack(walker, altbase, sha1))
565                         return 0;
566                 fetch_alternates(walker, data->alt->base);
567                 altbase = altbase->next;
568         }
569         return error("Unable to find %s under %s", sha1_to_hex(sha1),
570                      data->alt->base);
571 }
572
573 static int fetch_ref(struct walker *walker, struct ref *ref)
574 {
575         struct walker_data *data = walker->data;
576         return http_fetch_ref(data->alt->base, ref);
577 }
578
579 static void cleanup(struct walker *walker)
580 {
581         struct walker_data *data = walker->data;
582         struct alt_base *alt, *alt_next;
583
584         if (data) {
585                 alt = data->alt;
586                 while (alt) {
587                         alt_next = alt->next;
588
589                         free(alt->base);
590                         free(alt);
591
592                         alt = alt_next;
593                 }
594                 free(data);
595                 walker->data = NULL;
596         }
597 }
598
599 struct walker *get_http_walker(const char *url)
600 {
601         char *s;
602         struct walker_data *data = xmalloc(sizeof(struct walker_data));
603         struct walker *walker = xmalloc(sizeof(struct walker));
604
605         data->alt = xmalloc(sizeof(*data->alt));
606         data->alt->base = xstrdup(url);
607         for (s = data->alt->base + strlen(data->alt->base) - 1; *s == '/'; --s)
608                 *s = 0;
609
610         data->alt->got_indices = 0;
611         data->alt->packs = NULL;
612         data->alt->next = NULL;
613         data->got_alternates = -1;
614
615         walker->corrupt_object_found = 0;
616         walker->fetch = fetch;
617         walker->fetch_ref = fetch_ref;
618         walker->prefetch = prefetch;
619         walker->cleanup = cleanup;
620         walker->data = data;
621
622 #ifdef USE_CURL_MULTI
623         add_fill_function(walker, (int (*)(void *)) fill_active_slot);
624 #endif
625
626         return walker;
627 }