gitweb: gravatar url cache
[git] / http.c
1 #include "http.h"
2 #include "pack.h"
3
4 int data_received;
5 int active_requests;
6 int http_is_verbose;
7
8 #ifdef USE_CURL_MULTI
9 static int max_requests = -1;
10 static CURLM *curlm;
11 #endif
12 #ifndef NO_CURL_EASY_DUPHANDLE
13 static CURL *curl_default;
14 #endif
15
16 #define PREV_BUF_SIZE 4096
17 #define RANGE_HEADER_SIZE 30
18
19 char curl_errorstr[CURL_ERROR_SIZE];
20
21 static int curl_ssl_verify = -1;
22 static const char *ssl_cert;
23 #if LIBCURL_VERSION_NUM >= 0x070903
24 static const char *ssl_key;
25 #endif
26 #if LIBCURL_VERSION_NUM >= 0x070908
27 static const char *ssl_capath;
28 #endif
29 static const char *ssl_cainfo;
30 static long curl_low_speed_limit = -1;
31 static long curl_low_speed_time = -1;
32 static int curl_ftp_no_epsv;
33 static const char *curl_http_proxy;
34 static char *user_name, *user_pass;
35
36 static struct curl_slist *pragma_header;
37 static struct curl_slist *no_pragma_header;
38
39 static struct active_request_slot *active_queue_head;
40
41 size_t fread_buffer(void *ptr, size_t eltsize, size_t nmemb, void *buffer_)
42 {
43         size_t size = eltsize * nmemb;
44         struct buffer *buffer = buffer_;
45
46         if (size > buffer->buf.len - buffer->posn)
47                 size = buffer->buf.len - buffer->posn;
48         memcpy(ptr, buffer->buf.buf + buffer->posn, size);
49         buffer->posn += size;
50
51         return size;
52 }
53
54 #ifndef NO_CURL_IOCTL
55 curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
56 {
57         struct buffer *buffer = clientp;
58
59         switch (cmd) {
60         case CURLIOCMD_NOP:
61                 return CURLIOE_OK;
62
63         case CURLIOCMD_RESTARTREAD:
64                 buffer->posn = 0;
65                 return CURLIOE_OK;
66
67         default:
68                 return CURLIOE_UNKNOWNCMD;
69         }
70 }
71 #endif
72
73 size_t fwrite_buffer(const void *ptr, size_t eltsize, size_t nmemb, void *buffer_)
74 {
75         size_t size = eltsize * nmemb;
76         struct strbuf *buffer = buffer_;
77
78         strbuf_add(buffer, ptr, size);
79         data_received++;
80         return size;
81 }
82
83 size_t fwrite_null(const void *ptr, size_t eltsize, size_t nmemb, void *strbuf)
84 {
85         data_received++;
86         return eltsize * nmemb;
87 }
88
89 static void finish_active_slot(struct active_request_slot *slot);
90
91 #ifdef USE_CURL_MULTI
92 static void process_curl_messages(void)
93 {
94         int num_messages;
95         struct active_request_slot *slot;
96         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
97
98         while (curl_message != NULL) {
99                 if (curl_message->msg == CURLMSG_DONE) {
100                         int curl_result = curl_message->data.result;
101                         slot = active_queue_head;
102                         while (slot != NULL &&
103                                slot->curl != curl_message->easy_handle)
104                                 slot = slot->next;
105                         if (slot != NULL) {
106                                 curl_multi_remove_handle(curlm, slot->curl);
107                                 slot->curl_result = curl_result;
108                                 finish_active_slot(slot);
109                         } else {
110                                 fprintf(stderr, "Received DONE message for unknown request!\n");
111                         }
112                 } else {
113                         fprintf(stderr, "Unknown CURL message received: %d\n",
114                                 (int)curl_message->msg);
115                 }
116                 curl_message = curl_multi_info_read(curlm, &num_messages);
117         }
118 }
119 #endif
120
121 static int http_options(const char *var, const char *value, void *cb)
122 {
123         if (!strcmp("http.sslverify", var)) {
124                 curl_ssl_verify = git_config_bool(var, value);
125                 return 0;
126         }
127         if (!strcmp("http.sslcert", var))
128                 return git_config_string(&ssl_cert, var, value);
129 #if LIBCURL_VERSION_NUM >= 0x070903
130         if (!strcmp("http.sslkey", var))
131                 return git_config_string(&ssl_key, var, value);
132 #endif
133 #if LIBCURL_VERSION_NUM >= 0x070908
134         if (!strcmp("http.sslcapath", var))
135                 return git_config_string(&ssl_capath, var, value);
136 #endif
137         if (!strcmp("http.sslcainfo", var))
138                 return git_config_string(&ssl_cainfo, var, value);
139 #ifdef USE_CURL_MULTI
140         if (!strcmp("http.maxrequests", var)) {
141                 max_requests = git_config_int(var, value);
142                 return 0;
143         }
144 #endif
145         if (!strcmp("http.lowspeedlimit", var)) {
146                 curl_low_speed_limit = (long)git_config_int(var, value);
147                 return 0;
148         }
149         if (!strcmp("http.lowspeedtime", var)) {
150                 curl_low_speed_time = (long)git_config_int(var, value);
151                 return 0;
152         }
153
154         if (!strcmp("http.noepsv", var)) {
155                 curl_ftp_no_epsv = git_config_bool(var, value);
156                 return 0;
157         }
158         if (!strcmp("http.proxy", var))
159                 return git_config_string(&curl_http_proxy, var, value);
160
161         /* Fall back on the default ones */
162         return git_default_config(var, value, cb);
163 }
164
165 static void init_curl_http_auth(CURL *result)
166 {
167         if (user_name) {
168                 struct strbuf up = STRBUF_INIT;
169                 if (!user_pass)
170                         user_pass = xstrdup(getpass("Password: "));
171                 strbuf_addf(&up, "%s:%s", user_name, user_pass);
172                 curl_easy_setopt(result, CURLOPT_USERPWD,
173                                  strbuf_detach(&up, NULL));
174         }
175 }
176
177 static CURL *get_curl_handle(void)
178 {
179         CURL *result = curl_easy_init();
180
181         if (!curl_ssl_verify) {
182                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
183                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
184         } else {
185                 /* Verify authenticity of the peer's certificate */
186                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
187                 /* The name in the cert must match whom we tried to connect */
188                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
189         }
190
191 #if LIBCURL_VERSION_NUM >= 0x070907
192         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
193 #endif
194
195         init_curl_http_auth(result);
196
197         if (ssl_cert != NULL)
198                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
199 #if LIBCURL_VERSION_NUM >= 0x070903
200         if (ssl_key != NULL)
201                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
202 #endif
203 #if LIBCURL_VERSION_NUM >= 0x070908
204         if (ssl_capath != NULL)
205                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
206 #endif
207         if (ssl_cainfo != NULL)
208                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
209         curl_easy_setopt(result, CURLOPT_FAILONERROR, 1);
210
211         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
212                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
213                                  curl_low_speed_limit);
214                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
215                                  curl_low_speed_time);
216         }
217
218         curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
219
220         if (getenv("GIT_CURL_VERBOSE"))
221                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
222
223         curl_easy_setopt(result, CURLOPT_USERAGENT, GIT_USER_AGENT);
224
225         if (curl_ftp_no_epsv)
226                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
227
228         if (curl_http_proxy)
229                 curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
230
231         return result;
232 }
233
234 static void http_auth_init(const char *url)
235 {
236         char *at, *colon, *cp, *slash;
237         int len;
238
239         cp = strstr(url, "://");
240         if (!cp)
241                 return;
242
243         /*
244          * Ok, the URL looks like "proto://something".  Which one?
245          * "proto://<user>:<pass>@<host>/...",
246          * "proto://<user>@<host>/...", or just
247          * "proto://<host>/..."?
248          */
249         cp += 3;
250         at = strchr(cp, '@');
251         colon = strchr(cp, ':');
252         slash = strchrnul(cp, '/');
253         if (!at || slash <= at)
254                 return; /* No credentials */
255         if (!colon || at <= colon) {
256                 /* Only username */
257                 len = at - cp;
258                 user_name = xmalloc(len + 1);
259                 memcpy(user_name, cp, len);
260                 user_name[len] = '\0';
261                 user_pass = NULL;
262         } else {
263                 len = colon - cp;
264                 user_name = xmalloc(len + 1);
265                 memcpy(user_name, cp, len);
266                 user_name[len] = '\0';
267                 len = at - (colon + 1);
268                 user_pass = xmalloc(len + 1);
269                 memcpy(user_pass, colon + 1, len);
270                 user_pass[len] = '\0';
271         }
272 }
273
274 static void set_from_env(const char **var, const char *envname)
275 {
276         const char *val = getenv(envname);
277         if (val)
278                 *var = val;
279 }
280
281 void http_init(struct remote *remote)
282 {
283         char *low_speed_limit;
284         char *low_speed_time;
285
286         http_is_verbose = 0;
287
288         git_config(http_options, NULL);
289
290         curl_global_init(CURL_GLOBAL_ALL);
291
292         if (remote && remote->http_proxy)
293                 curl_http_proxy = xstrdup(remote->http_proxy);
294
295         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
296         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
297
298 #ifdef USE_CURL_MULTI
299         {
300                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
301                 if (http_max_requests != NULL)
302                         max_requests = atoi(http_max_requests);
303         }
304
305         curlm = curl_multi_init();
306         if (curlm == NULL) {
307                 fprintf(stderr, "Error creating curl multi handle.\n");
308                 exit(1);
309         }
310 #endif
311
312         if (getenv("GIT_SSL_NO_VERIFY"))
313                 curl_ssl_verify = 0;
314
315         set_from_env(&ssl_cert, "GIT_SSL_CERT");
316 #if LIBCURL_VERSION_NUM >= 0x070903
317         set_from_env(&ssl_key, "GIT_SSL_KEY");
318 #endif
319 #if LIBCURL_VERSION_NUM >= 0x070908
320         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
321 #endif
322         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
323
324         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
325         if (low_speed_limit != NULL)
326                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
327         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
328         if (low_speed_time != NULL)
329                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
330
331         if (curl_ssl_verify == -1)
332                 curl_ssl_verify = 1;
333
334 #ifdef USE_CURL_MULTI
335         if (max_requests < 1)
336                 max_requests = DEFAULT_MAX_REQUESTS;
337 #endif
338
339         if (getenv("GIT_CURL_FTP_NO_EPSV"))
340                 curl_ftp_no_epsv = 1;
341
342         if (remote && remote->url && remote->url[0])
343                 http_auth_init(remote->url[0]);
344
345 #ifndef NO_CURL_EASY_DUPHANDLE
346         curl_default = get_curl_handle();
347 #endif
348 }
349
350 void http_cleanup(void)
351 {
352         struct active_request_slot *slot = active_queue_head;
353
354         while (slot != NULL) {
355                 struct active_request_slot *next = slot->next;
356                 if (slot->curl != NULL) {
357 #ifdef USE_CURL_MULTI
358                         curl_multi_remove_handle(curlm, slot->curl);
359 #endif
360                         curl_easy_cleanup(slot->curl);
361                 }
362                 free(slot);
363                 slot = next;
364         }
365         active_queue_head = NULL;
366
367 #ifndef NO_CURL_EASY_DUPHANDLE
368         curl_easy_cleanup(curl_default);
369 #endif
370
371 #ifdef USE_CURL_MULTI
372         curl_multi_cleanup(curlm);
373 #endif
374         curl_global_cleanup();
375
376         curl_slist_free_all(pragma_header);
377         pragma_header = NULL;
378
379         curl_slist_free_all(no_pragma_header);
380         no_pragma_header = NULL;
381
382         if (curl_http_proxy) {
383                 free((void *)curl_http_proxy);
384                 curl_http_proxy = NULL;
385         }
386 }
387
388 struct active_request_slot *get_active_slot(void)
389 {
390         struct active_request_slot *slot = active_queue_head;
391         struct active_request_slot *newslot;
392
393 #ifdef USE_CURL_MULTI
394         int num_transfers;
395
396         /* Wait for a slot to open up if the queue is full */
397         while (active_requests >= max_requests) {
398                 curl_multi_perform(curlm, &num_transfers);
399                 if (num_transfers < active_requests)
400                         process_curl_messages();
401         }
402 #endif
403
404         while (slot != NULL && slot->in_use)
405                 slot = slot->next;
406
407         if (slot == NULL) {
408                 newslot = xmalloc(sizeof(*newslot));
409                 newslot->curl = NULL;
410                 newslot->in_use = 0;
411                 newslot->next = NULL;
412
413                 slot = active_queue_head;
414                 if (slot == NULL) {
415                         active_queue_head = newslot;
416                 } else {
417                         while (slot->next != NULL)
418                                 slot = slot->next;
419                         slot->next = newslot;
420                 }
421                 slot = newslot;
422         }
423
424         if (slot->curl == NULL) {
425 #ifdef NO_CURL_EASY_DUPHANDLE
426                 slot->curl = get_curl_handle();
427 #else
428                 slot->curl = curl_easy_duphandle(curl_default);
429 #endif
430         }
431
432         active_requests++;
433         slot->in_use = 1;
434         slot->local = NULL;
435         slot->results = NULL;
436         slot->finished = NULL;
437         slot->callback_data = NULL;
438         slot->callback_func = NULL;
439         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
440         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
441         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
442         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
443         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
444         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
445         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
446
447         return slot;
448 }
449
450 int start_active_slot(struct active_request_slot *slot)
451 {
452 #ifdef USE_CURL_MULTI
453         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
454         int num_transfers;
455
456         if (curlm_result != CURLM_OK &&
457             curlm_result != CURLM_CALL_MULTI_PERFORM) {
458                 active_requests--;
459                 slot->in_use = 0;
460                 return 0;
461         }
462
463         /*
464          * We know there must be something to do, since we just added
465          * something.
466          */
467         curl_multi_perform(curlm, &num_transfers);
468 #endif
469         return 1;
470 }
471
472 #ifdef USE_CURL_MULTI
473 struct fill_chain {
474         void *data;
475         int (*fill)(void *);
476         struct fill_chain *next;
477 };
478
479 static struct fill_chain *fill_cfg;
480
481 void add_fill_function(void *data, int (*fill)(void *))
482 {
483         struct fill_chain *new = xmalloc(sizeof(*new));
484         struct fill_chain **linkp = &fill_cfg;
485         new->data = data;
486         new->fill = fill;
487         new->next = NULL;
488         while (*linkp)
489                 linkp = &(*linkp)->next;
490         *linkp = new;
491 }
492
493 void fill_active_slots(void)
494 {
495         struct active_request_slot *slot = active_queue_head;
496
497         while (active_requests < max_requests) {
498                 struct fill_chain *fill;
499                 for (fill = fill_cfg; fill; fill = fill->next)
500                         if (fill->fill(fill->data))
501                                 break;
502
503                 if (!fill)
504                         break;
505         }
506
507         while (slot != NULL) {
508                 if (!slot->in_use && slot->curl != NULL) {
509                         curl_easy_cleanup(slot->curl);
510                         slot->curl = NULL;
511                 }
512                 slot = slot->next;
513         }
514 }
515
516 void step_active_slots(void)
517 {
518         int num_transfers;
519         CURLMcode curlm_result;
520
521         do {
522                 curlm_result = curl_multi_perform(curlm, &num_transfers);
523         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
524         if (num_transfers < active_requests) {
525                 process_curl_messages();
526                 fill_active_slots();
527         }
528 }
529 #endif
530
531 void run_active_slot(struct active_request_slot *slot)
532 {
533 #ifdef USE_CURL_MULTI
534         long last_pos = 0;
535         long current_pos;
536         fd_set readfds;
537         fd_set writefds;
538         fd_set excfds;
539         int max_fd;
540         struct timeval select_timeout;
541         int finished = 0;
542
543         slot->finished = &finished;
544         while (!finished) {
545                 data_received = 0;
546                 step_active_slots();
547
548                 if (!data_received && slot->local != NULL) {
549                         current_pos = ftell(slot->local);
550                         if (current_pos > last_pos)
551                                 data_received++;
552                         last_pos = current_pos;
553                 }
554
555                 if (slot->in_use && !data_received) {
556                         max_fd = 0;
557                         FD_ZERO(&readfds);
558                         FD_ZERO(&writefds);
559                         FD_ZERO(&excfds);
560                         select_timeout.tv_sec = 0;
561                         select_timeout.tv_usec = 50000;
562                         select(max_fd, &readfds, &writefds,
563                                &excfds, &select_timeout);
564                 }
565         }
566 #else
567         while (slot->in_use) {
568                 slot->curl_result = curl_easy_perform(slot->curl);
569                 finish_active_slot(slot);
570         }
571 #endif
572 }
573
574 static void closedown_active_slot(struct active_request_slot *slot)
575 {
576         active_requests--;
577         slot->in_use = 0;
578 }
579
580 void release_active_slot(struct active_request_slot *slot)
581 {
582         closedown_active_slot(slot);
583         if (slot->curl) {
584 #ifdef USE_CURL_MULTI
585                 curl_multi_remove_handle(curlm, slot->curl);
586 #endif
587                 curl_easy_cleanup(slot->curl);
588                 slot->curl = NULL;
589         }
590 #ifdef USE_CURL_MULTI
591         fill_active_slots();
592 #endif
593 }
594
595 static void finish_active_slot(struct active_request_slot *slot)
596 {
597         closedown_active_slot(slot);
598         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
599
600         if (slot->finished != NULL)
601                 (*slot->finished) = 1;
602
603         /* Store slot results so they can be read after the slot is reused */
604         if (slot->results != NULL) {
605                 slot->results->curl_result = slot->curl_result;
606                 slot->results->http_code = slot->http_code;
607         }
608
609         /* Run callback if appropriate */
610         if (slot->callback_func != NULL)
611                 slot->callback_func(slot->callback_data);
612 }
613
614 void finish_all_active_slots(void)
615 {
616         struct active_request_slot *slot = active_queue_head;
617
618         while (slot != NULL)
619                 if (slot->in_use) {
620                         run_active_slot(slot);
621                         slot = active_queue_head;
622                 } else {
623                         slot = slot->next;
624                 }
625 }
626
627 /* Helpers for modifying and creating URLs */
628 static inline int needs_quote(int ch)
629 {
630         if (((ch >= 'A') && (ch <= 'Z'))
631                         || ((ch >= 'a') && (ch <= 'z'))
632                         || ((ch >= '0') && (ch <= '9'))
633                         || (ch == '/')
634                         || (ch == '-')
635                         || (ch == '.'))
636                 return 0;
637         return 1;
638 }
639
640 static inline int hex(int v)
641 {
642         if (v < 10)
643                 return '0' + v;
644         else
645                 return 'A' + v - 10;
646 }
647
648 static void end_url_with_slash(struct strbuf *buf, const char *url)
649 {
650         strbuf_addstr(buf, url);
651         if (buf->len && buf->buf[buf->len - 1] != '/')
652                 strbuf_addstr(buf, "/");
653 }
654
655 static char *quote_ref_url(const char *base, const char *ref)
656 {
657         struct strbuf buf = STRBUF_INIT;
658         const char *cp;
659         int ch;
660
661         end_url_with_slash(&buf, base);
662
663         for (cp = ref; (ch = *cp) != 0; cp++)
664                 if (needs_quote(ch))
665                         strbuf_addf(&buf, "%%%02x", ch);
666                 else
667                         strbuf_addch(&buf, *cp);
668
669         return strbuf_detach(&buf, NULL);
670 }
671
672 void append_remote_object_url(struct strbuf *buf, const char *url,
673                               const char *hex,
674                               int only_two_digit_prefix)
675 {
676         strbuf_addf(buf, "%s/objects/%.*s/", url, 2, hex);
677         if (!only_two_digit_prefix)
678                 strbuf_addf(buf, "%s", hex+2);
679 }
680
681 char *get_remote_object_url(const char *url, const char *hex,
682                             int only_two_digit_prefix)
683 {
684         struct strbuf buf = STRBUF_INIT;
685         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
686         return strbuf_detach(&buf, NULL);
687 }
688
689 /* http_request() targets */
690 #define HTTP_REQUEST_STRBUF     0
691 #define HTTP_REQUEST_FILE       1
692
693 static int http_request(const char *url, void *result, int target, int options)
694 {
695         struct active_request_slot *slot;
696         struct slot_results results;
697         struct curl_slist *headers = NULL;
698         struct strbuf buf = STRBUF_INIT;
699         int ret;
700
701         slot = get_active_slot();
702         slot->results = &results;
703         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
704
705         if (result == NULL) {
706                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
707         } else {
708                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
709                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
710
711                 if (target == HTTP_REQUEST_FILE) {
712                         long posn = ftell(result);
713                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
714                                          fwrite);
715                         if (posn > 0) {
716                                 strbuf_addf(&buf, "Range: bytes=%ld-", posn);
717                                 headers = curl_slist_append(headers, buf.buf);
718                                 strbuf_reset(&buf);
719                         }
720                         slot->local = result;
721                 } else
722                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
723                                          fwrite_buffer);
724         }
725
726         strbuf_addstr(&buf, "Pragma:");
727         if (options & HTTP_NO_CACHE)
728                 strbuf_addstr(&buf, " no-cache");
729
730         headers = curl_slist_append(headers, buf.buf);
731
732         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
733         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
734
735         if (start_active_slot(slot)) {
736                 run_active_slot(slot);
737                 if (results.curl_result == CURLE_OK)
738                         ret = HTTP_OK;
739                 else if (missing_target(&results))
740                         ret = HTTP_MISSING_TARGET;
741                 else
742                         ret = HTTP_ERROR;
743         } else {
744                 error("Unable to start HTTP request for %s", url);
745                 ret = HTTP_START_FAILED;
746         }
747
748         slot->local = NULL;
749         curl_slist_free_all(headers);
750         strbuf_release(&buf);
751
752         return ret;
753 }
754
755 int http_get_strbuf(const char *url, struct strbuf *result, int options)
756 {
757         return http_request(url, result, HTTP_REQUEST_STRBUF, options);
758 }
759
760 int http_get_file(const char *url, const char *filename, int options)
761 {
762         int ret;
763         struct strbuf tmpfile = STRBUF_INIT;
764         FILE *result;
765
766         strbuf_addf(&tmpfile, "%s.temp", filename);
767         result = fopen(tmpfile.buf, "a");
768         if (! result) {
769                 error("Unable to open local file %s", tmpfile.buf);
770                 ret = HTTP_ERROR;
771                 goto cleanup;
772         }
773
774         ret = http_request(url, result, HTTP_REQUEST_FILE, options);
775         fclose(result);
776
777         if ((ret == HTTP_OK) && move_temp_to_file(tmpfile.buf, filename))
778                 ret = HTTP_ERROR;
779 cleanup:
780         strbuf_release(&tmpfile);
781         return ret;
782 }
783
784 int http_error(const char *url, int ret)
785 {
786         /* http_request has already handled HTTP_START_FAILED. */
787         if (ret != HTTP_START_FAILED)
788                 error("%s while accessing %s\n", curl_errorstr, url);
789
790         return ret;
791 }
792
793 int http_fetch_ref(const char *base, struct ref *ref)
794 {
795         char *url;
796         struct strbuf buffer = STRBUF_INIT;
797         int ret = -1;
798
799         url = quote_ref_url(base, ref->name);
800         if (http_get_strbuf(url, &buffer, HTTP_NO_CACHE) == HTTP_OK) {
801                 strbuf_rtrim(&buffer);
802                 if (buffer.len == 40)
803                         ret = get_sha1_hex(buffer.buf, ref->old_sha1);
804                 else if (!prefixcmp(buffer.buf, "ref: ")) {
805                         ref->symref = xstrdup(buffer.buf + 5);
806                         ret = 0;
807                 }
808         }
809
810         strbuf_release(&buffer);
811         free(url);
812         return ret;
813 }
814
815 /* Helpers for fetching packs */
816 static int fetch_pack_index(unsigned char *sha1, const char *base_url)
817 {
818         int ret = 0;
819         char *hex = xstrdup(sha1_to_hex(sha1));
820         char *filename;
821         char *url;
822         struct strbuf buf = STRBUF_INIT;
823
824         /* Don't use the index if the pack isn't there */
825         end_url_with_slash(&buf, base_url);
826         strbuf_addf(&buf, "objects/pack/pack-%s.pack", hex);
827         url = strbuf_detach(&buf, 0);
828
829         if (http_get_strbuf(url, NULL, 0)) {
830                 ret = error("Unable to verify pack %s is available",
831                             hex);
832                 goto cleanup;
833         }
834
835         if (has_pack_index(sha1)) {
836                 ret = 0;
837                 goto cleanup;
838         }
839
840         if (http_is_verbose)
841                 fprintf(stderr, "Getting index for pack %s\n", hex);
842
843         end_url_with_slash(&buf, base_url);
844         strbuf_addf(&buf, "objects/pack/pack-%s.idx", hex);
845         url = strbuf_detach(&buf, NULL);
846
847         filename = sha1_pack_index_name(sha1);
848         if (http_get_file(url, filename, 0) != HTTP_OK)
849                 ret = error("Unable to get pack index %s\n", url);
850
851 cleanup:
852         free(hex);
853         free(url);
854         return ret;
855 }
856
857 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
858         unsigned char *sha1, const char *base_url)
859 {
860         struct packed_git *new_pack;
861
862         if (fetch_pack_index(sha1, base_url))
863                 return -1;
864
865         new_pack = parse_pack_index(sha1);
866         if (!new_pack)
867                 return -1; /* parse_pack_index() already issued error message */
868         new_pack->next = *packs_head;
869         *packs_head = new_pack;
870         return 0;
871 }
872
873 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
874 {
875         int ret = 0, i = 0;
876         char *url, *data;
877         struct strbuf buf = STRBUF_INIT;
878         unsigned char sha1[20];
879
880         end_url_with_slash(&buf, base_url);
881         strbuf_addstr(&buf, "objects/info/packs");
882         url = strbuf_detach(&buf, NULL);
883
884         ret = http_get_strbuf(url, &buf, HTTP_NO_CACHE);
885         if (ret != HTTP_OK)
886                 goto cleanup;
887
888         data = buf.buf;
889         while (i < buf.len) {
890                 switch (data[i]) {
891                 case 'P':
892                         i++;
893                         if (i + 52 <= buf.len &&
894                             !prefixcmp(data + i, " pack-") &&
895                             !prefixcmp(data + i + 46, ".pack\n")) {
896                                 get_sha1_hex(data + i + 6, sha1);
897                                 fetch_and_setup_pack_index(packs_head, sha1,
898                                                       base_url);
899                                 i += 51;
900                                 break;
901                         }
902                 default:
903                         while (i < buf.len && data[i] != '\n')
904                                 i++;
905                 }
906                 i++;
907         }
908
909 cleanup:
910         free(url);
911         return ret;
912 }
913
914 void release_http_pack_request(struct http_pack_request *preq)
915 {
916         if (preq->packfile != NULL) {
917                 fclose(preq->packfile);
918                 preq->packfile = NULL;
919                 preq->slot->local = NULL;
920         }
921         if (preq->range_header != NULL) {
922                 curl_slist_free_all(preq->range_header);
923                 preq->range_header = NULL;
924         }
925         preq->slot = NULL;
926         free(preq->url);
927 }
928
929 int finish_http_pack_request(struct http_pack_request *preq)
930 {
931         int ret;
932         struct packed_git **lst;
933
934         preq->target->pack_size = ftell(preq->packfile);
935
936         if (preq->packfile != NULL) {
937                 fclose(preq->packfile);
938                 preq->packfile = NULL;
939                 preq->slot->local = NULL;
940         }
941
942         ret = move_temp_to_file(preq->tmpfile, preq->filename);
943         if (ret)
944                 return ret;
945
946         lst = preq->lst;
947         while (*lst != preq->target)
948                 lst = &((*lst)->next);
949         *lst = (*lst)->next;
950
951         if (verify_pack(preq->target))
952                 return -1;
953         install_packed_git(preq->target);
954
955         return 0;
956 }
957
958 struct http_pack_request *new_http_pack_request(
959         struct packed_git *target, const char *base_url)
960 {
961         char *url;
962         char *filename;
963         long prev_posn = 0;
964         char range[RANGE_HEADER_SIZE];
965         struct strbuf buf = STRBUF_INIT;
966         struct http_pack_request *preq;
967
968         preq = xmalloc(sizeof(*preq));
969         preq->target = target;
970         preq->range_header = NULL;
971
972         end_url_with_slash(&buf, base_url);
973         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
974                 sha1_to_hex(target->sha1));
975         url = strbuf_detach(&buf, NULL);
976         preq->url = xstrdup(url);
977
978         filename = sha1_pack_name(target->sha1);
979         snprintf(preq->filename, sizeof(preq->filename), "%s", filename);
980         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp", filename);
981         preq->packfile = fopen(preq->tmpfile, "a");
982         if (!preq->packfile) {
983                 error("Unable to open local file %s for pack",
984                       preq->tmpfile);
985                 goto abort;
986         }
987
988         preq->slot = get_active_slot();
989         preq->slot->local = preq->packfile;
990         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
991         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
992         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, url);
993         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
994                 no_pragma_header);
995
996         /*
997          * If there is data present from a previous transfer attempt,
998          * resume where it left off
999          */
1000         prev_posn = ftell(preq->packfile);
1001         if (prev_posn>0) {
1002                 if (http_is_verbose)
1003                         fprintf(stderr,
1004                                 "Resuming fetch of pack %s at byte %ld\n",
1005                                 sha1_to_hex(target->sha1), prev_posn);
1006                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1007                 preq->range_header = curl_slist_append(NULL, range);
1008                 curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1009                         preq->range_header);
1010         }
1011
1012         return preq;
1013
1014 abort:
1015         free(filename);
1016         return NULL;
1017 }
1018
1019 /* Helpers for fetching objects (loose) */
1020 static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
1021                                void *data)
1022 {
1023         unsigned char expn[4096];
1024         size_t size = eltsize * nmemb;
1025         int posn = 0;
1026         struct http_object_request *freq =
1027                 (struct http_object_request *)data;
1028         do {
1029                 ssize_t retval = xwrite(freq->localfile,
1030                                         (char *) ptr + posn, size - posn);
1031                 if (retval < 0)
1032                         return posn;
1033                 posn += retval;
1034         } while (posn < size);
1035
1036         freq->stream.avail_in = size;
1037         freq->stream.next_in = ptr;
1038         do {
1039                 freq->stream.next_out = expn;
1040                 freq->stream.avail_out = sizeof(expn);
1041                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1042                 git_SHA1_Update(&freq->c, expn,
1043                                 sizeof(expn) - freq->stream.avail_out);
1044         } while (freq->stream.avail_in && freq->zret == Z_OK);
1045         data_received++;
1046         return size;
1047 }
1048
1049 struct http_object_request *new_http_object_request(const char *base_url,
1050         unsigned char *sha1)
1051 {
1052         char *hex = sha1_to_hex(sha1);
1053         char *filename;
1054         char prevfile[PATH_MAX];
1055         char *url;
1056         int prevlocal;
1057         unsigned char prev_buf[PREV_BUF_SIZE];
1058         ssize_t prev_read = 0;
1059         long prev_posn = 0;
1060         char range[RANGE_HEADER_SIZE];
1061         struct curl_slist *range_header = NULL;
1062         struct http_object_request *freq;
1063
1064         freq = xmalloc(sizeof(*freq));
1065         hashcpy(freq->sha1, sha1);
1066         freq->localfile = -1;
1067
1068         filename = sha1_file_name(sha1);
1069         snprintf(freq->filename, sizeof(freq->filename), "%s", filename);
1070         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1071                  "%s.temp", filename);
1072
1073         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1074         unlink_or_warn(prevfile);
1075         rename(freq->tmpfile, prevfile);
1076         unlink_or_warn(freq->tmpfile);
1077
1078         if (freq->localfile != -1)
1079                 error("fd leakage in start: %d", freq->localfile);
1080         freq->localfile = open(freq->tmpfile,
1081                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1082         /*
1083          * This could have failed due to the "lazy directory creation";
1084          * try to mkdir the last path component.
1085          */
1086         if (freq->localfile < 0 && errno == ENOENT) {
1087                 char *dir = strrchr(freq->tmpfile, '/');
1088                 if (dir) {
1089                         *dir = 0;
1090                         mkdir(freq->tmpfile, 0777);
1091                         *dir = '/';
1092                 }
1093                 freq->localfile = open(freq->tmpfile,
1094                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1095         }
1096
1097         if (freq->localfile < 0) {
1098                 error("Couldn't create temporary file %s for %s: %s",
1099                       freq->tmpfile, freq->filename, strerror(errno));
1100                 goto abort;
1101         }
1102
1103         memset(&freq->stream, 0, sizeof(freq->stream));
1104
1105         git_inflate_init(&freq->stream);
1106
1107         git_SHA1_Init(&freq->c);
1108
1109         url = get_remote_object_url(base_url, hex, 0);
1110         freq->url = xstrdup(url);
1111
1112         /*
1113          * If a previous temp file is present, process what was already
1114          * fetched.
1115          */
1116         prevlocal = open(prevfile, O_RDONLY);
1117         if (prevlocal != -1) {
1118                 do {
1119                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1120                         if (prev_read>0) {
1121                                 if (fwrite_sha1_file(prev_buf,
1122                                                      1,
1123                                                      prev_read,
1124                                                      freq) == prev_read) {
1125                                         prev_posn += prev_read;
1126                                 } else {
1127                                         prev_read = -1;
1128                                 }
1129                         }
1130                 } while (prev_read > 0);
1131                 close(prevlocal);
1132         }
1133         unlink_or_warn(prevfile);
1134
1135         /*
1136          * Reset inflate/SHA1 if there was an error reading the previous temp
1137          * file; also rewind to the beginning of the local file.
1138          */
1139         if (prev_read == -1) {
1140                 memset(&freq->stream, 0, sizeof(freq->stream));
1141                 git_inflate_init(&freq->stream);
1142                 git_SHA1_Init(&freq->c);
1143                 if (prev_posn>0) {
1144                         prev_posn = 0;
1145                         lseek(freq->localfile, 0, SEEK_SET);
1146                         ftruncate(freq->localfile, 0);
1147                 }
1148         }
1149
1150         freq->slot = get_active_slot();
1151
1152         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1153         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1154         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1155         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, url);
1156         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1157
1158         /*
1159          * If we have successfully processed data from a previous fetch
1160          * attempt, only fetch the data we don't already have.
1161          */
1162         if (prev_posn>0) {
1163                 if (http_is_verbose)
1164                         fprintf(stderr,
1165                                 "Resuming fetch of object %s at byte %ld\n",
1166                                 hex, prev_posn);
1167                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1168                 range_header = curl_slist_append(range_header, range);
1169                 curl_easy_setopt(freq->slot->curl,
1170                                  CURLOPT_HTTPHEADER, range_header);
1171         }
1172
1173         return freq;
1174
1175         free(url);
1176 abort:
1177         free(filename);
1178         free(freq);
1179         return NULL;
1180 }
1181
1182 void process_http_object_request(struct http_object_request *freq)
1183 {
1184         if (freq->slot == NULL)
1185                 return;
1186         freq->curl_result = freq->slot->curl_result;
1187         freq->http_code = freq->slot->http_code;
1188         freq->slot = NULL;
1189 }
1190
1191 int finish_http_object_request(struct http_object_request *freq)
1192 {
1193         struct stat st;
1194
1195         close(freq->localfile);
1196         freq->localfile = -1;
1197
1198         process_http_object_request(freq);
1199
1200         if (freq->http_code == 416) {
1201                 fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
1202         } else if (freq->curl_result != CURLE_OK) {
1203                 if (stat(freq->tmpfile, &st) == 0)
1204                         if (st.st_size == 0)
1205                                 unlink_or_warn(freq->tmpfile);
1206                 return -1;
1207         }
1208
1209         git_inflate_end(&freq->stream);
1210         git_SHA1_Final(freq->real_sha1, &freq->c);
1211         if (freq->zret != Z_STREAM_END) {
1212                 unlink_or_warn(freq->tmpfile);
1213                 return -1;
1214         }
1215         if (hashcmp(freq->sha1, freq->real_sha1)) {
1216                 unlink_or_warn(freq->tmpfile);
1217                 return -1;
1218         }
1219         freq->rename =
1220                 move_temp_to_file(freq->tmpfile, freq->filename);
1221
1222         return freq->rename;
1223 }
1224
1225 void abort_http_object_request(struct http_object_request *freq)
1226 {
1227         unlink_or_warn(freq->tmpfile);
1228
1229         release_http_object_request(freq);
1230 }
1231
1232 void release_http_object_request(struct http_object_request *freq)
1233 {
1234         if (freq->localfile != -1) {
1235                 close(freq->localfile);
1236                 freq->localfile = -1;
1237         }
1238         if (freq->url != NULL) {
1239                 free(freq->url);
1240                 freq->url = NULL;
1241         }
1242         freq->slot = NULL;
1243 }