t7004: give the test a bit more stack space
[git] / http.c
1 #include "http.h"
2 #include "pack.h"
3 #include "sideband.h"
4 #include "run-command.h"
5 #include "url.h"
6 #include "urlmatch.h"
7 #include "credential.h"
8 #include "version.h"
9 #include "pkt-line.h"
10
11 int active_requests;
12 int http_is_verbose;
13 size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
14
15 #if LIBCURL_VERSION_NUM >= 0x070a06
16 #define LIBCURL_CAN_HANDLE_AUTH_ANY
17 #endif
18
19 static int min_curl_sessions = 1;
20 static int curl_session_count;
21 #ifdef USE_CURL_MULTI
22 static int max_requests = -1;
23 static CURLM *curlm;
24 #endif
25 #ifndef NO_CURL_EASY_DUPHANDLE
26 static CURL *curl_default;
27 #endif
28
29 #define PREV_BUF_SIZE 4096
30 #define RANGE_HEADER_SIZE 30
31
32 char curl_errorstr[CURL_ERROR_SIZE];
33
34 static int curl_ssl_verify = -1;
35 static int curl_ssl_try;
36 static const char *ssl_cert;
37 #if LIBCURL_VERSION_NUM >= 0x070903
38 static const char *ssl_key;
39 #endif
40 #if LIBCURL_VERSION_NUM >= 0x070908
41 static const char *ssl_capath;
42 #endif
43 static const char *ssl_cainfo;
44 static long curl_low_speed_limit = -1;
45 static long curl_low_speed_time = -1;
46 static int curl_ftp_no_epsv;
47 static const char *curl_http_proxy;
48 static const char *curl_cookie_file;
49 static int curl_save_cookies;
50 struct credential http_auth = CREDENTIAL_INIT;
51 static int http_proactive_auth;
52 static const char *user_agent;
53
54 #if LIBCURL_VERSION_NUM >= 0x071700
55 /* Use CURLOPT_KEYPASSWD as is */
56 #elif LIBCURL_VERSION_NUM >= 0x070903
57 #define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
58 #else
59 #define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
60 #endif
61
62 static struct credential cert_auth = CREDENTIAL_INIT;
63 static int ssl_cert_password_required;
64
65 static struct curl_slist *pragma_header;
66 static struct curl_slist *no_pragma_header;
67
68 static struct active_request_slot *active_queue_head;
69
70 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
71 {
72         size_t size = eltsize * nmemb;
73         struct buffer *buffer = buffer_;
74
75         if (size > buffer->buf.len - buffer->posn)
76                 size = buffer->buf.len - buffer->posn;
77         memcpy(ptr, buffer->buf.buf + buffer->posn, size);
78         buffer->posn += size;
79
80         return size;
81 }
82
83 #ifndef NO_CURL_IOCTL
84 curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
85 {
86         struct buffer *buffer = clientp;
87
88         switch (cmd) {
89         case CURLIOCMD_NOP:
90                 return CURLIOE_OK;
91
92         case CURLIOCMD_RESTARTREAD:
93                 buffer->posn = 0;
94                 return CURLIOE_OK;
95
96         default:
97                 return CURLIOE_UNKNOWNCMD;
98         }
99 }
100 #endif
101
102 size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
103 {
104         size_t size = eltsize * nmemb;
105         struct strbuf *buffer = buffer_;
106
107         strbuf_add(buffer, ptr, size);
108         return size;
109 }
110
111 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
112 {
113         return eltsize * nmemb;
114 }
115
116 #ifdef USE_CURL_MULTI
117 static void process_curl_messages(void)
118 {
119         int num_messages;
120         struct active_request_slot *slot;
121         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
122
123         while (curl_message != NULL) {
124                 if (curl_message->msg == CURLMSG_DONE) {
125                         int curl_result = curl_message->data.result;
126                         slot = active_queue_head;
127                         while (slot != NULL &&
128                                slot->curl != curl_message->easy_handle)
129                                 slot = slot->next;
130                         if (slot != NULL) {
131                                 curl_multi_remove_handle(curlm, slot->curl);
132                                 slot->curl_result = curl_result;
133                                 finish_active_slot(slot);
134                         } else {
135                                 fprintf(stderr, "Received DONE message for unknown request!\n");
136                         }
137                 } else {
138                         fprintf(stderr, "Unknown CURL message received: %d\n",
139                                 (int)curl_message->msg);
140                 }
141                 curl_message = curl_multi_info_read(curlm, &num_messages);
142         }
143 }
144 #endif
145
146 static int http_options(const char *var, const char *value, void *cb)
147 {
148         if (!strcmp("http.sslverify", var)) {
149                 curl_ssl_verify = git_config_bool(var, value);
150                 return 0;
151         }
152         if (!strcmp("http.sslcert", var))
153                 return git_config_string(&ssl_cert, var, value);
154 #if LIBCURL_VERSION_NUM >= 0x070903
155         if (!strcmp("http.sslkey", var))
156                 return git_config_string(&ssl_key, var, value);
157 #endif
158 #if LIBCURL_VERSION_NUM >= 0x070908
159         if (!strcmp("http.sslcapath", var))
160                 return git_config_string(&ssl_capath, var, value);
161 #endif
162         if (!strcmp("http.sslcainfo", var))
163                 return git_config_string(&ssl_cainfo, var, value);
164         if (!strcmp("http.sslcertpasswordprotected", var)) {
165                 ssl_cert_password_required = git_config_bool(var, value);
166                 return 0;
167         }
168         if (!strcmp("http.ssltry", var)) {
169                 curl_ssl_try = git_config_bool(var, value);
170                 return 0;
171         }
172         if (!strcmp("http.minsessions", var)) {
173                 min_curl_sessions = git_config_int(var, value);
174 #ifndef USE_CURL_MULTI
175                 if (min_curl_sessions > 1)
176                         min_curl_sessions = 1;
177 #endif
178                 return 0;
179         }
180 #ifdef USE_CURL_MULTI
181         if (!strcmp("http.maxrequests", var)) {
182                 max_requests = git_config_int(var, value);
183                 return 0;
184         }
185 #endif
186         if (!strcmp("http.lowspeedlimit", var)) {
187                 curl_low_speed_limit = (long)git_config_int(var, value);
188                 return 0;
189         }
190         if (!strcmp("http.lowspeedtime", var)) {
191                 curl_low_speed_time = (long)git_config_int(var, value);
192                 return 0;
193         }
194
195         if (!strcmp("http.noepsv", var)) {
196                 curl_ftp_no_epsv = git_config_bool(var, value);
197                 return 0;
198         }
199         if (!strcmp("http.proxy", var))
200                 return git_config_string(&curl_http_proxy, var, value);
201
202         if (!strcmp("http.cookiefile", var))
203                 return git_config_string(&curl_cookie_file, var, value);
204         if (!strcmp("http.savecookies", var)) {
205                 curl_save_cookies = git_config_bool(var, value);
206                 return 0;
207         }
208
209         if (!strcmp("http.postbuffer", var)) {
210                 http_post_buffer = git_config_int(var, value);
211                 if (http_post_buffer < LARGE_PACKET_MAX)
212                         http_post_buffer = LARGE_PACKET_MAX;
213                 return 0;
214         }
215
216         if (!strcmp("http.useragent", var))
217                 return git_config_string(&user_agent, var, value);
218
219         /* Fall back on the default ones */
220         return git_default_config(var, value, cb);
221 }
222
223 static void init_curl_http_auth(CURL *result)
224 {
225         if (!http_auth.username)
226                 return;
227
228         credential_fill(&http_auth);
229
230 #if LIBCURL_VERSION_NUM >= 0x071301
231         curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
232         curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
233 #else
234         {
235                 static struct strbuf up = STRBUF_INIT;
236                 /*
237                  * Note that we assume we only ever have a single set of
238                  * credentials in a given program run, so we do not have
239                  * to worry about updating this buffer, only setting its
240                  * initial value.
241                  */
242                 if (!up.len)
243                         strbuf_addf(&up, "%s:%s",
244                                 http_auth.username, http_auth.password);
245                 curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
246         }
247 #endif
248 }
249
250 static int has_cert_password(void)
251 {
252         if (ssl_cert == NULL || ssl_cert_password_required != 1)
253                 return 0;
254         if (!cert_auth.password) {
255                 cert_auth.protocol = xstrdup("cert");
256                 cert_auth.username = xstrdup("");
257                 cert_auth.path = xstrdup(ssl_cert);
258                 credential_fill(&cert_auth);
259         }
260         return 1;
261 }
262
263 #if LIBCURL_VERSION_NUM >= 0x071900
264 static void set_curl_keepalive(CURL *c)
265 {
266         curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
267 }
268
269 #elif LIBCURL_VERSION_NUM >= 0x071000
270 static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
271 {
272         int ka = 1;
273         int rc;
274         socklen_t len = (socklen_t)sizeof(ka);
275
276         if (type != CURLSOCKTYPE_IPCXN)
277                 return 0;
278
279         rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
280         if (rc < 0)
281                 warning("unable to set SO_KEEPALIVE on socket %s",
282                         strerror(errno));
283
284         return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
285 }
286
287 static void set_curl_keepalive(CURL *c)
288 {
289         curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
290 }
291
292 #else
293 static void set_curl_keepalive(CURL *c)
294 {
295         /* not supported on older curl versions */
296 }
297 #endif
298
299 static CURL *get_curl_handle(void)
300 {
301         CURL *result = curl_easy_init();
302
303         if (!curl_ssl_verify) {
304                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
305                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
306         } else {
307                 /* Verify authenticity of the peer's certificate */
308                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
309                 /* The name in the cert must match whom we tried to connect */
310                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
311         }
312
313 #if LIBCURL_VERSION_NUM >= 0x070907
314         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
315 #endif
316 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
317         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
318 #endif
319
320         if (http_proactive_auth)
321                 init_curl_http_auth(result);
322
323         if (ssl_cert != NULL)
324                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
325         if (has_cert_password())
326                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
327 #if LIBCURL_VERSION_NUM >= 0x070903
328         if (ssl_key != NULL)
329                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
330 #endif
331 #if LIBCURL_VERSION_NUM >= 0x070908
332         if (ssl_capath != NULL)
333                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
334 #endif
335         if (ssl_cainfo != NULL)
336                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
337
338         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
339                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
340                                  curl_low_speed_limit);
341                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
342                                  curl_low_speed_time);
343         }
344
345         curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
346 #if LIBCURL_VERSION_NUM >= 0x071301
347         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
348 #elif LIBCURL_VERSION_NUM >= 0x071101
349         curl_easy_setopt(result, CURLOPT_POST301, 1);
350 #endif
351
352         if (getenv("GIT_CURL_VERBOSE"))
353                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
354
355         curl_easy_setopt(result, CURLOPT_USERAGENT,
356                 user_agent ? user_agent : git_user_agent());
357
358         if (curl_ftp_no_epsv)
359                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
360
361 #ifdef CURLOPT_USE_SSL
362         if (curl_ssl_try)
363                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
364 #endif
365
366         if (curl_http_proxy) {
367                 curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
368                 curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
369         }
370
371         set_curl_keepalive(result);
372
373         return result;
374 }
375
376 static void set_from_env(const char **var, const char *envname)
377 {
378         const char *val = getenv(envname);
379         if (val)
380                 *var = val;
381 }
382
383 void http_init(struct remote *remote, const char *url, int proactive_auth)
384 {
385         char *low_speed_limit;
386         char *low_speed_time;
387         char *normalized_url;
388         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
389
390         config.section = "http";
391         config.key = NULL;
392         config.collect_fn = http_options;
393         config.cascade_fn = git_default_config;
394         config.cb = NULL;
395
396         http_is_verbose = 0;
397         normalized_url = url_normalize(url, &config.url);
398
399         git_config(urlmatch_config_entry, &config);
400         free(normalized_url);
401
402         curl_global_init(CURL_GLOBAL_ALL);
403
404         http_proactive_auth = proactive_auth;
405
406         if (remote && remote->http_proxy)
407                 curl_http_proxy = xstrdup(remote->http_proxy);
408
409         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
410         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
411
412 #ifdef USE_CURL_MULTI
413         {
414                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
415                 if (http_max_requests != NULL)
416                         max_requests = atoi(http_max_requests);
417         }
418
419         curlm = curl_multi_init();
420         if (curlm == NULL) {
421                 fprintf(stderr, "Error creating curl multi handle.\n");
422                 exit(1);
423         }
424 #endif
425
426         if (getenv("GIT_SSL_NO_VERIFY"))
427                 curl_ssl_verify = 0;
428
429         set_from_env(&ssl_cert, "GIT_SSL_CERT");
430 #if LIBCURL_VERSION_NUM >= 0x070903
431         set_from_env(&ssl_key, "GIT_SSL_KEY");
432 #endif
433 #if LIBCURL_VERSION_NUM >= 0x070908
434         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
435 #endif
436         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
437
438         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
439
440         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
441         if (low_speed_limit != NULL)
442                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
443         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
444         if (low_speed_time != NULL)
445                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
446
447         if (curl_ssl_verify == -1)
448                 curl_ssl_verify = 1;
449
450         curl_session_count = 0;
451 #ifdef USE_CURL_MULTI
452         if (max_requests < 1)
453                 max_requests = DEFAULT_MAX_REQUESTS;
454 #endif
455
456         if (getenv("GIT_CURL_FTP_NO_EPSV"))
457                 curl_ftp_no_epsv = 1;
458
459         if (url) {
460                 credential_from_url(&http_auth, url);
461                 if (!ssl_cert_password_required &&
462                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
463                     starts_with(url, "https://"))
464                         ssl_cert_password_required = 1;
465         }
466
467 #ifndef NO_CURL_EASY_DUPHANDLE
468         curl_default = get_curl_handle();
469 #endif
470 }
471
472 void http_cleanup(void)
473 {
474         struct active_request_slot *slot = active_queue_head;
475
476         while (slot != NULL) {
477                 struct active_request_slot *next = slot->next;
478                 if (slot->curl != NULL) {
479 #ifdef USE_CURL_MULTI
480                         curl_multi_remove_handle(curlm, slot->curl);
481 #endif
482                         curl_easy_cleanup(slot->curl);
483                 }
484                 free(slot);
485                 slot = next;
486         }
487         active_queue_head = NULL;
488
489 #ifndef NO_CURL_EASY_DUPHANDLE
490         curl_easy_cleanup(curl_default);
491 #endif
492
493 #ifdef USE_CURL_MULTI
494         curl_multi_cleanup(curlm);
495 #endif
496         curl_global_cleanup();
497
498         curl_slist_free_all(pragma_header);
499         pragma_header = NULL;
500
501         curl_slist_free_all(no_pragma_header);
502         no_pragma_header = NULL;
503
504         if (curl_http_proxy) {
505                 free((void *)curl_http_proxy);
506                 curl_http_proxy = NULL;
507         }
508
509         if (cert_auth.password != NULL) {
510                 memset(cert_auth.password, 0, strlen(cert_auth.password));
511                 free(cert_auth.password);
512                 cert_auth.password = NULL;
513         }
514         ssl_cert_password_required = 0;
515 }
516
517 struct active_request_slot *get_active_slot(void)
518 {
519         struct active_request_slot *slot = active_queue_head;
520         struct active_request_slot *newslot;
521
522 #ifdef USE_CURL_MULTI
523         int num_transfers;
524
525         /* Wait for a slot to open up if the queue is full */
526         while (active_requests >= max_requests) {
527                 curl_multi_perform(curlm, &num_transfers);
528                 if (num_transfers < active_requests)
529                         process_curl_messages();
530         }
531 #endif
532
533         while (slot != NULL && slot->in_use)
534                 slot = slot->next;
535
536         if (slot == NULL) {
537                 newslot = xmalloc(sizeof(*newslot));
538                 newslot->curl = NULL;
539                 newslot->in_use = 0;
540                 newslot->next = NULL;
541
542                 slot = active_queue_head;
543                 if (slot == NULL) {
544                         active_queue_head = newslot;
545                 } else {
546                         while (slot->next != NULL)
547                                 slot = slot->next;
548                         slot->next = newslot;
549                 }
550                 slot = newslot;
551         }
552
553         if (slot->curl == NULL) {
554 #ifdef NO_CURL_EASY_DUPHANDLE
555                 slot->curl = get_curl_handle();
556 #else
557                 slot->curl = curl_easy_duphandle(curl_default);
558 #endif
559                 curl_session_count++;
560         }
561
562         active_requests++;
563         slot->in_use = 1;
564         slot->results = NULL;
565         slot->finished = NULL;
566         slot->callback_data = NULL;
567         slot->callback_func = NULL;
568         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
569         if (curl_save_cookies)
570                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
571         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
572         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
573         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
574         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
575         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
576         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
577         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
578         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
579         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
580         if (http_auth.password)
581                 init_curl_http_auth(slot->curl);
582
583         return slot;
584 }
585
586 int start_active_slot(struct active_request_slot *slot)
587 {
588 #ifdef USE_CURL_MULTI
589         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
590         int num_transfers;
591
592         if (curlm_result != CURLM_OK &&
593             curlm_result != CURLM_CALL_MULTI_PERFORM) {
594                 active_requests--;
595                 slot->in_use = 0;
596                 return 0;
597         }
598
599         /*
600          * We know there must be something to do, since we just added
601          * something.
602          */
603         curl_multi_perform(curlm, &num_transfers);
604 #endif
605         return 1;
606 }
607
608 #ifdef USE_CURL_MULTI
609 struct fill_chain {
610         void *data;
611         int (*fill)(void *);
612         struct fill_chain *next;
613 };
614
615 static struct fill_chain *fill_cfg;
616
617 void add_fill_function(void *data, int (*fill)(void *))
618 {
619         struct fill_chain *new = xmalloc(sizeof(*new));
620         struct fill_chain **linkp = &fill_cfg;
621         new->data = data;
622         new->fill = fill;
623         new->next = NULL;
624         while (*linkp)
625                 linkp = &(*linkp)->next;
626         *linkp = new;
627 }
628
629 void fill_active_slots(void)
630 {
631         struct active_request_slot *slot = active_queue_head;
632
633         while (active_requests < max_requests) {
634                 struct fill_chain *fill;
635                 for (fill = fill_cfg; fill; fill = fill->next)
636                         if (fill->fill(fill->data))
637                                 break;
638
639                 if (!fill)
640                         break;
641         }
642
643         while (slot != NULL) {
644                 if (!slot->in_use && slot->curl != NULL
645                         && curl_session_count > min_curl_sessions) {
646                         curl_easy_cleanup(slot->curl);
647                         slot->curl = NULL;
648                         curl_session_count--;
649                 }
650                 slot = slot->next;
651         }
652 }
653
654 void step_active_slots(void)
655 {
656         int num_transfers;
657         CURLMcode curlm_result;
658
659         do {
660                 curlm_result = curl_multi_perform(curlm, &num_transfers);
661         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
662         if (num_transfers < active_requests) {
663                 process_curl_messages();
664                 fill_active_slots();
665         }
666 }
667 #endif
668
669 void run_active_slot(struct active_request_slot *slot)
670 {
671 #ifdef USE_CURL_MULTI
672         fd_set readfds;
673         fd_set writefds;
674         fd_set excfds;
675         int max_fd;
676         struct timeval select_timeout;
677         int finished = 0;
678
679         slot->finished = &finished;
680         while (!finished) {
681                 step_active_slots();
682
683                 if (slot->in_use) {
684 #if LIBCURL_VERSION_NUM >= 0x070f04
685                         long curl_timeout;
686                         curl_multi_timeout(curlm, &curl_timeout);
687                         if (curl_timeout == 0) {
688                                 continue;
689                         } else if (curl_timeout == -1) {
690                                 select_timeout.tv_sec  = 0;
691                                 select_timeout.tv_usec = 50000;
692                         } else {
693                                 select_timeout.tv_sec  =  curl_timeout / 1000;
694                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
695                         }
696 #else
697                         select_timeout.tv_sec  = 0;
698                         select_timeout.tv_usec = 50000;
699 #endif
700
701                         max_fd = -1;
702                         FD_ZERO(&readfds);
703                         FD_ZERO(&writefds);
704                         FD_ZERO(&excfds);
705                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
706
707                         /*
708                          * It can happen that curl_multi_timeout returns a pathologically
709                          * long timeout when curl_multi_fdset returns no file descriptors
710                          * to read.  See commit message for more details.
711                          */
712                         if (max_fd < 0 &&
713                             (select_timeout.tv_sec > 0 ||
714                              select_timeout.tv_usec > 50000)) {
715                                 select_timeout.tv_sec  = 0;
716                                 select_timeout.tv_usec = 50000;
717                         }
718
719                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
720                 }
721         }
722 #else
723         while (slot->in_use) {
724                 slot->curl_result = curl_easy_perform(slot->curl);
725                 finish_active_slot(slot);
726         }
727 #endif
728 }
729
730 static void closedown_active_slot(struct active_request_slot *slot)
731 {
732         active_requests--;
733         slot->in_use = 0;
734 }
735
736 static void release_active_slot(struct active_request_slot *slot)
737 {
738         closedown_active_slot(slot);
739         if (slot->curl && curl_session_count > min_curl_sessions) {
740 #ifdef USE_CURL_MULTI
741                 curl_multi_remove_handle(curlm, slot->curl);
742 #endif
743                 curl_easy_cleanup(slot->curl);
744                 slot->curl = NULL;
745                 curl_session_count--;
746         }
747 #ifdef USE_CURL_MULTI
748         fill_active_slots();
749 #endif
750 }
751
752 void finish_active_slot(struct active_request_slot *slot)
753 {
754         closedown_active_slot(slot);
755         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
756
757         if (slot->finished != NULL)
758                 (*slot->finished) = 1;
759
760         /* Store slot results so they can be read after the slot is reused */
761         if (slot->results != NULL) {
762                 slot->results->curl_result = slot->curl_result;
763                 slot->results->http_code = slot->http_code;
764 #if LIBCURL_VERSION_NUM >= 0x070a08
765                 curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
766                                   &slot->results->auth_avail);
767 #else
768                 slot->results->auth_avail = 0;
769 #endif
770         }
771
772         /* Run callback if appropriate */
773         if (slot->callback_func != NULL)
774                 slot->callback_func(slot->callback_data);
775 }
776
777 void finish_all_active_slots(void)
778 {
779         struct active_request_slot *slot = active_queue_head;
780
781         while (slot != NULL)
782                 if (slot->in_use) {
783                         run_active_slot(slot);
784                         slot = active_queue_head;
785                 } else {
786                         slot = slot->next;
787                 }
788 }
789
790 /* Helpers for modifying and creating URLs */
791 static inline int needs_quote(int ch)
792 {
793         if (((ch >= 'A') && (ch <= 'Z'))
794                         || ((ch >= 'a') && (ch <= 'z'))
795                         || ((ch >= '0') && (ch <= '9'))
796                         || (ch == '/')
797                         || (ch == '-')
798                         || (ch == '.'))
799                 return 0;
800         return 1;
801 }
802
803 static char *quote_ref_url(const char *base, const char *ref)
804 {
805         struct strbuf buf = STRBUF_INIT;
806         const char *cp;
807         int ch;
808
809         end_url_with_slash(&buf, base);
810
811         for (cp = ref; (ch = *cp) != 0; cp++)
812                 if (needs_quote(ch))
813                         strbuf_addf(&buf, "%%%02x", ch);
814                 else
815                         strbuf_addch(&buf, *cp);
816
817         return strbuf_detach(&buf, NULL);
818 }
819
820 void append_remote_object_url(struct strbuf *buf, const char *url,
821                               const char *hex,
822                               int only_two_digit_prefix)
823 {
824         end_url_with_slash(buf, url);
825
826         strbuf_addf(buf, "objects/%.*s/", 2, hex);
827         if (!only_two_digit_prefix)
828                 strbuf_addf(buf, "%s", hex+2);
829 }
830
831 char *get_remote_object_url(const char *url, const char *hex,
832                             int only_two_digit_prefix)
833 {
834         struct strbuf buf = STRBUF_INIT;
835         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
836         return strbuf_detach(&buf, NULL);
837 }
838
839 int handle_curl_result(struct slot_results *results)
840 {
841         /*
842          * If we see a failing http code with CURLE_OK, we have turned off
843          * FAILONERROR (to keep the server's custom error response), and should
844          * translate the code into failure here.
845          */
846         if (results->curl_result == CURLE_OK &&
847             results->http_code >= 400) {
848                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
849                 /*
850                  * Normally curl will already have put the "reason phrase"
851                  * from the server into curl_errorstr; unfortunately without
852                  * FAILONERROR it is lost, so we can give only the numeric
853                  * status code.
854                  */
855                 snprintf(curl_errorstr, sizeof(curl_errorstr),
856                          "The requested URL returned error: %ld",
857                          results->http_code);
858         }
859
860         if (results->curl_result == CURLE_OK) {
861                 credential_approve(&http_auth);
862                 return HTTP_OK;
863         } else if (missing_target(results))
864                 return HTTP_MISSING_TARGET;
865         else if (results->http_code == 401) {
866                 if (http_auth.username && http_auth.password) {
867                         credential_reject(&http_auth);
868                         return HTTP_NOAUTH;
869                 } else {
870                         return HTTP_REAUTH;
871                 }
872         } else {
873 #if LIBCURL_VERSION_NUM >= 0x070c00
874                 if (!curl_errorstr[0])
875                         strlcpy(curl_errorstr,
876                                 curl_easy_strerror(results->curl_result),
877                                 sizeof(curl_errorstr));
878 #endif
879                 return HTTP_ERROR;
880         }
881 }
882
883 int run_one_slot(struct active_request_slot *slot,
884                  struct slot_results *results)
885 {
886         slot->results = results;
887         if (!start_active_slot(slot)) {
888                 snprintf(curl_errorstr, sizeof(curl_errorstr),
889                          "failed to start HTTP request");
890                 return HTTP_START_FAILED;
891         }
892
893         run_active_slot(slot);
894         return handle_curl_result(results);
895 }
896
897 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
898 {
899         char *ptr;
900         CURLcode ret;
901
902         strbuf_reset(buf);
903         ret = curl_easy_getinfo(curl, info, &ptr);
904         if (!ret && ptr)
905                 strbuf_addstr(buf, ptr);
906         return ret;
907 }
908
909 /* http_request() targets */
910 #define HTTP_REQUEST_STRBUF     0
911 #define HTTP_REQUEST_FILE       1
912
913 static int http_request(const char *url,
914                         void *result, int target,
915                         const struct http_get_options *options)
916 {
917         struct active_request_slot *slot;
918         struct slot_results results;
919         struct curl_slist *headers = NULL;
920         struct strbuf buf = STRBUF_INIT;
921         int ret;
922
923         slot = get_active_slot();
924         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
925
926         if (result == NULL) {
927                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
928         } else {
929                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
930                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
931
932                 if (target == HTTP_REQUEST_FILE) {
933                         long posn = ftell(result);
934                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
935                                          fwrite);
936                         if (posn > 0) {
937                                 strbuf_addf(&buf, "Range: bytes=%ld-", posn);
938                                 headers = curl_slist_append(headers, buf.buf);
939                                 strbuf_reset(&buf);
940                         }
941                 } else
942                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
943                                          fwrite_buffer);
944         }
945
946         strbuf_addstr(&buf, "Pragma:");
947         if (options && options->no_cache)
948                 strbuf_addstr(&buf, " no-cache");
949         if (options && options->keep_error)
950                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
951
952         headers = curl_slist_append(headers, buf.buf);
953
954         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
955         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
956         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
957
958         ret = run_one_slot(slot, &results);
959
960         if (options && options->content_type)
961                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE,
962                                 options->content_type);
963
964         if (options && options->effective_url)
965                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
966                                 options->effective_url);
967
968         curl_slist_free_all(headers);
969         strbuf_release(&buf);
970
971         return ret;
972 }
973
974 /*
975  * Update the "base" url to a more appropriate value, as deduced by
976  * redirects seen when requesting a URL starting with "url".
977  *
978  * The "asked" parameter is a URL that we asked curl to access, and must begin
979  * with "base".
980  *
981  * The "got" parameter is the URL that curl reported to us as where we ended
982  * up.
983  *
984  * Returns 1 if we updated the base url, 0 otherwise.
985  *
986  * Our basic strategy is to compare "base" and "asked" to find the bits
987  * specific to our request. We then strip those bits off of "got" to yield the
988  * new base. So for example, if our base is "http://example.com/foo.git",
989  * and we ask for "http://example.com/foo.git/info/refs", we might end up
990  * with "https://other.example.com/foo.git/info/refs". We would want the
991  * new URL to become "https://other.example.com/foo.git".
992  *
993  * Note that this assumes a sane redirect scheme. It's entirely possible
994  * in the example above to end up at a URL that does not even end in
995  * "info/refs".  In such a case we simply punt, as there is not much we can
996  * do (and such a scheme is unlikely to represent a real git repository,
997  * which means we are likely about to abort anyway).
998  */
999 static int update_url_from_redirect(struct strbuf *base,
1000                                     const char *asked,
1001                                     const struct strbuf *got)
1002 {
1003         const char *tail;
1004         size_t tail_len;
1005
1006         if (!strcmp(asked, got->buf))
1007                 return 0;
1008
1009         if (!starts_with(asked, base->buf))
1010                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1011                     asked, base->buf);
1012
1013         tail = asked + base->len;
1014         tail_len = strlen(tail);
1015
1016         if (got->len < tail_len ||
1017             strcmp(tail, got->buf + got->len - tail_len))
1018                 return 0; /* insane redirect scheme */
1019
1020         strbuf_reset(base);
1021         strbuf_add(base, got->buf, got->len - tail_len);
1022         return 1;
1023 }
1024
1025 static int http_request_reauth(const char *url,
1026                                void *result, int target,
1027                                struct http_get_options *options)
1028 {
1029         int ret = http_request(url, result, target, options);
1030
1031         if (options && options->effective_url && options->base_url) {
1032                 if (update_url_from_redirect(options->base_url,
1033                                              url, options->effective_url)) {
1034                         credential_from_url(&http_auth, options->base_url->buf);
1035                         url = options->effective_url->buf;
1036                 }
1037         }
1038
1039         if (ret != HTTP_REAUTH)
1040                 return ret;
1041
1042         /*
1043          * If we are using KEEP_ERROR, the previous request may have
1044          * put cruft into our output stream; we should clear it out before
1045          * making our next request. We only know how to do this for
1046          * the strbuf case, but that is enough to satisfy current callers.
1047          */
1048         if (options && options->keep_error) {
1049                 switch (target) {
1050                 case HTTP_REQUEST_STRBUF:
1051                         strbuf_reset(result);
1052                         break;
1053                 default:
1054                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1055                 }
1056         }
1057
1058         credential_fill(&http_auth);
1059
1060         return http_request(url, result, target, options);
1061 }
1062
1063 int http_get_strbuf(const char *url,
1064                     struct strbuf *result,
1065                     struct http_get_options *options)
1066 {
1067         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1068 }
1069
1070 /*
1071  * Downloads a URL and stores the result in the given file.
1072  *
1073  * If a previous interrupted download is detected (i.e. a previous temporary
1074  * file is still around) the download is resumed.
1075  */
1076 static int http_get_file(const char *url, const char *filename,
1077                          struct http_get_options *options)
1078 {
1079         int ret;
1080         struct strbuf tmpfile = STRBUF_INIT;
1081         FILE *result;
1082
1083         strbuf_addf(&tmpfile, "%s.temp", filename);
1084         result = fopen(tmpfile.buf, "a");
1085         if (!result) {
1086                 error("Unable to open local file %s", tmpfile.buf);
1087                 ret = HTTP_ERROR;
1088                 goto cleanup;
1089         }
1090
1091         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1092         fclose(result);
1093
1094         if (ret == HTTP_OK && move_temp_to_file(tmpfile.buf, filename))
1095                 ret = HTTP_ERROR;
1096 cleanup:
1097         strbuf_release(&tmpfile);
1098         return ret;
1099 }
1100
1101 int http_fetch_ref(const char *base, struct ref *ref)
1102 {
1103         struct http_get_options options = {0};
1104         char *url;
1105         struct strbuf buffer = STRBUF_INIT;
1106         int ret = -1;
1107
1108         options.no_cache = 1;
1109
1110         url = quote_ref_url(base, ref->name);
1111         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1112                 strbuf_rtrim(&buffer);
1113                 if (buffer.len == 40)
1114                         ret = get_sha1_hex(buffer.buf, ref->old_sha1);
1115                 else if (starts_with(buffer.buf, "ref: ")) {
1116                         ref->symref = xstrdup(buffer.buf + 5);
1117                         ret = 0;
1118                 }
1119         }
1120
1121         strbuf_release(&buffer);
1122         free(url);
1123         return ret;
1124 }
1125
1126 /* Helpers for fetching packs */
1127 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1128 {
1129         char *url, *tmp;
1130         struct strbuf buf = STRBUF_INIT;
1131
1132         if (http_is_verbose)
1133                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1134
1135         end_url_with_slash(&buf, base_url);
1136         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1137         url = strbuf_detach(&buf, NULL);
1138
1139         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1140         tmp = strbuf_detach(&buf, NULL);
1141
1142         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1143                 error("Unable to get pack index %s", url);
1144                 free(tmp);
1145                 tmp = NULL;
1146         }
1147
1148         free(url);
1149         return tmp;
1150 }
1151
1152 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1153         unsigned char *sha1, const char *base_url)
1154 {
1155         struct packed_git *new_pack;
1156         char *tmp_idx = NULL;
1157         int ret;
1158
1159         if (has_pack_index(sha1)) {
1160                 new_pack = parse_pack_index(sha1, NULL);
1161                 if (!new_pack)
1162                         return -1; /* parse_pack_index() already issued error message */
1163                 goto add_pack;
1164         }
1165
1166         tmp_idx = fetch_pack_index(sha1, base_url);
1167         if (!tmp_idx)
1168                 return -1;
1169
1170         new_pack = parse_pack_index(sha1, tmp_idx);
1171         if (!new_pack) {
1172                 unlink(tmp_idx);
1173                 free(tmp_idx);
1174
1175                 return -1; /* parse_pack_index() already issued error message */
1176         }
1177
1178         ret = verify_pack_index(new_pack);
1179         if (!ret) {
1180                 close_pack_index(new_pack);
1181                 ret = move_temp_to_file(tmp_idx, sha1_pack_index_name(sha1));
1182         }
1183         free(tmp_idx);
1184         if (ret)
1185                 return -1;
1186
1187 add_pack:
1188         new_pack->next = *packs_head;
1189         *packs_head = new_pack;
1190         return 0;
1191 }
1192
1193 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1194 {
1195         struct http_get_options options = {0};
1196         int ret = 0, i = 0;
1197         char *url, *data;
1198         struct strbuf buf = STRBUF_INIT;
1199         unsigned char sha1[20];
1200
1201         end_url_with_slash(&buf, base_url);
1202         strbuf_addstr(&buf, "objects/info/packs");
1203         url = strbuf_detach(&buf, NULL);
1204
1205         options.no_cache = 1;
1206         ret = http_get_strbuf(url, &buf, &options);
1207         if (ret != HTTP_OK)
1208                 goto cleanup;
1209
1210         data = buf.buf;
1211         while (i < buf.len) {
1212                 switch (data[i]) {
1213                 case 'P':
1214                         i++;
1215                         if (i + 52 <= buf.len &&
1216                             starts_with(data + i, " pack-") &&
1217                             starts_with(data + i + 46, ".pack\n")) {
1218                                 get_sha1_hex(data + i + 6, sha1);
1219                                 fetch_and_setup_pack_index(packs_head, sha1,
1220                                                       base_url);
1221                                 i += 51;
1222                                 break;
1223                         }
1224                 default:
1225                         while (i < buf.len && data[i] != '\n')
1226                                 i++;
1227                 }
1228                 i++;
1229         }
1230
1231 cleanup:
1232         free(url);
1233         return ret;
1234 }
1235
1236 void release_http_pack_request(struct http_pack_request *preq)
1237 {
1238         if (preq->packfile != NULL) {
1239                 fclose(preq->packfile);
1240                 preq->packfile = NULL;
1241         }
1242         if (preq->range_header != NULL) {
1243                 curl_slist_free_all(preq->range_header);
1244                 preq->range_header = NULL;
1245         }
1246         preq->slot = NULL;
1247         free(preq->url);
1248 }
1249
1250 int finish_http_pack_request(struct http_pack_request *preq)
1251 {
1252         struct packed_git **lst;
1253         struct packed_git *p = preq->target;
1254         char *tmp_idx;
1255         struct child_process ip;
1256         const char *ip_argv[8];
1257
1258         close_pack_index(p);
1259
1260         fclose(preq->packfile);
1261         preq->packfile = NULL;
1262
1263         lst = preq->lst;
1264         while (*lst != p)
1265                 lst = &((*lst)->next);
1266         *lst = (*lst)->next;
1267
1268         tmp_idx = xstrdup(preq->tmpfile);
1269         strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
1270                ".idx.temp");
1271
1272         ip_argv[0] = "index-pack";
1273         ip_argv[1] = "-o";
1274         ip_argv[2] = tmp_idx;
1275         ip_argv[3] = preq->tmpfile;
1276         ip_argv[4] = NULL;
1277
1278         memset(&ip, 0, sizeof(ip));
1279         ip.argv = ip_argv;
1280         ip.git_cmd = 1;
1281         ip.no_stdin = 1;
1282         ip.no_stdout = 1;
1283
1284         if (run_command(&ip)) {
1285                 unlink(preq->tmpfile);
1286                 unlink(tmp_idx);
1287                 free(tmp_idx);
1288                 return -1;
1289         }
1290
1291         unlink(sha1_pack_index_name(p->sha1));
1292
1293         if (move_temp_to_file(preq->tmpfile, sha1_pack_name(p->sha1))
1294          || move_temp_to_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1295                 free(tmp_idx);
1296                 return -1;
1297         }
1298
1299         install_packed_git(p);
1300         free(tmp_idx);
1301         return 0;
1302 }
1303
1304 struct http_pack_request *new_http_pack_request(
1305         struct packed_git *target, const char *base_url)
1306 {
1307         long prev_posn = 0;
1308         char range[RANGE_HEADER_SIZE];
1309         struct strbuf buf = STRBUF_INIT;
1310         struct http_pack_request *preq;
1311
1312         preq = xcalloc(1, sizeof(*preq));
1313         preq->target = target;
1314
1315         end_url_with_slash(&buf, base_url);
1316         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1317                 sha1_to_hex(target->sha1));
1318         preq->url = strbuf_detach(&buf, NULL);
1319
1320         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1321                 sha1_pack_name(target->sha1));
1322         preq->packfile = fopen(preq->tmpfile, "a");
1323         if (!preq->packfile) {
1324                 error("Unable to open local file %s for pack",
1325                       preq->tmpfile);
1326                 goto abort;
1327         }
1328
1329         preq->slot = get_active_slot();
1330         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1331         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1332         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1333         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1334                 no_pragma_header);
1335
1336         /*
1337          * If there is data present from a previous transfer attempt,
1338          * resume where it left off
1339          */
1340         prev_posn = ftell(preq->packfile);
1341         if (prev_posn>0) {
1342                 if (http_is_verbose)
1343                         fprintf(stderr,
1344                                 "Resuming fetch of pack %s at byte %ld\n",
1345                                 sha1_to_hex(target->sha1), prev_posn);
1346                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1347                 preq->range_header = curl_slist_append(NULL, range);
1348                 curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1349                         preq->range_header);
1350         }
1351
1352         return preq;
1353
1354 abort:
1355         free(preq->url);
1356         free(preq);
1357         return NULL;
1358 }
1359
1360 /* Helpers for fetching objects (loose) */
1361 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1362                                void *data)
1363 {
1364         unsigned char expn[4096];
1365         size_t size = eltsize * nmemb;
1366         int posn = 0;
1367         struct http_object_request *freq =
1368                 (struct http_object_request *)data;
1369         do {
1370                 ssize_t retval = xwrite(freq->localfile,
1371                                         (char *) ptr + posn, size - posn);
1372                 if (retval < 0)
1373                         return posn;
1374                 posn += retval;
1375         } while (posn < size);
1376
1377         freq->stream.avail_in = size;
1378         freq->stream.next_in = (void *)ptr;
1379         do {
1380                 freq->stream.next_out = expn;
1381                 freq->stream.avail_out = sizeof(expn);
1382                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1383                 git_SHA1_Update(&freq->c, expn,
1384                                 sizeof(expn) - freq->stream.avail_out);
1385         } while (freq->stream.avail_in && freq->zret == Z_OK);
1386         return size;
1387 }
1388
1389 struct http_object_request *new_http_object_request(const char *base_url,
1390         unsigned char *sha1)
1391 {
1392         char *hex = sha1_to_hex(sha1);
1393         const char *filename;
1394         char prevfile[PATH_MAX];
1395         int prevlocal;
1396         char prev_buf[PREV_BUF_SIZE];
1397         ssize_t prev_read = 0;
1398         long prev_posn = 0;
1399         char range[RANGE_HEADER_SIZE];
1400         struct curl_slist *range_header = NULL;
1401         struct http_object_request *freq;
1402
1403         freq = xcalloc(1, sizeof(*freq));
1404         hashcpy(freq->sha1, sha1);
1405         freq->localfile = -1;
1406
1407         filename = sha1_file_name(sha1);
1408         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1409                  "%s.temp", filename);
1410
1411         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1412         unlink_or_warn(prevfile);
1413         rename(freq->tmpfile, prevfile);
1414         unlink_or_warn(freq->tmpfile);
1415
1416         if (freq->localfile != -1)
1417                 error("fd leakage in start: %d", freq->localfile);
1418         freq->localfile = open(freq->tmpfile,
1419                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1420         /*
1421          * This could have failed due to the "lazy directory creation";
1422          * try to mkdir the last path component.
1423          */
1424         if (freq->localfile < 0 && errno == ENOENT) {
1425                 char *dir = strrchr(freq->tmpfile, '/');
1426                 if (dir) {
1427                         *dir = 0;
1428                         mkdir(freq->tmpfile, 0777);
1429                         *dir = '/';
1430                 }
1431                 freq->localfile = open(freq->tmpfile,
1432                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1433         }
1434
1435         if (freq->localfile < 0) {
1436                 error("Couldn't create temporary file %s: %s",
1437                       freq->tmpfile, strerror(errno));
1438                 goto abort;
1439         }
1440
1441         git_inflate_init(&freq->stream);
1442
1443         git_SHA1_Init(&freq->c);
1444
1445         freq->url = get_remote_object_url(base_url, hex, 0);
1446
1447         /*
1448          * If a previous temp file is present, process what was already
1449          * fetched.
1450          */
1451         prevlocal = open(prevfile, O_RDONLY);
1452         if (prevlocal != -1) {
1453                 do {
1454                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1455                         if (prev_read>0) {
1456                                 if (fwrite_sha1_file(prev_buf,
1457                                                      1,
1458                                                      prev_read,
1459                                                      freq) == prev_read) {
1460                                         prev_posn += prev_read;
1461                                 } else {
1462                                         prev_read = -1;
1463                                 }
1464                         }
1465                 } while (prev_read > 0);
1466                 close(prevlocal);
1467         }
1468         unlink_or_warn(prevfile);
1469
1470         /*
1471          * Reset inflate/SHA1 if there was an error reading the previous temp
1472          * file; also rewind to the beginning of the local file.
1473          */
1474         if (prev_read == -1) {
1475                 memset(&freq->stream, 0, sizeof(freq->stream));
1476                 git_inflate_init(&freq->stream);
1477                 git_SHA1_Init(&freq->c);
1478                 if (prev_posn>0) {
1479                         prev_posn = 0;
1480                         lseek(freq->localfile, 0, SEEK_SET);
1481                         if (ftruncate(freq->localfile, 0) < 0) {
1482                                 error("Couldn't truncate temporary file %s: %s",
1483                                           freq->tmpfile, strerror(errno));
1484                                 goto abort;
1485                         }
1486                 }
1487         }
1488
1489         freq->slot = get_active_slot();
1490
1491         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1492         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1493         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1494         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1495         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1496
1497         /*
1498          * If we have successfully processed data from a previous fetch
1499          * attempt, only fetch the data we don't already have.
1500          */
1501         if (prev_posn>0) {
1502                 if (http_is_verbose)
1503                         fprintf(stderr,
1504                                 "Resuming fetch of object %s at byte %ld\n",
1505                                 hex, prev_posn);
1506                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1507                 range_header = curl_slist_append(range_header, range);
1508                 curl_easy_setopt(freq->slot->curl,
1509                                  CURLOPT_HTTPHEADER, range_header);
1510         }
1511
1512         return freq;
1513
1514 abort:
1515         free(freq->url);
1516         free(freq);
1517         return NULL;
1518 }
1519
1520 void process_http_object_request(struct http_object_request *freq)
1521 {
1522         if (freq->slot == NULL)
1523                 return;
1524         freq->curl_result = freq->slot->curl_result;
1525         freq->http_code = freq->slot->http_code;
1526         freq->slot = NULL;
1527 }
1528
1529 int finish_http_object_request(struct http_object_request *freq)
1530 {
1531         struct stat st;
1532
1533         close(freq->localfile);
1534         freq->localfile = -1;
1535
1536         process_http_object_request(freq);
1537
1538         if (freq->http_code == 416) {
1539                 warning("requested range invalid; we may already have all the data.");
1540         } else if (freq->curl_result != CURLE_OK) {
1541                 if (stat(freq->tmpfile, &st) == 0)
1542                         if (st.st_size == 0)
1543                                 unlink_or_warn(freq->tmpfile);
1544                 return -1;
1545         }
1546
1547         git_inflate_end(&freq->stream);
1548         git_SHA1_Final(freq->real_sha1, &freq->c);
1549         if (freq->zret != Z_STREAM_END) {
1550                 unlink_or_warn(freq->tmpfile);
1551                 return -1;
1552         }
1553         if (hashcmp(freq->sha1, freq->real_sha1)) {
1554                 unlink_or_warn(freq->tmpfile);
1555                 return -1;
1556         }
1557         freq->rename =
1558                 move_temp_to_file(freq->tmpfile, sha1_file_name(freq->sha1));
1559
1560         return freq->rename;
1561 }
1562
1563 void abort_http_object_request(struct http_object_request *freq)
1564 {
1565         unlink_or_warn(freq->tmpfile);
1566
1567         release_http_object_request(freq);
1568 }
1569
1570 void release_http_object_request(struct http_object_request *freq)
1571 {
1572         if (freq->localfile != -1) {
1573                 close(freq->localfile);
1574                 freq->localfile = -1;
1575         }
1576         if (freq->url != NULL) {
1577                 free(freq->url);
1578                 freq->url = NULL;
1579         }
1580         if (freq->slot != NULL) {
1581                 freq->slot->callback_func = NULL;
1582                 freq->slot->callback_data = NULL;
1583                 release_active_slot(freq->slot);
1584                 freq->slot = NULL;
1585         }
1586 }