Merge branch 'jk/prompt-stash-could-be-packed' into maint
[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 /*
910  * Check for and extract a content-type parameter. "raw"
911  * should be positioned at the start of the potential
912  * parameter, with any whitespace already removed.
913  *
914  * "name" is the name of the parameter. The value is appended
915  * to "out".
916  */
917 static int extract_param(const char *raw, const char *name,
918                          struct strbuf *out)
919 {
920         size_t len = strlen(name);
921
922         if (strncasecmp(raw, name, len))
923                 return -1;
924         raw += len;
925
926         if (*raw != '=')
927                 return -1;
928         raw++;
929
930         while (*raw && !isspace(*raw) && *raw != ';')
931                 strbuf_addch(out, *raw++);
932         return 0;
933 }
934
935 /*
936  * Extract a normalized version of the content type, with any
937  * spaces suppressed, all letters lowercased, and no trailing ";"
938  * or parameters.
939  *
940  * Note that we will silently remove even invalid whitespace. For
941  * example, "text / plain" is specifically forbidden by RFC 2616,
942  * but "text/plain" is the only reasonable output, and this keeps
943  * our code simple.
944  *
945  * If the "charset" argument is not NULL, store the value of any
946  * charset parameter there.
947  *
948  * Example:
949  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
950  *   "text / plain" -> "text/plain"
951  */
952 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
953                                  struct strbuf *charset)
954 {
955         const char *p;
956
957         strbuf_reset(type);
958         strbuf_grow(type, raw->len);
959         for (p = raw->buf; *p; p++) {
960                 if (isspace(*p))
961                         continue;
962                 if (*p == ';') {
963                         p++;
964                         break;
965                 }
966                 strbuf_addch(type, tolower(*p));
967         }
968
969         if (!charset)
970                 return;
971
972         strbuf_reset(charset);
973         while (*p) {
974                 while (isspace(*p) || *p == ';')
975                         p++;
976                 if (!extract_param(p, "charset", charset))
977                         return;
978                 while (*p && !isspace(*p))
979                         p++;
980         }
981
982         if (!charset->len && starts_with(type->buf, "text/"))
983                 strbuf_addstr(charset, "ISO-8859-1");
984 }
985
986 /* http_request() targets */
987 #define HTTP_REQUEST_STRBUF     0
988 #define HTTP_REQUEST_FILE       1
989
990 static int http_request(const char *url,
991                         void *result, int target,
992                         const struct http_get_options *options)
993 {
994         struct active_request_slot *slot;
995         struct slot_results results;
996         struct curl_slist *headers = NULL;
997         struct strbuf buf = STRBUF_INIT;
998         int ret;
999
1000         slot = get_active_slot();
1001         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1002
1003         if (result == NULL) {
1004                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1005         } else {
1006                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1007                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1008
1009                 if (target == HTTP_REQUEST_FILE) {
1010                         long posn = ftell(result);
1011                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1012                                          fwrite);
1013                         if (posn > 0) {
1014                                 strbuf_addf(&buf, "Range: bytes=%ld-", posn);
1015                                 headers = curl_slist_append(headers, buf.buf);
1016                                 strbuf_reset(&buf);
1017                         }
1018                 } else
1019                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1020                                          fwrite_buffer);
1021         }
1022
1023         strbuf_addstr(&buf, "Pragma:");
1024         if (options && options->no_cache)
1025                 strbuf_addstr(&buf, " no-cache");
1026         if (options && options->keep_error)
1027                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1028
1029         headers = curl_slist_append(headers, buf.buf);
1030
1031         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1032         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1033         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
1034
1035         ret = run_one_slot(slot, &results);
1036
1037         if (options && options->content_type) {
1038                 struct strbuf raw = STRBUF_INIT;
1039                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1040                 extract_content_type(&raw, options->content_type,
1041                                      options->charset);
1042                 strbuf_release(&raw);
1043         }
1044
1045         if (options && options->effective_url)
1046                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1047                                 options->effective_url);
1048
1049         curl_slist_free_all(headers);
1050         strbuf_release(&buf);
1051
1052         return ret;
1053 }
1054
1055 /*
1056  * Update the "base" url to a more appropriate value, as deduced by
1057  * redirects seen when requesting a URL starting with "url".
1058  *
1059  * The "asked" parameter is a URL that we asked curl to access, and must begin
1060  * with "base".
1061  *
1062  * The "got" parameter is the URL that curl reported to us as where we ended
1063  * up.
1064  *
1065  * Returns 1 if we updated the base url, 0 otherwise.
1066  *
1067  * Our basic strategy is to compare "base" and "asked" to find the bits
1068  * specific to our request. We then strip those bits off of "got" to yield the
1069  * new base. So for example, if our base is "http://example.com/foo.git",
1070  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1071  * with "https://other.example.com/foo.git/info/refs". We would want the
1072  * new URL to become "https://other.example.com/foo.git".
1073  *
1074  * Note that this assumes a sane redirect scheme. It's entirely possible
1075  * in the example above to end up at a URL that does not even end in
1076  * "info/refs".  In such a case we simply punt, as there is not much we can
1077  * do (and such a scheme is unlikely to represent a real git repository,
1078  * which means we are likely about to abort anyway).
1079  */
1080 static int update_url_from_redirect(struct strbuf *base,
1081                                     const char *asked,
1082                                     const struct strbuf *got)
1083 {
1084         const char *tail;
1085         size_t tail_len;
1086
1087         if (!strcmp(asked, got->buf))
1088                 return 0;
1089
1090         if (!skip_prefix(asked, base->buf, &tail))
1091                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1092                     asked, base->buf);
1093
1094         tail_len = strlen(tail);
1095
1096         if (got->len < tail_len ||
1097             strcmp(tail, got->buf + got->len - tail_len))
1098                 return 0; /* insane redirect scheme */
1099
1100         strbuf_reset(base);
1101         strbuf_add(base, got->buf, got->len - tail_len);
1102         return 1;
1103 }
1104
1105 static int http_request_reauth(const char *url,
1106                                void *result, int target,
1107                                struct http_get_options *options)
1108 {
1109         int ret = http_request(url, result, target, options);
1110
1111         if (options && options->effective_url && options->base_url) {
1112                 if (update_url_from_redirect(options->base_url,
1113                                              url, options->effective_url)) {
1114                         credential_from_url(&http_auth, options->base_url->buf);
1115                         url = options->effective_url->buf;
1116                 }
1117         }
1118
1119         if (ret != HTTP_REAUTH)
1120                 return ret;
1121
1122         /*
1123          * If we are using KEEP_ERROR, the previous request may have
1124          * put cruft into our output stream; we should clear it out before
1125          * making our next request. We only know how to do this for
1126          * the strbuf case, but that is enough to satisfy current callers.
1127          */
1128         if (options && options->keep_error) {
1129                 switch (target) {
1130                 case HTTP_REQUEST_STRBUF:
1131                         strbuf_reset(result);
1132                         break;
1133                 default:
1134                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1135                 }
1136         }
1137
1138         credential_fill(&http_auth);
1139
1140         return http_request(url, result, target, options);
1141 }
1142
1143 int http_get_strbuf(const char *url,
1144                     struct strbuf *result,
1145                     struct http_get_options *options)
1146 {
1147         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1148 }
1149
1150 /*
1151  * Downloads a URL and stores the result in the given file.
1152  *
1153  * If a previous interrupted download is detected (i.e. a previous temporary
1154  * file is still around) the download is resumed.
1155  */
1156 static int http_get_file(const char *url, const char *filename,
1157                          struct http_get_options *options)
1158 {
1159         int ret;
1160         struct strbuf tmpfile = STRBUF_INIT;
1161         FILE *result;
1162
1163         strbuf_addf(&tmpfile, "%s.temp", filename);
1164         result = fopen(tmpfile.buf, "a");
1165         if (!result) {
1166                 error("Unable to open local file %s", tmpfile.buf);
1167                 ret = HTTP_ERROR;
1168                 goto cleanup;
1169         }
1170
1171         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1172         fclose(result);
1173
1174         if (ret == HTTP_OK && move_temp_to_file(tmpfile.buf, filename))
1175                 ret = HTTP_ERROR;
1176 cleanup:
1177         strbuf_release(&tmpfile);
1178         return ret;
1179 }
1180
1181 int http_fetch_ref(const char *base, struct ref *ref)
1182 {
1183         struct http_get_options options = {0};
1184         char *url;
1185         struct strbuf buffer = STRBUF_INIT;
1186         int ret = -1;
1187
1188         options.no_cache = 1;
1189
1190         url = quote_ref_url(base, ref->name);
1191         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1192                 strbuf_rtrim(&buffer);
1193                 if (buffer.len == 40)
1194                         ret = get_sha1_hex(buffer.buf, ref->old_sha1);
1195                 else if (starts_with(buffer.buf, "ref: ")) {
1196                         ref->symref = xstrdup(buffer.buf + 5);
1197                         ret = 0;
1198                 }
1199         }
1200
1201         strbuf_release(&buffer);
1202         free(url);
1203         return ret;
1204 }
1205
1206 /* Helpers for fetching packs */
1207 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1208 {
1209         char *url, *tmp;
1210         struct strbuf buf = STRBUF_INIT;
1211
1212         if (http_is_verbose)
1213                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1214
1215         end_url_with_slash(&buf, base_url);
1216         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1217         url = strbuf_detach(&buf, NULL);
1218
1219         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1220         tmp = strbuf_detach(&buf, NULL);
1221
1222         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1223                 error("Unable to get pack index %s", url);
1224                 free(tmp);
1225                 tmp = NULL;
1226         }
1227
1228         free(url);
1229         return tmp;
1230 }
1231
1232 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1233         unsigned char *sha1, const char *base_url)
1234 {
1235         struct packed_git *new_pack;
1236         char *tmp_idx = NULL;
1237         int ret;
1238
1239         if (has_pack_index(sha1)) {
1240                 new_pack = parse_pack_index(sha1, NULL);
1241                 if (!new_pack)
1242                         return -1; /* parse_pack_index() already issued error message */
1243                 goto add_pack;
1244         }
1245
1246         tmp_idx = fetch_pack_index(sha1, base_url);
1247         if (!tmp_idx)
1248                 return -1;
1249
1250         new_pack = parse_pack_index(sha1, tmp_idx);
1251         if (!new_pack) {
1252                 unlink(tmp_idx);
1253                 free(tmp_idx);
1254
1255                 return -1; /* parse_pack_index() already issued error message */
1256         }
1257
1258         ret = verify_pack_index(new_pack);
1259         if (!ret) {
1260                 close_pack_index(new_pack);
1261                 ret = move_temp_to_file(tmp_idx, sha1_pack_index_name(sha1));
1262         }
1263         free(tmp_idx);
1264         if (ret)
1265                 return -1;
1266
1267 add_pack:
1268         new_pack->next = *packs_head;
1269         *packs_head = new_pack;
1270         return 0;
1271 }
1272
1273 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1274 {
1275         struct http_get_options options = {0};
1276         int ret = 0, i = 0;
1277         char *url, *data;
1278         struct strbuf buf = STRBUF_INIT;
1279         unsigned char sha1[20];
1280
1281         end_url_with_slash(&buf, base_url);
1282         strbuf_addstr(&buf, "objects/info/packs");
1283         url = strbuf_detach(&buf, NULL);
1284
1285         options.no_cache = 1;
1286         ret = http_get_strbuf(url, &buf, &options);
1287         if (ret != HTTP_OK)
1288                 goto cleanup;
1289
1290         data = buf.buf;
1291         while (i < buf.len) {
1292                 switch (data[i]) {
1293                 case 'P':
1294                         i++;
1295                         if (i + 52 <= buf.len &&
1296                             starts_with(data + i, " pack-") &&
1297                             starts_with(data + i + 46, ".pack\n")) {
1298                                 get_sha1_hex(data + i + 6, sha1);
1299                                 fetch_and_setup_pack_index(packs_head, sha1,
1300                                                       base_url);
1301                                 i += 51;
1302                                 break;
1303                         }
1304                 default:
1305                         while (i < buf.len && data[i] != '\n')
1306                                 i++;
1307                 }
1308                 i++;
1309         }
1310
1311 cleanup:
1312         free(url);
1313         return ret;
1314 }
1315
1316 void release_http_pack_request(struct http_pack_request *preq)
1317 {
1318         if (preq->packfile != NULL) {
1319                 fclose(preq->packfile);
1320                 preq->packfile = NULL;
1321         }
1322         if (preq->range_header != NULL) {
1323                 curl_slist_free_all(preq->range_header);
1324                 preq->range_header = NULL;
1325         }
1326         preq->slot = NULL;
1327         free(preq->url);
1328 }
1329
1330 int finish_http_pack_request(struct http_pack_request *preq)
1331 {
1332         struct packed_git **lst;
1333         struct packed_git *p = preq->target;
1334         char *tmp_idx;
1335         struct child_process ip;
1336         const char *ip_argv[8];
1337
1338         close_pack_index(p);
1339
1340         fclose(preq->packfile);
1341         preq->packfile = NULL;
1342
1343         lst = preq->lst;
1344         while (*lst != p)
1345                 lst = &((*lst)->next);
1346         *lst = (*lst)->next;
1347
1348         tmp_idx = xstrdup(preq->tmpfile);
1349         strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
1350                ".idx.temp");
1351
1352         ip_argv[0] = "index-pack";
1353         ip_argv[1] = "-o";
1354         ip_argv[2] = tmp_idx;
1355         ip_argv[3] = preq->tmpfile;
1356         ip_argv[4] = NULL;
1357
1358         memset(&ip, 0, sizeof(ip));
1359         ip.argv = ip_argv;
1360         ip.git_cmd = 1;
1361         ip.no_stdin = 1;
1362         ip.no_stdout = 1;
1363
1364         if (run_command(&ip)) {
1365                 unlink(preq->tmpfile);
1366                 unlink(tmp_idx);
1367                 free(tmp_idx);
1368                 return -1;
1369         }
1370
1371         unlink(sha1_pack_index_name(p->sha1));
1372
1373         if (move_temp_to_file(preq->tmpfile, sha1_pack_name(p->sha1))
1374          || move_temp_to_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1375                 free(tmp_idx);
1376                 return -1;
1377         }
1378
1379         install_packed_git(p);
1380         free(tmp_idx);
1381         return 0;
1382 }
1383
1384 struct http_pack_request *new_http_pack_request(
1385         struct packed_git *target, const char *base_url)
1386 {
1387         long prev_posn = 0;
1388         char range[RANGE_HEADER_SIZE];
1389         struct strbuf buf = STRBUF_INIT;
1390         struct http_pack_request *preq;
1391
1392         preq = xcalloc(1, sizeof(*preq));
1393         preq->target = target;
1394
1395         end_url_with_slash(&buf, base_url);
1396         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1397                 sha1_to_hex(target->sha1));
1398         preq->url = strbuf_detach(&buf, NULL);
1399
1400         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1401                 sha1_pack_name(target->sha1));
1402         preq->packfile = fopen(preq->tmpfile, "a");
1403         if (!preq->packfile) {
1404                 error("Unable to open local file %s for pack",
1405                       preq->tmpfile);
1406                 goto abort;
1407         }
1408
1409         preq->slot = get_active_slot();
1410         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1411         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1412         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1413         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1414                 no_pragma_header);
1415
1416         /*
1417          * If there is data present from a previous transfer attempt,
1418          * resume where it left off
1419          */
1420         prev_posn = ftell(preq->packfile);
1421         if (prev_posn>0) {
1422                 if (http_is_verbose)
1423                         fprintf(stderr,
1424                                 "Resuming fetch of pack %s at byte %ld\n",
1425                                 sha1_to_hex(target->sha1), prev_posn);
1426                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1427                 preq->range_header = curl_slist_append(NULL, range);
1428                 curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1429                         preq->range_header);
1430         }
1431
1432         return preq;
1433
1434 abort:
1435         free(preq->url);
1436         free(preq);
1437         return NULL;
1438 }
1439
1440 /* Helpers for fetching objects (loose) */
1441 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1442                                void *data)
1443 {
1444         unsigned char expn[4096];
1445         size_t size = eltsize * nmemb;
1446         int posn = 0;
1447         struct http_object_request *freq =
1448                 (struct http_object_request *)data;
1449         do {
1450                 ssize_t retval = xwrite(freq->localfile,
1451                                         (char *) ptr + posn, size - posn);
1452                 if (retval < 0)
1453                         return posn;
1454                 posn += retval;
1455         } while (posn < size);
1456
1457         freq->stream.avail_in = size;
1458         freq->stream.next_in = (void *)ptr;
1459         do {
1460                 freq->stream.next_out = expn;
1461                 freq->stream.avail_out = sizeof(expn);
1462                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1463                 git_SHA1_Update(&freq->c, expn,
1464                                 sizeof(expn) - freq->stream.avail_out);
1465         } while (freq->stream.avail_in && freq->zret == Z_OK);
1466         return size;
1467 }
1468
1469 struct http_object_request *new_http_object_request(const char *base_url,
1470         unsigned char *sha1)
1471 {
1472         char *hex = sha1_to_hex(sha1);
1473         const char *filename;
1474         char prevfile[PATH_MAX];
1475         int prevlocal;
1476         char prev_buf[PREV_BUF_SIZE];
1477         ssize_t prev_read = 0;
1478         long prev_posn = 0;
1479         char range[RANGE_HEADER_SIZE];
1480         struct curl_slist *range_header = NULL;
1481         struct http_object_request *freq;
1482
1483         freq = xcalloc(1, sizeof(*freq));
1484         hashcpy(freq->sha1, sha1);
1485         freq->localfile = -1;
1486
1487         filename = sha1_file_name(sha1);
1488         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1489                  "%s.temp", filename);
1490
1491         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1492         unlink_or_warn(prevfile);
1493         rename(freq->tmpfile, prevfile);
1494         unlink_or_warn(freq->tmpfile);
1495
1496         if (freq->localfile != -1)
1497                 error("fd leakage in start: %d", freq->localfile);
1498         freq->localfile = open(freq->tmpfile,
1499                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1500         /*
1501          * This could have failed due to the "lazy directory creation";
1502          * try to mkdir the last path component.
1503          */
1504         if (freq->localfile < 0 && errno == ENOENT) {
1505                 char *dir = strrchr(freq->tmpfile, '/');
1506                 if (dir) {
1507                         *dir = 0;
1508                         mkdir(freq->tmpfile, 0777);
1509                         *dir = '/';
1510                 }
1511                 freq->localfile = open(freq->tmpfile,
1512                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1513         }
1514
1515         if (freq->localfile < 0) {
1516                 error("Couldn't create temporary file %s: %s",
1517                       freq->tmpfile, strerror(errno));
1518                 goto abort;
1519         }
1520
1521         git_inflate_init(&freq->stream);
1522
1523         git_SHA1_Init(&freq->c);
1524
1525         freq->url = get_remote_object_url(base_url, hex, 0);
1526
1527         /*
1528          * If a previous temp file is present, process what was already
1529          * fetched.
1530          */
1531         prevlocal = open(prevfile, O_RDONLY);
1532         if (prevlocal != -1) {
1533                 do {
1534                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1535                         if (prev_read>0) {
1536                                 if (fwrite_sha1_file(prev_buf,
1537                                                      1,
1538                                                      prev_read,
1539                                                      freq) == prev_read) {
1540                                         prev_posn += prev_read;
1541                                 } else {
1542                                         prev_read = -1;
1543                                 }
1544                         }
1545                 } while (prev_read > 0);
1546                 close(prevlocal);
1547         }
1548         unlink_or_warn(prevfile);
1549
1550         /*
1551          * Reset inflate/SHA1 if there was an error reading the previous temp
1552          * file; also rewind to the beginning of the local file.
1553          */
1554         if (prev_read == -1) {
1555                 memset(&freq->stream, 0, sizeof(freq->stream));
1556                 git_inflate_init(&freq->stream);
1557                 git_SHA1_Init(&freq->c);
1558                 if (prev_posn>0) {
1559                         prev_posn = 0;
1560                         lseek(freq->localfile, 0, SEEK_SET);
1561                         if (ftruncate(freq->localfile, 0) < 0) {
1562                                 error("Couldn't truncate temporary file %s: %s",
1563                                           freq->tmpfile, strerror(errno));
1564                                 goto abort;
1565                         }
1566                 }
1567         }
1568
1569         freq->slot = get_active_slot();
1570
1571         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1572         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1573         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1574         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1575         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1576
1577         /*
1578          * If we have successfully processed data from a previous fetch
1579          * attempt, only fetch the data we don't already have.
1580          */
1581         if (prev_posn>0) {
1582                 if (http_is_verbose)
1583                         fprintf(stderr,
1584                                 "Resuming fetch of object %s at byte %ld\n",
1585                                 hex, prev_posn);
1586                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1587                 range_header = curl_slist_append(range_header, range);
1588                 curl_easy_setopt(freq->slot->curl,
1589                                  CURLOPT_HTTPHEADER, range_header);
1590         }
1591
1592         return freq;
1593
1594 abort:
1595         free(freq->url);
1596         free(freq);
1597         return NULL;
1598 }
1599
1600 void process_http_object_request(struct http_object_request *freq)
1601 {
1602         if (freq->slot == NULL)
1603                 return;
1604         freq->curl_result = freq->slot->curl_result;
1605         freq->http_code = freq->slot->http_code;
1606         freq->slot = NULL;
1607 }
1608
1609 int finish_http_object_request(struct http_object_request *freq)
1610 {
1611         struct stat st;
1612
1613         close(freq->localfile);
1614         freq->localfile = -1;
1615
1616         process_http_object_request(freq);
1617
1618         if (freq->http_code == 416) {
1619                 warning("requested range invalid; we may already have all the data.");
1620         } else if (freq->curl_result != CURLE_OK) {
1621                 if (stat(freq->tmpfile, &st) == 0)
1622                         if (st.st_size == 0)
1623                                 unlink_or_warn(freq->tmpfile);
1624                 return -1;
1625         }
1626
1627         git_inflate_end(&freq->stream);
1628         git_SHA1_Final(freq->real_sha1, &freq->c);
1629         if (freq->zret != Z_STREAM_END) {
1630                 unlink_or_warn(freq->tmpfile);
1631                 return -1;
1632         }
1633         if (hashcmp(freq->sha1, freq->real_sha1)) {
1634                 unlink_or_warn(freq->tmpfile);
1635                 return -1;
1636         }
1637         freq->rename =
1638                 move_temp_to_file(freq->tmpfile, sha1_file_name(freq->sha1));
1639
1640         return freq->rename;
1641 }
1642
1643 void abort_http_object_request(struct http_object_request *freq)
1644 {
1645         unlink_or_warn(freq->tmpfile);
1646
1647         release_http_object_request(freq);
1648 }
1649
1650 void release_http_object_request(struct http_object_request *freq)
1651 {
1652         if (freq->localfile != -1) {
1653                 close(freq->localfile);
1654                 freq->localfile = -1;
1655         }
1656         if (freq->url != NULL) {
1657                 free(freq->url);
1658                 freq->url = NULL;
1659         }
1660         if (freq->slot != NULL) {
1661                 freq->slot->callback_func = NULL;
1662                 freq->slot->callback_data = NULL;
1663                 release_active_slot(freq->slot);
1664                 freq->slot = NULL;
1665         }
1666 }