Merge branch 'jt/itimer-autoconf'
[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 (!result)
304                 die("curl_easy_init failed");
305
306         if (!curl_ssl_verify) {
307                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
308                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
309         } else {
310                 /* Verify authenticity of the peer's certificate */
311                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
312                 /* The name in the cert must match whom we tried to connect */
313                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
314         }
315
316 #if LIBCURL_VERSION_NUM >= 0x070907
317         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
318 #endif
319 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
320         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
321 #endif
322
323         if (http_proactive_auth)
324                 init_curl_http_auth(result);
325
326         if (ssl_cert != NULL)
327                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
328         if (has_cert_password())
329                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
330 #if LIBCURL_VERSION_NUM >= 0x070903
331         if (ssl_key != NULL)
332                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
333 #endif
334 #if LIBCURL_VERSION_NUM >= 0x070908
335         if (ssl_capath != NULL)
336                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
337 #endif
338         if (ssl_cainfo != NULL)
339                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
340
341         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
342                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
343                                  curl_low_speed_limit);
344                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
345                                  curl_low_speed_time);
346         }
347
348         curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
349 #if LIBCURL_VERSION_NUM >= 0x071301
350         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
351 #elif LIBCURL_VERSION_NUM >= 0x071101
352         curl_easy_setopt(result, CURLOPT_POST301, 1);
353 #endif
354
355         if (getenv("GIT_CURL_VERBOSE"))
356                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
357
358         curl_easy_setopt(result, CURLOPT_USERAGENT,
359                 user_agent ? user_agent : git_user_agent());
360
361         if (curl_ftp_no_epsv)
362                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
363
364 #ifdef CURLOPT_USE_SSL
365         if (curl_ssl_try)
366                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
367 #endif
368
369         if (curl_http_proxy) {
370                 curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
371                 curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
372         }
373
374         set_curl_keepalive(result);
375
376         return result;
377 }
378
379 static void set_from_env(const char **var, const char *envname)
380 {
381         const char *val = getenv(envname);
382         if (val)
383                 *var = val;
384 }
385
386 void http_init(struct remote *remote, const char *url, int proactive_auth)
387 {
388         char *low_speed_limit;
389         char *low_speed_time;
390         char *normalized_url;
391         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
392
393         config.section = "http";
394         config.key = NULL;
395         config.collect_fn = http_options;
396         config.cascade_fn = git_default_config;
397         config.cb = NULL;
398
399         http_is_verbose = 0;
400         normalized_url = url_normalize(url, &config.url);
401
402         git_config(urlmatch_config_entry, &config);
403         free(normalized_url);
404
405         if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
406                 die("curl_global_init failed");
407
408         http_proactive_auth = proactive_auth;
409
410         if (remote && remote->http_proxy)
411                 curl_http_proxy = xstrdup(remote->http_proxy);
412
413         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
414         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
415
416 #ifdef USE_CURL_MULTI
417         {
418                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
419                 if (http_max_requests != NULL)
420                         max_requests = atoi(http_max_requests);
421         }
422
423         curlm = curl_multi_init();
424         if (!curlm)
425                 die("curl_multi_init failed");
426 #endif
427
428         if (getenv("GIT_SSL_NO_VERIFY"))
429                 curl_ssl_verify = 0;
430
431         set_from_env(&ssl_cert, "GIT_SSL_CERT");
432 #if LIBCURL_VERSION_NUM >= 0x070903
433         set_from_env(&ssl_key, "GIT_SSL_KEY");
434 #endif
435 #if LIBCURL_VERSION_NUM >= 0x070908
436         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
437 #endif
438         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
439
440         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
441
442         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
443         if (low_speed_limit != NULL)
444                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
445         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
446         if (low_speed_time != NULL)
447                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
448
449         if (curl_ssl_verify == -1)
450                 curl_ssl_verify = 1;
451
452         curl_session_count = 0;
453 #ifdef USE_CURL_MULTI
454         if (max_requests < 1)
455                 max_requests = DEFAULT_MAX_REQUESTS;
456 #endif
457
458         if (getenv("GIT_CURL_FTP_NO_EPSV"))
459                 curl_ftp_no_epsv = 1;
460
461         if (url) {
462                 credential_from_url(&http_auth, url);
463                 if (!ssl_cert_password_required &&
464                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
465                     starts_with(url, "https://"))
466                         ssl_cert_password_required = 1;
467         }
468
469 #ifndef NO_CURL_EASY_DUPHANDLE
470         curl_default = get_curl_handle();
471 #endif
472 }
473
474 void http_cleanup(void)
475 {
476         struct active_request_slot *slot = active_queue_head;
477
478         while (slot != NULL) {
479                 struct active_request_slot *next = slot->next;
480                 if (slot->curl != NULL) {
481 #ifdef USE_CURL_MULTI
482                         curl_multi_remove_handle(curlm, slot->curl);
483 #endif
484                         curl_easy_cleanup(slot->curl);
485                 }
486                 free(slot);
487                 slot = next;
488         }
489         active_queue_head = NULL;
490
491 #ifndef NO_CURL_EASY_DUPHANDLE
492         curl_easy_cleanup(curl_default);
493 #endif
494
495 #ifdef USE_CURL_MULTI
496         curl_multi_cleanup(curlm);
497 #endif
498         curl_global_cleanup();
499
500         curl_slist_free_all(pragma_header);
501         pragma_header = NULL;
502
503         curl_slist_free_all(no_pragma_header);
504         no_pragma_header = NULL;
505
506         if (curl_http_proxy) {
507                 free((void *)curl_http_proxy);
508                 curl_http_proxy = NULL;
509         }
510
511         if (cert_auth.password != NULL) {
512                 memset(cert_auth.password, 0, strlen(cert_auth.password));
513                 free(cert_auth.password);
514                 cert_auth.password = NULL;
515         }
516         ssl_cert_password_required = 0;
517 }
518
519 struct active_request_slot *get_active_slot(void)
520 {
521         struct active_request_slot *slot = active_queue_head;
522         struct active_request_slot *newslot;
523
524 #ifdef USE_CURL_MULTI
525         int num_transfers;
526
527         /* Wait for a slot to open up if the queue is full */
528         while (active_requests >= max_requests) {
529                 curl_multi_perform(curlm, &num_transfers);
530                 if (num_transfers < active_requests)
531                         process_curl_messages();
532         }
533 #endif
534
535         while (slot != NULL && slot->in_use)
536                 slot = slot->next;
537
538         if (slot == NULL) {
539                 newslot = xmalloc(sizeof(*newslot));
540                 newslot->curl = NULL;
541                 newslot->in_use = 0;
542                 newslot->next = NULL;
543
544                 slot = active_queue_head;
545                 if (slot == NULL) {
546                         active_queue_head = newslot;
547                 } else {
548                         while (slot->next != NULL)
549                                 slot = slot->next;
550                         slot->next = newslot;
551                 }
552                 slot = newslot;
553         }
554
555         if (slot->curl == NULL) {
556 #ifdef NO_CURL_EASY_DUPHANDLE
557                 slot->curl = get_curl_handle();
558 #else
559                 slot->curl = curl_easy_duphandle(curl_default);
560 #endif
561                 curl_session_count++;
562         }
563
564         active_requests++;
565         slot->in_use = 1;
566         slot->results = NULL;
567         slot->finished = NULL;
568         slot->callback_data = NULL;
569         slot->callback_func = NULL;
570         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
571         if (curl_save_cookies)
572                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
573         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
574         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
575         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
576         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
577         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
578         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
579         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
580         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
581         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
582         if (http_auth.password)
583                 init_curl_http_auth(slot->curl);
584
585         return slot;
586 }
587
588 int start_active_slot(struct active_request_slot *slot)
589 {
590 #ifdef USE_CURL_MULTI
591         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
592         int num_transfers;
593
594         if (curlm_result != CURLM_OK &&
595             curlm_result != CURLM_CALL_MULTI_PERFORM) {
596                 active_requests--;
597                 slot->in_use = 0;
598                 return 0;
599         }
600
601         /*
602          * We know there must be something to do, since we just added
603          * something.
604          */
605         curl_multi_perform(curlm, &num_transfers);
606 #endif
607         return 1;
608 }
609
610 #ifdef USE_CURL_MULTI
611 struct fill_chain {
612         void *data;
613         int (*fill)(void *);
614         struct fill_chain *next;
615 };
616
617 static struct fill_chain *fill_cfg;
618
619 void add_fill_function(void *data, int (*fill)(void *))
620 {
621         struct fill_chain *new = xmalloc(sizeof(*new));
622         struct fill_chain **linkp = &fill_cfg;
623         new->data = data;
624         new->fill = fill;
625         new->next = NULL;
626         while (*linkp)
627                 linkp = &(*linkp)->next;
628         *linkp = new;
629 }
630
631 void fill_active_slots(void)
632 {
633         struct active_request_slot *slot = active_queue_head;
634
635         while (active_requests < max_requests) {
636                 struct fill_chain *fill;
637                 for (fill = fill_cfg; fill; fill = fill->next)
638                         if (fill->fill(fill->data))
639                                 break;
640
641                 if (!fill)
642                         break;
643         }
644
645         while (slot != NULL) {
646                 if (!slot->in_use && slot->curl != NULL
647                         && curl_session_count > min_curl_sessions) {
648                         curl_easy_cleanup(slot->curl);
649                         slot->curl = NULL;
650                         curl_session_count--;
651                 }
652                 slot = slot->next;
653         }
654 }
655
656 void step_active_slots(void)
657 {
658         int num_transfers;
659         CURLMcode curlm_result;
660
661         do {
662                 curlm_result = curl_multi_perform(curlm, &num_transfers);
663         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
664         if (num_transfers < active_requests) {
665                 process_curl_messages();
666                 fill_active_slots();
667         }
668 }
669 #endif
670
671 void run_active_slot(struct active_request_slot *slot)
672 {
673 #ifdef USE_CURL_MULTI
674         fd_set readfds;
675         fd_set writefds;
676         fd_set excfds;
677         int max_fd;
678         struct timeval select_timeout;
679         int finished = 0;
680
681         slot->finished = &finished;
682         while (!finished) {
683                 step_active_slots();
684
685                 if (slot->in_use) {
686 #if LIBCURL_VERSION_NUM >= 0x070f04
687                         long curl_timeout;
688                         curl_multi_timeout(curlm, &curl_timeout);
689                         if (curl_timeout == 0) {
690                                 continue;
691                         } else if (curl_timeout == -1) {
692                                 select_timeout.tv_sec  = 0;
693                                 select_timeout.tv_usec = 50000;
694                         } else {
695                                 select_timeout.tv_sec  =  curl_timeout / 1000;
696                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
697                         }
698 #else
699                         select_timeout.tv_sec  = 0;
700                         select_timeout.tv_usec = 50000;
701 #endif
702
703                         max_fd = -1;
704                         FD_ZERO(&readfds);
705                         FD_ZERO(&writefds);
706                         FD_ZERO(&excfds);
707                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
708
709                         /*
710                          * It can happen that curl_multi_timeout returns a pathologically
711                          * long timeout when curl_multi_fdset returns no file descriptors
712                          * to read.  See commit message for more details.
713                          */
714                         if (max_fd < 0 &&
715                             (select_timeout.tv_sec > 0 ||
716                              select_timeout.tv_usec > 50000)) {
717                                 select_timeout.tv_sec  = 0;
718                                 select_timeout.tv_usec = 50000;
719                         }
720
721                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
722                 }
723         }
724 #else
725         while (slot->in_use) {
726                 slot->curl_result = curl_easy_perform(slot->curl);
727                 finish_active_slot(slot);
728         }
729 #endif
730 }
731
732 static void closedown_active_slot(struct active_request_slot *slot)
733 {
734         active_requests--;
735         slot->in_use = 0;
736 }
737
738 static void release_active_slot(struct active_request_slot *slot)
739 {
740         closedown_active_slot(slot);
741         if (slot->curl && curl_session_count > min_curl_sessions) {
742 #ifdef USE_CURL_MULTI
743                 curl_multi_remove_handle(curlm, slot->curl);
744 #endif
745                 curl_easy_cleanup(slot->curl);
746                 slot->curl = NULL;
747                 curl_session_count--;
748         }
749 #ifdef USE_CURL_MULTI
750         fill_active_slots();
751 #endif
752 }
753
754 void finish_active_slot(struct active_request_slot *slot)
755 {
756         closedown_active_slot(slot);
757         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
758
759         if (slot->finished != NULL)
760                 (*slot->finished) = 1;
761
762         /* Store slot results so they can be read after the slot is reused */
763         if (slot->results != NULL) {
764                 slot->results->curl_result = slot->curl_result;
765                 slot->results->http_code = slot->http_code;
766 #if LIBCURL_VERSION_NUM >= 0x070a08
767                 curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
768                                   &slot->results->auth_avail);
769 #else
770                 slot->results->auth_avail = 0;
771 #endif
772         }
773
774         /* Run callback if appropriate */
775         if (slot->callback_func != NULL)
776                 slot->callback_func(slot->callback_data);
777 }
778
779 void finish_all_active_slots(void)
780 {
781         struct active_request_slot *slot = active_queue_head;
782
783         while (slot != NULL)
784                 if (slot->in_use) {
785                         run_active_slot(slot);
786                         slot = active_queue_head;
787                 } else {
788                         slot = slot->next;
789                 }
790 }
791
792 /* Helpers for modifying and creating URLs */
793 static inline int needs_quote(int ch)
794 {
795         if (((ch >= 'A') && (ch <= 'Z'))
796                         || ((ch >= 'a') && (ch <= 'z'))
797                         || ((ch >= '0') && (ch <= '9'))
798                         || (ch == '/')
799                         || (ch == '-')
800                         || (ch == '.'))
801                 return 0;
802         return 1;
803 }
804
805 static char *quote_ref_url(const char *base, const char *ref)
806 {
807         struct strbuf buf = STRBUF_INIT;
808         const char *cp;
809         int ch;
810
811         end_url_with_slash(&buf, base);
812
813         for (cp = ref; (ch = *cp) != 0; cp++)
814                 if (needs_quote(ch))
815                         strbuf_addf(&buf, "%%%02x", ch);
816                 else
817                         strbuf_addch(&buf, *cp);
818
819         return strbuf_detach(&buf, NULL);
820 }
821
822 void append_remote_object_url(struct strbuf *buf, const char *url,
823                               const char *hex,
824                               int only_two_digit_prefix)
825 {
826         end_url_with_slash(buf, url);
827
828         strbuf_addf(buf, "objects/%.*s/", 2, hex);
829         if (!only_two_digit_prefix)
830                 strbuf_addf(buf, "%s", hex+2);
831 }
832
833 char *get_remote_object_url(const char *url, const char *hex,
834                             int only_two_digit_prefix)
835 {
836         struct strbuf buf = STRBUF_INIT;
837         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
838         return strbuf_detach(&buf, NULL);
839 }
840
841 int handle_curl_result(struct slot_results *results)
842 {
843         /*
844          * If we see a failing http code with CURLE_OK, we have turned off
845          * FAILONERROR (to keep the server's custom error response), and should
846          * translate the code into failure here.
847          */
848         if (results->curl_result == CURLE_OK &&
849             results->http_code >= 400) {
850                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
851                 /*
852                  * Normally curl will already have put the "reason phrase"
853                  * from the server into curl_errorstr; unfortunately without
854                  * FAILONERROR it is lost, so we can give only the numeric
855                  * status code.
856                  */
857                 snprintf(curl_errorstr, sizeof(curl_errorstr),
858                          "The requested URL returned error: %ld",
859                          results->http_code);
860         }
861
862         if (results->curl_result == CURLE_OK) {
863                 credential_approve(&http_auth);
864                 return HTTP_OK;
865         } else if (missing_target(results))
866                 return HTTP_MISSING_TARGET;
867         else if (results->http_code == 401) {
868                 if (http_auth.username && http_auth.password) {
869                         credential_reject(&http_auth);
870                         return HTTP_NOAUTH;
871                 } else {
872                         return HTTP_REAUTH;
873                 }
874         } else {
875 #if LIBCURL_VERSION_NUM >= 0x070c00
876                 if (!curl_errorstr[0])
877                         strlcpy(curl_errorstr,
878                                 curl_easy_strerror(results->curl_result),
879                                 sizeof(curl_errorstr));
880 #endif
881                 return HTTP_ERROR;
882         }
883 }
884
885 int run_one_slot(struct active_request_slot *slot,
886                  struct slot_results *results)
887 {
888         slot->results = results;
889         if (!start_active_slot(slot)) {
890                 snprintf(curl_errorstr, sizeof(curl_errorstr),
891                          "failed to start HTTP request");
892                 return HTTP_START_FAILED;
893         }
894
895         run_active_slot(slot);
896         return handle_curl_result(results);
897 }
898
899 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
900 {
901         char *ptr;
902         CURLcode ret;
903
904         strbuf_reset(buf);
905         ret = curl_easy_getinfo(curl, info, &ptr);
906         if (!ret && ptr)
907                 strbuf_addstr(buf, ptr);
908         return ret;
909 }
910
911 /*
912  * Check for and extract a content-type parameter. "raw"
913  * should be positioned at the start of the potential
914  * parameter, with any whitespace already removed.
915  *
916  * "name" is the name of the parameter. The value is appended
917  * to "out".
918  */
919 static int extract_param(const char *raw, const char *name,
920                          struct strbuf *out)
921 {
922         size_t len = strlen(name);
923
924         if (strncasecmp(raw, name, len))
925                 return -1;
926         raw += len;
927
928         if (*raw != '=')
929                 return -1;
930         raw++;
931
932         while (*raw && !isspace(*raw) && *raw != ';')
933                 strbuf_addch(out, *raw++);
934         return 0;
935 }
936
937 /*
938  * Extract a normalized version of the content type, with any
939  * spaces suppressed, all letters lowercased, and no trailing ";"
940  * or parameters.
941  *
942  * Note that we will silently remove even invalid whitespace. For
943  * example, "text / plain" is specifically forbidden by RFC 2616,
944  * but "text/plain" is the only reasonable output, and this keeps
945  * our code simple.
946  *
947  * If the "charset" argument is not NULL, store the value of any
948  * charset parameter there.
949  *
950  * Example:
951  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
952  *   "text / plain" -> "text/plain"
953  */
954 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
955                                  struct strbuf *charset)
956 {
957         const char *p;
958
959         strbuf_reset(type);
960         strbuf_grow(type, raw->len);
961         for (p = raw->buf; *p; p++) {
962                 if (isspace(*p))
963                         continue;
964                 if (*p == ';') {
965                         p++;
966                         break;
967                 }
968                 strbuf_addch(type, tolower(*p));
969         }
970
971         if (!charset)
972                 return;
973
974         strbuf_reset(charset);
975         while (*p) {
976                 while (isspace(*p) || *p == ';')
977                         p++;
978                 if (!extract_param(p, "charset", charset))
979                         return;
980                 while (*p && !isspace(*p))
981                         p++;
982         }
983
984         if (!charset->len && starts_with(type->buf, "text/"))
985                 strbuf_addstr(charset, "ISO-8859-1");
986 }
987
988 /* http_request() targets */
989 #define HTTP_REQUEST_STRBUF     0
990 #define HTTP_REQUEST_FILE       1
991
992 static int http_request(const char *url,
993                         void *result, int target,
994                         const struct http_get_options *options)
995 {
996         struct active_request_slot *slot;
997         struct slot_results results;
998         struct curl_slist *headers = NULL;
999         struct strbuf buf = STRBUF_INIT;
1000         int ret;
1001
1002         slot = get_active_slot();
1003         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1004
1005         if (result == NULL) {
1006                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1007         } else {
1008                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1009                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1010
1011                 if (target == HTTP_REQUEST_FILE) {
1012                         long posn = ftell(result);
1013                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1014                                          fwrite);
1015                         if (posn > 0) {
1016                                 strbuf_addf(&buf, "Range: bytes=%ld-", posn);
1017                                 headers = curl_slist_append(headers, buf.buf);
1018                                 strbuf_reset(&buf);
1019                         }
1020                 } else
1021                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1022                                          fwrite_buffer);
1023         }
1024
1025         strbuf_addstr(&buf, "Pragma:");
1026         if (options && options->no_cache)
1027                 strbuf_addstr(&buf, " no-cache");
1028         if (options && options->keep_error)
1029                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1030
1031         headers = curl_slist_append(headers, buf.buf);
1032
1033         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1034         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1035         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
1036
1037         ret = run_one_slot(slot, &results);
1038
1039         if (options && options->content_type) {
1040                 struct strbuf raw = STRBUF_INIT;
1041                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1042                 extract_content_type(&raw, options->content_type,
1043                                      options->charset);
1044                 strbuf_release(&raw);
1045         }
1046
1047         if (options && options->effective_url)
1048                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1049                                 options->effective_url);
1050
1051         curl_slist_free_all(headers);
1052         strbuf_release(&buf);
1053
1054         return ret;
1055 }
1056
1057 /*
1058  * Update the "base" url to a more appropriate value, as deduced by
1059  * redirects seen when requesting a URL starting with "url".
1060  *
1061  * The "asked" parameter is a URL that we asked curl to access, and must begin
1062  * with "base".
1063  *
1064  * The "got" parameter is the URL that curl reported to us as where we ended
1065  * up.
1066  *
1067  * Returns 1 if we updated the base url, 0 otherwise.
1068  *
1069  * Our basic strategy is to compare "base" and "asked" to find the bits
1070  * specific to our request. We then strip those bits off of "got" to yield the
1071  * new base. So for example, if our base is "http://example.com/foo.git",
1072  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1073  * with "https://other.example.com/foo.git/info/refs". We would want the
1074  * new URL to become "https://other.example.com/foo.git".
1075  *
1076  * Note that this assumes a sane redirect scheme. It's entirely possible
1077  * in the example above to end up at a URL that does not even end in
1078  * "info/refs".  In such a case we simply punt, as there is not much we can
1079  * do (and such a scheme is unlikely to represent a real git repository,
1080  * which means we are likely about to abort anyway).
1081  */
1082 static int update_url_from_redirect(struct strbuf *base,
1083                                     const char *asked,
1084                                     const struct strbuf *got)
1085 {
1086         const char *tail;
1087         size_t tail_len;
1088
1089         if (!strcmp(asked, got->buf))
1090                 return 0;
1091
1092         if (!skip_prefix(asked, base->buf, &tail))
1093                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1094                     asked, base->buf);
1095
1096         tail_len = strlen(tail);
1097
1098         if (got->len < tail_len ||
1099             strcmp(tail, got->buf + got->len - tail_len))
1100                 return 0; /* insane redirect scheme */
1101
1102         strbuf_reset(base);
1103         strbuf_add(base, got->buf, got->len - tail_len);
1104         return 1;
1105 }
1106
1107 static int http_request_reauth(const char *url,
1108                                void *result, int target,
1109                                struct http_get_options *options)
1110 {
1111         int ret = http_request(url, result, target, options);
1112
1113         if (options && options->effective_url && options->base_url) {
1114                 if (update_url_from_redirect(options->base_url,
1115                                              url, options->effective_url)) {
1116                         credential_from_url(&http_auth, options->base_url->buf);
1117                         url = options->effective_url->buf;
1118                 }
1119         }
1120
1121         if (ret != HTTP_REAUTH)
1122                 return ret;
1123
1124         /*
1125          * If we are using KEEP_ERROR, the previous request may have
1126          * put cruft into our output stream; we should clear it out before
1127          * making our next request. We only know how to do this for
1128          * the strbuf case, but that is enough to satisfy current callers.
1129          */
1130         if (options && options->keep_error) {
1131                 switch (target) {
1132                 case HTTP_REQUEST_STRBUF:
1133                         strbuf_reset(result);
1134                         break;
1135                 default:
1136                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1137                 }
1138         }
1139
1140         credential_fill(&http_auth);
1141
1142         return http_request(url, result, target, options);
1143 }
1144
1145 int http_get_strbuf(const char *url,
1146                     struct strbuf *result,
1147                     struct http_get_options *options)
1148 {
1149         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1150 }
1151
1152 /*
1153  * Downloads a URL and stores the result in the given file.
1154  *
1155  * If a previous interrupted download is detected (i.e. a previous temporary
1156  * file is still around) the download is resumed.
1157  */
1158 static int http_get_file(const char *url, const char *filename,
1159                          struct http_get_options *options)
1160 {
1161         int ret;
1162         struct strbuf tmpfile = STRBUF_INIT;
1163         FILE *result;
1164
1165         strbuf_addf(&tmpfile, "%s.temp", filename);
1166         result = fopen(tmpfile.buf, "a");
1167         if (!result) {
1168                 error("Unable to open local file %s", tmpfile.buf);
1169                 ret = HTTP_ERROR;
1170                 goto cleanup;
1171         }
1172
1173         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1174         fclose(result);
1175
1176         if (ret == HTTP_OK && move_temp_to_file(tmpfile.buf, filename))
1177                 ret = HTTP_ERROR;
1178 cleanup:
1179         strbuf_release(&tmpfile);
1180         return ret;
1181 }
1182
1183 int http_fetch_ref(const char *base, struct ref *ref)
1184 {
1185         struct http_get_options options = {0};
1186         char *url;
1187         struct strbuf buffer = STRBUF_INIT;
1188         int ret = -1;
1189
1190         options.no_cache = 1;
1191
1192         url = quote_ref_url(base, ref->name);
1193         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1194                 strbuf_rtrim(&buffer);
1195                 if (buffer.len == 40)
1196                         ret = get_sha1_hex(buffer.buf, ref->old_sha1);
1197                 else if (starts_with(buffer.buf, "ref: ")) {
1198                         ref->symref = xstrdup(buffer.buf + 5);
1199                         ret = 0;
1200                 }
1201         }
1202
1203         strbuf_release(&buffer);
1204         free(url);
1205         return ret;
1206 }
1207
1208 /* Helpers for fetching packs */
1209 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1210 {
1211         char *url, *tmp;
1212         struct strbuf buf = STRBUF_INIT;
1213
1214         if (http_is_verbose)
1215                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1216
1217         end_url_with_slash(&buf, base_url);
1218         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1219         url = strbuf_detach(&buf, NULL);
1220
1221         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1222         tmp = strbuf_detach(&buf, NULL);
1223
1224         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1225                 error("Unable to get pack index %s", url);
1226                 free(tmp);
1227                 tmp = NULL;
1228         }
1229
1230         free(url);
1231         return tmp;
1232 }
1233
1234 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1235         unsigned char *sha1, const char *base_url)
1236 {
1237         struct packed_git *new_pack;
1238         char *tmp_idx = NULL;
1239         int ret;
1240
1241         if (has_pack_index(sha1)) {
1242                 new_pack = parse_pack_index(sha1, NULL);
1243                 if (!new_pack)
1244                         return -1; /* parse_pack_index() already issued error message */
1245                 goto add_pack;
1246         }
1247
1248         tmp_idx = fetch_pack_index(sha1, base_url);
1249         if (!tmp_idx)
1250                 return -1;
1251
1252         new_pack = parse_pack_index(sha1, tmp_idx);
1253         if (!new_pack) {
1254                 unlink(tmp_idx);
1255                 free(tmp_idx);
1256
1257                 return -1; /* parse_pack_index() already issued error message */
1258         }
1259
1260         ret = verify_pack_index(new_pack);
1261         if (!ret) {
1262                 close_pack_index(new_pack);
1263                 ret = move_temp_to_file(tmp_idx, sha1_pack_index_name(sha1));
1264         }
1265         free(tmp_idx);
1266         if (ret)
1267                 return -1;
1268
1269 add_pack:
1270         new_pack->next = *packs_head;
1271         *packs_head = new_pack;
1272         return 0;
1273 }
1274
1275 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1276 {
1277         struct http_get_options options = {0};
1278         int ret = 0, i = 0;
1279         char *url, *data;
1280         struct strbuf buf = STRBUF_INIT;
1281         unsigned char sha1[20];
1282
1283         end_url_with_slash(&buf, base_url);
1284         strbuf_addstr(&buf, "objects/info/packs");
1285         url = strbuf_detach(&buf, NULL);
1286
1287         options.no_cache = 1;
1288         ret = http_get_strbuf(url, &buf, &options);
1289         if (ret != HTTP_OK)
1290                 goto cleanup;
1291
1292         data = buf.buf;
1293         while (i < buf.len) {
1294                 switch (data[i]) {
1295                 case 'P':
1296                         i++;
1297                         if (i + 52 <= buf.len &&
1298                             starts_with(data + i, " pack-") &&
1299                             starts_with(data + i + 46, ".pack\n")) {
1300                                 get_sha1_hex(data + i + 6, sha1);
1301                                 fetch_and_setup_pack_index(packs_head, sha1,
1302                                                       base_url);
1303                                 i += 51;
1304                                 break;
1305                         }
1306                 default:
1307                         while (i < buf.len && data[i] != '\n')
1308                                 i++;
1309                 }
1310                 i++;
1311         }
1312
1313 cleanup:
1314         free(url);
1315         return ret;
1316 }
1317
1318 void release_http_pack_request(struct http_pack_request *preq)
1319 {
1320         if (preq->packfile != NULL) {
1321                 fclose(preq->packfile);
1322                 preq->packfile = NULL;
1323         }
1324         if (preq->range_header != NULL) {
1325                 curl_slist_free_all(preq->range_header);
1326                 preq->range_header = NULL;
1327         }
1328         preq->slot = NULL;
1329         free(preq->url);
1330 }
1331
1332 int finish_http_pack_request(struct http_pack_request *preq)
1333 {
1334         struct packed_git **lst;
1335         struct packed_git *p = preq->target;
1336         char *tmp_idx;
1337         struct child_process ip = CHILD_PROCESS_INIT;
1338         const char *ip_argv[8];
1339
1340         close_pack_index(p);
1341
1342         fclose(preq->packfile);
1343         preq->packfile = NULL;
1344
1345         lst = preq->lst;
1346         while (*lst != p)
1347                 lst = &((*lst)->next);
1348         *lst = (*lst)->next;
1349
1350         tmp_idx = xstrdup(preq->tmpfile);
1351         strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
1352                ".idx.temp");
1353
1354         ip_argv[0] = "index-pack";
1355         ip_argv[1] = "-o";
1356         ip_argv[2] = tmp_idx;
1357         ip_argv[3] = preq->tmpfile;
1358         ip_argv[4] = NULL;
1359
1360         ip.argv = ip_argv;
1361         ip.git_cmd = 1;
1362         ip.no_stdin = 1;
1363         ip.no_stdout = 1;
1364
1365         if (run_command(&ip)) {
1366                 unlink(preq->tmpfile);
1367                 unlink(tmp_idx);
1368                 free(tmp_idx);
1369                 return -1;
1370         }
1371
1372         unlink(sha1_pack_index_name(p->sha1));
1373
1374         if (move_temp_to_file(preq->tmpfile, sha1_pack_name(p->sha1))
1375          || move_temp_to_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1376                 free(tmp_idx);
1377                 return -1;
1378         }
1379
1380         install_packed_git(p);
1381         free(tmp_idx);
1382         return 0;
1383 }
1384
1385 struct http_pack_request *new_http_pack_request(
1386         struct packed_git *target, const char *base_url)
1387 {
1388         long prev_posn = 0;
1389         char range[RANGE_HEADER_SIZE];
1390         struct strbuf buf = STRBUF_INIT;
1391         struct http_pack_request *preq;
1392
1393         preq = xcalloc(1, sizeof(*preq));
1394         preq->target = target;
1395
1396         end_url_with_slash(&buf, base_url);
1397         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1398                 sha1_to_hex(target->sha1));
1399         preq->url = strbuf_detach(&buf, NULL);
1400
1401         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1402                 sha1_pack_name(target->sha1));
1403         preq->packfile = fopen(preq->tmpfile, "a");
1404         if (!preq->packfile) {
1405                 error("Unable to open local file %s for pack",
1406                       preq->tmpfile);
1407                 goto abort;
1408         }
1409
1410         preq->slot = get_active_slot();
1411         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1412         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1413         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1414         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1415                 no_pragma_header);
1416
1417         /*
1418          * If there is data present from a previous transfer attempt,
1419          * resume where it left off
1420          */
1421         prev_posn = ftell(preq->packfile);
1422         if (prev_posn>0) {
1423                 if (http_is_verbose)
1424                         fprintf(stderr,
1425                                 "Resuming fetch of pack %s at byte %ld\n",
1426                                 sha1_to_hex(target->sha1), prev_posn);
1427                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1428                 preq->range_header = curl_slist_append(NULL, range);
1429                 curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1430                         preq->range_header);
1431         }
1432
1433         return preq;
1434
1435 abort:
1436         free(preq->url);
1437         free(preq);
1438         return NULL;
1439 }
1440
1441 /* Helpers for fetching objects (loose) */
1442 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1443                                void *data)
1444 {
1445         unsigned char expn[4096];
1446         size_t size = eltsize * nmemb;
1447         int posn = 0;
1448         struct http_object_request *freq =
1449                 (struct http_object_request *)data;
1450         do {
1451                 ssize_t retval = xwrite(freq->localfile,
1452                                         (char *) ptr + posn, size - posn);
1453                 if (retval < 0)
1454                         return posn;
1455                 posn += retval;
1456         } while (posn < size);
1457
1458         freq->stream.avail_in = size;
1459         freq->stream.next_in = (void *)ptr;
1460         do {
1461                 freq->stream.next_out = expn;
1462                 freq->stream.avail_out = sizeof(expn);
1463                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1464                 git_SHA1_Update(&freq->c, expn,
1465                                 sizeof(expn) - freq->stream.avail_out);
1466         } while (freq->stream.avail_in && freq->zret == Z_OK);
1467         return size;
1468 }
1469
1470 struct http_object_request *new_http_object_request(const char *base_url,
1471         unsigned char *sha1)
1472 {
1473         char *hex = sha1_to_hex(sha1);
1474         const char *filename;
1475         char prevfile[PATH_MAX];
1476         int prevlocal;
1477         char prev_buf[PREV_BUF_SIZE];
1478         ssize_t prev_read = 0;
1479         long prev_posn = 0;
1480         char range[RANGE_HEADER_SIZE];
1481         struct curl_slist *range_header = NULL;
1482         struct http_object_request *freq;
1483
1484         freq = xcalloc(1, sizeof(*freq));
1485         hashcpy(freq->sha1, sha1);
1486         freq->localfile = -1;
1487
1488         filename = sha1_file_name(sha1);
1489         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1490                  "%s.temp", filename);
1491
1492         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1493         unlink_or_warn(prevfile);
1494         rename(freq->tmpfile, prevfile);
1495         unlink_or_warn(freq->tmpfile);
1496
1497         if (freq->localfile != -1)
1498                 error("fd leakage in start: %d", freq->localfile);
1499         freq->localfile = open(freq->tmpfile,
1500                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1501         /*
1502          * This could have failed due to the "lazy directory creation";
1503          * try to mkdir the last path component.
1504          */
1505         if (freq->localfile < 0 && errno == ENOENT) {
1506                 char *dir = strrchr(freq->tmpfile, '/');
1507                 if (dir) {
1508                         *dir = 0;
1509                         mkdir(freq->tmpfile, 0777);
1510                         *dir = '/';
1511                 }
1512                 freq->localfile = open(freq->tmpfile,
1513                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1514         }
1515
1516         if (freq->localfile < 0) {
1517                 error("Couldn't create temporary file %s: %s",
1518                       freq->tmpfile, strerror(errno));
1519                 goto abort;
1520         }
1521
1522         git_inflate_init(&freq->stream);
1523
1524         git_SHA1_Init(&freq->c);
1525
1526         freq->url = get_remote_object_url(base_url, hex, 0);
1527
1528         /*
1529          * If a previous temp file is present, process what was already
1530          * fetched.
1531          */
1532         prevlocal = open(prevfile, O_RDONLY);
1533         if (prevlocal != -1) {
1534                 do {
1535                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1536                         if (prev_read>0) {
1537                                 if (fwrite_sha1_file(prev_buf,
1538                                                      1,
1539                                                      prev_read,
1540                                                      freq) == prev_read) {
1541                                         prev_posn += prev_read;
1542                                 } else {
1543                                         prev_read = -1;
1544                                 }
1545                         }
1546                 } while (prev_read > 0);
1547                 close(prevlocal);
1548         }
1549         unlink_or_warn(prevfile);
1550
1551         /*
1552          * Reset inflate/SHA1 if there was an error reading the previous temp
1553          * file; also rewind to the beginning of the local file.
1554          */
1555         if (prev_read == -1) {
1556                 memset(&freq->stream, 0, sizeof(freq->stream));
1557                 git_inflate_init(&freq->stream);
1558                 git_SHA1_Init(&freq->c);
1559                 if (prev_posn>0) {
1560                         prev_posn = 0;
1561                         lseek(freq->localfile, 0, SEEK_SET);
1562                         if (ftruncate(freq->localfile, 0) < 0) {
1563                                 error("Couldn't truncate temporary file %s: %s",
1564                                           freq->tmpfile, strerror(errno));
1565                                 goto abort;
1566                         }
1567                 }
1568         }
1569
1570         freq->slot = get_active_slot();
1571
1572         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1573         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1574         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1575         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1576         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1577
1578         /*
1579          * If we have successfully processed data from a previous fetch
1580          * attempt, only fetch the data we don't already have.
1581          */
1582         if (prev_posn>0) {
1583                 if (http_is_verbose)
1584                         fprintf(stderr,
1585                                 "Resuming fetch of object %s at byte %ld\n",
1586                                 hex, prev_posn);
1587                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1588                 range_header = curl_slist_append(range_header, range);
1589                 curl_easy_setopt(freq->slot->curl,
1590                                  CURLOPT_HTTPHEADER, range_header);
1591         }
1592
1593         return freq;
1594
1595 abort:
1596         free(freq->url);
1597         free(freq);
1598         return NULL;
1599 }
1600
1601 void process_http_object_request(struct http_object_request *freq)
1602 {
1603         if (freq->slot == NULL)
1604                 return;
1605         freq->curl_result = freq->slot->curl_result;
1606         freq->http_code = freq->slot->http_code;
1607         freq->slot = NULL;
1608 }
1609
1610 int finish_http_object_request(struct http_object_request *freq)
1611 {
1612         struct stat st;
1613
1614         close(freq->localfile);
1615         freq->localfile = -1;
1616
1617         process_http_object_request(freq);
1618
1619         if (freq->http_code == 416) {
1620                 warning("requested range invalid; we may already have all the data.");
1621         } else if (freq->curl_result != CURLE_OK) {
1622                 if (stat(freq->tmpfile, &st) == 0)
1623                         if (st.st_size == 0)
1624                                 unlink_or_warn(freq->tmpfile);
1625                 return -1;
1626         }
1627
1628         git_inflate_end(&freq->stream);
1629         git_SHA1_Final(freq->real_sha1, &freq->c);
1630         if (freq->zret != Z_STREAM_END) {
1631                 unlink_or_warn(freq->tmpfile);
1632                 return -1;
1633         }
1634         if (hashcmp(freq->sha1, freq->real_sha1)) {
1635                 unlink_or_warn(freq->tmpfile);
1636                 return -1;
1637         }
1638         freq->rename =
1639                 move_temp_to_file(freq->tmpfile, sha1_file_name(freq->sha1));
1640
1641         return freq->rename;
1642 }
1643
1644 void abort_http_object_request(struct http_object_request *freq)
1645 {
1646         unlink_or_warn(freq->tmpfile);
1647
1648         release_http_object_request(freq);
1649 }
1650
1651 void release_http_object_request(struct http_object_request *freq)
1652 {
1653         if (freq->localfile != -1) {
1654                 close(freq->localfile);
1655                 freq->localfile = -1;
1656         }
1657         if (freq->url != NULL) {
1658                 free(freq->url);
1659                 freq->url = NULL;
1660         }
1661         if (freq->slot != NULL) {
1662                 freq->slot->callback_func = NULL;
1663                 freq->slot->callback_data = NULL;
1664                 release_active_slot(freq->slot);
1665                 freq->slot = NULL;
1666         }
1667 }