Merge branch 'jk/pack-corruption-post-mortem' into maint
[git] / http.c
1 #include "git-compat-util.h"
2 #include "http.h"
3 #include "pack.h"
4 #include "sideband.h"
5 #include "run-command.h"
6 #include "url.h"
7 #include "urlmatch.h"
8 #include "credential.h"
9 #include "version.h"
10 #include "pkt-line.h"
11
12 int active_requests;
13 int http_is_verbose;
14 size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
15
16 #if LIBCURL_VERSION_NUM >= 0x070a06
17 #define LIBCURL_CAN_HANDLE_AUTH_ANY
18 #endif
19
20 static int min_curl_sessions = 1;
21 static int curl_session_count;
22 #ifdef USE_CURL_MULTI
23 static int max_requests = -1;
24 static CURLM *curlm;
25 #endif
26 #ifndef NO_CURL_EASY_DUPHANDLE
27 static CURL *curl_default;
28 #endif
29
30 #define PREV_BUF_SIZE 4096
31 #define RANGE_HEADER_SIZE 30
32
33 char curl_errorstr[CURL_ERROR_SIZE];
34
35 static int curl_ssl_verify = -1;
36 static int curl_ssl_try;
37 static const char *ssl_cert;
38 #if LIBCURL_VERSION_NUM >= 0x070903
39 static const char *ssl_key;
40 #endif
41 #if LIBCURL_VERSION_NUM >= 0x070908
42 static const char *ssl_capath;
43 #endif
44 static const char *ssl_cainfo;
45 static long curl_low_speed_limit = -1;
46 static long curl_low_speed_time = -1;
47 static int curl_ftp_no_epsv;
48 static const char *curl_http_proxy;
49 static const char *curl_cookie_file;
50 static int curl_save_cookies;
51 struct credential http_auth = CREDENTIAL_INIT;
52 static int http_proactive_auth;
53 static const char *user_agent;
54
55 #if LIBCURL_VERSION_NUM >= 0x071700
56 /* Use CURLOPT_KEYPASSWD as is */
57 #elif LIBCURL_VERSION_NUM >= 0x070903
58 #define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
59 #else
60 #define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
61 #endif
62
63 static struct credential cert_auth = CREDENTIAL_INIT;
64 static int ssl_cert_password_required;
65 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
66 static unsigned long http_auth_methods = CURLAUTH_ANY;
67 #endif
68
69 static struct curl_slist *pragma_header;
70 static struct curl_slist *no_pragma_header;
71
72 static struct active_request_slot *active_queue_head;
73
74 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
75 {
76         size_t size = eltsize * nmemb;
77         struct buffer *buffer = buffer_;
78
79         if (size > buffer->buf.len - buffer->posn)
80                 size = buffer->buf.len - buffer->posn;
81         memcpy(ptr, buffer->buf.buf + buffer->posn, size);
82         buffer->posn += size;
83
84         return size;
85 }
86
87 #ifndef NO_CURL_IOCTL
88 curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
89 {
90         struct buffer *buffer = clientp;
91
92         switch (cmd) {
93         case CURLIOCMD_NOP:
94                 return CURLIOE_OK;
95
96         case CURLIOCMD_RESTARTREAD:
97                 buffer->posn = 0;
98                 return CURLIOE_OK;
99
100         default:
101                 return CURLIOE_UNKNOWNCMD;
102         }
103 }
104 #endif
105
106 size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
107 {
108         size_t size = eltsize * nmemb;
109         struct strbuf *buffer = buffer_;
110
111         strbuf_add(buffer, ptr, size);
112         return size;
113 }
114
115 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
116 {
117         return eltsize * nmemb;
118 }
119
120 #ifdef USE_CURL_MULTI
121 static void process_curl_messages(void)
122 {
123         int num_messages;
124         struct active_request_slot *slot;
125         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
126
127         while (curl_message != NULL) {
128                 if (curl_message->msg == CURLMSG_DONE) {
129                         int curl_result = curl_message->data.result;
130                         slot = active_queue_head;
131                         while (slot != NULL &&
132                                slot->curl != curl_message->easy_handle)
133                                 slot = slot->next;
134                         if (slot != NULL) {
135                                 curl_multi_remove_handle(curlm, slot->curl);
136                                 slot->curl_result = curl_result;
137                                 finish_active_slot(slot);
138                         } else {
139                                 fprintf(stderr, "Received DONE message for unknown request!\n");
140                         }
141                 } else {
142                         fprintf(stderr, "Unknown CURL message received: %d\n",
143                                 (int)curl_message->msg);
144                 }
145                 curl_message = curl_multi_info_read(curlm, &num_messages);
146         }
147 }
148 #endif
149
150 static int http_options(const char *var, const char *value, void *cb)
151 {
152         if (!strcmp("http.sslverify", var)) {
153                 curl_ssl_verify = git_config_bool(var, value);
154                 return 0;
155         }
156         if (!strcmp("http.sslcert", var))
157                 return git_config_string(&ssl_cert, var, value);
158 #if LIBCURL_VERSION_NUM >= 0x070903
159         if (!strcmp("http.sslkey", var))
160                 return git_config_string(&ssl_key, var, value);
161 #endif
162 #if LIBCURL_VERSION_NUM >= 0x070908
163         if (!strcmp("http.sslcapath", var))
164                 return git_config_string(&ssl_capath, var, value);
165 #endif
166         if (!strcmp("http.sslcainfo", var))
167                 return git_config_string(&ssl_cainfo, var, value);
168         if (!strcmp("http.sslcertpasswordprotected", var)) {
169                 ssl_cert_password_required = git_config_bool(var, value);
170                 return 0;
171         }
172         if (!strcmp("http.ssltry", var)) {
173                 curl_ssl_try = git_config_bool(var, value);
174                 return 0;
175         }
176         if (!strcmp("http.minsessions", var)) {
177                 min_curl_sessions = git_config_int(var, value);
178 #ifndef USE_CURL_MULTI
179                 if (min_curl_sessions > 1)
180                         min_curl_sessions = 1;
181 #endif
182                 return 0;
183         }
184 #ifdef USE_CURL_MULTI
185         if (!strcmp("http.maxrequests", var)) {
186                 max_requests = git_config_int(var, value);
187                 return 0;
188         }
189 #endif
190         if (!strcmp("http.lowspeedlimit", var)) {
191                 curl_low_speed_limit = (long)git_config_int(var, value);
192                 return 0;
193         }
194         if (!strcmp("http.lowspeedtime", var)) {
195                 curl_low_speed_time = (long)git_config_int(var, value);
196                 return 0;
197         }
198
199         if (!strcmp("http.noepsv", var)) {
200                 curl_ftp_no_epsv = git_config_bool(var, value);
201                 return 0;
202         }
203         if (!strcmp("http.proxy", var))
204                 return git_config_string(&curl_http_proxy, var, value);
205
206         if (!strcmp("http.cookiefile", var))
207                 return git_config_string(&curl_cookie_file, var, value);
208         if (!strcmp("http.savecookies", var)) {
209                 curl_save_cookies = git_config_bool(var, value);
210                 return 0;
211         }
212
213         if (!strcmp("http.postbuffer", var)) {
214                 http_post_buffer = git_config_int(var, value);
215                 if (http_post_buffer < LARGE_PACKET_MAX)
216                         http_post_buffer = LARGE_PACKET_MAX;
217                 return 0;
218         }
219
220         if (!strcmp("http.useragent", var))
221                 return git_config_string(&user_agent, var, value);
222
223         /* Fall back on the default ones */
224         return git_default_config(var, value, cb);
225 }
226
227 static void init_curl_http_auth(CURL *result)
228 {
229         if (!http_auth.username)
230                 return;
231
232         credential_fill(&http_auth);
233
234 #if LIBCURL_VERSION_NUM >= 0x071301
235         curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
236         curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
237 #else
238         {
239                 static struct strbuf up = STRBUF_INIT;
240                 /*
241                  * Note that we assume we only ever have a single set of
242                  * credentials in a given program run, so we do not have
243                  * to worry about updating this buffer, only setting its
244                  * initial value.
245                  */
246                 if (!up.len)
247                         strbuf_addf(&up, "%s:%s",
248                                 http_auth.username, http_auth.password);
249                 curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
250         }
251 #endif
252 }
253
254 static int has_cert_password(void)
255 {
256         if (ssl_cert == NULL || ssl_cert_password_required != 1)
257                 return 0;
258         if (!cert_auth.password) {
259                 cert_auth.protocol = xstrdup("cert");
260                 cert_auth.username = xstrdup("");
261                 cert_auth.path = xstrdup(ssl_cert);
262                 credential_fill(&cert_auth);
263         }
264         return 1;
265 }
266
267 #if LIBCURL_VERSION_NUM >= 0x071900
268 static void set_curl_keepalive(CURL *c)
269 {
270         curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
271 }
272
273 #elif LIBCURL_VERSION_NUM >= 0x071000
274 static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
275 {
276         int ka = 1;
277         int rc;
278         socklen_t len = (socklen_t)sizeof(ka);
279
280         if (type != CURLSOCKTYPE_IPCXN)
281                 return 0;
282
283         rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
284         if (rc < 0)
285                 warning("unable to set SO_KEEPALIVE on socket %s",
286                         strerror(errno));
287
288         return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
289 }
290
291 static void set_curl_keepalive(CURL *c)
292 {
293         curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
294 }
295
296 #else
297 static void set_curl_keepalive(CURL *c)
298 {
299         /* not supported on older curl versions */
300 }
301 #endif
302
303 static CURL *get_curl_handle(void)
304 {
305         CURL *result = curl_easy_init();
306
307         if (!result)
308                 die("curl_easy_init failed");
309
310         if (!curl_ssl_verify) {
311                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
312                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
313         } else {
314                 /* Verify authenticity of the peer's certificate */
315                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
316                 /* The name in the cert must match whom we tried to connect */
317                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
318         }
319
320 #if LIBCURL_VERSION_NUM >= 0x070907
321         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
322 #endif
323 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
324         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
325 #endif
326
327         if (http_proactive_auth)
328                 init_curl_http_auth(result);
329
330         if (ssl_cert != NULL)
331                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
332         if (has_cert_password())
333                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
334 #if LIBCURL_VERSION_NUM >= 0x070903
335         if (ssl_key != NULL)
336                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
337 #endif
338 #if LIBCURL_VERSION_NUM >= 0x070908
339         if (ssl_capath != NULL)
340                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
341 #endif
342         if (ssl_cainfo != NULL)
343                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
344
345         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
346                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
347                                  curl_low_speed_limit);
348                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
349                                  curl_low_speed_time);
350         }
351
352         curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
353 #if LIBCURL_VERSION_NUM >= 0x071301
354         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
355 #elif LIBCURL_VERSION_NUM >= 0x071101
356         curl_easy_setopt(result, CURLOPT_POST301, 1);
357 #endif
358
359         if (getenv("GIT_CURL_VERBOSE"))
360                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
361
362         curl_easy_setopt(result, CURLOPT_USERAGENT,
363                 user_agent ? user_agent : git_user_agent());
364
365         if (curl_ftp_no_epsv)
366                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
367
368 #ifdef CURLOPT_USE_SSL
369         if (curl_ssl_try)
370                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
371 #endif
372
373         if (curl_http_proxy) {
374                 curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
375                 curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
376         }
377
378         set_curl_keepalive(result);
379
380         return result;
381 }
382
383 static void set_from_env(const char **var, const char *envname)
384 {
385         const char *val = getenv(envname);
386         if (val)
387                 *var = val;
388 }
389
390 void http_init(struct remote *remote, const char *url, int proactive_auth)
391 {
392         char *low_speed_limit;
393         char *low_speed_time;
394         char *normalized_url;
395         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
396
397         config.section = "http";
398         config.key = NULL;
399         config.collect_fn = http_options;
400         config.cascade_fn = git_default_config;
401         config.cb = NULL;
402
403         http_is_verbose = 0;
404         normalized_url = url_normalize(url, &config.url);
405
406         git_config(urlmatch_config_entry, &config);
407         free(normalized_url);
408
409         if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
410                 die("curl_global_init failed");
411
412         http_proactive_auth = proactive_auth;
413
414         if (remote && remote->http_proxy)
415                 curl_http_proxy = xstrdup(remote->http_proxy);
416
417         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
418         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
419
420 #ifdef USE_CURL_MULTI
421         {
422                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
423                 if (http_max_requests != NULL)
424                         max_requests = atoi(http_max_requests);
425         }
426
427         curlm = curl_multi_init();
428         if (!curlm)
429                 die("curl_multi_init failed");
430 #endif
431
432         if (getenv("GIT_SSL_NO_VERIFY"))
433                 curl_ssl_verify = 0;
434
435         set_from_env(&ssl_cert, "GIT_SSL_CERT");
436 #if LIBCURL_VERSION_NUM >= 0x070903
437         set_from_env(&ssl_key, "GIT_SSL_KEY");
438 #endif
439 #if LIBCURL_VERSION_NUM >= 0x070908
440         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
441 #endif
442         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
443
444         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
445
446         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
447         if (low_speed_limit != NULL)
448                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
449         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
450         if (low_speed_time != NULL)
451                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
452
453         if (curl_ssl_verify == -1)
454                 curl_ssl_verify = 1;
455
456         curl_session_count = 0;
457 #ifdef USE_CURL_MULTI
458         if (max_requests < 1)
459                 max_requests = DEFAULT_MAX_REQUESTS;
460 #endif
461
462         if (getenv("GIT_CURL_FTP_NO_EPSV"))
463                 curl_ftp_no_epsv = 1;
464
465         if (url) {
466                 credential_from_url(&http_auth, url);
467                 if (!ssl_cert_password_required &&
468                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
469                     starts_with(url, "https://"))
470                         ssl_cert_password_required = 1;
471         }
472
473 #ifndef NO_CURL_EASY_DUPHANDLE
474         curl_default = get_curl_handle();
475 #endif
476 }
477
478 void http_cleanup(void)
479 {
480         struct active_request_slot *slot = active_queue_head;
481
482         while (slot != NULL) {
483                 struct active_request_slot *next = slot->next;
484                 if (slot->curl != NULL) {
485 #ifdef USE_CURL_MULTI
486                         curl_multi_remove_handle(curlm, slot->curl);
487 #endif
488                         curl_easy_cleanup(slot->curl);
489                 }
490                 free(slot);
491                 slot = next;
492         }
493         active_queue_head = NULL;
494
495 #ifndef NO_CURL_EASY_DUPHANDLE
496         curl_easy_cleanup(curl_default);
497 #endif
498
499 #ifdef USE_CURL_MULTI
500         curl_multi_cleanup(curlm);
501 #endif
502         curl_global_cleanup();
503
504         curl_slist_free_all(pragma_header);
505         pragma_header = NULL;
506
507         curl_slist_free_all(no_pragma_header);
508         no_pragma_header = NULL;
509
510         if (curl_http_proxy) {
511                 free((void *)curl_http_proxy);
512                 curl_http_proxy = NULL;
513         }
514
515         if (cert_auth.password != NULL) {
516                 memset(cert_auth.password, 0, strlen(cert_auth.password));
517                 free(cert_auth.password);
518                 cert_auth.password = NULL;
519         }
520         ssl_cert_password_required = 0;
521 }
522
523 struct active_request_slot *get_active_slot(void)
524 {
525         struct active_request_slot *slot = active_queue_head;
526         struct active_request_slot *newslot;
527
528 #ifdef USE_CURL_MULTI
529         int num_transfers;
530
531         /* Wait for a slot to open up if the queue is full */
532         while (active_requests >= max_requests) {
533                 curl_multi_perform(curlm, &num_transfers);
534                 if (num_transfers < active_requests)
535                         process_curl_messages();
536         }
537 #endif
538
539         while (slot != NULL && slot->in_use)
540                 slot = slot->next;
541
542         if (slot == NULL) {
543                 newslot = xmalloc(sizeof(*newslot));
544                 newslot->curl = NULL;
545                 newslot->in_use = 0;
546                 newslot->next = NULL;
547
548                 slot = active_queue_head;
549                 if (slot == NULL) {
550                         active_queue_head = newslot;
551                 } else {
552                         while (slot->next != NULL)
553                                 slot = slot->next;
554                         slot->next = newslot;
555                 }
556                 slot = newslot;
557         }
558
559         if (slot->curl == NULL) {
560 #ifdef NO_CURL_EASY_DUPHANDLE
561                 slot->curl = get_curl_handle();
562 #else
563                 slot->curl = curl_easy_duphandle(curl_default);
564 #endif
565                 curl_session_count++;
566         }
567
568         active_requests++;
569         slot->in_use = 1;
570         slot->results = NULL;
571         slot->finished = NULL;
572         slot->callback_data = NULL;
573         slot->callback_func = NULL;
574         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
575         if (curl_save_cookies)
576                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
577         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
578         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
579         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
580         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
581         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
582         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
583         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
584         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
585         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
586 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
587         curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
588 #endif
589         if (http_auth.password)
590                 init_curl_http_auth(slot->curl);
591
592         return slot;
593 }
594
595 int start_active_slot(struct active_request_slot *slot)
596 {
597 #ifdef USE_CURL_MULTI
598         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
599         int num_transfers;
600
601         if (curlm_result != CURLM_OK &&
602             curlm_result != CURLM_CALL_MULTI_PERFORM) {
603                 active_requests--;
604                 slot->in_use = 0;
605                 return 0;
606         }
607
608         /*
609          * We know there must be something to do, since we just added
610          * something.
611          */
612         curl_multi_perform(curlm, &num_transfers);
613 #endif
614         return 1;
615 }
616
617 #ifdef USE_CURL_MULTI
618 struct fill_chain {
619         void *data;
620         int (*fill)(void *);
621         struct fill_chain *next;
622 };
623
624 static struct fill_chain *fill_cfg;
625
626 void add_fill_function(void *data, int (*fill)(void *))
627 {
628         struct fill_chain *new = xmalloc(sizeof(*new));
629         struct fill_chain **linkp = &fill_cfg;
630         new->data = data;
631         new->fill = fill;
632         new->next = NULL;
633         while (*linkp)
634                 linkp = &(*linkp)->next;
635         *linkp = new;
636 }
637
638 void fill_active_slots(void)
639 {
640         struct active_request_slot *slot = active_queue_head;
641
642         while (active_requests < max_requests) {
643                 struct fill_chain *fill;
644                 for (fill = fill_cfg; fill; fill = fill->next)
645                         if (fill->fill(fill->data))
646                                 break;
647
648                 if (!fill)
649                         break;
650         }
651
652         while (slot != NULL) {
653                 if (!slot->in_use && slot->curl != NULL
654                         && curl_session_count > min_curl_sessions) {
655                         curl_easy_cleanup(slot->curl);
656                         slot->curl = NULL;
657                         curl_session_count--;
658                 }
659                 slot = slot->next;
660         }
661 }
662
663 void step_active_slots(void)
664 {
665         int num_transfers;
666         CURLMcode curlm_result;
667
668         do {
669                 curlm_result = curl_multi_perform(curlm, &num_transfers);
670         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
671         if (num_transfers < active_requests) {
672                 process_curl_messages();
673                 fill_active_slots();
674         }
675 }
676 #endif
677
678 void run_active_slot(struct active_request_slot *slot)
679 {
680 #ifdef USE_CURL_MULTI
681         fd_set readfds;
682         fd_set writefds;
683         fd_set excfds;
684         int max_fd;
685         struct timeval select_timeout;
686         int finished = 0;
687
688         slot->finished = &finished;
689         while (!finished) {
690                 step_active_slots();
691
692                 if (slot->in_use) {
693 #if LIBCURL_VERSION_NUM >= 0x070f04
694                         long curl_timeout;
695                         curl_multi_timeout(curlm, &curl_timeout);
696                         if (curl_timeout == 0) {
697                                 continue;
698                         } else if (curl_timeout == -1) {
699                                 select_timeout.tv_sec  = 0;
700                                 select_timeout.tv_usec = 50000;
701                         } else {
702                                 select_timeout.tv_sec  =  curl_timeout / 1000;
703                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
704                         }
705 #else
706                         select_timeout.tv_sec  = 0;
707                         select_timeout.tv_usec = 50000;
708 #endif
709
710                         max_fd = -1;
711                         FD_ZERO(&readfds);
712                         FD_ZERO(&writefds);
713                         FD_ZERO(&excfds);
714                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
715
716                         /*
717                          * It can happen that curl_multi_timeout returns a pathologically
718                          * long timeout when curl_multi_fdset returns no file descriptors
719                          * to read.  See commit message for more details.
720                          */
721                         if (max_fd < 0 &&
722                             (select_timeout.tv_sec > 0 ||
723                              select_timeout.tv_usec > 50000)) {
724                                 select_timeout.tv_sec  = 0;
725                                 select_timeout.tv_usec = 50000;
726                         }
727
728                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
729                 }
730         }
731 #else
732         while (slot->in_use) {
733                 slot->curl_result = curl_easy_perform(slot->curl);
734                 finish_active_slot(slot);
735         }
736 #endif
737 }
738
739 static void closedown_active_slot(struct active_request_slot *slot)
740 {
741         active_requests--;
742         slot->in_use = 0;
743 }
744
745 static void release_active_slot(struct active_request_slot *slot)
746 {
747         closedown_active_slot(slot);
748         if (slot->curl && curl_session_count > min_curl_sessions) {
749 #ifdef USE_CURL_MULTI
750                 curl_multi_remove_handle(curlm, slot->curl);
751 #endif
752                 curl_easy_cleanup(slot->curl);
753                 slot->curl = NULL;
754                 curl_session_count--;
755         }
756 #ifdef USE_CURL_MULTI
757         fill_active_slots();
758 #endif
759 }
760
761 void finish_active_slot(struct active_request_slot *slot)
762 {
763         closedown_active_slot(slot);
764         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
765
766         if (slot->finished != NULL)
767                 (*slot->finished) = 1;
768
769         /* Store slot results so they can be read after the slot is reused */
770         if (slot->results != NULL) {
771                 slot->results->curl_result = slot->curl_result;
772                 slot->results->http_code = slot->http_code;
773 #if LIBCURL_VERSION_NUM >= 0x070a08
774                 curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
775                                   &slot->results->auth_avail);
776 #else
777                 slot->results->auth_avail = 0;
778 #endif
779         }
780
781         /* Run callback if appropriate */
782         if (slot->callback_func != NULL)
783                 slot->callback_func(slot->callback_data);
784 }
785
786 void finish_all_active_slots(void)
787 {
788         struct active_request_slot *slot = active_queue_head;
789
790         while (slot != NULL)
791                 if (slot->in_use) {
792                         run_active_slot(slot);
793                         slot = active_queue_head;
794                 } else {
795                         slot = slot->next;
796                 }
797 }
798
799 /* Helpers for modifying and creating URLs */
800 static inline int needs_quote(int ch)
801 {
802         if (((ch >= 'A') && (ch <= 'Z'))
803                         || ((ch >= 'a') && (ch <= 'z'))
804                         || ((ch >= '0') && (ch <= '9'))
805                         || (ch == '/')
806                         || (ch == '-')
807                         || (ch == '.'))
808                 return 0;
809         return 1;
810 }
811
812 static char *quote_ref_url(const char *base, const char *ref)
813 {
814         struct strbuf buf = STRBUF_INIT;
815         const char *cp;
816         int ch;
817
818         end_url_with_slash(&buf, base);
819
820         for (cp = ref; (ch = *cp) != 0; cp++)
821                 if (needs_quote(ch))
822                         strbuf_addf(&buf, "%%%02x", ch);
823                 else
824                         strbuf_addch(&buf, *cp);
825
826         return strbuf_detach(&buf, NULL);
827 }
828
829 void append_remote_object_url(struct strbuf *buf, const char *url,
830                               const char *hex,
831                               int only_two_digit_prefix)
832 {
833         end_url_with_slash(buf, url);
834
835         strbuf_addf(buf, "objects/%.*s/", 2, hex);
836         if (!only_two_digit_prefix)
837                 strbuf_addf(buf, "%s", hex+2);
838 }
839
840 char *get_remote_object_url(const char *url, const char *hex,
841                             int only_two_digit_prefix)
842 {
843         struct strbuf buf = STRBUF_INIT;
844         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
845         return strbuf_detach(&buf, NULL);
846 }
847
848 int handle_curl_result(struct slot_results *results)
849 {
850         /*
851          * If we see a failing http code with CURLE_OK, we have turned off
852          * FAILONERROR (to keep the server's custom error response), and should
853          * translate the code into failure here.
854          */
855         if (results->curl_result == CURLE_OK &&
856             results->http_code >= 400) {
857                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
858                 /*
859                  * Normally curl will already have put the "reason phrase"
860                  * from the server into curl_errorstr; unfortunately without
861                  * FAILONERROR it is lost, so we can give only the numeric
862                  * status code.
863                  */
864                 snprintf(curl_errorstr, sizeof(curl_errorstr),
865                          "The requested URL returned error: %ld",
866                          results->http_code);
867         }
868
869         if (results->curl_result == CURLE_OK) {
870                 credential_approve(&http_auth);
871                 return HTTP_OK;
872         } else if (missing_target(results))
873                 return HTTP_MISSING_TARGET;
874         else if (results->http_code == 401) {
875                 if (http_auth.username && http_auth.password) {
876                         credential_reject(&http_auth);
877                         return HTTP_NOAUTH;
878                 } else {
879 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
880                         http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
881 #endif
882                         return HTTP_REAUTH;
883                 }
884         } else {
885 #if LIBCURL_VERSION_NUM >= 0x070c00
886                 if (!curl_errorstr[0])
887                         strlcpy(curl_errorstr,
888                                 curl_easy_strerror(results->curl_result),
889                                 sizeof(curl_errorstr));
890 #endif
891                 return HTTP_ERROR;
892         }
893 }
894
895 int run_one_slot(struct active_request_slot *slot,
896                  struct slot_results *results)
897 {
898         slot->results = results;
899         if (!start_active_slot(slot)) {
900                 snprintf(curl_errorstr, sizeof(curl_errorstr),
901                          "failed to start HTTP request");
902                 return HTTP_START_FAILED;
903         }
904
905         run_active_slot(slot);
906         return handle_curl_result(results);
907 }
908
909 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
910 {
911         char *ptr;
912         CURLcode ret;
913
914         strbuf_reset(buf);
915         ret = curl_easy_getinfo(curl, info, &ptr);
916         if (!ret && ptr)
917                 strbuf_addstr(buf, ptr);
918         return ret;
919 }
920
921 /*
922  * Check for and extract a content-type parameter. "raw"
923  * should be positioned at the start of the potential
924  * parameter, with any whitespace already removed.
925  *
926  * "name" is the name of the parameter. The value is appended
927  * to "out".
928  */
929 static int extract_param(const char *raw, const char *name,
930                          struct strbuf *out)
931 {
932         size_t len = strlen(name);
933
934         if (strncasecmp(raw, name, len))
935                 return -1;
936         raw += len;
937
938         if (*raw != '=')
939                 return -1;
940         raw++;
941
942         while (*raw && !isspace(*raw) && *raw != ';')
943                 strbuf_addch(out, *raw++);
944         return 0;
945 }
946
947 /*
948  * Extract a normalized version of the content type, with any
949  * spaces suppressed, all letters lowercased, and no trailing ";"
950  * or parameters.
951  *
952  * Note that we will silently remove even invalid whitespace. For
953  * example, "text / plain" is specifically forbidden by RFC 2616,
954  * but "text/plain" is the only reasonable output, and this keeps
955  * our code simple.
956  *
957  * If the "charset" argument is not NULL, store the value of any
958  * charset parameter there.
959  *
960  * Example:
961  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
962  *   "text / plain" -> "text/plain"
963  */
964 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
965                                  struct strbuf *charset)
966 {
967         const char *p;
968
969         strbuf_reset(type);
970         strbuf_grow(type, raw->len);
971         for (p = raw->buf; *p; p++) {
972                 if (isspace(*p))
973                         continue;
974                 if (*p == ';') {
975                         p++;
976                         break;
977                 }
978                 strbuf_addch(type, tolower(*p));
979         }
980
981         if (!charset)
982                 return;
983
984         strbuf_reset(charset);
985         while (*p) {
986                 while (isspace(*p) || *p == ';')
987                         p++;
988                 if (!extract_param(p, "charset", charset))
989                         return;
990                 while (*p && !isspace(*p))
991                         p++;
992         }
993
994         if (!charset->len && starts_with(type->buf, "text/"))
995                 strbuf_addstr(charset, "ISO-8859-1");
996 }
997
998
999 /* http_request() targets */
1000 #define HTTP_REQUEST_STRBUF     0
1001 #define HTTP_REQUEST_FILE       1
1002
1003 static int http_request(const char *url,
1004                         void *result, int target,
1005                         const struct http_get_options *options)
1006 {
1007         struct active_request_slot *slot;
1008         struct slot_results results;
1009         struct curl_slist *headers = NULL;
1010         struct strbuf buf = STRBUF_INIT;
1011         int ret;
1012
1013         slot = get_active_slot();
1014         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1015
1016         if (result == NULL) {
1017                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1018         } else {
1019                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1020                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1021
1022                 if (target == HTTP_REQUEST_FILE) {
1023                         long posn = ftell(result);
1024                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1025                                          fwrite);
1026                         if (posn > 0) {
1027                                 strbuf_addf(&buf, "Range: bytes=%ld-", posn);
1028                                 headers = curl_slist_append(headers, buf.buf);
1029                                 strbuf_reset(&buf);
1030                         }
1031                 } else
1032                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1033                                          fwrite_buffer);
1034         }
1035
1036         strbuf_addstr(&buf, "Pragma:");
1037         if (options && options->no_cache)
1038                 strbuf_addstr(&buf, " no-cache");
1039         if (options && options->keep_error)
1040                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1041
1042         headers = curl_slist_append(headers, buf.buf);
1043
1044         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1045         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1046         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
1047
1048         ret = run_one_slot(slot, &results);
1049
1050         if (options && options->content_type) {
1051                 struct strbuf raw = STRBUF_INIT;
1052                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1053                 extract_content_type(&raw, options->content_type,
1054                                      options->charset);
1055                 strbuf_release(&raw);
1056         }
1057
1058         if (options && options->effective_url)
1059                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1060                                 options->effective_url);
1061
1062         curl_slist_free_all(headers);
1063         strbuf_release(&buf);
1064
1065         return ret;
1066 }
1067
1068 /*
1069  * Update the "base" url to a more appropriate value, as deduced by
1070  * redirects seen when requesting a URL starting with "url".
1071  *
1072  * The "asked" parameter is a URL that we asked curl to access, and must begin
1073  * with "base".
1074  *
1075  * The "got" parameter is the URL that curl reported to us as where we ended
1076  * up.
1077  *
1078  * Returns 1 if we updated the base url, 0 otherwise.
1079  *
1080  * Our basic strategy is to compare "base" and "asked" to find the bits
1081  * specific to our request. We then strip those bits off of "got" to yield the
1082  * new base. So for example, if our base is "http://example.com/foo.git",
1083  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1084  * with "https://other.example.com/foo.git/info/refs". We would want the
1085  * new URL to become "https://other.example.com/foo.git".
1086  *
1087  * Note that this assumes a sane redirect scheme. It's entirely possible
1088  * in the example above to end up at a URL that does not even end in
1089  * "info/refs".  In such a case we simply punt, as there is not much we can
1090  * do (and such a scheme is unlikely to represent a real git repository,
1091  * which means we are likely about to abort anyway).
1092  */
1093 static int update_url_from_redirect(struct strbuf *base,
1094                                     const char *asked,
1095                                     const struct strbuf *got)
1096 {
1097         const char *tail;
1098         size_t tail_len;
1099
1100         if (!strcmp(asked, got->buf))
1101                 return 0;
1102
1103         if (!skip_prefix(asked, base->buf, &tail))
1104                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1105                     asked, base->buf);
1106
1107         tail_len = strlen(tail);
1108
1109         if (got->len < tail_len ||
1110             strcmp(tail, got->buf + got->len - tail_len))
1111                 return 0; /* insane redirect scheme */
1112
1113         strbuf_reset(base);
1114         strbuf_add(base, got->buf, got->len - tail_len);
1115         return 1;
1116 }
1117
1118 static int http_request_reauth(const char *url,
1119                                void *result, int target,
1120                                struct http_get_options *options)
1121 {
1122         int ret = http_request(url, result, target, options);
1123
1124         if (options && options->effective_url && options->base_url) {
1125                 if (update_url_from_redirect(options->base_url,
1126                                              url, options->effective_url)) {
1127                         credential_from_url(&http_auth, options->base_url->buf);
1128                         url = options->effective_url->buf;
1129                 }
1130         }
1131
1132         if (ret != HTTP_REAUTH)
1133                 return ret;
1134
1135         /*
1136          * If we are using KEEP_ERROR, the previous request may have
1137          * put cruft into our output stream; we should clear it out before
1138          * making our next request. We only know how to do this for
1139          * the strbuf case, but that is enough to satisfy current callers.
1140          */
1141         if (options && options->keep_error) {
1142                 switch (target) {
1143                 case HTTP_REQUEST_STRBUF:
1144                         strbuf_reset(result);
1145                         break;
1146                 default:
1147                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1148                 }
1149         }
1150
1151         credential_fill(&http_auth);
1152
1153         return http_request(url, result, target, options);
1154 }
1155
1156 int http_get_strbuf(const char *url,
1157                     struct strbuf *result,
1158                     struct http_get_options *options)
1159 {
1160         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1161 }
1162
1163 /*
1164  * Downloads a URL and stores the result in the given file.
1165  *
1166  * If a previous interrupted download is detected (i.e. a previous temporary
1167  * file is still around) the download is resumed.
1168  */
1169 static int http_get_file(const char *url, const char *filename,
1170                          struct http_get_options *options)
1171 {
1172         int ret;
1173         struct strbuf tmpfile = STRBUF_INIT;
1174         FILE *result;
1175
1176         strbuf_addf(&tmpfile, "%s.temp", filename);
1177         result = fopen(tmpfile.buf, "a");
1178         if (!result) {
1179                 error("Unable to open local file %s", tmpfile.buf);
1180                 ret = HTTP_ERROR;
1181                 goto cleanup;
1182         }
1183
1184         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1185         fclose(result);
1186
1187         if (ret == HTTP_OK && move_temp_to_file(tmpfile.buf, filename))
1188                 ret = HTTP_ERROR;
1189 cleanup:
1190         strbuf_release(&tmpfile);
1191         return ret;
1192 }
1193
1194 int http_fetch_ref(const char *base, struct ref *ref)
1195 {
1196         struct http_get_options options = {0};
1197         char *url;
1198         struct strbuf buffer = STRBUF_INIT;
1199         int ret = -1;
1200
1201         options.no_cache = 1;
1202
1203         url = quote_ref_url(base, ref->name);
1204         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1205                 strbuf_rtrim(&buffer);
1206                 if (buffer.len == 40)
1207                         ret = get_sha1_hex(buffer.buf, ref->old_sha1);
1208                 else if (starts_with(buffer.buf, "ref: ")) {
1209                         ref->symref = xstrdup(buffer.buf + 5);
1210                         ret = 0;
1211                 }
1212         }
1213
1214         strbuf_release(&buffer);
1215         free(url);
1216         return ret;
1217 }
1218
1219 /* Helpers for fetching packs */
1220 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1221 {
1222         char *url, *tmp;
1223         struct strbuf buf = STRBUF_INIT;
1224
1225         if (http_is_verbose)
1226                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1227
1228         end_url_with_slash(&buf, base_url);
1229         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1230         url = strbuf_detach(&buf, NULL);
1231
1232         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1233         tmp = strbuf_detach(&buf, NULL);
1234
1235         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1236                 error("Unable to get pack index %s", url);
1237                 free(tmp);
1238                 tmp = NULL;
1239         }
1240
1241         free(url);
1242         return tmp;
1243 }
1244
1245 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1246         unsigned char *sha1, const char *base_url)
1247 {
1248         struct packed_git *new_pack;
1249         char *tmp_idx = NULL;
1250         int ret;
1251
1252         if (has_pack_index(sha1)) {
1253                 new_pack = parse_pack_index(sha1, sha1_pack_index_name(sha1));
1254                 if (!new_pack)
1255                         return -1; /* parse_pack_index() already issued error message */
1256                 goto add_pack;
1257         }
1258
1259         tmp_idx = fetch_pack_index(sha1, base_url);
1260         if (!tmp_idx)
1261                 return -1;
1262
1263         new_pack = parse_pack_index(sha1, tmp_idx);
1264         if (!new_pack) {
1265                 unlink(tmp_idx);
1266                 free(tmp_idx);
1267
1268                 return -1; /* parse_pack_index() already issued error message */
1269         }
1270
1271         ret = verify_pack_index(new_pack);
1272         if (!ret) {
1273                 close_pack_index(new_pack);
1274                 ret = move_temp_to_file(tmp_idx, sha1_pack_index_name(sha1));
1275         }
1276         free(tmp_idx);
1277         if (ret)
1278                 return -1;
1279
1280 add_pack:
1281         new_pack->next = *packs_head;
1282         *packs_head = new_pack;
1283         return 0;
1284 }
1285
1286 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1287 {
1288         struct http_get_options options = {0};
1289         int ret = 0, i = 0;
1290         char *url, *data;
1291         struct strbuf buf = STRBUF_INIT;
1292         unsigned char sha1[20];
1293
1294         end_url_with_slash(&buf, base_url);
1295         strbuf_addstr(&buf, "objects/info/packs");
1296         url = strbuf_detach(&buf, NULL);
1297
1298         options.no_cache = 1;
1299         ret = http_get_strbuf(url, &buf, &options);
1300         if (ret != HTTP_OK)
1301                 goto cleanup;
1302
1303         data = buf.buf;
1304         while (i < buf.len) {
1305                 switch (data[i]) {
1306                 case 'P':
1307                         i++;
1308                         if (i + 52 <= buf.len &&
1309                             starts_with(data + i, " pack-") &&
1310                             starts_with(data + i + 46, ".pack\n")) {
1311                                 get_sha1_hex(data + i + 6, sha1);
1312                                 fetch_and_setup_pack_index(packs_head, sha1,
1313                                                       base_url);
1314                                 i += 51;
1315                                 break;
1316                         }
1317                 default:
1318                         while (i < buf.len && data[i] != '\n')
1319                                 i++;
1320                 }
1321                 i++;
1322         }
1323
1324 cleanup:
1325         free(url);
1326         return ret;
1327 }
1328
1329 void release_http_pack_request(struct http_pack_request *preq)
1330 {
1331         if (preq->packfile != NULL) {
1332                 fclose(preq->packfile);
1333                 preq->packfile = NULL;
1334         }
1335         if (preq->range_header != NULL) {
1336                 curl_slist_free_all(preq->range_header);
1337                 preq->range_header = NULL;
1338         }
1339         preq->slot = NULL;
1340         free(preq->url);
1341 }
1342
1343 int finish_http_pack_request(struct http_pack_request *preq)
1344 {
1345         struct packed_git **lst;
1346         struct packed_git *p = preq->target;
1347         char *tmp_idx;
1348         struct child_process ip = CHILD_PROCESS_INIT;
1349         const char *ip_argv[8];
1350
1351         close_pack_index(p);
1352
1353         fclose(preq->packfile);
1354         preq->packfile = NULL;
1355
1356         lst = preq->lst;
1357         while (*lst != p)
1358                 lst = &((*lst)->next);
1359         *lst = (*lst)->next;
1360
1361         tmp_idx = xstrdup(preq->tmpfile);
1362         strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
1363                ".idx.temp");
1364
1365         ip_argv[0] = "index-pack";
1366         ip_argv[1] = "-o";
1367         ip_argv[2] = tmp_idx;
1368         ip_argv[3] = preq->tmpfile;
1369         ip_argv[4] = NULL;
1370
1371         ip.argv = ip_argv;
1372         ip.git_cmd = 1;
1373         ip.no_stdin = 1;
1374         ip.no_stdout = 1;
1375
1376         if (run_command(&ip)) {
1377                 unlink(preq->tmpfile);
1378                 unlink(tmp_idx);
1379                 free(tmp_idx);
1380                 return -1;
1381         }
1382
1383         unlink(sha1_pack_index_name(p->sha1));
1384
1385         if (move_temp_to_file(preq->tmpfile, sha1_pack_name(p->sha1))
1386          || move_temp_to_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1387                 free(tmp_idx);
1388                 return -1;
1389         }
1390
1391         install_packed_git(p);
1392         free(tmp_idx);
1393         return 0;
1394 }
1395
1396 struct http_pack_request *new_http_pack_request(
1397         struct packed_git *target, const char *base_url)
1398 {
1399         long prev_posn = 0;
1400         char range[RANGE_HEADER_SIZE];
1401         struct strbuf buf = STRBUF_INIT;
1402         struct http_pack_request *preq;
1403
1404         preq = xcalloc(1, sizeof(*preq));
1405         preq->target = target;
1406
1407         end_url_with_slash(&buf, base_url);
1408         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1409                 sha1_to_hex(target->sha1));
1410         preq->url = strbuf_detach(&buf, NULL);
1411
1412         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1413                 sha1_pack_name(target->sha1));
1414         preq->packfile = fopen(preq->tmpfile, "a");
1415         if (!preq->packfile) {
1416                 error("Unable to open local file %s for pack",
1417                       preq->tmpfile);
1418                 goto abort;
1419         }
1420
1421         preq->slot = get_active_slot();
1422         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1423         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1424         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1425         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1426                 no_pragma_header);
1427
1428         /*
1429          * If there is data present from a previous transfer attempt,
1430          * resume where it left off
1431          */
1432         prev_posn = ftell(preq->packfile);
1433         if (prev_posn>0) {
1434                 if (http_is_verbose)
1435                         fprintf(stderr,
1436                                 "Resuming fetch of pack %s at byte %ld\n",
1437                                 sha1_to_hex(target->sha1), prev_posn);
1438                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1439                 preq->range_header = curl_slist_append(NULL, range);
1440                 curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1441                         preq->range_header);
1442         }
1443
1444         return preq;
1445
1446 abort:
1447         free(preq->url);
1448         free(preq);
1449         return NULL;
1450 }
1451
1452 /* Helpers for fetching objects (loose) */
1453 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1454                                void *data)
1455 {
1456         unsigned char expn[4096];
1457         size_t size = eltsize * nmemb;
1458         int posn = 0;
1459         struct http_object_request *freq =
1460                 (struct http_object_request *)data;
1461         do {
1462                 ssize_t retval = xwrite(freq->localfile,
1463                                         (char *) ptr + posn, size - posn);
1464                 if (retval < 0)
1465                         return posn;
1466                 posn += retval;
1467         } while (posn < size);
1468
1469         freq->stream.avail_in = size;
1470         freq->stream.next_in = (void *)ptr;
1471         do {
1472                 freq->stream.next_out = expn;
1473                 freq->stream.avail_out = sizeof(expn);
1474                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1475                 git_SHA1_Update(&freq->c, expn,
1476                                 sizeof(expn) - freq->stream.avail_out);
1477         } while (freq->stream.avail_in && freq->zret == Z_OK);
1478         return size;
1479 }
1480
1481 struct http_object_request *new_http_object_request(const char *base_url,
1482         unsigned char *sha1)
1483 {
1484         char *hex = sha1_to_hex(sha1);
1485         const char *filename;
1486         char prevfile[PATH_MAX];
1487         int prevlocal;
1488         char prev_buf[PREV_BUF_SIZE];
1489         ssize_t prev_read = 0;
1490         long prev_posn = 0;
1491         char range[RANGE_HEADER_SIZE];
1492         struct curl_slist *range_header = NULL;
1493         struct http_object_request *freq;
1494
1495         freq = xcalloc(1, sizeof(*freq));
1496         hashcpy(freq->sha1, sha1);
1497         freq->localfile = -1;
1498
1499         filename = sha1_file_name(sha1);
1500         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1501                  "%s.temp", filename);
1502
1503         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1504         unlink_or_warn(prevfile);
1505         rename(freq->tmpfile, prevfile);
1506         unlink_or_warn(freq->tmpfile);
1507
1508         if (freq->localfile != -1)
1509                 error("fd leakage in start: %d", freq->localfile);
1510         freq->localfile = open(freq->tmpfile,
1511                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1512         /*
1513          * This could have failed due to the "lazy directory creation";
1514          * try to mkdir the last path component.
1515          */
1516         if (freq->localfile < 0 && errno == ENOENT) {
1517                 char *dir = strrchr(freq->tmpfile, '/');
1518                 if (dir) {
1519                         *dir = 0;
1520                         mkdir(freq->tmpfile, 0777);
1521                         *dir = '/';
1522                 }
1523                 freq->localfile = open(freq->tmpfile,
1524                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1525         }
1526
1527         if (freq->localfile < 0) {
1528                 error("Couldn't create temporary file %s: %s",
1529                       freq->tmpfile, strerror(errno));
1530                 goto abort;
1531         }
1532
1533         git_inflate_init(&freq->stream);
1534
1535         git_SHA1_Init(&freq->c);
1536
1537         freq->url = get_remote_object_url(base_url, hex, 0);
1538
1539         /*
1540          * If a previous temp file is present, process what was already
1541          * fetched.
1542          */
1543         prevlocal = open(prevfile, O_RDONLY);
1544         if (prevlocal != -1) {
1545                 do {
1546                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1547                         if (prev_read>0) {
1548                                 if (fwrite_sha1_file(prev_buf,
1549                                                      1,
1550                                                      prev_read,
1551                                                      freq) == prev_read) {
1552                                         prev_posn += prev_read;
1553                                 } else {
1554                                         prev_read = -1;
1555                                 }
1556                         }
1557                 } while (prev_read > 0);
1558                 close(prevlocal);
1559         }
1560         unlink_or_warn(prevfile);
1561
1562         /*
1563          * Reset inflate/SHA1 if there was an error reading the previous temp
1564          * file; also rewind to the beginning of the local file.
1565          */
1566         if (prev_read == -1) {
1567                 memset(&freq->stream, 0, sizeof(freq->stream));
1568                 git_inflate_init(&freq->stream);
1569                 git_SHA1_Init(&freq->c);
1570                 if (prev_posn>0) {
1571                         prev_posn = 0;
1572                         lseek(freq->localfile, 0, SEEK_SET);
1573                         if (ftruncate(freq->localfile, 0) < 0) {
1574                                 error("Couldn't truncate temporary file %s: %s",
1575                                           freq->tmpfile, strerror(errno));
1576                                 goto abort;
1577                         }
1578                 }
1579         }
1580
1581         freq->slot = get_active_slot();
1582
1583         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1584         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1585         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1586         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1587         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1588
1589         /*
1590          * If we have successfully processed data from a previous fetch
1591          * attempt, only fetch the data we don't already have.
1592          */
1593         if (prev_posn>0) {
1594                 if (http_is_verbose)
1595                         fprintf(stderr,
1596                                 "Resuming fetch of object %s at byte %ld\n",
1597                                 hex, prev_posn);
1598                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1599                 range_header = curl_slist_append(range_header, range);
1600                 curl_easy_setopt(freq->slot->curl,
1601                                  CURLOPT_HTTPHEADER, range_header);
1602         }
1603
1604         return freq;
1605
1606 abort:
1607         free(freq->url);
1608         free(freq);
1609         return NULL;
1610 }
1611
1612 void process_http_object_request(struct http_object_request *freq)
1613 {
1614         if (freq->slot == NULL)
1615                 return;
1616         freq->curl_result = freq->slot->curl_result;
1617         freq->http_code = freq->slot->http_code;
1618         freq->slot = NULL;
1619 }
1620
1621 int finish_http_object_request(struct http_object_request *freq)
1622 {
1623         struct stat st;
1624
1625         close(freq->localfile);
1626         freq->localfile = -1;
1627
1628         process_http_object_request(freq);
1629
1630         if (freq->http_code == 416) {
1631                 warning("requested range invalid; we may already have all the data.");
1632         } else if (freq->curl_result != CURLE_OK) {
1633                 if (stat(freq->tmpfile, &st) == 0)
1634                         if (st.st_size == 0)
1635                                 unlink_or_warn(freq->tmpfile);
1636                 return -1;
1637         }
1638
1639         git_inflate_end(&freq->stream);
1640         git_SHA1_Final(freq->real_sha1, &freq->c);
1641         if (freq->zret != Z_STREAM_END) {
1642                 unlink_or_warn(freq->tmpfile);
1643                 return -1;
1644         }
1645         if (hashcmp(freq->sha1, freq->real_sha1)) {
1646                 unlink_or_warn(freq->tmpfile);
1647                 return -1;
1648         }
1649         freq->rename =
1650                 move_temp_to_file(freq->tmpfile, sha1_file_name(freq->sha1));
1651
1652         return freq->rename;
1653 }
1654
1655 void abort_http_object_request(struct http_object_request *freq)
1656 {
1657         unlink_or_warn(freq->tmpfile);
1658
1659         release_http_object_request(freq);
1660 }
1661
1662 void release_http_object_request(struct http_object_request *freq)
1663 {
1664         if (freq->localfile != -1) {
1665                 close(freq->localfile);
1666                 freq->localfile = -1;
1667         }
1668         if (freq->url != NULL) {
1669                 free(freq->url);
1670                 freq->url = NULL;
1671         }
1672         if (freq->slot != NULL) {
1673                 freq->slot->callback_func = NULL;
1674                 freq->slot->callback_data = NULL;
1675                 release_active_slot(freq->slot);
1676                 freq->slot = NULL;
1677         }
1678 }