Merge branch 'ld/p4-detached-head' 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 #include "gettext.h"
12 #include "transport.h"
13
14 int active_requests;
15 int http_is_verbose;
16 size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
17
18 #if LIBCURL_VERSION_NUM >= 0x070a06
19 #define LIBCURL_CAN_HANDLE_AUTH_ANY
20 #endif
21
22 static int min_curl_sessions = 1;
23 static int curl_session_count;
24 #ifdef USE_CURL_MULTI
25 static int max_requests = -1;
26 static CURLM *curlm;
27 #endif
28 #ifndef NO_CURL_EASY_DUPHANDLE
29 static CURL *curl_default;
30 #endif
31
32 #define PREV_BUF_SIZE 4096
33 #define RANGE_HEADER_SIZE 30
34
35 char curl_errorstr[CURL_ERROR_SIZE];
36
37 static int curl_ssl_verify = -1;
38 static int curl_ssl_try;
39 static const char *ssl_cert;
40 static const char *ssl_cipherlist;
41 static const char *ssl_version;
42 static struct {
43         const char *name;
44         long ssl_version;
45 } sslversions[] = {
46         { "sslv2", CURL_SSLVERSION_SSLv2 },
47         { "sslv3", CURL_SSLVERSION_SSLv3 },
48         { "tlsv1", CURL_SSLVERSION_TLSv1 },
49 #if LIBCURL_VERSION_NUM >= 0x072200
50         { "tlsv1.0", CURL_SSLVERSION_TLSv1_0 },
51         { "tlsv1.1", CURL_SSLVERSION_TLSv1_1 },
52         { "tlsv1.2", CURL_SSLVERSION_TLSv1_2 },
53 #endif
54 };
55 #if LIBCURL_VERSION_NUM >= 0x070903
56 static const char *ssl_key;
57 #endif
58 #if LIBCURL_VERSION_NUM >= 0x070908
59 static const char *ssl_capath;
60 #endif
61 static const char *ssl_cainfo;
62 static long curl_low_speed_limit = -1;
63 static long curl_low_speed_time = -1;
64 static int curl_ftp_no_epsv;
65 static const char *curl_http_proxy;
66 static const char *curl_cookie_file;
67 static int curl_save_cookies;
68 struct credential http_auth = CREDENTIAL_INIT;
69 static int http_proactive_auth;
70 static const char *user_agent;
71
72 #if LIBCURL_VERSION_NUM >= 0x071700
73 /* Use CURLOPT_KEYPASSWD as is */
74 #elif LIBCURL_VERSION_NUM >= 0x070903
75 #define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
76 #else
77 #define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
78 #endif
79
80 static struct credential cert_auth = CREDENTIAL_INIT;
81 static int ssl_cert_password_required;
82 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
83 static unsigned long http_auth_methods = CURLAUTH_ANY;
84 #endif
85
86 static struct curl_slist *pragma_header;
87 static struct curl_slist *no_pragma_header;
88
89 static struct active_request_slot *active_queue_head;
90
91 static char *cached_accept_language;
92
93 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
94 {
95         size_t size = eltsize * nmemb;
96         struct buffer *buffer = buffer_;
97
98         if (size > buffer->buf.len - buffer->posn)
99                 size = buffer->buf.len - buffer->posn;
100         memcpy(ptr, buffer->buf.buf + buffer->posn, size);
101         buffer->posn += size;
102
103         return size;
104 }
105
106 #ifndef NO_CURL_IOCTL
107 curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
108 {
109         struct buffer *buffer = clientp;
110
111         switch (cmd) {
112         case CURLIOCMD_NOP:
113                 return CURLIOE_OK;
114
115         case CURLIOCMD_RESTARTREAD:
116                 buffer->posn = 0;
117                 return CURLIOE_OK;
118
119         default:
120                 return CURLIOE_UNKNOWNCMD;
121         }
122 }
123 #endif
124
125 size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
126 {
127         size_t size = eltsize * nmemb;
128         struct strbuf *buffer = buffer_;
129
130         strbuf_add(buffer, ptr, size);
131         return size;
132 }
133
134 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
135 {
136         return eltsize * nmemb;
137 }
138
139 static void closedown_active_slot(struct active_request_slot *slot)
140 {
141         active_requests--;
142         slot->in_use = 0;
143 }
144
145 static void finish_active_slot(struct active_request_slot *slot)
146 {
147         closedown_active_slot(slot);
148         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
149
150         if (slot->finished != NULL)
151                 (*slot->finished) = 1;
152
153         /* Store slot results so they can be read after the slot is reused */
154         if (slot->results != NULL) {
155                 slot->results->curl_result = slot->curl_result;
156                 slot->results->http_code = slot->http_code;
157 #if LIBCURL_VERSION_NUM >= 0x070a08
158                 curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
159                                   &slot->results->auth_avail);
160 #else
161                 slot->results->auth_avail = 0;
162 #endif
163         }
164
165         /* Run callback if appropriate */
166         if (slot->callback_func != NULL)
167                 slot->callback_func(slot->callback_data);
168 }
169
170 #ifdef USE_CURL_MULTI
171 static void process_curl_messages(void)
172 {
173         int num_messages;
174         struct active_request_slot *slot;
175         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
176
177         while (curl_message != NULL) {
178                 if (curl_message->msg == CURLMSG_DONE) {
179                         int curl_result = curl_message->data.result;
180                         slot = active_queue_head;
181                         while (slot != NULL &&
182                                slot->curl != curl_message->easy_handle)
183                                 slot = slot->next;
184                         if (slot != NULL) {
185                                 curl_multi_remove_handle(curlm, slot->curl);
186                                 slot->curl_result = curl_result;
187                                 finish_active_slot(slot);
188                         } else {
189                                 fprintf(stderr, "Received DONE message for unknown request!\n");
190                         }
191                 } else {
192                         fprintf(stderr, "Unknown CURL message received: %d\n",
193                                 (int)curl_message->msg);
194                 }
195                 curl_message = curl_multi_info_read(curlm, &num_messages);
196         }
197 }
198 #endif
199
200 static int http_options(const char *var, const char *value, void *cb)
201 {
202         if (!strcmp("http.sslverify", var)) {
203                 curl_ssl_verify = git_config_bool(var, value);
204                 return 0;
205         }
206         if (!strcmp("http.sslcipherlist", var))
207                 return git_config_string(&ssl_cipherlist, var, value);
208         if (!strcmp("http.sslversion", var))
209                 return git_config_string(&ssl_version, var, value);
210         if (!strcmp("http.sslcert", var))
211                 return git_config_string(&ssl_cert, var, value);
212 #if LIBCURL_VERSION_NUM >= 0x070903
213         if (!strcmp("http.sslkey", var))
214                 return git_config_string(&ssl_key, var, value);
215 #endif
216 #if LIBCURL_VERSION_NUM >= 0x070908
217         if (!strcmp("http.sslcapath", var))
218                 return git_config_pathname(&ssl_capath, var, value);
219 #endif
220         if (!strcmp("http.sslcainfo", var))
221                 return git_config_pathname(&ssl_cainfo, var, value);
222         if (!strcmp("http.sslcertpasswordprotected", var)) {
223                 ssl_cert_password_required = git_config_bool(var, value);
224                 return 0;
225         }
226         if (!strcmp("http.ssltry", var)) {
227                 curl_ssl_try = git_config_bool(var, value);
228                 return 0;
229         }
230         if (!strcmp("http.minsessions", var)) {
231                 min_curl_sessions = git_config_int(var, value);
232 #ifndef USE_CURL_MULTI
233                 if (min_curl_sessions > 1)
234                         min_curl_sessions = 1;
235 #endif
236                 return 0;
237         }
238 #ifdef USE_CURL_MULTI
239         if (!strcmp("http.maxrequests", var)) {
240                 max_requests = git_config_int(var, value);
241                 return 0;
242         }
243 #endif
244         if (!strcmp("http.lowspeedlimit", var)) {
245                 curl_low_speed_limit = (long)git_config_int(var, value);
246                 return 0;
247         }
248         if (!strcmp("http.lowspeedtime", var)) {
249                 curl_low_speed_time = (long)git_config_int(var, value);
250                 return 0;
251         }
252
253         if (!strcmp("http.noepsv", var)) {
254                 curl_ftp_no_epsv = git_config_bool(var, value);
255                 return 0;
256         }
257         if (!strcmp("http.proxy", var))
258                 return git_config_string(&curl_http_proxy, var, value);
259
260         if (!strcmp("http.cookiefile", var))
261                 return git_config_string(&curl_cookie_file, var, value);
262         if (!strcmp("http.savecookies", var)) {
263                 curl_save_cookies = git_config_bool(var, value);
264                 return 0;
265         }
266
267         if (!strcmp("http.postbuffer", var)) {
268                 http_post_buffer = git_config_int(var, value);
269                 if (http_post_buffer < LARGE_PACKET_MAX)
270                         http_post_buffer = LARGE_PACKET_MAX;
271                 return 0;
272         }
273
274         if (!strcmp("http.useragent", var))
275                 return git_config_string(&user_agent, var, value);
276
277         /* Fall back on the default ones */
278         return git_default_config(var, value, cb);
279 }
280
281 static void init_curl_http_auth(CURL *result)
282 {
283         if (!http_auth.username)
284                 return;
285
286         credential_fill(&http_auth);
287
288 #if LIBCURL_VERSION_NUM >= 0x071301
289         curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
290         curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
291 #else
292         {
293                 static struct strbuf up = STRBUF_INIT;
294                 /*
295                  * Note that we assume we only ever have a single set of
296                  * credentials in a given program run, so we do not have
297                  * to worry about updating this buffer, only setting its
298                  * initial value.
299                  */
300                 if (!up.len)
301                         strbuf_addf(&up, "%s:%s",
302                                 http_auth.username, http_auth.password);
303                 curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
304         }
305 #endif
306 }
307
308 static int has_cert_password(void)
309 {
310         if (ssl_cert == NULL || ssl_cert_password_required != 1)
311                 return 0;
312         if (!cert_auth.password) {
313                 cert_auth.protocol = xstrdup("cert");
314                 cert_auth.username = xstrdup("");
315                 cert_auth.path = xstrdup(ssl_cert);
316                 credential_fill(&cert_auth);
317         }
318         return 1;
319 }
320
321 #if LIBCURL_VERSION_NUM >= 0x071900
322 static void set_curl_keepalive(CURL *c)
323 {
324         curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
325 }
326
327 #elif LIBCURL_VERSION_NUM >= 0x071000
328 static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
329 {
330         int ka = 1;
331         int rc;
332         socklen_t len = (socklen_t)sizeof(ka);
333
334         if (type != CURLSOCKTYPE_IPCXN)
335                 return 0;
336
337         rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
338         if (rc < 0)
339                 warning("unable to set SO_KEEPALIVE on socket %s",
340                         strerror(errno));
341
342         return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
343 }
344
345 static void set_curl_keepalive(CURL *c)
346 {
347         curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
348 }
349
350 #else
351 static void set_curl_keepalive(CURL *c)
352 {
353         /* not supported on older curl versions */
354 }
355 #endif
356
357 static CURL *get_curl_handle(void)
358 {
359         CURL *result = curl_easy_init();
360         long allowed_protocols = 0;
361
362         if (!result)
363                 die("curl_easy_init failed");
364
365         if (!curl_ssl_verify) {
366                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
367                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
368         } else {
369                 /* Verify authenticity of the peer's certificate */
370                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
371                 /* The name in the cert must match whom we tried to connect */
372                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
373         }
374
375 #if LIBCURL_VERSION_NUM >= 0x070907
376         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
377 #endif
378 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
379         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
380 #endif
381
382         if (http_proactive_auth)
383                 init_curl_http_auth(result);
384
385         if (getenv("GIT_SSL_VERSION"))
386                 ssl_version = getenv("GIT_SSL_VERSION");
387         if (ssl_version && *ssl_version) {
388                 int i;
389                 for (i = 0; i < ARRAY_SIZE(sslversions); i++) {
390                         if (!strcmp(ssl_version, sslversions[i].name)) {
391                                 curl_easy_setopt(result, CURLOPT_SSLVERSION,
392                                                  sslversions[i].ssl_version);
393                                 break;
394                         }
395                 }
396                 if (i == ARRAY_SIZE(sslversions))
397                         warning("unsupported ssl version %s: using default",
398                                 ssl_version);
399         }
400
401         if (getenv("GIT_SSL_CIPHER_LIST"))
402                 ssl_cipherlist = getenv("GIT_SSL_CIPHER_LIST");
403         if (ssl_cipherlist != NULL && *ssl_cipherlist)
404                 curl_easy_setopt(result, CURLOPT_SSL_CIPHER_LIST,
405                                 ssl_cipherlist);
406
407         if (ssl_cert != NULL)
408                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
409         if (has_cert_password())
410                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
411 #if LIBCURL_VERSION_NUM >= 0x070903
412         if (ssl_key != NULL)
413                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
414 #endif
415 #if LIBCURL_VERSION_NUM >= 0x070908
416         if (ssl_capath != NULL)
417                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
418 #endif
419         if (ssl_cainfo != NULL)
420                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
421
422         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
423                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
424                                  curl_low_speed_limit);
425                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
426                                  curl_low_speed_time);
427         }
428
429         curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
430         curl_easy_setopt(result, CURLOPT_MAXREDIRS, 20);
431 #if LIBCURL_VERSION_NUM >= 0x071301
432         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
433 #elif LIBCURL_VERSION_NUM >= 0x071101
434         curl_easy_setopt(result, CURLOPT_POST301, 1);
435 #endif
436 #if LIBCURL_VERSION_NUM >= 0x071304
437         if (is_transport_allowed("http"))
438                 allowed_protocols |= CURLPROTO_HTTP;
439         if (is_transport_allowed("https"))
440                 allowed_protocols |= CURLPROTO_HTTPS;
441         if (is_transport_allowed("ftp"))
442                 allowed_protocols |= CURLPROTO_FTP;
443         if (is_transport_allowed("ftps"))
444                 allowed_protocols |= CURLPROTO_FTPS;
445         curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS, allowed_protocols);
446 #else
447         if (transport_restrict_protocols())
448                 warning("protocol restrictions not applied to curl redirects because\n"
449                         "your curl version is too old (>= 7.19.4)");
450 #endif
451
452         if (getenv("GIT_CURL_VERBOSE"))
453                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
454
455         curl_easy_setopt(result, CURLOPT_USERAGENT,
456                 user_agent ? user_agent : git_user_agent());
457
458         if (curl_ftp_no_epsv)
459                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
460
461 #ifdef CURLOPT_USE_SSL
462         if (curl_ssl_try)
463                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
464 #endif
465
466         if (curl_http_proxy) {
467                 curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
468 #if LIBCURL_VERSION_NUM >= 0x071800
469                 if (starts_with(curl_http_proxy, "socks5"))
470                         curl_easy_setopt(result,
471                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
472                 else if (starts_with(curl_http_proxy, "socks4a"))
473                         curl_easy_setopt(result,
474                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4A);
475                 else if (starts_with(curl_http_proxy, "socks"))
476                         curl_easy_setopt(result,
477                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
478 #endif
479         }
480 #if LIBCURL_VERSION_NUM >= 0x070a07
481         curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
482 #endif
483
484         set_curl_keepalive(result);
485
486         return result;
487 }
488
489 static void set_from_env(const char **var, const char *envname)
490 {
491         const char *val = getenv(envname);
492         if (val)
493                 *var = val;
494 }
495
496 void http_init(struct remote *remote, const char *url, int proactive_auth)
497 {
498         char *low_speed_limit;
499         char *low_speed_time;
500         char *normalized_url;
501         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
502
503         config.section = "http";
504         config.key = NULL;
505         config.collect_fn = http_options;
506         config.cascade_fn = git_default_config;
507         config.cb = NULL;
508
509         http_is_verbose = 0;
510         normalized_url = url_normalize(url, &config.url);
511
512         git_config(urlmatch_config_entry, &config);
513         free(normalized_url);
514
515         if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
516                 die("curl_global_init failed");
517
518         http_proactive_auth = proactive_auth;
519
520         if (remote && remote->http_proxy)
521                 curl_http_proxy = xstrdup(remote->http_proxy);
522
523         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
524         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
525
526 #ifdef USE_CURL_MULTI
527         {
528                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
529                 if (http_max_requests != NULL)
530                         max_requests = atoi(http_max_requests);
531         }
532
533         curlm = curl_multi_init();
534         if (!curlm)
535                 die("curl_multi_init failed");
536 #endif
537
538         if (getenv("GIT_SSL_NO_VERIFY"))
539                 curl_ssl_verify = 0;
540
541         set_from_env(&ssl_cert, "GIT_SSL_CERT");
542 #if LIBCURL_VERSION_NUM >= 0x070903
543         set_from_env(&ssl_key, "GIT_SSL_KEY");
544 #endif
545 #if LIBCURL_VERSION_NUM >= 0x070908
546         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
547 #endif
548         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
549
550         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
551
552         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
553         if (low_speed_limit != NULL)
554                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
555         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
556         if (low_speed_time != NULL)
557                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
558
559         if (curl_ssl_verify == -1)
560                 curl_ssl_verify = 1;
561
562         curl_session_count = 0;
563 #ifdef USE_CURL_MULTI
564         if (max_requests < 1)
565                 max_requests = DEFAULT_MAX_REQUESTS;
566 #endif
567
568         if (getenv("GIT_CURL_FTP_NO_EPSV"))
569                 curl_ftp_no_epsv = 1;
570
571         if (url) {
572                 credential_from_url(&http_auth, url);
573                 if (!ssl_cert_password_required &&
574                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
575                     starts_with(url, "https://"))
576                         ssl_cert_password_required = 1;
577         }
578
579 #ifndef NO_CURL_EASY_DUPHANDLE
580         curl_default = get_curl_handle();
581 #endif
582 }
583
584 void http_cleanup(void)
585 {
586         struct active_request_slot *slot = active_queue_head;
587
588         while (slot != NULL) {
589                 struct active_request_slot *next = slot->next;
590                 if (slot->curl != NULL) {
591 #ifdef USE_CURL_MULTI
592                         curl_multi_remove_handle(curlm, slot->curl);
593 #endif
594                         curl_easy_cleanup(slot->curl);
595                 }
596                 free(slot);
597                 slot = next;
598         }
599         active_queue_head = NULL;
600
601 #ifndef NO_CURL_EASY_DUPHANDLE
602         curl_easy_cleanup(curl_default);
603 #endif
604
605 #ifdef USE_CURL_MULTI
606         curl_multi_cleanup(curlm);
607 #endif
608         curl_global_cleanup();
609
610         curl_slist_free_all(pragma_header);
611         pragma_header = NULL;
612
613         curl_slist_free_all(no_pragma_header);
614         no_pragma_header = NULL;
615
616         if (curl_http_proxy) {
617                 free((void *)curl_http_proxy);
618                 curl_http_proxy = NULL;
619         }
620
621         if (cert_auth.password != NULL) {
622                 memset(cert_auth.password, 0, strlen(cert_auth.password));
623                 free(cert_auth.password);
624                 cert_auth.password = NULL;
625         }
626         ssl_cert_password_required = 0;
627
628         free(cached_accept_language);
629         cached_accept_language = NULL;
630 }
631
632 struct active_request_slot *get_active_slot(void)
633 {
634         struct active_request_slot *slot = active_queue_head;
635         struct active_request_slot *newslot;
636
637 #ifdef USE_CURL_MULTI
638         int num_transfers;
639
640         /* Wait for a slot to open up if the queue is full */
641         while (active_requests >= max_requests) {
642                 curl_multi_perform(curlm, &num_transfers);
643                 if (num_transfers < active_requests)
644                         process_curl_messages();
645         }
646 #endif
647
648         while (slot != NULL && slot->in_use)
649                 slot = slot->next;
650
651         if (slot == NULL) {
652                 newslot = xmalloc(sizeof(*newslot));
653                 newslot->curl = NULL;
654                 newslot->in_use = 0;
655                 newslot->next = NULL;
656
657                 slot = active_queue_head;
658                 if (slot == NULL) {
659                         active_queue_head = newslot;
660                 } else {
661                         while (slot->next != NULL)
662                                 slot = slot->next;
663                         slot->next = newslot;
664                 }
665                 slot = newslot;
666         }
667
668         if (slot->curl == NULL) {
669 #ifdef NO_CURL_EASY_DUPHANDLE
670                 slot->curl = get_curl_handle();
671 #else
672                 slot->curl = curl_easy_duphandle(curl_default);
673 #endif
674                 curl_session_count++;
675         }
676
677         active_requests++;
678         slot->in_use = 1;
679         slot->results = NULL;
680         slot->finished = NULL;
681         slot->callback_data = NULL;
682         slot->callback_func = NULL;
683         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
684         if (curl_save_cookies)
685                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
686         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
687         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
688         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
689         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
690         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
691         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
692         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
693         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
694         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
695 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
696         curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
697 #endif
698         if (http_auth.password)
699                 init_curl_http_auth(slot->curl);
700
701         return slot;
702 }
703
704 int start_active_slot(struct active_request_slot *slot)
705 {
706 #ifdef USE_CURL_MULTI
707         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
708         int num_transfers;
709
710         if (curlm_result != CURLM_OK &&
711             curlm_result != CURLM_CALL_MULTI_PERFORM) {
712                 active_requests--;
713                 slot->in_use = 0;
714                 return 0;
715         }
716
717         /*
718          * We know there must be something to do, since we just added
719          * something.
720          */
721         curl_multi_perform(curlm, &num_transfers);
722 #endif
723         return 1;
724 }
725
726 #ifdef USE_CURL_MULTI
727 struct fill_chain {
728         void *data;
729         int (*fill)(void *);
730         struct fill_chain *next;
731 };
732
733 static struct fill_chain *fill_cfg;
734
735 void add_fill_function(void *data, int (*fill)(void *))
736 {
737         struct fill_chain *new = xmalloc(sizeof(*new));
738         struct fill_chain **linkp = &fill_cfg;
739         new->data = data;
740         new->fill = fill;
741         new->next = NULL;
742         while (*linkp)
743                 linkp = &(*linkp)->next;
744         *linkp = new;
745 }
746
747 void fill_active_slots(void)
748 {
749         struct active_request_slot *slot = active_queue_head;
750
751         while (active_requests < max_requests) {
752                 struct fill_chain *fill;
753                 for (fill = fill_cfg; fill; fill = fill->next)
754                         if (fill->fill(fill->data))
755                                 break;
756
757                 if (!fill)
758                         break;
759         }
760
761         while (slot != NULL) {
762                 if (!slot->in_use && slot->curl != NULL
763                         && curl_session_count > min_curl_sessions) {
764                         curl_easy_cleanup(slot->curl);
765                         slot->curl = NULL;
766                         curl_session_count--;
767                 }
768                 slot = slot->next;
769         }
770 }
771
772 void step_active_slots(void)
773 {
774         int num_transfers;
775         CURLMcode curlm_result;
776
777         do {
778                 curlm_result = curl_multi_perform(curlm, &num_transfers);
779         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
780         if (num_transfers < active_requests) {
781                 process_curl_messages();
782                 fill_active_slots();
783         }
784 }
785 #endif
786
787 void run_active_slot(struct active_request_slot *slot)
788 {
789 #ifdef USE_CURL_MULTI
790         fd_set readfds;
791         fd_set writefds;
792         fd_set excfds;
793         int max_fd;
794         struct timeval select_timeout;
795         int finished = 0;
796
797         slot->finished = &finished;
798         while (!finished) {
799                 step_active_slots();
800
801                 if (slot->in_use) {
802 #if LIBCURL_VERSION_NUM >= 0x070f04
803                         long curl_timeout;
804                         curl_multi_timeout(curlm, &curl_timeout);
805                         if (curl_timeout == 0) {
806                                 continue;
807                         } else if (curl_timeout == -1) {
808                                 select_timeout.tv_sec  = 0;
809                                 select_timeout.tv_usec = 50000;
810                         } else {
811                                 select_timeout.tv_sec  =  curl_timeout / 1000;
812                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
813                         }
814 #else
815                         select_timeout.tv_sec  = 0;
816                         select_timeout.tv_usec = 50000;
817 #endif
818
819                         max_fd = -1;
820                         FD_ZERO(&readfds);
821                         FD_ZERO(&writefds);
822                         FD_ZERO(&excfds);
823                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
824
825                         /*
826                          * It can happen that curl_multi_timeout returns a pathologically
827                          * long timeout when curl_multi_fdset returns no file descriptors
828                          * to read.  See commit message for more details.
829                          */
830                         if (max_fd < 0 &&
831                             (select_timeout.tv_sec > 0 ||
832                              select_timeout.tv_usec > 50000)) {
833                                 select_timeout.tv_sec  = 0;
834                                 select_timeout.tv_usec = 50000;
835                         }
836
837                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
838                 }
839         }
840 #else
841         while (slot->in_use) {
842                 slot->curl_result = curl_easy_perform(slot->curl);
843                 finish_active_slot(slot);
844         }
845 #endif
846 }
847
848 static void release_active_slot(struct active_request_slot *slot)
849 {
850         closedown_active_slot(slot);
851         if (slot->curl && curl_session_count > min_curl_sessions) {
852 #ifdef USE_CURL_MULTI
853                 curl_multi_remove_handle(curlm, slot->curl);
854 #endif
855                 curl_easy_cleanup(slot->curl);
856                 slot->curl = NULL;
857                 curl_session_count--;
858         }
859 #ifdef USE_CURL_MULTI
860         fill_active_slots();
861 #endif
862 }
863
864 void finish_all_active_slots(void)
865 {
866         struct active_request_slot *slot = active_queue_head;
867
868         while (slot != NULL)
869                 if (slot->in_use) {
870                         run_active_slot(slot);
871                         slot = active_queue_head;
872                 } else {
873                         slot = slot->next;
874                 }
875 }
876
877 /* Helpers for modifying and creating URLs */
878 static inline int needs_quote(int ch)
879 {
880         if (((ch >= 'A') && (ch <= 'Z'))
881                         || ((ch >= 'a') && (ch <= 'z'))
882                         || ((ch >= '0') && (ch <= '9'))
883                         || (ch == '/')
884                         || (ch == '-')
885                         || (ch == '.'))
886                 return 0;
887         return 1;
888 }
889
890 static char *quote_ref_url(const char *base, const char *ref)
891 {
892         struct strbuf buf = STRBUF_INIT;
893         const char *cp;
894         int ch;
895
896         end_url_with_slash(&buf, base);
897
898         for (cp = ref; (ch = *cp) != 0; cp++)
899                 if (needs_quote(ch))
900                         strbuf_addf(&buf, "%%%02x", ch);
901                 else
902                         strbuf_addch(&buf, *cp);
903
904         return strbuf_detach(&buf, NULL);
905 }
906
907 void append_remote_object_url(struct strbuf *buf, const char *url,
908                               const char *hex,
909                               int only_two_digit_prefix)
910 {
911         end_url_with_slash(buf, url);
912
913         strbuf_addf(buf, "objects/%.*s/", 2, hex);
914         if (!only_two_digit_prefix)
915                 strbuf_addf(buf, "%s", hex+2);
916 }
917
918 char *get_remote_object_url(const char *url, const char *hex,
919                             int only_two_digit_prefix)
920 {
921         struct strbuf buf = STRBUF_INIT;
922         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
923         return strbuf_detach(&buf, NULL);
924 }
925
926 static int handle_curl_result(struct slot_results *results)
927 {
928         /*
929          * If we see a failing http code with CURLE_OK, we have turned off
930          * FAILONERROR (to keep the server's custom error response), and should
931          * translate the code into failure here.
932          */
933         if (results->curl_result == CURLE_OK &&
934             results->http_code >= 400) {
935                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
936                 /*
937                  * Normally curl will already have put the "reason phrase"
938                  * from the server into curl_errorstr; unfortunately without
939                  * FAILONERROR it is lost, so we can give only the numeric
940                  * status code.
941                  */
942                 snprintf(curl_errorstr, sizeof(curl_errorstr),
943                          "The requested URL returned error: %ld",
944                          results->http_code);
945         }
946
947         if (results->curl_result == CURLE_OK) {
948                 credential_approve(&http_auth);
949                 return HTTP_OK;
950         } else if (missing_target(results))
951                 return HTTP_MISSING_TARGET;
952         else if (results->http_code == 401) {
953                 if (http_auth.username && http_auth.password) {
954                         credential_reject(&http_auth);
955                         return HTTP_NOAUTH;
956                 } else {
957 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
958                         http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
959 #endif
960                         return HTTP_REAUTH;
961                 }
962         } else {
963 #if LIBCURL_VERSION_NUM >= 0x070c00
964                 if (!curl_errorstr[0])
965                         strlcpy(curl_errorstr,
966                                 curl_easy_strerror(results->curl_result),
967                                 sizeof(curl_errorstr));
968 #endif
969                 return HTTP_ERROR;
970         }
971 }
972
973 int run_one_slot(struct active_request_slot *slot,
974                  struct slot_results *results)
975 {
976         slot->results = results;
977         if (!start_active_slot(slot)) {
978                 snprintf(curl_errorstr, sizeof(curl_errorstr),
979                          "failed to start HTTP request");
980                 return HTTP_START_FAILED;
981         }
982
983         run_active_slot(slot);
984         return handle_curl_result(results);
985 }
986
987 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
988 {
989         char *ptr;
990         CURLcode ret;
991
992         strbuf_reset(buf);
993         ret = curl_easy_getinfo(curl, info, &ptr);
994         if (!ret && ptr)
995                 strbuf_addstr(buf, ptr);
996         return ret;
997 }
998
999 /*
1000  * Check for and extract a content-type parameter. "raw"
1001  * should be positioned at the start of the potential
1002  * parameter, with any whitespace already removed.
1003  *
1004  * "name" is the name of the parameter. The value is appended
1005  * to "out".
1006  */
1007 static int extract_param(const char *raw, const char *name,
1008                          struct strbuf *out)
1009 {
1010         size_t len = strlen(name);
1011
1012         if (strncasecmp(raw, name, len))
1013                 return -1;
1014         raw += len;
1015
1016         if (*raw != '=')
1017                 return -1;
1018         raw++;
1019
1020         while (*raw && !isspace(*raw) && *raw != ';')
1021                 strbuf_addch(out, *raw++);
1022         return 0;
1023 }
1024
1025 /*
1026  * Extract a normalized version of the content type, with any
1027  * spaces suppressed, all letters lowercased, and no trailing ";"
1028  * or parameters.
1029  *
1030  * Note that we will silently remove even invalid whitespace. For
1031  * example, "text / plain" is specifically forbidden by RFC 2616,
1032  * but "text/plain" is the only reasonable output, and this keeps
1033  * our code simple.
1034  *
1035  * If the "charset" argument is not NULL, store the value of any
1036  * charset parameter there.
1037  *
1038  * Example:
1039  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
1040  *   "text / plain" -> "text/plain"
1041  */
1042 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
1043                                  struct strbuf *charset)
1044 {
1045         const char *p;
1046
1047         strbuf_reset(type);
1048         strbuf_grow(type, raw->len);
1049         for (p = raw->buf; *p; p++) {
1050                 if (isspace(*p))
1051                         continue;
1052                 if (*p == ';') {
1053                         p++;
1054                         break;
1055                 }
1056                 strbuf_addch(type, tolower(*p));
1057         }
1058
1059         if (!charset)
1060                 return;
1061
1062         strbuf_reset(charset);
1063         while (*p) {
1064                 while (isspace(*p) || *p == ';')
1065                         p++;
1066                 if (!extract_param(p, "charset", charset))
1067                         return;
1068                 while (*p && !isspace(*p))
1069                         p++;
1070         }
1071
1072         if (!charset->len && starts_with(type->buf, "text/"))
1073                 strbuf_addstr(charset, "ISO-8859-1");
1074 }
1075
1076 static void write_accept_language(struct strbuf *buf)
1077 {
1078         /*
1079          * MAX_DECIMAL_PLACES must not be larger than 3. If it is larger than
1080          * that, q-value will be smaller than 0.001, the minimum q-value the
1081          * HTTP specification allows. See
1082          * http://tools.ietf.org/html/rfc7231#section-5.3.1 for q-value.
1083          */
1084         const int MAX_DECIMAL_PLACES = 3;
1085         const int MAX_LANGUAGE_TAGS = 1000;
1086         const int MAX_ACCEPT_LANGUAGE_HEADER_SIZE = 4000;
1087         char **language_tags = NULL;
1088         int num_langs = 0;
1089         const char *s = get_preferred_languages();
1090         int i;
1091         struct strbuf tag = STRBUF_INIT;
1092
1093         /* Don't add Accept-Language header if no language is preferred. */
1094         if (!s)
1095                 return;
1096
1097         /*
1098          * Split the colon-separated string of preferred languages into
1099          * language_tags array.
1100          */
1101         do {
1102                 /* collect language tag */
1103                 for (; *s && (isalnum(*s) || *s == '_'); s++)
1104                         strbuf_addch(&tag, *s == '_' ? '-' : *s);
1105
1106                 /* skip .codeset, @modifier and any other unnecessary parts */
1107                 while (*s && *s != ':')
1108                         s++;
1109
1110                 if (tag.len) {
1111                         num_langs++;
1112                         REALLOC_ARRAY(language_tags, num_langs);
1113                         language_tags[num_langs - 1] = strbuf_detach(&tag, NULL);
1114                         if (num_langs >= MAX_LANGUAGE_TAGS - 1) /* -1 for '*' */
1115                                 break;
1116                 }
1117         } while (*s++);
1118
1119         /* write Accept-Language header into buf */
1120         if (num_langs) {
1121                 int last_buf_len = 0;
1122                 int max_q;
1123                 int decimal_places;
1124                 char q_format[32];
1125
1126                 /* add '*' */
1127                 REALLOC_ARRAY(language_tags, num_langs + 1);
1128                 language_tags[num_langs++] = "*"; /* it's OK; this won't be freed */
1129
1130                 /* compute decimal_places */
1131                 for (max_q = 1, decimal_places = 0;
1132                      max_q < num_langs && decimal_places <= MAX_DECIMAL_PLACES;
1133                      decimal_places++, max_q *= 10)
1134                         ;
1135
1136                 sprintf(q_format, ";q=0.%%0%dd", decimal_places);
1137
1138                 strbuf_addstr(buf, "Accept-Language: ");
1139
1140                 for (i = 0; i < num_langs; i++) {
1141                         if (i > 0)
1142                                 strbuf_addstr(buf, ", ");
1143
1144                         strbuf_addstr(buf, language_tags[i]);
1145
1146                         if (i > 0)
1147                                 strbuf_addf(buf, q_format, max_q - i);
1148
1149                         if (buf->len > MAX_ACCEPT_LANGUAGE_HEADER_SIZE) {
1150                                 strbuf_remove(buf, last_buf_len, buf->len - last_buf_len);
1151                                 break;
1152                         }
1153
1154                         last_buf_len = buf->len;
1155                 }
1156         }
1157
1158         /* free language tags -- last one is a static '*' */
1159         for (i = 0; i < num_langs - 1; i++)
1160                 free(language_tags[i]);
1161         free(language_tags);
1162 }
1163
1164 /*
1165  * Get an Accept-Language header which indicates user's preferred languages.
1166  *
1167  * Examples:
1168  *   LANGUAGE= -> ""
1169  *   LANGUAGE=ko:en -> "Accept-Language: ko, en; q=0.9, *; q=0.1"
1170  *   LANGUAGE=ko_KR.UTF-8:sr@latin -> "Accept-Language: ko-KR, sr; q=0.9, *; q=0.1"
1171  *   LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *; q=0.1"
1172  *   LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *; q=0.1"
1173  *   LANGUAGE= LANG=C -> ""
1174  */
1175 static const char *get_accept_language(void)
1176 {
1177         if (!cached_accept_language) {
1178                 struct strbuf buf = STRBUF_INIT;
1179                 write_accept_language(&buf);
1180                 if (buf.len > 0)
1181                         cached_accept_language = strbuf_detach(&buf, NULL);
1182         }
1183
1184         return cached_accept_language;
1185 }
1186
1187 /* http_request() targets */
1188 #define HTTP_REQUEST_STRBUF     0
1189 #define HTTP_REQUEST_FILE       1
1190
1191 static int http_request(const char *url,
1192                         void *result, int target,
1193                         const struct http_get_options *options)
1194 {
1195         struct active_request_slot *slot;
1196         struct slot_results results;
1197         struct curl_slist *headers = NULL;
1198         struct strbuf buf = STRBUF_INIT;
1199         const char *accept_language;
1200         int ret;
1201
1202         slot = get_active_slot();
1203         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1204
1205         if (result == NULL) {
1206                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1207         } else {
1208                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1209                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1210
1211                 if (target == HTTP_REQUEST_FILE) {
1212                         long posn = ftell(result);
1213                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1214                                          fwrite);
1215                         if (posn > 0) {
1216                                 strbuf_addf(&buf, "Range: bytes=%ld-", posn);
1217                                 headers = curl_slist_append(headers, buf.buf);
1218                                 strbuf_reset(&buf);
1219                         }
1220                 } else
1221                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1222                                          fwrite_buffer);
1223         }
1224
1225         accept_language = get_accept_language();
1226
1227         if (accept_language)
1228                 headers = curl_slist_append(headers, accept_language);
1229
1230         strbuf_addstr(&buf, "Pragma:");
1231         if (options && options->no_cache)
1232                 strbuf_addstr(&buf, " no-cache");
1233         if (options && options->keep_error)
1234                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1235
1236         headers = curl_slist_append(headers, buf.buf);
1237
1238         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1239         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1240         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
1241
1242         ret = run_one_slot(slot, &results);
1243
1244         if (options && options->content_type) {
1245                 struct strbuf raw = STRBUF_INIT;
1246                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1247                 extract_content_type(&raw, options->content_type,
1248                                      options->charset);
1249                 strbuf_release(&raw);
1250         }
1251
1252         if (options && options->effective_url)
1253                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1254                                 options->effective_url);
1255
1256         curl_slist_free_all(headers);
1257         strbuf_release(&buf);
1258
1259         return ret;
1260 }
1261
1262 /*
1263  * Update the "base" url to a more appropriate value, as deduced by
1264  * redirects seen when requesting a URL starting with "url".
1265  *
1266  * The "asked" parameter is a URL that we asked curl to access, and must begin
1267  * with "base".
1268  *
1269  * The "got" parameter is the URL that curl reported to us as where we ended
1270  * up.
1271  *
1272  * Returns 1 if we updated the base url, 0 otherwise.
1273  *
1274  * Our basic strategy is to compare "base" and "asked" to find the bits
1275  * specific to our request. We then strip those bits off of "got" to yield the
1276  * new base. So for example, if our base is "http://example.com/foo.git",
1277  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1278  * with "https://other.example.com/foo.git/info/refs". We would want the
1279  * new URL to become "https://other.example.com/foo.git".
1280  *
1281  * Note that this assumes a sane redirect scheme. It's entirely possible
1282  * in the example above to end up at a URL that does not even end in
1283  * "info/refs".  In such a case we simply punt, as there is not much we can
1284  * do (and such a scheme is unlikely to represent a real git repository,
1285  * which means we are likely about to abort anyway).
1286  */
1287 static int update_url_from_redirect(struct strbuf *base,
1288                                     const char *asked,
1289                                     const struct strbuf *got)
1290 {
1291         const char *tail;
1292         size_t tail_len;
1293
1294         if (!strcmp(asked, got->buf))
1295                 return 0;
1296
1297         if (!skip_prefix(asked, base->buf, &tail))
1298                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1299                     asked, base->buf);
1300
1301         tail_len = strlen(tail);
1302
1303         if (got->len < tail_len ||
1304             strcmp(tail, got->buf + got->len - tail_len))
1305                 return 0; /* insane redirect scheme */
1306
1307         strbuf_reset(base);
1308         strbuf_add(base, got->buf, got->len - tail_len);
1309         return 1;
1310 }
1311
1312 static int http_request_reauth(const char *url,
1313                                void *result, int target,
1314                                struct http_get_options *options)
1315 {
1316         int ret = http_request(url, result, target, options);
1317
1318         if (options && options->effective_url && options->base_url) {
1319                 if (update_url_from_redirect(options->base_url,
1320                                              url, options->effective_url)) {
1321                         credential_from_url(&http_auth, options->base_url->buf);
1322                         url = options->effective_url->buf;
1323                 }
1324         }
1325
1326         if (ret != HTTP_REAUTH)
1327                 return ret;
1328
1329         /*
1330          * If we are using KEEP_ERROR, the previous request may have
1331          * put cruft into our output stream; we should clear it out before
1332          * making our next request. We only know how to do this for
1333          * the strbuf case, but that is enough to satisfy current callers.
1334          */
1335         if (options && options->keep_error) {
1336                 switch (target) {
1337                 case HTTP_REQUEST_STRBUF:
1338                         strbuf_reset(result);
1339                         break;
1340                 default:
1341                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1342                 }
1343         }
1344
1345         credential_fill(&http_auth);
1346
1347         return http_request(url, result, target, options);
1348 }
1349
1350 int http_get_strbuf(const char *url,
1351                     struct strbuf *result,
1352                     struct http_get_options *options)
1353 {
1354         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1355 }
1356
1357 /*
1358  * Downloads a URL and stores the result in the given file.
1359  *
1360  * If a previous interrupted download is detected (i.e. a previous temporary
1361  * file is still around) the download is resumed.
1362  */
1363 static int http_get_file(const char *url, const char *filename,
1364                          struct http_get_options *options)
1365 {
1366         int ret;
1367         struct strbuf tmpfile = STRBUF_INIT;
1368         FILE *result;
1369
1370         strbuf_addf(&tmpfile, "%s.temp", filename);
1371         result = fopen(tmpfile.buf, "a");
1372         if (!result) {
1373                 error("Unable to open local file %s", tmpfile.buf);
1374                 ret = HTTP_ERROR;
1375                 goto cleanup;
1376         }
1377
1378         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1379         fclose(result);
1380
1381         if (ret == HTTP_OK && finalize_object_file(tmpfile.buf, filename))
1382                 ret = HTTP_ERROR;
1383 cleanup:
1384         strbuf_release(&tmpfile);
1385         return ret;
1386 }
1387
1388 int http_fetch_ref(const char *base, struct ref *ref)
1389 {
1390         struct http_get_options options = {0};
1391         char *url;
1392         struct strbuf buffer = STRBUF_INIT;
1393         int ret = -1;
1394
1395         options.no_cache = 1;
1396
1397         url = quote_ref_url(base, ref->name);
1398         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1399                 strbuf_rtrim(&buffer);
1400                 if (buffer.len == 40)
1401                         ret = get_sha1_hex(buffer.buf, ref->old_sha1);
1402                 else if (starts_with(buffer.buf, "ref: ")) {
1403                         ref->symref = xstrdup(buffer.buf + 5);
1404                         ret = 0;
1405                 }
1406         }
1407
1408         strbuf_release(&buffer);
1409         free(url);
1410         return ret;
1411 }
1412
1413 /* Helpers for fetching packs */
1414 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1415 {
1416         char *url, *tmp;
1417         struct strbuf buf = STRBUF_INIT;
1418
1419         if (http_is_verbose)
1420                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1421
1422         end_url_with_slash(&buf, base_url);
1423         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1424         url = strbuf_detach(&buf, NULL);
1425
1426         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1427         tmp = strbuf_detach(&buf, NULL);
1428
1429         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1430                 error("Unable to get pack index %s", url);
1431                 free(tmp);
1432                 tmp = NULL;
1433         }
1434
1435         free(url);
1436         return tmp;
1437 }
1438
1439 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1440         unsigned char *sha1, const char *base_url)
1441 {
1442         struct packed_git *new_pack;
1443         char *tmp_idx = NULL;
1444         int ret;
1445
1446         if (has_pack_index(sha1)) {
1447                 new_pack = parse_pack_index(sha1, sha1_pack_index_name(sha1));
1448                 if (!new_pack)
1449                         return -1; /* parse_pack_index() already issued error message */
1450                 goto add_pack;
1451         }
1452
1453         tmp_idx = fetch_pack_index(sha1, base_url);
1454         if (!tmp_idx)
1455                 return -1;
1456
1457         new_pack = parse_pack_index(sha1, tmp_idx);
1458         if (!new_pack) {
1459                 unlink(tmp_idx);
1460                 free(tmp_idx);
1461
1462                 return -1; /* parse_pack_index() already issued error message */
1463         }
1464
1465         ret = verify_pack_index(new_pack);
1466         if (!ret) {
1467                 close_pack_index(new_pack);
1468                 ret = finalize_object_file(tmp_idx, sha1_pack_index_name(sha1));
1469         }
1470         free(tmp_idx);
1471         if (ret)
1472                 return -1;
1473
1474 add_pack:
1475         new_pack->next = *packs_head;
1476         *packs_head = new_pack;
1477         return 0;
1478 }
1479
1480 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1481 {
1482         struct http_get_options options = {0};
1483         int ret = 0, i = 0;
1484         char *url, *data;
1485         struct strbuf buf = STRBUF_INIT;
1486         unsigned char sha1[20];
1487
1488         end_url_with_slash(&buf, base_url);
1489         strbuf_addstr(&buf, "objects/info/packs");
1490         url = strbuf_detach(&buf, NULL);
1491
1492         options.no_cache = 1;
1493         ret = http_get_strbuf(url, &buf, &options);
1494         if (ret != HTTP_OK)
1495                 goto cleanup;
1496
1497         data = buf.buf;
1498         while (i < buf.len) {
1499                 switch (data[i]) {
1500                 case 'P':
1501                         i++;
1502                         if (i + 52 <= buf.len &&
1503                             starts_with(data + i, " pack-") &&
1504                             starts_with(data + i + 46, ".pack\n")) {
1505                                 get_sha1_hex(data + i + 6, sha1);
1506                                 fetch_and_setup_pack_index(packs_head, sha1,
1507                                                       base_url);
1508                                 i += 51;
1509                                 break;
1510                         }
1511                 default:
1512                         while (i < buf.len && data[i] != '\n')
1513                                 i++;
1514                 }
1515                 i++;
1516         }
1517
1518 cleanup:
1519         free(url);
1520         return ret;
1521 }
1522
1523 void release_http_pack_request(struct http_pack_request *preq)
1524 {
1525         if (preq->packfile != NULL) {
1526                 fclose(preq->packfile);
1527                 preq->packfile = NULL;
1528         }
1529         if (preq->range_header != NULL) {
1530                 curl_slist_free_all(preq->range_header);
1531                 preq->range_header = NULL;
1532         }
1533         preq->slot = NULL;
1534         free(preq->url);
1535         free(preq);
1536 }
1537
1538 int finish_http_pack_request(struct http_pack_request *preq)
1539 {
1540         struct packed_git **lst;
1541         struct packed_git *p = preq->target;
1542         char *tmp_idx;
1543         struct child_process ip = CHILD_PROCESS_INIT;
1544         const char *ip_argv[8];
1545
1546         close_pack_index(p);
1547
1548         fclose(preq->packfile);
1549         preq->packfile = NULL;
1550
1551         lst = preq->lst;
1552         while (*lst != p)
1553                 lst = &((*lst)->next);
1554         *lst = (*lst)->next;
1555
1556         tmp_idx = xstrdup(preq->tmpfile);
1557         strcpy(tmp_idx + strlen(tmp_idx) - strlen(".pack.temp"),
1558                ".idx.temp");
1559
1560         ip_argv[0] = "index-pack";
1561         ip_argv[1] = "-o";
1562         ip_argv[2] = tmp_idx;
1563         ip_argv[3] = preq->tmpfile;
1564         ip_argv[4] = NULL;
1565
1566         ip.argv = ip_argv;
1567         ip.git_cmd = 1;
1568         ip.no_stdin = 1;
1569         ip.no_stdout = 1;
1570
1571         if (run_command(&ip)) {
1572                 unlink(preq->tmpfile);
1573                 unlink(tmp_idx);
1574                 free(tmp_idx);
1575                 return -1;
1576         }
1577
1578         unlink(sha1_pack_index_name(p->sha1));
1579
1580         if (finalize_object_file(preq->tmpfile, sha1_pack_name(p->sha1))
1581          || finalize_object_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1582                 free(tmp_idx);
1583                 return -1;
1584         }
1585
1586         install_packed_git(p);
1587         free(tmp_idx);
1588         return 0;
1589 }
1590
1591 struct http_pack_request *new_http_pack_request(
1592         struct packed_git *target, const char *base_url)
1593 {
1594         long prev_posn = 0;
1595         char range[RANGE_HEADER_SIZE];
1596         struct strbuf buf = STRBUF_INIT;
1597         struct http_pack_request *preq;
1598
1599         preq = xcalloc(1, sizeof(*preq));
1600         preq->target = target;
1601
1602         end_url_with_slash(&buf, base_url);
1603         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1604                 sha1_to_hex(target->sha1));
1605         preq->url = strbuf_detach(&buf, NULL);
1606
1607         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1608                 sha1_pack_name(target->sha1));
1609         preq->packfile = fopen(preq->tmpfile, "a");
1610         if (!preq->packfile) {
1611                 error("Unable to open local file %s for pack",
1612                       preq->tmpfile);
1613                 goto abort;
1614         }
1615
1616         preq->slot = get_active_slot();
1617         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1618         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1619         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1620         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1621                 no_pragma_header);
1622
1623         /*
1624          * If there is data present from a previous transfer attempt,
1625          * resume where it left off
1626          */
1627         prev_posn = ftell(preq->packfile);
1628         if (prev_posn>0) {
1629                 if (http_is_verbose)
1630                         fprintf(stderr,
1631                                 "Resuming fetch of pack %s at byte %ld\n",
1632                                 sha1_to_hex(target->sha1), prev_posn);
1633                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1634                 preq->range_header = curl_slist_append(NULL, range);
1635                 curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1636                         preq->range_header);
1637         }
1638
1639         return preq;
1640
1641 abort:
1642         free(preq->url);
1643         free(preq);
1644         return NULL;
1645 }
1646
1647 /* Helpers for fetching objects (loose) */
1648 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1649                                void *data)
1650 {
1651         unsigned char expn[4096];
1652         size_t size = eltsize * nmemb;
1653         int posn = 0;
1654         struct http_object_request *freq =
1655                 (struct http_object_request *)data;
1656         do {
1657                 ssize_t retval = xwrite(freq->localfile,
1658                                         (char *) ptr + posn, size - posn);
1659                 if (retval < 0)
1660                         return posn;
1661                 posn += retval;
1662         } while (posn < size);
1663
1664         freq->stream.avail_in = size;
1665         freq->stream.next_in = (void *)ptr;
1666         do {
1667                 freq->stream.next_out = expn;
1668                 freq->stream.avail_out = sizeof(expn);
1669                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1670                 git_SHA1_Update(&freq->c, expn,
1671                                 sizeof(expn) - freq->stream.avail_out);
1672         } while (freq->stream.avail_in && freq->zret == Z_OK);
1673         return size;
1674 }
1675
1676 struct http_object_request *new_http_object_request(const char *base_url,
1677         unsigned char *sha1)
1678 {
1679         char *hex = sha1_to_hex(sha1);
1680         const char *filename;
1681         char prevfile[PATH_MAX];
1682         int prevlocal;
1683         char prev_buf[PREV_BUF_SIZE];
1684         ssize_t prev_read = 0;
1685         long prev_posn = 0;
1686         char range[RANGE_HEADER_SIZE];
1687         struct curl_slist *range_header = NULL;
1688         struct http_object_request *freq;
1689
1690         freq = xcalloc(1, sizeof(*freq));
1691         hashcpy(freq->sha1, sha1);
1692         freq->localfile = -1;
1693
1694         filename = sha1_file_name(sha1);
1695         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1696                  "%s.temp", filename);
1697
1698         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1699         unlink_or_warn(prevfile);
1700         rename(freq->tmpfile, prevfile);
1701         unlink_or_warn(freq->tmpfile);
1702
1703         if (freq->localfile != -1)
1704                 error("fd leakage in start: %d", freq->localfile);
1705         freq->localfile = open(freq->tmpfile,
1706                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1707         /*
1708          * This could have failed due to the "lazy directory creation";
1709          * try to mkdir the last path component.
1710          */
1711         if (freq->localfile < 0 && errno == ENOENT) {
1712                 char *dir = strrchr(freq->tmpfile, '/');
1713                 if (dir) {
1714                         *dir = 0;
1715                         mkdir(freq->tmpfile, 0777);
1716                         *dir = '/';
1717                 }
1718                 freq->localfile = open(freq->tmpfile,
1719                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1720         }
1721
1722         if (freq->localfile < 0) {
1723                 error("Couldn't create temporary file %s: %s",
1724                       freq->tmpfile, strerror(errno));
1725                 goto abort;
1726         }
1727
1728         git_inflate_init(&freq->stream);
1729
1730         git_SHA1_Init(&freq->c);
1731
1732         freq->url = get_remote_object_url(base_url, hex, 0);
1733
1734         /*
1735          * If a previous temp file is present, process what was already
1736          * fetched.
1737          */
1738         prevlocal = open(prevfile, O_RDONLY);
1739         if (prevlocal != -1) {
1740                 do {
1741                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1742                         if (prev_read>0) {
1743                                 if (fwrite_sha1_file(prev_buf,
1744                                                      1,
1745                                                      prev_read,
1746                                                      freq) == prev_read) {
1747                                         prev_posn += prev_read;
1748                                 } else {
1749                                         prev_read = -1;
1750                                 }
1751                         }
1752                 } while (prev_read > 0);
1753                 close(prevlocal);
1754         }
1755         unlink_or_warn(prevfile);
1756
1757         /*
1758          * Reset inflate/SHA1 if there was an error reading the previous temp
1759          * file; also rewind to the beginning of the local file.
1760          */
1761         if (prev_read == -1) {
1762                 memset(&freq->stream, 0, sizeof(freq->stream));
1763                 git_inflate_init(&freq->stream);
1764                 git_SHA1_Init(&freq->c);
1765                 if (prev_posn>0) {
1766                         prev_posn = 0;
1767                         lseek(freq->localfile, 0, SEEK_SET);
1768                         if (ftruncate(freq->localfile, 0) < 0) {
1769                                 error("Couldn't truncate temporary file %s: %s",
1770                                           freq->tmpfile, strerror(errno));
1771                                 goto abort;
1772                         }
1773                 }
1774         }
1775
1776         freq->slot = get_active_slot();
1777
1778         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1779         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1780         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1781         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1782         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1783
1784         /*
1785          * If we have successfully processed data from a previous fetch
1786          * attempt, only fetch the data we don't already have.
1787          */
1788         if (prev_posn>0) {
1789                 if (http_is_verbose)
1790                         fprintf(stderr,
1791                                 "Resuming fetch of object %s at byte %ld\n",
1792                                 hex, prev_posn);
1793                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1794                 range_header = curl_slist_append(range_header, range);
1795                 curl_easy_setopt(freq->slot->curl,
1796                                  CURLOPT_HTTPHEADER, range_header);
1797         }
1798
1799         return freq;
1800
1801 abort:
1802         free(freq->url);
1803         free(freq);
1804         return NULL;
1805 }
1806
1807 void process_http_object_request(struct http_object_request *freq)
1808 {
1809         if (freq->slot == NULL)
1810                 return;
1811         freq->curl_result = freq->slot->curl_result;
1812         freq->http_code = freq->slot->http_code;
1813         freq->slot = NULL;
1814 }
1815
1816 int finish_http_object_request(struct http_object_request *freq)
1817 {
1818         struct stat st;
1819
1820         close(freq->localfile);
1821         freq->localfile = -1;
1822
1823         process_http_object_request(freq);
1824
1825         if (freq->http_code == 416) {
1826                 warning("requested range invalid; we may already have all the data.");
1827         } else if (freq->curl_result != CURLE_OK) {
1828                 if (stat(freq->tmpfile, &st) == 0)
1829                         if (st.st_size == 0)
1830                                 unlink_or_warn(freq->tmpfile);
1831                 return -1;
1832         }
1833
1834         git_inflate_end(&freq->stream);
1835         git_SHA1_Final(freq->real_sha1, &freq->c);
1836         if (freq->zret != Z_STREAM_END) {
1837                 unlink_or_warn(freq->tmpfile);
1838                 return -1;
1839         }
1840         if (hashcmp(freq->sha1, freq->real_sha1)) {
1841                 unlink_or_warn(freq->tmpfile);
1842                 return -1;
1843         }
1844         freq->rename =
1845                 finalize_object_file(freq->tmpfile, sha1_file_name(freq->sha1));
1846
1847         return freq->rename;
1848 }
1849
1850 void abort_http_object_request(struct http_object_request *freq)
1851 {
1852         unlink_or_warn(freq->tmpfile);
1853
1854         release_http_object_request(freq);
1855 }
1856
1857 void release_http_object_request(struct http_object_request *freq)
1858 {
1859         if (freq->localfile != -1) {
1860                 close(freq->localfile);
1861                 freq->localfile = -1;
1862         }
1863         if (freq->url != NULL) {
1864                 free(freq->url);
1865                 freq->url = NULL;
1866         }
1867         if (freq->slot != NULL) {
1868                 freq->slot->callback_func = NULL;
1869                 freq->slot->callback_data = NULL;
1870                 release_active_slot(freq->slot);
1871                 freq->slot = NULL;
1872         }
1873 }