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