Remove the temp file if it is empty after the request has failed
[git] / http-fetch.c
1 #include "cache.h"
2 #include "commit.h"
3 #include "pack.h"
4 #include "fetch.h"
5
6 #include <curl/curl.h>
7 #include <curl/easy.h>
8
9 #if LIBCURL_VERSION_NUM >= 0x070908
10 #define USE_CURL_MULTI
11 #define DEFAULT_MAX_REQUESTS 5
12 #endif
13
14 #if LIBCURL_VERSION_NUM < 0x070704
15 #define curl_global_cleanup() do { /* nothing */ } while(0)
16 #endif
17 #if LIBCURL_VERSION_NUM < 0x070800
18 #define curl_global_init(a) do { /* nothing */ } while(0)
19 #endif
20
21 #if LIBCURL_VERSION_NUM < 0x070c04
22 #define NO_CURL_EASY_DUPHANDLE
23 #endif
24
25 #define PREV_BUF_SIZE 4096
26 #define RANGE_HEADER_SIZE 30
27
28 static int got_alternates = 0;
29 static int active_requests = 0;
30 static int data_received;
31
32 #ifdef USE_CURL_MULTI
33 static int max_requests = -1;
34 static CURLM *curlm;
35 #endif
36 #ifndef NO_CURL_EASY_DUPHANDLE
37 static CURL *curl_default;
38 #endif
39 static struct curl_slist *pragma_header;
40 static struct curl_slist *no_pragma_header;
41 static struct curl_slist *no_range_header;
42 static char curl_errorstr[CURL_ERROR_SIZE];
43
44 struct alt_base
45 {
46         char *base;
47         int got_indices;
48         struct packed_git *packs;
49         struct alt_base *next;
50 };
51
52 static struct alt_base *alt = NULL;
53
54 enum transfer_state {
55         WAITING,
56         ABORTED,
57         ACTIVE,
58         COMPLETE,
59 };
60
61 struct transfer_request
62 {
63         unsigned char sha1[20];
64         struct alt_base *repo;
65         char *url;
66         char filename[PATH_MAX];
67         char tmpfile[PATH_MAX];
68         int local;
69         enum transfer_state state;
70         CURLcode curl_result;
71         char errorstr[CURL_ERROR_SIZE];
72         long http_code;
73         unsigned char real_sha1[20];
74         SHA_CTX c;
75         z_stream stream;
76         int zret;
77         int rename;
78         struct active_request_slot *slot;
79         struct transfer_request *next;
80 };
81
82 struct active_request_slot
83 {
84         CURL *curl;
85         FILE *local;
86         int in_use;
87         int done;
88         CURLcode curl_result;
89         long http_code;
90         struct active_request_slot *next;
91 };
92
93 static struct transfer_request *request_queue_head = NULL;
94 static struct active_request_slot *active_queue_head = NULL;
95
96 static int curl_ssl_verify = -1;
97 static char *ssl_cert = NULL;
98 #if LIBCURL_VERSION_NUM >= 0x070902
99 static char *ssl_key = NULL;
100 #endif
101 #if LIBCURL_VERSION_NUM >= 0x070908
102 static char *ssl_capath = NULL;
103 #endif
104 static char *ssl_cainfo = NULL;
105 static long curl_low_speed_limit = -1;
106 static long curl_low_speed_time = -1;
107
108 struct buffer
109 {
110         size_t posn;
111         size_t size;
112         void *buffer;
113 };
114
115 static int http_options(const char *var, const char *value)
116 {
117         if (!strcmp("http.sslverify", var)) {
118                 if (curl_ssl_verify == -1) {
119                         curl_ssl_verify = git_config_bool(var, value);
120                 }
121                 return 0;
122         }
123
124         if (!strcmp("http.sslcert", var)) {
125                 if (ssl_cert == NULL) {
126                         ssl_cert = xmalloc(strlen(value)+1);
127                         strcpy(ssl_cert, value);
128                 }
129                 return 0;
130         }
131 #if LIBCURL_VERSION_NUM >= 0x070902
132         if (!strcmp("http.sslkey", var)) {
133                 if (ssl_key == NULL) {
134                         ssl_key = xmalloc(strlen(value)+1);
135                         strcpy(ssl_key, value);
136                 }
137                 return 0;
138         }
139 #endif
140 #if LIBCURL_VERSION_NUM >= 0x070908
141         if (!strcmp("http.sslcapath", var)) {
142                 if (ssl_capath == NULL) {
143                         ssl_capath = xmalloc(strlen(value)+1);
144                         strcpy(ssl_capath, value);
145                 }
146                 return 0;
147         }
148 #endif
149         if (!strcmp("http.sslcainfo", var)) {
150                 if (ssl_cainfo == NULL) {
151                         ssl_cainfo = xmalloc(strlen(value)+1);
152                         strcpy(ssl_cainfo, value);
153                 }
154                 return 0;
155         }
156
157 #ifdef USE_CURL_MULTI   
158         if (!strcmp("http.maxrequests", var)) {
159                 if (max_requests == -1)
160                         max_requests = git_config_int(var, value);
161                 return 0;
162         }
163 #endif
164
165         if (!strcmp("http.lowspeedlimit", var)) {
166                 if (curl_low_speed_limit == -1)
167                         curl_low_speed_limit = (long)git_config_int(var, value);
168                 return 0;
169         }
170         if (!strcmp("http.lowspeedtime", var)) {
171                 if (curl_low_speed_time == -1)
172                         curl_low_speed_time = (long)git_config_int(var, value);
173                 return 0;
174         }
175
176         /* Fall back on the default ones */
177         return git_default_config(var, value);
178 }
179
180 static size_t fwrite_buffer(void *ptr, size_t eltsize, size_t nmemb,
181                             struct buffer *buffer)
182 {
183         size_t size = eltsize * nmemb;
184         if (size > buffer->size - buffer->posn)
185                 size = buffer->size - buffer->posn;
186         memcpy(buffer->buffer + buffer->posn, ptr, size);
187         buffer->posn += size;
188         data_received++;
189         return size;
190 }
191
192 static size_t fwrite_buffer_dynamic(const void *ptr, size_t eltsize,
193                                     size_t nmemb, struct buffer *buffer)
194 {
195         size_t size = eltsize * nmemb;
196         if (size > buffer->size - buffer->posn) {
197                 buffer->size = buffer->size * 3 / 2;
198                 if (buffer->size < buffer->posn + size)
199                         buffer->size = buffer->posn + size;
200                 buffer->buffer = xrealloc(buffer->buffer, buffer->size);
201         }
202         memcpy(buffer->buffer + buffer->posn, ptr, size);
203         buffer->posn += size;
204         data_received++;
205         return size;
206 }
207
208 static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
209                                void *data)
210 {
211         unsigned char expn[4096];
212         size_t size = eltsize * nmemb;
213         int posn = 0;
214         struct transfer_request *request = (struct transfer_request *)data;
215         do {
216                 ssize_t retval = write(request->local,
217                                        ptr + posn, size - posn);
218                 if (retval < 0)
219                         return posn;
220                 posn += retval;
221         } while (posn < size);
222
223         request->stream.avail_in = size;
224         request->stream.next_in = ptr;
225         do {
226                 request->stream.next_out = expn;
227                 request->stream.avail_out = sizeof(expn);
228                 request->zret = inflate(&request->stream, Z_SYNC_FLUSH);
229                 SHA1_Update(&request->c, expn,
230                             sizeof(expn) - request->stream.avail_out);
231         } while (request->stream.avail_in && request->zret == Z_OK);
232         data_received++;
233         return size;
234 }
235
236 #ifdef USE_CURL_MULTI
237 static void process_curl_messages(void);
238 static void process_request_queue(void);
239 #endif
240 static int fetch_alternates(char *base);
241
242 static CURL* get_curl_handle(void)
243 {
244         CURL* result = curl_easy_init();
245
246         curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
247 #if LIBCURL_VERSION_NUM >= 0x070907
248         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
249 #endif
250
251         if (ssl_cert != NULL)
252                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
253 #if LIBCURL_VERSION_NUM >= 0x070902
254         if (ssl_key != NULL)
255                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
256 #endif
257 #if LIBCURL_VERSION_NUM >= 0x070908
258         if (ssl_capath != NULL)
259                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
260 #endif
261         if (ssl_cainfo != NULL)
262                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
263         curl_easy_setopt(result, CURLOPT_FAILONERROR, 1);
264
265         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
266                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
267                                  curl_low_speed_limit);
268                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
269                                  curl_low_speed_time);
270         }
271
272         return result;
273 }
274
275 static struct active_request_slot *get_active_slot(void)
276 {
277         struct active_request_slot *slot = active_queue_head;
278         struct active_request_slot *newslot;
279
280 #ifdef USE_CURL_MULTI
281         int num_transfers;
282
283         /* Wait for a slot to open up if the queue is full */
284         while (active_requests >= max_requests) {
285                 curl_multi_perform(curlm, &num_transfers);
286                 if (num_transfers < active_requests) {
287                         process_curl_messages();
288                 }
289         }
290 #endif
291
292         while (slot != NULL && slot->in_use) {
293                 slot = slot->next;
294         }
295         if (slot == NULL) {
296                 newslot = xmalloc(sizeof(*newslot));
297                 newslot->curl = NULL;
298                 newslot->in_use = 0;
299                 newslot->next = NULL;
300
301                 slot = active_queue_head;
302                 if (slot == NULL) {
303                         active_queue_head = newslot;
304                 } else {
305                         while (slot->next != NULL) {
306                                 slot = slot->next;
307                         }
308                         slot->next = newslot;
309                 }
310                 slot = newslot;
311         }
312
313         if (slot->curl == NULL) {
314 #ifdef NO_CURL_EASY_DUPHANDLE
315                 slot->curl = get_curl_handle();
316 #else
317                 slot->curl = curl_easy_duphandle(curl_default);
318 #endif
319         }
320
321         active_requests++;
322         slot->in_use = 1;
323         slot->done = 0;
324         slot->local = NULL;
325         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
326         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_range_header);
327         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
328
329         return slot;
330 }
331
332 static int start_active_slot(struct active_request_slot *slot)
333 {
334 #ifdef USE_CURL_MULTI
335         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
336
337         if (curlm_result != CURLM_OK &&
338             curlm_result != CURLM_CALL_MULTI_PERFORM) {
339                 active_requests--;
340                 slot->in_use = 0;
341                 return 0;
342         }
343 #endif
344         return 1;
345 }
346
347 static void run_active_slot(struct active_request_slot *slot)
348 {
349 #ifdef USE_CURL_MULTI
350         int num_transfers;
351         long last_pos = 0;
352         long current_pos;
353         fd_set readfds;
354         fd_set writefds;
355         fd_set excfds;
356         int max_fd;
357         struct timeval select_timeout;
358         CURLMcode curlm_result;
359
360         while (!slot->done) {
361                 data_received = 0;
362                 do {
363                         curlm_result = curl_multi_perform(curlm,
364                                                           &num_transfers);
365                 } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
366                 if (num_transfers < active_requests) {
367                         process_curl_messages();
368                         process_request_queue();
369                 }
370
371                 if (!data_received && slot->local != NULL) {
372                         current_pos = ftell(slot->local);
373                         if (current_pos > last_pos)
374                                 data_received++;
375                         last_pos = current_pos;
376                 }
377
378                 if (!slot->done && !data_received) {
379                         max_fd = 0;
380                         FD_ZERO(&readfds);
381                         FD_ZERO(&writefds);
382                         FD_ZERO(&excfds);
383                         select_timeout.tv_sec = 0;
384                         select_timeout.tv_usec = 50000;
385                         select(max_fd, &readfds, &writefds,
386                                &excfds, &select_timeout);
387                 }
388         }
389 #else
390         slot->curl_result = curl_easy_perform(slot->curl);
391         active_requests--;
392 #endif
393 }
394
395 static void start_request(struct transfer_request *request)
396 {
397         char *hex = sha1_to_hex(request->sha1);
398         char prevfile[PATH_MAX];
399         char *url;
400         char *posn;
401         int prevlocal;
402         unsigned char prev_buf[PREV_BUF_SIZE];
403         ssize_t prev_read = 0;
404         long prev_posn = 0;
405         char range[RANGE_HEADER_SIZE];
406         struct curl_slist *range_header = NULL;
407         struct active_request_slot *slot;
408
409         snprintf(prevfile, sizeof(prevfile), "%s.prev", request->filename);
410         unlink(prevfile);
411         rename(request->tmpfile, prevfile);
412         unlink(request->tmpfile);
413
414         request->local = open(request->tmpfile,
415                               O_WRONLY | O_CREAT | O_EXCL, 0666);
416         /* This could have failed due to the "lazy directory creation";
417          * try to mkdir the last path component.
418          */
419         if (request->local < 0 && errno == ENOENT) {
420                 char *dir = strrchr(request->tmpfile, '/');
421                 if (dir) {
422                         *dir = 0;
423                         mkdir(request->tmpfile, 0777);
424                         *dir = '/';
425                 }
426                 request->local = open(request->tmpfile,
427                                       O_WRONLY | O_CREAT | O_EXCL, 0666);
428         }
429
430         if (request->local < 0) {
431                 request->state = ABORTED;
432                 error("Couldn't create temporary file %s for %s: %s\n",
433                       request->tmpfile, request->filename, strerror(errno));
434                 return;
435         }
436
437         memset(&request->stream, 0, sizeof(request->stream));
438
439         inflateInit(&request->stream);
440
441         SHA1_Init(&request->c);
442
443         url = xmalloc(strlen(request->repo->base) + 50);
444         request->url = xmalloc(strlen(request->repo->base) + 50);
445         strcpy(url, request->repo->base);
446         posn = url + strlen(request->repo->base);
447         strcpy(posn, "objects/");
448         posn += 8;
449         memcpy(posn, hex, 2);
450         posn += 2;
451         *(posn++) = '/';
452         strcpy(posn, hex + 2);
453         strcpy(request->url, url);
454
455         /* If a previous temp file is present, process what was already
456            fetched. */
457         prevlocal = open(prevfile, O_RDONLY);
458         if (prevlocal != -1) {
459                 do {
460                         prev_read = read(prevlocal, prev_buf, PREV_BUF_SIZE);
461                         if (prev_read>0) {
462                                 if (fwrite_sha1_file(prev_buf,
463                                                      1,
464                                                      prev_read,
465                                                      request) == prev_read) {
466                                         prev_posn += prev_read;
467                                 } else {
468                                         prev_read = -1;
469                                 }
470                         }
471                 } while (prev_read > 0);
472                 close(prevlocal);
473         }
474         unlink(prevfile);
475
476         /* Reset inflate/SHA1 if there was an error reading the previous temp
477            file; also rewind to the beginning of the local file. */
478         if (prev_read == -1) {
479                 memset(&request->stream, 0, sizeof(request->stream));
480                 inflateInit(&request->stream);
481                 SHA1_Init(&request->c);
482                 if (prev_posn>0) {
483                         prev_posn = 0;
484                         lseek(request->local, SEEK_SET, 0);
485                         ftruncate(request->local, 0);
486                 }
487         }
488
489         slot = get_active_slot();
490         curl_easy_setopt(slot->curl, CURLOPT_FILE, request);
491         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
492         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, request->errorstr);
493         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
494         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
495
496         /* If we have successfully processed data from a previous fetch
497            attempt, only fetch the data we don't already have. */
498         if (prev_posn>0) {
499                 if (get_verbosely)
500                         fprintf(stderr,
501                                 "Resuming fetch of object %s at byte %ld\n",
502                                 hex, prev_posn);
503                 sprintf(range, "Range: bytes=%ld-", prev_posn);
504                 range_header = curl_slist_append(range_header, range);
505                 curl_easy_setopt(slot->curl,
506                                  CURLOPT_HTTPHEADER, range_header);
507         }
508
509         /* Try to get the request started, abort the request on error */
510         if (!start_active_slot(slot)) {
511                 request->state = ABORTED;
512                 close(request->local);
513                 free(request->url);
514                 return;
515         }
516         
517         request->slot = slot;
518         request->state = ACTIVE;
519 }
520
521 static void finish_request(struct transfer_request *request)
522 {
523         struct stat st;
524
525         fchmod(request->local, 0444);
526         close(request->local);
527
528         if (request->http_code == 416) {
529                 fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
530         } else if (request->curl_result != CURLE_OK) {
531                 if (stat(request->tmpfile, &st) == 0)
532                         if (st.st_size == 0)
533                                 unlink(request->tmpfile);
534                 return;
535         }
536
537         inflateEnd(&request->stream);
538         SHA1_Final(request->real_sha1, &request->c);
539         if (request->zret != Z_STREAM_END) {
540                 unlink(request->tmpfile);
541                 return;
542         }
543         if (memcmp(request->sha1, request->real_sha1, 20)) {
544                 unlink(request->tmpfile);
545                 return;
546         }
547         request->rename =
548                 move_temp_to_file(request->tmpfile, request->filename);
549
550         if (request->rename == 0)
551                 pull_say("got %s\n", sha1_to_hex(request->sha1));
552 }
553
554 static void release_request(struct transfer_request *request)
555 {
556         struct transfer_request *entry = request_queue_head;
557
558         if (request == request_queue_head) {
559                 request_queue_head = request->next;
560         } else {
561                 while (entry->next != NULL && entry->next != request)
562                         entry = entry->next;
563                 if (entry->next == request)
564                         entry->next = entry->next->next;
565         }
566
567         free(request->url);
568         free(request);
569 }
570
571 #ifdef USE_CURL_MULTI
572 void process_curl_messages(void)
573 {
574         int num_messages;
575         struct active_request_slot *slot;
576         struct transfer_request *request = NULL;
577         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
578
579         while (curl_message != NULL) {
580                 if (curl_message->msg == CURLMSG_DONE) {
581                         slot = active_queue_head;
582                         while (slot != NULL &&
583                                slot->curl != curl_message->easy_handle)
584                                 slot = slot->next;
585                         if (slot != NULL) {
586                                 curl_multi_remove_handle(curlm, slot->curl);
587                                 active_requests--;
588                                 slot->done = 1;
589                                 slot->in_use = 0;
590                                 slot->curl_result = curl_message->data.result;
591                                 curl_easy_getinfo(slot->curl,
592                                                   CURLINFO_HTTP_CODE,
593                                                   &slot->http_code);
594                                 request = request_queue_head;
595                                 while (request != NULL &&
596                                        request->slot != slot)
597                                         request = request->next;
598                         } else {
599                                 fprintf(stderr, "Received DONE message for unknown request!\n");
600                         }
601                         if (request != NULL) {
602                                 request->curl_result =
603                                         curl_message->data.result;
604                                 request->http_code = slot->http_code;
605                                 request->slot = NULL;
606                                 request->state = COMPLETE;
607
608                                 /* Use alternates if necessary */
609                                 if (request->http_code == 404) {
610                                         fetch_alternates(alt->base);
611                                         if (request->repo->next != NULL) {
612                                                 request->repo =
613                                                         request->repo->next;
614                                                 start_request(request);
615                                         }
616                                 } else {
617                                         finish_request(request);
618                                 }
619                         }
620                 } else {
621                         fprintf(stderr, "Unknown CURL message received: %d\n",
622                                 (int)curl_message->msg);
623                 }
624                 curl_message = curl_multi_info_read(curlm, &num_messages);
625         }
626 }
627
628 void process_request_queue(void)
629 {
630         struct transfer_request *request = request_queue_head;
631         struct active_request_slot *slot = active_queue_head;
632         int num_transfers;
633
634         while (active_requests < max_requests && request != NULL) {
635                 if (request->state == WAITING) {
636                         if (has_sha1_file(request->sha1))
637                                 release_request(request);
638                         else
639                                 start_request(request);
640                         curl_multi_perform(curlm, &num_transfers);
641                 }
642                 request = request->next;
643         }
644
645         while (slot != NULL) {
646                 if (!slot->in_use && slot->curl != NULL) {
647                         curl_easy_cleanup(slot->curl);
648                         slot->curl = NULL;
649                 }
650                 slot = slot->next;
651         }                               
652 }
653 #endif
654
655 void prefetch(unsigned char *sha1)
656 {
657         struct transfer_request *newreq;
658         struct transfer_request *tail;
659         char *filename = sha1_file_name(sha1);
660
661         newreq = xmalloc(sizeof(*newreq));
662         memcpy(newreq->sha1, sha1, 20);
663         newreq->repo = alt;
664         newreq->url = NULL;
665         newreq->local = -1;
666         newreq->state = WAITING;
667         snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
668         snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
669                  "%s.temp", filename);
670         newreq->next = NULL;
671
672         if (request_queue_head == NULL) {
673                 request_queue_head = newreq;
674         } else {
675                 tail = request_queue_head;
676                 while (tail->next != NULL) {
677                         tail = tail->next;
678                 }
679                 tail->next = newreq;
680         }
681 #ifdef USE_CURL_MULTI
682         process_request_queue();
683         process_curl_messages();
684 #endif
685 }
686
687 static int fetch_index(struct alt_base *repo, unsigned char *sha1)
688 {
689         char *hex = sha1_to_hex(sha1);
690         char *filename;
691         char *url;
692         char tmpfile[PATH_MAX];
693         long prev_posn = 0;
694         char range[RANGE_HEADER_SIZE];
695         struct curl_slist *range_header = NULL;
696
697         FILE *indexfile;
698         struct active_request_slot *slot;
699
700         if (has_pack_index(sha1))
701                 return 0;
702
703         if (get_verbosely)
704                 fprintf(stderr, "Getting index for pack %s\n", hex);
705         
706         url = xmalloc(strlen(repo->base) + 64);
707         sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
708         
709         filename = sha1_pack_index_name(sha1);
710         snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
711         indexfile = fopen(tmpfile, "a");
712         if (!indexfile)
713                 return error("Unable to open local file %s for pack index",
714                              filename);
715
716         slot = get_active_slot();
717         curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
718         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
719         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
720         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
721         slot->local = indexfile;
722
723         /* If there is data present from a previous transfer attempt,
724            resume where it left off */
725         prev_posn = ftell(indexfile);
726         if (prev_posn>0) {
727                 if (get_verbosely)
728                         fprintf(stderr,
729                                 "Resuming fetch of index for pack %s at byte %ld\n",
730                                 hex, prev_posn);
731                 sprintf(range, "Range: bytes=%ld-", prev_posn);
732                 range_header = curl_slist_append(range_header, range);
733                 curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
734         }
735
736         if (start_active_slot(slot)) {
737                 run_active_slot(slot);
738                 if (slot->curl_result != CURLE_OK) {
739                         fclose(indexfile);
740                         return error("Unable to get pack index %s\n%s", url,
741                                      curl_errorstr);
742                 }
743         } else {
744                 return error("Unable to start request");
745         }
746
747         fclose(indexfile);
748
749         return move_temp_to_file(tmpfile, filename);
750 }
751
752 static int setup_index(struct alt_base *repo, unsigned char *sha1)
753 {
754         struct packed_git *new_pack;
755         if (has_pack_file(sha1))
756                 return 0; // don't list this as something we can get
757
758         if (fetch_index(repo, sha1))
759                 return -1;
760
761         new_pack = parse_pack_index(sha1);
762         new_pack->next = repo->packs;
763         repo->packs = new_pack;
764         return 0;
765 }
766
767 static int fetch_alternates(char *base)
768 {
769         int ret = 0;
770         struct buffer buffer;
771         char *url;
772         char *data;
773         int i = 0;
774         int http_specific = 1;
775         struct alt_base *tail = alt;
776         static const char null_byte = '\0';
777
778         struct active_request_slot *slot;
779
780         if (got_alternates)
781                 return 0;
782
783         data = xmalloc(4096);
784         buffer.size = 4096;
785         buffer.posn = 0;
786         buffer.buffer = data;
787
788         if (get_verbosely)
789                 fprintf(stderr, "Getting alternates list\n");
790         
791         url = xmalloc(strlen(base) + 31);
792         sprintf(url, "%s/objects/info/http-alternates", base);
793
794         slot = get_active_slot();
795         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
796         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
797                          fwrite_buffer_dynamic);
798         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
799         if (start_active_slot(slot)) {
800                 run_active_slot(slot);
801                 if (slot->curl_result != CURLE_OK || !buffer.posn) {
802                         http_specific = 0;
803
804                         sprintf(url, "%s/objects/info/alternates", base);
805
806                         slot = get_active_slot();
807                         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
808                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
809                                          fwrite_buffer_dynamic);
810                         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
811                         if (start_active_slot(slot)) {
812                                 run_active_slot(slot);
813                                 if (slot->curl_result != CURLE_OK) {
814                                         free(buffer.buffer);
815                                         if (slot->http_code == 404)
816                                                 got_alternates = 1;
817                                         return 0;
818                                 }
819                         }
820                 }
821         } else {
822                 free(buffer.buffer);
823                 return 0;
824         }
825
826         fwrite_buffer_dynamic(&null_byte, 1, 1, &buffer);
827         buffer.posn--;
828         data = buffer.buffer;
829
830         while (i < buffer.posn) {
831                 int posn = i;
832                 while (posn < buffer.posn && data[posn] != '\n')
833                         posn++;
834                 if (data[posn] == '\n') {
835                         int okay = 0;
836                         int serverlen = 0;
837                         struct alt_base *newalt;
838                         char *target = NULL;
839                         if (data[i] == '/') {
840                                 serverlen = strchr(base + 8, '/') - base;
841                                 okay = 1;
842                         } else if (!memcmp(data + i, "../", 3)) {
843                                 i += 3;
844                                 serverlen = strlen(base);
845                                 while (i + 2 < posn && 
846                                        !memcmp(data + i, "../", 3)) {
847                                         do {
848                                                 serverlen--;
849                                         } while (serverlen &&
850                                                  base[serverlen - 1] != '/');
851                                         i += 3;
852                                 }
853                                 // If the server got removed, give up.
854                                 okay = strchr(base, ':') - base + 3 < 
855                                         serverlen;
856                         } else if (http_specific) {
857                                 char *colon = strchr(data + i, ':');
858                                 char *slash = strchr(data + i, '/');
859                                 if (colon && slash && colon < data + posn &&
860                                     slash < data + posn && colon < slash) {
861                                         okay = 1;
862                                 }
863                         }
864                         // skip 'objects' at end
865                         if (okay) {
866                                 target = xmalloc(serverlen + posn - i - 6);
867                                 strncpy(target, base, serverlen);
868                                 strncpy(target + serverlen, data + i,
869                                         posn - i - 7);
870                                 target[serverlen + posn - i - 7] = '\0';
871                                 if (get_verbosely)
872                                         fprintf(stderr, 
873                                                 "Also look at %s\n", target);
874                                 newalt = xmalloc(sizeof(*newalt));
875                                 newalt->next = NULL;
876                                 newalt->base = target;
877                                 newalt->got_indices = 0;
878                                 newalt->packs = NULL;
879                                 while (tail->next != NULL)
880                                         tail = tail->next;
881                                 tail->next = newalt;
882                                 ret++;
883                         }
884                 }
885                 i = posn + 1;
886         }
887
888         got_alternates = 1;
889         free(buffer.buffer);
890         return ret;
891 }
892
893 static int fetch_indices(struct alt_base *repo)
894 {
895         unsigned char sha1[20];
896         char *url;
897         struct buffer buffer;
898         char *data;
899         int i = 0;
900
901         struct active_request_slot *slot;
902
903         if (repo->got_indices)
904                 return 0;
905
906         data = xmalloc(4096);
907         buffer.size = 4096;
908         buffer.posn = 0;
909         buffer.buffer = data;
910
911         if (get_verbosely)
912                 fprintf(stderr, "Getting pack list\n");
913         
914         url = xmalloc(strlen(repo->base) + 21);
915         sprintf(url, "%s/objects/info/packs", repo->base);
916
917         slot = get_active_slot();
918         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
919         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
920                          fwrite_buffer_dynamic);
921         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
922         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
923         if (start_active_slot(slot)) {
924                 run_active_slot(slot);
925                 if (slot->curl_result != CURLE_OK) {
926                         free(buffer.buffer);
927                         return error("%s", curl_errorstr);
928                 }
929         } else {
930                 free(buffer.buffer);
931                 return error("Unable to start request");
932         }
933
934         data = buffer.buffer;
935         while (i < buffer.posn) {
936                 switch (data[i]) {
937                 case 'P':
938                         i++;
939                         if (i + 52 < buffer.posn &&
940                             !strncmp(data + i, " pack-", 6) &&
941                             !strncmp(data + i + 46, ".pack\n", 6)) {
942                                 get_sha1_hex(data + i + 6, sha1);
943                                 setup_index(repo, sha1);
944                                 i += 51;
945                                 break;
946                         }
947                 default:
948                         while (data[i] != '\n')
949                                 i++;
950                 }
951                 i++;
952         }
953
954         free(buffer.buffer);
955         repo->got_indices = 1;
956         return 0;
957 }
958
959 static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
960 {
961         char *url;
962         struct packed_git *target;
963         struct packed_git **lst;
964         FILE *packfile;
965         char *filename;
966         char tmpfile[PATH_MAX];
967         int ret;
968         long prev_posn = 0;
969         char range[RANGE_HEADER_SIZE];
970         struct curl_slist *range_header = NULL;
971
972         struct active_request_slot *slot;
973
974         if (fetch_indices(repo))
975                 return -1;
976         target = find_sha1_pack(sha1, repo->packs);
977         if (!target)
978                 return -1;
979
980         if (get_verbosely) {
981                 fprintf(stderr, "Getting pack %s\n",
982                         sha1_to_hex(target->sha1));
983                 fprintf(stderr, " which contains %s\n",
984                         sha1_to_hex(sha1));
985         }
986
987         url = xmalloc(strlen(repo->base) + 65);
988         sprintf(url, "%s/objects/pack/pack-%s.pack",
989                 repo->base, sha1_to_hex(target->sha1));
990
991         filename = sha1_pack_name(target->sha1);
992         snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
993         packfile = fopen(tmpfile, "a");
994         if (!packfile)
995                 return error("Unable to open local file %s for pack",
996                              filename);
997
998         slot = get_active_slot();
999         curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
1000         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1001         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1002         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1003         slot->local = packfile;
1004
1005         /* If there is data present from a previous transfer attempt,
1006            resume where it left off */
1007         prev_posn = ftell(packfile);
1008         if (prev_posn>0) {
1009                 if (get_verbosely)
1010                         fprintf(stderr,
1011                                 "Resuming fetch of pack %s at byte %ld\n",
1012                                 sha1_to_hex(target->sha1), prev_posn);
1013                 sprintf(range, "Range: bytes=%ld-", prev_posn);
1014                 range_header = curl_slist_append(range_header, range);
1015                 curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
1016         }
1017
1018         if (start_active_slot(slot)) {
1019                 run_active_slot(slot);
1020                 if (slot->curl_result != CURLE_OK) {
1021                         fclose(packfile);
1022                         return error("Unable to get pack file %s\n%s", url,
1023                                      curl_errorstr);
1024                 }
1025         } else {
1026                 return error("Unable to start request");
1027         }
1028
1029         fclose(packfile);
1030
1031         ret = move_temp_to_file(tmpfile, filename);
1032         if (ret)
1033                 return ret;
1034
1035         lst = &repo->packs;
1036         while (*lst != target)
1037                 lst = &((*lst)->next);
1038         *lst = (*lst)->next;
1039
1040         if (verify_pack(target, 0))
1041                 return -1;
1042         install_packed_git(target);
1043
1044         return 0;
1045 }
1046
1047 static int fetch_object(struct alt_base *repo, unsigned char *sha1)
1048 {
1049         char *hex = sha1_to_hex(sha1);
1050         int ret;
1051         struct transfer_request *request = request_queue_head;
1052
1053         while (request != NULL && memcmp(request->sha1, sha1, 20))
1054                 request = request->next;
1055         if (request == NULL)
1056                 return error("Couldn't find request for %s in the queue", hex);
1057
1058         if (has_sha1_file(request->sha1)) {
1059                 release_request(request);
1060                 return 0;
1061         }
1062
1063 #ifdef USE_CURL_MULTI
1064         while (request->state == WAITING) {
1065                 int num_transfers;
1066                 curl_multi_perform(curlm, &num_transfers);
1067                 if (num_transfers < active_requests) {
1068                         process_curl_messages();
1069                         process_request_queue();
1070                 }
1071         }
1072 #else
1073         start_request(request);
1074 #endif
1075
1076         while (request->state == ACTIVE) {
1077                 run_active_slot(request->slot);
1078 #ifndef USE_CURL_MULTI
1079                 request->curl_result = request->slot->curl_result;
1080                 request->http_code = request->slot->http_code;
1081                 request->slot = NULL;
1082
1083                 /* Use alternates if necessary */
1084                 if (request->http_code == 404) {
1085                         fetch_alternates(alt->base);
1086                         if (request->repo->next != NULL) {
1087                                 request->repo = request->repo->next;
1088                                 start_request(request);
1089                         }
1090                 } else {
1091                         finish_request(request);
1092                         request->state = COMPLETE;
1093                 }
1094 #endif
1095         }
1096
1097         if (request->state == ABORTED) {
1098                 release_request(request);
1099                 return error("Request for %s aborted", hex);
1100         }
1101
1102         if (request->curl_result != CURLE_OK && request->http_code != 416) {
1103                 if (request->http_code == 404)
1104                         ret = -1; /* Be silent, it is probably in a pack. */
1105                 else
1106                         ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)",
1107                                     request->errorstr, request->curl_result,
1108                                     request->http_code, hex);
1109                 release_request(request);
1110                 return ret;
1111         }
1112
1113         if (request->zret != Z_STREAM_END) {
1114                 ret = error("File %s (%s) corrupt\n", hex, request->url);
1115                 release_request(request);
1116                 return ret;
1117         }
1118
1119         if (memcmp(request->sha1, request->real_sha1, 20)) {
1120                 release_request(request);
1121                 return error("File %s has bad hash\n", hex);
1122         }
1123
1124         if (request->rename < 0) {
1125                 ret = error("unable to write sha1 filename %s: %s",
1126                             request->filename,
1127                             strerror(request->rename));
1128                 release_request(request);
1129                 return ret;
1130         }
1131
1132         release_request(request);
1133         return 0;
1134 }
1135
1136 int fetch(unsigned char *sha1)
1137 {
1138         struct alt_base *altbase = alt;
1139
1140         if (!fetch_object(altbase, sha1))
1141                 return 0;
1142         while (altbase) {
1143                 if (!fetch_pack(altbase, sha1))
1144                         return 0;
1145                 fetch_alternates(alt->base);
1146                 altbase = altbase->next;
1147         }
1148         return error("Unable to find %s under %s\n", sha1_to_hex(sha1), 
1149                      alt->base);
1150 }
1151
1152 static inline int needs_quote(int ch)
1153 {
1154         switch (ch) {
1155         case '/': case '-': case '.':
1156         case 'A'...'Z': case 'a'...'z': case '0'...'9':
1157                 return 0;
1158         default:
1159                 return 1;
1160         }
1161 }
1162
1163 static inline int hex(int v)
1164 {
1165         if (v < 10) return '0' + v;
1166         else return 'A' + v - 10;
1167 }
1168
1169 static char *quote_ref_url(const char *base, const char *ref)
1170 {
1171         const char *cp;
1172         char *dp, *qref;
1173         int len, baselen, ch;
1174
1175         baselen = strlen(base);
1176         len = baselen + 6; /* "refs/" + NUL */
1177         for (cp = ref; (ch = *cp) != 0; cp++, len++)
1178                 if (needs_quote(ch))
1179                         len += 2; /* extra two hex plus replacement % */
1180         qref = xmalloc(len);
1181         memcpy(qref, base, baselen);
1182         memcpy(qref + baselen, "refs/", 5);
1183         for (cp = ref, dp = qref + baselen + 5; (ch = *cp) != 0; cp++) {
1184                 if (needs_quote(ch)) {
1185                         *dp++ = '%';
1186                         *dp++ = hex((ch >> 4) & 0xF);
1187                         *dp++ = hex(ch & 0xF);
1188                 }
1189                 else
1190                         *dp++ = ch;
1191         }
1192         *dp = 0;
1193
1194         return qref;
1195 }
1196
1197 int fetch_ref(char *ref, unsigned char *sha1)
1198 {
1199         char *url;
1200         char hex[42];
1201         struct buffer buffer;
1202         char *base = alt->base;
1203         struct active_request_slot *slot;
1204         buffer.size = 41;
1205         buffer.posn = 0;
1206         buffer.buffer = hex;
1207         hex[41] = '\0';
1208         
1209         url = quote_ref_url(base, ref);
1210         slot = get_active_slot();
1211         curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
1212         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
1213         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
1214         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1215         if (start_active_slot(slot)) {
1216                 run_active_slot(slot);
1217                 if (slot->curl_result != CURLE_OK)
1218                         return error("Couldn't get %s for %s\n%s",
1219                                      url, ref, curl_errorstr);
1220         } else {
1221                 return error("Unable to start request");
1222         }
1223
1224         hex[40] = '\0';
1225         get_sha1_hex(hex, sha1);
1226         return 0;
1227 }
1228
1229 int main(int argc, char **argv)
1230 {
1231         char *commit_id;
1232         char *url;
1233         int arg = 1;
1234         struct active_request_slot *slot;
1235         char *low_speed_limit;
1236         char *low_speed_time;
1237         char *wait_url;
1238         int rc = 0;
1239
1240         while (arg < argc && argv[arg][0] == '-') {
1241                 if (argv[arg][1] == 't') {
1242                         get_tree = 1;
1243                 } else if (argv[arg][1] == 'c') {
1244                         get_history = 1;
1245                 } else if (argv[arg][1] == 'a') {
1246                         get_all = 1;
1247                         get_tree = 1;
1248                         get_history = 1;
1249                 } else if (argv[arg][1] == 'v') {
1250                         get_verbosely = 1;
1251                 } else if (argv[arg][1] == 'w') {
1252                         write_ref = argv[arg + 1];
1253                         arg++;
1254                 } else if (!strcmp(argv[arg], "--recover")) {
1255                         get_recover = 1;
1256                 }
1257                 arg++;
1258         }
1259         if (argc < arg + 2) {
1260                 usage("git-http-fetch [-c] [-t] [-a] [-d] [-v] [--recover] [-w ref] commit-id url");
1261                 return 1;
1262         }
1263         commit_id = argv[arg];
1264         url = argv[arg + 1];
1265
1266         curl_global_init(CURL_GLOBAL_ALL);
1267
1268 #ifdef USE_CURL_MULTI
1269         {
1270                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
1271                 if (http_max_requests != NULL)
1272                         max_requests = atoi(http_max_requests);
1273         }
1274
1275         curlm = curl_multi_init();
1276         if (curlm == NULL) {
1277                 fprintf(stderr, "Error creating curl multi handle.\n");
1278                 return 1;
1279         }
1280 #endif
1281
1282         if (getenv("GIT_SSL_NO_VERIFY"))
1283                 curl_ssl_verify = 0;
1284
1285         ssl_cert = getenv("GIT_SSL_CERT");
1286 #if LIBCURL_VERSION_NUM >= 0x070902
1287         ssl_key = getenv("GIT_SSL_KEY");
1288 #endif
1289 #if LIBCURL_VERSION_NUM >= 0x070908
1290         ssl_capath = getenv("GIT_SSL_CAPATH");
1291 #endif
1292         ssl_cainfo = getenv("GIT_SSL_CAINFO");
1293
1294         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
1295         if (low_speed_limit != NULL)
1296                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
1297         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
1298         if (low_speed_time != NULL)
1299                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
1300
1301         git_config(http_options);
1302
1303         if (curl_ssl_verify == -1)
1304                 curl_ssl_verify = 1;
1305
1306 #ifdef USE_CURL_MULTI
1307         if (max_requests < 1)
1308                 max_requests = DEFAULT_MAX_REQUESTS;
1309 #endif
1310
1311         pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
1312         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
1313         no_range_header = curl_slist_append(no_range_header, "Range:");
1314
1315 #ifndef NO_CURL_EASY_DUPHANDLE
1316         curl_default = get_curl_handle();
1317 #endif
1318
1319         alt = xmalloc(sizeof(*alt));
1320         alt->base = url;
1321         alt->got_indices = 0;
1322         alt->packs = NULL;
1323         alt->next = NULL;
1324
1325         if (pull(commit_id))
1326                 rc = 1;
1327
1328         curl_slist_free_all(pragma_header);
1329         curl_slist_free_all(no_pragma_header);
1330         curl_slist_free_all(no_range_header);
1331 #ifndef NO_CURL_EASY_DUPHANDLE
1332         curl_easy_cleanup(curl_default);
1333 #endif
1334         slot = active_queue_head;
1335         while (slot != NULL) {
1336                 if (slot->in_use) {
1337                         if (get_verbosely) {
1338                                 curl_easy_getinfo(slot->curl,
1339                                                   CURLINFO_EFFECTIVE_URL,
1340                                                   &wait_url);
1341                                 fprintf(stderr, "Waiting for %s\n", wait_url);
1342                         }
1343                         run_active_slot(slot);
1344                 }
1345                 if (slot->curl != NULL)
1346                         curl_easy_cleanup(slot->curl);
1347                 slot = slot->next;
1348         }
1349 #ifdef USE_CURL_MULTI
1350         curl_multi_cleanup(curlm);
1351 #endif
1352         curl_global_cleanup();
1353         return rc;
1354 }