Merge branch 'rs/obsd-getcwd-workaround'
[git] / http.c
1 #include "git-compat-util.h"
2 #include "http.h"
3 #include "config.h"
4 #include "pack.h"
5 #include "sideband.h"
6 #include "run-command.h"
7 #include "url.h"
8 #include "urlmatch.h"
9 #include "credential.h"
10 #include "version.h"
11 #include "pkt-line.h"
12 #include "gettext.h"
13 #include "transport.h"
14
15 static struct trace_key trace_curl = TRACE_KEY_INIT(CURL);
16 #if LIBCURL_VERSION_NUM >= 0x070a08
17 long int git_curl_ipresolve = CURL_IPRESOLVE_WHATEVER;
18 #else
19 long int git_curl_ipresolve;
20 #endif
21 int active_requests;
22 int http_is_verbose;
23 ssize_t http_post_buffer = 16 * LARGE_PACKET_MAX;
24
25 #if LIBCURL_VERSION_NUM >= 0x070a06
26 #define LIBCURL_CAN_HANDLE_AUTH_ANY
27 #endif
28
29 static int min_curl_sessions = 1;
30 static int curl_session_count;
31 #ifdef USE_CURL_MULTI
32 static int max_requests = -1;
33 static CURLM *curlm;
34 #endif
35 #ifndef NO_CURL_EASY_DUPHANDLE
36 static CURL *curl_default;
37 #endif
38
39 #define PREV_BUF_SIZE 4096
40
41 char curl_errorstr[CURL_ERROR_SIZE];
42
43 static int curl_ssl_verify = -1;
44 static int curl_ssl_try;
45 static const char *ssl_cert;
46 static const char *ssl_cipherlist;
47 static const char *ssl_version;
48 static struct {
49         const char *name;
50         long ssl_version;
51 } sslversions[] = {
52         { "sslv2", CURL_SSLVERSION_SSLv2 },
53         { "sslv3", CURL_SSLVERSION_SSLv3 },
54         { "tlsv1", CURL_SSLVERSION_TLSv1 },
55 #if LIBCURL_VERSION_NUM >= 0x072200
56         { "tlsv1.0", CURL_SSLVERSION_TLSv1_0 },
57         { "tlsv1.1", CURL_SSLVERSION_TLSv1_1 },
58         { "tlsv1.2", CURL_SSLVERSION_TLSv1_2 },
59 #endif
60 };
61 #if LIBCURL_VERSION_NUM >= 0x070903
62 static const char *ssl_key;
63 #endif
64 #if LIBCURL_VERSION_NUM >= 0x070908
65 static const char *ssl_capath;
66 #endif
67 #if LIBCURL_VERSION_NUM >= 0x072c00
68 static const char *ssl_pinnedkey;
69 #endif
70 static const char *ssl_cainfo;
71 static long curl_low_speed_limit = -1;
72 static long curl_low_speed_time = -1;
73 static int curl_ftp_no_epsv;
74 static const char *curl_http_proxy;
75 static const char *curl_no_proxy;
76 static const char *http_proxy_authmethod;
77 static struct {
78         const char *name;
79         long curlauth_param;
80 } proxy_authmethods[] = {
81         { "basic", CURLAUTH_BASIC },
82         { "digest", CURLAUTH_DIGEST },
83         { "negotiate", CURLAUTH_GSSNEGOTIATE },
84         { "ntlm", CURLAUTH_NTLM },
85 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
86         { "anyauth", CURLAUTH_ANY },
87 #endif
88         /*
89          * CURLAUTH_DIGEST_IE has no corresponding command-line option in
90          * curl(1) and is not included in CURLAUTH_ANY, so we leave it out
91          * here, too
92          */
93 };
94 #if LIBCURL_VERSION_NUM >= 0x071600
95 static const char *curl_deleg;
96 static struct {
97         const char *name;
98         long curl_deleg_param;
99 } curl_deleg_levels[] = {
100         { "none", CURLGSSAPI_DELEGATION_NONE },
101         { "policy", CURLGSSAPI_DELEGATION_POLICY_FLAG },
102         { "always", CURLGSSAPI_DELEGATION_FLAG },
103 };
104 #endif
105
106 static struct credential proxy_auth = CREDENTIAL_INIT;
107 static const char *curl_proxyuserpwd;
108 static const char *curl_cookie_file;
109 static int curl_save_cookies;
110 struct credential http_auth = CREDENTIAL_INIT;
111 static int http_proactive_auth;
112 static const char *user_agent;
113 static int curl_empty_auth = -1;
114
115 enum http_follow_config http_follow_config = HTTP_FOLLOW_INITIAL;
116
117 #if LIBCURL_VERSION_NUM >= 0x071700
118 /* Use CURLOPT_KEYPASSWD as is */
119 #elif LIBCURL_VERSION_NUM >= 0x070903
120 #define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
121 #else
122 #define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
123 #endif
124
125 static struct credential cert_auth = CREDENTIAL_INIT;
126 static int ssl_cert_password_required;
127 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
128 static unsigned long http_auth_methods = CURLAUTH_ANY;
129 static int http_auth_methods_restricted;
130 /* Modes for which empty_auth cannot actually help us. */
131 static unsigned long empty_auth_useless =
132         CURLAUTH_BASIC
133 #ifdef CURLAUTH_DIGEST_IE
134         | CURLAUTH_DIGEST_IE
135 #endif
136         | CURLAUTH_DIGEST;
137 #endif
138
139 static struct curl_slist *pragma_header;
140 static struct curl_slist *no_pragma_header;
141 static struct curl_slist *extra_http_headers;
142
143 static struct active_request_slot *active_queue_head;
144
145 static char *cached_accept_language;
146
147 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
148 {
149         size_t size = eltsize * nmemb;
150         struct buffer *buffer = buffer_;
151
152         if (size > buffer->buf.len - buffer->posn)
153                 size = buffer->buf.len - buffer->posn;
154         memcpy(ptr, buffer->buf.buf + buffer->posn, size);
155         buffer->posn += size;
156
157         return size;
158 }
159
160 #ifndef NO_CURL_IOCTL
161 curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
162 {
163         struct buffer *buffer = clientp;
164
165         switch (cmd) {
166         case CURLIOCMD_NOP:
167                 return CURLIOE_OK;
168
169         case CURLIOCMD_RESTARTREAD:
170                 buffer->posn = 0;
171                 return CURLIOE_OK;
172
173         default:
174                 return CURLIOE_UNKNOWNCMD;
175         }
176 }
177 #endif
178
179 size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
180 {
181         size_t size = eltsize * nmemb;
182         struct strbuf *buffer = buffer_;
183
184         strbuf_add(buffer, ptr, size);
185         return size;
186 }
187
188 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
189 {
190         return eltsize * nmemb;
191 }
192
193 static void closedown_active_slot(struct active_request_slot *slot)
194 {
195         active_requests--;
196         slot->in_use = 0;
197 }
198
199 static void finish_active_slot(struct active_request_slot *slot)
200 {
201         closedown_active_slot(slot);
202         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
203
204         if (slot->finished != NULL)
205                 (*slot->finished) = 1;
206
207         /* Store slot results so they can be read after the slot is reused */
208         if (slot->results != NULL) {
209                 slot->results->curl_result = slot->curl_result;
210                 slot->results->http_code = slot->http_code;
211 #if LIBCURL_VERSION_NUM >= 0x070a08
212                 curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
213                                   &slot->results->auth_avail);
214 #else
215                 slot->results->auth_avail = 0;
216 #endif
217
218                 curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CONNECTCODE,
219                         &slot->results->http_connectcode);
220         }
221
222         /* Run callback if appropriate */
223         if (slot->callback_func != NULL)
224                 slot->callback_func(slot->callback_data);
225 }
226
227 static void xmulti_remove_handle(struct active_request_slot *slot)
228 {
229 #ifdef USE_CURL_MULTI
230         curl_multi_remove_handle(curlm, slot->curl);
231 #endif
232 }
233
234 #ifdef USE_CURL_MULTI
235 static void process_curl_messages(void)
236 {
237         int num_messages;
238         struct active_request_slot *slot;
239         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
240
241         while (curl_message != NULL) {
242                 if (curl_message->msg == CURLMSG_DONE) {
243                         int curl_result = curl_message->data.result;
244                         slot = active_queue_head;
245                         while (slot != NULL &&
246                                slot->curl != curl_message->easy_handle)
247                                 slot = slot->next;
248                         if (slot != NULL) {
249                                 xmulti_remove_handle(slot);
250                                 slot->curl_result = curl_result;
251                                 finish_active_slot(slot);
252                         } else {
253                                 fprintf(stderr, "Received DONE message for unknown request!\n");
254                         }
255                 } else {
256                         fprintf(stderr, "Unknown CURL message received: %d\n",
257                                 (int)curl_message->msg);
258                 }
259                 curl_message = curl_multi_info_read(curlm, &num_messages);
260         }
261 }
262 #endif
263
264 static int http_options(const char *var, const char *value, void *cb)
265 {
266         if (!strcmp("http.sslverify", var)) {
267                 curl_ssl_verify = git_config_bool(var, value);
268                 return 0;
269         }
270         if (!strcmp("http.sslcipherlist", var))
271                 return git_config_string(&ssl_cipherlist, var, value);
272         if (!strcmp("http.sslversion", var))
273                 return git_config_string(&ssl_version, var, value);
274         if (!strcmp("http.sslcert", var))
275                 return git_config_pathname(&ssl_cert, var, value);
276 #if LIBCURL_VERSION_NUM >= 0x070903
277         if (!strcmp("http.sslkey", var))
278                 return git_config_pathname(&ssl_key, var, value);
279 #endif
280 #if LIBCURL_VERSION_NUM >= 0x070908
281         if (!strcmp("http.sslcapath", var))
282                 return git_config_pathname(&ssl_capath, var, value);
283 #endif
284         if (!strcmp("http.sslcainfo", var))
285                 return git_config_pathname(&ssl_cainfo, var, value);
286         if (!strcmp("http.sslcertpasswordprotected", var)) {
287                 ssl_cert_password_required = git_config_bool(var, value);
288                 return 0;
289         }
290         if (!strcmp("http.ssltry", var)) {
291                 curl_ssl_try = git_config_bool(var, value);
292                 return 0;
293         }
294         if (!strcmp("http.minsessions", var)) {
295                 min_curl_sessions = git_config_int(var, value);
296 #ifndef USE_CURL_MULTI
297                 if (min_curl_sessions > 1)
298                         min_curl_sessions = 1;
299 #endif
300                 return 0;
301         }
302 #ifdef USE_CURL_MULTI
303         if (!strcmp("http.maxrequests", var)) {
304                 max_requests = git_config_int(var, value);
305                 return 0;
306         }
307 #endif
308         if (!strcmp("http.lowspeedlimit", var)) {
309                 curl_low_speed_limit = (long)git_config_int(var, value);
310                 return 0;
311         }
312         if (!strcmp("http.lowspeedtime", var)) {
313                 curl_low_speed_time = (long)git_config_int(var, value);
314                 return 0;
315         }
316
317         if (!strcmp("http.noepsv", var)) {
318                 curl_ftp_no_epsv = git_config_bool(var, value);
319                 return 0;
320         }
321         if (!strcmp("http.proxy", var))
322                 return git_config_string(&curl_http_proxy, var, value);
323
324         if (!strcmp("http.proxyauthmethod", var))
325                 return git_config_string(&http_proxy_authmethod, var, value);
326
327         if (!strcmp("http.cookiefile", var))
328                 return git_config_pathname(&curl_cookie_file, var, value);
329         if (!strcmp("http.savecookies", var)) {
330                 curl_save_cookies = git_config_bool(var, value);
331                 return 0;
332         }
333
334         if (!strcmp("http.postbuffer", var)) {
335                 http_post_buffer = git_config_ssize_t(var, value);
336                 if (http_post_buffer < 0)
337                         warning(_("negative value for http.postbuffer; defaulting to %d"), LARGE_PACKET_MAX);
338                 if (http_post_buffer < LARGE_PACKET_MAX)
339                         http_post_buffer = LARGE_PACKET_MAX;
340                 return 0;
341         }
342
343         if (!strcmp("http.useragent", var))
344                 return git_config_string(&user_agent, var, value);
345
346         if (!strcmp("http.emptyauth", var)) {
347                 if (value && !strcmp("auto", value))
348                         curl_empty_auth = -1;
349                 else
350                         curl_empty_auth = git_config_bool(var, value);
351                 return 0;
352         }
353
354         if (!strcmp("http.delegation", var)) {
355 #if LIBCURL_VERSION_NUM >= 0x071600
356                 return git_config_string(&curl_deleg, var, value);
357 #else
358                 warning(_("Delegation control is not supported with cURL < 7.22.0"));
359                 return 0;
360 #endif
361         }
362
363         if (!strcmp("http.pinnedpubkey", var)) {
364 #if LIBCURL_VERSION_NUM >= 0x072c00
365                 return git_config_pathname(&ssl_pinnedkey, var, value);
366 #else
367                 warning(_("Public key pinning not supported with cURL < 7.44.0"));
368                 return 0;
369 #endif
370         }
371
372         if (!strcmp("http.extraheader", var)) {
373                 if (!value) {
374                         return config_error_nonbool(var);
375                 } else if (!*value) {
376                         curl_slist_free_all(extra_http_headers);
377                         extra_http_headers = NULL;
378                 } else {
379                         extra_http_headers =
380                                 curl_slist_append(extra_http_headers, value);
381                 }
382                 return 0;
383         }
384
385         if (!strcmp("http.followredirects", var)) {
386                 if (value && !strcmp(value, "initial"))
387                         http_follow_config = HTTP_FOLLOW_INITIAL;
388                 else if (git_config_bool(var, value))
389                         http_follow_config = HTTP_FOLLOW_ALWAYS;
390                 else
391                         http_follow_config = HTTP_FOLLOW_NONE;
392                 return 0;
393         }
394
395         /* Fall back on the default ones */
396         return git_default_config(var, value, cb);
397 }
398
399 static int curl_empty_auth_enabled(void)
400 {
401         if (curl_empty_auth >= 0)
402                 return curl_empty_auth;
403
404 #ifndef LIBCURL_CAN_HANDLE_AUTH_ANY
405         /*
406          * Our libcurl is too old to do AUTH_ANY in the first place;
407          * just default to turning the feature off.
408          */
409 #else
410         /*
411          * In the automatic case, kick in the empty-auth
412          * hack as long as we would potentially try some
413          * method more exotic than "Basic" or "Digest".
414          *
415          * But only do this when this is our second or
416          * subsequent request, as by then we know what
417          * methods are available.
418          */
419         if (http_auth_methods_restricted &&
420             (http_auth_methods & ~empty_auth_useless))
421                 return 1;
422 #endif
423         return 0;
424 }
425
426 static void init_curl_http_auth(CURL *result)
427 {
428         if (!http_auth.username || !*http_auth.username) {
429                 if (curl_empty_auth_enabled())
430                         curl_easy_setopt(result, CURLOPT_USERPWD, ":");
431                 return;
432         }
433
434         credential_fill(&http_auth);
435
436 #if LIBCURL_VERSION_NUM >= 0x071301
437         curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
438         curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
439 #else
440         {
441                 static struct strbuf up = STRBUF_INIT;
442                 /*
443                  * Note that we assume we only ever have a single set of
444                  * credentials in a given program run, so we do not have
445                  * to worry about updating this buffer, only setting its
446                  * initial value.
447                  */
448                 if (!up.len)
449                         strbuf_addf(&up, "%s:%s",
450                                 http_auth.username, http_auth.password);
451                 curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
452         }
453 #endif
454 }
455
456 /* *var must be free-able */
457 static void var_override(const char **var, char *value)
458 {
459         if (value) {
460                 free((void *)*var);
461                 *var = xstrdup(value);
462         }
463 }
464
465 static void set_proxyauth_name_password(CURL *result)
466 {
467 #if LIBCURL_VERSION_NUM >= 0x071301
468                 curl_easy_setopt(result, CURLOPT_PROXYUSERNAME,
469                         proxy_auth.username);
470                 curl_easy_setopt(result, CURLOPT_PROXYPASSWORD,
471                         proxy_auth.password);
472 #else
473                 struct strbuf s = STRBUF_INIT;
474
475                 strbuf_addstr_urlencode(&s, proxy_auth.username, 1);
476                 strbuf_addch(&s, ':');
477                 strbuf_addstr_urlencode(&s, proxy_auth.password, 1);
478                 curl_proxyuserpwd = strbuf_detach(&s, NULL);
479                 curl_easy_setopt(result, CURLOPT_PROXYUSERPWD, curl_proxyuserpwd);
480 #endif
481 }
482
483 static void init_curl_proxy_auth(CURL *result)
484 {
485         if (proxy_auth.username) {
486                 if (!proxy_auth.password)
487                         credential_fill(&proxy_auth);
488                 set_proxyauth_name_password(result);
489         }
490
491         var_override(&http_proxy_authmethod, getenv("GIT_HTTP_PROXY_AUTHMETHOD"));
492
493 #if LIBCURL_VERSION_NUM >= 0x070a07 /* CURLOPT_PROXYAUTH and CURLAUTH_ANY */
494         if (http_proxy_authmethod) {
495                 int i;
496                 for (i = 0; i < ARRAY_SIZE(proxy_authmethods); i++) {
497                         if (!strcmp(http_proxy_authmethod, proxy_authmethods[i].name)) {
498                                 curl_easy_setopt(result, CURLOPT_PROXYAUTH,
499                                                 proxy_authmethods[i].curlauth_param);
500                                 break;
501                         }
502                 }
503                 if (i == ARRAY_SIZE(proxy_authmethods)) {
504                         warning("unsupported proxy authentication method %s: using anyauth",
505                                         http_proxy_authmethod);
506                         curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
507                 }
508         }
509         else
510                 curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
511 #endif
512 }
513
514 static int has_cert_password(void)
515 {
516         if (ssl_cert == NULL || ssl_cert_password_required != 1)
517                 return 0;
518         if (!cert_auth.password) {
519                 cert_auth.protocol = xstrdup("cert");
520                 cert_auth.username = xstrdup("");
521                 cert_auth.path = xstrdup(ssl_cert);
522                 credential_fill(&cert_auth);
523         }
524         return 1;
525 }
526
527 #if LIBCURL_VERSION_NUM >= 0x071900
528 static void set_curl_keepalive(CURL *c)
529 {
530         curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
531 }
532
533 #elif LIBCURL_VERSION_NUM >= 0x071000
534 static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
535 {
536         int ka = 1;
537         int rc;
538         socklen_t len = (socklen_t)sizeof(ka);
539
540         if (type != CURLSOCKTYPE_IPCXN)
541                 return 0;
542
543         rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
544         if (rc < 0)
545                 warning_errno("unable to set SO_KEEPALIVE on socket");
546
547         return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
548 }
549
550 static void set_curl_keepalive(CURL *c)
551 {
552         curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
553 }
554
555 #else
556 static void set_curl_keepalive(CURL *c)
557 {
558         /* not supported on older curl versions */
559 }
560 #endif
561
562 static void redact_sensitive_header(struct strbuf *header)
563 {
564         const char *sensitive_header;
565
566         if (skip_prefix(header->buf, "Authorization:", &sensitive_header) ||
567             skip_prefix(header->buf, "Proxy-Authorization:", &sensitive_header)) {
568                 /* The first token is the type, which is OK to log */
569                 while (isspace(*sensitive_header))
570                         sensitive_header++;
571                 while (*sensitive_header && !isspace(*sensitive_header))
572                         sensitive_header++;
573                 /* Everything else is opaque and possibly sensitive */
574                 strbuf_setlen(header,  sensitive_header - header->buf);
575                 strbuf_addstr(header, " <redacted>");
576         }
577 }
578
579 static void curl_dump_header(const char *text, unsigned char *ptr, size_t size, int hide_sensitive_header)
580 {
581         struct strbuf out = STRBUF_INIT;
582         struct strbuf **headers, **header;
583
584         strbuf_addf(&out, "%s, %10.10ld bytes (0x%8.8lx)\n",
585                 text, (long)size, (long)size);
586         trace_strbuf(&trace_curl, &out);
587         strbuf_reset(&out);
588         strbuf_add(&out, ptr, size);
589         headers = strbuf_split_max(&out, '\n', 0);
590
591         for (header = headers; *header; header++) {
592                 if (hide_sensitive_header)
593                         redact_sensitive_header(*header);
594                 strbuf_insert((*header), 0, text, strlen(text));
595                 strbuf_insert((*header), strlen(text), ": ", 2);
596                 strbuf_rtrim((*header));
597                 strbuf_addch((*header), '\n');
598                 trace_strbuf(&trace_curl, (*header));
599         }
600         strbuf_list_free(headers);
601         strbuf_release(&out);
602 }
603
604 static void curl_dump_data(const char *text, unsigned char *ptr, size_t size)
605 {
606         size_t i;
607         struct strbuf out = STRBUF_INIT;
608         unsigned int width = 60;
609
610         strbuf_addf(&out, "%s, %10.10ld bytes (0x%8.8lx)\n",
611                 text, (long)size, (long)size);
612         trace_strbuf(&trace_curl, &out);
613
614         for (i = 0; i < size; i += width) {
615                 size_t w;
616
617                 strbuf_reset(&out);
618                 strbuf_addf(&out, "%s: ", text);
619                 for (w = 0; (w < width) && (i + w < size); w++) {
620                         unsigned char ch = ptr[i + w];
621
622                         strbuf_addch(&out,
623                                        (ch >= 0x20) && (ch < 0x80)
624                                        ? ch : '.');
625                 }
626                 strbuf_addch(&out, '\n');
627                 trace_strbuf(&trace_curl, &out);
628         }
629         strbuf_release(&out);
630 }
631
632 static int curl_trace(CURL *handle, curl_infotype type, char *data, size_t size, void *userp)
633 {
634         const char *text;
635         enum { NO_FILTER = 0, DO_FILTER = 1 };
636
637         switch (type) {
638         case CURLINFO_TEXT:
639                 trace_printf_key(&trace_curl, "== Info: %s", data);
640         default:                /* we ignore unknown types by default */
641                 return 0;
642
643         case CURLINFO_HEADER_OUT:
644                 text = "=> Send header";
645                 curl_dump_header(text, (unsigned char *)data, size, DO_FILTER);
646                 break;
647         case CURLINFO_DATA_OUT:
648                 text = "=> Send data";
649                 curl_dump_data(text, (unsigned char *)data, size);
650                 break;
651         case CURLINFO_SSL_DATA_OUT:
652                 text = "=> Send SSL data";
653                 curl_dump_data(text, (unsigned char *)data, size);
654                 break;
655         case CURLINFO_HEADER_IN:
656                 text = "<= Recv header";
657                 curl_dump_header(text, (unsigned char *)data, size, NO_FILTER);
658                 break;
659         case CURLINFO_DATA_IN:
660                 text = "<= Recv data";
661                 curl_dump_data(text, (unsigned char *)data, size);
662                 break;
663         case CURLINFO_SSL_DATA_IN:
664                 text = "<= Recv SSL data";
665                 curl_dump_data(text, (unsigned char *)data, size);
666                 break;
667         }
668         return 0;
669 }
670
671 void setup_curl_trace(CURL *handle)
672 {
673         if (!trace_want(&trace_curl))
674                 return;
675         curl_easy_setopt(handle, CURLOPT_VERBOSE, 1L);
676         curl_easy_setopt(handle, CURLOPT_DEBUGFUNCTION, curl_trace);
677         curl_easy_setopt(handle, CURLOPT_DEBUGDATA, NULL);
678 }
679
680 static long get_curl_allowed_protocols(int from_user)
681 {
682         long allowed_protocols = 0;
683
684         if (is_transport_allowed("http", from_user))
685                 allowed_protocols |= CURLPROTO_HTTP;
686         if (is_transport_allowed("https", from_user))
687                 allowed_protocols |= CURLPROTO_HTTPS;
688         if (is_transport_allowed("ftp", from_user))
689                 allowed_protocols |= CURLPROTO_FTP;
690         if (is_transport_allowed("ftps", from_user))
691                 allowed_protocols |= CURLPROTO_FTPS;
692
693         return allowed_protocols;
694 }
695
696 static CURL *get_curl_handle(void)
697 {
698         CURL *result = curl_easy_init();
699
700         if (!result)
701                 die("curl_easy_init failed");
702
703         if (!curl_ssl_verify) {
704                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
705                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
706         } else {
707                 /* Verify authenticity of the peer's certificate */
708                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
709                 /* The name in the cert must match whom we tried to connect */
710                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
711         }
712
713 #if LIBCURL_VERSION_NUM >= 0x070907
714         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
715 #endif
716 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
717         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
718 #endif
719
720 #if LIBCURL_VERSION_NUM >= 0x071600
721         if (curl_deleg) {
722                 int i;
723                 for (i = 0; i < ARRAY_SIZE(curl_deleg_levels); i++) {
724                         if (!strcmp(curl_deleg, curl_deleg_levels[i].name)) {
725                                 curl_easy_setopt(result, CURLOPT_GSSAPI_DELEGATION,
726                                                 curl_deleg_levels[i].curl_deleg_param);
727                                 break;
728                         }
729                 }
730                 if (i == ARRAY_SIZE(curl_deleg_levels))
731                         warning("Unknown delegation method '%s': using default",
732                                 curl_deleg);
733         }
734 #endif
735
736         if (http_proactive_auth)
737                 init_curl_http_auth(result);
738
739         if (getenv("GIT_SSL_VERSION"))
740                 ssl_version = getenv("GIT_SSL_VERSION");
741         if (ssl_version && *ssl_version) {
742                 int i;
743                 for (i = 0; i < ARRAY_SIZE(sslversions); i++) {
744                         if (!strcmp(ssl_version, sslversions[i].name)) {
745                                 curl_easy_setopt(result, CURLOPT_SSLVERSION,
746                                                  sslversions[i].ssl_version);
747                                 break;
748                         }
749                 }
750                 if (i == ARRAY_SIZE(sslversions))
751                         warning("unsupported ssl version %s: using default",
752                                 ssl_version);
753         }
754
755         if (getenv("GIT_SSL_CIPHER_LIST"))
756                 ssl_cipherlist = getenv("GIT_SSL_CIPHER_LIST");
757         if (ssl_cipherlist != NULL && *ssl_cipherlist)
758                 curl_easy_setopt(result, CURLOPT_SSL_CIPHER_LIST,
759                                 ssl_cipherlist);
760
761         if (ssl_cert != NULL)
762                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
763         if (has_cert_password())
764                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
765 #if LIBCURL_VERSION_NUM >= 0x070903
766         if (ssl_key != NULL)
767                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
768 #endif
769 #if LIBCURL_VERSION_NUM >= 0x070908
770         if (ssl_capath != NULL)
771                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
772 #endif
773 #if LIBCURL_VERSION_NUM >= 0x072c00
774         if (ssl_pinnedkey != NULL)
775                 curl_easy_setopt(result, CURLOPT_PINNEDPUBLICKEY, ssl_pinnedkey);
776 #endif
777         if (ssl_cainfo != NULL)
778                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
779
780         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
781                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
782                                  curl_low_speed_limit);
783                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
784                                  curl_low_speed_time);
785         }
786
787         curl_easy_setopt(result, CURLOPT_MAXREDIRS, 20);
788 #if LIBCURL_VERSION_NUM >= 0x071301
789         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
790 #elif LIBCURL_VERSION_NUM >= 0x071101
791         curl_easy_setopt(result, CURLOPT_POST301, 1);
792 #endif
793 #if LIBCURL_VERSION_NUM >= 0x071304
794         curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS,
795                          get_curl_allowed_protocols(0));
796         curl_easy_setopt(result, CURLOPT_PROTOCOLS,
797                          get_curl_allowed_protocols(-1));
798 #else
799         warning("protocol restrictions not applied to curl redirects because\n"
800                 "your curl version is too old (>= 7.19.4)");
801 #endif
802         if (getenv("GIT_CURL_VERBOSE"))
803                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1L);
804         setup_curl_trace(result);
805
806         curl_easy_setopt(result, CURLOPT_USERAGENT,
807                 user_agent ? user_agent : git_user_agent());
808
809         if (curl_ftp_no_epsv)
810                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
811
812 #ifdef CURLOPT_USE_SSL
813         if (curl_ssl_try)
814                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
815 #endif
816
817         /*
818          * CURL also examines these variables as a fallback; but we need to query
819          * them here in order to decide whether to prompt for missing password (cf.
820          * init_curl_proxy_auth()).
821          *
822          * Unlike many other common environment variables, these are historically
823          * lowercase only. It appears that CURL did not know this and implemented
824          * only uppercase variants, which was later corrected to take both - with
825          * the exception of http_proxy, which is lowercase only also in CURL. As
826          * the lowercase versions are the historical quasi-standard, they take
827          * precedence here, as in CURL.
828          */
829         if (!curl_http_proxy) {
830                 if (http_auth.protocol && !strcmp(http_auth.protocol, "https")) {
831                         var_override(&curl_http_proxy, getenv("HTTPS_PROXY"));
832                         var_override(&curl_http_proxy, getenv("https_proxy"));
833                 } else {
834                         var_override(&curl_http_proxy, getenv("http_proxy"));
835                 }
836                 if (!curl_http_proxy) {
837                         var_override(&curl_http_proxy, getenv("ALL_PROXY"));
838                         var_override(&curl_http_proxy, getenv("all_proxy"));
839                 }
840         }
841
842         if (curl_http_proxy && curl_http_proxy[0] == '\0') {
843                 /*
844                  * Handle case with the empty http.proxy value here to keep
845                  * common code clean.
846                  * NB: empty option disables proxying at all.
847                  */
848                 curl_easy_setopt(result, CURLOPT_PROXY, "");
849         } else if (curl_http_proxy) {
850 #if LIBCURL_VERSION_NUM >= 0x071800
851                 if (starts_with(curl_http_proxy, "socks5h"))
852                         curl_easy_setopt(result,
853                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5_HOSTNAME);
854                 else if (starts_with(curl_http_proxy, "socks5"))
855                         curl_easy_setopt(result,
856                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
857                 else if (starts_with(curl_http_proxy, "socks4a"))
858                         curl_easy_setopt(result,
859                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4A);
860                 else if (starts_with(curl_http_proxy, "socks"))
861                         curl_easy_setopt(result,
862                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
863 #endif
864                 if (strstr(curl_http_proxy, "://"))
865                         credential_from_url(&proxy_auth, curl_http_proxy);
866                 else {
867                         struct strbuf url = STRBUF_INIT;
868                         strbuf_addf(&url, "http://%s", curl_http_proxy);
869                         credential_from_url(&proxy_auth, url.buf);
870                         strbuf_release(&url);
871                 }
872
873                 if (!proxy_auth.host)
874                         die("Invalid proxy URL '%s'", curl_http_proxy);
875
876                 curl_easy_setopt(result, CURLOPT_PROXY, proxy_auth.host);
877 #if LIBCURL_VERSION_NUM >= 0x071304
878                 var_override(&curl_no_proxy, getenv("NO_PROXY"));
879                 var_override(&curl_no_proxy, getenv("no_proxy"));
880                 curl_easy_setopt(result, CURLOPT_NOPROXY, curl_no_proxy);
881 #endif
882         }
883         init_curl_proxy_auth(result);
884
885         set_curl_keepalive(result);
886
887         return result;
888 }
889
890 static void set_from_env(const char **var, const char *envname)
891 {
892         const char *val = getenv(envname);
893         if (val)
894                 *var = val;
895 }
896
897 void http_init(struct remote *remote, const char *url, int proactive_auth)
898 {
899         char *low_speed_limit;
900         char *low_speed_time;
901         char *normalized_url;
902         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
903
904         config.section = "http";
905         config.key = NULL;
906         config.collect_fn = http_options;
907         config.cascade_fn = git_default_config;
908         config.cb = NULL;
909
910         http_is_verbose = 0;
911         normalized_url = url_normalize(url, &config.url);
912
913         git_config(urlmatch_config_entry, &config);
914         free(normalized_url);
915
916         if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
917                 die("curl_global_init failed");
918
919         http_proactive_auth = proactive_auth;
920
921         if (remote && remote->http_proxy)
922                 curl_http_proxy = xstrdup(remote->http_proxy);
923
924         if (remote)
925                 var_override(&http_proxy_authmethod, remote->http_proxy_authmethod);
926
927         pragma_header = curl_slist_append(http_copy_default_headers(),
928                 "Pragma: no-cache");
929         no_pragma_header = curl_slist_append(http_copy_default_headers(),
930                 "Pragma:");
931
932 #ifdef USE_CURL_MULTI
933         {
934                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
935                 if (http_max_requests != NULL)
936                         max_requests = atoi(http_max_requests);
937         }
938
939         curlm = curl_multi_init();
940         if (!curlm)
941                 die("curl_multi_init failed");
942 #endif
943
944         if (getenv("GIT_SSL_NO_VERIFY"))
945                 curl_ssl_verify = 0;
946
947         set_from_env(&ssl_cert, "GIT_SSL_CERT");
948 #if LIBCURL_VERSION_NUM >= 0x070903
949         set_from_env(&ssl_key, "GIT_SSL_KEY");
950 #endif
951 #if LIBCURL_VERSION_NUM >= 0x070908
952         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
953 #endif
954         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
955
956         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
957
958         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
959         if (low_speed_limit != NULL)
960                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
961         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
962         if (low_speed_time != NULL)
963                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
964
965         if (curl_ssl_verify == -1)
966                 curl_ssl_verify = 1;
967
968         curl_session_count = 0;
969 #ifdef USE_CURL_MULTI
970         if (max_requests < 1)
971                 max_requests = DEFAULT_MAX_REQUESTS;
972 #endif
973
974         if (getenv("GIT_CURL_FTP_NO_EPSV"))
975                 curl_ftp_no_epsv = 1;
976
977         if (url) {
978                 credential_from_url(&http_auth, url);
979                 if (!ssl_cert_password_required &&
980                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
981                     starts_with(url, "https://"))
982                         ssl_cert_password_required = 1;
983         }
984
985 #ifndef NO_CURL_EASY_DUPHANDLE
986         curl_default = get_curl_handle();
987 #endif
988 }
989
990 void http_cleanup(void)
991 {
992         struct active_request_slot *slot = active_queue_head;
993
994         while (slot != NULL) {
995                 struct active_request_slot *next = slot->next;
996                 if (slot->curl != NULL) {
997                         xmulti_remove_handle(slot);
998                         curl_easy_cleanup(slot->curl);
999                 }
1000                 free(slot);
1001                 slot = next;
1002         }
1003         active_queue_head = NULL;
1004
1005 #ifndef NO_CURL_EASY_DUPHANDLE
1006         curl_easy_cleanup(curl_default);
1007 #endif
1008
1009 #ifdef USE_CURL_MULTI
1010         curl_multi_cleanup(curlm);
1011 #endif
1012         curl_global_cleanup();
1013
1014         curl_slist_free_all(extra_http_headers);
1015         extra_http_headers = NULL;
1016
1017         curl_slist_free_all(pragma_header);
1018         pragma_header = NULL;
1019
1020         curl_slist_free_all(no_pragma_header);
1021         no_pragma_header = NULL;
1022
1023         if (curl_http_proxy) {
1024                 free((void *)curl_http_proxy);
1025                 curl_http_proxy = NULL;
1026         }
1027
1028         if (proxy_auth.password) {
1029                 memset(proxy_auth.password, 0, strlen(proxy_auth.password));
1030                 FREE_AND_NULL(proxy_auth.password);
1031         }
1032
1033         free((void *)curl_proxyuserpwd);
1034         curl_proxyuserpwd = NULL;
1035
1036         free((void *)http_proxy_authmethod);
1037         http_proxy_authmethod = NULL;
1038
1039         if (cert_auth.password != NULL) {
1040                 memset(cert_auth.password, 0, strlen(cert_auth.password));
1041                 FREE_AND_NULL(cert_auth.password);
1042         }
1043         ssl_cert_password_required = 0;
1044
1045         FREE_AND_NULL(cached_accept_language);
1046 }
1047
1048 struct active_request_slot *get_active_slot(void)
1049 {
1050         struct active_request_slot *slot = active_queue_head;
1051         struct active_request_slot *newslot;
1052
1053 #ifdef USE_CURL_MULTI
1054         int num_transfers;
1055
1056         /* Wait for a slot to open up if the queue is full */
1057         while (active_requests >= max_requests) {
1058                 curl_multi_perform(curlm, &num_transfers);
1059                 if (num_transfers < active_requests)
1060                         process_curl_messages();
1061         }
1062 #endif
1063
1064         while (slot != NULL && slot->in_use)
1065                 slot = slot->next;
1066
1067         if (slot == NULL) {
1068                 newslot = xmalloc(sizeof(*newslot));
1069                 newslot->curl = NULL;
1070                 newslot->in_use = 0;
1071                 newslot->next = NULL;
1072
1073                 slot = active_queue_head;
1074                 if (slot == NULL) {
1075                         active_queue_head = newslot;
1076                 } else {
1077                         while (slot->next != NULL)
1078                                 slot = slot->next;
1079                         slot->next = newslot;
1080                 }
1081                 slot = newslot;
1082         }
1083
1084         if (slot->curl == NULL) {
1085 #ifdef NO_CURL_EASY_DUPHANDLE
1086                 slot->curl = get_curl_handle();
1087 #else
1088                 slot->curl = curl_easy_duphandle(curl_default);
1089 #endif
1090                 curl_session_count++;
1091         }
1092
1093         active_requests++;
1094         slot->in_use = 1;
1095         slot->results = NULL;
1096         slot->finished = NULL;
1097         slot->callback_data = NULL;
1098         slot->callback_func = NULL;
1099         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
1100         if (curl_save_cookies)
1101                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
1102         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
1103         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
1104         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
1105         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
1106         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
1107         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
1108         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
1109         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1110         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
1111         curl_easy_setopt(slot->curl, CURLOPT_RANGE, NULL);
1112
1113         /*
1114          * Default following to off unless "ALWAYS" is configured; this gives
1115          * callers a sane starting point, and they can tweak for individual
1116          * HTTP_FOLLOW_* cases themselves.
1117          */
1118         if (http_follow_config == HTTP_FOLLOW_ALWAYS)
1119                 curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
1120         else
1121                 curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 0);
1122
1123 #if LIBCURL_VERSION_NUM >= 0x070a08
1124         curl_easy_setopt(slot->curl, CURLOPT_IPRESOLVE, git_curl_ipresolve);
1125 #endif
1126 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
1127         curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
1128 #endif
1129         if (http_auth.password || curl_empty_auth_enabled())
1130                 init_curl_http_auth(slot->curl);
1131
1132         return slot;
1133 }
1134
1135 int start_active_slot(struct active_request_slot *slot)
1136 {
1137 #ifdef USE_CURL_MULTI
1138         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
1139         int num_transfers;
1140
1141         if (curlm_result != CURLM_OK &&
1142             curlm_result != CURLM_CALL_MULTI_PERFORM) {
1143                 warning("curl_multi_add_handle failed: %s",
1144                         curl_multi_strerror(curlm_result));
1145                 active_requests--;
1146                 slot->in_use = 0;
1147                 return 0;
1148         }
1149
1150         /*
1151          * We know there must be something to do, since we just added
1152          * something.
1153          */
1154         curl_multi_perform(curlm, &num_transfers);
1155 #endif
1156         return 1;
1157 }
1158
1159 #ifdef USE_CURL_MULTI
1160 struct fill_chain {
1161         void *data;
1162         int (*fill)(void *);
1163         struct fill_chain *next;
1164 };
1165
1166 static struct fill_chain *fill_cfg;
1167
1168 void add_fill_function(void *data, int (*fill)(void *))
1169 {
1170         struct fill_chain *new = xmalloc(sizeof(*new));
1171         struct fill_chain **linkp = &fill_cfg;
1172         new->data = data;
1173         new->fill = fill;
1174         new->next = NULL;
1175         while (*linkp)
1176                 linkp = &(*linkp)->next;
1177         *linkp = new;
1178 }
1179
1180 void fill_active_slots(void)
1181 {
1182         struct active_request_slot *slot = active_queue_head;
1183
1184         while (active_requests < max_requests) {
1185                 struct fill_chain *fill;
1186                 for (fill = fill_cfg; fill; fill = fill->next)
1187                         if (fill->fill(fill->data))
1188                                 break;
1189
1190                 if (!fill)
1191                         break;
1192         }
1193
1194         while (slot != NULL) {
1195                 if (!slot->in_use && slot->curl != NULL
1196                         && curl_session_count > min_curl_sessions) {
1197                         curl_easy_cleanup(slot->curl);
1198                         slot->curl = NULL;
1199                         curl_session_count--;
1200                 }
1201                 slot = slot->next;
1202         }
1203 }
1204
1205 void step_active_slots(void)
1206 {
1207         int num_transfers;
1208         CURLMcode curlm_result;
1209
1210         do {
1211                 curlm_result = curl_multi_perform(curlm, &num_transfers);
1212         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
1213         if (num_transfers < active_requests) {
1214                 process_curl_messages();
1215                 fill_active_slots();
1216         }
1217 }
1218 #endif
1219
1220 void run_active_slot(struct active_request_slot *slot)
1221 {
1222 #ifdef USE_CURL_MULTI
1223         fd_set readfds;
1224         fd_set writefds;
1225         fd_set excfds;
1226         int max_fd;
1227         struct timeval select_timeout;
1228         int finished = 0;
1229
1230         slot->finished = &finished;
1231         while (!finished) {
1232                 step_active_slots();
1233
1234                 if (slot->in_use) {
1235 #if LIBCURL_VERSION_NUM >= 0x070f04
1236                         long curl_timeout;
1237                         curl_multi_timeout(curlm, &curl_timeout);
1238                         if (curl_timeout == 0) {
1239                                 continue;
1240                         } else if (curl_timeout == -1) {
1241                                 select_timeout.tv_sec  = 0;
1242                                 select_timeout.tv_usec = 50000;
1243                         } else {
1244                                 select_timeout.tv_sec  =  curl_timeout / 1000;
1245                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
1246                         }
1247 #else
1248                         select_timeout.tv_sec  = 0;
1249                         select_timeout.tv_usec = 50000;
1250 #endif
1251
1252                         max_fd = -1;
1253                         FD_ZERO(&readfds);
1254                         FD_ZERO(&writefds);
1255                         FD_ZERO(&excfds);
1256                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
1257
1258                         /*
1259                          * It can happen that curl_multi_timeout returns a pathologically
1260                          * long timeout when curl_multi_fdset returns no file descriptors
1261                          * to read.  See commit message for more details.
1262                          */
1263                         if (max_fd < 0 &&
1264                             (select_timeout.tv_sec > 0 ||
1265                              select_timeout.tv_usec > 50000)) {
1266                                 select_timeout.tv_sec  = 0;
1267                                 select_timeout.tv_usec = 50000;
1268                         }
1269
1270                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
1271                 }
1272         }
1273 #else
1274         while (slot->in_use) {
1275                 slot->curl_result = curl_easy_perform(slot->curl);
1276                 finish_active_slot(slot);
1277         }
1278 #endif
1279 }
1280
1281 static void release_active_slot(struct active_request_slot *slot)
1282 {
1283         closedown_active_slot(slot);
1284         if (slot->curl) {
1285                 xmulti_remove_handle(slot);
1286                 if (curl_session_count > min_curl_sessions) {
1287                         curl_easy_cleanup(slot->curl);
1288                         slot->curl = NULL;
1289                         curl_session_count--;
1290                 }
1291         }
1292 #ifdef USE_CURL_MULTI
1293         fill_active_slots();
1294 #endif
1295 }
1296
1297 void finish_all_active_slots(void)
1298 {
1299         struct active_request_slot *slot = active_queue_head;
1300
1301         while (slot != NULL)
1302                 if (slot->in_use) {
1303                         run_active_slot(slot);
1304                         slot = active_queue_head;
1305                 } else {
1306                         slot = slot->next;
1307                 }
1308 }
1309
1310 /* Helpers for modifying and creating URLs */
1311 static inline int needs_quote(int ch)
1312 {
1313         if (((ch >= 'A') && (ch <= 'Z'))
1314                         || ((ch >= 'a') && (ch <= 'z'))
1315                         || ((ch >= '0') && (ch <= '9'))
1316                         || (ch == '/')
1317                         || (ch == '-')
1318                         || (ch == '.'))
1319                 return 0;
1320         return 1;
1321 }
1322
1323 static char *quote_ref_url(const char *base, const char *ref)
1324 {
1325         struct strbuf buf = STRBUF_INIT;
1326         const char *cp;
1327         int ch;
1328
1329         end_url_with_slash(&buf, base);
1330
1331         for (cp = ref; (ch = *cp) != 0; cp++)
1332                 if (needs_quote(ch))
1333                         strbuf_addf(&buf, "%%%02x", ch);
1334                 else
1335                         strbuf_addch(&buf, *cp);
1336
1337         return strbuf_detach(&buf, NULL);
1338 }
1339
1340 void append_remote_object_url(struct strbuf *buf, const char *url,
1341                               const char *hex,
1342                               int only_two_digit_prefix)
1343 {
1344         end_url_with_slash(buf, url);
1345
1346         strbuf_addf(buf, "objects/%.*s/", 2, hex);
1347         if (!only_two_digit_prefix)
1348                 strbuf_addstr(buf, hex + 2);
1349 }
1350
1351 char *get_remote_object_url(const char *url, const char *hex,
1352                             int only_two_digit_prefix)
1353 {
1354         struct strbuf buf = STRBUF_INIT;
1355         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
1356         return strbuf_detach(&buf, NULL);
1357 }
1358
1359 static int handle_curl_result(struct slot_results *results)
1360 {
1361         /*
1362          * If we see a failing http code with CURLE_OK, we have turned off
1363          * FAILONERROR (to keep the server's custom error response), and should
1364          * translate the code into failure here.
1365          *
1366          * Likewise, if we see a redirect (30x code), that means we turned off
1367          * redirect-following, and we should treat the result as an error.
1368          */
1369         if (results->curl_result == CURLE_OK &&
1370             results->http_code >= 300) {
1371                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
1372                 /*
1373                  * Normally curl will already have put the "reason phrase"
1374                  * from the server into curl_errorstr; unfortunately without
1375                  * FAILONERROR it is lost, so we can give only the numeric
1376                  * status code.
1377                  */
1378                 xsnprintf(curl_errorstr, sizeof(curl_errorstr),
1379                           "The requested URL returned error: %ld",
1380                           results->http_code);
1381         }
1382
1383         if (results->curl_result == CURLE_OK) {
1384                 credential_approve(&http_auth);
1385                 if (proxy_auth.password)
1386                         credential_approve(&proxy_auth);
1387                 return HTTP_OK;
1388         } else if (missing_target(results))
1389                 return HTTP_MISSING_TARGET;
1390         else if (results->http_code == 401) {
1391                 if (http_auth.username && http_auth.password) {
1392                         credential_reject(&http_auth);
1393                         return HTTP_NOAUTH;
1394                 } else {
1395 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
1396                         http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
1397                         if (results->auth_avail) {
1398                                 http_auth_methods &= results->auth_avail;
1399                                 http_auth_methods_restricted = 1;
1400                         }
1401 #endif
1402                         return HTTP_REAUTH;
1403                 }
1404         } else {
1405                 if (results->http_connectcode == 407)
1406                         credential_reject(&proxy_auth);
1407 #if LIBCURL_VERSION_NUM >= 0x070c00
1408                 if (!curl_errorstr[0])
1409                         strlcpy(curl_errorstr,
1410                                 curl_easy_strerror(results->curl_result),
1411                                 sizeof(curl_errorstr));
1412 #endif
1413                 return HTTP_ERROR;
1414         }
1415 }
1416
1417 int run_one_slot(struct active_request_slot *slot,
1418                  struct slot_results *results)
1419 {
1420         slot->results = results;
1421         if (!start_active_slot(slot)) {
1422                 xsnprintf(curl_errorstr, sizeof(curl_errorstr),
1423                           "failed to start HTTP request");
1424                 return HTTP_START_FAILED;
1425         }
1426
1427         run_active_slot(slot);
1428         return handle_curl_result(results);
1429 }
1430
1431 struct curl_slist *http_copy_default_headers(void)
1432 {
1433         struct curl_slist *headers = NULL, *h;
1434
1435         for (h = extra_http_headers; h; h = h->next)
1436                 headers = curl_slist_append(headers, h->data);
1437
1438         return headers;
1439 }
1440
1441 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
1442 {
1443         char *ptr;
1444         CURLcode ret;
1445
1446         strbuf_reset(buf);
1447         ret = curl_easy_getinfo(curl, info, &ptr);
1448         if (!ret && ptr)
1449                 strbuf_addstr(buf, ptr);
1450         return ret;
1451 }
1452
1453 /*
1454  * Check for and extract a content-type parameter. "raw"
1455  * should be positioned at the start of the potential
1456  * parameter, with any whitespace already removed.
1457  *
1458  * "name" is the name of the parameter. The value is appended
1459  * to "out".
1460  */
1461 static int extract_param(const char *raw, const char *name,
1462                          struct strbuf *out)
1463 {
1464         size_t len = strlen(name);
1465
1466         if (strncasecmp(raw, name, len))
1467                 return -1;
1468         raw += len;
1469
1470         if (*raw != '=')
1471                 return -1;
1472         raw++;
1473
1474         while (*raw && !isspace(*raw) && *raw != ';')
1475                 strbuf_addch(out, *raw++);
1476         return 0;
1477 }
1478
1479 /*
1480  * Extract a normalized version of the content type, with any
1481  * spaces suppressed, all letters lowercased, and no trailing ";"
1482  * or parameters.
1483  *
1484  * Note that we will silently remove even invalid whitespace. For
1485  * example, "text / plain" is specifically forbidden by RFC 2616,
1486  * but "text/plain" is the only reasonable output, and this keeps
1487  * our code simple.
1488  *
1489  * If the "charset" argument is not NULL, store the value of any
1490  * charset parameter there.
1491  *
1492  * Example:
1493  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
1494  *   "text / plain" -> "text/plain"
1495  */
1496 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
1497                                  struct strbuf *charset)
1498 {
1499         const char *p;
1500
1501         strbuf_reset(type);
1502         strbuf_grow(type, raw->len);
1503         for (p = raw->buf; *p; p++) {
1504                 if (isspace(*p))
1505                         continue;
1506                 if (*p == ';') {
1507                         p++;
1508                         break;
1509                 }
1510                 strbuf_addch(type, tolower(*p));
1511         }
1512
1513         if (!charset)
1514                 return;
1515
1516         strbuf_reset(charset);
1517         while (*p) {
1518                 while (isspace(*p) || *p == ';')
1519                         p++;
1520                 if (!extract_param(p, "charset", charset))
1521                         return;
1522                 while (*p && !isspace(*p))
1523                         p++;
1524         }
1525
1526         if (!charset->len && starts_with(type->buf, "text/"))
1527                 strbuf_addstr(charset, "ISO-8859-1");
1528 }
1529
1530 static void write_accept_language(struct strbuf *buf)
1531 {
1532         /*
1533          * MAX_DECIMAL_PLACES must not be larger than 3. If it is larger than
1534          * that, q-value will be smaller than 0.001, the minimum q-value the
1535          * HTTP specification allows. See
1536          * http://tools.ietf.org/html/rfc7231#section-5.3.1 for q-value.
1537          */
1538         const int MAX_DECIMAL_PLACES = 3;
1539         const int MAX_LANGUAGE_TAGS = 1000;
1540         const int MAX_ACCEPT_LANGUAGE_HEADER_SIZE = 4000;
1541         char **language_tags = NULL;
1542         int num_langs = 0;
1543         const char *s = get_preferred_languages();
1544         int i;
1545         struct strbuf tag = STRBUF_INIT;
1546
1547         /* Don't add Accept-Language header if no language is preferred. */
1548         if (!s)
1549                 return;
1550
1551         /*
1552          * Split the colon-separated string of preferred languages into
1553          * language_tags array.
1554          */
1555         do {
1556                 /* collect language tag */
1557                 for (; *s && (isalnum(*s) || *s == '_'); s++)
1558                         strbuf_addch(&tag, *s == '_' ? '-' : *s);
1559
1560                 /* skip .codeset, @modifier and any other unnecessary parts */
1561                 while (*s && *s != ':')
1562                         s++;
1563
1564                 if (tag.len) {
1565                         num_langs++;
1566                         REALLOC_ARRAY(language_tags, num_langs);
1567                         language_tags[num_langs - 1] = strbuf_detach(&tag, NULL);
1568                         if (num_langs >= MAX_LANGUAGE_TAGS - 1) /* -1 for '*' */
1569                                 break;
1570                 }
1571         } while (*s++);
1572
1573         /* write Accept-Language header into buf */
1574         if (num_langs) {
1575                 int last_buf_len = 0;
1576                 int max_q;
1577                 int decimal_places;
1578                 char q_format[32];
1579
1580                 /* add '*' */
1581                 REALLOC_ARRAY(language_tags, num_langs + 1);
1582                 language_tags[num_langs++] = "*"; /* it's OK; this won't be freed */
1583
1584                 /* compute decimal_places */
1585                 for (max_q = 1, decimal_places = 0;
1586                      max_q < num_langs && decimal_places <= MAX_DECIMAL_PLACES;
1587                      decimal_places++, max_q *= 10)
1588                         ;
1589
1590                 xsnprintf(q_format, sizeof(q_format), ";q=0.%%0%dd", decimal_places);
1591
1592                 strbuf_addstr(buf, "Accept-Language: ");
1593
1594                 for (i = 0; i < num_langs; i++) {
1595                         if (i > 0)
1596                                 strbuf_addstr(buf, ", ");
1597
1598                         strbuf_addstr(buf, language_tags[i]);
1599
1600                         if (i > 0)
1601                                 strbuf_addf(buf, q_format, max_q - i);
1602
1603                         if (buf->len > MAX_ACCEPT_LANGUAGE_HEADER_SIZE) {
1604                                 strbuf_remove(buf, last_buf_len, buf->len - last_buf_len);
1605                                 break;
1606                         }
1607
1608                         last_buf_len = buf->len;
1609                 }
1610         }
1611
1612         /* free language tags -- last one is a static '*' */
1613         for (i = 0; i < num_langs - 1; i++)
1614                 free(language_tags[i]);
1615         free(language_tags);
1616 }
1617
1618 /*
1619  * Get an Accept-Language header which indicates user's preferred languages.
1620  *
1621  * Examples:
1622  *   LANGUAGE= -> ""
1623  *   LANGUAGE=ko:en -> "Accept-Language: ko, en; q=0.9, *; q=0.1"
1624  *   LANGUAGE=ko_KR.UTF-8:sr@latin -> "Accept-Language: ko-KR, sr; q=0.9, *; q=0.1"
1625  *   LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *; q=0.1"
1626  *   LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *; q=0.1"
1627  *   LANGUAGE= LANG=C -> ""
1628  */
1629 static const char *get_accept_language(void)
1630 {
1631         if (!cached_accept_language) {
1632                 struct strbuf buf = STRBUF_INIT;
1633                 write_accept_language(&buf);
1634                 if (buf.len > 0)
1635                         cached_accept_language = strbuf_detach(&buf, NULL);
1636         }
1637
1638         return cached_accept_language;
1639 }
1640
1641 static void http_opt_request_remainder(CURL *curl, off_t pos)
1642 {
1643         char buf[128];
1644         xsnprintf(buf, sizeof(buf), "%"PRIuMAX"-", (uintmax_t)pos);
1645         curl_easy_setopt(curl, CURLOPT_RANGE, buf);
1646 }
1647
1648 /* http_request() targets */
1649 #define HTTP_REQUEST_STRBUF     0
1650 #define HTTP_REQUEST_FILE       1
1651
1652 static int http_request(const char *url,
1653                         void *result, int target,
1654                         const struct http_get_options *options)
1655 {
1656         struct active_request_slot *slot;
1657         struct slot_results results;
1658         struct curl_slist *headers = http_copy_default_headers();
1659         struct strbuf buf = STRBUF_INIT;
1660         const char *accept_language;
1661         int ret;
1662
1663         slot = get_active_slot();
1664         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1665
1666         if (result == NULL) {
1667                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1668         } else {
1669                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1670                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1671
1672                 if (target == HTTP_REQUEST_FILE) {
1673                         off_t posn = ftello(result);
1674                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1675                                          fwrite);
1676                         if (posn > 0)
1677                                 http_opt_request_remainder(slot->curl, posn);
1678                 } else
1679                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1680                                          fwrite_buffer);
1681         }
1682
1683         accept_language = get_accept_language();
1684
1685         if (accept_language)
1686                 headers = curl_slist_append(headers, accept_language);
1687
1688         strbuf_addstr(&buf, "Pragma:");
1689         if (options && options->no_cache)
1690                 strbuf_addstr(&buf, " no-cache");
1691         if (options && options->keep_error)
1692                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1693         if (options && options->initial_request &&
1694             http_follow_config == HTTP_FOLLOW_INITIAL)
1695                 curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
1696
1697         headers = curl_slist_append(headers, buf.buf);
1698
1699         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1700         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1701         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
1702
1703         ret = run_one_slot(slot, &results);
1704
1705         if (options && options->content_type) {
1706                 struct strbuf raw = STRBUF_INIT;
1707                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1708                 extract_content_type(&raw, options->content_type,
1709                                      options->charset);
1710                 strbuf_release(&raw);
1711         }
1712
1713         if (options && options->effective_url)
1714                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1715                                 options->effective_url);
1716
1717         curl_slist_free_all(headers);
1718         strbuf_release(&buf);
1719
1720         return ret;
1721 }
1722
1723 /*
1724  * Update the "base" url to a more appropriate value, as deduced by
1725  * redirects seen when requesting a URL starting with "url".
1726  *
1727  * The "asked" parameter is a URL that we asked curl to access, and must begin
1728  * with "base".
1729  *
1730  * The "got" parameter is the URL that curl reported to us as where we ended
1731  * up.
1732  *
1733  * Returns 1 if we updated the base url, 0 otherwise.
1734  *
1735  * Our basic strategy is to compare "base" and "asked" to find the bits
1736  * specific to our request. We then strip those bits off of "got" to yield the
1737  * new base. So for example, if our base is "http://example.com/foo.git",
1738  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1739  * with "https://other.example.com/foo.git/info/refs". We would want the
1740  * new URL to become "https://other.example.com/foo.git".
1741  *
1742  * Note that this assumes a sane redirect scheme. It's entirely possible
1743  * in the example above to end up at a URL that does not even end in
1744  * "info/refs".  In such a case we die. There's not much we can do, such a
1745  * scheme is unlikely to represent a real git repository, and failing to
1746  * rewrite the base opens options for malicious redirects to do funny things.
1747  */
1748 static int update_url_from_redirect(struct strbuf *base,
1749                                     const char *asked,
1750                                     const struct strbuf *got)
1751 {
1752         const char *tail;
1753         size_t new_len;
1754
1755         if (!strcmp(asked, got->buf))
1756                 return 0;
1757
1758         if (!skip_prefix(asked, base->buf, &tail))
1759                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1760                     asked, base->buf);
1761
1762         new_len = got->len;
1763         if (!strip_suffix_mem(got->buf, &new_len, tail))
1764                 die(_("unable to update url base from redirection:\n"
1765                       "  asked for: %s\n"
1766                       "   redirect: %s"),
1767                     asked, got->buf);
1768
1769         strbuf_reset(base);
1770         strbuf_add(base, got->buf, new_len);
1771
1772         return 1;
1773 }
1774
1775 static int http_request_reauth(const char *url,
1776                                void *result, int target,
1777                                struct http_get_options *options)
1778 {
1779         int ret = http_request(url, result, target, options);
1780
1781         if (ret != HTTP_OK && ret != HTTP_REAUTH)
1782                 return ret;
1783
1784         if (options && options->effective_url && options->base_url) {
1785                 if (update_url_from_redirect(options->base_url,
1786                                              url, options->effective_url)) {
1787                         credential_from_url(&http_auth, options->base_url->buf);
1788                         url = options->effective_url->buf;
1789                 }
1790         }
1791
1792         if (ret != HTTP_REAUTH)
1793                 return ret;
1794
1795         /*
1796          * If we are using KEEP_ERROR, the previous request may have
1797          * put cruft into our output stream; we should clear it out before
1798          * making our next request. We only know how to do this for
1799          * the strbuf case, but that is enough to satisfy current callers.
1800          */
1801         if (options && options->keep_error) {
1802                 switch (target) {
1803                 case HTTP_REQUEST_STRBUF:
1804                         strbuf_reset(result);
1805                         break;
1806                 default:
1807                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1808                 }
1809         }
1810
1811         credential_fill(&http_auth);
1812
1813         return http_request(url, result, target, options);
1814 }
1815
1816 int http_get_strbuf(const char *url,
1817                     struct strbuf *result,
1818                     struct http_get_options *options)
1819 {
1820         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1821 }
1822
1823 /*
1824  * Downloads a URL and stores the result in the given file.
1825  *
1826  * If a previous interrupted download is detected (i.e. a previous temporary
1827  * file is still around) the download is resumed.
1828  */
1829 static int http_get_file(const char *url, const char *filename,
1830                          struct http_get_options *options)
1831 {
1832         int ret;
1833         struct strbuf tmpfile = STRBUF_INIT;
1834         FILE *result;
1835
1836         strbuf_addf(&tmpfile, "%s.temp", filename);
1837         result = fopen(tmpfile.buf, "a");
1838         if (!result) {
1839                 error("Unable to open local file %s", tmpfile.buf);
1840                 ret = HTTP_ERROR;
1841                 goto cleanup;
1842         }
1843
1844         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1845         fclose(result);
1846
1847         if (ret == HTTP_OK && finalize_object_file(tmpfile.buf, filename))
1848                 ret = HTTP_ERROR;
1849 cleanup:
1850         strbuf_release(&tmpfile);
1851         return ret;
1852 }
1853
1854 int http_fetch_ref(const char *base, struct ref *ref)
1855 {
1856         struct http_get_options options = {0};
1857         char *url;
1858         struct strbuf buffer = STRBUF_INIT;
1859         int ret = -1;
1860
1861         options.no_cache = 1;
1862
1863         url = quote_ref_url(base, ref->name);
1864         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1865                 strbuf_rtrim(&buffer);
1866                 if (buffer.len == 40)
1867                         ret = get_oid_hex(buffer.buf, &ref->old_oid);
1868                 else if (starts_with(buffer.buf, "ref: ")) {
1869                         ref->symref = xstrdup(buffer.buf + 5);
1870                         ret = 0;
1871                 }
1872         }
1873
1874         strbuf_release(&buffer);
1875         free(url);
1876         return ret;
1877 }
1878
1879 /* Helpers for fetching packs */
1880 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1881 {
1882         char *url, *tmp;
1883         struct strbuf buf = STRBUF_INIT;
1884
1885         if (http_is_verbose)
1886                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1887
1888         end_url_with_slash(&buf, base_url);
1889         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1890         url = strbuf_detach(&buf, NULL);
1891
1892         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1893         tmp = strbuf_detach(&buf, NULL);
1894
1895         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1896                 error("Unable to get pack index %s", url);
1897                 FREE_AND_NULL(tmp);
1898         }
1899
1900         free(url);
1901         return tmp;
1902 }
1903
1904 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1905         unsigned char *sha1, const char *base_url)
1906 {
1907         struct packed_git *new_pack;
1908         char *tmp_idx = NULL;
1909         int ret;
1910
1911         if (has_pack_index(sha1)) {
1912                 new_pack = parse_pack_index(sha1, sha1_pack_index_name(sha1));
1913                 if (!new_pack)
1914                         return -1; /* parse_pack_index() already issued error message */
1915                 goto add_pack;
1916         }
1917
1918         tmp_idx = fetch_pack_index(sha1, base_url);
1919         if (!tmp_idx)
1920                 return -1;
1921
1922         new_pack = parse_pack_index(sha1, tmp_idx);
1923         if (!new_pack) {
1924                 unlink(tmp_idx);
1925                 free(tmp_idx);
1926
1927                 return -1; /* parse_pack_index() already issued error message */
1928         }
1929
1930         ret = verify_pack_index(new_pack);
1931         if (!ret) {
1932                 close_pack_index(new_pack);
1933                 ret = finalize_object_file(tmp_idx, sha1_pack_index_name(sha1));
1934         }
1935         free(tmp_idx);
1936         if (ret)
1937                 return -1;
1938
1939 add_pack:
1940         new_pack->next = *packs_head;
1941         *packs_head = new_pack;
1942         return 0;
1943 }
1944
1945 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1946 {
1947         struct http_get_options options = {0};
1948         int ret = 0, i = 0;
1949         char *url, *data;
1950         struct strbuf buf = STRBUF_INIT;
1951         unsigned char sha1[20];
1952
1953         end_url_with_slash(&buf, base_url);
1954         strbuf_addstr(&buf, "objects/info/packs");
1955         url = strbuf_detach(&buf, NULL);
1956
1957         options.no_cache = 1;
1958         ret = http_get_strbuf(url, &buf, &options);
1959         if (ret != HTTP_OK)
1960                 goto cleanup;
1961
1962         data = buf.buf;
1963         while (i < buf.len) {
1964                 switch (data[i]) {
1965                 case 'P':
1966                         i++;
1967                         if (i + 52 <= buf.len &&
1968                             starts_with(data + i, " pack-") &&
1969                             starts_with(data + i + 46, ".pack\n")) {
1970                                 get_sha1_hex(data + i + 6, sha1);
1971                                 fetch_and_setup_pack_index(packs_head, sha1,
1972                                                       base_url);
1973                                 i += 51;
1974                                 break;
1975                         }
1976                 default:
1977                         while (i < buf.len && data[i] != '\n')
1978                                 i++;
1979                 }
1980                 i++;
1981         }
1982
1983 cleanup:
1984         free(url);
1985         return ret;
1986 }
1987
1988 void release_http_pack_request(struct http_pack_request *preq)
1989 {
1990         if (preq->packfile != NULL) {
1991                 fclose(preq->packfile);
1992                 preq->packfile = NULL;
1993         }
1994         preq->slot = NULL;
1995         free(preq->url);
1996         free(preq);
1997 }
1998
1999 int finish_http_pack_request(struct http_pack_request *preq)
2000 {
2001         struct packed_git **lst;
2002         struct packed_git *p = preq->target;
2003         char *tmp_idx;
2004         size_t len;
2005         struct child_process ip = CHILD_PROCESS_INIT;
2006         const char *ip_argv[8];
2007
2008         close_pack_index(p);
2009
2010         fclose(preq->packfile);
2011         preq->packfile = NULL;
2012
2013         lst = preq->lst;
2014         while (*lst != p)
2015                 lst = &((*lst)->next);
2016         *lst = (*lst)->next;
2017
2018         if (!strip_suffix(preq->tmpfile, ".pack.temp", &len))
2019                 die("BUG: pack tmpfile does not end in .pack.temp?");
2020         tmp_idx = xstrfmt("%.*s.idx.temp", (int)len, preq->tmpfile);
2021
2022         ip_argv[0] = "index-pack";
2023         ip_argv[1] = "-o";
2024         ip_argv[2] = tmp_idx;
2025         ip_argv[3] = preq->tmpfile;
2026         ip_argv[4] = NULL;
2027
2028         ip.argv = ip_argv;
2029         ip.git_cmd = 1;
2030         ip.no_stdin = 1;
2031         ip.no_stdout = 1;
2032
2033         if (run_command(&ip)) {
2034                 unlink(preq->tmpfile);
2035                 unlink(tmp_idx);
2036                 free(tmp_idx);
2037                 return -1;
2038         }
2039
2040         unlink(sha1_pack_index_name(p->sha1));
2041
2042         if (finalize_object_file(preq->tmpfile, sha1_pack_name(p->sha1))
2043          || finalize_object_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
2044                 free(tmp_idx);
2045                 return -1;
2046         }
2047
2048         install_packed_git(p);
2049         free(tmp_idx);
2050         return 0;
2051 }
2052
2053 struct http_pack_request *new_http_pack_request(
2054         struct packed_git *target, const char *base_url)
2055 {
2056         off_t prev_posn = 0;
2057         struct strbuf buf = STRBUF_INIT;
2058         struct http_pack_request *preq;
2059
2060         preq = xcalloc(1, sizeof(*preq));
2061         preq->target = target;
2062
2063         end_url_with_slash(&buf, base_url);
2064         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
2065                 sha1_to_hex(target->sha1));
2066         preq->url = strbuf_detach(&buf, NULL);
2067
2068         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
2069                 sha1_pack_name(target->sha1));
2070         preq->packfile = fopen(preq->tmpfile, "a");
2071         if (!preq->packfile) {
2072                 error("Unable to open local file %s for pack",
2073                       preq->tmpfile);
2074                 goto abort;
2075         }
2076
2077         preq->slot = get_active_slot();
2078         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
2079         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
2080         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
2081         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
2082                 no_pragma_header);
2083
2084         /*
2085          * If there is data present from a previous transfer attempt,
2086          * resume where it left off
2087          */
2088         prev_posn = ftello(preq->packfile);
2089         if (prev_posn>0) {
2090                 if (http_is_verbose)
2091                         fprintf(stderr,
2092                                 "Resuming fetch of pack %s at byte %"PRIuMAX"\n",
2093                                 sha1_to_hex(target->sha1), (uintmax_t)prev_posn);
2094                 http_opt_request_remainder(preq->slot->curl, prev_posn);
2095         }
2096
2097         return preq;
2098
2099 abort:
2100         free(preq->url);
2101         free(preq);
2102         return NULL;
2103 }
2104
2105 /* Helpers for fetching objects (loose) */
2106 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
2107                                void *data)
2108 {
2109         unsigned char expn[4096];
2110         size_t size = eltsize * nmemb;
2111         int posn = 0;
2112         struct http_object_request *freq = data;
2113         struct active_request_slot *slot = freq->slot;
2114
2115         if (slot) {
2116                 CURLcode c = curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE,
2117                                                 &slot->http_code);
2118                 if (c != CURLE_OK)
2119                         die("BUG: curl_easy_getinfo for HTTP code failed: %s",
2120                                 curl_easy_strerror(c));
2121                 if (slot->http_code >= 300)
2122                         return size;
2123         }
2124
2125         do {
2126                 ssize_t retval = xwrite(freq->localfile,
2127                                         (char *) ptr + posn, size - posn);
2128                 if (retval < 0)
2129                         return posn;
2130                 posn += retval;
2131         } while (posn < size);
2132
2133         freq->stream.avail_in = size;
2134         freq->stream.next_in = (void *)ptr;
2135         do {
2136                 freq->stream.next_out = expn;
2137                 freq->stream.avail_out = sizeof(expn);
2138                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
2139                 git_SHA1_Update(&freq->c, expn,
2140                                 sizeof(expn) - freq->stream.avail_out);
2141         } while (freq->stream.avail_in && freq->zret == Z_OK);
2142         return size;
2143 }
2144
2145 struct http_object_request *new_http_object_request(const char *base_url,
2146         unsigned char *sha1)
2147 {
2148         char *hex = sha1_to_hex(sha1);
2149         const char *filename;
2150         char prevfile[PATH_MAX];
2151         int prevlocal;
2152         char prev_buf[PREV_BUF_SIZE];
2153         ssize_t prev_read = 0;
2154         off_t prev_posn = 0;
2155         struct http_object_request *freq;
2156
2157         freq = xcalloc(1, sizeof(*freq));
2158         hashcpy(freq->sha1, sha1);
2159         freq->localfile = -1;
2160
2161         filename = sha1_file_name(sha1);
2162         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
2163                  "%s.temp", filename);
2164
2165         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
2166         unlink_or_warn(prevfile);
2167         rename(freq->tmpfile, prevfile);
2168         unlink_or_warn(freq->tmpfile);
2169
2170         if (freq->localfile != -1)
2171                 error("fd leakage in start: %d", freq->localfile);
2172         freq->localfile = open(freq->tmpfile,
2173                                O_WRONLY | O_CREAT | O_EXCL, 0666);
2174         /*
2175          * This could have failed due to the "lazy directory creation";
2176          * try to mkdir the last path component.
2177          */
2178         if (freq->localfile < 0 && errno == ENOENT) {
2179                 char *dir = strrchr(freq->tmpfile, '/');
2180                 if (dir) {
2181                         *dir = 0;
2182                         mkdir(freq->tmpfile, 0777);
2183                         *dir = '/';
2184                 }
2185                 freq->localfile = open(freq->tmpfile,
2186                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
2187         }
2188
2189         if (freq->localfile < 0) {
2190                 error_errno("Couldn't create temporary file %s", freq->tmpfile);
2191                 goto abort;
2192         }
2193
2194         git_inflate_init(&freq->stream);
2195
2196         git_SHA1_Init(&freq->c);
2197
2198         freq->url = get_remote_object_url(base_url, hex, 0);
2199
2200         /*
2201          * If a previous temp file is present, process what was already
2202          * fetched.
2203          */
2204         prevlocal = open(prevfile, O_RDONLY);
2205         if (prevlocal != -1) {
2206                 do {
2207                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
2208                         if (prev_read>0) {
2209                                 if (fwrite_sha1_file(prev_buf,
2210                                                      1,
2211                                                      prev_read,
2212                                                      freq) == prev_read) {
2213                                         prev_posn += prev_read;
2214                                 } else {
2215                                         prev_read = -1;
2216                                 }
2217                         }
2218                 } while (prev_read > 0);
2219                 close(prevlocal);
2220         }
2221         unlink_or_warn(prevfile);
2222
2223         /*
2224          * Reset inflate/SHA1 if there was an error reading the previous temp
2225          * file; also rewind to the beginning of the local file.
2226          */
2227         if (prev_read == -1) {
2228                 memset(&freq->stream, 0, sizeof(freq->stream));
2229                 git_inflate_init(&freq->stream);
2230                 git_SHA1_Init(&freq->c);
2231                 if (prev_posn>0) {
2232                         prev_posn = 0;
2233                         lseek(freq->localfile, 0, SEEK_SET);
2234                         if (ftruncate(freq->localfile, 0) < 0) {
2235                                 error_errno("Couldn't truncate temporary file %s",
2236                                             freq->tmpfile);
2237                                 goto abort;
2238                         }
2239                 }
2240         }
2241
2242         freq->slot = get_active_slot();
2243
2244         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
2245         curl_easy_setopt(freq->slot->curl, CURLOPT_FAILONERROR, 0);
2246         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
2247         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
2248         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
2249         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
2250
2251         /*
2252          * If we have successfully processed data from a previous fetch
2253          * attempt, only fetch the data we don't already have.
2254          */
2255         if (prev_posn>0) {
2256                 if (http_is_verbose)
2257                         fprintf(stderr,
2258                                 "Resuming fetch of object %s at byte %"PRIuMAX"\n",
2259                                 hex, (uintmax_t)prev_posn);
2260                 http_opt_request_remainder(freq->slot->curl, prev_posn);
2261         }
2262
2263         return freq;
2264
2265 abort:
2266         free(freq->url);
2267         free(freq);
2268         return NULL;
2269 }
2270
2271 void process_http_object_request(struct http_object_request *freq)
2272 {
2273         if (freq->slot == NULL)
2274                 return;
2275         freq->curl_result = freq->slot->curl_result;
2276         freq->http_code = freq->slot->http_code;
2277         freq->slot = NULL;
2278 }
2279
2280 int finish_http_object_request(struct http_object_request *freq)
2281 {
2282         struct stat st;
2283
2284         close(freq->localfile);
2285         freq->localfile = -1;
2286
2287         process_http_object_request(freq);
2288
2289         if (freq->http_code == 416) {
2290                 warning("requested range invalid; we may already have all the data.");
2291         } else if (freq->curl_result != CURLE_OK) {
2292                 if (stat(freq->tmpfile, &st) == 0)
2293                         if (st.st_size == 0)
2294                                 unlink_or_warn(freq->tmpfile);
2295                 return -1;
2296         }
2297
2298         git_inflate_end(&freq->stream);
2299         git_SHA1_Final(freq->real_sha1, &freq->c);
2300         if (freq->zret != Z_STREAM_END) {
2301                 unlink_or_warn(freq->tmpfile);
2302                 return -1;
2303         }
2304         if (hashcmp(freq->sha1, freq->real_sha1)) {
2305                 unlink_or_warn(freq->tmpfile);
2306                 return -1;
2307         }
2308         freq->rename =
2309                 finalize_object_file(freq->tmpfile, sha1_file_name(freq->sha1));
2310
2311         return freq->rename;
2312 }
2313
2314 void abort_http_object_request(struct http_object_request *freq)
2315 {
2316         unlink_or_warn(freq->tmpfile);
2317
2318         release_http_object_request(freq);
2319 }
2320
2321 void release_http_object_request(struct http_object_request *freq)
2322 {
2323         if (freq->localfile != -1) {
2324                 close(freq->localfile);
2325                 freq->localfile = -1;
2326         }
2327         if (freq->url != NULL) {
2328                 FREE_AND_NULL(freq->url);
2329         }
2330         if (freq->slot != NULL) {
2331                 freq->slot->callback_func = NULL;
2332                 freq->slot->callback_data = NULL;
2333                 release_active_slot(freq->slot);
2334                 freq->slot = NULL;
2335         }
2336 }