Merge branch 'md/list-objects-filter-combo'
[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 #include "packfile.h"
15 #include "protocol.h"
16 #include "string-list.h"
17 #include "object-store.h"
18
19 static struct trace_key trace_curl = TRACE_KEY_INIT(CURL);
20 static int trace_curl_data = 1;
21 static struct string_list cookies_to_redact = STRING_LIST_INIT_DUP;
22 #if LIBCURL_VERSION_NUM >= 0x070a08
23 long int git_curl_ipresolve = CURL_IPRESOLVE_WHATEVER;
24 #else
25 long int git_curl_ipresolve;
26 #endif
27 int active_requests;
28 int http_is_verbose;
29 ssize_t http_post_buffer = 16 * LARGE_PACKET_MAX;
30
31 #if LIBCURL_VERSION_NUM >= 0x070a06
32 #define LIBCURL_CAN_HANDLE_AUTH_ANY
33 #endif
34
35 static int min_curl_sessions = 1;
36 static int curl_session_count;
37 #ifdef USE_CURL_MULTI
38 static int max_requests = -1;
39 static CURLM *curlm;
40 #endif
41 #ifndef NO_CURL_EASY_DUPHANDLE
42 static CURL *curl_default;
43 #endif
44
45 #define PREV_BUF_SIZE 4096
46
47 char curl_errorstr[CURL_ERROR_SIZE];
48
49 static int curl_ssl_verify = -1;
50 static int curl_ssl_try;
51 static const char *curl_http_version = NULL;
52 static const char *ssl_cert;
53 static const char *ssl_cipherlist;
54 static const char *ssl_version;
55 static struct {
56         const char *name;
57         long ssl_version;
58 } sslversions[] = {
59         { "sslv2", CURL_SSLVERSION_SSLv2 },
60         { "sslv3", CURL_SSLVERSION_SSLv3 },
61         { "tlsv1", CURL_SSLVERSION_TLSv1 },
62 #if LIBCURL_VERSION_NUM >= 0x072200
63         { "tlsv1.0", CURL_SSLVERSION_TLSv1_0 },
64         { "tlsv1.1", CURL_SSLVERSION_TLSv1_1 },
65         { "tlsv1.2", CURL_SSLVERSION_TLSv1_2 },
66 #endif
67 #if LIBCURL_VERSION_NUM >= 0x073400
68         { "tlsv1.3", CURL_SSLVERSION_TLSv1_3 },
69 #endif
70 };
71 #if LIBCURL_VERSION_NUM >= 0x070903
72 static const char *ssl_key;
73 #endif
74 #if LIBCURL_VERSION_NUM >= 0x070908
75 static const char *ssl_capath;
76 #endif
77 #if LIBCURL_VERSION_NUM >= 0x071304
78 static const char *curl_no_proxy;
79 #endif
80 #if LIBCURL_VERSION_NUM >= 0x072c00
81 static const char *ssl_pinnedkey;
82 #endif
83 static const char *ssl_cainfo;
84 static long curl_low_speed_limit = -1;
85 static long curl_low_speed_time = -1;
86 static int curl_ftp_no_epsv;
87 static const char *curl_http_proxy;
88 static const char *http_proxy_authmethod;
89 static struct {
90         const char *name;
91         long curlauth_param;
92 } proxy_authmethods[] = {
93         { "basic", CURLAUTH_BASIC },
94         { "digest", CURLAUTH_DIGEST },
95         { "negotiate", CURLAUTH_GSSNEGOTIATE },
96         { "ntlm", CURLAUTH_NTLM },
97 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
98         { "anyauth", CURLAUTH_ANY },
99 #endif
100         /*
101          * CURLAUTH_DIGEST_IE has no corresponding command-line option in
102          * curl(1) and is not included in CURLAUTH_ANY, so we leave it out
103          * here, too
104          */
105 };
106 #ifdef CURLGSSAPI_DELEGATION_FLAG
107 static const char *curl_deleg;
108 static struct {
109         const char *name;
110         long curl_deleg_param;
111 } curl_deleg_levels[] = {
112         { "none", CURLGSSAPI_DELEGATION_NONE },
113         { "policy", CURLGSSAPI_DELEGATION_POLICY_FLAG },
114         { "always", CURLGSSAPI_DELEGATION_FLAG },
115 };
116 #endif
117
118 static struct credential proxy_auth = CREDENTIAL_INIT;
119 static const char *curl_proxyuserpwd;
120 static const char *curl_cookie_file;
121 static int curl_save_cookies;
122 struct credential http_auth = CREDENTIAL_INIT;
123 static int http_proactive_auth;
124 static const char *user_agent;
125 static int curl_empty_auth = -1;
126
127 enum http_follow_config http_follow_config = HTTP_FOLLOW_INITIAL;
128
129 #if LIBCURL_VERSION_NUM >= 0x071700
130 /* Use CURLOPT_KEYPASSWD as is */
131 #elif LIBCURL_VERSION_NUM >= 0x070903
132 #define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
133 #else
134 #define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
135 #endif
136
137 static struct credential cert_auth = CREDENTIAL_INIT;
138 static int ssl_cert_password_required;
139 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
140 static unsigned long http_auth_methods = CURLAUTH_ANY;
141 static int http_auth_methods_restricted;
142 /* Modes for which empty_auth cannot actually help us. */
143 static unsigned long empty_auth_useless =
144         CURLAUTH_BASIC
145 #ifdef CURLAUTH_DIGEST_IE
146         | CURLAUTH_DIGEST_IE
147 #endif
148         | CURLAUTH_DIGEST;
149 #endif
150
151 static struct curl_slist *pragma_header;
152 static struct curl_slist *no_pragma_header;
153 static struct curl_slist *extra_http_headers;
154
155 static struct active_request_slot *active_queue_head;
156
157 static char *cached_accept_language;
158
159 static char *http_ssl_backend;
160
161 static int http_schannel_check_revoke = 1;
162 /*
163  * With the backend being set to `schannel`, setting sslCAinfo would override
164  * the Certificate Store in cURL v7.60.0 and later, which is not what we want
165  * by default.
166  */
167 static int http_schannel_use_ssl_cainfo;
168
169 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
170 {
171         size_t size = eltsize * nmemb;
172         struct buffer *buffer = buffer_;
173
174         if (size > buffer->buf.len - buffer->posn)
175                 size = buffer->buf.len - buffer->posn;
176         memcpy(ptr, buffer->buf.buf + buffer->posn, size);
177         buffer->posn += size;
178
179         return size / eltsize;
180 }
181
182 #ifndef NO_CURL_IOCTL
183 curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
184 {
185         struct buffer *buffer = clientp;
186
187         switch (cmd) {
188         case CURLIOCMD_NOP:
189                 return CURLIOE_OK;
190
191         case CURLIOCMD_RESTARTREAD:
192                 buffer->posn = 0;
193                 return CURLIOE_OK;
194
195         default:
196                 return CURLIOE_UNKNOWNCMD;
197         }
198 }
199 #endif
200
201 size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
202 {
203         size_t size = eltsize * nmemb;
204         struct strbuf *buffer = buffer_;
205
206         strbuf_add(buffer, ptr, size);
207         return nmemb;
208 }
209
210 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
211 {
212         return nmemb;
213 }
214
215 static void closedown_active_slot(struct active_request_slot *slot)
216 {
217         active_requests--;
218         slot->in_use = 0;
219 }
220
221 static void finish_active_slot(struct active_request_slot *slot)
222 {
223         closedown_active_slot(slot);
224         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
225
226         if (slot->finished != NULL)
227                 (*slot->finished) = 1;
228
229         /* Store slot results so they can be read after the slot is reused */
230         if (slot->results != NULL) {
231                 slot->results->curl_result = slot->curl_result;
232                 slot->results->http_code = slot->http_code;
233 #if LIBCURL_VERSION_NUM >= 0x070a08
234                 curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
235                                   &slot->results->auth_avail);
236 #else
237                 slot->results->auth_avail = 0;
238 #endif
239
240                 curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CONNECTCODE,
241                         &slot->results->http_connectcode);
242         }
243
244         /* Run callback if appropriate */
245         if (slot->callback_func != NULL)
246                 slot->callback_func(slot->callback_data);
247 }
248
249 static void xmulti_remove_handle(struct active_request_slot *slot)
250 {
251 #ifdef USE_CURL_MULTI
252         curl_multi_remove_handle(curlm, slot->curl);
253 #endif
254 }
255
256 #ifdef USE_CURL_MULTI
257 static void process_curl_messages(void)
258 {
259         int num_messages;
260         struct active_request_slot *slot;
261         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
262
263         while (curl_message != NULL) {
264                 if (curl_message->msg == CURLMSG_DONE) {
265                         int curl_result = curl_message->data.result;
266                         slot = active_queue_head;
267                         while (slot != NULL &&
268                                slot->curl != curl_message->easy_handle)
269                                 slot = slot->next;
270                         if (slot != NULL) {
271                                 xmulti_remove_handle(slot);
272                                 slot->curl_result = curl_result;
273                                 finish_active_slot(slot);
274                         } else {
275                                 fprintf(stderr, "Received DONE message for unknown request!\n");
276                         }
277                 } else {
278                         fprintf(stderr, "Unknown CURL message received: %d\n",
279                                 (int)curl_message->msg);
280                 }
281                 curl_message = curl_multi_info_read(curlm, &num_messages);
282         }
283 }
284 #endif
285
286 static int http_options(const char *var, const char *value, void *cb)
287 {
288         if (!strcmp("http.version", var)) {
289                 return git_config_string(&curl_http_version, var, value);
290         }
291         if (!strcmp("http.sslverify", var)) {
292                 curl_ssl_verify = git_config_bool(var, value);
293                 return 0;
294         }
295         if (!strcmp("http.sslcipherlist", var))
296                 return git_config_string(&ssl_cipherlist, var, value);
297         if (!strcmp("http.sslversion", var))
298                 return git_config_string(&ssl_version, var, value);
299         if (!strcmp("http.sslcert", var))
300                 return git_config_pathname(&ssl_cert, var, value);
301 #if LIBCURL_VERSION_NUM >= 0x070903
302         if (!strcmp("http.sslkey", var))
303                 return git_config_pathname(&ssl_key, var, value);
304 #endif
305 #if LIBCURL_VERSION_NUM >= 0x070908
306         if (!strcmp("http.sslcapath", var))
307                 return git_config_pathname(&ssl_capath, var, value);
308 #endif
309         if (!strcmp("http.sslcainfo", var))
310                 return git_config_pathname(&ssl_cainfo, var, value);
311         if (!strcmp("http.sslcertpasswordprotected", var)) {
312                 ssl_cert_password_required = git_config_bool(var, value);
313                 return 0;
314         }
315         if (!strcmp("http.ssltry", var)) {
316                 curl_ssl_try = git_config_bool(var, value);
317                 return 0;
318         }
319         if (!strcmp("http.sslbackend", var)) {
320                 free(http_ssl_backend);
321                 http_ssl_backend = xstrdup_or_null(value);
322                 return 0;
323         }
324
325         if (!strcmp("http.schannelcheckrevoke", var)) {
326                 http_schannel_check_revoke = git_config_bool(var, value);
327                 return 0;
328         }
329
330         if (!strcmp("http.schannelusesslcainfo", var)) {
331                 http_schannel_use_ssl_cainfo = git_config_bool(var, value);
332                 return 0;
333         }
334
335         if (!strcmp("http.minsessions", var)) {
336                 min_curl_sessions = git_config_int(var, value);
337 #ifndef USE_CURL_MULTI
338                 if (min_curl_sessions > 1)
339                         min_curl_sessions = 1;
340 #endif
341                 return 0;
342         }
343 #ifdef USE_CURL_MULTI
344         if (!strcmp("http.maxrequests", var)) {
345                 max_requests = git_config_int(var, value);
346                 return 0;
347         }
348 #endif
349         if (!strcmp("http.lowspeedlimit", var)) {
350                 curl_low_speed_limit = (long)git_config_int(var, value);
351                 return 0;
352         }
353         if (!strcmp("http.lowspeedtime", var)) {
354                 curl_low_speed_time = (long)git_config_int(var, value);
355                 return 0;
356         }
357
358         if (!strcmp("http.noepsv", var)) {
359                 curl_ftp_no_epsv = git_config_bool(var, value);
360                 return 0;
361         }
362         if (!strcmp("http.proxy", var))
363                 return git_config_string(&curl_http_proxy, var, value);
364
365         if (!strcmp("http.proxyauthmethod", var))
366                 return git_config_string(&http_proxy_authmethod, var, value);
367
368         if (!strcmp("http.cookiefile", var))
369                 return git_config_pathname(&curl_cookie_file, var, value);
370         if (!strcmp("http.savecookies", var)) {
371                 curl_save_cookies = git_config_bool(var, value);
372                 return 0;
373         }
374
375         if (!strcmp("http.postbuffer", var)) {
376                 http_post_buffer = git_config_ssize_t(var, value);
377                 if (http_post_buffer < 0)
378                         warning(_("negative value for http.postbuffer; defaulting to %d"), LARGE_PACKET_MAX);
379                 if (http_post_buffer < LARGE_PACKET_MAX)
380                         http_post_buffer = LARGE_PACKET_MAX;
381                 return 0;
382         }
383
384         if (!strcmp("http.useragent", var))
385                 return git_config_string(&user_agent, var, value);
386
387         if (!strcmp("http.emptyauth", var)) {
388                 if (value && !strcmp("auto", value))
389                         curl_empty_auth = -1;
390                 else
391                         curl_empty_auth = git_config_bool(var, value);
392                 return 0;
393         }
394
395         if (!strcmp("http.delegation", var)) {
396 #ifdef CURLGSSAPI_DELEGATION_FLAG
397                 return git_config_string(&curl_deleg, var, value);
398 #else
399                 warning(_("Delegation control is not supported with cURL < 7.22.0"));
400                 return 0;
401 #endif
402         }
403
404         if (!strcmp("http.pinnedpubkey", var)) {
405 #if LIBCURL_VERSION_NUM >= 0x072c00
406                 return git_config_pathname(&ssl_pinnedkey, var, value);
407 #else
408                 warning(_("Public key pinning not supported with cURL < 7.44.0"));
409                 return 0;
410 #endif
411         }
412
413         if (!strcmp("http.extraheader", var)) {
414                 if (!value) {
415                         return config_error_nonbool(var);
416                 } else if (!*value) {
417                         curl_slist_free_all(extra_http_headers);
418                         extra_http_headers = NULL;
419                 } else {
420                         extra_http_headers =
421                                 curl_slist_append(extra_http_headers, value);
422                 }
423                 return 0;
424         }
425
426         if (!strcmp("http.followredirects", var)) {
427                 if (value && !strcmp(value, "initial"))
428                         http_follow_config = HTTP_FOLLOW_INITIAL;
429                 else if (git_config_bool(var, value))
430                         http_follow_config = HTTP_FOLLOW_ALWAYS;
431                 else
432                         http_follow_config = HTTP_FOLLOW_NONE;
433                 return 0;
434         }
435
436         /* Fall back on the default ones */
437         return git_default_config(var, value, cb);
438 }
439
440 static int curl_empty_auth_enabled(void)
441 {
442         if (curl_empty_auth >= 0)
443                 return curl_empty_auth;
444
445 #ifndef LIBCURL_CAN_HANDLE_AUTH_ANY
446         /*
447          * Our libcurl is too old to do AUTH_ANY in the first place;
448          * just default to turning the feature off.
449          */
450 #else
451         /*
452          * In the automatic case, kick in the empty-auth
453          * hack as long as we would potentially try some
454          * method more exotic than "Basic" or "Digest".
455          *
456          * But only do this when this is our second or
457          * subsequent request, as by then we know what
458          * methods are available.
459          */
460         if (http_auth_methods_restricted &&
461             (http_auth_methods & ~empty_auth_useless))
462                 return 1;
463 #endif
464         return 0;
465 }
466
467 static void init_curl_http_auth(CURL *result)
468 {
469         if (!http_auth.username || !*http_auth.username) {
470                 if (curl_empty_auth_enabled())
471                         curl_easy_setopt(result, CURLOPT_USERPWD, ":");
472                 return;
473         }
474
475         credential_fill(&http_auth);
476
477 #if LIBCURL_VERSION_NUM >= 0x071301
478         curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
479         curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
480 #else
481         {
482                 static struct strbuf up = STRBUF_INIT;
483                 /*
484                  * Note that we assume we only ever have a single set of
485                  * credentials in a given program run, so we do not have
486                  * to worry about updating this buffer, only setting its
487                  * initial value.
488                  */
489                 if (!up.len)
490                         strbuf_addf(&up, "%s:%s",
491                                 http_auth.username, http_auth.password);
492                 curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
493         }
494 #endif
495 }
496
497 /* *var must be free-able */
498 static void var_override(const char **var, char *value)
499 {
500         if (value) {
501                 free((void *)*var);
502                 *var = xstrdup(value);
503         }
504 }
505
506 static void set_proxyauth_name_password(CURL *result)
507 {
508 #if LIBCURL_VERSION_NUM >= 0x071301
509                 curl_easy_setopt(result, CURLOPT_PROXYUSERNAME,
510                         proxy_auth.username);
511                 curl_easy_setopt(result, CURLOPT_PROXYPASSWORD,
512                         proxy_auth.password);
513 #else
514                 struct strbuf s = STRBUF_INIT;
515
516                 strbuf_addstr_urlencode(&s, proxy_auth.username,
517                                         is_rfc3986_unreserved);
518                 strbuf_addch(&s, ':');
519                 strbuf_addstr_urlencode(&s, proxy_auth.password,
520                                         is_rfc3986_unreserved);
521                 curl_proxyuserpwd = strbuf_detach(&s, NULL);
522                 curl_easy_setopt(result, CURLOPT_PROXYUSERPWD, curl_proxyuserpwd);
523 #endif
524 }
525
526 static void init_curl_proxy_auth(CURL *result)
527 {
528         if (proxy_auth.username) {
529                 if (!proxy_auth.password)
530                         credential_fill(&proxy_auth);
531                 set_proxyauth_name_password(result);
532         }
533
534         var_override(&http_proxy_authmethod, getenv("GIT_HTTP_PROXY_AUTHMETHOD"));
535
536 #if LIBCURL_VERSION_NUM >= 0x070a07 /* CURLOPT_PROXYAUTH and CURLAUTH_ANY */
537         if (http_proxy_authmethod) {
538                 int i;
539                 for (i = 0; i < ARRAY_SIZE(proxy_authmethods); i++) {
540                         if (!strcmp(http_proxy_authmethod, proxy_authmethods[i].name)) {
541                                 curl_easy_setopt(result, CURLOPT_PROXYAUTH,
542                                                 proxy_authmethods[i].curlauth_param);
543                                 break;
544                         }
545                 }
546                 if (i == ARRAY_SIZE(proxy_authmethods)) {
547                         warning("unsupported proxy authentication method %s: using anyauth",
548                                         http_proxy_authmethod);
549                         curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
550                 }
551         }
552         else
553                 curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
554 #endif
555 }
556
557 static int has_cert_password(void)
558 {
559         if (ssl_cert == NULL || ssl_cert_password_required != 1)
560                 return 0;
561         if (!cert_auth.password) {
562                 cert_auth.protocol = xstrdup("cert");
563                 cert_auth.username = xstrdup("");
564                 cert_auth.path = xstrdup(ssl_cert);
565                 credential_fill(&cert_auth);
566         }
567         return 1;
568 }
569
570 #if LIBCURL_VERSION_NUM >= 0x071900
571 static void set_curl_keepalive(CURL *c)
572 {
573         curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
574 }
575
576 #elif LIBCURL_VERSION_NUM >= 0x071000
577 static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
578 {
579         int ka = 1;
580         int rc;
581         socklen_t len = (socklen_t)sizeof(ka);
582
583         if (type != CURLSOCKTYPE_IPCXN)
584                 return 0;
585
586         rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
587         if (rc < 0)
588                 warning_errno("unable to set SO_KEEPALIVE on socket");
589
590         return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
591 }
592
593 static void set_curl_keepalive(CURL *c)
594 {
595         curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
596 }
597
598 #else
599 static void set_curl_keepalive(CURL *c)
600 {
601         /* not supported on older curl versions */
602 }
603 #endif
604
605 static void redact_sensitive_header(struct strbuf *header)
606 {
607         const char *sensitive_header;
608
609         if (skip_prefix(header->buf, "Authorization:", &sensitive_header) ||
610             skip_prefix(header->buf, "Proxy-Authorization:", &sensitive_header)) {
611                 /* The first token is the type, which is OK to log */
612                 while (isspace(*sensitive_header))
613                         sensitive_header++;
614                 while (*sensitive_header && !isspace(*sensitive_header))
615                         sensitive_header++;
616                 /* Everything else is opaque and possibly sensitive */
617                 strbuf_setlen(header,  sensitive_header - header->buf);
618                 strbuf_addstr(header, " <redacted>");
619         } else if (cookies_to_redact.nr &&
620                    skip_prefix(header->buf, "Cookie:", &sensitive_header)) {
621                 struct strbuf redacted_header = STRBUF_INIT;
622                 char *cookie;
623
624                 while (isspace(*sensitive_header))
625                         sensitive_header++;
626
627                 /*
628                  * The contents of header starting from sensitive_header will
629                  * subsequently be overridden, so it is fine to mutate this
630                  * string (hence the assignment to "char *").
631                  */
632                 cookie = (char *) sensitive_header;
633
634                 while (cookie) {
635                         char *equals;
636                         char *semicolon = strstr(cookie, "; ");
637                         if (semicolon)
638                                 *semicolon = 0;
639                         equals = strchrnul(cookie, '=');
640                         if (!equals) {
641                                 /* invalid cookie, just append and continue */
642                                 strbuf_addstr(&redacted_header, cookie);
643                                 continue;
644                         }
645                         *equals = 0; /* temporarily set to NUL for lookup */
646                         if (string_list_lookup(&cookies_to_redact, cookie)) {
647                                 strbuf_addstr(&redacted_header, cookie);
648                                 strbuf_addstr(&redacted_header, "=<redacted>");
649                         } else {
650                                 *equals = '=';
651                                 strbuf_addstr(&redacted_header, cookie);
652                         }
653                         if (semicolon) {
654                                 /*
655                                  * There are more cookies. (Or, for some
656                                  * reason, the input string ends in "; ".)
657                                  */
658                                 strbuf_addstr(&redacted_header, "; ");
659                                 cookie = semicolon + strlen("; ");
660                         } else {
661                                 cookie = NULL;
662                         }
663                 }
664
665                 strbuf_setlen(header, sensitive_header - header->buf);
666                 strbuf_addbuf(header, &redacted_header);
667         }
668 }
669
670 static void curl_dump_header(const char *text, unsigned char *ptr, size_t size, int hide_sensitive_header)
671 {
672         struct strbuf out = STRBUF_INIT;
673         struct strbuf **headers, **header;
674
675         strbuf_addf(&out, "%s, %10.10ld bytes (0x%8.8lx)\n",
676                 text, (long)size, (long)size);
677         trace_strbuf(&trace_curl, &out);
678         strbuf_reset(&out);
679         strbuf_add(&out, ptr, size);
680         headers = strbuf_split_max(&out, '\n', 0);
681
682         for (header = headers; *header; header++) {
683                 if (hide_sensitive_header)
684                         redact_sensitive_header(*header);
685                 strbuf_insert((*header), 0, text, strlen(text));
686                 strbuf_insert((*header), strlen(text), ": ", 2);
687                 strbuf_rtrim((*header));
688                 strbuf_addch((*header), '\n');
689                 trace_strbuf(&trace_curl, (*header));
690         }
691         strbuf_list_free(headers);
692         strbuf_release(&out);
693 }
694
695 static void curl_dump_data(const char *text, unsigned char *ptr, size_t size)
696 {
697         size_t i;
698         struct strbuf out = STRBUF_INIT;
699         unsigned int width = 60;
700
701         strbuf_addf(&out, "%s, %10.10ld bytes (0x%8.8lx)\n",
702                 text, (long)size, (long)size);
703         trace_strbuf(&trace_curl, &out);
704
705         for (i = 0; i < size; i += width) {
706                 size_t w;
707
708                 strbuf_reset(&out);
709                 strbuf_addf(&out, "%s: ", text);
710                 for (w = 0; (w < width) && (i + w < size); w++) {
711                         unsigned char ch = ptr[i + w];
712
713                         strbuf_addch(&out,
714                                        (ch >= 0x20) && (ch < 0x80)
715                                        ? ch : '.');
716                 }
717                 strbuf_addch(&out, '\n');
718                 trace_strbuf(&trace_curl, &out);
719         }
720         strbuf_release(&out);
721 }
722
723 static int curl_trace(CURL *handle, curl_infotype type, char *data, size_t size, void *userp)
724 {
725         const char *text;
726         enum { NO_FILTER = 0, DO_FILTER = 1 };
727
728         switch (type) {
729         case CURLINFO_TEXT:
730                 trace_printf_key(&trace_curl, "== Info: %s", data);
731                 break;
732         case CURLINFO_HEADER_OUT:
733                 text = "=> Send header";
734                 curl_dump_header(text, (unsigned char *)data, size, DO_FILTER);
735                 break;
736         case CURLINFO_DATA_OUT:
737                 if (trace_curl_data) {
738                         text = "=> Send data";
739                         curl_dump_data(text, (unsigned char *)data, size);
740                 }
741                 break;
742         case CURLINFO_SSL_DATA_OUT:
743                 if (trace_curl_data) {
744                         text = "=> Send SSL data";
745                         curl_dump_data(text, (unsigned char *)data, size);
746                 }
747                 break;
748         case CURLINFO_HEADER_IN:
749                 text = "<= Recv header";
750                 curl_dump_header(text, (unsigned char *)data, size, NO_FILTER);
751                 break;
752         case CURLINFO_DATA_IN:
753                 if (trace_curl_data) {
754                         text = "<= Recv data";
755                         curl_dump_data(text, (unsigned char *)data, size);
756                 }
757                 break;
758         case CURLINFO_SSL_DATA_IN:
759                 if (trace_curl_data) {
760                         text = "<= Recv SSL data";
761                         curl_dump_data(text, (unsigned char *)data, size);
762                 }
763                 break;
764
765         default:                /* we ignore unknown types by default */
766                 return 0;
767         }
768         return 0;
769 }
770
771 void setup_curl_trace(CURL *handle)
772 {
773         if (!trace_want(&trace_curl))
774                 return;
775         curl_easy_setopt(handle, CURLOPT_VERBOSE, 1L);
776         curl_easy_setopt(handle, CURLOPT_DEBUGFUNCTION, curl_trace);
777         curl_easy_setopt(handle, CURLOPT_DEBUGDATA, NULL);
778 }
779
780 #ifdef CURLPROTO_HTTP
781 static long get_curl_allowed_protocols(int from_user)
782 {
783         long allowed_protocols = 0;
784
785         if (is_transport_allowed("http", from_user))
786                 allowed_protocols |= CURLPROTO_HTTP;
787         if (is_transport_allowed("https", from_user))
788                 allowed_protocols |= CURLPROTO_HTTPS;
789         if (is_transport_allowed("ftp", from_user))
790                 allowed_protocols |= CURLPROTO_FTP;
791         if (is_transport_allowed("ftps", from_user))
792                 allowed_protocols |= CURLPROTO_FTPS;
793
794         return allowed_protocols;
795 }
796 #endif
797
798 #if LIBCURL_VERSION_NUM >=0x072f00
799 static int get_curl_http_version_opt(const char *version_string, long *opt)
800 {
801         int i;
802         static struct {
803                 const char *name;
804                 long opt_token;
805         } choice[] = {
806                 { "HTTP/1.1", CURL_HTTP_VERSION_1_1 },
807                 { "HTTP/2", CURL_HTTP_VERSION_2 }
808         };
809
810         for (i = 0; i < ARRAY_SIZE(choice); i++) {
811                 if (!strcmp(version_string, choice[i].name)) {
812                         *opt = choice[i].opt_token;
813                         return 0;
814                 }
815         }
816
817         warning("unknown value given to http.version: '%s'", version_string);
818         return -1; /* not found */
819 }
820
821 #endif
822
823 static CURL *get_curl_handle(void)
824 {
825         CURL *result = curl_easy_init();
826
827         if (!result)
828                 die("curl_easy_init failed");
829
830         if (!curl_ssl_verify) {
831                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
832                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
833         } else {
834                 /* Verify authenticity of the peer's certificate */
835                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
836                 /* The name in the cert must match whom we tried to connect */
837                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
838         }
839
840 #if LIBCURL_VERSION_NUM >= 0x072f00 // 7.47.0
841     if (curl_http_version) {
842                 long opt;
843                 if (!get_curl_http_version_opt(curl_http_version, &opt)) {
844                         /* Set request use http version */
845                         curl_easy_setopt(result, CURLOPT_HTTP_VERSION, opt);
846                 }
847     }
848 #endif
849
850 #if LIBCURL_VERSION_NUM >= 0x070907
851         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
852 #endif
853 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
854         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
855 #endif
856
857 #ifdef CURLGSSAPI_DELEGATION_FLAG
858         if (curl_deleg) {
859                 int i;
860                 for (i = 0; i < ARRAY_SIZE(curl_deleg_levels); i++) {
861                         if (!strcmp(curl_deleg, curl_deleg_levels[i].name)) {
862                                 curl_easy_setopt(result, CURLOPT_GSSAPI_DELEGATION,
863                                                 curl_deleg_levels[i].curl_deleg_param);
864                                 break;
865                         }
866                 }
867                 if (i == ARRAY_SIZE(curl_deleg_levels))
868                         warning("Unknown delegation method '%s': using default",
869                                 curl_deleg);
870         }
871 #endif
872
873         if (http_ssl_backend && !strcmp("schannel", http_ssl_backend) &&
874             !http_schannel_check_revoke) {
875 #if LIBCURL_VERSION_NUM >= 0x072c00
876                 curl_easy_setopt(result, CURLOPT_SSL_OPTIONS, CURLSSLOPT_NO_REVOKE);
877 #else
878                 warning(_("CURLSSLOPT_NO_REVOKE not supported with cURL < 7.44.0"));
879 #endif
880         }
881
882         if (http_proactive_auth)
883                 init_curl_http_auth(result);
884
885         if (getenv("GIT_SSL_VERSION"))
886                 ssl_version = getenv("GIT_SSL_VERSION");
887         if (ssl_version && *ssl_version) {
888                 int i;
889                 for (i = 0; i < ARRAY_SIZE(sslversions); i++) {
890                         if (!strcmp(ssl_version, sslversions[i].name)) {
891                                 curl_easy_setopt(result, CURLOPT_SSLVERSION,
892                                                  sslversions[i].ssl_version);
893                                 break;
894                         }
895                 }
896                 if (i == ARRAY_SIZE(sslversions))
897                         warning("unsupported ssl version %s: using default",
898                                 ssl_version);
899         }
900
901         if (getenv("GIT_SSL_CIPHER_LIST"))
902                 ssl_cipherlist = getenv("GIT_SSL_CIPHER_LIST");
903         if (ssl_cipherlist != NULL && *ssl_cipherlist)
904                 curl_easy_setopt(result, CURLOPT_SSL_CIPHER_LIST,
905                                 ssl_cipherlist);
906
907         if (ssl_cert != NULL)
908                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
909         if (has_cert_password())
910                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
911 #if LIBCURL_VERSION_NUM >= 0x070903
912         if (ssl_key != NULL)
913                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
914 #endif
915 #if LIBCURL_VERSION_NUM >= 0x070908
916         if (ssl_capath != NULL)
917                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
918 #endif
919 #if LIBCURL_VERSION_NUM >= 0x072c00
920         if (ssl_pinnedkey != NULL)
921                 curl_easy_setopt(result, CURLOPT_PINNEDPUBLICKEY, ssl_pinnedkey);
922 #endif
923         if (http_ssl_backend && !strcmp("schannel", http_ssl_backend) &&
924             !http_schannel_use_ssl_cainfo) {
925                 curl_easy_setopt(result, CURLOPT_CAINFO, NULL);
926 #if LIBCURL_VERSION_NUM >= 0x073400
927                 curl_easy_setopt(result, CURLOPT_PROXY_CAINFO, NULL);
928 #endif
929         } else if (ssl_cainfo != NULL)
930                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
931
932         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
933                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
934                                  curl_low_speed_limit);
935                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
936                                  curl_low_speed_time);
937         }
938
939         curl_easy_setopt(result, CURLOPT_MAXREDIRS, 20);
940 #if LIBCURL_VERSION_NUM >= 0x071301
941         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
942 #elif LIBCURL_VERSION_NUM >= 0x071101
943         curl_easy_setopt(result, CURLOPT_POST301, 1);
944 #endif
945 #ifdef CURLPROTO_HTTP
946         curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS,
947                          get_curl_allowed_protocols(0));
948         curl_easy_setopt(result, CURLOPT_PROTOCOLS,
949                          get_curl_allowed_protocols(-1));
950 #else
951         warning(_("Protocol restrictions not supported with cURL < 7.19.4"));
952 #endif
953         if (getenv("GIT_CURL_VERBOSE"))
954                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1L);
955         setup_curl_trace(result);
956         if (getenv("GIT_TRACE_CURL_NO_DATA"))
957                 trace_curl_data = 0;
958         if (getenv("GIT_REDACT_COOKIES")) {
959                 string_list_split(&cookies_to_redact,
960                                   getenv("GIT_REDACT_COOKIES"), ',', -1);
961                 string_list_sort(&cookies_to_redact);
962         }
963
964         curl_easy_setopt(result, CURLOPT_USERAGENT,
965                 user_agent ? user_agent : git_user_agent());
966
967         if (curl_ftp_no_epsv)
968                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
969
970 #ifdef CURLOPT_USE_SSL
971         if (curl_ssl_try)
972                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
973 #endif
974
975         /*
976          * CURL also examines these variables as a fallback; but we need to query
977          * them here in order to decide whether to prompt for missing password (cf.
978          * init_curl_proxy_auth()).
979          *
980          * Unlike many other common environment variables, these are historically
981          * lowercase only. It appears that CURL did not know this and implemented
982          * only uppercase variants, which was later corrected to take both - with
983          * the exception of http_proxy, which is lowercase only also in CURL. As
984          * the lowercase versions are the historical quasi-standard, they take
985          * precedence here, as in CURL.
986          */
987         if (!curl_http_proxy) {
988                 if (http_auth.protocol && !strcmp(http_auth.protocol, "https")) {
989                         var_override(&curl_http_proxy, getenv("HTTPS_PROXY"));
990                         var_override(&curl_http_proxy, getenv("https_proxy"));
991                 } else {
992                         var_override(&curl_http_proxy, getenv("http_proxy"));
993                 }
994                 if (!curl_http_proxy) {
995                         var_override(&curl_http_proxy, getenv("ALL_PROXY"));
996                         var_override(&curl_http_proxy, getenv("all_proxy"));
997                 }
998         }
999
1000         if (curl_http_proxy && curl_http_proxy[0] == '\0') {
1001                 /*
1002                  * Handle case with the empty http.proxy value here to keep
1003                  * common code clean.
1004                  * NB: empty option disables proxying at all.
1005                  */
1006                 curl_easy_setopt(result, CURLOPT_PROXY, "");
1007         } else if (curl_http_proxy) {
1008 #if LIBCURL_VERSION_NUM >= 0x071800
1009                 if (starts_with(curl_http_proxy, "socks5h"))
1010                         curl_easy_setopt(result,
1011                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5_HOSTNAME);
1012                 else if (starts_with(curl_http_proxy, "socks5"))
1013                         curl_easy_setopt(result,
1014                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
1015                 else if (starts_with(curl_http_proxy, "socks4a"))
1016                         curl_easy_setopt(result,
1017                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4A);
1018                 else if (starts_with(curl_http_proxy, "socks"))
1019                         curl_easy_setopt(result,
1020                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
1021 #endif
1022 #if LIBCURL_VERSION_NUM >= 0x073400
1023                 else if (starts_with(curl_http_proxy, "https"))
1024                         curl_easy_setopt(result,
1025                                 CURLOPT_PROXYTYPE, CURLPROXY_HTTPS);
1026 #endif
1027                 if (strstr(curl_http_proxy, "://"))
1028                         credential_from_url(&proxy_auth, curl_http_proxy);
1029                 else {
1030                         struct strbuf url = STRBUF_INIT;
1031                         strbuf_addf(&url, "http://%s", curl_http_proxy);
1032                         credential_from_url(&proxy_auth, url.buf);
1033                         strbuf_release(&url);
1034                 }
1035
1036                 if (!proxy_auth.host)
1037                         die("Invalid proxy URL '%s'", curl_http_proxy);
1038
1039                 curl_easy_setopt(result, CURLOPT_PROXY, proxy_auth.host);
1040 #if LIBCURL_VERSION_NUM >= 0x071304
1041                 var_override(&curl_no_proxy, getenv("NO_PROXY"));
1042                 var_override(&curl_no_proxy, getenv("no_proxy"));
1043                 curl_easy_setopt(result, CURLOPT_NOPROXY, curl_no_proxy);
1044 #endif
1045         }
1046         init_curl_proxy_auth(result);
1047
1048         set_curl_keepalive(result);
1049
1050         return result;
1051 }
1052
1053 static void set_from_env(const char **var, const char *envname)
1054 {
1055         const char *val = getenv(envname);
1056         if (val)
1057                 *var = val;
1058 }
1059
1060 void http_init(struct remote *remote, const char *url, int proactive_auth)
1061 {
1062         char *low_speed_limit;
1063         char *low_speed_time;
1064         char *normalized_url;
1065         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
1066
1067         config.section = "http";
1068         config.key = NULL;
1069         config.collect_fn = http_options;
1070         config.cascade_fn = git_default_config;
1071         config.cb = NULL;
1072
1073         http_is_verbose = 0;
1074         normalized_url = url_normalize(url, &config.url);
1075
1076         git_config(urlmatch_config_entry, &config);
1077         free(normalized_url);
1078
1079 #if LIBCURL_VERSION_NUM >= 0x073800
1080         if (http_ssl_backend) {
1081                 const curl_ssl_backend **backends;
1082                 struct strbuf buf = STRBUF_INIT;
1083                 int i;
1084
1085                 switch (curl_global_sslset(-1, http_ssl_backend, &backends)) {
1086                 case CURLSSLSET_UNKNOWN_BACKEND:
1087                         strbuf_addf(&buf, _("Unsupported SSL backend '%s'. "
1088                                             "Supported SSL backends:"),
1089                                             http_ssl_backend);
1090                         for (i = 0; backends[i]; i++)
1091                                 strbuf_addf(&buf, "\n\t%s", backends[i]->name);
1092                         die("%s", buf.buf);
1093                 case CURLSSLSET_NO_BACKENDS:
1094                         die(_("Could not set SSL backend to '%s': "
1095                               "cURL was built without SSL backends"),
1096                             http_ssl_backend);
1097                 case CURLSSLSET_TOO_LATE:
1098                         die(_("Could not set SSL backend to '%s': already set"),
1099                             http_ssl_backend);
1100                 case CURLSSLSET_OK:
1101                         break; /* Okay! */
1102                 }
1103         }
1104 #endif
1105
1106         if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
1107                 die("curl_global_init failed");
1108
1109         http_proactive_auth = proactive_auth;
1110
1111         if (remote && remote->http_proxy)
1112                 curl_http_proxy = xstrdup(remote->http_proxy);
1113
1114         if (remote)
1115                 var_override(&http_proxy_authmethod, remote->http_proxy_authmethod);
1116
1117         pragma_header = curl_slist_append(http_copy_default_headers(),
1118                 "Pragma: no-cache");
1119         no_pragma_header = curl_slist_append(http_copy_default_headers(),
1120                 "Pragma:");
1121
1122 #ifdef USE_CURL_MULTI
1123         {
1124                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
1125                 if (http_max_requests != NULL)
1126                         max_requests = atoi(http_max_requests);
1127         }
1128
1129         curlm = curl_multi_init();
1130         if (!curlm)
1131                 die("curl_multi_init failed");
1132 #endif
1133
1134         if (getenv("GIT_SSL_NO_VERIFY"))
1135                 curl_ssl_verify = 0;
1136
1137         set_from_env(&ssl_cert, "GIT_SSL_CERT");
1138 #if LIBCURL_VERSION_NUM >= 0x070903
1139         set_from_env(&ssl_key, "GIT_SSL_KEY");
1140 #endif
1141 #if LIBCURL_VERSION_NUM >= 0x070908
1142         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
1143 #endif
1144         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
1145
1146         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
1147
1148         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
1149         if (low_speed_limit != NULL)
1150                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
1151         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
1152         if (low_speed_time != NULL)
1153                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
1154
1155         if (curl_ssl_verify == -1)
1156                 curl_ssl_verify = 1;
1157
1158         curl_session_count = 0;
1159 #ifdef USE_CURL_MULTI
1160         if (max_requests < 1)
1161                 max_requests = DEFAULT_MAX_REQUESTS;
1162 #endif
1163
1164         if (getenv("GIT_CURL_FTP_NO_EPSV"))
1165                 curl_ftp_no_epsv = 1;
1166
1167         if (url) {
1168                 credential_from_url(&http_auth, url);
1169                 if (!ssl_cert_password_required &&
1170                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
1171                     starts_with(url, "https://"))
1172                         ssl_cert_password_required = 1;
1173         }
1174
1175 #ifndef NO_CURL_EASY_DUPHANDLE
1176         curl_default = get_curl_handle();
1177 #endif
1178 }
1179
1180 void http_cleanup(void)
1181 {
1182         struct active_request_slot *slot = active_queue_head;
1183
1184         while (slot != NULL) {
1185                 struct active_request_slot *next = slot->next;
1186                 if (slot->curl != NULL) {
1187                         xmulti_remove_handle(slot);
1188                         curl_easy_cleanup(slot->curl);
1189                 }
1190                 free(slot);
1191                 slot = next;
1192         }
1193         active_queue_head = NULL;
1194
1195 #ifndef NO_CURL_EASY_DUPHANDLE
1196         curl_easy_cleanup(curl_default);
1197 #endif
1198
1199 #ifdef USE_CURL_MULTI
1200         curl_multi_cleanup(curlm);
1201 #endif
1202         curl_global_cleanup();
1203
1204         curl_slist_free_all(extra_http_headers);
1205         extra_http_headers = NULL;
1206
1207         curl_slist_free_all(pragma_header);
1208         pragma_header = NULL;
1209
1210         curl_slist_free_all(no_pragma_header);
1211         no_pragma_header = NULL;
1212
1213         if (curl_http_proxy) {
1214                 free((void *)curl_http_proxy);
1215                 curl_http_proxy = NULL;
1216         }
1217
1218         if (proxy_auth.password) {
1219                 memset(proxy_auth.password, 0, strlen(proxy_auth.password));
1220                 FREE_AND_NULL(proxy_auth.password);
1221         }
1222
1223         free((void *)curl_proxyuserpwd);
1224         curl_proxyuserpwd = NULL;
1225
1226         free((void *)http_proxy_authmethod);
1227         http_proxy_authmethod = NULL;
1228
1229         if (cert_auth.password != NULL) {
1230                 memset(cert_auth.password, 0, strlen(cert_auth.password));
1231                 FREE_AND_NULL(cert_auth.password);
1232         }
1233         ssl_cert_password_required = 0;
1234
1235         FREE_AND_NULL(cached_accept_language);
1236 }
1237
1238 struct active_request_slot *get_active_slot(void)
1239 {
1240         struct active_request_slot *slot = active_queue_head;
1241         struct active_request_slot *newslot;
1242
1243 #ifdef USE_CURL_MULTI
1244         int num_transfers;
1245
1246         /* Wait for a slot to open up if the queue is full */
1247         while (active_requests >= max_requests) {
1248                 curl_multi_perform(curlm, &num_transfers);
1249                 if (num_transfers < active_requests)
1250                         process_curl_messages();
1251         }
1252 #endif
1253
1254         while (slot != NULL && slot->in_use)
1255                 slot = slot->next;
1256
1257         if (slot == NULL) {
1258                 newslot = xmalloc(sizeof(*newslot));
1259                 newslot->curl = NULL;
1260                 newslot->in_use = 0;
1261                 newslot->next = NULL;
1262
1263                 slot = active_queue_head;
1264                 if (slot == NULL) {
1265                         active_queue_head = newslot;
1266                 } else {
1267                         while (slot->next != NULL)
1268                                 slot = slot->next;
1269                         slot->next = newslot;
1270                 }
1271                 slot = newslot;
1272         }
1273
1274         if (slot->curl == NULL) {
1275 #ifdef NO_CURL_EASY_DUPHANDLE
1276                 slot->curl = get_curl_handle();
1277 #else
1278                 slot->curl = curl_easy_duphandle(curl_default);
1279 #endif
1280                 curl_session_count++;
1281         }
1282
1283         active_requests++;
1284         slot->in_use = 1;
1285         slot->results = NULL;
1286         slot->finished = NULL;
1287         slot->callback_data = NULL;
1288         slot->callback_func = NULL;
1289         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
1290         if (curl_save_cookies)
1291                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
1292         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
1293         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
1294         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
1295         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
1296         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
1297         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
1298         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
1299         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1300         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
1301         curl_easy_setopt(slot->curl, CURLOPT_RANGE, NULL);
1302
1303         /*
1304          * Default following to off unless "ALWAYS" is configured; this gives
1305          * callers a sane starting point, and they can tweak for individual
1306          * HTTP_FOLLOW_* cases themselves.
1307          */
1308         if (http_follow_config == HTTP_FOLLOW_ALWAYS)
1309                 curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
1310         else
1311                 curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 0);
1312
1313 #if LIBCURL_VERSION_NUM >= 0x070a08
1314         curl_easy_setopt(slot->curl, CURLOPT_IPRESOLVE, git_curl_ipresolve);
1315 #endif
1316 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
1317         curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
1318 #endif
1319         if (http_auth.password || curl_empty_auth_enabled())
1320                 init_curl_http_auth(slot->curl);
1321
1322         return slot;
1323 }
1324
1325 int start_active_slot(struct active_request_slot *slot)
1326 {
1327 #ifdef USE_CURL_MULTI
1328         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
1329         int num_transfers;
1330
1331         if (curlm_result != CURLM_OK &&
1332             curlm_result != CURLM_CALL_MULTI_PERFORM) {
1333                 warning("curl_multi_add_handle failed: %s",
1334                         curl_multi_strerror(curlm_result));
1335                 active_requests--;
1336                 slot->in_use = 0;
1337                 return 0;
1338         }
1339
1340         /*
1341          * We know there must be something to do, since we just added
1342          * something.
1343          */
1344         curl_multi_perform(curlm, &num_transfers);
1345 #endif
1346         return 1;
1347 }
1348
1349 #ifdef USE_CURL_MULTI
1350 struct fill_chain {
1351         void *data;
1352         int (*fill)(void *);
1353         struct fill_chain *next;
1354 };
1355
1356 static struct fill_chain *fill_cfg;
1357
1358 void add_fill_function(void *data, int (*fill)(void *))
1359 {
1360         struct fill_chain *new_fill = xmalloc(sizeof(*new_fill));
1361         struct fill_chain **linkp = &fill_cfg;
1362         new_fill->data = data;
1363         new_fill->fill = fill;
1364         new_fill->next = NULL;
1365         while (*linkp)
1366                 linkp = &(*linkp)->next;
1367         *linkp = new_fill;
1368 }
1369
1370 void fill_active_slots(void)
1371 {
1372         struct active_request_slot *slot = active_queue_head;
1373
1374         while (active_requests < max_requests) {
1375                 struct fill_chain *fill;
1376                 for (fill = fill_cfg; fill; fill = fill->next)
1377                         if (fill->fill(fill->data))
1378                                 break;
1379
1380                 if (!fill)
1381                         break;
1382         }
1383
1384         while (slot != NULL) {
1385                 if (!slot->in_use && slot->curl != NULL
1386                         && curl_session_count > min_curl_sessions) {
1387                         curl_easy_cleanup(slot->curl);
1388                         slot->curl = NULL;
1389                         curl_session_count--;
1390                 }
1391                 slot = slot->next;
1392         }
1393 }
1394
1395 void step_active_slots(void)
1396 {
1397         int num_transfers;
1398         CURLMcode curlm_result;
1399
1400         do {
1401                 curlm_result = curl_multi_perform(curlm, &num_transfers);
1402         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
1403         if (num_transfers < active_requests) {
1404                 process_curl_messages();
1405                 fill_active_slots();
1406         }
1407 }
1408 #endif
1409
1410 void run_active_slot(struct active_request_slot *slot)
1411 {
1412 #ifdef USE_CURL_MULTI
1413         fd_set readfds;
1414         fd_set writefds;
1415         fd_set excfds;
1416         int max_fd;
1417         struct timeval select_timeout;
1418         int finished = 0;
1419
1420         slot->finished = &finished;
1421         while (!finished) {
1422                 step_active_slots();
1423
1424                 if (slot->in_use) {
1425 #if LIBCURL_VERSION_NUM >= 0x070f04
1426                         long curl_timeout;
1427                         curl_multi_timeout(curlm, &curl_timeout);
1428                         if (curl_timeout == 0) {
1429                                 continue;
1430                         } else if (curl_timeout == -1) {
1431                                 select_timeout.tv_sec  = 0;
1432                                 select_timeout.tv_usec = 50000;
1433                         } else {
1434                                 select_timeout.tv_sec  =  curl_timeout / 1000;
1435                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
1436                         }
1437 #else
1438                         select_timeout.tv_sec  = 0;
1439                         select_timeout.tv_usec = 50000;
1440 #endif
1441
1442                         max_fd = -1;
1443                         FD_ZERO(&readfds);
1444                         FD_ZERO(&writefds);
1445                         FD_ZERO(&excfds);
1446                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
1447
1448                         /*
1449                          * It can happen that curl_multi_timeout returns a pathologically
1450                          * long timeout when curl_multi_fdset returns no file descriptors
1451                          * to read.  See commit message for more details.
1452                          */
1453                         if (max_fd < 0 &&
1454                             (select_timeout.tv_sec > 0 ||
1455                              select_timeout.tv_usec > 50000)) {
1456                                 select_timeout.tv_sec  = 0;
1457                                 select_timeout.tv_usec = 50000;
1458                         }
1459
1460                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
1461                 }
1462         }
1463 #else
1464         while (slot->in_use) {
1465                 slot->curl_result = curl_easy_perform(slot->curl);
1466                 finish_active_slot(slot);
1467         }
1468 #endif
1469 }
1470
1471 static void release_active_slot(struct active_request_slot *slot)
1472 {
1473         closedown_active_slot(slot);
1474         if (slot->curl) {
1475                 xmulti_remove_handle(slot);
1476                 if (curl_session_count > min_curl_sessions) {
1477                         curl_easy_cleanup(slot->curl);
1478                         slot->curl = NULL;
1479                         curl_session_count--;
1480                 }
1481         }
1482 #ifdef USE_CURL_MULTI
1483         fill_active_slots();
1484 #endif
1485 }
1486
1487 void finish_all_active_slots(void)
1488 {
1489         struct active_request_slot *slot = active_queue_head;
1490
1491         while (slot != NULL)
1492                 if (slot->in_use) {
1493                         run_active_slot(slot);
1494                         slot = active_queue_head;
1495                 } else {
1496                         slot = slot->next;
1497                 }
1498 }
1499
1500 /* Helpers for modifying and creating URLs */
1501 static inline int needs_quote(int ch)
1502 {
1503         if (((ch >= 'A') && (ch <= 'Z'))
1504                         || ((ch >= 'a') && (ch <= 'z'))
1505                         || ((ch >= '0') && (ch <= '9'))
1506                         || (ch == '/')
1507                         || (ch == '-')
1508                         || (ch == '.'))
1509                 return 0;
1510         return 1;
1511 }
1512
1513 static char *quote_ref_url(const char *base, const char *ref)
1514 {
1515         struct strbuf buf = STRBUF_INIT;
1516         const char *cp;
1517         int ch;
1518
1519         end_url_with_slash(&buf, base);
1520
1521         for (cp = ref; (ch = *cp) != 0; cp++)
1522                 if (needs_quote(ch))
1523                         strbuf_addf(&buf, "%%%02x", ch);
1524                 else
1525                         strbuf_addch(&buf, *cp);
1526
1527         return strbuf_detach(&buf, NULL);
1528 }
1529
1530 void append_remote_object_url(struct strbuf *buf, const char *url,
1531                               const char *hex,
1532                               int only_two_digit_prefix)
1533 {
1534         end_url_with_slash(buf, url);
1535
1536         strbuf_addf(buf, "objects/%.*s/", 2, hex);
1537         if (!only_two_digit_prefix)
1538                 strbuf_addstr(buf, hex + 2);
1539 }
1540
1541 char *get_remote_object_url(const char *url, const char *hex,
1542                             int only_two_digit_prefix)
1543 {
1544         struct strbuf buf = STRBUF_INIT;
1545         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
1546         return strbuf_detach(&buf, NULL);
1547 }
1548
1549 void normalize_curl_result(CURLcode *result, long http_code,
1550                            char *errorstr, size_t errorlen)
1551 {
1552         /*
1553          * If we see a failing http code with CURLE_OK, we have turned off
1554          * FAILONERROR (to keep the server's custom error response), and should
1555          * translate the code into failure here.
1556          *
1557          * Likewise, if we see a redirect (30x code), that means we turned off
1558          * redirect-following, and we should treat the result as an error.
1559          */
1560         if (*result == CURLE_OK && http_code >= 300) {
1561                 *result = CURLE_HTTP_RETURNED_ERROR;
1562                 /*
1563                  * Normally curl will already have put the "reason phrase"
1564                  * from the server into curl_errorstr; unfortunately without
1565                  * FAILONERROR it is lost, so we can give only the numeric
1566                  * status code.
1567                  */
1568                 xsnprintf(errorstr, errorlen,
1569                           "The requested URL returned error: %ld",
1570                           http_code);
1571         }
1572 }
1573
1574 static int handle_curl_result(struct slot_results *results)
1575 {
1576         normalize_curl_result(&results->curl_result, results->http_code,
1577                               curl_errorstr, sizeof(curl_errorstr));
1578
1579         if (results->curl_result == CURLE_OK) {
1580                 credential_approve(&http_auth);
1581                 if (proxy_auth.password)
1582                         credential_approve(&proxy_auth);
1583                 return HTTP_OK;
1584         } else if (missing_target(results))
1585                 return HTTP_MISSING_TARGET;
1586         else if (results->http_code == 401) {
1587                 if (http_auth.username && http_auth.password) {
1588                         credential_reject(&http_auth);
1589                         return HTTP_NOAUTH;
1590                 } else {
1591 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
1592                         http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
1593                         if (results->auth_avail) {
1594                                 http_auth_methods &= results->auth_avail;
1595                                 http_auth_methods_restricted = 1;
1596                         }
1597 #endif
1598                         return HTTP_REAUTH;
1599                 }
1600         } else {
1601                 if (results->http_connectcode == 407)
1602                         credential_reject(&proxy_auth);
1603 #if LIBCURL_VERSION_NUM >= 0x070c00
1604                 if (!curl_errorstr[0])
1605                         strlcpy(curl_errorstr,
1606                                 curl_easy_strerror(results->curl_result),
1607                                 sizeof(curl_errorstr));
1608 #endif
1609                 return HTTP_ERROR;
1610         }
1611 }
1612
1613 int run_one_slot(struct active_request_slot *slot,
1614                  struct slot_results *results)
1615 {
1616         slot->results = results;
1617         if (!start_active_slot(slot)) {
1618                 xsnprintf(curl_errorstr, sizeof(curl_errorstr),
1619                           "failed to start HTTP request");
1620                 return HTTP_START_FAILED;
1621         }
1622
1623         run_active_slot(slot);
1624         return handle_curl_result(results);
1625 }
1626
1627 struct curl_slist *http_copy_default_headers(void)
1628 {
1629         struct curl_slist *headers = NULL, *h;
1630
1631         for (h = extra_http_headers; h; h = h->next)
1632                 headers = curl_slist_append(headers, h->data);
1633
1634         return headers;
1635 }
1636
1637 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
1638 {
1639         char *ptr;
1640         CURLcode ret;
1641
1642         strbuf_reset(buf);
1643         ret = curl_easy_getinfo(curl, info, &ptr);
1644         if (!ret && ptr)
1645                 strbuf_addstr(buf, ptr);
1646         return ret;
1647 }
1648
1649 /*
1650  * Check for and extract a content-type parameter. "raw"
1651  * should be positioned at the start of the potential
1652  * parameter, with any whitespace already removed.
1653  *
1654  * "name" is the name of the parameter. The value is appended
1655  * to "out".
1656  */
1657 static int extract_param(const char *raw, const char *name,
1658                          struct strbuf *out)
1659 {
1660         size_t len = strlen(name);
1661
1662         if (strncasecmp(raw, name, len))
1663                 return -1;
1664         raw += len;
1665
1666         if (*raw != '=')
1667                 return -1;
1668         raw++;
1669
1670         while (*raw && !isspace(*raw) && *raw != ';')
1671                 strbuf_addch(out, *raw++);
1672         return 0;
1673 }
1674
1675 /*
1676  * Extract a normalized version of the content type, with any
1677  * spaces suppressed, all letters lowercased, and no trailing ";"
1678  * or parameters.
1679  *
1680  * Note that we will silently remove even invalid whitespace. For
1681  * example, "text / plain" is specifically forbidden by RFC 2616,
1682  * but "text/plain" is the only reasonable output, and this keeps
1683  * our code simple.
1684  *
1685  * If the "charset" argument is not NULL, store the value of any
1686  * charset parameter there.
1687  *
1688  * Example:
1689  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
1690  *   "text / plain" -> "text/plain"
1691  */
1692 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
1693                                  struct strbuf *charset)
1694 {
1695         const char *p;
1696
1697         strbuf_reset(type);
1698         strbuf_grow(type, raw->len);
1699         for (p = raw->buf; *p; p++) {
1700                 if (isspace(*p))
1701                         continue;
1702                 if (*p == ';') {
1703                         p++;
1704                         break;
1705                 }
1706                 strbuf_addch(type, tolower(*p));
1707         }
1708
1709         if (!charset)
1710                 return;
1711
1712         strbuf_reset(charset);
1713         while (*p) {
1714                 while (isspace(*p) || *p == ';')
1715                         p++;
1716                 if (!extract_param(p, "charset", charset))
1717                         return;
1718                 while (*p && !isspace(*p))
1719                         p++;
1720         }
1721
1722         if (!charset->len && starts_with(type->buf, "text/"))
1723                 strbuf_addstr(charset, "ISO-8859-1");
1724 }
1725
1726 static void write_accept_language(struct strbuf *buf)
1727 {
1728         /*
1729          * MAX_DECIMAL_PLACES must not be larger than 3. If it is larger than
1730          * that, q-value will be smaller than 0.001, the minimum q-value the
1731          * HTTP specification allows. See
1732          * http://tools.ietf.org/html/rfc7231#section-5.3.1 for q-value.
1733          */
1734         const int MAX_DECIMAL_PLACES = 3;
1735         const int MAX_LANGUAGE_TAGS = 1000;
1736         const int MAX_ACCEPT_LANGUAGE_HEADER_SIZE = 4000;
1737         char **language_tags = NULL;
1738         int num_langs = 0;
1739         const char *s = get_preferred_languages();
1740         int i;
1741         struct strbuf tag = STRBUF_INIT;
1742
1743         /* Don't add Accept-Language header if no language is preferred. */
1744         if (!s)
1745                 return;
1746
1747         /*
1748          * Split the colon-separated string of preferred languages into
1749          * language_tags array.
1750          */
1751         do {
1752                 /* collect language tag */
1753                 for (; *s && (isalnum(*s) || *s == '_'); s++)
1754                         strbuf_addch(&tag, *s == '_' ? '-' : *s);
1755
1756                 /* skip .codeset, @modifier and any other unnecessary parts */
1757                 while (*s && *s != ':')
1758                         s++;
1759
1760                 if (tag.len) {
1761                         num_langs++;
1762                         REALLOC_ARRAY(language_tags, num_langs);
1763                         language_tags[num_langs - 1] = strbuf_detach(&tag, NULL);
1764                         if (num_langs >= MAX_LANGUAGE_TAGS - 1) /* -1 for '*' */
1765                                 break;
1766                 }
1767         } while (*s++);
1768
1769         /* write Accept-Language header into buf */
1770         if (num_langs) {
1771                 int last_buf_len = 0;
1772                 int max_q;
1773                 int decimal_places;
1774                 char q_format[32];
1775
1776                 /* add '*' */
1777                 REALLOC_ARRAY(language_tags, num_langs + 1);
1778                 language_tags[num_langs++] = "*"; /* it's OK; this won't be freed */
1779
1780                 /* compute decimal_places */
1781                 for (max_q = 1, decimal_places = 0;
1782                      max_q < num_langs && decimal_places <= MAX_DECIMAL_PLACES;
1783                      decimal_places++, max_q *= 10)
1784                         ;
1785
1786                 xsnprintf(q_format, sizeof(q_format), ";q=0.%%0%dd", decimal_places);
1787
1788                 strbuf_addstr(buf, "Accept-Language: ");
1789
1790                 for (i = 0; i < num_langs; i++) {
1791                         if (i > 0)
1792                                 strbuf_addstr(buf, ", ");
1793
1794                         strbuf_addstr(buf, language_tags[i]);
1795
1796                         if (i > 0)
1797                                 strbuf_addf(buf, q_format, max_q - i);
1798
1799                         if (buf->len > MAX_ACCEPT_LANGUAGE_HEADER_SIZE) {
1800                                 strbuf_remove(buf, last_buf_len, buf->len - last_buf_len);
1801                                 break;
1802                         }
1803
1804                         last_buf_len = buf->len;
1805                 }
1806         }
1807
1808         /* free language tags -- last one is a static '*' */
1809         for (i = 0; i < num_langs - 1; i++)
1810                 free(language_tags[i]);
1811         free(language_tags);
1812 }
1813
1814 /*
1815  * Get an Accept-Language header which indicates user's preferred languages.
1816  *
1817  * Examples:
1818  *   LANGUAGE= -> ""
1819  *   LANGUAGE=ko:en -> "Accept-Language: ko, en; q=0.9, *; q=0.1"
1820  *   LANGUAGE=ko_KR.UTF-8:sr@latin -> "Accept-Language: ko-KR, sr; q=0.9, *; q=0.1"
1821  *   LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *; q=0.1"
1822  *   LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *; q=0.1"
1823  *   LANGUAGE= LANG=C -> ""
1824  */
1825 static const char *get_accept_language(void)
1826 {
1827         if (!cached_accept_language) {
1828                 struct strbuf buf = STRBUF_INIT;
1829                 write_accept_language(&buf);
1830                 if (buf.len > 0)
1831                         cached_accept_language = strbuf_detach(&buf, NULL);
1832         }
1833
1834         return cached_accept_language;
1835 }
1836
1837 static void http_opt_request_remainder(CURL *curl, off_t pos)
1838 {
1839         char buf[128];
1840         xsnprintf(buf, sizeof(buf), "%"PRIuMAX"-", (uintmax_t)pos);
1841         curl_easy_setopt(curl, CURLOPT_RANGE, buf);
1842 }
1843
1844 /* http_request() targets */
1845 #define HTTP_REQUEST_STRBUF     0
1846 #define HTTP_REQUEST_FILE       1
1847
1848 static int http_request(const char *url,
1849                         void *result, int target,
1850                         const struct http_get_options *options)
1851 {
1852         struct active_request_slot *slot;
1853         struct slot_results results;
1854         struct curl_slist *headers = http_copy_default_headers();
1855         struct strbuf buf = STRBUF_INIT;
1856         const char *accept_language;
1857         int ret;
1858
1859         slot = get_active_slot();
1860         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1861
1862         if (result == NULL) {
1863                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1864         } else {
1865                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1866                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1867
1868                 if (target == HTTP_REQUEST_FILE) {
1869                         off_t posn = ftello(result);
1870                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1871                                          fwrite);
1872                         if (posn > 0)
1873                                 http_opt_request_remainder(slot->curl, posn);
1874                 } else
1875                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1876                                          fwrite_buffer);
1877         }
1878
1879         accept_language = get_accept_language();
1880
1881         if (accept_language)
1882                 headers = curl_slist_append(headers, accept_language);
1883
1884         strbuf_addstr(&buf, "Pragma:");
1885         if (options && options->no_cache)
1886                 strbuf_addstr(&buf, " no-cache");
1887         if (options && options->initial_request &&
1888             http_follow_config == HTTP_FOLLOW_INITIAL)
1889                 curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
1890
1891         headers = curl_slist_append(headers, buf.buf);
1892
1893         /* Add additional headers here */
1894         if (options && options->extra_headers) {
1895                 const struct string_list_item *item;
1896                 for_each_string_list_item(item, options->extra_headers) {
1897                         headers = curl_slist_append(headers, item->string);
1898                 }
1899         }
1900
1901         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1902         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1903         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "");
1904         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1905
1906         ret = run_one_slot(slot, &results);
1907
1908         if (options && options->content_type) {
1909                 struct strbuf raw = STRBUF_INIT;
1910                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1911                 extract_content_type(&raw, options->content_type,
1912                                      options->charset);
1913                 strbuf_release(&raw);
1914         }
1915
1916         if (options && options->effective_url)
1917                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1918                                 options->effective_url);
1919
1920         curl_slist_free_all(headers);
1921         strbuf_release(&buf);
1922
1923         return ret;
1924 }
1925
1926 /*
1927  * Update the "base" url to a more appropriate value, as deduced by
1928  * redirects seen when requesting a URL starting with "url".
1929  *
1930  * The "asked" parameter is a URL that we asked curl to access, and must begin
1931  * with "base".
1932  *
1933  * The "got" parameter is the URL that curl reported to us as where we ended
1934  * up.
1935  *
1936  * Returns 1 if we updated the base url, 0 otherwise.
1937  *
1938  * Our basic strategy is to compare "base" and "asked" to find the bits
1939  * specific to our request. We then strip those bits off of "got" to yield the
1940  * new base. So for example, if our base is "http://example.com/foo.git",
1941  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1942  * with "https://other.example.com/foo.git/info/refs". We would want the
1943  * new URL to become "https://other.example.com/foo.git".
1944  *
1945  * Note that this assumes a sane redirect scheme. It's entirely possible
1946  * in the example above to end up at a URL that does not even end in
1947  * "info/refs".  In such a case we die. There's not much we can do, such a
1948  * scheme is unlikely to represent a real git repository, and failing to
1949  * rewrite the base opens options for malicious redirects to do funny things.
1950  */
1951 static int update_url_from_redirect(struct strbuf *base,
1952                                     const char *asked,
1953                                     const struct strbuf *got)
1954 {
1955         const char *tail;
1956         size_t new_len;
1957
1958         if (!strcmp(asked, got->buf))
1959                 return 0;
1960
1961         if (!skip_prefix(asked, base->buf, &tail))
1962                 BUG("update_url_from_redirect: %s is not a superset of %s",
1963                     asked, base->buf);
1964
1965         new_len = got->len;
1966         if (!strip_suffix_mem(got->buf, &new_len, tail))
1967                 die(_("unable to update url base from redirection:\n"
1968                       "  asked for: %s\n"
1969                       "   redirect: %s"),
1970                     asked, got->buf);
1971
1972         strbuf_reset(base);
1973         strbuf_add(base, got->buf, new_len);
1974
1975         return 1;
1976 }
1977
1978 static int http_request_reauth(const char *url,
1979                                void *result, int target,
1980                                struct http_get_options *options)
1981 {
1982         int ret = http_request(url, result, target, options);
1983
1984         if (ret != HTTP_OK && ret != HTTP_REAUTH)
1985                 return ret;
1986
1987         if (options && options->effective_url && options->base_url) {
1988                 if (update_url_from_redirect(options->base_url,
1989                                              url, options->effective_url)) {
1990                         credential_from_url(&http_auth, options->base_url->buf);
1991                         url = options->effective_url->buf;
1992                 }
1993         }
1994
1995         if (ret != HTTP_REAUTH)
1996                 return ret;
1997
1998         /*
1999          * The previous request may have put cruft into our output stream; we
2000          * should clear it out before making our next request.
2001          */
2002         switch (target) {
2003         case HTTP_REQUEST_STRBUF:
2004                 strbuf_reset(result);
2005                 break;
2006         case HTTP_REQUEST_FILE:
2007                 if (fflush(result)) {
2008                         error_errno("unable to flush a file");
2009                         return HTTP_START_FAILED;
2010                 }
2011                 rewind(result);
2012                 if (ftruncate(fileno(result), 0) < 0) {
2013                         error_errno("unable to truncate a file");
2014                         return HTTP_START_FAILED;
2015                 }
2016                 break;
2017         default:
2018                 BUG("Unknown http_request target");
2019         }
2020
2021         credential_fill(&http_auth);
2022
2023         return http_request(url, result, target, options);
2024 }
2025
2026 int http_get_strbuf(const char *url,
2027                     struct strbuf *result,
2028                     struct http_get_options *options)
2029 {
2030         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
2031 }
2032
2033 /*
2034  * Downloads a URL and stores the result in the given file.
2035  *
2036  * If a previous interrupted download is detected (i.e. a previous temporary
2037  * file is still around) the download is resumed.
2038  */
2039 static int http_get_file(const char *url, const char *filename,
2040                          struct http_get_options *options)
2041 {
2042         int ret;
2043         struct strbuf tmpfile = STRBUF_INIT;
2044         FILE *result;
2045
2046         strbuf_addf(&tmpfile, "%s.temp", filename);
2047         result = fopen(tmpfile.buf, "a");
2048         if (!result) {
2049                 error("Unable to open local file %s", tmpfile.buf);
2050                 ret = HTTP_ERROR;
2051                 goto cleanup;
2052         }
2053
2054         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
2055         fclose(result);
2056
2057         if (ret == HTTP_OK && finalize_object_file(tmpfile.buf, filename))
2058                 ret = HTTP_ERROR;
2059 cleanup:
2060         strbuf_release(&tmpfile);
2061         return ret;
2062 }
2063
2064 int http_fetch_ref(const char *base, struct ref *ref)
2065 {
2066         struct http_get_options options = {0};
2067         char *url;
2068         struct strbuf buffer = STRBUF_INIT;
2069         int ret = -1;
2070
2071         options.no_cache = 1;
2072
2073         url = quote_ref_url(base, ref->name);
2074         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
2075                 strbuf_rtrim(&buffer);
2076                 if (buffer.len == the_hash_algo->hexsz)
2077                         ret = get_oid_hex(buffer.buf, &ref->old_oid);
2078                 else if (starts_with(buffer.buf, "ref: ")) {
2079                         ref->symref = xstrdup(buffer.buf + 5);
2080                         ret = 0;
2081                 }
2082         }
2083
2084         strbuf_release(&buffer);
2085         free(url);
2086         return ret;
2087 }
2088
2089 /* Helpers for fetching packs */
2090 static char *fetch_pack_index(unsigned char *hash, const char *base_url)
2091 {
2092         char *url, *tmp;
2093         struct strbuf buf = STRBUF_INIT;
2094
2095         if (http_is_verbose)
2096                 fprintf(stderr, "Getting index for pack %s\n", hash_to_hex(hash));
2097
2098         end_url_with_slash(&buf, base_url);
2099         strbuf_addf(&buf, "objects/pack/pack-%s.idx", hash_to_hex(hash));
2100         url = strbuf_detach(&buf, NULL);
2101
2102         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(hash));
2103         tmp = strbuf_detach(&buf, NULL);
2104
2105         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
2106                 error("Unable to get pack index %s", url);
2107                 FREE_AND_NULL(tmp);
2108         }
2109
2110         free(url);
2111         return tmp;
2112 }
2113
2114 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
2115         unsigned char *sha1, const char *base_url)
2116 {
2117         struct packed_git *new_pack;
2118         char *tmp_idx = NULL;
2119         int ret;
2120
2121         if (has_pack_index(sha1)) {
2122                 new_pack = parse_pack_index(sha1, sha1_pack_index_name(sha1));
2123                 if (!new_pack)
2124                         return -1; /* parse_pack_index() already issued error message */
2125                 goto add_pack;
2126         }
2127
2128         tmp_idx = fetch_pack_index(sha1, base_url);
2129         if (!tmp_idx)
2130                 return -1;
2131
2132         new_pack = parse_pack_index(sha1, tmp_idx);
2133         if (!new_pack) {
2134                 unlink(tmp_idx);
2135                 free(tmp_idx);
2136
2137                 return -1; /* parse_pack_index() already issued error message */
2138         }
2139
2140         ret = verify_pack_index(new_pack);
2141         if (!ret) {
2142                 close_pack_index(new_pack);
2143                 ret = finalize_object_file(tmp_idx, sha1_pack_index_name(sha1));
2144         }
2145         free(tmp_idx);
2146         if (ret)
2147                 return -1;
2148
2149 add_pack:
2150         new_pack->next = *packs_head;
2151         *packs_head = new_pack;
2152         return 0;
2153 }
2154
2155 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
2156 {
2157         struct http_get_options options = {0};
2158         int ret = 0;
2159         char *url;
2160         const char *data;
2161         struct strbuf buf = STRBUF_INIT;
2162         struct object_id oid;
2163
2164         end_url_with_slash(&buf, base_url);
2165         strbuf_addstr(&buf, "objects/info/packs");
2166         url = strbuf_detach(&buf, NULL);
2167
2168         options.no_cache = 1;
2169         ret = http_get_strbuf(url, &buf, &options);
2170         if (ret != HTTP_OK)
2171                 goto cleanup;
2172
2173         data = buf.buf;
2174         while (*data) {
2175                 if (skip_prefix(data, "P pack-", &data) &&
2176                     !parse_oid_hex(data, &oid, &data) &&
2177                     skip_prefix(data, ".pack", &data) &&
2178                     (*data == '\n' || *data == '\0')) {
2179                         fetch_and_setup_pack_index(packs_head, oid.hash, base_url);
2180                 } else {
2181                         data = strchrnul(data, '\n');
2182                 }
2183                 if (*data)
2184                         data++; /* skip past newline */
2185         }
2186
2187 cleanup:
2188         free(url);
2189         return ret;
2190 }
2191
2192 void release_http_pack_request(struct http_pack_request *preq)
2193 {
2194         if (preq->packfile != NULL) {
2195                 fclose(preq->packfile);
2196                 preq->packfile = NULL;
2197         }
2198         preq->slot = NULL;
2199         strbuf_release(&preq->tmpfile);
2200         free(preq->url);
2201         free(preq);
2202 }
2203
2204 int finish_http_pack_request(struct http_pack_request *preq)
2205 {
2206         struct packed_git **lst;
2207         struct packed_git *p = preq->target;
2208         char *tmp_idx;
2209         size_t len;
2210         struct child_process ip = CHILD_PROCESS_INIT;
2211
2212         close_pack_index(p);
2213
2214         fclose(preq->packfile);
2215         preq->packfile = NULL;
2216
2217         lst = preq->lst;
2218         while (*lst != p)
2219                 lst = &((*lst)->next);
2220         *lst = (*lst)->next;
2221
2222         if (!strip_suffix(preq->tmpfile.buf, ".pack.temp", &len))
2223                 BUG("pack tmpfile does not end in .pack.temp?");
2224         tmp_idx = xstrfmt("%.*s.idx.temp", (int)len, preq->tmpfile.buf);
2225
2226         argv_array_push(&ip.args, "index-pack");
2227         argv_array_pushl(&ip.args, "-o", tmp_idx, NULL);
2228         argv_array_push(&ip.args, preq->tmpfile.buf);
2229         ip.git_cmd = 1;
2230         ip.no_stdin = 1;
2231         ip.no_stdout = 1;
2232
2233         if (run_command(&ip)) {
2234                 unlink(preq->tmpfile.buf);
2235                 unlink(tmp_idx);
2236                 free(tmp_idx);
2237                 return -1;
2238         }
2239
2240         unlink(sha1_pack_index_name(p->hash));
2241
2242         if (finalize_object_file(preq->tmpfile.buf, sha1_pack_name(p->hash))
2243          || finalize_object_file(tmp_idx, sha1_pack_index_name(p->hash))) {
2244                 free(tmp_idx);
2245                 return -1;
2246         }
2247
2248         install_packed_git(the_repository, p);
2249         free(tmp_idx);
2250         return 0;
2251 }
2252
2253 struct http_pack_request *new_http_pack_request(
2254         struct packed_git *target, const char *base_url)
2255 {
2256         off_t prev_posn = 0;
2257         struct strbuf buf = STRBUF_INIT;
2258         struct http_pack_request *preq;
2259
2260         preq = xcalloc(1, sizeof(*preq));
2261         strbuf_init(&preq->tmpfile, 0);
2262         preq->target = target;
2263
2264         end_url_with_slash(&buf, base_url);
2265         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
2266                 hash_to_hex(target->hash));
2267         preq->url = strbuf_detach(&buf, NULL);
2268
2269         strbuf_addf(&preq->tmpfile, "%s.temp", sha1_pack_name(target->hash));
2270         preq->packfile = fopen(preq->tmpfile.buf, "a");
2271         if (!preq->packfile) {
2272                 error("Unable to open local file %s for pack",
2273                       preq->tmpfile.buf);
2274                 goto abort;
2275         }
2276
2277         preq->slot = get_active_slot();
2278         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
2279         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
2280         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
2281         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
2282                 no_pragma_header);
2283
2284         /*
2285          * If there is data present from a previous transfer attempt,
2286          * resume where it left off
2287          */
2288         prev_posn = ftello(preq->packfile);
2289         if (prev_posn>0) {
2290                 if (http_is_verbose)
2291                         fprintf(stderr,
2292                                 "Resuming fetch of pack %s at byte %"PRIuMAX"\n",
2293                                 hash_to_hex(target->hash),
2294                                 (uintmax_t)prev_posn);
2295                 http_opt_request_remainder(preq->slot->curl, prev_posn);
2296         }
2297
2298         return preq;
2299
2300 abort:
2301         strbuf_release(&preq->tmpfile);
2302         free(preq->url);
2303         free(preq);
2304         return NULL;
2305 }
2306
2307 /* Helpers for fetching objects (loose) */
2308 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
2309                                void *data)
2310 {
2311         unsigned char expn[4096];
2312         size_t size = eltsize * nmemb;
2313         int posn = 0;
2314         struct http_object_request *freq = data;
2315         struct active_request_slot *slot = freq->slot;
2316
2317         if (slot) {
2318                 CURLcode c = curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE,
2319                                                 &slot->http_code);
2320                 if (c != CURLE_OK)
2321                         BUG("curl_easy_getinfo for HTTP code failed: %s",
2322                                 curl_easy_strerror(c));
2323                 if (slot->http_code >= 300)
2324                         return nmemb;
2325         }
2326
2327         do {
2328                 ssize_t retval = xwrite(freq->localfile,
2329                                         (char *) ptr + posn, size - posn);
2330                 if (retval < 0)
2331                         return posn / eltsize;
2332                 posn += retval;
2333         } while (posn < size);
2334
2335         freq->stream.avail_in = size;
2336         freq->stream.next_in = (void *)ptr;
2337         do {
2338                 freq->stream.next_out = expn;
2339                 freq->stream.avail_out = sizeof(expn);
2340                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
2341                 the_hash_algo->update_fn(&freq->c, expn,
2342                                          sizeof(expn) - freq->stream.avail_out);
2343         } while (freq->stream.avail_in && freq->zret == Z_OK);
2344         return nmemb;
2345 }
2346
2347 struct http_object_request *new_http_object_request(const char *base_url,
2348                                                     const struct object_id *oid)
2349 {
2350         char *hex = oid_to_hex(oid);
2351         struct strbuf filename = STRBUF_INIT;
2352         struct strbuf prevfile = STRBUF_INIT;
2353         int prevlocal;
2354         char prev_buf[PREV_BUF_SIZE];
2355         ssize_t prev_read = 0;
2356         off_t prev_posn = 0;
2357         struct http_object_request *freq;
2358
2359         freq = xcalloc(1, sizeof(*freq));
2360         strbuf_init(&freq->tmpfile, 0);
2361         oidcpy(&freq->oid, oid);
2362         freq->localfile = -1;
2363
2364         loose_object_path(the_repository, &filename, oid);
2365         strbuf_addf(&freq->tmpfile, "%s.temp", filename.buf);
2366
2367         strbuf_addf(&prevfile, "%s.prev", filename.buf);
2368         unlink_or_warn(prevfile.buf);
2369         rename(freq->tmpfile.buf, prevfile.buf);
2370         unlink_or_warn(freq->tmpfile.buf);
2371         strbuf_release(&filename);
2372
2373         if (freq->localfile != -1)
2374                 error("fd leakage in start: %d", freq->localfile);
2375         freq->localfile = open(freq->tmpfile.buf,
2376                                O_WRONLY | O_CREAT | O_EXCL, 0666);
2377         /*
2378          * This could have failed due to the "lazy directory creation";
2379          * try to mkdir the last path component.
2380          */
2381         if (freq->localfile < 0 && errno == ENOENT) {
2382                 char *dir = strrchr(freq->tmpfile.buf, '/');
2383                 if (dir) {
2384                         *dir = 0;
2385                         mkdir(freq->tmpfile.buf, 0777);
2386                         *dir = '/';
2387                 }
2388                 freq->localfile = open(freq->tmpfile.buf,
2389                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
2390         }
2391
2392         if (freq->localfile < 0) {
2393                 error_errno("Couldn't create temporary file %s",
2394                             freq->tmpfile.buf);
2395                 goto abort;
2396         }
2397
2398         git_inflate_init(&freq->stream);
2399
2400         the_hash_algo->init_fn(&freq->c);
2401
2402         freq->url = get_remote_object_url(base_url, hex, 0);
2403
2404         /*
2405          * If a previous temp file is present, process what was already
2406          * fetched.
2407          */
2408         prevlocal = open(prevfile.buf, O_RDONLY);
2409         if (prevlocal != -1) {
2410                 do {
2411                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
2412                         if (prev_read>0) {
2413                                 if (fwrite_sha1_file(prev_buf,
2414                                                      1,
2415                                                      prev_read,
2416                                                      freq) == prev_read) {
2417                                         prev_posn += prev_read;
2418                                 } else {
2419                                         prev_read = -1;
2420                                 }
2421                         }
2422                 } while (prev_read > 0);
2423                 close(prevlocal);
2424         }
2425         unlink_or_warn(prevfile.buf);
2426         strbuf_release(&prevfile);
2427
2428         /*
2429          * Reset inflate/SHA1 if there was an error reading the previous temp
2430          * file; also rewind to the beginning of the local file.
2431          */
2432         if (prev_read == -1) {
2433                 memset(&freq->stream, 0, sizeof(freq->stream));
2434                 git_inflate_init(&freq->stream);
2435                 the_hash_algo->init_fn(&freq->c);
2436                 if (prev_posn>0) {
2437                         prev_posn = 0;
2438                         lseek(freq->localfile, 0, SEEK_SET);
2439                         if (ftruncate(freq->localfile, 0) < 0) {
2440                                 error_errno("Couldn't truncate temporary file %s",
2441                                             freq->tmpfile.buf);
2442                                 goto abort;
2443                         }
2444                 }
2445         }
2446
2447         freq->slot = get_active_slot();
2448
2449         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
2450         curl_easy_setopt(freq->slot->curl, CURLOPT_FAILONERROR, 0);
2451         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
2452         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
2453         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
2454         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
2455
2456         /*
2457          * If we have successfully processed data from a previous fetch
2458          * attempt, only fetch the data we don't already have.
2459          */
2460         if (prev_posn>0) {
2461                 if (http_is_verbose)
2462                         fprintf(stderr,
2463                                 "Resuming fetch of object %s at byte %"PRIuMAX"\n",
2464                                 hex, (uintmax_t)prev_posn);
2465                 http_opt_request_remainder(freq->slot->curl, prev_posn);
2466         }
2467
2468         return freq;
2469
2470 abort:
2471         strbuf_release(&prevfile);
2472         free(freq->url);
2473         free(freq);
2474         return NULL;
2475 }
2476
2477 void process_http_object_request(struct http_object_request *freq)
2478 {
2479         if (freq->slot == NULL)
2480                 return;
2481         freq->curl_result = freq->slot->curl_result;
2482         freq->http_code = freq->slot->http_code;
2483         freq->slot = NULL;
2484 }
2485
2486 int finish_http_object_request(struct http_object_request *freq)
2487 {
2488         struct stat st;
2489         struct strbuf filename = STRBUF_INIT;
2490
2491         close(freq->localfile);
2492         freq->localfile = -1;
2493
2494         process_http_object_request(freq);
2495
2496         if (freq->http_code == 416) {
2497                 warning("requested range invalid; we may already have all the data.");
2498         } else if (freq->curl_result != CURLE_OK) {
2499                 if (stat(freq->tmpfile.buf, &st) == 0)
2500                         if (st.st_size == 0)
2501                                 unlink_or_warn(freq->tmpfile.buf);
2502                 return -1;
2503         }
2504
2505         git_inflate_end(&freq->stream);
2506         the_hash_algo->final_fn(freq->real_oid.hash, &freq->c);
2507         if (freq->zret != Z_STREAM_END) {
2508                 unlink_or_warn(freq->tmpfile.buf);
2509                 return -1;
2510         }
2511         if (!oideq(&freq->oid, &freq->real_oid)) {
2512                 unlink_or_warn(freq->tmpfile.buf);
2513                 return -1;
2514         }
2515         loose_object_path(the_repository, &filename, &freq->oid);
2516         freq->rename = finalize_object_file(freq->tmpfile.buf, filename.buf);
2517         strbuf_release(&filename);
2518
2519         return freq->rename;
2520 }
2521
2522 void abort_http_object_request(struct http_object_request *freq)
2523 {
2524         unlink_or_warn(freq->tmpfile.buf);
2525
2526         release_http_object_request(freq);
2527 }
2528
2529 void release_http_object_request(struct http_object_request *freq)
2530 {
2531         if (freq->localfile != -1) {
2532                 close(freq->localfile);
2533                 freq->localfile = -1;
2534         }
2535         FREE_AND_NULL(freq->url);
2536         if (freq->slot != NULL) {
2537                 freq->slot->callback_func = NULL;
2538                 freq->slot->callback_data = NULL;
2539                 release_active_slot(freq->slot);
2540                 freq->slot = NULL;
2541         }
2542         strbuf_release(&freq->tmpfile);
2543 }