Merge branch 'rt/rebase-p-no-merge-summary' into maint
[git] / http-backend.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "pkt-line.h"
4 #include "object.h"
5 #include "tag.h"
6 #include "exec_cmd.h"
7 #include "run-command.h"
8 #include "string-list.h"
9 #include "url.h"
10 #include "argv-array.h"
11
12 static const char content_type[] = "Content-Type";
13 static const char content_length[] = "Content-Length";
14 static const char last_modified[] = "Last-Modified";
15 static int getanyfile = 1;
16
17 static struct string_list *query_params;
18
19 struct rpc_service {
20         const char *name;
21         const char *config_name;
22         signed enabled : 2;
23 };
24
25 static struct rpc_service rpc_service[] = {
26         { "upload-pack", "uploadpack", 1 },
27         { "receive-pack", "receivepack", -1 },
28 };
29
30 static struct string_list *get_parameters(void)
31 {
32         if (!query_params) {
33                 const char *query = getenv("QUERY_STRING");
34
35                 query_params = xcalloc(1, sizeof(*query_params));
36                 while (query && *query) {
37                         char *name = url_decode_parameter_name(&query);
38                         char *value = url_decode_parameter_value(&query);
39                         struct string_list_item *i;
40
41                         i = string_list_lookup(query_params, name);
42                         if (!i)
43                                 i = string_list_insert(query_params, name);
44                         else
45                                 free(i->util);
46                         i->util = value;
47                 }
48         }
49         return query_params;
50 }
51
52 static const char *get_parameter(const char *name)
53 {
54         struct string_list_item *i;
55         i = string_list_lookup(get_parameters(), name);
56         return i ? i->util : NULL;
57 }
58
59 __attribute__((format (printf, 2, 3)))
60 static void format_write(int fd, const char *fmt, ...)
61 {
62         static char buffer[1024];
63
64         va_list args;
65         unsigned n;
66
67         va_start(args, fmt);
68         n = vsnprintf(buffer, sizeof(buffer), fmt, args);
69         va_end(args);
70         if (n >= sizeof(buffer))
71                 die("protocol error: impossibly long line");
72
73         write_or_die(fd, buffer, n);
74 }
75
76 static void http_status(unsigned code, const char *msg)
77 {
78         format_write(1, "Status: %u %s\r\n", code, msg);
79 }
80
81 static void hdr_str(const char *name, const char *value)
82 {
83         format_write(1, "%s: %s\r\n", name, value);
84 }
85
86 static void hdr_int(const char *name, uintmax_t value)
87 {
88         format_write(1, "%s: %" PRIuMAX "\r\n", name, value);
89 }
90
91 static void hdr_date(const char *name, unsigned long when)
92 {
93         const char *value = show_date(when, 0, DATE_RFC2822);
94         hdr_str(name, value);
95 }
96
97 static void hdr_nocache(void)
98 {
99         hdr_str("Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
100         hdr_str("Pragma", "no-cache");
101         hdr_str("Cache-Control", "no-cache, max-age=0, must-revalidate");
102 }
103
104 static void hdr_cache_forever(void)
105 {
106         unsigned long now = time(NULL);
107         hdr_date("Date", now);
108         hdr_date("Expires", now + 31536000);
109         hdr_str("Cache-Control", "public, max-age=31536000");
110 }
111
112 static void end_headers(void)
113 {
114         write_or_die(1, "\r\n", 2);
115 }
116
117 __attribute__((format (printf, 1, 2)))
118 static NORETURN void not_found(const char *err, ...)
119 {
120         va_list params;
121
122         http_status(404, "Not Found");
123         hdr_nocache();
124         end_headers();
125
126         va_start(params, err);
127         if (err && *err)
128                 vfprintf(stderr, err, params);
129         va_end(params);
130         exit(0);
131 }
132
133 __attribute__((format (printf, 1, 2)))
134 static NORETURN void forbidden(const char *err, ...)
135 {
136         va_list params;
137
138         http_status(403, "Forbidden");
139         hdr_nocache();
140         end_headers();
141
142         va_start(params, err);
143         if (err && *err)
144                 vfprintf(stderr, err, params);
145         va_end(params);
146         exit(0);
147 }
148
149 static void select_getanyfile(void)
150 {
151         if (!getanyfile)
152                 forbidden("Unsupported service: getanyfile");
153 }
154
155 static void send_strbuf(const char *type, struct strbuf *buf)
156 {
157         hdr_int(content_length, buf->len);
158         hdr_str(content_type, type);
159         end_headers();
160         write_or_die(1, buf->buf, buf->len);
161 }
162
163 static void send_local_file(const char *the_type, const char *name)
164 {
165         const char *p = git_path("%s", name);
166         size_t buf_alloc = 8192;
167         char *buf = xmalloc(buf_alloc);
168         int fd;
169         struct stat sb;
170
171         fd = open(p, O_RDONLY);
172         if (fd < 0)
173                 not_found("Cannot open '%s': %s", p, strerror(errno));
174         if (fstat(fd, &sb) < 0)
175                 die_errno("Cannot stat '%s'", p);
176
177         hdr_int(content_length, sb.st_size);
178         hdr_str(content_type, the_type);
179         hdr_date(last_modified, sb.st_mtime);
180         end_headers();
181
182         for (;;) {
183                 ssize_t n = xread(fd, buf, buf_alloc);
184                 if (n < 0)
185                         die_errno("Cannot read '%s'", p);
186                 if (!n)
187                         break;
188                 write_or_die(1, buf, n);
189         }
190         close(fd);
191         free(buf);
192 }
193
194 static void get_text_file(char *name)
195 {
196         select_getanyfile();
197         hdr_nocache();
198         send_local_file("text/plain", name);
199 }
200
201 static void get_loose_object(char *name)
202 {
203         select_getanyfile();
204         hdr_cache_forever();
205         send_local_file("application/x-git-loose-object", name);
206 }
207
208 static void get_pack_file(char *name)
209 {
210         select_getanyfile();
211         hdr_cache_forever();
212         send_local_file("application/x-git-packed-objects", name);
213 }
214
215 static void get_idx_file(char *name)
216 {
217         select_getanyfile();
218         hdr_cache_forever();
219         send_local_file("application/x-git-packed-objects-toc", name);
220 }
221
222 static int http_config(const char *var, const char *value, void *cb)
223 {
224         if (!strcmp(var, "http.getanyfile")) {
225                 getanyfile = git_config_bool(var, value);
226                 return 0;
227         }
228
229         if (!prefixcmp(var, "http.")) {
230                 int i;
231
232                 for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
233                         struct rpc_service *svc = &rpc_service[i];
234                         if (!strcmp(var + 5, svc->config_name)) {
235                                 svc->enabled = git_config_bool(var, value);
236                                 return 0;
237                         }
238                 }
239         }
240
241         /* we are not interested in parsing any other configuration here */
242         return 0;
243 }
244
245 static struct rpc_service *select_service(const char *name)
246 {
247         struct rpc_service *svc = NULL;
248         int i;
249
250         if (prefixcmp(name, "git-"))
251                 forbidden("Unsupported service: '%s'", name);
252
253         for (i = 0; i < ARRAY_SIZE(rpc_service); i++) {
254                 struct rpc_service *s = &rpc_service[i];
255                 if (!strcmp(s->name, name + 4)) {
256                         svc = s;
257                         break;
258                 }
259         }
260
261         if (!svc)
262                 forbidden("Unsupported service: '%s'", name);
263
264         if (svc->enabled < 0) {
265                 const char *user = getenv("REMOTE_USER");
266                 svc->enabled = (user && *user) ? 1 : 0;
267         }
268         if (!svc->enabled)
269                 forbidden("Service not enabled: '%s'", svc->name);
270         return svc;
271 }
272
273 static void inflate_request(const char *prog_name, int out)
274 {
275         git_zstream stream;
276         unsigned char in_buf[8192];
277         unsigned char out_buf[8192];
278         unsigned long cnt = 0;
279
280         memset(&stream, 0, sizeof(stream));
281         git_inflate_init_gzip_only(&stream);
282
283         while (1) {
284                 ssize_t n = xread(0, in_buf, sizeof(in_buf));
285                 if (n <= 0)
286                         die("request ended in the middle of the gzip stream");
287
288                 stream.next_in = in_buf;
289                 stream.avail_in = n;
290
291                 while (0 < stream.avail_in) {
292                         int ret;
293
294                         stream.next_out = out_buf;
295                         stream.avail_out = sizeof(out_buf);
296
297                         ret = git_inflate(&stream, Z_NO_FLUSH);
298                         if (ret != Z_OK && ret != Z_STREAM_END)
299                                 die("zlib error inflating request, result %d", ret);
300
301                         n = stream.total_out - cnt;
302                         if (write_in_full(out, out_buf, n) != n)
303                                 die("%s aborted reading request", prog_name);
304                         cnt += n;
305
306                         if (ret == Z_STREAM_END)
307                                 goto done;
308                 }
309         }
310
311 done:
312         git_inflate_end(&stream);
313         close(out);
314 }
315
316 static void run_service(const char **argv)
317 {
318         const char *encoding = getenv("HTTP_CONTENT_ENCODING");
319         const char *user = getenv("REMOTE_USER");
320         const char *host = getenv("REMOTE_ADDR");
321         struct argv_array env = ARGV_ARRAY_INIT;
322         int gzipped_request = 0;
323         struct child_process cld;
324
325         if (encoding && !strcmp(encoding, "gzip"))
326                 gzipped_request = 1;
327         else if (encoding && !strcmp(encoding, "x-gzip"))
328                 gzipped_request = 1;
329
330         if (!user || !*user)
331                 user = "anonymous";
332         if (!host || !*host)
333                 host = "(none)";
334
335         if (!getenv("GIT_COMMITTER_NAME"))
336                 argv_array_pushf(&env, "GIT_COMMITTER_NAME=%s", user);
337         if (!getenv("GIT_COMMITTER_EMAIL"))
338                 argv_array_pushf(&env, "GIT_COMMITTER_EMAIL=%s@http.%s",
339                                  user, host);
340
341         memset(&cld, 0, sizeof(cld));
342         cld.argv = argv;
343         cld.env = env.argv;
344         if (gzipped_request)
345                 cld.in = -1;
346         cld.git_cmd = 1;
347         if (start_command(&cld))
348                 exit(1);
349
350         close(1);
351         if (gzipped_request)
352                 inflate_request(argv[0], cld.in);
353         else
354                 close(0);
355
356         if (finish_command(&cld))
357                 exit(1);
358         argv_array_clear(&env);
359 }
360
361 static int show_text_ref(const char *name, const unsigned char *sha1,
362         int flag, void *cb_data)
363 {
364         const char *name_nons = strip_namespace(name);
365         struct strbuf *buf = cb_data;
366         struct object *o = parse_object(sha1);
367         if (!o)
368                 return 0;
369
370         strbuf_addf(buf, "%s\t%s\n", sha1_to_hex(sha1), name_nons);
371         if (o->type == OBJ_TAG) {
372                 o = deref_tag(o, name, 0);
373                 if (!o)
374                         return 0;
375                 strbuf_addf(buf, "%s\t%s^{}\n", sha1_to_hex(o->sha1),
376                             name_nons);
377         }
378         return 0;
379 }
380
381 static void get_info_refs(char *arg)
382 {
383         const char *service_name = get_parameter("service");
384         struct strbuf buf = STRBUF_INIT;
385
386         hdr_nocache();
387
388         if (service_name) {
389                 const char *argv[] = {NULL /* service name */,
390                         "--stateless-rpc", "--advertise-refs",
391                         ".", NULL};
392                 struct rpc_service *svc = select_service(service_name);
393
394                 strbuf_addf(&buf, "application/x-git-%s-advertisement",
395                         svc->name);
396                 hdr_str(content_type, buf.buf);
397                 end_headers();
398
399                 packet_write(1, "# service=git-%s\n", svc->name);
400                 packet_flush(1);
401
402                 argv[0] = svc->name;
403                 run_service(argv);
404
405         } else {
406                 select_getanyfile();
407                 for_each_namespaced_ref(show_text_ref, &buf);
408                 send_strbuf("text/plain", &buf);
409         }
410         strbuf_release(&buf);
411 }
412
413 static int show_head_ref(const char *refname, const unsigned char *sha1,
414         int flag, void *cb_data)
415 {
416         struct strbuf *buf = cb_data;
417
418         if (flag & REF_ISSYMREF) {
419                 unsigned char unused[20];
420                 const char *target = resolve_ref_unsafe(refname, unused, 1, NULL);
421                 const char *target_nons = strip_namespace(target);
422
423                 strbuf_addf(buf, "ref: %s\n", target_nons);
424         } else {
425                 strbuf_addf(buf, "%s\n", sha1_to_hex(sha1));
426         }
427
428         return 0;
429 }
430
431 static void get_head(char *arg)
432 {
433         struct strbuf buf = STRBUF_INIT;
434
435         select_getanyfile();
436         head_ref_namespaced(show_head_ref, &buf);
437         send_strbuf("text/plain", &buf);
438         strbuf_release(&buf);
439 }
440
441 static void get_info_packs(char *arg)
442 {
443         size_t objdirlen = strlen(get_object_directory());
444         struct strbuf buf = STRBUF_INIT;
445         struct packed_git *p;
446         size_t cnt = 0;
447
448         select_getanyfile();
449         prepare_packed_git();
450         for (p = packed_git; p; p = p->next) {
451                 if (p->pack_local)
452                         cnt++;
453         }
454
455         strbuf_grow(&buf, cnt * 53 + 2);
456         for (p = packed_git; p; p = p->next) {
457                 if (p->pack_local)
458                         strbuf_addf(&buf, "P %s\n", p->pack_name + objdirlen + 6);
459         }
460         strbuf_addch(&buf, '\n');
461
462         hdr_nocache();
463         send_strbuf("text/plain; charset=utf-8", &buf);
464         strbuf_release(&buf);
465 }
466
467 static void check_content_type(const char *accepted_type)
468 {
469         const char *actual_type = getenv("CONTENT_TYPE");
470
471         if (!actual_type)
472                 actual_type = "";
473
474         if (strcmp(actual_type, accepted_type)) {
475                 http_status(415, "Unsupported Media Type");
476                 hdr_nocache();
477                 end_headers();
478                 format_write(1,
479                         "Expected POST with Content-Type '%s',"
480                         " but received '%s' instead.\n",
481                         accepted_type, actual_type);
482                 exit(0);
483         }
484 }
485
486 static void service_rpc(char *service_name)
487 {
488         const char *argv[] = {NULL, "--stateless-rpc", ".", NULL};
489         struct rpc_service *svc = select_service(service_name);
490         struct strbuf buf = STRBUF_INIT;
491
492         strbuf_reset(&buf);
493         strbuf_addf(&buf, "application/x-git-%s-request", svc->name);
494         check_content_type(buf.buf);
495
496         hdr_nocache();
497
498         strbuf_reset(&buf);
499         strbuf_addf(&buf, "application/x-git-%s-result", svc->name);
500         hdr_str(content_type, buf.buf);
501
502         end_headers();
503
504         argv[0] = svc->name;
505         run_service(argv);
506         strbuf_release(&buf);
507 }
508
509 static NORETURN void die_webcgi(const char *err, va_list params)
510 {
511         static int dead;
512
513         if (!dead) {
514                 dead = 1;
515                 http_status(500, "Internal Server Error");
516                 hdr_nocache();
517                 end_headers();
518
519                 vreportf("fatal: ", err, params);
520         }
521         exit(0); /* we successfully reported a failure ;-) */
522 }
523
524 static char* getdir(void)
525 {
526         struct strbuf buf = STRBUF_INIT;
527         char *pathinfo = getenv("PATH_INFO");
528         char *root = getenv("GIT_PROJECT_ROOT");
529         char *path = getenv("PATH_TRANSLATED");
530
531         if (root && *root) {
532                 if (!pathinfo || !*pathinfo)
533                         die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
534                 if (daemon_avoid_alias(pathinfo))
535                         die("'%s': aliased", pathinfo);
536                 end_url_with_slash(&buf, root);
537                 if (pathinfo[0] == '/')
538                         pathinfo++;
539                 strbuf_addstr(&buf, pathinfo);
540                 return strbuf_detach(&buf, NULL);
541         } else if (path && *path) {
542                 return xstrdup(path);
543         } else
544                 die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
545         return NULL;
546 }
547
548 static struct service_cmd {
549         const char *method;
550         const char *pattern;
551         void (*imp)(char *);
552 } services[] = {
553         {"GET", "/HEAD$", get_head},
554         {"GET", "/info/refs$", get_info_refs},
555         {"GET", "/objects/info/alternates$", get_text_file},
556         {"GET", "/objects/info/http-alternates$", get_text_file},
557         {"GET", "/objects/info/packs$", get_info_packs},
558         {"GET", "/objects/[0-9a-f]{2}/[0-9a-f]{38}$", get_loose_object},
559         {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.pack$", get_pack_file},
560         {"GET", "/objects/pack/pack-[0-9a-f]{40}\\.idx$", get_idx_file},
561
562         {"POST", "/git-upload-pack$", service_rpc},
563         {"POST", "/git-receive-pack$", service_rpc}
564 };
565
566 int main(int argc, char **argv)
567 {
568         char *method = getenv("REQUEST_METHOD");
569         char *dir;
570         struct service_cmd *cmd = NULL;
571         char *cmd_arg = NULL;
572         int i;
573
574         git_setup_gettext();
575
576         git_extract_argv0_path(argv[0]);
577         set_die_routine(die_webcgi);
578
579         if (!method)
580                 die("No REQUEST_METHOD from server");
581         if (!strcmp(method, "HEAD"))
582                 method = "GET";
583         dir = getdir();
584
585         for (i = 0; i < ARRAY_SIZE(services); i++) {
586                 struct service_cmd *c = &services[i];
587                 regex_t re;
588                 regmatch_t out[1];
589
590                 if (regcomp(&re, c->pattern, REG_EXTENDED))
591                         die("Bogus regex in service table: %s", c->pattern);
592                 if (!regexec(&re, dir, 1, out, 0)) {
593                         size_t n;
594
595                         if (strcmp(method, c->method)) {
596                                 const char *proto = getenv("SERVER_PROTOCOL");
597                                 if (proto && !strcmp(proto, "HTTP/1.1"))
598                                         http_status(405, "Method Not Allowed");
599                                 else
600                                         http_status(400, "Bad Request");
601                                 hdr_nocache();
602                                 end_headers();
603                                 return 0;
604                         }
605
606                         cmd = c;
607                         n = out[0].rm_eo - out[0].rm_so;
608                         cmd_arg = xmalloc(n);
609                         memcpy(cmd_arg, dir + out[0].rm_so + 1, n-1);
610                         cmd_arg[n-1] = '\0';
611                         dir[out[0].rm_so] = 0;
612                         break;
613                 }
614                 regfree(&re);
615         }
616
617         if (!cmd)
618                 not_found("Request not supported: '%s'", dir);
619
620         setup_path();
621         if (!enter_repo(dir, 0))
622                 not_found("Not a git repository: '%s'", dir);
623         if (!getenv("GIT_HTTP_EXPORT_ALL") &&
624             access("git-daemon-export-ok", F_OK) )
625                 not_found("Repository not exported: '%s'", dir);
626
627         git_config(http_config, NULL);
628         cmd->imp(cmd_arg);
629         return 0;
630 }