[PATCH] git-local-fetch: Avoid confusing error messages on packed repositories
[git.git] / http-fetch.c
1 #include "cache.h"
2 #include "commit.h"
3
4 #include "fetch.h"
5
6 #include <curl/curl.h>
7 #include <curl/easy.h>
8
9 #if LIBCURL_VERSION_NUM < 0x070704
10 #define curl_global_cleanup() do { /* nothing */ } while(0)
11 #endif
12 #if LIBCURL_VERSION_NUM < 0x070800
13 #define curl_global_init(a) do { /* nothing */ } while(0)
14 #endif
15
16 static CURL *curl;
17 static struct curl_slist *no_pragma_header;
18
19 static char *initial_base;
20
21 struct alt_base
22 {
23         char *base;
24         int got_indices;
25         struct packed_git *packs;
26         struct alt_base *next;
27 };
28
29 struct alt_base *alt = NULL;
30
31 static SHA_CTX c;
32 static z_stream stream;
33
34 static int local;
35 static int zret;
36
37 static int curl_ssl_verify;
38
39 struct buffer
40 {
41         size_t posn;
42         size_t size;
43         void *buffer;
44 };
45
46 static size_t fwrite_buffer(void *ptr, size_t eltsize, size_t nmemb,
47                             struct buffer *buffer)
48 {
49         size_t size = eltsize * nmemb;
50         if (size > buffer->size - buffer->posn)
51                 size = buffer->size - buffer->posn;
52         memcpy(buffer->buffer + buffer->posn, ptr, size);
53         buffer->posn += size;
54         return size;
55 }
56
57 static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
58                                void *data)
59 {
60         unsigned char expn[4096];
61         size_t size = eltsize * nmemb;
62         int posn = 0;
63         do {
64                 ssize_t retval = write(local, ptr + posn, size - posn);
65                 if (retval < 0)
66                         return posn;
67                 posn += retval;
68         } while (posn < size);
69
70         stream.avail_in = size;
71         stream.next_in = ptr;
72         do {
73                 stream.next_out = expn;
74                 stream.avail_out = sizeof(expn);
75                 zret = inflate(&stream, Z_SYNC_FLUSH);
76                 SHA1_Update(&c, expn, sizeof(expn) - stream.avail_out);
77         } while (stream.avail_in && zret == Z_OK);
78         return size;
79 }
80
81 void prefetch(unsigned char *sha1)
82 {
83 }
84
85 static int got_alternates = 0;
86
87 static int fetch_index(struct alt_base *repo, unsigned char *sha1)
88 {
89         char *filename;
90         char *url;
91
92         FILE *indexfile;
93
94         if (has_pack_index(sha1))
95                 return 0;
96
97         if (get_verbosely)
98                 fprintf(stderr, "Getting index for pack %s\n",
99                         sha1_to_hex(sha1));
100         
101         url = xmalloc(strlen(repo->base) + 64);
102         sprintf(url, "%s/objects/pack/pack-%s.idx",
103                 repo->base, sha1_to_hex(sha1));
104         
105         filename = sha1_pack_index_name(sha1);
106         indexfile = fopen(filename, "w");
107         if (!indexfile)
108                 return error("Unable to open local file %s for pack index",
109                              filename);
110
111         curl_easy_setopt(curl, CURLOPT_FILE, indexfile);
112         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite);
113         curl_easy_setopt(curl, CURLOPT_URL, url);
114         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_pragma_header);
115         
116         if (curl_easy_perform(curl)) {
117                 fclose(indexfile);
118                 return error("Unable to get pack index %s", url);
119         }
120
121         fclose(indexfile);
122         return 0;
123 }
124
125 static int setup_index(struct alt_base *repo, unsigned char *sha1)
126 {
127         struct packed_git *new_pack;
128         if (has_pack_file(sha1))
129                 return 0; // don't list this as something we can get
130
131         if (fetch_index(repo, sha1))
132                 return -1;
133
134         new_pack = parse_pack_index(sha1);
135         new_pack->next = repo->packs;
136         repo->packs = new_pack;
137         return 0;
138 }
139
140 static int fetch_alternates(char *base)
141 {
142         int ret = 0;
143         struct buffer buffer;
144         char *url;
145         char *data;
146         int i = 0;
147         int http_specific = 1;
148         if (got_alternates)
149                 return 0;
150         data = xmalloc(4096);
151         buffer.size = 4095;
152         buffer.posn = 0;
153         buffer.buffer = data;
154
155         if (get_verbosely)
156                 fprintf(stderr, "Getting alternates list\n");
157         
158         url = xmalloc(strlen(base) + 31);
159         sprintf(url, "%s/objects/info/http-alternates", base);
160
161         curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
162         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
163         curl_easy_setopt(curl, CURLOPT_URL, url);
164
165         if (curl_easy_perform(curl) || !buffer.posn) {
166                 http_specific = 0;
167
168                 sprintf(url, "%s/objects/info/alternates", base);
169                 
170                 curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
171                 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
172                 curl_easy_setopt(curl, CURLOPT_URL, url);
173                 
174                 if (curl_easy_perform(curl)) {
175                         return 0;
176                 }
177         }
178
179         data[buffer.posn] = '\0';
180
181         while (i < buffer.posn) {
182                 int posn = i;
183                 while (posn < buffer.posn && data[posn] != '\n')
184                         posn++;
185                 if (data[posn] == '\n') {
186                         int okay = 0;
187                         int serverlen = 0;
188                         struct alt_base *newalt;
189                         char *target = NULL;
190                         if (data[i] == '/') {
191                                 serverlen = strchr(base + 8, '/') - base;
192                                 okay = 1;
193                         } else if (!memcmp(data + i, "../", 3)) {
194                                 i += 3;
195                                 serverlen = strlen(base);
196                                 while (i + 2 < posn && 
197                                        !memcmp(data + i, "../", 3)) {
198                                         do {
199                                                 serverlen--;
200                                         } while (serverlen &&
201                                                  base[serverlen - 1] != '/');
202                                         i += 3;
203                                 }
204                                 // If the server got removed, give up.
205                                 okay = strchr(base, ':') - base + 3 < 
206                                         serverlen;
207                         } else if (http_specific) {
208                                 char *colon = strchr(data + i, ':');
209                                 char *slash = strchr(data + i, '/');
210                                 if (colon && slash && colon < data + posn &&
211                                     slash < data + posn && colon < slash) {
212                                         okay = 1;
213                                 }
214                         }
215                         // skip 'objects' at end
216                         if (okay) {
217                                 target = xmalloc(serverlen + posn - i - 6);
218                                 strncpy(target, base, serverlen);
219                                 strncpy(target + serverlen, data + i,
220                                         posn - i - 7);
221                                 target[serverlen + posn - i - 7] = '\0';
222                                 if (get_verbosely)
223                                         fprintf(stderr, 
224                                                 "Also look at %s\n", target);
225                                 newalt = xmalloc(sizeof(*newalt));
226                                 newalt->next = alt;
227                                 newalt->base = target;
228                                 newalt->got_indices = 0;
229                                 newalt->packs = NULL;
230                                 alt = newalt;
231                                 ret++;
232                         }
233                 }
234                 i = posn + 1;
235         }
236         got_alternates = 1;
237         
238         return ret;
239 }
240
241 static int fetch_indices(struct alt_base *repo)
242 {
243         unsigned char sha1[20];
244         char *url;
245         struct buffer buffer;
246         char *data;
247         int i = 0;
248
249         if (repo->got_indices)
250                 return 0;
251
252         data = xmalloc(4096);
253         buffer.size = 4096;
254         buffer.posn = 0;
255         buffer.buffer = data;
256
257         if (get_verbosely)
258                 fprintf(stderr, "Getting pack list\n");
259         
260         url = xmalloc(strlen(repo->base) + 21);
261         sprintf(url, "%s/objects/info/packs", repo->base);
262
263         curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
264         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
265         curl_easy_setopt(curl, CURLOPT_URL, url);
266         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
267         
268         if (curl_easy_perform(curl)) {
269                 return -1;
270         }
271
272         while (i < buffer.posn) {
273                 switch (data[i]) {
274                 case 'P':
275                         i++;
276                         if (i + 52 < buffer.posn &&
277                             !strncmp(data + i, " pack-", 6) &&
278                             !strncmp(data + i + 46, ".pack\n", 6)) {
279                                 get_sha1_hex(data + i + 6, sha1);
280                                 setup_index(repo, sha1);
281                                 i += 51;
282                                 break;
283                         }
284                 default:
285                         while (data[i] != '\n')
286                                 i++;
287                 }
288                 i++;
289         }
290
291         repo->got_indices = 1;
292         return 0;
293 }
294
295 static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
296 {
297         char *url;
298         struct packed_git *target;
299         struct packed_git **lst;
300         FILE *packfile;
301         char *filename;
302
303         if (fetch_indices(repo))
304                 return -1;
305         target = find_sha1_pack(sha1, repo->packs);
306         if (!target)
307                 return -1;
308
309         if (get_verbosely) {
310                 fprintf(stderr, "Getting pack %s\n",
311                         sha1_to_hex(target->sha1));
312                 fprintf(stderr, " which contains %s\n",
313                         sha1_to_hex(sha1));
314         }
315
316         url = xmalloc(strlen(repo->base) + 65);
317         sprintf(url, "%s/objects/pack/pack-%s.pack",
318                 repo->base, sha1_to_hex(target->sha1));
319
320         filename = sha1_pack_name(target->sha1);
321         packfile = fopen(filename, "w");
322         if (!packfile)
323                 return error("Unable to open local file %s for pack",
324                              filename);
325
326         curl_easy_setopt(curl, CURLOPT_FILE, packfile);
327         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite);
328         curl_easy_setopt(curl, CURLOPT_URL, url);
329         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_pragma_header);
330         
331         if (curl_easy_perform(curl)) {
332                 fclose(packfile);
333                 return error("Unable to get pack file %s", url);
334         }
335
336         fclose(packfile);
337
338         lst = &repo->packs;
339         while (*lst != target)
340                 lst = &((*lst)->next);
341         *lst = (*lst)->next;
342
343         install_packed_git(target);
344
345         return 0;
346 }
347
348 int fetch_object(struct alt_base *repo, unsigned char *sha1)
349 {
350         char *hex = sha1_to_hex(sha1);
351         char *filename = sha1_file_name(sha1);
352         unsigned char real_sha1[20];
353         char tmpfile[PATH_MAX];
354         int ret;
355         char *url;
356         char *posn;
357
358         snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX",
359                  get_object_directory());
360
361         local = mkstemp(tmpfile);
362         if (local < 0)
363                 return error("Couldn't create temporary file %s for %s: %s\n",
364                              tmpfile, filename, strerror(errno));
365
366         memset(&stream, 0, sizeof(stream));
367
368         inflateInit(&stream);
369
370         SHA1_Init(&c);
371
372         curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
373         curl_easy_setopt(curl, CURLOPT_FILE, NULL);
374         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
375         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, no_pragma_header);
376
377         url = xmalloc(strlen(repo->base) + 50);
378         strcpy(url, repo->base);
379         posn = url + strlen(repo->base);
380         strcpy(posn, "objects/");
381         posn += 8;
382         memcpy(posn, hex, 2);
383         posn += 2;
384         *(posn++) = '/';
385         strcpy(posn, hex + 2);
386
387         curl_easy_setopt(curl, CURLOPT_URL, url);
388
389         if (curl_easy_perform(curl)) {
390                 unlink(filename);
391                 return -1;
392         }
393
394         fchmod(local, 0444);
395         close(local);
396         inflateEnd(&stream);
397         SHA1_Final(real_sha1, &c);
398         if (zret != Z_STREAM_END) {
399                 unlink(tmpfile);
400                 return error("File %s (%s) corrupt\n", hex, url);
401         }
402         if (memcmp(sha1, real_sha1, 20)) {
403                 unlink(tmpfile);
404                 return error("File %s has bad hash\n", hex);
405         }
406         ret = link(tmpfile, filename);
407         if (ret < 0) {
408                 /* Same Coda hack as in write_sha1_file(sha1_file.c) */
409                 ret = errno;
410                 if (ret == EXDEV && !rename(tmpfile, filename))
411                         goto out;
412         }
413         unlink(tmpfile);
414         if (ret) {
415                 if (ret != EEXIST)
416                         return error("unable to write sha1 filename %s: %s",
417                                      filename, strerror(ret));
418         }
419  out:
420         pull_say("got %s\n", hex);
421         return 0;
422 }
423
424 int fetch(unsigned char *sha1)
425 {
426         struct alt_base *altbase = alt;
427         while (altbase) {
428                 if (!fetch_object(altbase, sha1))
429                         return 0;
430                 if (!fetch_pack(altbase, sha1))
431                         return 0;
432                 if (fetch_alternates(altbase->base) > 0) {
433                         altbase = alt;
434                         continue;
435                 }
436                 altbase = altbase->next;
437         }
438         return error("Unable to find %s under %s\n", sha1_to_hex(sha1), 
439                      initial_base);
440 }
441
442 int fetch_ref(char *ref, unsigned char *sha1)
443 {
444         char *url, *posn;
445         char hex[42];
446         struct buffer buffer;
447         char *base = initial_base;
448         buffer.size = 41;
449         buffer.posn = 0;
450         buffer.buffer = hex;
451         hex[41] = '\0';
452         
453         curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
454         curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
455         curl_easy_setopt(curl, CURLOPT_HTTPHEADER, NULL);
456
457         url = xmalloc(strlen(base) + 6 + strlen(ref));
458         strcpy(url, base);
459         posn = url + strlen(base);
460         strcpy(posn, "refs/");
461         posn += 5;
462         strcpy(posn, ref);
463
464         curl_easy_setopt(curl, CURLOPT_URL, url);
465
466         if (curl_easy_perform(curl))
467                 return error("Couldn't get %s for %s\n", url, ref);
468
469         hex[40] = '\0';
470         get_sha1_hex(hex, sha1);
471         return 0;
472 }
473
474 int main(int argc, char **argv)
475 {
476         char *commit_id;
477         char *url;
478         int arg = 1;
479
480         while (arg < argc && argv[arg][0] == '-') {
481                 if (argv[arg][1] == 't') {
482                         get_tree = 1;
483                 } else if (argv[arg][1] == 'c') {
484                         get_history = 1;
485                 } else if (argv[arg][1] == 'a') {
486                         get_all = 1;
487                         get_tree = 1;
488                         get_history = 1;
489                 } else if (argv[arg][1] == 'v') {
490                         get_verbosely = 1;
491                 } else if (argv[arg][1] == 'w') {
492                         write_ref = argv[arg + 1];
493                         arg++;
494                 }
495                 arg++;
496         }
497         if (argc < arg + 2) {
498                 usage("git-http-fetch [-c] [-t] [-a] [-d] [-v] [--recover] [-w ref] commit-id url");
499                 return 1;
500         }
501         commit_id = argv[arg];
502         url = argv[arg + 1];
503
504         curl_global_init(CURL_GLOBAL_ALL);
505
506         curl = curl_easy_init();
507         no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
508
509         curl_ssl_verify = getenv("GIT_SSL_NO_VERIFY") ? 0 : 1;
510         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, curl_ssl_verify);
511 #if LIBCURL_VERSION_NUM >= 0x070907
512         curl_easy_setopt(curl, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
513 #endif
514
515         alt = xmalloc(sizeof(*alt));
516         alt->base = url;
517         alt->got_indices = 0;
518         alt->packs = NULL;
519         alt->next = NULL;
520         initial_base = url;
521
522         if (pull(commit_id))
523                 return 1;
524
525         curl_slist_free_all(no_pragma_header);
526         curl_global_cleanup();
527         return 0;
528 }