ui-snapshot.c

   1 /* ui-snapshot.c: generate snapshot of a commit
   2  *
   3  * Copyright (C) 2006-2014 cgit Development Team <cgit@lists.zx2c4.com>
   4  *
   5  * Licensed under GNU General Public License v2
   6  *   (see COPYING for full license text)
   7  */
   8
   9 #include "cgit.h"
  10 #include "ui-snapshot.h"
  11 #include "html.h"
  12 #include "ui-shared.h"
  13
  14 static int write_archive_type(const char *format, const char *hex, const char *prefix)
  15 {
  16         struct argv_array argv = ARGV_ARRAY_INIT;
  17         const char **nargv;
  18         int result;
  19         argv_array_push(&argv, "snapshot");
  20         argv_array_push(&argv, format);
  21         if (prefix) {
  22                 struct strbuf buf = STRBUF_INIT;
  23                 strbuf_addstr(&buf, prefix);
  24                 strbuf_addch(&buf, '/');
  25                 argv_array_push(&argv, "--prefix");
  26                 argv_array_push(&argv, buf.buf);
  27                 strbuf_release(&buf);
  28         }
  29         argv_array_push(&argv, hex);
  30         /*
  31          * Now we need to copy the pointers to arguments into a new
  32          * structure because write_archive will rearrange its arguments
  33          * which may result in duplicated/missing entries causing leaks
  34          * or double-frees in argv_array_clear.
  35          */
  36         nargv = xmalloc(sizeof(char *) * (argv.argc + 1));
  37         /* argv_array guarantees a trailing NULL entry. */
  38         memcpy(nargv, argv.argv, sizeof(char *) * (argv.argc + 1));
  39
  40         result = write_archive(argv.argc, nargv, NULL, NULL, 0);
  41         argv_array_clear(&argv);
  42         free(nargv);
  43         return result;
  44 }
  45
  46 static int write_tar_archive(const char *hex, const char *prefix)
  47 {
  48         return write_archive_type("--format=tar", hex, prefix);
  49 }
  50
  51 static int write_zip_archive(const char *hex, const char *prefix)
  52 {
  53         return write_archive_type("--format=zip", hex, prefix);
  54 }
  55
  56 static int write_compressed_tar_archive(const char *hex,
  57                                         const char *prefix,
  58                                         char *filter_argv[])
  59 {
  60         int rv;
  61         struct cgit_exec_filter f;
  62         cgit_exec_filter_init(&f, filter_argv[0], filter_argv);
  63
  64         cgit_open_filter(&f.base);
  65         rv = write_tar_archive(hex, prefix);
  66         cgit_close_filter(&f.base);
  67         return rv;
  68 }
  69
  70 static int write_tar_gzip_archive(const char *hex, const char *prefix)
  71 {
  72         char *argv[] = { "gzip", "-n", NULL };
  73         return write_compressed_tar_archive(hex, prefix, argv);
  74 }
  75
  76 static int write_tar_bzip2_archive(const char *hex, const char *prefix)
  77 {
  78         char *argv[] = { "bzip2", NULL };
  79         return write_compressed_tar_archive(hex, prefix, argv);
  80 }
  81
  82 static int write_tar_xz_archive(const char *hex, const char *prefix)
  83 {
  84         char *argv[] = { "xz", NULL };
  85         return write_compressed_tar_archive(hex, prefix, argv);
  86 }
  87
  88 const struct cgit_snapshot_format cgit_snapshot_formats[] = {
  89         { ".tar",       "application/x-tar",    write_tar_archive       },
  90         { ".tar.gz",    "application/x-gzip",   write_tar_gzip_archive  },
  91         { ".tar.bz2",   "application/x-bzip2",  write_tar_bzip2_archive },
  92         { ".tar.xz",    "application/x-xz",     write_tar_xz_archive    },
  93         { ".zip",       "application/x-zip",    write_zip_archive       },
  94         { NULL }
  95 };
  96
  97 static struct notes_tree snapshot_sig_notes[ARRAY_SIZE(cgit_snapshot_formats)];
  98
  99 const struct object_id *cgit_snapshot_get_sig(const char *ref,
 100                                               const struct cgit_snapshot_format *f)
 101 {
 102         struct notes_tree *tree;
 103         struct object_id oid;
 104
 105         if (get_oid(ref, &oid))
 106                 return NULL;
 107
 108         tree = &snapshot_sig_notes[f - &cgit_snapshot_formats[0]];
 109         if (!tree->initialized) {
 110                 struct strbuf notes_ref = STRBUF_INIT;
 111
 112                 strbuf_addf(&notes_ref, "refs/notes/signatures/%s",
 113                             f->suffix + 1);
 114
 115                 init_notes(tree, notes_ref.buf, combine_notes_ignore, 0);
 116                 strbuf_release(&notes_ref);
 117         }
 118
 119         return get_note(tree, &oid);
 120 }
 121
 122 static const struct cgit_snapshot_format *get_format(const char *filename)
 123 {
 124         const struct cgit_snapshot_format *fmt;
 125
 126         for (fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
 127                 if (ends_with(filename, fmt->suffix))
 128                         return fmt;
 129         }
 130         return NULL;
 131 }
 132
 133 const unsigned cgit_snapshot_format_bit(const struct cgit_snapshot_format *f)
 134 {
 135         return BIT(f - &cgit_snapshot_formats[0]);
 136 }
 137
 138 static int make_snapshot(const struct cgit_snapshot_format *format,
 139                          const char *hex, const char *prefix,
 140                          const char *filename)
 141 {
 142         struct object_id oid;
 143
 144         if (get_oid(hex, &oid)) {
 145                 cgit_print_error_page(404, "Not found",
 146                                 "Bad object id: %s", hex);
 147                 return 1;
 148         }
 149         if (!lookup_commit_reference(&oid)) {
 150                 cgit_print_error_page(400, "Bad request",
 151                                 "Not a commit reference: %s", hex);
 152                 return 1;
 153         }
 154         ctx.page.etag = oid_to_hex(&oid);
 155         ctx.page.mimetype = xstrdup(format->mimetype);
 156         ctx.page.filename = xstrdup(filename);
 157         cgit_print_http_headers();
 158         format->write_func(hex, prefix);
 159         return 0;
 160 }
 161
 162 static int write_sig(const struct cgit_snapshot_format *format,
 163                      const char *hex, const char *archive,
 164                      const char *filename)
 165 {
 166         const struct object_id *note = cgit_snapshot_get_sig(hex, format);
 167         enum object_type type;
 168         unsigned long size;
 169         char *buf;
 170
 171         if (!note) {
 172                 cgit_print_error_page(404, "Not found",
 173                                 "No signature for %s", archive);
 174                 return 0;
 175         }
 176
 177         buf = read_object_file(note, &type, &size);
 178         if (!buf) {
 179                 cgit_print_error_page(404, "Not found", "Not found");
 180                 return 0;
 181         }
 182
 183         html("X-Content-Type-Options: nosniff\n");
 184         html("Content-Security-Policy: default-src 'none'\n");
 185         ctx.page.etag = oid_to_hex(note);
 186         ctx.page.mimetype = xstrdup("application/pgp-signature");
 187         ctx.page.filename = xstrdup(filename);
 188         cgit_print_http_headers();
 189
 190         html_raw(buf, size);
 191         free(buf);
 192         return 0;
 193 }
 194
 195 /* Try to guess the requested revision from the requested snapshot name.
 196  * First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
 197  * "cgit-0.7.2". If this is a valid commit object name we've got a winner.
 198  * Otherwise, if the snapshot name has a prefix matching the result from
 199  * repo_basename(), we strip the basename and any following '-' and '_'
 200  * characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
 201  * more. If this still isn't a valid commit object name, we check if pre-
 202  * pending a 'v' or a 'V' to the remaining snapshot name ("0.7.2" ->
 203  * "v0.7.2") gives us something valid.
 204  */
 205 static const char *get_ref_from_filename(const struct cgit_repo *repo,
 206                                          const char *filename,
 207                                          const struct cgit_snapshot_format *format)
 208 {
 209         const char *reponame;
 210         struct object_id oid;
 211         struct strbuf snapshot = STRBUF_INIT;
 212         int result = 1;
 213
 214         strbuf_addstr(&snapshot, filename);
 215         strbuf_setlen(&snapshot, snapshot.len - strlen(format->suffix));
 216
 217         if (get_oid(snapshot.buf, &oid) == 0)
 218                 goto out;
 219
 220         reponame = cgit_snapshot_prefix(repo);
 221         if (starts_with(snapshot.buf, reponame)) {
 222                 const char *new_start = snapshot.buf;
 223                 new_start += strlen(reponame);
 224                 while (new_start && (*new_start == '-' || *new_start == '_'))
 225                         new_start++;
 226                 strbuf_splice(&snapshot, 0, new_start - snapshot.buf, "", 0);
 227         }
 228
 229         if (get_oid(snapshot.buf, &oid) == 0)
 230                 goto out;
 231
 232         strbuf_insert(&snapshot, 0, "v", 1);
 233         if (get_oid(snapshot.buf, &oid) == 0)
 234                 goto out;
 235
 236         strbuf_splice(&snapshot, 0, 1, "V", 1);
 237         if (get_oid(snapshot.buf, &oid) == 0)
 238                 goto out;
 239
 240         result = 0;
 241         strbuf_release(&snapshot);
 242
 243 out:
 244         return result ? strbuf_detach(&snapshot, NULL) : NULL;
 245 }
 246
 247 void cgit_print_snapshot(const char *head, const char *hex,
 248                          const char *filename, int dwim)
 249 {
 250         const struct cgit_snapshot_format* f;
 251         const char *sig_filename = NULL;
 252         char *adj_filename = NULL;
 253         char *prefix = NULL;
 254
 255         if (!filename) {
 256                 cgit_print_error_page(400, "Bad request",
 257                                 "No snapshot name specified");
 258                 return;
 259         }
 260
 261         if (ends_with(filename, ".asc")) {
 262                 sig_filename = filename;
 263
 264                 /* Strip ".asc" from filename for common format processing */
 265                 adj_filename = xstrdup(filename);
 266                 adj_filename[strlen(adj_filename) - 4] = '\0';
 267                 filename = adj_filename;
 268         }
 269
 270         f = get_format(filename);
 271         if (!f || !(ctx.repo->snapshots & cgit_snapshot_format_bit(f))) {
 272                 cgit_print_error_page(400, "Bad request",
 273                                 "Unsupported snapshot format: %s", filename);
 274                 return;
 275         }
 276
 277         if (!hex && dwim) {
 278                 hex = get_ref_from_filename(ctx.repo, filename, f);
 279                 if (hex == NULL) {
 280                         cgit_print_error_page(404, "Not found", "Not found");
 281                         return;
 282                 }
 283                 prefix = xstrdup(filename);
 284                 prefix[strlen(filename) - strlen(f->suffix)] = '\0';
 285         }
 286
 287         if (!hex)
 288                 hex = head;
 289
 290         if (!prefix)
 291                 prefix = xstrdup(cgit_snapshot_prefix(ctx.repo));
 292
 293         if (sig_filename)
 294                 write_sig(f, hex, filename, sig_filename);
 295         else
 296                 make_snapshot(f, hex, prefix, filename);
 297
 298         free(prefix);
 299         free(adj_filename);
 300 }