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, the_repository, 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 must remain the 0 index */
  90         { ".tar",       "application/x-tar",    write_tar_archive       },
  91         { ".tar.gz",    "application/x-gzip",   write_tar_gzip_archive  },
  92         { ".tar.bz2",   "application/x-bzip2",  write_tar_bzip2_archive },
  93         { ".tar.xz",    "application/x-xz",     write_tar_xz_archive    },
  94         { ".zip",       "application/x-zip",    write_zip_archive       },
  95         { NULL }
  96 };
  97
  98 static struct notes_tree snapshot_sig_notes[ARRAY_SIZE(cgit_snapshot_formats)];
  99
 100 const struct object_id *cgit_snapshot_get_sig(const char *ref,
 101                                               const struct cgit_snapshot_format *f)
 102 {
 103         struct notes_tree *tree;
 104         struct object_id oid;
 105
 106         if (get_oid(ref, &oid))
 107                 return NULL;
 108
 109         tree = &snapshot_sig_notes[f - &cgit_snapshot_formats[0]];
 110         if (!tree->initialized) {
 111                 struct strbuf notes_ref = STRBUF_INIT;
 112
 113                 strbuf_addf(&notes_ref, "refs/notes/signatures/%s",
 114                             f->suffix + 1);
 115
 116                 init_notes(tree, notes_ref.buf, combine_notes_ignore, 0);
 117                 strbuf_release(&notes_ref);
 118         }
 119
 120         return get_note(tree, &oid);
 121 }
 122
 123 static const struct cgit_snapshot_format *get_format(const char *filename)
 124 {
 125         const struct cgit_snapshot_format *fmt;
 126
 127         for (fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
 128                 if (ends_with(filename, fmt->suffix))
 129                         return fmt;
 130         }
 131         return NULL;
 132 }
 133
 134 const unsigned cgit_snapshot_format_bit(const struct cgit_snapshot_format *f)
 135 {
 136         return BIT(f - &cgit_snapshot_formats[0]);
 137 }
 138
 139 static int make_snapshot(const struct cgit_snapshot_format *format,
 140                          const char *hex, const char *prefix,
 141                          const char *filename)
 142 {
 143         struct object_id oid;
 144
 145         if (get_oid(hex, &oid)) {
 146                 cgit_print_error_page(404, "Not found",
 147                                 "Bad object id: %s", hex);
 148                 return 1;
 149         }
 150         if (!lookup_commit_reference(the_repository, &oid)) {
 151                 cgit_print_error_page(400, "Bad request",
 152                                 "Not a commit reference: %s", hex);
 153                 return 1;
 154         }
 155         ctx.page.etag = oid_to_hex(&oid);
 156         ctx.page.mimetype = xstrdup(format->mimetype);
 157         ctx.page.filename = xstrdup(filename);
 158         cgit_print_http_headers();
 159         init_archivers();
 160         format->write_func(hex, prefix);
 161         return 0;
 162 }
 163
 164 static int write_sig(const struct cgit_snapshot_format *format,
 165                      const char *hex, const char *archive,
 166                      const char *filename)
 167 {
 168         const struct object_id *note = cgit_snapshot_get_sig(hex, format);
 169         enum object_type type;
 170         unsigned long size;
 171         char *buf;
 172
 173         if (!note) {
 174                 cgit_print_error_page(404, "Not found",
 175                                 "No signature for %s", archive);
 176                 return 0;
 177         }
 178
 179         buf = read_object_file(note, &type, &size);
 180         if (!buf) {
 181                 cgit_print_error_page(404, "Not found", "Not found");
 182                 return 0;
 183         }
 184
 185         html("X-Content-Type-Options: nosniff\n");
 186         html("Content-Security-Policy: default-src 'none'\n");
 187         ctx.page.etag = oid_to_hex(note);
 188         ctx.page.mimetype = xstrdup("application/pgp-signature");
 189         ctx.page.filename = xstrdup(filename);
 190         cgit_print_http_headers();
 191
 192         html_raw(buf, size);
 193         free(buf);
 194         return 0;
 195 }
 196
 197 /* Try to guess the requested revision from the requested snapshot name.
 198  * First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
 199  * "cgit-0.7.2". If this is a valid commit object name we've got a winner.
 200  * Otherwise, if the snapshot name has a prefix matching the result from
 201  * repo_basename(), we strip the basename and any following '-' and '_'
 202  * characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
 203  * more. If this still isn't a valid commit object name, we check if pre-
 204  * pending a 'v' or a 'V' to the remaining snapshot name ("0.7.2" ->
 205  * "v0.7.2") gives us something valid.
 206  */
 207 static const char *get_ref_from_filename(const struct cgit_repo *repo,
 208                                          const char *filename,
 209                                          const struct cgit_snapshot_format *format)
 210 {
 211         const char *reponame;
 212         struct object_id oid;
 213         struct strbuf snapshot = STRBUF_INIT;
 214         int result = 1;
 215
 216         strbuf_addstr(&snapshot, filename);
 217         strbuf_setlen(&snapshot, snapshot.len - strlen(format->suffix));
 218
 219         if (get_oid(snapshot.buf, &oid) == 0)
 220                 goto out;
 221
 222         reponame = cgit_snapshot_prefix(repo);
 223         if (starts_with(snapshot.buf, reponame)) {
 224                 const char *new_start = snapshot.buf;
 225                 new_start += strlen(reponame);
 226                 while (new_start && (*new_start == '-' || *new_start == '_'))
 227                         new_start++;
 228                 strbuf_splice(&snapshot, 0, new_start - snapshot.buf, "", 0);
 229         }
 230
 231         if (get_oid(snapshot.buf, &oid) == 0)
 232                 goto out;
 233
 234         strbuf_insert(&snapshot, 0, "v", 1);
 235         if (get_oid(snapshot.buf, &oid) == 0)
 236                 goto out;
 237
 238         strbuf_splice(&snapshot, 0, 1, "V", 1);
 239         if (get_oid(snapshot.buf, &oid) == 0)
 240                 goto out;
 241
 242         result = 0;
 243         strbuf_release(&snapshot);
 244
 245 out:
 246         return result ? strbuf_detach(&snapshot, NULL) : NULL;
 247 }
 248
 249 void cgit_print_snapshot(const char *head, const char *hex,
 250                          const char *filename, int dwim)
 251 {
 252         const struct cgit_snapshot_format* f;
 253         const char *sig_filename = NULL;
 254         char *adj_filename = NULL;
 255         char *prefix = NULL;
 256
 257         if (!filename) {
 258                 cgit_print_error_page(400, "Bad request",
 259                                 "No snapshot name specified");
 260                 return;
 261         }
 262
 263         if (ends_with(filename, ".asc")) {
 264                 sig_filename = filename;
 265
 266                 /* Strip ".asc" from filename for common format processing */
 267                 adj_filename = xstrdup(filename);
 268                 adj_filename[strlen(adj_filename) - 4] = '\0';
 269                 filename = adj_filename;
 270         }
 271
 272         f = get_format(filename);
 273         if (!f || (!sig_filename && !(ctx.repo->snapshots & cgit_snapshot_format_bit(f)))) {
 274                 cgit_print_error_page(400, "Bad request",
 275                                 "Unsupported snapshot format: %s", filename);
 276                 return;
 277         }
 278
 279         if (!hex && dwim) {
 280                 hex = get_ref_from_filename(ctx.repo, filename, f);
 281                 if (hex == NULL) {
 282                         cgit_print_error_page(404, "Not found", "Not found");
 283                         return;
 284                 }
 285                 prefix = xstrdup(filename);
 286                 prefix[strlen(filename) - strlen(f->suffix)] = '\0';
 287         }
 288
 289         if (!hex)
 290                 hex = head;
 291
 292         if (!prefix)
 293                 prefix = xstrdup(cgit_snapshot_prefix(ctx.repo));
 294
 295         if (sig_filename)
 296                 write_sig(f, hex, filename, sig_filename);
 297         else
 298                 make_snapshot(f, hex, prefix, filename);
 299
 300         free(prefix);
 301         free(adj_filename);
 302 }