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, 1, 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         { ".zip", "application/x-zip", write_zip_archive, 0x01 },
  90         { ".tar.gz", "application/x-gzip", write_tar_gzip_archive, 0x02 },
  91         { ".tar.bz2", "application/x-bzip2", write_tar_bzip2_archive, 0x04 },
  92         { ".tar", "application/x-tar", write_tar_archive, 0x08 },
  93         { ".tar.xz", "application/x-xz", write_tar_xz_archive, 0x10 },
  94         { NULL }
  95 };
  96
  97 static const struct cgit_snapshot_format *get_format(const char *filename)
  98 {
  99         const struct cgit_snapshot_format *fmt;
 100
 101         for (fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
 102                 if (ends_with(filename, fmt->suffix))
 103                         return fmt;
 104         }
 105         return NULL;
 106 }
 107
 108 static int make_snapshot(const struct cgit_snapshot_format *format,
 109                          const char *hex, const char *prefix,
 110                          const char *filename)
 111 {
 112         unsigned char sha1[20];
 113
 114         if (get_sha1(hex, sha1)) {
 115                 cgit_print_error_page(404, "Not found",
 116                                 "Bad object id: %s", hex);
 117                 return 1;
 118         }
 119         if (!lookup_commit_reference(sha1)) {
 120                 cgit_print_error_page(400, "Bad request",
 121                                 "Not a commit reference: %s", hex);
 122                 return 1;
 123         }
 124         ctx.page.etag = sha1_to_hex(sha1);
 125         ctx.page.mimetype = xstrdup(format->mimetype);
 126         ctx.page.filename = xstrdup(filename);
 127         cgit_print_http_headers();
 128         format->write_func(hex, prefix);
 129         return 0;
 130 }
 131
 132 /* Try to guess the requested revision from the requested snapshot name.
 133  * First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
 134  * "cgit-0.7.2". If this is a valid commit object name we've got a winner.
 135  * Otherwise, if the snapshot name has a prefix matching the result from
 136  * repo_basename(), we strip the basename and any following '-' and '_'
 137  * characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
 138  * more. If this still isn't a valid commit object name, we check if pre-
 139  * pending a 'v' or a 'V' to the remaining snapshot name ("0.7.2" ->
 140  * "v0.7.2") gives us something valid.
 141  */
 142 static const char *get_ref_from_filename(const char *url, const char *filename,
 143                                          const struct cgit_snapshot_format *format)
 144 {
 145         const char *reponame;
 146         unsigned char sha1[20];
 147         struct strbuf snapshot = STRBUF_INIT;
 148         int result = 1;
 149
 150         strbuf_addstr(&snapshot, filename);
 151         strbuf_setlen(&snapshot, snapshot.len - strlen(format->suffix));
 152
 153         if (get_sha1(snapshot.buf, sha1) == 0)
 154                 goto out;
 155
 156         reponame = cgit_repobasename(url);
 157         if (starts_with(snapshot.buf, reponame)) {
 158                 const char *new_start = snapshot.buf;
 159                 new_start += strlen(reponame);
 160                 while (new_start && (*new_start == '-' || *new_start == '_'))
 161                         new_start++;
 162                 strbuf_splice(&snapshot, 0, new_start - snapshot.buf, "", 0);
 163         }
 164
 165         if (get_sha1(snapshot.buf, sha1) == 0)
 166                 goto out;
 167
 168         strbuf_insert(&snapshot, 0, "v", 1);
 169         if (get_sha1(snapshot.buf, sha1) == 0)
 170                 goto out;
 171
 172         strbuf_splice(&snapshot, 0, 1, "V", 1);
 173         if (get_sha1(snapshot.buf, sha1) == 0)
 174                 goto out;
 175
 176         result = 0;
 177         strbuf_release(&snapshot);
 178
 179 out:
 180         return result ? strbuf_detach(&snapshot, NULL) : NULL;
 181 }
 182
 183 void cgit_print_snapshot(const char *head, const char *hex,
 184                          const char *filename, int dwim)
 185 {
 186         const struct cgit_snapshot_format* f;
 187         char *prefix = NULL;
 188
 189         if (!filename) {
 190                 cgit_print_error_page(400, "Bad request",
 191                                 "No snapshot name specified");
 192                 return;
 193         }
 194
 195         f = get_format(filename);
 196         if (!f) {
 197                 cgit_print_error_page(400, "Bad request",
 198                                 "Unsupported snapshot format: %s", filename);
 199                 return;
 200         }
 201
 202         if (!hex && dwim) {
 203                 hex = get_ref_from_filename(ctx.repo->url, filename, f);
 204                 if (hex == NULL) {
 205                         cgit_print_error_page(404, "Not found", "Not found");
 206                         return;
 207                 }
 208                 prefix = xstrdup(filename);
 209                 prefix[strlen(filename) - strlen(f->suffix)] = '\0';
 210         }
 211
 212         if (!hex)
 213                 hex = head;
 214
 215         if (!prefix)
 216                 prefix = xstrdup(cgit_repobasename(ctx.repo->url));
 217
 218         make_snapshot(f, hex, prefix, filename);
 219         free(prefix);
 220 }