ui-snapshot.c

   1 /* ui-snapshot.c: generate snapshot of a commit
   2  *
   3  * Copyright (C) 2006 Lars Hjemli
   4  * Copyright (C) 2012 Jason A. Donenfeld <Jason@zx2c4.com>
   5  *
   6  * Licensed under GNU General Public License v2
   7  *   (see COPYING for full license text)
   8  */
   9
  10 #include "cgit.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         argv_array_push(&argv, "snapshot");
  18         argv_array_push(&argv, format);
  19         if (prefix) {
  20                 argv_array_push(&argv, "--prefix");
  21                 argv_array_push(&argv, fmt("%s/", prefix));
  22         }
  23         argv_array_push(&argv, hex);
  24         return write_archive(argv.argc, argv.argv, NULL, 1, NULL, 0);
  25 }
  26
  27 static int write_tar_archive(const char *hex, const char *prefix)
  28 {
  29         return write_archive_type("--format=tar", hex, prefix);
  30 }
  31
  32 static int write_zip_archive(const char *hex, const char *prefix)
  33 {
  34         return write_archive_type("--format=zip", hex, prefix);
  35 }
  36
  37 static int write_compressed_tar_archive(const char *hex,
  38                                         const char *prefix,
  39                                         char *filter_argv[])
  40 {
  41         int rv;
  42         struct cgit_filter f;
  43
  44         f.cmd = filter_argv[0];
  45         f.argv = filter_argv;
  46         cgit_open_filter(&f);
  47         rv = write_tar_archive(hex, prefix);
  48         cgit_close_filter(&f);
  49         return rv;
  50 }
  51
  52 static int write_tar_gzip_archive(const char *hex, const char *prefix)
  53 {
  54         char *argv[] = { "gzip", "-n", NULL };
  55         return write_compressed_tar_archive(hex, prefix, argv);
  56 }
  57
  58 static int write_tar_bzip2_archive(const char *hex, const char *prefix)
  59 {
  60         char *argv[] = { "bzip2", NULL };
  61         return write_compressed_tar_archive(hex, prefix, argv);
  62 }
  63
  64 static int write_tar_xz_archive(const char *hex, const char *prefix)
  65 {
  66         char *argv[] = { "xz", NULL };
  67         return write_compressed_tar_archive(hex, prefix, argv);
  68 }
  69
  70 const struct cgit_snapshot_format cgit_snapshot_formats[] = {
  71         { ".zip", "application/x-zip", write_zip_archive, 0x01 },
  72         { ".tar.gz", "application/x-gzip", write_tar_gzip_archive, 0x02 },
  73         { ".tar.bz2", "application/x-bzip2", write_tar_bzip2_archive, 0x04 },
  74         { ".tar", "application/x-tar", write_tar_archive, 0x08 },
  75         { ".tar.xz", "application/x-xz", write_tar_xz_archive, 0x10 },
  76         { NULL }
  77 };
  78
  79 static const struct cgit_snapshot_format *get_format(const char *filename)
  80 {
  81         const struct cgit_snapshot_format *fmt;
  82         int fl, sl;
  83
  84         fl = strlen(filename);
  85         for (fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
  86                 sl = strlen(fmt->suffix);
  87                 if (sl >= fl)
  88                         continue;
  89                 if (!strcmp(fmt->suffix, filename + fl - sl))
  90                         return fmt;
  91         }
  92         return NULL;
  93 }
  94
  95 static int make_snapshot(const struct cgit_snapshot_format *format,
  96                          const char *hex, const char *prefix,
  97                          const char *filename)
  98 {
  99         unsigned char sha1[20];
 100
 101         if (get_sha1(hex, sha1)) {
 102                 cgit_print_error(fmt("Bad object id: %s", hex));
 103                 return 1;
 104         }
 105         if (!lookup_commit_reference(sha1)) {
 106                 cgit_print_error(fmt("Not a commit reference: %s", hex));
 107                 return 1;
 108         }
 109         ctx.page.mimetype = xstrdup(format->mimetype);
 110         ctx.page.filename = xstrdup(filename);
 111         cgit_print_http_headers(&ctx);
 112         format->write_func(hex, prefix);
 113         return 0;
 114 }
 115
 116 /* Try to guess the requested revision from the requested snapshot name.
 117  * First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
 118  * "cgit-0.7.2". If this is a valid commit object name we've got a winner.
 119  * Otherwise, if the snapshot name has a prefix matching the result from
 120  * repo_basename(), we strip the basename and any following '-' and '_'
 121  * characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
 122  * more. If this still isn't a valid commit object name, we check if pre-
 123  * pending a 'v' to the remaining snapshot name ("0.7.2" -> "v0.7.2") gives
 124  * us something valid.
 125  */
 126 static const char *get_ref_from_filename(const char *url, const char *filename,
 127                                          const struct cgit_snapshot_format *format)
 128 {
 129         const char *reponame;
 130         unsigned char sha1[20];
 131         char *snapshot;
 132
 133         snapshot = xstrdup(filename);
 134         snapshot[strlen(snapshot) - strlen(format->suffix)] = '\0';
 135
 136         if (get_sha1(snapshot, sha1) == 0)
 137                 return snapshot;
 138
 139         reponame = cgit_repobasename(url);
 140         if (prefixcmp(snapshot, reponame) == 0) {
 141                 snapshot += strlen(reponame);
 142                 while (snapshot && (*snapshot == '-' || *snapshot == '_'))
 143                         snapshot++;
 144         }
 145
 146         if (get_sha1(snapshot, sha1) == 0)
 147                 return snapshot;
 148
 149         snapshot = fmt("v%s", snapshot);
 150         if (get_sha1(snapshot, sha1) == 0)
 151                 return snapshot;
 152
 153         return NULL;
 154 }
 155
 156 static void show_error(char *msg)
 157 {
 158         ctx.page.mimetype = "text/html";
 159         cgit_print_http_headers(&ctx);
 160         cgit_print_docstart(&ctx);
 161         cgit_print_pageheader(&ctx);
 162         cgit_print_error(msg);
 163         cgit_print_docend();
 164 }
 165
 166 void cgit_print_snapshot(const char *head, const char *hex,
 167                          const char *filename, int snapshots, int dwim)
 168 {
 169         const struct cgit_snapshot_format* f;
 170         char *prefix = NULL;
 171
 172         if (!filename) {
 173                 show_error("No snapshot name specified");
 174                 return;
 175         }
 176
 177         f = get_format(filename);
 178         if (!f) {
 179                 show_error(xstrdup(fmt("Unsupported snapshot format: %s",
 180                                        filename)));
 181                 return;
 182         }
 183
 184         if (!hex && dwim) {
 185                 hex = get_ref_from_filename(ctx.repo->url, filename, f);
 186                 if (hex == NULL) {
 187                         html_status(404, "Not found", 0);
 188                         return;
 189                 }
 190                 prefix = xstrdup(filename);
 191                 prefix[strlen(filename) - strlen(f->suffix)] = '\0';
 192         }
 193
 194         if (!hex)
 195                 hex = head;
 196
 197         if (!prefix)
 198                 prefix = xstrdup(cgit_repobasename(ctx.repo->url));
 199
 200         make_snapshot(f, hex, prefix, filename);
 201         free(prefix);
 202 }