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 "ui-snapshot.h"
  12 #include "html.h"
  13 #include "ui-shared.h"
  14
  15 static int write_archive_type(const char *format, const char *hex, const char *prefix)
  16 {
  17         struct argv_array argv = ARGV_ARRAY_INIT;
  18         const char **nargv;
  19         char *user_home, *xdg_home;
  20         int result;
  21         argv_array_push(&argv, "snapshot");
  22         argv_array_push(&argv, format);
  23         if (prefix) {
  24                 struct strbuf buf = STRBUF_INIT;
  25                 strbuf_addstr(&buf, prefix);
  26                 strbuf_addch(&buf, '/');
  27                 argv_array_push(&argv, "--prefix");
  28                 argv_array_push(&argv, buf.buf);
  29                 strbuf_release(&buf);
  30         }
  31         argv_array_push(&argv, hex);
  32         /*
  33          * Now we need to copy the pointers to arguments into a new
  34          * structure because write_archive will rearrange its arguments
  35          * which may result in duplicated/missing entries causing leaks
  36          * or double-frees in argv_array_clear.
  37          */
  38         nargv = xmalloc(sizeof(char *) * (argv.argc + 1));
  39         /* argv_array guarantees a trailing NULL entry. */
  40         memcpy(nargv, argv.argv, sizeof(char *) * (argv.argc + 1));
  41
  42         user_home = getenv("HOME");
  43         xdg_home = getenv("XDG_CONFIG_HOME");
  44         unsetenv("HOME");
  45         unsetenv("XDG_CONFIG_HOME");
  46         result = write_archive(argv.argc, nargv, NULL, 1, NULL, 0);
  47         if (user_home)
  48                 setenv("HOME", user_home, 1);
  49         if (xdg_home)
  50                 setenv("XDG_CONFIG_HOME", xdg_home, 1);
  51         argv_array_clear(&argv);
  52         free(nargv);
  53         return result;
  54 }
  55
  56 static int write_tar_archive(const char *hex, const char *prefix)
  57 {
  58         return write_archive_type("--format=tar", hex, prefix);
  59 }
  60
  61 static int write_zip_archive(const char *hex, const char *prefix)
  62 {
  63         return write_archive_type("--format=zip", hex, prefix);
  64 }
  65
  66 static int write_compressed_tar_archive(const char *hex,
  67                                         const char *prefix,
  68                                         char *filter_argv[])
  69 {
  70         int rv;
  71         struct cgit_filter f;
  72
  73         f.cmd = filter_argv[0];
  74         f.argv = filter_argv;
  75         cgit_open_filter(&f);
  76         rv = write_tar_archive(hex, prefix);
  77         cgit_close_filter(&f);
  78         return rv;
  79 }
  80
  81 static int write_tar_gzip_archive(const char *hex, const char *prefix)
  82 {
  83         char *argv[] = { "gzip", "-n", NULL };
  84         return write_compressed_tar_archive(hex, prefix, argv);
  85 }
  86
  87 static int write_tar_bzip2_archive(const char *hex, const char *prefix)
  88 {
  89         char *argv[] = { "bzip2", NULL };
  90         return write_compressed_tar_archive(hex, prefix, argv);
  91 }
  92
  93 static int write_tar_xz_archive(const char *hex, const char *prefix)
  94 {
  95         char *argv[] = { "xz", NULL };
  96         return write_compressed_tar_archive(hex, prefix, argv);
  97 }
  98
  99 const struct cgit_snapshot_format cgit_snapshot_formats[] = {
 100         { ".zip", "application/x-zip", write_zip_archive, 0x01 },
 101         { ".tar.gz", "application/x-gzip", write_tar_gzip_archive, 0x02 },
 102         { ".tar.bz2", "application/x-bzip2", write_tar_bzip2_archive, 0x04 },
 103         { ".tar", "application/x-tar", write_tar_archive, 0x08 },
 104         { ".tar.xz", "application/x-xz", write_tar_xz_archive, 0x10 },
 105         { NULL }
 106 };
 107
 108 static const struct cgit_snapshot_format *get_format(const char *filename)
 109 {
 110         const struct cgit_snapshot_format *fmt;
 111         int fl, sl;
 112
 113         fl = strlen(filename);
 114         for (fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
 115                 sl = strlen(fmt->suffix);
 116                 if (sl >= fl)
 117                         continue;
 118                 if (!strcmp(fmt->suffix, filename + fl - sl))
 119                         return fmt;
 120         }
 121         return NULL;
 122 }
 123
 124 static int make_snapshot(const struct cgit_snapshot_format *format,
 125                          const char *hex, const char *prefix,
 126                          const char *filename)
 127 {
 128         unsigned char sha1[20];
 129
 130         if (get_sha1(hex, sha1)) {
 131                 cgit_print_error("Bad object id: %s", hex);
 132                 return 1;
 133         }
 134         if (!lookup_commit_reference(sha1)) {
 135                 cgit_print_error("Not a commit reference: %s", hex);
 136                 return 1;
 137         }
 138         ctx.page.mimetype = xstrdup(format->mimetype);
 139         ctx.page.filename = xstrdup(filename);
 140         cgit_print_http_headers(&ctx);
 141         format->write_func(hex, prefix);
 142         return 0;
 143 }
 144
 145 /* Try to guess the requested revision from the requested snapshot name.
 146  * First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
 147  * "cgit-0.7.2". If this is a valid commit object name we've got a winner.
 148  * Otherwise, if the snapshot name has a prefix matching the result from
 149  * repo_basename(), we strip the basename and any following '-' and '_'
 150  * characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
 151  * more. If this still isn't a valid commit object name, we check if pre-
 152  * pending a 'v' or a 'V' to the remaining snapshot name ("0.7.2" ->
 153  * "v0.7.2") gives us something valid.
 154  */
 155 static const char *get_ref_from_filename(const char *url, const char *filename,
 156                                          const struct cgit_snapshot_format *format)
 157 {
 158         const char *reponame;
 159         unsigned char sha1[20];
 160         struct strbuf snapshot = STRBUF_INIT;
 161         int result = 1;
 162
 163         strbuf_addstr(&snapshot, filename);
 164         strbuf_setlen(&snapshot, snapshot.len - strlen(format->suffix));
 165
 166         if (get_sha1(snapshot.buf, sha1) == 0)
 167                 goto out;
 168
 169         reponame = cgit_repobasename(url);
 170         if (prefixcmp(snapshot.buf, reponame) == 0) {
 171                 const char *new_start = snapshot.buf;
 172                 new_start += strlen(reponame);
 173                 while (new_start && (*new_start == '-' || *new_start == '_'))
 174                         new_start++;
 175                 strbuf_splice(&snapshot, 0, new_start - snapshot.buf, "", 0);
 176         }
 177
 178         if (get_sha1(snapshot.buf, sha1) == 0)
 179                 goto out;
 180
 181         strbuf_insert(&snapshot, 0, "v", 1);
 182         if (get_sha1(snapshot.buf, sha1) == 0)
 183                 goto out;
 184
 185         strbuf_splice(&snapshot, 0, 1, "V", 1);
 186         if (get_sha1(snapshot.buf, sha1) == 0)
 187                 goto out;
 188
 189         result = 0;
 190         strbuf_release(&snapshot);
 191
 192 out:
 193         return result ? strbuf_detach(&snapshot, NULL) : NULL;
 194 }
 195
 196 __attribute__((format (printf, 1, 2)))
 197 static void show_error(char *fmt, ...)
 198 {
 199         va_list ap;
 200
 201         ctx.page.mimetype = "text/html";
 202         cgit_print_http_headers(&ctx);
 203         cgit_print_docstart(&ctx);
 204         cgit_print_pageheader(&ctx);
 205         va_start(ap, fmt);
 206         cgit_vprint_error(fmt, ap);
 207         va_end(ap);
 208         cgit_print_docend();
 209 }
 210
 211 void cgit_print_snapshot(const char *head, const char *hex,
 212                          const char *filename, int snapshots, int dwim)
 213 {
 214         const struct cgit_snapshot_format* f;
 215         char *prefix = NULL;
 216
 217         if (!filename) {
 218                 show_error("No snapshot name specified");
 219                 return;
 220         }
 221
 222         f = get_format(filename);
 223         if (!f) {
 224                 show_error("Unsupported snapshot format: %s", filename);
 225                 return;
 226         }
 227
 228         if (!hex && dwim) {
 229                 hex = get_ref_from_filename(ctx.repo->url, filename, f);
 230                 if (hex == NULL) {
 231                         html_status(404, "Not found", 0);
 232                         return;
 233                 }
 234                 prefix = xstrdup(filename);
 235                 prefix[strlen(filename) - strlen(f->suffix)] = '\0';
 236         }
 237
 238         if (!hex)
 239                 hex = head;
 240
 241         if (!prefix)
 242                 prefix = xstrdup(cgit_repobasename(ctx.repo->url));
 243
 244         make_snapshot(f, hex, prefix, filename);
 245         free(prefix);
 246 }