| 1 | /* |
| 2 | * Example implementation for the Git filter protocol version 2 |
| 3 | * See Documentation/gitattributes.adoc, section "Filter Protocol" |
| 4 | * |
| 5 | * Usage: test-tool rot13-filter [--always-delay] --log=<path> <capabilities> |
| 6 | * |
| 7 | * Log path defines a debug log file that the script writes to. The |
| 8 | * subsequent arguments define a list of supported protocol capabilities |
| 9 | * ("clean", "smudge", etc). |
| 10 | * |
| 11 | * When --always-delay is given all pathnames with the "can-delay" flag |
| 12 | * that don't appear on the list below are delayed with a count of 1 |
| 13 | * (see more below). |
| 14 | * |
| 15 | * This implementation supports special test cases: |
| 16 | * (1) If data with the pathname "clean-write-fail.r" is processed with |
| 17 | * a "clean" operation then the write operation will die. |
| 18 | * (2) If data with the pathname "smudge-write-fail.r" is processed with |
| 19 | * a "smudge" operation then the write operation will die. |
| 20 | * (3) If data with the pathname "error.r" is processed with any |
| 21 | * operation then the filter signals that it cannot or does not want |
| 22 | * to process the file. |
| 23 | * (4) If data with the pathname "abort.r" is processed with any |
| 24 | * operation then the filter signals that it cannot or does not want |
| 25 | * to process the file and any file after that is processed with the |
| 26 | * same command. |
| 27 | * (5) If data with a pathname that is a key in the delay hash is |
| 28 | * requested (e.g. "test-delay10.a") then the filter responds with |
| 29 | * a "delay" status and sets the "requested" field in the delay hash. |
| 30 | * The filter will signal the availability of this object after |
| 31 | * "count" (field in delay hash) "list_available_blobs" commands. |
| 32 | * (6) If data with the pathname "missing-delay.a" is processed that the |
| 33 | * filter will drop the path from the "list_available_blobs" response. |
| 34 | * (7) If data with the pathname "invalid-delay.a" is processed that the |
| 35 | * filter will add the path "unfiltered" which was not delayed before |
| 36 | * to the "list_available_blobs" response. |
| 37 | */ |
| 38 | |
| 39 | #include "test-tool.h" |
| 40 | #include "pkt-line.h" |
| 41 | #include "string-list.h" |
| 42 | #include "strmap.h" |
| 43 | #include "parse-options.h" |
| 44 | |
| 45 | static FILE *logfile; |
| 46 | static int always_delay, has_clean_cap, has_smudge_cap; |
| 47 | static struct strmap delay = STRMAP_INIT; |
| 48 | |
| 49 | static inline const char *str_or_null(const char *str) |
| 50 | { |
| 51 | return str ? str : "(null)"; |
| 52 | } |
| 53 | |
| 54 | static char *rot13(char *str) |
| 55 | { |
| 56 | char *c; |
| 57 | for (c = str; *c; c++) |
| 58 | if (isalpha(*c)) |
| 59 | *c += tolower(*c) < 'n' ? 13 : -13; |
| 60 | return str; |
| 61 | } |
| 62 | |
| 63 | static char *get_value(char *buf, const char *key) |
| 64 | { |
| 65 | const char *orig_buf = buf; |
| 66 | if (!buf || |
| 67 | !skip_prefix((const char *)buf, key, (const char **)&buf) || |
| 68 | !skip_prefix((const char *)buf, "=", (const char **)&buf) || |
| 69 | !*buf) |
| 70 | die("expected key '%s', got '%s'", key, str_or_null(orig_buf)); |
| 71 | return buf; |
| 72 | } |
| 73 | |
| 74 | /* |
| 75 | * Read a text packet, expecting that it is in the form "key=value" for |
| 76 | * the given key. An EOF does not trigger any error and is reported |
| 77 | * back to the caller with NULL. Die if the "key" part of "key=value" does |
| 78 | * not match the given key, or the value part is empty. |
| 79 | */ |
| 80 | static char *packet_key_val_read(const char *key) |
| 81 | { |
| 82 | char *buf; |
| 83 | if (packet_read_line_gently(0, NULL, &buf) < 0) |
| 84 | return NULL; |
| 85 | return xstrdup(get_value(buf, key)); |
| 86 | } |
| 87 | |
| 88 | static inline void assert_remote_capability(struct strset *caps, const char *cap) |
| 89 | { |
| 90 | if (!strset_contains(caps, cap)) |
| 91 | die("required '%s' capability not available from remote", cap); |
| 92 | } |
| 93 | |
| 94 | static void read_capabilities(struct strset *remote_caps) |
| 95 | { |
| 96 | for (;;) { |
| 97 | char *buf = packet_read_line(0, NULL); |
| 98 | if (!buf) |
| 99 | break; |
| 100 | strset_add(remote_caps, get_value(buf, "capability")); |
| 101 | } |
| 102 | |
| 103 | assert_remote_capability(remote_caps, "clean"); |
| 104 | assert_remote_capability(remote_caps, "smudge"); |
| 105 | assert_remote_capability(remote_caps, "delay"); |
| 106 | } |
| 107 | |
| 108 | static void check_and_write_capabilities(struct strset *remote_caps, |
| 109 | const char **caps, int nr_caps) |
| 110 | { |
| 111 | int i; |
| 112 | for (i = 0; i < nr_caps; i++) { |
| 113 | if (!strset_contains(remote_caps, caps[i])) |
| 114 | die("our capability '%s' is not available from remote", |
| 115 | caps[i]); |
| 116 | packet_write_fmt(1, "capability=%s\n", caps[i]); |
| 117 | } |
| 118 | packet_flush(1); |
| 119 | } |
| 120 | |
| 121 | struct delay_entry { |
| 122 | int requested, count; |
| 123 | char *output; |
| 124 | }; |
| 125 | |
| 126 | static void free_delay_entries(void) |
| 127 | { |
| 128 | struct hashmap_iter iter; |
| 129 | struct strmap_entry *ent; |
| 130 | |
| 131 | strmap_for_each_entry(&delay, &iter, ent) { |
| 132 | struct delay_entry *delay_entry = ent->value; |
| 133 | free(delay_entry->output); |
| 134 | free(delay_entry); |
| 135 | } |
| 136 | strmap_clear(&delay, 0); |
| 137 | } |
| 138 | |
| 139 | static void add_delay_entry(const char *pathname, int count, int requested) |
| 140 | { |
| 141 | struct delay_entry *entry = xcalloc(1, sizeof(*entry)); |
| 142 | entry->count = count; |
| 143 | entry->requested = requested; |
| 144 | if (strmap_put(&delay, pathname, entry)) |
| 145 | BUG("adding the same path twice to delay hash?"); |
| 146 | } |
| 147 | |
| 148 | static void reply_list_available_blobs_cmd(void) |
| 149 | { |
| 150 | struct hashmap_iter iter; |
| 151 | struct strmap_entry *ent; |
| 152 | struct string_list_item *str_item; |
| 153 | struct string_list paths = STRING_LIST_INIT_NODUP; |
| 154 | |
| 155 | /* flush */ |
| 156 | if (packet_read_line(0, NULL)) |
| 157 | die("bad list_available_blobs end"); |
| 158 | |
| 159 | strmap_for_each_entry(&delay, &iter, ent) { |
| 160 | struct delay_entry *delay_entry = ent->value; |
| 161 | if (!delay_entry->requested) |
| 162 | continue; |
| 163 | delay_entry->count--; |
| 164 | if (!strcmp(ent->key, "invalid-delay.a")) { |
| 165 | /* Send Git a pathname that was not delayed earlier */ |
| 166 | packet_write_fmt(1, "pathname=unfiltered"); |
| 167 | } |
| 168 | if (!strcmp(ent->key, "missing-delay.a")) { |
| 169 | /* Do not signal Git that this file is available */ |
| 170 | } else if (!delay_entry->count) { |
| 171 | string_list_append(&paths, ent->key); |
| 172 | packet_write_fmt(1, "pathname=%s", ent->key); |
| 173 | } |
| 174 | } |
| 175 | |
| 176 | /* Print paths in sorted order. */ |
| 177 | string_list_sort(&paths); |
| 178 | for_each_string_list_item(str_item, &paths) |
| 179 | fprintf(logfile, " %s", str_item->string); |
| 180 | string_list_clear(&paths, 0); |
| 181 | |
| 182 | packet_flush(1); |
| 183 | |
| 184 | fprintf(logfile, " [OK]\n"); |
| 185 | packet_write_fmt(1, "status=success"); |
| 186 | packet_flush(1); |
| 187 | } |
| 188 | |
| 189 | static void command_loop(void) |
| 190 | { |
| 191 | for (;;) { |
| 192 | char *buf; |
| 193 | const char *output; |
| 194 | char *pathname; |
| 195 | struct delay_entry *entry; |
| 196 | struct strbuf input = STRBUF_INIT; |
| 197 | char *command = packet_key_val_read("command"); |
| 198 | |
| 199 | if (!command) { |
| 200 | fprintf(logfile, "STOP\n"); |
| 201 | break; |
| 202 | } |
| 203 | fprintf(logfile, "IN: %s", command); |
| 204 | |
| 205 | if (!strcmp(command, "list_available_blobs")) { |
| 206 | reply_list_available_blobs_cmd(); |
| 207 | free(command); |
| 208 | continue; |
| 209 | } |
| 210 | |
| 211 | pathname = packet_key_val_read("pathname"); |
| 212 | if (!pathname) |
| 213 | die("unexpected EOF while expecting pathname"); |
| 214 | fprintf(logfile, " %s", pathname); |
| 215 | |
| 216 | /* Read until flush */ |
| 217 | while ((buf = packet_read_line(0, NULL))) { |
| 218 | if (!strcmp(buf, "can-delay=1")) { |
| 219 | entry = strmap_get(&delay, pathname); |
| 220 | if (entry && !entry->requested) |
| 221 | entry->requested = 1; |
| 222 | else if (!entry && always_delay) |
| 223 | add_delay_entry(pathname, 1, 1); |
| 224 | } else if (starts_with(buf, "ref=") || |
| 225 | starts_with(buf, "treeish=") || |
| 226 | starts_with(buf, "blob=")) { |
| 227 | fprintf(logfile, " %s", buf); |
| 228 | } else { |
| 229 | /* |
| 230 | * In general, filters need to be graceful about |
| 231 | * new metadata, since it's documented that we |
| 232 | * can pass any key-value pairs, but for tests, |
| 233 | * let's be a little stricter. |
| 234 | */ |
| 235 | die("Unknown message '%s'", buf); |
| 236 | } |
| 237 | } |
| 238 | |
| 239 | read_packetized_to_strbuf(0, &input, 0); |
| 240 | fprintf(logfile, " %"PRIuMAX" [OK] -- ", (uintmax_t)input.len); |
| 241 | |
| 242 | entry = strmap_get(&delay, pathname); |
| 243 | if (entry && entry->output) { |
| 244 | output = entry->output; |
| 245 | } else if (!strcmp(pathname, "error.r") || !strcmp(pathname, "abort.r")) { |
| 246 | output = ""; |
| 247 | } else if (!strcmp(command, "clean") && has_clean_cap) { |
| 248 | output = rot13(input.buf); |
| 249 | } else if (!strcmp(command, "smudge") && has_smudge_cap) { |
| 250 | output = rot13(input.buf); |
| 251 | } else { |
| 252 | die("bad command '%s'", command); |
| 253 | } |
| 254 | |
| 255 | if (!strcmp(pathname, "error.r")) { |
| 256 | fprintf(logfile, "[ERROR]\n"); |
| 257 | packet_write_fmt(1, "status=error"); |
| 258 | packet_flush(1); |
| 259 | } else if (!strcmp(pathname, "abort.r")) { |
| 260 | fprintf(logfile, "[ABORT]\n"); |
| 261 | packet_write_fmt(1, "status=abort"); |
| 262 | packet_flush(1); |
| 263 | } else if (!strcmp(command, "smudge") && |
| 264 | (entry = strmap_get(&delay, pathname)) && |
| 265 | entry->requested == 1) { |
| 266 | fprintf(logfile, "[DELAYED]\n"); |
| 267 | packet_write_fmt(1, "status=delayed"); |
| 268 | packet_flush(1); |
| 269 | entry->requested = 2; |
| 270 | if (entry->output != output) { |
| 271 | free(entry->output); |
| 272 | entry->output = xstrdup(output); |
| 273 | } |
| 274 | } else { |
| 275 | int i, nr_packets = 0; |
| 276 | size_t output_len; |
| 277 | const char *p; |
| 278 | packet_write_fmt(1, "status=success"); |
| 279 | packet_flush(1); |
| 280 | |
| 281 | if (skip_prefix(pathname, command, &p) && |
| 282 | !strcmp(p, "-write-fail.r")) { |
| 283 | fprintf(logfile, "[WRITE FAIL]\n"); |
| 284 | die("%s write error", command); |
| 285 | } |
| 286 | |
| 287 | output_len = strlen(output); |
| 288 | fprintf(logfile, "OUT: %"PRIuMAX" ", (uintmax_t)output_len); |
| 289 | |
| 290 | if (write_packetized_from_buf_no_flush_count(output, |
| 291 | output_len, 1, &nr_packets)) |
| 292 | die("failed to write buffer to stdout"); |
| 293 | packet_flush(1); |
| 294 | |
| 295 | for (i = 0; i < nr_packets; i++) |
| 296 | fprintf(logfile, "."); |
| 297 | fprintf(logfile, " [OK]\n"); |
| 298 | |
| 299 | packet_flush(1); |
| 300 | } |
| 301 | free(pathname); |
| 302 | strbuf_release(&input); |
| 303 | free(command); |
| 304 | } |
| 305 | } |
| 306 | |
| 307 | static void packet_initialize(void) |
| 308 | { |
| 309 | char *pkt_buf = packet_read_line(0, NULL); |
| 310 | |
| 311 | if (!pkt_buf || strcmp(pkt_buf, "git-filter-client")) |
| 312 | die("bad initialize: '%s'", str_or_null(pkt_buf)); |
| 313 | |
| 314 | pkt_buf = packet_read_line(0, NULL); |
| 315 | if (!pkt_buf || strcmp(pkt_buf, "version=2")) |
| 316 | die("bad version: '%s'", str_or_null(pkt_buf)); |
| 317 | |
| 318 | pkt_buf = packet_read_line(0, NULL); |
| 319 | if (pkt_buf) |
| 320 | die("bad version end: '%s'", pkt_buf); |
| 321 | |
| 322 | packet_write_fmt(1, "git-filter-server"); |
| 323 | packet_write_fmt(1, "version=2"); |
| 324 | packet_flush(1); |
| 325 | } |
| 326 | |
| 327 | static const char *const rot13_usage[] = { |
| 328 | "test-tool rot13-filter [--always-delay] --log=<path> <capabilities>", |
| 329 | NULL |
| 330 | }; |
| 331 | |
| 332 | int cmd__rot13_filter(int argc, const char **argv) |
| 333 | { |
| 334 | int i, nr_caps; |
| 335 | struct strset remote_caps = STRSET_INIT; |
| 336 | const char *log_path = NULL; |
| 337 | |
| 338 | struct option options[] = { |
| 339 | OPT_BOOL(0, "always-delay", &always_delay, |
| 340 | "delay all paths with the can-delay flag"), |
| 341 | OPT_STRING(0, "log", &log_path, "path", |
| 342 | "path to the debug log file"), |
| 343 | OPT_END() |
| 344 | }; |
| 345 | nr_caps = parse_options(argc, argv, NULL, options, rot13_usage, |
| 346 | PARSE_OPT_STOP_AT_NON_OPTION); |
| 347 | |
| 348 | if (!log_path || !nr_caps) |
| 349 | usage_with_options(rot13_usage, options); |
| 350 | |
| 351 | logfile = fopen(log_path, "a"); |
| 352 | if (!logfile) |
| 353 | die_errno("failed to open log file"); |
| 354 | |
| 355 | for (i = 0; i < nr_caps; i++) { |
| 356 | if (!strcmp(argv[i], "smudge")) |
| 357 | has_smudge_cap = 1; |
| 358 | if (!strcmp(argv[i], "clean")) |
| 359 | has_clean_cap = 1; |
| 360 | } |
| 361 | |
| 362 | add_delay_entry("test-delay10.a", 1, 0); |
| 363 | add_delay_entry("test-delay11.a", 1, 0); |
| 364 | add_delay_entry("test-delay20.a", 2, 0); |
| 365 | add_delay_entry("test-delay10.b", 1, 0); |
| 366 | add_delay_entry("missing-delay.a", 1, 0); |
| 367 | add_delay_entry("invalid-delay.a", 1, 0); |
| 368 | |
| 369 | fprintf(logfile, "START\n"); |
| 370 | packet_initialize(); |
| 371 | |
| 372 | read_capabilities(&remote_caps); |
| 373 | check_and_write_capabilities(&remote_caps, argv, nr_caps); |
| 374 | fprintf(logfile, "init handshake complete\n"); |
| 375 | strset_clear(&remote_caps); |
| 376 | |
| 377 | command_loop(); |
| 378 | |
| 379 | if (fclose(logfile)) |
| 380 | die_errno("error closing logfile"); |
| 381 | free_delay_entries(); |
| 382 | return 0; |
| 383 | } |