receive-pack.c

   1 #include "cache.h"
   2 #include "pack.h"
   3 #include "refs.h"
   4 #include "pkt-line.h"
   5 #include "run-command.h"
   6 #include "commit.h"
   7 #include "object.h"
   8
   9 static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
  10
  11 static int deny_non_fast_forwards = 0;
  12 static int unpack_limit = 5000;
  13 static int report_status;
  14
  15 static char capabilities[] = "report-status";
  16 static int capabilities_sent;
  17
  18 static int receive_pack_config(const char *var, const char *value)
  19 {
  20         git_default_config(var, value);
  21
  22         if (strcmp(var, "receive.denynonfastforwards") == 0)
  23         {
  24                 deny_non_fast_forwards = git_config_bool(var, value);
  25                 return 0;
  26         }
  27
  28         if (strcmp(var, "receive.unpacklimit") == 0)
  29         {
  30                 unpack_limit = git_config_int(var, value);
  31                 return 0;
  32         }
  33
  34         return 0;
  35 }
  36
  37 static int show_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  38 {
  39         if (capabilities_sent)
  40                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
  41         else
  42                 packet_write(1, "%s %s%c%s\n",
  43                              sha1_to_hex(sha1), path, 0, capabilities);
  44         capabilities_sent = 1;
  45         return 0;
  46 }
  47
  48 static void write_head_info(void)
  49 {
  50         for_each_ref(show_ref, NULL);
  51         if (!capabilities_sent)
  52                 show_ref("capabilities^{}", null_sha1, 0, NULL);
  53
  54 }
  55
  56 struct command {
  57         struct command *next;
  58         const char *error_string;
  59         unsigned char old_sha1[20];
  60         unsigned char new_sha1[20];
  61         char ref_name[FLEX_ARRAY]; /* more */
  62 };
  63
  64 static struct command *commands;
  65
  66 static char update_hook[] = "hooks/update";
  67
  68 static int run_update_hook(const char *refname,
  69                            char *old_hex, char *new_hex)
  70 {
  71         int code;
  72
  73         if (access(update_hook, X_OK) < 0)
  74                 return 0;
  75         code = run_command(update_hook, refname, old_hex, new_hex, NULL);
  76         switch (code) {
  77         case 0:
  78                 return 0;
  79         case -ERR_RUN_COMMAND_FORK:
  80                 return error("hook fork failed");
  81         case -ERR_RUN_COMMAND_EXEC:
  82                 return error("hook execute failed");
  83         case -ERR_RUN_COMMAND_WAITPID:
  84                 return error("waitpid failed");
  85         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
  86                 return error("waitpid is confused");
  87         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
  88                 return error("%s died of signal", update_hook);
  89         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
  90                 return error("%s died strangely", update_hook);
  91         default:
  92                 error("%s exited with error code %d", update_hook, -code);
  93                 return -code;
  94         }
  95 }
  96
  97 static int update(struct command *cmd)
  98 {
  99         const char *name = cmd->ref_name;
 100         unsigned char *old_sha1 = cmd->old_sha1;
 101         unsigned char *new_sha1 = cmd->new_sha1;
 102         char new_hex[41], old_hex[41];
 103         struct ref_lock *lock;
 104
 105         cmd->error_string = NULL;
 106         if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5)) {
 107                 cmd->error_string = "funny refname";
 108                 return error("refusing to create funny ref '%s' locally",
 109                              name);
 110         }
 111
 112         strcpy(new_hex, sha1_to_hex(new_sha1));
 113         strcpy(old_hex, sha1_to_hex(old_sha1));
 114         if (!has_sha1_file(new_sha1)) {
 115                 cmd->error_string = "bad pack";
 116                 return error("unpack should have generated %s, "
 117                              "but I can't find it!", new_hex);
 118         }
 119         if (deny_non_fast_forwards && !is_null_sha1(old_sha1)) {
 120                 struct commit *old_commit, *new_commit;
 121                 struct commit_list *bases, *ent;
 122
 123                 old_commit = (struct commit *)parse_object(old_sha1);
 124                 new_commit = (struct commit *)parse_object(new_sha1);
 125                 bases = get_merge_bases(old_commit, new_commit, 1);
 126                 for (ent = bases; ent; ent = ent->next)
 127                         if (!hashcmp(old_sha1, ent->item->object.sha1))
 128                                 break;
 129                 free_commit_list(bases);
 130                 if (!ent)
 131                         return error("denying non-fast forward;"
 132                                      " you should pull first");
 133         }
 134         if (run_update_hook(name, old_hex, new_hex)) {
 135                 cmd->error_string = "hook declined";
 136                 return error("hook declined to update %s", name);
 137         }
 138
 139         lock = lock_any_ref_for_update(name, old_sha1);
 140         if (!lock) {
 141                 cmd->error_string = "failed to lock";
 142                 return error("failed to lock %s", name);
 143         }
 144         write_ref_sha1(lock, new_sha1, "push");
 145
 146         fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
 147         return 0;
 148 }
 149
 150 static char update_post_hook[] = "hooks/post-update";
 151
 152 static void run_update_post_hook(struct command *cmd)
 153 {
 154         struct command *cmd_p;
 155         int argc;
 156         const char **argv;
 157
 158         if (access(update_post_hook, X_OK) < 0)
 159                 return;
 160         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 161                 if (cmd_p->error_string)
 162                         continue;
 163                 argc++;
 164         }
 165         argv = xmalloc(sizeof(*argv) * (1 + argc));
 166         argv[0] = update_post_hook;
 167
 168         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 169                 char *p;
 170                 if (cmd_p->error_string)
 171                         continue;
 172                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
 173                 strcpy(p, cmd_p->ref_name);
 174                 argv[argc] = p;
 175                 argc++;
 176         }
 177         argv[argc] = NULL;
 178         run_command_v_opt(argc, argv, RUN_COMMAND_NO_STDIO);
 179 }
 180
 181 /*
 182  * This gets called after(if) we've successfully
 183  * unpacked the data payload.
 184  */
 185 static void execute_commands(void)
 186 {
 187         struct command *cmd = commands;
 188
 189         while (cmd) {
 190                 update(cmd);
 191                 cmd = cmd->next;
 192         }
 193         run_update_post_hook(commands);
 194 }
 195
 196 static void read_head_info(void)
 197 {
 198         struct command **p = &commands;
 199         for (;;) {
 200                 static char line[1000];
 201                 unsigned char old_sha1[20], new_sha1[20];
 202                 struct command *cmd;
 203                 char *refname;
 204                 int len, reflen;
 205
 206                 len = packet_read_line(0, line, sizeof(line));
 207                 if (!len)
 208                         break;
 209                 if (line[len-1] == '\n')
 210                         line[--len] = 0;
 211                 if (len < 83 ||
 212                     line[40] != ' ' ||
 213                     line[81] != ' ' ||
 214                     get_sha1_hex(line, old_sha1) ||
 215                     get_sha1_hex(line + 41, new_sha1))
 216                         die("protocol error: expected old/new/ref, got '%s'",
 217                             line);
 218
 219                 refname = line + 82;
 220                 reflen = strlen(refname);
 221                 if (reflen + 82 < len) {
 222                         if (strstr(refname + reflen + 1, "report-status"))
 223                                 report_status = 1;
 224                 }
 225                 cmd = xmalloc(sizeof(struct command) + len - 80);
 226                 hashcpy(cmd->old_sha1, old_sha1);
 227                 hashcpy(cmd->new_sha1, new_sha1);
 228                 memcpy(cmd->ref_name, line + 82, len - 81);
 229                 cmd->error_string = "n/a (unpacker error)";
 230                 cmd->next = NULL;
 231                 *p = cmd;
 232                 p = &cmd->next;
 233         }
 234 }
 235
 236 static const char *parse_pack_header(struct pack_header *hdr)
 237 {
 238         char *c = (char*)hdr;
 239         ssize_t remaining = sizeof(struct pack_header);
 240         do {
 241                 ssize_t r = xread(0, c, remaining);
 242                 if (r <= 0)
 243                         return "eof before pack header was fully read";
 244                 remaining -= r;
 245                 c += r;
 246         } while (remaining > 0);
 247         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
 248                 return "protocol error (pack signature mismatch detected)";
 249         if (!pack_version_ok(hdr->hdr_version))
 250                 return "protocol error (pack version unsupported)";
 251         return NULL;
 252 }
 253
 254 static const char *unpack(void)
 255 {
 256         struct pack_header hdr;
 257         const char *hdr_err;
 258         char hdr_arg[38];
 259         int code;
 260
 261         hdr_err = parse_pack_header(&hdr);
 262         if (hdr_err)
 263                 return hdr_err;
 264         snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
 265                         ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
 266
 267         if (ntohl(hdr.hdr_entries) < unpack_limit) {
 268                 const char *unpacker[3];
 269                 unpacker[0] = "unpack-objects";
 270                 unpacker[1] = hdr_arg;
 271                 unpacker[2] = NULL;
 272                 code = run_command_v_opt(1, unpacker, RUN_GIT_CMD);
 273         } else {
 274                 const char *keeper[6];
 275                 char my_host[255], keep_arg[128 + 255];
 276
 277                 if (gethostname(my_host, sizeof(my_host)))
 278                         strcpy(my_host, "localhost");
 279                 snprintf(keep_arg, sizeof(keep_arg),
 280                                 "--keep=receive-pack %i on %s",
 281                                 getpid(), my_host);
 282
 283                 keeper[0] = "index-pack";
 284                 keeper[1] = "--stdin";
 285                 keeper[2] = "--fix-thin";
 286                 keeper[3] = hdr_arg;
 287                 keeper[4] = keep_arg;
 288                 keeper[5] = NULL;
 289                 code = run_command_v_opt(1, keeper, RUN_GIT_CMD);
 290                 if (!code)
 291                         reprepare_packed_git();
 292         }
 293
 294         switch (code) {
 295                 case 0:
 296                         return NULL;
 297                 case -ERR_RUN_COMMAND_FORK:
 298                         return "unpack fork failed";
 299                 case -ERR_RUN_COMMAND_EXEC:
 300                         return "unpack execute failed";
 301                 case -ERR_RUN_COMMAND_WAITPID:
 302                         return "waitpid failed";
 303                 case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 304                         return "waitpid is confused";
 305                 case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 306                         return "unpacker died of signal";
 307                 case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 308                         return "unpacker died strangely";
 309                 default:
 310                         return "unpacker exited with error code";
 311         }
 312 }
 313
 314 static void report(const char *unpack_status)
 315 {
 316         struct command *cmd;
 317         packet_write(1, "unpack %s\n",
 318                      unpack_status ? unpack_status : "ok");
 319         for (cmd = commands; cmd; cmd = cmd->next) {
 320                 if (!cmd->error_string)
 321                         packet_write(1, "ok %s\n",
 322                                      cmd->ref_name);
 323                 else
 324                         packet_write(1, "ng %s %s\n",
 325                                      cmd->ref_name, cmd->error_string);
 326         }
 327         packet_flush(1);
 328 }
 329
 330 int main(int argc, char **argv)
 331 {
 332         int i;
 333         char *dir = NULL;
 334
 335         argv++;
 336         for (i = 1; i < argc; i++) {
 337                 char *arg = *argv++;
 338
 339                 if (*arg == '-') {
 340                         /* Do flag handling here */
 341                         usage(receive_pack_usage);
 342                 }
 343                 if (dir)
 344                         usage(receive_pack_usage);
 345                 dir = arg;
 346         }
 347         if (!dir)
 348                 usage(receive_pack_usage);
 349
 350         if (!enter_repo(dir, 0))
 351                 die("'%s': unable to chdir or not a git archive", dir);
 352
 353         setup_ident();
 354         git_config(receive_pack_config);
 355
 356         write_head_info();
 357
 358         /* EOF */
 359         packet_flush(1);
 360
 361         read_head_info();
 362         if (commands) {
 363                 const char *unpack_status = unpack();
 364                 if (!unpack_status)
 365                         execute_commands();
 366                 if (report_status)
 367                         report(unpack_status);
 368         }
 369         return 0;
 370 }