receive-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4 #include "run-command.h"
   5 #include "commit.h"
   6 #include "object.h"
   7
   8 static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
   9
  10 static const char *unpacker[] = { "unpack-objects", NULL };
  11
  12 static int deny_non_fast_forwards = 0;
  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         return 0;
  29 }
  30
  31 static int show_ref(const char *path, const unsigned char *sha1)
  32 {
  33         if (capabilities_sent)
  34                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
  35         else
  36                 packet_write(1, "%s %s%c%s\n",
  37                              sha1_to_hex(sha1), path, 0, capabilities);
  38         capabilities_sent = 1;
  39         return 0;
  40 }
  41
  42 static void write_head_info(void)
  43 {
  44         for_each_ref(show_ref);
  45         if (!capabilities_sent)
  46                 show_ref("capabilities^{}", null_sha1);
  47
  48 }
  49
  50 struct command {
  51         struct command *next;
  52         const char *error_string;
  53         unsigned char old_sha1[20];
  54         unsigned char new_sha1[20];
  55         char ref_name[FLEX_ARRAY]; /* more */
  56 };
  57
  58 static struct command *commands;
  59
  60 static int is_all_zeroes(const char *hex)
  61 {
  62         int i;
  63         for (i = 0; i < 40; i++)
  64                 if (*hex++ != '0')
  65                         return 0;
  66         return 1;
  67 }
  68
  69 static int verify_old_ref(const char *name, char *hex_contents)
  70 {
  71         int fd, ret;
  72         char buffer[60];
  73
  74         if (is_all_zeroes(hex_contents))
  75                 return 0;
  76         fd = open(name, O_RDONLY);
  77         if (fd < 0)
  78                 return -1;
  79         ret = read(fd, buffer, 40);
  80         close(fd);
  81         if (ret != 40)
  82                 return -1;
  83         if (memcmp(buffer, hex_contents, 40))
  84                 return -1;
  85         return 0;
  86 }
  87
  88 static char update_hook[] = "hooks/update";
  89
  90 static int run_update_hook(const char *refname,
  91                            char *old_hex, char *new_hex)
  92 {
  93         int code;
  94
  95         if (access(update_hook, X_OK) < 0)
  96                 return 0;
  97         code = run_command(update_hook, refname, old_hex, new_hex, NULL);
  98         switch (code) {
  99         case 0:
 100                 return 0;
 101         case -ERR_RUN_COMMAND_FORK:
 102                 return error("hook fork failed");
 103         case -ERR_RUN_COMMAND_EXEC:
 104                 return error("hook execute failed");
 105         case -ERR_RUN_COMMAND_WAITPID:
 106                 return error("waitpid failed");
 107         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 108                 return error("waitpid is confused");
 109         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 110                 return error("%s died of signal", update_hook);
 111         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 112                 return error("%s died strangely", update_hook);
 113         default:
 114                 error("%s exited with error code %d", update_hook, -code);
 115                 return -code;
 116         }
 117 }
 118
 119 static int update(struct command *cmd)
 120 {
 121         const char *name = cmd->ref_name;
 122         unsigned char *old_sha1 = cmd->old_sha1;
 123         unsigned char *new_sha1 = cmd->new_sha1;
 124         char new_hex[60], *old_hex, *lock_name;
 125         int newfd, namelen, written;
 126
 127         cmd->error_string = NULL;
 128         if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5)) {
 129                 cmd->error_string = "funny refname";
 130                 return error("refusing to create funny ref '%s' locally",
 131                              name);
 132         }
 133
 134         namelen = strlen(name);
 135         lock_name = xmalloc(namelen + 10);
 136         memcpy(lock_name, name, namelen);
 137         memcpy(lock_name + namelen, ".lock", 6);
 138
 139         strcpy(new_hex, sha1_to_hex(new_sha1));
 140         old_hex = sha1_to_hex(old_sha1);
 141         if (!has_sha1_file(new_sha1)) {
 142                 cmd->error_string = "bad pack";
 143                 return error("unpack should have generated %s, "
 144                              "but I can't find it!", new_hex);
 145         }
 146         if (deny_non_fast_forwards && !is_null_sha1(old_sha1)) {
 147                 struct commit *old_commit, *new_commit;
 148                 struct commit_list *bases, *ent;
 149
 150                 old_commit = (struct commit *)parse_object(old_sha1);
 151                 new_commit = (struct commit *)parse_object(new_sha1);
 152                 bases = get_merge_bases(old_commit, new_commit, 1);
 153                 for (ent = bases; ent; ent = ent->next)
 154                         if (!hashcmp(old_sha1, ent->item->object.sha1))
 155                                 break;
 156                 free_commit_list(bases);
 157                 if (!ent)
 158                         return error("denying non-fast forward;"
 159                                      " you should pull first");
 160         }
 161         safe_create_leading_directories(lock_name);
 162
 163         newfd = open(lock_name, O_CREAT | O_EXCL | O_WRONLY, 0666);
 164         if (newfd < 0) {
 165                 cmd->error_string = "can't lock";
 166                 return error("unable to create %s (%s)",
 167                              lock_name, strerror(errno));
 168         }
 169
 170         /* Write the ref with an ending '\n' */
 171         new_hex[40] = '\n';
 172         new_hex[41] = 0;
 173         written = write(newfd, new_hex, 41);
 174         /* Remove the '\n' again */
 175         new_hex[40] = 0;
 176
 177         close(newfd);
 178         if (written != 41) {
 179                 unlink(lock_name);
 180                 cmd->error_string = "can't write";
 181                 return error("unable to write %s", lock_name);
 182         }
 183         if (verify_old_ref(name, old_hex) < 0) {
 184                 unlink(lock_name);
 185                 cmd->error_string = "raced";
 186                 return error("%s changed during push", name);
 187         }
 188         if (run_update_hook(name, old_hex, new_hex)) {
 189                 unlink(lock_name);
 190                 cmd->error_string = "hook declined";
 191                 return error("hook declined to update %s", name);
 192         }
 193         else if (rename(lock_name, name) < 0) {
 194                 unlink(lock_name);
 195                 cmd->error_string = "can't rename";
 196                 return error("unable to replace %s", name);
 197         }
 198         else {
 199                 fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
 200                 return 0;
 201         }
 202 }
 203
 204 static char update_post_hook[] = "hooks/post-update";
 205
 206 static void run_update_post_hook(struct command *cmd)
 207 {
 208         struct command *cmd_p;
 209         int argc;
 210         const char **argv;
 211
 212         if (access(update_post_hook, X_OK) < 0)
 213                 return;
 214         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 215                 if (cmd_p->error_string)
 216                         continue;
 217                 argc++;
 218         }
 219         argv = xmalloc(sizeof(*argv) * (1 + argc));
 220         argv[0] = update_post_hook;
 221
 222         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 223                 char *p;
 224                 if (cmd_p->error_string)
 225                         continue;
 226                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
 227                 strcpy(p, cmd_p->ref_name);
 228                 argv[argc] = p;
 229                 argc++;
 230         }
 231         argv[argc] = NULL;
 232         run_command_v_opt(argc, argv, RUN_COMMAND_NO_STDIO);
 233 }
 234
 235 /*
 236  * This gets called after(if) we've successfully
 237  * unpacked the data payload.
 238  */
 239 static void execute_commands(void)
 240 {
 241         struct command *cmd = commands;
 242
 243         while (cmd) {
 244                 update(cmd);
 245                 cmd = cmd->next;
 246         }
 247         run_update_post_hook(commands);
 248 }
 249
 250 static void read_head_info(void)
 251 {
 252         struct command **p = &commands;
 253         for (;;) {
 254                 static char line[1000];
 255                 unsigned char old_sha1[20], new_sha1[20];
 256                 struct command *cmd;
 257                 char *refname;
 258                 int len, reflen;
 259
 260                 len = packet_read_line(0, line, sizeof(line));
 261                 if (!len)
 262                         break;
 263                 if (line[len-1] == '\n')
 264                         line[--len] = 0;
 265                 if (len < 83 ||
 266                     line[40] != ' ' ||
 267                     line[81] != ' ' ||
 268                     get_sha1_hex(line, old_sha1) ||
 269                     get_sha1_hex(line + 41, new_sha1))
 270                         die("protocol error: expected old/new/ref, got '%s'",
 271                             line);
 272
 273                 refname = line + 82;
 274                 reflen = strlen(refname);
 275                 if (reflen + 82 < len) {
 276                         if (strstr(refname + reflen + 1, "report-status"))
 277                                 report_status = 1;
 278                 }
 279                 cmd = xmalloc(sizeof(struct command) + len - 80);
 280                 hashcpy(cmd->old_sha1, old_sha1);
 281                 hashcpy(cmd->new_sha1, new_sha1);
 282                 memcpy(cmd->ref_name, line + 82, len - 81);
 283                 cmd->error_string = "n/a (unpacker error)";
 284                 cmd->next = NULL;
 285                 *p = cmd;
 286                 p = &cmd->next;
 287         }
 288 }
 289
 290 static const char *unpack(int *error_code)
 291 {
 292         int code = run_command_v_opt(1, unpacker, RUN_GIT_CMD);
 293
 294         *error_code = 0;
 295         switch (code) {
 296         case 0:
 297                 return NULL;
 298         case -ERR_RUN_COMMAND_FORK:
 299                 return "unpack fork failed";
 300         case -ERR_RUN_COMMAND_EXEC:
 301                 return "unpack execute failed";
 302         case -ERR_RUN_COMMAND_WAITPID:
 303                 return "waitpid failed";
 304         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 305                 return "waitpid is confused";
 306         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 307                 return "unpacker died of signal";
 308         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 309                 return "unpacker died strangely";
 310         default:
 311                 *error_code = -code;
 312                 return "unpacker exited with error code";
 313         }
 314 }
 315
 316 static void report(const char *unpack_status)
 317 {
 318         struct command *cmd;
 319         packet_write(1, "unpack %s\n",
 320                      unpack_status ? unpack_status : "ok");
 321         for (cmd = commands; cmd; cmd = cmd->next) {
 322                 if (!cmd->error_string)
 323                         packet_write(1, "ok %s\n",
 324                                      cmd->ref_name);
 325                 else
 326                         packet_write(1, "ng %s %s\n",
 327                                      cmd->ref_name, cmd->error_string);
 328         }
 329         packet_flush(1);
 330 }
 331
 332 int main(int argc, char **argv)
 333 {
 334         int i;
 335         char *dir = NULL;
 336
 337         argv++;
 338         for (i = 1; i < argc; i++) {
 339                 char *arg = *argv++;
 340
 341                 if (*arg == '-') {
 342                         /* Do flag handling here */
 343                         usage(receive_pack_usage);
 344                 }
 345                 if (dir)
 346                         usage(receive_pack_usage);
 347                 dir = arg;
 348         }
 349         if (!dir)
 350                 usage(receive_pack_usage);
 351
 352         if(!enter_repo(dir, 0))
 353                 die("'%s': unable to chdir or not a git archive", dir);
 354
 355         git_config(receive_pack_config);
 356
 357         write_head_info();
 358
 359         /* EOF */
 360         packet_flush(1);
 361
 362         read_head_info();
 363         if (commands) {
 364                 int code;
 365                 const char *unpack_status = unpack(&code);
 366                 if (!unpack_status)
 367                         execute_commands();
 368                 if (report_status)
 369                         report(unpack_status);
 370         }
 371         return 0;
 372 }