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 report_status;
  13
  14 static char capabilities[] = "report-status";
  15 static int capabilities_sent;
  16
  17 static int show_ref(const char *path, const unsigned char *sha1)
  18 {
  19         if (capabilities_sent)
  20                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
  21         else
  22                 packet_write(1, "%s %s%c%s\n",
  23                              sha1_to_hex(sha1), path, 0, capabilities);
  24         capabilities_sent = 1;
  25         return 0;
  26 }
  27
  28 static void write_head_info(void)
  29 {
  30         for_each_ref(show_ref);
  31         if (!capabilities_sent)
  32                 show_ref("capabilities^{}", null_sha1);
  33
  34 }
  35
  36 struct command {
  37         struct command *next;
  38         const char *error_string;
  39         unsigned char old_sha1[20];
  40         unsigned char new_sha1[20];
  41         char ref_name[FLEX_ARRAY]; /* more */
  42 };
  43
  44 static struct command *commands;
  45
  46 static int is_all_zeroes(const char *hex)
  47 {
  48         int i;
  49         for (i = 0; i < 40; i++)
  50                 if (*hex++ != '0')
  51                         return 0;
  52         return 1;
  53 }
  54
  55 static int verify_old_ref(const char *name, char *hex_contents)
  56 {
  57         int fd, ret;
  58         char buffer[60];
  59
  60         if (is_all_zeroes(hex_contents))
  61                 return 0;
  62         fd = open(name, O_RDONLY);
  63         if (fd < 0)
  64                 return -1;
  65         ret = read(fd, buffer, 40);
  66         close(fd);
  67         if (ret != 40)
  68                 return -1;
  69         if (memcmp(buffer, hex_contents, 40))
  70                 return -1;
  71         return 0;
  72 }
  73
  74 static char update_hook[] = "hooks/update";
  75
  76 static int run_update_hook(const char *refname,
  77                            char *old_hex, char *new_hex)
  78 {
  79         int code;
  80
  81         if (access(update_hook, X_OK) < 0)
  82                 return 0;
  83         code = run_command(update_hook, refname, old_hex, new_hex, NULL);
  84         switch (code) {
  85         case 0:
  86                 return 0;
  87         case -ERR_RUN_COMMAND_FORK:
  88                 return error("hook fork failed");
  89         case -ERR_RUN_COMMAND_EXEC:
  90                 return error("hook execute failed");
  91         case -ERR_RUN_COMMAND_WAITPID:
  92                 return error("waitpid failed");
  93         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
  94                 return error("waitpid is confused");
  95         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
  96                 return error("%s died of signal", update_hook);
  97         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
  98                 return error("%s died strangely", update_hook);
  99         default:
 100                 error("%s exited with error code %d", update_hook, -code);
 101                 return -code;
 102         }
 103 }
 104
 105 static int update(struct command *cmd)
 106 {
 107         const char *name = cmd->ref_name;
 108         unsigned char *old_sha1 = cmd->old_sha1;
 109         unsigned char *new_sha1 = cmd->new_sha1;
 110         char new_hex[60], *old_hex, *lock_name;
 111         int newfd, namelen, written;
 112
 113         cmd->error_string = NULL;
 114         if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5)) {
 115                 cmd->error_string = "funny refname";
 116                 return error("refusing to create funny ref '%s' locally",
 117                              name);
 118         }
 119
 120         namelen = strlen(name);
 121         lock_name = xmalloc(namelen + 10);
 122         memcpy(lock_name, name, namelen);
 123         memcpy(lock_name + namelen, ".lock", 6);
 124
 125         strcpy(new_hex, sha1_to_hex(new_sha1));
 126         old_hex = sha1_to_hex(old_sha1);
 127         if (!has_sha1_file(new_sha1)) {
 128                 cmd->error_string = "bad pack";
 129                 return error("unpack should have generated %s, "
 130                              "but I can't find it!", new_hex);
 131         }
 132         if (deny_non_fast_forwards && !is_null_sha1(old_sha1)) {
 133                 struct commit *old_commit, *new_commit;
 134                 struct commit_list *bases;
 135
 136                 old_commit = (struct commit *)parse_object(old_sha1);
 137                 new_commit = (struct commit *)parse_object(new_sha1);
 138                 for (bases = get_merge_bases(old_commit, new_commit, 1);
 139                                 bases; bases = bases->next)
 140                         if (!hashcmp(old_sha1, bases->item->object.sha1))
 141                                 break;
 142                 if (!bases)
 143                         return error("denying non-fast forward;"
 144                                         " you should pull first");
 145         }
 146         safe_create_leading_directories(lock_name);
 147
 148         newfd = open(lock_name, O_CREAT | O_EXCL | O_WRONLY, 0666);
 149         if (newfd < 0) {
 150                 cmd->error_string = "can't lock";
 151                 return error("unable to create %s (%s)",
 152                              lock_name, strerror(errno));
 153         }
 154
 155         /* Write the ref with an ending '\n' */
 156         new_hex[40] = '\n';
 157         new_hex[41] = 0;
 158         written = write(newfd, new_hex, 41);
 159         /* Remove the '\n' again */
 160         new_hex[40] = 0;
 161
 162         close(newfd);
 163         if (written != 41) {
 164                 unlink(lock_name);
 165                 cmd->error_string = "can't write";
 166                 return error("unable to write %s", lock_name);
 167         }
 168         if (verify_old_ref(name, old_hex) < 0) {
 169                 unlink(lock_name);
 170                 cmd->error_string = "raced";
 171                 return error("%s changed during push", name);
 172         }
 173         if (run_update_hook(name, old_hex, new_hex)) {
 174                 unlink(lock_name);
 175                 cmd->error_string = "hook declined";
 176                 return error("hook declined to update %s", name);
 177         }
 178         else if (rename(lock_name, name) < 0) {
 179                 unlink(lock_name);
 180                 cmd->error_string = "can't rename";
 181                 return error("unable to replace %s", name);
 182         }
 183         else {
 184                 fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
 185                 return 0;
 186         }
 187 }
 188
 189 static char update_post_hook[] = "hooks/post-update";
 190
 191 static void run_update_post_hook(struct command *cmd)
 192 {
 193         struct command *cmd_p;
 194         int argc;
 195         const char **argv;
 196
 197         if (access(update_post_hook, X_OK) < 0)
 198                 return;
 199         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 200                 if (cmd_p->error_string)
 201                         continue;
 202                 argc++;
 203         }
 204         argv = xmalloc(sizeof(*argv) * (1 + argc));
 205         argv[0] = update_post_hook;
 206
 207         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 208                 char *p;
 209                 if (cmd_p->error_string)
 210                         continue;
 211                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
 212                 strcpy(p, cmd_p->ref_name);
 213                 argv[argc] = p;
 214                 argc++;
 215         }
 216         argv[argc] = NULL;
 217         run_command_v_opt(argc, argv, RUN_COMMAND_NO_STDIO);
 218 }
 219
 220 /*
 221  * This gets called after(if) we've successfully
 222  * unpacked the data payload.
 223  */
 224 static void execute_commands(void)
 225 {
 226         struct command *cmd = commands;
 227
 228         while (cmd) {
 229                 update(cmd);
 230                 cmd = cmd->next;
 231         }
 232         run_update_post_hook(commands);
 233 }
 234
 235 static void read_head_info(void)
 236 {
 237         struct command **p = &commands;
 238         for (;;) {
 239                 static char line[1000];
 240                 unsigned char old_sha1[20], new_sha1[20];
 241                 struct command *cmd;
 242                 char *refname;
 243                 int len, reflen;
 244
 245                 len = packet_read_line(0, line, sizeof(line));
 246                 if (!len)
 247                         break;
 248                 if (line[len-1] == '\n')
 249                         line[--len] = 0;
 250                 if (len < 83 ||
 251                     line[40] != ' ' ||
 252                     line[81] != ' ' ||
 253                     get_sha1_hex(line, old_sha1) ||
 254                     get_sha1_hex(line + 41, new_sha1))
 255                         die("protocol error: expected old/new/ref, got '%s'",
 256                             line);
 257
 258                 refname = line + 82;
 259                 reflen = strlen(refname);
 260                 if (reflen + 82 < len) {
 261                         if (strstr(refname + reflen + 1, "report-status"))
 262                                 report_status = 1;
 263                 }
 264                 cmd = xmalloc(sizeof(struct command) + len - 80);
 265                 hashcpy(cmd->old_sha1, old_sha1);
 266                 hashcpy(cmd->new_sha1, new_sha1);
 267                 memcpy(cmd->ref_name, line + 82, len - 81);
 268                 cmd->error_string = "n/a (unpacker error)";
 269                 cmd->next = NULL;
 270                 *p = cmd;
 271                 p = &cmd->next;
 272         }
 273 }
 274
 275 static const char *unpack(int *error_code)
 276 {
 277         int code = run_command_v_opt(1, unpacker, RUN_GIT_CMD);
 278
 279         *error_code = 0;
 280         switch (code) {
 281         case 0:
 282                 return NULL;
 283         case -ERR_RUN_COMMAND_FORK:
 284                 return "unpack fork failed";
 285         case -ERR_RUN_COMMAND_EXEC:
 286                 return "unpack execute failed";
 287         case -ERR_RUN_COMMAND_WAITPID:
 288                 return "waitpid failed";
 289         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 290                 return "waitpid is confused";
 291         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 292                 return "unpacker died of signal";
 293         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 294                 return "unpacker died strangely";
 295         default:
 296                 *error_code = -code;
 297                 return "unpacker exited with error code";
 298         }
 299 }
 300
 301 static void report(const char *unpack_status)
 302 {
 303         struct command *cmd;
 304         packet_write(1, "unpack %s\n",
 305                      unpack_status ? unpack_status : "ok");
 306         for (cmd = commands; cmd; cmd = cmd->next) {
 307                 if (!cmd->error_string)
 308                         packet_write(1, "ok %s\n",
 309                                      cmd->ref_name);
 310                 else
 311                         packet_write(1, "ng %s %s\n",
 312                                      cmd->ref_name, cmd->error_string);
 313         }
 314         packet_flush(1);
 315 }
 316
 317 int main(int argc, char **argv)
 318 {
 319         int i;
 320         char *dir = NULL;
 321
 322         argv++;
 323         for (i = 1; i < argc; i++) {
 324                 char *arg = *argv++;
 325
 326                 if (*arg == '-') {
 327                         /* Do flag handling here */
 328                         usage(receive_pack_usage);
 329                 }
 330                 if (dir)
 331                         usage(receive_pack_usage);
 332                 dir = arg;
 333         }
 334         if (!dir)
 335                 usage(receive_pack_usage);
 336
 337         if(!enter_repo(dir, 0))
 338                 die("'%s': unable to chdir or not a git archive", dir);
 339
 340         write_head_info();
 341
 342         /* EOF */
 343         packet_flush(1);
 344
 345         read_head_info();
 346         if (commands) {
 347                 int code;
 348                 const char *unpack_status = unpack(&code);
 349                 if (!unpack_status)
 350                         execute_commands();
 351                 if (report_status)
 352                         report(unpack_status);
 353         }
 354         return 0;
 355 }