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, *ent;
 135
 136                 old_commit = (struct commit *)parse_object(old_sha1);
 137                 new_commit = (struct commit *)parse_object(new_sha1);
 138                 bases = get_merge_bases(old_commit, new_commit, 1);
 139                 for (ent = bases; ent; ent = ent->next)
 140                         if (!hashcmp(old_sha1, ent->item->object.sha1))
 141                                 break;
 142                 free_commit_list(bases);
 143                 if (!ent)
 144                         return error("denying non-fast forward;"
 145                                      " you should pull first");
 146         }
 147         safe_create_leading_directories(lock_name);
 148
 149         newfd = open(lock_name, O_CREAT | O_EXCL | O_WRONLY, 0666);
 150         if (newfd < 0) {
 151                 cmd->error_string = "can't lock";
 152                 return error("unable to create %s (%s)",
 153                              lock_name, strerror(errno));
 154         }
 155
 156         /* Write the ref with an ending '\n' */
 157         new_hex[40] = '\n';
 158         new_hex[41] = 0;
 159         written = write(newfd, new_hex, 41);
 160         /* Remove the '\n' again */
 161         new_hex[40] = 0;
 162
 163         close(newfd);
 164         if (written != 41) {
 165                 unlink(lock_name);
 166                 cmd->error_string = "can't write";
 167                 return error("unable to write %s", lock_name);
 168         }
 169         if (verify_old_ref(name, old_hex) < 0) {
 170                 unlink(lock_name);
 171                 cmd->error_string = "raced";
 172                 return error("%s changed during push", name);
 173         }
 174         if (run_update_hook(name, old_hex, new_hex)) {
 175                 unlink(lock_name);
 176                 cmd->error_string = "hook declined";
 177                 return error("hook declined to update %s", name);
 178         }
 179         else if (rename(lock_name, name) < 0) {
 180                 unlink(lock_name);
 181                 cmd->error_string = "can't rename";
 182                 return error("unable to replace %s", name);
 183         }
 184         else {
 185                 fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
 186                 return 0;
 187         }
 188 }
 189
 190 static char update_post_hook[] = "hooks/post-update";
 191
 192 static void run_update_post_hook(struct command *cmd)
 193 {
 194         struct command *cmd_p;
 195         int argc;
 196         const char **argv;
 197
 198         if (access(update_post_hook, X_OK) < 0)
 199                 return;
 200         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 201                 if (cmd_p->error_string)
 202                         continue;
 203                 argc++;
 204         }
 205         argv = xmalloc(sizeof(*argv) * (1 + argc));
 206         argv[0] = update_post_hook;
 207
 208         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 209                 char *p;
 210                 if (cmd_p->error_string)
 211                         continue;
 212                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
 213                 strcpy(p, cmd_p->ref_name);
 214                 argv[argc] = p;
 215                 argc++;
 216         }
 217         argv[argc] = NULL;
 218         run_command_v_opt(argc, argv, RUN_COMMAND_NO_STDIO);
 219 }
 220
 221 /*
 222  * This gets called after(if) we've successfully
 223  * unpacked the data payload.
 224  */
 225 static void execute_commands(void)
 226 {
 227         struct command *cmd = commands;
 228
 229         while (cmd) {
 230                 update(cmd);
 231                 cmd = cmd->next;
 232         }
 233         run_update_post_hook(commands);
 234 }
 235
 236 static void read_head_info(void)
 237 {
 238         struct command **p = &commands;
 239         for (;;) {
 240                 static char line[1000];
 241                 unsigned char old_sha1[20], new_sha1[20];
 242                 struct command *cmd;
 243                 char *refname;
 244                 int len, reflen;
 245
 246                 len = packet_read_line(0, line, sizeof(line));
 247                 if (!len)
 248                         break;
 249                 if (line[len-1] == '\n')
 250                         line[--len] = 0;
 251                 if (len < 83 ||
 252                     line[40] != ' ' ||
 253                     line[81] != ' ' ||
 254                     get_sha1_hex(line, old_sha1) ||
 255                     get_sha1_hex(line + 41, new_sha1))
 256                         die("protocol error: expected old/new/ref, got '%s'",
 257                             line);
 258
 259                 refname = line + 82;
 260                 reflen = strlen(refname);
 261                 if (reflen + 82 < len) {
 262                         if (strstr(refname + reflen + 1, "report-status"))
 263                                 report_status = 1;
 264                 }
 265                 cmd = xmalloc(sizeof(struct command) + len - 80);
 266                 hashcpy(cmd->old_sha1, old_sha1);
 267                 hashcpy(cmd->new_sha1, new_sha1);
 268                 memcpy(cmd->ref_name, line + 82, len - 81);
 269                 cmd->error_string = "n/a (unpacker error)";
 270                 cmd->next = NULL;
 271                 *p = cmd;
 272                 p = &cmd->next;
 273         }
 274 }
 275
 276 static const char *unpack(int *error_code)
 277 {
 278         int code = run_command_v_opt(1, unpacker, RUN_GIT_CMD);
 279
 280         *error_code = 0;
 281         switch (code) {
 282         case 0:
 283                 return NULL;
 284         case -ERR_RUN_COMMAND_FORK:
 285                 return "unpack fork failed";
 286         case -ERR_RUN_COMMAND_EXEC:
 287                 return "unpack execute failed";
 288         case -ERR_RUN_COMMAND_WAITPID:
 289                 return "waitpid failed";
 290         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 291                 return "waitpid is confused";
 292         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 293                 return "unpacker died of signal";
 294         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 295                 return "unpacker died strangely";
 296         default:
 297                 *error_code = -code;
 298                 return "unpacker exited with error code";
 299         }
 300 }
 301
 302 static void report(const char *unpack_status)
 303 {
 304         struct command *cmd;
 305         packet_write(1, "unpack %s\n",
 306                      unpack_status ? unpack_status : "ok");
 307         for (cmd = commands; cmd; cmd = cmd->next) {
 308                 if (!cmd->error_string)
 309                         packet_write(1, "ok %s\n",
 310                                      cmd->ref_name);
 311                 else
 312                         packet_write(1, "ng %s %s\n",
 313                                      cmd->ref_name, cmd->error_string);
 314         }
 315         packet_flush(1);
 316 }
 317
 318 int main(int argc, char **argv)
 319 {
 320         int i;
 321         char *dir = NULL;
 322
 323         argv++;
 324         for (i = 1; i < argc; i++) {
 325                 char *arg = *argv++;
 326
 327                 if (*arg == '-') {
 328                         /* Do flag handling here */
 329                         usage(receive_pack_usage);
 330                 }
 331                 if (dir)
 332                         usage(receive_pack_usage);
 333                 dir = arg;
 334         }
 335         if (!dir)
 336                 usage(receive_pack_usage);
 337
 338         if(!enter_repo(dir, 0))
 339                 die("'%s': unable to chdir or not a git archive", dir);
 340
 341         write_head_info();
 342
 343         /* EOF */
 344         packet_flush(1);
 345
 346         read_head_info();
 347         if (commands) {
 348                 int code;
 349                 const char *unpack_status = unpack(&code);
 350                 if (!unpack_status)
 351                         execute_commands();
 352                 if (report_status)
 353                         report(unpack_status);
 354         }
 355         return 0;
 356 }