receive-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4 #include "run-command.h"
   5
   6 static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
   7
   8 static const char *unpacker[] = { "unpack-objects", NULL };
   9
  10 static int report_status;
  11
  12 static char capabilities[] = "report-status";
  13 static int capabilities_sent;
  14
  15 static int show_ref(const char *path, const unsigned char *sha1)
  16 {
  17         if (capabilities_sent)
  18                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
  19         else
  20                 packet_write(1, "%s %s%c%s\n",
  21                              sha1_to_hex(sha1), path, 0, capabilities);
  22         capabilities_sent = 1;
  23         return 0;
  24 }
  25
  26 static void write_head_info(void)
  27 {
  28         for_each_ref(show_ref);
  29         if (!capabilities_sent)
  30                 show_ref("capabilities^{}", null_sha1);
  31
  32 }
  33
  34 struct command {
  35         struct command *next;
  36         const char *error_string;
  37         unsigned char old_sha1[20];
  38         unsigned char new_sha1[20];
  39         char ref_name[FLEX_ARRAY]; /* more */
  40 };
  41
  42 static struct command *commands;
  43
  44 static int is_all_zeroes(const char *hex)
  45 {
  46         int i;
  47         for (i = 0; i < 40; i++)
  48                 if (*hex++ != '0')
  49                         return 0;
  50         return 1;
  51 }
  52
  53 static int verify_old_ref(const char *name, char *hex_contents)
  54 {
  55         int fd, ret;
  56         char buffer[60];
  57
  58         if (is_all_zeroes(hex_contents))
  59                 return 0;
  60         fd = open(name, O_RDONLY);
  61         if (fd < 0)
  62                 return -1;
  63         ret = read(fd, buffer, 40);
  64         close(fd);
  65         if (ret != 40)
  66                 return -1;
  67         if (memcmp(buffer, hex_contents, 40))
  68                 return -1;
  69         return 0;
  70 }
  71
  72 static char update_hook[] = "hooks/update";
  73
  74 static int run_update_hook(const char *refname,
  75                            char *old_hex, char *new_hex)
  76 {
  77         int code;
  78
  79         if (access(update_hook, X_OK) < 0)
  80                 return 0;
  81         code = run_command(update_hook, refname, old_hex, new_hex, NULL);
  82         switch (code) {
  83         case 0:
  84                 return 0;
  85         case -ERR_RUN_COMMAND_FORK:
  86                 return error("hook fork failed");
  87         case -ERR_RUN_COMMAND_EXEC:
  88                 return error("hook execute failed");
  89         case -ERR_RUN_COMMAND_WAITPID:
  90                 return error("waitpid failed");
  91         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
  92                 return error("waitpid is confused");
  93         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
  94                 return error("%s died of signal", update_hook);
  95         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
  96                 return error("%s died strangely", update_hook);
  97         default:
  98                 error("%s exited with error code %d", update_hook, -code);
  99                 return -code;
 100         }
 101 }
 102
 103 static int update(struct command *cmd)
 104 {
 105         const char *name = cmd->ref_name;
 106         unsigned char *old_sha1 = cmd->old_sha1;
 107         unsigned char *new_sha1 = cmd->new_sha1;
 108         char new_hex[60], *old_hex, *lock_name;
 109         int newfd, namelen, written;
 110
 111         cmd->error_string = NULL;
 112         if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5)) {
 113                 cmd->error_string = "funny refname";
 114                 return error("refusing to create funny ref '%s' locally",
 115                              name);
 116         }
 117
 118         namelen = strlen(name);
 119         lock_name = xmalloc(namelen + 10);
 120         memcpy(lock_name, name, namelen);
 121         memcpy(lock_name + namelen, ".lock", 6);
 122
 123         strcpy(new_hex, sha1_to_hex(new_sha1));
 124         old_hex = sha1_to_hex(old_sha1);
 125         if (!has_sha1_file(new_sha1)) {
 126                 cmd->error_string = "bad pack";
 127                 return error("unpack should have generated %s, "
 128                              "but I can't find it!", new_hex);
 129         }
 130         safe_create_leading_directories(lock_name);
 131
 132         newfd = open(lock_name, O_CREAT | O_EXCL | O_WRONLY, 0666);
 133         if (newfd < 0) {
 134                 cmd->error_string = "can't lock";
 135                 return error("unable to create %s (%s)",
 136                              lock_name, strerror(errno));
 137         }
 138
 139         /* Write the ref with an ending '\n' */
 140         new_hex[40] = '\n';
 141         new_hex[41] = 0;
 142         written = write(newfd, new_hex, 41);
 143         /* Remove the '\n' again */
 144         new_hex[40] = 0;
 145
 146         close(newfd);
 147         if (written != 41) {
 148                 unlink(lock_name);
 149                 cmd->error_string = "can't write";
 150                 return error("unable to write %s", lock_name);
 151         }
 152         if (verify_old_ref(name, old_hex) < 0) {
 153                 unlink(lock_name);
 154                 cmd->error_string = "raced";
 155                 return error("%s changed during push", name);
 156         }
 157         if (run_update_hook(name, old_hex, new_hex)) {
 158                 unlink(lock_name);
 159                 cmd->error_string = "hook declined";
 160                 return error("hook declined to update %s", name);
 161         }
 162         else if (rename(lock_name, name) < 0) {
 163                 unlink(lock_name);
 164                 cmd->error_string = "can't rename";
 165                 return error("unable to replace %s", name);
 166         }
 167         else {
 168                 fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
 169                 return 0;
 170         }
 171 }
 172
 173 static char update_post_hook[] = "hooks/post-update";
 174
 175 static void run_update_post_hook(struct command *cmd)
 176 {
 177         struct command *cmd_p;
 178         int argc;
 179         const char **argv;
 180
 181         if (access(update_post_hook, X_OK) < 0)
 182                 return;
 183         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 184                 if (cmd_p->error_string)
 185                         continue;
 186                 argc++;
 187         }
 188         argv = xmalloc(sizeof(*argv) * (1 + argc));
 189         argv[0] = update_post_hook;
 190
 191         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 192                 char *p;
 193                 if (cmd_p->error_string)
 194                         continue;
 195                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
 196                 strcpy(p, cmd_p->ref_name);
 197                 argv[argc] = p;
 198                 argc++;
 199         }
 200         argv[argc] = NULL;
 201         run_command_v_opt(argc, argv, RUN_COMMAND_NO_STDIO);
 202 }
 203
 204 /*
 205  * This gets called after(if) we've successfully
 206  * unpacked the data payload.
 207  */
 208 static void execute_commands(void)
 209 {
 210         struct command *cmd = commands;
 211
 212         while (cmd) {
 213                 update(cmd);
 214                 cmd = cmd->next;
 215         }
 216         run_update_post_hook(commands);
 217 }
 218
 219 static void read_head_info(void)
 220 {
 221         struct command **p = &commands;
 222         for (;;) {
 223                 static char line[1000];
 224                 unsigned char old_sha1[20], new_sha1[20];
 225                 struct command *cmd;
 226                 char *refname;
 227                 int len, reflen;
 228
 229                 len = packet_read_line(0, line, sizeof(line));
 230                 if (!len)
 231                         break;
 232                 if (line[len-1] == '\n')
 233                         line[--len] = 0;
 234                 if (len < 83 ||
 235                     line[40] != ' ' ||
 236                     line[81] != ' ' ||
 237                     get_sha1_hex(line, old_sha1) ||
 238                     get_sha1_hex(line + 41, new_sha1))
 239                         die("protocol error: expected old/new/ref, got '%s'",
 240                             line);
 241
 242                 refname = line + 82;
 243                 reflen = strlen(refname);
 244                 if (reflen + 82 < len) {
 245                         if (strstr(refname + reflen + 1, "report-status"))
 246                                 report_status = 1;
 247                 }
 248                 cmd = xmalloc(sizeof(struct command) + len - 80);
 249                 hashcpy(cmd->old_sha1, old_sha1);
 250                 hashcpy(cmd->new_sha1, new_sha1);
 251                 memcpy(cmd->ref_name, line + 82, len - 81);
 252                 cmd->error_string = "n/a (unpacker error)";
 253                 cmd->next = NULL;
 254                 *p = cmd;
 255                 p = &cmd->next;
 256         }
 257 }
 258
 259 static const char *unpack(int *error_code)
 260 {
 261         int code = run_command_v_opt(1, unpacker, RUN_GIT_CMD);
 262
 263         *error_code = 0;
 264         switch (code) {
 265         case 0:
 266                 return NULL;
 267         case -ERR_RUN_COMMAND_FORK:
 268                 return "unpack fork failed";
 269         case -ERR_RUN_COMMAND_EXEC:
 270                 return "unpack execute failed";
 271         case -ERR_RUN_COMMAND_WAITPID:
 272                 return "waitpid failed";
 273         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 274                 return "waitpid is confused";
 275         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 276                 return "unpacker died of signal";
 277         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 278                 return "unpacker died strangely";
 279         default:
 280                 *error_code = -code;
 281                 return "unpacker exited with error code";
 282         }
 283 }
 284
 285 static void report(const char *unpack_status)
 286 {
 287         struct command *cmd;
 288         packet_write(1, "unpack %s\n",
 289                      unpack_status ? unpack_status : "ok");
 290         for (cmd = commands; cmd; cmd = cmd->next) {
 291                 if (!cmd->error_string)
 292                         packet_write(1, "ok %s\n",
 293                                      cmd->ref_name);
 294                 else
 295                         packet_write(1, "ng %s %s\n",
 296                                      cmd->ref_name, cmd->error_string);
 297         }
 298         packet_flush(1);
 299 }
 300
 301 int main(int argc, char **argv)
 302 {
 303         int i;
 304         char *dir = NULL;
 305
 306         argv++;
 307         for (i = 1; i < argc; i++) {
 308                 char *arg = *argv++;
 309
 310                 if (*arg == '-') {
 311                         /* Do flag handling here */
 312                         usage(receive_pack_usage);
 313                 }
 314                 if (dir)
 315                         usage(receive_pack_usage);
 316                 dir = arg;
 317         }
 318         if (!dir)
 319                 usage(receive_pack_usage);
 320
 321         if(!enter_repo(dir, 0))
 322                 die("'%s': unable to chdir or not a git archive", dir);
 323
 324         write_head_info();
 325
 326         /* EOF */
 327         packet_flush(1);
 328
 329         read_head_info();
 330         if (commands) {
 331                 int code;
 332                 const char *unpack_status = unpack(&code);
 333                 if (!unpack_status)
 334                         execute_commands();
 335                 if (report_status)
 336                         report(unpack_status);
 337         }
 338         return 0;
 339 }