Andrew's git - gitweb.git/blob

ef50226f4d6bf462e5346e8d75234ce1dc7c2a62
   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
   8static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
   9
  10static const char *unpacker[] = { "unpack-objects", NULL };
  11static const char *keep_packer[] = {
  12        "index-pack", "--stdin", "--fix-thin", NULL
  13};
  14
  15static int report_status;
  16static int keep_pack;
  17
  18static char capabilities[] = "report-status keep-pack";
  19static int capabilities_sent;
  20
  21static int show_ref(const char *path, const unsigned char *sha1)
  22{
  23        if (capabilities_sent)
  24                packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
  25        else
  26                packet_write(1, "%s %s%c%s\n",
  27                             sha1_to_hex(sha1), path, 0, capabilities);
  28        capabilities_sent = 1;
  29        return 0;
  30}
  31
  32static void write_head_info(void)
  33{
  34        for_each_ref(show_ref);
  35        if (!capabilities_sent)
  36                show_ref("capabilities^{}", null_sha1);
  37
  38}
  39
  40struct command {
  41        struct command *next;
  42        const char *error_string;
  43        unsigned char old_sha1[20];
  44        unsigned char new_sha1[20];
  45        char ref_name[FLEX_ARRAY]; /* more */
  46};
  47
  48static struct command *commands;
  49
  50static int is_all_zeroes(const char *hex)
  51{
  52        int i;
  53        for (i = 0; i < 40; i++)
  54                if (*hex++ != '0')
  55                        return 0;
  56        return 1;
  57}
  58
  59static int verify_old_ref(const char *name, char *hex_contents)
  60{
  61        int fd, ret;
  62        char buffer[60];
  63
  64        if (is_all_zeroes(hex_contents))
  65                return 0;
  66        fd = open(name, O_RDONLY);
  67        if (fd < 0)
  68                return -1;
  69        ret = read(fd, buffer, 40);
  70        close(fd);
  71        if (ret != 40)
  72                return -1;
  73        if (memcmp(buffer, hex_contents, 40))
  74                return -1;
  75        return 0;
  76}
  77
  78static char update_hook[] = "hooks/update";
  79
  80static int run_update_hook(const char *refname,
  81                           char *old_hex, char *new_hex)
  82{
  83        int code;
  84
  85        if (access(update_hook, X_OK) < 0)
  86                return 0;
  87        code = run_command(update_hook, refname, old_hex, new_hex, NULL);
  88        switch (code) {
  89        case 0:
  90                return 0;
  91        case -ERR_RUN_COMMAND_FORK:
  92                return error("hook fork failed");
  93        case -ERR_RUN_COMMAND_EXEC:
  94                return error("hook execute failed");
  95        case -ERR_RUN_COMMAND_WAITPID:
  96                return error("waitpid failed");
  97        case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
  98                return error("waitpid is confused");
  99        case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 100                return error("%s died of signal", update_hook);
 101        case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 102                return error("%s died strangely", update_hook);
 103        default:
 104                error("%s exited with error code %d", update_hook, -code);
 105                return -code;
 106        }
 107}
 108
 109static int update(struct command *cmd)
 110{
 111        const char *name = cmd->ref_name;
 112        unsigned char *old_sha1 = cmd->old_sha1;
 113        unsigned char *new_sha1 = cmd->new_sha1;
 114        char new_hex[60], *old_hex, *lock_name;
 115        int newfd, namelen, written;
 116
 117        cmd->error_string = NULL;
 118        if (!strncmp(name, "refs/", 5) && check_ref_format(name + 5)) {
 119                cmd->error_string = "funny refname";
 120                return error("refusing to create funny ref '%s' locally",
 121                             name);
 122        }
 123
 124        namelen = strlen(name);
 125        lock_name = xmalloc(namelen + 10);
 126        memcpy(lock_name, name, namelen);
 127        memcpy(lock_name + namelen, ".lock", 6);
 128
 129        strcpy(new_hex, sha1_to_hex(new_sha1));
 130        old_hex = sha1_to_hex(old_sha1);
 131        if (!has_sha1_file(new_sha1)) {
 132                cmd->error_string = "bad pack";
 133                return error("unpack should have generated %s, "
 134                             "but I can't find it!", new_hex);
 135        }
 136        if (deny_non_fast_forwards && !is_null_sha1(old_sha1)) {
 137                struct commit *old_commit, *new_commit;
 138                struct commit_list *bases, *ent;
 139
 140                old_commit = (struct commit *)parse_object(old_sha1);
 141                new_commit = (struct commit *)parse_object(new_sha1);
 142                bases = get_merge_bases(old_commit, new_commit, 1);
 143                for (ent = bases; ent; ent = ent->next)
 144                        if (!hashcmp(old_sha1, ent->item->object.sha1))
 145                                break;
 146                free_commit_list(bases);
 147                if (!ent)
 148                        return error("denying non-fast forward;"
 149                                     " you should pull first");
 150        }
 151        safe_create_leading_directories(lock_name);
 152
 153        newfd = open(lock_name, O_CREAT | O_EXCL | O_WRONLY, 0666);
 154        if (newfd < 0) {
 155                cmd->error_string = "can't lock";
 156                return error("unable to create %s (%s)",
 157                             lock_name, strerror(errno));
 158        }
 159
 160        /* Write the ref with an ending '\n' */
 161        new_hex[40] = '\n';
 162        new_hex[41] = 0;
 163        written = write(newfd, new_hex, 41);
 164        /* Remove the '\n' again */
 165        new_hex[40] = 0;
 166
 167        close(newfd);
 168        if (written != 41) {
 169                unlink(lock_name);
 170                cmd->error_string = "can't write";
 171                return error("unable to write %s", lock_name);
 172        }
 173        if (verify_old_ref(name, old_hex) < 0) {
 174                unlink(lock_name);
 175                cmd->error_string = "raced";
 176                return error("%s changed during push", name);
 177        }
 178        if (run_update_hook(name, old_hex, new_hex)) {
 179                unlink(lock_name);
 180                cmd->error_string = "hook declined";
 181                return error("hook declined to update %s", name);
 182        }
 183        else if (rename(lock_name, name) < 0) {
 184                unlink(lock_name);
 185                cmd->error_string = "can't rename";
 186                return error("unable to replace %s", name);
 187        }
 188        else {
 189                fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
 190                return 0;
 191        }
 192}
 193
 194static char update_post_hook[] = "hooks/post-update";
 195
 196static void run_update_post_hook(struct command *cmd)
 197{
 198        struct command *cmd_p;
 199        int argc;
 200        const char **argv;
 201
 202        if (access(update_post_hook, X_OK) < 0)
 203                return;
 204        for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 205                if (cmd_p->error_string)
 206                        continue;
 207                argc++;
 208        }
 209        argv = xmalloc(sizeof(*argv) * (1 + argc));
 210        argv[0] = update_post_hook;
 211
 212        for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 213                char *p;
 214                if (cmd_p->error_string)
 215                        continue;
 216                p = xmalloc(strlen(cmd_p->ref_name) + 1);
 217                strcpy(p, cmd_p->ref_name);
 218                argv[argc] = p;
 219                argc++;
 220        }
 221        argv[argc] = NULL;
 222        run_command_v_opt(argc, argv, RUN_COMMAND_NO_STDIO);
 223}
 224
 225/*
 226 * This gets called after(if) we've successfully
 227 * unpacked the data payload.
 228 */
 229static void execute_commands(void)
 230{
 231        struct command *cmd = commands;
 232
 233        while (cmd) {
 234                update(cmd);
 235                cmd = cmd->next;
 236        }
 237        run_update_post_hook(commands);
 238}
 239
 240static void read_head_info(void)
 241{
 242        struct command **p = &commands;
 243        for (;;) {
 244                static char line[1000];
 245                unsigned char old_sha1[20], new_sha1[20];
 246                struct command *cmd;
 247                char *refname;
 248                int len, reflen;
 249
 250                len = packet_read_line(0, line, sizeof(line));
 251                if (!len)
 252                        break;
 253                if (line[len-1] == '\n')
 254                        line[--len] = 0;
 255                if (len < 83 ||
 256                    line[40] != ' ' ||
 257                    line[81] != ' ' ||
 258                    get_sha1_hex(line, old_sha1) ||
 259                    get_sha1_hex(line + 41, new_sha1))
 260                        die("protocol error: expected old/new/ref, got '%s'",
 261                            line);
 262
 263                refname = line + 82;
 264                reflen = strlen(refname);
 265                if (reflen + 82 < len) {
 266                        if (strstr(refname + reflen + 1, "report-status"))
 267                                report_status = 1;
 268                        if (strstr(refname + reflen + 1, "keep-pack"))
 269                                keep_pack = 1;
 270                }
 271                cmd = xmalloc(sizeof(struct command) + len - 80);
 272                hashcpy(cmd->old_sha1, old_sha1);
 273                hashcpy(cmd->new_sha1, new_sha1);
 274                memcpy(cmd->ref_name, line + 82, len - 81);
 275                cmd->error_string = "n/a (unpacker error)";
 276                cmd->next = NULL;
 277                *p = cmd;
 278                p = &cmd->next;
 279        }
 280}
 281
 282static const char *unpack(int *error_code)
 283{
 284        int code;
 285
 286        if (keep_pack)
 287                code = run_command_v_opt(ARRAY_SIZE(keep_packer) - 1,
 288                                         keep_packer, RUN_GIT_CMD);
 289        else
 290                code = run_command_v_opt(ARRAY_SIZE(unpacker) - 1,
 291                                         unpacker, RUN_GIT_CMD);
 292
 293        *error_code = 0;
 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                *error_code = -code;
 311                return "unpacker exited with error code";
 312        }
 313}
 314
 315static void report(const char *unpack_status)
 316{
 317        struct command *cmd;
 318        packet_write(1, "unpack %s\n",
 319                     unpack_status ? unpack_status : "ok");
 320        for (cmd = commands; cmd; cmd = cmd->next) {
 321                if (!cmd->error_string)
 322                        packet_write(1, "ok %s\n",
 323                                     cmd->ref_name);
 324                else
 325                        packet_write(1, "ng %s %s\n",
 326                                     cmd->ref_name, cmd->error_string);
 327        }
 328        packet_flush(1);
 329}
 330
 331int main(int argc, char **argv)
 332{
 333        int i;
 334        char *dir = NULL;
 335
 336        argv++;
 337        for (i = 1; i < argc; i++) {
 338                char *arg = *argv++;
 339
 340                if (*arg == '-') {
 341                        /* Do flag handling here */
 342                        usage(receive_pack_usage);
 343                }
 344                if (dir)
 345                        usage(receive_pack_usage);
 346                dir = arg;
 347        }
 348        if (!dir)
 349                usage(receive_pack_usage);
 350
 351        if (!enter_repo(dir, 0))
 352                die("'%s': unable to chdir or not a git archive", dir);
 353
 354        write_head_info();
 355
 356        /* EOF */
 357        packet_flush(1);
 358
 359        read_head_info();
 360        if (commands) {
 361                int code;
 362                const char *unpack_status = unpack(&code);
 363                if (!unpack_status)
 364                        execute_commands();
 365                if (report_status)
 366                        report(unpack_status);
 367        }
 368        return 0;
 369}