Andrew's git - gitweb.git/blob

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