receive-pack.c

   1 #include "cache.h"
   2 #include "pkt-line.h"
   3 #include <sys/wait.h>
   4
   5 static const char receive_pack_usage[] = "git-receive-pack [--unpack=executable] <git-dir> [heads]";
   6
   7 static const char *unpacker = "git-unpack-objects";
   8
   9 static int path_match(const char *path, int nr, char **match)
  10 {
  11         int i;
  12         int pathlen = strlen(path);
  13
  14         for (i = 0; i < nr; i++) {
  15                 char *s = match[i];
  16                 int len = strlen(s);
  17
  18                 if (!len || len > pathlen)
  19                         continue;
  20                 if (memcmp(path + pathlen - len, s, len))
  21                         continue;
  22                 if (pathlen > len && path[pathlen - len - 1] != '/')
  23                         continue;
  24                 *s = 0;
  25                 return 1;
  26         }
  27         return 0;
  28 }
  29
  30 static void show_ref(const char *path, unsigned char *sha1)
  31 {
  32         packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
  33 }
  34
  35 static int read_ref(const char *path, unsigned char *sha1)
  36 {
  37         int ret = -1;
  38         int fd = open(path, O_RDONLY);
  39
  40         if (fd >= 0) {
  41                 char buffer[60];
  42                 if (read(fd, buffer, sizeof(buffer)) >= 40)
  43                         ret = get_sha1_hex(buffer, sha1);
  44                 close(fd);
  45         }
  46         return ret;
  47 }
  48
  49 static void write_head_info(const char *base, int nr, char **match)
  50 {
  51         DIR *dir = opendir(base);
  52
  53         if (dir) {
  54                 struct dirent *de;
  55                 int baselen = strlen(base);
  56                 char *path = xmalloc(baselen + 257);
  57                 memcpy(path, base, baselen);
  58
  59                 while ((de = readdir(dir)) != NULL) {
  60                         char sha1[20];
  61                         struct stat st;
  62                         int namelen;
  63
  64                         if (de->d_name[0] == '.')
  65                                 continue;
  66                         namelen = strlen(de->d_name);
  67                         if (namelen > 255)
  68                                 continue;
  69                         memcpy(path + baselen, de->d_name, namelen+1);
  70                         if (lstat(path, &st) < 0)
  71                                 continue;
  72                         if (S_ISDIR(st.st_mode)) {
  73                                 path[baselen + namelen] = '/';
  74                                 path[baselen + namelen + 1] = 0;
  75                                 write_head_info(path, nr, match);
  76                                 continue;
  77                         }
  78                         if (read_ref(path, sha1) < 0)
  79                                 continue;
  80                         if (!has_sha1_file(sha1))
  81                                 continue;
  82                         if (nr && !path_match(path, nr, match))
  83                                 continue;
  84                         show_ref(path, sha1);
  85                 }
  86                 free(path);
  87                 closedir(dir);
  88         }
  89 }
  90
  91 struct command {
  92         struct command *next;
  93         unsigned char old_sha1[20];
  94         unsigned char new_sha1[20];
  95         char ref_name[0];
  96 };
  97
  98 struct command *commands = NULL;
  99
 100 static int verify_old_ref(const char *name, char *hex_contents)
 101 {
 102         int fd, ret;
 103         char buffer[60];
 104
 105         fd = open(name, O_RDONLY);
 106         if (fd < 0)
 107                 return -1;
 108         ret = read(fd, buffer, 40);
 109         close(fd);
 110         if (ret != 40)
 111                 return -1;
 112         if (memcmp(buffer, hex_contents, 40))
 113                 return -1;
 114         return 0;
 115 }
 116
 117 static void update(const char *name, unsigned char *old_sha1, unsigned char *new_sha1)
 118 {
 119         char new_hex[60], *old_hex, *lock_name;
 120         int newfd, namelen, written;
 121
 122         namelen = strlen(name);
 123         lock_name = xmalloc(namelen + 10);
 124         memcpy(lock_name, name, namelen);
 125         memcpy(lock_name + namelen, ".lock", 6);
 126
 127         strcpy(new_hex, sha1_to_hex(new_sha1));
 128         new_hex[40] = '\n';
 129         new_hex[41] = 0;
 130         old_hex = sha1_to_hex(old_sha1);
 131         if (!has_sha1_file(new_sha1))
 132                 die("unpack should have generated %s, but I can't find it!", new_hex);
 133
 134         newfd = open(lock_name, O_CREAT | O_EXCL | O_WRONLY, 0644);
 135         if (newfd < 0)
 136                 die("unable to create %s (%s)", lock_name, strerror(errno));
 137         written = write(newfd, new_hex, 41);
 138         close(newfd);
 139         if (written != 41) {
 140                 unlink(lock_name);
 141                 die("unable to write %s", lock_name);
 142         }
 143         if (verify_old_ref(name, old_hex) < 0) {
 144                 unlink(lock_name);
 145                 die("%s changed during push", name);
 146         }
 147         if (rename(lock_name, name) < 0) {
 148                 unlink(lock_name);
 149                 die("unable to replace %s", name);
 150         }
 151         fprintf(stderr, "%s: %s -> %s\n", name, old_hex, new_hex);
 152 }
 153
 154
 155 /*
 156  * This gets called after(if) we've successfully
 157  * unpacked the data payload.
 158  */
 159 static void execute_commands(void)
 160 {
 161         struct command *cmd = commands;
 162
 163         while (cmd) {
 164                 update(cmd->ref_name, cmd->old_sha1, cmd->new_sha1);
 165                 cmd = cmd->next;
 166         }
 167 }
 168
 169 static void read_head_info(void)
 170 {
 171         struct command **p = &commands;
 172         for (;;) {
 173                 static char line[1000];
 174                 unsigned char old_sha1[20], new_sha1[20];
 175                 struct command *cmd;
 176                 int len;
 177
 178                 len = packet_read_line(0, line, sizeof(line));
 179                 if (!len)
 180                         break;
 181                 if (line[len-1] == '\n')
 182                         line[--len] = 0;
 183                 if (len < 83 ||
 184                     line[40] != ' ' ||
 185                     line[81] != ' ' ||
 186                     get_sha1_hex(line, old_sha1) ||
 187                     get_sha1_hex(line + 41, new_sha1))
 188                         die("protocol error: expected old/new/ref, got '%s'", line);
 189                 cmd = xmalloc(sizeof(struct command) + len - 80);
 190                 memcpy(cmd->old_sha1, old_sha1, 20);
 191                 memcpy(cmd->new_sha1, new_sha1, 20);
 192                 memcpy(cmd->ref_name, line + 82, len - 81);
 193                 cmd->next = NULL;
 194                 *p = cmd;
 195                 p = &cmd->next;
 196         }
 197 }
 198
 199 static void unpack(void)
 200 {
 201         pid_t pid = fork();
 202
 203         if (pid < 0)
 204                 die("unpack fork failed");
 205         if (!pid) {
 206                 execlp(unpacker, unpacker, NULL);
 207                 die("unpack execute failed");
 208         }
 209
 210         for (;;) {
 211                 int status, code;
 212                 int retval = waitpid(pid, &status, 0);
 213
 214                 if (retval < 0) {
 215                         if (errno == EINTR)
 216                                 continue;
 217                         die("waitpid failed (%s)", strerror(retval));
 218                 }
 219                 if (retval != pid)
 220                         die("waitpid is confused");
 221                 if (WIFSIGNALED(status))
 222                         die("%s died of signal %d", unpacker, WTERMSIG(status));
 223                 if (!WIFEXITED(status))
 224                         die("%s died out of really strange complications", unpacker);
 225                 code = WEXITSTATUS(status);
 226                 if (code)
 227                         die("%s exited with error code %d", unpacker, code);
 228                 return;
 229         }
 230 }
 231
 232 int main(int argc, char **argv)
 233 {
 234         int i, nr_heads = 0;
 235         const char *dir = NULL;
 236         char **heads = NULL;
 237
 238         argv++;
 239         for (i = 1; i < argc; i++) {
 240                 const char *arg = *argv++;
 241
 242                 if (*arg == '-') {
 243                         if (!strncmp(arg, "--unpack=", 9)) {
 244                                 unpacker = arg+9;
 245                                 continue;
 246                         }
 247                         /* Do flag handling here */
 248                         usage(receive_pack_usage);
 249                 }
 250                 dir = arg;
 251                 heads = argv;
 252                 nr_heads = argc - i - 1;
 253                 break;
 254         }
 255         if (!dir)
 256                 usage(receive_pack_usage);
 257
 258         /* chdir to the directory. If that fails, try appending ".git" */
 259         if (chdir(dir) < 0) {
 260                 static char path[PATH_MAX];
 261                 snprintf(path, sizeof(path), "%s.git", dir);
 262                 if (chdir(path) < 0)
 263                         die("unable to cd to %s", dir);
 264         }
 265
 266         /* If we have a ".git" directory, chdir to it */
 267         chdir(".git");
 268         setenv("GIT_DIR", ".", 1);
 269
 270         if (access("objects", X_OK) < 0 || access("refs/heads", X_OK) < 0)
 271                 die("%s doesn't appear to be a git directory", dir);
 272         write_head_info("refs/", nr_heads, heads);
 273
 274         /* EOF */
 275         packet_flush(1);
 276
 277         read_head_info();
 278         if (commands) {
 279                 unpack();
 280                 execute_commands();
 281         }
 282         return 0;
 283 }