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 (nr && !path_match(path, nr, match))
  81                                 continue;
  82                         show_ref(path, sha1);
  83                 }
  84                 free(path);
  85                 closedir(dir);
  86         }
  87 }
  88
  89 struct command {
  90         struct command *next;
  91         unsigned char old_sha1[20];
  92         unsigned char new_sha1[20];
  93         char ref_name[0];
  94 };
  95
  96 struct command *commands = NULL;
  97
  98 /*
  99  * This gets called after(if) we've successfully
 100  * unpacked the data payload.
 101  */
 102 static void execute_commands(void)
 103 {
 104         struct command *cmd = commands;
 105
 106         while (cmd) {
 107                 char old_hex[60], *new_hex;
 108                 strcpy(old_hex, sha1_to_hex(cmd->old_sha1));
 109                 new_hex = sha1_to_hex(cmd->new_sha1);
 110                 fprintf(stderr, "%s: %s -> %s\n", cmd->ref_name, old_hex, new_hex);
 111                 cmd = cmd->next;
 112         }
 113 }
 114
 115 static void read_head_info(void)
 116 {
 117         struct command **p = &commands;
 118         for (;;) {
 119                 static char line[1000];
 120                 unsigned char old_sha1[20], new_sha1[20];
 121                 struct command *cmd;
 122                 int len;
 123
 124                 len = packet_read_line(0, line, sizeof(line));
 125                 if (!len)
 126                         break;
 127                 if (line[len-1] == '\n')
 128                         line[--len] = 0;
 129                 if (len < 83 ||
 130                     line[40] != ' ' ||
 131                     line[81] != ' ' ||
 132                     get_sha1_hex(line, old_sha1) ||
 133                     get_sha1_hex(line + 41, new_sha1))
 134                         die("protocol error: expected old/new/ref, got '%s'", line);
 135                 cmd = xmalloc(sizeof(struct command) + len - 80);
 136                 memcpy(cmd->old_sha1, old_sha1, 20);
 137                 memcpy(cmd->new_sha1, new_sha1, 20);
 138                 memcpy(cmd->ref_name, line + 82, len - 81);
 139                 cmd->next = NULL;
 140                 *p = cmd;
 141                 p = &cmd->next;
 142         }
 143 }
 144
 145 static void unpack(void)
 146 {
 147         pid_t pid = fork();
 148
 149         if (pid < 0)
 150                 die("unpack fork failed");
 151         if (!pid) {
 152                 setenv("GIT_DIR", ".", 1);
 153                 execlp(unpacker, unpacker, NULL);
 154                 die("unpack execute failed");
 155         }
 156
 157         for (;;) {
 158                 int status, code;
 159                 int retval = waitpid(pid, &status, 0);
 160
 161                 if (retval < 0) {
 162                         if (errno == EINTR)
 163                                 continue;
 164                         die("waitpid failed (%s)", strerror(retval));
 165                 }
 166                 if (retval != pid)
 167                         die("waitpid is confused");
 168                 if (WIFSIGNALED(status))
 169                         die("%s died of signal %d", unpacker, WTERMSIG(status));
 170                 if (!WIFEXITED(status))
 171                         die("%s died out of really strange complications", unpacker);
 172                 code = WEXITSTATUS(status);
 173                 if (code)
 174                         die("%s exited with error code %d", unpacker, code);
 175                 return;
 176         }
 177 }
 178
 179 int main(int argc, char **argv)
 180 {
 181         int i, nr_heads = 0;
 182         const char *dir = NULL;
 183         char **heads = NULL;
 184
 185         argv++;
 186         for (i = 1; i < argc; i++) {
 187                 const char *arg = *argv++;
 188
 189                 if (*arg == '-') {
 190                         if (!strncmp(arg, "--unpack=", 9)) {
 191                                 unpacker = arg+9;
 192                                 continue;
 193                         }
 194                         /* Do flag handling here */
 195                         usage(receive_pack_usage);
 196                 }
 197                 dir = arg;
 198                 heads = argv;
 199                 nr_heads = argc - i - 1;
 200                 break;
 201         }
 202         if (!dir)
 203                 usage(receive_pack_usage);
 204
 205         /* chdir to the directory. If that fails, try appending ".git" */
 206         if (chdir(dir) < 0) {
 207                 static char path[PATH_MAX];
 208                 snprintf(path, sizeof(path), "%s.git", dir);
 209                 if (chdir(path) < 0)
 210                         die("unable to cd to %s", dir);
 211         }
 212
 213         /* If we have a ".git" directory, chdir to it */
 214         chdir(".git");
 215
 216         if (access("objects", X_OK) < 0 || access("refs/heads", X_OK) < 0)
 217                 die("%s doesn't appear to be a git directory", dir);
 218         write_head_info("refs/", nr_heads, heads);
 219
 220         /* EOF */
 221         packet_flush(1);
 222
 223         read_head_info();
 224         if (commands) {
 225                 unpack();
 226                 execute_commands();
 227         }
 228         return 0;
 229 }