upload-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4 #include "tag.h"
   5 #include "object.h"
   6
   7 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
   8
   9 #define MAX_HAS 256
  10 #define MAX_NEEDS 256
  11 static int nr_has = 0, nr_needs = 0;
  12 static unsigned char has_sha1[MAX_HAS][20];
  13 static unsigned char needs_sha1[MAX_NEEDS][20];
  14 static unsigned int timeout = 0;
  15
  16 static void reset_timeout(void)
  17 {
  18         alarm(timeout);
  19 }
  20
  21 static int strip(char *line, int len)
  22 {
  23         if (len && line[len-1] == '\n')
  24                 line[--len] = 0;
  25         return len;
  26 }
  27
  28 static void create_pack_file(void)
  29 {
  30         int fd[2];
  31         pid_t pid;
  32
  33         if (pipe(fd) < 0)
  34                 die("git-upload-pack: unable to create pipe");
  35         pid = fork();
  36         if (pid < 0)
  37                 die("git-upload-pack: unable to fork git-rev-list");
  38
  39         if (!pid) {
  40                 int i;
  41                 int args;
  42                 char **argv;
  43                 char *buf;
  44                 char **p;
  45
  46                 if (MAX_NEEDS <= nr_needs)
  47                         args = nr_has + 10;
  48                 else
  49                         args = nr_has + nr_needs + 5;
  50                 argv = xmalloc(args * sizeof(char *));
  51                 buf = xmalloc(args * 45);
  52                 p = argv;
  53
  54                 dup2(fd[1], 1);
  55                 close(0);
  56                 close(fd[0]);
  57                 close(fd[1]);
  58                 *p++ = "git-rev-list";
  59                 *p++ = "--objects";
  60                 if (MAX_NEEDS <= nr_needs)
  61                         *p++ = "--all";
  62                 else {
  63                         for (i = 0; i < nr_needs; i++) {
  64                                 *p++ = buf;
  65                                 memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
  66                                 buf += 41;
  67                         }
  68                 }
  69                 for (i = 0; i < nr_has; i++) {
  70                         *p++ = buf;
  71                         *buf++ = '^';
  72                         memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
  73                         buf += 41;
  74                 }
  75                 *p++ = NULL;
  76                 execvp("git-rev-list", argv);
  77                 die("git-upload-pack: unable to exec git-rev-list");
  78         }
  79         dup2(fd[0], 0);
  80         close(fd[0]);
  81         close(fd[1]);
  82         execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
  83         die("git-upload-pack: unable to exec git-pack-objects");
  84 }
  85
  86 static int got_sha1(char *hex, unsigned char *sha1)
  87 {
  88         int nr;
  89         if (get_sha1_hex(hex, sha1))
  90                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
  91         if (!has_sha1_file(sha1))
  92                 return 0;
  93         nr = nr_has;
  94         if (nr < MAX_HAS) {
  95                 memcpy(has_sha1[nr], sha1, 20);
  96                 nr_has = nr+1;
  97         }
  98         return 1;
  99 }
 100
 101 static int get_common_commits(void)
 102 {
 103         static char line[1000];
 104         unsigned char sha1[20];
 105         int len;
 106
 107         for(;;) {
 108                 len = packet_read_line(0, line, sizeof(line));
 109                 reset_timeout();
 110
 111                 if (!len) {
 112                         packet_write(1, "NAK\n");
 113                         continue;
 114                 }
 115                 len = strip(line, len);
 116                 if (!strncmp(line, "have ", 5)) {
 117                         if (got_sha1(line+5, sha1)) {
 118                                 packet_write(1, "ACK %s\n", sha1_to_hex(sha1));
 119                                 break;
 120                         }
 121                         continue;
 122                 }
 123                 if (!strcmp(line, "done")) {
 124                         packet_write(1, "NAK\n");
 125                         return -1;
 126                 }
 127                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 128         }
 129
 130         for (;;) {
 131                 len = packet_read_line(0, line, sizeof(line));
 132                 reset_timeout();
 133                 if (!len)
 134                         continue;
 135                 len = strip(line, len);
 136                 if (!strncmp(line, "have ", 5)) {
 137                         got_sha1(line+5, sha1);
 138                         continue;
 139                 }
 140                 if (!strcmp(line, "done"))
 141                         break;
 142                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 143         }
 144         return 0;
 145 }
 146
 147 static int receive_needs(void)
 148 {
 149         static char line[1000];
 150         int len, needs;
 151
 152         needs = 0;
 153         for (;;) {
 154                 unsigned char dummy[20], *sha1_buf;
 155                 len = packet_read_line(0, line, sizeof(line));
 156                 reset_timeout();
 157                 if (!len)
 158                         return needs;
 159
 160                 sha1_buf = dummy;
 161                 if (needs == MAX_NEEDS) {
 162                         fprintf(stderr,
 163                                 "warning: supporting only a max of %d requests. "
 164                                 "sending everything instead.\n",
 165                                 MAX_NEEDS);
 166                 }
 167                 else if (needs < MAX_NEEDS)
 168                         sha1_buf = needs_sha1[needs];
 169
 170                 if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
 171                         die("git-upload-pack: protocol error, "
 172                             "expected to get sha, not '%s'", line);
 173                 needs++;
 174         }
 175 }
 176
 177 static int send_ref(const char *refname, const unsigned char *sha1)
 178 {
 179         struct object *o = parse_object(sha1);
 180
 181         packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 182         if (o->type == tag_type) {
 183                 o = deref_tag(o);
 184                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 185         }
 186         return 0;
 187 }
 188
 189 static int upload_pack(void)
 190 {
 191         reset_timeout();
 192         head_ref(send_ref);
 193         for_each_ref(send_ref);
 194         packet_flush(1);
 195         nr_needs = receive_needs();
 196         if (!nr_needs)
 197                 return 0;
 198         get_common_commits();
 199         create_pack_file();
 200         return 0;
 201 }
 202
 203 int main(int argc, char **argv)
 204 {
 205         const char *dir;
 206         int i;
 207         int strict = 0;
 208
 209         for (i = 1; i < argc; i++) {
 210                 char *arg = argv[i];
 211
 212                 if (arg[0] != '-')
 213                         break;
 214                 if (!strcmp(arg, "--strict")) {
 215                         strict = 1;
 216                         continue;
 217                 }
 218                 if (!strncmp(arg, "--timeout=", 10)) {
 219                         timeout = atoi(arg+10);
 220                         continue;
 221                 }
 222                 if (!strcmp(arg, "--")) {
 223                         i++;
 224                         break;
 225                 }
 226         }
 227
 228         if (i != argc-1)
 229                 usage(upload_pack_usage);
 230         dir = argv[i];
 231
 232         /* chdir to the directory. If that fails, try appending ".git" */
 233         if (chdir(dir) < 0) {
 234                 if (strict || chdir(mkpath("%s.git", dir)) < 0)
 235                         die("git-upload-pack unable to chdir to %s", dir);
 236         }
 237         if (!strict)
 238                 chdir(".git");
 239
 240         if (access("objects", X_OK) || access("refs", X_OK))
 241                 die("git-upload-pack: %s doesn't seem to be a git archive", dir);
 242
 243         putenv("GIT_DIR=.");
 244         upload_pack();
 245         return 0;
 246 }