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 OUR_REF (1U << 1)
  10 #define WANTED (1U << 2)
  11 #define MAX_HAS 256
  12 #define MAX_NEEDS 256
  13 static int nr_has = 0, nr_needs = 0, nr_our_refs = 0;
  14 static unsigned char has_sha1[MAX_HAS][20];
  15 static unsigned char needs_sha1[MAX_NEEDS][20];
  16 static unsigned int timeout = 0;
  17
  18 static void reset_timeout(void)
  19 {
  20         alarm(timeout);
  21 }
  22
  23 static int strip(char *line, int len)
  24 {
  25         if (len && line[len-1] == '\n')
  26                 line[--len] = 0;
  27         return len;
  28 }
  29
  30 static void create_pack_file(void)
  31 {
  32         int fd[2];
  33         pid_t pid;
  34         int create_full_pack = (nr_our_refs == nr_needs && !nr_has);
  35
  36         if (pipe(fd) < 0)
  37                 die("git-upload-pack: unable to create pipe");
  38         pid = fork();
  39         if (pid < 0)
  40                 die("git-upload-pack: unable to fork git-rev-list");
  41
  42         if (!pid) {
  43                 int i;
  44                 int args;
  45                 char **argv;
  46                 char *buf;
  47                 char **p;
  48
  49                 if (create_full_pack)
  50                         args = 10;
  51                 else
  52                         args = nr_has + nr_needs + 5;
  53                 argv = xmalloc(args * sizeof(char *));
  54                 buf = xmalloc(args * 45);
  55                 p = argv;
  56
  57                 dup2(fd[1], 1);
  58                 close(0);
  59                 close(fd[0]);
  60                 close(fd[1]);
  61                 *p++ = "git-rev-list";
  62                 *p++ = "--objects";
  63                 if (MAX_NEEDS <= nr_needs)
  64                         *p++ = "--all";
  65                 else {
  66                         for (i = 0; i < nr_needs; i++) {
  67                                 *p++ = buf;
  68                                 memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
  69                                 buf += 41;
  70                         }
  71                 }
  72                 for (i = 0; i < nr_has; i++) {
  73                         *p++ = buf;
  74                         *buf++ = '^';
  75                         memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
  76                         buf += 41;
  77                 }
  78                 *p++ = NULL;
  79                 execvp("git-rev-list", argv);
  80                 die("git-upload-pack: unable to exec git-rev-list");
  81         }
  82         dup2(fd[0], 0);
  83         close(fd[0]);
  84         close(fd[1]);
  85         execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
  86         die("git-upload-pack: unable to exec git-pack-objects");
  87 }
  88
  89 static int got_sha1(char *hex, unsigned char *sha1)
  90 {
  91         int nr;
  92         if (get_sha1_hex(hex, sha1))
  93                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
  94         if (!has_sha1_file(sha1))
  95                 return 0;
  96         nr = nr_has;
  97         if (nr < MAX_HAS) {
  98                 memcpy(has_sha1[nr], sha1, 20);
  99                 nr_has = nr+1;
 100         }
 101         return 1;
 102 }
 103
 104 static int get_common_commits(void)
 105 {
 106         static char line[1000];
 107         unsigned char sha1[20];
 108         int len;
 109
 110         for(;;) {
 111                 len = packet_read_line(0, line, sizeof(line));
 112                 reset_timeout();
 113
 114                 if (!len) {
 115                         packet_write(1, "NAK\n");
 116                         continue;
 117                 }
 118                 len = strip(line, len);
 119                 if (!strncmp(line, "have ", 5)) {
 120                         if (got_sha1(line+5, sha1)) {
 121                                 packet_write(1, "ACK %s\n", sha1_to_hex(sha1));
 122                                 break;
 123                         }
 124                         continue;
 125                 }
 126                 if (!strcmp(line, "done")) {
 127                         packet_write(1, "NAK\n");
 128                         return -1;
 129                 }
 130                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 131         }
 132
 133         for (;;) {
 134                 len = packet_read_line(0, line, sizeof(line));
 135                 reset_timeout();
 136                 if (!len)
 137                         continue;
 138                 len = strip(line, len);
 139                 if (!strncmp(line, "have ", 5)) {
 140                         got_sha1(line+5, sha1);
 141                         continue;
 142                 }
 143                 if (!strcmp(line, "done"))
 144                         break;
 145                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 146         }
 147         return 0;
 148 }
 149
 150 static int receive_needs(void)
 151 {
 152         static char line[1000];
 153         int len, needs;
 154
 155         needs = 0;
 156         for (;;) {
 157                 struct object *o;
 158                 unsigned char dummy[20], *sha1_buf;
 159                 len = packet_read_line(0, line, sizeof(line));
 160                 reset_timeout();
 161                 if (!len)
 162                         return needs;
 163
 164                 sha1_buf = dummy;
 165                 if (needs == MAX_NEEDS) {
 166                         fprintf(stderr,
 167                                 "warning: supporting only a max of %d requests. "
 168                                 "sending everything instead.\n",
 169                                 MAX_NEEDS);
 170                 }
 171                 else if (needs < MAX_NEEDS)
 172                         sha1_buf = needs_sha1[needs];
 173
 174                 if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
 175                         die("git-upload-pack: protocol error, "
 176                             "expected to get sha, not '%s'", line);
 177
 178                 /* We have sent all our refs already, and the other end
 179                  * should have chosen out of them; otherwise they are
 180                  * asking for nonsense.
 181                  *
 182                  * Hmph.  We may later want to allow "want" line that
 183                  * asks for something like "master~10" (symbolic)...
 184                  * would it make sense?  I don't know.
 185                  */
 186                 o = lookup_object(sha1_buf);
 187                 if (!o || !(o->flags & OUR_REF))
 188                         die("git-upload-pack: not our ref %s", line+5);
 189                 if (!(o->flags & WANTED)) {
 190                         o->flags |= WANTED;
 191                         needs++;
 192                 }
 193         }
 194 }
 195
 196 static int send_ref(const char *refname, const unsigned char *sha1)
 197 {
 198         struct object *o = parse_object(sha1);
 199
 200         packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 201         if (!(o->flags & OUR_REF)) {
 202                 o->flags |= OUR_REF;
 203                 nr_our_refs++;
 204         }
 205         if (o->type == tag_type) {
 206                 o = deref_tag(o);
 207                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 208         }
 209         return 0;
 210 }
 211
 212 static int upload_pack(void)
 213 {
 214         reset_timeout();
 215         head_ref(send_ref);
 216         for_each_ref(send_ref);
 217         packet_flush(1);
 218         nr_needs = receive_needs();
 219         if (!nr_needs)
 220                 return 0;
 221         get_common_commits();
 222         create_pack_file();
 223         return 0;
 224 }
 225
 226 int main(int argc, char **argv)
 227 {
 228         const char *dir;
 229         int i;
 230         int strict = 0;
 231
 232         for (i = 1; i < argc; i++) {
 233                 char *arg = argv[i];
 234
 235                 if (arg[0] != '-')
 236                         break;
 237                 if (!strcmp(arg, "--strict")) {
 238                         strict = 1;
 239                         continue;
 240                 }
 241                 if (!strncmp(arg, "--timeout=", 10)) {
 242                         timeout = atoi(arg+10);
 243                         continue;
 244                 }
 245                 if (!strcmp(arg, "--")) {
 246                         i++;
 247                         break;
 248                 }
 249         }
 250
 251         if (i != argc-1)
 252                 usage(upload_pack_usage);
 253         dir = argv[i];
 254
 255         /* chdir to the directory. If that fails, try appending ".git" */
 256         if (chdir(dir) < 0) {
 257                 if (strict || chdir(mkpath("%s.git", dir)) < 0)
 258                         die("git-upload-pack unable to chdir to %s", dir);
 259         }
 260         if (!strict)
 261                 chdir(".git");
 262
 263         if (access("objects", X_OK) || access("refs", X_OK))
 264                 die("git-upload-pack: %s doesn't seem to be a git archive", dir);
 265
 266         putenv("GIT_DIR=.");
 267         upload_pack();
 268         return 0;
 269 }