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 (create_full_pack || 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                 if (!create_full_pack)
  73                         for (i = 0; i < nr_has; i++) {
  74                                 *p++ = buf;
  75                                 *buf++ = '^';
  76                                 memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
  77                                 buf += 41;
  78                         }
  79                 *p++ = NULL;
  80                 execvp("git-rev-list", argv);
  81                 die("git-upload-pack: unable to exec git-rev-list");
  82         }
  83         dup2(fd[0], 0);
  84         close(fd[0]);
  85         close(fd[1]);
  86         execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
  87         die("git-upload-pack: unable to exec git-pack-objects");
  88 }
  89
  90 static int got_sha1(char *hex, unsigned char *sha1)
  91 {
  92         int nr;
  93         if (get_sha1_hex(hex, sha1))
  94                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
  95         if (!has_sha1_file(sha1))
  96                 return 0;
  97         nr = nr_has;
  98         if (nr < MAX_HAS) {
  99                 memcpy(has_sha1[nr], sha1, 20);
 100                 nr_has = nr+1;
 101         }
 102         return 1;
 103 }
 104
 105 static int get_common_commits(void)
 106 {
 107         static char line[1000];
 108         unsigned char sha1[20];
 109         int len;
 110
 111         for(;;) {
 112                 len = packet_read_line(0, line, sizeof(line));
 113                 reset_timeout();
 114
 115                 if (!len) {
 116                         packet_write(1, "NAK\n");
 117                         continue;
 118                 }
 119                 len = strip(line, len);
 120                 if (!strncmp(line, "have ", 5)) {
 121                         if (got_sha1(line+5, sha1)) {
 122                                 packet_write(1, "ACK %s\n", sha1_to_hex(sha1));
 123                                 break;
 124                         }
 125                         continue;
 126                 }
 127                 if (!strcmp(line, "done")) {
 128                         packet_write(1, "NAK\n");
 129                         return -1;
 130                 }
 131                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 132         }
 133
 134         for (;;) {
 135                 len = packet_read_line(0, line, sizeof(line));
 136                 reset_timeout();
 137                 if (!len)
 138                         continue;
 139                 len = strip(line, len);
 140                 if (!strncmp(line, "have ", 5)) {
 141                         got_sha1(line+5, sha1);
 142                         continue;
 143                 }
 144                 if (!strcmp(line, "done"))
 145                         break;
 146                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 147         }
 148         return 0;
 149 }
 150
 151 static int receive_needs(void)
 152 {
 153         static char line[1000];
 154         int len, needs;
 155
 156         needs = 0;
 157         for (;;) {
 158                 struct object *o;
 159                 unsigned char dummy[20], *sha1_buf;
 160                 len = packet_read_line(0, line, sizeof(line));
 161                 reset_timeout();
 162                 if (!len)
 163                         return needs;
 164
 165                 sha1_buf = dummy;
 166                 if (needs == MAX_NEEDS) {
 167                         fprintf(stderr,
 168                                 "warning: supporting only a max of %d requests. "
 169                                 "sending everything instead.\n",
 170                                 MAX_NEEDS);
 171                 }
 172                 else if (needs < MAX_NEEDS)
 173                         sha1_buf = needs_sha1[needs];
 174
 175                 if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
 176                         die("git-upload-pack: protocol error, "
 177                             "expected to get sha, not '%s'", line);
 178
 179                 /* We have sent all our refs already, and the other end
 180                  * should have chosen out of them; otherwise they are
 181                  * asking for nonsense.
 182                  *
 183                  * Hmph.  We may later want to allow "want" line that
 184                  * asks for something like "master~10" (symbolic)...
 185                  * would it make sense?  I don't know.
 186                  */
 187                 o = lookup_object(sha1_buf);
 188                 if (!o || !(o->flags & OUR_REF))
 189                         die("git-upload-pack: not our ref %s", line+5);
 190                 if (!(o->flags & WANTED)) {
 191                         o->flags |= WANTED;
 192                         needs++;
 193                 }
 194         }
 195 }
 196
 197 static int send_ref(const char *refname, const unsigned char *sha1)
 198 {
 199         struct object *o = parse_object(sha1);
 200
 201         packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 202         if (!(o->flags & OUR_REF)) {
 203                 o->flags |= OUR_REF;
 204                 nr_our_refs++;
 205         }
 206         if (o->type == tag_type) {
 207                 o = deref_tag(o);
 208                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 209         }
 210         return 0;
 211 }
 212
 213 static int upload_pack(void)
 214 {
 215         reset_timeout();
 216         head_ref(send_ref);
 217         for_each_ref(send_ref);
 218         packet_flush(1);
 219         nr_needs = receive_needs();
 220         if (!nr_needs)
 221                 return 0;
 222         get_common_commits();
 223         create_pack_file();
 224         return 0;
 225 }
 226
 227 int main(int argc, char **argv)
 228 {
 229         const char *dir;
 230         int i;
 231         int strict = 0;
 232
 233         for (i = 1; i < argc; i++) {
 234                 char *arg = argv[i];
 235
 236                 if (arg[0] != '-')
 237                         break;
 238                 if (!strcmp(arg, "--strict")) {
 239                         strict = 1;
 240                         continue;
 241                 }
 242                 if (!strncmp(arg, "--timeout=", 10)) {
 243                         timeout = atoi(arg+10);
 244                         continue;
 245                 }
 246                 if (!strcmp(arg, "--")) {
 247                         i++;
 248                         break;
 249                 }
 250         }
 251
 252         if (i != argc-1)
 253                 usage(upload_pack_usage);
 254         dir = argv[i];
 255
 256         /* chdir to the directory. If that fails, try appending ".git" */
 257         if (chdir(dir) < 0) {
 258                 if (strict || chdir(mkpath("%s.git", dir)) < 0)
 259                         die("git-upload-pack unable to chdir to %s", dir);
 260         }
 261         if (!strict)
 262                 chdir(".git");
 263
 264         if (access("objects", X_OK) || access("refs", X_OK))
 265                 die("git-upload-pack: %s doesn't seem to be a git archive", dir);
 266
 267         putenv("GIT_DIR=.");
 268         upload_pack();
 269         return 0;
 270 }