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 #include "commit.h"
   7 #include "exec_cmd.h"
   8
   9 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
  10
  11 #define THEY_HAVE (1U << 0)
  12 #define OUR_REF (1U << 1)
  13 #define WANTED (1U << 2)
  14 #define MAX_HAS 256
  15 #define MAX_NEEDS 256
  16 static int nr_has = 0, nr_needs = 0, multi_ack = 0, nr_our_refs = 0;
  17 static unsigned char has_sha1[MAX_HAS][20];
  18 static unsigned char needs_sha1[MAX_NEEDS][20];
  19 static unsigned int timeout = 0;
  20
  21 static void reset_timeout(void)
  22 {
  23         alarm(timeout);
  24 }
  25
  26 static int strip(char *line, int len)
  27 {
  28         if (len && line[len-1] == '\n')
  29                 line[--len] = 0;
  30         return len;
  31 }
  32
  33 static void create_pack_file(void)
  34 {
  35         int fd[2];
  36         pid_t pid;
  37         int create_full_pack = (nr_our_refs == nr_needs && !nr_has);
  38
  39         if (pipe(fd) < 0)
  40                 die("git-upload-pack: unable to create pipe");
  41         pid = fork();
  42         if (pid < 0)
  43                 die("git-upload-pack: unable to fork git-rev-list");
  44
  45         if (!pid) {
  46                 int i;
  47                 int args;
  48                 char **argv;
  49                 char *buf;
  50                 char **p;
  51
  52                 if (create_full_pack)
  53                         args = 10;
  54                 else
  55                         args = nr_has + nr_needs + 5;
  56                 argv = xmalloc(args * sizeof(char *));
  57                 buf = xmalloc(args * 45);
  58                 p = argv;
  59
  60                 dup2(fd[1], 1);
  61                 close(0);
  62                 close(fd[0]);
  63                 close(fd[1]);
  64                 *p++ = "rev-list";
  65                 *p++ = "--objects";
  66                 if (create_full_pack || MAX_NEEDS <= nr_needs)
  67                         *p++ = "--all";
  68                 else {
  69                         for (i = 0; i < nr_needs; i++) {
  70                                 *p++ = buf;
  71                                 memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
  72                                 buf += 41;
  73                         }
  74                 }
  75                 if (!create_full_pack)
  76                         for (i = 0; i < nr_has; i++) {
  77                                 *p++ = buf;
  78                                 *buf++ = '^';
  79                                 memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
  80                                 buf += 41;
  81                         }
  82                 *p++ = NULL;
  83                 execv_git_cmd(argv);
  84                 die("git-upload-pack: unable to exec git-rev-list");
  85         }
  86         dup2(fd[0], 0);
  87         close(fd[0]);
  88         close(fd[1]);
  89         execl_git_cmd("pack-objects", "--stdout", NULL);
  90         die("git-upload-pack: unable to exec git-pack-objects");
  91 }
  92
  93 static int got_sha1(char *hex, unsigned char *sha1)
  94 {
  95         if (get_sha1_hex(hex, sha1))
  96                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
  97         if (!has_sha1_file(sha1))
  98                 return 0;
  99         if (nr_has < MAX_HAS) {
 100                 struct object *o = lookup_object(sha1);
 101                 if (!(o && o->parsed))
 102                         o = parse_object(sha1);
 103                 if (!o)
 104                         die("oops (%s)", sha1_to_hex(sha1));
 105                 if (o->type == commit_type) {
 106                         struct commit_list *parents;
 107                         if (o->flags & THEY_HAVE)
 108                                 return 0;
 109                         o->flags |= THEY_HAVE;
 110                         for (parents = ((struct commit*)o)->parents;
 111                              parents;
 112                              parents = parents->next)
 113                                 parents->item->object.flags |= THEY_HAVE;
 114                 }
 115                 memcpy(has_sha1[nr_has++], sha1, 20);
 116         }
 117         return 1;
 118 }
 119
 120 static int get_common_commits(void)
 121 {
 122         static char line[1000];
 123         unsigned char sha1[20], last_sha1[20];
 124         int len;
 125
 126         track_object_refs = 0;
 127         save_commit_buffer = 0;
 128
 129         for(;;) {
 130                 len = packet_read_line(0, line, sizeof(line));
 131                 reset_timeout();
 132
 133                 if (!len) {
 134                         if (nr_has == 0 || multi_ack)
 135                                 packet_write(1, "NAK\n");
 136                         continue;
 137                 }
 138                 len = strip(line, len);
 139                 if (!strncmp(line, "have ", 5)) {
 140                         if (got_sha1(line+5, sha1) &&
 141                                         (multi_ack || nr_has == 1)) {
 142                                 if (nr_has >= MAX_HAS)
 143                                         multi_ack = 0;
 144                                 packet_write(1, "ACK %s%s\n",
 145                                         sha1_to_hex(sha1),
 146                                         multi_ack ?  " continue" : "");
 147                                 if (multi_ack)
 148                                         memcpy(last_sha1, sha1, 20);
 149                         }
 150                         continue;
 151                 }
 152                 if (!strcmp(line, "done")) {
 153                         if (nr_has > 0) {
 154                                 if (multi_ack)
 155                                         packet_write(1, "ACK %s\n",
 156                                                         sha1_to_hex(last_sha1));
 157                                 return 0;
 158                         }
 159                         packet_write(1, "NAK\n");
 160                         return -1;
 161                 }
 162                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 163         }
 164 }
 165
 166 static int receive_needs(void)
 167 {
 168         static char line[1000];
 169         int len, needs;
 170
 171         needs = 0;
 172         for (;;) {
 173                 struct object *o;
 174                 unsigned char dummy[20], *sha1_buf;
 175                 len = packet_read_line(0, line, sizeof(line));
 176                 reset_timeout();
 177                 if (!len)
 178                         return needs;
 179
 180                 sha1_buf = dummy;
 181                 if (needs == MAX_NEEDS) {
 182                         fprintf(stderr,
 183                                 "warning: supporting only a max of %d requests. "
 184                                 "sending everything instead.\n",
 185                                 MAX_NEEDS);
 186                 }
 187                 else if (needs < MAX_NEEDS)
 188                         sha1_buf = needs_sha1[needs];
 189
 190                 if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
 191                         die("git-upload-pack: protocol error, "
 192                             "expected to get sha, not '%s'", line);
 193                 if (strstr(line+45, "multi_ack"))
 194                         multi_ack = 1;
 195
 196                 /* We have sent all our refs already, and the other end
 197                  * should have chosen out of them; otherwise they are
 198                  * asking for nonsense.
 199                  *
 200                  * Hmph.  We may later want to allow "want" line that
 201                  * asks for something like "master~10" (symbolic)...
 202                  * would it make sense?  I don't know.
 203                  */
 204                 o = lookup_object(sha1_buf);
 205                 if (!o || !(o->flags & OUR_REF))
 206                         die("git-upload-pack: not our ref %s", line+5);
 207                 if (!(o->flags & WANTED)) {
 208                         o->flags |= WANTED;
 209                         needs++;
 210                 }
 211         }
 212 }
 213
 214 static int send_ref(const char *refname, const unsigned char *sha1)
 215 {
 216         static char *capabilities = "multi_ack";
 217         struct object *o = parse_object(sha1);
 218
 219         if (!o)
 220                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 221
 222         if (capabilities)
 223                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 224                         0, capabilities);
 225         else
 226                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 227         capabilities = NULL;
 228         if (!(o->flags & OUR_REF)) {
 229                 o->flags |= OUR_REF;
 230                 nr_our_refs++;
 231         }
 232         if (o->type == tag_type) {
 233                 o = deref_tag(o, refname, 0);
 234                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 235         }
 236         return 0;
 237 }
 238
 239 static int upload_pack(void)
 240 {
 241         reset_timeout();
 242         head_ref(send_ref);
 243         for_each_ref(send_ref);
 244         packet_flush(1);
 245         nr_needs = receive_needs();
 246         if (!nr_needs)
 247                 return 0;
 248         get_common_commits();
 249         create_pack_file();
 250         return 0;
 251 }
 252
 253 int main(int argc, char **argv)
 254 {
 255         char *dir;
 256         int i;
 257         int strict = 0;
 258
 259         for (i = 1; i < argc; i++) {
 260                 char *arg = argv[i];
 261
 262                 if (arg[0] != '-')
 263                         break;
 264                 if (!strcmp(arg, "--strict")) {
 265                         strict = 1;
 266                         continue;
 267                 }
 268                 if (!strncmp(arg, "--timeout=", 10)) {
 269                         timeout = atoi(arg+10);
 270                         continue;
 271                 }
 272                 if (!strcmp(arg, "--")) {
 273                         i++;
 274                         break;
 275                 }
 276         }
 277
 278         if (i != argc-1)
 279                 usage(upload_pack_usage);
 280         dir = argv[i];
 281
 282         if (!enter_repo(dir, strict))
 283                 die("'%s': unable to chdir or not a git archive", dir);
 284
 285         upload_pack();
 286         return 0;
 287 }