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
   8 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
   9
  10 #define THEY_HAVE (1U << 0)
  11 #define MAX_HAS 256
  12 #define MAX_NEEDS 256
  13 static int nr_has = 0, nr_needs = 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
  35         if (pipe(fd) < 0)
  36                 die("git-upload-pack: unable to create pipe");
  37         pid = fork();
  38         if (pid < 0)
  39                 die("git-upload-pack: unable to fork git-rev-list");
  40
  41         if (!pid) {
  42                 int i;
  43                 int args;
  44                 char **argv;
  45                 char *buf;
  46                 char **p;
  47
  48                 if (MAX_NEEDS <= nr_needs)
  49                         args = nr_has + 10;
  50                 else
  51                         args = nr_has + nr_needs + 5;
  52                 argv = xmalloc(args * sizeof(char *));
  53                 buf = xmalloc(args * 45);
  54                 p = argv;
  55
  56                 dup2(fd[1], 1);
  57                 close(0);
  58                 close(fd[0]);
  59                 close(fd[1]);
  60                 *p++ = "git-rev-list";
  61                 *p++ = "--objects";
  62                 if (MAX_NEEDS <= nr_needs)
  63                         *p++ = "--all";
  64                 else {
  65                         for (i = 0; i < nr_needs; i++) {
  66                                 *p++ = buf;
  67                                 memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
  68                                 buf += 41;
  69                         }
  70                 }
  71                 for (i = 0; i < nr_has; i++) {
  72                         *p++ = buf;
  73                         *buf++ = '^';
  74                         memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
  75                         buf += 41;
  76                 }
  77                 *p++ = NULL;
  78                 execvp("git-rev-list", argv);
  79                 die("git-upload-pack: unable to exec git-rev-list");
  80         }
  81         dup2(fd[0], 0);
  82         close(fd[0]);
  83         close(fd[1]);
  84         execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
  85         die("git-upload-pack: unable to exec git-pack-objects");
  86 }
  87
  88 static int got_sha1(char *hex, unsigned char *sha1)
  89 {
  90         if (get_sha1_hex(hex, sha1))
  91                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
  92         if (!has_sha1_file(sha1))
  93                 return 0;
  94         if (nr_has < MAX_HAS) {
  95                 struct object *o = lookup_object(sha1);
  96                 if (!o || (!o->parsed && !parse_object(sha1)))
  97                         die("oops (%s)", sha1_to_hex(sha1));
  98                 if (o->type == commit_type) {
  99                         struct commit_list *parents;
 100                         if (o->flags & THEY_HAVE)
 101                                 return 0;
 102                         o->flags |= THEY_HAVE;
 103                         for (parents = ((struct commit*)o)->parents;
 104                              parents;
 105                              parents = parents->next)
 106                                 parents->item->object.flags |= THEY_HAVE;
 107                 }
 108                 memcpy(has_sha1[nr_has++], sha1, 20);
 109         }
 110         return 1;
 111 }
 112
 113 static int get_common_commits(void)
 114 {
 115         static char line[1000];
 116         unsigned char sha1[20];
 117         int len;
 118
 119         track_object_refs = 0;
 120         save_commit_buffer = 0;
 121
 122         for(;;) {
 123                 len = packet_read_line(0, line, sizeof(line));
 124                 reset_timeout();
 125
 126                 if (!len) {
 127                         packet_write(1, "NAK\n");
 128                         continue;
 129                 }
 130                 len = strip(line, len);
 131                 if (!strncmp(line, "have ", 5)) {
 132                         if (got_sha1(line+5, sha1)) {
 133                                 packet_write(1, "ACK %s\n", sha1_to_hex(sha1));
 134                                 break;
 135                         }
 136                         continue;
 137                 }
 138                 if (!strcmp(line, "done")) {
 139                         packet_write(1, "NAK\n");
 140                         return -1;
 141                 }
 142                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 143         }
 144
 145         for (;;) {
 146                 len = packet_read_line(0, line, sizeof(line));
 147                 reset_timeout();
 148                 if (!len)
 149                         continue;
 150                 len = strip(line, len);
 151                 if (!strncmp(line, "have ", 5)) {
 152                         got_sha1(line+5, sha1);
 153                         continue;
 154                 }
 155                 if (!strcmp(line, "done"))
 156                         break;
 157                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 158         }
 159         return 0;
 160 }
 161
 162 static int receive_needs(void)
 163 {
 164         static char line[1000];
 165         int len, needs;
 166
 167         needs = 0;
 168         for (;;) {
 169                 unsigned char dummy[20], *sha1_buf;
 170                 len = packet_read_line(0, line, sizeof(line));
 171                 reset_timeout();
 172                 if (!len)
 173                         return needs;
 174
 175                 sha1_buf = dummy;
 176                 if (needs == MAX_NEEDS) {
 177                         fprintf(stderr,
 178                                 "warning: supporting only a max of %d requests. "
 179                                 "sending everything instead.\n",
 180                                 MAX_NEEDS);
 181                 }
 182                 else if (needs < MAX_NEEDS)
 183                         sha1_buf = needs_sha1[needs];
 184
 185                 if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
 186                         die("git-upload-pack: protocol error, "
 187                             "expected to get sha, not '%s'", line);
 188                 needs++;
 189         }
 190 }
 191
 192 static int send_ref(const char *refname, const unsigned char *sha1)
 193 {
 194         struct object *o = parse_object(sha1);
 195
 196         packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 197         if (o->type == tag_type) {
 198                 o = deref_tag(o);
 199                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 200         }
 201         return 0;
 202 }
 203
 204 static int upload_pack(void)
 205 {
 206         reset_timeout();
 207         head_ref(send_ref);
 208         for_each_ref(send_ref);
 209         packet_flush(1);
 210         nr_needs = receive_needs();
 211         if (!nr_needs)
 212                 return 0;
 213         get_common_commits();
 214         create_pack_file();
 215         return 0;
 216 }
 217
 218 int main(int argc, char **argv)
 219 {
 220         const char *dir;
 221         int i;
 222         int strict = 0;
 223
 224         for (i = 1; i < argc; i++) {
 225                 char *arg = argv[i];
 226
 227                 if (arg[0] != '-')
 228                         break;
 229                 if (!strcmp(arg, "--strict")) {
 230                         strict = 1;
 231                         continue;
 232                 }
 233                 if (!strncmp(arg, "--timeout=", 10)) {
 234                         timeout = atoi(arg+10);
 235                         continue;
 236                 }
 237                 if (!strcmp(arg, "--")) {
 238                         i++;
 239                         break;
 240                 }
 241         }
 242
 243         if (i != argc-1)
 244                 usage(upload_pack_usage);
 245         dir = argv[i];
 246
 247         /* chdir to the directory. If that fails, try appending ".git" */
 248         if (chdir(dir) < 0) {
 249                 if (strict || chdir(mkpath("%s.git", dir)) < 0)
 250                         die("git-upload-pack unable to chdir to %s", dir);
 251         }
 252         if (!strict)
 253                 chdir(".git");
 254
 255         if (access("objects", X_OK) || access("refs", X_OK))
 256                 die("git-upload-pack: %s doesn't seem to be a git archive", dir);
 257
 258         putenv("GIT_DIR=.");
 259         upload_pack();
 260         return 0;
 261 }