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, multi_ack = 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                         if (multi_ack || nr_has == 0)
 128                                 packet_write(1, "NAK\n");
 129                         continue;
 130                 }
 131                 len = strip(line, len);
 132                 if (!strncmp(line, "have ", 5)) {
 133                         if (got_sha1(line+5, sha1) &&
 134                                         (multi_ack || nr_has == 1))
 135                                 packet_write(1, "ACK %s%s\n",
 136                                         sha1_to_hex(sha1),
 137                                         multi_ack && nr_has < MAX_HAS ?
 138                                         " continue" : "");
 139                         continue;
 140                 }
 141                 if (!strcmp(line, "done")) {
 142                         if (nr_has > 0)
 143                                 return 0;
 144                         packet_write(1, "NAK\n");
 145                         return -1;
 146                 }
 147                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 148         }
 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                 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                 if (strstr(line+45, "multi_ack"))
 179                         multi_ack = 1;
 180
 181                 needs++;
 182         }
 183 }
 184
 185 static int send_ref(const char *refname, const unsigned char *sha1)
 186 {
 187         struct object *o = parse_object(sha1);
 188
 189         packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 190         if (o->type == tag_type) {
 191                 o = deref_tag(o);
 192                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 193         }
 194         return 0;
 195 }
 196
 197 static int upload_pack(void)
 198 {
 199         reset_timeout();
 200         head_ref(send_ref);
 201         for_each_ref(send_ref);
 202         packet_flush(1);
 203         nr_needs = receive_needs();
 204         if (!nr_needs)
 205                 return 0;
 206         get_common_commits();
 207         create_pack_file();
 208         return 0;
 209 }
 210
 211 int main(int argc, char **argv)
 212 {
 213         const char *dir;
 214         int i;
 215         int strict = 0;
 216
 217         for (i = 1; i < argc; i++) {
 218                 char *arg = argv[i];
 219
 220                 if (arg[0] != '-')
 221                         break;
 222                 if (!strcmp(arg, "--strict")) {
 223                         strict = 1;
 224                         continue;
 225                 }
 226                 if (!strncmp(arg, "--timeout=", 10)) {
 227                         timeout = atoi(arg+10);
 228                         continue;
 229                 }
 230                 if (!strcmp(arg, "--")) {
 231                         i++;
 232                         break;
 233                 }
 234         }
 235
 236         if (i != argc-1)
 237                 usage(upload_pack_usage);
 238         dir = argv[i];
 239
 240         /* chdir to the directory. If that fails, try appending ".git" */
 241         if (chdir(dir) < 0) {
 242                 if (strict || chdir(mkpath("%s.git", dir)) < 0)
 243                         die("git-upload-pack unable to chdir to %s", dir);
 244         }
 245         if (!strict)
 246                 chdir(".git");
 247
 248         if (access("objects", X_OK) || access("refs", X_OK))
 249                 die("git-upload-pack: %s doesn't seem to be a git archive", dir);
 250
 251         putenv("GIT_DIR=.");
 252         upload_pack();
 253         return 0;
 254 }