upload-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4
   5 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
   6
   7 #define MAX_HAS (16)
   8 #define MAX_NEEDS (256)
   9 static int nr_has = 0, nr_needs = 0;
  10 static unsigned char has_sha1[MAX_HAS][20];
  11 static unsigned char needs_sha1[MAX_NEEDS][20];
  12 static unsigned int timeout = 0;
  13
  14 static void reset_timeout(void)
  15 {
  16         alarm(timeout);
  17 }
  18
  19 static int strip(char *line, int len)
  20 {
  21         if (len && line[len-1] == '\n')
  22                 line[--len] = 0;
  23         return len;
  24 }
  25
  26 static void create_pack_file(void)
  27 {
  28         int fd[2];
  29         pid_t pid;
  30
  31         if (pipe(fd) < 0)
  32                 die("git-upload-pack: unable to create pipe");
  33         pid = fork();
  34         if (pid < 0)
  35                 die("git-upload-pack: unable to fork git-rev-list");
  36
  37         if (!pid) {
  38                 int i;
  39                 int args;
  40                 char **argv;
  41                 char *buf;
  42                 char **p;
  43
  44                 if (MAX_NEEDS <= nr_needs)
  45                         args = nr_has + 10;
  46                 else
  47                         args = nr_has + nr_needs + 5;
  48                 argv = xmalloc(args * sizeof(char *));
  49                 buf = xmalloc(args * 45);
  50                 p = argv;
  51
  52                 dup2(fd[1], 1);
  53                 close(0);
  54                 close(fd[0]);
  55                 close(fd[1]);
  56                 *p++ = "git-rev-list";
  57                 *p++ = "--objects";
  58                 if (MAX_NEEDS <= nr_needs)
  59                         *p++ = "--all";
  60                 else {
  61                         for (i = 0; i < nr_needs; i++) {
  62                                 *p++ = buf;
  63                                 memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
  64                                 buf += 41;
  65                         }
  66                 }
  67                 for (i = 0; i < nr_has; i++) {
  68                         *p++ = buf;
  69                         *buf++ = '^';
  70                         memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
  71                         buf += 41;
  72                 }
  73                 *p++ = NULL;
  74                 execvp("git-rev-list", argv);
  75                 die("git-upload-pack: unable to exec git-rev-list");
  76         }
  77         dup2(fd[0], 0);
  78         close(fd[0]);
  79         close(fd[1]);
  80         execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
  81         die("git-upload-pack: unable to exec git-pack-objects");
  82 }
  83
  84 static int got_sha1(char *hex, unsigned char *sha1)
  85 {
  86         int nr;
  87         if (get_sha1_hex(hex, sha1))
  88                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
  89         if (!has_sha1_file(sha1))
  90                 return 0;
  91         nr = nr_has;
  92         if (nr < MAX_HAS) {
  93                 memcpy(has_sha1[nr], sha1, 20);
  94                 nr_has = nr+1;
  95         }
  96         return 1;
  97 }
  98
  99 static int get_common_commits(void)
 100 {
 101         static char line[1000];
 102         unsigned char sha1[20];
 103         int len;
 104
 105         for(;;) {
 106                 len = packet_read_line(0, line, sizeof(line));
 107                 reset_timeout();
 108
 109                 if (!len) {
 110                         packet_write(1, "NAK\n");
 111                         continue;
 112                 }
 113                 len = strip(line, len);
 114                 if (!strncmp(line, "have ", 5)) {
 115                         if (got_sha1(line+5, sha1)) {
 116                                 packet_write(1, "ACK %s\n", sha1_to_hex(sha1));
 117                                 break;
 118                         }
 119                         continue;
 120                 }
 121                 if (!strcmp(line, "done")) {
 122                         packet_write(1, "NAK\n");
 123                         return -1;
 124                 }
 125                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 126         }
 127
 128         for (;;) {
 129                 len = packet_read_line(0, line, sizeof(line));
 130                 reset_timeout();
 131                 if (!len)
 132                         continue;
 133                 len = strip(line, len);
 134                 if (!strncmp(line, "have ", 5)) {
 135                         got_sha1(line+5, sha1);
 136                         continue;
 137                 }
 138                 if (!strcmp(line, "done"))
 139                         break;
 140                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 141         }
 142         return 0;
 143 }
 144
 145 static int receive_needs(void)
 146 {
 147         static char line[1000];
 148         int len, needs;
 149
 150         needs = 0;
 151         for (;;) {
 152                 unsigned char dummy[20], *sha1_buf;
 153                 len = packet_read_line(0, line, sizeof(line));
 154                 reset_timeout();
 155                 if (!len)
 156                         return needs;
 157
 158                 sha1_buf = dummy;
 159                 if (needs == MAX_NEEDS) {
 160                         fprintf(stderr,
 161                                 "warning: supporting only a max of %d requests. "
 162                                 "sending everything instead.\n",
 163                                 MAX_NEEDS);
 164                 }
 165                 else if (needs < MAX_NEEDS)
 166                         sha1_buf = needs_sha1[needs];
 167
 168                 if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
 169                         die("git-upload-pack: protocol error, "
 170                             "expected to get sha, not '%s'", line);
 171                 needs++;
 172         }
 173 }
 174
 175 static int send_ref(const char *refname, const unsigned char *sha1)
 176 {
 177         packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 178         return 0;
 179 }
 180
 181 static int upload_pack(void)
 182 {
 183         reset_timeout();
 184         head_ref(send_ref);
 185         for_each_ref(send_ref);
 186         packet_flush(1);
 187         nr_needs = receive_needs();
 188         if (!nr_needs)
 189                 return 0;
 190         get_common_commits();
 191         create_pack_file();
 192         return 0;
 193 }
 194
 195 int main(int argc, char **argv)
 196 {
 197         const char *dir;
 198         int i;
 199         int strict = 0;
 200
 201         for (i = 1; i < argc; i++) {
 202                 char *arg = argv[i];
 203
 204                 if (arg[0] != '-')
 205                         break;
 206                 if (!strcmp(arg, "--strict")) {
 207                         strict = 1;
 208                         continue;
 209                 }
 210                 if (!strncmp(arg, "--timeout=", 10)) {
 211                         timeout = atoi(arg+10);
 212                         continue;
 213                 }
 214                 if (!strcmp(arg, "--")) {
 215                         i++;
 216                         break;
 217                 }
 218         }
 219
 220         if (i != argc-1)
 221                 usage(upload_pack_usage);
 222         dir = argv[i];
 223
 224         /* chdir to the directory. If that fails, try appending ".git" */
 225         if (chdir(dir) < 0) {
 226                 if (strict || chdir(mkpath("%s.git", dir)) < 0)
 227                         die("git-upload-pack unable to chdir to %s", dir);
 228         }
 229         if (!strict)
 230                 chdir(".git");
 231
 232         if (access("objects", X_OK) || access("refs", X_OK))
 233                 die("git-upload-pack: %s doesn't seem to be a git archive", dir);
 234
 235         putenv("GIT_DIR=.");
 236         upload_pack();
 237         return 0;
 238 }