connect.c

   1 #include "cache.h"
   2 #include "pkt-line.h"
   3 #include "quote.h"
   4 #include "refs.h"
   5 #include <sys/wait.h>
   6 #include <sys/socket.h>
   7 #include <netinet/in.h>
   8 #include <arpa/inet.h>
   9 #include <netdb.h>
  10
  11 static char *server_capabilities = NULL;
  12
  13 /*
  14  * Read all the refs from the other end
  15  */
  16 struct ref **get_remote_heads(int in, struct ref **list,
  17                               int nr_match, char **match, int ignore_funny)
  18 {
  19         *list = NULL;
  20         for (;;) {
  21                 struct ref *ref;
  22                 unsigned char old_sha1[20];
  23                 static char buffer[1000];
  24                 char *name;
  25                 int len, name_len;
  26
  27                 len = packet_read_line(in, buffer, sizeof(buffer));
  28                 if (!len)
  29                         break;
  30                 if (buffer[len-1] == '\n')
  31                         buffer[--len] = 0;
  32
  33                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  34                         die("protocol error: expected sha/ref, got '%s'", buffer);
  35                 name = buffer + 41;
  36
  37                 if (ignore_funny && 45 < len && !memcmp(name, "refs/", 5) &&
  38                     check_ref_format(name + 5))
  39                         continue;
  40
  41                 name_len = strlen(name);
  42                 if (len != name_len + 41) {
  43                         if (server_capabilities)
  44                                 free(server_capabilities);
  45                         server_capabilities = strdup(name + name_len + 1);
  46                 }
  47
  48                 if (nr_match && !path_match(name, nr_match, match))
  49                         continue;
  50                 ref = xcalloc(1, sizeof(*ref) + len - 40);
  51                 memcpy(ref->old_sha1, old_sha1, 20);
  52                 memcpy(ref->name, buffer + 41, len - 40);
  53                 *list = ref;
  54                 list = &ref->next;
  55         }
  56         return list;
  57 }
  58
  59 int server_supports(const char *feature)
  60 {
  61         return server_capabilities &&
  62                 strstr(server_capabilities, feature) != NULL;
  63 }
  64
  65 int get_ack(int fd, unsigned char *result_sha1)
  66 {
  67         static char line[1000];
  68         int len = packet_read_line(fd, line, sizeof(line));
  69
  70         if (!len)
  71                 die("git-fetch-pack: expected ACK/NAK, got EOF");
  72         if (line[len-1] == '\n')
  73                 line[--len] = 0;
  74         if (!strcmp(line, "NAK"))
  75                 return 0;
  76         if (!strncmp(line, "ACK ", 3)) {
  77                 if (!get_sha1_hex(line+4, result_sha1)) {
  78                         if (strstr(line+45, "continue"))
  79                                 return 2;
  80                         return 1;
  81                 }
  82         }
  83         die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
  84 }
  85
  86 int path_match(const char *path, int nr, char **match)
  87 {
  88         int i;
  89         int pathlen = strlen(path);
  90
  91         for (i = 0; i < nr; i++) {
  92                 char *s = match[i];
  93                 int len = strlen(s);
  94
  95                 if (!len || len > pathlen)
  96                         continue;
  97                 if (memcmp(path + pathlen - len, s, len))
  98                         continue;
  99                 if (pathlen > len && path[pathlen - len - 1] != '/')
 100                         continue;
 101                 *s = 0;
 102                 return 1;
 103         }
 104         return 0;
 105 }
 106
 107 struct refspec {
 108         char *src;
 109         char *dst;
 110         char force;
 111 };
 112
 113 /*
 114  * A:B means fast forward remote B with local A.
 115  * +A:B means overwrite remote B with local A.
 116  * +A is a shorthand for +A:A.
 117  * A is a shorthand for A:A.
 118  */
 119 static struct refspec *parse_ref_spec(int nr_refspec, char **refspec)
 120 {
 121         int i;
 122         struct refspec *rs = xcalloc(sizeof(*rs), (nr_refspec + 1));
 123         for (i = 0; i < nr_refspec; i++) {
 124                 char *sp, *dp, *ep;
 125                 sp = refspec[i];
 126                 if (*sp == '+') {
 127                         rs[i].force = 1;
 128                         sp++;
 129                 }
 130                 ep = strchr(sp, ':');
 131                 if (ep) {
 132                         dp = ep + 1;
 133                         *ep = 0;
 134                 }
 135                 else
 136                         dp = sp;
 137                 rs[i].src = sp;
 138                 rs[i].dst = dp;
 139         }
 140         rs[nr_refspec].src = rs[nr_refspec].dst = NULL;
 141         return rs;
 142 }
 143
 144 static int count_refspec_match(const char *pattern,
 145                                struct ref *refs,
 146                                struct ref **matched_ref)
 147 {
 148         int match;
 149         int patlen = strlen(pattern);
 150
 151         for (match = 0; refs; refs = refs->next) {
 152                 char *name = refs->name;
 153                 int namelen = strlen(name);
 154                 if (namelen < patlen ||
 155                     memcmp(name + namelen - patlen, pattern, patlen))
 156                         continue;
 157                 if (namelen != patlen && name[namelen - patlen - 1] != '/')
 158                         continue;
 159                 match++;
 160                 *matched_ref = refs;
 161         }
 162         return match;
 163 }
 164
 165 static void link_dst_tail(struct ref *ref, struct ref ***tail)
 166 {
 167         **tail = ref;
 168         *tail = &ref->next;
 169         **tail = NULL;
 170 }
 171
 172 static struct ref *try_explicit_object_name(const char *name)
 173 {
 174         unsigned char sha1[20];
 175         struct ref *ref;
 176         int len;
 177         if (get_sha1(name, sha1))
 178                 return NULL;
 179         len = strlen(name) + 1;
 180         ref = xcalloc(1, sizeof(*ref) + len);
 181         memcpy(ref->name, name, len);
 182         memcpy(ref->new_sha1, sha1, 20);
 183         return ref;
 184 }
 185
 186 static int match_explicit_refs(struct ref *src, struct ref *dst,
 187                                struct ref ***dst_tail, struct refspec *rs)
 188 {
 189         int i, errs;
 190         for (i = errs = 0; rs[i].src; i++) {
 191                 struct ref *matched_src, *matched_dst;
 192
 193                 matched_src = matched_dst = NULL;
 194                 switch (count_refspec_match(rs[i].src, src, &matched_src)) {
 195                 case 1:
 196                         break;
 197                 case 0:
 198                         /* The source could be in the get_sha1() format
 199                          * not a reference name.
 200                          */
 201                         matched_src = try_explicit_object_name(rs[i].src);
 202                         if (matched_src)
 203                                 break;
 204                         errs = 1;
 205                         error("src refspec %s does not match any.",
 206                               rs[i].src);
 207                         break;
 208                 default:
 209                         errs = 1;
 210                         error("src refspec %s matches more than one.",
 211                               rs[i].src);
 212                         break;
 213                 }
 214                 switch (count_refspec_match(rs[i].dst, dst, &matched_dst)) {
 215                 case 1:
 216                         break;
 217                 case 0:
 218                         if (!memcmp(rs[i].dst, "refs/", 5)) {
 219                                 int len = strlen(rs[i].dst) + 1;
 220                                 matched_dst = xcalloc(1, sizeof(*dst) + len);
 221                                 memcpy(matched_dst->name, rs[i].dst, len);
 222                                 link_dst_tail(matched_dst, dst_tail);
 223                         }
 224                         else if (!strcmp(rs[i].src, rs[i].dst) &&
 225                                  matched_src) {
 226                                 /* pushing "master:master" when
 227                                  * remote does not have master yet.
 228                                  */
 229                                 int len = strlen(matched_src->name) + 1;
 230                                 matched_dst = xcalloc(1, sizeof(*dst) + len);
 231                                 memcpy(matched_dst->name, matched_src->name,
 232                                        len);
 233                                 link_dst_tail(matched_dst, dst_tail);
 234                         }
 235                         else {
 236                                 errs = 1;
 237                                 error("dst refspec %s does not match any "
 238                                       "existing ref on the remote and does "
 239                                       "not start with refs/.", rs[i].dst);
 240                         }
 241                         break;
 242                 default:
 243                         errs = 1;
 244                         error("dst refspec %s matches more than one.",
 245                               rs[i].dst);
 246                         break;
 247                 }
 248                 if (errs)
 249                         continue;
 250                 if (matched_dst->peer_ref) {
 251                         errs = 1;
 252                         error("dst ref %s receives from more than one src.",
 253                               matched_dst->name);
 254                 }
 255                 else {
 256                         matched_dst->peer_ref = matched_src;
 257                         matched_dst->force = rs[i].force;
 258                 }
 259         }
 260         return -errs;
 261 }
 262
 263 static struct ref *find_ref_by_name(struct ref *list, const char *name)
 264 {
 265         for ( ; list; list = list->next)
 266                 if (!strcmp(list->name, name))
 267                         return list;
 268         return NULL;
 269 }
 270
 271 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 272                int nr_refspec, char **refspec, int all)
 273 {
 274         struct refspec *rs = parse_ref_spec(nr_refspec, refspec);
 275
 276         if (nr_refspec)
 277                 return match_explicit_refs(src, dst, dst_tail, rs);
 278
 279         /* pick the remainder */
 280         for ( ; src; src = src->next) {
 281                 struct ref *dst_peer;
 282                 if (src->peer_ref)
 283                         continue;
 284                 dst_peer = find_ref_by_name(dst, src->name);
 285                 if ((dst_peer && dst_peer->peer_ref) || (!dst_peer && !all))
 286                         continue;
 287                 if (!dst_peer) {
 288                         /* Create a new one and link it */
 289                         int len = strlen(src->name) + 1;
 290                         dst_peer = xcalloc(1, sizeof(*dst_peer) + len);
 291                         memcpy(dst_peer->name, src->name, len);
 292                         memcpy(dst_peer->new_sha1, src->new_sha1, 20);
 293                         link_dst_tail(dst_peer, dst_tail);
 294                 }
 295                 dst_peer->peer_ref = src;
 296         }
 297         return 0;
 298 }
 299
 300 enum protocol {
 301         PROTO_LOCAL = 1,
 302         PROTO_SSH,
 303         PROTO_GIT,
 304 };
 305
 306 static enum protocol get_protocol(const char *name)
 307 {
 308         if (!strcmp(name, "ssh"))
 309                 return PROTO_SSH;
 310         if (!strcmp(name, "git"))
 311                 return PROTO_GIT;
 312         if (!strcmp(name, "git+ssh"))
 313                 return PROTO_SSH;
 314         if (!strcmp(name, "ssh+git"))
 315                 return PROTO_SSH;
 316         die("I don't handle protocol '%s'", name);
 317 }
 318
 319 #define STR_(s) # s
 320 #define STR(s)  STR_(s)
 321
 322 #ifndef NO_IPV6
 323
 324 static int git_tcp_connect(int fd[2], const char *prog, char *host, char *path)
 325 {
 326         int sockfd = -1;
 327         char *colon, *end;
 328         char *port = STR(DEFAULT_GIT_PORT);
 329         struct addrinfo hints, *ai0, *ai;
 330         int gai;
 331
 332         if (host[0] == '[') {
 333                 end = strchr(host + 1, ']');
 334                 if (end) {
 335                         *end = 0;
 336                         end++;
 337                         host++;
 338                 } else
 339                         end = host;
 340         } else
 341                 end = host;
 342         colon = strchr(end, ':');
 343
 344         if (colon) {
 345                 *colon = 0;
 346                 port = colon + 1;
 347         }
 348
 349         memset(&hints, 0, sizeof(hints));
 350         hints.ai_socktype = SOCK_STREAM;
 351         hints.ai_protocol = IPPROTO_TCP;
 352
 353         gai = getaddrinfo(host, port, &hints, &ai);
 354         if (gai)
 355                 die("Unable to look up %s (%s)", host, gai_strerror(gai));
 356
 357         for (ai0 = ai; ai; ai = ai->ai_next) {
 358                 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 359                 if (sockfd < 0)
 360                         continue;
 361                 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 362                         close(sockfd);
 363                         sockfd = -1;
 364                         continue;
 365                 }
 366                 break;
 367         }
 368
 369         freeaddrinfo(ai0);
 370
 371         if (sockfd < 0)
 372                 die("unable to connect a socket (%s)", strerror(errno));
 373
 374         fd[0] = sockfd;
 375         fd[1] = sockfd;
 376         packet_write(sockfd, "%s %s\n", prog, path);
 377         return 0;
 378 }
 379
 380 #else /* NO_IPV6 */
 381
 382 static int git_tcp_connect(int fd[2], const char *prog, char *host, char *path)
 383 {
 384         int sockfd = -1;
 385         char *colon, *end;
 386         char *port = STR(DEFAULT_GIT_PORT), *ep;
 387         struct hostent *he;
 388         struct sockaddr_in sa;
 389         char **ap;
 390         unsigned int nport;
 391
 392         if (host[0] == '[') {
 393                 end = strchr(host + 1, ']');
 394                 if (end) {
 395                         *end = 0;
 396                         end++;
 397                         host++;
 398                 } else
 399                         end = host;
 400         } else
 401                 end = host;
 402         colon = strchr(end, ':');
 403
 404         if (colon) {
 405                 *colon = 0;
 406                 port = colon + 1;
 407         }
 408
 409
 410         he = gethostbyname(host);
 411         if (!he)
 412                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 413         nport = strtoul(port, &ep, 10);
 414         if ( ep == port || *ep ) {
 415                 /* Not numeric */
 416                 struct servent *se = getservbyname(port,"tcp");
 417                 if ( !se )
 418                         die("Unknown port %s\n", port);
 419                 nport = se->s_port;
 420         }
 421
 422         for (ap = he->h_addr_list; *ap; ap++) {
 423                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 424                 if (sockfd < 0)
 425                         continue;
 426
 427                 memset(&sa, 0, sizeof sa);
 428                 sa.sin_family = he->h_addrtype;
 429                 sa.sin_port = htons(nport);
 430                 memcpy(&sa.sin_addr, ap, he->h_length);
 431
 432                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 433                         close(sockfd);
 434                         sockfd = -1;
 435                         continue;
 436                 }
 437                 break;
 438         }
 439
 440         if (sockfd < 0)
 441                 die("unable to connect a socket (%s)", strerror(errno));
 442
 443         fd[0] = sockfd;
 444         fd[1] = sockfd;
 445         packet_write(sockfd, "%s %s\n", prog, path);
 446         return 0;
 447 }
 448
 449 #endif /* NO_IPV6 */
 450
 451 /*
 452  * Yeah, yeah, fixme. Need to pass in the heads etc.
 453  */
 454 int git_connect(int fd[2], char *url, const char *prog)
 455 {
 456         char command[1024];
 457         char *host, *path;
 458         char *colon;
 459         int pipefd[2][2];
 460         pid_t pid;
 461         enum protocol protocol;
 462
 463         host = NULL;
 464         path = url;
 465         colon = strchr(url, ':');
 466         protocol = PROTO_LOCAL;
 467         if (colon) {
 468                 *colon = 0;
 469                 host = url;
 470                 path = colon+1;
 471                 protocol = PROTO_SSH;
 472                 if (!memcmp(path, "//", 2)) {
 473                         char *slash = strchr(path + 2, '/');
 474                         if (slash) {
 475                                 int nr = slash - path - 2;
 476                                 memmove(path, path+2, nr);
 477                                 path[nr] = 0;
 478                                 protocol = get_protocol(url);
 479                                 host = path;
 480                                 path = slash;
 481                         }
 482                 }
 483         }
 484
 485         if (protocol == PROTO_GIT)
 486                 return git_tcp_connect(fd, prog, host, path);
 487
 488         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 489                 die("unable to create pipe pair for communication");
 490         pid = fork();
 491         if (!pid) {
 492                 snprintf(command, sizeof(command), "%s %s", prog,
 493                          sq_quote(path));
 494                 dup2(pipefd[1][0], 0);
 495                 dup2(pipefd[0][1], 1);
 496                 close(pipefd[0][0]);
 497                 close(pipefd[0][1]);
 498                 close(pipefd[1][0]);
 499                 close(pipefd[1][1]);
 500                 if (protocol == PROTO_SSH) {
 501                         const char *ssh, *ssh_basename;
 502                         ssh = getenv("GIT_SSH");
 503                         if (!ssh) ssh = "ssh";
 504                         ssh_basename = strrchr(ssh, '/');
 505                         if (!ssh_basename)
 506                                 ssh_basename = ssh;
 507                         else
 508                                 ssh_basename++;
 509                         execlp(ssh, ssh_basename, host, command, NULL);
 510                 }
 511                 else
 512                         execlp("sh", "sh", "-c", command, NULL);
 513                 die("exec failed");
 514         }
 515         fd[0] = pipefd[0][0];
 516         fd[1] = pipefd[1][1];
 517         close(pipefd[0][1]);
 518         close(pipefd[1][0]);
 519         return pid;
 520 }
 521
 522 int finish_connect(pid_t pid)
 523 {
 524         int ret;
 525
 526         for (;;) {
 527                 ret = waitpid(pid, NULL, 0);
 528                 if (!ret)
 529                         break;
 530                 if (errno != EINTR)
 531                         break;
 532         }
 533         return ret;
 534 }