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