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