connect.c

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