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