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