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