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                         break;
 171                 default:
 172                         errs = 1;
 173                         error("src refspec %s matches more than one.",
 174                               rs[i].src);
 175                         break;
 176                 }
 177                 switch (count_refspec_match(rs[i].dst, dst, &matched_dst)) {
 178                 case 1:
 179                         break;
 180                 case 0:
 181                         if (!memcmp(rs[i].dst, "refs/", 5)) {
 182                                 int len = strlen(rs[i].dst) + 1;
 183                                 matched_dst = xcalloc(1, sizeof(*dst) + len);
 184                                 memcpy(matched_dst->name, rs[i].dst, len);
 185                                 link_dst_tail(matched_dst, dst_tail);
 186                         }
 187                         else if (!strcmp(rs[i].src, rs[i].dst) &&
 188                                  matched_src) {
 189                                 /* pushing "master:master" when
 190                                  * remote does not have master yet.
 191                                  */
 192                                 int len = strlen(matched_src->name) + 1;
 193                                 matched_dst = xcalloc(1, sizeof(*dst) + len);
 194                                 memcpy(matched_dst->name, matched_src->name,
 195                                        len);
 196                                 link_dst_tail(matched_dst, dst_tail);
 197                         }
 198                         else {
 199                                 errs = 1;
 200                                 error("dst refspec %s does not match any "
 201                                       "existing ref on the remote and does "
 202                                       "not start with refs/.", rs[i].dst);
 203                         }
 204                         break;
 205                 default:
 206                         errs = 1;
 207                         error("dst refspec %s matches more than one.",
 208                               rs[i].dst);
 209                         break;
 210                 }
 211                 if (errs)
 212                         continue;
 213                 if (matched_dst->peer_ref) {
 214                         errs = 1;
 215                         error("dst ref %s receives from more than one src.",
 216                               matched_dst->name);
 217                 }
 218                 else
 219                         matched_dst->peer_ref = matched_src;
 220         }
 221         return -errs;
 222 }
 223
 224 static struct ref *find_ref_by_name(struct ref *list, const char *name)
 225 {
 226         for ( ; list; list = list->next)
 227                 if (!strcmp(list->name, name))
 228                         return list;
 229         return NULL;
 230 }
 231
 232 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 233                int nr_refspec, char **refspec, int all)
 234 {
 235         struct refspec *rs = parse_ref_spec(nr_refspec, refspec);
 236
 237         if (nr_refspec)
 238                 return match_explicit_refs(src, dst, dst_tail, rs);
 239
 240         /* pick the remainder */
 241         for ( ; src; src = src->next) {
 242                 struct ref *dst_peer;
 243                 if (src->peer_ref)
 244                         continue;
 245                 dst_peer = find_ref_by_name(dst, src->name);
 246                 if ((dst_peer && dst_peer->peer_ref) || (!dst_peer && !all))
 247                         continue;
 248                 if (!dst_peer) {
 249                         /* Create a new one and link it */
 250                         int len = strlen(src->name) + 1;
 251                         dst_peer = xcalloc(1, sizeof(*dst_peer) + len);
 252                         memcpy(dst_peer->name, src->name, len);
 253                         memcpy(dst_peer->new_sha1, src->new_sha1, 20);
 254                         link_dst_tail(dst_peer, dst_tail);
 255                 }
 256                 dst_peer->peer_ref = src;
 257         }
 258         return 0;
 259 }
 260
 261 enum protocol {
 262         PROTO_LOCAL = 1,
 263         PROTO_SSH,
 264         PROTO_GIT,
 265 };
 266
 267 static enum protocol get_protocol(const char *name)
 268 {
 269         if (!strcmp(name, "ssh"))
 270                 return PROTO_SSH;
 271         if (!strcmp(name, "git"))
 272                 return PROTO_GIT;
 273         die("I don't handle protocol '%s'", name);
 274 }
 275
 276 #define STR_(s) # s
 277 #define STR(s)  STR_(s)
 278
 279 static int git_tcp_connect(int fd[2], const char *prog, char *host, char *path)
 280 {
 281         int sockfd = -1;
 282         char *colon, *end;
 283         char *port = STR(DEFAULT_GIT_PORT);
 284         struct addrinfo hints, *ai0, *ai;
 285         int gai;
 286
 287         if (host[0] == '[') {
 288                 end = strchr(host + 1, ']');
 289                 if (end) {
 290                         *end = 0;
 291                         end++;
 292                         host++;
 293                 } else
 294                         end = host;
 295         } else
 296                 end = host;
 297         colon = strchr(end, ':');
 298
 299         if (colon) {
 300                 *colon = 0;
 301                 port = colon + 1;
 302         }
 303
 304         memset(&hints, 0, sizeof(hints));
 305         hints.ai_socktype = SOCK_STREAM;
 306         hints.ai_protocol = IPPROTO_TCP;
 307
 308         gai = getaddrinfo(host, port, &hints, &ai);
 309         if (gai)
 310                 die("Unable to look up %s (%s)", host, gai_strerror(gai));
 311
 312         for (ai0 = ai; ai; ai = ai->ai_next) {
 313                 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 314                 if (sockfd < 0)
 315                         continue;
 316                 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 317                         close(sockfd);
 318                         sockfd = -1;
 319                         continue;
 320                 }
 321                 break;
 322         }
 323
 324         freeaddrinfo(ai0);
 325
 326         if (sockfd < 0)
 327                 die("unable to connect a socket (%s)", strerror(errno));
 328
 329         fd[0] = sockfd;
 330         fd[1] = sockfd;
 331         packet_write(sockfd, "%s %s\n", prog, path);
 332         return 0;
 333 }
 334
 335 /*
 336  * Yeah, yeah, fixme. Need to pass in the heads etc.
 337  */
 338 int git_connect(int fd[2], char *url, const char *prog)
 339 {
 340         char command[1024];
 341         char *host, *path;
 342         char *colon;
 343         int pipefd[2][2];
 344         pid_t pid;
 345         enum protocol protocol;
 346
 347         host = NULL;
 348         path = url;
 349         colon = strchr(url, ':');
 350         protocol = PROTO_LOCAL;
 351         if (colon) {
 352                 *colon = 0;
 353                 host = url;
 354                 path = colon+1;
 355                 protocol = PROTO_SSH;
 356                 if (!memcmp(path, "//", 2)) {
 357                         char *slash = strchr(path + 2, '/');
 358                         if (slash) {
 359                                 int nr = slash - path - 2;
 360                                 memmove(path, path+2, nr);
 361                                 path[nr] = 0;
 362                                 protocol = get_protocol(url);
 363                                 host = path;
 364                                 path = slash;
 365                         }
 366                 }
 367         }
 368
 369         if (protocol == PROTO_GIT)
 370                 return git_tcp_connect(fd, prog, host, path);
 371
 372         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 373                 die("unable to create pipe pair for communication");
 374         pid = fork();
 375         if (!pid) {
 376                 snprintf(command, sizeof(command), "%s %s", prog,
 377                          sq_quote(path));
 378                 dup2(pipefd[1][0], 0);
 379                 dup2(pipefd[0][1], 1);
 380                 close(pipefd[0][0]);
 381                 close(pipefd[0][1]);
 382                 close(pipefd[1][0]);
 383                 close(pipefd[1][1]);
 384                 if (protocol == PROTO_SSH)
 385                         execlp("ssh", "ssh", host, command, NULL);
 386                 else
 387                         execlp("sh", "sh", "-c", command, NULL);
 388                 die("exec failed");
 389         }
 390         fd[0] = pipefd[0][0];
 391         fd[1] = pipefd[1][1];
 392         close(pipefd[0][1]);
 393         close(pipefd[1][0]);
 394         return pid;
 395 }
 396
 397 int finish_connect(pid_t pid)
 398 {
 399         int ret;
 400
 401         for (;;) {
 402                 ret = waitpid(pid, NULL, 0);
 403                 if (!ret)
 404                         break;
 405                 if (errno != EINTR)
 406                         break;
 407         }
 408         return ret;
 409 }