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