Andrew's git / gitweb.git / connect.c
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connect.con commit git-fetch-pack: Support multi_ack extension (c4c86f0)
   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
  11static char *server_capabilities = "";
  12
  13/*
  14 * Read all the refs from the other end
  15 */
  16struct ref **get_remote_heads(int in, struct ref **list,
  17                              int nr_match, char **match, int ignore_funny)
  18{
  19        *list = NULL;
  20        for (;;) {
  21                struct ref *ref;
  22                unsigned char old_sha1[20];
  23                static char buffer[1000];
  24                char *name;
  25                int len, name_len;
  26
  27                len = packet_read_line(in, buffer, sizeof(buffer));
  28                if (!len)
  29                        break;
  30                if (buffer[len-1] == '\n')
  31                        buffer[--len] = 0;
  32
  33                if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  34                        die("protocol error: expected sha/ref, got '%s'", buffer);
  35                name = buffer + 41;
  36
  37                if (ignore_funny && 45 < len && !memcmp(name, "refs/", 5) &&
  38                    check_ref_format(name + 5))
  39                        continue;
  40
  41                name_len = strlen(name);
  42                if (len != name_len + 41) {
  43                        if (server_capabilities)
  44                                free(server_capabilities);
  45                        server_capabilities = strdup(name + name_len + 1);
  46                }
  47
  48                if (nr_match && !path_match(name, nr_match, match))
  49                        continue;
  50                ref = xcalloc(1, sizeof(*ref) + len - 40);
  51                memcpy(ref->old_sha1, old_sha1, 20);
  52                memcpy(ref->name, buffer + 41, len - 40);
  53                *list = ref;
  54                list = &ref->next;
  55        }
  56        return list;
  57}
  58
  59int server_supports(const char *feature)
  60{
  61        return strstr(feature, server_capabilities) != NULL;
  62}
  63
  64int get_ack(int fd, unsigned char *result_sha1)
  65{
  66        static char line[1000];
  67        int len = packet_read_line(fd, line, sizeof(line));
  68
  69        if (!len)
  70                die("git-fetch-pack: expected ACK/NAK, got EOF");
  71        if (line[len-1] == '\n')
  72                line[--len] = 0;
  73        if (!strcmp(line, "NAK"))
  74                return 0;
  75        if (!strncmp(line, "ACK ", 3)) {
  76                if (!get_sha1_hex(line+4, result_sha1)) {
  77                        if (strstr(line+45, "continue"))
  78                                return 2;
  79                        return 1;
  80                }
  81        }
  82        die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
  83}
  84
  85int path_match(const char *path, int nr, char **match)
  86{
  87        int i;
  88        int pathlen = strlen(path);
  89
  90        for (i = 0; i < nr; i++) {
  91                char *s = match[i];
  92                int len = strlen(s);
  93
  94                if (!len || len > pathlen)
  95                        continue;
  96                if (memcmp(path + pathlen - len, s, len))
  97                        continue;
  98                if (pathlen > len && path[pathlen - len - 1] != '/')
  99                        continue;
 100                *s = 0;
 101                return 1;
 102        }
 103        return 0;
 104}
 105
 106struct refspec {
 107        char *src;
 108        char *dst;
 109        char force;
 110};
 111
 112/*
 113 * A:B means fast forward remote B with local A.
 114 * +A:B means overwrite remote B with local A.
 115 * +A is a shorthand for +A:A.
 116 * A is a shorthand for A:A.
 117 */
 118static struct refspec *parse_ref_spec(int nr_refspec, char **refspec)
 119{
 120        int i;
 121        struct refspec *rs = xcalloc(sizeof(*rs), (nr_refspec + 1));
 122        for (i = 0; i < nr_refspec; i++) {
 123                char *sp, *dp, *ep;
 124                sp = refspec[i];
 125                if (*sp == '+') {
 126                        rs[i].force = 1;
 127                        sp++;
 128                }
 129                ep = strchr(sp, ':');
 130                if (ep) {
 131                        dp = ep + 1;
 132                        *ep = 0;
 133                }
 134                else
 135                        dp = sp;
 136                rs[i].src = sp;
 137                rs[i].dst = dp;
 138        }
 139        rs[nr_refspec].src = rs[nr_refspec].dst = NULL;
 140        return rs;
 141}
 142
 143static int count_refspec_match(const char *pattern,
 144                               struct ref *refs,
 145                               struct ref **matched_ref)
 146{
 147        int match;
 148        int patlen = strlen(pattern);
 149
 150        for (match = 0; refs; refs = refs->next) {
 151                char *name = refs->name;
 152                int namelen = strlen(name);
 153                if (namelen < patlen ||
 154                    memcmp(name + namelen - patlen, pattern, patlen))
 155                        continue;
 156                if (namelen != patlen && name[namelen - patlen - 1] != '/')
 157                        continue;
 158                match++;
 159                *matched_ref = refs;
 160        }
 161        return match;
 162}
 163
 164static void link_dst_tail(struct ref *ref, struct ref ***tail)
 165{
 166        **tail = ref;
 167        *tail = &ref->next;
 168        **tail = NULL;
 169}
 170
 171static struct ref *try_explicit_object_name(const char *name)
 172{
 173        unsigned char sha1[20];
 174        struct ref *ref;
 175        int len;
 176        if (get_sha1(name, sha1))
 177                return NULL;
 178        len = strlen(name) + 1;
 179        ref = xcalloc(1, sizeof(*ref) + len);
 180        memcpy(ref->name, name, len);
 181        memcpy(ref->new_sha1, sha1, 20);
 182        return ref;
 183}
 184
 185static int match_explicit_refs(struct ref *src, struct ref *dst,
 186                               struct ref ***dst_tail, struct refspec *rs)
 187{
 188        int i, errs;
 189        for (i = errs = 0; rs[i].src; i++) {
 190                struct ref *matched_src, *matched_dst;
 191
 192                matched_src = matched_dst = NULL;
 193                switch (count_refspec_match(rs[i].src, src, &matched_src)) {
 194                case 1:
 195                        break;
 196                case 0:
 197                        /* The source could be in the get_sha1() format
 198                         * not a reference name.
 199                         */
 200                        matched_src = try_explicit_object_name(rs[i].src);
 201                        if (matched_src)
 202                                break;
 203                        errs = 1;
 204                        error("src refspec %s does not match any.",
 205                              rs[i].src);
 206                        break;
 207                default:
 208                        errs = 1;
 209                        error("src refspec %s matches more than one.",
 210                              rs[i].src);
 211                        break;
 212                }
 213                switch (count_refspec_match(rs[i].dst, dst, &matched_dst)) {
 214                case 1:
 215                        break;
 216                case 0:
 217                        if (!memcmp(rs[i].dst, "refs/", 5)) {
 218                                int len = strlen(rs[i].dst) + 1;
 219                                matched_dst = xcalloc(1, sizeof(*dst) + len);
 220                                memcpy(matched_dst->name, rs[i].dst, len);
 221                                link_dst_tail(matched_dst, dst_tail);
 222                        }
 223                        else if (!strcmp(rs[i].src, rs[i].dst) &&
 224                                 matched_src) {
 225                                /* pushing "master:master" when
 226                                 * remote does not have master yet.
 227                                 */
 228                                int len = strlen(matched_src->name) + 1;
 229                                matched_dst = xcalloc(1, sizeof(*dst) + len);
 230                                memcpy(matched_dst->name, matched_src->name,
 231                                       len);
 232                                link_dst_tail(matched_dst, dst_tail);
 233                        }
 234                        else {
 235                                errs = 1;
 236                                error("dst refspec %s does not match any "
 237                                      "existing ref on the remote and does "
 238                                      "not start with refs/.", rs[i].dst);
 239                        }
 240                        break;
 241                default:
 242                        errs = 1;
 243                        error("dst refspec %s matches more than one.",
 244                              rs[i].dst);
 245                        break;
 246                }
 247                if (errs)
 248                        continue;
 249                if (matched_dst->peer_ref) {
 250                        errs = 1;
 251                        error("dst ref %s receives from more than one src.",
 252                              matched_dst->name);
 253                }
 254                else {
 255                        matched_dst->peer_ref = matched_src;
 256                        matched_dst->force = rs[i].force;
 257                }
 258        }
 259        return -errs;
 260}
 261
 262static struct ref *find_ref_by_name(struct ref *list, const char *name)
 263{
 264        for ( ; list; list = list->next)
 265                if (!strcmp(list->name, name))
 266                        return list;
 267        return NULL;
 268}
 269
 270int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 271               int nr_refspec, char **refspec, int all)
 272{
 273        struct refspec *rs = parse_ref_spec(nr_refspec, refspec);
 274
 275        if (nr_refspec)
 276                return match_explicit_refs(src, dst, dst_tail, rs);
 277
 278        /* pick the remainder */
 279        for ( ; src; src = src->next) {
 280                struct ref *dst_peer;
 281                if (src->peer_ref)
 282                        continue;
 283                dst_peer = find_ref_by_name(dst, src->name);
 284                if ((dst_peer && dst_peer->peer_ref) || (!dst_peer && !all))
 285                        continue;
 286                if (!dst_peer) {
 287                        /* Create a new one and link it */
 288                        int len = strlen(src->name) + 1;
 289                        dst_peer = xcalloc(1, sizeof(*dst_peer) + len);
 290                        memcpy(dst_peer->name, src->name, len);
 291                        memcpy(dst_peer->new_sha1, src->new_sha1, 20);
 292                        link_dst_tail(dst_peer, dst_tail);
 293                }
 294                dst_peer->peer_ref = src;
 295        }
 296        return 0;
 297}
 298
 299enum protocol {
 300        PROTO_LOCAL = 1,
 301        PROTO_SSH,
 302        PROTO_GIT,
 303};
 304
 305static enum protocol get_protocol(const char *name)
 306{
 307        if (!strcmp(name, "ssh"))
 308                return PROTO_SSH;
 309        if (!strcmp(name, "git"))
 310                return PROTO_GIT;
 311        if (!strcmp(name, "git+ssh"))
 312                return PROTO_SSH;
 313        if (!strcmp(name, "ssh+git"))
 314                return PROTO_SSH;
 315        die("I don't handle protocol '%s'", name);
 316}
 317
 318#define STR_(s) # s
 319#define STR(s)  STR_(s)
 320
 321#ifndef NO_IPV6
 322
 323static int git_tcp_connect(int fd[2], const char *prog, char *host, char *path)
 324{
 325        int sockfd = -1;
 326        char *colon, *end;
 327        char *port = STR(DEFAULT_GIT_PORT);
 328        struct addrinfo hints, *ai0, *ai;
 329        int gai;
 330
 331        if (host[0] == '[') {
 332                end = strchr(host + 1, ']');
 333                if (end) {
 334                        *end = 0;
 335                        end++;
 336                        host++;
 337                } else
 338                        end = host;
 339        } else
 340                end = host;
 341        colon = strchr(end, ':');
 342
 343        if (colon) {
 344                *colon = 0;
 345                port = colon + 1;
 346        }
 347
 348        memset(&hints, 0, sizeof(hints));
 349        hints.ai_socktype = SOCK_STREAM;
 350        hints.ai_protocol = IPPROTO_TCP;
 351
 352        gai = getaddrinfo(host, port, &hints, &ai);
 353        if (gai)
 354                die("Unable to look up %s (%s)", host, gai_strerror(gai));
 355
 356        for (ai0 = ai; ai; ai = ai->ai_next) {
 357                sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 358                if (sockfd < 0)
 359                        continue;
 360                if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 361                        close(sockfd);
 362                        sockfd = -1;
 363                        continue;
 364                }
 365                break;
 366        }
 367
 368        freeaddrinfo(ai0);
 369
 370        if (sockfd < 0)
 371                die("unable to connect a socket (%s)", strerror(errno));
 372
 373        fd[0] = sockfd;
 374        fd[1] = sockfd;
 375        packet_write(sockfd, "%s %s\n", prog, path);
 376        return 0;
 377}
 378
 379#else /* NO_IPV6 */
 380
 381static int git_tcp_connect(int fd[2], const char *prog, char *host, char *path)
 382{
 383        int sockfd = -1;
 384        char *colon, *end;
 385        char *port = STR(DEFAULT_GIT_PORT), *ep;
 386        struct hostent *he;
 387        struct sockaddr_in sa;
 388        char **ap;
 389        unsigned int nport;
 390
 391        if (host[0] == '[') {
 392                end = strchr(host + 1, ']');
 393                if (end) {
 394                        *end = 0;
 395                        end++;
 396                        host++;
 397                } else
 398                        end = host;
 399        } else
 400                end = host;
 401        colon = strchr(end, ':');
 402
 403        if (colon) {
 404                *colon = 0;
 405                port = colon + 1;
 406        }
 407
 408
 409        he = gethostbyname(host);
 410        if (!he)
 411                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 412        nport = strtoul(port, &ep, 10);
 413        if ( ep == port || *ep ) {
 414                /* Not numeric */
 415                struct servent *se = getservbyname(port,"tcp");
 416                if ( !se )
 417                        die("Unknown port %s\n", port);
 418                nport = se->s_port;
 419        }
 420
 421        for (ap = he->h_addr_list; *ap; ap++) {
 422                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 423                if (sockfd < 0)
 424                        continue;
 425
 426                memset(&sa, 0, sizeof sa);
 427                sa.sin_family = he->h_addrtype;
 428                sa.sin_port = htons(nport);
 429                memcpy(&sa.sin_addr, ap, he->h_length);
 430
 431                if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 432                        close(sockfd);
 433                        sockfd = -1;
 434                        continue;
 435                }
 436                break;
 437        }
 438
 439        if (sockfd < 0)
 440                die("unable to connect a socket (%s)", strerror(errno));
 441
 442        fd[0] = sockfd;
 443        fd[1] = sockfd;
 444        packet_write(sockfd, "%s %s\n", prog, path);
 445        return 0;
 446}
 447
 448#endif /* NO_IPV6 */
 449
 450/*
 451 * Yeah, yeah, fixme. Need to pass in the heads etc.
 452 */
 453int git_connect(int fd[2], char *url, const char *prog)
 454{
 455        char command[1024];
 456        char *host, *path;
 457        char *colon;
 458        int pipefd[2][2];
 459        pid_t pid;
 460        enum protocol protocol;
 461
 462        host = NULL;
 463        path = url;
 464        colon = strchr(url, ':');
 465        protocol = PROTO_LOCAL;
 466        if (colon) {
 467                *colon = 0;
 468                host = url;
 469                path = colon+1;
 470                protocol = PROTO_SSH;
 471                if (!memcmp(path, "//", 2)) {
 472                        char *slash = strchr(path + 2, '/');
 473                        if (slash) {
 474                                int nr = slash - path - 2;
 475                                memmove(path, path+2, nr);
 476                                path[nr] = 0;
 477                                protocol = get_protocol(url);
 478                                host = path;
 479                                path = slash;
 480                        }
 481                }
 482        }
 483
 484        if (protocol == PROTO_GIT)
 485                return git_tcp_connect(fd, prog, host, path);
 486
 487        if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 488                die("unable to create pipe pair for communication");
 489        pid = fork();
 490        if (!pid) {
 491                snprintf(command, sizeof(command), "%s %s", prog,
 492                         sq_quote(path));
 493                dup2(pipefd[1][0], 0);
 494                dup2(pipefd[0][1], 1);
 495                close(pipefd[0][0]);
 496                close(pipefd[0][1]);
 497                close(pipefd[1][0]);
 498                close(pipefd[1][1]);
 499                if (protocol == PROTO_SSH) {
 500                        const char *ssh, *ssh_basename;
 501                        ssh = getenv("GIT_SSH");
 502                        if (!ssh) ssh = "ssh";
 503                        ssh_basename = strrchr(ssh, '/');
 504                        if (!ssh_basename)
 505                                ssh_basename = ssh;
 506                        else
 507                                ssh_basename++;
 508                        execlp(ssh, ssh_basename, host, command, NULL);
 509                }
 510                else
 511                        execlp("sh", "sh", "-c", command, NULL);
 512                die("exec failed");
 513        }               
 514        fd[0] = pipefd[0][0];
 515        fd[1] = pipefd[1][1];
 516        close(pipefd[0][1]);
 517        close(pipefd[1][0]);
 518        return pid;
 519}
 520
 521int finish_connect(pid_t pid)
 522{
 523        int ret;
 524
 525        for (;;) {
 526                ret = waitpid(pid, NULL, 0);
 527                if (!ret)
 528                        break;
 529                if (errno != EINTR)
 530                        break;
 531        }
 532        return ret;
 533}