Andrew's git / gitweb.git / connect.c
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connect.con commit Merge branch 'mm/levenstein-penalize-deletion-less' (7a824d3)
   1#include "git-compat-util.h"
   2#include "cache.h"
   3#include "pkt-line.h"
   4#include "quote.h"
   5#include "refs.h"
   6#include "run-command.h"
   7#include "remote.h"
   8#include "url.h"
   9
  10static char *server_capabilities;
  11
  12static int check_ref(const char *name, int len, unsigned int flags)
  13{
  14        if (!flags)
  15                return 1;
  16
  17        if (len < 5 || memcmp(name, "refs/", 5))
  18                return 0;
  19
  20        /* Skip the "refs/" part */
  21        name += 5;
  22        len -= 5;
  23
  24        /* REF_NORMAL means that we don't want the magic fake tag refs */
  25        if ((flags & REF_NORMAL) && check_refname_format(name, 0))
  26                return 0;
  27
  28        /* REF_HEADS means that we want regular branch heads */
  29        if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6))
  30                return 1;
  31
  32        /* REF_TAGS means that we want tags */
  33        if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5))
  34                return 1;
  35
  36        /* All type bits clear means that we are ok with anything */
  37        return !(flags & ~REF_NORMAL);
  38}
  39
  40int check_ref_type(const struct ref *ref, int flags)
  41{
  42        return check_ref(ref->name, strlen(ref->name), flags);
  43}
  44
  45static void add_extra_have(struct extra_have_objects *extra, unsigned char *sha1)
  46{
  47        ALLOC_GROW(extra->array, extra->nr + 1, extra->alloc);
  48        hashcpy(&(extra->array[extra->nr][0]), sha1);
  49        extra->nr++;
  50}
  51
  52/*
  53 * Read all the refs from the other end
  54 */
  55struct ref **get_remote_heads(int in, struct ref **list,
  56                              unsigned int flags,
  57                              struct extra_have_objects *extra_have)
  58{
  59        *list = NULL;
  60        for (;;) {
  61                struct ref *ref;
  62                unsigned char old_sha1[20];
  63                static char buffer[1000];
  64                char *name;
  65                int len, name_len;
  66
  67                len = packet_read_line(in, buffer, sizeof(buffer));
  68                if (!len)
  69                        break;
  70                if (buffer[len-1] == '\n')
  71                        buffer[--len] = 0;
  72
  73                if (len > 4 && !prefixcmp(buffer, "ERR "))
  74                        die("remote error: %s", buffer + 4);
  75
  76                if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  77                        die("protocol error: expected sha/ref, got '%s'", buffer);
  78                name = buffer + 41;
  79
  80                name_len = strlen(name);
  81                if (len != name_len + 41) {
  82                        free(server_capabilities);
  83                        server_capabilities = xstrdup(name + name_len + 1);
  84                }
  85
  86                if (extra_have &&
  87                    name_len == 5 && !memcmp(".have", name, 5)) {
  88                        add_extra_have(extra_have, old_sha1);
  89                        continue;
  90                }
  91
  92                if (!check_ref(name, name_len, flags))
  93                        continue;
  94                ref = alloc_ref(buffer + 41);
  95                hashcpy(ref->old_sha1, old_sha1);
  96                *list = ref;
  97                list = &ref->next;
  98        }
  99        return list;
 100}
 101
 102int server_supports(const char *feature)
 103{
 104        return !!parse_feature_request(server_capabilities, feature);
 105}
 106
 107const char *parse_feature_request(const char *feature_list, const char *feature)
 108{
 109        int len;
 110
 111        if (!feature_list)
 112                return NULL;
 113
 114        len = strlen(feature);
 115        while (*feature_list) {
 116                const char *found = strstr(feature_list, feature);
 117                if (!found)
 118                        return NULL;
 119                if ((feature_list == found || isspace(found[-1])) &&
 120                    (!found[len] || isspace(found[len]) || found[len] == '='))
 121                        return found;
 122                feature_list = found + 1;
 123        }
 124        return NULL;
 125}
 126
 127enum protocol {
 128        PROTO_LOCAL = 1,
 129        PROTO_SSH,
 130        PROTO_GIT
 131};
 132
 133static enum protocol get_protocol(const char *name)
 134{
 135        if (!strcmp(name, "ssh"))
 136                return PROTO_SSH;
 137        if (!strcmp(name, "git"))
 138                return PROTO_GIT;
 139        if (!strcmp(name, "git+ssh"))
 140                return PROTO_SSH;
 141        if (!strcmp(name, "ssh+git"))
 142                return PROTO_SSH;
 143        if (!strcmp(name, "file"))
 144                return PROTO_LOCAL;
 145        die("I don't handle protocol '%s'", name);
 146}
 147
 148#define STR_(s) # s
 149#define STR(s)  STR_(s)
 150
 151static void get_host_and_port(char **host, const char **port)
 152{
 153        char *colon, *end;
 154
 155        if (*host[0] == '[') {
 156                end = strchr(*host + 1, ']');
 157                if (end) {
 158                        *end = 0;
 159                        end++;
 160                        (*host)++;
 161                } else
 162                        end = *host;
 163        } else
 164                end = *host;
 165        colon = strchr(end, ':');
 166
 167        if (colon) {
 168                *colon = 0;
 169                *port = colon + 1;
 170        }
 171}
 172
 173static void enable_keepalive(int sockfd)
 174{
 175        int ka = 1;
 176
 177        if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 178                fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 179                        strerror(errno));
 180}
 181
 182#ifndef NO_IPV6
 183
 184static const char *ai_name(const struct addrinfo *ai)
 185{
 186        static char addr[NI_MAXHOST];
 187        if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 188                        NI_NUMERICHOST) != 0)
 189                strcpy(addr, "(unknown)");
 190
 191        return addr;
 192}
 193
 194/*
 195 * Returns a connected socket() fd, or else die()s.
 196 */
 197static int git_tcp_connect_sock(char *host, int flags)
 198{
 199        struct strbuf error_message = STRBUF_INIT;
 200        int sockfd = -1;
 201        const char *port = STR(DEFAULT_GIT_PORT);
 202        struct addrinfo hints, *ai0, *ai;
 203        int gai;
 204        int cnt = 0;
 205
 206        get_host_and_port(&host, &port);
 207        if (!*port)
 208                port = "<none>";
 209
 210        memset(&hints, 0, sizeof(hints));
 211        hints.ai_socktype = SOCK_STREAM;
 212        hints.ai_protocol = IPPROTO_TCP;
 213
 214        if (flags & CONNECT_VERBOSE)
 215                fprintf(stderr, "Looking up %s ... ", host);
 216
 217        gai = getaddrinfo(host, port, &hints, &ai);
 218        if (gai)
 219                die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 220
 221        if (flags & CONNECT_VERBOSE)
 222                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 223
 224        for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 225                sockfd = socket(ai->ai_family,
 226                                ai->ai_socktype, ai->ai_protocol);
 227                if ((sockfd < 0) ||
 228                    (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 229                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 230                                    host, cnt, ai_name(ai), strerror(errno));
 231                        if (0 <= sockfd)
 232                                close(sockfd);
 233                        sockfd = -1;
 234                        continue;
 235                }
 236                if (flags & CONNECT_VERBOSE)
 237                        fprintf(stderr, "%s ", ai_name(ai));
 238                break;
 239        }
 240
 241        freeaddrinfo(ai0);
 242
 243        if (sockfd < 0)
 244                die("unable to connect to %s:\n%s", host, error_message.buf);
 245
 246        enable_keepalive(sockfd);
 247
 248        if (flags & CONNECT_VERBOSE)
 249                fprintf(stderr, "done.\n");
 250
 251        strbuf_release(&error_message);
 252
 253        return sockfd;
 254}
 255
 256#else /* NO_IPV6 */
 257
 258/*
 259 * Returns a connected socket() fd, or else die()s.
 260 */
 261static int git_tcp_connect_sock(char *host, int flags)
 262{
 263        struct strbuf error_message = STRBUF_INIT;
 264        int sockfd = -1;
 265        const char *port = STR(DEFAULT_GIT_PORT);
 266        char *ep;
 267        struct hostent *he;
 268        struct sockaddr_in sa;
 269        char **ap;
 270        unsigned int nport;
 271        int cnt;
 272
 273        get_host_and_port(&host, &port);
 274
 275        if (flags & CONNECT_VERBOSE)
 276                fprintf(stderr, "Looking up %s ... ", host);
 277
 278        he = gethostbyname(host);
 279        if (!he)
 280                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 281        nport = strtoul(port, &ep, 10);
 282        if ( ep == port || *ep ) {
 283                /* Not numeric */
 284                struct servent *se = getservbyname(port,"tcp");
 285                if ( !se )
 286                        die("Unknown port %s", port);
 287                nport = se->s_port;
 288        }
 289
 290        if (flags & CONNECT_VERBOSE)
 291                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 292
 293        for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 294                memset(&sa, 0, sizeof sa);
 295                sa.sin_family = he->h_addrtype;
 296                sa.sin_port = htons(nport);
 297                memcpy(&sa.sin_addr, *ap, he->h_length);
 298
 299                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 300                if ((sockfd < 0) ||
 301                    connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 302                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 303                                host,
 304                                cnt,
 305                                inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 306                                strerror(errno));
 307                        if (0 <= sockfd)
 308                                close(sockfd);
 309                        sockfd = -1;
 310                        continue;
 311                }
 312                if (flags & CONNECT_VERBOSE)
 313                        fprintf(stderr, "%s ",
 314                                inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 315                break;
 316        }
 317
 318        if (sockfd < 0)
 319                die("unable to connect to %s:\n%s", host, error_message.buf);
 320
 321        enable_keepalive(sockfd);
 322
 323        if (flags & CONNECT_VERBOSE)
 324                fprintf(stderr, "done.\n");
 325
 326        return sockfd;
 327}
 328
 329#endif /* NO_IPV6 */
 330
 331
 332static void git_tcp_connect(int fd[2], char *host, int flags)
 333{
 334        int sockfd = git_tcp_connect_sock(host, flags);
 335
 336        fd[0] = sockfd;
 337        fd[1] = dup(sockfd);
 338}
 339
 340
 341static char *git_proxy_command;
 342
 343static int git_proxy_command_options(const char *var, const char *value,
 344                void *cb)
 345{
 346        if (!strcmp(var, "core.gitproxy")) {
 347                const char *for_pos;
 348                int matchlen = -1;
 349                int hostlen;
 350                const char *rhost_name = cb;
 351                int rhost_len = strlen(rhost_name);
 352
 353                if (git_proxy_command)
 354                        return 0;
 355                if (!value)
 356                        return config_error_nonbool(var);
 357                /* [core]
 358                 * ;# matches www.kernel.org as well
 359                 * gitproxy = netcatter-1 for kernel.org
 360                 * gitproxy = netcatter-2 for sample.xz
 361                 * gitproxy = netcatter-default
 362                 */
 363                for_pos = strstr(value, " for ");
 364                if (!for_pos)
 365                        /* matches everybody */
 366                        matchlen = strlen(value);
 367                else {
 368                        hostlen = strlen(for_pos + 5);
 369                        if (rhost_len < hostlen)
 370                                matchlen = -1;
 371                        else if (!strncmp(for_pos + 5,
 372                                          rhost_name + rhost_len - hostlen,
 373                                          hostlen) &&
 374                                 ((rhost_len == hostlen) ||
 375                                  rhost_name[rhost_len - hostlen -1] == '.'))
 376                                matchlen = for_pos - value;
 377                        else
 378                                matchlen = -1;
 379                }
 380                if (0 <= matchlen) {
 381                        /* core.gitproxy = none for kernel.org */
 382                        if (matchlen == 4 &&
 383                            !memcmp(value, "none", 4))
 384                                matchlen = 0;
 385                        git_proxy_command = xmemdupz(value, matchlen);
 386                }
 387                return 0;
 388        }
 389
 390        return git_default_config(var, value, cb);
 391}
 392
 393static int git_use_proxy(const char *host)
 394{
 395        git_proxy_command = getenv("GIT_PROXY_COMMAND");
 396        git_config(git_proxy_command_options, (void*)host);
 397        return (git_proxy_command && *git_proxy_command);
 398}
 399
 400static struct child_process *git_proxy_connect(int fd[2], char *host)
 401{
 402        const char *port = STR(DEFAULT_GIT_PORT);
 403        const char **argv;
 404        struct child_process *proxy;
 405
 406        get_host_and_port(&host, &port);
 407
 408        argv = xmalloc(sizeof(*argv) * 4);
 409        argv[0] = git_proxy_command;
 410        argv[1] = host;
 411        argv[2] = port;
 412        argv[3] = NULL;
 413        proxy = xcalloc(1, sizeof(*proxy));
 414        proxy->argv = argv;
 415        proxy->in = -1;
 416        proxy->out = -1;
 417        if (start_command(proxy))
 418                die("cannot start proxy %s", argv[0]);
 419        fd[0] = proxy->out; /* read from proxy stdout */
 420        fd[1] = proxy->in;  /* write to proxy stdin */
 421        return proxy;
 422}
 423
 424#define MAX_CMD_LEN 1024
 425
 426static char *get_port(char *host)
 427{
 428        char *end;
 429        char *p = strchr(host, ':');
 430
 431        if (p) {
 432                long port = strtol(p + 1, &end, 10);
 433                if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 434                        *p = '\0';
 435                        return p+1;
 436                }
 437        }
 438
 439        return NULL;
 440}
 441
 442static struct child_process no_fork;
 443
 444/*
 445 * This returns a dummy child_process if the transport protocol does not
 446 * need fork(2), or a struct child_process object if it does.  Once done,
 447 * finish the connection with finish_connect() with the value returned from
 448 * this function (it is safe to call finish_connect() with NULL to support
 449 * the former case).
 450 *
 451 * If it returns, the connect is successful; it just dies on errors (this
 452 * will hopefully be changed in a libification effort, to return NULL when
 453 * the connection failed).
 454 */
 455struct child_process *git_connect(int fd[2], const char *url_orig,
 456                                  const char *prog, int flags)
 457{
 458        char *url;
 459        char *host, *path;
 460        char *end;
 461        int c;
 462        struct child_process *conn = &no_fork;
 463        enum protocol protocol = PROTO_LOCAL;
 464        int free_path = 0;
 465        char *port = NULL;
 466        const char **arg;
 467        struct strbuf cmd;
 468
 469        /* Without this we cannot rely on waitpid() to tell
 470         * what happened to our children.
 471         */
 472        signal(SIGCHLD, SIG_DFL);
 473
 474        if (is_url(url_orig))
 475                url = url_decode(url_orig);
 476        else
 477                url = xstrdup(url_orig);
 478
 479        host = strstr(url, "://");
 480        if (host) {
 481                *host = '\0';
 482                protocol = get_protocol(url);
 483                host += 3;
 484                c = '/';
 485        } else {
 486                host = url;
 487                c = ':';
 488        }
 489
 490        /*
 491         * Don't do destructive transforms with git:// as that
 492         * protocol code does '[]' unwrapping of its own.
 493         */
 494        if (host[0] == '[') {
 495                end = strchr(host + 1, ']');
 496                if (end) {
 497                        if (protocol != PROTO_GIT) {
 498                                *end = 0;
 499                                host++;
 500                        }
 501                        end++;
 502                } else
 503                        end = host;
 504        } else
 505                end = host;
 506
 507        path = strchr(end, c);
 508        if (path && !has_dos_drive_prefix(end)) {
 509                if (c == ':') {
 510                        protocol = PROTO_SSH;
 511                        *path++ = '\0';
 512                }
 513        } else
 514                path = end;
 515
 516        if (!path || !*path)
 517                die("No path specified. See 'man git-pull' for valid url syntax");
 518
 519        /*
 520         * null-terminate hostname and point path to ~ for URL's like this:
 521         *    ssh://host.xz/~user/repo
 522         */
 523        if (protocol != PROTO_LOCAL && host != url) {
 524                char *ptr = path;
 525                if (path[1] == '~')
 526                        path++;
 527                else {
 528                        path = xstrdup(ptr);
 529                        free_path = 1;
 530                }
 531
 532                *ptr = '\0';
 533        }
 534
 535        /*
 536         * Add support for ssh port: ssh://host.xy:<port>/...
 537         */
 538        if (protocol == PROTO_SSH && host != url)
 539                port = get_port(host);
 540
 541        if (protocol == PROTO_GIT) {
 542                /* These underlying connection commands die() if they
 543                 * cannot connect.
 544                 */
 545                char *target_host = xstrdup(host);
 546                if (git_use_proxy(host))
 547                        conn = git_proxy_connect(fd, host);
 548                else
 549                        git_tcp_connect(fd, host, flags);
 550                /*
 551                 * Separate original protocol components prog and path
 552                 * from extended host header with a NUL byte.
 553                 *
 554                 * Note: Do not add any other headers here!  Doing so
 555                 * will cause older git-daemon servers to crash.
 556                 */
 557                packet_write(fd[1],
 558                             "%s %s%chost=%s%c",
 559                             prog, path, 0,
 560                             target_host, 0);
 561                free(target_host);
 562                free(url);
 563                if (free_path)
 564                        free(path);
 565                return conn;
 566        }
 567
 568        conn = xcalloc(1, sizeof(*conn));
 569
 570        strbuf_init(&cmd, MAX_CMD_LEN);
 571        strbuf_addstr(&cmd, prog);
 572        strbuf_addch(&cmd, ' ');
 573        sq_quote_buf(&cmd, path);
 574        if (cmd.len >= MAX_CMD_LEN)
 575                die("command line too long");
 576
 577        conn->in = conn->out = -1;
 578        conn->argv = arg = xcalloc(7, sizeof(*arg));
 579        if (protocol == PROTO_SSH) {
 580                const char *ssh = getenv("GIT_SSH");
 581                int putty = ssh && strcasestr(ssh, "plink");
 582                if (!ssh) ssh = "ssh";
 583
 584                *arg++ = ssh;
 585                if (putty && !strcasestr(ssh, "tortoiseplink"))
 586                        *arg++ = "-batch";
 587                if (port) {
 588                        /* P is for PuTTY, p is for OpenSSH */
 589                        *arg++ = putty ? "-P" : "-p";
 590                        *arg++ = port;
 591                }
 592                *arg++ = host;
 593        }
 594        else {
 595                /* remove repo-local variables from the environment */
 596                conn->env = local_repo_env;
 597                conn->use_shell = 1;
 598        }
 599        *arg++ = cmd.buf;
 600        *arg = NULL;
 601
 602        if (start_command(conn))
 603                die("unable to fork");
 604
 605        fd[0] = conn->out; /* read from child's stdout */
 606        fd[1] = conn->in;  /* write to child's stdin */
 607        strbuf_release(&cmd);
 608        free(url);
 609        if (free_path)
 610                free(path);
 611        return conn;
 612}
 613
 614int git_connection_is_socket(struct child_process *conn)
 615{
 616        return conn == &no_fork;
 617}
 618
 619int finish_connect(struct child_process *conn)
 620{
 621        int code;
 622        if (!conn || git_connection_is_socket(conn))
 623                return 0;
 624
 625        code = finish_command(conn);
 626        free(conn->argv);
 627        free(conn);
 628        return code;
 629}