Andrew's git / gitweb.git / connect.c
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connect.con commit parse_feature_request: make it easier to see feature values (9442710)
   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
 102const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
 103{
 104        int len;
 105
 106        if (!feature_list)
 107                return NULL;
 108
 109        len = strlen(feature);
 110        while (*feature_list) {
 111                const char *found = strstr(feature_list, feature);
 112                if (!found)
 113                        return NULL;
 114                if (feature_list == found || isspace(found[-1])) {
 115                        const char *value = found + len;
 116                        /* feature with no value (e.g., "thin-pack") */
 117                        if (!*value || isspace(*value)) {
 118                                if (lenp)
 119                                        *lenp = 0;
 120                                return value;
 121                        }
 122                        /* feature with a value (e.g., "agent=git/1.2.3") */
 123                        else if (*value == '=') {
 124                                value++;
 125                                if (lenp)
 126                                        *lenp = strcspn(value, " \t\n");
 127                                return value;
 128                        }
 129                        /*
 130                         * otherwise we matched a substring of another feature;
 131                         * keep looking
 132                         */
 133                }
 134                feature_list = found + 1;
 135        }
 136        return NULL;
 137}
 138
 139int parse_feature_request(const char *feature_list, const char *feature)
 140{
 141        return !!parse_feature_value(feature_list, feature, NULL);
 142}
 143
 144const char *server_feature_value(const char *feature, int *len)
 145{
 146        return parse_feature_value(server_capabilities, feature, len);
 147}
 148
 149int server_supports(const char *feature)
 150{
 151        return !!server_feature_value(feature, NULL);
 152}
 153
 154enum protocol {
 155        PROTO_LOCAL = 1,
 156        PROTO_SSH,
 157        PROTO_GIT
 158};
 159
 160static enum protocol get_protocol(const char *name)
 161{
 162        if (!strcmp(name, "ssh"))
 163                return PROTO_SSH;
 164        if (!strcmp(name, "git"))
 165                return PROTO_GIT;
 166        if (!strcmp(name, "git+ssh"))
 167                return PROTO_SSH;
 168        if (!strcmp(name, "ssh+git"))
 169                return PROTO_SSH;
 170        if (!strcmp(name, "file"))
 171                return PROTO_LOCAL;
 172        die("I don't handle protocol '%s'", name);
 173}
 174
 175#define STR_(s) # s
 176#define STR(s)  STR_(s)
 177
 178static void get_host_and_port(char **host, const char **port)
 179{
 180        char *colon, *end;
 181
 182        if (*host[0] == '[') {
 183                end = strchr(*host + 1, ']');
 184                if (end) {
 185                        *end = 0;
 186                        end++;
 187                        (*host)++;
 188                } else
 189                        end = *host;
 190        } else
 191                end = *host;
 192        colon = strchr(end, ':');
 193
 194        if (colon) {
 195                *colon = 0;
 196                *port = colon + 1;
 197        }
 198}
 199
 200static void enable_keepalive(int sockfd)
 201{
 202        int ka = 1;
 203
 204        if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 205                fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 206                        strerror(errno));
 207}
 208
 209#ifndef NO_IPV6
 210
 211static const char *ai_name(const struct addrinfo *ai)
 212{
 213        static char addr[NI_MAXHOST];
 214        if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 215                        NI_NUMERICHOST) != 0)
 216                strcpy(addr, "(unknown)");
 217
 218        return addr;
 219}
 220
 221/*
 222 * Returns a connected socket() fd, or else die()s.
 223 */
 224static int git_tcp_connect_sock(char *host, int flags)
 225{
 226        struct strbuf error_message = STRBUF_INIT;
 227        int sockfd = -1;
 228        const char *port = STR(DEFAULT_GIT_PORT);
 229        struct addrinfo hints, *ai0, *ai;
 230        int gai;
 231        int cnt = 0;
 232
 233        get_host_and_port(&host, &port);
 234        if (!*port)
 235                port = "<none>";
 236
 237        memset(&hints, 0, sizeof(hints));
 238        hints.ai_socktype = SOCK_STREAM;
 239        hints.ai_protocol = IPPROTO_TCP;
 240
 241        if (flags & CONNECT_VERBOSE)
 242                fprintf(stderr, "Looking up %s ... ", host);
 243
 244        gai = getaddrinfo(host, port, &hints, &ai);
 245        if (gai)
 246                die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 247
 248        if (flags & CONNECT_VERBOSE)
 249                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 250
 251        for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 252                sockfd = socket(ai->ai_family,
 253                                ai->ai_socktype, ai->ai_protocol);
 254                if ((sockfd < 0) ||
 255                    (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 256                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 257                                    host, cnt, ai_name(ai), strerror(errno));
 258                        if (0 <= sockfd)
 259                                close(sockfd);
 260                        sockfd = -1;
 261                        continue;
 262                }
 263                if (flags & CONNECT_VERBOSE)
 264                        fprintf(stderr, "%s ", ai_name(ai));
 265                break;
 266        }
 267
 268        freeaddrinfo(ai0);
 269
 270        if (sockfd < 0)
 271                die("unable to connect to %s:\n%s", host, error_message.buf);
 272
 273        enable_keepalive(sockfd);
 274
 275        if (flags & CONNECT_VERBOSE)
 276                fprintf(stderr, "done.\n");
 277
 278        strbuf_release(&error_message);
 279
 280        return sockfd;
 281}
 282
 283#else /* NO_IPV6 */
 284
 285/*
 286 * Returns a connected socket() fd, or else die()s.
 287 */
 288static int git_tcp_connect_sock(char *host, int flags)
 289{
 290        struct strbuf error_message = STRBUF_INIT;
 291        int sockfd = -1;
 292        const char *port = STR(DEFAULT_GIT_PORT);
 293        char *ep;
 294        struct hostent *he;
 295        struct sockaddr_in sa;
 296        char **ap;
 297        unsigned int nport;
 298        int cnt;
 299
 300        get_host_and_port(&host, &port);
 301
 302        if (flags & CONNECT_VERBOSE)
 303                fprintf(stderr, "Looking up %s ... ", host);
 304
 305        he = gethostbyname(host);
 306        if (!he)
 307                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 308        nport = strtoul(port, &ep, 10);
 309        if ( ep == port || *ep ) {
 310                /* Not numeric */
 311                struct servent *se = getservbyname(port,"tcp");
 312                if ( !se )
 313                        die("Unknown port %s", port);
 314                nport = se->s_port;
 315        }
 316
 317        if (flags & CONNECT_VERBOSE)
 318                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 319
 320        for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 321                memset(&sa, 0, sizeof sa);
 322                sa.sin_family = he->h_addrtype;
 323                sa.sin_port = htons(nport);
 324                memcpy(&sa.sin_addr, *ap, he->h_length);
 325
 326                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 327                if ((sockfd < 0) ||
 328                    connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 329                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 330                                host,
 331                                cnt,
 332                                inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 333                                strerror(errno));
 334                        if (0 <= sockfd)
 335                                close(sockfd);
 336                        sockfd = -1;
 337                        continue;
 338                }
 339                if (flags & CONNECT_VERBOSE)
 340                        fprintf(stderr, "%s ",
 341                                inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 342                break;
 343        }
 344
 345        if (sockfd < 0)
 346                die("unable to connect to %s:\n%s", host, error_message.buf);
 347
 348        enable_keepalive(sockfd);
 349
 350        if (flags & CONNECT_VERBOSE)
 351                fprintf(stderr, "done.\n");
 352
 353        return sockfd;
 354}
 355
 356#endif /* NO_IPV6 */
 357
 358
 359static void git_tcp_connect(int fd[2], char *host, int flags)
 360{
 361        int sockfd = git_tcp_connect_sock(host, flags);
 362
 363        fd[0] = sockfd;
 364        fd[1] = dup(sockfd);
 365}
 366
 367
 368static char *git_proxy_command;
 369
 370static int git_proxy_command_options(const char *var, const char *value,
 371                void *cb)
 372{
 373        if (!strcmp(var, "core.gitproxy")) {
 374                const char *for_pos;
 375                int matchlen = -1;
 376                int hostlen;
 377                const char *rhost_name = cb;
 378                int rhost_len = strlen(rhost_name);
 379
 380                if (git_proxy_command)
 381                        return 0;
 382                if (!value)
 383                        return config_error_nonbool(var);
 384                /* [core]
 385                 * ;# matches www.kernel.org as well
 386                 * gitproxy = netcatter-1 for kernel.org
 387                 * gitproxy = netcatter-2 for sample.xz
 388                 * gitproxy = netcatter-default
 389                 */
 390                for_pos = strstr(value, " for ");
 391                if (!for_pos)
 392                        /* matches everybody */
 393                        matchlen = strlen(value);
 394                else {
 395                        hostlen = strlen(for_pos + 5);
 396                        if (rhost_len < hostlen)
 397                                matchlen = -1;
 398                        else if (!strncmp(for_pos + 5,
 399                                          rhost_name + rhost_len - hostlen,
 400                                          hostlen) &&
 401                                 ((rhost_len == hostlen) ||
 402                                  rhost_name[rhost_len - hostlen -1] == '.'))
 403                                matchlen = for_pos - value;
 404                        else
 405                                matchlen = -1;
 406                }
 407                if (0 <= matchlen) {
 408                        /* core.gitproxy = none for kernel.org */
 409                        if (matchlen == 4 &&
 410                            !memcmp(value, "none", 4))
 411                                matchlen = 0;
 412                        git_proxy_command = xmemdupz(value, matchlen);
 413                }
 414                return 0;
 415        }
 416
 417        return git_default_config(var, value, cb);
 418}
 419
 420static int git_use_proxy(const char *host)
 421{
 422        git_proxy_command = getenv("GIT_PROXY_COMMAND");
 423        git_config(git_proxy_command_options, (void*)host);
 424        return (git_proxy_command && *git_proxy_command);
 425}
 426
 427static struct child_process *git_proxy_connect(int fd[2], char *host)
 428{
 429        const char *port = STR(DEFAULT_GIT_PORT);
 430        const char **argv;
 431        struct child_process *proxy;
 432
 433        get_host_and_port(&host, &port);
 434
 435        argv = xmalloc(sizeof(*argv) * 4);
 436        argv[0] = git_proxy_command;
 437        argv[1] = host;
 438        argv[2] = port;
 439        argv[3] = NULL;
 440        proxy = xcalloc(1, sizeof(*proxy));
 441        proxy->argv = argv;
 442        proxy->in = -1;
 443        proxy->out = -1;
 444        if (start_command(proxy))
 445                die("cannot start proxy %s", argv[0]);
 446        fd[0] = proxy->out; /* read from proxy stdout */
 447        fd[1] = proxy->in;  /* write to proxy stdin */
 448        return proxy;
 449}
 450
 451#define MAX_CMD_LEN 1024
 452
 453static char *get_port(char *host)
 454{
 455        char *end;
 456        char *p = strchr(host, ':');
 457
 458        if (p) {
 459                long port = strtol(p + 1, &end, 10);
 460                if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 461                        *p = '\0';
 462                        return p+1;
 463                }
 464        }
 465
 466        return NULL;
 467}
 468
 469static struct child_process no_fork;
 470
 471/*
 472 * This returns a dummy child_process if the transport protocol does not
 473 * need fork(2), or a struct child_process object if it does.  Once done,
 474 * finish the connection with finish_connect() with the value returned from
 475 * this function (it is safe to call finish_connect() with NULL to support
 476 * the former case).
 477 *
 478 * If it returns, the connect is successful; it just dies on errors (this
 479 * will hopefully be changed in a libification effort, to return NULL when
 480 * the connection failed).
 481 */
 482struct child_process *git_connect(int fd[2], const char *url_orig,
 483                                  const char *prog, int flags)
 484{
 485        char *url;
 486        char *host, *path;
 487        char *end;
 488        int c;
 489        struct child_process *conn = &no_fork;
 490        enum protocol protocol = PROTO_LOCAL;
 491        int free_path = 0;
 492        char *port = NULL;
 493        const char **arg;
 494        struct strbuf cmd;
 495
 496        /* Without this we cannot rely on waitpid() to tell
 497         * what happened to our children.
 498         */
 499        signal(SIGCHLD, SIG_DFL);
 500
 501        if (is_url(url_orig))
 502                url = url_decode(url_orig);
 503        else
 504                url = xstrdup(url_orig);
 505
 506        host = strstr(url, "://");
 507        if (host) {
 508                *host = '\0';
 509                protocol = get_protocol(url);
 510                host += 3;
 511                c = '/';
 512        } else {
 513                host = url;
 514                c = ':';
 515        }
 516
 517        /*
 518         * Don't do destructive transforms with git:// as that
 519         * protocol code does '[]' unwrapping of its own.
 520         */
 521        if (host[0] == '[') {
 522                end = strchr(host + 1, ']');
 523                if (end) {
 524                        if (protocol != PROTO_GIT) {
 525                                *end = 0;
 526                                host++;
 527                        }
 528                        end++;
 529                } else
 530                        end = host;
 531        } else
 532                end = host;
 533
 534        path = strchr(end, c);
 535        if (path && !has_dos_drive_prefix(end)) {
 536                if (c == ':') {
 537                        protocol = PROTO_SSH;
 538                        *path++ = '\0';
 539                }
 540        } else
 541                path = end;
 542
 543        if (!path || !*path)
 544                die("No path specified. See 'man git-pull' for valid url syntax");
 545
 546        /*
 547         * null-terminate hostname and point path to ~ for URL's like this:
 548         *    ssh://host.xz/~user/repo
 549         */
 550        if (protocol != PROTO_LOCAL && host != url) {
 551                char *ptr = path;
 552                if (path[1] == '~')
 553                        path++;
 554                else {
 555                        path = xstrdup(ptr);
 556                        free_path = 1;
 557                }
 558
 559                *ptr = '\0';
 560        }
 561
 562        /*
 563         * Add support for ssh port: ssh://host.xy:<port>/...
 564         */
 565        if (protocol == PROTO_SSH && host != url)
 566                port = get_port(host);
 567
 568        if (protocol == PROTO_GIT) {
 569                /* These underlying connection commands die() if they
 570                 * cannot connect.
 571                 */
 572                char *target_host = xstrdup(host);
 573                if (git_use_proxy(host))
 574                        conn = git_proxy_connect(fd, host);
 575                else
 576                        git_tcp_connect(fd, host, flags);
 577                /*
 578                 * Separate original protocol components prog and path
 579                 * from extended host header with a NUL byte.
 580                 *
 581                 * Note: Do not add any other headers here!  Doing so
 582                 * will cause older git-daemon servers to crash.
 583                 */
 584                packet_write(fd[1],
 585                             "%s %s%chost=%s%c",
 586                             prog, path, 0,
 587                             target_host, 0);
 588                free(target_host);
 589                free(url);
 590                if (free_path)
 591                        free(path);
 592                return conn;
 593        }
 594
 595        conn = xcalloc(1, sizeof(*conn));
 596
 597        strbuf_init(&cmd, MAX_CMD_LEN);
 598        strbuf_addstr(&cmd, prog);
 599        strbuf_addch(&cmd, ' ');
 600        sq_quote_buf(&cmd, path);
 601        if (cmd.len >= MAX_CMD_LEN)
 602                die("command line too long");
 603
 604        conn->in = conn->out = -1;
 605        conn->argv = arg = xcalloc(7, sizeof(*arg));
 606        if (protocol == PROTO_SSH) {
 607                const char *ssh = getenv("GIT_SSH");
 608                int putty = ssh && strcasestr(ssh, "plink");
 609                if (!ssh) ssh = "ssh";
 610
 611                *arg++ = ssh;
 612                if (putty && !strcasestr(ssh, "tortoiseplink"))
 613                        *arg++ = "-batch";
 614                if (port) {
 615                        /* P is for PuTTY, p is for OpenSSH */
 616                        *arg++ = putty ? "-P" : "-p";
 617                        *arg++ = port;
 618                }
 619                *arg++ = host;
 620        }
 621        else {
 622                /* remove repo-local variables from the environment */
 623                conn->env = local_repo_env;
 624                conn->use_shell = 1;
 625        }
 626        *arg++ = cmd.buf;
 627        *arg = NULL;
 628
 629        if (start_command(conn))
 630                die("unable to fork");
 631
 632        fd[0] = conn->out; /* read from child's stdout */
 633        fd[1] = conn->in;  /* write to child's stdin */
 634        strbuf_release(&cmd);
 635        free(url);
 636        if (free_path)
 637                free(path);
 638        return conn;
 639}
 640
 641int git_connection_is_socket(struct child_process *conn)
 642{
 643        return conn == &no_fork;
 644}
 645
 646int finish_connect(struct child_process *conn)
 647{
 648        int code;
 649        if (!conn || git_connection_is_socket(conn))
 650                return 0;
 651
 652        code = finish_command(conn);
 653        free(conn->argv);
 654        free(conn);
 655        return code;
 656}