Andrew's git / gitweb.git / connect.c
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connect.con commit Add how-to on using update-hook. (7311d9f)
   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 */
  13struct 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
  43int 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
  61int 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
  82struct refspec {
  83        char *src;
  84        char *dst;
  85        char force;
  86};
  87
  88/*
  89 * A:B means fast forward remote B with local A.
  90 * +A:B means overwrite remote B with local A.
  91 * +A is a shorthand for +A:A.
  92 * A is a shorthand for A:A.
  93 */
  94static struct refspec *parse_ref_spec(int nr_refspec, char **refspec)
  95{
  96        int i;
  97        struct refspec *rs = xcalloc(sizeof(*rs), (nr_refspec + 1));
  98        for (i = 0; i < nr_refspec; i++) {
  99                char *sp, *dp, *ep;
 100                sp = refspec[i];
 101                if (*sp == '+') {
 102                        rs[i].force = 1;
 103                        sp++;
 104                }
 105                ep = strchr(sp, ':');
 106                if (ep) {
 107                        dp = ep + 1;
 108                        *ep = 0;
 109                }
 110                else
 111                        dp = sp;
 112                rs[i].src = sp;
 113                rs[i].dst = dp;
 114        }
 115        rs[nr_refspec].src = rs[nr_refspec].dst = NULL;
 116        return rs;
 117}
 118
 119static int count_refspec_match(const char *pattern,
 120                               struct ref *refs,
 121                               struct ref **matched_ref)
 122{
 123        int match;
 124        int patlen = strlen(pattern);
 125
 126        for (match = 0; refs; refs = refs->next) {
 127                char *name = refs->name;
 128                int namelen = strlen(name);
 129                if (namelen < patlen ||
 130                    memcmp(name + namelen - patlen, pattern, patlen))
 131                        continue;
 132                if (namelen != patlen && name[namelen - patlen - 1] != '/')
 133                        continue;
 134                match++;
 135                *matched_ref = refs;
 136        }
 137        return match;
 138}
 139
 140static void link_dst_tail(struct ref *ref, struct ref ***tail)
 141{
 142        **tail = ref;
 143        *tail = &ref->next;
 144        **tail = NULL;
 145}
 146
 147static struct ref *try_explicit_object_name(const char *name)
 148{
 149        unsigned char sha1[20];
 150        struct ref *ref;
 151        int len;
 152        if (get_sha1(name, sha1))
 153                return NULL;
 154        len = strlen(name) + 1;
 155        ref = xcalloc(1, sizeof(*ref) + len);
 156        memcpy(ref->name, name, len);
 157        memcpy(ref->new_sha1, sha1, 20);
 158        return ref;
 159}
 160
 161static int match_explicit_refs(struct ref *src, struct ref *dst,
 162                               struct ref ***dst_tail, struct refspec *rs)
 163{
 164        int i, errs;
 165        for (i = errs = 0; rs[i].src; i++) {
 166                struct ref *matched_src, *matched_dst;
 167
 168                matched_src = matched_dst = NULL;
 169                switch (count_refspec_match(rs[i].src, src, &matched_src)) {
 170                case 1:
 171                        break;
 172                case 0:
 173                        /* The source could be in the get_sha1() format
 174                         * not a reference name.
 175                         */
 176                        matched_src = try_explicit_object_name(rs[i].src);
 177                        if (matched_src)
 178                                break;
 179                        errs = 1;
 180                        error("src refspec %s does not match any.",
 181                              rs[i].src);
 182                        break;
 183                default:
 184                        errs = 1;
 185                        error("src refspec %s matches more than one.",
 186                              rs[i].src);
 187                        break;
 188                }
 189                switch (count_refspec_match(rs[i].dst, dst, &matched_dst)) {
 190                case 1:
 191                        break;
 192                case 0:
 193                        if (!memcmp(rs[i].dst, "refs/", 5)) {
 194                                int len = strlen(rs[i].dst) + 1;
 195                                matched_dst = xcalloc(1, sizeof(*dst) + len);
 196                                memcpy(matched_dst->name, rs[i].dst, len);
 197                                link_dst_tail(matched_dst, dst_tail);
 198                        }
 199                        else if (!strcmp(rs[i].src, rs[i].dst) &&
 200                                 matched_src) {
 201                                /* pushing "master:master" when
 202                                 * remote does not have master yet.
 203                                 */
 204                                int len = strlen(matched_src->name) + 1;
 205                                matched_dst = xcalloc(1, sizeof(*dst) + len);
 206                                memcpy(matched_dst->name, matched_src->name,
 207                                       len);
 208                                link_dst_tail(matched_dst, dst_tail);
 209                        }
 210                        else {
 211                                errs = 1;
 212                                error("dst refspec %s does not match any "
 213                                      "existing ref on the remote and does "
 214                                      "not start with refs/.", rs[i].dst);
 215                        }
 216                        break;
 217                default:
 218                        errs = 1;
 219                        error("dst refspec %s matches more than one.",
 220                              rs[i].dst);
 221                        break;
 222                }
 223                if (errs)
 224                        continue;
 225                if (matched_dst->peer_ref) {
 226                        errs = 1;
 227                        error("dst ref %s receives from more than one src.",
 228                              matched_dst->name);
 229                }
 230                else {
 231                        matched_dst->peer_ref = matched_src;
 232                        matched_dst->force = rs[i].force;
 233                }
 234        }
 235        return -errs;
 236}
 237
 238static struct ref *find_ref_by_name(struct ref *list, const char *name)
 239{
 240        for ( ; list; list = list->next)
 241                if (!strcmp(list->name, name))
 242                        return list;
 243        return NULL;
 244}
 245
 246int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 247               int nr_refspec, char **refspec, int all)
 248{
 249        struct refspec *rs = parse_ref_spec(nr_refspec, refspec);
 250
 251        if (nr_refspec)
 252                return match_explicit_refs(src, dst, dst_tail, rs);
 253
 254        /* pick the remainder */
 255        for ( ; src; src = src->next) {
 256                struct ref *dst_peer;
 257                if (src->peer_ref)
 258                        continue;
 259                dst_peer = find_ref_by_name(dst, src->name);
 260                if ((dst_peer && dst_peer->peer_ref) || (!dst_peer && !all))
 261                        continue;
 262                if (!dst_peer) {
 263                        /* Create a new one and link it */
 264                        int len = strlen(src->name) + 1;
 265                        dst_peer = xcalloc(1, sizeof(*dst_peer) + len);
 266                        memcpy(dst_peer->name, src->name, len);
 267                        memcpy(dst_peer->new_sha1, src->new_sha1, 20);
 268                        link_dst_tail(dst_peer, dst_tail);
 269                }
 270                dst_peer->peer_ref = src;
 271        }
 272        return 0;
 273}
 274
 275enum protocol {
 276        PROTO_LOCAL = 1,
 277        PROTO_SSH,
 278        PROTO_GIT,
 279};
 280
 281static enum protocol get_protocol(const char *name)
 282{
 283        if (!strcmp(name, "ssh"))
 284                return PROTO_SSH;
 285        if (!strcmp(name, "git"))
 286                return PROTO_GIT;
 287        die("I don't handle protocol '%s'", name);
 288}
 289
 290#define STR_(s) # s
 291#define STR(s)  STR_(s)
 292
 293static int git_tcp_connect(int fd[2], const char *prog, char *host, char *path)
 294{
 295        int sockfd = -1;
 296        char *colon, *end;
 297        char *port = STR(DEFAULT_GIT_PORT);
 298        struct addrinfo hints, *ai0, *ai;
 299        int gai;
 300
 301        if (host[0] == '[') {
 302                end = strchr(host + 1, ']');
 303                if (end) {
 304                        *end = 0;
 305                        end++;
 306                        host++;
 307                } else
 308                        end = host;
 309        } else
 310                end = host;
 311        colon = strchr(end, ':');
 312
 313        if (colon) {
 314                *colon = 0;
 315                port = colon + 1;
 316        }
 317
 318        memset(&hints, 0, sizeof(hints));
 319        hints.ai_socktype = SOCK_STREAM;
 320        hints.ai_protocol = IPPROTO_TCP;
 321
 322        gai = getaddrinfo(host, port, &hints, &ai);
 323        if (gai)
 324                die("Unable to look up %s (%s)", host, gai_strerror(gai));
 325
 326        for (ai0 = ai; ai; ai = ai->ai_next) {
 327                sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 328                if (sockfd < 0)
 329                        continue;
 330                if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 331                        close(sockfd);
 332                        sockfd = -1;
 333                        continue;
 334                }
 335                break;
 336        }
 337
 338        freeaddrinfo(ai0);
 339
 340        if (sockfd < 0)
 341                die("unable to connect a socket (%s)", strerror(errno));
 342
 343        fd[0] = sockfd;
 344        fd[1] = sockfd;
 345        packet_write(sockfd, "%s %s\n", prog, path);
 346        return 0;
 347}
 348
 349/*
 350 * Yeah, yeah, fixme. Need to pass in the heads etc.
 351 */
 352int git_connect(int fd[2], char *url, const char *prog)
 353{
 354        char command[1024];
 355        char *host, *path;
 356        char *colon;
 357        int pipefd[2][2];
 358        pid_t pid;
 359        enum protocol protocol;
 360
 361        host = NULL;
 362        path = url;
 363        colon = strchr(url, ':');
 364        protocol = PROTO_LOCAL;
 365        if (colon) {
 366                *colon = 0;
 367                host = url;
 368                path = colon+1;
 369                protocol = PROTO_SSH;
 370                if (!memcmp(path, "//", 2)) {
 371                        char *slash = strchr(path + 2, '/');
 372                        if (slash) {
 373                                int nr = slash - path - 2;
 374                                memmove(path, path+2, nr);
 375                                path[nr] = 0;
 376                                protocol = get_protocol(url);
 377                                host = path;
 378                                path = slash;
 379                        }
 380                }
 381        }
 382
 383        if (protocol == PROTO_GIT)
 384                return git_tcp_connect(fd, prog, host, path);
 385
 386        if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 387                die("unable to create pipe pair for communication");
 388        pid = fork();
 389        if (!pid) {
 390                snprintf(command, sizeof(command), "%s %s", prog,
 391                         sq_quote(path));
 392                dup2(pipefd[1][0], 0);
 393                dup2(pipefd[0][1], 1);
 394                close(pipefd[0][0]);
 395                close(pipefd[0][1]);
 396                close(pipefd[1][0]);
 397                close(pipefd[1][1]);
 398                if (protocol == PROTO_SSH) {
 399                        const char *ssh = getenv("GIT_SSH") ? : "ssh";
 400                        const char *ssh_basename = strrchr(ssh, '/');
 401                        if (!ssh_basename)
 402                                ssh_basename = ssh;
 403                        else
 404                                ssh_basename++;
 405                        execlp(ssh, ssh_basename, host, command, NULL);
 406                }
 407                else
 408                        execlp("sh", "sh", "-c", command, NULL);
 409                die("exec failed");
 410        }               
 411        fd[0] = pipefd[0][0];
 412        fd[1] = pipefd[1][1];
 413        close(pipefd[0][1]);
 414        close(pipefd[1][0]);
 415        return pid;
 416}
 417
 418int finish_connect(pid_t pid)
 419{
 420        int ret;
 421
 422        for (;;) {
 423                ret = waitpid(pid, NULL, 0);
 424                if (!ret)
 425                        break;
 426                if (errno != EINTR)
 427                        break;
 428        }
 429        return ret;
 430}