/src/git/transport-helper.c

Source (jump to first uncovered line)
#define USE_THE_REPOSITORY_VARIABLE

#include "git-compat-util.h"
#include "transport.h"
#include "quote.h"
#include "run-command.h"
#include "commit.h"
#include "environment.h"
#include "gettext.h"
#include "hex.h"
#include "object-name.h"
#include "repository.h"
#include "remote.h"
#include "string-list.h"
#include "thread-utils.h"
#include "sigchain.h"
#include "strvec.h"
#include "refs.h"
#include "refspec.h"
#include "transport-internal.h"
#include "protocol.h"
#include "packfile.h"

static int debug;

struct helper_data {
  char *name;
  struct child_process *helper;
  FILE *out;
  unsigned fetch : 1,
    import : 1,
    bidi_import : 1,
    export : 1,
    option : 1,
    push : 1,
    connect : 1,
    stateless_connect : 1,
    signed_tags : 1,
    check_connectivity : 1,
    no_disconnect_req : 1,
    no_private_update : 1,
    object_format : 1;

  /*
   * As an optimization, the transport code may invoke fetch before
   * get_refs_list. If this happens, and if the transport helper doesn't
   * support connect or stateless_connect, we need to invoke
   * get_refs_list ourselves if we haven't already done so. Keep track of
   * whether we have invoked get_refs_list.
   */
  unsigned get_refs_list_called : 1;

  char *export_marks;
  char *import_marks;
  /* These go from remote name (as in "list") to private name */
  struct refspec rs;
  /* Transport options for fetch-pack/send-pack (should one of
   * those be invoked).
   */
  struct git_transport_options transport_options;
};

static void sendline(struct helper_data *helper, struct strbuf *buffer)
{
  if (debug)
    fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  if (write_in_full(helper->helper->in, buffer->buf, buffer->len) < 0)
    die_errno(_("full write to remote helper failed"));
}

static int recvline_fh(FILE *helper, struct strbuf *buffer)
{
  strbuf_reset(buffer);
  if (debug)
    fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  if (strbuf_getline(buffer, helper) == EOF) {
    if (debug)
      fprintf(stderr, "Debug: Remote helper quit.\n");
    return 1;
  }

  if (debug)
    fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  return 0;
}

static int recvline(struct helper_data *helper, struct strbuf *buffer)
{
  return recvline_fh(helper->out, buffer);
}

static void write_constant(int fd, const char *str)
{
  if (debug)
    fprintf(stderr, "Debug: Remote helper: -> %s", str);
  if (write_in_full(fd, str, strlen(str)) < 0)
    die_errno(_("full write to remote helper failed"));
}

static const char *remove_ext_force(const char *url)
{
  if (url) {
    const char *colon = strchr(url, ':');
    if (colon && colon[1] == ':')
      return colon + 2;
  }
  return url;
}

static void do_take_over(struct transport *transport)
{
  struct helper_data *data;
  data = (struct helper_data *)transport->data;
  transport_take_over(transport, data->helper);
  fclose(data->out);
  free(data->name);
  free(data);
}

static void standard_options(struct transport *t);

static struct child_process *get_helper(struct transport *transport)
{
  struct helper_data *data = transport->data;
  struct strbuf buf = STRBUF_INIT;
  struct child_process *helper;
  int duped;
  int code;

  if (data->helper)
    return data->helper;

  helper = xmalloc(sizeof(*helper));
  child_process_init(helper);
  helper->in = -1;
  helper->out = -1;
  helper->err = 0;
  strvec_pushf(&helper->args, "remote-%s", data->name);
  strvec_push(&helper->args, transport->remote->name);
  strvec_push(&helper->args, remove_ext_force(transport->url));
  helper->git_cmd = 1;
  helper->silent_exec_failure = 1;

  if (have_git_dir())
    strvec_pushf(&helper->env, "%s=%s",
           GIT_DIR_ENVIRONMENT, get_git_dir());

  helper->trace2_child_class = helper->args.v[0]; /* "remote-<name>" */

  code = start_command(helper);
  if (code < 0 && errno == ENOENT)
    die(_("unable to find remote helper for '%s'"), data->name);
  else if (code != 0)
    exit(code);

  data->helper = helper;
  data->no_disconnect_req = 0;
  refspec_init(&data->rs, REFSPEC_FETCH);

  /*
   * Open the output as FILE* so strbuf_getline_*() family of
   * functions can be used.
   * Do this with duped fd because fclose() will close the fd,
   * and stuff like taking over will require the fd to remain.
   */
  duped = dup(helper->out);
  if (duped < 0)
    die_errno(_("can't dup helper output fd"));
  data->out = xfdopen(duped, "r");

  write_constant(helper->in, "capabilities\n");

  while (1) {
    const char *capname, *arg;
    int mandatory = 0;
    if (recvline(data, &buf))
      exit(128);

    if (!*buf.buf)
      break;

    if (*buf.buf == '*') {
      capname = buf.buf + 1;
      mandatory = 1;
    } else
      capname = buf.buf;

    if (debug)
      fprintf(stderr, "Debug: Got cap %s\n", capname);
    if (!strcmp(capname, "fetch"))
      data->fetch = 1;
    else if (!strcmp(capname, "option"))
      data->option = 1;
    else if (!strcmp(capname, "push"))
      data->push = 1;
    else if (!strcmp(capname, "import"))
      data->import = 1;
    else if (!strcmp(capname, "bidi-import"))
      data->bidi_import = 1;
    else if (!strcmp(capname, "export"))
      data->export = 1;
    else if (!strcmp(capname, "check-connectivity"))
      data->check_connectivity = 1;
    else if (skip_prefix(capname, "refspec ", &arg)) {
      refspec_append(&data->rs, arg);
    } else if (!strcmp(capname, "connect")) {
      data->connect = 1;
    } else if (!strcmp(capname, "stateless-connect")) {
      data->stateless_connect = 1;
    } else if (!strcmp(capname, "signed-tags")) {
      data->signed_tags = 1;
    } else if (skip_prefix(capname, "export-marks ", &arg)) {
      data->export_marks = xstrdup(arg);
    } else if (skip_prefix(capname, "import-marks ", &arg)) {
      data->import_marks = xstrdup(arg);
    } else if (starts_with(capname, "no-private-update")) {
      data->no_private_update = 1;
    } else if (starts_with(capname, "object-format")) {
      data->object_format = 1;
    } else if (mandatory) {
      die(_("unknown mandatory capability %s; this remote "
            "helper probably needs newer version of Git"),
          capname);
    }
  }
  if (!data->rs.nr && (data->import || data->bidi_import || data->export)) {
    warning(_("this remote helper should implement refspec capability"));
  }
  strbuf_release(&buf);
  if (debug)
    fprintf(stderr, "Debug: Capabilities complete.\n");
  standard_options(transport);
  return data->helper;
}

static int disconnect_helper(struct transport *transport)
{
  struct helper_data *data = transport->data;
  int res = 0;

  if (data->helper) {
    if (debug)
      fprintf(stderr, "Debug: Disconnecting.\n");
    if (!data->no_disconnect_req) {
      /*
       * Ignore write errors; there's nothing we can do,
       * since we're about to close the pipe anyway. And the
       * most likely error is EPIPE due to the helper dying
       * to report an error itself.
       */
      sigchain_push(SIGPIPE, SIG_IGN);
      xwrite(data->helper->in, "\n", 1);
      sigchain_pop(SIGPIPE);
    }
    close(data->helper->in);
    close(data->helper->out);
    fclose(data->out);
    res = finish_command(data->helper);
    FREE_AND_NULL(data->name);
    FREE_AND_NULL(data->helper);
  }
  return res;
}

static const char *unsupported_options[] = {
  TRANS_OPT_UPLOADPACK,
  TRANS_OPT_RECEIVEPACK,
  TRANS_OPT_THIN,
  TRANS_OPT_KEEP
  };

static const char *boolean_options[] = {
  TRANS_OPT_THIN,
  TRANS_OPT_KEEP,
  TRANS_OPT_FOLLOWTAGS,
  TRANS_OPT_DEEPEN_RELATIVE
  };

static int strbuf_set_helper_option(struct helper_data *data,
            struct strbuf *buf)
{
  int ret;

  sendline(data, buf);
  if (recvline(data, buf))
    exit(128);

  if (!strcmp(buf->buf, "ok"))
    ret = 0;
  else if (starts_with(buf->buf, "error"))
    ret = -1;
  else if (!strcmp(buf->buf, "unsupported"))
    ret = 1;
  else {
    warning(_("%s unexpectedly said: '%s'"), data->name, buf->buf);
    ret = 1;
  }
  return ret;
}

static int string_list_set_helper_option(struct helper_data *data,
           const char *name,
           struct string_list *list)
{
  struct strbuf buf = STRBUF_INIT;
  int i, ret = 0;

  for (i = 0; i < list->nr; i++) {
    strbuf_addf(&buf, "option %s ", name);
    quote_c_style(list->items[i].string, &buf, NULL, 0);
    strbuf_addch(&buf, '\n');

    if ((ret = strbuf_set_helper_option(data, &buf)))
      break;
    strbuf_reset(&buf);
  }
  strbuf_release(&buf);
  return ret;
}

static int set_helper_option(struct transport *transport,
        const char *name, const char *value)
{
  struct helper_data *data = transport->data;
  struct strbuf buf = STRBUF_INIT;
  int i, ret, is_bool = 0;

  get_helper(transport);

  if (!data->option)
    return 1;

  if (!strcmp(name, "deepen-not"))
    return string_list_set_helper_option(data, name,
                 (struct string_list *)value);

  for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
    if (!strcmp(name, unsupported_options[i]))
      return 1;
  }

  for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
    if (!strcmp(name, boolean_options[i])) {
      is_bool = 1;
      break;
    }
  }

  strbuf_addf(&buf, "option %s ", name);
  if (is_bool)
    strbuf_addstr(&buf, value ? "true" : "false");
  else
    quote_c_style(value, &buf, NULL, 0);
  strbuf_addch(&buf, '\n');

  ret = strbuf_set_helper_option(data, &buf);
  strbuf_release(&buf);
  return ret;
}

static void standard_options(struct transport *t)
{
  char buf[16];
  int v = t->verbose;

  set_helper_option(t, "progress", t->progress ? "true" : "false");

  xsnprintf(buf, sizeof(buf), "%d", v + 1);
  set_helper_option(t, "verbosity", buf);

  switch (t->family) {
  case TRANSPORT_FAMILY_ALL:
    /*
     * this is already the default,
     * do not break old remote helpers by setting "all" here
     */
    break;
  case TRANSPORT_FAMILY_IPV4:
    set_helper_option(t, "family", "ipv4");
    break;
  case TRANSPORT_FAMILY_IPV6:
    set_helper_option(t, "family", "ipv6");
    break;
  }
}

static int release_helper(struct transport *transport)
{
  int res = 0;
  struct helper_data *data = transport->data;
  refspec_clear(&data->rs);
  res = disconnect_helper(transport);
  free(transport->data);
  return res;
}

static int fetch_with_fetch(struct transport *transport,
          int nr_heads, struct ref **to_fetch)
{
  struct helper_data *data = transport->data;
  int i;
  struct strbuf buf = STRBUF_INIT;

  for (i = 0; i < nr_heads; i++) {
    const struct ref *posn = to_fetch[i];
    if (posn->status & REF_STATUS_UPTODATE)
      continue;

    strbuf_addf(&buf, "fetch %s %s\n",
          oid_to_hex(&posn->old_oid),
          posn->symref ? posn->symref : posn->name);
  }

  strbuf_addch(&buf, '\n');
  sendline(data, &buf);

  while (1) {
    const char *name;

    if (recvline(data, &buf))
      exit(128);

    if (skip_prefix(buf.buf, "lock ", &name)) {
      if (transport->pack_lockfiles.nr)
        warning(_("%s also locked %s"), data->name, name);
      else
        string_list_append(&transport->pack_lockfiles,
               name);
    }
    else if (data->check_connectivity &&
       data->transport_options.check_self_contained_and_connected &&
       !strcmp(buf.buf, "connectivity-ok"))
      data->transport_options.self_contained_and_connected = 1;
    else if (!buf.len)
      break;
    else
      warning(_("%s unexpectedly said: '%s'"), data->name, buf.buf);
  }
  strbuf_release(&buf);

  reprepare_packed_git(the_repository);
  return 0;
}

static int get_importer(struct transport *transport, struct child_process *fastimport)
{
  struct child_process *helper = get_helper(transport);
  struct helper_data *data = transport->data;
  int cat_blob_fd, code;
  child_process_init(fastimport);
  fastimport->in = xdup(helper->out);
  strvec_push(&fastimport->args, "fast-import");
  strvec_push(&fastimport->args, "--allow-unsafe-features");
  strvec_push(&fastimport->args, debug ? "--stats" : "--quiet");

  if (data->bidi_import) {
    cat_blob_fd = xdup(helper->in);
    strvec_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
  }
  fastimport->git_cmd = 1;

  code = start_command(fastimport);
  return code;
}

static int get_exporter(struct transport *transport,
      struct child_process *fastexport,
      struct string_list *revlist_args)
{
  struct helper_data *data = transport->data;
  struct child_process *helper = get_helper(transport);
  int i;

  child_process_init(fastexport);

  /* we need to duplicate helper->in because we want to use it after
   * fastexport is done with it. */
  fastexport->out = dup(helper->in);
  strvec_push(&fastexport->args, "fast-export");
  strvec_push(&fastexport->args, "--use-done-feature");
  strvec_push(&fastexport->args, data->signed_tags ?
    "--signed-tags=verbatim" : "--signed-tags=warn-strip");
  if (data->export_marks)
    strvec_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
  if (data->import_marks)
    strvec_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);

  for (i = 0; i < revlist_args->nr; i++)
    strvec_push(&fastexport->args, revlist_args->items[i].string);

  fastexport->git_cmd = 1;
  return start_command(fastexport);
}

static int fetch_with_import(struct transport *transport,
           int nr_heads, struct ref **to_fetch)
{
  struct child_process fastimport;
  struct helper_data *data = transport->data;
  int i;
  struct ref *posn;
  struct strbuf buf = STRBUF_INIT;

  get_helper(transport);

  if (get_importer(transport, &fastimport))
    die(_("couldn't run fast-import"));

  for (i = 0; i < nr_heads; i++) {
    posn = to_fetch[i];
    if (posn->status & REF_STATUS_UPTODATE)
      continue;

    strbuf_addf(&buf, "import %s\n",
          posn->symref ? posn->symref : posn->name);
    sendline(data, &buf);
    strbuf_reset(&buf);
  }

  write_constant(data->helper->in, "\n");
  /*
   * remote-helpers that advertise the bidi-import capability are required to
   * buffer the complete batch of import commands until this newline before
   * sending data to fast-import.
   * These helpers read back data from fast-import on their stdin, which could
   * be mixed with import commands, otherwise.
   */

  if (finish_command(&fastimport))
    die(_("error while running fast-import"));

  /*
   * The fast-import stream of a remote helper that advertises
   * the "refspec" capability writes to the refs named after the
   * right hand side of the first refspec matching each ref we
   * were fetching.
   *
   * (If no "refspec" capability was specified, for historical
   * reasons we default to the equivalent of *:*.)
   *
   * Store the result in to_fetch[i].old_sha1.  Callers such
   * as "git fetch" can use the value to write feedback to the
   * terminal, populate FETCH_HEAD, and determine what new value
   * should be written to peer_ref if the update is a
   * fast-forward or this is a forced update.
   */
  for (i = 0; i < nr_heads; i++) {
    char *private, *name;
    posn = to_fetch[i];
    if (posn->status & REF_STATUS_UPTODATE)
      continue;
    name = posn->symref ? posn->symref : posn->name;
    if (data->rs.nr)
      private = apply_refspecs(&data->rs, name);
    else
      private = xstrdup(name);
    if (private) {
      if (refs_read_ref(get_main_ref_store(the_repository), private, &posn->old_oid) < 0)
        die(_("could not read ref %s"), private);
      free(private);
    }
  }
  strbuf_release(&buf);
  return 0;
}

static int run_connect(struct transport *transport, struct strbuf *cmdbuf)
{
  struct helper_data *data = transport->data;
  int ret = 0;
  int duped;
  FILE *input;
  struct child_process *helper;

  helper = get_helper(transport);

  /*
   * Yes, dup the pipe another time, as we need unbuffered version
   * of input pipe as FILE*. fclose() closes the underlying fd and
   * stream buffering only can be changed before first I/O operation
   * on it.
   */
  duped = dup(helper->out);
  if (duped < 0)
    die_errno(_("can't dup helper output fd"));
  input = xfdopen(duped, "r");
  setvbuf(input, NULL, _IONBF, 0);

  sendline(data, cmdbuf);
  if (recvline_fh(input, cmdbuf))
    exit(128);

  if (!strcmp(cmdbuf->buf, "")) {
    data->no_disconnect_req = 1;
    if (debug)
      fprintf(stderr, "Debug: Smart transport connection "
        "ready.\n");
    ret = 1;
  } else if (!strcmp(cmdbuf->buf, "fallback")) {
    if (debug)
      fprintf(stderr, "Debug: Falling back to dumb "
        "transport.\n");
  } else {
    die(_("unknown response to connect: %s"),
        cmdbuf->buf);
  }

  fclose(input);
  return ret;
}

static int process_connect_service(struct transport *transport,
           const char *name, const char *exec)
{
  struct helper_data *data = transport->data;
  struct strbuf cmdbuf = STRBUF_INIT;
  int ret = 0;

  /*
   * Handle --upload-pack and friends. This is fire and forget...
   * just warn if it fails.
   */
  if (strcmp(name, exec)) {
    int r = set_helper_option(transport, "servpath", exec);
    if (r > 0)
      warning(_("setting remote service path not supported by protocol"));
    else if (r < 0)
      warning(_("invalid remote service path"));
  }

  if (data->connect) {
    strbuf_addf(&cmdbuf, "connect %s\n", name);
    ret = run_connect(transport, &cmdbuf);
  } else if (data->stateless_connect &&
       (get_protocol_version_config() == protocol_v2) &&
       (!strcmp("git-upload-pack", name) ||
        !strcmp("git-upload-archive", name))) {
    strbuf_addf(&cmdbuf, "stateless-connect %s\n", name);
    ret = run_connect(transport, &cmdbuf);
    if (ret)
      transport->stateless_rpc = 1;
  }

  strbuf_release(&cmdbuf);
  return ret;
}

static int process_connect(struct transport *transport,
             int for_push)
{
  struct helper_data *data = transport->data;
  const char *name;
  const char *exec;
  int ret;

  name = for_push ? "git-receive-pack" : "git-upload-pack";
  if (for_push)
    exec = data->transport_options.receivepack;
  else
    exec = data->transport_options.uploadpack;

  ret = process_connect_service(transport, name, exec);
  if (ret)
    do_take_over(transport);
  return ret;
}

static int connect_helper(struct transport *transport, const char *name,
       const char *exec, int fd[2])
{
  struct helper_data *data = transport->data;

  /* Get_helper so connect is inited. */
  get_helper(transport);

  if (!process_connect_service(transport, name, exec))
    die(_("can't connect to subservice %s"), name);

  fd[0] = data->helper->out;
  fd[1] = data->helper->in;

  do_take_over(transport);
  return 0;
}

static struct ref *get_refs_list_using_list(struct transport *transport,
              int for_push);

static int fetch_refs(struct transport *transport,
          int nr_heads, struct ref **to_fetch)
{
  struct helper_data *data = transport->data;
  int i, count;

  get_helper(transport);

  if (process_connect(transport, 0))
    return transport->vtable->fetch_refs(transport, nr_heads, to_fetch);

  /*
   * If we reach here, then the server, the client, and/or the transport
   * helper does not support protocol v2. --negotiate-only requires
   * protocol v2.
   */
  if (data->transport_options.acked_commits) {
    warning(_("--negotiate-only requires protocol v2"));
    return -1;
  }

  if (!data->get_refs_list_called)
    get_refs_list_using_list(transport, 0);

  count = 0;
  for (i = 0; i < nr_heads; i++)
    if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
      count++;

  if (!count)
    return 0;

  if (data->check_connectivity &&
      data->transport_options.check_self_contained_and_connected)
    set_helper_option(transport, "check-connectivity", "true");

  if (transport->cloning)
    set_helper_option(transport, "cloning", "true");

  if (data->transport_options.update_shallow)
    set_helper_option(transport, "update-shallow", "true");

  if (data->transport_options.refetch)
    set_helper_option(transport, "refetch", "true");

  if (data->transport_options.filter_options.choice) {
    const char *spec = expand_list_objects_filter_spec(
      &data->transport_options.filter_options);
    set_helper_option(transport, "filter", spec);
  }

  if (data->transport_options.negotiation_tips)
    warning("Ignoring --negotiation-tip because the protocol does not support it.");

  if (data->fetch)
    return fetch_with_fetch(transport, nr_heads, to_fetch);

  if (data->import)
    return fetch_with_import(transport, nr_heads, to_fetch);

  return -1;
}

struct push_update_ref_state {
  struct ref *hint;
  struct ref_push_report *report;
  int new_report;
};

static int push_update_ref_status(struct strbuf *buf,
           struct push_update_ref_state *state,
           struct ref *remote_refs)
{
  char *refname, *msg;
  int status, forced = 0;

  if (starts_with(buf->buf, "option ")) {
    struct object_id old_oid, new_oid;
    const char *key, *val;
    char *p;

    if (!state->hint || !(state->report || state->new_report))
      die(_("'option' without a matching 'ok/error' directive"));
    if (state->new_report) {
      if (!state->hint->report) {
        CALLOC_ARRAY(state->hint->report, 1);
        state->report = state->hint->report;
      } else {
        state->report = state->hint->report;
        while (state->report->next)
          state->report = state->report->next;
        CALLOC_ARRAY(state->report->next, 1);
        state->report = state->report->next;
      }
      state->new_report = 0;
    }
    key = buf->buf + 7;
    p = strchr(key, ' ');
    if (p)
      *p++ = '\0';
    val = p;
    if (!strcmp(key, "refname"))
      state->report->ref_name = xstrdup_or_null(val);
    else if (!strcmp(key, "old-oid") && val &&
       !parse_oid_hex(val, &old_oid, &val))
      state->report->old_oid = oiddup(&old_oid);
    else if (!strcmp(key, "new-oid") && val &&
       !parse_oid_hex(val, &new_oid, &val))
      state->report->new_oid = oiddup(&new_oid);
    else if (!strcmp(key, "forced-update"))
      state->report->forced_update = 1;
    /* Not update remote namespace again. */
    return 1;
  }

  state->report = NULL;
  state->new_report = 0;

  if (starts_with(buf->buf, "ok ")) {
    status = REF_STATUS_OK;
    refname = buf->buf + 3;
  } else if (starts_with(buf->buf, "error ")) {
    status = REF_STATUS_REMOTE_REJECT;
    refname = buf->buf + 6;
  } else
    die(_("expected ok/error, helper said '%s'"), buf->buf);

  msg = strchr(refname, ' ');
  if (msg) {
    struct strbuf msg_buf = STRBUF_INIT;
    const char *end;

    *msg++ = '\0';
    if (!unquote_c_style(&msg_buf, msg, &end))
      msg = strbuf_detach(&msg_buf, NULL);
    else
      msg = xstrdup(msg);
    strbuf_release(&msg_buf);

    if (!strcmp(msg, "no match")) {
      status = REF_STATUS_NONE;
      FREE_AND_NULL(msg);
    }
    else if (!strcmp(msg, "up to date")) {
      status = REF_STATUS_UPTODATE;
      FREE_AND_NULL(msg);
    }
    else if (!strcmp(msg, "non-fast forward")) {
      status = REF_STATUS_REJECT_NONFASTFORWARD;
      FREE_AND_NULL(msg);
    }
    else if (!strcmp(msg, "already exists")) {
      status = REF_STATUS_REJECT_ALREADY_EXISTS;
      FREE_AND_NULL(msg);
    }
    else if (!strcmp(msg, "fetch first")) {
      status = REF_STATUS_REJECT_FETCH_FIRST;
      FREE_AND_NULL(msg);
    }
    else if (!strcmp(msg, "needs force")) {
      status = REF_STATUS_REJECT_NEEDS_FORCE;
      FREE_AND_NULL(msg);
    }
    else if (!strcmp(msg, "stale info")) {
      status = REF_STATUS_REJECT_STALE;
      FREE_AND_NULL(msg);
    }
    else if (!strcmp(msg, "remote ref updated since checkout")) {
      status = REF_STATUS_REJECT_REMOTE_UPDATED;
      FREE_AND_NULL(msg);
    }
    else if (!strcmp(msg, "forced update")) {
      forced = 1;
      FREE_AND_NULL(msg);
    }
    else if (!strcmp(msg, "expecting report")) {
      status = REF_STATUS_EXPECTING_REPORT;
      FREE_AND_NULL(msg);
    }
  }

  if (state->hint)
    state->hint = find_ref_by_name(state->hint, refname);
  if (!state->hint)
    state->hint = find_ref_by_name(remote_refs, refname);
  if (!state->hint) {
    warning(_("helper reported unexpected status of %s"), refname);
    return 1;
  }

  if (state->hint->status != REF_STATUS_NONE) {
    /*
     * Earlier, the ref was marked not to be pushed, so ignore the ref
     * status reported by the remote helper if the latter is 'no match'.
     */
    if (status == REF_STATUS_NONE)
      return 1;
  }

  if (status == REF_STATUS_OK)
    state->new_report = 1;
  state->hint->status = status;
  state->hint->forced_update |= forced;
  state->hint->remote_status = msg;
  return !(status == REF_STATUS_OK);
}

static int push_update_refs_status(struct helper_data *data,
            struct ref *remote_refs,
            int flags)
{
  struct ref *ref;
  struct ref_push_report *report;
  struct strbuf buf = STRBUF_INIT;
  struct push_update_ref_state state = { remote_refs, NULL, 0 };

  for (;;) {
    if (recvline(data, &buf)) {
      strbuf_release(&buf);
      return 1;
    }
    if (!buf.len)
      break;
    push_update_ref_status(&buf, &state, remote_refs);
  }
  strbuf_release(&buf);

  if (flags & TRANSPORT_PUSH_DRY_RUN || !data->rs.nr || data->no_private_update)
    return 0;

  /* propagate back the update to the remote namespace */
  for (ref = remote_refs; ref; ref = ref->next) {
    char *private;

    if (ref->status != REF_STATUS_OK)
      continue;

    if (!ref->report) {
      private = apply_refspecs(&data->rs, ref->name);
      if (!private)
        continue;
      refs_update_ref(get_main_ref_store(the_repository),
          "update by helper", private,
          &(ref->new_oid),
          NULL, 0, 0);
      free(private);
    } else {
      for (report = ref->report; report; report = report->next) {
        private = apply_refspecs(&data->rs,
               report->ref_name
               ? report->ref_name
               : ref->name);
        if (!private)
          continue;
        refs_update_ref(get_main_ref_store(the_repository),
            "update by helper", private,
            report->new_oid
            ? report->new_oid
            : &(ref->new_oid),
            NULL, 0, 0);
        free(private);
      }
    }
  }
  return 0;
}

static void set_common_push_options(struct transport *transport,
           const char *name, int flags)
{
  if (flags & TRANSPORT_PUSH_DRY_RUN) {
    if (set_helper_option(transport, "dry-run", "true") != 0)
      die(_("helper %s does not support dry-run"), name);
  } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
    if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
      die(_("helper %s does not support --signed"), name);
  } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
    if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
      die(_("helper %s does not support --signed=if-asked"), name);
  }

  if (flags & TRANSPORT_PUSH_ATOMIC)
    if (set_helper_option(transport, TRANS_OPT_ATOMIC, "true") != 0)
      die(_("helper %s does not support --atomic"), name);

  if (flags & TRANSPORT_PUSH_FORCE_IF_INCLUDES)
    if (set_helper_option(transport, TRANS_OPT_FORCE_IF_INCLUDES, "true") != 0)
      die(_("helper %s does not support --%s"),
          name, TRANS_OPT_FORCE_IF_INCLUDES);

  if (flags & TRANSPORT_PUSH_OPTIONS) {
    struct string_list_item *item;
    for_each_string_list_item(item, transport->push_options)
      if (set_helper_option(transport, "push-option", item->string) != 0)
        die(_("helper %s does not support 'push-option'"), name);
  }
}

static int push_refs_with_push(struct transport *transport,
             struct ref *remote_refs, int flags)
{
  int force_all = flags & TRANSPORT_PUSH_FORCE;
  int mirror = flags & TRANSPORT_PUSH_MIRROR;
  int atomic = flags & TRANSPORT_PUSH_ATOMIC;
  struct helper_data *data = transport->data;
  struct strbuf buf = STRBUF_INIT;
  struct ref *ref;
  struct string_list cas_options = STRING_LIST_INIT_DUP;
  struct string_list_item *cas_option;

  get_helper(transport);
  if (!data->push)
    return 1;

  for (ref = remote_refs; ref; ref = ref->next) {
    if (!ref->peer_ref && !mirror)
      continue;

    /* Check for statuses set by set_ref_status_for_push() */
    switch (ref->status) {
    case REF_STATUS_REJECT_NONFASTFORWARD:
    case REF_STATUS_REJECT_STALE:
    case REF_STATUS_REJECT_ALREADY_EXISTS:
    case REF_STATUS_REJECT_REMOTE_UPDATED:
      if (atomic) {
        reject_atomic_push(remote_refs, mirror);
        string_list_clear(&cas_options, 0);
        return 0;
      } else
        continue;
    case REF_STATUS_UPTODATE:
      continue;
    default:
      ; /* do nothing */
    }

    if (force_all)
      ref->force = 1;

    strbuf_addstr(&buf, "push ");
    if (!ref->deletion) {
      if (ref->force)
        strbuf_addch(&buf, '+');
      if (ref->peer_ref)
        strbuf_addstr(&buf, ref->peer_ref->name);
      else
        strbuf_addstr(&buf, oid_to_hex(&ref->new_oid));
    }
    strbuf_addch(&buf, ':');
    strbuf_addstr(&buf, ref->name);
    strbuf_addch(&buf, '\n');

    /*
     * The "--force-with-lease" options without explicit
     * values to expect have already been expanded into
     * the ref->old_oid_expect[] field; we can ignore
     * transport->smart_options->cas altogether and instead
     * can enumerate them from the refs.
     */
    if (ref->expect_old_sha1) {
      struct strbuf cas = STRBUF_INIT;
      strbuf_addf(&cas, "%s:%s",
            ref->name, oid_to_hex(&ref->old_oid_expect));
      string_list_append_nodup(&cas_options,
             strbuf_detach(&cas, NULL));
    }
  }
  if (buf.len == 0) {
    string_list_clear(&cas_options, 0);
    return 0;
  }

  for_each_string_list_item(cas_option, &cas_options)
    set_helper_option(transport, "cas", cas_option->string);
  set_common_push_options(transport, data->name, flags);

  strbuf_addch(&buf, '\n');
  sendline(data, &buf);
  strbuf_release(&buf);
  string_list_clear(&cas_options, 0);

  return push_update_refs_status(data, remote_refs, flags);
}

static int push_refs_with_export(struct transport *transport,
    struct ref *remote_refs, int flags)
{
  struct ref *ref;
  struct child_process *helper, exporter;
  struct helper_data *data = transport->data;
  struct string_list revlist_args = STRING_LIST_INIT_DUP;
  struct strbuf buf = STRBUF_INIT;

  if (!data->rs.nr)
    die(_("remote-helper doesn't support push; refspec needed"));

  set_common_push_options(transport, data->name, flags);
  if (flags & TRANSPORT_PUSH_FORCE) {
    if (set_helper_option(transport, "force", "true") != 0)
      warning(_("helper %s does not support '--force'"), data->name);
  }

  helper = get_helper(transport);

  write_constant(helper->in, "export\n");

  for (ref = remote_refs; ref; ref = ref->next) {
    char *private;
    struct object_id oid;

    private = apply_refspecs(&data->rs, ref->name);
    if (private && !repo_get_oid(the_repository, private, &oid)) {
      strbuf_addf(&buf, "^%s", private);
      string_list_append_nodup(&revlist_args,
             strbuf_detach(&buf, NULL));
      oidcpy(&ref->old_oid, &oid);
    }
    free(private);

    if (ref->peer_ref) {
      if (strcmp(ref->name, ref->peer_ref->name)) {
        if (!ref->deletion) {
          const char *name;
          int flag;

          /* Follow symbolic refs (mainly for HEAD). */
          name = refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
                       ref->peer_ref->name,
                       RESOLVE_REF_READING,
                       &oid,
                       &flag);
          if (!name || !(flag & REF_ISSYMREF))
            name = ref->peer_ref->name;

          strbuf_addf(&buf, "%s:%s", name, ref->name);
        } else
          strbuf_addf(&buf, ":%s", ref->name);

        string_list_append(&revlist_args, "--refspec");
        string_list_append(&revlist_args, buf.buf);
        strbuf_release(&buf);
      }
      if (!ref->deletion)
        string_list_append(&revlist_args, ref->peer_ref->name);
    }
  }

  if (get_exporter(transport, &exporter, &revlist_args))
    die(_("couldn't run fast-export"));

  string_list_clear(&revlist_args, 1);

  if (finish_command(&exporter))
    die(_("error while running fast-export"));
  if (push_update_refs_status(data, remote_refs, flags))
    return 1;

  if (data->export_marks) {
    strbuf_addf(&buf, "%s.tmp", data->export_marks);
    rename(buf.buf, data->export_marks);
    strbuf_release(&buf);
  }

  return 0;
}

static int push_refs(struct transport *transport,
    struct ref *remote_refs, int flags)
{
  struct helper_data *data = transport->data;

  if (process_connect(transport, 1))
    return transport->vtable->push_refs(transport, remote_refs, flags);

  if (!remote_refs) {
    fprintf(stderr,
      _("No refs in common and none specified; doing nothing.\n"
        "Perhaps you should specify a branch.\n"));
    return 0;
  }

  if (data->push)
    return push_refs_with_push(transport, remote_refs, flags);

  if (data->export)
    return push_refs_with_export(transport, remote_refs, flags);

  return -1;
}


static int has_attribute(const char *attrs, const char *attr)
{
  int len;
  if (!attrs)
    return 0;

  len = strlen(attr);
  for (;;) {
    const char *space = strchrnul(attrs, ' ');
    if (len == space - attrs && !strncmp(attrs, attr, len))
      return 1;
    if (!*space)
      return 0;
    attrs = space + 1;
  }
}

static struct ref *get_refs_list(struct transport *transport, int for_push,
         struct transport_ls_refs_options *transport_options)
{
  get_helper(transport);

  if (process_connect(transport, for_push))
    return transport->vtable->get_refs_list(transport, for_push,
              transport_options);

  return get_refs_list_using_list(transport, for_push);
}

static struct ref *get_refs_list_using_list(struct transport *transport,
              int for_push)
{
  struct helper_data *data = transport->data;
  struct child_process *helper;
  struct ref *ret = NULL;
  struct ref **tail = &ret;
  struct ref *posn;
  struct strbuf buf = STRBUF_INIT;

  data->get_refs_list_called = 1;
  helper = get_helper(transport);

  if (data->object_format)
    set_helper_option(transport, "object-format", "true");

  if (data->push && for_push)
    write_constant(helper->in, "list for-push\n");
  else
    write_constant(helper->in, "list\n");

  while (1) {
    char *eov, *eon;
    if (recvline(data, &buf))
      exit(128);

    if (!*buf.buf)
      break;
    else if (buf.buf[0] == ':') {
      const char *value;
      if (skip_prefix(buf.buf, ":object-format ", &value)) {
        int algo = hash_algo_by_name(value);
        if (algo == GIT_HASH_UNKNOWN)
          die(_("unsupported object format '%s'"),
              value);
        transport->hash_algo = &hash_algos[algo];
      }
      continue;
    }

    eov = strchr(buf.buf, ' ');
    if (!eov)
      die(_("malformed response in ref list: %s"), buf.buf);
    eon = strchr(eov + 1, ' ');
    *eov = '\0';
    if (eon)
      *eon = '\0';
    *tail = alloc_ref(eov + 1);
    if (buf.buf[0] == '@')
      (*tail)->symref = xstrdup(buf.buf + 1);
    else if (buf.buf[0] != '?')
      get_oid_hex_algop(buf.buf, &(*tail)->old_oid, transport->hash_algo);
    if (eon) {
      if (has_attribute(eon + 1, "unchanged")) {
        (*tail)->status |= REF_STATUS_UPTODATE;
        if (refs_read_ref(get_main_ref_store(the_repository), (*tail)->name, &(*tail)->old_oid) < 0)
          die(_("could not read ref %s"),
              (*tail)->name);
      }
    }
    tail = &((*tail)->next);
  }
  if (debug)
    fprintf(stderr, "Debug: Read ref listing.\n");
  strbuf_release(&buf);

  for (posn = ret; posn; posn = posn->next)
    resolve_remote_symref(posn, ret);

  return ret;
}

static int get_bundle_uri(struct transport *transport)
{
  get_helper(transport);

  if (process_connect(transport, 0))
    return transport->vtable->get_bundle_uri(transport);

  return -1;
}

static struct transport_vtable vtable = {
  .set_option = set_helper_option,
  .get_refs_list  = get_refs_list,
  .get_bundle_uri = get_bundle_uri,
  .fetch_refs = fetch_refs,
  .push_refs  = push_refs,
  .connect  = connect_helper,
  .disconnect = release_helper
};

int transport_helper_init(struct transport *transport, const char *name)
{
  struct helper_data *data = xcalloc(1, sizeof(*data));
  data->name = xstrdup(name);

  transport_check_allowed(name);

  if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
    debug = 1;

  list_objects_filter_init(&data->transport_options.filter_options);

  transport->data = data;
  transport->vtable = &vtable;
  transport->smart_options = &(data->transport_options);
  return 0;
}

/*
 * Linux pipes can buffer 65536 bytes at once (and most platforms can
 * buffer less), so attempt reads and writes with up to that size.
 */
#define BUFFERSIZE 65536
/* This should be enough to hold debugging message. */
#define PBUFFERSIZE 8192

/* Print bidirectional transfer loop debug message. */
__attribute__((format (printf, 1, 2)))
static void transfer_debug(const char *fmt, ...)
{
  /*
   * NEEDSWORK: This function is sometimes used from multiple threads, and
   * we end up using debug_enabled racily. That "should not matter" since
   * we always write the same value, but it's still wrong. This function
   * is listed in .tsan-suppressions for the time being.
   */

  va_list args;
  char msgbuf[PBUFFERSIZE];
  static int debug_enabled = -1;

  if (debug_enabled < 0)
    debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
  if (!debug_enabled)
    return;

  va_start(args, fmt);
  vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
  va_end(args);
  fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
}

/* Stream state: More data may be coming in this direction. */
#define SSTATE_TRANSFERRING 0
/*
 * Stream state: No more data coming in this direction, flushing rest of
 * data.
 */
#define SSTATE_FLUSHING 1
/* Stream state: Transfer in this direction finished. */
#define SSTATE_FINISHED 2

#define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERRING)
#define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
#define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)

/* Unidirectional transfer. */
struct unidirectional_transfer {
  /* Source */
  int src;
  /* Destination */
  int dest;
  /* Is source socket? */
  int src_is_sock;
  /* Is destination socket? */
  int dest_is_sock;
  /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
  int state;
  /* Buffer. */
  char buf[BUFFERSIZE];
  /* Buffer used. */
  size_t bufuse;
  /* Name of source. */
  const char *src_name;
  /* Name of destination. */
  const char *dest_name;
};

/* Closes the target (for writing) if transfer has finished. */
static void udt_close_if_finished(struct unidirectional_transfer *t)
{
  if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
    t->state = SSTATE_FINISHED;
    if (t->dest_is_sock)
      shutdown(t->dest, SHUT_WR);
    else
      close(t->dest);
    transfer_debug("Closed %s.", t->dest_name);
  }
}

/*
 * Tries to read data from source into buffer. If buffer is full,
 * no data is read. Returns 0 on success, -1 on error.
 */
static int udt_do_read(struct unidirectional_transfer *t)
{
  ssize_t bytes;

  if (t->bufuse == BUFFERSIZE)
    return 0; /* No space for more. */

  transfer_debug("%s is readable", t->src_name);
  bytes = xread(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
  if (bytes < 0) {
    error_errno(_("read(%s) failed"), t->src_name);
    return -1;
  } else if (bytes == 0) {
    transfer_debug("%s EOF (with %i bytes in buffer)",
      t->src_name, (int)t->bufuse);
    t->state = SSTATE_FLUSHING;
  } else if (bytes > 0) {
    t->bufuse += bytes;
    transfer_debug("Read %i bytes from %s (buffer now at %i)",
      (int)bytes, t->src_name, (int)t->bufuse);
  }
  return 0;
}

/* Tries to write data from buffer into destination. If buffer is empty,
 * no data is written. Returns 0 on success, -1 on error.
 */
static int udt_do_write(struct unidirectional_transfer *t)
{
  ssize_t bytes;

  if (t->bufuse == 0)
    return 0; /* Nothing to write. */

  transfer_debug("%s is writable", t->dest_name);
  bytes = xwrite(t->dest, t->buf, t->bufuse);
  if (bytes < 0) {
    error_errno(_("write(%s) failed"), t->dest_name);
    return -1;
  } else if (bytes > 0) {
    t->bufuse -= bytes;
    if (t->bufuse)
      memmove(t->buf, t->buf + bytes, t->bufuse);
    transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
      (int)bytes, t->dest_name, (int)t->bufuse);
  }
  return 0;
}


/* State of bidirectional transfer loop. */
struct bidirectional_transfer_state {
  /* Direction from program to git. */
  struct unidirectional_transfer ptg;
  /* Direction from git to program. */
  struct unidirectional_transfer gtp;
};

static void *udt_copy_task_routine(void *udt)
{
  struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
  while (t->state != SSTATE_FINISHED) {
    if (STATE_NEEDS_READING(t->state))
      if (udt_do_read(t))
        return NULL;
    if (STATE_NEEDS_WRITING(t->state))
      if (udt_do_write(t))
        return NULL;
    if (STATE_NEEDS_CLOSING(t->state))
      udt_close_if_finished(t);
  }
  return udt; /* Just some non-NULL value. */
}

#ifndef NO_PTHREADS

/*
 * Join thread, with appropriate errors on failure. Name is name for the
 * thread (for error messages). Returns 0 on success, 1 on failure.
 */
static int tloop_join(pthread_t thread, const char *name)
{
  int err;
  void *tret;
  err = pthread_join(thread, &tret);
  if (!tret) {
    error(_("%s thread failed"), name);
    return 1;
  }
  if (err) {
    error(_("%s thread failed to join: %s"), name, strerror(err));
    return 1;
  }
  return 0;
}

/*
 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
 * -1 on failure.
 */
static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
{
  pthread_t gtp_thread;
  pthread_t ptg_thread;
  int err;
  int ret = 0;
  err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
    &s->gtp);
  if (err)
    die(_("can't start thread for copying data: %s"), strerror(err));
  err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
    &s->ptg);
  if (err)
    die(_("can't start thread for copying data: %s"), strerror(err));

  ret |= tloop_join(gtp_thread, "Git to program copy");
  ret |= tloop_join(ptg_thread, "Program to git copy");
  return ret;
}
#else

/* Close the source and target (for writing) for transfer. */
static void udt_kill_transfer(struct unidirectional_transfer *t)
{
  t->state = SSTATE_FINISHED;
  /*
   * Socket read end left open isn't a disaster if nobody
   * attempts to read from it (mingw compat headers do not
   * have SHUT_RD)...
   *
   * We can't fully close the socket since otherwise gtp
   * task would first close the socket it sends data to
   * while closing the ptg file descriptors.
   */
  if (!t->src_is_sock)
    close(t->src);
  if (t->dest_is_sock)
    shutdown(t->dest, SHUT_WR);
  else
    close(t->dest);
}

/*
 * Join process, with appropriate errors on failure. Name is name for the
 * process (for error messages). Returns 0 on success, 1 on failure.
 */
static int tloop_join(pid_t pid, const char *name)
{
  int tret;
  if (waitpid(pid, &tret, 0) < 0) {
    error_errno(_("%s process failed to wait"), name);
    return 1;
  }
  if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
    error(_("%s process failed"), name);
    return 1;
  }
  return 0;
}

/*
 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
 * -1 on failure.
 */
static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
{
  pid_t pid1, pid2;
  int ret = 0;

  /* Fork thread #1: git to program. */
  pid1 = fork();
  if (pid1 < 0)
    die_errno(_("can't start thread for copying data"));
  else if (pid1 == 0) {
    udt_kill_transfer(&s->ptg);
    exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
  }

  /* Fork thread #2: program to git. */
  pid2 = fork();
  if (pid2 < 0)
    die_errno(_("can't start thread for copying data"));
  else if (pid2 == 0) {
    udt_kill_transfer(&s->gtp);
    exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
  }

  /*
   * Close both streams in parent as to not interfere with
   * end of file detection and wait for both tasks to finish.
   */
  udt_kill_transfer(&s->gtp);
  udt_kill_transfer(&s->ptg);
  ret |= tloop_join(pid1, "Git to program copy");
  ret |= tloop_join(pid2, "Program to git copy");
  return ret;
}
#endif

/*
 * Copies data from stdin to output and from input to stdout simultaneously.
 * Additionally filtering through given filter. If filter is NULL, uses
 * identity filter.
 */
int bidirectional_transfer_loop(int input, int output)
{
  struct bidirectional_transfer_state state;

  /* Fill the state fields. */
  state.ptg.src = input;
  state.ptg.dest = 1;
  state.ptg.src_is_sock = (input == output);
  state.ptg.dest_is_sock = 0;
  state.ptg.state = SSTATE_TRANSFERRING;
  state.ptg.bufuse = 0;
  state.ptg.src_name = "remote input";
  state.ptg.dest_name = "stdout";

  state.gtp.src = 0;
  state.gtp.dest = output;
  state.gtp.src_is_sock = 0;
  state.gtp.dest_is_sock = (input == output);
  state.gtp.state = SSTATE_TRANSFERRING;
  state.gtp.bufuse = 0;
  state.gtp.src_name = "stdin";
  state.gtp.dest_name = "remote output";

  return tloop_spawnwait_tasks(&state);
}

void reject_atomic_push(struct ref *remote_refs, int mirror_mode)
{
  struct ref *ref;

  /* Mark other refs as failed */
  for (ref = remote_refs; ref; ref = ref->next) {
    if (!ref->peer_ref && !mirror_mode)
      continue;

    switch (ref->status) {
    case REF_STATUS_NONE:
    case REF_STATUS_OK:
    case REF_STATUS_EXPECTING_REPORT:
      ref->status = REF_STATUS_ATOMIC_PUSH_FAILED;
      continue;
    default:
      break; /* do nothing */
    }
  }
  return;
}

Coverage Report

Created: 2024-09-16 06:10