git/transport-helper.c
Jonathan Tan 6ab4055775 transport: list refs before fetch if necessary
The built-in bundle transport and the transport helper interface do not
work when transport_fetch_refs() is called immediately after transport
creation. This will be needed in a subsequent patch, so fix this.

Evidence: fetch_refs_from_bundle() relies on data->header being
initialized in get_refs_from_bundle(), and fetch() in transport-helper.c
relies on either data->fetch or data->import being set by get_helper(),
but neither transport_helper_init() nor fetch() calls get_helper().

Up until the introduction of the partial clone feature, this has not
been a problem, because transport_fetch_refs() is always called after
transport_get_remote_refs(). With the introduction of the partial clone
feature, which involves calling transport_fetch_refs() (to fetch objects
by their OIDs) without transport_get_remote_refs(), this is still not a
problem, but only coincidentally - we do not support partially cloning a
bundle, and as for cloning using a transport-helper-using protocol, it
so happens that before transport_fetch_refs() is called, fetch_refs() in
fetch-object.c calls transport_set_option(), which means that the
aforementioned get_helper() is invoked through set_helper_option() in
transport-helper.c.

This could be fixed by fixing the transports themselves, but it doesn't
seem like a good idea to me to open up previously untested code paths;
also, there may be transport helpers in the wild that assume that "list"
is always called before "fetch". Instead, fix this by having
transport_fetch_refs() call transport_get_remote_refs() to ensure that
the latter is always called at least once, unless the transport
explicitly states that it supports fetching without listing refs.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 09:53:19 +09:00

1450 lines
37 KiB
C

#include "cache.h"
#include "transport.h"
#include "quote.h"
#include "run-command.h"
#include "commit.h"
#include "diff.h"
#include "revision.h"
#include "remote.h"
#include "string-list.h"
#include "thread-utils.h"
#include "sigchain.h"
#include "argv-array.h"
#include "refs.h"
#include "refspec.h"
#include "transport-internal.h"
#include "protocol.h"
static int debug;
struct helper_data {
const 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;
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);
}
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;
argv_array_pushf(&helper->args, "git-remote-%s", data->name);
argv_array_push(&helper->args, transport->remote->name);
argv_array_push(&helper->args, remove_ext_force(transport->url));
helper->git_cmd = 0;
helper->silent_exec_failure = 1;
if (have_git_dir())
argv_array_pushf(&helper->env_array, "%s=%s",
GIT_DIR_ENVIRONMENT, get_git_dir());
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 (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->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) {
if (recvline(data, &buf))
exit(128);
if (starts_with(buf.buf, "lock ")) {
const char *name = buf.buf + 5;
if (transport->pack_lockfile)
warning(_("%s also locked %s"), data->name, name);
else
transport->pack_lockfile = xstrdup(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);
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 = helper->out;
argv_array_push(&fastimport->args, "fast-import");
argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
if (data->bidi_import) {
cat_blob_fd = xdup(helper->in);
argv_array_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);
argv_array_push(&fastexport->args, "fast-export");
argv_array_push(&fastexport->args, "--use-done-feature");
argv_array_push(&fastexport->args, data->signed_tags ?
"--signed-tags=verbatim" : "--signed-tags=warn-strip");
if (data->export_marks)
argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
if (data->import_marks)
argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
for (i = 0; i < revlist_args->nr; i++)
argv_array_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 (read_ref(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)) {
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;
name = for_push ? "git-receive-pack" : "git-upload-pack";
if (for_push)
exec = data->transport_options.receivepack;
else
exec = data->transport_options.uploadpack;
return process_connect_service(transport, name, exec);
}
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 (!data->connect)
die(_("operation not supported by protocol"));
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;
return 0;
}
static int fetch(struct transport *transport,
int nr_heads, struct ref **to_fetch)
{
struct helper_data *data = transport->data;
int i, count;
if (process_connect(transport, 0)) {
do_take_over(transport);
return transport->vtable->fetch(transport, nr_heads, to_fetch);
}
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.filter_options.choice)
set_helper_option(
transport, "filter",
data->transport_options.filter_options.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;
}
static int push_update_ref_status(struct strbuf *buf,
struct ref **ref,
struct ref *remote_refs)
{
char *refname, *msg;
int status, forced = 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, "forced update")) {
forced = 1;
FREE_AND_NULL(msg);
}
}
if (*ref)
*ref = find_ref_by_name(*ref, refname);
if (!*ref)
*ref = find_ref_by_name(remote_refs, refname);
if (!*ref) {
warning(_("helper reported unexpected status of %s"), refname);
return 1;
}
if ((*ref)->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;
}
(*ref)->status = status;
(*ref)->forced_update |= forced;
(*ref)->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 strbuf buf = STRBUF_INIT;
struct ref *ref = remote_refs;
int ret = 0;
for (;;) {
char *private;
if (recvline(data, &buf)) {
ret = 1;
break;
}
if (!buf.len)
break;
if (push_update_ref_status(&buf, &ref, remote_refs))
continue;
if (flags & TRANSPORT_PUSH_DRY_RUN || !data->rs.nr || data->no_private_update)
continue;
/* propagate back the update to the remote namespace */
private = apply_refspecs(&data->rs, ref->name);
if (!private)
continue;
update_ref("update by helper", private, &ref->new_oid, NULL,
0, 0);
free(private);
}
strbuf_release(&buf);
return ret;
}
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_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;
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_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 && !get_oid(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 = resolve_ref_unsafe(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)) {
do_take_over(transport);
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 such as 'master'.\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,
const struct argv_array *ref_prefixes)
{
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;
helper = get_helper(transport);
if (process_connect(transport, for_push)) {
do_take_over(transport);
return transport->vtable->get_refs_list(transport, for_push, ref_prefixes);
}
if (data->push && for_push)
write_str_in_full(helper->in, "list for-push\n");
else
write_str_in_full(helper->in, "list\n");
while (1) {
char *eov, *eon;
if (recvline(data, &buf))
exit(128);
if (!*buf.buf)
break;
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(buf.buf, &(*tail)->old_oid);
if (eon) {
if (has_attribute(eon + 1, "unchanged")) {
(*tail)->status |= REF_STATUS_UPTODATE;
if (read_ref((*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 struct transport_vtable vtable = {
0,
set_helper_option,
get_refs_list,
fetch,
push_refs,
connect_helper,
release_helper
};
int transport_helper_init(struct transport *transport, const char *name)
{
struct helper_data *data = xcalloc(1, sizeof(*data));
data->name = name;
transport_check_allowed(name);
if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
debug = 1;
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 = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
errno != EINTR) {
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 && errno != EWOULDBLOCK) {
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);
}