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git/upload-pack.c

846 lines
20 KiB
C
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#include "cache.h"
#include "refs.h"
#include "pkt-line.h"
#include "sideband.h"
#include "tag.h"
#include "object.h"
#include "commit.h"
#include "exec_cmd.h"
#include "diff.h"
#include "revision.h"
#include "list-objects.h"
#include "run-command.h"
#include "sigchain.h"
static const char upload_pack_usage[] = "git upload-pack [--strict] [--timeout=<n>] <dir>";
/* bits #0..7 in revision.h, #8..10 in commit.c */
#define THEY_HAVE (1u << 11)
#define OUR_REF (1u << 12)
#define WANTED (1u << 13)
#define COMMON_KNOWN (1u << 14)
#define REACHABLE (1u << 15)
#define SHALLOW (1u << 16)
#define NOT_SHALLOW (1u << 17)
#define CLIENT_SHALLOW (1u << 18)
static unsigned long oldest_have;
static int multi_ack, nr_our_refs;
static int no_done;
static int use_thin_pack, use_ofs_delta, use_include_tag;
static int no_progress, daemon_mode;
static int shallow_nr;
static struct object_array have_obj;
static struct object_array want_obj;
static struct object_array extra_edge_obj;
static unsigned int timeout;
/* 0 for no sideband,
* otherwise maximum packet size (up to 65520 bytes).
*/
static int use_sideband;
static int debug_fd;
static int advertise_refs;
static int stateless_rpc;
static void reset_timeout(void)
{
alarm(timeout);
}
static int strip(char *line, int len)
{
if (len && line[len-1] == '\n')
line[--len] = 0;
return len;
}
static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
{
if (use_sideband)
return send_sideband(1, fd, data, sz, use_sideband);
if (fd == 3)
/* emergency quit */
fd = 2;
if (fd == 2) {
/* XXX: are we happy to lose stuff here? */
xwrite(fd, data, sz);
return sz;
}
return safe_write(fd, data, sz);
}
static FILE *pack_pipe = NULL;
static void show_commit(struct commit *commit, void *data)
{
if (commit->object.flags & BOUNDARY)
fputc('-', pack_pipe);
if (fputs(sha1_to_hex(commit->object.sha1), pack_pipe) < 0)
die("broken output pipe");
fputc('\n', pack_pipe);
fflush(pack_pipe);
free(commit->buffer);
commit->buffer = NULL;
}
static void show_object(struct object *obj, const struct name_path *path, const char *component)
{
/* An object with name "foo\n0000000..." can be used to
* confuse downstream git-pack-objects very badly.
*/
const char *name = path_name(path, component);
const char *ep = strchr(name, '\n');
if (ep) {
fprintf(pack_pipe, "%s %.*s\n", sha1_to_hex(obj->sha1),
(int) (ep - name),
name);
}
else
fprintf(pack_pipe, "%s %s\n",
sha1_to_hex(obj->sha1), name);
free((char *)name);
}
static void show_edge(struct commit *commit)
{
fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
}
static int do_rev_list(int in, int out, void *user_data)
{
int i;
struct rev_info revs;
pack_pipe = xfdopen(out, "w");
init_revisions(&revs, NULL);
revs.tag_objects = 1;
revs.tree_objects = 1;
revs.blob_objects = 1;
if (use_thin_pack)
revs.edge_hint = 1;
for (i = 0; i < want_obj.nr; i++) {
struct object *o = want_obj.objects[i].item;
/* why??? */
o->flags &= ~UNINTERESTING;
add_pending_object(&revs, o, NULL);
}
for (i = 0; i < have_obj.nr; i++) {
struct object *o = have_obj.objects[i].item;
o->flags |= UNINTERESTING;
add_pending_object(&revs, o, NULL);
}
setup_revisions(0, NULL, &revs, NULL);
if (prepare_revision_walk(&revs))
die("revision walk setup failed");
mark_edges_uninteresting(revs.commits, &revs, show_edge);
if (use_thin_pack)
for (i = 0; i < extra_edge_obj.nr; i++)
fprintf(pack_pipe, "-%s\n", sha1_to_hex(
extra_edge_obj.objects[i].item->sha1));
traverse_commit_list(&revs, show_commit, show_object, NULL);
fflush(pack_pipe);
fclose(pack_pipe);
return 0;
}
static void create_pack_file(void)
{
struct async rev_list;
struct child_process pack_objects;
int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
char data[8193], progress[128];
char abort_msg[] = "aborting due to possible repository "
"corruption on the remote side.";
int buffered = -1;
ssize_t sz;
const char *argv[10];
int arg = 0;
argv[arg++] = "pack-objects";
if (!shallow_nr) {
argv[arg++] = "--revs";
if (create_full_pack)
argv[arg++] = "--all";
else if (use_thin_pack)
argv[arg++] = "--thin";
}
argv[arg++] = "--stdout";
if (!no_progress)
argv[arg++] = "--progress";
if (use_ofs_delta)
argv[arg++] = "--delta-base-offset";
if (use_include_tag)
argv[arg++] = "--include-tag";
argv[arg++] = NULL;
memset(&pack_objects, 0, sizeof(pack_objects));
pack_objects.in = -1;
pack_objects.out = -1;
pack_objects.err = -1;
pack_objects.git_cmd = 1;
pack_objects.argv = argv;
if (start_command(&pack_objects))
die("git upload-pack: unable to fork git-pack-objects");
if (shallow_nr) {
memset(&rev_list, 0, sizeof(rev_list));
rev_list.proc = do_rev_list;
rev_list.out = pack_objects.in;
if (start_async(&rev_list))
die("git upload-pack: unable to fork git-rev-list");
}
else {
FILE *pipe_fd = xfdopen(pack_objects.in, "w");
if (!create_full_pack) {
int i;
for (i = 0; i < want_obj.nr; i++)
fprintf(pipe_fd, "%s\n", sha1_to_hex(want_obj.objects[i].item->sha1));
fprintf(pipe_fd, "--not\n");
for (i = 0; i < have_obj.nr; i++)
fprintf(pipe_fd, "%s\n", sha1_to_hex(have_obj.objects[i].item->sha1));
}
fprintf(pipe_fd, "\n");
fflush(pipe_fd);
fclose(pipe_fd);
}
/* We read from pack_objects.err to capture stderr output for
* progress bar, and pack_objects.out to capture the pack data.
*/
while (1) {
struct pollfd pfd[2];
int pe, pu, pollsize;
reset_timeout();
pollsize = 0;
pe = pu = -1;
if (0 <= pack_objects.out) {
pfd[pollsize].fd = pack_objects.out;
pfd[pollsize].events = POLLIN;
pu = pollsize;
pollsize++;
}
if (0 <= pack_objects.err) {
pfd[pollsize].fd = pack_objects.err;
pfd[pollsize].events = POLLIN;
pe = pollsize;
pollsize++;
}
if (!pollsize)
break;
if (poll(pfd, pollsize, -1) < 0) {
if (errno != EINTR) {
error("poll failed, resuming: %s",
strerror(errno));
sleep(1);
}
continue;
}
if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
/* Status ready; we ship that in the side-band
* or dump to the standard error.
*/
sz = xread(pack_objects.err, progress,
sizeof(progress));
if (0 < sz)
send_client_data(2, progress, sz);
else if (sz == 0) {
close(pack_objects.err);
pack_objects.err = -1;
}
else
goto fail;
/* give priority to status messages */
continue;
}
if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
/* Data ready; we keep the last byte to ourselves
* in case we detect broken rev-list, so that we
* can leave the stream corrupted. This is
* unfortunate -- unpack-objects would happily
* accept a valid packdata with trailing garbage,
* so appending garbage after we pass all the
* pack data is not good enough to signal
* breakage to downstream.
*/
char *cp = data;
ssize_t outsz = 0;
if (0 <= buffered) {
*cp++ = buffered;
outsz++;
}
sz = xread(pack_objects.out, cp,
sizeof(data) - outsz);
if (0 < sz)
;
else if (sz == 0) {
close(pack_objects.out);
pack_objects.out = -1;
}
else
goto fail;
sz += outsz;
if (1 < sz) {
buffered = data[sz-1] & 0xFF;
sz--;
}
else
buffered = -1;
sz = send_client_data(1, data, sz);
if (sz < 0)
goto fail;
}
}
if (finish_command(&pack_objects)) {
error("git upload-pack: git-pack-objects died with error.");
goto fail;
}
if (shallow_nr && finish_async(&rev_list))
goto fail; /* error was already reported */
/* flush the data */
if (0 <= buffered) {
data[0] = buffered;
sz = send_client_data(1, data, 1);
if (sz < 0)
goto fail;
fprintf(stderr, "flushed.\n");
}
if (use_sideband)
packet_flush(1);
return;
fail:
send_client_data(3, abort_msg, sizeof(abort_msg));
die("git upload-pack: %s", abort_msg);
}
static int got_sha1(char *hex, unsigned char *sha1)
{
struct object *o;
int we_knew_they_have = 0;
if (get_sha1_hex(hex, sha1))
die("git upload-pack: expected SHA1 object, got '%s'", hex);
if (!has_sha1_file(sha1))
return -1;
o = lookup_object(sha1);
if (!(o && o->parsed))
o = parse_object(sha1);
if (!o)
die("oops (%s)", sha1_to_hex(sha1));
if (o->type == OBJ_COMMIT) {
struct commit_list *parents;
struct commit *commit = (struct commit *)o;
if (o->flags & THEY_HAVE)
we_knew_they_have = 1;
else
o->flags |= THEY_HAVE;
if (!oldest_have || (commit->date < oldest_have))
oldest_have = commit->date;
for (parents = commit->parents;
parents;
parents = parents->next)
parents->item->object.flags |= THEY_HAVE;
}
if (!we_knew_they_have) {
add_object_array(o, NULL, &have_obj);
return 1;
}
return 0;
}
static int reachable(struct commit *want)
{
struct commit_list *work = NULL;
commit_list_insert_by_date(want, &work);
while (work) {
struct commit_list *list = work->next;
struct commit *commit = work->item;
free(work);
work = list;
if (commit->object.flags & THEY_HAVE) {
want->object.flags |= COMMON_KNOWN;
break;
}
if (!commit->object.parsed)
parse_object(commit->object.sha1);
if (commit->object.flags & REACHABLE)
continue;
commit->object.flags |= REACHABLE;
if (commit->date < oldest_have)
continue;
for (list = commit->parents; list; list = list->next) {
struct commit *parent = list->item;
if (!(parent->object.flags & REACHABLE))
commit_list_insert_by_date(parent, &work);
}
}
want->object.flags |= REACHABLE;
clear_commit_marks(want, REACHABLE);
free_commit_list(work);
return (want->object.flags & COMMON_KNOWN);
}
static int ok_to_give_up(void)
{
int i;
if (!have_obj.nr)
return 0;
for (i = 0; i < want_obj.nr; i++) {
struct object *want = want_obj.objects[i].item;
if (want->flags & COMMON_KNOWN)
continue;
want = deref_tag(want, "a want line", 0);
if (!want || want->type != OBJ_COMMIT) {
/* no way to tell if this is reachable by
* looking at the ancestry chain alone, so
* leave a note to ourselves not to worry about
* this object anymore.
*/
want_obj.objects[i].item->flags |= COMMON_KNOWN;
continue;
}
if (!reachable((struct commit *)want))
return 0;
}
return 1;
}
static int get_common_commits(void)
{
static char line[1000];
unsigned char sha1[20];
char last_hex[41];
int got_common = 0;
int got_other = 0;
int sent_ready = 0;
save_commit_buffer = 0;
for (;;) {
int len = packet_read_line(0, line, sizeof(line));
reset_timeout();
if (!len) {
if (multi_ack == 2 && got_common
&& !got_other && ok_to_give_up()) {
sent_ready = 1;
packet_write(1, "ACK %s ready\n", last_hex);
}
if (have_obj.nr == 0 || multi_ack)
packet_write(1, "NAK\n");
if (no_done && sent_ready) {
packet_write(1, "ACK %s\n", last_hex);
return 0;
}
if (stateless_rpc)
exit(0);
got_common = 0;
got_other = 0;
continue;
}
strip(line, len);
if (!prefixcmp(line, "have ")) {
switch (got_sha1(line+5, sha1)) {
case -1: /* they have what we do not */
got_other = 1;
if (multi_ack && ok_to_give_up()) {
const char *hex = sha1_to_hex(sha1);
if (multi_ack == 2) {
sent_ready = 1;
packet_write(1, "ACK %s ready\n", hex);
} else
packet_write(1, "ACK %s continue\n", hex);
}
break;
default:
got_common = 1;
memcpy(last_hex, sha1_to_hex(sha1), 41);
if (multi_ack == 2)
packet_write(1, "ACK %s common\n", last_hex);
else if (multi_ack)
packet_write(1, "ACK %s continue\n", last_hex);
else if (have_obj.nr == 1)
packet_write(1, "ACK %s\n", last_hex);
break;
}
continue;
}
if (!strcmp(line, "done")) {
if (have_obj.nr > 0) {
if (multi_ack)
packet_write(1, "ACK %s\n", last_hex);
return 0;
}
packet_write(1, "NAK\n");
return -1;
}
die("git upload-pack: expected SHA1 list, got '%s'", line);
}
}
static void check_non_tip(void)
{
static const char *argv[] = {
"rev-list", "--stdin", NULL,
};
static struct child_process cmd;
struct object *o;
char namebuf[42]; /* ^ + SHA-1 + LF */
int i;
/* In the normal in-process case non-tip request can never happen */
if (!stateless_rpc)
goto error;
cmd.argv = argv;
cmd.git_cmd = 1;
cmd.no_stderr = 1;
cmd.in = -1;
cmd.out = -1;
if (start_command(&cmd))
goto error;
/*
* If rev-list --stdin encounters an unknown commit, it
* terminates, which will cause SIGPIPE in the write loop
* below.
*/
sigchain_push(SIGPIPE, SIG_IGN);
namebuf[0] = '^';
namebuf[41] = '\n';
for (i = get_max_object_index(); 0 < i; ) {
o = get_indexed_object(--i);
if (!o)
continue;
if (!(o->flags & OUR_REF))
continue;
memcpy(namebuf + 1, sha1_to_hex(o->sha1), 40);
if (write_in_full(cmd.in, namebuf, 42) < 0)
goto error;
}
namebuf[40] = '\n';
for (i = 0; i < want_obj.nr; i++) {
o = want_obj.objects[i].item;
if (o->flags & OUR_REF)
continue;
memcpy(namebuf, sha1_to_hex(o->sha1), 40);
if (write_in_full(cmd.in, namebuf, 41) < 0)
goto error;
}
close(cmd.in);
sigchain_pop(SIGPIPE);
/*
* The commits out of the rev-list are not ancestors of
* our ref.
*/
i = read_in_full(cmd.out, namebuf, 1);
if (i)
goto error;
close(cmd.out);
/*
* rev-list may have died by encountering a bad commit
* in the history, in which case we do want to bail out
* even when it showed no commit.
*/
if (finish_command(&cmd))
goto error;
/* All the non-tip ones are ancestors of what we advertised */
return;
error:
/* Pick one of them (we know there at least is one) */
for (i = 0; i < want_obj.nr; i++) {
o = want_obj.objects[i].item;
if (!(o->flags & OUR_REF))
die("git upload-pack: not our ref %s",
sha1_to_hex(o->sha1));
}
}
static void receive_needs(void)
{
struct object_array shallows = OBJECT_ARRAY_INIT;
static char line[1000];
int len, depth = 0;
int has_non_tip = 0;
shallow_nr = 0;
if (debug_fd)
write_str_in_full(debug_fd, "#S\n");
for (;;) {
struct object *o;
unsigned char sha1_buf[20];
len = packet_read_line(0, line, sizeof(line));
reset_timeout();
if (!len)
break;
if (debug_fd)
write_in_full(debug_fd, line, len);
if (!prefixcmp(line, "shallow ")) {
unsigned char sha1[20];
struct object *object;
if (get_sha1(line + 8, sha1))
die("invalid shallow line: %s", line);
object = parse_object(sha1);
if (!object)
die("did not find object for %s", line);
object->flags |= CLIENT_SHALLOW;
add_object_array(object, NULL, &shallows);
continue;
}
if (!prefixcmp(line, "deepen ")) {
char *end;
depth = strtol(line + 7, &end, 0);
if (end == line + 7 || depth <= 0)
die("Invalid deepen: %s", line);
continue;
}
if (prefixcmp(line, "want ") ||
get_sha1_hex(line+5, sha1_buf))
die("git upload-pack: protocol error, "
"expected to get sha, not '%s'", line);
if (strstr(line+45, "multi_ack_detailed"))
multi_ack = 2;
else if (strstr(line+45, "multi_ack"))
multi_ack = 1;
if (strstr(line+45, "no-done"))
no_done = 1;
if (strstr(line+45, "thin-pack"))
use_thin_pack = 1;
if (strstr(line+45, "ofs-delta"))
use_ofs_delta = 1;
if (strstr(line+45, "side-band-64k"))
use_sideband = LARGE_PACKET_MAX;
else if (strstr(line+45, "side-band"))
use_sideband = DEFAULT_PACKET_MAX;
if (strstr(line+45, "no-progress"))
no_progress = 1;
if (strstr(line+45, "include-tag"))
use_include_tag = 1;
o = lookup_object(sha1_buf);
if (!o)
die("git upload-pack: not our ref %s",
sha1_to_hex(sha1_buf));
if (!(o->flags & WANTED)) {
o->flags |= WANTED;
if (!(o->flags & OUR_REF))
has_non_tip = 1;
add_object_array(o, NULL, &want_obj);
}
}
if (debug_fd)
write_str_in_full(debug_fd, "#E\n");
/*
* We have sent all our refs already, and the other end
* should have chosen out of them. When we are operating
* in the stateless RPC mode, however, their choice may
* have been based on the set of older refs advertised
* by another process that handled the initial request.
*/
if (has_non_tip)
check_non_tip();
if (!use_sideband && daemon_mode)
no_progress = 1;
if (depth == 0 && shallows.nr == 0)
return;
if (depth > 0) {
struct commit_list *result, *backup;
int i;
backup = result = get_shallow_commits(&want_obj, depth,
SHALLOW, NOT_SHALLOW);
while (result) {
struct object *object = &result->item->object;
if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
packet_write(1, "shallow %s",
sha1_to_hex(object->sha1));
register_shallow(object->sha1);
shallow_nr++;
}
result = result->next;
}
free_commit_list(backup);
for (i = 0; i < shallows.nr; i++) {
struct object *object = shallows.objects[i].item;
if (object->flags & NOT_SHALLOW) {
struct commit_list *parents;
packet_write(1, "unshallow %s",
sha1_to_hex(object->sha1));
object->flags &= ~CLIENT_SHALLOW;
/* make sure the real parents are parsed */
unregister_shallow(object->sha1);
object->parsed = 0;
if (parse_commit((struct commit *)object))
die("invalid commit");
parents = ((struct commit *)object)->parents;
while (parents) {
add_object_array(&parents->item->object,
NULL, &want_obj);
parents = parents->next;
}
add_object_array(object, NULL, &extra_edge_obj);
}
/* make sure commit traversal conforms to client */
register_shallow(object->sha1);
}
packet_flush(1);
} else
if (shallows.nr > 0) {
int i;
for (i = 0; i < shallows.nr; i++)
register_shallow(shallows.objects[i].item->sha1);
}
shallow_nr += shallows.nr;
free(shallows.objects);
}
static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
{
static const char *capabilities = "multi_ack thin-pack side-band"
" side-band-64k ofs-delta shallow no-progress"
" include-tag multi_ack_detailed";
struct object *o = parse_object(sha1);
const char *refname_nons = strip_namespace(refname);
if (!o)
die("git upload-pack: cannot find object %s:", sha1_to_hex(sha1));
if (capabilities)
packet_write(1, "%s %s%c%s%s\n", sha1_to_hex(sha1), refname_nons,
0, capabilities,
stateless_rpc ? " no-done" : "");
else
packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname_nons);
capabilities = NULL;
if (!(o->flags & OUR_REF)) {
o->flags |= OUR_REF;
nr_our_refs++;
}
if (o->type == OBJ_TAG) {
o = deref_tag(o, refname, 0);
if (o)
packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname_nons);
}
return 0;
}
static int mark_our_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
{
struct object *o = parse_object(sha1);
if (!o)
die("git upload-pack: cannot find object %s:", sha1_to_hex(sha1));
if (!(o->flags & OUR_REF)) {
o->flags |= OUR_REF;
nr_our_refs++;
}
return 0;
}
static void upload_pack(void)
{
if (advertise_refs || !stateless_rpc) {
reset_timeout();
head_ref_namespaced(send_ref, NULL);
for_each_namespaced_ref(send_ref, NULL);
packet_flush(1);
} else {
head_ref_namespaced(mark_our_ref, NULL);
for_each_namespaced_ref(mark_our_ref, NULL);
}
if (advertise_refs)
return;
receive_needs();
if (want_obj.nr) {
get_common_commits();
create_pack_file();
}
}
int main(int argc, char **argv)
{
char *dir;
int i;
int strict = 0;
packet_trace_identity("upload-pack");
git_extract_argv0_path(argv[0]);
read_replace_refs = 0;
for (i = 1; i < argc; i++) {
char *arg = argv[i];
if (arg[0] != '-')
break;
if (!strcmp(arg, "--advertise-refs")) {
advertise_refs = 1;
continue;
}
if (!strcmp(arg, "--stateless-rpc")) {
stateless_rpc = 1;
continue;
}
if (!strcmp(arg, "--strict")) {
strict = 1;
continue;
}
if (!prefixcmp(arg, "--timeout=")) {
timeout = atoi(arg+10);
daemon_mode = 1;
continue;
}
if (!strcmp(arg, "--")) {
i++;
break;
}
}
if (i != argc-1)
usage(upload_pack_usage);
setup_path();
dir = argv[i];
if (!enter_repo(dir, strict))
die("'%s' does not appear to be a git repository", dir);
if (is_repository_shallow())
die("attempt to fetch/clone from a shallow repository");
if (getenv("GIT_DEBUG_SEND_PACK"))
debug_fd = atoi(getenv("GIT_DEBUG_SEND_PACK"));
upload_pack();
return 0;
}
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