Revision b81401c1de0e0fec39f8643ce7a794fda083f7a1 authored by Jeff King on 27 August 2012, 13:27:15 UTC, committed by Junio C Hamano on 27 August 2012, 17:49:09 UTC
All of the smart-http GET requests go through the http_get_* functions, which will prompt for credentials and retry if we see an HTTP 401. POST requests, however, do not go through any central point. Moreover, it is difficult to retry in the general case; we cannot assume the request body fits in memory or is even seekable, and we don't know how much of it was consumed during the attempt. Most of the time, this is not a big deal; for both fetching and pushing, we make a GET request before doing any POSTs, so typically we figure out the credentials during the first request, then reuse them during the POST. However, some servers may allow a client to get the list of refs from receive-pack without authentication, and then require authentication when the client actually tries to POST the pack. This is not ideal, as the client may do a non-trivial amount of work to generate the pack (e.g., delta-compressing objects). However, for a long time it has been the recommended example configuration in git-http-backend(1) for setting up a repository with anonymous fetch and authenticated push. This setup has always been broken without putting a username into the URL. Prior to commit 986bbc0, it did work with a username in the URL, because git would prompt for credentials before making any requests at all. However, post-986bbc0, it is totally broken. Since it has been advertised in the manpage for some time, we should make sure it works. Unfortunately, it is not as easy as simply calling post_rpc again when it fails, due to the input issue mentioned above. However, we can still make this specific case work by retrying in two specific instances: 1. If the request is large (bigger than LARGE_PACKET_MAX), we will first send a probe request with a single flush packet. Since this request is static, we can freely retry it. 2. If the request is small and we are not using gzip, then we have the whole thing in-core, and we can freely retry. That means we will not retry in some instances, including: 1. If we are using gzip. However, we only do so when calling git-upload-pack, so it does not apply to pushes. 2. If we have a large request, the probe succeeds, but then the real POST wants authentication. This is an extremely unlikely configuration and not worth worrying about. While it might be nice to cover those instances, doing so would be significantly more complex for very little real-world gain. In the long run, we will be much better off when curl learns to internally handle authentication as a callback, and we can cleanly handle all cases that way. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 8809703
pack-refs.c
#include "cache.h"
#include "refs.h"
#include "tag.h"
#include "pack-refs.h"
struct ref_to_prune {
struct ref_to_prune *next;
unsigned char sha1[20];
char name[FLEX_ARRAY];
};
struct pack_refs_cb_data {
unsigned int flags;
struct ref_to_prune *ref_to_prune;
FILE *refs_file;
};
static int do_not_prune(int flags)
{
/* If it is already packed or if it is a symref,
* do not prune it.
*/
return (flags & (REF_ISSYMREF|REF_ISPACKED));
}
static int handle_one_ref(const char *path, const unsigned char *sha1,
int flags, void *cb_data)
{
struct pack_refs_cb_data *cb = cb_data;
int is_tag_ref;
/* Do not pack the symbolic refs */
if ((flags & REF_ISSYMREF))
return 0;
is_tag_ref = !prefixcmp(path, "refs/tags/");
/* ALWAYS pack refs that were already packed or are tags */
if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref && !(flags & REF_ISPACKED))
return 0;
fprintf(cb->refs_file, "%s %s\n", sha1_to_hex(sha1), path);
if (is_tag_ref) {
struct object *o = parse_object(sha1);
if (o->type == OBJ_TAG) {
o = deref_tag(o, path, 0);
if (o)
fprintf(cb->refs_file, "^%s\n",
sha1_to_hex(o->sha1));
}
}
if ((cb->flags & PACK_REFS_PRUNE) && !do_not_prune(flags)) {
int namelen = strlen(path) + 1;
struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
hashcpy(n->sha1, sha1);
strcpy(n->name, path);
n->next = cb->ref_to_prune;
cb->ref_to_prune = n;
}
return 0;
}
/*
* Remove empty parents, but spare refs/ and immediate subdirs.
* Note: munges *name.
*/
static void try_remove_empty_parents(char *name)
{
char *p, *q;
int i;
p = name;
for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
while (*p && *p != '/')
p++;
/* tolerate duplicate slashes; see check_refname_format() */
while (*p == '/')
p++;
}
for (q = p; *q; q++)
;
while (1) {
while (q > p && *q != '/')
q--;
while (q > p && *(q-1) == '/')
q--;
if (q == p)
break;
*q = '\0';
if (rmdir(git_path("%s", name)))
break;
}
}
/* make sure nobody touched the ref, and unlink */
static void prune_ref(struct ref_to_prune *r)
{
struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
if (lock) {
unlink_or_warn(git_path("%s", r->name));
unlock_ref(lock);
try_remove_empty_parents(r->name);
}
}
static void prune_refs(struct ref_to_prune *r)
{
while (r) {
prune_ref(r);
r = r->next;
}
}
static struct lock_file packed;
int pack_refs(unsigned int flags)
{
int fd;
struct pack_refs_cb_data cbdata;
memset(&cbdata, 0, sizeof(cbdata));
cbdata.flags = flags;
fd = hold_lock_file_for_update(&packed, git_path("packed-refs"),
LOCK_DIE_ON_ERROR);
cbdata.refs_file = fdopen(fd, "w");
if (!cbdata.refs_file)
die_errno("unable to create ref-pack file structure");
/* perhaps other traits later as well */
fprintf(cbdata.refs_file, "# pack-refs with: peeled \n");
for_each_ref(handle_one_ref, &cbdata);
if (ferror(cbdata.refs_file))
die("failed to write ref-pack file");
if (fflush(cbdata.refs_file) || fsync(fd) || fclose(cbdata.refs_file))
die_errno("failed to write ref-pack file");
/*
* Since the lock file was fdopen()'ed and then fclose()'ed above,
* assign -1 to the lock file descriptor so that commit_lock_file()
* won't try to close() it.
*/
packed.fd = -1;
if (commit_lock_file(&packed) < 0)
die_errno("unable to overwrite old ref-pack file");
prune_refs(cbdata.ref_to_prune);
return 0;
}
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