Commit Graph

89 Commits

Author SHA1 Message Date
Jeff King
4d99559147 packfile: convert find_sha1_pack() to use object_id
The find_sha1_pack() function has a few problems:

  - it's badly named, since it works with any object hash

  - it takes the hash as a bare pointer rather than an object_id struct

We can fix both of these easily, as all callers actually have a real
object_id anyway.

I also found the existence of this function somewhat confusing, as it is
about looking in an arbitrary set of linked packed_git structs. It's
good for things like dumb-http which are looking in downloaded remote
packs, and not our local packs. But despite the name, it is not a good
way to find the pack which contains a local object (it skips the use of
the midx, the pack mru list, and so on).

So let's also add an explanatory comment above the declaration that may
point people in the right direction.

I suspect the calls in fast-import.c, which use the packed_git list from
the repository struct, could actually just be using find_pack_entry().
But since we'd need to keep it anyway for dumb-http, I didn't dig
further there. If we eventually drop dumb-http support, then it might be
worth examining them to see if we can get rid of the function entirely.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2024-10-25 17:35:46 -04:00
Jeff King
0af861e0c8 http-walker: use object_id instead of bare hash
We long ago switched most code to using object_id structs instead of
bare "unsigned char *" hashes. This gives us more type safety from the
compiler, and generally makes it easier to understand what we expect in
each parameter.

But the dumb-http code has lagged behind. And indeed, the whole "walker"
subsystem interface has the same problem, though http-walker is the only
user left.

So let's update the walker interface to pass object_id structs (which we
already have anyway at all call sites!), and likewise use those within
the http-walker methods that it calls.

This cleans up the dumb-http code a bit, but will also let us fix a few
more commonly used helper functions.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2024-10-25 17:35:46 -04:00
Jeff King
134bfedf6d http-walker: free fake packed_git list
The dumb-http walker code creates a "fake" packed_git list representing
packs we've downloaded from the remote (I call it "fake" because
generally that struct is only used and managed by the local repository
struct). But during our cleanup phase we don't touch those at all,
causing a leak.

There's no support here from the rest of the object-database API, as
these structs are not meant to be freed, except when closing the object
store completely. But we can see that raw_object_store_clear() just
calls free() on them, and that's enough here to fix the leak.

I also added a call to close_pack() before each. In the regular code
this happens via close_object_store(), which we do as part of
raw_object_store_clear(). This is necessary to prevent leaking mmap'd
data (like the pack idx) or descriptors. The leak-checker won't catch
either of these itself, but I did confirm with some hacky warning()
calls and running t5550 that it's easy to leak at least index data.

This is all much more intimate with the packed_git struct than I'd like,
but I think fixing it would be a pretty big refactor. And it's just not
worth it for dumb-http code which is rarely used these days. If we can
silence the leak-checker without creating too much hassle, we should
just do that.

This lets us mark t5550 as leak-free.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-25 10:24:56 -07:00
Jeff King
a1bc3c88de http: fix leak of http_object_request struct
The new_http_object_request() function allocates a struct on the heap,
along with some fields inside the struct. But the matching function to
clean it up, release_http_object_request(), only frees the interior
fields without freeing the struct itself, causing a leak.

The related http_pack_request new/release pair gets this right, and at
first glance we should be able to do the same thing and just add a
single free() call. But there's a catch.

These http_object_request structs are typically embedded in the
object_request struct of http-walker.c. And when we clean up that parent
struct, it sanity-checks the embedded struct to make sure we are not
leaking descriptors. Which means a use-after-free if we simply free()
the embedded struct.

I have no idea how valuable that sanity-check is, or whether it can
simply be deleted. This all goes back to 5424bc557f (http*: add helper
methods for fetching objects (loose), 2009-06-06). But the obvious way
to make it all work is to be sure we set the pointer to NULL after
freeing it (and our freeing process closes the descriptor, so we know
there is no leak).

To make sure we do that consistently, we'll switch the pointer we take
in release_http_object_request() to a pointer-to-pointer, and we'll set
it to NULL ourselves. And then the compiler can help us find each caller
which needs to be updated.

Most cases will just pass "&obj_req->req", which will obviously do the
right thing. In a few cases, like http-push's finish_request(), we are
working with a copy of the pointer, so we don't NULL the original. But
it's OK because the next step is to free the struct containing the
original pointer anyway.

This lets us mark t5551 as leak-free. Ironically this is the "smart"
http test, and the leak here only affects dumb http. But there's a
single dumb-http invocation in there. The full dumb tests are in t5550,
which still has some more leaks.

This also makes t5559 leak-free, as it's just an HTTP/2 variant of
t5551. But we don't need to mark it as such, since it inherits the flag
from t5551.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-25 10:24:55 -07:00
Patrick Steinhardt
e7da938570 global: introduce USE_THE_REPOSITORY_VARIABLE macro
Use of the `the_repository` variable is deprecated nowadays, and we
slowly but steadily convert the codebase to not use it anymore. Instead,
callers should be passing down the repository to work on via parameters.

It is hard though to prove that a given code unit does not use this
variable anymore. The most trivial case, merely demonstrating that there
is no direct use of `the_repository`, is already a bit of a pain during
code reviews as the reviewer needs to manually verify claims made by the
patch author. The bigger problem though is that we have many interfaces
that implicitly rely on `the_repository`.

Introduce a new `USE_THE_REPOSITORY_VARIABLE` macro that allows code
units to opt into usage of `the_repository`. The intent of this macro is
to demonstrate that a certain code unit does not use this variable
anymore, and to keep it from new dependencies on it in future changes,
be it explicit or implicit

For now, the macro only guards `the_repository` itself as well as
`the_hash_algo`. There are many more known interfaces where we have an
implicit dependency on `the_repository`, but those are not guarded at
the current point in time. Over time though, we should start to add
guards as required (or even better, just remove them).

Define the macro as required in our code units. As expected, most of our
code still relies on the global variable. Nearly all of our builtins
rely on the variable as there is no way yet to pass `the_repository` to
their entry point. For now, declare the macro in "biultin.h" to keep the
required changes at least a little bit more contained.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 10:26:33 -07:00
Patrick Steinhardt
9da95bda74 hash: require hash algorithm in oidread() and oidclr()
Both `oidread()` and `oidclr()` use `the_repository` to derive the hash
function that shall be used. Require callers to pass in the hash
algorithm to get rid of this implicit dependency.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 10:26:32 -07:00
Patrick Steinhardt
f4836570a7 hash: require hash algorithm in hasheq(), hashcmp() and hashclr()
Many of our hash functions have two variants, one receiving a `struct
git_hash_algo` and one that derives it via `the_repository`. Adapt all
of those functions to always require the hash algorithm as input and
drop the variants that do not accept one.

As those functions are now independent of `the_repository`, we can move
them from "hash.h" to "hash-ll.h".

Note that both in this and subsequent commits in this series we always
just pass `the_repository->hash_algo` as input even if it is obvious
that there is a repository in the context that we should be using the
hash from instead. This is done to be on the safe side and not introduce
any regressions. All callsites should eventually be amended to use a
repo passed via parameters, but this is outside the scope of this patch
series.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-06-14 10:26:32 -07:00
Elijah Newren
eea0e59ffb treewide: remove unnecessary includes in source files
Each of these were checked with
   gcc -E -I. ${SOURCE_FILE} | grep ${HEADER_FILE}
to ensure that removing the direct inclusion of the header actually
resulted in that header no longer being included at all (i.e. that
no other header pulled it in transitively).

...except for a few cases where we verified that although the header
was brought in transitively, nothing from it was directly used in
that source file.  These cases were:
  * builtin/credential-cache.c
  * builtin/pull.c
  * builtin/send-pack.c

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-26 12:04:31 -08:00
Elijah Newren
a034e9106f object-store-ll.h: split this header out of object-store.h
The vast majority of files including object-store.h did not need dir.h
nor khash.h.  Split the header into two files, and let most just depend
upon object-store-ll.h, while letting the two callers that need it
depend on the full object-store.h.

After this patch:
    $ git grep -h include..object-store | sort | uniq -c
          2 #include "object-store.h"
        129 #include "object-store-ll.h"

Diff best viewed with `--color-moved`.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-21 13:39:54 -07:00
Junio C Hamano
0807e57807 Merge branch 'en/header-split-cache-h'
Header clean-up.

* en/header-split-cache-h: (24 commits)
  protocol.h: move definition of DEFAULT_GIT_PORT from cache.h
  mailmap, quote: move declarations of global vars to correct unit
  treewide: reduce includes of cache.h in other headers
  treewide: remove double forward declaration of read_in_full
  cache.h: remove unnecessary includes
  treewide: remove cache.h inclusion due to pager.h changes
  pager.h: move declarations for pager.c functions from cache.h
  treewide: remove cache.h inclusion due to editor.h changes
  editor: move editor-related functions and declarations into common file
  treewide: remove cache.h inclusion due to object.h changes
  object.h: move some inline functions and defines from cache.h
  treewide: remove cache.h inclusion due to object-file.h changes
  object-file.h: move declarations for object-file.c functions from cache.h
  treewide: remove cache.h inclusion due to git-zlib changes
  git-zlib: move declarations for git-zlib functions from cache.h
  treewide: remove cache.h inclusion due to object-name.h changes
  object-name.h: move declarations for object-name.c functions from cache.h
  treewide: remove unnecessary cache.h inclusion
  treewide: be explicit about dependence on mem-pool.h
  treewide: be explicit about dependence on oid-array.h
  ...
2023-04-25 13:56:20 -07:00
Elijah Newren
b6fdc44c84 treewide: remove cache.h inclusion due to object-file.h changes
Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-11 08:52:10 -07:00
Junio C Hamano
72871b198f Merge branch 'ab/remove-implicit-use-of-the-repository'
Code clean-up around the use of the_repository.

* ab/remove-implicit-use-of-the-repository:
  libs: use "struct repository *" argument, not "the_repository"
  post-cocci: adjust comments for recent repo_* migration
  cocci: apply the "revision.h" part of "the_repository.pending"
  cocci: apply the "rerere.h" part of "the_repository.pending"
  cocci: apply the "refs.h" part of "the_repository.pending"
  cocci: apply the "promisor-remote.h" part of "the_repository.pending"
  cocci: apply the "packfile.h" part of "the_repository.pending"
  cocci: apply the "pretty.h" part of "the_repository.pending"
  cocci: apply the "object-store.h" part of "the_repository.pending"
  cocci: apply the "diff.h" part of "the_repository.pending"
  cocci: apply the "commit.h" part of "the_repository.pending"
  cocci: apply the "commit-reach.h" part of "the_repository.pending"
  cocci: apply the "cache.h" part of "the_repository.pending"
  cocci: add missing "the_repository" macros to "pending"
  cocci: sort "the_repository" rules by header
  cocci: fix incorrect & verbose "the_repository" rules
  cocci: remove dead rule from "the_repository.pending.cocci"
2023-04-06 13:38:30 -07:00
Junio C Hamano
e7dca80692 Merge branch 'ab/remove-implicit-use-of-the-repository' into en/header-split-cache-h
* ab/remove-implicit-use-of-the-repository:
  libs: use "struct repository *" argument, not "the_repository"
  post-cocci: adjust comments for recent repo_* migration
  cocci: apply the "revision.h" part of "the_repository.pending"
  cocci: apply the "rerere.h" part of "the_repository.pending"
  cocci: apply the "refs.h" part of "the_repository.pending"
  cocci: apply the "promisor-remote.h" part of "the_repository.pending"
  cocci: apply the "packfile.h" part of "the_repository.pending"
  cocci: apply the "pretty.h" part of "the_repository.pending"
  cocci: apply the "object-store.h" part of "the_repository.pending"
  cocci: apply the "diff.h" part of "the_repository.pending"
  cocci: apply the "commit.h" part of "the_repository.pending"
  cocci: apply the "commit-reach.h" part of "the_repository.pending"
  cocci: apply the "cache.h" part of "the_repository.pending"
  cocci: add missing "the_repository" macros to "pending"
  cocci: sort "the_repository" rules by header
  cocci: fix incorrect & verbose "the_repository" rules
  cocci: remove dead rule from "the_repository.pending.cocci"
2023-04-04 08:25:52 -07:00
Ævar Arnfjörð Bjarmason
bc726bd075 cocci: apply the "object-store.h" part of "the_repository.pending"
Apply the part of "the_repository.pending.cocci" pertaining to
"object-store.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-28 07:36:45 -07:00
Jeff King
1e5e097496 http: mark unused parameter in fill_active_slot() callbacks
We have a generic "fill" function that is used by both the dumb http
push and fetch code paths. It takes a void parameter in case the caller
wants to pass along extra data, but (since the previous commit) neither
does so.

So we could simply drop the extra parameter. But since it's good
practice to provide a void pointer for in callback functions, we'll
leave it here for the future, and just annotate it as unused (to appease
-Wunused-parameter).

While we're marking it, let's also fix the type in http-walker's
function to have the correct "void" type. The original had to cast the
function pointer and was technically undefined behavior (though
generally OK in practice).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-17 14:17:48 -07:00
Jeff King
647edf79d6 http: drop unused parameter from start_object_request()
We take a "walker" parameter for the request, but don't actually look at
it. This is due to 5424bc557f (http*: add helper methods for fetching
objects (loose), 2009-06-06). Before then, we consulted the "walker"
struct to tell us if we should be verbose, but now those messages are
printed elsewhere.

Let's drop the unused parameter to make -Wunused-parameter happy.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-17 14:17:48 -07:00
Elijah Newren
41771fa435 cache.h: remove dependence on hex.h; make other files include it explicitly
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-23 17:25:29 -08:00
Junio C Hamano
afe8a9070b tree-wide: apply equals-null.cocci
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-02 09:50:37 -07:00
Ævar Arnfjörð Bjarmason
8dda4cbdf2 http: rename CURLOPT_FILE to CURLOPT_WRITEDATA
The CURLOPT_FILE name is an alias for CURLOPT_WRITEDATA, the
CURLOPT_WRITEDATA name has been preferred since curl 7.9.7, released
in May 2002[1].

1. https://curl.se/libcurl/c/CURLOPT_WRITEDATA.html

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-30 16:01:54 -07:00
Jeff King
013c7e2b07 http: drop support for curl < 7.16.0
In the last commit we dropped support for curl < 7.11.1, let's
continue that and drop support for versions older than 7.16.0. This
allows us to get rid of some now-obsolete #ifdefs.

Choosing 7.16.0 is a somewhat arbitrary cutoff:

  1. It came out in October of 2006, almost 15 years ago.
     Besides being a nice round number, around 10 years is
     a common end-of-life support period, even for conservative
     distributions.

  2. That version introduced the curl_multi interface, which
     gives us a lot of bang for the buck in removing #ifdefs

RHEL 5 came with curl 7.15.5[1] (released in August 2006). RHEL 5's
extended life cycle program ended on 2020-11-30[1]. RHEL 6 comes with
curl 7.19.7 (released in November 2009), and RHEL 7 comes with
7.29.0 (released in February 2013).

1. http://lore.kernel.org/git/873e1f31-2a96-5b72-2f20-a5816cad1b51@jupiterrise.com

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-30 09:11:15 -07:00
brian m. carlson
92e2cab96b Always use oidread to read into struct object_id
In the future, we'll want oidread to automatically set the hash
algorithm member for an object ID we read into it, so ensure we use
oidread instead of hashcpy everywhere we're copying a hash value into a
struct object_id.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-27 16:31:38 +09:00
Jonathan Tan
eb05349247 http: refactor finish_http_pack_request()
finish_http_pack_request() does multiple tasks, including some
housekeeping on a struct packed_git - (1) closing its index, (2)
removing it from a list, and (3) installing it. These concerns are
independent of fetching a pack through HTTP: they are there only because
(1) the calling code opens the pack's index before deciding to fetch it,
(2) the calling code maintains a list of packfiles that can be fetched,
and (3) the calling code fetches it in order to make use of its objects
in the same process.

In preparation for a subsequent commit, which adds a feature that does
not need any of this housekeeping, remove (1), (2), and (3) from
finish_http_pack_request(). (2) and (3) are now done by a helper
function, and (1) is the responsibility of the caller (in this patch,
done closer to the point where the pack index is opened).

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-10 18:06:34 -07:00
Junio C Hamano
d4e568b2a3 Merge branch 'bc/hash-transition-16'
Conversion from unsigned char[20] to struct object_id continues.

* bc/hash-transition-16: (35 commits)
  gitweb: make hash size independent
  Git.pm: make hash size independent
  read-cache: read data in a hash-independent way
  dir: make untracked cache extension hash size independent
  builtin/difftool: use parse_oid_hex
  refspec: make hash size independent
  archive: convert struct archiver_args to object_id
  builtin/get-tar-commit-id: make hash size independent
  get-tar-commit-id: parse comment record
  hash: add a function to lookup hash algorithm by length
  remote-curl: make hash size independent
  http: replace sha1_to_hex
  http: compute hash of downloaded objects using the_hash_algo
  http: replace hard-coded constant with the_hash_algo
  http-walker: replace sha1_to_hex
  http-push: remove remaining uses of sha1_to_hex
  http-backend: allow 64-character hex names
  http-push: convert to use the_hash_algo
  builtin/pull: make hash-size independent
  builtin/am: make hash size independent
  ...
2019-04-25 16:41:17 +09:00
brian m. carlson
2bf1db7862 http-walker: replace sha1_to_hex
Since sha1_to_hex is limited to SHA-1, replace the uses of it in this
file with hash_to_hex.  Rename several variables accordingly to reflect
that they are no longer limited to SHA-1.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01 11:57:38 +09:00
brian m. carlson
538b152324 object-store: rename and expand packed_git's sha1 member
This member is used to represent the pack checksum of the pack in
question.  Expand this member to be GIT_MAX_RAWSZ bytes in length so it
works with longer hashes and rename it to be "hash" instead of "sha1".
This transformation was made with a change to the definition and the
following semantic patch:

@@
struct packed_git *E1;
@@
- E1->sha1
+ E1->hash

@@
struct packed_git E1;
@@
- E1.sha1
+ E1.hash

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01 11:57:38 +09:00
Jeff King
3d10f72ef8 http: use normalize_curl_result() instead of manual conversion
When we switched off CURLOPT_FAILONERROR in 17966c0a63 (http: avoid
disconnecting on 404s for loose objects, 2016-07-11), the fetch_object()
function started manually handling 404's. Since we now have
normalize_curl_result() for use elsewhere, we can use it here as well,
shortening the code.

Note that we lose the check for http/https in the URL here. None of the
other result-normalizing code paths bother with this. Looking at
missing_target(), which checks specifically for an FTP-specific CURLcode
and "http" code 550, it seems likely that git-over-ftp has been subtly
broken since 17966c0a63. This patch does nothing to fix that, but nor
should it make anything worse (in fact, it may be slightly better
because we'll actually recognize an error as such, rather than assuming
CURLE_OK means we actually got some data).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-24 21:22:40 +09:00
Jeff King
ccbbd8bf66 http: normalize curl results for dumb loose and alternates fetches
If the dumb-http walker encounters a 404 when fetching a loose object,
it then looks at any http-alternates for the object. The 404 check is
implemented by missing_target(), which checks not only the http code,
but also that we got an http error from the CURLcode.

That broke when we stopped using CURLOPT_FAILONERROR in 17966c0a63
(http: avoid disconnecting on 404s for loose objects, 2016-07-11), since
our CURLcode will now be CURLE_OK. As a result, fetching over dumb-http
from a repository with alternates could result in Git printing "Unable
to find abcd1234..." and aborting.

We could probably fix this just by loosening missing_target(). However,
there's other code which looks at the curl result, and it would have to
be tweaked as well. Instead, let's just normalize the result the same
way the smart-http code does.

There's a similar case in processing the alternates (where we failover
from "info/http-alternates" to "info/alternates"). We'll give it the
same treatment.

After this patch, we should be hitting all code paths that need this
normalization (notably absent here is the http_pack_request path, but it
does not use FAILONERROR, nor missing_target()).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-24 21:22:40 +09:00
Jeff King
98374a07c9 convert has_sha1_file() callers to has_object_file()
The only remaining callers of has_sha1_file() actually have an object_id
already. They can use the "object" variant, rather than dereferencing
the hash themselves.

The code changes here were completely generated by the included
coccinelle patch.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08 09:41:06 -08:00
Jeff King
514c5fdd03 sha1-file: modernize loose object file functions
The loose object access code in sha1-file.c is some of the oldest in
Git, and could use some modernizing. It mostly uses "unsigned char *"
for object ids, which these days should be "struct object_id".

It also uses the term "sha1_file" in many functions, which is confusing.
The term "loose_objects" is much better. It clearly distinguishes
them from packed objects (which didn't even exist back when the name
"sha1_file" came into being). And it also distinguishes it from the
checksummed-file concept in csum-file.c (which until recently was
actually called "struct sha1file"!).

This patch converts the functions {open,close,map,stat}_sha1_file() into
open_loose_object(), etc, and switches their sha1 arguments for
object_id structs. Similarly, path functions like fill_sha1_path()
become fill_loose_path() and use object_ids.

The function sha1_loose_object_info() already says "loose", so we can
just drop the "sha1" (and teach it to use object_id).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08 09:40:19 -08:00
Jeff King
f0be0db13d http: use struct object_id instead of bare sha1
The dumb-http walker code still passes around and stores object ids as
"unsigned char *sha1". Let's modernize it.

There's probably still more work to be done to handle dumb-http fetches
with a new, larger hash. But that can wait; this is enough that we can
now convert some of the low-level object routines that we call into from
here (and in fact, some of the "oid.hash" references added here will be
further improved in the next patch).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08 09:40:19 -08:00
Jeff King
b69fb867b4 sha1_file_name(): overwrite buffer instead of appending
The sha1_file_name() function is used to generate the path to a loose
object in the object directory. It doesn't make much sense for it to
append, since the the path we write may be absolute (i.e., you cannot
reliably build up a path with it). Because many callers use it with a
static buffer, they have to strbuf_reset() manually before each call
(and the other callers always use an empty buffer, so they don't care
either way). Let's handle this automatically.

Since we're changing the semantics, let's take the opportunity to give
it a more hash-neutral name (which will also catch any callers from
topics in flight).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-13 14:22:02 +09:00
Jeff King
67947c34ae convert "hashcmp() != 0" to "!hasheq()"
This rounds out the previous three patches, covering the
inequality logic for the "hash" variant of the functions.

As with the previous three, the accompanying code changes
are the mechanical result of applying the coccinelle patch;
see those patches for more discussion.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29 11:32:49 -07:00
Jeff King
e3ff0683e2 convert "hashcmp() == 0" to hasheq()
This is the partner patch to the previous one, but covering
the "hash" variants instead of "oid".  Note that our
coccinelle rule is slightly more complex to avoid triggering
the call in hasheq().

I didn't bother to add a new rule to convert:

  - hasheq(E1->hash, E2->hash)
  + oideq(E1, E2)

Since these are new functions, there won't be any such
existing callers. And since most of the code is already
using oideq, we're not likely to introduce new ones.

We might still see "!hashcmp(E1->hash, E2->hash)" from topics
in flight. But because our new rule comes after the existing
ones, that should first get converted to "!oidcmp(E1, E2)"
and then to "oideq(E1, E2)".

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29 11:32:49 -07:00
Junio C Hamano
cf0b1793ea Merge branch 'sb/object-store'
Refactoring the internal global data structure to make it possible
to open multiple repositories, work with and then close them.

Rerolled by Duy on top of a separate preliminary clean-up topic.
The resulting structure of the topics looked very sensible.

* sb/object-store: (27 commits)
  sha1_file: allow sha1_loose_object_info to handle arbitrary repositories
  sha1_file: allow map_sha1_file to handle arbitrary repositories
  sha1_file: allow map_sha1_file_1 to handle arbitrary repositories
  sha1_file: allow open_sha1_file to handle arbitrary repositories
  sha1_file: allow stat_sha1_file to handle arbitrary repositories
  sha1_file: allow sha1_file_name to handle arbitrary repositories
  sha1_file: add repository argument to sha1_loose_object_info
  sha1_file: add repository argument to map_sha1_file
  sha1_file: add repository argument to map_sha1_file_1
  sha1_file: add repository argument to open_sha1_file
  sha1_file: add repository argument to stat_sha1_file
  sha1_file: add repository argument to sha1_file_name
  sha1_file: allow prepare_alt_odb to handle arbitrary repositories
  sha1_file: allow link_alt_odb_entries to handle arbitrary repositories
  sha1_file: add repository argument to prepare_alt_odb
  sha1_file: add repository argument to link_alt_odb_entries
  sha1_file: add repository argument to read_info_alternates
  sha1_file: add repository argument to link_alt_odb_entry
  sha1_file: add raw_object_store argument to alt_odb_usable
  pack: move approximate object count to object store
  ...
2018-04-11 13:09:55 +09:00
Stefan Beller
cf78ae4f3d sha1_file: add repository argument to sha1_file_name
Add a repository argument to allow sha1_file_name callers to be more
specific about which repository to handle. This is a small mechanical
change; it doesn't change the implementation to handle repositories
other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

While at it, move the declaration to object-store.h, where it should
be easier to find.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-26 10:05:55 -07:00
Stefan Beller
a80d72db2a object-store: move packed_git and packed_git_mru to object store
In a process with multiple repositories open, packfile accessors
should be associated to a single repository and not shared globally.
Move packed_git and packed_git_mru into the_repository and adjust
callers to reflect this.

[nd: while at there, wrap access to these two fields in get_packed_git()
and get_packed_git_mru(). This allows us to lazily initialize these
fields without caller doing that explicitly]

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-26 10:05:46 -07:00
brian m. carlson
16f0705df1 http-walker: convert struct object_request to use struct object_id
Convert struct object_request to use struct object_id by updating the
definition and applying the following semantic patch, plus the standard
object_id transforms:

@@
struct object_request E1;
@@
- E1.sha1
+ E1.oid.hash

@@
struct object_request *E1;
@@
- E1->sha1
+ E1->oid.hash

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-14 09:23:48 -07:00
Christian Couder
ea6577303f sha1_file: remove static strbuf from sha1_file_name()
Using a static buffer in sha1_file_name() is error prone
and the performance improvements it gives are not needed
in many of the callers.

So let's get rid of this static buffer and, if necessary
or helpful, let's use one in the caller.

Suggested-by: Jeff Hostetler <git@jeffhostetler.com>
Helped-by: Kevin Daudt <me@ikke.info>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-01-17 12:21:32 -08:00
Jonathan Tan
d6fe0036fd pack: move find_sha1_pack()
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-23 15:12:07 -07:00
Junio C Hamano
2af882be01 Merge branch 'jk/http-walker-buffer-underflow-fix'
"Dumb http" transport used to misparse a nonsense http-alternates
response, which has been fixed.

* jk/http-walker-buffer-underflow-fix:
  http-walker: fix buffer underflow processing remote alternates
2017-03-17 13:50:26 -07:00
Jeff King
d61434ae81 http-walker: fix buffer underflow processing remote alternates
If we parse a remote alternates (or http-alternates), we
expect relative lines like:

  ../../foo.git/objects

which we convert into "$URL/../foo.git/" (and then use that
as a base for fetching more objects).

But if the remote feeds us nonsense like just:

  ../

we will try to blindly strip the last 7 characters, assuming
they contain the string "objects". Since we don't _have_ 7
characters at all, this results in feeding a small negative
value to strbuf_add(), which converts it to a size_t,
resulting in a big positive value. This should consistently
fail (since we can't generall allocate the max size_t minus
7 bytes), so there shouldn't be any security implications.

Let's fix this by using strbuf_strip_suffix() to drop the
characters we want. If they're not present, we'll ignore the
alternate (in theory we could use it as-is, but the rest of
the http-walker code unconditionally tacks "objects/" back
on, so it is it not prepared to handle such a case).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-13 10:20:29 -07:00
Eric Wong
5cae73d5d2 http: release strbuf on disabled alternates
This likely has no real-world impact on memory usage,
but it is cleaner for future readers.

Fixes: abcbdc0389 ("http: respect protocol.*.allow=user for http-alternates")
Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-06 10:52:57 -08:00
Eric Wong
de46138826 http: inform about alternates-as-redirects behavior
It is disconcerting for users to not notice the behavior
change in handling alternates from commit cb4d2d35c4
("http: treat http-alternates like redirects")

Give the user a hint about the config option so they can
see the URL and decide whether or not they want to enable
http.followRedirects in their config.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-06 10:52:15 -08:00
Jeff King
abcbdc0389 http: respect protocol.*.allow=user for http-alternates
The http-walker may fetch the http-alternates (or
alternates) file from a remote in order to find more
objects. This should count as a "not from the user" use of
the protocol. But because we implement the redirection
ourselves and feed the new URL to curl, it will use the
CURLOPT_PROTOCOLS rules, not the more restrictive
CURLOPT_REDIR_PROTOCOLS.

The ideal solution would be for each curl request we make to
know whether or not is directly from the user or part of an
alternates redirect, and then set CURLOPT_PROTOCOLS as
appropriate. However, that would require plumbing that
information through all of the various layers of the http
code.

Instead, let's check the protocol at the source: when we are
parsing the remote http-alternates file. The only downside
is that if there's any mismatch between what protocol we
think it is versus what curl thinks it is, it could violate
the policy.

To address this, we'll make the parsing err on the picky
side, and only allow protocols that it can parse
definitively. So for example, you can't elude the "http"
policy by asking for "HTTP://", even though curl might
handle it; we would reject it as unknown. The only unsafe
case would be if you have a URL that starts with "http://"
but curl interprets as another protocol. That seems like an
unlikely failure mode (and we are still protected by our
base CURLOPT_PROTOCOL setting, so the worst you could do is
trigger one of https, ftp, or ftps).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-15 09:29:13 -08:00
Jeff King
3680f16f9d http-walker: complain about non-404 loose object errors
Since commit 17966c0a6 (http: avoid disconnecting on 404s
for loose objects, 2016-07-11), we turn off curl's
FAILONERROR option and instead manually deal with failing
HTTP codes.

However, the logic to do so only recognizes HTTP 404 as a
failure. This is probably the most common result, but if we
were to get another code, the curl result remains CURLE_OK,
and we treat it as success. We still end up detecting the
failure when we try to zlib-inflate the object (which will
fail), but instead of reporting the HTTP error, we just
claim that the object is corrupt.

Instead, let's catch anything in the 300's or above as an
error (300's are redirects which are not an error at the
HTTP level, but are an indication that we've explicitly
disabled redirects, so we should treat them as such; we
certainly don't have the resulting object content).

Note that we also fill in req->errorstr, which we didn't do
before. Without FAILONERROR, curl will not have filled this
in, and it will remain a blank string. This never mattered
for the 404 case, because in the logic below we hit the
"missing_target()" branch and print nothing. But for other
errors, we'd want to say _something_, if only to fill in the
blank slot in the error message.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-06 12:43:34 -08:00
Junio C Hamano
43ec089eea Merge branch 'ew/http-walker' into jk/http-walker-limit-redirect
* ew/http-walker:
  list: avoid incompatibility with *BSD sys/queue.h
  http-walker: reduce O(n) ops with doubly-linked list
  http: avoid disconnecting on 404s for loose objects
  http-walker: remove unused parameter from fetch_object
2016-12-06 12:43:23 -08:00
Jeff King
cb4d2d35c4 http: treat http-alternates like redirects
The previous commit made HTTP redirects more obvious and
tightened up the default behavior. However, there's another
way for a server to ask a git client to fetch arbitrary
content: by having an http-alternates file (or a regular
alternates file, which is used as a backup).

Similar to the HTTP redirect case, a malicious server can
claim to have refs pointing at object X, return a 404 when
the client asks for X, but point to some other URL via
http-alternates, which the client will transparently fetch.
The end result is that it looks from the user's perspective
like the objects came from the malicious server, as the
other URL is not mentioned at all.

Worse, because we feed the new URL to curl ourselves, the
usual protocol restrictions do not kick in (neither curl's
default of disallowing file://, nor the protocol
whitelisting in f4113cac0 (http: limit redirection to
protocol-whitelist, 2015-09-22).

Let's apply the same rules here as we do for HTTP redirects.
Namely:

  - unless http.followRedirects is set to "always", we will
    not follow remote redirects from http-alternates (or
    alternates) at all

  - set CURLOPT_PROTOCOLS alongside CURLOPT_REDIR_PROTOCOLS
    restrict ourselves to a known-safe set and respect any
    user-provided whitelist.

  - mention alternate object stores on stderr so that the
    user is aware another source of objects may be involved

The first item may prove to be too restrictive. The most
common use of alternates is to point to another path on the
same server. While it's possible for a single-server
redirect to be an attack, it takes a fairly obscure setup
(victim and evil repository on the same host, host speaks
dumb http, and evil repository has access to edit its own
http-alternates file).

So we could make the checks more specific, and only cover
cross-server redirects. But that means parsing the URLs
ourselves, rather than letting curl handle them. This patch
goes for the simpler approach. Given that they are only used
with dumb http, http-alternates are probably pretty rare.
And there's an escape hatch: the user can allow redirects on
a specific server by setting http.<url>.followRedirects to
"always".

Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-06 12:32:48 -08:00
Eric Wong
94e99012fc http-walker: reduce O(n) ops with doubly-linked list
Using the a Linux-kernel-derived doubly-linked list
implementation from the Userspace RCU library allows us to
enqueue and delete items from the object request queue in
constant time.

This change reduces enqueue times in the prefetch() function
where object request queue could grow to several thousand
objects.

I left out the list_for_each_entry* family macros from list.h
which relied on the __typeof__ operator as we support platforms
without it.  Thus, list_entry (aka "container_of") needs to be
called explicitly inside macro-wrapped for loops.

The downside is this costs us an additional pointer per object
request, but this is offset by reduced overhead on queue
operations leading to improved performance and shorter queue
depths.

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-12 15:17:42 -07:00
Eric Wong
17966c0a63 http: avoid disconnecting on 404s for loose objects
404s are common when fetching loose objects on static HTTP
servers, and reestablishing a connection for every single
404 adds additional latency.

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-12 15:17:42 -07:00
Eric Wong
43b8bba6b6 http-walker: remove unused parameter from fetch_object
This parameter has not been used since commit 1d389ab65d
("Add support for parallel HTTP transfers") back in 2005

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-12 15:17:41 -07:00