git/connect.c, branch v2.41.2

Merge branch 'jk/protocol-cap-parse-fix'

2023-04-25T20:56:20Z

The code to parse capability list for v0 on-wire protocol fell into an infinite loop when a capability appears multiple times, which has been corrected. * jk/protocol-cap-parse-fix: v0 protocol: use size_t for capability length/offset t5512: test "ls-remote --heads --symref" filtering with v0 and v2 t5512: allow any protocol version for filtered symref test t5512: add v2 support for "ls-remote --symref" test v0 protocol: fix sha1/sha256 confusion for capabilities^{} t5512: stop referring to "v1" protocol v0 protocol: fix infinite loop when parsing multi-valued capabilities

Merge branch 'en/header-split-cache-h'

2023-04-25T20:56:20Z

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 ...

v0 protocol: use size_t for capability length/offset

2023-04-14T22:08:13Z

When parsing server capabilities, we use "int" to store lengths and offsets. At first glance this seems like a spot where our parser may be confused by integer overflow if somebody sent us a malicious response. In practice these strings are all bounded by the 64k limit of a pkt-line, so using "int" is OK. However, it makes the code simpler to audit if they just use size_t everywhere. Note that because we take these parameters as pointers, this also forces many callers to update their declared types. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

v0 protocol: fix sha1/sha256 confusion for capabilities^{}

2023-04-14T22:08:12Z

Commit eb398797cd (connect: advertized capability is not a ref, 2016-09-09) added support for an upload-pack server responding with: 0000000000000000000000000000000000000000 capabilities^{} followed by a NUL and the actual capabilities. We correctly parse the oid using the packet_reader's hash_algo field, but then we compare it to null_oid(), which will instead use our current repo's default algorithm. If we're defaulting to sha256 locally but the other side is sha1, they won't match and we'll fail to parse the line (and thus die()). This can cause a test failure when the suite is run with GIT_TEST_DEFAULT_HASH=sha256, and we even do so regularly via the linux-sha256 CI job. But since the test requires JGit to run, it's usually just skipped, and nobody noticed the problem. The reason the original patch used JGit is that Git itself does not ever produce such a line via upload-pack; the feature was added to fix a real-world problem when interacting with JGit. That was good for verifying that the incompatibility was fixed, but it's not a good regression test: - hardly anybody runs it, because you have to have jgit installed; hence this bug going unnoticed - we're depending on jgit's behavior for the test to do anything useful. In particular, this behavior is only relevant to the v0 protocol, but these days we ask for the v2 protocol by default. So for modern jgit, this is probably testing nothing. - it's complicated and slow. We had to do some fifo trickery to handle races, and this one test makes up 40% of the runtime of the total script. Instead, let's just hard-code the response that's of interest to us. That will test exactly what we want for every run, and reveals the bug when run in sha256 mode. And of course we'll fix the actual bug by using the correct hash_algo struct. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

v0 protocol: fix infinite loop when parsing multi-valued capabilities

2023-04-14T22:08:12Z

If Git's client-side parsing of an upload-pack response (so git-fetch or ls-remote) sees multiple instances of a single capability, it can enter an infinite loop due to a bug in advancing the "offset" parameter in the parser. This bug can't happen between a client and server of the same Git version. The client bug is in parse_feature_value() when the caller passes in an offset parameter. And that only happens when the v0 protocol is parsing "symref" and "object-format" capabilities, via next_server_feature_value(). But Git has never produced multiple object-format capabilities, and it stopped producing multiple symref values in d007dbf7d6 (Revert "upload-pack: send non-HEAD symbolic refs", 2013-11-18). However, upload-pack did produce multiple symref entries for a while, and they are valid. Plus other implementations, such as Dulwich will still do so. So we should handle them. And even if we do not expect it, it is obviously a bug for the parser to enter an infinite loop. The bug itself is pretty simple. Commit 2c6a403d96 (connect: add function to parse multiple v1 capability values, 2020-05-25) added the "offset" parameter, which is used as both an in- and out-parameter. When parsing the first "symref" capability, *offset will be 0 on input, and after parsing the capability, we set *offset to an index just past the value by taking a pointer difference "(value + end) - feature_list". But on the second call, now *offset is set to that larger index, which lets us skip past the first "symref" capability. However, we do so by incrementing feature_list. That means our pointer difference is now too small; it is counting from where we resumed parsing, not from the start of the original feature_list pointer. And because we incremented feature_list only inside our function, and not the caller, that increment is lost next time the function is called. One solution would be to account for those skipped bytes by incrementing *offset, rather than assigning to it. But wait, there's more! We also increment feature_list if we have a near-miss. Say we are looking for "symref" and find "almost-symref". In that case we'll point feature_list to the "y" in "almost-symref" and restart our search. But that again means our offset won't be correct, as it won't account for the bytes between the start of the string and that "y". So instead, let's just record the beginning of the feature_list string in a separate pointer that we never touch. That offset we take in and return is meant to be using that point as a base, and now we'll do so consistently. Since the bug can't be reproduced using the current version of git-upload-pack, we'll instead hard-code an input which triggers the problem. Before this patch it loops forever re-parsing the second symref entry. Now we check both that it finishes, and that it parses both entries correctly (a case we could not test at all before). We don't need to worry about testing v2 here; it communicates the capabilities in a completely different way, and doesn't use this code at all. There are tests earlier in t5512 that are meant to cover this (they don't, but we'll address that in a future patch). Reported-by: Jonas Haag Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

treewide: remove unnecessary cache.h inclusion

2023-04-11T15:52:09Z

Several files were including cache.h solely to get other headers, such as trace.h and trace2.h. Since the last few commits have modified files to make these dependencies more explicit, the inclusion of cache.h is no longer needed in several cases. Remove it. Signed-off-by: Elijah Newren Acked-by: Calvin Wan Signed-off-by: Junio C Hamano

treewide: be explicit about dependence on trace.h & trace2.h

2023-04-11T15:52:08Z

Dozens of files made use of trace and trace2 functions, without explicitly including trace.h or trace2.h. This made it more difficult to find which files could remove a dependence on cache.h. Make C files explicitly include trace.h or trace2.h if they are using them. Signed-off-by: Elijah Newren Acked-by: Calvin Wan Signed-off-by: Junio C Hamano

Merge branch 'en/header-split-cleanup'

2023-04-06T20:38:31Z

Split key function and data structure definitions out of cache.h to new header files and adjust the users. * en/header-split-cleanup: csum-file.h: remove unnecessary inclusion of cache.h write-or-die.h: move declarations for write-or-die.c functions from cache.h treewide: remove cache.h inclusion due to setup.h changes setup.h: move declarations for setup.c functions from cache.h treewide: remove cache.h inclusion due to environment.h changes environment.h: move declarations for environment.c functions from cache.h treewide: remove unnecessary includes of cache.h wrapper.h: move declarations for wrapper.c functions from cache.h path.h: move function declarations for path.c functions from cache.h cache.h: remove expand_user_path() abspath.h: move absolute path functions from cache.h environment: move comment_line_char from cache.h treewide: remove unnecessary cache.h inclusion from several sources treewide: remove unnecessary inclusion of gettext.h treewide: be explicit about dependence on gettext.h treewide: remove unnecessary cache.h inclusion from a few headers

Merge branch 'jk/fix-proto-downgrade-to-v0'

2023-03-28T17:51:52Z

Transports that do not support protocol v2 did not correctly fall back to protocol v0 under certain conditions, which has been corrected. * jk/fix-proto-downgrade-to-v0: git_connect(): fix corner cases in downgrading v2 to v0

environment.h: move declarations for environment.c functions from cache.h

2023-03-21T17:56:53Z

Signed-off-by: Elijah Newren Signed-off-by: Junio C Hamano