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2022-04-06serve.c: remove unnecessary includeGarrit Franke
Remove include "strvec.h" from serve.c, which is orphaned since f0a35c9ce52 (serve: drop "keys" strvec, 2021-09-15) Signed-off-by: Garrit Franke <garrit@slashdev.space> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-15serve: reject commands used as capabilitiesJeff King
Our table of v2 "capabilities" contains everything we might tell the client we support. But there are differences in how we expect the client to respond. Some of the entries are true capabilities (i.e., we expect the client to say "yes, I support this"), and some are ones we expect them to send as commands (with "command=ls-refs" or similar). When we receive a capability used as a command, we complain about that. But when we receive a command used as a capability (e.g., just "ls-refs" in a pkt-line by itself), we silently ignore it. This isn't really hurting anything (clients shouldn't send it, and we'll ignore it), but we can tighten up the protocol to match what we expect to happen. There are two new tests here. The first one checks a capability used as a command, which already passes. The second tests a command as a capability, which this patch fixes. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-15serve: reject bogus v2 "command=ls-refs=foo"Jeff King
When we see a line from the client like "command=ls-refs", we parse everything after the equals sign as a capability, which we check against our capabilities table. If we don't recognize the command (e.g., "command=foo"), we'll reject it. But in parse_command(), we use the same get_capability() parser for parsing non-command lines. So if we see "command=ls-refs=foo", we will feed "ls-refs=foo" to get_capability(), which will say "OK, that's ls-refs, with value 'foo'". But then we simply ignore the value entirely. The client is violating the spec here, which says: command = PKT-LINE("command=" key LF) key = 1*(ALPHA | DIGIT | "-_") I.e., the key is not even allowed to have an equals sign in it. Whereas a real non-command capability does allow a value: capability = PKT-LINE(key[=value] LF) So by reusing the same get_capability() parser, we are mixing up the "key" and "capability" tokens. However, since that parser tells us whether it saw an "=", we can still use it; we just need to reject any input that produces a non-NULL value field. The current behavior isn't really hurting anything (the client should never send such a request, and if it does, we just ignore the "value" part). But since it does violate the spec, let's tighten it up to prevent any surprising behavior. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-15serve: drop "keys" strvecJeff King
We collect the set of capabilities the client sends us in a strvec. While this is usually small, there's no limit to the number of capabilities the client can send us (e.g., they could just send us "agent" pkt-lines over and over, and we'd keep adding them to the list). Since all code has been converted away from using this list, let's get rid of it. This avoids a potential attack where clients waste our memory. Note that we do have to replace it with a flag, because some of the flush-packet logic checks whether we've seen any valid commands or keys. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-15serve: provide "receive" function for session-id capabilityJeff King
Rather than pulling the session-id string from the list of collected capabilities, we can handle it as soon as we receive it. This gets us closer to dropping the collected list entirely. The behavior should be the same, with one exception. Previously if the client sent us multiple session-id lines, we'd report only the first. Now we'll pass each one along to trace2. This shouldn't matter in practice, since clients shouldn't do that (and if they do, it's probably sensible to log them all). As this removes the last caller of the static has_capability(), we can remove it, as well (and in fact we must to avoid -Wunused-function complaining). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-15serve: provide "receive" function for object-format capabilityJeff King
We get any "object-format" specified by the client by searching for it in the collected list of capabilities the client sent. We can instead just handle it as soon as they send it. This is slightly more efficient, and gets us one step closer to dropping that collected list. Note that we do still have to do our final hash check after receiving all capabilities (because they might not have sent an object-format line at all, and we still have to check that the default matches our repository algorithm). Since the check_algorithm() function would now be down to a single if() statement, I've just inlined it in its only caller. There should be no change of behavior here, except for two broken-protocol cases: - if the client sends multiple conflicting object-format capabilities (which they should not), we'll now choose the last one rather than the first. We could also detect and complain about the duplicates quite easily now, which we could not before, but I didn't do so here. - if the client sends a bogus "object-format" with no equals sign, we'll now say so, rather than "unknown object format: ''" Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-14serve: add "receive" method for v2 capabilities tableJeff King
We have a capabilities table that tells us what we should tell the client we are capable of, and what to do when a client gives us a particular command (e.g., "command=ls-refs"). But it doesn't tell us what to do when the client sends us back a capability (e.g., "object-format=sha256"). We just collect them all in a strvec and hope somebody can use them later. Instead, let's provide a function pointer in the table to act on these. This will eventually help us avoid collecting the strings, which will be more efficient and less prone to mischief. Using the new method is optional, which helps in two ways: - we can move existing capabilities over to this new system gradually in individual commits - some capabilities we don't actually do anything with anyway. For example, the client is free to say "agent=git/1.2.3" to us, but we do not act on the information in any way. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-14serve: return capability "value" from get_capability()Jeff King
When the client sends v2 capabilities, they may be simple, like: foo or have a value like: foo=bar (all of the current capabilities actually expect a value, but the protocol allows for boolean ones). We use get_capability() to make sure the client's pktline matches a capability. In doing so, we parse enough to see the "=" and the value (if any), but we immediately forget it. Nobody cares for now, because they end up parsing the values out later using has_capability(). But in preparation for changing that, let's pass back a pointer so the callers know what we found. Note that unlike has_capability(), we'll return NULL for a "simple" capability. Distinguishing these will be useful for some future patches. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-14serve: rename is_command() to parse_command()Jeff King
The is_command() function not only tells us whether the pktline is a valid command string, but it also parses out the command (and complains if we see a duplicate). Let's rename it to make those extra functions a bit more obvious. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-05serve.[ch]: remove "serve_options", split up --advertise-refs codeÆvar Arnfjörð Bjarmason
The "advertise capabilities" mode of serve.c added in ed10cb952d3 (serve: introduce git-serve, 2018-03-15) is only used by the http-backend.c to call {upload,receive}-pack with the --advertise-refs parameter. See 42526b478e3 (Add stateless RPC options to upload-pack, receive-pack, 2009-10-30). Let's just make cmd_upload_pack() take the two (v2) or three (v2) parameters the the v2/v1 servicing functions need directly, and pass those in via the function signature. The logic of whether daemon mode is implied by the timeout belongs in the v1 function (only used there). Once we split up the "advertise v2 refs" from "serve v2 request" it becomes clear that v2 never cared about those in combination. The only time it mattered was for v1 to emit its ref advertisement, in that case we wanted to emit the smart-http-only "no-done" capability. Since we only do that in the --advertise-refs codepath let's just have it set "do_done" itself in v1's upload_pack() just before send_ref(), at that point --advertise-refs and --stateless-rpc in combination are redundant (the only user is get_info_refs() in http-backend.c), so we can just pass in --advertise-refs only. Since we need to touch all the serve() and advertise_capabilities() codepaths let's rename them to less clever and obvious names, it's been suggested numerous times, the latest of which is [1]'s suggestion for protocol_v2_serve_loop(). Let's go with that. 1. https://lore.kernel.org/git/CAFQ2z_NyGb8rju5CKzmo6KhZXD0Dp21u-BbyCb2aNxLEoSPRJw@mail.gmail.com/ Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-05serve.c: move version line to advertise_capabilities()Ævar Arnfjörð Bjarmason
The advertise_capabilities() is only called from serve() and we always emit this version line before it. In a subsequent commit I'll make builtin/upload-pack.c sometimes call advertise_capabilities() directly, so it'll make sense to have this line emitted by advertise_capabilities(), not serve() itself. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-05serve: move transfer.advertiseSID check into session_id_advertise()Ævar Arnfjörð Bjarmason
In 6b5b6e422ee (serve: advertise session ID in v2 capabilities, 2020-11-11) the check for transfer.advertiseSID was added to the beginning of the main serve() loop. Thus on startup of the server we'd populate it. Let's instead use an explicit lazy initialization pattern in session_id_advertise() itself, we'll still look the config up only once per-process, but by moving it out of serve() itself the further changing of that routine becomes easier. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-05serve.[ch]: don't pass "struct strvec *keys" to commandsÆvar Arnfjörð Bjarmason
The serve.c API added in ed10cb952d3 (serve: introduce git-serve, 2018-03-15) was passing in the raw capabilities "keys", but nothing downstream of it ever used them. Let's remove that code because it's not needed. If we do end up needing to pass information about the advertisement in the future it'll make more sense to have serve.c parse the capabilities keys and pass the result of its parsing, rather than expecting expecting its API users to parse the same keys again. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-05serve: use designated initializersÆvar Arnfjörð Bjarmason
Change the declaration of the protocol_capability struct to use designated initializers, this makes this more verbose now, but a follow-up commit will add a new field. At that point these lines would be too dense to be on one line comfortably. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-05serve: mark has_capability() as staticÆvar Arnfjörð Bjarmason
The has_capability() function introduced in ed10cb952d3 (serve: introduce git-serve, 2018-03-15) has never been used anywhere except serve.c, so let's mark it as static. It was later changed from "extern" in 554544276a6 (*.[ch]: remove extern from function declarations using spatch, 2019-04-29), but we could have simply marked it as "static" instead. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-28Merge branch 'dl/packet-read-response-end-fix'Junio C Hamano
Error message update. * dl/packet-read-response-end-fix: pkt-line: replace "stateless separator" with "response end"
2021-07-09pkt-line: replace "stateless separator" with "response end"Denton Liu
In 0181b600a6 (pkt-line: define PACKET_READ_RESPONSE_END, 2020-05-19), the Response End packet was defined for Git's network protocol. When the patch was sent, it included an oversight where the error messages referenced "stateless separator", the work-in-progress name, over "response end", the final name chosen. Correct these error messages by having them correctly reference a "response end" packet. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-21object-info: support for retrieving object infoBruno Albuquerque
Sometimes it is useful to get information of an object without having to download it completely. Add the "object-info" capability that lets the client ask for object-related information with their full hexadecimal object names. Only sizes are returned for now. Signed-off-by: Bruno Albuquerque <bga@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-05ls-refs: report unborn targets of symrefsJonathan Tan
When cloning, we choose the default branch based on the remote HEAD. But if there is no remote HEAD reported (which could happen if the target of the remote HEAD is unborn), we'll fall back to using our local init.defaultBranch. Traditionally this hasn't been a big deal, because most repos used "master" as the default. But these days it is likely to cause confusion if the server and client implementations choose different values (e.g., if the remote started with "main", we may choose "master" locally, create commits there, and then the user is surprised when they push to "master" and not "main"). To solve this, the remote needs to communicate the target of the HEAD symref, even if it is unborn, and "git clone" needs to use this information. Currently, symrefs that have unborn targets (such as in this case) are not communicated by the protocol. Teach Git to advertise and support the "unborn" feature in "ls-refs" (by default, this is advertised, but server administrators may turn this off through the lsrefs.unborn config). This feature indicates that "ls-refs" supports the "unborn" argument; when it is specified, "ls-refs" will send the HEAD symref with the name of its unborn target. This change is only for protocol v2. A similar change for protocol v0 would require independent protocol design (there being no analogous position to signal support for "unborn") and client-side plumbing of the data required, so the scope of this patch set is limited to protocol v2. The client side will be updated to use this in a subsequent commit. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-12upload-pack, serve: log received client session IDJosh Steadmon
When upload-pack (protocol v0/v1) or a protocol v2 server receives a session-id capability from a client, log the received session ID via a trace2 data event. Signed-off-by: Josh Steadmon <steadmon@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-12serve: advertise session ID in v2 capabilitiesJosh Steadmon
When transfer.advertiseSID is true, advertise the server's session ID for all protocol v2 connections via the new session-id capability. Signed-off-by: Josh Steadmon <steadmon@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-31strvec: rename struct fieldsJeff King
The "argc" and "argv" names made sense when the struct was argv_array, but now they're just confusing. Let's rename them to "nr" (which we use for counts elsewhere) and "v" (which is rather terse, but reads well when combined with typical variable names like "args.v"). Note that we have to update all of the callers immediately. Playing tricks with the preprocessor is hard here, because we wouldn't want to rewrite unrelated tokens. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28strvec: convert remaining callers away from argv_array nameJeff King
We eventually want to drop the argv_array name and just use strvec consistently. There's no particular reason we have to do it all at once, or care about interactions between converted and unconverted bits. Because of our preprocessor compat layer, the names are interchangeable to the compiler (so even a definition and declaration using different names is OK). This patch converts all of the remaining files, as the resulting diff is reasonably sized. The conversion was done purely mechanically with: git ls-files '*.c' '*.h' | xargs perl -i -pe ' s/ARGV_ARRAY/STRVEC/g; s/argv_array/strvec/g; ' We'll deal with any indentation/style fallouts separately. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28strvec: rename files from argv-array to strvecJeff King
This requires updating #include lines across the code-base, but that's all fairly mechanical, and was done with: git ls-files '*.c' '*.h' | xargs perl -i -pe 's/argv-array.h/strvec.h/' Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-07Merge branch 'bc/sha-256-part-2'Junio C Hamano
SHA-256 migration work continues. * bc/sha-256-part-2: (44 commits) remote-testgit: adapt for object-format bundle: detect hash algorithm when reading refs t5300: pass --object-format to git index-pack t5704: send object-format capability with SHA-256 t5703: use object-format serve option t5702: offer an object-format capability in the test t/helper: initialize the repository for test-sha1-array remote-curl: avoid truncating refs with ls-remote t1050: pass algorithm to index-pack when outside repo builtin/index-pack: add option to specify hash algorithm remote-curl: detect algorithm for dumb HTTP by size builtin/ls-remote: initialize repository based on fetch t5500: make hash independent serve: advertise object-format capability for protocol v2 connect: parse v2 refs with correct hash algorithm connect: pass full packet reader when parsing v2 refs Documentation/technical: document object-format for protocol v2 t1302: expect repo format version 1 for SHA-256 builtin/show-index: provide options to determine hash algo t5302: modernize test formatting ...
2020-05-27serve: advertise object-format capability for protocol v2brian m. carlson
In order to communicate the protocol supported by the server side, add support for advertising the object-format capability. We check that the client side sends us an identical algorithm if it sends us its own object-format capability, and assume it speaks SHA-1 if not. In the test, when we're using an algorithm other than SHA-1, we need to specify the algorithm in use so we don't get a failure with an "unknown format" message. Add a test that we handle a mismatched algorithm. Remove the test_oid_init call since it's no longer necessary. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-05-24pkt-line: define PACKET_READ_RESPONSE_ENDDenton Liu
In a future commit, we will use PACKET_READ_RESPONSE_END to separate messages proxied by remote-curl. To prepare for this, add the PACKET_READ_RESPONSE_END enum value. In switch statements that need a case added, die() or BUG() when a PACKET_READ_RESPONSE_END is unexpected. Otherwise, mirror how PACKET_READ_DELIM is implemented (especially in cases where packets are being forwarded). Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-02pack-protocol.txt: accept error packets in any contextMasaya Suzuki
In the Git pack protocol definition, an error packet may appear only in a certain context. However, servers can face a runtime error (e.g. I/O error) at an arbitrary timing. This patch changes the protocol to allow an error packet to be sent instead of any packet. Without this protocol spec change, when a server cannot process a request, there's no way to tell that to a client. Since the server cannot produce a valid response, it would be forced to cut a connection without telling why. With this protocol spec change, the server can be more gentle in this situation. An old client may see these error packets as an unexpected packet, but this is not worse than having an unexpected EOF. Following this protocol spec change, the error packet handling code is moved to pkt-line.c. Implementation wise, this implementation uses pkt-line to communicate with a subprocess. Since this is not a part of Git protocol, it's possible that a packet that is not supposed to be an error packet is mistakenly parsed as an error packet. This error packet handling is enabled only for the Git pack protocol parsing code considering this. Signed-off-by: Masaya Suzuki <masayasuzuki@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-24serve: introduce the server-option capabilityBrandon Williams
Introduce the "server-option" capability to protocol version 2. This enables future clients the ability to send server specific options in command requests when using protocol version 2. Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-15fetch-pack: perform a fetch using v2Brandon Williams
When communicating with a v2 server, perform a fetch by requesting the 'fetch' command. Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-15upload-pack: introduce fetch server commandBrandon Williams
Introduce the 'fetch' server command. Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-15ls-refs: introduce ls-refs server commandBrandon Williams
Introduce the ls-refs server command. In protocol v2, the ls-refs command is used to request the ref advertisement from the server. Since it is a command which can be requested (as opposed to mandatory in v1), a client can sent a number of parameters in its request to limit the ref advertisement based on provided ref-prefixes. Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-15serve: introduce git-serveBrandon Williams
Introduce git-serve, the base server for protocol version 2. Protocol version 2 is intended to be a replacement for Git's current wire protocol. The intention is that it will be a simpler, less wasteful protocol which can evolve over time. Protocol version 2 improves upon version 1 by eliminating the initial ref advertisement. In its place a server will export a list of capabilities and commands which it supports in a capability advertisement. A client can then request that a particular command be executed by providing a number of capabilities and command specific parameters. At the completion of a command, a client can request that another command be executed or can terminate the connection by sending a flush packet. Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>