Merge branch 'jk/reduce-malloc-in-v2-servers'

Code cleanup to limit memory consumption and tighten protocol
message parsing.

* jk/reduce-malloc-in-v2-servers:
  ls-refs: reject unknown arguments
  serve: reject commands used as capabilities
  serve: reject bogus v2 "command=ls-refs=foo"
  docs/protocol-v2: clarify some ls-refs ref-prefix details
  ls-refs: ignore very long ref-prefix counts
  serve: drop "keys" strvec
  serve: provide "receive" function for session-id capability
  serve: provide "receive" function for object-format capability
  serve: add "receive" method for v2 capabilities table
  serve: return capability "value" from get_capability()
  serve: rename is_command() to parse_command()
This commit is contained in:
Junio C Hamano
2021-09-28 13:06:53 -07:00
4 changed files with 164 additions and 59 deletions

View File

@@ -40,6 +40,12 @@ static void ensure_config_read(void)
config_read = 1;
}
/*
* If we see this many or more "ref-prefix" lines from the client, we consider
* it "too many" and will avoid using the prefix feature entirely.
*/
#define TOO_MANY_PREFIXES 65536
/*
* Check if one of the prefixes is a prefix of the ref.
* If no prefixes were provided, all refs match.
@@ -158,15 +164,27 @@ int ls_refs(struct repository *r, struct packet_reader *request)
data.peel = 1;
else if (!strcmp("symrefs", arg))
data.symrefs = 1;
else if (skip_prefix(arg, "ref-prefix ", &out))
strvec_push(&data.prefixes, out);
else if (skip_prefix(arg, "ref-prefix ", &out)) {
if (data.prefixes.nr < TOO_MANY_PREFIXES)
strvec_push(&data.prefixes, out);
}
else if (!strcmp("unborn", arg))
data.unborn = allow_unborn;
else
die(_("unexpected line: '%s'"), arg);
}
if (request->status != PACKET_READ_FLUSH)
die(_("expected flush after ls-refs arguments"));
/*
* If we saw too many prefixes, we must avoid using them at all; as
* soon as we have any prefix, they are meant to form a comprehensive
* list.
*/
if (data.prefixes.nr >= TOO_MANY_PREFIXES)
strvec_clear(&data.prefixes);
send_possibly_unborn_head(&data);
if (!data.prefixes.nr)
strvec_push(&data.prefixes, "");