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Re: [PATCH v2 06/11] serve: drop "keys" strvec

From
Junio C Hamano <gitster@pobox.com>
Date
Sep 15, 2021, 17:01 UTC
Message-ID
<xmqqczp9ydqn.fsf@gitster.g>
In-Reply-To
<YUE1hExkU9V12iZv@coredump.intra.peff.net>
Jeff King <peff@peff.net> writes:
Show 36 quoted lines
> 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>
> ---
>  serve.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/serve.c b/serve.c
> index 6bbf54cbbe..5ea6c915cb 100644
> --- a/serve.c
> +++ b/serve.c
> @@ -239,7 +239,7 @@ static int process_request(void)
>  {
>  	enum request_state state = PROCESS_REQUEST_KEYS;
>  	struct packet_reader reader;
> -	struct strvec keys = STRVEC_INIT;
> +	int seen_capability_or_command = 0;
>  	struct protocol_capability *command = NULL;
>  
>  	packet_reader_init(&reader, 0, NULL, 0,
> @@ -263,7 +263,7 @@ static int process_request(void)
>  			/* collect request; a sequence of keys and values */
>  			if (parse_command(reader.line, &command) ||
>  			    receive_client_capability(reader.line))
> -				strvec_push(&keys, reader.line);
> +				seen_capability_or_command = 1;

OK, we no longer "collect" request in the keys strvec, but I guess what receive_client_capability() does still counts as "collecting", so the "tentatively stale" comment is not wrong after all at the end (we have tentatively been collecting in two different places and one of them is dropped here).

Show 16 quoted lines
> @@ -275,7 +275,7 @@ static int process_request(void)
>  			 * If no command and no keys were given then the client
>  			 * wanted to terminate the connection.
>  			 */
> -			if (!keys.nr)
> +			if (!seen_capability_or_command)
>  				return 1;
>  
>  			/*
> @@ -309,7 +309,6 @@ static int process_request(void)
>  
>  	command->command(the_repository, &reader);
>  
> -	strvec_clear(&keys);
>  	return 0;
>  }
Nice.
Previous: Jeff KingNext: Jeff King
Message 49 of 77 in “reducing memory allocations for v2 servers”
  1. 0/9 reducing memory allocations for v2 serversJeff King, Sep 14, 2021
  2. 1/9 serve: rename is_command() to parse_command()Jeff King, Sep 14, 2021
  3. 2/9 serve: return capability "value" from get_capability()Jeff King, Sep 14, 2021
  4. 3/9 serve: add "receive" method for v2 capabilities tableJeff King, Sep 14, 2021
  5. 4/9 serve: provide "receive" function for object-format capabilityJeff King, Sep 14, 2021
  6. Martin ÅgrenSep 14, 2021
  7. 5/9 serve: provide "receive" function for session-id capabilityJeff King, Sep 14, 2021
  8. Taylor BlauSep 14, 2021
  9. Jeff KingSep 14, 2021
  10. Taylor BlauSep 14, 2021
  11. Martin ÅgrenSep 14, 2021
  12. Jeff KingSep 14, 2021
  13. 6/9 serve: drop "keys" strvecJeff King, Sep 14, 2021
  14. Taylor BlauSep 14, 2021
  15. Jeff KingSep 14, 2021
  16. 7/9 ls-refs: ignore very long ref-prefix countsJeff King, Sep 14, 2021
  17. Taylor BlauSep 14, 2021
  18. Jeff KingSep 14, 2021
  19. Jeff KingSep 14, 2021
  20. Martin ÅgrenSep 14, 2021
  21. Jeff KingSep 14, 2021
  22. Jeff KingSep 14, 2021
  23. Taylor BlauSep 14, 2021
  24. Jeff KingSep 14, 2021
  25. 8/9 serve: reject bogus v2 "command=ls-refs=foo"Jeff King, Sep 14, 2021
  26. Taylor BlauSep 14, 2021
  27. 9/9 serve: reject commands used as capabilitiesJeff King, Sep 14, 2021
  28. Taylor BlauSep 14, 2021
  29. Junio C HamanoSep 14, 2021
  30. Jeff KingSep 14, 2021
  31. 0/11 limit memory allocations for v2 serversJeff King, Sep 14, 2021
  32. 01/11 serve: rename is_command() to parse_command()Jeff King, Sep 14, 2021
  33. 02/11 serve: return capability "value" from get_capability()Jeff King, Sep 14, 2021
  34. 03/11 serve: add "receive" method for v2 capabilities tableJeff King, Sep 14, 2021
  35. Ævar Arnfjörð BjarmasonSep 15, 2021
  36. Jeff KingSep 15, 2021
  37. Junio C HamanoSep 15, 2021
  38. Jeff KingSep 15, 2021
  39. 04/11 serve: provide "receive" function for object-format capabilityJeff King, Sep 14, 2021
  40. Junio C HamanoSep 15, 2021
  41. 05/11 serve: provide "receive" function for session-id capabilityJeff King, Sep 14, 2021
  42. Junio C HamanoSep 15, 2021
  43. 07/11 ls-refs: ignore very long ref-prefix countsJeff King, Sep 14, 2021
  44. Taylor BlauSep 15, 2021
  45. Jeff KingSep 15, 2021
  46. Eric SunshineSep 15, 2021
  47. Jeff KingSep 15, 2021
  48. 06/11 serve: drop "keys" strvecJeff King, Sep 14, 2021
  49. Junio C HamanoSep 15, 2021
  50. 08/11 docs/protocol-v2: clarify some ls-refs ref-prefix detailsJeff King, Sep 14, 2021
  51. 09/11 serve: reject bogus v2 "command=ls-refs=foo"Jeff King, Sep 14, 2021
  52. Ævar Arnfjörð BjarmasonSep 15, 2021
  53. Jeff KingSep 15, 2021
  54. Eric SunshineSep 15, 2021
  55. Jeff KingSep 15, 2021
  56. Junio C HamanoSep 15, 2021
  57. Jeff KingSep 15, 2021
  58. 10/11 serve: reject commands used as capabilitiesJeff King, Sep 14, 2021
  59. 11/11 ls-refs: reject unknown argumentsJeff King, Sep 14, 2021
  60. Ævar Arnfjörð BjarmasonSep 15, 2021
  61. Jeff KingSep 15, 2021
  62. Taylor BlauSep 15, 2021
  63. Jeff KingSep 15, 2021
  64. 0/11 limit memory allocations for v2 serversJeff King, Sep 15, 2021
  65. 01/11 serve: rename is_command() to parse_command()Jeff King, Sep 15, 2021
  66. 02/11 serve: return capability "value" from get_capability()Jeff King, Sep 15, 2021
  67. 03/11 serve: add "receive" method for v2 capabilities tableJeff King, Sep 15, 2021
  68. 04/11 serve: provide "receive" function for object-format capabilityJeff King, Sep 15, 2021
  69. 05/11 serve: provide "receive" function for session-id capabilityJeff King, Sep 15, 2021
  70. 06/11 serve: drop "keys" strvecJeff King, Sep 15, 2021
  71. 07/11 ls-refs: ignore very long ref-prefix countsJeff King, Sep 15, 2021
  72. 08/11 docs/protocol-v2: clarify some ls-refs ref-prefix detailsJeff King, Sep 15, 2021
  73. 09/11 serve: reject bogus v2 "command=ls-refs=foo"Jeff King, Sep 15, 2021
  74. 10/11 serve: reject commands used as capabilitiesJeff King, Sep 15, 2021
  75. 11/11 ls-refs: reject unknown argumentsJeff King, Sep 15, 2021
  76. Ævar Arnfjörð BjarmasonSep 15, 2021
  77. Jeff KingSep 15, 2021

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