On 12/16/2011 05:44 PM, Xi Wang wrote:
> Commit 8ffd3208 voids the previous patches f6778aab and 810c0719 for
> limiting the autoclose value. If userspace passes in -1 on 32-bit
> platform, the overflow check didn't work and autoclose would be set
> to 0xffffffff.
>
> This patch defines a max_autoclose (in seconds) for limiting the value
> and exposes it through sysctl, with the following intentions.
>
> 1) Avoid overflowing autoclose * HZ.
>
> 2) Keep the default autoclose bound consistent across 32- and 64-bit
> platforms (INT_MAX / HZ in this patch).
>
> 3) Keep the autoclose value consistent between setsockopt() and
> getsockopt() calls.
>
> Suggested-by: Vlad Yasevich <vladislav.yasevich@xxxxxx>
> Signed-off-by: Xi Wang <xi.wang@xxxxxxxxx>
Looks good to me.
Acked-by: Vlad Yasevich <vladislav.yasevich@xxxxxx>
-vlad
P.S. Sorry, took so long. Just got back from a long vacation.
> ---
> include/net/sctp/structs.h | 4 ++++
> net/sctp/associola.c | 2 +-
> net/sctp/protocol.c | 3 +++
> net/sctp/socket.c | 2 --
> net/sctp/sysctl.c | 13 +++++++++++++
> 5 files changed, 21 insertions(+), 3 deletions(-)
>
> diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
> index e90e7a9..a15432da 100644
> --- a/include/net/sctp/structs.h
> +++ b/include/net/sctp/structs.h
> @@ -241,6 +241,9 @@ extern struct sctp_globals {
> * bits is an indicator of when to send and window update SACK.
> */
> int rwnd_update_shift;
> +
> + /* Threshold for autoclose timeout, in seconds. */
> + unsigned long max_autoclose;
> } sctp_globals;
>
> #define sctp_rto_initial (sctp_globals.rto_initial)
> @@ -281,6 +284,7 @@ extern struct sctp_globals {
> #define sctp_auth_enable (sctp_globals.auth_enable)
> #define sctp_checksum_disable (sctp_globals.checksum_disable)
> #define sctp_rwnd_upd_shift (sctp_globals.rwnd_update_shift)
> +#define sctp_max_autoclose (sctp_globals.max_autoclose)
>
> /* SCTP Socket type: UDP or TCP style. */
> typedef enum {
> diff --git a/net/sctp/associola.c b/net/sctp/associola.c
> index 152b5b3..acd2edb 100644
> --- a/net/sctp/associola.c
> +++ b/net/sctp/associola.c
> @@ -173,7 +173,7 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
> asoc->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = 0;
> asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
> asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =
> - (unsigned long)sp->autoclose * HZ;
> + min_t(unsigned long, sp->autoclose, sctp_max_autoclose) * HZ;
>
> /* Initializes the timers */
> for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
> diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
> index 61b9fca..6f6ad86 100644
> --- a/net/sctp/protocol.c
> +++ b/net/sctp/protocol.c
> @@ -1285,6 +1285,9 @@ SCTP_STATIC __init int sctp_init(void)
> sctp_max_instreams = SCTP_DEFAULT_INSTREAMS;
> sctp_max_outstreams = SCTP_DEFAULT_OUTSTREAMS;
>
> + /* Initialize maximum autoclose timeout. */
> + sctp_max_autoclose = INT_MAX / HZ;
> +
> /* Initialize handle used for association ids. */
> idr_init(&sctp_assocs_id);
>
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index 13bf5fc..54a7cd2 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -2200,8 +2200,6 @@ static int sctp_setsockopt_autoclose(struct sock *sk, char __user *optval,
> return -EINVAL;
> if (copy_from_user(&sp->autoclose, optval, optlen))
> return -EFAULT;
> - /* make sure it won't exceed MAX_SCHEDULE_TIMEOUT */
> - sp->autoclose = min_t(long, sp->autoclose, MAX_SCHEDULE_TIMEOUT / HZ);
>
> return 0;
> }
> diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
> index 6b39529..60ffbd0 100644
> --- a/net/sctp/sysctl.c
> +++ b/net/sctp/sysctl.c
> @@ -53,6 +53,10 @@ static int sack_timer_min = 1;
> static int sack_timer_max = 500;
> static int addr_scope_max = 3; /* check sctp_scope_policy_t in include/net/sctp/constants.h for max entries */
> static int rwnd_scale_max = 16;
> +static unsigned long max_autoclose_min = 0;
> +static unsigned long max_autoclose_max =
> + (MAX_SCHEDULE_TIMEOUT / HZ > UINT_MAX)
> + ? UINT_MAX : MAX_SCHEDULE_TIMEOUT / HZ;
>
> extern long sysctl_sctp_mem[3];
> extern int sysctl_sctp_rmem[3];
> @@ -258,6 +262,15 @@ static ctl_table sctp_table[] = {
> .extra1 = &one,
> .extra2 = &rwnd_scale_max,
> },
> + {
> + .procname = "max_autoclose",
> + .data = &sctp_max_autoclose,
> + .maxlen = sizeof(unsigned long),
> + .mode = 0644,
> + .proc_handler = &proc_doulongvec_minmax,
> + .extra1 = &max_autoclose_min,
> + .extra2 = &max_autoclose_max,
> + },
>
> { /* sentinel */ }
> };
--
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