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author | lstewart <lstewart@FreeBSD.org> | 2011-02-01 13:32:27 +0000 |
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committer | lstewart <lstewart@FreeBSD.org> | 2011-02-01 13:32:27 +0000 |
commit | 8d21b8a169673629dd4d42ca14c9bf19531dbbd2 (patch) | |
tree | b4ea1238e9f79be6e4219505fd50eb54d5093fe7 | |
parent | ae0c590545466a1eddcb72adf32869f46d8dc51f (diff) | |
download | FreeBSD-src-8d21b8a169673629dd4d42ca14c9bf19531dbbd2.zip FreeBSD-src-8d21b8a169673629dd4d42ca14c9bf19531dbbd2.tar.gz |
Algorithm modules can define their own private congestion signal types in the
top 8 bits of the 32 bit signal bit field space for internal use. These private
signals should not be leaked outside of a module.
Given that many algorithm modules use the NewReno hook functions to simplify
their implementation, the obvious place such a leak would show up is in the
NewReno cong_signal hook function.
- Show the full number of significant bits in the signal type definitions in
<netinet/cc.h>.
- Add a bitmask to simplify figuring out if a given signal is in the private or
public bit range.
- Add a sanity check in newreno_cong_signal() to ensure private signals are not
being leaked into the hook function.
Sponsored by: FreeBSD Foundation
Discussed with: David Hayes <dahayes at swin edu au>
MFC after: 1 week
X-MFC with: r215166
-rw-r--r-- | sys/netinet/cc.h | 10 | ||||
-rw-r--r-- | sys/netinet/cc/cc_newreno.c | 4 |
2 files changed, 10 insertions, 4 deletions
diff --git a/sys/netinet/cc.h b/sys/netinet/cc.h index aaa1d67..332e51c 100644 --- a/sys/netinet/cc.h +++ b/sys/netinet/cc.h @@ -101,10 +101,12 @@ struct cc_var { * bits (0x01000000 - 0x80000000) are reserved for CC algos to declare their own * congestion signal types. */ -#define CC_ECN 0x000001/* ECN marked packet received. */ -#define CC_RTO 0x000002/* RTO fired. */ -#define CC_RTO_ERR 0x000004/* RTO fired in error. */ -#define CC_NDUPACK 0x000008/* Threshold of dupack's reached. */ +#define CC_ECN 0x00000001 /* ECN marked packet received. */ +#define CC_RTO 0x00000002 /* RTO fired. */ +#define CC_RTO_ERR 0x00000004 /* RTO fired in error. */ +#define CC_NDUPACK 0x00000008 /* Threshold of dupack's reached. */ + +#define CC_SIGPRIVMASK 0xFF000000 /* Mask to check if sig is private. */ /* * Structure to hold data and function pointers that together represent a diff --git a/sys/netinet/cc/cc_newreno.c b/sys/netinet/cc/cc_newreno.c index c095540..f26553d 100644 --- a/sys/netinet/cc/cc_newreno.c +++ b/sys/netinet/cc/cc_newreno.c @@ -182,6 +182,10 @@ newreno_cong_signal(struct cc_var *ccv, uint32_t type) { u_int win; + /* Catch algos which mistakenly leak private signal types. */ + KASSERT((type & CC_SIGPRIVMASK) == 0, + ("%s: congestion signal type 0x%08x is private\n", __func__, type)); + win = max(CCV(ccv, snd_cwnd) / 2 / CCV(ccv, t_maxseg), 2) * CCV(ccv, t_maxseg); |