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|The hard limit for the BPF buffer size is 32KB, which appears too low

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|for high speed networks (even at 100Mbit/s this corresponds to 1/300th
|of a second). The default buffer size is 4KB, but libpcap and ipfilter
|both override this (using the BIOCSBLEN ioctl) and allocate 32KB.
|
|The following patch adds an sysctl for bpf_maxbufsize, similar to the
|one for bpf_bufsize that you added back in December 1995. I choose to
|make the default for this limit 512KB (the value suggested by NFR).

Submitted by:	se
Reviewed by:	phk
This commit is contained in:
Poul-Henning Kamp 2000-01-15 19:46:12 +00:00
parent f6ac6875d7
commit eba2a1aeb9
2 changed files with 6 additions and 3 deletions
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7
sys/net/bpf.c
View File

@ -104,6 +104,9 @@ static caddr_t bpf_alloc();
static int bpf_bufsize = BPF_BUFSIZE;
SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
&bpf_bufsize, 0, "");
static int bpf_maxbufsize = BPF_MAXBUFSIZE;
SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
&bpf_maxbufsize, 0, "");
/*
* bpf_iflist is the list of interfaces; each corresponds to an ifnet
@ -698,8 +701,8 @@ bpfioctl(dev, cmd, addr, flags, p)
else {
register u_int size = *(u_int *)addr;
if (size > BPF_MAXBUFSIZE)
*(u_int *)addr = size = BPF_MAXBUFSIZE;
if (size > bpf_maxbufsize)
*(u_int *)addr = size = bpf_maxbufsize;
else if (size < BPF_MINBUFSIZE)
*(u_int *)addr = size = BPF_MINBUFSIZE;
d->bd_bufsize = size;

2
sys/net/bpf.h
View File

@ -58,7 +58,7 @@ typedef u_int32_t bpf_u_int32;
#define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
#define BPF_MAXINSNS 512
#define BPF_MAXBUFSIZE 0x8000
#define BPF_MAXBUFSIZE 0x80000
#define BPF_MINBUFSIZE 32
/*