2007-10-22 18:27:24

by cheng renquan

Subject: [PATCH] [net/ipv4]: fib_seq_show function adjustment to get a more sensable output of /proc/net/route

the temporary bf[127] char array is redundant, and the specified width 127 make the output of /proc/net/route include many trailing spaces;
since most terminal's cols are less than 127, this made every fib entry occupy two lines,

after applied this patch, the output of /proc/net/route is more sensable like this:

Iface Destination Gateway Flags RefCnt Use Metric Mask MTU Window IRTT
eth0 0001A8C0 00000000 0001 0 0 0 00FFFFFF 0 0 0
lo 0000007F 00000000 0001 0 0 0 000000FF 0 0 0
eth0 00000000 0101A8C0 0003 0 0 0 00000000 0 0 0

Signed-off-by: Denis Cheng <[email protected]>
---
net/ipv4/fib_hash.c | 15 +++++++--------
1 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/net/ipv4/fib_hash.c b/net/ipv4/fib_hash.c
index 527a6e0..2a4033e 100644
--- a/net/ipv4/fib_hash.c
+++ b/net/ipv4/fib_hash.c
@@ -992,7 +992,6 @@ static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
static int fib_seq_show(struct seq_file *seq, void *v)
{
struct fib_iter_state *iter;
- char bf[128];
__be32 prefix, mask;
unsigned flags;
struct fib_node *f;
@@ -1000,9 +999,9 @@ static int fib_seq_show(struct seq_file *seq, void *v)
struct fib_info *fi;

if (v == SEQ_START_TOKEN) {
- seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
+ seq_printf(seq, "Iface\tDestination\tGateway "
"\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
- "\tWindow\tIRTT");
+ "\tWindow\tIRTT\n");
goto out;
}

@@ -1014,18 +1013,18 @@ static int fib_seq_show(struct seq_file *seq, void *v)
mask = FZ_MASK(iter->zone);
flags = fib_flag_trans(fa->fa_type, mask, fi);
if (fi)
- snprintf(bf, sizeof(bf),
- "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
+ seq_printf(seq,
+ "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u\n",
fi->fib_dev ? fi->fib_dev->name : "*", prefix,
fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
fi->fib_window,
fi->fib_rtt >> 3);
else
- snprintf(bf, sizeof(bf),
- "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u",
+ seq_printf(seq,
+ "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u\n",
prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0);
- seq_printf(seq, "%-127s\n", bf);
+
out:
return 0;
}
--
1.5.3.4

2007-10-22 19:35:29

by Eric Dumazet

Subject: Re: [PATCH] [net/ipv4]: fib_seq_show function adjustment to get a more sensable output of /proc/net/route

Denis Cheng a ?crit :
> the temporary bf[127] char array is redundant, and the specified width 127 make the output of /proc/net/route include many trailing spaces;
> since most terminal's cols are less than 127, this made every fib entry occupy two lines,
>
> after applied this patch, the output of /proc/net/route is more sensable like this:
>
> Iface Destination Gateway Flags RefCnt Use Metric Mask MTU Window IRTT
> eth0 0001A8C0 00000000 0001 0 0 0 00FFFFFF 0 0 0
> lo 0000007F 00000000 0001 0 0 0 000000FF 0 0 0
> eth0 00000000 0101A8C0 0003 0 0 0 00000000 0 0 0
>
> Signed-off-by: Denis Cheng <[email protected]>

Hum... did you test your patch with many routes declared ? (more than 32 on
i386/x86_64)

127 is not a random value, but chosen as a power of two minus 1.
PAGE_SIZE is garanted to be a multiple of 128 (127 chars + line_feed) on all
arches.

So each read() on /proc/net/route delivers PAGE_SIZE/128 lines.

With your patch, some lines might be truncated (one every 32 on i386)