| Message ID | 1462363884-34968-1-git-send-email-Eugene.Crosser@ru.ibm.com |
|---|---|
| State | Rejected, archived |
| Delegated to: | David Miller |
| Headers | show |
On Wed, 2016-05-04 at 14:11 +0200, Eugene Crosser wrote: > /proc/net/igmp is a readonly attribute that shows multicast groups > to which different network interfaces are subscribed. Among other > things, it displays `multiaddr` which is a 32 bit network-byte-order > field, in hexadecimal format. Prior to this patch, the field was > displayed as an integer, resulting in reverse byte order on little > endian architectures. This patch converts it with ntohl() for display > the same way as this is done for the /proc/net/mcfilter attribute. > > The patch changes (corrects) user-visible behaviour. > > Signed-off-by: Eugene Crosser <Eugene.Crosser@ru.ibm.com> > --- > net/ipv4/igmp.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c > index b3086cf..f9d2139 100644 > --- a/net/ipv4/igmp.c > +++ b/net/ipv4/igmp.c > @@ -2722,7 +2722,7 @@ static int igmp_mc_seq_show(struct seq_file *seq, void *v) > delta = im->timer.expires - jiffies; > seq_printf(seq, > "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n", > - im->multiaddr, im->users, > + ntohl(im->multiaddr), im->users, > im->tm_running, > im->tm_running ? jiffies_delta_to_clock_t(delta) : 0, > im->reporter); I do not believe we can change this. This is unfortunately too late. /proc/net/tcp has the same 'issue' or if you prefer, well known behavior. Such change would break basically all /proc/net/igmp users.
-----Eric Dumazet <eric.dumazet@gmail.com> wrote: ----- >To: Evgeny Cherkashin/Russia/IBM@IBMRU >From: Eric Dumazet <eric.dumazet@gmail.com> >Date: 2016-05-04 16:13 >Cc: crosser@average.org, netdev@vger.kernel.org >Subject: Re: [PATCH net] igmp: fix byte order in /proc/net/igmp >output > >On Wed, 2016-05-04 at 14:11 +0200, Eugene Crosser wrote: >> /proc/net/igmp is a readonly attribute that shows multicast groups >> to which different network interfaces are subscribed. Among other >> things, it displays `multiaddr` which is a 32 bit >network-byte-order >> field, in hexadecimal format. Prior to this patch, the field was >> displayed as an integer, resulting in reverse byte order on little >> endian architectures. This patch converts it with ntohl() for >display >> the same way as this is done for the /proc/net/mcfilter attribute. >> >> The patch changes (corrects) user-visible behaviour. >> >> Signed-off-by: Eugene Crosser <Eugene.Crosser@ru.ibm.com> >> --- >> net/ipv4/igmp.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c >> index b3086cf..f9d2139 100644 >> --- a/net/ipv4/igmp.c >> +++ b/net/ipv4/igmp.c >> @@ -2722,7 +2722,7 @@ static int igmp_mc_seq_show(struct seq_file >*seq, void *v) >> delta = im->timer.expires - jiffies; >> seq_printf(seq, >> "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n", >> - im->multiaddr, im->users, >> + ntohl(im->multiaddr), im->users, >> im->tm_running, >> im->tm_running ? jiffies_delta_to_clock_t(delta) : 0, >> im->reporter); > > >I do not believe we can change this. This is unfortunately too late. > >/proc/net/tcp has the same 'issue' or if you prefer, well known >behavior. > >Such change would break basically all /proc/net/igmp users. I understand that. It is unfortunate though that the byte order is not _just_ wrong, it's _different_ on BE and LE machines... Oh well. Thanks, Eugene
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Wed, 04 May 2016 06:13:36 -0700 > On Wed, 2016-05-04 at 14:11 +0200, Eugene Crosser wrote: >> /proc/net/igmp is a readonly attribute that shows multicast groups >> to which different network interfaces are subscribed. Among other >> things, it displays `multiaddr` which is a 32 bit network-byte-order >> field, in hexadecimal format. Prior to this patch, the field was >> displayed as an integer, resulting in reverse byte order on little >> endian architectures. This patch converts it with ntohl() for display >> the same way as this is done for the /proc/net/mcfilter attribute. >> >> The patch changes (corrects) user-visible behaviour. >> >> Signed-off-by: Eugene Crosser <Eugene.Crosser@ru.ibm.com> >> --- >> net/ipv4/igmp.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c >> index b3086cf..f9d2139 100644 >> --- a/net/ipv4/igmp.c >> +++ b/net/ipv4/igmp.c >> @@ -2722,7 +2722,7 @@ static int igmp_mc_seq_show(struct seq_file *seq, void *v) >> delta = im->timer.expires - jiffies; >> seq_printf(seq, >> "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n", >> - im->multiaddr, im->users, >> + ntohl(im->multiaddr), im->users, >> im->tm_running, >> im->tm_running ? jiffies_delta_to_clock_t(delta) : 0, >> im->reporter); > > > I do not believe we can change this. This is unfortunately too late. > > /proc/net/tcp has the same 'issue' or if you prefer, well known > behavior. > > Such change would break basically all /proc/net/igmp users. Agreed.
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index b3086cf..f9d2139 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -2722,7 +2722,7 @@ static int igmp_mc_seq_show(struct seq_file *seq, void *v) delta = im->timer.expires - jiffies; seq_printf(seq, "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n", - im->multiaddr, im->users, + ntohl(im->multiaddr), im->users, im->tm_running, im->tm_running ? jiffies_delta_to_clock_t(delta) : 0, im->reporter);
/proc/net/igmp is a readonly attribute that shows multicast groups to which different network interfaces are subscribed. Among other things, it displays `multiaddr` which is a 32 bit network-byte-order field, in hexadecimal format. Prior to this patch, the field was displayed as an integer, resulting in reverse byte order on little endian architectures. This patch converts it with ntohl() for display the same way as this is done for the /proc/net/mcfilter attribute. The patch changes (corrects) user-visible behaviour. Signed-off-by: Eugene Crosser <Eugene.Crosser@ru.ibm.com> --- net/ipv4/igmp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)