[PATCH] iproute2: enhance addr label validation

[PATCH] iproute2: enhance addr label validation

[Joe Harvell]

The ip addr command today rejects address labels that would break
ifconfig.  However, it allows some labels which still break it. Enhance
enforcement to reject all known incompatible labels, and allow the
existing -force option to allow someone to use a label even if it is not
ifconfig compatible

Make existing -force option of ip addr add skip enforcement of ifconfig
compatible address labels.
Change enforcement to properly reject labels that do begin with
<devname> but are followed by a string that does not begin with colon.

The following changes since commit 4612d04d6b8f07274bd5d0688f717ccc189499ad:

   tc class: Show class names from file (2015-03-15 12:27:40 -0700)

are available in the git repository at:

   git@github.com:jharvell/iproute2.git addr-label-noncompat

for you to fetch changes up to 44931a448ac2b375c703cb79fb814ec575fe253b:

   Signed-off-by: Joe Harvell <joe.harvell@tekcomms.com> (2015-03-21 14:45:36 -0500)

----------------------------------------------------------------
Joe Harvell (6):
       Making -force option of ip command also allow address labels that are not     backward-compatible with ifconfig.  Note that even without this change     the ip command does allow some incompatible address labels to be created.     ifconfig depends on the labels beginning with <interface-name><colon>, but     the ip command (even before the changes in this commit) only requires the     prefix of the label to be <interface-name>.  Thus, if you add a label such     as eth0-media, it will be accepted by ip but ifconfig will barf on ifconfig -a.     The motivation for this change is that the lenght allowed for a lable is small,     so requiring a long prefix for ifconfig backwards compatibility limits the     usefulness of the label.  For embedded systems (or any system) where ifconfig  
    is not even installed, it is useful to be able to create longer labels.
       Enhancing enforcement of ifconfig compatible label.     Prior implementation allowed incompatible labels that started with dev but not dev:
       Adding parentheses for clarity     Removing code comment since it is now clearly spelled out in fprintf error message
       Using strncmp instead of matches for clarity and to avoid extra strlen calls
       Fixed indenting by replacing spaces with tabs     Minor re-word of man page text
       Signed-off-by: Joe Harvell <joe.harvell@tekcomms.com>

  include/utils.h |  1 +
  ip/ip.c         |  2 ++
  ip/ipaddress.c  | 12 +++++++++---
  man/man8/ip.8   |  2 ++
  4 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/include/utils.h b/include/utils.h
index 9151c4f..e8a5467 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -25,6 +25,7 @@ extern char * _SL_;
  extern int max_flush_loops;
  extern int batch_mode;
  extern bool do_all;
+extern bool require_ifconfig_compat;
  
  #ifndef IPPROTO_ESP
  #define IPPROTO_ESP    50
diff --git a/ip/ip.c b/ip/ip.c
index da16b15..78b0197 100644
--- a/ip/ip.c
+++ b/ip/ip.c
@@ -37,6 +37,7 @@ int force = 0;
  int max_flush_loops = 10;
  int batch_mode = 0;
  bool do_all = false;
+bool require_ifconfig_compat = true;
  
  struct rtnl_handle rth = { .fd = -1 };
  
@@ -246,6 +247,7 @@ int main(int argc, char **argv)
                         exit(0);
                 } else if (matches(opt, "-force") == 0) {
                         ++force;
+                       require_ifconfig_compat = false;
                 } else if (matches(opt, "-batch") == 0) {
                         argc--;
                         argv++;
diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index 99a6ab5..be027c6 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -1691,11 +1691,17 @@ static int ipaddr_modify(int cmd, int flags, int argc, char **argv)
                 fprintf(stderr, "Not enough information: \"dev\" argument is required.\n");
                 return -1;
         }
-       if (l && matches(d, l) != 0) {
-               fprintf(stderr, "\"dev\" (%s) must match \"label\" (%s).\n", d, l);
+       if ( require_ifconfig_compat && l) {
+               bool isCompat = false;
+               size_t dLen = strlen(d);
+               size_t lLen = strlen(l);
+               if(lLen >= dLen && strncmp(d, l, dLen) == 0)
+                       isCompat =  (dLen == lLen || l[dLen] == ':');
+               if( !isCompat ) {
+                       fprintf(stderr, "\"label\" (%s) must either be \"dev\" (%s) or start with \"dev\" followed by a colon (%s:).\n", l, d, d);
                 return -1;
+               }
         }
-
         if (peer_len == 0 && local_len) {
                 if (cmd == RTM_DELADDR && lcl.family == AF_INET && !(lcl.flags & PREFIXLEN_SPECIFIED)) {
                         fprintf(stderr,
diff --git a/man/man8/ip.8 b/man/man8/ip.8
index 016e8c6..f58241f 100644
--- a/man/man8/ip.8
+++ b/man/man8/ip.8
@@ -54,6 +54,8 @@ First failure will cause termination of ip.
  Don't terminate ip on errors in batch mode.
  If there were any errors during execution of the commands, the application return code will be non zero.
  
+This option also allows creation of address labels that may not be compatible with ifconfig.
+
  .TP
  .BR "\-s" , " \-stats" , " \-statistics"
  Output more information.  If the option

Re: [PATCH] iproute2: enhance addr label validation

[Simon Horman]

Hi Joe,

On Sat, Mar 21, 2015 at 03:14:53PM -0500, Joe Harvell wrote:
> The ip addr command today rejects address labels that would break
> ifconfig.  However, it allows some labels which still break it. Enhance
> enforcement to reject all known incompatible labels, and allow the
> existing -force option to allow someone to use a label even if it is not
> ifconfig compatible

I am concerned this will break existing users who are relying on setting
labels that would now be rejected without using -force.

> 
> Make existing -force option of ip addr add skip enforcement of ifconfig
> compatible address labels.
> Change enforcement to properly reject labels that do begin with
> <devname> but are followed by a string that does not begin with colon.
> 
> The following changes since commit 4612d04d6b8f07274bd5d0688f717ccc189499ad:
> 
>   tc class: Show class names from file (2015-03-15 12:27:40 -0700)
> 
> are available in the git repository at:
> 
>   git@github.com:jharvell/iproute2.git addr-label-noncompat
> 
> for you to fetch changes up to 44931a448ac2b375c703cb79fb814ec575fe253b:
> 
>   Signed-off-by: Joe Harvell <joe.harvell@tekcomms.com> (2015-03-21 14:45:36 -0500)
> 
> ----------------------------------------------------------------
> Joe Harvell (6):
>       Making -force option of ip command also allow address labels that are not     backward-compatible with ifconfig.  Note that even without this change     the ip command does allow some incompatible address labels to be created.     ifconfig depends on the labels beginning with <interface-name><colon>, but     the ip command (even before the changes in this commit) only requires the     prefix of the label to be <interface-name>.  Thus, if you add a label such     as eth0-media, it will be accepted by ip but ifconfig will barf on ifconfig -a.     The motivation for this change is that the lenght allowed for a lable is small,     so requiring a long prefix for ifconfig backwards compatibility limits the     usefulness of the label.  For embedded systems (or any system) where ifconfig 
     is not even installed, it is useful to be able to create longer labels.
>       Enhancing enforcement of ifconfig compatible label.     Prior implementation allowed incompatible labels that started with dev but not dev:
>       Adding parentheses for clarity     Removing code comment since it is now clearly spelled out in fprintf error message
>       Using strncmp instead of matches for clarity and to avoid extra strlen calls
>       Fixed indenting by replacing spaces with tabs     Minor re-word of man page text
>       Signed-off-by: Joe Harvell <joe.harvell@tekcomms.com>
> 
>  include/utils.h |  1 +
>  ip/ip.c         |  2 ++
>  ip/ipaddress.c  | 12 +++++++++---
>  man/man8/ip.8   |  2 ++
>  4 files changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/include/utils.h b/include/utils.h
> index 9151c4f..e8a5467 100644
> --- a/include/utils.h
> +++ b/include/utils.h
> @@ -25,6 +25,7 @@ extern char * _SL_;
>  extern int max_flush_loops;
>  extern int batch_mode;
>  extern bool do_all;
> +extern bool require_ifconfig_compat;
>  #ifndef IPPROTO_ESP
>  #define IPPROTO_ESP    50
> diff --git a/ip/ip.c b/ip/ip.c
> index da16b15..78b0197 100644
> --- a/ip/ip.c
> +++ b/ip/ip.c
> @@ -37,6 +37,7 @@ int force = 0;
>  int max_flush_loops = 10;
>  int batch_mode = 0;
>  bool do_all = false;
> +bool require_ifconfig_compat = true;
>  struct rtnl_handle rth = { .fd = -1 };
> @@ -246,6 +247,7 @@ int main(int argc, char **argv)
>                         exit(0);
>                 } else if (matches(opt, "-force") == 0) {
>                         ++force;
> +                       require_ifconfig_compat = false;
>                 } else if (matches(opt, "-batch") == 0) {
>                         argc--;
>                         argv++;
> diff --git a/ip/ipaddress.c b/ip/ipaddress.c
> index 99a6ab5..be027c6 100644
> --- a/ip/ipaddress.c
> +++ b/ip/ipaddress.c
> @@ -1691,11 +1691,17 @@ static int ipaddr_modify(int cmd, int flags, int argc, char **argv)
>                 fprintf(stderr, "Not enough information: \"dev\" argument is required.\n");
>                 return -1;
>         }
> -       if (l && matches(d, l) != 0) {
> -               fprintf(stderr, "\"dev\" (%s) must match \"label\" (%s).\n", d, l);
> +       if ( require_ifconfig_compat && l) {
> +               bool isCompat = false;
> +               size_t dLen = strlen(d);
> +               size_t lLen = strlen(l);
> +               if(lLen >= dLen && strncmp(d, l, dLen) == 0)
> +                       isCompat =  (dLen == lLen || l[dLen] == ':');
> +               if( !isCompat ) {
> +                       fprintf(stderr, "\"label\" (%s) must either be \"dev\" (%s) or start with \"dev\" followed by a colon (%s:).\n", l, d, d);
>                 return -1;
> +               }
>         }
> -
>         if (peer_len == 0 && local_len) {
>                 if (cmd == RTM_DELADDR && lcl.family == AF_INET && !(lcl.flags & PREFIXLEN_SPECIFIED)) {
>                         fprintf(stderr,
> diff --git a/man/man8/ip.8 b/man/man8/ip.8
> index 016e8c6..f58241f 100644
> --- a/man/man8/ip.8
> +++ b/man/man8/ip.8
> @@ -54,6 +54,8 @@ First failure will cause termination of ip.
>  Don't terminate ip on errors in batch mode.
>  If there were any errors during execution of the commands, the application return code will be non zero.
> +This option also allows creation of address labels that may not be compatible with ifconfig.
> +
>  .TP
>  .BR "\-s" , " \-stats" , " \-statistics"
>  Output more information.  If the option
> 
> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

Re: [PATCH] iproute2: enhance addr label validation

[Joe Harvell]

> Hi Joe,
>
> On Sat, Mar 21, 2015 at 03:14:53PM -0500, Joe Harvell wrote:
>> The ip addr command today rejects address labels that would break
>> ifconfig.  However, it allows some labels which still break it. Enhance
>> enforcement to reject all known incompatible labels, and allow the
>> existing -force option to allow someone to use a label even if it is not
>> ifconfig compatible
> I am concerned this will break existing users who are relying on setting
> labels that would now be rejected without using -force.
>
[snip]

Simon,

Good point.  I propose the following:

When a label is specified without -force, and that label begins with the 
interface
name but is followed by something other than a colon, accept the label 
but emit
a warning message indicating this label is incompatible with ifconfig 
and that later
versions of the 'ip address' command may reject it.  This message can 
also indicate
that -force can be specified to explicitly indicate a label that is non 
ifconfig compatible
is desired.

At some point in the future, the behavior could then be changed to 
reject such labels.

What do you think?

---
Joe

Re: [PATCH] iproute2: enhance addr label validation

[Joe Harvell]

>
>> Hi Joe,
>>
>> On Sat, Mar 21, 2015 at 03:14:53PM -0500, Joe Harvell wrote:
>>> The ip addr command today rejects address labels that would break
>>> ifconfig.  However, it allows some labels which still break it. Enhance
>>> enforcement to reject all known incompatible labels, and allow the
>>> existing -force option to allow someone to use a label even if it is 
>>> not
>>> ifconfig compatible
>> I am concerned this will break existing users who are relying on setting
>> labels that would now be rejected without using -force.
>>
> [snip]
>
> Simon,
>
> Good point.  I propose the following:
>
> When a label is specified without -force, and that label begins with 
> the interface
> name but is followed by something other than a colon, accept the label 
> but emit
> a warning message indicating this label is incompatible with ifconfig 
> and that later
> versions of the 'ip address' command may reject it.  This message can 
> also indicate
> that -force can be specified to explicitly indicate a label that is 
> non ifconfig compatible
> is desired.
>
> At some point in the future, the behavior could then be changed to 
> reject such labels.
>
> What do you think?
>
> ---
> Joe
Ok, I made the changes I propose above, and have pushed them to 
'git@github.com:jharvell/iproute2.git addr-label-noncompat'
with a new signoff commit (303f46819883d4c808974629a6d3515102c5c0d0) 
that summarizes all the changes from master.
But I'm not sure what I'm supposed to do with respect to the patch in 
patchwork to designate that I want the new code
to be merged instead of before the change.  Do I reject this patch 
request and submit another one?  Do I send an email
with the same subject as this one with the new patch against master?

Thanks.
---
Joe

Re: [PATCH] iproute2: enhance addr label validation

[Simon Horman]

Hi Joe,

On Mon, Mar 23, 2015 at 10:43:03AM -0500, Joe Harvell wrote:
> >
> >>Hi Joe,
> >>
> >>On Sat, Mar 21, 2015 at 03:14:53PM -0500, Joe Harvell wrote:
> >>>The ip addr command today rejects address labels that would break
> >>>ifconfig.  However, it allows some labels which still break it. Enhance
> >>>enforcement to reject all known incompatible labels, and allow the
> >>>existing -force option to allow someone to use a label even if it is
> >>>not
> >>>ifconfig compatible
> >>I am concerned this will break existing users who are relying on setting
> >>labels that would now be rejected without using -force.
> >>
> >[snip]
> >
> >Simon,
> >
> >Good point.  I propose the following:
> >
> >When a label is specified without -force, and that label begins with the
> >interface
> >name but is followed by something other than a colon, accept the label but
> >emit
> >a warning message indicating this label is incompatible with ifconfig and
> >that later
> >versions of the 'ip address' command may reject it.  This message can also
> >indicate
> >that -force can be specified to explicitly indicate a label that is non
> >ifconfig compatible
> >is desired.
> >
> >At some point in the future, the behavior could then be changed to reject
> >such labels.
> >
> >What do you think?
> >
> >---
> >Joe
>
> Ok, I made the changes I propose above, and have pushed them to
> 'git@github.com:jharvell/iproute2.git addr-label-noncompat' with a new
> signoff commit (303f46819883d4c808974629a6d3515102c5c0d0) that summarizes
> all the changes from master.  But I'm not sure what I'm supposed to do
> with respect to the patch in patchwork to designate that I want the new
> code to be merged instead of before the change.  Do I reject this patch
> request and submit another one?  Do I send an email with the same subject
> as this one with the new patch against master?

To some extent this is up to Stephen, who is the maintainer.
But I expect the following should be close to the mark:

1. If you new patch has the same title as the previous patch then
   you can post it as [PATCH v2] and it should be fairly clear that
   it supersedes the previous version.

2. If you new patch has a different title then there could be a note
  in response to it noting that it has been superseded. In effect your
  previous email is such a note.

Re: [PATCH] iproute2: enhance addr label validation

[Simon Horman]

Hi Joe,

On Mon, Mar 23, 2015 at 09:02:47AM -0500, Joe Harvell wrote:
> >Hi Joe,
> >
> >On Sat, Mar 21, 2015 at 03:14:53PM -0500, Joe Harvell wrote:
> >>The ip addr command today rejects address labels that would break
> >>ifconfig.  However, it allows some labels which still break it. Enhance
> >>enforcement to reject all known incompatible labels, and allow the
> >>existing -force option to allow someone to use a label even if it is not
> >>ifconfig compatible
> >I am concerned this will break existing users who are relying on setting
> >labels that would now be rejected without using -force.
> >
> [snip]
> 
> Simon,
> 
> Good point.  I propose the following:
> 
> When a label is specified without -force, and that label begins with the
> interface name but is followed by something other than a colon, accept
> the label but emit a warning message indicating this label is
> incompatible with ifconfig and that later versions of the 'ip address'
> command may reject it.  This message can also indicate that -force can be
> specified to explicitly indicate a label that is non ifconfig compatible
> is desired.
> 
> At some point in the future, the behavior could then be changed to reject
> such labels.
> 
> What do you think?

That sounds entirely reasonable to me.

[PATCH] iproute2: enhance addr label validation

[Joe Harvell]

The ip addr command today rejects address labels that would break 
ifconfig.  However, it allows some labels which still break it. Enhance
enforcement to reject all known incompatible labels, and allow the
existing -force option to allow someone to use a label even if it is not 
ifconfig compatible

Make existing -force option of ip addr add skip enforcement of ifconfig
compatible address labels.
Change enforcement to properly reject labels that do begin with 
<devname> but are followed by a string that does not begin with colon.

The following changes since commit 4612d04d6b8f07274bd5d0688f717ccc189499ad:

   tc class: Show class names from file (2015-03-15 12:27:40 -0700)

are available in the git repository at:

   git@github.com:jharvell/iproute2.git addr-label-noncompat

for you to fetch changes up to 44931a448ac2b375c703cb79fb814ec575fe253b:

   Signed-off-by: Joe Harvell <joe.harvell@tekcomms.com> (2015-03-21 
14:45:36 -0500)

----------------------------------------------------------------
Joe Harvell (6):
       Making -force option of ip command also allow address labels that 
are not     backward-compatible with ifconfig.  Note that even without 
this change     the ip command does allow some incompatible address 
labels to be created.     ifconfig depends on the labels beginning with 
<interface-name><colon>, but     the ip command (even before the changes 
in this commit) only requires the     prefix of the label to be 
<interface-name>.  Thus, if you add a label such     as eth0-media, it 
will be accepted by ip but ifconfig will barf on ifconfig -a.     The 
motivation for this change is that the lenght allowed for a lable is 
small,     so requiring a long prefix for ifconfig backwards 
compatibility limits the     usefulness of the label.  For embedded 
systems (or any system) where ifconfig     is not even installed, it is 
useful to be able to create longer labels.
       Enhancing enforcement of ifconfig compatible label.     Prior 
implementation allowed incompatible labels that started with dev but not 
dev:
       Adding parentheses for clarity     Removing code comment since it 
is now clearly spelled out in fprintf error message
       Using strncmp instead of matches for clarity and to avoid extra 
strlen calls
       Fixed indenting by replacing spaces with tabs     Minor re-word 
of man page text
       Signed-off-by: Joe Harvell <joe.harvell@tekcomms.com>

  include/utils.h |  1 +
  ip/ip.c         |  2 ++
  ip/ipaddress.c  | 12 +++++++++---
  man/man8/ip.8   |  2 ++
  4 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/include/utils.h b/include/utils.h
index 9151c4f..e8a5467 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -25,6 +25,7 @@ extern char * _SL_;
  extern int max_flush_loops;
  extern int batch_mode;
  extern bool do_all;
+extern bool require_ifconfig_compat;

  #ifndef IPPROTO_ESP
  #define IPPROTO_ESP    50
diff --git a/ip/ip.c b/ip/ip.c
index da16b15..78b0197 100644
--- a/ip/ip.c
+++ b/ip/ip.c
@@ -37,6 +37,7 @@ int force = 0;
  int max_flush_loops = 10;
  int batch_mode = 0;
  bool do_all = false;
+bool require_ifconfig_compat = true;

  struct rtnl_handle rth = { .fd = -1 };

@@ -246,6 +247,7 @@ int main(int argc, char **argv)
                         exit(0);
                 } else if (matches(opt, "-force") == 0) {
                         ++force;
+                       require_ifconfig_compat = false;
                 } else if (matches(opt, "-batch") == 0) {
                         argc--;
                         argv++;
diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index 99a6ab5..be027c6 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -1691,11 +1691,17 @@ static int ipaddr_modify(int cmd, int flags, int 
argc, char **argv)
                 fprintf(stderr, "Not enough information: \"dev\" 
argument is required.\n");
                 return -1;
         }
-       if (l && matches(d, l) != 0) {
-               fprintf(stderr, "\"dev\" (%s) must match \"label\" 
(%s).\n", d, l);
+       if ( require_ifconfig_compat && l) {
+               bool isCompat = false;
+               size_t dLen = strlen(d);
+               size_t lLen = strlen(l);
+               if(lLen >= dLen && strncmp(d, l, dLen) == 0)
+                       isCompat =  (dLen == lLen || l[dLen] == ':');
+               if( !isCompat ) {
+                       fprintf(stderr, "\"label\" (%s) must either be 
\"dev\" (%s) or start with \"dev\" followed by a colon (%s:).\n", l, d, d);
                 return -1;
+               }
         }
-
         if (peer_len == 0 && local_len) {
                 if (cmd == RTM_DELADDR && lcl.family == AF_INET && 
!(lcl.flags & PREFIXLEN_SPECIFIED)) {
                         fprintf(stderr,
diff --git a/man/man8/ip.8 b/man/man8/ip.8
index 016e8c6..f58241f 100644
--- a/man/man8/ip.8
+++ b/man/man8/ip.8
@@ -54,6 +54,8 @@ First failure will cause termination of ip.
  Don't terminate ip on errors in batch mode.
  If there were any errors during execution of the commands, the 
application return code will be non zero.

+This option also allows creation of address labels that may not be 
compatible with ifconfig.
+
  .TP
  .BR "\-s" , " \-stats" , " \-statistics"
  Output more information.  If the option