ip: mpls: fix printing of mpls labels
Subsystems (3)
PATCH 1/1 ip: mpls: fix printing of mpls labels
If the kernel returns more labels than iproute2 expects, none of the labels are printed and (null) is shown instead:
$ ip -f mpls ro ls
101 as to (null) via inet 172.16.2.2 dev virt12
201 as to 202/203 via inet6 2001:db8:2::2 dev virt12Remove the use of MPLS_MAX_LABELS and rely on buffer length that is passed to mpls_ntop. With this change ip can print the label stack returned by the kernel up to 255 characters (limit is due to size of buf passed in) which amounts to 31 labels with a separator.
With this change the above is:
$ ip/ip -f mpls ro ls
101 as to 102/103/104/105/106/107/108/109/110 via inet 172.16.2.2 dev virt12--- lib/mpls_ntop.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
lib/mpls_ntop.c +6 -4
@@ -10,18 +10,20 @@ static const char *mpls_ntop1(const struct mpls_label *addr, char *buf, size_t b {size_t destlen = buflen;char *dest = buf; -int count; +int count =0 ; -for (count =0 ; count <MPLS_MAX_LABELS ; count++) { -uint32_t entry =ntohl (addr[count].entry); +while (1 ) { +uint32_t entry =ntohl (addr[count++].entry);uint32_t label = (entry &MPLS_LS_LABEL_MASK ) >>MPLS_LS_LABEL_SHIFT ;int len =snprintf (dest, destlen,"%u" , label); +if (len >= destlen) +break ; +/* Is this the end? */ if (entry &MPLS_LS_S_MASK )return buf; - dest += len; destlen -= len;if (destlen) {
Signature · 1 line
2.11.0 (Apple Git-81)
Quoted 11 lines · David Ahern
If the kernel returns more labels than iproute2 expects, none of the labels are printed and (null) is shown instead:
$ ip -f mpls ro ls 101 as to (null) via inet 172.16.2.2 dev virt12 201 as to 202/203 via inet6 2001:db8:2::2 dev virt12Remove the use of
MPLS_MAX_LABELSand rely on buffer length that is passed tompls_ntop. With this change ip can print the label stack returned by the kernel up to 255 characters (limit is due to size of buf passed in) which amounts to 31 labels with a separator.
Quoted 5 lines
With this change the above is:
$ ip/ip -f mpls ro ls 101 as to 102/103/104/105/106/107/108/109/110 via inet 172.16.2.2 dev virt12Signed-off-by David Ahern <[email protected]>
Quoted 11 lines · On Mon, 8 May 2017 23:04:13 -0700 David Ahern <[email protected]> wrote:
If the kernel returns more labels than iproute2 expects, none of the labels are printed and (null) is shown instead:
$ ip -f mpls ro ls 101 as to (null) via inet 172.16.2.2 dev virt12 201 as to 202/203 via inet6 2001:db8:2::2 dev virt12Remove the use of
MPLS_MAX_LABELSand rely on buffer length that is passed tompls_ntop. With this change ip can print the label stack returned by the kernel up to 255 characters (limit is due to size of buf passed in) which amounts to 31 labels with a separator.
Quoted 5 lines
With this change the above is:
$ ip/ip -f mpls ro ls 101 as to 102/103/104/105/106/107/108/109/110 via inet 172.16.2.2 dev virt12Signed-off-by David Ahern <[email protected]>
Much better. Applied thanks.
Quoted 14 lines · Stephen Hemminger
Quoted 11 lines · On Mon, 8 May 2017 23:04:13 -0700 David Ahern <[email protected]> wrote:
If the kernel returns more labels than iproute2 expects, none of the labels are printed and (null) is shown instead:
$ ip -f mpls ro ls 101 as to (null) via inet 172.16.2.2 dev virt12 201 as to 202/203 via inet6 2001:db8:2::2 dev virt12Remove the use of
MPLS_MAX_LABELSand rely on buffer length that is passed tompls_ntop. With this change ip can print the label stack returned by the kernel up to 255 characters (limit is due to size of buf passed in) which amounts to 31 labels with a separator.
Quoted 8 lines
Quoted 5 lines
With this change the above is:
$ ip/ip -f mpls ro ls 101 as to 102/103/104/105/106/107/108/109/110 via inet 172.16.2.2 dev virt12Signed-off-by David Ahern <[email protected]>Much better. Applied thanks.
This is only one-half of the solution; the install side is harder. I'll send something in the next few days.