From: Roopa Prabhu <ro...@cumulusnetworks.com>
This patch adds support to lookup a neigh entry
using recently added support in the kernel using RTM_GETNEIGH
example:
$ip neigh get 10.0.2.4 dev test-dummy0
10.0.2.4 dev test-dummy0 lladdr de:ad:be:ef:13:37 PERMANENT
Signed-off-by: Roopa Prabhu <ro...@cumulusnetworks.com>
---
ip/ipneigh.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++---
man/man8/ip-neighbour.8 | 29 +++++++++++++++++
2 files changed, 109 insertions(+), 4 deletions(-)
diff --git a/ip/ipneigh.c b/ip/ipneigh.c
index a3869c8..c88c346 100644
--- a/ip/ipneigh.c
+++ b/ip/ipneigh.c
@@ -55,6 +55,7 @@ static void usage(void)
"\n"
" ip neigh { show | flush } [ proxy ] [ to PREFIX ] [ dev
DEV ] [ nud STATE ]\n"
" [ vrf NAME ]\n"
+ " ip neigh get { ADDR | proxy ADDR } dev DEV\n"
"\n"
"STATE := { permanent | noarp | stale | reachable | none |\n"
" incomplete | delay | probe | failed }\n");
@@ -599,6 +600,83 @@ static int do_show_or_flush(int argc, char **argv, int
flush)
return 0;
}
+static int ipneigh_get(int argc, char **argv)
+{
+ struct {
+ struct nlmsghdr n;
+ struct ndmsg ndm;
+ char buf[1024];
+ } req = {
+ .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg)),
+ .n.nlmsg_flags = NLM_F_REQUEST,
+ .n.nlmsg_type = RTM_GETNEIGH,
+ .ndm.ndm_family = preferred_family,
+ };
+ struct nlmsghdr *answer;
+ char *d = NULL;
+ int dst_ok = 0;
+ int dev_ok = 0;
+ inet_prefix dst;
+
+ while (argc > 0) {
+ if (strcmp(*argv, "dev") == 0) {
+ NEXT_ARG();
+ d = *argv;
+ dev_ok = 1;
+ } else if (matches(*argv, "proxy") == 0) {
+ NEXT_ARG();
+ if (matches(*argv, "help") == 0)
+ usage();
+ if (dst_ok)
+ duparg("address", *argv);
+ get_addr(&dst, *argv, preferred_family);
+ dst_ok = 1;
+ dev_ok = 1;
+ req.ndm.ndm_flags |= NTF_PROXY;
+ } else {
+ if (strcmp(*argv, "to") == 0)
+ NEXT_ARG();
+
+ if (matches(*argv, "help") == 0)
+ usage();
+ if (dst_ok)
+ duparg2("to", *argv);
+ get_addr(&dst, *argv, preferred_family);
+ dst_ok = 1;
+ }
+ argc--; argv++;
+ }
+
+ if (!dev_ok || !dst_ok || dst.family == AF_UNSPEC) {
+ fprintf(stderr, "Device and address are required arguments.\n");
+ return -1;
+ }
+
+ req.ndm.ndm_family = dst.family;
+ if (addattr_l(&req.n, sizeof(req), NDA_DST, &dst.data, dst.bytelen) < 0)
+ return -1;
+
+ if (d) {
+ ll_init_map(&rth);
+ req.ndm.ndm_ifindex = ll_name_to_index(d);
+ if (!req.ndm.ndm_ifindex) {
+ fprintf(stderr, "Cannot find device \"%s\"\n", d);
+ return -1;
+ }
+ }
+
+ if (rtnl_talk(&rth, &req.n, &answer) < 0)
+ return -2;
+
+ ipneigh_reset_filter(0);
+ if (print_neigh(answer, (void *)stdout) < 0) {
+ fprintf(stderr, "An error :-)\n");
+ return -1;
+ }
+
+ return 0;
+}
+
int do_ipneigh(int argc, char **argv)
{
if (argc > 0) {
@@ -611,10 +689,8 @@ int do_ipneigh(int argc, char **argv)
return ipneigh_modify(RTM_NEWNEIGH,
NLM_F_CREATE|NLM_F_REPLACE, argc-1, argv+1);
if (matches(*argv, "delete") == 0)
return ipneigh_modify(RTM_DELNEIGH, 0, argc-1, argv+1);
- if (matches(*argv, "get") == 0) {
- fprintf(stderr, "Sorry, \"neigh get\" is not
implemented :-(\n");
- return -1;
- }
+ if (matches(*argv, "get") == 0)
+ return ipneigh_get(argc-1, argv+1);
if (matches(*argv, "show") == 0 ||
matches(*argv, "lst") == 0 ||
matches(*argv, "list") == 0)
diff --git a/man/man8/ip-neighbour.8 b/man/man8/ip-neighbour.8
index 4a672bb..bc77b43 100644
--- a/man/man8/ip-neighbour.8
+++ b/man/man8/ip-neighbour.8
@@ -38,6 +38,12 @@ ip-neighbour \- neighbour/arp tables management.
.IR NAME " ] "
.ti -8
+.B ip neigh get
+.IR ADDR
+.B dev
+.IR DEV
+
+.ti -8
.IR STATE " := {"
.BR permanent " | " noarp " | " stale " | " reachable " | " none " |"
.BR incomplete " | " delay " | " probe " | " failed " }"
@@ -231,6 +237,23 @@ twice,
also dumps all the deleted neighbours.
.RE
+.TP
+ip neigh get
+lookup a neighbour entry to a destination given a device
+.RS
+
+.TP
+.BI proxy
+indicates whether we should lookup a proxy neigbour entry
+
+.TP
+.BI to " ADDRESS " (default)
+the prefix selecting the neighbour to query.
+
+.TP
+.BI dev " NAME"
+get neighbour entry attached to this device.
+
.SH EXAMPLES
.PP
ip neighbour
@@ -242,6 +265,12 @@ ip neigh flush dev eth0
.RS
Removes entries in the neighbour table on device eth0.
.RE
+.PP
+ip neigh get 10.0.1.10 dev eth0
+.RS
+Performs a neighbour lookup in the kernel and returns
+a neighbour entry.
+.RE
.SH SEE ALSO
.br
--
2.1.4
