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[iproute2-next,v2,2/2] iproute2: add 'ip monitor mcaddr' support

Message ID 20241121055615.826882-2-yuyanghuang@google.com (mailing list archive)
State New
Delegated to: David Ahern
Headers show
Series [iproute2-next,v2,1/2] iproute2: expose netlink constants in UAPI | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Yuyang Huang Nov. 21, 2024, 5:56 a.m. UTC
Enhanced the 'ip monitor' command to track changes in IPv4 and IPv6
multicast addresses. This update allows the command to listen for
events related to multicast address additions and deletions by
registering to the newly introduced RTNLGRP_IPV4_MCADDR and
RTNLGRP_IPV6_MCADDR netlink groups.

This patch depends on the kernel patch that adds RTNLGRP_IPV4_MCADDR
and RTNLGRP_IPV6_MCADDR being merged first.

Here is an example usage:

root@uml-x86-64:/# ip monitor mcaddr
8: nettest123    inet6 mcast ff01::1 scope global
8: nettest123    inet6 mcast ff02::1 scope global
8: nettest123    inet mcast 224.0.0.1 scope global
8: nettest123    inet6 mcast ff02::1:ff00:7b01 scope global
Deleted 8: nettest123    inet mcast 224.0.0.1 scope global
Deleted 8: nettest123    inet6 mcast ff02::1:ff00:7b01 scope global
Deleted 8: nettest123    inet6 mcast ff02::1 scope global

Cc: Maciej Żenczykowski <maze@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Yuyang Huang <yuyanghuang@google.com>
---

Changelog since v1:
- Move the UAPI constants to a separate patch.
- Update the commit message.
- Fix the indentation format.

 ip/ipaddress.c | 17 +++++++++++++++--
 ip/ipmonitor.c | 25 ++++++++++++++++++++++++-
 2 files changed, 39 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index d90ba94d..373f613f 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -1504,7 +1504,10 @@  int print_addrinfo(struct nlmsghdr *n, void *arg)
 
 	SPRINT_BUF(b1);
 
-	if (n->nlmsg_type != RTM_NEWADDR && n->nlmsg_type != RTM_DELADDR)
+	if (n->nlmsg_type != RTM_NEWADDR
+	    && n->nlmsg_type != RTM_DELADDR
+	    && n->nlmsg_type != RTM_NEWMULTICAST
+	    && n->nlmsg_type != RTM_DELMULTICAST)
 		return 0;
 	len -= NLMSG_LENGTH(sizeof(*ifa));
 	if (len < 0) {
@@ -1564,7 +1567,7 @@  int print_addrinfo(struct nlmsghdr *n, void *arg)
 
 	print_headers(fp, "[ADDR]");
 
-	if (n->nlmsg_type == RTM_DELADDR)
+	if (n->nlmsg_type == RTM_DELADDR || n->nlmsg_type == RTM_DELMULTICAST)
 		print_bool(PRINT_ANY, "deleted", "Deleted ", true);
 
 	if (!brief) {
@@ -1639,6 +1642,16 @@  int print_addrinfo(struct nlmsghdr *n, void *arg)
 						   rta_tb[IFA_ANYCAST]));
 	}
 
+	if (rta_tb[IFA_MULTICAST]) {
+		print_string(PRINT_FP, NULL, "%s ", "mcast");
+		print_color_string(PRINT_ANY,
+				   ifa_family_color(ifa->ifa_family),
+				   "multicast",
+				   "%s ",
+				   format_host_rta(ifa->ifa_family,
+						   rta_tb[IFA_MULTICAST]));
+	}
+
 	print_string(PRINT_ANY,
 		     "scope",
 		     "scope %s ",
diff --git a/ip/ipmonitor.c b/ip/ipmonitor.c
index de67f2c9..4743b3e1 100644
--- a/ip/ipmonitor.c
+++ b/ip/ipmonitor.c
@@ -30,7 +30,7 @@  static void usage(void)
 	fprintf(stderr,
 		"Usage: ip monitor [ all | OBJECTS ] [ FILE ] [ label ] [ all-nsid ]\n"
 		"                  [ dev DEVICE ]\n"
-		"OBJECTS :=  address | link | mroute | neigh | netconf |\n"
+		"OBJECTS :=  address | link | mroute | mcaddr | neigh | netconf |\n"
 		"            nexthop | nsid | prefix | route | rule | stats\n"
 		"FILE := file FILENAME\n");
 	exit(-1);
@@ -152,6 +152,11 @@  static int accept_msg(struct rtnl_ctrl_data *ctrl,
 		ipstats_print(n, arg);
 		return 0;
 
+	case RTM_DELMULTICAST:
+	case RTM_NEWMULTICAST:
+		print_addrinfo(n, arg);
+		return 0;
+
 	case NLMSG_ERROR:
 	case NLMSG_NOOP:
 	case NLMSG_DONE:
@@ -178,6 +183,7 @@  static int accept_msg(struct rtnl_ctrl_data *ctrl,
 #define IPMON_LRULE		BIT(8)
 #define IPMON_LNSID		BIT(9)
 #define IPMON_LNEXTHOP		BIT(10)
+#define IPMON_LMCADDR		BIT(11)
 
 #define IPMON_L_ALL		(~0)
 
@@ -220,6 +226,8 @@  int do_ipmonitor(int argc, char **argv)
 			lmask |= IPMON_LNEXTHOP;
 		} else if (strcmp(*argv, "stats") == 0) {
 			lmask |= IPMON_LSTATS;
+		} else if (strcmp(*argv, "mcaddr") == 0) {
+			lmask |= IPMON_LMCADDR;
 		} else if (strcmp(*argv, "all") == 0) {
 			prefix_banner = 1;
 		} else if (matches(*argv, "all-nsid") == 0) {
@@ -326,6 +334,21 @@  int do_ipmonitor(int argc, char **argv)
 		exit(1);
 	}
 
+	if (lmask & IPMON_LMCADDR) {
+		if ((!preferred_family || preferred_family == AF_INET) &&
+		    rtnl_add_nl_group(&rth, RTNLGRP_IPV4_MCADDR) < 0) {
+			fprintf(stderr,
+				"Failed to add ipv4 mcaddr group to list\n");
+			exit(1);
+		}
+		if ((!preferred_family || preferred_family == AF_INET6) &&
+		    rtnl_add_nl_group(&rth, RTNLGRP_IPV6_MCADDR) < 0) {
+			fprintf(stderr,
+				"Failed to add ipv6 mcaddr group to list\n");
+			exit(1);
+		}
+	}
+
 	if (listen_all_nsid && rtnl_listen_all_nsid(&rth) < 0)
 		exit(1);