xfrmmonitor: allows to monitor in several netns

With this patch, it's now possible to listen in all netns that have an nsid
assigned into the netns where is socket is opened.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>

ip/xfrm_monitor.c

@@ -35,10 +35,11 @@
 #include "ip_common.h"
 
 static void usage(void) __attribute__((noreturn));
+int listen_all_nsid;
 
 static void usage(void)
 {
-	fprintf(stderr, "Usage: ip xfrm monitor [ all | OBJECTS | help ]\n");
+	fprintf(stderr, "Usage: ip xfrm monitor [all-nsid] [ all | OBJECTS | help ]\n");
 	fprintf(stderr, "OBJECTS := { acquire | expire | SA | aevent | policy | report }\n");
 	exit(-1);
 }
@@ -298,6 +299,13 @@ static int xfrm_accept_msg(const struct sockaddr_nl *who,
 	if (timestamp)
 		print_timestamp(fp);
 
+	if (listen_all_nsid) {
+		if (ctrl == NULL || ctrl->nsid < 0)
+			fprintf(fp, "[nsid current]");
+		else
+			fprintf(fp, "[nsid %d]", ctrl->nsid);
+	}
+
 	switch (n->nlmsg_type) {
 	case XFRM_MSG_NEWSA:
 	case XFRM_MSG_DELSA:
@@ -360,6 +368,8 @@ int do_xfrm_monitor(int argc, char **argv)
 		if (matches(*argv, "file") == 0) {
 			NEXT_ARG();
 			file = *argv;
+		} else if (matches(*argv, "all-nsid") == 0) {
+			listen_all_nsid = 1;
 		} else if (matches(*argv, "acquire") == 0) {
 			lacquire=1;
 			groups = 0;
@@ -412,6 +422,8 @@ int do_xfrm_monitor(int argc, char **argv)
 
 	if (rtnl_open_byproto(&rth, groups, NETLINK_XFRM) < 0)
 		exit(1);
+	if (listen_all_nsid && rtnl_listen_all_nsid(&rth) < 0)
+		exit(1);
 
 	if (rtnl_listen(&rth, xfrm_accept_msg, (void*)stdout) < 0)
 		exit(2);

man/man8/ip-xfrm.8

@@ -364,7 +364,11 @@ ip-xfrm \- transform configuration
 .BR required " | " use
 
 .ti -8
-.BR "ip xfrm monitor" " [ " all " |"
+.BR "ip xfrm monitor" " ["
+.BI all-nsid
+] [
+.BI all
+ |
 .IR LISTofXFRM-OBJECTS " ]"
 
 .ti -8
@@ -669,7 +673,22 @@ ip xfrm monitor 	state monitoring for xfrm objects
 .PP
 The xfrm objects to monitor can be optionally specified.
 
+.P
+If the
+.BI all-nsid
+option is set, the program listens to all network namespaces that have a
+nsid assigned into the network namespace were the program is running.
+A prefix is displayed to show the network namespace where the message
+originates. Example:
+.sp
+.in +2
+[nsid 1]Flushed state proto 0
+.in -2
+.sp
+
 .SH AUTHOR
 Manpage revised by David Ward <david.ward@ll.mit.edu>
 .br
 Manpage revised by Christophe Gouault <christophe.gouault@6wind.com>
+.br
+Manpage revised by Nicolas Dichtel <nicolas.dichtel@6wind.com>