ss: Show stats from specified network namespace

Added new '-N NSNAME, --net=NSNAME' option to show socket stats
from the specified network namespace name.
Signed-off-by: Vadim Kochan <vadim4j@gmail.com>

man/man8/ss.8

@@ -84,6 +84,9 @@ context of the creating process, however the context shown will reflect
 any policy role, type and/or range transition rules applied,
 and is therefore a useful reference.
 .TP
+.B \-N NSNAME, \-\-net=NSNAME
+Switch to the specified network namespace name.
+.TP
 .B \-b, \-\-bpf
 Show socket BPF filters (only administrators are allowed to get these information).
 .TP

misc/Makefile

@@ -10,6 +10,10 @@ ifeq ($(HAVE_SELINUX),y)
 	CFLAGS += $(shell pkg-config --cflags libselinux) -DHAVE_SELINUX
 endif
 
+ifeq ($(IP_CONFIG_SETNS),y)
+	CFLAGS += -DHAVE_SETNS
+endif
+
 all: $(TARGETS)
 
 ss: $(SSOBJ)

misc/ss.c

@@ -31,6 +31,7 @@
 #include "rt_names.h"
 #include "ll_map.h"
 #include "libnetlink.h"
+#include "namespace.h"
 #include "SNAPSHOT.h"
 
 #include <linux/tcp.h>
@@ -3246,6 +3247,7 @@ static void _usage(FILE *dest)
 "   -b, --bpf           show bpf filter socket information\n"
 "   -Z, --context       display process SELinux security contexts\n"
 "   -z, --contexts      display process and socket SELinux security contexts\n"
+"   -N, --net           switch to the specified network namespace name\n"
 "\n"
 "   -4, --ipv4          display only IP version 4 sockets\n"
 "   -6, --ipv6          display only IP version 6 sockets\n"
@@ -3345,6 +3347,7 @@ static const struct option long_opts[] = {
 	{ "help", 0, 0, 'h' },
 	{ "context", 0, 0, 'Z' },
 	{ "contexts", 0, 0, 'z' },
+	{ "net", 1, 0, 'N' },
 	{ 0 }
 
 };
@@ -3360,7 +3363,7 @@ int main(int argc, char *argv[])
 	struct filter dbs_filter = {};
 	int state_filter = 0;
 
-	while ((ch = getopt_long(argc, argv, "dhaletuwxnro460spbf:miA:D:F:vVzZ",
+	while ((ch = getopt_long(argc, argv, "dhaletuwxnro460spbf:miA:D:F:vVzZN:",
 				 long_opts, NULL)) != EOF) {
 		switch(ch) {
 		case 'n':
@@ -3532,6 +3535,10 @@ int main(int argc, char *argv[])
 			show_proc_ctx++;
 			user_ent_hash_build();
 			break;
+		case 'N':
+			if (netns_switch(optarg))
+				exit(1);
+			break;
 		case 'h':
 		case '?':
 			help();