[patch iproute2-next v2 1/2] ip: add support for alternative name addition/deletion/list

[Jiri Pirko <jiri@resnulli.us>]

From: Jiri Pirko <jiri@mellanox.com>

Implement addition/deletion of lists of properties, currently
alternative ifnames. Also extent the ip link show command to list them.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
---
v1->v2:
- s/\"NULL\"/NULL/ in print_string arg
rfc->v1:
- convert to generic property lists
- added patch description
- use ll_name_to_index() and ifindex as handle
- fixed parsing with nested flag on
- adjusted output
- added arg name to check_altifname header prototype
- added help and man parts
---
 include/uapi/linux/if_link.h   |  2 +
 include/uapi/linux/rtnetlink.h |  7 +++
 include/utils.h                |  1 +
 ip/ipaddress.c                 | 20 ++++++++-
 ip/iplink.c                    | 82 +++++++++++++++++++++++++++++++++-
 lib/utils.c                    | 19 +++++---
 man/man8/ip-link.8.in          | 11 +++++
 7 files changed, 134 insertions(+), 8 deletions(-)

diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index d36919fb4024..1c49f436424d 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -167,6 +167,8 @@ enum {
 	IFLA_NEW_IFINDEX,
 	IFLA_MIN_MTU,
 	IFLA_MAX_MTU,
+	IFLA_PROP_LIST,
+	IFLA_ALT_IFNAME, /* Alternative ifname */
 	__IFLA_MAX
 };
 
diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 358e83ee134d..4b93791cdbd4 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -164,6 +164,13 @@ enum {
 	RTM_GETNEXTHOP,
 #define RTM_GETNEXTHOP	RTM_GETNEXTHOP
 
+	RTM_NEWLINKPROP = 108,
+#define RTM_NEWLINKPROP	RTM_NEWLINKPROP
+	RTM_DELLINKPROP,
+#define RTM_DELLINKPROP	RTM_DELLINKPROP
+	RTM_GETLINKPROP,
+#define RTM_GETLINKPROP	RTM_GETLINKPROP
+
 	__RTM_MAX,
 #define RTM_MAX		(((__RTM_MAX + 3) & ~3) - 1)
 };
diff --git a/include/utils.h b/include/utils.h
index 794d36053634..001491a1eb40 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -196,6 +196,7 @@ void duparg(const char *, const char *) __attribute__((noreturn));
 void duparg2(const char *, const char *) __attribute__((noreturn));
 int nodev(const char *dev);
 int check_ifname(const char *);
+int check_altifname(const char *name);
 int get_ifname(char *, const char *);
 const char *get_ifname_rta(int ifindex, const struct rtattr *rta);
 bool matches(const char *prefix, const char *string);
diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index bc8f5ba13c33..b72eb7a1f808 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -879,7 +879,7 @@ int print_linkinfo(struct nlmsghdr *n, void *arg)
 	if (filter.up && !(ifi->ifi_flags&IFF_UP))
 		return -1;
 
-	parse_rtattr(tb, IFLA_MAX, IFLA_RTA(ifi), len);
+	parse_rtattr_flags(tb, IFLA_MAX, IFLA_RTA(ifi), len, NLA_F_NESTED);
 
 	name = get_ifname_rta(ifi->ifi_index, tb[IFLA_IFNAME]);
 	if (!name)
@@ -1139,7 +1139,23 @@ int print_linkinfo(struct nlmsghdr *n, void *arg)
 		close_json_array(PRINT_JSON, NULL);
 	}
 
-	print_string(PRINT_FP, NULL, "%s", "\n");
+	if (tb[IFLA_PROP_LIST]) {
+		struct rtattr *i, *proplist = tb[IFLA_PROP_LIST];
+		int rem = RTA_PAYLOAD(proplist);
+
+		open_json_array(PRINT_JSON, "altnames");
+		for (i = RTA_DATA(proplist); RTA_OK(i, rem);
+		     i = RTA_NEXT(i, rem)) {
+			if (i->rta_type != IFLA_ALT_IFNAME)
+				continue;
+			print_string(PRINT_FP, NULL, "%s    altname ", _SL_);
+			print_string(PRINT_ANY, NULL,
+				     "%s", rta_getattr_str(i));
+		}
+		close_json_array(PRINT_JSON, NULL);
+	}
+
+	print_string(PRINT_FP, NULL, "%s", _SL_);
 	fflush(fp);
 	return 1;
 }
diff --git a/ip/iplink.c b/ip/iplink.c
index 212a088535da..e3f8a28fe94c 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -111,7 +111,9 @@ void iplink_usage(void)
 		"\n"
 		"	ip link xstats type TYPE [ ARGS ]\n"
 		"\n"
-		"	ip link afstats [ dev DEVICE ]\n");
+		"	ip link afstats [ dev DEVICE ]\n"
+		"	ip link prop add dev DEVICE [ altname NAME .. ]\n"
+		"	ip link prop del dev DEVICE [ altname NAME .. ]\n");
 
 	if (iplink_have_newlink()) {
 		fprintf(stderr,
@@ -1617,6 +1619,81 @@ static int iplink_afstats(int argc, char **argv)
 	return 0;
 }
 
+static int iplink_prop_mod(int argc, char **argv, struct iplink_req *req)
+{
+	struct rtattr *proplist;
+	char *dev = NULL;
+	char *name;
+
+	proplist = addattr_nest(&req->n, sizeof(*req),
+				IFLA_PROP_LIST | NLA_F_NESTED);
+
+	while (argc > 0) {
+		if (matches(*argv, "altname") == 0) {
+			NEXT_ARG();
+			if (check_altifname(*argv))
+				invarg("not a valid altname", *argv);
+			name = *argv;
+			addattr_l(&req->n, sizeof(*req), IFLA_ALT_IFNAME,
+				  name, strlen(name) + 1);
+		} else if (matches(*argv, "help") == 0) {
+			usage();
+		} else {
+			if (strcmp(*argv, "dev") == 0)
+				NEXT_ARG();
+			if (dev)
+				duparg2("dev", *argv);
+			if (check_altifname(*argv))
+				invarg("\"dev\" not a valid ifname", *argv);
+			dev = *argv;
+		}
+		argv++; argc--;
+	}
+	addattr_nest_end(&req->n, proplist);
+
+	if (!dev) {
+		fprintf(stderr, "Not enough of information: \"dev\" argument is required.\n");
+		exit(-1);
+	}
+
+	req->i.ifi_index = ll_name_to_index(dev);
+	if (!req->i.ifi_index)
+		return nodev(dev);
+
+	if (rtnl_talk(&rth, &req->n, NULL) < 0)
+		return -2;
+
+	return 0;
+}
+
+static int iplink_prop(int argc, char **argv)
+{
+	struct iplink_req req = {
+		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
+		.n.nlmsg_flags = NLM_F_REQUEST,
+		.i.ifi_family = preferred_family,
+	};
+
+	if (argc <= 0) {
+		usage();
+		exit(-1);
+	}
+
+	if (matches(*argv, "add") == 0) {
+		req.n.nlmsg_flags |= NLM_F_EXCL | NLM_F_CREATE | NLM_F_APPEND;
+		req.n.nlmsg_type = RTM_NEWLINKPROP;
+	} else if (matches(*argv, "del") == 0) {
+		req.n.nlmsg_flags |= RTM_DELLINK;
+		req.n.nlmsg_type = RTM_DELLINKPROP;
+	} else if (matches(*argv, "help") == 0) {
+		usage();
+	} else {
+		fprintf(stderr, "Operator required\n");
+		exit(-1);
+	}
+	return iplink_prop_mod(argc - 1, argv + 1, &req);
+}
+
 static void do_help(int argc, char **argv)
 {
 	struct link_util *lu = NULL;
@@ -1674,6 +1751,9 @@ int do_iplink(int argc, char **argv)
 		return 0;
 	}
 
+	if (matches(*argv, "prop") == 0)
+		return iplink_prop(argc-1, argv+1);
+
 	if (matches(*argv, "help") == 0) {
 		do_help(argc-1, argv+1);
 		return 0;
diff --git a/lib/utils.c b/lib/utils.c
index 95d46ff210aa..bbb3bdcfa80b 100644
--- a/lib/utils.c
+++ b/lib/utils.c
@@ -824,14 +824,10 @@ int nodev(const char *dev)
 	return -1;
 }
 
-int check_ifname(const char *name)
+static int __check_ifname(const char *name)
 {
-	/* These checks mimic kernel checks in dev_valid_name */
 	if (*name == '\0')
 		return -1;
-	if (strlen(name) >= IFNAMSIZ)
-		return -1;
-
 	while (*name) {
 		if (*name == '/' || isspace(*name))
 			return -1;
@@ -840,6 +836,19 @@ int check_ifname(const char *name)
 	return 0;
 }
 
+int check_ifname(const char *name)
+{
+	/* These checks mimic kernel checks in dev_valid_name */
+	if (strlen(name) >= IFNAMSIZ)
+		return -1;
+	return __check_ifname(name);
+}
+
+int check_altifname(const char *name)
+{
+	return __check_ifname(name);
+}
+
 /* buf is assumed to be IFNAMSIZ */
 int get_ifname(char *buf, const char *name)
 {
diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index a8ae72d2b097..7cb4d56726d8 100644
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -244,6 +244,17 @@ ip-link \- network device configuration
 .IR VLAN-QOS " ] ["
 .B proto
 .IR VLAN-PROTO " ] ]"
+.in -8
+
+.ti -8
+.BI "ip link prop add"
+.RB "[ " altname
+.IR NAME " .. ]"
+
+.ti -8
+.BI "ip link prop del"
+.RB "[ " altname
+.IR NAME " .. ]"
 
 .SH "DESCRIPTION"
 .SS ip link add - add virtual link
-- 
2.21.0