[iproute2-next V4 2/6] netshaper: Add bw-min and weight parameter support

[Mohsin Bashir <mohsin.bashr@gmail.com>]

From: Mohsin Bashir <hmohsin@meta.com>

Add bw-min and weight parameters to the set command. Previously
only bw-max was supported. Use boolean flags (has_bw_min,
has_bw_max, has_weight) to track which parameters were provided,
so that zero-valued attrs like bw-max 0 are correctly sent.
Only emit rate and weight attrs for the set command. Add device
name validation and only send handle id when explicitly provided.
Update usage text to reflect the new parameters.

Assisted-by: Claude:claude-opus-4.7
Signed-off-by: Mohsin Bashir <hmohsin@meta.com>
---
 netshaper/netshaper.c | 59 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 47 insertions(+), 12 deletions(-)

diff --git a/netshaper/netshaper.c b/netshaper/netshaper.c
index f90ceb11..74175b39 100644
--- a/netshaper/netshaper.c
+++ b/netshaper/netshaper.c
@@ -33,11 +33,13 @@ static void usage(void)
 		"OPTIONS := { -V[ersion] | -c[olor] | -help }\n"
 		"COMMAND := { set | get | delete } dev DEVNAME\n"
 		"	    handle scope HANDLE_SCOPE [id HANDLE_ID]\n"
-		"	    [bw-max BW_MAX]\n"
+		"	    [bw-min BW_MIN] [bw-max BW_MAX] [weight WEIGHT]\n"
+		"\n"
 		"Where: DEVNAME         := STRING\n"
 		"       HANDLE_SCOPE    := { netdev | queue | node }\n"
 		"       HANDLE_ID       := UINT (required for queue/node, optional for netdev)\n"
-		"       BW_MAX          := UINT{ kbit | mbit | gbit }\n");
+		"       BW_MIN/BW_MAX   := UINT{ kbit | mbit | gbit }\n"
+		"       WEIGHT          := UINT\n");
 }
 
 static const char *net_shaper_scope_names[NET_SHAPER_SCOPE_MAX + 1] = {
@@ -123,22 +125,40 @@ static int do_cmd(int argc, char **argv, int cmd)
 	GENL_REQUEST(req, 1024, genl_family, 0, NET_SHAPER_FAMILY_VERSION, cmd,
 		     NLM_F_REQUEST | NLM_F_ACK);
 
-	struct nlmsghdr *answer;
-	__u64 bw_max_bps = 0;
-	int ifindex = -1;
+	bool has_bw_min = false, has_bw_max = false, has_weight = false;
 	int handle_scope = NET_SHAPER_SCOPE_UNSPEC;
-	__u32 handle_id = 0;
+	__u64 bw_min_bps = 0, bw_max_bps = 0;
+	__u32 handle_id = 0, weight = 0;
 	bool handle_present = false;
-	int err;
+	bool has_handle_id = false;
+	struct nlmsghdr *answer;
+	int err, ifindex = -1;
 
 	while (argc > 0) {
 		if (strcmp(*argv, "dev") == 0) {
 			NEXT_ARG();
 			ifindex = ll_name_to_index(*argv);
+			if (ifindex == 0) {
+				fprintf(stderr, "Device \"%s\" not found\n", *argv);
+				return -1;
+			}
+		} else if (strcmp(*argv, "bw-min") == 0) {
+			NEXT_ARG();
+			if (parse_rate(*argv, &bw_min_bps))
+				return -1;
+			has_bw_min = true;
 		} else if (strcmp(*argv, "bw-max") == 0) {
 			NEXT_ARG();
 			if (parse_rate(*argv, &bw_max_bps))
 				return -1;
+			has_bw_max = true;
+		} else if (strcmp(*argv, "weight") == 0) {
+			NEXT_ARG();
+			if (get_unsigned(&weight, *argv, 10)) {
+				fprintf(stderr, "Invalid weight value\n");
+				return -1;
+			}
+			has_weight = true;
 		} else if (strcmp(*argv, "handle") == 0) {
 			handle_present = true;
 			NEXT_ARG();
@@ -165,6 +185,7 @@ static int do_cmd(int argc, char **argv, int cmd)
 						fprintf(stderr, "Invalid handle id\n");
 						return -1;
 					}
+					has_handle_id = true;
 				}
 			} else {
 				/* For queue/node scope, id is required */
@@ -179,6 +200,7 @@ static int do_cmd(int argc, char **argv, int cmd)
 					fprintf(stderr, "Invalid handle id\n");
 					return -1;
 				}
+				has_handle_id = true;
 			}
 		} else {
 			fprintf(stderr, "What is \"%s\"\n", *argv);
@@ -195,19 +217,32 @@ static int do_cmd(int argc, char **argv, int cmd)
 	if (!handle_present)
 		missarg("handle");
 
-	if (cmd == NET_SHAPER_CMD_SET && bw_max_bps == 0)
-		missarg("bw-max");
+	if (cmd == NET_SHAPER_CMD_SET && !has_bw_min && !has_bw_max && !has_weight)
+		missarg("bw-min, bw-max, or weight");
 
 	addattr32(&req.n, sizeof(req), NET_SHAPER_A_IFINDEX, ifindex);
 
 	struct rtattr *handle = addattr_nest(&req.n, sizeof(req),
 					     NET_SHAPER_A_HANDLE | NLA_F_NESTED);
 	addattr32(&req.n, sizeof(req), NET_SHAPER_A_HANDLE_SCOPE, handle_scope);
-	addattr32(&req.n, sizeof(req), NET_SHAPER_A_HANDLE_ID, handle_id);
+	if (has_handle_id)
+		addattr32(&req.n, sizeof(req), NET_SHAPER_A_HANDLE_ID, handle_id);
 	addattr_nest_end(&req.n, handle);
 
-	if (cmd == NET_SHAPER_CMD_SET)
-		addattr64(&req.n, sizeof(req), NET_SHAPER_A_BW_MAX, bw_max_bps);
+	if (cmd == NET_SHAPER_CMD_SET) {
+		if (has_bw_min)
+			addattr64(&req.n, sizeof(req), NET_SHAPER_A_BW_MIN,
+				  bw_min_bps);
+		if (has_bw_max)
+			addattr64(&req.n, sizeof(req), NET_SHAPER_A_BW_MAX,
+				  bw_max_bps);
+		if (has_weight)
+			addattr32(&req.n, sizeof(req), NET_SHAPER_A_WEIGHT,
+				  weight);
+		if (has_bw_min || has_bw_max)
+			addattr32(&req.n, sizeof(req), NET_SHAPER_A_METRIC,
+				  NET_SHAPER_METRIC_BPS);
+	}
 
 	err = rtnl_talk(&gen_rth, &req.n, &answer);
 	if (err < 0) {
-- 
2.53.0-Meta