[PATCH iproute2-next] devlink: support u32-array values in devlink param show/set

[PATCH iproute2-next] devlink: support u32-array values in devlink param show/set

[Ratheesh Kannoth]

Teach param value printing about MNL type 129 by walking nested attributes,
collecting u32 elements, and formatting them for output

For param set, accept a space- or comma-separated list of integers and encode
it as multiple DEVLINK_ATTR_PARAM_VALUE_DATA u32 attributes.

Pass the enclosing netlink attribute into pr_out_param_value_print so nested
payloads can be parsed alongside the existing scalar types.

  - Show search order

  devlink dev param show pci/0002:01:00.0 name npc_srch_order
  pci/0002:01:00.0:
    name npc_srch_order type driver-specific
      values:
        cmode runtime value  value  0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

   - Set search order

   devlink dev param set pci/0002:01:00.0 name npc_srch_order value 31,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,\
		22,23,24,25,26,27,28,29,30  cmode runtime

Signed-off-by: Ratheesh Kannoth <rkannoth@marvell.com>
---
 devlink/devlink.c | 47 +++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 43 insertions(+), 4 deletions(-)

diff --git a/devlink/devlink.c b/devlink/devlink.c
index b4deba30..efb558c5 100644
--- a/devlink/devlink.c
+++ b/devlink/devlink.c
@@ -3497,12 +3497,28 @@ static const struct param_val_conv param_val_conv[] = {
 
 #define PARAM_VAL_CONV_LEN ARRAY_SIZE(param_val_conv)
 
+struct devlink_param_u32_array {
+	uint32_t size;
+	uint32_t val[32];
+};
+
+static int param_value_nested_u32_attr_cb(const struct nlattr *attr, void *data)
+{
+	struct devlink_param_u32_array *arr = data;
+
+	arr->val[arr->size++] = mnl_attr_get_u32(attr);
+
+	return MNL_CB_OK;
+}
+
 static int pr_out_param_value_print(const char *nla_name, int nla_type,
 				     struct nlattr *val_attr, bool conv_exists,
-				     const char *label, bool flag_as_u8)
+				     const char *label, bool flag_as_u8, struct nlattr *nl)
 {
+	struct devlink_param_u32_array u32_arr = { };
 	const char *vstr;
-	int err;
+	char buffer[1024];
+	int err, cnt = 0;
 
 	print_string(PRINT_FP, NULL, " %s ", label);
 
@@ -3563,6 +3579,18 @@ static int pr_out_param_value_print(const char *nla_name, int nla_type,
 		else
 			print_bool(PRINT_ANY, label, "%s", val_attr);
 		break;
+	case 129:
+		err = mnl_attr_parse_nested(nl, param_value_nested_u32_attr_cb,
+					    (void *)&u32_arr);
+		if (err != MNL_CB_OK)
+			return -EINVAL;
+
+		for (int i = 1; i < u32_arr.size; i++)
+			cnt += snprintf(buffer + cnt, sizeof(buffer) - cnt, "%u ", u32_arr.val[i]);
+
+		print_string(PRINT_ANY, "value def", " value  %s", buffer);
+
+		break;
 	}
 
 	return 0;
@@ -3595,14 +3623,14 @@ static void pr_out_param_value(struct dl *dl, const char *nla_name,
 					    nla_name);
 
 	err = pr_out_param_value_print(nla_name, nla_type, val_attr,
-				       conv_exists, "value", false);
+				       conv_exists, "value", false, nl);
 	if (err)
 		return;
 
 	val_attr = nla_value[DEVLINK_ATTR_PARAM_VALUE_DEFAULT];
 	if (val_attr) {
 		err = pr_out_param_value_print(nla_name, nla_type, val_attr,
-					       conv_exists, "default", true);
+					       conv_exists, "default", true, nl);
 		if (err)
 			return;
 	}
@@ -3685,6 +3713,7 @@ struct param_ctx {
 		uint64_t vu64;
 		const char *vstr;
 		bool vbool;
+		struct devlink_param_u32_array u32arr;
 	} value;
 };
 
@@ -3764,12 +3793,14 @@ static int cmd_dev_param_set(struct dl *dl)
 {
 	struct param_ctx ctx = {};
 	struct nlmsghdr *nlh;
+	char delim[] = " ,";
 	bool conv_exists;
 	uint64_t val_u64 = 0;
 	uint32_t val_u32;
 	uint16_t val_u16;
 	uint8_t val_u8;
 	bool val_bool;
+	char *token, *buf;
 	int err;
 
 	err = dl_argv_parse(dl, DL_OPT_HANDLE |
@@ -3904,6 +3935,14 @@ static int cmd_dev_param_set(struct dl *dl)
 		if (!strcmp(dl->opts.param_value, ctx.value.vstr))
 			return 0;
 		break;
+	case 129:
+		buf = (char *)dl->opts.param_value;
+		token = strtok(buf,  delim);
+		while (token) {
+			mnl_attr_put_u32(nlh, DEVLINK_ATTR_PARAM_VALUE_DATA, atoi(token));
+			token = strtok(NULL, delim);
+		}
+		break;
 	default:
 		printf("Value type not supported\n");
 		return -ENOTSUP;
-- 
2.43.0

Re: [PATCH iproute2-next] devlink: support u32-array values in devlink param show/set

[David Ahern]

On 6/14/26 10:10 PM, Ratheesh Kannoth wrote:
> @@ -3904,6 +3935,14 @@ static int cmd_dev_param_set(struct dl *dl)
>  		if (!strcmp(dl->opts.param_value, ctx.value.vstr))
>  			return 0;
>  		break;
> +	case 129:

no magic numbers. What does 129 represent? Is there a named macro for
it? If not, why not if this is part of a UAPI?

> +		buf = (char *)dl->opts.param_value;
> +		token = strtok(buf,  delim);
> +		while (token) {
> +			mnl_attr_put_u32(nlh, DEVLINK_ATTR_PARAM_VALUE_DATA, atoi(token));
> +			token = strtok(NULL, delim);
> +		}
> +		break;
>  	default:
>  		printf("Value type not supported\n");
>  		return -ENOTSUP;