nfc: netlink: Add capability to reply to vendor_cmd with data
A proprietary vendor command may send back useful data to the user
application.
For example, the field level applied on the NFC router antenna.
Still based on net/wireless/nl80211.c implementation,
add nfc_vendor_cmd_alloc_reply_skb and nfc_vendor_cmd_reply in
order to send back over netlink data generated by a proprietary
command.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
index 73d1ca7..853172c 100644
--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -63,6 +63,8 @@
[NFC_ATTR_FIRMWARE_NAME] = { .type = NLA_STRING,
.len = NFC_FIRMWARE_NAME_MAXSIZE },
[NFC_ATTR_SE_APDU] = { .type = NLA_BINARY },
+ [NFC_ATTR_VENDOR_DATA] = { .type = NLA_BINARY },
+
};
static const struct nla_policy nfc_sdp_genl_policy[NFC_SDP_ATTR_MAX + 1] = {
@@ -1503,7 +1505,7 @@
u32 dev_idx, vid, subcmd;
u8 *data;
size_t data_len;
- int i;
+ int i, err;
if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
!info->attrs[NFC_ATTR_VENDOR_ID] ||
@@ -1534,12 +1536,92 @@
if (cmd->vendor_id != vid || cmd->subcmd != subcmd)
continue;
- return cmd->doit(dev, data, data_len);
+ dev->cur_cmd_info = info;
+ err = cmd->doit(dev, data, data_len);
+ dev->cur_cmd_info = NULL;
+ return err;
}
return -EOPNOTSUPP;
}
+/* message building helper */
+static inline void *nfc_hdr_put(struct sk_buff *skb, u32 portid, u32 seq,
+ int flags, u8 cmd)
+{
+ /* since there is no private header just add the generic one */
+ return genlmsg_put(skb, portid, seq, &nfc_genl_family, flags, cmd);
+}
+
+static struct sk_buff *
+__nfc_alloc_vendor_cmd_skb(struct nfc_dev *dev, int approxlen,
+ u32 portid, u32 seq,
+ enum nfc_attrs attr,
+ u32 oui, u32 subcmd, gfp_t gfp)
+{
+ struct sk_buff *skb;
+ void *hdr;
+
+ skb = nlmsg_new(approxlen + 100, gfp);
+ if (!skb)
+ return NULL;
+
+ hdr = nfc_hdr_put(skb, portid, seq, 0, NFC_CMD_VENDOR);
+ if (!hdr) {
+ kfree_skb(skb);
+ return NULL;
+ }
+
+ if (nla_put_u32(skb, NFC_ATTR_DEVICE_INDEX, dev->idx))
+ goto nla_put_failure;
+ if (nla_put_u32(skb, NFC_ATTR_VENDOR_ID, oui))
+ goto nla_put_failure;
+ if (nla_put_u32(skb, NFC_ATTR_VENDOR_SUBCMD, subcmd))
+ goto nla_put_failure;
+
+ ((void **)skb->cb)[0] = dev;
+ ((void **)skb->cb)[1] = hdr;
+
+ return skb;
+
+nla_put_failure:
+ kfree_skb(skb);
+ return NULL;
+}
+
+struct sk_buff *__nfc_alloc_vendor_cmd_reply_skb(struct nfc_dev *dev,
+ enum nfc_attrs attr,
+ u32 oui, u32 subcmd,
+ int approxlen)
+{
+ if (WARN_ON(!dev->cur_cmd_info))
+ return NULL;
+
+ return __nfc_alloc_vendor_cmd_skb(dev, approxlen,
+ dev->cur_cmd_info->snd_portid,
+ dev->cur_cmd_info->snd_seq, attr,
+ oui, subcmd, GFP_KERNEL);
+}
+EXPORT_SYMBOL(__nfc_alloc_vendor_cmd_reply_skb);
+
+int nfc_vendor_cmd_reply(struct sk_buff *skb)
+{
+ struct nfc_dev *dev = ((void **)skb->cb)[0];
+ void *hdr = ((void **)skb->cb)[1];
+
+ /* clear CB data for netlink core to own from now on */
+ memset(skb->cb, 0, sizeof(skb->cb));
+
+ if (WARN_ON(!dev->cur_cmd_info)) {
+ kfree_skb(skb);
+ return -EINVAL;
+ }
+
+ genlmsg_end(skb, hdr);
+ return genlmsg_reply(skb, dev->cur_cmd_info);
+}
+EXPORT_SYMBOL(nfc_vendor_cmd_reply);
+
static const struct genl_ops nfc_genl_ops[] = {
{
.cmd = NFC_CMD_GET_DEVICE,