media: cec: support CEC_MSG_FL_RAW

If this flag is set, then check for root permissions and skip
all message checks expect for the core checks (i.e. validate the
length etc.).

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

diff --git a/drivers/media/cec/cec-adap.c b/drivers/media/cec/cec-adap.c
index 5b9232b..9a1ec92 100644 (file)
--- a/drivers/media/cec/cec-adap.c
+++ b/drivers/media/cec/cec-adap.c
@@ -720,6 +720,7 @@ int cec_transmit_msg_fh(struct cec_adapter *adap, struct cec_msg *msg,
                        struct cec_fh *fh, bool block)
 {
        struct cec_data *data;
+       bool is_raw = msg_is_raw(msg);
 
        msg->rx_ts = 0;
        msg->tx_ts = 0;
@@ -735,10 +736,10 @@ int cec_transmit_msg_fh(struct cec_adapter *adap, struct cec_msg *msg,
                /* Make sure the timeout isn't 0. */
                msg->timeout = 1000;
        }
-       if (msg->timeout)
-               msg->flags &= CEC_MSG_FL_REPLY_TO_FOLLOWERS;
-       else
-               msg->flags = 0;
+       msg->flags &= CEC_MSG_FL_REPLY_TO_FOLLOWERS | CEC_MSG_FL_RAW;
+
+       if (!msg->timeout)
+               msg->flags &= ~CEC_MSG_FL_REPLY_TO_FOLLOWERS;
 
        /* Sanity checks */
        if (msg->len == 0 || msg->len > CEC_MAX_MSG_SIZE) {
@@ -761,54 +762,70 @@ int cec_transmit_msg_fh(struct cec_adapter *adap, struct cec_msg *msg,
                return -EINVAL;
        }
 
-       /* A CDC-Only device can only send CDC messages */
-       if ((adap->log_addrs.flags & CEC_LOG_ADDRS_FL_CDC_ONLY) &&
-           (msg->len == 1 || msg->msg[1] != CEC_MSG_CDC_MESSAGE))
-               return -EINVAL;
+       if (is_raw) {
+               if (!capable(CAP_SYS_RAWIO))
+                       return -EPERM;
+       } else {
+               /* A CDC-Only device can only send CDC messages */
+               if ((adap->log_addrs.flags & CEC_LOG_ADDRS_FL_CDC_ONLY) &&
+                   (msg->len == 1 || msg->msg[1] != CEC_MSG_CDC_MESSAGE)) {
+                       dprintk(1, "%s: not a CDC message\n", __func__);
+                       return -EINVAL;
+               }
 
-       if (msg->len >= 4 && msg->msg[1] == CEC_MSG_CDC_MESSAGE) {
-               msg->msg[2] = adap->phys_addr >> 8;
-               msg->msg[3] = adap->phys_addr & 0xff;
-       }
+               if (msg->len >= 4 && msg->msg[1] == CEC_MSG_CDC_MESSAGE) {
+                       msg->msg[2] = adap->phys_addr >> 8;
+                       msg->msg[3] = adap->phys_addr & 0xff;
+               }
 
-       if (msg->len == 1) {
-               if (cec_msg_destination(msg) == 0xf) {
-                       dprintk(1, "%s: invalid poll message\n", __func__);
+               if (msg->len == 1) {
+                       if (cec_msg_destination(msg) == 0xf) {
+                               dprintk(1, "%s: invalid poll message\n",
+                                       __func__);
+                               return -EINVAL;
+                       }
+                       if (cec_has_log_addr(adap, cec_msg_destination(msg))) {
+                               /*
+                                * If the destination is a logical address our
+                                * adapter has already claimed, then just NACK
+                                * this. It depends on the hardware what it will
+                                * do with a POLL to itself (some OK this), so
+                                * it is just as easy to handle it here so the
+                                * behavior will be consistent.
+                                */
+                               msg->tx_ts = ktime_get_ns();
+                               msg->tx_status = CEC_TX_STATUS_NACK |
+                                       CEC_TX_STATUS_MAX_RETRIES;
+                               msg->tx_nack_cnt = 1;
+                               msg->sequence = ++adap->sequence;
+                               if (!msg->sequence)
+                                       msg->sequence = ++adap->sequence;
+                               return 0;
+                       }
+               }
+               if (msg->len > 1 && !cec_msg_is_broadcast(msg) &&
+                   cec_has_log_addr(adap, cec_msg_destination(msg))) {
+                       dprintk(1, "%s: destination is the adapter itself\n",
+                               __func__);
                        return -EINVAL;
                }
-               if (cec_has_log_addr(adap, cec_msg_destination(msg))) {
-                       /*
-                        * If the destination is a logical address our adapter
-                        * has already claimed, then just NACK this.
-                        * It depends on the hardware what it will do with a
-                        * POLL to itself (some OK this), so it is just as
-                        * easy to handle it here so the behavior will be
-                        * consistent.
-                        */
-                       msg->tx_ts = ktime_get_ns();
-                       msg->tx_status = CEC_TX_STATUS_NACK |
-                                        CEC_TX_STATUS_MAX_RETRIES;
-                       msg->tx_nack_cnt = 1;
-                       msg->sequence = ++adap->sequence;
-                       if (!msg->sequence)
-                               msg->sequence = ++adap->sequence;
-                       return 0;
+               if (msg->len > 1 && adap->is_configured &&
+                   !cec_has_log_addr(adap, cec_msg_initiator(msg))) {
+                       dprintk(1, "%s: initiator has unknown logical address %d\n",
+                               __func__, cec_msg_initiator(msg));
+                       return -EINVAL;
+               }
+               if (!adap->is_configured && !adap->is_configuring &&
+                   msg->msg[0] != 0xf0) {
+                       dprintk(1, "%s: adapter is unconfigured\n", __func__);
+                       return -ENONET;
                }
        }
-       if (msg->len > 1 && !cec_msg_is_broadcast(msg) &&
-           cec_has_log_addr(adap, cec_msg_destination(msg))) {
-               dprintk(1, "%s: destination is the adapter itself\n", __func__);
-               return -EINVAL;
-       }
-       if (msg->len > 1 && adap->is_configured &&
-           !cec_has_log_addr(adap, cec_msg_initiator(msg))) {
-               dprintk(1, "%s: initiator has unknown logical address %d\n",
-                       __func__, cec_msg_initiator(msg));
-               return -EINVAL;
-       }
+
        if (!adap->is_configured && !adap->is_configuring) {
-               if (adap->needs_hpd || msg->msg[0] != 0xf0) {
-                       dprintk(1, "%s: adapter is unconfigured\n", __func__);
+               if (adap->needs_hpd) {
+                       dprintk(1, "%s: adapter is unconfigured and needs HPD\n",
+                               __func__);
                        return -ENONET;
                }
                if (msg->reply) {