Bluetooth: Move SMP crypto functions to a workqueue

The function crypto_blkcipher_setkey() called by smp_e()
can sleep, so all the crypto work has to be moved to
hci_dev workqueue.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

2 files changed, 177 insertions, 102 deletions

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index e699837c3b8c..4bfb7d22d171 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -991,7 +991,7 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
 
         if (test_and_clear_bit(HCI_CONN_LE_SMP_PEND, &hcon->pend)) {
                 del_timer(&conn->security_timer);
-                hci_conn_put(hcon);
+                smp_chan_destroy(conn);
         }
 
         hcon->l2cap_data = NULL;
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index b5e1b4a300cc..03489e5815ef 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -243,16 +243,170 @@ static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
         return 0;
 }
 
+static void confirm_work(struct work_struct *work)
+{
+        struct smp_chan *smp = container_of(work, struct smp_chan, confirm);
+        struct l2cap_conn *conn = smp->conn;
+        struct crypto_blkcipher *tfm;
+        struct smp_cmd_pairing_confirm cp;
+        int ret;
+        u8 res[16], reason;
+
+        BT_DBG("conn %p", conn);
+
+        tfm = crypto_alloc_blkcipher("ecb(aes)", 0, CRYPTO_ALG_ASYNC);
+        if (IS_ERR(tfm)) {
+                reason = SMP_UNSPECIFIED;
+                goto error;
+        }
+
+        smp->tfm = tfm;
+
+        if (conn->hcon->out)
+                ret = smp_c1(tfm, smp->tk, smp->prnd, smp->preq, smp->prsp, 0,
+                                conn->src, conn->hcon->dst_type, conn->dst,
+                                res);
+        else
+                ret = smp_c1(tfm, smp->tk, smp->prnd, smp->preq, smp->prsp,
+                                conn->hcon->dst_type, conn->dst, 0, conn->src,
+                                res);
+        if (ret) {
+                reason = SMP_UNSPECIFIED;
+                goto error;
+        }
+
+        swap128(res, cp.confirm_val);
+        smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
+
+        return;
+
+error:
+        smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason), &reason);
+        smp_chan_destroy(conn);
+}
+
+static void random_work(struct work_struct *work)
+{
+        struct smp_chan *smp = container_of(work, struct smp_chan, random);
+        struct l2cap_conn *conn = smp->conn;
+        struct hci_conn *hcon = conn->hcon;
+        struct crypto_blkcipher *tfm = smp->tfm;
+        u8 reason, confirm[16], res[16], key[16];
+        int ret;
+
+        if (IS_ERR_OR_NULL(tfm)) {
+                reason = SMP_UNSPECIFIED;
+                goto error;
+        }
+
+        BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
+
+        if (hcon->out)
+                ret = smp_c1(tfm, smp->tk, smp->rrnd, smp->preq, smp->prsp, 0,
+                                conn->src, hcon->dst_type, conn->dst,
+                                res);
+        else
+                ret = smp_c1(tfm, smp->tk, smp->rrnd, smp->preq, smp->prsp,
+                                hcon->dst_type, conn->dst, 0, conn->src,
+                                res);
+        if (ret) {
+                reason = SMP_UNSPECIFIED;
+                goto error;
+        }
+
+        swap128(res, confirm);
+
+        if (memcmp(smp->pcnf, confirm, sizeof(smp->pcnf)) != 0) {
+                BT_ERR("Pairing failed (confirmation values mismatch)");
+                reason = SMP_CONFIRM_FAILED;
+                goto error;
+        }
+
+        if (hcon->out) {
+                u8 stk[16], rand[8];
+                __le16 ediv;
+
+                memset(rand, 0, sizeof(rand));
+                ediv = 0;
+
+                smp_s1(tfm, smp->tk, smp->rrnd, smp->prnd, key);
+                swap128(key, stk);
+
+                memset(stk + smp->smp_key_size, 0,
+                                SMP_MAX_ENC_KEY_SIZE - smp->smp_key_size);
+
+                if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend)) {
+                        reason = SMP_UNSPECIFIED;
+                        goto error;
+                }
+
+                hci_le_start_enc(hcon, ediv, rand, stk);
+                hcon->enc_key_size = smp->smp_key_size;
+        } else {
+                u8 stk[16], r[16], rand[8];
+                __le16 ediv;
+
+                memset(rand, 0, sizeof(rand));
+                ediv = 0;
+
+                swap128(smp->prnd, r);
+                smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(r), r);
+
+                smp_s1(tfm, smp->tk, smp->prnd, smp->rrnd, key);
+                swap128(key, stk);
+
+                memset(stk + smp->smp_key_size, 0,
+                                SMP_MAX_ENC_KEY_SIZE - smp->smp_key_size);
+
+                hci_add_ltk(hcon->hdev, 0, conn->dst, smp->smp_key_size,
+                                                        ediv, rand, stk);
+        }
+
+        return;
+
+error:
+        smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason), &reason);
+        smp_chan_destroy(conn);
+}
+
+static struct smp_chan *smp_chan_create(struct l2cap_conn *conn)
+{
+        struct smp_chan *smp;
+
+        smp = kzalloc(sizeof(struct smp_chan), GFP_ATOMIC);
+        if (!smp)
+                return NULL;
+
+        INIT_WORK(&smp->confirm, confirm_work);
+        INIT_WORK(&smp->random, random_work);
+
+        smp->conn = conn;
+        conn->smp_chan = smp;
+
+        hci_conn_hold(conn->hcon);
+
+        return smp;
+}
+
+void smp_chan_destroy(struct l2cap_conn *conn)
+{
+        kfree(conn->smp_chan);
+        hci_conn_put(conn->hcon);
+}
+
 static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
 {
         struct smp_cmd_pairing rsp, *req = (void *) skb->data;
-        struct smp_chan *smp = conn->smp_chan;
+        struct smp_chan *smp;
         u8 key_size;
+        int ret;
 
         BT_DBG("conn %p", conn);
 
         if (!test_and_set_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->pend))
-                hci_conn_hold(conn->hcon);
+                smp = smp_chan_create(conn);
+
+        smp = conn->smp_chan;
 
         smp->preq[0] = SMP_CMD_PAIRING_REQ;
         memcpy(&smp->preq[1], req, sizeof(*req));
@@ -271,6 +425,10 @@ static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
         /* Just works */
         memset(smp->tk, 0, sizeof(smp->tk));
 
+        ret = smp_rand(smp->prnd);
+        if (ret)
+                return SMP_UNSPECIFIED;
+
         smp->prsp[0] = SMP_CMD_PAIRING_RSP;
         memcpy(&smp->prsp[1], &rsp, sizeof(rsp));
 
@@ -282,12 +440,10 @@ static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
 static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
 {
         struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
-        struct smp_cmd_pairing_confirm cp;
         struct smp_chan *smp = conn->smp_chan;
-        struct crypto_blkcipher *tfm = smp->tfm;
-
+        struct hci_dev *hdev = conn->hcon->hdev;
+        u8 key_size;
         int ret;
-        u8 res[16], key_size;
 
         BT_DBG("conn %p", conn);
 
@@ -305,21 +461,14 @@ static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
         /* Just works */
         memset(smp->tk, 0, sizeof(smp->tk));
 
-        smp->prsp[0] = SMP_CMD_PAIRING_RSP;
-        memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
-
         ret = smp_rand(smp->prnd);
         if (ret)
                 return SMP_UNSPECIFIED;
 
-        ret = smp_c1(tfm, smp->tk, smp->prnd, smp->preq, smp->prsp, 0,
-                        conn->src, conn->hcon->dst_type, conn->dst, res);
-        if (ret)
-                return SMP_UNSPECIFIED;
-
-        swap128(res, cp.confirm_val);
+        smp->prsp[0] = SMP_CMD_PAIRING_RSP;
+        memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
 
-        smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
+        queue_work(hdev->workqueue, &smp->confirm);
 
         return 0;
 }
@@ -327,7 +476,7 @@ static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
 static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
 {
         struct smp_chan *smp = conn->smp_chan;
-        struct crypto_blkcipher *tfm = smp->tfm;
+        struct hci_dev *hdev = conn->hcon->hdev;
 
         BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
 
@@ -341,23 +490,7 @@ static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
                 smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(random),
                                                                 random);
         } else {
-                struct smp_cmd_pairing_confirm cp;
-                int ret;
-                u8 res[16];
-
-                ret = smp_rand(smp->prnd);
-                if (ret)
-                        return SMP_UNSPECIFIED;
-
-                ret = smp_c1(tfm, smp->tk, smp->prnd, smp->preq, smp->prsp,
-                                                conn->hcon->dst_type, conn->dst,
-                                                0, conn->src, res);
-                if (ret)
-                        return SMP_CONFIRM_FAILED;
-
-                swap128(res, cp.confirm_val);
-
-                smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
+                queue_work(hdev->workqueue, &smp->confirm);
         }
 
         return 0;
@@ -365,72 +498,15 @@ static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
 
 static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
 {
-        struct hci_conn *hcon = conn->hcon;
         struct smp_chan *smp = conn->smp_chan;
-        struct crypto_blkcipher *tfm = smp->tfm;
-        int ret;
-        u8 key[16], res[16], random[16], confirm[16];
-
-        swap128(skb->data, random);
-        skb_pull(skb, sizeof(random));
+        struct hci_dev *hdev = conn->hcon->hdev;
 
-        if (conn->hcon->out)
-                ret = smp_c1(tfm, smp->tk, random, smp->preq, smp->prsp, 0,
-                                conn->src, conn->hcon->dst_type, conn->dst,
-                                res);
-        else
-                ret = smp_c1(tfm, smp->tk, random, smp->preq, smp->prsp,
-                                conn->hcon->dst_type, conn->dst, 0, conn->src,
-                                res);
-        if (ret)
-                return SMP_UNSPECIFIED;
-
-        BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
-
-        swap128(res, confirm);
-
-        if (memcmp(smp->pcnf, confirm, sizeof(smp->pcnf)) != 0) {
-                BT_ERR("Pairing failed (confirmation values mismatch)");
-                return SMP_CONFIRM_FAILED;
-        }
-
-        if (conn->hcon->out) {
-                u8 stk[16], rand[8];
-                __le16 ediv;
-
-                memset(rand, 0, sizeof(rand));
-                ediv = 0;
-
-                smp_s1(tfm, smp->tk, random, smp->prnd, key);
-                swap128(key, stk);
-
-                memset(stk + smp->smp_key_size, 0,
-                                SMP_MAX_ENC_KEY_SIZE - smp->smp_key_size);
-
-                if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend))
-                        return SMP_UNSPECIFIED;
-
-                hci_le_start_enc(hcon, ediv, rand, stk);
-                hcon->enc_key_size = smp->smp_key_size;
-        } else {
-                u8 stk[16], r[16], rand[8];
-                __le16 ediv;
-
-                memset(rand, 0, sizeof(rand));
-                ediv = 0;
-
-                swap128(smp->prnd, r);
-                smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(r), r);
-
-                smp_s1(tfm, smp->tk, smp->prnd, random, key);
-                swap128(key, stk);
+        BT_DBG("conn %p", conn);
 
-                memset(stk + smp->smp_key_size, 0,
-                                SMP_MAX_ENC_KEY_SIZE - smp->smp_key_size);
+        swap128(skb->data, smp->rrnd);
+        skb_pull(skb, sizeof(smp->rrnd));
 
-                hci_add_ltk(conn->hcon->hdev, 0, conn->dst, smp->smp_key_size,
-                                                        ediv, rand, stk);
-        }
+        queue_work(hdev->workqueue, &smp->random);
 
         return 0;
 }
@@ -440,14 +516,14 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
         struct smp_cmd_security_req *rp = (void *) skb->data;
         struct smp_cmd_pairing cp;
         struct hci_conn *hcon = conn->hcon;
-        struct smp_chan *smp = conn->smp_chan;
+        struct smp_chan *smp;
 
         BT_DBG("conn %p", conn);
 
         if (test_and_set_bit(HCI_CONN_LE_SMP_PEND, &hcon->pend))
                 return 0;
 
-        hci_conn_hold(hcon);
+        smp = smp_chan_create(conn);
 
         skb_pull(skb, sizeof(*rp));
 
@@ -502,8 +578,7 @@ int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level)
         if (test_and_set_bit(HCI_CONN_LE_SMP_PEND, &hcon->pend))
                 return 0;
 
-        /* While SMP is going on */
-        hci_conn_hold(hcon);
+        smp = smp_chan_create(conn);
 
         authreq = seclevel_to_authreq(sec_level);
 
@@ -710,7 +785,7 @@ int smp_distribute_keys(struct l2cap_conn *conn, __u8 force)
         if (conn->hcon->out || force) {
                 clear_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->pend);
                 del_timer(&conn->security_timer);
-                hci_conn_put(conn->hcon);
+                smp_chan_destroy(conn);
         }
 
         return 0;