Bluetooth: Mesh: Encrypt friend packets on send
Stores friend queue packets unencrypted, removing any out-of-order issues caused by seqnum allocation. Also moves as much of the metadata storage as possible into the packet, allowing us to free up some bytes of net_buf user data for friend packets. Fixes #18488 Signed-off-by: Trond Einar Snekvik <Trond.Einar.Snekvik@nordicsemi.no>
This commit is contained in:
Trond Einar Snekvik
Johan Hedberg
parent
9e85c33239
commit
532241d5ad
2 changed files with 145 additions and 119 deletions
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@ -31,17 +31,11 @@ struct bt_mesh_adv {
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u8_t type:2,
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busy:1;
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u8_t xmit;
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union {
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/* Address, used e.g. for Friend Queue messages */
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u16_t addr;
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/* For transport layer segment sending */
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struct {
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u8_t attempts;
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} seg;
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};
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};
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typedef struct bt_mesh_adv *(*bt_mesh_adv_alloc_t)(int id);
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@ -35,9 +35,6 @@
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#define FRIEND_BUF_COUNT ((CONFIG_BT_MESH_FRIEND_QUEUE_SIZE + 1) * \
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CONFIG_BT_MESH_FRIEND_LPN_COUNT)
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#define FRIEND_ADV(buf) CONTAINER_OF(BT_MESH_ADV(buf), \
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struct friend_adv, adv)
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/* PDUs from Friend to the LPN should only be transmitted once with the
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* smallest possible interval (20ms).
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*/
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@ -58,14 +55,11 @@ struct friend_pdu_info {
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NET_BUF_POOL_FIXED_DEFINE(friend_buf_pool, FRIEND_BUF_COUNT,
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BT_MESH_ADV_DATA_SIZE, NULL);
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static struct friend_adv {
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struct bt_mesh_adv adv;
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u64_t seq_auth;
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} adv_pool[FRIEND_BUF_COUNT];
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static struct bt_mesh_adv adv_pool[FRIEND_BUF_COUNT];
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static struct bt_mesh_adv *adv_alloc(int id)
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{
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return &adv_pool[id].adv;
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return &adv_pool[id];
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}
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static bool is_lpn_unicast(struct bt_mesh_friend *frnd, u16_t addr)
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@ -295,13 +289,7 @@ static struct net_buf *create_friend_pdu(struct bt_mesh_friend *frnd,
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struct friend_pdu_info *info,
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struct net_buf_simple *sdu)
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{
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struct bt_mesh_subnet *sub;
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const u8_t *enc, *priv;
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struct net_buf *buf;
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u8_t nid;
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sub = bt_mesh_subnet_get(frnd->net_idx);
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__ASSERT_NO_MSG(sub != NULL);
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buf = bt_mesh_adv_create_from_pool(&friend_buf_pool, adv_alloc,
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BT_MESH_ADV_DATA,
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@ -310,22 +298,7 @@ static struct net_buf *create_friend_pdu(struct bt_mesh_friend *frnd,
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return NULL;
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}
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BT_MESH_ADV(buf)->addr = info->src;
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FRIEND_ADV(buf)->seq_auth = TRANS_SEQ_AUTH_NVAL;
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/* Friend Offer needs master security credentials */
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if (info->ctl && TRANS_CTL_OP(sdu->data) == TRANS_CTL_OP_FRIEND_OFFER) {
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enc = sub->keys[sub->kr_flag].enc;
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priv = sub->keys[sub->kr_flag].privacy;
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nid = sub->keys[sub->kr_flag].nid;
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} else {
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if (friend_cred_get(sub, frnd->lpn, &nid, &enc, &priv)) {
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BT_ERR("friend_cred_get failed");
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goto failed;
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}
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}
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net_buf_add_u8(buf, (nid | (info->iv_index & 1) << 7));
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net_buf_add_u8(buf, (info->iv_index & 1) << 7); /* Will be reset in encryption */
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if (info->ctl) {
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net_buf_add_u8(buf, info->ttl | 0x80);
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@ -340,25 +313,55 @@ static struct net_buf *create_friend_pdu(struct bt_mesh_friend *frnd,
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net_buf_add_mem(buf, sdu->data, sdu->len);
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/* We re-encrypt and obfuscate using the received IVI rather than
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* the normal TX IVI (which may be different) since the transport
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* layer nonce includes the IVI.
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*/
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if (bt_mesh_net_encrypt(enc, &buf->b, info->iv_index, false)) {
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BT_ERR("Re-encrypting failed");
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goto failed;
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}
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if (bt_mesh_net_obfuscate(buf->data, info->iv_index, priv)) {
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BT_ERR("Re-obfuscating failed");
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goto failed;
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}
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return buf;
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}
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failed:
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net_buf_unref(buf);
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return NULL;
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static int encrypt_friend_pdu(struct bt_mesh_friend *frnd, struct net_buf *buf, bool master_cred)
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{
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struct bt_mesh_subnet *sub = bt_mesh_subnet_get(frnd->net_idx);
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const u8_t *enc, *priv;
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u32_t iv_index;
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u16_t src;
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u8_t nid;
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if (master_cred) {
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enc = sub->keys[sub->kr_flag].enc;
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priv = sub->keys[sub->kr_flag].privacy;
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nid = sub->keys[sub->kr_flag].nid;
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} else {
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if (friend_cred_get(sub, frnd->lpn, &nid, &enc, &priv)) {
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BT_ERR("friend_cred_get failed");
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return -ENOENT;
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}
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}
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src = sys_get_be16(&buf->data[5]);
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if (bt_mesh_elem_find(src)) {
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/* Local messages were stored with a blank seqnum */
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u32_t seq = bt_mesh_next_seq();
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buf->data[2] = seq >> 16;
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buf->data[3] = seq >> 8;
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buf->data[4] = seq;
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iv_index = BT_MESH_NET_IVI_TX;
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} else {
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u8_t ivi = (buf->data[0] >> 7);
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iv_index = (bt_mesh.iv_index - ((bt_mesh.iv_index & 1) != ivi));
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}
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buf->data[0] = (nid | (iv_index & 1) << 7);
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if (bt_mesh_net_encrypt(enc, &buf->b, iv_index, false)) {
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BT_ERR("Encrypting failed");
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return -EINVAL;
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}
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if (bt_mesh_net_obfuscate(buf->data, iv_index, priv)) {
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BT_ERR("Obfuscating failed");
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return -EINVAL;
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}
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return 0;
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}
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static struct net_buf *encode_friend_ctl(struct bt_mesh_friend *frnd,
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@ -366,7 +369,6 @@ static struct net_buf *encode_friend_ctl(struct bt_mesh_friend *frnd,
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struct net_buf_simple *sdu)
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{
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struct friend_pdu_info info;
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u32_t seq;
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BT_DBG("LPN 0x%04x", frnd->lpn);
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@ -378,10 +380,7 @@ static struct net_buf *encode_friend_ctl(struct bt_mesh_friend *frnd,
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info.ctl = 1U;
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info.ttl = 0U;
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seq = bt_mesh_next_seq();
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info.seq[0] = seq >> 16;
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info.seq[1] = seq >> 8;
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info.seq[2] = seq;
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memset(info.seq, 0, sizeof(info.seq));
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info.iv_index = BT_MESH_NET_IVI_TX;
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@ -427,6 +426,10 @@ static void enqueue_sub_cfm(struct bt_mesh_friend *frnd, u8_t xact)
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return;
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}
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if (encrypt_friend_pdu(frnd, buf, false)) {
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return;
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}
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if (frnd->last) {
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BT_DBG("Discarding last PDU");
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net_buf_unref(frnd->last);
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@ -733,6 +736,10 @@ static void enqueue_offer(struct bt_mesh_friend *frnd, s8_t rssi)
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return;
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}
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if (encrypt_friend_pdu(frnd, buf, true)) {
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return;
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}
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frnd->counter++;
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if (frnd->last) {
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@ -872,8 +879,29 @@ init_friend:
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return 0;
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}
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static bool is_seg(struct bt_mesh_friend_seg *seg, u16_t src, u16_t seq_zero)
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{
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struct net_buf *buf = (void *)sys_slist_peek_head(&seg->queue);
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struct net_buf_simple_state state;
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u16_t buf_seq_zero;
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u16_t buf_src;
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if (!buf) {
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return false;
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}
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net_buf_simple_save(&buf->b, &state);
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net_buf_skip(buf, 5); /* skip IVI, NID, CTL, TTL, SEQ */
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buf_src = net_buf_pull_be16(buf);
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net_buf_skip(buf, 3); /* skip DST, OP/AID */
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buf_seq_zero = ((net_buf_pull_be16(buf) >> 2) & TRANS_SEQ_ZERO_MASK);
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net_buf_simple_restore(&buf->b, &state);
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return ((src == buf_src) && (seq_zero == buf_seq_zero));
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}
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static struct bt_mesh_friend_seg *get_seg(struct bt_mesh_friend *frnd,
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u16_t src, u64_t *seq_auth,
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u16_t src, u16_t seq_zero,
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u8_t seg_count)
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{
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struct bt_mesh_friend_seg *unassigned = NULL;
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@ -881,14 +909,12 @@ static struct bt_mesh_friend_seg *get_seg(struct bt_mesh_friend *frnd,
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for (i = 0; i < ARRAY_SIZE(frnd->seg); i++) {
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struct bt_mesh_friend_seg *seg = &frnd->seg[i];
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struct net_buf *buf = (void *)sys_slist_peek_head(&seg->queue);
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if (buf && BT_MESH_ADV(buf)->addr == src &&
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FRIEND_ADV(buf)->seq_auth == *seq_auth) {
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if (is_seg(seg, src, seq_zero)) {
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return seg;
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}
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if (!unassigned && !buf) {
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if (!unassigned && !sys_slist_peek_head(&seg->queue)) {
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unassigned = seg;
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}
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}
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@ -902,10 +928,10 @@ static struct bt_mesh_friend_seg *get_seg(struct bt_mesh_friend *frnd,
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static void enqueue_friend_pdu(struct bt_mesh_friend *frnd,
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enum bt_mesh_friend_pdu_type type,
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u8_t seg_count, struct net_buf *buf)
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u16_t src, u8_t seg_count,
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struct net_buf *buf)
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{
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struct bt_mesh_friend_seg *seg;
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struct friend_adv *adv;
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BT_DBG("type %u", type);
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@ -918,11 +944,11 @@ static void enqueue_friend_pdu(struct bt_mesh_friend *frnd,
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return;
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}
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adv = FRIEND_ADV(buf);
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seg = get_seg(frnd, BT_MESH_ADV(buf)->addr, &adv->seq_auth, seg_count);
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u16_t seq_zero = (((buf->data[10] << 8 | buf->data[11]) >> 2) & TRANS_SEQ_ZERO_MASK);
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seg = get_seg(frnd, src, seq_zero, seg_count);
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if (!seg) {
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BT_ERR("No free friend segment RX contexts for 0x%04x",
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BT_MESH_ADV(buf)->addr);
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BT_ERR("No free friend segment RX contexts for 0x%04x", src);
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net_buf_unref(buf);
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return;
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}
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@ -934,16 +960,9 @@ static void enqueue_friend_pdu(struct bt_mesh_friend *frnd,
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enqueue_update(frnd, 1);
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}
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/* Only acks should have a valid SeqAuth in the Friend queue
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* (otherwise we can't easily detect them there), so clear
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* the SeqAuth information from the segments before merging.
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*/
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SYS_SLIST_FOR_EACH_CONTAINER(&seg->queue, buf, node) {
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FRIEND_ADV(buf)->seq_auth = TRANS_SEQ_AUTH_NVAL;
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frnd->queue_size++;
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}
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sys_slist_merge_slist(&frnd->queue, &seg->queue);
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frnd->queue_size += seg->seg_count;
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seg->seg_count = 0U;
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} else {
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/* Mark the buffer as having more to come after it */
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@ -1015,11 +1034,16 @@ static void friend_timeout(struct k_work *work)
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frnd->last = (void *)sys_slist_get(&frnd->queue);
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if (!frnd->last) {
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BT_WARN("Friendship not established with 0x%04x", frnd->lpn);
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BT_WARN("Friendship not established with 0x%04x",
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frnd->lpn);
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friend_clear(frnd);
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return;
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}
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if (encrypt_friend_pdu(frnd, frnd->last, false)) {
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return;
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}
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/* Clear the flag we use for segment tracking */
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frnd->last->flags &= ~NET_BUF_FRAGS;
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frnd->last->frags = NULL;
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@ -1057,6 +1081,42 @@ int bt_mesh_friend_init(void)
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return 0;
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}
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static bool is_segack(struct net_buf *buf, u64_t *seqauth, u16_t src)
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{
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struct net_buf_simple_state state;
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bool found = false;
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if (buf->len != 16) {
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return false;
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}
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net_buf_simple_save(&buf->b, &state);
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net_buf_skip(buf, 1); /* skip IVI, NID */
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if (!(net_buf_pull_u8(buf) >> 7)) {
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goto end;
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}
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net_buf_pull(buf, 3); /* skip SEQNUM */
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if (src != net_buf_pull_be16(buf)) {
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goto end;
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}
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net_buf_skip(buf, 2); /* skip dst */
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if (TRANS_CTL_OP((u8_t *) net_buf_pull_mem(buf, 1)) != TRANS_CTL_OP_ACK) {
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goto end;
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}
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found = ((net_buf_pull_be16(buf) >> 2) & TRANS_SEQ_ZERO_MASK) ==
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(*seqauth & TRANS_SEQ_ZERO_MASK);
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end:
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net_buf_simple_restore(&buf->b, &state);
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return found;
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}
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static void friend_purge_old_ack(struct bt_mesh_friend *frnd, u64_t *seq_auth,
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u16_t src)
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{
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@ -1068,8 +1128,7 @@ static void friend_purge_old_ack(struct bt_mesh_friend *frnd, u64_t *seq_auth,
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cur != NULL; prev = cur, cur = sys_slist_peek_next(cur)) {
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struct net_buf *buf = (void *)cur;
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if (BT_MESH_ADV(buf)->addr == src &&
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FRIEND_ADV(buf)->seq_auth == *seq_auth) {
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if (is_segack(buf, seq_auth, src)) {
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BT_DBG("Removing old ack from Friend Queue");
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sys_slist_remove(&frnd->queue, prev, cur);
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@ -1121,11 +1180,7 @@ static void friend_lpn_enqueue_rx(struct bt_mesh_friend *frnd,
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return;
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}
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if (seq_auth) {
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FRIEND_ADV(buf)->seq_auth = *seq_auth;
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}
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enqueue_friend_pdu(frnd, type, seg_count, buf);
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enqueue_friend_pdu(frnd, type, info.src, seg_count, buf);
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BT_DBG("Queued message for LPN 0x%04x, queue_size %u",
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frnd->lpn, frnd->queue_size);
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@ -1139,7 +1194,6 @@ static void friend_lpn_enqueue_tx(struct bt_mesh_friend *frnd,
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{
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struct friend_pdu_info info;
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struct net_buf *buf;
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u32_t seq;
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BT_DBG("LPN 0x%04x", frnd->lpn);
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@ -1153,10 +1207,7 @@ static void friend_lpn_enqueue_tx(struct bt_mesh_friend *frnd,
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info.ttl = tx->ctx->send_ttl;
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info.ctl = (tx->ctx->app_idx == BT_MESH_KEY_UNUSED);
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seq = bt_mesh_next_seq();
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info.seq[0] = seq >> 16;
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info.seq[1] = seq >> 8;
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info.seq[2] = seq;
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memset(info.seq, 0, sizeof(info.seq)); /* Will be allocated before encryption */
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info.iv_index = BT_MESH_NET_IVI_TX;
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@ -1166,11 +1217,7 @@ static void friend_lpn_enqueue_tx(struct bt_mesh_friend *frnd,
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return;
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}
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if (seq_auth) {
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FRIEND_ADV(buf)->seq_auth = *seq_auth;
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}
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enqueue_friend_pdu(frnd, type, seg_count, buf);
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enqueue_friend_pdu(frnd, type, info.src, seg_count, buf);
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BT_DBG("Queued message for LPN 0x%04x", frnd->lpn);
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}
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@ -1233,18 +1280,12 @@ static bool friend_queue_has_space(struct bt_mesh_friend *frnd, u16_t addr,
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for (i = 0; i < ARRAY_SIZE(frnd->seg); i++) {
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struct bt_mesh_friend_seg *seg = &frnd->seg[i];
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if (seq_auth) {
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struct net_buf *buf;
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if (seq_auth && is_seg(seg, addr, *seq_auth & TRANS_SEQ_ZERO_MASK)) {
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/* If there's a segment queue for this message then the
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* space verification has already happened.
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*/
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buf = (void *)sys_slist_peek_head(&seg->queue);
|
||||
if (buf && BT_MESH_ADV(buf)->addr == addr &&
|
||||
FRIEND_ADV(buf)->seq_auth == *seq_auth) {
|
||||
return true;
|
||||
}
|
||||
}
|
||||
|
||||
total += seg->seg_count;
|
||||
}
|
||||
|
|
@ -1417,18 +1458,8 @@ void bt_mesh_friend_clear_incomplete(struct bt_mesh_subnet *sub, u16_t src,
|
|||
|
||||
for (j = 0; j < ARRAY_SIZE(frnd->seg); j++) {
|
||||
struct bt_mesh_friend_seg *seg = &frnd->seg[j];
|
||||
struct net_buf *buf;
|
||||
|
||||
buf = (void *)sys_slist_peek_head(&seg->queue);
|
||||
if (!buf) {
|
||||
continue;
|
||||
}
|
||||
|
||||
if (BT_MESH_ADV(buf)->addr != src) {
|
||||
continue;
|
||||
}
|
||||
|
||||
if (FRIEND_ADV(buf)->seq_auth != *seq_auth) {
|
||||
if (!is_seg(seg, src, *seq_auth & TRANS_SEQ_ZERO_MASK)) {
|
||||
continue;
|
||||
}
|
||||
|
||||
|
|
@ -1436,6 +1467,7 @@ void bt_mesh_friend_clear_incomplete(struct bt_mesh_subnet *sub, u16_t src,
|
|||
|
||||
purge_buffers(&seg->queue);
|
||||
seg->seg_count = 0U;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue